Now showing items 1-20 of 28

Analysis and optimization for the process of glass tempering using autoclave

Acevedo Peñaloza, Carlos Humberto; VALENCIA OCHOA, GUILLERMO ELIECER; CARDENAS ESCORCIA, YULINETH DEL CARMEN (Journal of Physics: Conference SeriesEstados Unidos, 2018-12-07)

A mathematical analysis of the glass tempering process was carried out using an autoclave, varying the operating parameters of the system. It was found that the process time can be reduced by up to 3.23% by changing the ...
Applied Bibliometric in the Advancement of Solar Energy Research

Torres Moreno, James; Acevedo Peñaloza, Carlos Humberto; Coba Salcedo, Milton Fabian (International Journal of Energy Economics and PolicyDubai, United Arab Emirates, 2022-07-19)

Bibliometrics has proven to be an efficient method for quantitative research on the statistical behavior of academic production, which allows analyzing existing data and documents to resolve trends in specific research ...
Articulation of environmental management in projects of non-conventional energy sources in the Caribbean Colombian region

Acevedo Peñaloza, Carlos Humberto; VALENCIA OCHOA, GUILLERMO ELIECER; CARDENAS ESCORCIA, YULINETH DEL CARMEN (Journal of Physics: Conference SeriesEstados Unidos, 2018-12-07)

This work addresses an inclusion methodology based on criteria for the implementation of non-conventional energy sources and critical environmental factors for the licensing of the same, which is applied to the case study ...
Artisanal filter with geo-materials: a basic water treatment alternative for human consumption in marginal areas

Martinez Yanez, Daniela; PEDROZA ROJAS, ALVARO ORLANDO; Acevedo Peñaloza, Carlos Humberto (Contemporary Engineering SciencesBulgaria, 2018-11-29)

The article presents the design and development of filters (easy to implement in homes) that have the capacity to eliminate microorganisms and chemical substances; therefore, they act as handmade water purifiers. It ...
Behaviour of the contact trace in a cam-follower system when the displacement law has been designed using bézier curves

Acevedo Peñaloza, Carlos Humberto; Henao Leon, Diego; Rojas Suárez, Jhan Piero (Contemporary Engineering SciencesBulgaria, 2018-11-06)

The study shows the distribution of the contact trace in a cam - follower mechanism in which the Bézier curves of degrees 5, 7 and 9 have been used for the design of displacement of the follower. The equations that ...
Bibliometric study of state observer research applied to internal combustion engine

VALENCIA OCHOA, GUILLERMO ELIECER; Acevedo Peñaloza, Carlos Humberto; CARDENAS ESCORCIA, YULINETH DEL CARMEN (Journal of Physics: Conference SeriesEstados Unidos, 2018-12-07)

The present study was conducted to evaluate the worldwide scientific production related to observers applied to internal combustion engines by taking information from the Web of Science (WoS) database and taking the papers ...
Clay surface characteristics using atomic force microscopy

Acevedo Peñaloza, Carlos Humberto; Florez, Eder; García León, Ricardo Andres (Revista Facultad de Ingeniería Universidad de AntioquiaColombia, 2018-06-07)

The first component for the manufacture of masonry products used in construction is clay, which provides the plasticity that facilitates the molding and handling of the product. The second component is the feldspar in form ...
Coating of tricalcium phosphates by flame spray

Ferrer Pacheco, Martha Yasmid; García, I H; Rodríguez, L F (Journal of Physics: Conference SeriesInglaterra, 2019-11-29)

The metal alloys used for prostheses with high mechanical requirements are bioinerts, it means they have low integration with bone tissue, therefore, bioactive coatings are used in order to improve this integration. ...
A comparative study of the cutting parameter in milling process under different material

Acevedo Peñaloza, Carlos Humberto; Valencia, Guillermo; Coba Salcedo, Milton Fabian (Contemporary Engineering SciencesBulgaria, 2018-06-18)

In the present study, the incidence of the variation in feed rate per tooth and depth of cut for SAE 4340 alloy steel and SAE J431 steel castings was analysed and in which material this variation is most noticeable. For ...
Comparison of the radius of curvature in the cams which used in the displacement law beziér curves and cyclic and harmonic curves

