A Compact 1:4 Lossless T-Junction Power Divider Using Open Complementary Split Ring Resonator

This paper presents the size miniaturized and harmonic suppressed lossless 1:4 T-junction unequal power divider using an open complementary split ring resonator (OCSRR). By embedding the OCSRR structure in the microstrip transmission line, slow wave effect is introduced and thereby size reduction is achieved. The dimensions of OCSRR are optimized to reduce the length of high impedance and low impedance quarter-wavelength transmission lines. In our design high impedance line length is reduced to 58.6%, and low impedance line length is reduced to 12% when compared to the conventional quarter wavelength lines. The proposed power divider is having small dimensions of 0.18 λg × 0.33 λg and is 51.94% smaller than the conventional unequal power divider

Optimization of a horizontal axis marine current turbine via surrogate models

Flow through a scaled horizontal axis marine current turbine was numerically simulated after validation and the turbine design was optimized. The computational fluid dynamics (CFD) code Ansys-CFX 16.1 for numerical modeling, an in-house blade element momentum (BEM) code for analytical modeling and an in-house surrogate-based optimization (SBO) code were used to find an optimal turbine design. The blade-pitch angle (θ) and the number of rotor blades (NR) were taken as design variables. A single objective optimization approach was utilized in the present work. The defined objective function was the turbine’s power coefficient (CP). A 3x3 full-factorial sampling technique was used to define the sample space. This sampling technique gave different turbine designs, which were further evaluated for the objective function by solving the Reynolds-Averaged Navier–Stokes equations (RANS). Finally, the SBO technique with search algorithm produced an optimal design. It is found that the optimal design has improved the objective function by 26.5%. This article presents the solution approach, analysis of the turbine flow field and the predictability of various surrogate based techniques

Crumpled sheet like graphene based WO3-Fe2O3 nanocomposites for enhanced charge transfer and solar photocatalysts for environmental remediation

The combination of two or more metal oxides onto graphene sheets with even distribution is projected to enhanced charge transfer properties in photocatalytic applications. We report, tungsten oxide (WO3) with iron oxide (Fe2O3) nanoparticles grown on graphene sheets via a facile economical one pot hydrothermal method and consequently characterized by standard analytical techniques. Synthesized Fe2O3 with WO3 nanoparticles were well ornamented on surface of the graphene sheets which have a significant charge transfer properties. The resulting hybrid WO3-Fe2O3-rGO (WFG) nanocomposites showed enhanced photocatalytic, heavy metal removal and antibacterial activities. The superior photocatalytic removal efficiencies were observed for the removal of rhodamine B (∼94%) and methylene blue dyes (∼98%) under solar light irradiation. The antibacterial activity of WFG nanocomposites were performed against Escherichia coli (E.coli) and Staphylococcus aureus (S.aureus) as models for Gram-negative and Gram-positive bacteria. The outcome of the results have an intellectual effect on the use of WFG nanocomposites to address the upcoming energy and environment issues

Histological and immunological correlates of suspected leprosy lesions

Thirty-two subjects with suspected leprosy lesions were investigated to assess various modalities of sensibility and sweatfunction and these were correlated with immunological and histological parameters. It was found that pain and temperature, mediated by small unmyelinated fibres were impaired in the early lesions. Impairment of sweat function was seen only when one of the modalities of sensibility was also affected Antibodies specific to a protein (35 kDa) antigen and phenolic glycolipid 1 of Mycobacterium leprae were positive in nine and 12 cases respectively, while 15 of the 31 biopsies revealed the presence of mycobacterial antigens in these lesions. The implications of these findings are discussed

Susceptibility baselines for the invasive mealybugs Phenacoccus manihoti and Paracoccus marginatus (Hemiptera: Pseudococcidae) in cassava ecosystem against selected neonicotinoid insecticides

