Mostrando ítems 1-20 de 34

Application of LEAN tool "line balancing" to determine the productivity of workforce in activities of plastering and internal detailing in two-story houses made of masonry

Hurtado-Figueroa, Oswaldo; Cárdenas-Gutiérrez, Javier Alfonso; Rojas Suárez, Jhan Piero (Contemporary Engineering SciencesBulgaria, 2018-11-26)

The finishing work of construction represents an aggregated value that makes the difference when a client is deciding to buy a house. The stipulated costs for plastering and detail activities for houses, in occasions, ...
The architecture on land and its construction techniques, millenary tradition that is reborn

Hurtado-Figueroa, Oswaldo; Cárdenas-Gutiérrez, Javier Alfonso; Acevedo Peñaloza, Carlos Humberto (Contemporary Engineering SciencesBulgaria, 2018-08-30)

In the context of sustainable development, the use of materials of low environmental impact in the activities inherent to the construction of houses plays an important role when it comes to reducing waste pollution. The ...
CFD study of industrial safety valves in a virtual environment with OpenFOAM® software

Rojas Suárez, Jhan Piero; Cárdenas-Gutiérrez, Javier Alfonso; PABON LEON, JHON ANTUNY (International Review of Mechanical EngineeringItalia, 2020-11-30)

Numerical advances in the numerical analysis of safety valves have enabled the development of approximated predictions related to the hydraulic behavior of turbulent flows, which influence the mechanical behavior of the ...
Comparative analysis of supercritical CO2 Brayton cycles with simple and partial cooling configurations

Cárdenas-Gutiérrez, Javier Alfonso; Duarte Forero, Jorge; Valencia Ochoa, Guillermo Eliecer (International Journal on Energy ConversionItalia, 2020-09)

The theoretical analysis of the thermodynamic cycles and the physical processes that occur in a cyclical way has improved the knowledge needed to improve the energy efficiency and the performance of the energy transfer ...
A comparative study of the energy, exergetic and thermo-economic performance of a novelty combined Brayton S-CO2-ORC configurations as bottoming cycles

Cárdenas-Gutiérrez, Javier Alfonso; Duarte Forero, Jorge; Valencia Ochoa, Guillermo (HeliyonReino Unido, 2020-07-14)

This paper presents a comparative study on the energy, exergetic and thermo-economic performance of a novelty thermal power system integrated by a supercritical CO2 Brayton cycle, and a recuperative organic Rankine cycle ...
Computational fluid dynamics analysis of combined cycle power plant heat exchanger with OpenFOAM® software

Cárdenas-Gutiérrez, Javier Alfonso; Acevedo Peñaloza, Carlos Humberto; Orjuela Abril, Martha Sofia (International Review on Modelling and SimulationsItalia, 2020-10)

The heat exchangers application in combined cycle power plants is a key aspect in the thermal and fluid mechanics sciences due to their elevated functionality in industrial processes related to the quality and the efficiency ...
Determination of the quality of coarse aggregates for the elaboration of concrete mixes from 3 water sources in the City of Cucuta-Colombia

Hurtado-Figueroa, Oswaldo; Cárdenas-Gutiérrez, Javier Alfonso; Rojas Suárez, Jhan Piero (Journal of Physics: Conference SeriesReino Unido, 2018-12-07)

A comparative analysis was performed on the mineral material extracted from 3 water sources in the city of Cucuta, from the rivers Tachira, Pamplonita and Zulia to determine the viability of their incorporation in the ...
Las estructuras industrializadas como elemento innovador bajo el contraste de las percepciones de los ingenieros

Cárdenas-Gutiérrez, Javier Alfonso; barrientos, ender jose; Bravo Fuentes, Carlos Javier (Revista Colombiana de Tecnologías de AvanzadaColombia, 2020-04)

The objective of the research was to make known the experiences of calculating engineers in the face of the behavior of industrialized buildings in earthquakes of great magnitude in the departments of Santander and Norte ...
Exergy, economic, and life-cycle assessment of orc system for waste heat recovery in a natural gas internal combustion engine

Valencia, Guillermo; Cárdenas-Gutiérrez, Javier Alfonso; Duarte Forero, Jorge (ResourcesSuiza, 2020-01-01)

