Now showing items 9-28 of 38

Determination of expandability clay from San José de Cucuta metropolitan area, by varying calcination temperature and time

Sanchez Molina, Jorge; caceres rubio, jose rafael; Rojas Suárez, Jhan Piero (Journal of Physics: Conference SeriesReino Unido, 2019-11-19)

In this article, the volumetric change of the clay granules and sewage sludge (technological nutrient), San José de Cúcuta metropolitan area raw materials, when calcined at different temperatures and different burning times ...
Determination of expandability clay from San José de Cúcuta metropolitan area, by adding different percentages of sewage sludge

caceres rubio, jose rafael; Rojas Suárez, Jhan Piero; Sanchez Molina, Jorge (Journal of Physics: Conference SeriesReino Unido, 2019-11-19)

This article shows the research carried out on clay from the San José de Cúcuta metropolitan area, Colombia, to which was added several percentages of a wastewater sludge, which is called as a technological nutrient. The ...
Determination of the structural efficiency of short bridges according to their physical and economic characteristics

Pineda Rodríguez, J R; Rojas Suárez, J P; Prato Duarte, Fabian Alberto (Reino Unido, 2021-06-04)

Bridges are structures designed and built to overcome natural and artificial obstacles. The analysis and design of bridges is carried out following principles of physics applied to engineering. The aim is to estimate the ...
Development of a gravimetric fuel measurement system for the evaluation of engine performance physical parameters

Prada Botia, Gaudy Carolina; Rojas Suárez, J P; Orjuela Abril, M S (Reino Unido, 2021)

This paper presents the implementation and design features of a gravimetric-based fuel consumption system. The proposed system comprises a gravimetric balance with serial output, a fuel pump, and a control valve that are ...
Development of a numerical methodology for evaluating physical properties and technical specifications in thermoelectric devices

Prada Botia, Gaudy Carolina; Rojas Suárez, J P; Orjuela Abril, Martha Sofia (Reino Unido, 2021-06-04)

Typically, the performance evaluation of thermoelectric devices is done using experimental methods and analytical models, which require detailed information on the thermoelectric properties of the materials that make up ...
Development of a virtual bench for the analysis of the physical processes of internal combustion engines

Rojas Suárez, J P; Pabón León, J A; Orjuela Abril, M S (2021-08-27)

Currently, internal combustion engines face the challenge of reducing fuel consumption and reducing polluting emissions due to their significant impact on the environment. Therefore, it is necessary to use tools that allow ...
Document details - A numerical model for the analysis of the bearings of a diesel engine subjected to conditions of wear and misalignment

Pardo García, Carlos Eduardo; Rojas Suárez, Jhan Piero; Orjuela Abril, Martha Sofia (LubricantsSuiza, 2021-04-09)

In the present work, a numerical model is developed to investigate the influence of wear and misalignment on the bearings of a stationary diesel engine. The model implemented considers the effects of surface wear on the ...
Economic and Environmental Multiobjective Optimization of a Hybrid Power Generation System using Solar and Wind Energy Source

Rojas Suárez, Jhan Piero; Romero-Garcia , Gonzalo; Villada Castillo, Dora Clemencia (International Journal of Energy Economics and PolicyTurquía, 2022-01-19)

This article presents a comparison of energy generation using two methods of power production for different geographical locations. For this comparison, the HOMER software was used, which allows simulating generation systems ...
Evaluation of recycled asphalt pavement in Colombia

Yung Vargas, Yee Wan; Rondón-Quintana, Hugo Alexander; Cordoba Maquilon, Jorge Eliecer (Journal of Physics: Conference SeriesReino Unido, 2022-01-06)

Reclaimed asphalt pavements are obtained from existing pavements through recovery techniques and are used for new asphalt mixtures production with the inclusion of virgin aggregates and asphalt cement, constituting ...
Evaluation of the fire resistance of steel-reinforced concretefilled steel tubular columns with a circular cross-section

Rojas Suárez, J P; Pabón León, Jhon Antuny; Orjuela Abril, Martha Sofia (Journal of Physics: Conference SeriesReino Unido, 2022-01-06)

In the present investigation, an analysis of the fire resistance of the steel-reinforced concrete-filled steel tubular columns with circular cross-sections was carried out by means of numerical simulation. The development ...
Experimental and CFD Study of a Centrifugal Fan Performance Under ANSI/AMCA Standard

