Enfoque UTE https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista <p>Enfoque UTE is a scientific journal on engineering. It publishes original papers and state-of-the-art review articles in science and technology.</p> <p>The journal covers the fields of Environmental, Food, Automotive, Industrial, Computer Science, Mecatronics and Petroleum engineerings.</p> <p>Enfoque UTE is focused on the community of undergraduate and graduate teachers, researchers and students in general.</p> en-US <p><a href="https://creativecommons.org/licenses/by/3.0/ec/" rel="license"><img style="border-width: 0;" src="http://i.creativecommons.org/l/by/3.0/88x31.png" alt="Creative Commons License"></a><br>This work is licensed under a <a href="https://creativecommons.org/licenses/by/3.0/ec/" rel="license">Creative Commons 3.0 BY EC License</a>.</p> enfoque-ute@ute.edu.ec (Comité Editorial) enfoque-ute@ute.edu.ec (Comité Editorial Enfoque UTE) Wed, 01 Apr 2020 05:21:59 -0500 OJS http://blogs.law.harvard.edu/tech/rss 60 Effect of neem on Phyllocnistis citrella Stainton and its parasitoid Ageniaspis citricola Logvinovskaya in Ecuador https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/519 <p>Efficacy of neem on Citrus Leafminer (CLM) and effect on its parasitoid <em>Ageniaspis citricola</em> was evaluated, using field, cage and olfactometer tests. Treatments were: aqueous extract of neem (50 gL<sup>-1</sup>), formulated oil of neem (10 mL L<sup>-1</sup>) and control. Field study was done in a <em>Citrus aurantifolia</em> orchard, three applications were carried out, which were evaluated every 48 hours until&nbsp;ten days after the treatment. Cage and olfactometer tests were performed in a greenhouse and repeated twice each time. In the cage, it were used 50 infested <em>Citrus reticulata</em> plants per experimental unit, while for the olfactometer test, as experimental arena, transparent plastic jars with 20 adults of CLM inside were used. Variables evaluated were: CLM infestation, dead, live and predated larvae, pupae,&nbsp;emerged adults and parasitized pupal chambers. The highest mortality of the CLM was caused by the aqueous extract of neem with 77.17%, which began 48 hours after application, suggesting inhibition of feeding. The aqueous extract of neem showed in average 88.80&nbsp;% of repellency of adults of CLM and neem&nbsp;oil 85.64%. The high mortality of CLM and the repellent effect of neem, seem to influence negatively in parasitism which fluctuated between 9.45 % and 20.16&nbsp;% in treated trees. &nbsp;</p> Ernesto Cañarte-Bermúdez, Bernardo Navarrete-Cedeño, Silvia Montero-Cedeño, Hugo César Arredondo-Bernal, Onésimo Chávez-López, Néstor Bautista-Martínez Copyright (c) 2020 Enfoque UTE https://creativecommons.org/licenses/by/3.0/ec/ https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/519 Wed, 01 Apr 2020 00:00:00 -0500 Technological alternatives for the control of Botrytis sp. In Andean blackberry (Rubus glaucus) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/521 <p>The Andean blackberry crop (<em>Rubus glaucus</em>) is very important for the farmers, since they must implement cultural practices that allow reducing the use of synthetic pesticides. The objective of the study was to evaluate the effect of different technological alternatives for the control of Botrytis sp. in the blackberry crop. The treatments were: 1: Absolute control (silwet+water), 2: Traditional chemical treatment (Carbendazim), 3: Mirtaceae extract (Iridium®), 4: Bacterial metabolite (Balus®) and 5: <em>Trichoderma </em>spp. (Tricomix®). The applications were carried out every 15 days for the synthetic product and every 8 days for the biologicals, organic and the control. A randomized complete block design (RCBD) was used with 3 repetitions and Tukey test at 5&nbsp;% were made. The studied variables were botrytis incidence (%), yield (g/plot), weight (g), polar and equatorial diameter (mm), firmness (N), total soluble solids (Brix), titratable acidity (% citric acid) and pH (log H<sup>+</sup>). Throughout a weekly incidence analysis, it was possibly to identify that the Carbendazim, <em>Trichoderma </em>spp. and mirtaceae extract had a better control in the incidence of <em>Botrytis </em>sp<em>. </em>in the blackberry fruit.</p> Martin Jamed Acosta Ruales, William Fernando Viera, Trevor Jackson, Wilson Vásquez Castillo Copyright (c) 2020 Enfoque UTE https://creativecommons.org/licenses/by/3.0/ec/ https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/521 Wed, 01 Apr 2020 00:00:00 -0500 Evaluation of the efficiency of three oil extraction equipments with different oil palm genotypes (Elaeis sp.) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/541 <p>This work was performed in the oil extraction laboratory of the African Palm Program, of the Experimental Station “Santo Domingo” of the INIAP. The main objective was to determine the efficiency of three oil extraction equipments, in three oil palm genotypes. The equipments used were Velp solvent extractor, Soxhlet extractor and a 1500 psi hydraulic press. The genotypes evaluated are part of the germplasm bank of the Palm Program at INIAP: <em>Elaeis guineensis</em> (african palm), <em>Elaeis oleifera</em> (american palm) and <em>E. oleifera</em> x <em>E. guineensis</em> (interspecific hybrid). The experimental design was a complete random design (DCA), with 20 observations, followed by student’s test and Tukey test at a 5&nbsp; significance, to determine differences between treatment means. The results showed highly significant differences between the different factors evaluated. The higher percentage of oil per bunch was obtained with the genotype <em>E. guineensis</em> in the Soxhlet extractor (18.43&nbsp;%) and the lowest percentage for <em>E. oleifera</em> with the hydraulic press (0.34&nbsp;%). The analysis of costs determined that the lowest cost was obtained with the hydraulic press with USD 8,20 per sample.</p> Mercedes Elizabeth Navarrete Párraga, Silvia Madeleim Zambrano Marcillo, Walter Ramón Zambrano Sabando, Martha Alicia Romero Pizarro, Marcelo Rafael Racines Jaramillo, Ernesto Ricardo Paredes Puga, Leonardo Andres Quintero Roman, Digner Santiago Ortega Cedillo Copyright (c) 2020 Enfoque UTE https://creativecommons.org/licenses/by/3.0/ec/ https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/541 Wed, 01 Apr 2020 00:00:00 -0500 Review of the state of art of DX-SAHP systems to obtain domestic hot water https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/565 <p>The investigation purpose is to elaborate a detailed review about previous published investigations with direct-expansion solar-assisted heat pumps (DX-SAHP) used for water heating, in the last years. The growing energy consumption, the using of refrigerants that weaken the ozone layer, the greenhouse gases emission to the atmosphere and the global warming effect are the main problems that the conventional water heating systems present. Using hydrocarbons as refrigerants represents a pollution reduction and it is also the best option to replace hydrochlorofluorocarbons and chlorofluorocarbons, due to their low values of global warming potential and ozone depletion potential, close to 0. A DX-SAHP system takes advantage of the thermal solar energy directly by using a bare flat-plate solar collector. These systems provide domestic hot water over 50&nbsp;°C and heating water volumes until 200 liters reaching COP values higher than 4. Solar energy and the using of alternative refrigerants with a low environmental impact are proposed to reach this purpose.</p> William Quitiaquez, Isaac Simbaña, César A. Isaza-Roldán, Patricio Quitiaquez, César Nieto-Londoño, Fernando Toapanta-Ramos Copyright (c) 2020 Enfoque UTE https://creativecommons.org/licenses/by/3.0/ec/ https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/565 Wed, 01 Apr 2020 00:00:00 -0500 Morphological, phenological and pomological differentiation of commercial cultivars of blackberry (Rubus glaucus Benth) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/529 <p>The genus Rubus is one of the most diverse in terms of morphology and genetics, presenting a wide spectrum of wild and cultivated species that are desired by their edible fruits. In Ecuador, the cultivation of blackberry (<em>R. glaucus</em> and <em>Rubus sp</em>.) is present along the Inter-Andean region, grown between 2000 and 3100 masl. This fruit crop is economically important for its high demand for fresh and processed consumption. This research was carried out in the Tumbaco Experimental Farm of INIAP (Ecuador) with the objective of finding characters that allow the morphological, phenological and pomological differentiation of four blackberry cultivars (Castilla, Andimora, Colombiana and Brazos). The multivariate analysis showed three conglomerates (C). Cultivars Andimora and Colombiana (C3) do not have spines unlike Castilla (C2) and Brazos (C1). Colombian was the earliest cultivar (161 days of sprouting to harvest) and Castilla the latest (186 days). Brazos cultivar showed the highest fruit weight (5.85 g). Andimora reached the highest content of soluble solids (11.86 ºBrix) and had firm fruits. The differentiating characters observed in this study make possible to establish parameters of distinction between the cultivars that are currently cultivated in Ecuador.</p> Monica Iza, Pablo Viteri, Milton Hinojosa, Anibal Martínez, Andrea Sotomayor Correa, William Viera Copyright (c) 2020 Enfoque UTE https://creativecommons.org/licenses/by/3.0/ec/ https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/529 Wed, 01 Apr 2020 00:00:00 -0500 In situ morphological characterization of soursop (Annona muricata L.) plants in Manabí, Ecuador https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/536 <p>Soursop (<em>Annona muricata</em> L.) germplasm, from the central region of the Ecuadorian littoral, has diverse phenotypic characteristics, which have been little studied. The main objective of this research was to characterize <em>in situ</em> the morphological variability of 60 accessions of soursop. The morphological traits were evaluated using 20 quantitative and 10 qualitative variables of the plant and the fruit. Multivariate statistical methods were used as principal components, hierarchical conglomerate aggregation, discriminant and correlation analysis (Pearson) were performed. Descriptive analysis such as central tendency and dispersion (coefficient of variation, range, mean and standard deviation) were determined for the quantitative data; while frequencies were calculated for qualitative data. In terms of morphological traits, 74 % of the total variability was explained by the fourth component. Three conglomerates of similarity were formed, in which the height, diameter of canopy and fruit number per tree, were the characters of greater contribution for its conformation.</p> Ricardo Gonzalo Moreira Macías, Héctor Rodríguez, Eduardo Héctor-Ardisana, Carlos Feicán-Mejía, Saúl Anibal Mestanza Velasco, William Viera Arroyo Copyright (c) 2020 Enfoque UTE https://creativecommons.org/licenses/by/3.0/ec/ https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/536 Wed, 01 Apr 2020 00:00:00 -0500 Third-party management in software development: proposal of a methodology https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/621 <p>Outsourcing allows organizations to reduce costs, optimize the use of resources, provide added value in services and goods, and concentrate on achieving the strategic objectives of the business. However, many software projects have failed due to the lack of knowledge of the factors involved in its planning. Some of these elements are poor communication with the supplier, weak monitoring of the status of tasks, lack of active participation of users and stakeholders at all stages of the process, and software quality assurance. Consequently, this research aims to aid the management of the outsourcing process and proposes a methodology for its management during system development. The methodology comprises 7 phases, each one with its inputs, tasks, and outputs, which are used by the following stages. In summary, it synthesizes the best practices for the management of third parties.</p> Yeison Núñez-Sánchez, Antonio González-Torres Copyright (c) 2020 Enfoque UTE https://creativecommons.org/licenses/by/3.0/ec/ https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/621 Wed, 01 Apr 2020 00:00:00 -0500 Design, evaluation and validation of an effluent treatment system for the leather tanning process: case Pieles del Sur E.I.R.L. https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/542 <p>In this project a treatment system for the effluents of a leather tanning process was designed. This system was evaluated based on laboratory tests to ensure its viability, and the treatment was validated by analyzing effluents from the plant already installed. The system has three units: the first one is a Pretreatment that allows the oxidation of sulphides for the liming and draught baths, as well as the precipitation of chromium for the leather tanning baths; the second one is a Physical-Chemical Treatment for the general effluents of the process that allows to obtain treated effluents and decanted solids; the third is a sludge treatment that allows to obtain conditioned and low volume sludge to be collected for final disposal. The analysis of treated effluents showed a considerable reduction in the concentration of polluting chemicals that allows reusing the water and brings the company closer to compliance with the maximum levels allowed.</p> Víctor Muñoz Paz, Víctor Longa Cuayla, Alejandra Carreño Arispe, José Aguilar Franco Copyright (c) 2020 Enfoque UTE https://creativecommons.org/licenses/by/3.0/ec/ https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/542 Wed, 01 Apr 2020 00:00:00 -0500 CFD Analysis of a solar flat plate collector with different cross sections https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/601 <p>Low and medium solar heating systems used for domestic and industrial applications, such as water and space heating, usually utilize solar flat plate collectors in order to absorb solar thermal energy converting it into heat and then transferring the heat to a fluid (usually water or air) that flows through it. The aim of this study is to evaluate the solar flat plate collector’s efficiency and the fluid behavior inside the pipeline with three different cross sections, whose hydraulic diameters are 10, 5.12 and 6.16 mm, by using ANSYS Fluent. The results obtained from the Computational Fluid Dynamics (CFD) tool showed that the collector with the Type I cross section reached temperatures up to 330 K at the pipe outlet obtaining an efficiency of 68&nbsp;%, higher than those of Types II and III, whose efficiencies were 51&nbsp;% and 60&nbsp;%, respectively. Type I cross section also presented the lowest values in both speed and pressure drop, these being 0.266 m/s and 108.3 Pa, respectively.</p> Anthony Xavier Andrade Cando, William Quitiaquez Sarzosa, Luis Fernando Toapanta Copyright (c) 2020 Enfoque UTE https://creativecommons.org/licenses/by/3.0/ec/ https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/601 Wed, 01 Apr 2020 00:00:00 -0500 Artificial neural network to estimate an index of water quality https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/633 <p>The artificial neural network (RNA) is a computational model that emulates the biological neural system in information processing. The originating models are suitable for the purpose of describing long-term specifics, in addition to nonlinear relationships. This tool is used to predict physical chemical and microbiological parameters that influence water quality. The United States National Sanitation Foundation proposed a water quality index, known as the NSF WQI. This article describes the design, training and use of the three-layer neural perceptron neural model for the calculation of the NSF WQI of the Utcubamba River and its tributaries. Using the Matlab software and applying the Levenberg-Marquardt training algorithm, the optimal RNA architecture was found to be 6-12-1, plus the percentage for the training, validation, and test sets of 70&nbsp;%, 10&nbsp;%, and 20 % respectively. RNA performance has been evaluated using the root of the root mean square error (RMSE) and the correlation coefficient (R). High correlations (greater than 0.94) were made between the measured and predicted values. Finally, the RNA proposal offers a useful alternative for the calculation and prediction of the water quality index in relation to dissolved oxygen (DO), biochemical demand for oxygen (BOD), nitrates, fecal coliforms, potential for hydrogen ions (pH) and turbidity.