Photothermal deflection studies on heat transport in intrinsic and extrinsic InP

Laser induced transverse photothermal deflection technique has been employed to determine the thermal parameters of InP doped with Sn, S and Fe as well as intrinsic InP. The thermal diffusivity values of these various samples are evaluated from the slope of the curve plotted between the phase of photothermal deflection signal and pump-probe offset. Analysis of the data shows that heat transport and hence the thermal diffusivity value, is greatly affected by the introduction of dopant. It is also seen that the direction of heat flow with respect to the plane of cleavage of semiconductor wafers influences the thermal diffusivity value. The results are explained in terms of dominating phonon assisted heat transfer mechanism in semiconductors.

Development and Analysis of a Compact Dual-Band Coplanar Antenna

The coplanar wave guide is an attractive device in microwave integrated circuits due to its uniplanar nature, ease of fabrication and low production cost. Several attempts are already done to explore the radiating modes in coplanar wave guide transmission lines. Usually coplanar wave guides are excited by an SMA connector with its centre conductor connected to the exact middle of the centre strip and the outer ground conductor to the two ground strips. The mode excited on it is purely a bound mode. The E-field distribution in the two slots are out of phase and there for cancels at the far field. This thesis addresses an attempt to excite an in phase E-field distribution in the two slots of the co planar wave guide by employing a feed asymmetry, in order to get radiation from the two large slot discontinuities of the coplanar waveguide. The omni directional distribution of the radiating energy can be achieved by widening the centre strip.The first part of the thesis deals with the investigations on the resonance phenomena of conventional coplanar waveguides at higher frequency bands. Then an offset fed open circuited coplanar waveguide supporting resonance/radiation phenomena is analyzed. Finally, a novel compact co planar antenna geometry with dual band characteristics, suitable for mobile terminal applications is designed and characterized using the inferences from the above study.

A marine candida sake as source of immunostimulants to fenneropenaeus indicus

Aquaculture has developed rapidly over the last three decades to become an important activity worldwide.The Food and Agricultural Organization (FAO) of the UN acknowledge that global fishery output must be increased by at least 50% to offset projected shortfalls in dietary protein by 2030.LAquaculture has developed rapidly over the last three decades and has become an importat industry as today’s demand for fish exceeds the natural supply.lmmunostimulants are chemical compounds that activate the immune system of animals and render them more resistant to infections by viruses, bacteria, fungi, and parasites. lmmunostimulants have been obtained from diverse natural sources where, microbial cell wall acts as the main source.The salient findings of the study are summariseSeven marine yeasts were screened for growth promoting and immunostimulant property in F. indicus. Candida sake S165 was found to be best in terms of its support for growth and protection against white spot virus infection.The study revealed that marine yeast Candida sake can be effectively used as potential source of immunostimulants for application in penaeid prawns culture systems. The study emphasise the fact that the dose and frequency of application of immunostimulants are to be standardised and validated before commercialisation to achieve optimum stimulation of the immune system and to avoid immune fatigue die to verdose.Marine yeast (whole cell) was found to support better immunostimulation compared to its cell wall component B-1,3-glucan. This study shows that administration of marine yeast (whole cell) or B-1,3-glucan as immunostimulants in aquaculture would definitely help in protection of the stock to a few more days even though total protection is not being imparted. This partial protection itself would be highly helpful to the farming industry so that they can get sufficient time to plan for a safe harvest and save the crop from cent percent mortality.

Investigations on the Radiation Characteristics of Broadband Strip Loaded Slotted Microstrip Antennas