Acevedo Peñaloza, Carlos Humberto; Daza Buitrago, Miguel; Prada Botia, Gaudy Carolina (Contemporary Engineering SciencesBulgaria, 2018-11-07)

The work shows the radius of curvature for different variations of the angle of rotation β and of the ratio of Ro/L, the study is shown for the case in which the laws of displacement of the cams have been designed by ...
Design of an automated cheese cutting machine prototype

Espinel Blanco, Edwin; Ardila Delgado, Armando; Acevedo Peñaloza, Carlos Humberto (Contemporary Engineering SciencesBulgaria, 2018-11-30)

This work describes each of the parameters for the design of a prototype of an automated machine to make cuts in different types of cheese, in cubic form and slices. Each mechanical and structural component is designed, ...
Determinación experimental de la formabilidad de láminas de acero SG295 mediante sus propiedades tensiles

CASADIEGO PERALTA, CLAUDIA LILIANA; Barbosa Jaimes, Jhon Erickson; García-Páez, Ismael H. (Revista Colombiana De Tecnologías De AvanzadaColombia, 2017)

En la presente investigación experimental se determinaron los límites de formabilidad de láminas de acero SG295 de 2.2 mm de espesor, las cuales son utilizadas en la manufactura de cilindros para gas. Se realizó inicialmente ...
Determination of correlation of compressive strength with maturity of concrete mixed with accelerator

Medrano, Carmen teresa; García-Páez, Ismael H.; Peña Rodriguez, Gabriel (Journal of Physics: Conference SeriesInglaterra, 2019-11-29)

The compressive strength of concrete mixtures with accelerator additives designed for structural elements with strength of 5000 psi was correlated with the maturity index of concrete at an early age. The design of the ...
Determination of the theoretical stress concentration factor in structural flat plates with two holes subjected to bending loads

Acevedo Peñaloza, Carlos Humberto; Rojas Suárez, Jhan Piero; Espinel Blanco, Edwin (Contemporary Engineering SciencesBulgaria, 2018-11-22)

Numerous research works have studied the stress distribution in sections with geometric discontinuities and the relationship with the theoretical factor of stress concentration using the finite element method. These works ...
Effects of Environmental Conditions on Photovoltaic Generation System Performance with Polycrystalline Panels

Mejía Ruiz, Saúl; Vanegas Chamorroa, Marley; Valencia Ochoa, Guillermo; Fábregas Villegas, Jonathan; Acevedo Peñaloza, Carlos Humberto (International Journal on Advanced Science Engineering and Information Technology, 2021-10-31)

Photovoltaic solar energy is the third most widely used renewable source worldwide, after hydroelectric and wind energy, and this energy source requires experimental and theoretical development in specific topics such as ...
Evaluation of the drinking water treatment system (STAP) San Fernando –Los Patios urbanization, Colombia. Efficiency and quality

castrillon jaimes, yusbely cecilia; Acevedo Peñaloza, Carlos Humberto; Rojas Suárez, Jhan Piero (Revista UIS IngenieríasColombia, 2020-08-26)

The quality of water for human consumption in the municipality of Los Patios in Colombia, depends 60% of the treatment systems for drinking water (STAP) independent, these are adapted according to the ...
Experimental study of the 2D variability roughness in the honing process of the steel cylinder

Acevedo Peñaloza, Carlos Humberto; Valencia, Guillermo; Coba Salcedo, Milton Fabian (Contemporary Engineering SciencesBulgaria, 2018-05-29)

This article presents the study of the surface roughness inside cylinders, machined by honing in industrial honing machines, with a detailed review of the variability of the values obtained in the measurement of the ...
Experimental study of the correlation the surface roughness 2D and 3D in the honing process of the steel cylinder

Coba Salcedo, Milton Fabian; Acevedo Peñaloza, Carlos Humberto; Valencia, Guillermo (Indian Journal of Science and TechnologyIndia, 2018-08)

