Korrelation zwischen der relativen Luftfeuchtigkeit und der Stromumwandlungseffizienz von Dünnschichtphotovoltaik

Diese Arbeit untersucht die verschiedenen Einflüsse des Wetters, insbesondere der relativen Luftfeuchtigkeit auf das auf der Erdoberfläche ankommende Sonnenspektrum. Die Auswirkungen der unterschiedlichen Sonnenspektren auf die Stromumwandlungseffizienz von Photovoltaik Modulen zu 3 unterschiedlichen Fertigungstechnologien werden untersucht. Die gängigen Photovoltaikmodultechnologien werden vor allem aufgrund der verwendeten Halbleiter unterschieden. Der Ertrag einzelner Module ändert sich dabei je nach Halbleitertyp mit den Einstrahlungsverhältnissen auf der Erdoberfläche. Im Rahmen des nationalen Projektes PV SPEC wurden verschiedene Modultypen (Mono, CdTe und a- Si) hinsichtlich ihres Verhaltens bezüglich spektraler Änderungen des einfallenden Sonnenlichtes und klimatischer bzw. meteorologischer Parameter untersucht. Schlussfolgerungen über die Umwandlungseffizienz der Module konnten getroffen werden. Dazu wurden Module jeder Type mit 35 Grad Neigungswinkel zu der horizontalen nach Osten, Süden und Westen an einem Flachlandstandort (170 m über Meer) über einen Zeitraum von circa 3 Jahren untersucht. Der Schwerpunkt der präsentierten Arbeit ist der Einfluss der relativen Feuchtigkeit der Luft sowie globale Einstrahlung - E - und spektral aufgelöste Einstrahlung auf die elektrischen Parameter der Module. Eine Veränderung der Wetter, oder feuchtebedingten spektralen Anteile der auf ein Modul treffenden Einstrahlung hin zum Roten (IR) oder Blauen (UV) Spektralbereich bedingt eine unmittelbare Änderung der StromUmwandlungseffizienz : über die spektrale Empfindlichkeit (SR) beeinflusst eine solche Änderung den im Modul aus dem Licht generierbaren Strom. Es wurden die Einflüsse der relativen Feuchtigkeit auf Bodenniveau in diesem Zeitraum mit jenen der relativen Feuchtigkeit des atmosphärischen Höhenprofils verglichen. Durch eine Simulation wurden die theoretischen Werte der Feuchteabhängigkeit mit den gemessenen Werten verglichen. Die Analyse aller Parameter gibt ein Mass für die Abhängigkeit der System- und klimarelevanten elektrischen Messgrößen von der relativen Feuchtigkeit der Luft. Für diese Arbeit wurden eine kristalline Modultechnologie (ein monokristallines Siliziummodul) und Dünnschichtmodule(ein amorphes Siliziummodul, und ein Kadmiumtelludrid Modul, CdTe) untersucht. Anwendung können die Ergebnisse dieser Arbeit in Planungsbüros für Photovoltaikanlagen finden, da sich gewisse Modultypen für einzelne Wetterbedingungen und bei einem bestimmten Mass der relativen Luftfeuchtigkeit besser eignen als andere.This thesis investigates different influences of the weather, primarily relative air-humidity on the on the earth's surface incoming solar spectrum. The impact of different solar spectra on the current conversion efficiency of 3 popular module technologies was investigated. The common different PV module technologies are distinguished primarily by the semiconductors used. The outcome of individual modules varies, depending on the type of semiconductor with the radiation conditions on the Earth's surface. As a part of the national project PV-SPEC, different types of modules (mono, CdTe and a-Si) were with respect to their spectral behavior with respect to the changes in the incident sunlight and climatic and meteorological parameters studied. Conclusions about the current output of the modules were made. Modules of each type were mounted of 35 degree angle of inclination (from the horizontal surface) to the east, south and west on a lowland site (170 m AMSL (Above Mean Sea Level)) over a period of 2 1/2 years. The focus of the presented work is the influence of the relative humidity of the air on the global irradiance, E and spectrally resolved irradiance on electrical module- parameters. A change due to the weather, or due to humidity on the spectral components of the irradiation through to Red (IR) or Blue (UV) spectral ranges causes an immediate change in the current conversion efficiency : through the spectral responsivity (SR) influences such a change the module output, that can be generated from the light. The influences of the relative humidity at ground level are during this period compared with those of the relative humidity of the atmospheric height pro files. Through a simulation the theoretical values of the humidity dependence are compared with the which of the measured values. The analysis of all datas gives a parameter for the dependence of the system-and climate-related electrical measurands and the relative humidity of the air. For this work were a crystalline module technology (a monocrystalline silicon module) and thin film modules (an amorphous silicon module, and a module Cadmiumtellurid, CdTe) examined. The application of the results of this work is in planning offices for photovoltaic systems. Because certain types of modules are more appropriate for individual weather conditions and at a certain degree of relative humidity than the others

