Mostrando ítems 221-240 de 1587

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 ...
Silver colloidal nanoparticles by electrochemistry: temporal evaluation and surface plasmon resonance

Padilla Sierra, H A; Peña Rodríguez, G; Chaves Bedoya, Giovanni (Reino Unido, 2021-06-04)

The electrochemical technique for obtaining silver nanoparticles has advantages over other methods. For the synthesis, a colloidal silver generator (Colloidal Silver Generator® model 1001) was used, where two electrodes ...
Resistance under Marshall monotonic load for asphalt concrete mixtures

Yung Vargas, Yee Wan; Rodriguez Lizcano, Adriana; Peña Soto, C A (Journal of Physics: Conference SeriesReino Unido, 2022-01-06)

The dense hot MDC-19 type asphalt mixes are considered, by the “Instituto Nacional de Vías” in Colombia, as continuous grading asphalt mixes (asphalt concrete). These constitute most of the surface course, in the structures ...
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 ...
Electrochemical synthesis of titanium dioxide nanostructures and its application in the in dye photocatalytic removal

RIVERA BERMUDEZ, INGRID PAOLA; Alarcón Rodríguez1, V; Peña Rodríguez, G (Reino Unido, 2021-06-04)

By electrochemical anodization to titanium sheets, titanium dioxide nanostructures were sintered for 10 V and 20 V and times of 3 hours and 5 hours. For the electrolytic solution, 0.3 g of ammonium fluoride, 97 mL of ...
Interpreting the slope of a straight line in kinematics graphs with school students

Prada Núñez, R; Gamboa Suárez, A A; Avendaño Castro, William Rodrigo (Journal of Physics: Conference SeriesReino Unido, 2022-01-10)

The interdisciplinary nature of knowledge is one of the objectives promoted in Colombia, fostering in students the ability to recognize that the curriculum does not work in isolation; if knowledge is complementary, its ...
Anticorrosive evaluation of copper-iron mixtures processed by powder metallurgy

Bautista-Ruiz, Jorge; Operador, W; Caicedo, J (Rasayan Journal of ChemistryIndia, 2021)

Through the powder metallurgy process, copper and iron powders were mixed in the proportions Cu between 15% to 75% and iron from 25% to 85% that made up the binary material systems. Material systems were topographically ...
Wear synergy of copper-iron mixtures processed by powder metallurgy

Operador, W; Bautista-Ruiz, Jorge; Caicedo, J (Rasayan Journal of ChemistryIndia, 2021)

Through the powder metallurgy process, copper and iron powders were mixed in the proportions Cu between 15% to 75% and iron from 25% to 85% that made up the binary material systems. The X-ray diffraction technique was ...
Implementation of an automated dryer with solar collector

Regino Ubarnes, fernando Jesús; Jaramillo, H Y; Moreno Garcia, F E Moreno-Garcia2 (Journal of Physics: Conference SeriesReino Unido, 2022-01-10)

This research work consists of the development of an automated sustainable drying system using forced and preheated air to reduce the production time of handmade bricks, so a dryer witha solar collector wasimplemented ...
Numerical and Experimental Analysis of the Potential Fuel Savings and Reduction in CO Emissions by Implementing Cylinder Bore Coating Materials Applied to Diesel Engines

Orjuela Abril, Martha Sofia ; Pardo García, Carlos Eduardo; Pabón León, Jhon (LubricantsSuiza, 2021-02-18)

Currently, internal combustion engines contribute to the problem of global warming due to their need to use products derived from fossil resources. To mitigate the above problem, this study proposes the use of coatings ...
Modelling of DHA Production from S. Limacinum ouc88: fed-batch perspectives

Contreras, B; Basto, D; Gelves Gelves, Elizabeth (Reino Unido, 2021-09-12)

Biotechnology and its need to improve industrial processes have shown the need for techniques that allow processes optimization. Computer simulation offers the advantage of determining production prospects without ...
Gestión pública en una ciudad fronteriza colombiana: La mirada de sus habitantes