Objectives: This research proposes the feasibility of working on surfaces obtained by honing with 2D roughness parameters, as the 3D roughness measurement commonly used in the industry requires many hours of measurement ...
Gerencia estratégica de proyectos: Aplicación del modelo de Constructibilidad

Ureña Villamizar, Yan Carlos; Cárdenas, Jairo Alberto; castrillon jaimes, yusbely cecilia (RespuestasColombia, 2018-07-28)

La presente indagación está dirigida a proponer estrategias gerenciales para la administración de proyectos de construcción, la cual se basa en un conjunto de conocimientos y experiencias que a lo largo del tiempo ha dado ...
In vitro study of the proliferation and growth of human fetal osteoblasts on Mg and Si co-substituted tricalcium phosphate ceramics

García-Páez, Ismael H.; de Aza, Antonio H.; Parra, Juan; Baudin, Carmen; Martín, M. Rocío; Pena, Pilar (Journal of Biomedical Materials Research Part AInglaterra, 2017-04-20)

The objective of this work was to study the feasibility of the solid state sintering, a conventional ceramic processing method, to obtain Mg and Si co-substituted tricalcium phosphate bioceramics and composites containing ...

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Analysis and optimization for the process of glass tempering using autoclave
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Acevedo Peñaloza, Carlos Humberto | 2018-12-07

A mathematical analysis of the glass tempering process was carried out using an autoclave, varying the operating parameters of the system. It was found that the process time can be reduced by up to 3.23% by changing the resistance to 15Ω, but increasing the resistance more than this value would mean compromising the quality of the final product. Thus, it is advisable to make variations of the resistance between 10Ω and15Ω, which will allow the optimization of the process time and pressures without affecting the quality of the result.

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Applied Bibliometric in the Advancement of Solar Energy Research
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Torres Moreno, James | 2022-07-19

Bibliometrics has proven to be an efficient method for quantitative research on the statistical behavior of academic production, which allows analyzing existing data and documents to resolve trends in specific research fields. Considering the database downloaded from Web of Science, with the help of Hitscite and VOSviewer data analysis tool and Microsoft Excel table, 7,259 publications related to solar energy research from 2010 to 2020 were obtained. The purpose of this research work is to apply bibliometric analysis methods to the development of scientific research on solar energy, as an important part of renewable energies, to evaluate its progress in the last decades and to describe these trends. The results showed that since 2015, research on solar energy has increased, especially in countries such as the United States and China, due to the Paris treaties where the goal is that the average temperature of the earth by the year 2100 does not exceed 1.5 °C. Since greenhouse gases are the cause of the greatest impact of the increase in global temperature, it is expected that researchers will focus on harnessing green energy and take a step further to reduce fossil fuels.

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Articulation of environmental management in projects of non-conventional energy sources in the Caribbean Colombian region
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Acevedo Peñaloza, Carlos Humberto | 2018-12-07

This work addresses an inclusion methodology based on criteria for the implementation of non-conventional energy sources and critical environmental factors for the licensing of the same, which is applied to the case study installation of wind turbines in seawater desalination plants in Isla Grande - Bolívar, this study was carried out taking into account field visits, and previous studies, where its main researchers and observers coincide with the authors of this article, the proposal includes aspects that involve the matrix of project stakeholders, work is completed with the qualitative and quantitative analysis of the factors of greater environmental impact, within the obtained results it is emphasized that the greatest impact that this project makes to 170 habitants of Isla Grande Bolivar is the changes of the current and/or potential use of soil, soil contamination and displacement of birds, In mammal, reptile and amphibian communities, it is suggested that Environmental Management Plans (PMA) be implemented, such as programs for conservation management, soil resource management, and vegetation and wildlife management programs, allowing for effective licensing of the project benefiting equally the interest group.

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Artisanal filter with geo-materials: a basic water treatment alternative for human consumption in marginal areas
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Martinez Yanez, Daniela | 2018-11-29

The article presents the design and development of filters (easy to implement in homes) that have the capacity to eliminate microorganisms and chemical substances; therefore, they act as handmade water purifiers. It constitutes a reasonable alternative solution to the problem of contaminated water consumption, which can be applied in places of low economic resources.

