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1.
Energy is one of the most important factors in the socioeconomic development of a country. In a developing country like Malaysia, the development of islands is mostly related to the availability of electric power. Power generated by renewable energy sources has recently become one of the most promising solutions for the electrification of islands and remote rural areas. But high dependency on weather conditions and the unpredictable nature of these renewable energy sources are the main drawbacks. To overcome this weakness, different green energy sources and power electronic converters need to be integrated with each other. This study presents a battery storage hybrid standalone photovoltaic-wind energy power supply system. In the proposed standalone hybrid system, a DC-DC buck-boost bidirectional converter controller is used to accumulates the surplus hybrid power in the battery bank and supplies this power to the load during the hybrid power shortage by maintaining the constant dc-link voltage. A three-phase voltage source inverter complex vector control scheme is used to control the load side voltage in terms of the voltage amplitude and frequency. Based on the simulation results obtained from MATLAB/Simulink, it has been found that the overall hybrid framework is capable of working under variable weather and load conditions. 相似文献
2.
Microbial mineralization of organic phosphate in soil 总被引:35,自引:0,他引:35
Summary Phosphate-dissolving microorganisms were isolated from non-rhizosphere and rhizosphere of plants. These isolates included
bacteria, fungi and actinomycetes. In broth cultures, Gram-negative short rod,Bacillus andStreptomyces species were found to be more active in solubilizing phosphate thanAspergillus, Penicillium, Proteus, Serratia, Pseudomonas andMicrococcus spp. The sterile soils mixed with isolated pure culture showed slower mineralization of organic phosphate than that of non-sterile
soil samples at all incubation periods. Maximum amount of phosphate mineralization by isolated microorganisms were obtained
at the 60th and the 75th day of incubation in sterile and non-sterile soils respectively. The mixed cultures were most effective
in mineralizing organic phosphate and individuallyBacillus sp. could be ranked next to mixed cultures. Species ofPseudomonas andMicrococcus were almost the same as that of the control under both sterile and non-sterile conditions. 相似文献
3.
Stopped-flow kinetic studies of the formation of ferrioxamine B were performed. Formation of the complex follows the rate law where Ka is the acid dissociation constant of the iron(III) aquo species in 0.1 M formate buffer. At 25°C k1 = 3.94 × 102M?1 sec?1, k2Ka = 1.18 × 10?1 sec?1, k3 = 3.6 × 10?1 sec?1. Activation parameters for k1 are ΔH≠ = 11.7 kcal mole?1 and ΔS≠ = ?8 cal K?1 mole?1. An associative mechanism is proposed. Attachment of the first chelate ring is the slow step and favorably positions the second chelate ring for attachment. Coordination of two chelate rings favorably positions the third chelate ring for attachment. These results are compared to kinetics of formation of model complexes and to a previous study of the formation of ferrioxamine B in which attachment of the third chelate ring was proposed as the slow step 相似文献
4.
Copper metabolism in a teleost, the plaice, Pleuronectes platessa (L.) from a natural environment has been studied. Distribution in the various tissues of the metal and of five key copper-dependent enzymes: ceruloplasmin EC 1.16.3.1; Superoxide dismutase EC 1.15.11; tryptophan oxygenase EC 1.13.1.12; cytochrome oxidase EC 1.9.3.1 and monoamine oxidase EC 1.4.3.4 have been determined. The copper distribution was found to be similar to that in mammals with the greatest concentrations in the brain and heart. Distribution of the copper enzymes is also similar to that found in mammals. A preliminary characterization of the copper enzymes showed that plaice cytochrome oxidase has a pH maximum 2 pH units more alkaline than the mammalian enzyme and that plaice tryptophan oxygenase is more sensitive to heat denaturation than the mammalian enzyme. The present data form a base-line against which studies on factors affecting the copper metabolism in a teleost can be assessed. 相似文献
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A composting experiment was conducted to evaluate the effect of a hyperlignocellulolytic fungal consortium and different nitrogen
amendments on paddy straw composting in terms of changes in physicochemical and biological parameters. A fungal consortium
comprising four lignocellulolytic mesophilic fungal cultures was used as inoculum for bioaugmentation of paddy straw in perforated
pits. The comparative effect of farmyard manure (FYM), soybean trash, poultry litter and urea on the composting process was
evaluated at monthly intervals in terms of physicochemical (pH, EC, available P, C:N ratio and humus content) and biological
(enzymatic and microbial activity) parameters. The compost prepared from bioaugmented paddy straw composting mixture, with
poultry manure as nitrogen supplement attained desirable C:N ratio in 1 month and displayed least phytotoxicity levels along
with higher production of β-1,4-Exoglucanase. The combined activity of the autochthonous composting microbiota as well as the externally applied fungal
inoculum accelerated the composting process of paddy straw. Supplementation of paddy straw with poultry manure in 8:1 ratio
was identified as the best treatment to hasten the composting process. This study highlights the importance of application
of fungal inoculum and an appropriate N-amendment such as poultry manure for preparation of compost using a substrate having
high C:N ratio, such as paddy straw. 相似文献