In this article, an organic Rankine cycle (ORC) was integrated into a 2-MW natural gas engine to evaluate the possibility of generating electricity by recovering the engine’s exhaust heat. The operational and design variables ...
Exhaust gas heat exchanger design based on the engine backpressure and heat rate criteria

Cárdenas-Gutiérrez, Javier Alfonso; Rojas Suárez, Jhan Piero; Acevedo Peñaloza, Carlos Humberto (International Review of Mechanical EngineeringItalia, 2020-10)

The use of shell and tube heat exchangers for waste heat recovery has shown excellent results in increasing engine performance, as well as offering a large surface area for small volumes, ease of cleaning, good mechanical ...
Experimental and CFD characterization of the jacket vessel heat transfer process

Cárdenas-Gutiérrez, Javier Alfonso; barrientos, ender jose; Romero Garcia, Gonzalo de la Cruz (International Review on Modelling and SimulationsItalia, 2020-10)

Heat exchange processes are widely applicable in industry and research. The process of design and optimization of these types of devices is of particular interest, since they generate a high rate of exergy destruction. In ...
Failure analysis methodology in industrial control valves using quality function

Rojas Suárez, Jhan Piero; Espinel Blanco, Edwin; Cárdenas-Gutiérrez, Javier Alfonso (International Review of Automatic ControlItalia, 2020-11-30)

Quality control methodologies and improvement methods have been applied to the process management in order to develop a set of fault diagnosis practices during the industrial operation of mechanical components in production ...
Gestión del capital intelectual en la dirección de programa de ingeniería civil de la Unefa núcleo Táchira

barrientos, ender jose; Cárdenas-Gutiérrez, Javier Alfonso; CORDERO DIAZ, MARLING CAROLINA (Revista AglalaColombia, 2020-12-17)

La gestión de intangibles en las organizaciones es un activo que está siendo perdido por organizaciones pequeñas y medianas, es por ello que el propósito de esta investigación fue describir las experiencias de los actores ...
Handling of concrete with addition of residual ceramic material in different % replacing conventional stony aggregate

Hurtado-Figueroa, Oswaldo; Cárdenas-Gutiérrez, Javier Alfonso; Cordero Estevez, Gerson David (Contemporary Engineering SciencesBulgaria, 2018-11-26)

A conventional concrete mixture elaborated according to the parameters described in the Colombian Technical Standards NTC under the conditioning established by the Quake Resistant Standard NSR-10 that regulates our ...
Implementation of hospital waste replacing stony aggregates in non-structural concrete mixes of low resistance

Hurtado-Figueroa, Oswaldo; Rojas Suárez, Jhan Piero; Cárdenas-Gutiérrez, Javier Alfonso (Contemporary Engineering SciencesBulgaria, 2018-11-29)

A non-structural concrete mix was elaborated with a resistance of 14.5 Megapascals under the parameters indicated in the American Concrete Institute (ACI), ASTM and the Colombian Technical Standards (NTC). Six mixing cylinders ...
Incidence of the lean philosophy construction in the productivity and analysis of processes in internal finishes in masonry living quarters in the construction projects: case-residential complex Callejas-Cucuta-Colombia

Hurtado-Figueroa, Oswaldo; Cárdenas-Gutiérrez, Javier Alfonso; Acevedo Peñaloza, Carlos Humberto (Contemporary Engineering SciencesBulgaria, 2018-08-30)

The technical supervision in the construction projects is of special importance for the correct execution of the activities, its objective is to reduce the errors that are incurred when carrying out the processes inherent ...
Influence of natural frequency on stability during milling of inconel and udimet 500

Coba Salcedo, Milton Fabian; Cárdenas-Gutiérrez, Javier Alfonso; Acevedo Peñaloza, Carlos Humberto (Contemporary Engineering SciencesBulgaria, 2018-09-18)

Chatter in the machine tools represents one of the biggest problems due to the instability in the machining process, breakage of the tool and accelerated wear of the tool and spindle or machine components in the metal ...
Influence of water/cement ratio on mechanical strength of concrete with partial addition of fly ash and hydrated lime

Cárdenas-Gutiérrez, Javier Alfonso; Hurtado-Figueroa, Oswaldo; Echavarria-Paez, FJ (Journal of Physics: Conference SeriesReino Unido, 2019-11-29)