With the recent progress and rapid increase in mobile terminals, the design of antennas for small mobile terminals is acquiring great importance. In view of this situation, several design concepts are already been addressed by the scientists and engineers. Compactness and efficiency are the major criteria for mobile terminal antennas. The challenging task of the microwave scientists and engineers is to device compact printed radiating systems having broadband behavior, together with good efficiency. Printed antenna technology has received popularity among antenna scientists after the introduction of microstrip antenna in 1970s. The successors in this kind such as printed monopoles and planar inverted F are also equally important. Scientists and Engineers are trying to explore this technology as a viable coast effective solution for forthcoming microwave revolution. The transmission line perspectives of antennas are very interesting. The concept behind any electromagnetic radiator is simple. Any electromagnetic system with a discontinuity is radiating electromagnetic energy. The size, shape and the orientation of the discontinuities controls the radiation characteristics of the system such as radiation pattern, gain, polarization etc. It can be either resonant or non resonant structure. Microstrip antennas are suitable for wireless applications due to their low cost, high gain and ease of fabrication. But the major disadvantage of micro strip antennas is their inherent narrow bandwidth. A lot of techniques are introduced by the researchers all over the world to enhance the bandwidth of micro strip patch antennas. The thesis addresses an attempt to enhance the bandwidth of micro strip patch antennas by incorporating impedance matching strip as a part of the micro strip patch antenna. The first part of the thesis deals with the broadband operation of the tilted square slot and polygonal slot loaded square micro strip patch antennas. The resonant mechanisms are clearly mentioned using the simulation and experimental studies. The bandwidth of the polygonal slotted broadband patch antenna is again enhanced by implementing an Lstrip feed mechanism. In the second major part of the thesis, a novel gain enhancement technique for single band and broadband square micro strip patch antennas is achieved by implementing offset stacked configurations.

Modifications of secondary reflector antenna patterns due to shaped beams from flanged primary horn feeds

With the advent of satellite communication and radio astronomy, the need for large and efficient reflector antennas had triggered a widespread investigation in reflector feed design techniques. Major improvements sought are reduction in spill-over, cross polarization losses and the enhancement of aperture efficiency. The search for such a feed culminated in the corrugated horn. The main idea behind the present work is to use the H-plane sectoral horns fitted with,corrugated flanges as feeds of a paraboloid and see how the secondary pattern of the reflector antenna varies with different parameters of the feed. An offset paraboloid is used as the secondary reflector in order to avoid the adverse effect of aperture ‘blocking by the feed horn structure on the secondary radiation pattern. The measurements were repeated for three different H-plane sectoral horns with the same set of corrugated flanges at various X-band frequencies. The following parameters of the whole system are studied: (a) Beam shaping. (b) Gain. (c) Variation of VSWR and (d) Cross polarization

The efficiency of direct payments versus tax reductions under uncertainty

This paper analyzes the optimal behavior of farmers in the presence of direct payments and uncertainty. In an empirical analysis for Switzerland, it confirms previously obtained theoretical results and determines the magnitude of the theoretical predicted effects. The results show that direct payments increase agricultural production between 3.7% to 4.8%. Alternatively to direct payments, the production effect of tax reductions is evaluated in order to determine its magnitude. The empirical analysis corroborates the theoretical results of the literature and demonstrates that tax reductions are also distorting, but to a substantially lesser degree if losses are not offset. However, tax reductions, independently whether losses are offset or not, lead to higher government spending than pure direct payments

Effects of Air Pollution Control on Climate

Urban air pollution and climate are closely connected due to shared generating processes (e.g., combustion) for emissions of the driving gases and aerosols. They are also connected because the atmospheric lifecycles of common air pollutants such as CO, NOx and VOCs, and of the climatically important methane gas (CH4) and sulfate aerosols, both involve the fast photochemistry of the hydroxyl free radical (OH). Thus policies designed to address air pollution may impact climate and vice versa. We present calculations using a model coupling economics, atmospheric chemistry, climate and ecosystems to illustrate some effects of air pollution policy alone on global warming. We consider caps on emissions of NOx, CO, volatile organic carbon, and SOx both individually and combined in two ways. These caps can lower ozone causing less warming, lower sulfate aerosols yielding more warming, lower OH and thus increase CH4 giving more warming, and finally, allow more carbon uptake by ecosystems leading to less warming. Overall, these effects significantly offset each other suggesting that air pollution policy has a relatively small net effect on the global mean surface temperature and sea level rise. However, our study does not account for the effects of air pollution policies on overall demand for fossil fuels and on the choice of fuels (coal, oil, gas), nor have we considered the effects of caps on black carbon or organic carbon aerosols on climate. These effects, if included, could lead to more substantial impacts of capping pollutant emissions on global temperature and sea level than concluded here. Caps on aerosols in general could also yield impacts on other important aspects of climate beyond those addressed here, such as the regional patterns of cloudiness and precipitation.