Rojas Suárez, Jhan Piero; Villada Castillo, Dora Clemencia; Flórez Solano, Eder (International Journal on Engineering ApplicationsItalia, 2021)

Centrifugal fans are widely employed for several technical applications in science and engineering due to their easy employment and practical use. Therefore, in this work, the centrifugal airfoil performance has been studied ...
Experimental assessment of swelling potential in montmorillonite soils

Pérez, J C; Rojas Suárez, Jhan Piero; Orjuela Castro, Javier Arturo; Ruge Cárdenas, Juan Carlos; Cáceres, J R (Journal of Physics: Conference SeriesReino Unido, 2021-06-09)

The study of the physicochemical activity of clays is essential to understand the mechanical-hydraulic behavior. The experimental analysis of the expansivity of soils is linked to the content of clay minerals present in ...
First International Seminar on Physical Infrastructure (1st ISPI)

Yung Vargas, Yee Wan; Rodriguez Lizcano, Adriana; Ortiz Vasquez, L F; Rojas Suárez, J P; V. Niño, Ely Dannier (Journal of Physics: Conference SeriesReino Unido, 2022-01-06)

The First International Seminar on Physical Infrastructure (1st ISPI) was an academic and scientific event organized by the Road Infrastructure Research Group and the Road Infrastructure Research Seedbed of the Universidad ...
Formation of critical thinking related to the energetic efficiency of applied physics processes of civil engineering works

Journal of Physics: Conference Series (Reino Unido, 2021-06-11)

Current problems associated to contamination and climate change claim for urgent solutions to make real a sustainable development of modern societies. To answer that call, the efficiency of applied physics processes must ...
Hydraulic modeling of combined sewers overflow integrating the results of the swmm and CFX models

Pulgarín, D A; De Plaza, J S; Ruge Cárdenas, Juan Carlos; Rojas, J P (Revista Internacional de Metodos Numericos para Calculo y Diseno en IngenieriaEspaña, 2021-01-19)

This study proposes a methodology for the calibration of combined sewer overflow (CSO), incorporating the results of the three-dimensional ANSYS CFX model in the SWMM onedimensional model. The procedure consists of ...
Management of urban solid waste in the two first decades of the XXI century in the city of San José de Cúcuta, Colombia

Carrillo Soto, Gustavo Adolfo; Rojas Suárez, Jhan Piero; Sayago Ortega, Juan Carlos (Journal of Physics: Conference SeriesReino Unido, 2019-11-19)

The research developed in this study is exploratory, descriptive and the quantitative method, it characterizes the urban solid waste of the ten communes of the city of San José de Cúcuta and compares the results obtained ...
Mineralogical, microstructural and porosimetry analysis in three different clayey soils

Rojas Suárez, Jhan Piero; Ruge, J C; Palacios, X; Molina-Gómez, F (Journal of Physics: Conference SeriesReino Unido, 2019-11-19)

Diffraction, scanning electron microscope and helium porosimetry techniques have been shown to be suitable for obtaining physical and mineralogical properties in soil samples. The X-ray fluorescence spectroscopy allows ...
Novel method for stress history analysis in normally consolidated clays

Martinez, J H; Ruge Cárdenas, Juan Carlos; Rojas Suárez, Jhan Piero (Journal of Physics: Conference SeriesReino Unido, 2021-06-09)

The historical investigation of stresses in a clay material is essential to predict the compressible behaviour of a soil layer that, in most cases functions as a foundation support of superstructures. Because the stresses ...
Numerical simulation to evaluate the influence of geometric parameters on the physical behavior of heat e

Rojas Suárez, Jhan Piero; Pabón León, Jhon Antuny; Orjuela Abril, Martha Sofia (Journal of Physics: Conference Series, 2021)

In the present investigation, a methodology was developed by means of numerical simulation for the evaluation of the influence of the geometric parameters of the heat exchangers used in thermoelectric generation devices. ...
Operational data set of a 2 MW natural gas-fired generation engine at shutdown times

Valencia Ochoa, Guillermo; Rojas Suárez, Jhan Piero; Duarte Forero, Jorge (Data in BriefPaíses Bajos, 2020-06)

In this paper, operational data of a natural gas-fired generation engine at 2 MW of power is presented. This engine is used as part of the power supply system of a flexible packaging transformation and conversion plant. ...