In recent years, an invasive cassava mealybug Phenacoccus manihoti has been threatening cassava cultivation alongside another invasive papaya mealybug Paracoccus marginatus which invaded the country more than a decade ago. In order to evaluate their responses against the commonly used neonicotinoid insecticides: thiamethoxam 25 WG and imidacloprid 17.8 SL,  acute toxicity experiments to determine the susceptibility baselines in populations of two invasive mealybugs in the cassava agro-ecosystem, namely, cassava mealybug P. manihoti and papaya mealybug P. marginatus were performed upto 15 generations. A systemic uptake method was used for the bioassay. The LC50 values of thiamethoxam for F1 generation were 3.298 ppm whereas it was 1.066 ppm for F15 in cassava mealybug. The LC50 values of F1 generation were 2.014 ppm and that of F15 generation was 1.384 ppm when tested with imidacloprid. In the case of papaya mealybug, the LC50 values ranged from 6.138 ppm (F1) to 2.503 ppm (F15) for thiamethoxam and 7.457 ppm (F1) to 3.231 ppm (F15) for imidacloprid. All the susceptibility indices calculated were less than threefold. The rate of resistance development was negative in all cases showing that none of the tested populations harboured any resistance without insecticidal selection pressure. Tentative discriminating doses were fixed for both chemicals with the help of LC95 values obtained from the bioassay experiments, namely five ppm for both thiamethoxam and imidacloprid in the case of cassava mealybug and 10 ppm and 15 ppm, respectively, for thiamethoxam and imidacloprid in the case of papaya mealybug.          

Effect of Industrial Effluent on the Growth of Marine Diatom, Chaetoceros simplex (Ostenfeld, 1901)

The marine centric diatom,Chaetoceros simplex (Ostenfeld, 1901) was exposed to five different concentrations of industrial effluent for 96 hrs to investigate the effect on growth. The physico-chemical parameters viz. colour, odour, temperature, salinity, dissolved oxygen, turbidity, pH, alkalinity, hardness, ammonia, nitrite, nitrate, inorganic phosphate, total phosphorous, reactive  silicate, calcium and magnesium were estimated in the effluent. The Ammonia  (326 μg. L-1), Nitrite (19.53 μg. L-1) and Nitrate (471.4 μg. L-1) were observed at higher levels. About 50% of the cell density of C. simplex reached a lesser dilutions of effluent viz. 1:625 and 1:1250 than the control. The highest cell density (14.3 × 104 cell ml-1) was recorded in 1:10000 diluted effluent followed by control and the lowest cell density was observed in 1:625 diluted effluents. From the results, it is evidenced that the lower volume of effluent discharge into higher volume of water could not affect the growth rate of phytoplankton. It is more important that to reduce the effect of pollution and environmental sustainability. @JASEMJ. Appl. Sci. Environ. Manage. December, 2010, Vol. 14 (4) 35 - 3

Characterization of Cold Sprayed CuCrAl-Coated and Uncoated GRCop-84 Substrates for Space Launch Vehicles

A newly developed Cu-23(wt.%)Cr-5%Al (CuCrAl) alloy is currently being considered as a protective coating for GRCop-84 (Cu-8(at.%)Cr-4%Nb). The coating was deposited on GRCop-84 substrates by the cold spray deposition technique. Cyclic oxidation tests conducted in air on both coated and uncoated substrates between 773 and 1073 K revealed that the coating remained intact and protected the substrate up to 1073 K. No significant weight loss of the coated specimens were observed at 773 and 873 K even after a cumulative cyclic time of 500 h. In contrast, the uncoated substrate lost as much as 80% of its original weight under similar test conditions. Low cycle fatigue tests revealed that the fatigue lives of thinly coated GRCop-84 specimens were similar to the uncoated specimens within the limits of experimental scatter. It is concluded that the cold sprayed CuCrAl coating is suitable for protecting GRCop-84 substrates

STUDIES ON GENETIC DIVERSITY IN Vigna mungo L. Hepper IN YMV HOTSPOT

            The present investigation was conducted to examine the 41 blackgram genotypes  along with one check (T-9) to study the genetic diversity. Analysis of variance showed highly significant differences among 41blackgram genotypes for 9 quantitative characters studied. Maximum genotypic and phenotypic variance was recorded for percentage of disease infection, single plant seed yield, and number of pods per plant.   Minimum   GCV and PCV were recorded for pod length, days to 50% flowering, number of seeds per pod. High heritability was recorded for percentage of disease infection, single plant seed yield, and number of pods per plant. High heritability coupled with high genetic advance as percent of mean was recorded for percentage of disease infection, single plant seed yield. Genetic diversity estimated in 41 blackgram genotypes using Mahalanobis’s D2 statistic. Forty one genotypes were grouped into seven clusters by Tocher method (Mahalanobis Euclidean Distance) cluster analysis.  The  maximum  inter-cluster  distance  was  observed  between  cluster VI  and  cluster  VII and maximum intra-cluster distance was observed in cluster VI.  Cluster VII showed maximum cluster mean value for seed yield per plant. Among all the characters, seed yield per plant and percentage of disease infection contributes maximum