Análisis de la relación entre las Organizaciones Internacionales (OI) y los Estados respecto a la elaboración de herramientas que mitiguen la violación de Derechos Humanos. Estudio de Caso: Desplazados en Colombia y ACNUR entre el 2004 - 2010.

La situación de Derechos Humanos en Colombia es un tema que merece toda la atención del gobierno y de las organizaciones internacionales dedicadas a estudiar y evaluar este tipo de problemáticas. En Colombia, dada su dinámica de construcción social, se han presentado violaciones masivas, generando problemáticas de orden social a gran escala como el desplazamiento forzado. Es mediante esta problemática que se evalúa la violación a los derechos humanos en Colombia, viendo desde allí, sus inicios, el impacto socio-político y las estrategias utilizadas para mitigar y buscar una solución duradera. Este trabajo de grado evaluó la relación que se da entre una organización Internacional como ACNUR y el Estado Colombiano a la luz de la Violación masiva a los derechos de la población civil, analizado concretamente desde el desplazamiento forzado.

Climate Change and Transregional Convergence: Carbon Markets in North Amer ica

National policies in North America have not been drafted properly to address the problem of climate change, following the impasse of international negotiations. Facing this scenario, new alternatives emerge with the leadership and participation of new actors. Local governments in North America, especially of British Columbia, Ontario and Quebec, have been developing strategies to face climate change and emissions reduction in parallel to the national efforts and the global governance strategies. These local governments have developed a transregional approach that has resulted in the creation of regional institutions such as the Western Climate Initiative, the Regional Greenhouse GasInitiative and the Midwestern GreenhouseGas Reduction Accord.Their main goal is to establish regional carbon markets to mitigate and adapt to climate change impacts in a cost-effective way. In spite of these efforts, these initiatives have faced the overlapping problem among them and with national and globalstrategies. The goal of this research is to explore how these carbon markets have developed convergence policies. Convergence among these markets is expressed in their offset system and in secondary markets.

Susceptibilidad genética para el desarrollo de la sepsis bacteriana grave y choque séptico

Objetivo: presentar el estado del arte de las investigaciones que, hasta el momento, relacionan el polimorfismo genético del paciente con la evolución de la sepsis, como herramienta diagnóstica y un nuevo enfoque terapéutico de esta condición. Los conceptos actuales basados en investigaciones sostienen que el polimorfismo genético del individuo es relevante en la evolución de la enfermedad y en la respuesta efectiva al tratamiento del paciente en estado crítico, en especial con sepsis bacteriana y choque séptico. Materiales y métodos: se revisó literatura indexada que relaciona los factores genéticos con la evolución de algunas enfermedades del paciente en estado crítico. Resultados: las características particulares de la enfermedad estarían influenciadas por el acervo genético del paciente, condicionando en gran medida la respuesta patofisiológica. Se ha evidenciado la susceptibilidad genética de algunos individuos a desarrollar infección; estos individuos con un tratamiento similar no evolucionan de igual forma, desencadenándose una sepsis bacteriana grave y choque séptico. El polimorfismo en los genes que codifican por el factor de necrosis tumoral -α (TNF-α) las interlucinas- 1 (IL-1), IL-6, IL-10, el factor soluble CD-14, los receptores similares a Toll y el inhibidor tipo 1 del activador del plasminógeno estaría asociado con el desarrollo de sepsis grave y choque séptico, en particular las mutaciones TNF-α 308 G/A, PAI-1 4G/4G, IL-6 174 G/C. Conclusiones: el conocimiento de la susceptibilidad genética, los factores de riesgo y el buen funcionamiento del sistema inmune de cada persona ayudan a reducir y compensar las complicaciones de la sepsis bacteriana. Es claro que el tratamiento oportuno individualizado en los pacientes con sepsis se asocia con disminución de la mortalidad y con reducción en el deterioro de la respuesta inflamatoria.

