Tecnura

Number 55, 2018

9
Estimación emisiones de compuestos orgánicos volátiles, plantel de distribución de combustibles Recope, el Alto de Ochomogo, Cartago, Costa Rica

Authors: Laura Vanessa Quesada Carvajal, Macario Pino Gómez, Rodolfo Elizondo Hernández

Abstract

View in PDF

Number of views: 264

Context:This study presents the estimation of the evaporative emissions generated in the fuel distribu-tion plant in El Alto de Ochomogo, Cartago, Costa Rica and the selection of the adequate recovery sys-tem to reduce the emission of these gases into the atmosphere, thus decreasing the adverse effects cau-sed by these compounds in the environment and the health of nearby populations. Method:The fugitive emission rate estimated in the tanker vehicle loading process, using load loss emis-sion factors, and fuel storage, through specialized software. Subsequently, we proceeded to make the selection of the appropriate treatment system, consi-dering the flow capacity of the gaseous current that each technology can treat. Results:It was determined that the generation of VOC is greater in the loading area than in the sto-rage tanks, since they correspond to 95% and 5% respectively. Due to this, the proposal of the vapor treatment system focuses on the fuel-loading zone, selecting the cryogenic condensation as non-des-tructive recovery treatment. Conclusions: The estimation of the fugitive emission rate allowed to have a base to establish a strategy for the reduction of these emissions in favor of the health of the workers who are constantly exposed to them.To reduce direct emissions to the atmosphere du-ring the loading of tanks. Necessary changes must be made to adapt them to an airtight system. That allows sending gasoline vapors that generated by the pre-sence of residual product on the walls of trucks and due to the turbulence that arises during the loading of the new product, to the vapor recovery unit.

10
Taxonomía de las bases de datos espaciotemporales con objetos en movimiento. Revisión de tema

Authors: Sergio Alejandro Rojas Barbosa

Abstract

View in PDF

Number of views: 280

Context: In the last decade, databases have evol-ved so much that we no longer speak only of spatial databases, but also of spatial and temporal databa-ses. This means that the event or record has a spatial or localization variable and a temporality variable, which allows updating the previously stored record Method: This paper presents a bibliographic review about concepts, spatio-temporal data models, speci-fically the models of data in movement. Results: Taxonomic considerations of the queries are presented in the models of data in movement, ac-cording to the persistence of the query (time, loca-tion, movement, object and patterns), as well as the different proposals of indexes and structures. Conclusions: The implementation of model pro-posals, such as indexes and structures, can lead to standardization problems. This is why it should be standardized under the standards and standards of the OGC (Open Geospatial Consortium).

12
Vigencia del método de Roth para la determinación de fuerzas de cortocircuito en devanados de transformadores

Authors: Guillermo Aponte Mayor, Diego Fernando García Gómez, Héctor Cadavid Ramírez, Guillermo Andrés Díaz Flórez, Wilver Correa Bravo, Andrés Felipe Zúñiga Calvache

Abstract

View in PDF

Number of views: 265

Context: Due to the difficulty of testing large power transformers, the International Electrotechnical Commission standard IEC 60076-5 2006 accepts as an alternative method to validate the short-circuit withstand ability, the forces and dynamic stresses estimation by means of calculation and design considerations. Method: In this paper, the Roth analytical method was used to calculate the axial and radial short-circuit forces in a three-phase 630kVA core type transformer. Results: The calculated forces provided by the Roth method are comparable to the values obtained through modern methods used for electrical transformers design as the finite element method, the difference among calculated values were minimum except the maximum axial force Conclusions: Although the Roth method is a traditional tool to solve electromagnetism problems, it is still suitable to compute magnetic parameters and transformers short-circuit forces in a fast and simple way

14
Determinación de los componentes entrópicos de la accidentalidad: el trinomio vehículo/usuario/camino en la metrópoli de Guadalajara, México

Authors: Fernando García De Quevedo Najar, Mario Guadalupe Gonzalez Pérez, Yefer Asprilla Lara

Abstract

View in PDF

Number of views: 304

Context: The recent increase in accidents, mishaps or road accidents in urban systems with metropoli-tan characteristics has caused concern in the autho-rities responsible for planning the issue of mobility and transport subsystems. Indeed, there is conver-gence that the occurrence of this type of events is away from purely stochastic factors, but are the re-sult of anomalies associated with the intrasystemic interaction of the vehicle, the user and the road. In this sense, the objective of this work is to determine through systemic analysis the components that are causing entropy in the second most important me-tropolis in Mexico. Method: In this analysis the precepts of systems theory are used; in such a way that through the tringulation of data obtained in situ and solved documentarily the causal components of intrasystemic entropy are determined. To do this, a modified derivation of the Pressure-State-Response model that identifies ho-meostasis in the urban system is elaborated Results: The high exposure rates force the user to oc-cupy the road subsystem for long periods of time, which triggers voluntary and involuntary human errors complemented by the lax requirements for obtaining driving licenses. From here, the compo-nents that produce accidents include in the road part the pavements in poor condition, absence of signa-ling, poor design of intersections, among others; in the vehicle part, mechanical failures due to the use-ful life of the internal components, flexible regula-tory frameworks, and other; in the part of the user for breach of the regulations, physiological factors among others Conclusions: From the systemic analysis, mobility is a subject of valuable study to detect the imbalances in the trinomial Vehicle-User-Road (V-C-U), which lead us to generate preventive and corrective mea-sures that suppress metropolitan accidents, morbidi-ty and mortality in the metropolis; or in our terms to reduce entropy levels in the system

16
Evaluación del riesgo por deslizamiento de una ladera en la ciudad de Tijuana, México

Authors: Aldo Onel Oliva González, Romel Jesús Gallardo Amaya

Abstract

View in PDF

Number of views: 355

Context: Risk reduction and prevention of disasters events produced by landslides on urban slopes, re-quires an integral assessment considering condition-ing and triggering natural and human factors. Such an assessment is a valuable prevention and mitiga-tion tool for communities under risk and also for au-thorities involved in the process Method: In this research, a general methodology for the assessment of landslides on an urban slope was studied and applied, considering the relationship between hazard and physical vulnerability in the zone of study. Hazard was determined by probabilis-tic methods, whereas vulnerability of the exposed el-ements was obtained taking into account two kinds of buildings and their spatial distribution, their struc-tural integrity state, their foundation depth and the unstable terrain probable mass volume. Results: Safety factors were obtained under allow-able levels to warrant stability of the slope under study, and valuation factors of the qualitative analysis indicate that the slope is unstable and that requires urgent maintenance. This confirms and validates the high probability of occurrence in the zone, obtained from historic records. Conclusions: It was found that landslide risk in the slope is high due to the high probability of its oc-currence, with three possible movement directions that may impact on several buildings located in the zone. Assessment constitutes a work tool for institu-tions and authorities related with risk reduction due to landslides, as a way of prevent and mitigate disas-ter prone events.