AMBOA SUAREZ, AUDIN ALOISO; Hernández Álvarez, Cesar Augusto; Ramirez Leal, Pastor (Revista de Ciencias SocialesColombia, 2021-08)

La gestión pública eficiente busca generar actuaciones transparentes que logren satisfacer necesidades básicas de los habitantes. El objetivo del artículo es identificar las percepciones de habitantes de la ciudad ...
Operating Mode Effect on Lipids Production from Rhodotorula mucilaginosa: Modelling and Simulation Trends

Gelves Gelves, Elizabeth; Duran, K; Cardozo, L (Reino Unido, 2021-09-12)

A sustainable alternative for fossil fuels substitution is the production of biodiesel from natural lipids. Mainly, such oil used is in the form of triglycerides and is characterized by being potentially renewable, ...
Thermodynamics performance optimization of a hybrid solar gas turbine power plant in Colombia

Moreno Gamboa, Faustino; Acevedo Paez, Juan Camilo; Sanin-Villa, Daniel (Journal of Physics: Conference SeriesReino Unido, 2022-02-10)

A thermodynamic model is presented for evaluation of a solar hybrid gas-turbine power plant. The model uses variable ambient temperature and estimates direct solar radiation at different day times. The plant is evaluated ...
Influence of compression rings on the dynamic characteristics and sealing capacity of the combustion chamber in diesel engines

Hernández Comas, Brando; Maestre Cambronel, Daniel Esteban; Pardo García, Carlos Eduardo; FONSECA VIGOYA, MARLEN DEL SOCORRO; Pabón León, Jhon (LubricantsSuiza, 2021-03-02)

Internal combustion engines are widely implemented in several applications; however, they still face significant challenges due to the sealing capacity of the compression rings. Gas leakage through the crankcase, also ...
Dynamic Simulation of Bioethanol Production from Banana Rejected using Flocculating Yeast

Contreras, J; Haro, Y; Gelves Gelves, Elizabeth (Reino Unido, 2021-09-12)

A dynamic model is presented to simulate a fermentation process for bioethanol production from banana rejected using a batch system. The critical model feature is using an inhibition function to relate substrate concentration ...
Construcción sostenible en Colombia: Análisis a partir del Proyecto de Ley No. 208/2019 Cámara

Avendaño Castro, William Rodrigo; rueda vera, gerson; Velasco Burgos, Blanca Mery (Revista de Ciencias Sociales (RCS)Colombia, 2021)

La industria de la construcción es una de las principales fuentes de contaminación en la actualidad, y por ello, las leyes destinadas a mitigar su impacto, resultan indispensables frente a problemas estructurales como ...
Problem solving in the physics classroom. An analysis with secondary school students

Hernández Suarez, C A; Paz Montes, L S; Avendaño Castro, William Rodrigo (Journal of Physics: Conference SeriesReino Unido, 2022-01-10)

The teaching of science, and specifically physics, has been associated with the acquisition of knowledge with a particular emphasis on problem solving, as an activity that brings students closer to the methodology and ...
Dynamic Modeling of Tannase Production from Bacillus cereus: A Framework Simulation based on Fed Batch Strategy

Gelves Gelves, Elizabeth; Niño, L. Elisa; Mendoza, D (Reino Unido, 2021-09-12)

Tannase enzyme is a metabolite of great interest in the industry. Typical examples of its use can be found in wines and beer production, beverage and juice fruits clarification and leather production. However, tannase ...
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 ...

Envíos recientes

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
Silver colloidal nanoparticles by electrochemistry: temporal evaluation and surface plasmon resonance
...
Padilla Sierra, H A | 2021-06-04

The electrochemical technique for obtaining silver nanoparticles has advantages over other methods. For the synthesis, a colloidal silver generator (Colloidal Silver Generator® model 1001) was used, where two electrodes coupled to high purity silver rods (99.99%) were used, with a potential difference of 24 V. Nanoparticle concentration was measured by total dissolved solids, using the SI-Analytic HandyLab 680 FK multiparameter in 200 mL of Milli-Q deionized water, reporting 18 ppm at 1 hour at room temperature. The determination of the resonance wavelength of the surface plasmons was carried out by finding the maximum absorbance by UVVisible spectrophotometry with λ = 423 nm. The morphology and size of the nanoparticles was determined by Transmission Electron Microscopy, observing spherical morphology and sizes smaller than 50 nm. The chemical composition was determined by X-ray energy dispersed spectroscopy, finding a weight concentration of 93.22% of silver. The results show an optimal synthesis of colloidal silver, with characteristics that will allow the inhibition of microorganisms of interest.

