Enfoque UTE

pp. 1 - 14

Authors: JUAN DAVID RAMIREZ, Krissia Cabezas, Pedro Jiménez, Raúl Canelos, Bolívar Escobar

This paper presents the voltage distributions along the insulator strings of a 500 kV overhead transmission line of Ecuador. The electrostatic problem related to the voltage distribution was solved using the Finite Element Method. A 1: 1 scale drawing is done on a CAD type drawing tool and then exported to the FEMM program that solves the problem and the results related to the voltages in the insulator string are obtained. The voltage differences in the different insulators that constitute a string are appreciated and the difference between the strings determined by the geometric location in the solution space is observed

pp. 25 - 34

Authors: Maritza Quijia-Quijia, Stephanie Castillo-Torres, Wilson Vasquez-Castillo, Mauricio Racines-Oliva

The research was carried out in the Nayón-Quito, Ecuadorian Pichincha-Province, with temperatures ranging between 18 - 22 ° C, located at an altitude of 2325 meters above sea level. Ice cream bean is a species used to provide shade in some crops such as coffee and cocoa. In this study, 15 ice cream bean trees were selected in which 30 vegetative buds/plant were marked to follow them in time and observe their development. Weekly observations were made of the transition of the vegetative to reproductive structures of the crop in order to establish the duration of each stage presented by the plant as well as the thermal cumulation necessary for these changes to occur. During the study, the selected trees selected presented constant bud break, foliage fall and fruiting. These changes varied according to the climatic conditions of Nayón. It was finally determined that ice cream bean flowering stage lasted 155 days and a total of 497 thermal units were needed to fruit harvest. The BBCH scale (Biologische Bundesanstalt, Bundessortenamt und Chemische Industrie) describes the phenological development of crops from germination to senescence, comprising 8 main stages that are germination, leaf development, bud formation, inflorescence formation, flowering, fruit development, fruit ripening and senescence. Based on this scale a visual-phenological description of the ice cream bean fruit setting was obtained with the most relevant subphases presented by the plants (521, 525, 529, 621, 625, 629, 723, 725, 729). This information constituted basic and outmost useful and relevant data to better understand the process of development of this crop and improve field and production practices.

pp. 46 - 54

Authors: Jorge Luis Miguel Loo Miranda, Gabriela Cristina Chire Fajardo , Milber Oswaldo Ureña Peralta

This study linked the fermentation index of two varieties of cocoa beans: CCN 51 and ICS 6 with electrical conductivity (EC) of the water where they were immersed using a laboratory conductimeter. Mixtures of 11 fermented cocoa beans and unfermented were performed in order to obtain fermentation index from 0% (unfermented beans) to that reached by the fermented cocoa beans. Immersion times tested for determination of the electrical conductivity were 90 and 180 minutes. The results of electrical conductivity for CCN 51 and ICS 6 were 56.1 ± 12.0 to 1375.0 ± 28.0 mS/cm and 150.0 ± 19.9 to 1199.3 ± 44.5 mS/cm, respectively. Subsequent conductivity values ​​did not represent significant increases over time. The relationship between the fermentation index and electrical conductivity for CCN 51 showed positive trend, achieving a R2 = 63.1%. The following function by regression: EC (CCN-51) = 1196 + 10.83 * (FI) – 0.06 *(FI)2 got a model with significant adjustment to be used to determine its fermentation index.

pp. 69 - 86

Authors: Bimael Justo Quispe Reymundo, Ronald Héctor Révolo Acevedo

The effect of surface temperature on the state of the vegetation in the forest of Polylepis spp and to relate it is the objective of this research. As methodology 9 satellite images of the Landsat 8 OLI / TIRS Sensor were used, evaluated using remote sensing, applying Pearson r correlation and statistical t student hypothesis. The following results were obtained: the relationships during the 9 months of the year 2018 - - 2019 between LST - NDVI r = 0.11, t = 0.29; LST - NDWI r = -0.43, t = 1.27; LST - SAVI r = 0.13, t = 0.34 and LST - MSI r = 0.56, t = 1.77; the average ratio of 9 images classified in Jenks Natural Breaks values ​​between LST - NDVI r = 0.99, t = 47.12; LST - NDWI r = -0.98, t = 28.93; LST - SAVI r = -0.99, t = 65.39 and LST - MSI r = 0.99, t = 30.39; and the effect of “TVX” for NDVI (East: -0.0778 / 0.0549; West: 0.6434 / -0.0120), NDWI (West: -0.6128 / -0.0463; East: 0.3057 / 0.0474), SAVI (West: 0.4089 / 0.0232; East: -0.0073 / -0.0011) and MSI (East: 0.5565 / 0.1856; West: 1.3993 / 0.0362). In conclusion, it is confirmed that during the 9 months that the monitoring lasted, there was no statistical correlation and that on average of the 9 images classified in Jenks Natural Breaks there is a correlation; TVX confirmed the influence of surface temperature on the state of vegetation within the forest over time.

pp. 102 - 110

Authors: Jaime Antamba Guasgua, Vladimir Azanza, Gorky Reyes, Alvaro Remache, Soraya Ruiz

All powered vehicles have a braking system adopted according to the type of vehicle and work for which they are designed. In Ecuador, there is a great variety of auto parts that are proposed as alternative replacement, varying in cost and quality. This research aims to quantitatively analyze the characteristics of the brake disc material between original and alternate auto parts. This research analyzes three brake disc samples (A, B, C) from different manufacturing sources, using the ASTM E415-08 spectrometry test and the metallography test under the ASTM A247-16A standard. The spectrometry detects 15 elements in each sample, the carbon equivalent of sample A is 18% and 20% higher in relation to sample B and C, which significantly influences the microstructure. The metallographic tests indicate a pearlitic matrix in each sample, however, there is a different distribution and size of the graphite flakes. According to the SAE J431 standard, each auto part meets the material conditions for the brake disc function.