Hydrodynamic Performance and Acoustic Response of Ship Propeller

The aim of the paper is to predict the hydrodynamic performance and noise generated by the propeller at different advance ratio and the speed of the propeller. Three bladed, DTMB 4119 propeller model was created using the NACA66 modified line, a = 0.8 hydrofoil profile. ANSYS Workbench software is used for mesh generation and computational analysis. A large-eddy simulation turbulence model and Ffowcs Williams-Hawkings (FWH) acoustic model is used for all simulations. A moving reference frame is used to simulate the rotational effects of the propeller. The speed of the propeller is 792 rpm, the propeller being 0.2 m, and inlet velocity is varied to study the effect of the advance ratio. A transient analysis is carried out using a time step value of 0.0005 seconds and the total simulation time is 0.6 seconds. The hydrodynamic performance parameters are validated by comparing with the experimental data available in the literature. The sound pressure level (SPL) is plotted over the frequency range of 0 to 1000 Hz at different locations, speed, and an advance ratio of 0.5, 0.7, 0.833, and 0.9,1. The structural, acoustic and hydrodynamic behaviour of the propeller was predicted using a two-way fluid structure interaction at an advance ratio of 0.833. The major conclusions drawn from the analysis are that the sound pressure level values are increased at the propeller off-design conditions and varying with the receiver locations. The data generated from this study is useful for the designers to carry out further research in order to reduce the noise generated from the propeller

Building Soil Health, Improving Carbon Footprint and Minimizing Greenhouse Gas Emissions through CSR

Unabated soil degradation due to low soil organic carbon (C) levels, multiple nutrient deficiencies including micro- and secondary nutrients, rising salinity and soil loos due to erosion jeopardizes food security of swiftly rising global population projected to be 9.7 billion by 2050. Soils also play a major role in global C cycling and huge C sequestration potential offers opportunities for mitigating carbon dioxide and other greenhouse gas emissions. The lessons learnt from CSR pilot and scaling-up initiatives indicated significant productivity benefits with soil health mapping based management..

Macro Benefits from Zinc, Boron and Sulphur Fertilization of Rainfed Systems in the Semi Arid Zone of India

Crop productivity in the rainfed semi arid tropics (SAT) of India is low due to water shortage and poor fertility status of the soils. Earlier research have shown that SAT soils are critically deficient in Zn, B and S in addition to N and P (Sahrawat et al., 2008; Wani et. al. 2009). For a sustainable increase in productivity and enhancing the resilience in rainfed systems, the issues related to soil fertility needs to be addressed. The objective of this communication is to show as to how balanced nutrition involving Zn, B and S can be used to enhance crop productivity on sustainable basis in the semi‐arid regions of India...

Comparative Evaluation of Inductively Coupled Plasma–Atomic Emission Spectroscopy and Colorimetric Methods for Determining Hot-Water-Extractable Boron in Soils

Frequency of boron (B) deficiency is increasing in rainfed systems, and hence there is a need to diagnose the deficiency. Colorimetric methods are still widely used in soil-testing laboratories in India for measuring B. Little information is available on the comparative evaluation of the colorimetric and inductively coupled plasma (ICP) methods for determining extractable B in soils. We describe results of the comparative evaluation of these methods for measuring extractable B in 57 soil samples with pH values ranging from 5.3 to 9.5. There was a significant correlation between B values determined by the two methods, and the correlation coefficient was greater for soil samples with pH in the neutral to alkaline range. Interaction between soil samples and methods (ICP or colorimetric) was significant except for soil samples in the pH range of 8.0 to 9.5. Precision for B determination was greater with the ICP than with the colorimetric method

Orientational order in three nO.m liquid crystalline compounds

Refractive index and density measurements have been carried out on three nO.m liquid crystalline compounds, namely, 4O.2, 4O.3 and 1O.10 belonging to the N-(p-n-alkoxybenzylidene)-p-n-alkylaniline series. From the data, the orientational order parameter has been estimated using Vuks and Neugebauer local field models. Furthermore, the orientational order parameter has been calculated directly from refractive index data employing the Vuks scaling factor method, Neugebauer f(B) parameter, effective geometry parameter and a method proposed by Kuczynski et al. It is observed that order parameter values estimated from different methods agree well near the nematic-isotropic transition and diverge as the nematic phase attains equilibrium. The temperature gradient of refractive indices and the nematic crossover temperatures have also been estimated for these compounds. The results obtained are compared and discussed