LEER
Resistance under Marshall monotonic load for asphalt concrete mixtures
...
Yung Vargas, Yee Wan | 2022-01-06

The dense hot MDC-19 type asphalt mixes are considered, by the “Instituto Nacional de Vías” in Colombia, as continuous grading asphalt mixes (asphalt concrete). These constitute most of the surface course, in the structures of in-service pavements, being the object of study and research in different projects to ensure their durability. In the present investigation, unlike other investigations, the mechanical behavior under Marshall monotonic load was studied in the laboratory between MDC-19 dense type asphalt mixtures, comparing plant-produced and laboratory-produced asphalt mixtures. To carry out this process, samples of uncompacted asphalt mixtures were taken, produced in four fixed plants, with which Marshall-type briquettes were compacted. Likewise, samples of mineral aggregates and asphalt cement were obtained from the same plants, which constitute the mixtures raw material produced there. With these materials, briquettes with the same characteristics were mixed and compacted. Subsequently, the resistance under Marshall monotonic load was determined on the briquettes manufactured in plant and laboratory. The optimal asphalt cement content was compared between plant and laboratoryproduced mixtures. An increase in Marshall Stability was found in the briquettes made with plant-produced mixtures, while these required a greater amount of asphalt cement for their production.

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
Electrochemical synthesis of titanium dioxide nanostructures and its application in the in dye photocatalytic removal
...
RIVERA BERMUDEZ, INGRID PAOLA | 2021-06-04

By electrochemical anodization to titanium sheets, titanium dioxide nanostructures were sintered for 10 V and 20 V and times of 3 hours and 5 hours. For the electrolytic solution, 0.3 g of ammonium fluoride, 97 mL of ethylene glycol and 3 mL of distilled water were used. The sheets (51 mm × 21 mm × 0.4 mm) were treated using abrasive paper and cleaned with a 1:1 solution of ethanol water by means of ultrasound and dried using hot air. A stirring frequency of 300 rpm was used during anodizing. For the sintering of the titanium dioxide anatase phase, heat treatment was applied at 550 °C for 3 hours by means of an electric muffle, with heating speed of 10 °C/min. The crystallinity index, and the quantification of the sintered phases was carried out by means of X-ray diffraction, while the nanoporosities and their distribution were carried out using imageJ software to the images taken by means of scanning electron microscopy. For the photocatalytic treatment of the methylene blue dye in water, the titanium dioxide nanostructures that reported the highest anatase phase were used, where ultraviolet C radiation from a led lamp was applied for 4 direct hours. The efficiency in the removal of the dye was studied by UV-Vis spectrophotometry, finding the highest degradation of the dye for the wavelength of 644 nm.

LEER
Interpreting the slope of a straight line in kinematics graphs with school students
...
Prada Núñez, R | 2022-01-10

The interdisciplinary nature of knowledge is one of the objectives promoted in Colombia, fostering in students the ability to recognize that the curriculum does not work in isolation; if knowledge is complementary, its joint development leads to better academic performance. This research is oriented towards showing an application of the mathematical concept of the slope of the straight line in physics applications, favoring the understanding of the relationships between variables, as occurs with the graphs of kinematics. A group of eleventh grade students from a private educational institution filled in a questionnaire for data collection, based on three situations proposed to answer three open questions in which a reasonably justified answer was required. A part of the group correctly interpreted the graphs by describing the characteristics of the movement in each time interval, but only a few were able to associate the slope of the line as the velocity or acceleration as a function of the variables mentioned in the graph, although their argumentation was based on the angle of elevation of the line.