Three mixtures were made for conventional concrete with different additions of cement, 300 kg/m3, 350 kg/m3 and 400 kg/m3, being these the 3 designs of mixtures more used for the elaboration of simple concretes. For each ...
An integral PEST study of biomass as energy resource

Mendoza Cassere, Daniel; Valencia, Guillermo Eliecer; Cárdenas-Gutiérrez, Javier Alfonso (Contemporary Engineering SciencesBulgaria, 2018-08-18)

The present work was carried out in order to evaluate the world's scientific production with respect to the topic of biomass, based on articles published from 2007 onwards. The data were obtained from the Web of Science ...
Mass transfer simulation of liquid-liquid extraction systems using an educational software

Roncallo, Gian Franco; Barrios, Kelly Johanna; Obregon, Luis Guillermo; Valencia, Guillermo Eliecer; Cárdenas-Gutiérrez, Javier Alfonso (Contemporary Engineering SciencesBulgaria, 2018-08-18)

In order to improve the learning process about the unit operation of Liquid Extraction, it is presented a GUI in Matlab® for designing extracting systems with different types of contact, where the stages reach the ...

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Application of LEAN tool "line balancing" to determine the productivity of workforce in activities of plastering and internal detailing in two-story houses made of masonry
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Hurtado-Figueroa, Oswaldo | 2018-11-26

The finishing work of construction represents an aggregated value that makes the difference when a client is deciding to buy a house. The stipulated costs for plastering and detail activities for houses, in occasions, surpasses 30% of the total value of the construction work, considerable costs that require constant control and supervision both in the analysis and the execution of the construction. The implementation of the LEAN philosophy in this activity is not commonly implemented due to the lack of knowledge of the tools that this method provides. This research shows the implementation of line balancing, as a LEAN tool, in the plastering and detailing activities for two-story masonry houses, constructed in the housing project Callejas del Este which took place in the city of Cucuta, Colombia. The implementation of this tool contemplated the analysis of execution times of the work crew, the results were synthesized in tables for better interpretation and conclusions of interest were developed for the improvement of the observed processes and activities.

LEER
The architecture on land and its construction techniques, millenary tradition that is reborn
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Hurtado-Figueroa, Oswaldo | 2018-08-30

In the context of sustainable development, the use of materials of low environmental impact in the activities inherent to the construction of houses plays an important role when it comes to reducing waste pollution. The alternative materials to be used in the various construction processes, besides being totally renewable, they must be reusable, available locally and have little or no energy expenditure in its extraction, preparation and application. The Bio resources or Eco materials meet these requirements, of which land as ancestral material used in millenary construction techniques, it becomes the most feasible alternative for its use as a construction material to replace the conventional ones. The main objective is the literary review of articles published in reliable databases, whose research topic was based on the analysis and use of land and natural materials for application in housing construction. The articles were categorized, analyzed and integrated into a synthesized structure to extract the important aspects in the thematic introduction, the constructive techniques, the results of the processes carried out and finally, the conclusions on the constructive implementation of the elements studied. In this way it offers information of interest to people who want to delve into the subject investigated.

LEER
CFD study of industrial safety valves in a virtual environment with OpenFOAM® software
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Rojas Suárez, Jhan Piero | 2020-11-30

Numerical advances in the numerical analysis of safety valves have enabled the development of approximated predictions related to the hydraulic behavior of turbulent flows, which influence the mechanical behavior of the main components coupled to the pneumatic system. Therefore, many studies have focused on the numerical analysis of the safety valves responsible for maintaining the system integrity subject to high-pressure values under real working conditions in a virtual and inexpensive environment through the CFD codes application with OpenFOAM software. Therefore, this paper is based on the technological prediction of the laminar or turbulent flows into a safety valve through the solution of the partial differential equations system, which describes the physical state of the pressure and mass flow rate in space and time. IcoFOAM solver has been applied to model the main flow fluctuations taken, considering the mean values of the pneumatic system. A mesh independence study has been used to compute and define the finite number of nodes and cells that discretize the continuous computational domain of the internal flow and generate an approximated numerical prediction of the safety valve performance, maintaining a low computational cost during the iterative solution of the conservation equations developed with computational tools. In this sense, the RANS KEpsilon approach has defined a high prediction of the turbulent flow behavior in a virtual environment with an error rate close to the 2 percent value between the numerical and the experimental models. This research shows a good agreement in the understanding of the physical phenomena with the computational tool application based on advanced theories of thermal and fluid mechanics sciences in a virtual environment.

