993 resultados para Solar greenhouses
Resumo:
Tesis (Maestría en Ciencias con Orientación en Química Analítica Ambiental) UANL, 2010.
Resumo:
Tesis (Maestría en Ciencias con Orientación en Procesos Sustentables) UANL, 2012.
Resumo:
Tesis (Maestría en Ciencias con Orientación en Química Analítica Ambiental) UANL, 2011.
Resumo:
Tesis (Maestría en Ciencias de la Ingeniería Mecánica con Especialidad en Materiales) UANL, 2013.
Resumo:
Tesis (Maestría en Ingeniería Física Industrial) UANL, 2014.
Resumo:
UANL
Resumo:
UANL
Resumo:
UANL
Resumo:
Tesis (Doctor en Ciencias con orientación en Química Analítica Ambiental) UANL, 2013.
Resumo:
Tesis (Doctorado en Ciencias con orientación en Química de los Materiales) UANL, 2014.
Resumo:
Thèse numérisée par la Division de la gestion de documents et des archives de l'Université de Montréal
Resumo:
The need for reliable predictions of the solar activity cycle motivates the development of dynamo models incorporating a representation of surface processes sufficiently detailed to allow assimilation of magnetographic data. In this series of papers we present one such dynamo model, and document its behavior and properties. This first paper focuses on one of the model's key components, namely surface magnetic flux evolution. Using a genetic algorithm, we obtain best-fit parameters of the transport model by least-squares minimization of the differences between the associated synthetic synoptic magnetogram and real magnetographic data for activity cycle 21. Our fitting procedure also returns Monte Carlo-like error estimates. We show that the range of acceptable surface meridional flow profiles is in good agreement with Doppler measurements, even though the latter are not used in the fitting process. Using a synthetic database of bipolar magnetic region (BMR) emergences reproducing the statistical properties of observed emergences, we also ascertain the sensitivity of global cycle properties, such as the strength of the dipole moment and timing of polarity reversal, to distinct realizations of BMR emergence, and on this basis argue that this stochasticity represents a primary source of uncertainty for predicting solar cycle characteristics.
Resumo:
The study on the fabrication and characterization of spray pyrolysed cadmium sulphide homojunction solar cells. As an alternative to the conventional energy source, the PV technology has to be improved. Study about the factors affecting the performance of the existing solar cells and this will result in the enhancement of efficiency of the cells. At the same time it is equally important to have R&D works on developing new photovoltaic devices and processes which are less expensive for large scale production. CdS is an important binary compound semiconductor, which is very useful in the field of photovoltaics. It is very easy to prepare large area CdS thin films. In order to fabricate thin film homojunction cadmium sulphide cells, prepared and characterized SnO2 thin film as the lower electrode, p-CdS as the active layer and n-CdS as window layer. Cadmium material used for the fabrication of homojunction solar cells is highly toxic. The major damage due to continued exposure to low levels of cadmium are on the kidneys, lungs and bones. The real advantage of spray pyrolysis process is that there is no emission of any toxic gases during the deposition. Very low concentration of the chemicals is needed in this process. The risk involved from this material is very low, though they are toxic. On large scale usage it may become necessary that the cells after their life, should be bought back by the companies to retrieve chemicals like cadmium. This will reduce environmental problem and also the material wastage
Resumo:
In the present work, structural, optical and electrical properties of indium sulfide are tuned by specific and controlled doping. Silver, tin, copper and chlorine were used as the doping elements. In2S3 thin films for the present study were prepared using a simple and low cost “Chemical Spray Pyrolysis (CSP)” technique. This technique is adaptable for large-area deposition of thin films in any required shape and facilitates easiness of doping and/or variation of atomic ratio. It involves spraying a solution, usually aqueous, containing soluble salts of the constituents of the desired compound onto a heated substrate. Doping process was optimized for different doping concentrations. On optimizing doping conditions, we tuned the structural, optical and electrical properties of indium sulfide thin films making them perform as an ideal buffer layer.