Análisis de la industria automotriz colombiana frente al Tratado de Libre Comercio con la República de Corea

Mediante este proyecto, se hace un análisis de la industria automotriz en Colombia, cómo se puede ver afectada y cuáles serán los pros y contras ante la puesta en ejecución del Tratado de Libre Comercio con la República de Corea, tomando como base diferentes agentes que incursionan directamente en la industria mencionada, como lo son sus consumidores, los comerciantes, productores (ensambladoras) y el gobierno nacional. Igualmente, la globalización como aspecto fundamental para las economías mundiales, genera la apertura de estas y afianza a su vez la firma de diferentes tratados que permitan mejorar el comercio y bajar los precios de bienes y servicios entre países; pero en este caso dicha apertura, puede no ser beneficiosa para la industria automotriz colombiana debido a las grandes diferencias en capacidad de producción y tecnología entre ambos países. Por lo anterior, se realizan comparaciones entre las dos economías y sus industrias (la automotriz), para encontrar los puntos en los cuales Colombia es más débil y buscar estrategias que permitan contrarrestar los efectos negativos que puede traer consigo el Tratado de Libre Comercio, así mismo, buscar oportunidades para mejorar el desarrollo tecnológico y de esta manera incentivar la inversión para consolidar dicha industria en el mercado.

Transformación de las instituciones colombianas que garanticen los derechos de los refugiados colombianos en el ecuador (2002-2013)

El objetivo de este trabajo de grado es realizar un análisis sobre las transformaciones institucionales colombianas que garanticen los derechos de refugiados colombianos en el Ecuador. Se analizará desde el enfoque neo institucionalista de la Ciencia Política, como la realidad de los refugiados colombianos en el Ecuador incide en las trasformaciones de las instituciones colombianas al constituirse en actores estratégicos en la configuración de las políticas y la institucionalidad del Estado colombiano. Al ser este un estudio de caso, se abordarán trayectorias vitales y migratorias de connacionales refugiados en Ecuador, víctimas del desplazamiento forzado, como también versiones de las instituciones del gobierno colombiano y opiniones, reflexiones y prácticas de fundaciones, ONG e instituciones internacionales especializadas, desde un enfoque cualitativo de investigación.

Releyendo los orígenes del enfretamiento frio en occidentes la contención y la cortina de hierro como estrategias textuales

El trabajo pretende brindar una aproximación crítica analítica a aquella propositiva histórica familiar dentro de la extensa literatura sobre los orígenes de la Guerra Fría. Reconociendo de antemano que el escenario de la Guerra Fría no fue necesariamente el efecto de una amenaza inminente.

Plan de negocios PetSpa móvil

El mercado de productos y servicios para las mascotas va en aumento cada año y se convierte en una oportunidad latente para realizar negocios. La atención que se le da a los animales hoy en día es comparable a la que se le da a un miembro más de la familia, por lo que la demanda de productos y servicios para ellos sobrepasa las expectativas del mercado. La tendencia al cuidado de las mascotas ya no solo se limita a atenciones básicas como la alimentación y la salud, por el contrario, el significado del bienestar y cuidado de estos animales han generado un cambio de paradigma donde el aseo e higiene de las mascotas ya no son un privilegio sino un derecho. Este nuevo cambio de pensamiento ha guiado a los dueños de mascotas a acceder a nuevos servicios más innovadores, creativos y útiles los cuales generan mayor tranquilidad y beneficios a sus mascotas. En vista de esta evidente oportunidad, en el presente documento se describe la estructuración, modelación y prospección del proyecto de emprendimiento PetSpa, con el fin de determinar la factibilidad y viabilidad de la creación de un modelo de negocio dedicado a prestar servicios de baño, peluquería y spa para mascotas en la ciudad de Bogotá. A través del estudio, se tendrá en cuenta un análisis de investigación de mercados, financiero, operativo, administrativo y legal, mediante los cuales se obtendrá la evidencia necesaria para la construcción y puesta en marcha del modelo de negocio propuesto.

Land Reform, Latifundia and Social Development at Local Level in Colombia, 1961-2010

The paper analyzes the effects of land reform on social development – poverty and land distribution-at the local level. Land reform in Colombia, understood as the allocation of public land to peasant, has granted 23 million hectares which comprises around 20% of Colombian territory and about 50% of usable productive land. Theoretically, the net impact of land reform on development is the combination of a poverty effect and a land distribution effect. Our findings suggest that land reform from 1961 onwards has slightly reduced poverty and mildly improved land distribution. Nonetheless,municipalities with strong presence of latifundia prior to1961 have experienced both a slower drop in poverty and a weaker improvement of land distribution .This paper finds that prevalence of latifundia partially offset the positive effect of land reform in promoting social development.