LEER
Comparative analysis of supercritical CO2 Brayton cycles with simple and partial cooling configurations
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Cárdenas-Gutiérrez, Javier Alfonso | 2020-09

The theoretical analysis of the thermodynamic cycles and the physical processes that occur in a cyclical way has improved the knowledge needed to improve the energy efficiency and the performance of the energy transfer systems in science and engineering. Power generation, cooling, and heating processes are improved by means of numerical methods to study the thermodynamic changes of flows involved in the energy transfer between mechanical devices coupled in industrial processes. Taking into account the growing concern in the recent years for the developing of the new power production schemes related to the steam or gas flows applied to non-conventional sources like solar radiation, residual heat production, wind energy, and, biomass combustion, this paper proposes a thermodynamic analysis of supercritical carbon dioxide (S – CO2) Brayton cycle considering new alternatives of power generation in order to satisfy the elevated energy demand with the improvement of the physical parameters simulated in the thermodynamic model. The first and the second laws of thermodynamics are computed in the mathematical algorithm applied in order to solve the steady-state of the flow pressure and the heat transferred during the power production under different working conditions. The simple and partial cooling configuration is studied in this research considering the less complex features of the supercritical carbon dioxide cycle with the aim to validate the prediction of the mathematical algorithm applied with MATLAB software and verify the improvement of the thermodynamic configuration proposed in this research. A good agreement has been reached during the numerical validation of the model with an error rate of less than 2 percent between the numerical data analyzed with a computed model.

LEER
A comparative study of the energy, exergetic and thermo-economic performance of a novelty combined Brayton S-CO2-ORC configurations as bottoming cycles
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Cárdenas-Gutiérrez, Javier Alfonso | 2020-07-14

This paper presents a comparative study on the energy, exergetic and thermo-economic performance of a novelty thermal power system integrated by a supercritical CO2 Brayton cycle, and a recuperative organic Rankine cycle (RORC) or a simple organic Rankine cycle (SORC). A thermodynamic model was developed applying the mass, energy and exergy balances to all the equipment, allowing to calculate the exergy destruction in the components. In addition, a sensitivity analysis allowed studying the effect of the primary turbine inlet temperature (TIT, PHIGH, rP and TC) on the net power generated, the thermal and exergy efficiency, and some thermo-economic indicators such as the payback period (PBP), the specific investment cost (SIC), and the levelized cost of energy (LCOE), when cyclohexane, acetone and toluene are used as working fluids in the bottoming organic Rankine cycle. The parametric study results show that cyclohexane is the organic fluid that presents the best thermo-economic performance, and the optimization with the PSO method conclude a 2308.91 USD/kWh in the SIC, 0.22 USD/kWh in the LCOE, and 9.89 year in the PBP for the RORC system. Therefore, to obtain technical and economic viability, and increase the industrial applications of these thermal systems, thermo-economic optimizations must be proposed to obtain lower values of the evaluated performance indicators.

LEER
Computational fluid dynamics analysis of combined cycle power plant heat exchanger with OpenFOAM® software
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Cárdenas-Gutiérrez, Javier Alfonso | 2020-10

The heat exchangers application in combined cycle power plants is a key aspect in the thermal and fluid mechanics sciences due to their elevated functionality in industrial processes related to the quality and the efficiency in the power generation. Heat exchangers are employed in thermal processes in order to remove a significant heat flow and to maintain temperature values under different working conditions. Taking into account the above, numerical methodologies have been developed with the aim to study and analyze the heat exchanger performance based on the thermal states of its physical values in space and time. Experimental methods may be applied to create models and describe the flow behavior in function of mass flow rate, pressure, and flow temperature in different measure points of the finite volume. However, it is necessary to apply numerical methods linked to computational tools in order to generate a high flow description into the heat exchanger under real working conditions. Therefore, this paper proposes a numerical analysis of the flow transported into a heat exchanger with computational tools to predict its performance under real Combined Cycle Power Plant conditions through a virtual environment. Random number generator KEpsilon turbulence model and Eulerian – Eulerian multiphase model is coupled in a Computational Fluid Dynamics code to solve the system of the partial differential equations which describes the flow behavior and heat transfer into the heat exchanger, and numerical results have been compared against the experimental model in order to verify the flow prediction of the simulation methodology employed in this particular case. The good agreement reached between the models defines an inexpensive way to evaluate and optimize the heat exchanger performance by means of OpenFOAM software.

