“A comparative study of medium and large pore zeolites in alkylation reactions”

Zeolites have established themselves as industrial catalysts for over two decades for a variety of hydrocarbon processing reactions where acidity and shape selectivity are important factors. As solid catalysts, zeolites may be advantageous and superior compared to their homogenous counterparts due to their characteristic properties. It is only in recent years that the utility of zeolites for organic synthesis is recognized for producing specific organic intermediates and fine chemicals in high selectivity. In this thesis an attempt has been made to compare the catalytic activity of some medium and large pore zeolites in a few alkylation and acylation reactions. The work reported in the present study is basically centered around the following zeolites namely, ZSM-5, mordenite, zeolite Y and beta. The major reactions carried out were benzoylation of o-xylene, propionylation of toluene and anisole and benzylation of oxylene. . The programme involves the synthesis, modifications and characterization of the zeolite catalysts by various methods. The influence of various parameters such as non-framework cations, Si/Al ratio of zeolites, temperature of the reaction, catalyst concentration, molar ratio of the reactants and recycling of the catalysts were also examined upon the conversion of reactants and the formation of the desired products in the alkylation/ acylation reactions. The general conclusions drawn by us from the results obtained are summarized in the last chapter of the thesis. Zeolite beta ofi'ers interesting opportunities as a potential catalyst in alkylation reactions and the area of catalysis by medium and large pore zeolites is very fascinating and there is plenty of scope for further research in this field. Moreover, zeolite based catalysts are effective in meeting current industrial processing and more stringent environment pollution limits.

Optimization of medium for the production of a novel aquaculture probiotic, Micrococcus MCCB 104 using central composite design

A marine isolate of jáÅêçÅçÅÅìë MCCB 104 has been identified as an aquaculture probiotic antagonistic to sáÄêáç. In the present study different carbon and nitrogen sources and growth factors in a mineral base medium were optimized for enhanced biomass production and antagonistic activity against the target pathogen, sáÄêáç=Ü~êîÉóá, following response surface methodology (RSM). Accordingly the minimum and maximum limits of the selected variables were determined and a set of fifty experiments programmed employing central composite design (CCD) of RSM for the final optimization. The response surface plots of biomass showed similar pattern with that of antagonistic activity, which indicated a strong correlation between the biomass and antagonism. The optimum concentration of the carbon sources, nitrogen sources, and growth factors for both biomass and antagonistic activity were glucose (17.4 g/L), lactose (17 g/L), sodium chloride (16.9 g/L), ammonium chloride (3.3 g/L), and mineral salts solution (18.3 mL/L). © KSBB

A novel medium for the development of in vitro cell culture system from Penaeus monodon

Lack of a valid shrimp cell line has been hampering the progress of research on shrimp viruses. One of the reasons identified was the absence of an appropriate medium which would satisfy the requirements of the cells in vitro. We report the first attempt to formulate an exclusive shrimp cell culture medium (SCCM) based on the haemolymph components of Penaeus monodon prepared in isosmotic seawater having 27 % salinity. The SCCM is composed of 22 amino acids, 4 sugars, 6 vitamins, cholesterol, FBS, phenol red, three antibiotics, potassium dihydrogen phosphate and di-sodium hydrogen phosphate at pH 6.8–7.2. Osmolality was adjusted to 720 ± 10 mOsm kg-1 and temperature of incubation was 25 8C. The most appropriate composition was finally selected based on the extent of attachment of cells and their proliferation by visual observation. Metabolic activity of cultured cells was measured by MTT assay and compared with that in L-15 (29), modified L-15 and Grace’s insect medium, and found better performance in SCCM especially for lymphoid cells with 107 % increase in activity and 85 ± 9 days of longevity. The cells from ovary and lymphoid organs were passaged twice using the newly designed shrimp cell dissociation ‘‘cocktail’’.

Fish flesh agar medium - a suitable experimental medium for the detection of spoilage bacteria

The spoilage characteristics of bacterial strains were studied by growing them at 28 _+ 2 °C in agar and broth media prepared with sterile fish and prawn flesh homogenates. The percentage of spoilers found among the bacterial isolates tested, as shown by odour production and halo zone formation, was independent of the source of flesh used. Indole and fluorescent pigment production were also observed in the broth. Pseudomonas, Vibrio and Acinetobacter exhibited faster growth in flesh media than in the usual artificial media. Decrease of protein and lipid concentration in the clear zone of agar media suggests the utilization of the available substrate by spoilage bacteria.