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Behaviour of the contact trace in a cam-follower system when the displacement law has been designed using bézier curves
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Acevedo Peñaloza, Carlos Humberto | 2018-11-06

The study shows the distribution of the contact trace in a cam - follower mechanism in which the Bézier curves of degrees 5, 7 and 9 have been used for the design of displacement of the follower. The equations that describe the movement of the follower and its derivatives are presented, the expressions are formulated for the contact trace, the force exerted on the mechanical assembly are formulated and the results obtained are presented in a model mechanism.

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Bibliometric study of state observer research applied to internal combustion engine
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VALENCIA OCHOA, GUILLERMO ELIECER | 2018-12-07

The present study was conducted to evaluate the worldwide scientific production related to observers applied to internal combustion engines by taking information from the Web of Science (WoS) database and taking the papers published between 2001 − 2017. The works found are mostly research articles with a total of 130 articles equivalent to 97.01%, of the 134 articles studied, and it was also noted that the production of this type of work increased in the last 3 years, with the maximum value in 2015 being 22 articles, even in those 3 years, the greatest number of references were also found. The United States is the country with the highest number of publications with 42 followed by People´s Republic of China, France and UK with 41, 11 and 11 respectively. Although the USA is the country with the highest number of publications, China has consolidated its position as the country with the highest number of publications and citations in the last 3 years. However, within the top 10 institutes with the highest number of publications, 4 of them are from the United States, among which Ohio State University stands out as the institute with the highest number of publications with 16 (11.9%). On the other hand, the most commonly used words in the documents were observer (91), control (47), engine (47), based (42) and estimation (41).

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Clay surface characteristics using atomic force microscopy
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Acevedo Peñaloza, Carlos Humberto | 2018-06-07

The first component for the manufacture of masonry products used in construction is clay, which provides the plasticity that facilitates the molding and handling of the product. The second component is the feldspar in form of alumina (Al2O3) which is used as flux. The third one is silica (SiO2) which is used as a filling material and stabilizer. These elements are determined by chemical composition using fluorescence analysis or X-ray diffraction, which is the basis of the modern classification of minerals. Thereby, the main objective of this research is to study the surface characteristics of clay samples from an industrial company producing H-10 blocks in the region of Norte de Santander, by studying the surfaces of the samples selected through the analysis by Atomic Force Microscopy, in order to compare the results with those found in the literature, and at the same time taking into account the chemical elements in their highest composition. The results show that this is a technique that allows the identification of clay components, thus validating what has been found in physical and chemical analysis, expecting to provide a scientific contribution by AFM, because there is little information related to the characterization topography of clay materials.

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Coating of tricalcium phosphates by flame spray
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Ferrer Pacheco, Martha Yasmid | 2019-11-29

The metal alloys used for prostheses with high mechanical requirements are bioinerts, it means they have low integration with bone tissue, therefore, bioactive coatings are used in order to improve this integration. Hydroxyapatite is one of the most studied materials for this application with good results, however, sometimes there are problems due to wear or tear of the coating leading prostheses loss. Tricalcium phosphate, Ca3(PO4)2, in its different phases shows osteoconductivity and higher solubility than hydroxyapatite, however, few studies have been carried out to determine its behavior as a coating for this type of applications. In this work, a study of the behavior of tricalcium phosphate as a coating on Ti6Al4V substrates obtained by flame spraying was carried out. As raw material were used tricalcium phosphate powders obtained by precipitation from calcium nitrate and ammonium phosphate dihydrogen solution, and subsequent calcination at 1,100°C. The Ca/P molar ratio obtained is 1.48 and the only present crystalline phase is beta -tricalcium phosphate. The coatings obtained have alpha tricalcium phosphate as only crystalline phase, they have compact morphology with low porosity and good wettability with the substrate, which is an index of good adhesion and good mechanical behavior. The transformation from beta- to alpha- tricalcium phosphate is product of the high temperatures used in the process, which are higher than 1,125°C where this transformation occurs.

