Comparative analysis of PWM techniques for Photovoltaic application with HERIC inverter

Photovoltaic inverters achieves an effective and efficient system and plays an important role in reducing the total cost of the system. The main objective  of this paper is to develope mathematical model and analyse the performance of photovoltaic fed  HERIC inverter for different Pulse-Width Modulation (PWM) techniques. The two different carrier signals such as sinusoidal carrier signal and triangular carrier signals are used. The required PWM pulses are generated by comparing the trapezoidal reference signal with those carrier signals. The simulation is carried out using MATLAB/Simulink. The performance indices used in this comparison are THD, output power, fundamental output voltage and RMS value of output voltage

Decreased pH does not alter metamorphosis but compromises juvenile calcification of the tube worm Hydroides elegans

Using CO2 perturbation experiments, we examined the pre- and post-settlement growth responses of a dominant biofouling tubeworm (Hydroides elegans) to a range of pH. In three different experiments, embryos were reared to, or past, metamorphosis in seawater equilibrated to CO 2 values of about 480 (control), 980, 1,480, and 2,300 μatm resulting in pH values of around 8.1 (control), 7.9, 7.7, and 7.5, respectively. These three decreased pH conditions did not affect either embryo or larval development, but both larval calcification at the time of metamorphosis and early juvenile growth were adversely affected. During the 24-h settlement assay experiment, half of the metamorphosed larvae were unable to calcify tubes at pH 7.9 while almost no tubes were calcified at pH 7.7. Decreased ability to calcify at decreased pH may indicate that these calcifying tubeworms may be one of the highly threatened species in the future ocean. © 2012 The Author(s).published_or_final_versio

A Perturbed Self-organizing Multiobjective Evolutionary Algorithm to solve Multiobjective TSP

Travelling Salesman Problem (TSP) is a very important NP-Hard problem getting focused more on these days. Having improvement on TSP, right now consider the multi-objective TSP (MOTSP), broadened occurrence of travelling salesman problem. Since TSP is NP-hard issue MOTSP is additionally a NP-hard issue. There are a lot of algorithms and methods to solve the MOTSP among which Multiobjective evolutionary algorithm based on decomposition is appropriate to solve it nowadays. This work presents a new algorithm which combines the Data Perturbation, Self-Organizing Map (SOM) and MOEA/D to solve the problem of MOTSP, named Perturbed Self-Organizing multiobjective Evolutionary Algorithm (P-SMEA). In P-SMEA Self-Organizing Map (SOM) is used extract neighborhood relationship information and with MOEA/D subproblems are generated and solved simultaneously to obtain the optimal solution. Data Perturbation is applied to avoid the local optima. So by using the P-SMEA, MOTSP can be handled efficiently. The experimental results show that P-SMEA outperforms MOEA/D and SMEA on a set of test instances

Response of bacterioplankton community structures to hydrological conditions and anthropogenic pollution in contrasting subtropical environments

Bacterioplankton community structures under contrasting subtropical marine environments (Hong Kong waters) were analyzed using 16S rRNA gene denaturing gradient gel electrophoresis (DGGE) and subsequent sequencing of predominant bands for samples collected bimonthly from 2004 to 2006 at five stations. Generally, bacterial abundance was significantly higher in the summer than in the winter. The general seasonal variations of the bacterial community structure, as indicated by cluster analysis of the DGGE pattern, were best correlated with temperature at most stations, except for the station close to a sewage discharge outfall, which was best explained by pollution-indicating parameters (e.g. biochemical oxygen demand). Anthropogenic pollutions appear to have affected the presence and the intensity of DGGE bands at the stations receiving discharge of primarily treated sewage. The relative abundance of major bacterial species, calculated by the relative intensity of DGGE bands after PCR amplification, also indicated the effects of hydrological or seasonal variations and sewage discharges. For the first time, a systematic molecular fingerprinting analysis of the bacterioplankton community composition was carried out along the environmental and pollution gradient in a subtropical marine environment, and it suggests that hydrological conditions and anthropogenic pollutions altered the total bacterial community as well as the dominant bacterial groups. © 2009 Federation of European Microbiological Societies. Published by Blackwell Publishing Ltd. All rights reserved.published_or_final_versio

Beyond population engagement: understanding counterinsurgency

The US military has made considerable progress in developing counterinsurgency (COIN) strategy and doctrine, including the publication of Army Field Manual 3-24 and the military's successes in working with the population to stem the insurgency in Iraq. The short-term goals of COIN are now fairly well understood: engage the population and win their support. Whichever side wins the support of the population--either the host nation (and US forces that support it) or the insurgents--wins the battle. The battle is not the war, however. the long-term goal of a counterinsurgency campaign requires the creation of a functioning state, a government that can stand on its own, provide for its citizens, and promote regional and international stability; this achievement is victory in a counterinsurgency. Transitioning from the short-term success of population engagement to long-term viability of the host nation is far more difficult and less understood

Angiotensin-Converting Enzyme Gene Polymorphism in Patients with Coronary Artery Disease

Several genetic investigations have been attempted to elucidate the association of gene polymorphism of angiotensin-converting enzyme (ACE) in coronary artery disease. This study was conducted to investigate the role of gene polymorphism of ACE in patients with coronary artery disease. The study included fifty-six numbers of patients with atherosclerotic coronary artery disease where proven angiographically and fifty-six numbers of healthy individuals of sex matched as a control group. The patients and control group were subjected to routine investigations, assays like, serum cholesterol, triglycerides, high-density Lipoprotein-cholesterol (HDL-C), low-density lipoprotein-cholesterol (LDL-C). Genomic DNA was extracted and analyzed for angiotensin-converting enzyme insertion/deletion polymorphism using polymerase chain reaction (PCR). When we compared the genotypes of patients with coronary artery disease and controls, it was observed that all three genotypes were not statistically different also no significant difference of alleles in ACE gene genotypes was found. Inpatient serum cholesterol, triglyceride and HDL-C (P <0.001, P <0.001 and P <0.001: respectively) showed a significant increase than the control group. In patients, LDL-C level was not more significant than controls. In the evaluated population, we conclude that the gene I/D polymorphism for ACE are not risk associated and may not be a useful marker for coronary artery disease