Wind and Solar Cell Based Distribution System for Different Load Variations Using Fuzzy Logic Controller

The proposed system presents power-control strategies of a grid-connected hybrid generation system with versatile power transfer. This hybrid system allows maximum utilization of freely available renewable energy sources like wind and photovoltaic energies . For this, an adaptive MPPT algorithm along with standard perturb and observe method will be used for the system.Also, this configuration allows the two sources to supply the load separately or simultaneously depending on the availability of the energy sources. The turbine rotor speed is the main determinant of mechanical output from wind energy and Solar cell operating voltage in the case of output power from solar energy. Permanent Magnet Synchronous Generator is coupled with wind turbine for attaining wind energy conversion system.The inverter converts the DC output from non-conventional energy into useful AC power for the connected load . This hybrid system operates under normal conditions which include normal room temperature in the case of solar energy and normal wind speed at plain area in the case of wind energy. A fuzzy based PWM system will be designed to reduce the harmonic ripples. The simulation results are presented to illustrate  the operating principle, feasibility and reliability of this proposed system. Keywords: smart grid, solar cell, fuzzy logic controlle

Wind and Solar Cell-Based Distribution System for Different Load Variations Using Fuzzy Logic Controller

The proposed system presents power-control strategies of a grid-connected hybrid generation system with versatile power transfer. This hybrid system allows maximum utilization of freely available renewable energy sources like wind and photovoltaic energies . For this, an adaptive MPPT algorithm along with standard perturb and observe method will be used for the system.Also, this configuration allows the two sources to supply the load separately or simultaneously depending on the availability of the energy sources. The turbine rotor speed is the main determinant of mechanical output from wind energy and Solar cell operating voltage in the case of output power from solar energy. Permanent Magnet Synchronous Generator is coupled with wind turbine for attaining wind energy conversion system . The inverter converts the DC output from non-conventional energy into useful AC power for the connected load . This hybrid system operates under normal conditions which include normal room temperature in the case of solar energy and normal wind speed at plain area in the case of wind energy. A fuzzy based PWM system will be designed to reduce the harmonic ripples. The simulation results are presented to illustrate  the operating principle, feasibility and reliability of this proposed system. Keywords: smart grid, solar cell, fuzzy logic controlle

Soil Surface Management Practices and Their Effects on Microorganisms of an Alfisol

Soil productivity greatly depends on the balance between physical, chemical and biological properties of soil Biological property of soil largely comprises the size and the activity o

Vesicular-arbuscular mycorrhizal fungi in earthworm casts and surrounding soil in relation to soil management of a semi-arid tropical Alfisol

Spores and infective propagules of vesicular-arbuscular (VA) mycorrhiza were examined in earthworm casts and field soils collected from three different soil management treatments (zero tillage with straw amendment, deep tillage without amendment (bare), and zero tillage with previous perennial cropping of Stylosanthes hamata) on an Alfisol in the semi-arid tropics (SAT) of India. The average mean of spore counts and most probable number (MPN) of infective propagules of VA mycorrhiza (VAM) were significantly (P earthworm casts than in field soil across the three soil management treatments. There was no significant difference in the number of VAM spores or propagules among field soils from the three different soil management treatments, but the number of VAM spores and propagules in the earthworm casts from the deep tillage bare treatment was significantly higher (P earthworm casts from the other two treatments. In the deep tillage bare treatment, the number of spores and MPN of infective propagules were significantly (P earthworm casts than in field soil. Therefore, it may be concluded that earthworms can concentrate VA mycorrhizal spores and propagules in their casts

Associative N2-fixation in pearl millet and sorghum: levels and response to inoculation.

N2-fixation was compared in pearl millet (Pennisetum glaucum), sorghum, pigeonpeas, chickpeas, and groundnuts and the responses of the two cereal crops to inoculation with N2-fixing bacteria was examined. The overall mean nitrogenase activity (C2H2 reduction) in pearl millet throughout the growing period was less than 0.1% of that in pigeonpeas and the activity in sorghum was only 1.3% of that in chickpeas. Whether assessed by the determination of the N balance in pots, using pigeonpeas as reference, or by the measurement of the natural abundance of 15N (δ15N) using groundnuts as reference, N gain by these cereals, even when they were inoculated with N2-fixing bacteria was not observed. Inoculation trials were conducted in pots and in the field with Azospirillum lipoferum and Azotobacter chroococcum. Only one trial with sterilized soil in pots showed a significant response to inoculation. It is concluded that associative N2-fixing systems in pearl millet and sorghum do not exert an agronomically significant impact through N input on the production of these crops

Effect of fertiliser nitrogen and irrigation on root growth and extension, and water uptake of post-rainy season sorghum

Effects of fertilizer nitrogen (N) and irrigation on root development are discussed by collating the observations in published reports with those in our study using field-grown sorghum [Sorghum biocolor (L.) Moench] on a deep Vertisol in semi-arid tropical India. In our study, the total root biomass was affected by fertilizer-N and irrigation and by their interaction. It is the top soil layers that contribute largely to increased root biomass due to fertilizer-N and irrigation. These observations agree with those in other reports. The total root length was not significantly affected by fertilizer-N, but was consistently higher under dry conditions than under irrigated conditions. Spatial distribution of root length did not fit a simple mathematical model such as linear, exponential or logistic curve, except at very young growth stages under irrigated conditions. Except the top 16- cm layer, the depth at which root length density zvas maximum shifted to deeper layers as sorghum grew. This may indicate that some roots die after water extraction and that new roots grow at the soil layers where water zvas available. This specific feature would contribute to the complexity of modeling of root development. Rooting depth was not affected by fertilizer-N, but it was consistently greater under dry conditions than under irrigated conditions. The root depth had a linear relationship with time under dry and irrigated conditions up to the physiological maturity stage. Water uptake by sorghum was determined as the difference between measured evapotranspiration and estimated soil evaporation. In non-irrigated treatment, the differences in water uptake among N treatments were not significant. In the irrigated treatment, the rates of 30 to 150 kg N ha (30 N and 150 N, respectively) resulted in significantly higher water uptake than no fertilizer-N. The fertilizer-N effect in our study zvas not as clear-cut as that in other reports

New Peptides Isolated from Lyngbya Species: A Review

Cyanobacteria of the genus Lyngbya have proven to be prodigious producers of secondary metabolites. Many of these compounds are bioactive and show potential for therapeutic use. This review covers peptides and hybrid polyketide-non-ribosomal peptides isolated from Lyngbya species. The structures and bioactivities of 50 Lyngbya peptides which were reported since 2007 are presented