Mostrando ítems 1-20 de 28

Processing and in vitro bioactivity of a β-Ca3(PO4)2-CaMg(SiO3)2 ceramic with the eutectic composition

García-Páez, Ismael H.; de Aza, Antonio H.; Peña, Pilar García; Baudin, Carmen; Córdoba Tuta, Elcy María; Rodríguez, Miguel A. (Boletín de la Sociedad Española de Cerámica y VidrioEspaña, 2016-02)

In this study, a dense bioactive ceramic, with nominal composition (wt.%) 40 Ca3(PO4)2–60 CaMg(SiO3)2, was prepared by solid state sintering of homogeneous compacted mixtures of fine synthetic Ca3(PO4)2 and CaMg(SiO3)2 ...
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 ...
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 ...
Síntesis en estado sólido y caracterización de fosfato tricálcico dopado con magnesio y zinc

García-Páez, Ismael H.; Ardila Melo, Reinaldo; Pinzón-Bedoya, Martha L. (Revista Latinoamericana de Metalurgia y MaterialesVenezuela, 2017-04-23)

El desarrollo de biocerámicas para aplicaciones estructurales está limitado debido a su baja tenacidad y resistencia. Estas limitaciones conllevan a investigaciones que buscan mejorar su rendimiento mecánico mediante dopado ...
Scientometric analysis of research on emissions control from 2007 to 2017

Acevedo Peñaloza, Carlos Humberto; Valencia, Guillermo; Cardenas Escorcia, Yulineth; Quiñones, Diego H.; Camargo Vanegas, Josué (International Journal of Applied Engineering ResearchColombia, 2018-01)

A scientometric analysis of the production of scientific publications on emissions control from 2007 to 2017 was carried out. HistCite was used to analyze information collected from Web of Science (WoS) on this topic during ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
Substitution of natural stony material aggregates in conventional 17.5 mpa non-structural concrete mixtures by means of percentage addition of hospital solid waste

Hurtado-Figueroa, Oswaldo; Cárdenas-Gutiérrez, Javier Alfonso; Acevedo Peñaloza, Carlos Humberto (Contemporary Engineering SciencesBulgaria, 2018-11-29)

An experimental character research was carried out. A conventional concrete mixture was made with the mechanical resistance to compression of 17.5 Mpa. The materials used in the concrete mixture were analyzed and selected ...
Principal stresses on the contact surface of a cam-tracker mechanism designed using Bézier curves

Acevedo Peñaloza, Carlos Humberto; Henao Leon, Diego; Prada Botia, Gaudy Carolina (Contemporary Engineering SciencesBulgaria, 2018-11-29)

The study exposes the variation of the main stresses in a cam mechanism with roller follower whose profile has been designed by means of Bézier curves. The contact theory for the cam case is proposed and the distribution ...
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, ...
PEST analysis of wind energy in the world: From the worldwide boom to the emergent in Colombia

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

This article presents the analysis of the political, economic, social and technological aspects of the countries with the greatest development and generation of wind energy in the world, with the aim of studying the successes ...
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 ...
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 ...

Envíos recientes

Processing and in vitro bioactivity of a β-Ca3(PO4)2-CaMg(SiO3)2 ceramic with the eutectic composition
...
García-Páez, Ismael H. | 2016-02

In this study, a dense bioactive ceramic, with nominal composition (wt.%) 40 Ca3(PO4)2–60 CaMg(SiO3)2, was prepared by solid state sintering of homogeneous compacted mixtures of fine synthetic Ca3(PO4)2 and CaMg(SiO3)2 powders. The results obtained by X-ray diffraction and field emission scanning electron microscopy with microanalysis indicate that the ceramic composite showed a fine grained and homogeneous microstructure consisting of diopside (CaMg(SiO3)2) and whitlockite (-Ca3(PO4)2ss) grains with very small amounts of apatite. The flexural strength and elastic modulus values of the composite are similar to those of cortical human bone. Bioactivity was experimentally evaluated by examining in vitro apatite formation in simulated body fluid (SBF). In addition, a simulation of the dissolution properties of the different phases present in the material in SBF was carried out by thermodynamic calculations, with the purpose of understanding the in vitro results obtained. The experimental results demonstrated that, during soaking in SBF, the grains of whitlockite dissolved preferentially than those of diopside, leaving a porous surface layer rich in diopside. Subsequently, partial dissolution of the remaining diopside occurred and the porous surface of the ceramic became coated by a bone-like apatite layer after 7 days in SBF. This bioceramic containing -Ca3(PO4)2 and CaMg(SiO3)2 is expected to be useful to fabricate scaffolds for bone repair

LEER
Determinación experimental de la formabilidad de láminas de acero SG295 mediante sus propiedades tensiles
...
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.

LEER
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. | 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.

LEER
Síntesis en estado sólido y caracterización de fosfato tricálcico dopado con magnesio y zinc
...
García-Páez, Ismael H. | 2017-04-23