</p> Lenin Quiñones Huatangari, Luis Ochoa Toledo, Nicolás Kemper Valverde, Oscar Gamarra Torres, José Bazán Correa, Jorge Delgado Soto Copyright (c) 2020 Enfoque UTE https://creativecommons.org/licenses/by/3.0/ec/ https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/633 Wed, 01 Apr 2020 00:00:00 -0500 In-situ co-design of Mobile Games using Design Thinking’s resources approach https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/574 <p>The contribution of this paper is to explore how in-situ co-design of indoor spaces (e.g. building) of Location-based Mobile Games could be handle, by describing the learned lessons on this topic. This paper presents a conceptual framework for in-situ co-design of indoor spaces on Location-based Mobile Games to assist to carry out this kind of experience using useful resources (as Design Thinking's resources). An experience of in-situ co-design for an indoor space on a Location-based Mobile Game is presented using this framework; for some phases an authoring tool was used which allows in-situ co-design of relevant locations for an application. Based on this experience, the authoring tool was extended to create a specific kind of Location-based Mobile Game. This paper presents this extension along with a proof of concept that shows how an in-situ co-designed game created by this extension was used by end-users.</p> Cecilia Challiol, Franco Martín Borrelli, Francisco Goin Plexevi, Candela Mariel Rouaux Servat, Facundo Ivan Mendiburu, Estevan Gomez-Torres, Silvia Ethel Gordillo Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/574 Fri, 31 Jan 2020 00:00:00 -0500 Evaluation of video traffic behavior metrics in an experimental multicast network https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/576 <p>Currently, there is a significant change in data traffic on networks, both local and Internet, across the spectrum of possible customers, whether fixed or mobile. The consumption of video traffic increases day by day in all its formats. Service providers are required more bandwidth, quality and performance, for all products, but mainly those based on video. This article presents an improved version of our laboratory tests for generic networks with four sub-scenarios, which allow injecting multicast video traffic, represented in different codecs. The topology of network used includes a streaming server and up to 20 desktop computers as clients. The most important metrics to be analyzed have been defined, based on performance and quality of service (QoS) measurements under limited bandwidth conditions. Experimental numerical results can be useful for administrators, simulation analysts, designers, and data network planners. But, also, this document aims to serve as a guide for the management of similar networks and the efficiently use available resources, without compromising performance and QoS.</p> Higinio Alberto Facchini, Santiago Cristobal Pérez, Alejandro Dantiacq Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/576 Fri, 31 Jan 2020 00:00:00 -0500 Novel Approach for Teaching English Language using Emerging Information and Communication Technologies for Visual Impairment Students https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/577 <p>Nowadays, Higher Education Institutions (HEI) need to be more inclusive from the methodological vision appropriate used in the classroom. Visual impairment students (VIS) become a challenge for teachers who look for incorporating different learning environments. This challenge increases when teaching and learning process to VIS is related to the English language; due to the absence of educational didactic resources available at the school and the lack of knowledge of appropriate teaching methodologies and strategies to develop the different language skills: listening, speaking, reading and writing that go with the educational process in the acquisition of the English language. In accordance with this problem, this research proposes a novel methodological strategy, based on the usage of meaningful learning with emerging technologies as a main guide for students with visual impairment. Thus, the road map of good practices in the use of this methodology will allow establishing a clear process to achieve students’ active, meaningful and autonomous participation, using the least time in the teaching-learning process of the English language.</p> Jorge Cardenas, Esteban Inga Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/577 Fri, 31 Jan 2020 00:00:00 -0500 Estimated cost of electricity with time horizon for micro grids based on the policy response of demand for real price of energy https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/579 <p>The intelligent microgrids are an efficient alternative, which allows to supply the demand decreasing the losses of the electrical system and at the same time; the environment and the consumers are the main beneficiaries. This article develops a heuristic based on an energy management model based on the real price of electricity, which will allow end users to encourage the implementation of a policy of response to demand, in order to optimize their consumption, for which a micro smart grid is analyzed, with conventional and non-conventional renewable generation, In addition, a mechanism of "real energy price" will be implemented as a policy of response to demand, with the aim of optimizing the costs of energy that will be transferred to users depending on the stratum to which it belongs, these costs will have a short-term horizon with hourly intervals, achieving a reduction in the purchase of energy from the system</p> EDWIN MARCELO GARCIA TORRES Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/579 Fri, 31 Jan 2020 00:00:00 -0500 Outlier detection with data mining techniques and statistical methods https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/584 <p>The detection of outliers in the field of data mining (DM) and the process of knowledge discovery in databases (KDD) is of great interest in areas that require support systems for decision making. A straightforward application can be found in the financial area, where DM can potentially detect financial fraud or find errors produced by the users. Thus, it is essential to evaluate the veracity of the information, through the use of methods for the detection of unusual behaviors in the data. This paper proposes a method to detect values ​​that are considered outliers in a database of nominal type data. The method implements a global algorithm of "k" closest neighbors, a clustering algorithm called k-means and a statistical method called chi-square. These techniques have been implemented on a database of clients who have requested a financial credit. The experiment was performed on a data set with 1180 tuples, where, outliers were deliberately introduced. The results showed that the proposed method is able to detect all the outliers entered.</p> Marcos Patricio Orellana Cordero, Priscila Cedillo Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/584 Fri, 31 Jan 2020 00:00:00 -0500 Impact of Ecodriving on fuel emissions and consumption on road of Quito https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/500 <p>This article presents the results of the impact of ecodriving on fuel consumption and the emission factors of polluting gases from a gasoline vehicle when performing road testing in the city of Quito, located at 2 810 meters above sea level. A route with traffic validated by the Technology Transfer Center has been selected for the training and investigation of vehicle emission control. A Chevrolet Aveo Family was used as a test vehicle, , considering is the bestselling vehicle in the city at the moment. And the equipment used to measure fuel consumption and the concentration of emissions was an onboard gas analyzer and a canister. The success and the measuring of the data in this experimentation were determined using the STATGRAPHICS Centurion XVI software. The results showed significant differences in fuel consumption and pollutant emissions of CO and NOx when applying an efficient driving, except for the HC in which there is no significant difference, but the emission is lower when is used on standard driving.</p> Julio César Leguísamo Milla, Edilberto Llanes Cedeño, Juan Rocha Hoyos Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/500 Fri, 31 Jan 2020 00:00:00 -0500 Optimal Location of Transformers in Electrical Distribution Networks Using Geographic Information Systems https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/593 <p>This research shows a heuristic model for the design of scalable and reliable electrical distribution networks. The algorithms presented allow to optimize the location of transformation centers using on their database geographic information systems from which it is possible to define user locations, candidate sites, possible routes for the deployment of the electricity grid and, in general, data for the reconstruction of the scenario. The model employs clustering and triangulation methods, as well as algorithms for creating a minimally expanding tree and the consequent site assignment for transformer placement. After setting the optimal locations for the transformer site, the algorithms compute voltage drops in secondary circuits, required transformation capability, execution times, and coverage achieved. The results obtained are adjusted to the requirements of an actual distribution power grid and show a good performance on the proposed scenario.</p> Stanislao Pinzón, Stéfany Yánez, Milton Ruiz Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/593 Fri, 31 Jan 2020 00:00:00 -0500 Alternative Under Frecuency Load Disconection Methodology Based on Semi-Adaptative Model https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/587 <p>Stability analysis in electrical power systems is based on the study in dynamic state of the voltage and frequency, since at the moment that there is some contingency it fluctuates drastically due to the primary and secondary controls of the voltage and frequency to the power systems that act on the generators. In order to solve the possible stability problems that may arise in power systems, various techniques have been developed that act on the generating machines for their protection as well as on the loads for the power cut. The present investigation proposes an alternative methodology for load disconnection by low frequency as an option to save the power system from a possible blackout due to instability due to a fall in the frequency, managing to improve the results affected by other improved techniques, the frequency change range, frequency deviation and the effects of demand disconnection. The proposed methodology was tested in the IEEE 14 bus system.</p> Diego Carrión, Alex Ayo, Jorge Wilson González Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/587 Fri, 31 Jan 2020 00:00:00 -0500 Analysis of the safety compartment material of a light vehicle by multi-criteria method https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/492 <p>There is a wide variety of materials with various properties available for designers to meet different design requirements. The objective of this study was to evaluate the properties of the relevant materials available in Ecuador through the multicriteria meth-od such as: Proportional complex evaluation (COP-RAS), Technique for the order of preference for similarity to real solution (TOPSIS), Optimization multi-disciplinary and compromise solution (VIKOR), in order to indicate which material would be a potential substitute for the original. It was concluded that 1045 steel is the best choice as a substitute for a safety compartment compared the base line the Aluminum-Magnesium alloy, considering that, despite being a light material, has low resistance to impact forces.</p> Edwin Chamba, Edilberto Llanes, Andres Cardenas, William Vega, Juan Carlos Rocha Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/492 Fri, 31 Jan 2020 00:00:00 -0500 Passion fruit oil (Passiflora edulis): Use of the seeds in cosmetic products https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/532 <p>The work documented in this essay is focused on harnessing the properties of Passion fruit seeds <em>Passiflora edulis </em>f<em>.</em>flavicarpa Deg to achieve the design of a cosmetic product: an exfoliating cream containing passion fruit seed oil and solid residue generated from oil extraction. The applied methodology for the formulation of the cream was initially based on a combination of a mechanical process through pressing, and oil extraction from the seeds by the use of organic solvents, ethyl ether. The physicochemical analysis variables evaluated in the exfoliating cream were pH, extensibility and emulsion capacity. The physical properties were considered as listed, colour, odour, brightness and grittiness. Furthermore, the absence of lumps was evaluated as macroscopic indicators of adequate particle size distribution and uniform texture. It was concluded that the oil from passionfruit seeds due to its composition in protein and liquid elements, optimally conserves the inherent properties of a product designed for skincare and conditioning. The use of solid residue that for primary industries is considered as unstable waste, represents an innovative alternative in the range of available semi-finished raw materials with properties capable of enhancing the products for human consumption.</p> Janeth Fabiola Proaño Bastidas, Erika Rivadeneira, Pablo Moncayo, Elizabeth Mosquera Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/532 Fri, 31 Jan 2020 00:00:00 -0500 In Vitro Organic Control Alternatives for Dactylonectria torresensis in Blackberry (Rubus glaucus) in Ecuador https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/525 <p>The following research evaluated, at laboratory level, the efficiency of fungicides of organic origin against chemical fungicides of conventional use in the control of the growth of <em>Dactylonectria torresensis</em>, considered a pathogen of economic importance that affects the blackberry (<em>Rubus glaucus</em>) in Ecuador. The objective of the study was to find natural, environmentally friendly alternatives that allow obtaining clean food for the population. For this purpose, the efficiency of conventional chemical synthesis fungicides was evaluated: Azoxystrobin, Benomil, Carbendazim, Difeconazole, Fosetyl Aluminum, Tachigaren, Propiconazole, Penconazole, Metalaxil and Thiabendazole each in doses of 100, 10 and 1&nbsp;ppm, compared to the efficiency of organic synthesis fungicides: neem oil, mirtaceous extract, garlic extract, pentahydrate cupric sulfate, thyme extract, applied in doses of 100, 200, and 300&nbsp;ppm. It was found that the mirtaceous extract controlled 100&nbsp;% of the mycelial growth of <em>Dactylonectria torresensis</em>, with results similar to those obtained with Carbendazim and Azoxystrobin, it is concluded that if there is an alternative for the control of the fungus, which could be used commercially by decreasing in this way the use and harmful effects of conventional agrochemicals.</p> M. Racines-Oliva, Evelin Alexandra Tamayo-Gutiérrez, M. Jarrín, F. Báez, C. Tello Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/525 Mon, 02 Dec 2019 08:19:04 -0500 Physical and chemical properties of cacao cultivars (Theobroma cacao L.) from Ecuador and Peru https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/462 <p>The objective of this work was to evaluate the physical and chemical properties of the fine National flavor cocoa beans and CCN 51 from Ecuador, as well as, ICS 6 and CCN 51 from Peru for the production of quality chocolate. They were determined, cacao bean index (g), cacao bean testa percentage, cacao bean dimensions (mm), porosity (%), fermentation index (%), whiteness index, acidity (%), pH and proximate analysis (%), using AOAC methods and the usual ones for cacao quality. According to proximate analysis: the average crude protein content for Peruvian cacao bean was 78.8&nbsp;% higher, the average crude fat content for Ecuador cacao bean was 10.1% higher, the crude fiber of ICS 6 cacao bean stands out among the other cocoa beans with 7.10 ± 0.28%, other components have a degree of similarity between the two countries, so both are suitable to be worked in the production of high quality chocolate, due to its chemical and sensory attributes, generating a quality and competitive product internationally, certifying interest from other latitudes drive the export process and economic benefit for each nation.</p> Jacinto Atanacio Andrade, J. Rivera-García, G. C. Chire-Fajardo, M. O. Ureña-Peralta Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/462 Mon, 02 Dec 2019 00:00:00 -0500 Effect of the filling percentage on tensile strength in 3D desktop printing for different printing patterns, using a randomized design of experiments https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/503 <p>The evaluation of the tensile strength of printed parts by means of fused deposition modeling (FDM) or fused filament fabrication (FFF) is essential, since parts whose resistance does not differ significantly depending on the percentage of filling used can be obtained, optimizing the use of the material. The present work details the analysis of polylactic acid (PLA) specimens manufactured according to ASTM D 638 with different percentages for the most commonly used filling patterns (Honeycomb, Octagram, Stars, Archimedean, Hilbert and Triangles). With the help of an analysis of variance and a design of experiments with a single factor, the appropriate percentages for printing parts according to the desired filling pattern are obtained.