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A comparative study of the cutting parameter in milling process under different material
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Acevedo Peñaloza, Carlos Humberto | 2018-06-18

In the present study, the incidence of the variation in feed rate per tooth and depth of cut for SAE 4340 alloy steel and SAE J431 steel castings was analysed and in which material this variation is most noticeable. For this purpose, the machining process studied was milling. This is a machining operation in which a workpiece is passed in front of a rotating cylindrical tool with multiple cutting edges. For this study, the feed rate per tooth and depth of cut were varied by 4 values each. The feed rate ranged from 0.002 mm to 0.008 mm and the depth of 2 mm to 8 mm found that for both parameter variations cutting speeds always decrease with increasing both feed per tooth and depth of cut and that feed per tooth and depth of cut significantly affect process costs.

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Comparison of the radius of curvature in the cams which used in the displacement law beziér curves and cyclic and harmonic curves
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Acevedo Peñaloza, Carlos Humberto | 2018-11-07

The work shows the radius of curvature for different variations of the angle of rotation β and of the ratio of Ro/L, the study is shown for the case in which the laws of displacement of the cams have been designed by Bézier curves and these results are compared with those obtained by harmonic and cyclic curves.

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Design of an automated cheese cutting machine prototype
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Espinel Blanco, Edwin | 2018-11-30

This work describes each of the parameters for the design of a prototype of an automated machine to make cuts in different types of cheese, in cubic form and slices. Each mechanical and structural component is designed, analyzed and calculated, with the implementation of a compression mechanism with power screw, simulating its operation in the SolidWorks Computer Aided Design (CAD) program, the equipment and accessories that constitute the control system for the automation of the prototype are selected, the programming of the Programmable Logical Control (PLC) in ladder language is carried out. Finally, the operation of the prototype is demonstrated through modeling and simulation with the use of the NI LabVIEW Softmotion module that allows integration with SolidWorks, making the application that involves some components of the prototype and controlling its movements from NI LabVIEW.

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Determinación experimental de la formabilidad de láminas de acero SG295 mediante sus propiedades tensiles
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CASADIEGO PERALTA, CLAUDIA LILIANA | 2017

En la presente investigación experimental se determinaron los límites de formabilidad de láminas de acero SG295 de 2.2 mm de espesor, las cuales son utilizadas en la manufactura de cilindros para gas. Se realizó inicialmente una caracterización química y un análisis metalográfico. Las propiedades mecánicas determinadas fueron la resistencia a la tracción, el límite elástico mediante la aplicación de ensayos de tracción (ASTM E 8M) y la ductilidad, la cual se determinó mediante el alargamiento hasta fractura. El índice de resistencia al angostamiento del material se midió con el ensayo ASTM E 517 que permite determinar el coeficiente de anisotropía, r. La capacidad del material para distribuir la deformación uniformemente se cuantificó mediante el coeficiente de endurecimiento por deformación, n, según la norma ASTM E 646. Los resultados muestran una ductilidad aceptable para un acero al carbono y un comportamiento anisotrópico adecuado para operaciones de embutido.

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Determination of correlation of compressive strength with maturity of concrete mixed with accelerator
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Medrano, Carmen teresa | 2019-11-29

The compressive strength of concrete mixtures with accelerator additives designed for structural elements with strength of 5000 psi was correlated with the maturity index of concrete at an early age. The design of the mixture was made by adding the quantity of additives according to the specifications of the supplier. The maturity index was calculated using the thermal profile of the concrete dependent of the setting time, which was obtained through an automated adiabatic system. The number of thermal sensors required for temperature measurement dependent of setting time (1, 3, 7, 14 and 28 days) was determined by a factorial experimental design of two factors. The correlation coefficient was 0.96, so the logarithmic model adequately explains the variability of the compressive strength. The equation obtained was validated by means of the values of resistance to compression measured by the standard method for each age of the concrete; all values are within the calibration range of the resistances estimated by the maturity method.

