Now showing items 1-20 of 93

Structure, mechanical and thermal behaviour of mixtures of polyester resin and dental ceramic waste

Peña Rodriguez, Gabriel; Moreno, J Dulce; Martínez Maldonado, L (Journal of Physics: Conference SeriesReino Unido, 2016-02-12)

The tensile strength and bending strength, structure and thermal behaviour of mixtures of polyester resin (P-2000) and powders (ASTM sieve 200, <75μm) of dental ceramic wastes (dentals impressions, alginate and gypsum) was ...
Quicklime as an alternative in the photodegradation of contaminants

Bautista-Ruiz, Jorge; Rincón Joya, Miryam; Raba Paez, Angela Mercedes (Journal of Physics: Conference SeriesEstados Unidos, 2016-02-12)

Chemical oxidation is one of the many different methods of removing contaminants that has emerged recently, is an alternative method to traditional techniques. According to this research calcium peroxide is suitable choice ...
Evaluation of micro-abrasion-corrosion on SiO2-TiO2-ZrO2 coatings synthesized by the sol-gel method

Bautista-Ruiz, Jorge; Aperador Chaparro, William Arnulfo; Caballero Gómez, J (Journal of Physics: Conference SeriesEstados Unidos, 2016-02-12)

The medical science and the engineering, work to improve the materials used in the manufacture of joint implants, since they have a direct impact on the quality of people life. The surgical interventions are increasing ...
Synthesis and characterization of the oxide nanoparticles obtained by the polymeric precursor method

Bautista-Ruiz, Jorge; Murillo, E; Raba, Angela Mercedes (Journal of Physics: Conference SeriesEstados Unidos, 2016-02-12)

Niobium pentoxide (Nb2O5) nanoparticles were prepared by the polymeric precursor method using citric acid as a chelating agent and ethylene glycol as a polymerizing agent. The powders obtained were characterized by X-ray ...
Effect of forming technique BixSiyOz coatings obtained by solgel and supported on 316L stainless steel

Bautista-Ruiz, Jorge; Aperador Chaparro, William Arnulfo; Olaya Flórez, J (Journal of Physics: Conference SeriesEstados Unidos, 2016-02-12)

BixSiyOz type coatings via sol-gel synthesized from bismuth nitrate pentahydrate, and tetraethyl orthosilicate as precursors; glacial acetic acid and 2-ethoxyethanol as solvents, and ethanolamine as complexing. The coatings ...
Pellet as a Technological Nutrient within the circular economy model: Compartive analysis of combustion efficiency and CO and NOx Emissions for pellets from olive and almond trees

molina, valentin; Leyva-Díaz, Juan Carlos; Sanchez Molina, Jorge (EnergiesSuiza, 2016-09-27)

This study analyzes the operation of Biomass System (BIO System) technology for the combustion of pellets from almond and olive trees within the circular economy model. Its aims are the reduction of greenhouse gas emissions ...
Synthesis and Structural Properties of Niobium Pentoxide Powders: A Comparative Study of the Growth Process

Bautista-Ruiz, Jorge; Rincón Joya, Miryam; Raba Paez, Angela Mercedes (Materials ResearchBrasil, 2016-10-10)

Powders Nb2 O5 were prepared by two different synthesis method, Sol-Gel and polymeric precursors (Pechini). In the Pechini method before adding the citric acid in the process, four different solutions were used to get the ...
Mineralogical characterization of zeolites present on basaltic rocks from Combia geological formation, La Pintada (Colombia)

Gelves Diaz, John Freddy; Sierra Gallego, G.; Marquez, M.A (Microporous and Mesoporous MaterialsAmsterdam , Paises Bajos, 2016-11)

The present study report the presence of natural zeolites, which were found in the andesitic basalts from the Combia geological formation, municipality of La Pintada, Antioquia department (Colombia). The collected samples ...
Estrategias para mejorar la productividad y competitividad de las empresas de calzado de Cúcuta

Monroy Sepulveda, Richard; Romero Arcos, Yebrail Alexis; Ramirez Delgado, Rosa Patricia (Espacios, 2017)

La presente investigación tiene como objetivo plantear estrategias para mejorar la productividad y competitividad de las empresas de calzado de Cúcuta. La población estuvo conformada por 32 empresas de calzado de Cúcuta, ...
Mechanical and tribological behavior of red clay ceramic tiles coated with fly ash powders by thermal sparying technique