LEER
Anticorrosive evaluation of copper-iron mixtures processed by powder metallurgy
...
Bautista-Ruiz, Jorge | 2021

Through the powder metallurgy process, copper and iron powders were mixed in the proportions Cu between 15% to 75% and iron from 25% to 85% that made up the binary material systems. Material systems were topographically characterized with atomic force microscopy. Corrosion tests were established using potentiodynamic polarization curves. The worn surfaces' characterization was carried out by means of a Confocal Scanning Laser Microscope to complement the study. It was determined that the mixtures' stability and behaviour have different behaviours depending on the evaluated system because the wear system caused, indicating that the phenomenon can be additive. The corrosive phenomenon is dominantly affected by the microstructure of the material. From the results found, it is possible to infer that the best systems evaluated by corrosive contain the highest percentage of copper content. The topographic variation indicates the transition from the active zone to the passive zone of the metal due to electrochemical reactions in the presence of aggressive media.

LEER
Wear synergy of copper-iron mixtures processed by powder metallurgy
...
Operador, W | 2021

Through the powder metallurgy process, copper and iron powders were mixed in the proportions Cu between 15% to 75% and iron from 25% to 85% that made up the binary material systems. The X-ray diffraction technique was used to determine the crystalline structure. Material systems were topographically characterized with optical microscopy. Tribology tests were established using a pin on the disk tribometer. It was determined that the stability of the mixture has different behaviors depending on the evaluated system because the wear system caused, indicating that the phenomenon can be additive. The mixed material is characterized by high friction coefficient and high wear due to the samples' specific properties by increasing the amount of iron in the mixture. The systems analyzed indicate that mechanical degradation was mainly reduced. Dimensional variation of the study specimens was evidenced due to the influence of copper in the system. Only the austenitic structure of the steel was observed, which indicates a complete diffusion of the copper.

LEER
Implementation of an automated dryer with solar collector
...
Regino Ubarnes, fernando Jesús | 2022-01-10

This research work consists of the development of an automated sustainable drying system using forced and preheated air to reduce the production time of handmade bricks, so a dryer witha solar collector wasimplemented to take advantage of the energy from solar radiation. A virtualinstrument was developed, which allows to visualize the variables of temperature and humidityinside the drying chamber, additionally a temperature control was implemented, this control allows the system to maintain a constant temperature during the drying process. Samples were taken from the production of the brick kiln “El Tejar” and dried by this device, thenthe drying times and their physical and mechanical properties were compared, finding that the bricks dried with the proposed prototype retained these properties. As for the compressive strength tests for samples of both processes was around 30.6 Kgf/cm² and 31.2 Kgf/cm², the deflection resistance was around 1.2 Kgf/cm² and 1.3 Kgf/cm², the initial absorption rate was around 0.3 g/cm²/min and 0.4 g/cm²/min, and finally the percentage of water absorption for both processes were around 12.9% and 13.1%. The difference lies in the drying times, since drying in the artisanal brick kilns takes about 15 daysin the proposed dryer takes 9 days, resulting in a decrease of 40% in this process.

LEER
Numerical and Experimental Analysis of the Potential Fuel Savings and Reduction in CO Emissions by Implementing Cylinder Bore Coating Materials Applied to Diesel Engines
...
Orjuela Abril, Martha Sofia | 2021-02-18

Currently, internal combustion engines contribute to the problem of global warming due to their need to use products derived from fossil resources. To mitigate the above problem, this study proposes the use of coatings on the cylinder bore in order to reduce fuel consumption and polluting emissions. Therefore, in the present study a numerical model is developed in which the tribological behavior, heat fluxes, and leakage of the combustion gases in the chamber are considered to evaluate the influence of the coating. Nickel nanocomposite (NNC) and diamond-like carbon (DLC) coatings are considered in the study. The results demonstrate that the NNC coating produces a 32% reduction in the total friction force of the compression ring. The estimated maximum temperatures for the lubricating oil were 214, 202, and 194 ◦C for the DLC, steel, and NNC materials. Increasing the temperature in the DLC coating can cause a reduction in the tribological performance of the lubricant. The estimates made show that the implementation of the NNC coating allows a maximum reduction of 5.28 ton of fuel and 39.30 kg of CO emissions, which are based on the global fleet of diesel engines forecast for the year 2025 (corresponding to one hundred and eighty million engines) and a test time of 1800 s. The proposed numerical model allows future analyses to be carried out for other types of materials used as coatings. Additionally, the model can be expanded and adapted to consider other systems that involve friction processes in the engine.