Purification and characterization of an extracellular alkaline cold-adapted serine metalo-protease from the cold tolerant bacterium, Stenotrophomonas sp. BTR88

444-450Proteases are the most economical enzymes in biotechnology and industry. Nowadays, a lot of attention is being paid to extremophiles microorganisms owing to the diversity of their enzymes. One hundred and Six proteolytic bacteria were isolated from Binaloud Mountain; one of them (strain BTR88) was selected as the best producer of extracellular protease and was used for further studies. This bacterium belongs to Stenotrophomonas sp., which were identified by the 16S rDNA sequence. Maximal protease production was detected at the beginning of exponential growth phase in the presence of starch and skim milk at 20°C and pH 9. This protease was purified to electrophoretic homogeneity with a fold: 27.5, yield: 33% and specific enzyme: 12.6 U/mg. SDS-PAGE and zymography analyses revealed a protein band of 22 kDa. The maximum activity was at pH 9 and in the range of 20-30°C; while, the enzyme exhibited a broad range of activity from 20-80°C as well as the pH of 5-10. Enzyme inhibition in the presence of phenylmethane sulfonyl fluoride (PMSF) and Ethylenediaminetetraacetic acid (EDTA) showed that the purified enzyme belongs to serine metallo-enzymes. Kinetic parameters of km, Vmax and kcat for the cold tolerant enzyme were determined to be 7.2 mg/mL, 1.45 mM/min and 33.2 sec−1, respectively. The characteristics of activity in cold and alkaline conditions and the broad range of pH and temperature suggest that serine metalloprotease has potential use in the detergent industry

Purification and characterization of an extracellular alkaline cold-adapted serine metalo-protease from the cold tolerant bacterium, Stenotrophomonas sp. BTR88

Proteases are the most economical enzymes in biotechnology and industry. Nowadays, a lot of attention is being paid to extremophiles microorganisms owing to the diversity of their enzymes. One hundred and Six proteolytic bacteria were isolated from Binaloud Mountain; one of them (strain BTR88) was selected as the best producer of extracellular protease and was used for further studies. This bacterium belongs to Stenotrophomonas sp., which were identified by the 16S rDNA sequence. Maximal protease production was detected at the beginning of exponential growth phase in the presence of starch and skim milk at 20°C and pH 9. This protease was purified to electrophoretic homogeneity with a fold: 27.5, yield: 33% and specific enzyme: 12.6 U/mg. SDS-PAGE and zymography analyses revealed a protein band of 22 kDa. The maximum activity was at pH 9 and in the range of 20-30°C; while, the enzyme exhibited a broad range of activity from 20-80°C as well as the pH of 5-10. Enzyme inhibition in the presence of phenylmethane sulfonyl fluoride (PMSF) and Ethylenediaminetetraacetic acid (EDTA) showed that the purified enzyme belongs to serine metallo-enzymes. Kinetic parameters of km, Vmax and kcat for the cold tolerant enzyme were determined to be 7.2 mg/mL, 1.45 mM/min and 33.2 sec−1, respectively. The characteristics of activity in cold and alkaline conditions and the broad range of pH and temperature suggest that serine metalloprotease has potential use in the detergent industry

Finite element simulation of magnetohydrodynamic convective nanofluid slip flow in porous media with nonlinear radiation

A numerical investigation of two dimensional steady state laminar boundary layer flow of a viscous electrically-conducting nanofluid in the vicinity of a stretching ∕ shrinking porous flat plate located in a Darcian porous medium is performed. The nonlinear Rosseland radiation effect is taken into account. Velocity slip and thermal slip at the boundary as well as the newly developed zero mass flux boundary conditions are also implemented to achieve physically applicable results. The governing transport equations are reduced to a system of nonlinear ordinary differential equations using appropriate similarity transformations and these are then solved numerically using a variational finite element method (FEM). The influence of the governing parameters (Darcy number, magnetic field, velocity and thermal slip, temperature ratio, transpiration, Brownian motion, thermophoresis, Lewis number and Reynolds number) on the dimensionless velocity, temperature, nanoparticle volume fraction as well as on the skin friction, the heat transfer rates and the mass transfer rates are examined and illustrated in detail. The FEM code is validated with earlier studies for non-magnetic non-slip flow demonstrating close correlation. The present study is relevant to high-temperature nano-materials processing operations