Barriers Faced By Micro, Small And Medium Enterprises In Raising Finance

Worldwide, Micro, Small and Medium Enterprises (MSMEs) have been accepted as an engine of economic growth and for promoting equitable development. In developing countries including India, Micro, Small and Medium Enterprises sector constitute an important part in its development. In spite of this importance, this sector face number of constraints like absence of adequate and timely supply of bank finance, difficulties in procuring raw materials, marketing and distribution challenges and non availability of suitable technology. Review of literature found that there exists problem in accessing finance from banks and financial institutions and this problem may differ from region to region, between sectors, or between individual enterprises within a sector. This paper tries to identify the various barriers faced by these units in raising finance and also try to identify the various sources of finance other than banks. The study is based upon the primary data collected from the 200 MSMEs owners in Kozhikode District of Kerala. The data has been analysed with the help of percentage. The study attempts to submit some recommendations to enhance the overall credit accessibility to MSMEs sector

Process Improvement of Coir Pith Degradation Involving White Rot Fungi By Substitution of Urea With Nitrogen Fixing Bacteria and Application of Biodegraded Coir Pith as Plant Growth Medium

In this study, a novel improved technology could be developed to convert the recalcitrant coir pith into environmental friendly organic manure. The standard method of composting involves the substitution of urea with nitrogen fixing bacteria viz. Azotobacter vinelandii and Azospirillum brasilense leading to the development of an improved method of coir pith. The combined action of the microorganisms could enhance the biodegradation of coir pith. In the present study, Pleurotus sajor caju, an edible mushroom which has the ability to degrade coir pith, and the addition of nitrogen fixing bacteria like Azotobacter vinelandii and Azospirillum brasilense could accelerate the action of the fungi on coir pith. The use of these microorganisms brings about definite changes in the NPK, Ammonia, Organic Carbon and Lignin contents in coir pith. This study will encourage the use of biodegraded coir pith as organic manure for agri/horti purpose to get better yields and can serve as a better technology to solve the problem of accumulated coir pith in coir based industries

Development of directly modulated high speed telecommunication lasers based on surface defined feedback gratings

High-speed semiconductor lasers are an integral part in the implemen- tation of high-bit-rate optical communications systems. They are com- pact, rugged, reliable, long-lived, and relatively inexpensive sources of coherent light. Due to the very low attenuation window that exists in the silica based optical fiber at 1.55 μm and the zero dispersion point at 1.3 μm, they have become the mainstay of optical fiber com- munication systems. For the fabrication of lasers with gratings such as, distributed bragg reflector or distributed feedback lasers, etching is the most critical step. Etching defines the lateral dimmensions of the structure which determines the performance of optoelectronic devices. In this thesis studies and experiments were carried out about the exist- ing etching processes for InP and a novel dry etching process was de- veloped. The newly developed process was based on Cl2/CH4/H2/Ar chemistry and resulted in very smooth surfaces and vertical side walls. With this process the grating definition was significantly improved as compared to other technological developments in the respective field. A surface defined grating definition approach is used in this thesis work which does not require any re-growth steps and makes the whole fabrication process simpler and cost effective. Moreover, this grating fabrication process is fully compatible with nano-imprint lithography and can be used for high throughput low-cost manufacturing. With usual etching techniques reported before it is not possible to etch very deep because of aspect ratio dependent etching phenomenon where with increasing etch depth the etch rate slows down resulting in non-vertical side walls and footing effects. Although with our de- veloped process quite vertical side walls were achieved but footing was still a problem. To overcome the challenges related to grating defini- tion and deep etching, a completely new three step gas chopping dry etching process was developed. This was the very first time that a time multiplexed etching process for an InP based material system was demonstrated. The developed gas chopping process showed extra ordinary results including high mask selectivity of 15, moderate etch- ing rate, very vertical side walls and a record high aspect ratio of 41. Both the developed etching processes are completely compatible with nano imprint lithography and can be used for low-cost high-throughput fabrication. A large number of broad area laser, ridge waveguide laser, distributed feedback laser, distributed bragg reflector laser and coupled cavity in- jection grating lasers were fabricated using the developed one step etch- ing process. Very extensive characterization was done to optimize all the important design and fabrication parameters. The devices devel- oped have shown excellent performance with a very high side mode suppression ratio of more than 52 dB, an output power of 17 mW per facet, high efficiency of 0.15 W/A, stable operation over temperature and injected currents and a threshold current as low as 30 mA for almost 1 mm long device. A record high modulation bandwidth of 15 GHz with electron-photon resonance and open eye diagrams for 10 Gbps data transmission were also shown.

