Effect of operating current dependent series resistance on the fill factor of a solar cell

The fill factor of a solar cell depends upon the series resistance, reverse saturation current, diode quality factor, operating current and voltage. Since the series resistance itself depends upon the operating current (or voltage), it makes the evaluation of fill factor very complicated. In this paper, we have evaluated the fill factor of a solar cell, taking into account operating current dependence of the series resistance.     

Carbon Nanotube Growth on Calcium Carbonate Supported Molybdenum-Transition Bimetal Catalysts

A comparison of different catalyst systems (Fe–Mo, Co–Mo or Ni–Mo nanoparticles supported on calcium carbonate) has been performed in order to optimize the carbon nanotube (CNT) growth. The influences of the reaction temperature, metal loading and carbon source on the synthesis of CNTs were investigated. Dense CNT networks have been synthesized by thermal chemical vapor deposition (CVD) of acetylene at 720 °C using the Co–Mo/CaCO₃ catalyst. The dependence of the CNT growth on the most important parameters was discussed exemplarily on the Co catalyst system. Based on the experimental observations, a phenomenological growth model for CVD synthesis of CNTs was proposed. The synergy effect of Mo and active metals was also discussed.     

Effect of gamma irradiation and sulphitation treatments on keeping quality of white button mushroom Agaricus bisporus (J. Lge)

Gamma irradiation, alone and in combination with sulphitation, was tested for preventing the browning and maintaining the quality attributes of the white button mushrooms. Mushrooms were subjected to treatment of gamma irradiation in the dose range of 0.5–2.0 kGy and to combination treatments of sulphitation at a concentration of 0.1% potassium metabisulphite (KMS) and gamma irradiation (dose range 0.5–2.0 kGy) followed by storage at 10 ± 2 °C (RH 85%). A dose of 2.0 kGy significantly reduced the weight loss, prevented browning and mould growth. Cap and veil opening of mushrooms was delayed by 9 days and shelf life was extended by 12 days at a dose level of 2.0 kGy. Sulphitation alone at a concentration of 0.1% KMS was effective in controlling browning only upto 3 days, beyond which both browning and cap opening increased significantly ( P  ≤ 0.05) and the samples were unacceptable after 6 days of storage. No synergistic effect of sulphitation and irradiation was observed with respect to the shelf-life extension of mushroom.     

Unsteady incompressible boundary layer flow of a micropolar fluid at a stagnation point

The flow, heat and mass transfer on the unsteady laminar incompressible boundary layer in micropolar fluid at the stagnation point of a 2-dimensional and an axisymmetric body have been studied when the free stream velocity and the wall temperature vary arbitrarily with time. The partial defferential equations governing the flow have been solved numerically using a quasilinear finite-difference scheme. The skin friction, microrotation gradient and heat transfer parameters are found to be strongly dependent on the coupling parameter, mass transfer and time, whereas the effect of the microrotation parameter on the skin friction and heat transfer is rather weak, but microrotation gradient is strongly affected by it. The Prandtl number and the variation of the wall temperature with time affect the heat-transfer very significantly but the skin friction and micrortation gradient are unaffected by them.     

Induction of ovulation in the human with centchroman: a preliminary report

After burn or resection of one submandibular salivary gland the contralateral gland responded by an increase of proliferation. The maximal mitotic index was observed 48 hours after the resection and 72 hours after the burn. Burn of the salivary gland initiated a stable, but weak compensatory hypertrophy of the contralateral gland. Hypertrophy of the gland was accompanied by an increase in the size of the cells and the nuclei whose area enlarged by 10 and 17%, respectively. Resection of the salivary gland caused an increase in the weight of the intact contralateral gland only at the early periods of the experiment. By the 30th and the 45th day after the operation the weight of the intact contralateral gland failed to differ from control. The detected differences in the compensatory growth of the intact glands in two types of action on the contralateral salivary gland depended on the quantity of the tissue degeneration products and on the period of their stay in the organism.     

On the sintering kinetics of titania doped ceramic lanthanum chromite

The sintering behaviour of lanthanum chromite with the addition of 1 to 3 wt% TiO₂ was studied. Densification was examined as a function of sintering temperature and TiO₂ concentration. The results showed that pure LaCrO₃ could not be densified to >75% of the theoretical density, while the densities exceeding 90% of the theoretical were achieved with 3 wt% titania addition at 1600° C. Metallographic study reveals a normal grain growth following the rate equationD ²−D ₀ ² =kt. Activation energies both for densification and grain growth have been estimated to be ≈ (80±5) k cal/mole in case of 3 wt% TiO₂ addition.     

Cytodiagnosis of primary malignant melanoma of the female urethra--a case report

Clinical course of multiple myeloma in patients under 40 years of age was analysed. In all cases diagnosis was established in III stage of the disease according to Durie and Salmon. In 4 cases good response to treatment (partial remission or stabilisation of proliferative process) was achieved. Survival time of 2 dead patients was 5 and 74 months, and that of 3 still alive patients is 41, 53, and 59 months and tends to be longer than median survival time of general population of patients with multiple myeloma.