Supramolecular Organization of Metal Nanoparticles in Solution and of Phenyleneethynylenes on Surfaces

Most of the procedures reported for the synthesis of metal nanoparticles involve the use of strong reducing agents or elevated temperatures. This limits the possibility of developing metal nanoparticle based sensors for the in situ detection of analytes. One of the objectives of the present investigations is to (i) develop newer methodologies for the synthesis of metal nanoparticles in aqueous medium at ambient conditions and (ii) their use in the detection of metal cations by taking advantage of the unique coordination ability. Ideally, biocompatible molecules which possess both the reducing and stabilizing groups are desirable for such applications. Formation of stable supramolecular assembly, by bringing metal nanoparticles close to each other, results in plasmon coupling and this strategy can be effectively utilized for the development of metal nanoparticle based sensors.Another objective of the present study is to understand the supramolecular organization of molecules on surfaces. Various noncovalent interactions between the molecules and with surface play a decisive role in their organizations. An in-depth understanding of these interactions is essential for device fabrications. Recent photophysical studies have revealed that phenyleneethynylene based molecular systems are ideal for device application. The second objective of the thesis focuses on understanding the (i) organization of phenyleneethynylenes on highly oriented pyrolytic graphite (HOPG) surface with atomic level precision and (ii) weak intermolecular interactions which drive their organization.

Novel Melt Transurethane Process for Cycloaliphatic Polyurethanes and Their Self-Organization for Nano-Materials

In this introduction part, importance has been given to the elastomeric properties of polyurethanes. Emphasis has been laid to this property based on microphase separation and how this could be modified by modifying the segment lengths, as well as the structure of the segments. Implication was also made on the mechanical and thermal properties of these copolymers based on various analytical methods usually used for characterization of polymers. A brief overview of the challenges faced by the polyurethane chemistry was also done, pointing to the fact that though polyurethane industry is more than 75 years old, still a lot of questions remain unanswered, that too mostly in the synthesis of polyurethanes. A major challenge in this industry is the utilization of more environmental friendly “Green Chemistry Routes” for the synthesis of polyurethanes which are devoid of any isocyanates or harsh solvents.The research work in this thesis was focused to develop non-isocyanate green chemical process for polyurethanes and also self-organize the resultant novel polymers into nano-materials. The thesis was focused on the following three major aspects:(i) Design and development of novel melt transurethane process for polyurethanes under non-isocyanate and solvent free melt condition. (ii) Solvent induced self-organization of the novel cycloaliphatic polyurethanes prepared by the melt transurethane process into microporous templates and nano-sized polymeric hexagons and spheres. (iii) Novel polyurethane-oligophenylenevinylene random block copolymer nano-materials and their photoluminescence properties. The second chapter of the thesis gives an elaborate discussion on the “Novel Melt Transurethane Process ” for the synthesis of polyurethanes under non-isocyanate and solvent free melt condition. The polycondensation reaction was carried out between equimolar amounts of a di-urethane monomer and a diol in the presence of a catalyst under melt condition to produce polyurethanes followed by the removal of low boiling alcohol from equilibrium. The polymers synthesized through this green chemical route were found to be soluble (devoid of any cross links), thermally stable and free from any isocyanate entities. The polymerization reaction was confirmed by various analytical techniques with specific references to the extent of reaction which is the main watchful point for any successful polymerization reaction. The mechanistic aspects of the reaction were another point of consideration for the novel polymerization route which was successfully dealt with by performing various model reactions. Since this route was successful enough in synthesizing polyurethanes with novel structures, they were employed for the solvent induced self-organization which is an important area of research in the polymer world in the present scenario. Chapter three mesmerizes the reader with multitudes of morphologies depending upon the chemical backbone structure of the polyurethane as well as on the nature and amount of various solvents employed for the self-organization tactics. The rationale towards these morphologies-“Hydrogen Bonding ” have been systematically probed by various techniques. These polyurethanes were then tagged with luminescent 0ligo(phenylene vinylene) units and the effects of these OPV blocks on the morphology of the polyurethanes were analyzed in chapter four. These blocks have resulted in the formation of novel “Blue Luminescent Balls” which could find various applications in optoelectronic devices as well as delivery vehicles.

