144 research outputs found
Competitiveness in Insular Regions: Case of Isla Grande in the Archapelago of Islas Del Rosario, Cartagena, Colombia
This article is based on a study whose objective was focused on identifying the variables and
key actors with the greatest impact on the competitiveness of a large island in the island region of the Rosario Islands in Cartagena, Colombia. The implemented methodology is exploratory, based on the qualitative paradigm, and had three phases. The first was developed through a competency diagnosis that was achieved from observations and discussions with the community. The second phase was the identification of the actors to determine how they affect the community. The final phase included the identification of probabilistic cross impacts. The main findings of the research include that the main external factor is the sociodemographic variable. In addition, the environmental variable directly influences competitiveness. The following internal variables of the large island community were identified: ecotourism, poverty and misery index, exploitation of natural resources, social innovation, tourism potential and generational change. Finally, it is necessary to perform immediate actions in favour of the development of competencies. Some of these actions include promoting the destination as
ecotourism and developing campaigns to raise awareness of the importance of the island for natural resources and that these resources should be conserved
Proyecto de modelo de negocio de share economy llamado Mobiel
En este trabajo se realizó un modelo de negocio basado en la metodología Lean Startup y en el modelo de sharing economy para el proyecto Mobiel, que tiene el objetivo de solucionar los problemas de movilidad de las personas que dejan sus autos en los talleres por más de 24 horas
Relación de la estructura con las propiedades eléctricas en solución sólida La2/3-xLi3xTiO3 (0.03 x 0.167)
En este trabajo se investigó la solución sólida
La2/3-xLi3xTiO3 (0.03<x<0.167) por las técnicas de
difracción de rayos-X en polvos (DRX), espectroscopía
de impedancias (EI) y resonancia magnética nuclear
(RMN) de 7Li. En estas muestras se observó un cambio
en la simetría de tetragonal a ortorrómbica cuando
disminuye el contenido de litio por debajo de
x=0.06. Hallamos que las modificaciones estructurales
producidas se deben principalmente al ordenamiento
de las vacancias a lo largo del eje c. Estas
modificaciones disminuyen gradualmente al
incrementarse el contenido de litio en la solución sólida.
Se detectaron dos señales de litio con diferente
constante cuadrupolar para el espectro de RMN del
7Li en las perovskitas ortorrómbicas/tetragonales, las
cuales asociamos con dos sitios cristalográficos para
el litio dentro de la estructura. Para la perovskita de
composición La0.5Li0.5TiO3, se realizó un experimento
enfriándola rápidamente desde 1300° C en nitrógeno
líquido. En ésta se detectó una elevada movili-
dad del litio en el espectro de RMN del 7Li. Para las
perovskitas analizadas, la dependencia de la conductividad
eléctrica con el contenido de litio no sigue
el comportamiento esperado, basado en la teoría
de una distribución aleatoria de los átomos de La y
Li sobre los sitios A. La conductividad DC aumenta
rápidamente con el contenido de litio en las muestras
ortorrómbicas, aunque el cambio es mucho más
gradual en las tetragonales, donde la distribución
de las vacancias se desordena progresivamente. En
todas las perovskitas analizadas, la dependencia de
la conductividad dc con la temperatura muestra un
comportamiento no-Arrhenius con energías de activación
de 0.39±0.02 eV y 0.29±0.02 eV en los
rangos de temperatura de 160 – 250 y 250 – 360
K, respectivamente
Photovoltaic Glass Waste Recycling in the Development of Glass Substrates for Photovoltaic Applications
Because of the increasing demand for photovoltaic energy and the generation of end-of-life
photovoltaic waste forecast, the feasibility to produce glass substrates for photovoltaic application
by recycling photovoltaic glass waste (PVWG) material was analyzed. PVWG was recovered from
photovoltaic house roof panels for developing windows glass substrates; PVWG was used as the main
material mixed with other industrial waste materials (wSG). The glass was casted by air quenching,
annealed, and polished to obtain transparent substrates samples. Fluorine-doped tin oxide (FTO) was
deposited as back contact on the glass substrates by spray pyrolysis. The chemical composition of the
glass materials was evaluated by X-ray fluorescence (XRF), the thermal stability was measured by
differential thermal analysis (DTA) and the transmittance was determined by UV-VIS spectroscopy.