Peña Rodriguez, Gabriel; Dulce Moreno, Hector Jaime; Daza Ramirez, Jessica Maria; Orozco Hernandez, Silvia Juliana; Vargas Galvis, Fabio (Journal of Physics: Conference SeriesInglaterra, 2017)

The mechanical and tribological performance of red clay ceramic tiles uncoated and coated by oxy-fuel thermal spraying process from fly ash powders was evaluated. The ceramic tile substrates were manufactured by uniaxial ...
Caracterización de cerámicos inmersos en soluciones del sistema sio2 – tio2 – zro2 sintetizadas por el método sol-gel

Sanchez Molina, Jorge; Rozo Rincón, Sandra Milena; Gelves Diaz, John Freddy; Bautista-Ruiz, Jorge (Revista UIS IngenieríasColombia, 2017-05-30)

Se presentan los resultados de la caracterización físico-cerámica, microquímica y estructural de muestras cerámicas de arcilla roja inmersas en soluciones de SiO2 – TiO2 – ZrO2 obtenidas por el método Sol-Gel utilizando ...
Production and structural, electrical and magnetic characterization of a composite material based on powdered magnetite and high density polyethylene

Garzón, Andrés; Landínez, David A.; Roa-Rojas, Jairo; Fajardo Tolosa, Fabio Enrique; Peña Rodriguez, Gabriel; Parra-Vargas, C.A (Revista De La Academia Colombiana De Ciencias Exactas, Físicas Y NaturalesColombia, 2017-06-30)

This work describes the production and characterization of a composite material based on magnetite filled HDPE, which is commonly known for its magnetic properties. Composites of this kind are used in different ...
Evaluación de arcillas caoliniticas-illiticas provenientes de la formación guayabo del Área Metropolitana de Cúcuta, Norte de Santander, Colombia

Cáceres, Vivianne Isel; Chaparro, Amanda; Sanchez Molina, Jorge (Revista IONColombia, 2017-07-28)

La caracterización de arcillas procedentes de la Formación Guayabo del Área Metropolitana de Cúcuta, Norte de Santander (Colombia) es presentada. Los resultados obtenidos de estos análisis permiten determinar las propiedades ...
Influence of raw materials and forming technique in the manufacture of stoneware ceramic

Alvarez Rozo, Diana; Sanchez Molina, Jorge; Gelves Diaz, John Freddy (Ingeniería Y CompetitividadColombia, 2017-09-15)

Se empleó material arcilloso y caliza proveniente de minas cercanas a la zona metropolitana de Cúcuta, así como el material de rotura después del proceso de cocción de productos cerámicos (chamota) para la conformación de ...
Biocompatibility of bismuth silicate coatings deposited on 316L stainless steel by sol-gel process

Bautista-Ruiz, Jorge; Olaya-Flórez, Jhon Jairo; Aperador Chaparro, William Arnulfo (Revista Facultad de IngenieríaColombia, 2017-09-25)

Bismuth silicate, (BSO) thin films have been fabricated by sol–gel process. The stable sol was synthesized by using bismuth nitrate (III) pentahydrate and tetraethyl orthosilicate (TEOS). The films were deposited by ...
Proposal to foster sustainability through circular economy based engineering: a profiteble chain from waste management to tunnel lighting

molina, valentin; Leyva Diaz, Juan Carlos; Sanchez Molina, Jorge; Peña García, Antonio Manuel (SustainabilitySuiza, 2017-12-02)

The increasing demands of infrastructures in terms of energy consumption, raw material demand, greenhouse gas emissions, waste management, treatment of components after their lifetime period, and financial costs are ...
Tribocorrosion Behavior of Amorphous Carbon-Silicon Coated Titanium in Biological Medium

Bautista-Ruiz, Jorge; Aperador Chaparro, William Arnulfo; Caicedo, J.C. (Tribology in IndustrySerbia, 2018)

Studies of materials in biomedical applications have focused on the generation of new biomaterials and the development of surface modifications, mainly of metals. Amorphous silicon containing diamond like carbon DLC-Si ...
Análisis de las propiedades físico cerámicas y efectos superficiales en un tipo de pasta cerámica, sometida a proceso de modelado mecanizado CNC por sustracción material, para la vinculación de un nuevo modelo de fabricación en la industria cerámica regio

