Enfoque UTE

pp. 1 - 15

Authors: Segundo M. Espín Lagos, Jorge P. Guamanquispe Toasa, Diana C. Coello-Fiallos, Jorge A. Paredes Zumbana

Shielding was performed on the flanks of teeth of a cane mill by means of the flame thermal projection technique using the Eutalloy 11496 micropulverized alloy. The material of the toner is AISI 1045 steel and the surface of shielding was prepared by the jet process with abrasive material of volcanic nature, in order to achieve an optimum anchorage surface for the alloy. Next, in software, iterations of the thickness of the shield were realized with the purpose of determining its useful life and through the distribution of Weibull we estimated the function of reliability and the function of probability of failure, considering a complete harvest of 240 days.

pp. 27 - 40

Authors: Ortega Holger, Rodrigo Tufiño, Juan Estévez

The present work has the objective of developing a system for the automatic recognition of a playing card on a table, as part of a more general project to create a device to assist the blind in the chance game called “cuarenta”. The aim of this device will be to inform the user about the cards being played, via audio. For this phase of the project the algorithm used was k-NN, trained with a set of alphanumeric synthetic characters. The test set contained photographs taken in controlled lighting conditions, with the card positioned in arbitrary orientations. The parameterization of the algorithm gave a value of 1 as the optimal k, with which a classification error of 5% was obtained in the test set. Only two characters were confused by the classifier, the “A” and the “J”, with 20% and 40% errors each one. The algorithm was implemented in an embedded Raspberry Pi 3 system, obtaining a response time of 5 seconds, including the conversion to audio, and a memory occupation no greater than 60% of the total capacity of the system. These results suggest its applicability in portable devices.

pp. 53 - 67

Authors: Patricio Castillo, Lorena Quinchuela, Paulina Echeverría, Gonzalo Jácome

This work established the conditions of covalent immobilization of trypsin on a Sepharose matrix, which could be applied for the purification of trypsin inhibitors. The higher values of retention of enzymatic activity and immobilized enzymatic activity were obtained with a Sepharose 6B-CL matrix, at room temperature, a pH value of 10.5, an enzymatic load of 25 mg/mL, and a minimum immobilization time of 12 hours, in order to obtain a stable immobilization. The most active trypsin inhibitors were selected through the comparison of, extracts obtained from the seeds of amaranth (Amaranthus caudatus L.), pea (Pisum sativum), lupine or “chocho” (Lupinus mutabilis), bean (Phaseolus vulgaris) and “sangorache” (Amaranthus hybridus L.). The inhibitors were partially purified using centrifugal ultrafiltration, heat treatment, and TCA precipitation. The permeated and retained fractions of “sangorache” were selected as the most active trypsin inhibitors, and they were selectively purified using affinity chromatography in a Trypsin - Glyoxyl - Sepharose 6B-CL matrix. The kinetic characterization showed the presence of two inhibitors; the first one corresponded to a competitive inhibitor, while the second one behaved as a mixed inhibitor.