LEER
Modelling of DHA Production from S. Limacinum ouc88: fed-batch perspectives
...
Contreras, B | 2021-09-12

Biotechnology and its need to improve industrial processes have shown the need for techniques that allow processes optimization. Computer simulation offers the advantage of determining production prospects without significant resources and experimentation time. That is why a kinetic study of DHA (docosahexaenoic acid) production from Schizochytrium limacinum OUC88 was developed in this investigation. Based on the above, a mathematical approach to simulate DHA production in a fed-batch model is proposed in this work, using Matlab software. The experimental data for determining kinetic parameters were taken from previous investigations, and a simulated DHA level in the fed-batch mode of 150 g/L was reached. On the contrary, the simulated results in batch mode present only a maximum value of 30 g/L, demonstrating the effectiveness of the fed-batch implementation with perspectives on improving processes.

LEER
Gestión pública en una ciudad fronteriza colombiana: La mirada de sus habitantes
...
AMBOA SUAREZ, AUDIN ALOISO | 2021-08

La gestión pública eficiente busca generar actuaciones transparentes que logren satisfacer necesidades básicas de los habitantes. El objetivo del artículo es identificar las percepciones de habitantes de la ciudad fronteriza de Cúcuta, en Colombia, sobre la gestión de sus gobernantes en aspectos relacionados con educación, empleo, salud, seguridad y vivienda. El componente metodológico estuvo determinado por el paradigma cuantitativo, con diseño descriptivo, no experimental, de corte transversal. Se aplicó un cuestionario de 16 ítems a 2.284 participantes de las diez comunas de la ciudad. Los resultados muestran que 63,5% de los encuestados manifestó que la ciudad ha empeorado en el último año, en contraste con 27,5% que considera que ha mejorado tras la aplicación de las políticas de gobierno, mientras que 9% no respondió. Se concluye, que la insatisfacción de la mayoría de los habitantes con la gestión del gobierno municipal se relaciona, principalmente, con el alto porcentaje del trabajo informal, la falta de oportunidades para empleo formal y los deficientes sistemas de salud y educación. Problemas que no surgieron con la pandemia, sino que se han configurado desde años anteriores, ante la poca ayuda que ha brindado el gobierno municipal para mitigar los problemas sociales de la región.

LEER
Operating Mode Effect on Lipids Production from Rhodotorula mucilaginosa: Modelling and Simulation Trends
...
Gelves Gelves, Elizabeth | 2021-09-12

A sustainable alternative for fossil fuels substitution is the production of biodiesel from natural lipids. Mainly, such oil used is in the form of triglycerides and is characterized by being potentially renewable, non-toxic, and biodegradable, thus making it a sustainable product. For producing such biofuel, yeast oil is one of the most viable and currently known options, obtaining theoretically optimal results. In this article, kinetic parameters from the oleaginous yeast Rhodotorula mucilaginosa will simulate lipid accumulation capacity based on different bioreactor operating modes. Likewise, The Matlab software is used to simulate batch and continuous operating modes to establish comparisons between the productions obtained and their respective yields. The results obtained for the batch mode were: 14 g/L for the growth of biomass and an estimate of 0.22 g/g for lipid production. Likewise, for the continuous mode, its results were: 19 g/L for biomass growth and a value of 0.30 g/g in lipid production. The simulated results in continuous mode would demonstrate the effectiveness of its implementation since a more significant lipid accumulation is reached.