Maldonado M, Alvaro E; Sanchez Molina, Jorge (Bistua Revista De La Facultad De Ciencias BasicasBogota , Colombia, 2018)

La investigación se desarrolla a partir del análisis superficial y físico cerámico en una pasta cerámica debidamente caracterizada; pasta atomizada que mediante proceso de extrusión se obtienen las muestras de arcilla que ...
Synthesis and corrosion resistance of SiO2-TiO2-ZrO2-Bi2O3 coatings spin-coated on Ti6Al4V alloy

Alférez Vega, Fabio Leonardo; Olaya, Jhon; Bautista-Ruiz, Jorge (Ceramics InternationalLondres , Inglaterra, 2018-02)

This report shows the synthesis and corrosion resistance of SiO2-TiO2-ZrO2-Bi2O3 coatings deposited by means of spin-coating on Ti6Al4V alloy. The sols were prepared from a mixture of organic precursors, tetraethoxysilane ...
Caracterización Anticorrosiva y de Biocompatibilidad en Recubrimientos Silicio-Titanio-Zirconio Sintetizados Vía Solgel y Depositados sobre Sustratos 316L

Bautista-Ruiz, Jorge (Informacion TecnologicaSantiago de Chile , Chile, 2018-02)

Se sintetizaron, los sistemas ternarios [Si/Ti/Zr: 10/70/20] y [Si/Ti/Zr: 10/20/70] vía sol-gel y se aplicaron sobre sustratos de acero inoxidable 316L mediante la técnica de inmersión. En los recubrimientos obtenidos se ...

Envíos recientes

Structure, mechanical and thermal behaviour of mixtures of polyester resin and dental ceramic waste
...
Peña Rodriguez, Gabriel | 2016-02-12

The tensile strength and bending strength, structure and thermal behaviour of mixtures of polyester resin (P-2000) and powders (ASTM sieve 200, <75μm) of dental ceramic wastes (dentals impressions, alginate and gypsum) was reported. The samples consisted of mixtures with percentage weights of 50-50%, 60-40%, 70-30%, 80-20%, 90-10%, where the resin was the majority phase, the Mekc (4% wt) was used as catalyst. The structure was studied using SEM and XRD, the thermal behaviour using DSC, TGA and DMA, while the mechanical strength was tested using standards ASTM D790 and D638. Irregular morphology and presence of small agglomerations was observed, with particle sizes between 29.63 and 38.67μm, the presence of different phases of calcium sulphate was found, and that to the increasing the concentration of the powder, the materials becomes more crystalline, increasing its density. An average service temperature of 69.15±4.60°C was found. Vickers hardness values are reported in ranges from 18.65 to 27.96. Considering the elastic modules was established that the materials become more rigid by having more powder concentration.

LEER
Quicklime as an alternative in the photodegradation of contaminants
...
Bautista-Ruiz, Jorge | 2016-02-12

Chemical oxidation is one of the many different methods of removing contaminants that has emerged recently, is an alternative method to traditional techniques. According to this research calcium peroxide is suitable choice for contaminant biodegradation in soil and ground water, but it happens at a very low speed. We hope that the method of synthesis of calcium peroxide in nano size by increased ratio of surface to volume can increase the speed of reaction and solve the problem. In the first synthesis of the material we obtained CaO instead of CaO2. Calcium oxide (CaO), commonly known as quicklime or burnt lime, is a widely used chemical compound in obtaining hypochlorite and to neutralize acidic soils. In this study we characterize the material by X-ray scanning electron microscopy, and ultraviolet-visible spectroscopy.

LEER
Evaluation of micro-abrasion-corrosion on SiO2-TiO2-ZrO2 coatings synthesized by the sol-gel method
...
Bautista-Ruiz, Jorge | 2016-02-12

The medical science and the engineering, work to improve the materials used in the manufacture of joint implants, since they have a direct impact on the quality of people life. The surgical interventions are increasing worldwide with a high probability of a second or even a third intervention. Around these circumstances, it was evaluated the behaviour against microabrasion-corrosion phenomena on SiO2 TiO2 ZrO2 coatings, synthesized by the sol-gel method with concentration of the Si/Ti/Zr precursors: 10/70/20 and 10/20/70. The coatings were deposited on AISI 316 LVM stainless steel substrates. The morphological characterization of the wear was made by AFM techniques. It was observed that the coatings with higher levels of titanium have a good response to the phenomena of microabrasion-corrosion.

