Ecology And Seasonal Variation Of Microalgal Community In An Oil Refinery Effluent Holding Pond: Monitoring And Assessment

The microalgal community as primary producers has to play a significant role in the biotic and abitoic interactions of any aquatic ecosystem. Whenever a community is exposed to a pollutant, responses can occur because individuals acclimate to pollutant caused changes and selection can occur favouring resistant genotypes within a population and selection among species can result in changes in community structure. The microalgal community of industrial effluent treatment systems are continuously exposed to pollutants and there is little data available on the structure and seasonal variation of microalgal community of industrial effluent holding ponds, especially of a complex effluent like that of refinery. The aim of the present study was to investigate the annual variation in the ecology, biomass, productivity and community structure of the algal community of a refinery effluent holding pond. The results of the study showed the pond to be a eutrophic system with a resistant microalgal community with distinct seasonal variation in species composition

FEM based Virtual Prototyping and Design of Third Harmonic Excitation System for Low Voltage Brushless Alternators

Salient pole brushless alternators coupled to IC engines are extensively used as stand-by power supply units for meeting in- dustrial power demands. Design of such generators demands high power to weight ratio, high e ciency and low cost per KVA out- put. Moreover, the performance characteristics of such machines like voltage regulation and short circuit ratio (SCR) are critical when these machines are put into parallel operation and alterna- tors for critical applications like defence and aerospace demand very low harmonic content in the output voltage. While designing such alternators, accurate prediction of machine characteristics, including total harmonic distortion (THD) is essential to mini- mize development cost and time. Total harmonic distortion in the output voltage of alternators should be as low as possible especially when powering very sophis- ticated and critical applications. The output voltage waveform of a practical AC generator is replica of the space distribution of the ux density in the air gap and several factors such as shape of the rotor pole face, core saturation, slotting and style of coil disposition make the realization of a sinusoidal air gap ux wave impossible. These ux harmonics introduce undesirable e ects on the alternator performance like high neutral current due to triplen harmonics, voltage distortion, noise, vibration, excessive heating and also extra losses resulting in poor e ciency, which in turn necessitate de-rating of the machine especially when connected to non-linear loads. As an important control unit of brushless alternator, the excitation system and its dynamic performance has a direct impact on alternator's stability and reliability. The thesis explores design and implementation of an excitation i system utilizing third harmonic ux in the air gap of brushless al- ternators, using an additional auxiliary winding, wound for 1=3rd pole pitch, embedded into the stator slots and electrically iso- lated from the main winding. In the third harmonic excitation system, the combined e ect of two auxiliary windings, one with 2=3rd pitch and another third harmonic winding with 1=3rd pitch, are used to ensure good voltage regulation without an electronic automatic voltage regulator (AVR) and also reduces the total harmonic content in the output voltage, cost e ectively. The design of the third harmonic winding by analytic methods demands accurate calculation of third harmonic ux density in the air gap of the machine. However, precise estimation of the amplitude of third harmonic ux in the air gap of a machine by conventional design procedures is di cult due to complex geome- try of the machine and non-linear characteristics of the magnetic materials. As such, prediction of the eld parameters by conven- tional design methods is unreliable and hence virtual prototyping of the machine is done to enable accurate design of the third har- monic excitation system. In the design and development cycle of electrical machines, it is recognized that the use of analytical and experimental methods followed by expensive and in exible prototyping is time consum- ing and no longer cost e ective. Due to advancements in com- putational capabilities over recent years, nite element method (FEM) based virtual prototyping has become an attractive al- ternative to well established semi-analytical and empirical design methods as well as to the still popular trial and error approach followed by the costly and time consuming prototyping. Hence, by virtually prototyping the alternator using FEM, the important performance characteristics of the machine are predicted. Design of third harmonic excitation system is done with the help of results obtained from virtual prototype of the machine. Third harmonic excitation (THE) system is implemented in a 45 KVA ii experimental machine and experiments are conducted to validate the simulation results. Simulation and experimental results show that by utilizing third harmonic ux in the air gap of the ma- chine for excitation purposes during loaded conditions, triplen harmonic content in the output phase voltage is signi cantly re- duced. The prototype machine with third harmonic excitation system designed and developed based on FEM analysis proved to be economical due to its simplicity and has the added advan- tage of reduced harmonics in the output phase voltage.