</p> Juan Carlos Parra Mena, Erling Ricardo Gallardo Vizuete, Erick Damian Torres Peñaloza Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/503 Mon, 02 Dec 2019 00:00:00 -0500 Evaluation of a wireless Broadband Network for VoIP in Huaytará https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/513 <p>It consists of designing and evaluating the performance of a wireless broadband network in the province of Huaytará, for internet connectivity. It is an applied and experimental investigation where the performance parameters of the network were evaluated. The dependent variable is the capacity of the Wlan cell and the QoS parameters; and as independent variables the coverage and density of the Wlan network. It can be said that for radios up to 8 meters, the experimental client's data rate is higher than the control client's data rate, and for radios greater than 15 meters, the experimental and control client's data rates are no different. As for the QoS parameters, they are favorable for multimedia applications. The network implemented with TDM-E1 / Ethernet and IEEE 802.11n technology, has a maximum capacity per cell of 32.5 Mbps in the 2.4G band and 65 Mbps in the 5.8G band, considering minimum operating parameters of the wireless devices. Users have a 15.2 Mbps field data rate for a maximum radius of 8 meters with up to 7 wireless users connected in the cell, at 2.4 Ghz.</p> Luis Alberto Núñez-Lira, Marco Aurelio Rosario Villarreal, Javier Francisco Javier Márquez Camarena, Janeth Bertha Mariño Arroyo Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/513 Mon, 02 Dec 2019 00:00:00 -0500 Implementation of a Wireless Sensor Network for Electric Light Bulb Management Using IPv6 https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/553 <p>In this study the results of the implementation of the wireless sensor network prototype, to manage the luminaires in homes are presented, using Iris sensors nodes, designed to work with battery for long periods of time and with limited processing capabilities. The nodes use 6LoWPAN addresses. The address conversion to IPv6 is done by a gateway. The luminaires are managed using devices connected to IPv6 network, with Android operating system. The correct functioning of the prototype is demonstrated by validating the functionalities of the management system implemented.</p> Carlos Roberto Egas, Darío Viracocha, Juan Rivera Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/553 Mon, 02 Dec 2019 00:00:00 -0500 Fruit Quality and Post-Harvest Losses of Organic Bananas (Musa acuminata) in Ecuador https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/545 <p>Ecuador is the world's first banana exporter with more than 317 million boxes per year, and contributes 26&nbsp;% of agricultural GDP, generating around 2.5 million direct and indirect jobs. Ecuador produces 19&nbsp;000&nbsp;ha and exports 36&nbsp;000&nbsp;t organic bananas. Postharvest losses fluctuate between 10 and 80&nbsp;%, caused by inadequate postharvest and crop management. The present study aims to determine the physical and chemical quality of organic fruit and quantify post-harvest losses. The research was carried out in the organic banana plantation located in the province of Los Ríos (Ecuador). A completely randomized block design (DBCA) was used in a 7&nbsp;x&nbsp;2 factorial arrangement. The factors were: 1) harvest time (February-August), and 2) quality of export fruit (1<sup>st</sup> and 2<sup>nd</sup>) with 3 repetitions. The variables studied were based on 20 clusters. From the results obtained, it follows that the physical and chemical quality of the fruit is influenced by the harvest season, since they grew and developed in different environmental conditions. In general, 82&nbsp;% of the production is destined for export, since it meets the quality standards.</p> Mauricio Racines-Oliva, Pablo Moncayo, William Viera, María Seraquive Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/545 Mon, 02 Dec 2019 00:00:00 -0500 Characterization of the tensile properties of an Epoxy-Carbon laminated composite used in the development of a single-seater Formula SAE type https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/381 <p>This article presents the analysis of the tensile properties of a carbon fiber reinforced polymer composite used in the manufacture of the single-seater for Formula SAE competition. Composites were manufactured from pre-pregs with different fiber orientations by a vacuum curing process. The effect of the fiber orientation on the strength and rigidity of the formulated composites was evaluated. The tensile specimens were instrumented with biaxial extensometers in order to obtain a real record of the deformation and subsequent determination of the Young's modulus. The experimental results were compared with the analytical results obtained from the Classical Laminate Theory using specialized software. A microscopic analysis of the fractured region of the specimens was also developed to evaluate the effect of the manufacturing process. The set of information generated from the experimental and analytical results provides an understanding of the anisotropy of Epoxy-Carbon fiber composites that will allow design decisions to be made in future developments within the Formula SAE project.</p> Jorge Fajardo, Micaela Villa, Jonatan Pozo, Diego Urgilés Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/381 Mon, 30 Sep 2019 00:00:00 -0500 3D printing technologies: FDM and Polyjet evaluations in the manufacture of automobile auto parts https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/414 <p>The objective of the study was to evaluate the 3D printing technologies made by Molded Deposition Modeling (FDM) and PolyJet from mechanical tests with Acrylonitrile Styrene Acrylate (ASA) and VeroWhitePlus RGD 835 materials, for the selection of the material and adequate technology in the manufacture of air ducts applied to automotive auto parts. To achieve the objective, mechanical tensile tests were carried out on specimens manufactured by both technologies, according to ASTM D638-14 for tensile tests and for bending tests according to ASTM 790; To evaluate the behavior of air flow in the pipeline, the air duct used in the Toyota Stout 2200 pick-up truck modeled by the Ansys Student software was selected as the case study. The results showed that the VeroWhitePlus RDG 835 material used in the construction of the duct by means of the PolyJet technology presented the best results with a yield strength of 4.7 MPa and a maximum bending stress of 28 MPa.</p> Bryan Jhon Briceño-Martínez, Edilberto Antonio Llanes Cedeño, Juan Carlos Rocha-Hoyos, Edwin Chamba, Diego Cuasapud, Andrés Cárdenaz-Yánez Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/414 Mon, 30 Sep 2019 00:00:00 -0500 Variations of the water quality of the Carrizal River in Manabi https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/423 <p>The objective of this work is to determine the physical-chemical variations in the water quality of Carrizal River (Manabí), in 21 sampling stations, covering an area of ​​51 km. Seven points were sampled in (i) the microbasin, 5 points in (ii) La Esperanza reservoir and 9 points in (iii) the sub-basin of Carrizal river. Samples were taken according to an experimental design of random blocks with factorial arrangement, and according to the results we show a correlation between the parameters and the different geographical positions monitored. Thus, we calculate a new water quality index called hardness index, which relates the alkalinity, oxide-reduction potential, hardness, conductivity, suspended solids, and total solids. According to this index, it is evident that, the concentration of minerals of calcium, magnesium, sulphates and carbonates, increased along with the concentration of solids in the water, as well as the REDOX potential and electrical conductivity, increased from the upper basin to the lower basin of Carrizal river. This correlation between physical-chemical parameters of the water and the different geographical positions monitored is probably influenced by anthropogenic activities.</p> Ana María Aveiga Ortiz, Patricio Noles, Aida de la Cruz, Fabián Peñarrieta, Francisco Alcántara Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/423 Mon, 30 Sep 2019 00:00:00 -0500 Optimization of the dark chocolate formulation from the mixture of cocoa beans and cocoa content by applying surface response method https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/432 <p>This research sought to optimize the mix of Peruvian cocoa beans and the cocoa content for the dark chocolate formulation, having as an optimization criterion the improvement of the physical properties of chocolate: color, particle size, rheological properties and texture, applying the response surface methodology. It was found that the optimal formulation presented a mixture of cocoa beans of 10 parts of CCN 51 plus 90 parts of ICS 6, dark chocolate at 70 % cocoa content, 29.6 % sugar and 0.4 % lecithin. Finally, the validation of physical properties reached 91.6 % on average.</p> Gabriela Cristina Chire-Fajardo, Milber Oswaldo Ureña-Peralta, S M García-Torres, R W Hartel Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/432 Mon, 30 Sep 2019 00:00:00 -0500 Multispectral study of tuna cultivation to determine the NDVI, CWSI and SAVI indexes from Sentinel 2A images, in Guano canton, Chimborazo province, Ecuador https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/453 <p>This work evaluates the Normalized Differential Vegetation Index (NDVI), Soil Adjusted Vegetation Index (SAVI), and Water Stress Index (CWSI) in tuna crops, located in the Guano Canton of Chimborazo Province, Ecuador. The area of interest (AOI) included the parishes of San Andres and Guano, in which the texture of the soil was determined with the existing data in Ecuador's National Information System (SNI), a satellite image of Sentinel 2A from June 16 2018 was used. Raster functions were applied to obtain an approximate and referential mean of NDVI, the reflectance received from both the soil and the tuna crop (SAVI) and the perspiration corresponding to the water stress (CSWI) of the tuna plots. Finally, we obtained approximate and referential NDVI data with a value of 0.31, SAVI values reflecting soil and crop data, and a very low CWSI, showing that perspiration is minimal, so it can be concluded that drip irrigation is a suitable technique for increasing tuna production.</p> Hernán Eriberto Chamorro Sevilla, Alex Erazo Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/453 Mon, 30 Sep 2019 00:00:00 -0500 Parametric Analysis of BFOA for Minimization Problems Using a Benchmark Function https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/490 <p>This paper presents the social foraging behavior of Escherichia coli (E. Coli) bacteria based on Bacteria Foraging Optimization algorithms (BFOA) to find optimization and distributed control values. The search strategy for E. coli is very complex to express and the dynamics of the simulated chemotaxis stage in BFOA is analyzed with the help of a simple mathematical model. The methodology starts from a detailed analysis of the parameters of bacterial swimming and tumbling (C) and the probability of elimination and dispersion (Ped), then an adaptive variant of BFOA is proposed, in which the size of the chemotherapeutic step is adjusted according to the current suitability of a virtual bacterium. To evaluate the performance of the algorithm in obtaining optimal values, the resolution was applied to one of the benchmark functions, in this case the Ackley minimization function, a comparative analysis of the BFOA is then performed. The simulation results have shown the validity of the optimal values (minimum or maximum) obtained on a specific function for real world problems, with a function belonging to the benchmark group of optimization functions.</p> Dannyll Michellc Zambrano Zambrano, Darío Vélez, Yohanna Daza, José Manuel Palomares Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/490 Mon, 30 Sep 2019 00:00:00 -0500 Topological analysis using the Finite Element Method of the chassis of a competition motorcycle https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/454 <p>This model presents a technical application of topological optimization, applied through the study of the behavior of the frame of a brand competition motorcycle, Honda CRF 230 model, with the aim of reducing the weight of the original component without altering its mechanical properties, and obtain a higher performance of the engine, greater maneuverability for the pilot and the reduction of manufacturing costs. This method of analysis is used to obtain the percentages of the chemical elements of a piece by the intensity of the light emitted by a spark, thereby acquiring the mechanical properties of the material. By means of the results, they are analyzed in different points of stress concentration of the frame; the conditions of the border are set to establish the simulation in the CAD model, and the application of the optimization of the structure through the use of the MEF method. Finally, the reduction of 67.6&nbsp;% of the weight of the original chassis was included, with a safety factor of 1.41.</p> Álvaro Remache, Julio Leguísamo, Edwin Tamayo Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/454 Mon, 30 Sep 2019 00:00:00 -0500 Facial recognition techniques using SVM: A comparative analysis https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/493 <p>This paper presents a literary review of facial recognition in 2D, which plays an important role in the life of the human being in terms of safety, work activity, etc. The focus is on the results obtained by some researchers with the application of feature extraction techniques, pattern classifiers, databases and their respective percentage of efficiency obtained. The objective is to determine efficient techniques that allow an optimal 2D facial recognition process, based on the quality of databases, feature extractors and pattern classifiers.</p> José Augusto Cadena Moreano, Nora Bertha La Serna Palomino, Alex Christian Llano Casa Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/493 Mon, 30 Sep 2019 00:00:00 -0500 Economic valuation of the limnetic service of Magdalena-Atillo lake - Riobamba Ecuador https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/332 <p>The present paper is a proposal of socio-economic sustainability of the water resource of the Magdalena lagoon in the Atillo lake complex of the Sangay National Park in the province of Chimborazo, by means of the indirect method of travel costs. In this study, spatial indicators of hydric situation are established and homogeneous units are established with GIS techniques, in order to find the optimal distance to apply the concentric circle methodology in the use of the econometric tool of travel costs. According to the image analysis, it can be concluded that the lake is in retreat; however, it still has limnimetric limits that are still stable. Because of this, it is proposed to limit the number of visits to the area to less than 300 per month and cost opportunity is proposed, for socio-economic sustainability, from the homogeneous units, where the price is considered by estimating the market price, the result being equal to the cost of the trip + Cost of travel time, based on the average stay time that does not exceed one day for the support of the ecosystem</p> Mónica Susana Delgado Yánez, Miguel Martínez-Fresneda Mestre, Antonio Villaruela Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/332 Fri, 28 Jun 2019 00:00:00 -0500 Wireless charging system for static electric vehicles https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/379 <p>The use of electric vehicles expands slowly due to many problems; one of them is charging the car using cable, a method known as plug-in. A technological alternative that can replace cables is the system of energy transfer by electromagnetic induction; for the moment this energy transfer is low power compared to the cable system. The objective of this research project is to demonstrate that the induction charging system is totally feasible for a parked vehicle. It uses a source coil located on the floor of the parking lot, and a pickup coil located in the frame of the car. This paper experimentally demonstrates how the power of transfer varies when the distances between the two coils vary too; three alternatives are considered: coils with cores of air, coils with common iron core and coils with separated iron cores. The measurements are made in a prototype formed by two coils separated by a distance d and provided with a scale of measurement in millimeters. Finally, the behavior of the transferred energy is evaluated according to the distance between coils and the three magnetic core alternatives</p> Iván Yánez Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/379 Fri, 28 Jun 2019 00:00:00 -0500 Incidence of the use of extra gasoline and mixing to the 5 % with anhydrous ethanol in the microfilters of the multipoint injectors https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/430 <p>The purpose of the study was to analyze the deposits in injectors with fuel mixture of 87 octane with percentages of anhydrous ethanol at 5&nbsp;%, and 87 octane gasoline. The experimental phase was carried out in two ignition engine vehicles at a test height of 2810 msnm when traveling, each one, a distance of 3000 km inside the Metropolitan District of Quito. Two methods were applied: Stereoscopy or Vision for the analysis of the microfilters of the injectors, and the semiquantitative chemical analysis Scanning Electron Microscopy for the samples of the residues originated in the filters. In the case of Stereoscopy, in both vehicles, a reduction of clogging of the filters occurred when using gasoline with 5&nbsp;% anhydrous ethanol. The Scanning Electron Microscopy allowed to conclude that there is a greater presence of the sulfur element with 4&nbsp;% in the residues when using gasoline with 5&nbsp;% ethanol, unlike 1&nbsp;% in the waste when 87 octane gasoline is applied.