953 resultados para Research work
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In the field of fluid mechanics, free surface phenomena is one of the most important physical processes. In the present research work, the surface deformation and surface wave caused by temperature difference of sidewalls in a rectangular cavity have been investigated. The horizontal cross-section of the container is 52 mmx42 mm, and there is a silicon oil layer of height 3.5 mm in the experimental cavity. Temperature difference between the two side walls of the cavity is increased gradually, and the flow on the liquid layer will develop from stable convection to un-stable convection. An optical diagnostic system consisting of a modified Michelson interferometer and image processor has been developed for study of the surface deformation and surface wave of thermal capillary convection. The Fourier transformation method is used to interferometer fringe analysis. The quantitative results of surface deformation and surface wave have been calculated from a serial of the interference fringe patterns.The characters of surface deformation and surface wave have been obtained. They are related with temperature gradient and surface tension. Surface deformation is fluctuant with time, which shows the character of surface wave. The cycle period of the wave is 4.8 s, and the amplitudes are from 0 to 0.55 mu m. The phase of the wave near the cool side of the cavity is opposite and correlative to that near the hot side. The present experiment proves that the surface wave of thermal capillary convection exists on liquid free surface, and it is wrapped in surface deformation.
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Resumen: En el presente trabajo se analizan los cambios en la forma de medición del apego de la infancia a la niñez. Se describen las historias lúdicas de apego, utilizadas como instrumentos para clasificar las representaciones de apego de niños desde los cuatro años. Se propone la incorporación de esta herramienta de investigación en el trabajo clínico: en la evaluación clínica para aprehender patrones relacionales y en la psicoterapia como herramienta para potenciar la capacidad de los padres de reflexionar sobre el mundo mental del hijo. Para ilustrar la manera en que las narrativas lúdicas permiten evocar las representaciones de apego en un niño se presentan y analizan viñetas de La Tarea de Historias de Apego para Niños (J. Green, C. Stanley, V. Smith & R. Goldwyn, 2000) completadas en el marco de una investigación clínica (I. Di Bartolo, 2009).
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[ES] En este trabajo realizamos un análisis de los artículos sobre contabilidad medioambiental publicados en las principales revistas españolas de gestión, durante el periodo 1993-2003. De esta forma, analizamos la situación actual y la evolución de la investigación en esta línea durante el periodo señalado, así como el papel desempeñado por las distintas revistas en el desarrollo del conocimiento sobre esta materia.
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2005年,力学所经历了几件大事:一是完成了中国科学院知识创新工程试点二期的总结和创新三期筹划,并顺利通过了现场评估,为进入2006年开始的创新三期奠定了坚实基础;二是成功举办丁“庆祝力学研究所建所50周年暨钱学森回国50周年大会”;二是在国家和(部门)重点实验室的评估中,我所非线性力学国家重点实验室和高温气体动力学重点实验室被评为数理科学“良好类”实验室.
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2003年,力学所在知识创新工程试点工作中取得了新的进展和成果.这一年有两件大事值得记忆:一是中长期发展战略规划的制定;二是抗击非典.力学所在这场战役中结合自己的工作基础,齐心协力,贡献了自己的力量.
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In the present research work, the thermal capillary convection has been investigated and measured by particle image velocimetry (PIV) technique. There is one liquid layer in a rectangular cavity with different temperature’s sidewalls. The cavity is 52mm,42mm,20mm, 4mm in height of the silicon oil liquid layer. A sidewall of the cavity is heated by electro-thermal film, another sidewall is cooled by the semiconductor cooling sheet. The velocity field and the stream lines in cross section in liquid layer have been obtained at different temperature difference. The present experiment demonstrates that the pattern of the convection mainly relates with temperature difference.
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[EN]The present research work, based on some of the components of the Common Assessment Framework, sets to analyse the influence held by leadership in specific factors that constitute the organisational climate, and also the impact that these factors have on the quality of municipal public services. For the purposes of this study, we propose Likert’s exploitative autocratic and participative leadership styles to explain the genesis, structure and workflow. As far as the organisational climate is concerned, the variables used are motivation, satisfaction, empowerment, conflict and stress. The main conclusions that arose was that a participative leader confers higher relevance to the quality of service, through motivation, satisfaction, empowerment and human resources positive results, than an exploitative autocratic leader. Performed contributions are based on the empiric research hereby presented, and new research guidelines are proposed. The research methodology used was qualitative, based on the case study.
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288 p. : il.
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215 p.
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This research work involves the determination and modelling of water parameter such as pH, temperature, turbidity, chloride, hardness. The result of the analysis was used as important operating variables to generate a model equation of pH, hardness, temperature, turbidity and chloride. The values obtained from the model equation were compared with those from experiment. On an average bases the values were close. These parameters can be used to monitor the extent of pollution of pond water and to monitor stress and diseases of fish. The experimental data of pH was in the range of 6.7 to 6.9 while the modelled result was also between 6.7 to 7.0. The turbidity experimental value was close to the modelled value also. The chloride value for the experimental data was in the range of 25.32 to 35.0. The total hardness value ranges between 4.5 to 65.1 mg/l while the modelled result ranges between 11.025 to 68.402 mg/l. The result was within the acceptable limit of world health organization standard on water quality parameter.