LEER
Synthesis and characterization of the oxide nanoparticles obtained by the polymeric precursor method
...
Bautista-Ruiz, Jorge | 2016-02-12

Niobium pentoxide (Nb2O5) nanoparticles were prepared by the polymeric precursor method using citric acid as a chelating agent and ethylene glycol as a polymerizing agent. The powders obtained were characterized by X-ray diffraction and scanning electron microscopy. The results showed that the presence of HNO3, HCl or NH4OH in the employed aqueous solution favour the solubility of the used precursor salt, as well as also inside the oxide phase formation. The initial Nb2O5 powders were amorphous. The amorphous powders heated at 500°C contained Nb2O5 TT-phase, whereas at 650°C the Nb2O5 T-phase was obtained. In this way an increase in the synthesis temperature is related to the increase of the crystallinity, according to the values of the crystallite sizes that were estimated using the Scherrer method.

LEER
Effect of forming technique BixSiyOz coatings obtained by solgel and supported on 316L stainless steel
...
Bautista-Ruiz, Jorge | 2016-02-12

BixSiyOz type coatings via sol-gel synthesized from bismuth nitrate pentahydrate, and tetraethyl orthosilicate as precursors; glacial acetic acid and 2-ethoxyethanol as solvents, and ethanolamine as complexing. The coatings were supported on AISI 316L stainless steel substrate through dip-coating and spin-coating techniques. The study showed that the spin-coating technique is efficient than dip-coating because it allows more dense and homogeneous films.

LEER
Pellet as a Technological Nutrient within the circular economy model: Compartive analysis of combustion efficiency and CO and NOx Emissions for pellets from olive and almond trees
...
molina, valentin | 2016-09-27

This study analyzes the operation of Biomass System (BIO System) technology for the combustion of pellets from almond and olive trees within the circular economy model. Its aims are the reduction of greenhouse gas emissions as well as waste removal and its energy use by reintroducing that waste into the production process as technological nutrient. In order to do so, combustion efficiency under optimal conditions at nominal power was analyzed. In addition, a TESTO 350-XL analyzer was employed to measure CO and NOx emissions. High combustion efficiency values were obtained, 87.7% and 86.3%, for pellets from olive tree and almond tree, respectively. The results of CO and NOx emission levels were very satisfactory. Under conditions close to nominal power, CO emission levels were 225.3 ppm at 6% O2 for pellet from almond tree and 351.6 ppm at 6% O2 for pellet from olive tree. Regarding NOx emissions, the values were 365.8 ppm at 6% O2 and 333.2 ppm at 6% O2 for pellets from almond tree and olive tree, respectively. In general, these values were below those legally established by current legislation in European countries. Therefore, BIO System technology is a perfectly feasible option in terms of energy use and circular economy.

LEER
Synthesis and Structural Properties of Niobium Pentoxide Powders: A Comparative Study of the Growth Process
...
Bautista-Ruiz, Jorge | 2016-10-10

Powders Nb2 O5 were prepared by two different synthesis method, Sol-Gel and polymeric precursors (Pechini). In the Pechini method before adding the citric acid in the process, four different solutions were used to get the samples. For Sol-gel method, two different processes were also used in obtaining powders. The precursor was completely solubilized in ethanol and then hydrolyzed with ammonia and water. The calcination of the samples was between 500 and 750°C. The resulting powders were characterized by Scanning Electron Microscopy (SEM), Brunauer, Emmett and Teller (BET) surface area measurements, UV-visible and Raman spectroscopy. The formation of T−Nb2 O5 orthorhombic took place upon calcination at 7500C. Crystallite sizes were determined using the Scherrer method which resulted in an uniformed size of about 25 − 65nm. Ultraviolet-Visible diffuse reflectance spectroscopy indicated a variation in the optical band gap values (3.32-3.40 eV) in crystal growth process. The Raman vibrational modes indicate the presence of the orthorhombic phase of the material.