LEER
Thermodynamics performance optimization of a hybrid solar gas turbine power plant in Colombia
...
Moreno Gamboa, Faustino | 2022-02-10

A thermodynamic model is presented for evaluation of a solar hybrid gas-turbine power plant. The model uses variable ambient temperature and estimates direct solar radiation at different day times. The plant is evaluated in Barranquilla, Colombia, with a solar concentration system and a combustion chamber that burns natural gas. The hybrid system enables to maintain almost constant the power output throughout day. The model allows optimizing the different plant parameters and evaluating maximum performance point. This work presents pressure ratio ranges where the maximum values of overall efficiency, power output, thermal engine efficiency and fuel conversion rate are found. The study is based on the environmental conditions of Barranquilla, Colombia. The results obtained shows that optimum pressure ratio range for power output and overall efficiency is between 6.4 and 8.3, when direct solar radiation its maximum at noon. This thermodynamic analysis is necessary to design new generations of solar thermal power plants.

LEER
Influence of compression rings on the dynamic characteristics and sealing capacity of the combustion chamber in diesel engines
...
Hernández Comas, Brando | 2021-03-02

Internal combustion engines are widely implemented in several applications; however, they still face significant challenges due to the sealing capacity of the compression rings. Gas leakage through the crankcase, also known as blow-by, directly impacts power losses, overall efficiency, and global emissions. Therefore, the present study investigates the influence of parameters such as the ring gap, ring masses, and twist angle of the compression rings on the sealing capacity of the combustion chamber. A mathematical model is proposed to account for geometric, dynamic, and operational characteristics in a single-cylinder diesel engine. The results indicated that the greatest gas losses to the crankcase occur during the compression and combustion stages as a consequence of extreme pressure conditions. Specifically, at least 0.5% of the gases locked in the combustion chamber are released on each cycle, while increasing the mass of the compression rings boosts the gas leakage due to higher inertial forces in the rings. In contrast, a positive twist angle of the compression rings reduced the combustion gases leakage by 7.33 × 10−5 g/cycle. Additionally, a combined reduction in the gap of both compression rings minimized the leakage flows by 37%. In conclusion, the proposed model served as a robust tool to evaluate different parameters on the sealing capacity of the combustion chamber that contribute to minimizing global emissions. Secondary piston motion and ring distortion represent significant opportunities in future studies.

LEER
Dynamic Simulation of Bioethanol Production from Banana Rejected using Flocculating Yeast
...
Contreras, J | 2021-09-12

A dynamic model is presented to simulate a fermentation process for bioethanol production from banana rejected using a batch system. The critical model feature is using an inhibition function to relate substrate concentration and specific growth rate. Kinetic parameters were calculated based on previous experimental data, and the optimal substrate concentration is investigated. The Andrews kinetic model was adapted to the concentration profiles, indicating that it could describe the existence of substrate and product inhibition. Different initial substrate concentrations were evaluated (90-400 g/L), and simulated results suggest 200 g/L of rejected banana as a starting point to reach a high and efficient bioethanol production since a maximal ethanol production is reached with a value of 150 g/L. However, when using a higher banana, rejected concentration inhibition occurs, and therefore bioethanol production decreases to reach levels lower than 100 g/L. Based on results found, kinetic models allow obtaining important observations on microbial metabolic processes and facilitating a good approximation for further large-scale stages.

LEER
Construcción sostenible en Colombia: Análisis a partir del Proyecto de Ley No. 208/2019 Cámara
...
Avendaño Castro, William Rodrigo | 2021

La industria de la construcción es una de las principales fuentes de contaminación en la actualidad, y por ello, las leyes destinadas a mitigar su impacto, resultan indispensables frente a problemas estructurales como el cambio climático. En esta investigación se analiza la construcción sostenible en Colombia y el Proyecto de Ley 208 2019 del Congreso de la República para su fomento. Se trata de un estudio cualitativo de tipo documental, enmarcado en el paradigma interpretativo. Se analizaron documentos publicados en los últimos cinco años que facilitaron el estudio del tema, así como la última iniciativa del legislativo colombiano para el fomento de la construcción sostenible. Los hallazgos del análisis evidencian, por un lado, una ausencia de estudios relacionados con el impacto de la industria de la construcción en el contexto colombiano, y por otro, una relación directa entre esta actividad económica, el desarrollo sostenible y el cambio climático. El frente legislativo es un escenario de acción para dar respuesta al complejo problema que se puede articular con la construcción sostenible. Se concluye, que en el país aún es incipiente el desarrollo normativo en la materia, y, por tanto, es necesario dar paso a una política pública de mayor alcance.

