Enfoque UTE

pp. 19 - 36

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

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. 52 - 68

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

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. 80 - 99

Authors: Jonathan Gustavo Castillo Sánchez, Jessica Estefanía Chimbo Solórzano

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.