LEER
Determination of the quality of coarse aggregates for the elaboration of concrete mixes from 3 water sources in the City of Cucuta-Colombia
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Hurtado-Figueroa, Oswaldo | 2018-12-07

A comparative analysis was performed on the mineral material extracted from 3 water sources in the city of Cucuta, from the rivers Tachira, Pamplonita and Zulia to determine the viability of their incorporation in the concrete mixtures for the construction of rigid floors. There were visits to the companies Preconcretos Trituradora la Roca y Concretos, and Tirurados, in charge of the material extractions, where samples of the crushed material "coarse aggregate" from each of the water sources were taken respectively. The granulometry of the coarse aggregate was performed according to the arranged parameters in the NCT 174 whose results were determinant for the conclusions. The trial of degradation to abrasion to each of the samples was executed, taking as guide the indications described by the Colombian INV-218-13 standard. The results obtained in the trial were analyzed and compared with the parameters stipulated by the INV standard described for the % of the degradation limit allowed for coarse aggregate for its usage as concrete material in the construction of rigid floors. It was concluded that each of the extracted materials from the water sources were viable according to the data obtained from their comparison.

LEER
Las estructuras industrializadas como elemento innovador bajo el contraste de las percepciones de los ingenieros
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Cárdenas-Gutiérrez, Javier Alfonso | 2020-04

The objective of the research was to make known the experiences of calculating engineers in the face of the behavior of industrialized buildings in earthquakes of great magnitude in the departments of Santander and Norte de Santander, Colombia. This industrialized construction system for houses was taken as object of study due to its novel implantation in the departments. The planning, execution and application of the 2010 seismic standard applied in Colombia in the field of building construction was analyzed. In addition to the field experiences of the professionals and university professors of both departments, the research was based mainly on the technical knowledge of the specialists. These two characteristics were taken into account due to the absence of information on the structural behavior under earthquakes of great magnitude of the buildings constructed with the system in the departments. The interpretative method was used with the support of the computer-assisted qualitative analysis program ATLAS.ti, which allowed the association of codes through the relationships of the interviews. The results concluded in the feasibility of implementing the system as a method of construction of buildings resistant to earthquakes of great magnitude subject to strict monitoring of the parameters described in the relevant regulations for the country, however the information provided is of great importance for individuals and contractors in the construction area in Colombia, since the expert engineers in calculations have some contradictions as for the industrialized system, and this can be factor of incidences in the response to earthquakes of these buildings, it is for that reason that the information revealed is a novelty to take into account the types of systems that calculate them the same but really have many structural differences and this could be a key element in an earthquake of great magnitude.

LEER
Exergy, economic, and life-cycle assessment of orc system for waste heat recovery in a natural gas internal combustion engine
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Valencia, Guillermo | 2020-01-01

In this article, an organic Rankine cycle (ORC) was integrated into a 2-MW natural gas engine to evaluate the possibility of generating electricity by recovering the engine’s exhaust heat. The operational and design variables with the greatest influence on the energy, economic, and environmental performance of the system were analyzed. Likewise, the components with greater exergy destruction were identified through the variety of different operating parameters. From the parametric results, it was found that the evaporation pressure has the greatest influence on the destruction of exergy. The highest fraction of exergy was obtained for the Shell and tube heat exchanger (ITC1) with 38% of the total exergy destruction of the system. It was also determined that the high value of the heat transfer area increases its acquisition costs and the levelized cost of energy (LCOE) of the thermal system. Therefore, these systems must have a turbine technology with an efficiency not exceeding 90% because, from this value, the LCOE of the system surpasses the LCOE of a gas turbine. Lastly, a life cycle analysis (LCA) was developed on the system operating under the selected organic working fluids. It was found that the component with the greatest environmental impact was the turbine, which reached a maximum value of 3013.65 Pts when the material was aluminum. Acetone was used as the organic working fluid.