LEER
Problem solving in the physics classroom. An analysis with secondary school students
...
Hernández Suarez, C A | 2022-01-10

The teaching of science, and specifically physics, has been associated with the acquisition of knowledge with a particular emphasis on problem solving, as an activity that brings students closer to the methodology and meaningful learning of science. However, problem solving is perhaps one of the sources of failure in physics teaching, which requires a careful analysis of this didactic activity. Therefore, the aim of this work is to analyze the development of students' problem-solving skills in a physics course. An analysis is presented using the quasiexperimental method through the application of a pre-test – post-test, for which a methodological intervention was used based on the problem-solving competence, which focused on identifying errors and difficulties by the students themselves and thus favoring the learning and development of this competence, which allowed the academic progress of the students to be analyzed. It is concluded that the intervention supported by problem solving improves students' performance, in addition to the positive assessment they make of the process, as well as its influence on the change in pedagogical practice.

LEER
Dynamic Modeling of Tannase Production from Bacillus cereus: A Framework Simulation based on Fed Batch Strategy
...
Gelves Gelves, Elizabeth | 2021-09-12

Tannase enzyme is a metabolite of great interest in the industry. Typical examples of its use can be found in wines and beer production, beverage and juice fruits clarification and leather production. However, tannase production on an industrial scale is limited to the operation batch mode. For this reason, its production is low and severe limitations take the place of being carried on a large scale. To improve production, this research proposes an operation strategy based on Fed-batch mode. The kinetic constants were taken from the literature to simulate trends obtained through a Feed-batch mode of operation. One of the most important findings of this research focuses on increasing tannase production with found values of 0.380 U/g. The latter indicates that tannase production could be almost twice the concentration obtained with the traditional batch mode (0.1900 U/g). Results obtained in this research may be promising for the enzyme production industry. Using computational techniques, it is possible to identify an improvement without investing in excessive experimentation and resources.

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

‹›

B. Investigación: Envíos recientes

Evaluation of the fire resistance of steel-reinforced concretefilled steel tubular columns with a circular cross-section ﻿

Silver colloidal nanoparticles by electrochemistry: temporal evaluation and surface plasmon resonance ﻿

Resistance under Marshall monotonic load for asphalt concrete mixtures ﻿

First International Seminar on Physical Infrastructure (1st ISPI) ﻿

Electrochemical synthesis of titanium dioxide nanostructures and its application in the in dye photocatalytic removal ﻿

Interpreting the slope of a straight line in kinematics graphs with school students ﻿

Anticorrosive evaluation of copper-iron mixtures processed by powder metallurgy ﻿

Wear synergy of copper-iron mixtures processed by powder metallurgy ﻿

Implementation of an automated dryer with solar collector ﻿

Numerical and Experimental Analysis of the Potential Fuel Savings and Reduction in CO Emissions by Implementing Cylinder Bore Coating Materials Applied to Diesel Engines ﻿

Modelling of DHA Production from S. Limacinum ouc88: fed-batch perspectives ﻿

Gestión pública en una ciudad fronteriza colombiana: La mirada de sus habitantes ﻿

Operating Mode Effect on Lipids Production from Rhodotorula mucilaginosa: Modelling and Simulation Trends ﻿

Thermodynamics performance optimization of a hybrid solar gas turbine power plant in Colombia ﻿

Influence of compression rings on the dynamic characteristics and sealing capacity of the combustion chamber in diesel engines ﻿

Dynamic Simulation of Bioethanol Production from Banana Rejected using Flocculating Yeast ﻿

Construcción sostenible en Colombia: Análisis a partir del Proyecto de Ley No. 208/2019 Cámara ﻿

