Analysis of Performance Parameters of Amorphous Photovoltaic Modules under Different Environmental Conditions

The effects of temperature and radiation intensity on the performance parameters of amorphous hydrogenated silicon (a-Si:H) photovoltaic module have been investigated. An outdoor experimental setup is installed to carryout a series of I-V curve measurements under different irradiance and temperature conditions for the module. A numerical model which considers the effect of series and shunt resistances is developed to evaluate the different parameters of PV modules. Orthogonal distance regression (ODR) algorithm is adapted for fitting I-V measurements and extracting module parameters from I-V measurements. The values of module parameters, series resistance Rs, shunt resistance Rsh, diode ideality factor n and reverse saturation current Io determined from I-V measurements at different irradiation intensity and temperature range are in good agreement with the corresponding parameters obtained from the developed numerical model. The module parameters extracted from I-V measurements are employed to calculate the module performance parameters, i.e. open circuit voltage Voc, fill factor FF and module efficiency h at different irradiation intensity and temperature range. Present results indicate that the module parameters have a significant effect on module performance. Also, the behavior of Voc is completely different at higher temperatures.Key words: Amorphous module parameters;  Ideality factor; Series resistance; Shunt resistanc

Zeolite abrogates cadmium-induced testicular damage in rats: implication of NF-κB/ TNF-α/IL-1β Pathway

ABSTRACT Cadmium (Cd) is an environmental pollutant affecting various tissues and organs, including the testis. Many studies demonstrated that Cd toxicity causes testicular impairment through oxidative stress and inflammatory action. Therefore, this study aimed to demonstrate Cd's testicular toxicity and the protective action of zeolite against cadmium's deleterious effects. Adult male rats were given Cd at a dose of 30mg/kg/day for 28 consecutive days with or without zeolite, which was given at a dose of 100mg/kg/day for 28 days. Testis weight, sperm (count, motility, and abnormalities), serum testosterone and luteinizing hormone (LH), testicular enzymes Acid phosphatase (ACP) and Alkaline phosphatase(ALP), inflammatory cytokines Tumor Necrosis Factor Alpha (TNF-α) , interleukin-1beta (IL-1β) , and Nuclear Factor Kappa B (NF-κB) and oxidative stress were evaluated. Herein, we found that cadmium caused alterations in sperm characteristics, sex hormone disturbance, decline in testicular enzymes, elevated malondialdehyde (MDA) contents, decreased glutathione (GSH), increased Nuclear Factor Kappa B (NF-κB) and pro-inflammatory cytokines Tumor Necrosis Factor Alpha (TNF-α) and interleukin-1beta (IL-1β) levels in testis homogenate. In contrast, zeolite significantly amended these deleterious effects, and the potential mechanism involved the downregulation of Nuclear Factor Kappa B (NF-κB), Tumor Necrosis Factor Alpha (TNF-α) and interleukin-1beta (IL-1β), restoring glutathione (GSH) and reducing malondialdehyde (MDA). Also, zeolite was associated with an increased rate of pregnancy. Our data suggested that oxidative stress and inflammation are responsible for Cd-induced testicular injury and co-administration of zeolite exerts a protective effect via NF-κB /TNF-α/IL-1β pathway

Geometrical study of ventilation system openings of pump room in nuclear power plant

Fire safety is important throughout the lifetime of nuclear power plant (NPP), from design to construction throughout plant operation. The integrity of the shutdown cables located in the pump room in NPPs is very important in the fire protection system. Therefore, the present numerically study investigates the effect of outlet vent opening geometry and the location of the ventilation system specifications on the heat transfer in pump room during a fire. Three-dimensional ANSYS- FLUENT Computational Fluid Dynamics with Realizable k–ε turbulence model is employed in the present work. The results found that the geometry (aspect ratio) of the outlet opening vent has major effects on the shutdown cable protection from fire according to their locations. Furthermore, as the aspect ratio for outlet vent decreases, then the suction of hot gasses from the upper half of the room is improved. Consequently, the temperature of the heat source and target decreases. When the two inlet and outlet vents are located at a same lower level from the ground the inlet velocity should be 1.25 m/s, while, when the two vents are located at two different level the inlet velocity should be 0.75 m/s in order to protect the shutdown cable insulation. Keywords: Nuclear power plant, Numerical, CFD, Pump room, Vents location

Effect of chemical structure on the cloud point of some new non-ionic surfactants based on bisphenol in relation to their surface active properties

AbstractA series of non-ionic surfactants were prepared from bisphenol derived from acetone (A), acetophenone (AC) and cyclohexanone (CH). The prepared bisphenols were ethoxylated at different degrees of ethylene oxide (27, 35, 43). The ethoxylated bisphenols were non-esterified by fatty acids; decanoic, lauric, myristic, palmitic, stearic, oleic, linoloic and linolinic. Some surface active properties for these surfactants were measured and calculated such as, surface tension [γ], critical micelle concentration [CMC], minimum area per molecule [Amin], surface excess [Cmax], free energy of micellization and adsorption [ΔGmic] and [ΔGads]. At a certain temperature, the cloud point was measured for these surfactants. From the obtained data it was found that; the cloud point is very sensitive to the increase of the alkyl chain length, content of ethylene oxide and degree of unsaturation. The core of bisphenol affected the cloud point sharply and they are ranked regarding bisphenol structure as BA>BCH>BAC. By inspection of the surface active properties of these surfactants, a good relation was obtained with their cloud points. The data were discussed on the light of their chemical structures

The teratogenic effects of imatinib mesylate on rat fetuses

AbstractImatinib mesylate, a selective tyrosine kinase inhibitor, is the first line treatment against chronic myelogenous leukemia and gastrointestinal stromal tumors. The aim of the present study is to investigate the effects of imatinib mesylate on the pregnant rats and their fetuses. Pregnant rats were divided into three groups; the first group served as a control group. The second and third groups were orally administered imatinib at doses of 36mg/kg body weight or 54mg/kg b.wt. on gestation days (SDs) 6 through 13 or SDs 13 through 19, respectively. All animals were sacrificed on the 20th day of gestation. Treatment with imatinib caused a reduction of maternal body weight gain, uterine and placental weights, increased rate of abortion and fetal resorptions. High dose of imatinib caused fetal congenital deformities represented in harelip, contraction of the fore limbs, and paralysis of the hind limbs, exencephaly, encephalocoele and distended abdominal wall, besides occurrence of wavy ribs and absence of other ribs in addition to skeletal growth retardation and lack of ossification of the most skeletal elements. The present work concluded that imatinib is teratogenic when given orally to pregnant rats at 54mg/kg b.wt. and causes direct maternal or developmental toxicity