Structural and Optical Properties of Cu2ZnSnS4 Nanoparticles for Solar Cell Applications

The Cu2ZnSnS4 (CZTS) nanoparticles were successfully synthesized by Chemical co-precipitation method with different synthesis temperatures. The synthesized nanoparticles were characterized by X-ray diffraction, Raman Spectroscopy, Scanning electron microscopy, Energy dispersive spectroscopy and UV-VIS-NIR spectrophotometer. XRD and Raman studies revealed that the CZTS nanoparticles exhibited Kesterite Structure with preferential orientation along the (112) direction. The CZTS nanoparticles synthesized at a temperature 150 C exhibited near stoichiometry. On further increasing the synthesis temperature sulphur composition was decreased due to volatile nature of the sulphur. The synthesized nanopar-ticles exhibited an optimum band gap of 1.4 eV. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3194

New crustacean resources in the trawl fishery off Mangalore coast

Since trawling operation started during the sixties, penaeid shrimps, crabs and stomatopods formed the major part of the crustacean fishery, in trawl catches off Mangalore coast with non-penaeids and lobsters to a minor extent

Photoluminescence and EPR studies of ZnS nanoparticles Co-doped with Mn and Te

ZnS nanoparticles Co-doped with Mn and Te (x = 0.05 and 0.10) have been synthesized for the first time by chemical co-precipitation method, thiophenol is used to passivate the surface of the particles. The as-prepared samples were amorphous in nature. Nanocrystallinity was induced after calcining the samples at 300oC/2hrs. The obtained nanoparticles were subjected to X-ray diffraction (XRD), Energy Dispersive Analysis of X-rays (EDAX), Transmission Electron Microscopy (TEM), hotoluminescence (PL) and Electron Paramagnetic Resonance (EPR) studies. All the samples exhibited cubic structure and the particle size was found to be 3-5 nm. EDAX revealed that the compositions did not deviate much from the target compositions. The photoluminescence studies showed emission in the red region and the emission wavelength is varied with composition. The Electron Paramagnetic Resonance (EPR) spectra showed paramagnetic nature of the samples at room temperature. EPR and PL results were quite consistent with each other. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2197

Comparison of Chiller Models for Use in Model-Based Fault Detection

Selecting the model is an important and essential step in model based fault detection and diagnosis (FDD). Factors that are considered in evaluating a model include accuracy, training data requirements, calibration effort, generality, and computational requirements. The objective of this study was to evaluate different modeling approaches for their applicability to model based FDD of vapor compression chillers. Three different models were studied: the Gordon and Ng Universal Chiller model (2nd generation) and a modified version of the ASHRAE Primary Toolkit model, which are both based on first principles, and the DOE-2 chiller model, as implemented in CoolToolsTM, which is empirical. The models were compared in terms of their ability to reproduce the observed performance of an older, centrifugal chiller operating in a commercial office building and a newer centrifugal chiller in a laboratory. All three models displayed similar levels of accuracy. Of the first principles models, the Gordon-Ng model has the advantage of being linear in the parameters, which allows more robust parameter estimation methods to be used and facilitates estimation of the uncertainty in the parameter values. The ASHRAE Toolkit Model may have advantages when refrigerant temperature measurements are also available. The DOE-2 model can be expected to have advantages when very limited data are available to calibrate the model, as long as one of the previously identified models in the CoolTools library matches the performance of the chiller in question

Unprecedented heavy landings of juvenile Kiddy shrimp, Parapenaeopsis stylifera along Karnataka coast

Parapenaeopsis stylifera is one of the most abundant and highly valued shrimp species in India. It forms about 20% of the penaeid shrimp catch of Karnataka with the period from January to June contributing the majority of the catch. In general, the post-monsoon months of August to December is considered as a lean period for P. stylifera. During this period single day fishing trawlers land catch of a mixture of fish, prawns, stomatopods and other crustaceans. The contribution of prawns in the catch is around 10 to 20%

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Catfish reappeared in Dakshina Kannada Coast

After a gap of several years catfish reappeared in Malpe during September, 1994. Three purse seiners together landed three tonnes of catfish Tachysurus serratus (90 per cent) and T. dussumieri (10 per cent

Preparation and Characterization of NiO Thin Films by DC Reactive Magnetron Sputtering

Nickel oxide (NiO) thin films were successfully deposited on Corning 7059 glass substrates at different oxygen partial pressures in the range of 1 × 10 – 4 to 9 × 10 – 4 mbar using dc reactive magnetron sputtering technique. Structural properties of NiO films showed polycrystalline nature with cubic structure along (220) orientation. The optical transmittance and band gap values of the films increased with increasing the oxygen partial pressure from 1 × 10 – 4 to 5 × 10 – 4 mbar and decreased on further increasing the oxygen partial pressure. Using Scanning Electron Microscopy (SEM), fine grains were observed at oxygen partial pressure of 5 × 10 – 4 mbar. The film resistivity decreases from 90.48 to 13.24 Ω cm with increase in oxygen partial pressure to 5 × 10 – 4 mbar and then increased on further increasing the oxygen partial pressure. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3025

Biology and exploitation of the blue swimmer crab, Portunus pelagicus (Linnaeus, 1758), from south Karnataka coast, India

Portunus pelagicus supports indigenous as well as mechanised fishery of Karnataka coast. Trawlers accounted for 98% of the landing and the highest landing was observed during 2001-2002 (403 t). The peak fishing season for crabs was during December-June. Size range observed in the fishery was 56 to 165 mm in males and 61 to 170 mm in females. The homogeneity of sex ratio (2 test) obtained for the years 1998-2005 was 1:1. Peak spawning activity occurred during February-March. Size at maturity (50%) of females was estimated at 96 mm carapace width. Growth was isometric and males were heavier than females of similar size. By von Bertalanffy's growth plot, it was estimated that males and females reach 123 and 128 mm (CW) respectively at the end of one year and reach 156 and 160 mm respectively in two years. Longevity of P. pelagicus is estimated as 3 years in both sexes. The total mortality coefficient (Z), natural mortality coefficient (M) and fishing mortality coefficient (F) values estimated for the species were 6.3, 2.2 and 4.1 respectively. The exploitation ratio (E) was 0.65 and Lc was estimated at 87.7 mm. MSY was estimated as 367 t against the present annual average yield of 333 t. From 'Thompson and Bell yield prediction analysis it is seen that any additional 10% effort from the present level will yield only less than 10% additional catch, indicating that increasing the effort will not be economical. Restricting the catch to MSY level (367 t) is suggested as a suitable management option for the sustainability of P. pelagicus fishery from the coast