LEER
Exhaust gas heat exchanger design based on the engine backpressure and heat rate criteria
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Cárdenas-Gutiérrez, Javier Alfonso | 2020-10

The use of shell and tube heat exchangers for waste heat recovery has shown excellent results in increasing engine performance, as well as offering a large surface area for small volumes, ease of cleaning, good mechanical layout, and well-known design procedure. This article presents the modeling of the coupling circuit and thermo-fluid design of the heat exchangers in the thermal oil circuit in order to maximize the heat transfer of this equipment at the lowest pressure drop and acquisition cost, which is obtained with a smaller heat transfer area. The research results show the existence of optimal values for the studied system parameters, type of organic working fluid, type of heat exchangers, besides the size of the other system components, which are particular for the studied application. However, these results cannot be compared with the real projects already implemented in the industry due to their absence. It has been verified that the fluids that have showed the best performance in terms of thermal efficiency have been acetone and benzene, with an overall thermal efficiency of 17% and 15%, respectively.

LEER
Experimental and CFD characterization of the jacket vessel heat transfer process
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Cárdenas-Gutiérrez, Javier Alfonso | 2020-10

Heat exchange processes are widely applicable in industry and research. The process of design and optimization of these types of devices is of particular interest, since they generate a high rate of exergy destruction. In this study, a correlation between the data presented by the OpenFOAM® software computer model of the assembly of a jacketed vessel heat exchanger has been made. The influence of the overall heat transfer coefficient on the temperature profile and the relationship between Reynolds number and the heat yielded by hot water have been studied. It has been concluded that the theoretical-experimental model has an analogy with the CFD one, which has showed an admissible error of 9.3% for different volumetric flows in relation to the overall heat transfer coefficient and temperature. Therefore, it shows a significant advantage in the use of the computational model to find a correlation with the experimental data. Additionally, the cost of experimentation can be reduced using computational tools.

LEER
Failure analysis methodology in industrial control valves using quality function
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Rojas Suárez, Jhan Piero | 2020-11-30

Quality control methodologies and improvement methods have been applied to the process management in order to develop a set of fault diagnosis practices during the industrial operation of mechanical components in production lines. These practices are based on the reliability concept, which defines the failure probability due to the building or design processes and maintenance activities. In this sense, a quality methodology may be considered a powerful tool employed to determine the main causes of the recurring failure events associated with the downtime cost and the material losses during the industrial production. A quality function development may be conformed by four main phases: scheme design, components definition, engineering and quality control, and manufacturing work order. Taking into account the above, this paper proposes a quality function deployment method in order to define the appropriate control parameters, which define the needs of the specific production processes related to the functionality of the mechanical devices or the minimal requirements where inspection, test specifications, and failure diagnosis are developed. In this sense, this paper purposes a quality function development methodology in order to analyze the failure analysis of the pressure–control valve implemented in a hydraulic system to verify the possible causes of non-conformity and to define a set of alternatives that improve the production process. This decision-making problem has been based on two steps: strategic and operational terms, where each point has been resolved to define a successful development of this quality control methodology. The qualitative assessment of this particular study identifies a containment loss of the pressure-control valve used to maintain the reactor oil level in the hydraulic system.

LEER
Gestión del capital intelectual en la dirección de programa de ingeniería civil de la Unefa núcleo Táchira
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barrientos, ender jose | 2020-12-17

La gestión de intangibles en las organizaciones es un activo que está siendo perdido por organizaciones pequeñas y medianas, es por ello que el propósito de esta investigación fue describir las experiencias de los actores principales de la universidad de la Fuerza Armada región occidente que abarca tres estados de Venezuela, y poder conocer sus realidades en cuanto a la gestión que vienen llevando y que está pasando actualmente con la gestión intangible en las direcciones de programa de ingeniería civil, esto por medio de una investigación bajo el paradigma interpretativo con apoyo de la investigación descriptiva y de campo, el trabajo se realizó por medio de entrevistas a profundidad y categorizadas por el programa Atlas Ti. Entre los resultados más importantes se develaron la perdida de este valioso activo y fundamentos de la administración tradicional en todas sus gestiones, y siendo una casa de estudios que se debe generar y promocionar el conocimiento tienen debilidades sobre este tipo de gestión que brinda competencias competitivas a la organización.