</p> Juan Rocha-Hoyos, Edilberto Antonio Llanes-Cedeño, Jefferson Andrade-Villarreal, Luis Caiza-Quishpe, Julio Leguísamo-Milla Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/430 Fri, 28 Jun 2019 00:00:00 -0500 Thermal Analysis of heat sink with Heat Pipes for High Performance Processors https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/469 <p>The objective of this document is to propose the thermal analysis of a heat dissipating device by using heat pipes containing different fluids, which are water, refrigerant R134a and methanol for the evaluation of these devices under certain design characteristics, due to the fact that at present the processors have a higher energy consumption and greater processing capacities, which causes a significant elevation of the temperature before demanding workloads. Through the use of the ANSYS simulation software, the thermal study of the device was carried out; in addition, the temperature gradient generated in it when in contact with a hot surface, which is going to be a high performance processor, demonstrating that stable temperatures can be obtained through the use of heat pipes at demanding workloads, ensuring correct operation and cooling of the processor.</p> Luis Fernando Toapanta Ramos, Cristian Andrade, Emilio Dávalos Álvarez, Sebastián Landázuri Zaldumbide, William Quitiaquez Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/469 Fri, 28 Jun 2019 00:00:00 -0500 Determination of the physicochemical quality of bee honey sold in Quito and comparison with artificial honey https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/406 <p>The quality of 27 bee honey samples commercialized in the southern markets of Quito was evaluated by performing the physicochemical analyses required by the quality standard of the&nbsp;Ecuadorian&nbsp;Service for&nbsp;Standarization&nbsp;NTE INEN 1572-1988.&nbsp;The results were compared with the same type of analyses performed on a sample of artificial honey.&nbsp;The methods used for each analytical determination were: AOAC 962.37 for density, AOAC 962.19 for humidity, AOAC 52.729 for acidity, AOAC 945.79 for insoluble solids, AOAC 920.181 for ash, AOAC 980.23 for hydroxymethylfurfural, AOAC 958.09 for diastase and the Luff-Schoorl method for the determination of sugars.&nbsp;With the exception of one sample that did not comply the maximum value of the content parameter of hydroxymethylfurfural, and three samples that did not comply with the percentage of reducing sugars, all the samples of bee honey met the requirements of the national standard, although they showed results with significant differences in several parameters among different brands.&nbsp;As for the comparison between bee honey and artificial honey, there was a significant difference in the content of insoluble solids in water, reducing sugars, sucrose and hydroxymethylfurfural, and the activity of diastase.</p> Doris Velásquez, Maria Lorena Goetschel Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/406 Fri, 28 Jun 2019 00:00:00 -0500 Natural scale inhibitor based on mucilage of the cayenne leaf (Hibiscus rosa sinensis) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/460 <p>Nowadays, mineral incrustations are one of the most frequent problems in the petroleum industry; they deteriorate the production systems, causing pressure losses and, consequently, the decrease of hydrocarbon production. Based on this problem, this research was conducted with the purpose of evaluate the efficiency of a natural scale inhibitor based on the leaf mucilage of the cayenne plant (<em>Hibiscus rosa sinensis</em>) in synthetic and production water samples. In order to do this, the physical-chemical characterization on the water samples was carried out, as well as the mucilage previously extracted from the plant. Subsequently, the natural inhibitor was formulated and characterized at three different concentrations (2, 4 and 6&nbsp;% m /V) and the efficiency of the product was evaluated in both water samples, considering three (3) different doses (55, 100 and 500 ppm) following the guidelines of the NACE standard TM0347-2007, with the result that the inhibitor of 2&nbsp;% m/V was the most efficient at its highest dose. In addition, the commercial inhibitor from Halliburton Company was used for comparative purposes in a statistical analysis that indicated the absence of a significant statistical difference between the product at 2&nbsp;% m / V and the commercial inhibitor.</p> Anabel Sarahis Reyes Sisco, José Antonio Ruiz Arenas, Luis Antonio Castillo Campos Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/460 Fri, 28 Jun 2019 00:00:00 -0500 Obtaining and Characterization of a Quinoa Protein Hydrolyzate (Chenopodium quinoa willd) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/424 <p>The present research focused on obtaining a hydrolyzate from a quinoa protein concentrate (isoelectric precipitation method), while the hydrolyzate was achieved with the application of papain enzyme in different concentrations and temperature. The nutritional and functional properties were evaluated in the hydrolyzate, establishing the fact that application of enzyme at a concentration of 0.159 AU/g and pH 6.5 allowed to reach a hydrolysis rate of 13&nbsp;%, a protein content of 73.41 g/100&nbsp;g, digestibility rate of 87.75&nbsp;%, and an amino acid profile within the standard requirements established for children, according to FAO. The functional properties of the hydrolyzate reflected an index of dispersibility of 83.71&nbsp;%, protein solubility of 85.35&nbsp;%, foaming capacity of 125&nbsp;% volume at pH 10, water retention capacity of 0.33 g/g protein and oil holding capacity of 0.56 g/g protein. These values ​​show the potential of the protein hydrolyzate in the elaboration of food formulas for diets with special regimes or as an ingredient in the food industry.</p> Maria Belén Quelal, Karina Nazate, Clara Elena Villacrés Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/424 Fri, 28 Jun 2019 00:00:00 -0500 Using SVG to develop web maps for people with visual disabilities https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/467 <p><span lang="en-US">This paper addresses the problem of accessibility in geographical web maps. A person with disability cannot use, nowadays, a web map with the same functionality as other users do. This problem signifies a huge gap in universal usability, since a wide range of people are left out. This contravenes clearly the principles of the Web, which was created to be of the benefit of anyone in any circumstances. Some software projects have tackled this issue by providing an additional version of the program or just by not dealing with it at all. Our stance is to take a step further and integrate completely the accessibility within the user experience. Everything needed to use the web map –with or without disabilities– is deployed on the same view every user interacts with. This means that an accessible web map has been successfully developed, allowing users with disabilities to explore and navigate not in the same way, but with the same results which others benefit from. This solution opens a discussion about good ways of achieving accessibility, the implications of the current state of art in actual software development and the current awareness about this topic in the computer community.</span></p> Sergio Juan-Armero, Sergio Luján-Mora Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/467 Fri, 28 Jun 2019 00:00:00 -0500 Use of the naranjilla (Solanum quitoense Lam.) variety INIAP Quitoense-2009 to obtain a carbonated beverage https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/425 <p>A carbonated beverage was made with natural naranjilla pulp (INIAP Quitoense 2009 variety). Combinations were made with three pulp concentrations (15, 20, 25&nbsp;%), three concentrations of the natural sweetener stevia (10, 12, 14&nbsp;%) and water, registering variables of soluble solids, pH and titratable acidity. The best formulation was determined by analysis of variance, Tukey test at 5&nbsp;% and acceptance by sensory analysis. Subsequently, 0.4, 0.5 and 0.6&nbsp;% stabilizer (gum arabic) and the same parameters and sedimentation height were measured. Results were analyzed statistically. For carbonation, the most stable beverage was pasteurized and bottled in 350 mL amber glass bottles and 1.8 g of solid CO<sub>2</sub> (dry ice) was added. The container was sealed and sensory tests were after 24 hours to determine the acceptance of the carbonated beverage. The most acceptable formulation was: 25&nbsp;% pulp, 10&nbsp;% sweetener, 0.5&nbsp;% stabilizer, 0.1&nbsp;% sodium benzoate, 0.05&nbsp;% citric acid, 0.5&nbsp;% solid CO<sub>2</sub> and water. The naranjilla pulp can be used in the elaboration of a carbonated beverage, since it fulfills the Ecuadorian regulations.</p> Juan Gaona-Gonzaga, Diego Montesdeoca-Espin, Beatriz Brito-Grandes, Andrea Sotomayor-Correa, William Viera Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/425 Fri, 28 Jun 2019 00:00:00 -0500 Influence of the type of spark plug in the evaluation of the performance and emissions caused in an ignition engine https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/465 <p>This research was made in Cuenca at 2500 meters above sea level (masl), and it studied the influence of the use of different types of spark plugs in a spark-ignition engine on the mechanical performance of the engine, the pollutant emissions, and fuel consumption. Six types of spark plugs that are available in the national market are made of different materials, have different thermal properties, and have different electrode openings. In addition, the mechanical performance of the engines and their fuel consumption were evaluated through dynamometer testing. Moreover, the polluting emissions were measured under the static test protocol established by the NTE INEN 2203 and with an 11 km route test in urban areas and on highway based on the New European Driving Cycle. The research showed that a specific spark plug increases 16&nbsp;% of the engine performance due to not only some factors such as less pollution, better cold behavior, lower fuel consumption, but also maintains the torque and power of the vehicle. In addition, this spark plug generates savings on maintenance and annual fuel consumption.</p> Gabriel Serpa, Xavier Zumba, Francisco Montalvo, Daysi Baño, Jorge Martinez, Iván Zambrano Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/465 Fri, 28 Jun 2019 00:00:00 -0500 Time and yield on the sawing process of Eucalyptus globulus Labill, with circular and band saw https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/477 <p>In order to determine the times and performance in the transformation process of round wood to squared wood of <em>Eucalyptus globulus</em>, a research was carried using circular saw (sawmill A) and circular saw more band saw (sawmill B). The sizes of the samples were 210 and 205 logs. To know the conversion time of the logs, the return-to-zero method was used and in the yield the sawn volume was related to the roll volume of the logs. The result indicate a significant behavior, whose times when processing 1.000 pt (2.36 m <sup>3</sup>) are of 112.73 with circular saw and 167.36 minutes by means of the circular saw system plus the band saw. With yields of 27.74% in the sawmill A and 48.84% in the sawmill B, means that for each cubic meter of round wood (m3. r) processed, 117 pt and 207 st of sawn wood were obtained respectively. Finally, in the sawmill A, as the diameter of the logs increases, the yield and productivity increase. However, in the sawmill B, the yield diminishes and the productivity showed a variable behavior, due to the different number of logs evaluated by diameter class in each factory.</p> Miguel Angel Guallpa Calva, José Suatunce, Hayron Canchignia Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/477 Fri, 28 Jun 2019 00:00:00 -0500 Optimal PMU placement considering N-1contingencies constraints in electrical power systems https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/437 <p>The measurement of electrical parameters through phasor measurement units in the power systems is fundamental, since the obtained data is used to estimate the state of its operation. In the present investigation the problem arises for the optimal deployment of phasor measurement units regarding restrictions of observability, redundancy and N-1 contingencies. Unit minimization considers the output of a transmission line or the failure of a phasor measurement unit and guarantees 100&nbsp;% observability of the power system; For the optimization mixed integer linear programming was used. The proposed algorithm was tested with the IEEE test models of 9, 14, 30 and 118 nodes.</p> Diego Francisco Carrión Galarza, Jorge Wilson González Sánchez Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/437 Fri, 29 Mar 2019 00:00:00 -0500 Parallel robot prototype driven by four cables: experimental results https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/440 <p>Parallel cable robots are a special class of parallel robots which are formed by replacing rigid links with cables. Due to the characteristics provided by the cables, like low inertia and greater range of motion, this type of robots can perform a wide range of applications such as: moving cameras from one place to another in sporting events, motoring industry and mainly in rehabilitation of limbs. However, due to the unilateral property of cables, keeping them tensioned becomes a great challenge. This article describes the construction of a parallel robot driven by four cables with the aim to draw three figures through the study of the kinematic and dynamic model considering the redundancy, i.e., more cables than degrees of freedom, in order to avoid those cables that require more tension during the motion of the end-effector.</p> Marco Antonio Herrera, Nelson Sotomayor, Oscar Camacho Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/440 Fri, 29 Mar 2019 00:00:00 -0500 Sustainable management for the production of biofungicides and strengthening of the Venezuelan agricultural bio-inputs sector https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/392 <p>The purpose of this work was the design of a management proposal for the production of biofungicides, based on international standards related to quality, environment and safety, and occupational health, aiming at strengthening the Venezuelan agricultural bio-inputs sector, in the production of excellent quality products obtained under sustainable production schemes. A diagnosis was made to establish the conformities of the current management of the laboratories dedicated to this activity with the provisions in the standards, besides of a situational diagnosis for the adoption of the proposal. It is an applied investigation, of field and level of descriptive study; the data were collected between April-September 2018 using the survey and structured observation as techniques, and the questionnaire and checklists as instruments. A sustainable management model was generated to promote the adequacy of the organization's task and being, with the duty to be, constituting an input to lay the foundations that propitiate the national and international recognition of the laboratories and platform, to ensure compliance with the requirements of the registration process, mainly in relation to quality assurance, safety conditions of the production process, required documentation and evaluation of the product.