Volume 5 | Issue 3 | July

 Abstract

For the purpose of better utilization and to have control over varying wind speeds we use variable speed wind turbines. The performance mainly depends on the system operating point. In this paper we implement extremum seeking (ES) which is a non-model based approach for maximum power extraction in the region between cut-in speed and rated speed. The convergence of the system depends mainly on the system dynamics so we go for non-linear control based on field oriented approach and also feedback linearization. For achieving maximum power at all wind speeds the outer loop of ES is used to tune the turbine speed in the sub rated region. By adjusting the voltage magnitude and electrical frequency through matrix converter we can achieve a fast transient response. The transient response can be improved by providing inner loop control based on field oriented control. Through this we can avoid magnetic saturation in the induction generator.

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 Keywords

Matrix Converter (MC); power generation control; Squirrel Cage Induction Generator (SCIG); Wind energy Conversion System (WECS)

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Transglutamine is the enzyme that forms cross-links between protein molecules to produce new proteins with novel functionalities. The present study is aimed to produce microbial transglutaminase (MTGase) using the soil as a source for MTGase producing strains. Selective isolation of actinomycetes strains and screening of the isolated strains to measure their ability to produce MTGase were carried out. Also, the genus and the species of the isolated MTGase strain were identified. The results of inoculated aqueous extracts of the soil samples using selective agar glycerol medium showed that the colonies were Gram positive, appear powdery and opaque white which described as actinomycetes-like colonies. Three samples from the first group (eight samples) which produced the highest amount of the enzyme were chosen to continue the screening steps. The second group (13 soil samples) and the samples which were selected from the first group were tested again for ability to produce MTGase using tryptic casein hydrolyzate instead casein as a substrate. The results indicated that there were seven strains only from the aforementioned strains produced high amount of MTGase (about 0.04 U/ ml). These strains were tested through the second screening which revealed that the maximum enzyme activity was obtained from four strains only which were subjected to further tests to investigate its taxa of bacterial classification. The light microscopic examination indicated that the four strains showed unfragmented hyphae. Beside, some sprouting spores were shown in only three strains which were subjected to the third screening using equal cell content rather than equal inoculum volume. The maximum produced enzyme was obtained from only one strain after four days of fermentation. It was selected to study the next part of the study. The light and scanning electron miscopy indicated that the isolated strain in the present study is related to the genus Streptomyces. The species was also identified by investigation of 34 tests of those used to identify the Streptomyces strains which indicated that the prepared strain is Streptomyces diastaticus.

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 Keywords

Actinomycetes; selective isolation; screening; identification; streptomyces

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 Abstract

Voltage stability is major phenomena in any power system network for reliability and continuity operation but the tight operation of power system due to overloading or fault on the system which is evitable and major threat to the power system. So it is necessary to maintain the voltages within the constraints at the overloading conditions also by placing of Static VAR Compensator (SVC) at optimal locations. New approaches are used to find the placement and size of the SVC at different locations. Fuzzy is used to find the location and the size of the SVC is fined by the Firefly algorithm. This paper considers different loading conditions of the power system network (125,150,175 over loading conditions). From the results we can conclude that the power losses are reduced and the voltages can be maintained within the limits .IEEE 14 bus, IEEE 30 bus system is taken for the implementing the above techniques.

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 Keywords

fuzzy approach; SVC placement; firefly algorithm

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 Abstract

Foliar anatomical studies of twelve taxa of Coffea have undertaken to reveal the interrelationship among them. The following are the taxa studied for anatomical characters (Coffea arabica, C. robusta, C. liberica, C. excelsa, C. abeokutae, C. stenophylla, C. eugenioides, C. bengalensis, C. congensis, C. kapakata, C. salvatrix and C. Wightiana). The study revealed anatomically, the various species of Coffea differ among one another by epidermal cells; number of stomata; stomatal index and mesophyll tissues. A marked distinction was observed among taxa of Coffea with reference to morphoanatomical parameters. Further, the leaf anatomical study revealed, a typical dicotyledonous type of leaf with one palisade layer in all the taxa except Coffea excelsa and C. abeokutae have two rows of palisade cells. Further, whereas, in Coffea stenophylla and C. wightiana there are mixed of single and double row of palisade parenchyma. All the species of Coffea have Rubiaceous type of stomata (paracytic). It is presumed, that either Coffea arabica or Coffea robusta may established first in its wild state (origin of species) and then derived many more Coffea species by genetical and environmental influence on the crop.

