Enfoque UTE

Number Vol.12-N.2, 2021

pp. 1 - 18
Determination of lead levels in blood in workers of battery factories located in Guayaquil-Ecuador

Authors: Kathya Rivera, Beatriz Pernía

Abstract

View in PDF

Number of views: 248

Lead is one of the most toxic heavy metals and its occupational exposure can generate plumbemia. For this reason, the objective of this investigation was to generate a baseline of lead concentrations in the blood of a group of battery factory workers in Guayaquil-Ecuador and of a control group not exposed to the metal at work, to establish the existence of occupational risk between sexes, ages, and jobs positions. For this, blood samples were taken from the workers and the control group. The samples were analyzed by atomic absorption spectrophotometry with a graphite furnace. 100 % of the workers presented Pb in an average concentration of 16.22 ± 6.82 µg / dL higher than the World Health Organization value, but lower than the limit established by Occupational Health and Safety Assessment of 40 µg / dL, also, the value was higher than of the control group (0.68 ± 0.15 µg / dL). Men presented higher levels of Pb than women and these values varied depending on the job in the factory. In conclusion, 4.55 % of the workers did not present a risk of lead poisoning, 13.64 % low risk, 78.79 % medium risk, and only 3.00 % high risk.

pp. 19 - 36
Viability of micro electrical networks with high penetration of renewable resources in urban areas: Case study of residential condominiums

Authors: Danny Javier Trujillo Sandoval, Fabricio Ismael Mosquera Velásquez, Edwin Marcelo García Torres

Abstract

View in PDF

Number of views: 305

This study addresses the implementation of electrical micro-grids in urban areas as a response to the need for the insertion of renewable energies in different societies. In a first phase, the energy consumption profile of a condominium with a residential, commercial type load is characterized. and community, addressing the construction of said profile by lifting real loads and statistical criteria of use and coincidence. In the second phase, the natural resources, wind speed and solar radiation available in the study area are analyzed through the specialized software Homer Pro with latitude and longitude coordinates, subsequently the viability of the renewable electricity generation elements is analyzed and defined use, a possible generator set and its use of fuel are also proposed in order to complement the micro-grid in aspects of inertia and stability. With the energy demand and generation resources raised, architectural alternatives of a potential micro-network for the condominium are designed, simulations are carried out for isolated and interconnected cases with real values of the environment and an economic analysis of the implementation, obtaining the viability of the micro network.

pp. 37 - 51
Experimental tests and numerical analysis of the structure of the alternative composite material for the repair of flight surfaces in aircraft

Authors: César Arroba Arroba, Manuel Telenchana Flores, Juan Paredes Salinas , Salomón Fiallo Ortega, Henry Vaca Ortega

Abstract

View in PDF

Number of views: 255

Nowadays, polymeric matrix composite materials are used in multiple applications. One of the important areas of application is in the aeronautical sector, due to the relatively low density of the combined materials; these compounds have good mechanical properties, comparable to metallic materials, but providing additional benefits. The objective of this work is to carry out the experimental tests and the numerical analysis of the structure of the alternative composite material to be used to repair of the flight surfaces of CIDFAE aircraft. A widely extended vacuum bagging process was used to obtain a more homogeneous compound, thus reducing defects in processing, better controlling the fiber fraction and the overall thickness of the compound. Specimens of epoxy resin reinforced with layers of flat fabric of three different fibers of: carbon, glass and aramid, in different orientations, were made, which were tested for traction, bending and impact to determine their mechanical properties. It has been shown that the results obtained by analytical methodology and the finite element method are approximate to the results obtained with destructive tests. The experimental results show that the tensile strength values are higher in epoxy resin materials reinforced with 4 layers of carbon fiber in orientation 0 ° -90 °.

pp. 52 - 68
Speed profile prediction model of rural roads in flat terrain in Costa Rica

Authors: Domingo E. Delgado Martínez, Liosber Medina García, José M. Ulate Zárate, René A. García Depestre

Abstract

View in PDF

Number of views: 280

For some time, a commonly used engineering practice has been to evaluate the influence of the geometric design of roads on road safety by analyzing geometric design consistency. When evaluating geometric design consistency, it is necessary to know the operating speed profiles of the road to be analyzed. To this end, a variety of models of operating speed profiles are used, which are designed for the specific conditions of a particular region or country. For any analysis of highway geometric design, it is important to have information related to the horizontal and vertical layout of the project, as well as to the operating speed of vehicles. However, one limitation, which is often a source of error, is determining the operating speed of the vehicles. The aim of this paper is to develop models for predicting vehicle operating speed in Costa Rica by considering the characteristics of the road geometric design and of the existing vehicles. The procedure followed in the model included a series of steps, including from the analysis of the roads in the region to the development of models for predicting the speed profiles, as well as its validation. For the first time, different models are proposed for rural national routes in flat terrain in Costa Rica. The study demonstrates that the proposed equations provide for lower estimations errors, if compared to international models.

pp. 69 - 79
Policies based on ISO 27001: 2013 and its influence on information security management in municipalities of Peru

Authors: Shonerly Bustamante García, Miguel Ángel Valles Coral, Immer Elías Cuellar Rodríguez , Danny Lévano Rodríguez

Abstract

View in PDF

Number of views: 250

Information security management within an organization must be a well-defined process, as it involves a huge effort from users, area managers and other servers to know how to respond to suspicious events and how to manage identified vulnerabilities. The objective of this research was to improve information security management in a Peruvian district municipality, through the implementation of a policy model under ISO 27001: 2013. For this, a preexperimental investigation was carried out with a sample of 30 workers, to whom a questionnaire was applied to measure the degree of satisfaction with the implanted model. On average, more than 90 % of those surveyed recognized improvements in the municipality, marking a great difference between the pre and postest, from 49 % to 96 %. It is concluded that the security policy model, based on three fundamental pillars: confidentiality, integrity, and availability, improved information security management, guaranteeing adequate data protection.

pp. 80 - 99
Efficiency in the removal of organic matter by wormfilters (Eisenia foetida) in domestic wastewater for rural areas

Authors: Jonathan Gustavo Castillo Sánchez, Jessica Estefanía Chimbo Solórzano

Abstract

View in PDF

Number of views: 209

Inadequate management of domestic wastewater in rural areas, the discharge of which to water bodies without prior treatment, is a major problem of environmental pollution, as well as a risk to public health. The purpose of this study was to assess the efficiency in the removal of organic matter by lombrifilters in domestic wastewater in a rural area. Under experimental conditions, the wormfilter was designed using as a theoretical basis the Tohá treatment system, created by Dr. José Tohá, which consisted of four strata: sawdaught + Eisenia foetida, activated charcoal, gravel and river stones. The concentration of organic matter of the tributary was evaluated obtaining high concentrations of BOD5, COD, TSS and TS. T1 achieved the highest efficiency percentages with a volumetric flow of 1.8×10-2 l/s and TRH of 0.92 h obtaining 52.25 % for BOD5 and COD, 66.74 % TSS and 52.91 % TS. In this way, it was determined that the implementation of wormfilters based on Eisenia foetida for the removal of organic matter, represents an ecological and innovative treatment system that requires a low investment, is efficient and friendly to the environment.