</p> Griselda Tamara Colmenares Lima; Miguel Asdrúbal Arcia Montezuma Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/392 Fri, 29 Mar 2019 00:00:00 -0500 Sliding Mode Control Based on Internal Model for a Non-minimum phase Buck and Boost Converter https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/442 <p>This work presents the application of different schemes to control a non-minimum phase Buck-Boost converter. Three control schemes are used. The first controller presented is a PI controller, the second one is Sliding Mode Control and the third one is a combination of two control schemes, Internal Model Control and Sliding Mode Control. The controllers are designed from a Right-Half Plane Zero (RHPZ) reduced order model. The RHPZ model is converted, using Taylor approximation, in a First Order Plus Dead Time (FOPDT) model and after that, the controllers are obtained. The performance of the SMC-IMC is compared against to a PI controller and a SMC. The simulation results show that SMC-IMC improves the converter response, reducing the chattering and presenting better robustness for load changes</p> Byron Cajamarca, Óscar Camacho Quintero, Danilo Chávez, Paulo Leica, Marcelo Pozo Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/442 Fri, 29 Mar 2019 00:00:00 -0500 Where to park? Architecture and implementation of an empty parking lot, automatic recognition system https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/445 <p>The traffic congestion present in practically every city has, among its increasing factors, the unavailability of enough parking spaces. A typical driver invests a considerable part of the total trip time looking for a free space where to park his vehicle; in many cases, this leads to delays and the consequent discomfort due to the undesired consequences of the generated tardiness. For this problem it is possible to find partial palliative solutions, minimizing the time spent searching for parking by applying Internet of Things techniques, oriented to smart cities and buildings. This research has been focused on finding an appropriate computer architecture that will allow the implementation of a distributed system, which, thanks to the use of computer vision and machine learning techniques, detects free parking spaces inside a parking lot, and provides real time information to the driver, allowing him to go as directly as possible to a vacant parking space.</p> Héctor Ávalos, Estevan Gómez, Diego Guzmán, Diego Ordóñez-Camacho, Jéssica Román, Oswaldo Taipe Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/445 Fri, 29 Mar 2019 00:00:00 -0500 Model to estimate the effort required by automation of business processes https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/372 <p>The development of software products has significantly impacted the business world, which has left behind its functional approach and has pledged resources into the quality modeling of its business processes. Numerous studies dedicated to measure indicators, such as quality, complexity and ease of modification, taking into account the constant organizational changes, have resulted in the definition of different metrics, which have mostly been selected, by analogy, with software metrics. In this work, a statistical model that allows the prediction of the effort required in the automation of business processes is defined, taking as a starting point its graphic representation. Metrics related to business process models are proposed in order to study their behavior and influence on the estimation of effort. A base of cases of business process models with their respective effort values ​​was built. The processing of data was carried out from statistical techniques, obtaining a prediction model that is able to explain 99.5&nbsp;% of the represented cases. A computer application was developed for the interpretation of the different output formats of tools that allow modeling business processes and the implementation of the obtained predictive model.</p> Yaimara Granados Hondares, Gheisa Lucia Ferreira Lorenzo Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/372 Fri, 29 Mar 2019 00:00:00 -0500 Reduction of the Probability of Occurrence of Differential Pressure Sticking Through the Use of Diesel on Water Based Drilling Fluids https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/366 <p>The drilling campaign on Pad C of the Tiputini Field, located on the Oriente Basin, Ecuador, started with the first exploratory well TPTC-002. Pressure tests performed on the M1 sandstone of the Napo Formation determined that the average reservoir pressure (Pr) was 1921 psi. Ten months later, Pr averaged 846 psi. This increased the risk of differential pressure sticking, event that indeed occurred while drilling the well TPTC-016. By using the “Bow-Tie” methodology as a predictive tool to analyze risks, and taking into account the preliminary studies that describe this phenomena, a solution was found for stablishing an additional barrier with the use of diesel on the water-based drilling fluid. Diesel was used in order to extend the ‘half value time’ and to decrease the friction coefficient between the mud cake and pipe.</p> David Esteban Almeida Campana, Marco Loaiza, Raul Valencia Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/366 Fri, 29 Mar 2019 00:00:00 -0500 Physical chemical evaluation of pitahaya fruit (Selenicereus megalanthus) in different development stages https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/386 <p>In this research, physical and chemical changes that occur during growth and ripening of pitahaya fruit were assessed. Using the color chart of yellow pitahaya (NTC-3554), fruits were collected in the six stages of ripening (0 dark green to 6 completely yellow) to evaluate the weight of the fruit; while for the variables pulp and skin percentage, pulp firmness (N), soluble solids (ºBrix), pH, acidity (%) and sensory evaluation of flavor and appearance, fruits were only taken in two states (0 and 6). Percentage of skin decreased from 55.93 to 33.40&nbsp;%, whereas that pulp increased from 44.07 to 66.60&nbsp;% among state 0 and 6, respectively. Fruit in the state 6 showed lower pulp firmness (6.20 N) and titulable acidity (0.14&nbsp;%), and higher soluble solids content (20.74&nbsp;%) and pH (4.86). On the other hand, in terms of sensory test, both states (0 and 6) were accepted by the consumer due to the high percentage of soluble solids.</p> Andrea Sotomayor Correa, Soledad Pitizaca, Maritza Sánchez, Armando Burbano, Alejandra Díaz, José Nicolalde, William Viera, Carlos Caicedo, Yadira Vargas Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/386 Fri, 29 Mar 2019 00:00:00 -0500 Assessment of the value chain of Peruvian cacao (Theobroma cacao l.) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/339 <p>The main objective of the research was to determine the deficiencies of the current situation of the Peruvian cocoa value chain and pose an integral improvement in its proposals through the competitive factors in question. In order to achieve it, these tools were used: the analysis of the value chain and the analysis of Porter's competitive diamond. The analysis of the value chain allowed a complete ‘photograph’ of those who have participated, how, with what interests and their interrelations, allowing to visualize the needs and potential of the different actors for individual and joint improvement. In the analysis of Porter's competitive diamond, the components of the cocoa sector were interrelated. The improvements in the value chain were: the result of the linkage of the strategy, the structure and the rivalry between the companies of the sector, the condition of the factors, the conditions of the demand, and the related and support sectors or cluster, which are activities linked between the companies involved in a cocoa sector; all of them fundamental to achieve competitive advantage; that will reduce the gap of the different links turned into competitive factors, to give rise to the development of capacities and to generate exportable supply of cocoa in different niche markets, which, to date, is around 100 000 tons. The operations of agricultural production, post-harvest and transformation requires substantial improvements to avoid non-quality costs and the low retribution of the value of cocoa to the farmer. From the problems encountered, a set of strategic guidelines is derived in the short, medium and long term, projecting a competitive chain for the future, such as positioning by ‘differentiation’, aimed at producing fine cocoa or aroma cocoa, organic cocoa and innovation in products with Peruvian cocoa.</p> Jorge Hilario Guzmán, G C Chire Fajardo Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/339 Fri, 29 Mar 2019 00:00:00 -0500 Development and innovation of electronic systems in an automobile: a review https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/350 <p>This article presents a study of the technological advances in the electronic part of an automobile, based on an analysis of the technical, economic, productive and environmental specifications considered in the design, development and innovation of components of a vehicle that meet the requirements of the automotive companies. It systematically explains the idea and content of the innovation systems implemented in vehicles in recent years, in the electrical-electronic part, after several studies carried out by scientists, researchers and innovation analysts in the field of automotive electronics. The transformations occurred in the last years in the electrical-electronic part of a vehicle are discussed and a comparative analysis of the modifications and / or improvements in the characteristics of the automotive systems is elaborated, in order to comply with the existing regulations regarding energy consumption. , performance, waste treatment, comfort, safety, among others. The introduction of new sensors, control units and actuators, related to microelectronics, telematics and multimedia to vehicles, provides profound changes in the design, production, operation and diagnosis of a car, which have been gradually implemented in the systems of brakes , transmission, steering, safety, comfort and engine.</p> Marco Noroña, Manuel Gómez Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/350 Fri, 29 Mar 2019 00:00:00 -0500 Modeling and simulation of plastic deformation of Aluminium ASTM A1200 during mechanical conformed process https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/375 <p>The research evaluates the behavior of a material when a plastic deformation occurs. The document describes the analytical process, finite elements and integrate process in order to develop shaped piece plan. Stress analysis and section variation were analyzed during the stuffing process. In the experimental part, the mechanical characteristics of the aluminum ASTM A1200 were determined (Yield strength was 214 MPa). The shaping process was carried out in a 5 tons press with pneumatic device. Several tests were executed with different depths in order to compare thicknesses with the physical model simulation. The maximum error was 3.67&nbsp;% at 15 mm depth and the minimum of 0.24&nbsp;% with the total depth. Respect to the efforts generated during the conforming, the maximum and minimum errors were 10.9&nbsp;% and 2.18&nbsp;% respectively.</p> Luis C Juiña, Víctor H Cabrera, Nancy V Moreno, Cristian A Anrango Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/375 Fri, 29 Mar 2019 00:00:00 -0500 Optimal allocation of communications resources for energy management systems https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/447 <p>This article proposes the optimal resource allocation of radio channels available in cellular networks for the transmission of data from the smart meters to information management systems. The model designed identifies and counts the subscribers of the electricity sector in a geographical area; through the kmeans algorithm the cellular radio bases are located. The optimal location of radio bases provides communication to all devices within its coverage radius. The communication channels available for data transmission are optimized using the Greedy algorithm, which set the time when smart meters must send their data through the disused communication channels.</p> Milton Gonzalo Ruiz Maldonado, Esteban Inga Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/447 Fri, 29 Mar 2019 00:00:00 -0500 Mechatronic device for the analysis and mitigation of involuntary movements in people with Parkinson's disease https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/452 <p>Considering that the Parkinson disease is a neurodegenerative, progressive and incurable pathology, and with the purpose of improving ill people life quality, the design and construction of a mechatronic device was proposed to help mitigating the involuntary movements produced by the disease. This device allows the analysis of the involuntary movements of pronosupination generated in the upper limbs using electromyographic signals produced by the muscles of the forearm and an algorithm based on artificial neural networks. To materialize the device, fast prototyping like 3D printing and the V model-based mechatronics methodology were considered. As a result of this investigation, a mechatronics device in the shape of an exoskeleton controlled by an embedded system which analyses, processes electromyographic signals and using neural networks allows tremor and involuntary movements classification produced by each patient. The system operation results are: for tremor prediction is 96.88% of success, and for the involuntary movement prediction is 100 % of success.</p> Gabriel Eduardo Rivera Cárdenas, Vladimir Bonilla, Moya Marcelo, Guillermo Mosquera, Anatoly Vitalyevich Litvin Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/452 Fri, 29 Mar 2019 00:00:00 -0500 Motion simulation of a hexapod robot in virtual reality environments https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/456 <p>The aim of this work is the development of an animation of a hexapod robot in virtual reality environments through the use of Unity software. The movement of the robot is 18 degrees of freedom, which are based on servo motors that are controlled by the use of a microcontroller; It also shows the processes necessary to transfer the 3D design of the hexapod robot made in the use of CAD (Computer Aided Design) software to a virtual reality environment without losing the physical characteristics of the original design. Finally, the results obtained from the simulation of movement and responses of the hexapod robot to disturbances such as roughness of the floor, uneven ground and gravity among others are presented; allowing a correct evaluation to possible designs of robots before being elaborated.</p> Jonnathan Chamba, Miguel Sánchez, Marcelo Javier Moya, Joaquín Noroña, Rafael Franco Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/456 Fri, 29 Mar 2019 00:00:00 -0500 Bioremediation of hydrocarbons in wastewater with mixed culture of microorganisms: case car washers Puyango https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/312 <p>Wastewater from car washers and lubricators contain high levels of hydrocarbons. These are discharged into the public sewer system without proper treatment and not complying with the regulations. In this study was evaluated the process of bioremediation of total hydrocarbons in Puyango’s wastewater, using bioaugmentation treatment, which means, applying hydrocarbons-degrading microorganisms. First, a characterization of the wastewater was carried out, and the content of total petroleum hydrocarbons (TPH) and the flow rate was determined for seven days. A mixture of bacteria: <em>Acinetobacter sp</em>., <em>Pseudomonas sp</em>. y <em>Mycobacterium sp</em> was applied in solid form (80 g tablet) with a minimum concentration of 4 x 10<sup>8</sup> CFU / ml soluble in water, using 2 tablets during 30 days of treatment. The concentration of the TPH was determined weekly, plotting the temporal variation and quantifying the&nbsp;% of removal. The results indicate that the technique of bioaugmentation was effective (p = 0.003) in the removal of the TPH, obtaining percentages above 86&nbsp;%. The time of greatest removal of TPH was obtained in the third week of treatment with 92&nbsp;%. In addition, COD removals were obtained –40&nbsp;%, Oils and fats - 50%, Surfactants –43&nbsp;% thus fulfilling the current regulations for discharge to the public sewer system for the TPH.</p> Judit García, Daniel Peñafiel Heredia, Remberto Rodríguez Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/312 Fri, 29 Mar 2019 00:00:00 -0500 Typical meteorological year based on the precipitation of Nanegalito and Pacto-Ecuador https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/422 <p>The typical meteorological year (TMY) based on daily rainfall data was calculated in the parish of Nanegalito; 12 years were considered, from 2004 to 2015, including both years. For the establishment of the TMY, the Finkelstein-Schafer (FS) statistical equation was chosen, together with the calculation of the cumulative distribution function for each month of each year considered. The weighted sum, calculated from the FS values, was used to finally choose the months that best represent the climatic characteristics of the period analyzed by applying the root mean square deviation (RMSD). Once these values were obtained, the TMY of Nanegalito was estimated based on the precipitation. The determination of Nanegalito TMY may be useful for the management of several processes, in this and other surrounding parishes, as an example, Pacto, such as irrigation planning in crops, analysis in drought risk scenarios, and if other variables are analyzed in the future, they could serve as tools for the study of possible renewable energies.</p> Francisco Rodríguez, Andrea Castro, Freddy Marín, Gloria Roldán, Fausto Viteri Moya Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/422 Fri, 29 Mar 2019 00:00:00 -0500 Analysis of the use of micro DC/DC converters focused on the maximum extraction of energy in photovoltaic farm https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/441 <p>This work presents an extended study of the work published in the magazine INCISCOS 2018 titled “Improving of the Photovoltaic High Power Plant Generation Using DC/DC Micro Converters”, and intented to increase the amount of electrical energy generation of a Photovoltaic Plant located in Salinas, Imbabura Province, Ecuador through the implementation of DC/DC converters in the solar panel arrays and tracking techniques of the maximum power point. The results show that the insertion of the DC/DC converters in the system causes an increase in the amount of active power. The system is analiced in variation of solar radiation or changes in the ambient temperature as well.