1.55 µm High-Speed QDs Lasers for Optical Telecommunication Applications

In this work investigation of the QDs formation and the fabrication of QD based semiconductor lasers for telecom applications are presented. InAs QDs grown on AlGaInAs lattice matched to InP substrates are used to fabricate lasers operating at 1.55 µm, which is the central wavelength for far distance data transmission. This wavelength is used due to its minimum attenuation in standard glass fibers. The incorporation of QDs in this material system is more complicated in comparison to InAs QDs in the GaAs system. Due to smaller lattice mismatch the formation of circular QDs, elongated QDs and quantum wires is possible. The influence of the different growth conditions, such as the growth temperature, beam equivalent pressure, amount of deposited material on the formation of the QDs is investigated. It was already demonstrated that the formation process of QDs can be changed by the arsenic species. The formation of more round shaped QDs was observed during the growth of QDs with As2, while for As4 dash-like QDs. In this work only As2 was used for the QD growth. Different growth parameters were investigated to optimize the optical properties, like photoluminescence linewidth, and to implement those QD ensembles into laser structures as active medium. By the implementation of those QDs into laser structures a full width at half maximum (FWHM) of 30 meV was achieved. Another part of the research includes the investigation of the influence of the layer design of lasers on its lasing properties. QD lasers were demonstrated with a modal gain of more than 10 cm-1 per QD layer. Another achievement is the large signal modulation with a maximum data rate of 15 Gbit/s. The implementation of optimized QDs in the laser structure allows to increase the modal gain up to 12 cm-1 per QD layer. A reduction of the waveguide layer thickness leads to a shorter transport time of the carriers into the active region and as a result a data rate up to 22 Gbit/s was achieved, which is so far the highest digital modulation rate obtained with any 1.55 µm QD laser. The implementation of etch stop layers into the laser structure provide the possibility to fabricate feedback gratings with well defined geometries for the realization of DFB lasers. These DFB lasers were fabricated by using a combination of dry and wet etching. Single mode operation at 1.55 µm with a high side mode suppression ratio of 50 dB was achieved.

Institutions, Behavior and Evolution

The three articles constituting this thesis are for reasons of content or method related to the following three fields in economics: Behavioral Economics, Evolutionary Game Theory and Formal Institutional Economics. A core element of these fields is the concept of individual preferences. Preferences are of central importance for the conceptional framework to analyze human behavior. They form the foundation for the theory of rational choice which is defined by the determination of the choice set and the selection of the most preferred alternative according to some consistency requirements. The theory of rational choice is based on a very simplified description of the problem of choice (object function and constraints). However, that choices depend on many more factors is for instance propagated by psychological theories and is supported by many empirical and experimental studies. This thesis adds to a better understanding of individual behavior to the extent that the evolution of certain characteristics of preferences and their consequences on human behavior forms the overarching theme of the dissertation. The long-term effect of evolutionary forces on a particular characteristic of importance in the theoretical, empirical and experimental economic literature, the concept of inequality aversion, is subject of the article “The evolution of inequality aversion in a simplified game of life” (Chapter 4). The contribution of the article is the overcoming of a restriction of former approaches to analyze the evolution of preferences in very simple environments. By classifying human interaction into three central economic games, the article provides a first step towards a simplified and sufficiently complete description of the interaction environment. Within such an environment the article characterizes the evolutionary stable preference distribution. One result shows, that the interaction of the aforementioned three classes can stabilize a preference of inequality aversion in the subpopulation which is favored in the problem of redistribution. The two remaining articles are concerned with social norms, which dissemination is determined by medium-run forces of cultural evolution. The article “The impact of market innovations on the evolution of social norms: the sustainability case.“ (Chapter 2) studies the interrelation between product innovations which are relevant from a sustainability perspective and an according social norm in consumption. This relation is based on a conformity bias in consumption and the attempt to avoid cognitive dissonances resulting from non-compliant consumption. Among others, it is shown that a conformity bias on the consumption side can lead to multiple equilibria on the side of norm adoption. The article “Evolution of cooperation in social dilemmas: signaling internalized norms.” (Chapter 3) studies the emergence of cooperation in social dilemmas based on the signaling of social norms. The article provides a potential explanation of cooperative behavior, which does not rely on the assumption of structured populations or on the unmotivated ability of social norms to restrict individual actions or strategy spaces. A comprehensive result of the single articles is the explanation of the phenomenon of partial norm adaption or dissemination of preferences. The plurality of the applied approaches with respect to the proximity to the rational choice approach and regarding the underlying evolutionary mechanics is a particular strength of the thesis. It shows the equality of these approaches in their potential to explain the phenomenon of cooperation in environments that provide material incentives for defective behavior. This also points to the need of a unified framework considering the biological and cultural coevolution of preference patterns.