LEER
Mineralogical characterization of zeolites present on basaltic rocks from Combia geological formation, La Pintada (Colombia)
...
Gelves Diaz, John Freddy | 2016-11

The present study report the presence of natural zeolites, which were found in the andesitic basalts from the Combia geological formation, municipality of La Pintada, Antioquia department (Colombia). The collected samples were characterized using X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy with detector X-ray energy dispersive (SEM/EDX), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and polarized light optical microscopy (PLOM). The results shown the presence of an associated zeolites heulandite group with predominance of heulandite phase rich in calcium and potassium, with prevalence of platy habit and in a lesser extent the habit coffin type, tabular and block were also evidenced. The presence of chabazite, phillipsite and mordenite, were evidenced as minority zeolites phases. Based on the zeolites properties, the phases founded in Combia formation could be an interest materials for technological applications in areas such agriculture, catalysis or gas separation applications. Especially in Colombia this kind of mineral can be important because much of the current consumption is imported from other territories.

LEER
Estrategias para mejorar la productividad y competitividad de las empresas de calzado de Cúcuta
...
Monroy Sepulveda, Richard | 2017

La presente investigación tiene como objetivo plantear estrategias para mejorar la productividad y competitividad de las empresas de calzado de Cúcuta. La población estuvo conformada por 32 empresas de calzado de Cúcuta, que se encuentran actualmente funcionando (carácter legal). La elaboración de las estrategias partió de un análisis interno de la cadena de valor de las empresas de calzado de Cúcuta y posteriormente de un análisis externo, conformado por el análisis del diamante de PORTER, las 5 fuerzas competitivas y las fuerzas macroambientales, económicas, tecnológicas y ambientales. Se determinó la posición competitiva a través de la Matriz de Evaluación Interna-Externa. Desde la posición competitiva, se elaboraron las estrategias y los planes de acción para mejorar la competitividad y productividad.

LEER
Mechanical and tribological behavior of red clay ceramic tiles coated with fly ash powders by thermal sparying technique
...
Peña Rodriguez, Gabriel | 2017

The mechanical and tribological performance of red clay ceramic tiles uncoated and coated by oxy-fuel thermal spraying process from fly ash powders was evaluated. The ceramic tile substrates were manufactured by uniaxial pressing at 26.17 bar pressure, and sintered at 1100 °C. The coating thickness was determined based on the number of projection-cycles oxyacetylene flame over substrate. Coal fly ash coatings were deposited, with average thickness of 56.18±12.18 µm, 180.42±20.32 µm, and 258.26±25.88µm. The mechanical resistance to bending and wear by abrasion deep, were studied using ISO 10545-4 standards and ISO 10545-6 respectively; adhesion was measured using Elcometer equipment Type III according to ASTM D-4541-02 and the average roughness (Ra) was found according to ASTM standard D7127-13, using the profilometer Mitutoyo SJ 201. The surface morphology presented the heterogeneous molten or semi molten splats with average size of 35.262±3.48 micrometers with good adhesion, justifying increased mechanical resistance to bending by 5%, as well as wear by abrasion deep. These results contribute to the development of ceramic products with added value, to be used in various technological applications.

LEER
Caracterización de cerámicos inmersos en soluciones del sistema sio2 – tio2 – zro2 sintetizadas por el método sol-gel
...
Sanchez Molina, Jorge | 2017-05-30

Se presentan los resultados de la caracterización físico-cerámica, microquímica y estructural de muestras cerámicas de arcilla roja inmersas en soluciones de SiO2 – TiO2 – ZrO2 obtenidas por el método Sol-Gel utilizando tetraetil ortosilacato, tetrabutóxido de titanio y tetrabutóxido de zirconio. Las muestras cerámicas fueron elaboradas con polvos atomizados de arcilla roja, cocidas a 1000°C. Después de la cocción las cerámicas fueron inmersas en las soluciones en concentraciones en volumen 10/20/70: Si/Ti/Zr y 10/70/20: Si/Ti/Zr con tiempos de permanencia de 2, 4 y 6 minutos. Posterior al secado las muestras se trataron térmicamente a 600°C durante 60 minutos, a una velocidad de 2°C/min. Aspectos microquímicos y microestructurales de las muestras cocidas fueron establecidos mediante el uso de difracción de rayos X (DRX), espectroscopia de infrarrojo (FTIR) y detección de energías dispersivas de rayos X (EDX). Las propiedades tecnológicas evaluadas fueron la absorción de agua, densidad aparente y resistencia mecánica a la flexión. El estudio permitió establecer que las muestras inmersas en la solución 10/70/20: Si/Ti/Zr permiten incrementar la resistencia mecánica a la flexión. De igual manera se observó una ligera reducción del porcentaje de absorción de agua con este mismo tratamiento. El tratamiento con mayor presencia de zirconio no muestra cambios significativos respecto al patrón empleado (muestra sin inmersión)