</p> Juan Vargas, Jorge Luis Medina Mora, Marcelo Pozo, Eduardo Ávila, NATALY POZO, GABRIEL SALAZAR Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/441 Fri, 29 Mar 2019 00:00:00 -0500 A visual analytics architecture for the analysis and understanding of software systems https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/455 <p>Visual analytics facilitates the creation of knowledge to interpret trends and relationships for better decision making. However, it has not being used widely for the understanding of software systems and the change process that takes place during their development and maintenance. This occurs despite the need of project managers and developers to analyze their systems to calculate the complexity, cohesion, direct, indirect and logical coupling, detect clones, defects and bad smells, and the comparison of individual revisions. This research considers the design of an extensible and scalable architecture to incorporate new and existing methods to retrieve source code from different versioning systems, to carry out the analysis of programs in different languages, to perform the calculation of software metrics and to present the results using visual representations, incorporated as Eclipse and Visual Studio extensions. Consequently, the aim of this work is to design a visual analytics architecture for the analysis and understanding of systems in different languages and its main contributions are the specification of the design and requirements of such architecture, taking as base the lessons learned in Maleku (A. González-Torres et al., 2016).</p> Antonio González-Torres, José Navas-Sú, Marco Hernández-Vásquez, Franklin Hernández-Castro, Jennier Solano-Cordero Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/455 Fri, 29 Mar 2019 00:00:00 -0500 Automatic device to manufacture paraffin rings used in the Textile Industry https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/458 <p>The work consists in the design and manufacture of an automatic device that allows to continuously elaborate paraffin rings used in the different processes of the Textile Industry. Paraffin is a byproduct of petroleum and is very useful in the Textile Industry, since it helps to reduce the friction between the threads and the different guides through which it passes, reducing the presence of exaggerated tensions that cause the breakage of the threads, defects in the tissues and the paralysis of machines and processes. The device, designed and validated in its mechanical structure by means of the use of a CAD program, consists of a rotating disc on which eight molds in the form of 54 cm<sup>3</sup> capacity rings are located, automatically spaced and controlled to be filled with paraffin liquid continuously, guaranteeing the solidification and extraction of each ring in a synchronized manner as the disc rotates. The performance was validated observing that the results of the tests of dosage, time of filling, time of transfer, solidification time and extraction time of the solidified ring contributed to the productivity of this product.</p> Luis Armando Hidalgo Aguilera, Santiago David Morejón Bravo Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/458 Fri, 29 Mar 2019 00:00:00 -0500 Enterprise Architecture, an enabler of change and knowledge management https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/459 <p>Organizations around the world require a sound process of change management to innovate and remain competitive over time. Change and knowledge management needs to be supported with the right tools to overcome the challenges of transformations and transitions in the business models and processes of diverse organizations. Steering boards can use enterprise architecture (EA) to implement new knowledge management initiatives in their strategic planning. EA allows companies to model the current situation (as-is models) of the organization and the desired future scenarios (to-be models) and to establish road maps to enable adequate transformations. Different frameworks exist in the market that support the management of organizations, for example: Control Objectives for Information and Related Technologies (COBIT), Information Technology Infrastructure Library (ITIL), quality models such as the one proposed by the European Foundation for Quality Management (EFQM) and systems such as the Balanced Scorecard (BSC) are widely used for the management of business and information technologies (IT).&nbsp; However, EA is not widely used with the other mentioned tools. This paper analyzes EA as a tool for change and knowledge management and compares its functionality with other frameworks in the market. The analysis performed in this paper checks if EA can be used and is compatible with other frameworks. To answer this question, an analysis of the most important processes, good practices, perspectives and tools provided by each framework was performed.</p> Oswaldo Moscoso-Zea, Joel Paredes-Gualtor, Sergio Luján-Mora Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/459 Fri, 29 Mar 2019 00:00:00 -0500 Data analysis and tools applied to modeling and simulation of a PV system in Ecuador https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/389 <p>This paper presents a research was carried out for the management of a photovoltaic system in a Microgrid, with applications and the use of tools applied to modeling and computational simulation in the Microgrid laboratory implanted in the facilities of the University of Cuenca (Ecuador). Additionally, through the use of automatic learning techniques, the behavior of the photovoltaic system has been modeled in the study area based on radiation and temperature with very good results. In addition, several applications can be made in real engineering studies such as feasibility, performance analysis, energy estimation, educational models, etc.</p> Darío Javier Benavides Padilla, F Jurado, Luis G González Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/389 Fri, 21 Dec 2018 00:00:00 -0500 Efficient solution of nonlinear model predictive control by a restricted enumeration method https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/393 <p>This work presents an alternative method to solve the nonlinear program (NLP) for nonlinear model predictive control (NMPC) problems. The NLP is the most computational demanding task in NMPC, which limits the industrial implementation of this control strategy. Therefore, it is important to consider algorithms that can solve the nonlinear program, not only in real time but also guaranteeing feasibility. In this work, the restricted enumeration method is proposed as alternative to solve the NLP for NMPC problems, showing successful results for pH control in a sugar cane process plant. This method enumerates in restricted way a set of final control element possible positions around the current one. Next, it tests all positions in that set to find the best one, taken as the optimization solution.</p> Jhon Alexander Isaza Hurtado, Diego A Muñoz, Hernán Álvarez Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/393 Fri, 21 Dec 2018 00:00:00 -0500 Predictive ADRC Control Using LMI https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/394 <p>On recent times Active Disturbance Rejection Control has drawn both the attention of industrial and scientific community due to its capability to handle uncertainties and nonlinearities without using an explicit model of the system; on this paper a modification of the ADRC algorithm is presented, first an Extended State Predictor is calculated and later, a controller is built using the LMI approach, the proposal is evaluated through simulations on the Cayley-Rodriguez representation of the Monoaxial satellite</p> Hanna Khalil Aboukheir Hernandez Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/394 Fri, 21 Dec 2018 00:00:00 -0500 Event-Triggered Control for a Three DoF Manipulator Robot https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/396 <p>In the classical approach of Time-Triggered Control (TTC),&nbsp; the control signal is updated&nbsp; at&nbsp; each&nbsp; sampling&nbsp; time&nbsp; as&nbsp; well&nbsp; as&nbsp; the&nbsp; system&nbsp; states&nbsp; to&nbsp; be&nbsp; controlled,&nbsp; which could imply a redundancy in the computational calculation as well as in the transfer of information in the regulation objective. On the other hand, the Event-Triggered Control (ETC) approach performs the same task in an asynchronous way, i.e,, it only updates the control signal when a performance requirement is violated and the states are updated at each sampling time. This reduces the amount of computational calculation without affecting the performance of the closed loop system. For this reason, in the present work the ETC is developed for the stabilization of a manipulator robot with three Degree of Freedom (DoF) in the joint space where a Lyapunov Control Function (LCF) is proposed to formulate the event function (e¯), which indicates whether or not&nbsp; is required&nbsp; the&nbsp; control&nbsp; signal&nbsp; updating.&nbsp; Simulation results show the reduction of the updates compared with a TTC.</p> Saul Enrique Benitez-Garcia, Miguel Gabriel Villarreal-Cervantes Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/396 Fri, 21 Dec 2018 00:00:00 -0500 Fractional order modeling of a nonlinear electromechanical system https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/398 <p><span style="font-family: Arial, serif;"><span lang="en-US">This paper presents a novel modeling technique for a VTOL electromechanical nonlinear dynamical system, based on fractional order derivatives. The proposed method evaluates the possible fractional differential equations of the electromechanical system model by a comparison against actual measurements and in order to estimate the optimal fractional parameters for the differential operators of the model, an extended Kalman filter was implemented. The main advantages of the fractional model over the classical model are the simultaneous representation of the nonlinear slow dynamics of the system due to the mechanical components and the nonlinear fast dynamics of the electrical components.</span></span></p> <p lang="en-US">&nbsp;</p> Carlos Enrique Mejia Salazar, Julián Esteban Rendón Roldán Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/398 Fri, 21 Dec 2018 00:00:00 -0500 Concurrent design of a lower limb rehabilitation mechanism https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/399 <p>The rehabilitation given by robotic systems is a choice for minimizing the recovery time of a patient and boost their muscular and skeletal capacity on a limb damaged. However, the high cost of these systems limits patients to receive these kind of treatments. The systems of one degree of freedom are a low cost alternative to health care and rehab at home.</p> <p>In this paper, the structural design of an 8-link mechanism for the rehabilitation of lower limbs is performed, based on the approach and solution of an optimization problem in which certain objectives are met, such as dimensional synthesis, and the minimizing of torque to make control easier.</p> José Saúl Muñoz Reina, Miguel Gabriel Villarreal Cervantes, Leonel German Corona Ramirez, Robero Castro Medina Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/399 Fri, 21 Dec 2018 00:00:00 -0500 Root-Locus Analysis of Delayed First and Second Order Systems https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/401 <p>For finite dimensional linear system the root-locus method is well established however for the case of delayed systems the method has some problems due to the transcendental term involved. This work intends to illustrate the problems that arises when a root-locus diagram is performed as well as to develop a Matlab function that provides the root-locus diagram for delayed low order systems. In this way, some comments about the problems that should be tackled to obtain a generalization of the computational method for delayed systems with real <em>m</em> poles and <em>n</em> zeros</p> Moisés Ríos Flores, J.F. Marquez-Rubio, B. del Muro-Cuellar, E. Aranda-Bricaire Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/401 Fri, 21 Dec 2018 00:00:00 -0500 Fault Tolerant MPC Controller for Electric Heater Control https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/402 <p>Los controladores MPC son buenos eliminando el error de estado estacionario aun si el sistema controlado es afectado por perturbaciones. Pero el MPC no fue pensado para mantener su desempeño bajo condiciones de falla por sí solo. El control tolerante a fallas se compone de algoritmos de control, estrategias de detección y compensación de fallas. En este trabajo se implementó un controlador MPC usando la estrategia de matriz dinámica junto con un generador de residuo basado en modelo para detectar la ocurrencia de una falla en el sistema controlado. La cuantificación de fallas se logró mediante el uso de Redes neuronales artificiales y un filtro pasa banda, lo cual permitió realizar una acción de compensación para mejorar el tiempo de recuperación del sistema ante una falla.</p> Raúl Esteban Alzate, Diego Martinez, Juan Carlos Mena, Bernado Sabogal, Jimmy Tombe Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/402 Fri, 21 Dec 2018 00:00:00 -0500 Modelling of Learning Styles in Relation to University- level Lectures https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/400 <p>Throughout this paper we seek to demonstrate the practicality of obtaining an approximate model of the relationship between a score that determines the learning styles of a student and the results obtained in a specific University-level lecture. The study considered the voluntary participation of over six hundred students from “Escuela Politécnica Nacional” of Ecuador (EPN). The Index of Learning Styles model was used to establish the various learning styles of the students. The analysis of the results considers the linear correlation and the correlation distance.</p> Ruth Cueva, Diego Salazar, Gabriel Francisco Grijalva Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/400 Fri, 21 Dec 2018 00:00:00 -0500 A Fuzzy Sliding Mode Controller for Planar 4-Cable Direct Driven Robot https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/403 <p>Cable Direct Driven Robots (CDDRs) are a special class of parallel robots but they are formed by replacing all the supporting rigid links with cables. Compare with traditional robots, these robots are good candidates for performing a wide range of potential applications. A Planar CDDR model is considered in this paper since no rotational move and no moment resistance are required on the end-effector, all 4 cables convene in a single point and the end-effector is modeled as a point mass. The main goal of this paper is to present a new approach in control by developing a Sliding Mode Controller (SMC) with a Fuzzy-PI as sliding surface using Fuzzy logic toolbox in Matlab/Simulink. The tests performed were Step change reference test and Tracking trajectory test to observe the behavior of the cables during the trajectory and the end-effector movement. Simulation was carried out on Planar 4-Cable CDDR to prove the effectiveness of the proposed control law and the results were compared with a PI Controller and a conventional SMC in terms of integral square error (ISE) index. Only the kinematic model of Planar 4-Cable CDDR is considered in this paper.</p> Xavier Iván Aguas, Andrés Cuaycal, Israel Paredes, Marco Herrera Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/403 Fri, 21 Dec 2018 00:00:00 -0500 Sliding modes control for a heat Exchange system: experimental validation https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/404 <p>Sliding modes control (SMC) is a nonlinear control method with a systematic design procedure that allows to obtain a explicit solution for the control input. This method has some advantages, such as robustness against external disturbances and unpredictable parametric variations. On this work, two conventional SMC techniques, one using the error and other using the error integral, are designed and validated in a heat exchange system composed of a single pass circulation electric heater, whose control objective is to regulate the output temperature of the fluid, under the influence of external disturbances, such as variations in the flow and inflow temperature, manipulating the electric current passing through the heater resistance. The two SMC algorithms are analyzed using numerical simulations and their performance is compared through the integral absolute error and the integral absolute control input, selecting the best one to be tested experimentally. The experimental results indicate that the SMC is capable of fulfilling the control objective with satisfactory performance.