The surface of the glass substrates and the deposited FTO were observed by scanning electron
microscopy (SEM), the amorphous or crystalline state of the specimens were determined by X-ray
diffraction (XRD) and the sheet resistance was evaluated by the four-point probe method. The sheet
resistance of the deposited FTO on the wSG substrate was 7.84 ± 3.11 Ω/, lower than that deposited
on commercial soda-lime glass (8.48 ± 3.67 Ω/), meaning that this material could present improved
conduction of the produced electrons by the photovoltaic effect. This process may represent an
alternative to produce glass substrates from waste materials that could be destined for photovoltaic
applications, especially the production of ecological photovoltaic windows
Environmental Impact Assessment for an Absorption Heat Transformer
Abstract This study presents the environmental impact assessment of an absorption heat transformer designed to recover 1 kW of thermal energy from each 2 kW of waste heat supplies. The net contribution of the heat transformer is a load avoided of 0.665 kg CO2 equivalents; the recovery process avoids 0.729 kg CO2 equivalents and the major contribution to the environment impacts is the pumping process with 0.0437 kg CO2 equivalents for each 1 kWh recovered. The study results show that absorption heat transformer is a good environmental option because it produces useful energy from waste heat and the final result is an environmental impact diminution
Analysis of Pyrolysis Kinetic Parameters Based on Various Mathematical Models for More than Twenty Different Biomasses: A Review
Today, energy use is an important and urgent issue for economic development worldwide. It is expected that raw material in the form of biomass and lignocellulosic residues will become increasingly significant sources of sustainable energy in the future because they contain components such as cellulose, hemicellulose, lignin, and extractables with high energy-producing potential. It is then essential to determine the behavior of these materials during thermal degradation processes, such as pyrolysis (total or partial absence of air/oxygen). Pyrolyzed biomass and its residual fractions can be processed to produce important chemical products, such as hydrogen gas (H2). Thermogravimetric (TGA) analysis and its derivative, DTG, are analytical techniques used to determine weight loss as a function of temperature or time and associate changes with certain degradation and mass conversion processes in order to evaluate kinetic properties. Applying kinetic methods (mathematical models) to degradation processes permits obtaining several useful parameters for predicting the behavior of biomass during pyrolysis. Current differential (Friedman) and integral (Flynn–Wall–Ozawa, Kissinger–Akahira–Sunose, Starink, Popescu) models vary in their range of heating speeds (β) and degree of advance (α), but some (e.g., Kissinger’s) do not consider the behavior of α. This article analyzes the results of numerous kinetic studies using pyrolysis and based on thermogravimetric processes involving over 20 distinct biomasses. The main goal of those studies was to generate products with high added value, such as bio-char, methane, hydrogen, and biodiesel. This broad review identifies models and determines the potential of lignocellulosic materials for generating bioenergy cleanly and sustainably
Medios de comunicación y derecho a la información en Jalisco, 2015
El octavo informe Q ITESO: Análisis Crítico de Medios revisa el funcionamiento del sistema de comunicación política durante el proceso electoral de 2015, así como diversos aspectos relevantes de unas elecciones que culminaron con un cambio radical en el panorama político en Jalisco. En el universo de los medios de comunicación, se analizan los cambios experimentados por estos en el marco de la coyuntura electoral local, la equidad y profundidad en la cobertura por parte de los periódicos y la difusión que hicieron de las encuestas, así como el discurso e impacto de la propaganda difundida a través de la televisión y la Internet, a lo que se suma los debates registrados en redes sociales como Twitter, y la percepción sobre las campañas por parte de la audiencia tapatía. El examen político se enfoca en la campaña realizada por los candidatos independientes, el planteamiento socioeconómico de los contendientes por la capital del estado y el impacto electoral de un personaje incómodo como el papá del gobernador, para culminar este informe con una reflexión general y un balance de quiénes perdieron y quiénes ganaron al término de las elecciones de 2015.ITESO, A.C
Nuevos registros geográficos y notas de infección de Triatoma gerstaeckeri (Stål) y Triatoma rubida (Uhler) (Hemiptera: Reduviidae: Triatominae) en Nuevo León y Coahuila, México
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