Envíos recientes

Determination of expandability clay from San José de Cucuta metropolitan area, by varying calcination temperature and time
...
Sanchez Molina, Jorge | 2019-11-19

In this article, the volumetric change of the clay granules and sewage sludge (technological nutrient), San José de Cúcuta metropolitan area raw materials, when calcined at different temperatures and different burning times is shown. The main objective is to evaluate out the work right conditions (temperature and time), for the production of light aggregates from expanded clay. The methodology that was followed consists of three phases: preparation and pelletization of clay mixtures and technological nutrient; application of heat treatment in a set of muffle furnaces; and application of statistical treatment with the help of Software R. One of the most important results is that the expansion of the clay is indifferent to the time it takes to cook the pellets, and that this property depends solely on the temperature of burning. The temperature that generates the greatest expansion is 1,200 Celsius degrees, using a set of muffle furnaces.

LEER
Determination of expandability clay from San José de Cúcuta metropolitan area, by adding different percentages of sewage sludge
...
caceres rubio, jose rafael | 2019-11-19

This article shows the research carried out on clay from the San José de Cúcuta metropolitan area, Colombia, to which was added several percentages of a wastewater sludge, which is called as a technological nutrient. The objective of the study is to find out with what percentage of technological nutrient the capacity of expansion of the granules is maximized. The methodology that was followed consists of four phases; preparation of raw materials; pelletizing of raw materials in granules of 5 to 10 millimeters; application of heat treatment in a rotary kiln at the pilot plant level; and application of descriptive statistics for analysis of results. It was determined that the mixture with a 20% of technological nutrient, produces the highest volumetric expansion ratio, with 1.56 times its initial size, while, when adding 30% of the nutrient the same expansion occurs when adding an 10% nutrient, which is 1.07 times the initial size of the particle.

LEER
Determination of the structural efficiency of short bridges according to their physical and economic characteristics
...
Pineda Rodríguez, J R | 2021-06-04

Bridges are structures designed and built to overcome natural and artificial obstacles. The analysis and design of bridges is carried out following principles of physics applied to engineering. The aim is to estimate the structural efficiency of short bridges according to their physical and economic characteristics through equations that measure the cost tendency, identifying which ones have the highest structural efficiency for a given length between supports. The design of short bridges was carried out by means of a mathematical modeling in a software based on finite elements. A comparative cost analysis was carried out for various types of short vehicular bridges designed with reinforced concrete decks supported by reinforced concrete beams; post-tensioned concrete beams; and structural steel beams. It was determined that the bridge with a reinforced concrete deck is the alternative with the best structural efficiency according to its physical and economic characteristics with spans of 12 meters and 18 meters. According to the estimated cost equations, it is concluded that, from 18.49 meters post-tensioned concrete bridges are the most efficient physically and economically. Structural steel bridges are the least structurally efficient for short bridges. Therefore, the construction of short vehicular bridges with structural steel is not feasible.

LEER
Development of a gravimetric fuel measurement system for the evaluation of engine performance physical parameters
...
Prada Botia, Gaudy Carolina | 2021

This paper presents the implementation and design features of a gravimetric-based fuel consumption system. The proposed system comprises a gravimetric balance with serial output, a fuel pump, and a control valve that are integrated into a complete engine test bench via Arduino UNO®. The study implements an instrumentation methodology to minimize measurement disturbance and error propagation, which represents a major concern in engine experimental testing. Moreover, an interactive virtual environment is developed to reinforce user interaction via LabView™. Results demonstrated that the proposed measurement system features robust and reliable operation while maintaining negligible disturbance and overall uncertainty ranging from 0.010-0.23 g/s. Additionally, it was evidenced that the measurement system allows the analysis of key parameters to evaluate engine performance. The study of the fuels blends shows that the ethanol content causes a 6.8% increase in brake specific fuel consumption and a 4% decrease in the brake thermal efficiency. Due to the low cost of the developed measurement system can be easily adapted to test bench laboratories to promote a better learning process and in industrial sectors for better energy management.