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Determination of the theoretical stress concentration factor in structural flat plates with two holes subjected to bending loads
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Acevedo Peñaloza, Carlos Humberto | 2018-11-22

Numerous research works have studied the stress distribution in sections with geometric discontinuities and the relationship with the theoretical factor of stress concentration using the finite element method. These works have dealt with topics such as the influence of the length of pieces on the 𝐾�𝑡� factor in rectangular orthotropic plates; The behavior of the stress concentration factor on short shafts with section changes under bending loads; The theoretical factor of stress concentration in flat parts subjected to tension with "U" grooves; The estimation of the theoretical stress concentration factor 𝐾�𝑡� for a flat plate with two holes subjected to tension loads. Other studies have compared the stress distribution by applying three methods: elasticity theory, finite element analysis and experimental techniques. Results show that the finite element method is effective in solving the problem. The goal of this research is to determine the theoretical stress concentration factor for a flat plate with two holes subjected to bending applying the finite element method. The modeling of the plate, the application of the loads, the mesh generation and the simulation of the stress distribution were made using the software ANSYS® Workbench. Four holes with different sizes were worked and for each of them 10 different values of the distance between centers were taken. In this way the relationship between the factor 𝐾�𝑡�, the size of the holes and the distance between centers was found. This information is of great importance for the design of mechanical elements that are under these conditions.

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Effects of Environmental Conditions on Photovoltaic Generation System Performance with Polycrystalline Panels
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Mejía Ruiz, Saúl | 2021-10-31

Photovoltaic solar energy is the third most widely used renewable source worldwide, after hydroelectric and wind energy, and this energy source requires experimental and theoretical development in specific topics such as the effect of environmental conditions on energy performance. Thus, this study's main objective was to determine the influence that meteorological conditions have on the performance of solar photovoltaic systems, based on measurements from a measurement station installed in the city of Barranquilla-Colombia, to determine the factors that significantly affect the system’s energy efficiency deviation. The experimental results show a dependence of the solar panel energy performance on some weather conditions, which is an uncontrolled phenomenon such as the ambient temperature and the atmosphere's humidity. Also, solar panel temperature and irradiance were the parameters with greater importance in the systems power generation. Also, the panel temperature must be controlled to obtain the desired response, because the panel temperature is inversely proportional to the voltage and directly proportional to the current. However, the negative effect of increased panel temperature in sunny climates is compensated by increased solar hours, so the summer system has less instantaneous efficiency, but it has higher solar output throughout the day. Therefore, solar energy production study should be related to total daily production.

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Evaluation of the drinking water treatment system (STAP) San Fernando –Los Patios urbanization, Colombia. Efficiency and quality
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castrillon jaimes, yusbely cecilia | 2020-08-26

The quality of water for human consumption in the municipality of Los Patios in Colombia, depends 60% of the treatment systems for drinking water (STAP) independent, these are adapted according to the population that conforms in 2014 and own resources. Urbanization San Fernando carries out the treatment in an efficient way guaranteeing the quality of water for human consumption, therefore, the field study is based on a quantitative approach and a method that describes the results of the analysis of the samples taken at the entrance and exit of the STAP, to evaluate the efficiency and quality of the system the sample is characterized from the analysis of the physical-chemical and microbiological parameters at the entrance and exit of the system in the Water Laboratory of the Universidad Francisco de Paula de Santander. The physical and microbiological results identify the efficiency of the system and the operator, indicating the quality of the water by the values in the parameters measured according to Decree 1575 of 2007 and 1525 of 2007 by the Ministry of Social Protection in Colombia. The chemical analyses detected a high percentage of calcium hardness in the sample at the system outlet, which is reportedto the directors of the urbanization. In accordance with this, the relevant controls and monitoring are carried out in the process for the purification and consumption of water, without neglecting the habits of water storage by the community in each home.

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Experimental study of the 2D variability roughness in the honing process of the steel cylinder
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Acevedo Peñaloza, Carlos Humberto | 2018-05-29

This article presents the study of the surface roughness inside cylinders, machined by honing in industrial honing machines, with a detailed review of the variability of the values obtained in the measurement of the machined surface. The determination of the amount of measurement data on the cover is displayed to get characteristic mean values of the measured surface. For this reason, and due to the randomness of the surfaces machined by honing, an experimental study has been proposed to carry out this analysis, where the roughness has been measured with a roughness meter with a contact probe, since this type of instrument is widely used academically and especially industrially, and is apparently standardized by international standards such as ISO 3274 or ASME B46.1.