Self-Assembly of Stimuli-Responsive Water-Soluble [60]Fullerene End-Capped Ampholytic Block Copolymer

Well-defined, water-soluble, pH and temperature stimuli-responsive [60]fullerene (C₆₀) containing ampholytic block copolymer of poly((methacrylic acid)-block-(2-(dimethylamino)ethyl methacrylate))-block–C₆₀ (P(MAA-b-DMAEMA)-b-C₆₀) was synthesized by the atom transfer radical polymerization (ATRP) technique. The self-assembly behaviour of the C₆₀ containing polyampholyte in aqueous solution was characterized by dynamic light scattering (DLS), and transmission electron microscopy. This amphiphilic mono-C₆₀ end-capped block copolymer shows enhanced solubility in aqueous medium at room and elevated temperatures and at low and high pH but phase-separates at intermediate pH of between 5.4 and 8.8. The self assembly of the copolymer is different from that of P(MAA-b-DMAEMA). Examination of the association behavior using DLS revealed the co-existence of unimers and aggregates at low pH at all temperatures studied, with the association being driven by the balance of hydrophobic and electrostatic interactions. Unimers and aggregates of different microstructures are also observed at high pH and at temperatures below the lower critical solution temperature (LCST) of PDMAEMA. At high pH and at temperatures above the LCST of PDMAEMA, the formation of micelles and aggregates co-existing in solution is driven by the combination of hydrophobic, electrostatic, and charge-transfer interactions.

Creación de una empresa virtual de servicios informativos para la industria musical de Bogotá

El presente trabajo describe el proceso de conformación de la empresa “C Music”, la cual tiene como meta posicionarse como líder en la consolidación, promoción y distribución de información relacionada con la industria de la música inicialmente en Bogotá. En el presente trabajo se plantea tanto el problema como la justificación que llevaron al autor a desarrollar la empresa, así como los objetivos y metas trazadas en el corto, mediano y largo plazo. En él se realiza una investigación de mercado, y se referencian las empresas que prestan servicios similares tanto en Colombia como en América Latina y España. Finalmente se definen las herramientas técnicas con las que se realizó la planificación de la empresa. El trabajo de grado tiene como soporte una fuerte labor investigativa que se realizó a través de visitas de campo, en las cuales se diligenciaba una encuesta que facilitó el proceso de sistematización de la información, ésta fue posteriormente condensada en una base de datos que estará a disposición del público, a través de un portal Web, que es el medio por el cual funcionará la empresa.

Plan de Mejoramiento Para la Empresa AAA PH SAS Asistencia y Administración A Propiedad Horizontal