LEER
Development of a numerical methodology for evaluating physical properties and technical specifications in thermoelectric devices
...
Prada Botia, Gaudy Carolina | 2021-06-04

Typically, the performance evaluation of thermoelectric devices is done using experimental methods and analytical models, which require detailed information on the thermoelectric properties of the materials that make up the thermoelectric devices. However, this type of information is generally not available. Due to this situation, the present investigation seeks to develop a numerical methodology to determine the performance of thermoelectric devices, using technical reference specifications that are normally provided by the manufacturer, such as maximum current, maximum voltage, maximum temperature difference, and efficiency. The numerical model is made up of a series of equations based on thermoelectric phenomena, which generates a contribution in the area of physics. The results obtained are validated through experimental comparisons and the technical data of the thermoelectric devices. The comparison between the different results shows a maximum error of 5%. Therefore, the developed methodology is considered a robust tool for the realistic analysis of the performance of thermoelectric generators and thermoelectric coolers. The foregoing will allow massive use of this type of device in industrial applications and its commercial accessibility.

LEER
Development of a virtual bench for the analysis of the physical processes of internal combustion engines
...
Rojas Suárez, J P | 2021-08-27

Currently, internal combustion engines face the challenge of reducing fuel consumption and reducing polluting emissions due to their significant impact on the environment. Therefore, it is necessary to use tools that allow us to evaluate the operating characteristics of this type of thermal machines. In the present investigation, the development of a virtual bench was proposed for the analysis of the behavior and performance characteristics of an internal combustion engine for use as a learning tool in higher education students. From the results obtained, it could be demonstrated that the pressure curves of the combustion chamber and the rate of heat release obtained by means of the virtual bench presented a high concordance with the experimental records. The maximum deviation obtained was 5% and 15% for the pressure curve and the heat release rate. Comparing the performance parameters of the brake specific fuel consumption of the engine and energy efficiency, a maximum deviation of 2.96% was shown compared to the real engine. In general, the virtual development bank can describe the behavior of the engine, allowing the characterization of physical phenomena, as well as evaluating the effect of auxiliary technologies such as turbo-compression systems.

LEER
Document details - A numerical model for the analysis of the bearings of a diesel engine subjected to conditions of wear and misalignment
...
Pardo García, Carlos Eduardo | 2021-04-09

In the present work, a numerical model is developed to investigate the influence of wear and misalignment on the bearings of a stationary diesel engine. The model implemented considers the effects of surface wear on the bearing, cavitation effects, and surface roughness. For the numerical analysis, changes in the surface roughness of σ = 0.75 µm, σ = 1 µm, and σ = 1.25 µm are defined, and changes in the bearing load of 50%, 75%, and 100%. The results demonstrated that increasing the surface roughness intensifies the bearing wear, which represents 18% and 140% of the bearing clearance for the roughness of σ = 1 µm and σ = 1.25 µm, respectively. Additionally, the surface roughness causes a considerable increase in the bearing wear rate. The results described a maximum wear rate of 20 µm/s. In general, increasing the bearing load by 25% doubles the hydrodynamic pressure conditions increases friction force by 33%, and reduces lubrication film thickness by 12%. The analysis of the angle of deflection, φx and φy, shows that the moment and the degree of misalignment tend to increase significantly with the increase in the magnitude of the angle φy. Negative angles of deflection, φx, produce a greater increase in the degree of misalignment and the moment. This implies a greater chance of contact with the bearing surface. In conclusion, the proposed methodology serves as a reliable tool to simultaneously evaluate key parameters on the tribological behavior of bearings that further extend their endurance and minimize wear damage.

LEER
Economic and Environmental Multiobjective Optimization of a Hybrid Power Generation System using Solar and Wind Energy Source
...
Rojas Suárez, Jhan Piero | 2022-01-19

This article presents a comparison of energy generation using two methods of power production for different geographical locations. For this comparison, the HOMER software was used, which allows simulating generation systems with different energy sources. For the development of these simulations it was necessary to collect three parameters in the locations to be analyzed, which were wind speed, solar radiation and temperature. The photovoltaic array system was simulated using from 10 to 200 units with a constant value of one wind turbine, while for the wind turbine system, 1 to 9 units were used together with a constant value of 100 photovoltaic arrays. For the photovoltaic system, there is no major difference in the net project cost, the renewable fraction and the annual carbon dioxide production when using a greater number of arrays, but an increase in energy production is observed, a greater effect is obtained by changing the location of the system, analyzing the wind system a greater number of turbines increases the energy production, but also increase the annual carbon dioxide production and project cost, there is no significant difference between locations for the project cost the other parameters are affected. By using an optimization algorithm in the systems, the best performance was obtained in Puerto Bolivar using 105 photovoltaic arrays of 1kW and 3 wind turbines of 1.5MW.