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LABURPENA: EAEko hezkuntza sistemak gero eta ikasle etorkin kopuru handiagoa du. Horrek ikasgeletan hizkuntz aniztasuna sortzen du, ezinezkoa bihurtuz irakasleek ume guztien ama hizkuntza jakitea. Egoera berri horren aurrean, lan honen helburua da jatorri etorkina duten ikasleen ama hizkuntzei eskolan ematen zaien trataera ezagutzea. Asmo horrekin, adituek eskolako hizkuntzaren ikaskuntza prozesuan umeen ama hizkuntzek duten garrantziaz diotena aztertu dugu eta, ondoren, etorkin kopuru handia duen eskola publiko batean murgildu gara errealitate hori ikertzeko. Azterketa-lanean lorturiko emaitzak ikusita, ez du ematen ikastetxe horretan jarraitzen ari diren hezkuntza elebiduna modu egokiena denik egoera berriari erantzuteko eta badirudi interesgarria izan daitekeela antolakuntza, metodologia eta estrategia berritzaileetan pentsatzea.
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[ES]El disulfuro de carbono (CS2) y el sulfuro de hidrógeno (H2S) son gases especialmente tóxicos presentes en una gran cantidad de emisiones gaseosas industriales, principalmente en la producción de fibras de rayón a partir de celulosa en el caso del CS2, y en la industria petroquímica en el caso del H2S. La legislación vigente en cuanto a las emisiones de estos compuestos se refiere hace que su tratamiento sea, en muchos casos, necesario. La biofiltración como tecnología para el tratamiento de corrientes gaseosas contaminadas se ha convertido en los últimos años en una alternativa a los tratamientos físico-químicos empleados hasta la fecha. Sin embargo, uno de los principales obstáculos a la hora de la implantación de este tratamiento biológico a escala industrial es la duración del periodo de aclimatación de la biomasa encargada de degradar los contaminantes, que en función del compuesto a tratar puede resultar demasiado largo para la aplicación comercial de esta tecnología. El presente trabajo se centra en el estudio de estos periodos de arranque y aclimatación, especialmente lentos en el caso del CS2, y propone una estrategia de arranque basada en la reutilización de biomasa capaz de degradar los compuestos de interés, almacenada tras usos anteriores, que permite reducir el tiempo necesario para alcanzar eficacias de eliminación elevadas. Paralelamente, se ha concluido que paradas de corta duración no afectan de manera importante a la operación del sistema.
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Climate change is amongst the most dreaded problems of the new millennium. Bangladesh is a coastal country bounded by Bay of Bengal on its southern part and here natural disasters are an ongoing part of human life. This paper discusses about the possible impact of climate change through tropical cyclones, storm surges, coastal erosion and sea level rise in the coastal community of Bangladesh and how they cope with these extreme events by the help of mangrove ecosystem. Both qualitative and quantitative discussions are made by collected data from different research work those are conducted in Bangladesh. Mangrove ecosystem provides both goods and services for coastal community, helps to improve livelihood options and protect them from natural disaster by providing variety of environmental support
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Experimental stocking density of Macrobrachium rosenbergii in larval rearing was conducted in A.G. Aqua Hatchery, Chakaria, Bangladesh to study the effect of different stocking densities on growth, survival rate and diseases stress under hatchery condition. The research work was conducted using six cemented rectangular tanks having 3m3 capacity (1.5mX2mX1m) each. Stocking density were maintained in three experimental setup as 200, 150 and 100ind/L of the T1, T2 and T3 respectively with one replicate each. The larvae were fed with Artemia nauplii, Custard, Maxima and brine shrimp flakes. Water quality was maintained by exchanging 20-30% (12ppt saline water) daily. During the study period, temperature, pH, DO, salinity, nitrite-nitrogen, ammonia and alkalinity were maintained from 28.5-31.5ºC, 7.5-7.8, 5.8-5.9mg/L, 12-13ppt, 0.14-0.2 mg/L, 0.22-0.3mg/L, and 140-160mg/L respectively. The growth rates of larvae at 11th stage were recorded in terms of body length 0.115, 0.136, and 0.169 mm/day whereas body weight were observed 0.000115, 0.000180, and 0.000240g/day. The survival rate of larvae were found 21.8%, 30.4% and 51.3% in treatments T1, T2 and T3 respectively. PL was obtained as 43, 45, and 51PL/L and days required of 41, 38 and 34 days in stocking density of 200, 150, and 100ind/L respectively. It was found that the minimum of 34 days was required to attain the PL (12th stage) using the stocking density of 100 individuals/L. Cannibalism, Zoothamnium, Exuvia Entrapment Disease (EED), and Bacterial Necrosis (BN) were found to be the threat to the commercial hatchery operation that might responsible for potential larval damages which can be reduced by lowering the stocking densities in larval rearing tank that also increased the survival and growth rate.
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Ephemera danica Müller, 1764 (Ephemeroptera) is one of the largest mayflies found in the British Isles with some females reaching over 30 mm. It is a common and widespread species found in rivers, lakes and streams throughout Europe and is particularly abundant in many of the lowland rivers of the British Isles. The larvae are burrowers – mainly found where silt accumulates below macrophytes. This article gives a general overview of research work on the factors affecting the life cycle of Ephemera danica over a seven year period (1995–2002) on two rivers, the River Test at Leckford in Hampshire and the North Wey at Tilford in Surrey.