La oportunidad del mercado se define como la necesidad de abarcar el mercado de la administración de propiedad horizontal y la venta de copropiedades. Mercado que se encuentra en crecimiento en Bogotá. Enfocándonos en los estratos 5 y 6 de las localidades de Usaquén, Suba y Chapinero. En la actualidad son muy pocas las empresas especializadas en la administración de propiedad horizontal. Existen muchas empresas que intentan abarcar este mercado, pero no hay estrategias de fondo que permitan la satisfacción de los clientes, ni que generen valor agregado. Por lo tanto consideramos que es posible incursionar en el mercado con una idea que introduzca valor, que sea flexible, que cuente con estándares de calidad y que involucre la tecnología, de la mano del internet y la intención de hacerle la vida más fácil a los consejeros y copropietarios. El servicio principal de este emprendimiento es la administración de propiedad horizontal y el servicio secundario es la administración inmobiliaria para la venta de copropiedades. Nuestra capacidad de generar valor está dada a través de nuestra oficina virtual, nuestra estrategia de comunicación, nuestros aliados estratégicos y la asistencia personal dedicada. Las cuales creemos son la base fundamental para aprovechar esta oportunidad de negocio, generando empleo y obteniendo muy buenas ganancias y rentabilidades en el mediano y largo plazo. Hoy el mercado de la propiedad horizontal se encuentra en crecimiento. El tamaño del mercado es de (61.200’000.000) sesenta y un mil doscientos millones de pesos anuales, y crece en promedio alrededor del 1 %. Lo anterior según un estudio de proyección - Perspectivas del mercado de vivienda nueva y del sector edificador en 2012- realizado por la Cámara Colombiana de La Construcción (CAMACOL). AAA PH SAS o Asistencia y Administración a Propiedad Horizontal, cuanta en la actualidad con una participación en el mercado del 0,07843 por ciento, pero para el final de esta proyección se contara con una participación del 0.3921 por ciento. El proyecto se encuentra ubicado en la Avenida carrera 15 número 144-43 apartamento 101, Bogotá DC. El radio de acción está enfocado en las localidades de Suba, Chapinero y Usaquén en las copropiedades estrato 5 y 6. En el futuro se espera abarcar un radio mucho más amplio con oficinas en puntos estratégicos de la ciudad e involucrar municipios aledaños a la ciudad de Bogotá (Chía, Cota, Cajicá), y tal vez otras ciudades del país (Cartagena, Medellín) La inversión es de 22 millones de pesos. Los ingresos por ventas en el primer año son de 77 millones de pesos, en el segundo año de 135 millones de pesos y en el tercer año de 211 millones de pesos. La utilidad neta del primer año es de $ 631.866 pesos, en el segundo año de $ 17.827.602 pesos y en el tercer año de $ 28.024.867 pesos. Los gastos en su mayoría se ven reflejados en la mano de obra fija, ya que nuestros empleados tienen muy buenas capacidades y son retribuidos con un salario por encima del promedio del mercado. Esto porque nuestra intención es posicionar nuestra marca por nuestra exclusiva calidad de servicio, experiencia y alto contenido tecnológica para agilizar y facilitar procesos. La rentabilidad bruta es de del 77.63% anual. La rentabilidad sobre las ventas es de 0.82% anual, pero es necesario considerar que los valores de venta están siendo aproximados y según nuestra experiencia estos valores de venta serán mucho mayores, debido a la capacidad y el reconocimiento que ya tiene la empresa. Teniendo en cuenta que en la actualidad tenemos contratos que representan ingresos del doble del promedio presentado en esta proyección. De igual forma hay que considerar que en el mercado inmobiliario las comisiones por ventas pueden aumentar significativamente. La rentabilidad sobre la inversión supera a la del comportamiento del mercado o interés de oportunidad en un poco más de 9 millones de pesos. Esto significa que es un proyecto viable que genera mejores resultados que los del mercado de oportunidad, evidenciando que podríamos generar muy buenos ingresos. La tasa interna de retorno o TIR es igual a 33.22 %. Es un valor considerado alto pero que está de acuerdo a la tendencia del mercado de los servicios, en donde la TIR suele ser mucho más alta. Con este valor se recomienda seguir con el proyecto. Eso significa que por cada peso invertido en el proyecto se recupera cada peso y se generaran beneficios adicionales por 33.22 pesos. El valor del VPN o valor presente neto arrojado es de $9, 152,729 pesos. Esto quiere decir que se generan 9 millones de pesos adicionales al invertir los recursos en este proyecto, que en uno que rente el 14 % anual, por lo tanto se sugiere continuar con el proyecto e invertir los recursos. El indicador de viabilidad financiera, es el periodo de recuperación de la inversión (PRI). La inversión es de 22 millones de pesos, como la suma de las utilidades de los tres años es superior se afirma que la inversión se recupera en el tercer año.

Investigación perfil en competencias y habilidades del empresario bogotano: trabajo de campo

Este documento corresponde al trabajo de campo para la investigación doctoral de Luis Alberto Estrada titulado “Perfil en competencias del empresario bogotano”. El objetivo que el equipo de investigación definió fue concretar las habilidades y competencias que acompañan a los emprendedores y fundadores de empresa en la primera década del siglo XXI. Para ello, se tomó una base de datos de la Cámara de Comercio de Bogotá, la cual contiene la información comercial de las empresas de la ciudad con matrícula mercantil vigente creadas en el periodo de 2000 a 2011 con un mínimo de 5 años de ventas registradas. Mediante el análisis de la información se seleccionó a las cincuenta empresas de mayor crecimiento en ventas, de las cuales ocho fueron encuestadas y entrevistadas junto a sus fundadores. Los hallazgos que se encontraron en este estudio muestran un perfil del grupo de encuestados con respecto a su formación, su relación, su gestión, sus aspiraciones, su compostura, su visión y su trascendencia.