LEER
Evaluation of recycled asphalt pavement in Colombia
...
Yung Vargas, Yee Wan | 2022-01-06

Reclaimed asphalt pavements are obtained from existing pavements through recovery techniques and are used for new asphalt mixtures production with the inclusion of virgin aggregates and asphalt cement, constituting environmentally friendly mixtures at a lower total cost, by requiring fewer quantities of new materials. This research, unlike the studies found on the subject, focuses on the study of reclaimed asphalt pavement by analyzing its granulometric distribution and asphalt cement content. For this purpose, representative reclaimed asphalt pavement samples were taken from four Colombia cities, to verify their heterogeneity. The obtained reclaimed asphalt pavement was analyzed in the laboratory, to obtain the material granulometric distribution, through extraction and asphalt content tests, following Colombian regulations from the “Instituto Nacional de Vías”. The results show that the granulometry of all cities has a central tendency (average) that moves towards an upper limit in the 2 mm particles. When analyzing the granulometry separately of the four cities, it is observed that they present a different trend in their granulometry, which shows their heterogeneity. The asphalt cement content presented values between 4.0% and 5.0%.

LEER
Evaluation of the fire resistance of steel-reinforced concretefilled steel tubular columns with a circular cross-section
...
Rojas Suárez, J P | 2022-01-06

In the present investigation, an analysis of the fire resistance of the steel-reinforced concrete-filled steel tubular columns with circular cross-sections was carried out by means of numerical simulation. The development of the study was carried out by means of numerical simulation to predict the behavior of the column against fire. The results of the numerical model are validated by comparing the temperature levels obtained through experimental tests. From the results obtained, it is shown that the increase in the contact area between the steel and the concrete reduces the average temperature of the column, which implies a greater resistance to fire. The fire resistance of the columns with the steel profile designs are between 3.4 - 3.6 times higher compared to the column only made of concrete, which is an indication of the excellent performance of the steel-reinforced concrete-filled steel tubular columns with circular crosssections columns. In general, the methodology proposed in this research allows the analysis of the thermal physical phenomena of the different columns used for the construction of buildings.

LEER
Experimental and CFD Study of a Centrifugal Fan Performance Under ANSI/AMCA Standard
...
Rojas Suárez, Jhan Piero | 2021

Centrifugal fans are widely employed for several technical applications in science and engineering due to their easy employment and practical use. Therefore, in this work, the centrifugal airfoil performance has been studied with experimental and computational fluid dynamics techniques in order to improve their energy efficiency influenced by the rotor-stator interaction. In this sense, this research proposes a study of the main components' aerodynamic performance in order to determine the optimal operating conditions for different geometries of the impeller blades. In order to validate the simulation results, an experimental study has been performed to configure the design of experiments with the data acquisition of velocity and pressure values of the air mass flow under different conditions in the test bench configured with the ANSI/AMCA 210-07 standard. The experimental procedure has been performed with 2500 rpm, like a constant value of the centrifugal fan's angular velocity. The experimentally acquired data have allowed validation and the definition of each treatment's response to establish a linear regression model in order to predict centrifugal fan performance under different working conditions. 5.4 kPa has been determined as the high static pressure value for different impeller blade configurations conformed by the blades' angle, number, and length features.

LEER
Experimental assessment of swelling potential in montmorillonite soils
...
Pérez, J C | 2021-06-09

The study of the physicochemical activity of clays is essential to understand the mechanical-hydraulic behavior. The experimental analysis of the expansivity of soils is linked to the content of clay minerals present in the tactoid tissue, which affect is directly in proportion to the volumetric change that soil may undergo. This work aims to carry out an analysis to understand the expansive behavior of the proposed clay materials, using different techniques, both conventional and modern. For this purpose, the bentonite clay used with a majority montmorillonite component was analyzed through petrographic tests and images analysis. The samples with a base material and different contents of montmorillonite were prepared. Montmorillonite is a clay mineral with a very high swelling potential because even when it was used in low proportions on a sandy base material, the influence of the material is strong and the expansivity remained high.

