Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

The satellite observations derived from the GNSS constellations are fully correlated with the moment in which the measurements are made, however, users can transfer them to different epochs as long as the necessary parameters are available. The quality of the GNSS measurements will in principle be affected by taking them to a different epoch than the original. In the case of the national geodetic frame of Costa Rica CR-SIRGAS, its current reference epoch is t0 = 2019,24 [1] but the georeferencing of spatial information for cadastral purposes must be in the reference time tk = 2014,59 [2]. A fixed adjustment process was carried out at the epoch ti = 2021.53 using as observations the baselines of each new point to a maximum of four CR-SIRGAS stations with their respective final weekly coordinates. This adjustment was then repeated using the same, but as reference coordinates the official reference epoch t0, implying a marked decrease in the original weight of the observations by a factor of 1.5 to 9.5. In addition, it was possible to quantify the discrepancies in the coordinates, accuracies and observations adjusted directly at this time t0. Finally, the official transformation parameters given by [1] were applied to take the set of coordinates from epoch t0 to epoch tk.

In Costa Rica, there is a gap in the creation of policies for the efficient management of resource consumption and the development of energy consumption statistics, to enable the measurement of the performance of sustainability in construction. Therefore, this investigation was carried out with the purpose of recognizing the state of control and efficient management development of energy resources consumption in the construction sector, both at an international and national level. Subsequently, processes and tools were developed to create a methodology, with the purpose of generating an initial approximation to estimate and record the energy consumption of vertical buildings during construction and define performance statistics. This methodology was applied to two vertical building projects during the construction of gray structure work, in order to analyze the management of resource consumption. During the process, this proposed methodology obtained a high degree of acceptance from a validation committee, who saw its potential for the estimation and recording of sustainability statistics throughout the performance of the project, and how it could help to control resource consumption.

The environmental impacts of landfills and incineration are compared for a strategic location where construction and operating activities have a significant impact on the environmental components. The study case proposes to quantify the impacts under assumed conditions, to measure the interaction between project activities and the impacts on environmental factors, by employing the Leopold Matrix. As a result, neither technique is environmentally feasible for the proposed site, where the landfill will have a greater impact. Technical studies are required to ensure the accuracy of the impact values, and environmental safeguards are required during implementation. To increase the project's viability, it is recommended that a site with less sensitive environmental and social characteristics be chosen.

The development of condition monitoring methods that follow the evolution of the degradation of power transformers (PT), is essential for a safe and reliable operation of power systems. Having condition monitoring tools has become a priority for utilities, this being a complex task, since different stresses are combined, such as: electrical, chemical and mechanical. Some authors propose the use of health indices (HI) that include the condition of the PT in a single parameter, to support the personal relationship with the decision-making process. To obtain the HI, the results of different tests are used to verify the status of the PT. This will be the basis for evaluating the global health and facilitating the identification of failure modes present in the PT and its subsystems, which lead to generalized degradation, or in key subsystems, which can lead to the end of the useful life of the PT. This research proposes a novel tool to evaluate power transformers based on a compound HI. The HI was obtained using: i) condition data, and ii) condition functions. The results obtained are weighted, reaching a final value that reflects the condition of the PT. It was possible to determine with expert criteria the importance of each executed test, granting the importance weights. The results showed a good performance of the proposed HI evaluating real transformers. This indicates that moving towards the use of HI to assess the condition of power transformers improves the reliability of electrical networks and, with this, the service to users.

The objective of this research work is to analyze and evaluate the quality of groundwater in the city of Sucre, Bolivia, specifically in the area covered by the Cajamarca flow. The methodology consisted initially in the characterization of the study area: location, topography, geology, hydrological and hydrogeological framework and rainfall. Subsequently, samples were selected and taken from seven wells (P1-P7). Microbiological, organoleptic, chemical and hydrogeochemical analyses were performed, as well as evaluation for agricultural use. The minimum requirements for water quality control for human consumption of Bolivian Standard 512, Law No. 1333 of the Environment and the guidelines for drinking water quality of the World Health Organization were considered. The results show that all the wells meet the requirements established in the chemical parameters. However, the seven wells are compromised in the microbiological and organoleptic characterization. Regarding the hydrogeochemical analysis, it is observed that most of the samples belong to the Na+-HCO3- group with a relatively high ionic content. On the other hand, only P2 and P7 are suitable for agricultural use, while P3 and P4 can be used under certain conditions. Although groundwater exploitation can be an alternative to water demand, a detailed analysis of its characteristics and, if necessary, a treatment for its use should be carried out.

Over time, several authors have investigated the relationship between climatic conditions and animal production, showing that the comfort state positively influences production. This research aimed to make a methodological proposal for the analysis of animal thermal comfort in isolated areas, taking as a case study, three Territorial Spaces for Training and Reincorporation, where productive projects are carried out within the framework of the Final Agreement for the Termination of the Conflict and the Construction of a Stable and Lasting Peace, using climatic data of temperature and relative humidity obtained of time series from 2002 to 2019, using remote sensors. The proposed methodology based on the use of free access digital platforms proved to be applicable, and in the case studies it found that the regions that may have the least impact on broilers, pigs and cattle are Tierra Grata and Miravalle, while in Caño Indio, it is suggests adopting climate control strategies to improve the animal thermal environment.

Fuel demand during the last 50 years in Costa Rica has increased constantly. Do the price of fuels and Gross National Income contribute to explain these trends? This paper explores the existence of causal relations between economic growth, fuel price, and transport demand (represented by fuel consumption and registered vehicles). Vector autoregression (VAR) models were estimated with a time series of data of 1965-2019. Causal relations were found between fuel demand and income, but not with registered vehicles. The effect of price on demand and income were documented, which is important for policy formulation (in particular, possible taxation of fuel demand as a carbon mitigation strategy).gation strategy.

III Research Conference of the Faculty of Engineering-2021

Explanatory note regarding the Special Volume: III Research Conference of the Faculty of Engineering.

The book reviewed here aims to expose the research process experienced by the author in recent years, with a retrospective look and the pursuit of a didactic purpose, that is, showing how categories and ideas are tied together in a process of knowledge production as a practice which is built from the spaces of the everyday life of subjects, from their own specific places and temporalities. In general terms, from secondary and primary sources, this work addresses different problems of three Argentine spatialities (Chaco-Salteño, the Santiago area and Andalgalá), in which it combines the decolonial perspective and edge research to account for how subjects think and inhabit a space-time marked by the colonial wound.