LEER
Production and structural, electrical and magnetic characterization of a composite material based on powdered magnetite and high density polyethylene
...
Garzón, Andrés | 2017-06-30

This work describes the production and characterization of a composite material based on magnetite filled HDPE, which is commonly known for its magnetic properties. Composites of this kind are used in different applications such as microwave absorption, transducers and biomedical applications like drug delivery, organs tagging, etc. The samples were produced according to different volume ratios of magnetite and HDPE. The semiquantitative analysis conducted by XRD revealed the presence of hematite within the mineral magnetite used as a filler in the composites. The crystallinity degree was calculated through X-ray diffraction tests. The XRD results showed how there is an amorphous-crystalline transition due to the magnetite increasing content. The crystallinity percent (χc ) for samples filled with 40% of magnetite volume was 90% while the (χc ) for samples filled with 10% of magnetite volume was 80%. Which may be related to the increased magnetite particles into the plastic matrix for reinforcement contents up to 30% by volume, as evidenced in the images obtained through scanning electron microscopy (SEM). The samples were electrically characterized through volume resistivity measurements and electric polarization. The results showed that for ratios less than the 20% of magnetite there is no substantial reduction in the resistivity of the composite samples compared to the unfilled HDPE samples, but for magnetite ratios above 30% the composite samples showed a substantial reduction of six orders of magnitude in their volumetric resistivity. The electric polarization showed how the composite material undergoes a transition, going from an insulating material (for samples with 10% of magnetite volume) to a resistive material where the current and voltage are in phase (for samples with 30% and 40% of magnetite volume). The magnetization curves showed that the saturation magnetization (from 17,3 to 60,5 emu/g) and remanence (from 0,94 to 5 emu/g) increase in samples with high magnetite contents. The presence of the hematite phase in the samples could have affected the magnetization saturation and the remanence values in the hysteresis curves. Magnetization curves as a function of temperature showed the Verwey samples transition around the 120K and confirmed that the magnetization increases as the magnetite volume within the matrix increases. © 2017. Acad. Colomb. Cienc. Ex. Fis. Nat.

LEER
Evaluación de arcillas caoliniticas-illiticas provenientes de la formación guayabo del Área Metropolitana de Cúcuta, Norte de Santander, Colombia
...
Cáceres, Vivianne Isel | 2017-07-28

La caracterización de arcillas procedentes de la Formación Guayabo del Área Metropolitana de Cúcuta, Norte de Santander (Colombia) es presentada. Los resultados obtenidos de estos análisis permiten determinar las propiedades de estas arcillas y potenciar su uso en la fabricación de materiales de construcción y en la elaboración de nuevos materiales cerámicos, generando impactos tecnológicos, económicos y sociales en la región, pues se podrá competir con productos de calidad en los exigentes mercados nacionales e internacionales. Es así que a través de este trabajo se realizó la caracterización química, mineralógica, térmica y físicocerámica, para determinar la estructura, composición y comportamiento de estas materias primas. Las muestras se obtuvieron de dos puntos diferentes de la formación, ubicados en los municipios del Zulia y Villa del Rosario. Para la evaluación se utilizó la información obtenida de la caracterización química mediante Fluorescencia de Rayos X (FRX), caracterización mineralógica mediante Difracción de Rayos X (DRX) e infrarrojo con transformada de Fourier (FTIR), caracterización térmica mediante análisis térmico gravimétrico (TGA) y calorimetría diferencial de barrido (DSC); y finalmente caracterización físico-cerámica. Los resultados indican que los minerales arcillosos están constituidos por aluminosilicatos hidratados con presencia de algunas impurezas como sodio, hierro, potasio, calcio, titanio por lo que presentan capacidad de ser sometidas a esfuerzos para su conformado a través de procesos de extrusión. Se evidencia que aunque ambas muestras se encuentran en diferentes municipios del área metropolitana de Cúcuta, presentan características similares en fases cristalinas, grupos funcionales, comportamientos térmicos y propiedades cerámicas.