LEER
First International Seminar on Physical Infrastructure (1st ISPI)
...
Yung Vargas, Yee Wan | 2022-01-06

The First International Seminar on Physical Infrastructure (1st ISPI) was an academic and scientific event organized by the Road Infrastructure Research Group and the Road Infrastructure Research Seedbed of the Universidad Francisco de Paula Santander, San José de Cúcuta, Colombia; the 1st ISPI was held from October 13 to 15, 2021. The purpose of the 1st ISPI was to allow the academic and scientific community, researchers, professors, professionals, and students, to share results and research proposals in the areas of Engineering, Mathematics, and Physics; during the 1st ISPI is presented 29 research work, of which 6 were plenary lectures from Spain, Brazil, Venezuela, and Colombia, and 23 talks, on different topics that allowed to the participants the to learn about the current state of the Physical Infrastructure, the Mathematical Modeling, the Physical and Numerical Modeling, the Physicochemical Phenomena in Engineering, the Advances in Materials Science and Engineering, the Simulation of PhysicalMathematical Problems in Engineering, and the Teaching and Research Techniques in Science and Engineering. The website of the conference is available at https://foristom.org/1ispi. On behalf of the organizing committee of the 1st ISPI, we are extremely thankful to all authors and participants for providing their valuable contributions to this Proceedings volume as well as the reviewers for their constructive recommendations and criticism aiding to improve the presented articles. Likewise, we like to thank the Universidad Francisco de Paula Santander, and the Foundation of Researchers in Materials Science and Technology, for all the support technical and logistical received. Likewise, the organizing committee 1st ISPI thanks all who attended this edition of the event, and we are very proud to have carried out this event successfully that allowing the generation and effective transfer of new knowledge regarding the topics addressed during the event; we will be waiting for you at the 2nd ISPI in 2022. Finally, the editor hopes that those interested in the area of physical infrastructure can enjoy this reading, of the volume of the Journal of Physics: Conference Series (JPCS), which reflects a wide variety of current issues.

LEER
Formation of critical thinking related to the energetic efficiency of applied physics processes of civil engineering works
...
| 2021-06-11

Current problems associated to contamination and climate change claim for urgent solutions to make real a sustainable development of modern societies. To answer that call, the efficiency of applied physics processes must be continuously evaluated. Particularly, engineering programs are called to strengthen the training offer related to basic and applied physics sciences considering energetic transformation and transferring processes. In the civil engineering field, design, construction, functioning, and final disposition of buildings can be understood as applied physics processes. This work proposes an approach for defining and studying possible variables related to energetic processes and their mutual relationship. Such variables must be able to describe the processes of energetic changes which can occur during construction of civil works. To do so, qualitative analysis of mathematic expressions is done to promote the formation of abstract mental connections made of sensitivity and logical thinking. The methodology is based on four moments: (a) students´ brainstorming related to a particular issue, (b) identification of main topics related to energy transformation, (c) variable operationalization, (d) proposal of mathematical expressions. This proposal is expected to facilitate the construction of concepts related to sustainable development and help students to trust themselves when taking well thought out risks.

LEER
Hydraulic modeling of combined sewers overflow integrating the results of the swmm and CFX models
...
Pulgarín, D A | 2021-01-19

This study proposes a methodology for the calibration of combined sewer overflow (CSO), incorporating the results of the three-dimensional ANSYS CFX model in the SWMM onedimensional model. The procedure consists of constructing calibration curves in ANSYS CFX that relate the input flow to the CSO with the overflow, to then incorporate them into the SWMM model. The results obtained show that the behavior of the flow over the crest of the overflow weir varies in space and time. Therefore, the flow of entry to the CSO and the flow of excesses maintain a non-linear relationship, contrary to the results obtained in the onedimensional model. However, the uncertainty associated with the idealization of flow methodologies in one dimension is reduced under the SWMM model with kinematic wave conditions and simulating CSO from curves obtained in ANSYS CFX. The result obtained facilitates the calibration of combined sewer networks for permanent or non-permanent flow conditions, by means of the construction of curves in a three-dimensional model, especially when the information collected in situ is limited.