Problem solving in the physics classroom. An analysis with secondary school students ﻿

Dynamic Modeling of Tannase Production from Bacillus cereus: A Framework Simulation based on Fed Batch Strategy ﻿

Economic and Environmental Multiobjective Optimization of a Hybrid Power Generation System using Solar and Wind Energy Source ﻿

Envíos recientes

Evaluation of the fire resistance of steel-reinforced concretefilled steel tubular columns with a circular cross-section

Silver colloidal nanoparticles by electrochemistry: temporal evaluation and surface plasmon resonance

Resistance under Marshall monotonic load for asphalt concrete mixtures

First International Seminar on Physical Infrastructure (1st ISPI)

Electrochemical synthesis of titanium dioxide nanostructures and its application in the in dye photocatalytic removal

Interpreting the slope of a straight line in kinematics graphs with school students

Anticorrosive evaluation of copper-iron mixtures processed by powder metallurgy

Wear synergy of copper-iron mixtures processed by powder metallurgy

Implementation of an automated dryer with solar collector

Numerical and Experimental Analysis of the Potential Fuel Savings and Reduction in CO Emissions by Implementing Cylinder Bore Coating Materials Applied to Diesel Engines

Modelling of DHA Production from S. Limacinum ouc88: fed-batch perspectives

Gestión pública en una ciudad fronteriza colombiana: La mirada de sus habitantes

Operating Mode Effect on Lipids Production from Rhodotorula mucilaginosa: Modelling and Simulation Trends

Thermodynamics performance optimization of a hybrid solar gas turbine power plant in Colombia

Influence of compression rings on the dynamic characteristics and sealing capacity of the combustion chamber in diesel engines

Dynamic Simulation of Bioethanol Production from Banana Rejected using Flocculating Yeast

Construcción sostenible en Colombia: Análisis a partir del Proyecto de Ley No. 208/2019 Cámara

Problem solving in the physics classroom. An analysis with secondary school students

Dynamic Modeling of Tannase Production from Bacillus cereus: A Framework Simulation based on Fed Batch Strategy

Economic and Environmental Multiobjective Optimization of a Hybrid Power Generation System using Solar and Wind Energy Source

Portales Institucionales

Evaluation of the fire resistance of steel-reinforced concretefilled steel tubular columns with a circular cross-section

Silver colloidal nanoparticles by electrochemistry: temporal evaluation and surface plasmon resonance

Resistance under Marshall monotonic load for asphalt concrete mixtures

First International Seminar on Physical Infrastructure (1st ISPI)

Electrochemical synthesis of titanium dioxide nanostructures and its application in the in dye photocatalytic removal

Interpreting the slope of a straight line in kinematics graphs with school students

Anticorrosive evaluation of copper-iron mixtures processed by powder metallurgy

Wear synergy of copper-iron mixtures processed by powder metallurgy

Implementation of an automated dryer with solar collector

Numerical and Experimental Analysis of the Potential Fuel Savings and Reduction in CO Emissions by Implementing Cylinder Bore Coating Materials Applied to Diesel Engines

Modelling of DHA Production from S. Limacinum ouc88: fed-batch perspectives

Gestión pública en una ciudad fronteriza colombiana: La mirada de sus habitantes

Operating Mode Effect on Lipids Production from Rhodotorula mucilaginosa: Modelling and Simulation Trends

Thermodynamics performance optimization of a hybrid solar gas turbine power plant in Colombia

Influence of compression rings on the dynamic characteristics and sealing capacity of the combustion chamber in diesel engines

Dynamic Simulation of Bioethanol Production from Banana Rejected using Flocculating Yeast

Construcción sostenible en Colombia: Análisis a partir del Proyecto de Ley No. 208/2019 Cámara

Problem solving in the physics classroom. An analysis with secondary school students

Dynamic Modeling of Tannase Production from Bacillus cereus: A Framework Simulation based on Fed Batch Strategy

Economic and Environmental Multiobjective Optimization of a Hybrid Power Generation System using Solar and Wind Energy Source