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 Keywords

Foliar anatomy, paracytic stomata, Coffea, Rubiaceae, Polyphyletic

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An epigeic earthworm species Eisenia Andrei, (Bouche) which is known to be a manure worm as it predominantly dwells in the midst of animal manure, was explored as potential bioagent for vermicomposting the highly invasive aquatic weed salvinia (Salvinia molesta, Mitchell). The concept of high-rate vermicomposting and associated technology earlier developed by S.A. Abbasi and co-workers were employed for the purpose. As reported in this paper, E. andrei was able to convert salvinia into vermicast without the need of any pre-composting or supplementation of animal manure. In a semicontinuous, pulse-fed, reactor operation at solids retention time of 20 days, a rising trend in the vermicast production was seen over the course of 100 days of the experiments indicating that the epigeic was taking increasingly to salvinia. There was no animal morality; rather there was reproduction as seen in the formation of juveniles and cocoons in the vermireactos.

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high-rate vermicomposting, salvinia, Eisenia andrei

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A new power quality index (PQI), which is proportional to the generation of distortion power from nonlinear harmonic loads, is presented to figure out harmonic pollution ranking in a distribution power system. The electric load composition rate (LCR) and the total harmonic distortions (THD) for the approximated voltages on each harmonic load are used to figure out the suggested PQI. The decreased multivariate polynomial (RMP) design with one-shot training property is used to recognize the PQI. The harmonic current injection design based time-domain simulations are performed to confirm the effectiveness of the suggested DPQI under the other circumstances with different nonlinear loads.

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 Keywords

Distortion power, Distribution power system, Euclidean norm, harmonic pollution ranking, power quality index

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 Abstract

A trial was experimented to assess the water quality of the pond located in Coimbatore city. Physico-chemical parameters of the pond water were analysed and microbial isolates of the study was determined. The results attributed that the pond water samples collected from Valankulam pond of Coimbatore city was appeared above the limit of WHO standards and its quality was discussed in detail.

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 Keywords

Physico-chemical, microbial isolates, Valankulam pond

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 Abstract

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adaptive capacity; climate change; exposure; principal component analysis; sensitivity

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Leaf and petiole anatomy of the three species of Rhizophora L. occurring in the Mangrove forest of Nigeria was carried out to search for stable characters useful in delimiting the species. Anatomical characters that are common to the three taxa show generic affinity. The three species are also distinguished based on the number of the vascular bundles of the lamina mid rib and the petiole. The mean stomata frequency, mean stomata index and the guard cell area are distinct for each species. However, the three Rhizophora species occurring in Nigeria can be distinguished anatomically based on the type and pattern of distribution of foliar sclereids. Osteosclereids occur in R. mangle: astero sclereids line the veins and veinlets, in R. racemosa while asterosclereids which are randomly distributed occur in R. harrisonii.

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 Keywords

anatomical characters; anticlinal walls; Rhizophora; sclereids; veinlets

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 Abstract

Study was carried out from the end of 2012 till 2014, from South Bengal region, to explore the diversity of insect pollinators in Helianthus annuus, PAC-361, and their influence on the seed yield and quality. Insect visitors / pollinators were recorded at time periods from 07.00 hrs to 18.00 hrs. 17 species belonging to 13 families under 5 orders were recorded among which 4 species (Apis dorsata, A. cerena, A. mellifera and Certaina unimaculata) were both pollen and nectar collectors and remaining 13 were only nectar collector. Hymenopteran abundance was maximum (50%) followed by Diptera (17%), Coleoptera (12%), Hemiptera (14%) and Lepidoptera (7%). Foraging behavior and pollination efficiency index were evaluated. Qualitative and quantitative effects of pollination on the number of seeds per flower head and mean weight of 100 seeds were reported to be significantly (p?0.05) higher in open pollinated flower than controlled one viz. 40.3 and 36.73% respectively. Further, pollination increases the germinability of the resulting seeds to 36%. Lower seed yield was probably due to the availability of less number of viable pollen.

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 Keywords

Pollinators, Helianthus annuus, non-Apis bee, pollination efficiency index, pollen viability

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