Dress- and Auto- Makers in the “Free Trade” Arena

Even though there have been many studies on the impact of trade liberalisation on labour standards, most of the studies are at national level, and there is a lack of research at industry level. This paper examines the impact of free trade on labour standards in capital- and labour-intensive industries in a developing country. For empirical findings, I take the case of the garment industry, representing labour-intensive industry, and automotive industry, representing capital-intensive industry, in Indonesia in the face of ASEAN Free Trade Area (AFTA). Since the garment industry is a women-dominated industry, while the automotive industry is a men-dominated industry, this paper also employs a feminist perspective. As such, this paper also investigates whether free trade equally affects men and women workers. Besides free trade, other independent variables are also taken into account. Employing quantitative and qualitative methods, empirical evidence shows that there is an indication that free trade has a negative relationship with labour standards in the garment industry, whereas a positive relationships with labour standards in the automotive industry. This implies that free trade might result in decreasing labour standards in labour-intensive industry, while increasing standards in capital-intensive industry. It can also be inferred that free trade unequally affect men and women workers, in that women workers bear the brunt of free trade. The results also show that other internal and external independent variables are indicated to have relationships with labour standards in the garment and automotive industries. Therefore, these variables need to be considered in examining the extent of the impact of free trade on labour standards in labour- and capital-intensive industries.

From Genetic Algorithms to Efficient Organization

The work described in this thesis began as an inquiry into the nature and use of optimization programs based on "genetic algorithms." That inquiry led, eventually, to three powerful heuristics that are broadly applicable in gradient-ascent programs: First, remember the locations of local maxima and restart the optimization program at a place distant from previously located local maxima. Second, adjust the size of probing steps to suit the local nature of the terrain, shrinking when probes do poorly and growing when probes do well. And third, keep track of the directions of recent successes, so as to probe preferentially in the direction of most rapid ascent. These algorithms lie at the core of a novel optimization program that illustrates the power to be had from deploying them together. The efficacy of this program is demonstrated on several test problems selected from a variety of fields, including De Jong's famous test-problem suite, the traveling salesman problem, the problem of coordinate registration for image guided surgery, the energy minimization problem for determining the shape of organic molecules, and the problem of assessing the structure of sedimentary deposits using seismic data.

Tubular Organization of SnO₂ Nanocrystallites for Improved Lithium Ion Battery Anode Performance

Porous tin oxide nanotubes were obtained by vacuum infiltration of tin oxide nanoparticles into porous aluminum oxide membranes, followed by calcination. The porous tin oxide nanotube arrays so prepared were characterized by FE-SEM, TEM, HRTEM, and XRD. The nanotubes are open-ended, highly ordered with uniform cross-sections, diameters and wall thickness. The tin oxide nanotubes were evaluated as a substitute anode material for the lithium ion batteries. The tin oxide nanotube anode could be charged and discharged repeatedly, retaining a specific capacity of 525 mAh/g after 80 cycles. This capacity is significantly higher than the theoretical capacity of commercial graphite anode (372 mAh/g) and the cyclability is outstanding for a tin based electrode. The cyclability and capacities of the tin oxide nanotubes were also higher than their building blocks of solid tin oxide nanoparticles. A few factors accounting for the good cycling performance and high capacity of tin oxide nanotubes are suggested.

Perspectives of auto-correcting lens distortions in mosaic-based underwater navigation

When unmanned underwater vehicles (UUVs) perform missions near the ocean floor, optical sensors can be used to improve local navigation. Video mosaics allow to efficiently process the images acquired by the vehicle, and also to obtain position estimates. We discuss in this paper the role of lens distortions in this context, proving that degenerate mosaics have their origin not only in the selected motion model or in registration errors, but also in the cumulative effect of radial distortion residuals. Additionally, we present results on the accuracy of different feature-based approaches for self-correction of lens distortions that may guide the choice of appropriate techniques for correcting distortions

La expansión del derecho penal : análisis de las capacidades auto-restrictivas de los sistemas modernos del delito a partir de la libertad de expresión

A través de la libertad de expresión se analiza la legitimidad en los sistemas modernos del delito con el fin de determinar su capacidad de respuesta frente al proceso expansivo que afronta el Derecho penal. Se propone la aplicación del funcionalismo moderado en armonía con postulados del finalismo y funcionalismo moderado que tienen asidero en la Constitución, particularmente en cuanto a dignidad humana.

Carpe Diem: Establish an Institutional Repository for Your Organization

An interesting article about repositories.