LEER
Influence of raw materials and forming technique in the manufacture of stoneware ceramic
...
Alvarez Rozo, Diana | 2017-09-15

Se empleó material arcilloso y caliza proveniente de minas cercanas a la zona metropolitana de Cúcuta, así como el material de rotura después del proceso de cocción de productos cerámicos (chamota) para la conformación de probetas de baldosas cerámicas mediante las técnicas de extrusión y prensado. Una vez realizado el proceso cerámico (con temperaturas de cocción entre 1050°C y 1250°C), se evaluó el efecto de las diferentes mezclas preparadas sobre las propiedades tecnológicas de resistencia mecánica a la flexión, abrasión profunda y porcentaje de absorción de agua de acuerdo a la norma técnica colombiana. Los productos cocidos fueron caracterizados mediante difracción de rayos X, fluorescencia de rayos X y microscopía electrónica de barrido a fin de evidenciar efectos causados por las materias primas y el tipo de moldeo empleado. Los resultados obtenidos dejan ver la existencia de un efecto de la composición mineralógica de las muestras y de la técnica de conformado sobre la propiedades tecnológicas analizadas al momento de elaborar cerámicos gresificados. Se evidenció que para las mezclas de materias primas utilizadas, la técnica de extrusión permite una más rápida formación de fase vítrea y contribuye a una recristalización más rápida en altas temperaturas. Los mejores valores para las propiedades tecnológicas analizadas fueron encontrados en la temperatura de 1150°C.

LEER
Biocompatibility of bismuth silicate coatings deposited on 316L stainless steel by sol-gel process
...
Bautista-Ruiz, Jorge | 2017-09-25

Bismuth silicate, (BSO) thin films have been fabricated by sol–gel process. The stable sol was synthesized by using bismuth nitrate (III) pentahydrate and tetraethyl orthosilicate (TEOS). The films were deposited by spin-coating at 1500 rpm on Stainless Steel 316L. The films were characterized by Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) besides the measured of the films thickness. This study aimed to evaluate the cell adhesion and cellular proliferation of osteoblast cells on BSO thin films and substrate 316L by MTT assay. It is concluded that the growth of osteoblasts is homogeneous in the surface of the coatings indicating that the medium offered by the films does not present active cytotoxicity and exceed in large number the level of cellular growth compared to Stainless Steel

LEER
Proposal to foster sustainability through circular economy based engineering: a profiteble chain from waste management to tunnel lighting
...
molina, valentin | 2017-12-02

The increasing demands of infrastructures in terms of energy consumption, raw material demand, greenhouse gas emissions, waste management, treatment of components after their lifetime period, and financial costs are nowadays a serious threat for sustainability. Given that the resources are limited, it is difficult to ensure an accurate level of well-being for future generations. For this reason, new perspectives in design, production and consumption are necessary. In this work, the principles of circular economy are applied to concrete branches of engineering. Departing from a design orientated to new uses after life period of infrastructures, a circular economy-aimed engineering makes possible the connection and mutual profit of such different branches like waste management and tunnel lighting. The benefits in environmental and financial terms are a strong argument in favor of a stronger link between engineering and circular economy.

LEER
Tribocorrosion Behavior of Amorphous Carbon-Silicon Coated Titanium in Biological Medium
...
Bautista-Ruiz, Jorge | 2018

Studies of materials in biomedical applications have focused on the generation of new biomaterials and the development of surface modifications, mainly of metals. Amorphous silicon containing diamond like carbon DLC-Si coating deposited on titanium substrate with the purpose of studying its biofunctionality. The behavior against the phenomenon of tribocorrosion of coatings DLC-Si deposited on titanium was evaluated, through the plasma-assisted chemical vapor deposition technique. The nanoindentation technique was used to determine the coating mechanical properties. The DLC-Si coatings were structurally analyzed through X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) techniques, the characteristic binding energy for the signal C1s was obtained from XPS. Via XRD results the amorphous structure of DLC-Si coating was determined. The triboelectrochemical results indicate that the coating shows an adequate wear and to corrosion protection when exposed to the synergic mechanism, thus demonstrating the protective coating effect