El desarrollo de biocerámicas para aplicaciones estructurales está limitado debido a su baja tenacidad y resistencia. Estas limitaciones conllevan a investigaciones que buscan mejorar su rendimiento mecánico mediante dopado con elementos similares a los presentes en el hueso humano y a materiales que no generen reacciones o toxicidad, tales como: CO32--, SiO44- , Mg2+, Zn2+, F-, Cl-, Ag+, Na+ y K+. Dentro de este contexto, la presente investigación fue enfocada a la síntesis de fosfato tricálcico (TCP) dopado con iones magnesio Mg+ y zinc Zn+, mediante sinterización en estado sólido. La adición de los dopantes se realizó en forma de óxidos, así: M-1(1 wt% Mg, 1wt% Zn), M-4 (4 wt% Mg, 1 wt% Zn) y M-7 (7 wt% Mg, 1 wt% Zn), mediante mezcla y calcinación de las materias primas a 900 °C y posterior sinterización a 1200, 1300 y 1400 °C. La caracterización microestructural se realizó mediante Microscopía Electrónica de Barrido, MEB, y la composicional mediante difracción de rayos X, DRX y espectrometría de energía dispersiva, EDX. Se determinó que la fase mayoritaria en todos los casos fue β-TCP y que el cambio de la faseβ→α-TCP solo se presentó en la muestra M-7 sinterizada a 1400°C. Adicionalmente, se realizó un estudio del comportamiento in vitro en suero fisiológico artificial (SFA), donde se observó baja formación de apatita en la superficie durante la inmersión de 28 días. Finalmente, se realizó un estudio mecánico mediante el ensayo de compresión diametral en probetas de disco de diámetro 10,0 ± 0,3 mm y espesor 2,8 ± 0,2 mm, donde se observó un ligero aumento de la resistencia comparado con fosfatos comerciales.

LEER
Scientometric analysis of research on emissions control from 2007 to 2017
...
Acevedo Peñaloza, Carlos Humberto | 2018-01

A scientometric analysis of the production of scientific publications on emissions control from 2007 to 2017 was carried out. HistCite was used to analyze information collected from Web of Science (WoS) on this topic during this period. The results suggest that scientific publications in this field have steadily increased over the years during the last decade. China is the country with the highest number of publications, and the Chinese Academy of Sciences represents the institution with the highest number of publications. Most of the papers and citations came from developed countries. The top three journals with highest number of papers in this field are Applied Physics Letter, Atmospheric Environment, and Environmental Science & Technology.

LEER
Experimental study of the 2D variability roughness in the honing process of the steel cylinder
...
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.

LEER
Clay surface characteristics using atomic force microscopy
...
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.

LEER
A comparative study of the cutting parameter in milling process under different material
...
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.

LEER
Gerencia estratégica de proyectos: Aplicación del modelo de Constructibilidad
...
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.

LEER
Experimental study of the correlation the surface roughness 2D and 3D in the honing process of the steel cylinder
...
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.

LEER
Behaviour of the contact trace in a cam-follower system when the displacement law has been designed using bézier curves
...
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.

LEER
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 | 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.

LEER
Determination of the theoretical stress concentration factor in structural flat plates with two holes subjected to bending loads
...
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.

LEER
Artisanal filter with geo-materials: a basic water treatment alternative for human consumption in marginal areas
...
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.

LEER
Substitution of natural stony material aggregates in conventional 17.5 mpa non-structural concrete mixtures by means of percentage addition of hospital solid waste
...
Hurtado-Figueroa, Oswaldo | 2018-11-29

An experimental character research was carried out. A conventional concrete mixture was made with the mechanical resistance to compression of 17.5 Mpa. The materials used in the concrete mixture were analyzed and selected based on the parameters established in the Colombian Technical Standards and the ASTM International Standards. They were made 6 test cylinders with the mentioned concrete mixture to which, the compressive strength of the concrete was checked it, 3 of them 7 days after they were made and the rest of them 28 days later, respectively. Thereafter, their drying process by immersion, the data thrown by the tests were averaged and tabulated. The Hospital waste solid incinerated and treated by Ecosteryl machine which is located at Guayabal environmental technology park in Cucuta city was collected. The material resulting from the incineration and treatment of the hospital solid waste was selected taking only the particles equal to or less than 20mm resulting from the crushing process by Ecosteryl. With the selected Particulate material, 3 experimental mix designs were made, which 2.5, 5 and 7.5% of the total weight of the natural stone aggregates present in the conventional concrete mixture was replaced. With each experimental mixture made, 6 cylinders were tested at 7 and 28 days, a process carried out in the same way as that implemented in the conventional concrete mix for both tests and data collection and analysis. The comparative tables showed that the experimental mixture I, where 2.5% of the total weight of the aggregate of the conventional concrete mixture was replaced, was the one that obtained the highest compressive strength surpassing the result of the conventional concrete mixture.

LEER
Principal stresses on the contact surface of a cam-tracker mechanism designed using Bézier curves
...
Acevedo Peñaloza, Carlos Humberto | 2018-11-29

The study exposes the variation of the main stresses in a cam mechanism with roller follower whose profile has been designed by means of Bézier curves. The contact theory for the cam case is proposed and the distribution of the stresses throughout the cam turning cycle is presented, applied to an established study model.

LEER
Design of an automated cheese cutting machine prototype
...
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.

LEER
PEST analysis of wind energy in the world: From the worldwide boom to the emergent in Colombia
...
Acevedo Peñaloza, Carlos Humberto | 2018-12-07

This article presents the analysis of the political, economic, social and technological aspects of the countries with the greatest development and generation of wind energy in the world, with the aim of studying the successes and disadvantages over the years and serve as a reference to a country like Colombia, which is in full technological development and is very interested in investing in new alternatives to the imminent ecological disaster resulting from polluting emissions. Colombia signs the Paris Agreement and immediately creates a large number of opportunities supported by state policies and economic investment, specifically in the construction of wind farms that guarantee a real alternative to the country's energy demand. Wind energy supplies 5% of the world's electricity, a contribution in which countries such as the United States, China, and Germany are the main producers. For this reason, it is necessary to study and analyze the factors that prevent the technological development of wind energy in Colombia, if it is considered a country with abundant resources in renewable energy sources and zero cost, a country that aspires to be a protagonist in the next 5 years according to the Ministry of Mines and Energy.

LEER
Bibliometric study of state observer research applied to internal combustion engine
...
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).

LEER
Analysis and optimization for the process of glass tempering using autoclave
...
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.

LEER