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  • Author: Md. Amirul Islam x
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Abstract

A field experiment was carried out to investigate the effect of different manures and fertilizers on the growth and yield of knol-khol (Brassica oleracea var. gongylodes) at Dr. Purnendu Gain Field Laboratory of Agrotechnology Discipline, Khulna University, Khulna from November 2014 to February 2015. The single factor experiment comprised of different types of fertilizers and manures viz., T0 (Control), T1 (Recommended doses of NPK), T2 (Cow dung), T3 (Vermicompost), T4 (Poultry manure), T5 (50 % Cow dung + 50 % NPK), T6 (50% Vermicompost + 50% Cow dung), T7 (50% Vermicompost + 50 % Poultry manure) and T8 (25% Cow dung+ 25% Vermicompost+ 25% Poultry manure + 25% NPK). The Experiment was laid out in Randomized Complete Block Design (RCBD) with four replications. The maximum plant height was obtained from the treatment T1 at 25, 35 and 45 Days after transplanting (DAT). The maximum spread of canopy was 36.75 cm, 52.50 cm and 66.05 cm from the treatment T3, T7 and T2, respectively. The maximum economic yield (21.92 t/ha) and biological yield (40.083 t/ha) were found in the treatment T1 and T7, respectively. Highest benefit cost ratio (3.07) was obtained from the treatment T1whilethe minimum (0.57) was obtained from T3 which indicates that high cost of vermicompost affect net return severely. Although, T1 produced maximum benefit cost ratio, the treatment T4 and T2 are very close to T1 and also statistically similar. So, we can consider poultry manure and cow dung for our soil health, environmental benefits and ecological safety.

Photocatalytic degradation of a heteropolyaromatic dye (methylene blue) in aqueous ZnO suspension was investigated under UV and visible light irradiation. Adsorption behavior was found to be well fitted with the Langmuir and Freundlich isotherms. Free energy of adsorption was found to be negative which indicates that adsorption was spontaneous. Under UV light irradiation for 6 hours, the catalytic process produced a net decolorization and mineralization (50 µM MB) of about 98% and 89% respectively. Meanwhile, under visible light irradiation (10 µM MB) for 8 hours these resulted ca. 95% and 77% decolorization and mineralization, respectively. Degradation efficiency was found to be highest at basic pH (8.6). Catalyst loading of 1.0 gl-1 was found to be optimum for the degradation of 100 µM MB solution. In all conditions the UV irradiation showed much better photo-assistance than the visible light irradiation.

Abstract

The cross sections of the reaction 98Mo(n, γ)99Mo at neutron energies of 0.0334 eV and 0.0536 eV were measured for the first time using the activation technique, and the resulting values of 116 ± 7 mb and 91 ± 5 mb, respectively, are in good agreement with the JENDL-4 and ENDF/B-VII data files. Those measured values were extrapolated to the energy 0.0253 eV assuming 1/v dependence in the thermal region and the results were compared with the integrally measured values reported in the literature. The new data are thus useful to check the evaluated excitation function.

Abstract

The neutron capture cross section for the 152Sm(n,  γ)153Sm reaction at an energy of 0.0334 eV was measured for the first time using monochromatic neutrons of a powder diffractometer at the TRIGA Mark II nuclear reactor at Dhaka, Bangladesh. The 197Au(n,  γ)198Au reaction was used to monitor the neutron beam intensity. The radioactivity of the products was determined via high resolution γ-ray spectrometry. The obtained cross section value is 184 ± 22 b, which is consistent with both the ENDF/B-VII and TENDL-2012 data libraries. The measured value at 0.0334 eV and the previous data at 0.0536 eV confirm the reliability of the data in the above libraries.

Oxidative degradation of Brilliant Red X–3B has been carried out using Fenton’s reagent both in the dark and in the presence of visible light. The degradation rate was increased using Fenton’s process in the order of Dark < Visible < UV. At pH 3.3, the maximum Fenton and photo-Fenton effect were noticed. At [H2O2]/[Fe(III)] = 3.5, a steady Fenton effect was observed. Meanwhile, at [H2O2]/[Fe(III)] = 0.7, Fenton process in the dark minimized the photo effect. The degradation rate was positively influenced by the temperature where the activation energy of degradation was evaluated as 36.98 kJ mol-1.

Abstract

To study the compositional trends of rare earth elements (REEs: La, Ce, Nd, Sm, Eu, Tb, Dy, Yb, Lu), Th and U in soil samples collected from a site for a potential coal based power plant as well as to conduct a preliminary assessment of environmental impact of the proposed power plant in terms of REEs, Th and U, we have analyzed nine soil samples by instrumental neutron activation analysis. Evaluation of data quality by repeated analysis of IAEA-Soil-7 and IAEA-SL-1 ensures a proper data base-line for the REEs, Th and U abundances of the sampling site. Chondrite-normalized abundance patterns demonstrate the heavy REEs–light rare earth elements and Th–U fractionations in our sample suite along with significant negative Eu anomaly. Thorium/U ratio in our study area ranges from 4.55 to 6.07 which is higher than that of upper continental crust. Preliminary assessment of environmental impact of the proposed power plant is evaluated by taking NIST-SRM-1633b (coal-fly-ash) as contaminant as coal-fly-ash will be the major byproduct of the power plant. Previous literature studies and our prevailing data invoke that proposed power plant will have no severe impact on soil originated biota and on human health in terms of REEs, Th and U abundances. However, the long term effect of excessive REEs, Th and U as well as the other elemental abundances originating from coal-fly-ash should also be taken into an account.