IOSR-JAP   Volume-4 ~ Issue-6 ~ Sep–Oct 2013

Abstract: The natural radioactivity concentrations from 40 different locations of waste dump sites in Owerri, Imo state Nigeria, has been measured using a gamma – ray spectrometer. The results indicate that the ranges of activity concentrations of 40K, 226Ra and 323Th in the samples were ˂17.2 – 686.17 BqKg-1 , ˂ 4.2 – 103.51 BqKg-1 and ˂ 5.1 – 65.28 BqKg-1 respectively. The highest outdoor effective dose obtained was 65.28 μSv.y-1 which is less than the world average outdoor value of 70 μSv.y-1 given by United Nations Scientific Committee on the Effect of Atomic Radiation ( UNSCEAR )

Keywords: Activity Concentration, Radiation Emission, Waste Dumpsites, Absorbed Dose rate, Effective Dose Equivalent

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Abstract: Single phase of CuInS2 nanoparticles was prepared by solid state melt growth process. The structural, morphological and elemental analyses were studied by using X-ray diffraction, Field Emission Scanning Electron Microscope and Energy Dispersive Analysis of X-rays. The differential thermal analysis (DTA) and thermo gravimetric analysis (TGA) confirms the phase transformation and stability of CuInS2 with its annealing effect at 200ºC. Micro-Raman studies evidencing a strong Raman A1 mode at 285 cm-1 and 302 cm-1, corresponds to totally symmetric vibration of anion  sub lattice of CuInS2 structure.

Keywords: Chalcopyrite type CuInS2 nanoparticles, Crystal Structure, Surface morphology, Elemental Composition, Microstructure and phase Transition

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Abstract: Evaporation suppression is the reduction of evaporation bycontrolling the rate at which water vapor escapes from water surfaces. The need for water saving is greatest in areas of little rainfall and low runoff. Water losses by evaporation from storage reservoirs must be minimized for greatest utility of limitedsupplies. Using trash of polyethylene with different densities (800, 875 and 900 kg/m3) as floating cover to the water filling cylindrical container with 8 cm diameter led to reduce the evaporation rate. A suitable trash density of 800 kg/m3 gave reduction in evaporation rate of 57% from the theoretical results calculated using equation (4) which is a good result if compared with previous researches.

Keywords: evaporation rate, evaporation suppression, water reservoir.

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