&nbsp;</p> <p><strong>Keywords:</strong> Conventional sliding modes control; heat exchange system; nonlinear control.</p> Maribel Cecilia Pérez Pirela, Juan Paulo García Sandoval Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/404 Fri, 21 Dec 2018 00:00:00 -0500 The Extended Kalman Filter in the Dynamic State Estimation of Electrical Power Systems https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/407 <p>The state estimation and the analysis of load flow are very important subjects in the analysis and management of Electrical Power Systems (EPS). This article describes the state estimation in EPS using the Extended Kalman Filter (EKF) and the method of Holt to linearize the process model and then calculates a performance error index as indicators of its accuracy. Besides, this error index can be used as a reference for further comparison between methodologies for state estimation in EPS such as the Unscented Kalman Filter, the Ensemble Kalman Filter, Monte Carlo methods, and others. Results of error indices obtained in the simulation process agree with the order of magnitude expected and the behavior of the filter is appropriate due to follows adequately &nbsp;the true value of the state variables. The simulation was done using Matlab and the electrical system used corresponds to the IEEE 14 and 30 bus test case systems. State Variables to consider in this study are the voltage and angle magnitudes.</p> Holger Ignacio Cevallos Ulloa, Gabriel Intriago, Douglas Plaza, Roger Idrovo Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/407 Fri, 21 Dec 2018 00:00:00 -0500 Potential of aquatic plants for the removal total coliforms and Escherichia coli in wastewaters https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/286 <p>In Ecuador, many communities depend on untreated surface water as the primary source of drinking water and are contaminated with fecal coliforms and <em>Escherichia coli</em>. The objective of the present study was to find aquatic plants with remove of contaminated water with <em>E. coli </em>and total coliforms. For this purpose, the following species were sampled: <em>Azolla caroliniana</em> Willd., <em>Eichhornia crassipes</em>, <em>Pistia stratiotes</em>, <em>Salvinia auriculata</em>, <em>Ceratopteris thalictroides a</em>nd <em>Lemna sp</em>. (Positive control). The plants were reproduced <em>in vitro</em> and bioassays were performed to verify their ability to remove <em>E. coli</em>. Assays were run by triplicate in 0.5 L of water with fertilizer and an <em>E. coli</em> ATCC25922 reference strain was inoculated. As negative control the bacteria without plants and positive control were inoculated with the plant <em>L. minor</em>. After 7 days, the remaining bacterial load was determined. To analyze <em>E. coli</em>, the technique ISO 9308-1 was used. A percentage of 99% <em>E. coli</em> removal was found for <em>A. caroliniana</em>, <em>E. crassipes, C. thalictroides </em>(L.)<em> Brongn</em> and <em>Lemna minor</em>. And 100% for <em>P. stratiotes</em> and <em>S. auriculata</em>. Subsequent waste water tests were performed in which <em>S. auriculate </em>and<em> A. caroliniana</em> achieved 100% removal of the coliforms and the remaining lower efficiency. The use of these species is proposed for the treatment of wastewaters.</p> R León, Beatriz Margarita Pernía Santos, Rosa Siguencia, S Franco, A Noboa, Xavier Cornejo Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/286 Fri, 21 Dec 2018 00:00:00 -0500 Quality parametres of four types of formulations based on Trichoderma asperellum and Purpuricillium lilacinum https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/348 <p>The genus <em>Trichoderma</em> and to a lesser extent <em>Purpureocillium</em>, have been studied extensively for their properties as beneficial microorganisms and their effectiveness in disease control. However, biological efficacy is not the only parameter considered when formulating a microorganism; viability, purity and concentration in the formulation are important characteristics to ensure success in the field. The aim of this study was to access different types of formulations (granules, powders, liquids) to record their behavior over time, using the variables viability, concentration and purity to select best formulations based on these parameters. As a result, it was obtained that the bioformulates based on <em>T. asperellum</em> showed greater stability during storage, with dry solid formulations being more stable in comparison with liquid products. In terms of the <em>P. lilacinum </em>formulations, it was observed that the presentation of wettable powders showed the highest concentration and stability over the time.</p> William Viera, Michelle Noboa, Johana Bermeo, Francisco Báez, Trevor Jackson Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/348 Fri, 21 Dec 2018 00:00:00 -0500 Analysis of benthic macroinvertebrates and biotic indices to evaluate water quality in Sardina´s river, Ecuadorian Chocó Andino https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/369 <p>An aquatic macroinvertebrates community analysis was made at Sardinas River, in the rainy and wet seasons of 2018, using macroinvertebrates as environmental bioindicators; these were collected with Surber net and hand collection, in five points along the river. In the laboratory they were classified and identified as class, order and family. They were studied by the analysis of richness (S) and abundance (N). The environmental quality was determinate applying the BMWP/Col and EPT indices. A total of 526 individuals belonging to 15 orders and 44 families were collected. 35 in the rainy season and 31 in the dry season. The most abundant family in rainy season was Leptophlebiidae, 34 specimens (12.8%). In dry season, the most representative was Chironomidae with 45 individuals (17.2%). In rainy season the point 2 had greater richness S16 and in the dry season P1, S18. P3 - P5 presented medium quality water (BMWP/Col = 69-94 and an EPT average of 47.05%). This study determined through BMWP/Col and EPT indices, in association with the taxa collected and the calculations of (S), (N) and relative abundance (%), the ecological status of the studies’ area.</p> Verónica Machado, Roberto Granda, Alexandra Endara González Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/369 Fri, 21 Dec 2018 00:00:00 -0500 Discovering behavioral patterns among air pollutants: A data mining approach https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/411 <p>Air pollutants affect both human health and the environment. For this reason, environmental managers and urban planners focus their efforts in monitoring air pollution. In this context, complete information is required to support the decision-making process to improve the quality of life in urban zones. Hence, it is important to extract knowledge not only on concentration levels but associations between air pollutants. Based on the Cross-industry standard process for data mining, this paper presents an approach which leads to identify correlations and incidence between the most harmful pollutants in the Andean Region: Ozone, Carbon monoxide, Sulfur dioxide, Nitrogen dioxide and, Particulate material. This paper describes an experiment using a real dataset from a monitoring station in Cuenca, Ecuador located in the Andean region.&nbsp; The results show that the proposed approach is effective to extract knowledge useful to support the evaluation of air quality in urban zones. In addition, this approach provides a starting point for future data mining applications for the analysis of air pollution in the context of the Andean region.</p> Diana Arce, Fernando Lima, Marcos Patricio Orellana Cordero, John Ortega, Chester Sellers, Patricia Ortega Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/411 Fri, 21 Dec 2018 00:00:00 -0500 Evaluation of the extract obtained as leached of coconut (Cocos nucifera) fiber as a bioestimulant in remediation of a soil contaminated with oil https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/303 <p><span style="font-family: Arial, serif;">The use of the extract obtained as a leaching of the coconut fiber (Cocos nucifera) as a biostimulant for the remediation of a savanna soil contaminated with heavy oil was evaluated. Through standardized procedures, the main characteristics of the extract, oil and soil were obtained. The soil was contaminated with 100 mL of heavy oil per kilogram. Four experimental units of 1 kg each were established, leaving the first as a pattern without treatment and 3 treated with extract in proportions of 50, 100 and 150 mL, each with 3 replicates distributed at random. The units were left under controlled laboratory conditions and the percentage of oils and fats and the pH were determined every 7 days by means of the EPA 9071b and ASTM D4972 standards, until complying with the Venezuelan standard Decree 2635. It was concluded by means of a Factorial ANOVA analysis, that both the volume of extract applied and the exposure time exert a statistically significant influence on the percentage of oils and fats and the pH with 95% confidence level. All soil units treated with extract reached the limit value established in Decree 2635 at 28 days.</span></p> Tomás Darío Marín Velásquez, Creisvy Nazaret Gota Díaz, Thania Carolina Ortiz Pinto Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/303 Fri, 21 Dec 2018 00:00:00 -0500 Analysis of the methodology for rate determination in commercial transportation service of conventional and executive taxis https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/343 <p>An efficient transport service allows a society to have economic progress and improves quality of life. Part of this structure is the issue in the determination of pricing the service of it, thus, the incomes of the offeror and good service to the user can be guaranteed. In Ecuador, the National Traffic Agency establishes a methodology that considers the offer of kilometers and operating costs. However, this methodology does not establish how to get and analyse the information that feeds the model, this aspect can generate biases and subjectivities at the time to define the rate. This study seeks to detect deficiencies in the methodology and suggest the relevant changes as an alternative to it, for this a mixed approach is considered, which not only considers surveys but also instrumentation and hi-technology to measure fuel consumption, tire wear, distance traveled and number of passengers. Once the analysis of the methodology was developed, a new approach to information gathering was proposed; and to validate, an experiment was applied to a canton of the country, with this it was possible to obtain rates that better represent the reality of the sector under analysis.</p> Gabriela Duque E, Iván Orellana O, Mateo Coello, Daniel Cordero-Moreno Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/343 Fri, 21 Dec 2018 00:00:00 -0500 Study of the dynamic performance of an Otto engine using mixtures two types of “Extra and Super” gasolines https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/335 <p>The purpose of this study is to compare and examine the performance of an engine, using gasoline with 92 octanes (Super), 87 octanes (Extra) and two volume mixtures of these two types of gasoline, the first one had 50% of volume of each type, the second one had a volume value of 70% of Super with 30% of Extra. To evaluate the performance of the engine, a dynamometer was used to obtain the characteristics curves of power and torque, a gas analyzer was used to determine the level of emission of pollutant gases from the engine (CO, CO<sub>2</sub>, HC, y NOx), finally an homologated cycle was carried out to measure fuel consumption. The mixture of Super 50% with Extra 50% obtained a higher power value with 81.3 HP, the Super gasoline obtained a higher torque value of 89.2 lb-ft, in cycle ASM 2525, the CO, HC and NOx were measured, the Super gasoline, Extra gasoline and the mixture of 50% of each gasoline were the least polluting ones, in cycle ASM 5015, CO, HC and NOx were measured, Super gasoline, Extra and the Super 70% V mixture with Extra 30% V respectively were less polluting, in the static gas test the least polluting was Super.</p> Alex Rodolfo Guzmán, Eduardo Cueva, Alexander Peralvo, Milton Revelo, Alexis Armas Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/335 Fri, 21 Dec 2018 00:00:00 -0500 Energy and exergy evaluation in a 1.6L Otto cycle internal combustion engine https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/365 <p>This paper aimed to evaluate the behavior of an Otto Cycle internal combustion of a 1.6 L engine measuring its performance by the energy and exergy balance. The energy calculation was developed in a previously set route at a constant speed of 50 km/h and &nbsp;&nbsp;&nbsp;90 km/h. It was determined, that the analysis of the energy and exergy balance contributes to recognize the performance of an internal combustion after the experimentation based on observation, measurement, methods of induction, deduction and synthesis. Also, it was resolved that the engine has an average energy efficiency of 27.57 % for a speed of&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; 50 km/h, while the total exergy flow of the system is 22 %. Therefore, there is no significant difference with the efficiency results at 90 km/h.</p> Edilberto Antonio Llanes Cedeño, José Bolívar Carguachi-Caizatoa, Juan Carlos Rocha-Hoyos Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/365 Fri, 21 Dec 2018 00:00:00 -0500 Production of a fermented drink based on quinoa (Chenopodium quinoa) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/329 <p>The aim of this study was to develop a beverage obtained from the fermentation of the soluble extract of germinated quinoa under the action of traditional yogurt cultures (<em>S. thermophilus </em>and<em> L. bulgaricus</em> ) and probiotic cultures (<em>Lactobacillus. acidophilus </em>and<em> Bifidobacterium</em> ). Two factors under study were established: the xanthan gum percentage (0.30%, 0.40 % and 0.50% w/w) and sucrose:fructose relation (90:10, 70:30, 50:50) added in the formulation. The quantified variables were: acidity, pH, viscosity and phase separation. The study was conducted under the completely randomized design (CRD), analysis of variance (ANOVA) and Tukey mean separation test with a confidence level of 95 %. The best treatment included 0.50 % xanthan gum and sucrose:fructose relation of &nbsp;90:10 in its formulation. The product was subjected to sensory tests in which it was determined that the product liked to consumers (score of 3.2 points on a 5-point hedonic scale). Finally, a fermented drink made from quinoa was obtained with 9 g of protein per 200 g of product and with a shelf life estimated in 70 days at 4<sup>o</sup>C. This product could be an alternative to fermented beverages such as cow's milk yogurt and soy-fermented drink.</p> Roberto Maldonado Jibaja, Paola Carrillo Herrera, Lucía Ramírez Cárdenas, Francisco Carvajal Larenas Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/329 Fri, 28 Sep 2018 00:00:00 -0500 Diversity and floristic composition of the Los Búhos Forest located in the province of Chimborazo, Ecuador https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/211 <p>To promote conservation processes it is essential to know the biodiversity under analysis. The objective of the present work was to determine the composition, diversity and floristic importance of El Bosque Los Búhos to generate a baseline that allows the management of the resource for academic purposes. A description of the floristic composition was made, the alpha (α) and beta (β) biodiversity indexes were determined and the ecological importance of the species (IVI's) was calculated. The data indicate that the floristic composition of the forest is formed in three strata by 56 species, 18 orders and 27 families. The arboreal stratum presents a biodiversity average (2,534-Margalef) and high dominance (0,8367-Simpson), the shrub layer has low biodiversity (1,811-Margalef) and low dominance (0,4441-Simpson), and the herbaceous stratum presents biodiversity average (3,882-Margalef) and high dominance (0,7101-Simpson). The species with the highest IVI's for the arboreal stratum are Mimosa quitensis (Benth.1848), Acacia retinodes (Schltdl.1847), y Tecoma stans (L.) Juss. ex Kunth. 1819). For the shrub layer are Agave americana (L.1753), Lantana megapotamica (Spreng. Tronc. 1974), Retama sphaerocarpa (L. Boiss. 1840) y Opuntia cylindrica (Lam. DC. 1828). Finally for the herbaceous stratum is Carpobrotus edulis (L.) N.E.Br. 1926).