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Handling of concrete with addition of residual ceramic material in different % replacing conventional stony aggregate
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Hurtado-Figueroa, Oswaldo | 2018-11-26

A conventional concrete mixture elaborated according to the parameters described in the Colombian Technical Standards NTC under the conditioning established by the Quake Resistant Standard NSR-10 that regulates our country. A residual ceramic sample was taken from elements of masonry and tiles from the brick industry Santa Rosa, the obtained material was taken to the crusher La Victoria, where the milling process and reduction of particles was performed as well as to the conventional mineral aggregates. The granulometry was performed to the coarse aggregate of the crushed ceramic material according to the NTC-77, simultaneously the respective test to determine its physical properties according to the stipulated by the same standards were performed. Designs of experimental mixtures were made, 10, 20-100% of the weight of the conventional concrete coarse aggregate was replaced by its equivalent in ceramic coarse aggregate. To the designs of both conventional and experimental mixtures, the test of concrete setting was performed with the help of the concrete slump test to determine its handling. The results obtained by the test performed to the different mixtures were portrayed in a table, were the obtained data for the conventional concrete mixture was used as a comparative base for the rest of the data.

LEER
Implementation of hospital waste replacing stony aggregates in non-structural concrete mixes of low resistance
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Hurtado-Figueroa, Oswaldo | 2018-11-29

A non-structural concrete mix was elaborated with a resistance of 14.5 Megapascals under the parameters indicated in the American Concrete Institute (ACI), ASTM and the Colombian Technical Standards (NTC). Six mixing cylinders were made with the concrete mix to test their mechanical resistance using the compressive resistance test, 3 were tested on day 7 and the 3 left were tested on day 28, the tests were performed in the IBERFEST machine, located in the laboratory of resistance of materials of the University Francisco de Paula Santander in the city of Cucuta, Colombia. The results were averaged to obtain the data of interest. Hospital solid waste was treated and processed in the Ecosteryl machine 250C, located in the environmental technology park Guayabal, Cucuta. The processes for the treatment of the waste material were performed under the established procedures in the Colombian decree 2676 of 2000. Taking particles, no bigger than 20mm of waste material, 2.5, 5 and 7.5% of the total stony aggregate used for the elaboration of the non-structural concrete was replaced, each of the 3 percentages were used for the elaboration of the 6-cylinder mixes (2 of each). The cylinders were tested on days 7 and 28 using the same procedure implemented to the mix of non-structural concrete. With the data obtained from the tests a comparative analysis was performed, identifying the presented characteristics of each.

LEER
Incidence of the lean philosophy construction in the productivity and analysis of processes in internal finishes in masonry living quarters in the construction projects: case-residential complex Callejas-Cucuta-Colombia
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Hurtado-Figueroa, Oswaldo | 2018-08-30

The technical supervision in the construction projects is of special importance for the correct execution of the activities, its objective is to reduce the errors that are incurred when carrying out the processes inherent to its development. The finishes, as a final stage in the construction of homes, generate visual appeal to customers by encouraging their option of purchase. However, the costs contemplated in this stage are important in the budget. Defining an efficient work method helps improve the completion time of the activity by promoting compliance with the schedule stipulated for the project, together with the improvement of profitability for the contractor. The present work applies some tools of the Lean Construction philosophy of the two methods implemented in the application of the coating and detailing or final finishing for houses built in masonry, through continuous observation, using the balance sheet tools, the Last Planner system with the weekly schedule and lines of balance for the programming of activities. From these measurements, time-operator relationships were obtained, which sought to identify productive, contributory and noncontributory activities that affect productivity in the development of the project, reaching conclusions that maximize productivity, reducing activities that do not generate value to the Project.

LEER
Influence of natural frequency on stability during milling of inconel and udimet 500
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Coba Salcedo, Milton Fabian | 2018-09-18

Chatter in the machine tools represents one of the biggest problems due to the instability in the machining process, breakage of the tool and accelerated wear of the tool and spindle or machine components in the metal cutting processes, such as turning, milling, boring, drilling, etc. Which translates into a poor-quality surface finish, this phenomenon consists of self-excited vibrations that are produced and maintained due to shear forces, the purpose of this article is to predict the optimal points of operation in the milling process for Ni-based Inconel and make a comparison with Ni-based Udimet 500 through observation supported by a graphical and analytical tool to generate stability lobe diagrams, a code was developed in the MATLAB® software capable of generating stability lobe diagrams for the milling operation that provides optimal operating points to avoid tool vibration, thus improving chip removal rates and increasing productivity.