La relación entre los conceptos de relación estratégica comunitaria de las organizaciones con las comunidades y la responsabilidad social

Para maximizar los beneficios, una compañía fundamenta sus acciones en ciertas estrategias que ayudan a cumplir su objetivo de generar utilidades. Entre las diferentes acciones que una organización puede utilizar, están las de responsabilidad social y las de relaciones estratégicas con la comunidad. Partiendo de la definición de comunidad, pasando por una descripción de responsabilidad social y sus diferentes formas de aplicabilidad dentro de una empresa, hasta la definición de relación estratégica con la comunidad; esta investigación dirige sus esfuerzos a determinar el vínculo que existe entre los conceptos de responsabilidad social y relación estratégica comunitaria. Adicionalmente, se plantea que otras estrategias de relacionamiento con clientes, como el mercadeo relacional o el CRM, las cuales enfocan sus esfuerzos en conocer a cada uno de los clientes de una compañía para plantear una oferta acorde a sus necesidades, no son muy efectivas a la hora de crear un vínculo emocional con la comunidad.

Métodos de análisis de las comunidades de clientes mediante la relación estratégica comunitaria y el marketing.

En este proyecto analizaremos como las organizaciones se relacionan con el medio y marketing. La idea es determinar cuáles son los métodos de análisis de las comunidades de clientes mediante la relación estratégica comunitaria y el marketing. Por medio del mercadeo se puede conocer el entorno y determinar qué métodos de análisis utilizar para conocer a la comunidad de clientes. Las personas de mercadeo se ocupan de todo lo que ocurre en el entorno, de estar al tanto para saber cuándo hay oportunidades que puedan ser provechosas para la organización o por otro lado cuando hay amenazas de las que debe tener cuidado. Dependiendo del entorno, la organización diseña sus actividades de mercadeo enfocadas en satisfacer las necesidades del consumidor. Las actividades del consumidor se conceptualizan en producto, precio, promoción y plaza que se definen y diseñan basados en la comunidad en la que este inmersa la organización. Es importante buscar información confiable sobre el grupo objetivo al cual se le va ofrecer el producto o servicio, ya que toca analizarlos y comprender a estas personas para diseñar una buena oferta que satisfaga sus necesidades y deseos. Esta persona que recibe el producto o servicio por parte de la organización es el cliente. Los clientes son las personas que llegan a una organización en búsqueda de satisfacer necesidades a través de los bienes y servicios que las empresas ofrecen. Es esencial determinar que los clientes viven en comunidad, es decir comparten ideas por la comunicación tan estrecha que tienen y viven en conjunto bajo las mismas costumbres. Debido a estos es que hoy en día, los consumidores se conglomeran en comunidades de clientes, y para saberles llegar a estos clientes, toca analizarlos por medio de diversos métodos. El uso de las estrategias comunitarias es necesario ya que por medio del marketing se analiza el entorno y se buscan los métodos para analizar a la comunidad de clientes, que comparten características y se analizan en conjunto no por individuo. Es necesario identificar los métodos para relacionarse con la comunidad de clientes, para poder acercarnos a estos y conocerlos bien, saber sus necesidades y deseos y ofrecerles productos y servicios de acuerdo a éstos. En la actualidad estos métodos no son muy comunes ni conocidos, es por esto que nuestro propósito es indagar e identificar estos métodos para saber analizar a las comunidades. En este proyecto se utilizara una metodología de estudio tipo teórico-conceptual buscando las fuentes de información necesarias para llevar a cabo nuestra investigación. Se considera trabajar con El Grupo de Investigación en Perdurabilidad Empresarial y se escogió la línea de gerencia ya que permite entrar en la sociedad del conocimiento, siendo capaces de identificar oportunidades gerenciales en el entorno. Es interesante investigar sobre estos métodos, ya que los clientes esperan un servicio excelente, atento y que se preocupe por ellos y sus necesidades.

Development and illustrative outputs of the Community Integrated Assessment System (CIAS), a multi-institutional modular integrated assessment approach for modelling climate change.

This paper describes the development and first results of the “Community Integrated Assessment System” (CIAS), a unique multi-institutional modular and flexible integrated assessment system for modelling climate change. Key to this development is the supporting software infrastructure, SoftIAM. Through it, CIAS is distributed between the community of institutions which has each contributed modules to the CIAS system. At the heart of SoftIAM is the Bespoke Framework Generator (BFG) which enables flexibility in the assembly and composition of individual modules from a pool to form coupled models within CIAS, and flexibility in their deployment onto the available software and hardware resources. Such flexibility greatly enhances modellers’ ability to re-configure the CIAS coupled models to answer different questions, thus tracking evolving policy needs. It also allows rigorous testing of the robustness of IA modelling results to the use of different component modules representing the same processes (for example, the economy). Such processes are often modelled in very different ways, using different paradigms, at the participating institutions. An illustrative application to the study of the relationship between the economy and the earth’s climate system is provided.