LEER
Análisis de las propiedades físico cerámicas y efectos superficiales en un tipo de pasta cerámica, sometida a proceso de modelado mecanizado CNC por sustracción material, para la vinculación de un nuevo modelo de fabricación en la industria cerámica regio
...
Maldonado M, Alvaro E | 2018

La investigación se desarrolla a partir del análisis superficial y físico cerámico en una pasta cerámica debidamente caracterizada; pasta atomizada que mediante proceso de extrusión se obtienen las muestras de arcilla que van a estar sometidas a un modelado mecanizado CNC por sustracción antes del proceso de cocción, las cuales son revisadas mediante Microscopia Óptica para analizar los cambios que se presentan a nivel de superficie. El estudio de los cambios superficiales o alteraciones en las propiedades físico cerámicas que se producen en este material por el proceso de mecanizado, es relevante para determinar con exactitud las alteraciones que se presentan en el material y la ejecución de las mismas piezas fabricadas mediante este proceso; el cual puede dar paso a diseños de morfologías de alta eficiencia energética e incorporar procesos de producción más consecuentes con las políticas ambientales en relación al impacto actual que la industria cerámica produce en la región. Es importante destacar que la investigación tiene como objetivo proponer un modelo más de producción cerámica, en la industria regional, el cual articula los nuevos medios de Fabricación Digital, ofreciendo a la industria regional nuevos desarrollos de alta competitividad a nivel nacional e internacional. Por ultimo las reflexiones económicas y ambientales de esta propuesta giran en torno al desarrollo de espacios productivos, que permitan a los proyectistas establecer nuevas soluciones de diseño, a problemáticas que están sujetas a la forma de cómo pensamos nuestro modo de habitar y de cómo construimos nuestras ciudades en un entorno de producción de bajo impacto ambiental.

LEER
Synthesis and corrosion resistance of SiO2-TiO2-ZrO2-Bi2O3 coatings spin-coated on Ti6Al4V alloy
...
Alférez Vega, Fabio Leonardo | 2018-02

This report shows the synthesis and corrosion resistance of SiO2-TiO2-ZrO2-Bi2O3 coatings deposited by means of spin-coating on Ti6Al4V alloy. The sols were prepared from a mixture of organic precursors, tetraethoxysilane (TEOS) 98%, titanium tetrabutoxide (TBT) 97%, Zirconium (IV) butoxide (TBZ) 80% in 1-butanol solution, and bismuth nitrate pentahydrate Bi (NO3)3 * 5H2O. The coatings were evaluated via potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests in an electrolytic solution of 3.5% wt NaCl + 0.5 M H2SO4. The rheology and pH of the prepared sols were studied through rheology, pH as a function of time, Fourier transform infrared spectroscopy (FTIR), and differential scanning calorimetry (DSC) analysis. The coatings were characterized via X-ray diffraction (XRD), scanning electron microscopy equipped with dispersive energy spectroscopy (SEMEDX), X-ray fluorescence (XRF), and adhesion measurements. The results showed that the films add good corrosion resistance to the metal substrate, decreasing current densities up to one order of magnitude.

LEER
Caracterización Anticorrosiva y de Biocompatibilidad en Recubrimientos Silicio-Titanio-Zirconio Sintetizados Vía Solgel y Depositados sobre Sustratos 316L
...
Bautista-Ruiz, Jorge | 2018-02

Se sintetizaron, los sistemas ternarios [Si/Ti/Zr: 10/70/20] y [Si/Ti/Zr: 10/20/70] vía sol-gel y se aplicaron sobre sustratos de acero inoxidable 316L mediante la técnica de inmersión. En los recubrimientos obtenidos se evaluó la respuesta anticorrosiva en una solución fisiológica simulada mediante curvas potenciodinámicas de polarización. Se estudió la biocompatibilidad celular de osteoblastos; la adhesión sustrato-recubrimiento; la topografía superficial, el espesor y la rugosidad en los recubrimientos. Los resultados de este estudio permiten establecer un alto grado de efectividad anticorrosiva y buena biocompatibilidad. Los recubrimientos sintetizados vía sol-gel establecen su potencialidad como barrera anticorrosiva en función del sistema ternario aplicado al sustrato de acero inoxidable 316L.

LEER