</p> Patricio Xavier Lozano Rodríguez, Aracely Armas, Martha Gualán, Miguel Guallpa Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/211 Fri, 28 Sep 2018 00:00:00 -0500 Forecasting of daily precipitation occurrence in an altitudinal gradient in southern Ecuador using a weather generator https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/209 <p>Precipitation forecast is fundamental for improving the management of water resources, for development projects and risk reduction. Due to its high variability, high quality rain forecasts are still a challenge. In the present study, a weather generator (WG) was used to study the quality of the forecast of daily rainfall occurrence. The WG was implemented using three variables as predictors: the binary variable precipitation occurrence of the previous day (Kt-1), the maximum and minimum temperatures of the previous day (Txt-1, Tnt-1, respectively); and two co-variables: monthly values of the observed Sea Surface Temperature Anomalies of the Regions 1+2 and 3.4 of El Niño-Southern Oscillation (Niño 1+2 and Niño 3.4 respectively). We found that the variables Kt-1, Tnt-1 and co-variable Niño 3.4 are those that improve the performance of the precipitation occurrence forecasting. There was a noticeable difference in the number of consecutive wet and dry spell days in the altitudinal gradient in a rainy period. We propose several hypotheses based on the use of WG, which allow the understanding of the functioning of the climate system and the improvement of the forecast of precipitation occurrence in a mountainous area.</p> Diego Hernán Urdiales Flores, Rolando Célleri Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/209 Fri, 28 Sep 2018 00:00:00 -0500 Determination of the optimum speed for MIG welding of alloy 5086-H116, by hardness test, tensile test and metallographic examination for the manufacture of aluminum tankers https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/215 <p>For the construction of the specimens welded by the GMAW process of the aluminum alloy 5086-H116, advance speeds of 300, 400, 500, 600 and 700 mm / min are used that are within the recommended range, the same as they allowed the energy contributed to the union. From the results obtained in the different tests, it was determined that the most suitable welding advance speed is 500 mm / min (with a contributed energy of 335.34 J / mm), this energy is the most suitable mechanical in the 5086-H116 alloy welding at an amperage of 148 A. At this energy level, the lowest loss of magnesium occurs; the particle size of Al3Mg2 is finer and easier distributed evenly on the α matrix, that allows obtaining the best mechanical properties.</p> José Omar Cabrera Escobar, Raúl Vinicio Cabrera Escobar Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/215 Fri, 28 Sep 2018 00:00:00 -0500 A context ontology for a mobile recommender system of advertisements) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/327 <p>Currently, most recommendation systems do not consider the context in which they are executed, being inappropriate to operate on mobile devices, this can be observed in the field of advertising, where users are overwhelmed by the excessive general information that they receive, causing widespread dissatisfaction with their use. One of the biggest challenges to incorporate contextual information to the software is the design of a formal model for its representation, because traditional methods are inadequate for this purpose, being necessary to use alternative approaches such as those based on ontologies. This work describes the process used in the construction of an ontology to represent the information of the advertisements and the contextual dimensions: location, time and users’ needs, to consider when recommending. Through the application of the NeOn methodology, an expressive and extensible ontological model was obtained that integrates the ontologies: FOAF, OWL-Time and WGS84 Geo Positioning. The proposed ontology is an initial contribution for the creation of a context-aware mobile recommender system of advertisements.</p> Lenin Xavier Erazo Garzón, Andrés Patiño Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/327 Fri, 28 Sep 2018 00:00:00 -0500 Use of an orthogonal arrangement for the analysis of the process of die sink electrical discharge machining with shape electrodes of graphite and copper on aluminum micro-casting) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/315 <p>This paper deals with the use of the Taguchi method in the realization of experiments to solve the multiple answers in the process of EDM machining using copper and graphite electrodes. This manufacturing process was carried out on the aluminum microfusion material widely used in the footwear manufacturing industry. The experimentation was carried out according to an orthogonal arrangement L8. Analysis of variance (ANOVA) was used to determine the effects of the input variables (tooling material, pulse time, tool shape and cutting depth) on the output variables (material removal rate and surface roughness); as well as a regression analysis to predict the results of the experimental analysis. The results have shown that machining parameters can be optimized with considerations of multiple responses effectively. It is evident that the pulse time is the main influencer in the material removal rate (MRR) and the machining time has a greater influence on the surface roughness (Ra). Finally, it was demonstrated that the copper electrode has better working efficiency and the graphite gives better surface roughness.</p> Cristian Fabian Pérez, Edwin Moya, Diana Coello Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/315 Fri, 28 Sep 2018 00:00:00 -0500 Numerical analysis of the speed profiles of a water flow through a gradual reduction pipe https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/290 <p>The objective of this research work is to understand the behavior of water flow through gradual contraction. Computational fluid dynamics (CFD) is a useful approach to solve the equations that describe the movement of fluids, using numerical methods and computational techniques. This area of mechanics provides the fundamentals of pipe hydraulics and channel hydraulics. A study of the flow through the pipeline has been made to calculate the children in the changes of the geometry. The energy losses derived from the pipes. Calculation of the cases: the occurrences of the incidents in the geometry on the part of the student and also with the help of the ANSYS software fluently. Calculations were used using the K-epsilon model. This simulation provides the values of pressure, velocity and kinetic turbulence in several sections of the pipe where water is its flow.</p> LUIS FERNANDO TOAPANTA RAMOS, Gabriel Alejandro Bohórquez Peñafiel, Luis Eduardo Caiza Vivas, William Quitiaquez Sarzosa Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/290 Fri, 28 Sep 2018 00:00:00 -0500 Reduction of the variability of a water demineralization process by ion exchange; for the production of soft drinks. https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/307 <p>The focus of this work was to find the necessary solutions to reduce variability, increase capacity and establish a plan to improve the water demineralization process for beverage production. For this, the diagnosis of the process was made and the elements, supplies and equipment were physically recognized, from the taking of the source to the manufacture of the beverages. The critical quality variables were determined by quality control according to laboratory tests and historical data. It was established within the problematic that the two critical quality variables were the hardness and alkalinity of the water; the process was studied with the reference in these two variables to know the root causes that caused the problems, measurements were made to calculate the capacity of the process and perform stability analysis, and the root causes of the problem were determined. The improvement included staff training, start-up manual and equipment regeneration manual, as well as process controls through type X-R control charts. The reduction of variability, the increase in capacity and improvement of the process was achieved.</p> Edgar Walter Vasquez Reino Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/307 Fri, 28 Sep 2018 00:00:00 -0500 Aerodynamic design of 100 KW blades for horizontal axis wind turbines located on the “Cerro Villonaco” zone https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/330 <p>In this paper, the design and aerodynamic simulation of a rotor for horizontal axis wind turbine for the Cerro Villonaco was carried out. The aerodynamic design aimed for a blade with an optimal geometry, which is defined by the chord and the twist angle of the airfoil. The design parameters conferred to the project were given by the characteristics of the wind in the Villonaco Wind Farm. Results were validated with an aerodynamic simulation, developed in a software employing the mathematical model known as blade element momentum theory, to verify its optimum performance against the requirements established with a TSR, with the goal to set a design method for subsequent investigations. Finally, a rotor analysis was carried out, obtaining an output mechanical power of 107 KW, thus corroborating the design power with the characteristics of the Villonaco Wind Farm.</p> Alexy Fabián Vinueza Lozada, Jorge Andrés Narváez Hidalgo Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/330 Fri, 28 Sep 2018 00:00:00 -0500 Generation of a Quality Model for Learning Objects Using the iStar Notation and the ISO/IEC 25010 Standard https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/234 <p>This study describes the process for the creation of a quality model that evaluates Learning Objects in terms of technology and didactics by using <em>i*</em> notation. In order to achieve the objective, quality models from both aspects were reviewed along with LO concepts and quality characteristics that a LO must accomplish were determined in order to consider the evaluation characteristics. The IQMC method was used to construct the diagram for strategic (SD) <em>i*</em> sections for the final quality model. With the SD model created, it was established the traceability between the generated model criteria and the ISO/IEC 25010 matrix to keep a correlation between the <em>i*</em> notation characteristics and the standard ISO matrix mentioned before. The matrix obtained was enriched with conceptual characteristics and with the attributes that a LO should fulfill. The different metrics in the ISO matrix were established for LO evaluations. As a result, a model through LO evaluation with each one of the selected metrics was generated.</p> Vanessa Alexandra Solis Cabrera, Juan Pablo Carvallo, Jorge Javier Maldonado Mahuad Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/234 Fri, 29 Jun 2018 00:00:00 -0500 Clarification of used cooking oil and discoloration of red palm oil with the use of ozone, activated carbon and hydrogen peroxide https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/192 <p>Alternative processes for the clarification of used cooking oil (UCO) and the discoloration of red palm oil (RPO) were evaluated. The clarification of UCO consisted of two steps, sediment removal and bleaching. In the first step, three methods were tested: heating, washing with brine, sedimentation and filtration; sedimentation alone; and washing with brine, sedimentation and filtration. The third method allowed the highest removal of impurities. For the second step, three methods were proved: adsorption with activated carbon (AC); ozonation, and application of hydrogen peroxide. The best method was ozonation, with a dose of 0.1946 mol O3/L and a post-treatment temperature of 60 °C; a 24.39% discoloration was reached. Regarding RPO, the best treatment was the adsorption with activated carbon. The ratio of oil: AC that produced the best results was 25:1; a 90.48% color decrease was achieved. The analysis of the quality parameters measured in the treated oils (acid value, saponification value, color and suspended solids) determined that both could be used as raw material for manufacturing soap.</p> Tania Parra, Freddy Alexander Marin Sinche, Gonzalo Jácome, Marco Sinche Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/192 Fri, 29 Jun 2018 00:00:00 -0500 Determination of cadmium and lead in water, sediment and bioindicator organisms in Estero Salado, Ecuador https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/246 <p>Evidence of pollution by heavy metals have been detected in the city of Guayaquil, province of Guayas, coastal Ecuador. The water and sediment in the mangrove environs of Puente Portete in Estero Salado were tested for concentrations of cadmium (Cd) and lead (Pb), as well as the following organisms: gastropods, including <em>Littorina varia </em>and <em>Cerithidea mazatlanica</em>, and the leaves of <em>Rhizophora racemosa</em>,<em> Laguncularia racemosa</em>, <em>Avicennia germinans</em>, and <em>Conocarpus erectus</em>. The samples were analyzed using flame atomic absorption spectrophotometry. The values of Cd and Pb in water and sediment exceeded the permissible limits established by Ecuadorian and Canadian standards. The gastropod species <em>L. varia</em> and <em>C. mazatlanica</em> were the best indicator organisms for detecting pollution by accumulating 2.45 ± 0.49 ppm Pb and 1.49 ± 0.67 ppm Cd, respectively. Because of the low bioavailability of heavy metals in sediments, mangrove plants did not accumulate Cd and Pb in leaves.</p> Beatriz Margarita Pernía Santos, Mariuxi Mero, Xavier Cornejo, Nelson Ramírez-Prado, Lissette Ramírez, Kenya Bravo, David López, Jorge Muñoz, Josué Zambrano Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/246 Fri, 29 Jun 2018 00:00:00 -0500 Evaluation of Micro-Algae Biomass in the Limoncocha Lagoon as a Raw Material for the Production of Bio-fuels https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/199 <p>It was determined the best experimental conditions for the production and evaluation of microalgae biomass, which come from Limoncocha, for the purpose of proving the feasibility of use in biofuel acquisition. Different crops were monitored in order to obtain the growth kinetics of microalgae and establish the yield with which they are produced on a laboratory scale controlling the different variables that interfere in this process. Once the biomass was gotten in the photo bioreactors, it was characterized to know its composition and lipid content. The productivity for the first consortium <em>Vischeria/Scenedesmus sp </em>was of 0,088&nbsp;g L<sup>-1 </sup>day<sup>-1</sup>, which reached a total of 5030000&nbsp;cel/mL and for the second consortium <em>Chlorella/Monoraphidium Contortum sp </em>was of 0,091<em>&nbsp;</em>g L<sup>-1</sup>&nbsp;day<sup>-1 </sup>with a total of 5537636 cel/mL. For the lipid composition through Soxhlet method by using a mixture of chloroform / methanol as solvents, the gotten results were from 16% out of the total lipids for <em>Vischeria/Scenedesmus sp</em>&nbsp;consortium and 42 % for <em>Chlorella/Monoraphidium Contortum sp</em> consortium.&nbsp;</p> Soledad Subía, Rodolfo Jefferson Rubio Aguiar Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/199 Fri, 29 Jun 2018 00:00:00 -0500 Characterization and spatio-temporal dynamics of Cylindrospermopsis raciborski in an Amazonian Lagoon, Ecuador. https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/195 <p>The cyanobacteria <em>Cylindrospermopsis raciborskii</em>, is a fresh water ubiquitous species from tropical to temperate weather. It is potentially capable of producing toxins.&nbsp; Thus it is necessary to monitor its presence in fresh waters associated to recreational use activities and human consumption. There are official reports and one thesis reporting the presence of <em>C. raciborskii </em>in Ecuador. Nevertheless, this country does not appear in the latest distribution maps of this species in the scientific literature. In this article, we report the presence of <em>C. raciborskii </em>in Ecuador, together with the characterization of the environmental conditions of one of the habitats where this species is present: the Limoncocha lagoon, province of Sucumbíos.</p> Judith Venegas, Pablo Castillejo Pons, Susana Chamorro, Ivonne Carrillo, Eduardo Lobo Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/195 Fri, 29 Jun 2018 00:00:00 -0500 Multitemporal Analysis of vegetation change at Chimborazo Reserve as a result of climate change https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/252 <p>Climate change is a global problem that affects the state of conservation of ecosystems in all regions of the world; as well as in the Chimborazo Fauna Production Reserve, which is linked to anthropogenic activities inside and outside it, such as the extensive and intensive grazing of sheep and cattle that have caused effects on vegetation and soil given to the consumption of native plants and all ecosystem processes because they are related to each other. The methodology used to achieve optimal discrimination of vegetation change and conservation status is obtained through the application of satellite images LANDSAT 5, LANDSAT 7, orthophotos and aerial photographs from 1962 to 1966 up to 2010 distributed in three periods; using procedures such as supervised classification and the calculation of the Normalized Differential Index of Vegetation. Anthropogenic activity for the period 1962-1966 determines 0.26% and snow is 10.30%, while for the period 2010-2011, the percentage of intervention increases to 9.54% and the snow decreases to 4.46%, evidencing the loss of perpetual snow due to solar radiation.</p> Pamela Andrea Paula, Luis Zambrano, Paulina Paula Copyright (c) https://ingenieria.ute.edu.ec/enfoqueute/index.php/revista/article/view/252 Fri, 29 Jun 2018 00:00:00 -0500