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Experimental study of the correlation the surface roughness 2D and 3D in the honing process of the steel cylinder
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Coba Salcedo, Milton Fabian | 2018-08

Objectives: This research proposes the feasibility of working on surfaces obtained by honing with 2D roughness parameters, as the 3D roughness measurement commonly used in the industry requires many hours of measurement time. Methods/Statistical Analysis: In this article, we study the values of surface roughness in two dimensions and three dimensions measured inside cylinders, machined by honing in industrial honing machines. Hardness has been measured with a contact probe roughness meter, as this type of instrument is widely used in academic and especially industrial applications and is standardized in international standards such as ISO 3274 or ASME B46.1. Findings: It is concluded that due to the excellent association obtained, it is sufficient to work with adjustments in two dimensions to characterize the surface, since the roughness in three dimensions takes a long time to be measured with a contact roughness meter like the one used in this investigation, so 2D parameters can be used because due to their normal behavior, they offer competitive advantages due to their ease of determination and require shorter measurement times. Application/Improvements: Manufacturers of hydraulic cylinders, surface finish of the inner wall of internal combustion engines and all those applications where it is machined with honing.

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Gerencia estratégica de proyectos: Aplicación del modelo de Constructibilidad
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Ureña Villamizar, Yan Carlos | 2018-07-28

La presente indagación está dirigida a proponer estrategias gerenciales para la administración de proyectos de construcción, la cual se basa en un conjunto de conocimientos y experiencias que a lo largo del tiempo ha dado resultado de gran valor en el contexto dela Industria de la Construcción respaldando el potencial de ahorro de costos de los esfuerzos, el uso óptimo de los conocimientos y experiencia en la construcción, las operaciones de planificación, diseño y sobre el terreno para alcanzar los objetivos generales del proyecto, en este sentido el propietario y el contratista deben estar a la par en cuanto a información en la aplicación de la constructibilidad debido a que el contratista se enfoca más en las prioridades establecidas por el propietario y no en el impacto progresivo y efectivo del proyecto. Por cual se requirió del análisis documental y estandarización de los conocimientos que integran la gestión estratégica, como herramienta su utiliza la hoja de ruta de aplicación siendo la guía para la organización, perfeccionamiento y aplicación de la constructibilidad, implementada por las empresas en los proyectos de construcción, la cual comprende cinco etapas, entre ellas: comprometerse a implementar constructibilidad, establecer un programa de constructibilidad corporativa; obtener las capacidades de constructibilidad, implementación del plan constructibilidad y actualización del programa corporativo.

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In vitro study of the proliferation and growth of human fetal osteoblasts on Mg and Si co-substituted tricalcium phosphate ceramics
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García-Páez, Ismael H. | 2017-04-20

The objective of this work was to study the feasibility of the solid state sintering, a conventional ceramic processing method, to obtain Mg and Si co-substituted tricalcium phosphate bioceramics and composites containing diopside. A series of new Ca3(PO4)2 based ceramics has been prepared from attrition milled mixtures of synthetic Ca3(PO4)2 and CaMg(SiO3)2 powders, isostatically pressed and sintered at 1250–1300°C. Materials containing 0, 1, and 5 wt % of CaMg(SiO3)2 were constituted by β + α - Ca3(PO4)2 solid solutions while the material containing 60 wt % of CaMg(SiO3)2 was a constituted by β- Ca3(PO4)2 and CaMg(SiO3)2. The biological responses of the developed ceramics were studied in vitro using human fetal osteoblast cultures. Culture times ranged from 1 to 21 days. The new family of materials promotes the adhesion and proliferation of human osteoblasts cultured onto their surface forming a monolayer and showing a normal morphology. The results of the MTT and Alamar Blue assays showed that the soluble components extracted from the Mg/Si- co-substituted Ca3(PO4)2 and the Ca3(PO4)2-CaMg(SiO3)2 composite were noncytotoxic. The specimens with diopside exhibited a better in vitro behavior which is attributed to the release of Si and Mg ions to the culture medium, enhancing the activity of cells. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2266–2275, 2017.

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