LEER
Influence of water/cement ratio on mechanical strength of concrete with partial addition of fly ash and hydrated lime
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Cárdenas-Gutiérrez, Javier Alfonso | 2019-11-29

Three mixtures were made for conventional concrete with different additions of cement, 300 kg/m3, 350 kg/m3 and 400 kg/m3, being these the 3 designs of mixtures more used for the elaboration of simple concretes. For each of the conventional mixtures, the % of water used for mixing was varied, which constituted 60%, 65% and 70% of the weight of the cementitious material. These % were taken in gradual increase to the one traditionally used in each of the mixing designs made. The aggregates used were assigned by Transmateriales S.A, located in the city of San José de Cúcuta, Colombia. The analysis of the materials of the mixtures, were carried out under the standards of the "Normas Tecnicas Colombianas" and the Tests of the "Instituto Nacional de Vías". 40% of the concrete mix cementitious material was replaced by fly ash and hydrated lime. In order to determine the mechanical behavior of the mixtures resulting from partial addiction. The ash was collected from the thermoelectric Termotasajero S.A, located in the city of San José de Cúcuta, Colombia. The hydrated lime was recovered from the municipality of Malaga located in the department of Santander, Colombia. Of the % of cementitious material replaced, 30% corresponded to lime and 70% to ash, as an experimental basis for the production of unconventional mixtures. Having the % of cementitious material to replace and the % of substitute material, 3 designs of experimental mixtures were made taking as base each one of the designs of conventional mixtures made, with equal % of water for its mixing. Twenty-seven cylinders were manufactured for the experimental mixtures and the same number for conventional mixtures, a figure that corresponded to the production of 3 specimens per % of water added in each of the established mixture designs. The compressive strength of the cylinders made in the materials resistance laboratory of the Universidad Francisco de Paula Santander, San José de Cúcuta, Colombia was tested. It was concluded in the influence of the % of water in the mechanical resistance of the experimental mixtures and the viability of the use of this type of mixtures in the elaboration of nonstructural concretes, data of importance with which the construction costs would be reduced considerably, generating in turn, a positive environmental impact by means of the inclusion of residual materials in the concrete mixtures.

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An integral PEST study of biomass as energy resource
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Mendoza Cassere, Daniel | 2018-08-18

The present work was carried out in order to evaluate the world's scientific production with respect to the topic of biomass, based on articles published from 2007 onwards. The data were obtained from the Web of Science data collection, and analyzed, through the HitsCite metadata processor, within which indicators were highlighted, such as the number of total publications, the countries that publish the most, in different periods of years, to establish the trend graphically and in the future, to be able to predict the behavior that will occur. The results show that of the 874 articles published to date, 168 were published by the United States, which is equivalent to 19.2%, followed by China, Italy and finally the United Kingdom with 65 articles published (7.4%), 64 articles (7.3%) and 56 articles published (6.4%) respectively. In addition, a PEST analysis was developed to analyses the behavior of the number of publications in relation to the political, economic, social and technological fields for each country studied, in order to be able to create means of prediction in the future.

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Mass transfer simulation of liquid-liquid extraction systems using an educational software
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Roncallo, Gian Franco | 2018-08-18

In order to improve the learning process about the unit operation of Liquid Extraction, it is presented a GUI in Matlab® for designing extracting systems with different types of contact, where the stages reach the equilibrium between both liquid phases. The program called ExtractING is an application of theoretical studies and material balances presented in highly relevant documents and popular academic books, which has a general procedure that initiates by introducing feed and solvent quantities with their respective compositions, and a raffinate exit condition for multistage equipment. It is necessary to introduce the ternary system (solute, dissolvent, diluent) and an operating temperature to calculate equilibrium conditions with Van Laar activity model equations. Material balances, multiple iterative routines, and equilibrium diagrams were used to calculate raffinate and extract conditions in all the stages as well as the minimum number of stages needed for the required separation allowing the user to get the approximate size and cost of the equipment, making this software a powerful academic tool. With the program, it was compared the maximum separation for specified conditions between counter-current and crosscurrent equipment, the separation percentage behavior with an increasing feed quantity, and the separation behavior with variations of temperature.

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