LEER
Management of urban solid waste in the two first decades of the XXI century in the city of San José de Cúcuta, Colombia
...
Carrillo Soto, Gustavo Adolfo | 2019-11-19

The research developed in this study is exploratory, descriptive and the quantitative method, it characterizes the urban solid waste of the ten communes of the city of San José de Cúcuta and compares the results obtained with those of a similar investigation carried out 20 years. This comparison concludes that there have been significant changes in solid waste generated in the city, increasing food waste, cardboard, plastic, glass and cans and decreasing garden waste, paper and metals. In addition, surveys were conducted indicating that about one third of the population makes waste separation evidencing the existence of the recycling culture.

LEER
Mineralogical, microstructural and porosimetry analysis in three different clayey soils
...
Rojas Suárez, Jhan Piero | 2019-11-19

Diffraction, scanning electron microscope and helium porosimetry techniques have been shown to be suitable for obtaining physical and mineralogical properties in soil samples. The X-ray fluorescence spectroscopy allows obtaining the elemental composition of the sample, while the X-ray diffraction technique permits obtaining a qualitative and quantitative composition of the soil minerals. On the other hand, scanning electron microscope shows the microstructure of the soil and the helium porosimetry measures the pore size, volume, distribution, density and other porosity-related characteristics of the material. This document presents the characterisation of three different clayey soils by an experimental plan that included mineralogical, microstructural and porosimetric tests. The soils used were bentonite, kaolin and a natural clay retrieved near to Bogotá city, Colombia. Results obtained from this study allow providing a better understanding of soil behaviour, which traditional mechanical tests do not explain.

LEER
Novel method for stress history analysis in normally consolidated clays
...
Martinez, J H | 2021-06-09

The historical investigation of stresses in a clay material is essential to predict the compressible behaviour of a soil layer that, in most cases functions as a foundation support of superstructures. Because the stresses underwent in the geological past provide useful information to understand the response of the soil today. There are numerous methods for the interpretation of the preconsolidation stress, defined by the standard unidimensional consolidation test. The concept of preconsolidation stress is extremely useful in the geotechnical field to analyze and estimate settlements in a clay deposit, in addition to normalizing other parameters for comparative purposes. Through mineralogical analysis and consolidation tests based on different models for the estimation of the vertical consolidation coefficient, preconsolidation stress is evaluated by applying disparate constitutive methods. In order to observe the dispersion of results for a particular soil. A new technique is proposed for the determination of the preconsolidation stress prescribed in differential terms and with a high degree of objective interpretation.

LEER
Numerical simulation to evaluate the influence of geometric parameters on the physical behavior of heat e
...
Rojas Suárez, Jhan Piero | 2021

In the present investigation, a methodology was developed by means of numerical simulation for the evaluation of the influence of the geometric parameters of the heat exchangers used in thermoelectric generation devices. The validation of the proposed methodology was carried out through experimental tests on a diesel engine test bench under four load conditions (2 Nm, 4 Nm, 6 Nm, and 8 Nm) and a constant speed of 3600 rpm. The results obtained show that the methodology proposed by means of the numerical simulation presents a high concordance with the behavior described experimentally. The deviation between the simulation predictions and the experimental results was less than 4%. Additionally, it was evidenced that the change in the geometry of the heat exchanger has a considerable impact on the parameters of heat flow and surface temperature. It was shown that a 50% reduction in fin distance causes an increase of 2% and 2.4% in the previous parameters. Through geometric modifications, the electrical power generated increased by 7.9%. In general, the methodology developed through numerical simulation allows the analysis of the physical, thermal, and hydraulic phenomena present in heat exchangers focused on use in thermoelectric devices.

LEER
Operational data set of a 2 MW natural gas-fired generation engine at shutdown times
...
Valencia Ochoa, Guillermo | 2020-06

In this paper, operational data of a natural gas-fired generation engine at 2 MW of power is presented. This engine is used as part of the power supply system of a flexible packaging transformation and conversion plant. This plant, besides having the power supply generated by the engine, receives electrical energy from the network. The data collected from this engine corresponds to measurements taken before, during and after engine stops, whether due to engine maintenance stops, engine failures or external power grid failures. The measurement was made every 10 seconds, and for the storage of these data a data acquisition software was used, which, besides allowing to take these data, shows in real time the electrical behavior of the electrical supply system, as well as the mechanical behavior of the engine.

LEER