Orientational order parameter of two cyano nematogens by optical spectroscopy

Refractive index and density measurements of two cyano nematogens, namely p-hexyloxybenzylidene p-aminobenzonitrile and p-octyloxybenzylidene p-aminobenzonitrile have been carried out. From these data, orientational order parameter S has been estimated using different methods. Principal polarizabilities have been calculated using the well-known Vuks isotropic and Neugebauer anisotropic models. Polarizability anisotropy has been estimated using Lippincott δ-function, molecular vibration, Haller's extrapolation and Vuks scaling methods. Using these values, the orientational order parameter S has been estimated at different temperatures in their nematic phases. The values obtained have been compared and discussed. Further, using the experimental refractive index data, the nematic crossover temperatures have also been estimated for these compounds

Orientational order parameter of two cyano nematogens by optical spectroscopy

Refractive index and density measurements of two cyano nematogens, namely p-hexyloxybenzylidene p-aminobenzonitrile and p-octyloxybenzylidene p-aminobenzonitrile have been carried out. From these data, orientational order parameter S has been estimated using different methods. Principal polarizabilities have been calculated using the well-known Vuks isotropic and Neugebauer anisotropic models. Polarizability anisotropy has been estimated using Lippincott δ-function, molecular vibration, Haller's extrapolation and Vuks scaling methods. Using these values, the orientational order parameter S has been estimated at different temperatures in their nematic phases. The values obtained have been compared and discussed. Further, using the experimental refractive index data, the nematic crossover temperatures have also been estimated for these compounds

5-Ethyl-2-mercaptothiazole as matrix for matrix-assisted laser desorption/ionization of a broad spectrum of analytes in positive and negative ion mode

A preliminary investigation of the use of 5-ethyl-2-mercaptothiazole as matrix in matrix-assisted laser desorption/ionization (MALDI) of a broad spectrum of analytes is reported. The analytes studied are substance P, insulin, β-cyclodextrin, triacylglycerols of coconut oil and polypropylene glycol 2000 (PPG 2000). In the positive ion mass spectra of the matrix/analyte combinations, the formation of [M + H]+ and [M + cation]+ species were observed and compared with those obtained by using well-established matrices such as α-cyano-4-hydroxycinnamic acid, genticic acid, sinapinic acid and dithranol. In addition, the usefulness of this new matrix for MALDI in negative ion mode is also described using substance P and β-cyclodextrin as examples

Development and Validation of Chiral Hplc Method for Quantitation of Enantiomer in Rosuvastatin Calcium

A new, simple, precise, rapid and accurate normal phase enantioselective high performance liquid chromatographic method was developed for enantiomeric resolution of Rosuvastatin, which is used for the treatment of hypercholesterolemia. This is a fourth highest selling drug in the United States, accounting approximately $5.2 billion in the year of 2013. The enantiomer of Rosuvastatin and lactone impurity of Rosuvastatin were resolved on a CHIRALPAK IB (250 x 4.6mm, 5?m) column using a simple mobile phase system containing nheptane, 2-propanol and trifluoroaceticacid (85:15:01v/v). The resolution between Rosuvastatin and enantiomer, Rosuvastatin and lactone impurity was good with resolution factors more than 2.0 and 4.0, respectively. The effect of organic modifier, namely 2-propanol in the mobile phase was optimized in order to obtain the best separation.The Limit of Detection and Limit of Quantitation of enantiomer were found to be 0.07?g/mL and 0.2?g/mL, respectively, for 10?L injection volume. The sample solution and mobile phase were stable for at least 48 hours. The proposed reproducible and accurate method can be useful for quantification of enantiomer of Rosuvastatin in the bulk drug substance.&nbsp