Actividad física en el tiempo libre y auto percepción del estado de salud en Colombia

Objetivo: El objetivo de este estudio fue determinar la relación entre la actividad física (AF) en el tiempo libre y la auto percepción del estado de salud en Colombia. Métodos: a partir de los datos de una muestra compleja se obtuvieron 14601 registros de sujetos entre 18 y 64 años de Colombia. Se aplicaron modelos de regresión logística para la auto percepción de la salud. Resultados: la prevalencia de AF en el tiempo libre fue de 5,8% en mujeres y de 13% en hombres (p < 0,001) y el auto reporte de salud encontró que 27,7% de las mujeres y 19,7% de los hombres se perciben regulares o malos (p < 0,001). Se encontró influencia de grupos de mayor edad, menor escolaridad, afiliados al sistema de seguridad social y área rural de residencia con pobres auto reportes de salud. Un OR de 1,92 (IC 95% 1,19 – 3,10) reportan las mujeres con bajos niveles de AF en el tiempo libre de auto percibirse pobre en su salud frente a las mujeres con alta AF en el tiempo libre. En los hombres no se encontró esta misma evidencia. Discusión: la influencia de un nivel vigoroso de AF en el tiempo libre sobre la auto percepción del estado de salud en el grupo de mujeres es uno de los principales hallazgos. Estos resultados permiten direccionar políticas públicas tendientes a fomentar la práctica de AF, garantizar el acceso a la educación y a la afiliación a un sistema de salud de la población.

Impacto de la auto - percepción de imagen corporal en sujetos con VIH y lipoatrofia facial.

La lipoatrofia facial es uno de los efectos secundarios que con más frecuencia se presenta y afecta la calidad de vida del paciente con VIH que recibe tratamiento antiretroviral. Metodología: Estudio observacional de corte transversal que involucró 126 sujetos, a quienes se aplicó una encuesta semi-estructurada para determinar cómo percibe el paciente que la lipoatrofia facial lo afecta en áreas afectiva, social, laboral y ocupacional; evaluar la percepción de la imagen corporal; caracterizar sociodemográficamente; determinar la prevalencia de lipoatrofia facial y establecer si hay diferencias de percepción de la imagen corporal según la caracterización sociodemográfica. Resultados: La Prevalencia de lipoatrofia facial fue del 57.1%. El grado de satisfacción en cuanto a apariencia física tuvo un promedio de 5.01±2.69. El 88.7% y 80.3% de los pacientes evaluados sintieron tristeza y frustración con su apariencia respectivamente. El 53.5% y el 42.9% informaron menos oportunidades laborales y educativas. La orientación sexual reportada con mayor frecuencia fue homosexualidad. No hubo diferencias estadísticamente significativas entre el grado de satisfacción de apariencia con aspectos sociodemográficos excepto en pacientes que recibieron apoyo psicológico. Conclusión: Primer estudio en el país que evalúa el impacto de la lipoatrofia facial en pacientes con VIH y tratamiento antiretroviral. Aunque la presencia de lipoatrofia facial sobre la cotidianidad no es estadísticamente significativa, si resulta trascendental pues existen porcentajes importantes de emociones y alteraciones psicológicas que afectan directamente a estos sujetos en las áreas afectiva, social, laboral y ocupacional. Se hace necesaria la realización de más estudios que permitan obtener mayor de evidencia.

Evaluation of the effectiveness of an organization in the field of brand perception using a computer agent-based simulation system

Este proyecto de investigación busca usar un sistema de cómputo basado en modelación por agentes para medir la percepción de marca de una organización en una población heterogénea. Se espera proporcionar información que permita dar soluciones a una organización acerca del comportamiento de sus consumidores y la asociada percepción de marca. El propósito de este sistema es el de modelar el proceso de percepción-razonamiento-acción para simular un proceso de razonamiento como el resultado de una acumulación de percepciones que resultan en las acciones del consumidor. Este resultado definirá la aceptación de marca o el rechazo del consumidor hacia la empresa. Se realizó un proceso de recolección información acerca de una organización específica en el campo de marketing. Después de compilar y procesar la información obtenida de la empresa, el análisis de la percepción de marca es aplicado mediante procesos de simulación. Los resultados del experimento son emitidos a la organización mediante un informe basado en conclusiones y recomendaciones a nivel de marketing para mejorar la percepción de marca por parte de los consumidores.