INTEGRATION OF THE OUTPUT OF A SILICON SOLAR CELL TO THE GRID SYSTEM

With the advent of the 21st century, the utilization of renewable energy in modern power generation has been leapt to a level that was unimaginable only even 100 years ago. Solar energy is one of the popular renewable energy sources as it is abundant in nature especially warm predominant countries like Bangladesh. In addition, some noteworthy upsides of solar energy are free fuel such as sunlight is free, environmental friendly operation, minimal maintenance and longer service life. This paper furnishes knowledge about the performance of a single crystalline silicon solar cell, based on the practical experimental results that have been obtained from different connections of the used modules like single module, series connection of double modules and parallel connection of double modules. The comparative results show that maximum open circuit voltage, maximum output power and maximum fill factor have been obtained from series connection of double modules whereas, parallel connection of double modules has given the largest amount of short circuit current. On the other hand, highest efficiency has been derived in case of single module connection. Besides, suitable arrangements have also been demonstrated in this paper so that the output of these solar modules can be connected to the grid system with a view to meeting up the increased power demand

Utilization of single phase inverters in photovoltaic system

This paper presents a Photovoltaic (PV) system, in which solar energy is taken into consideration as a renewable energy source. Furthermore, the variation in the output responses of PV system because of the effect of various factors, including solar irradiation, temperature, ideality factor and saturation current are shown here in great details. However, it has been noticed that these factors cause reduction in the system's performance. Therefore, in order to improve PV system's efficiency, it is recommended to use a solar panel which follows an ideal solar panel. Finally, with a view to supplying this derived solar energy to the consumer's end, the implementation of inverter is required. For this reason, this paper deals with both half bridge and full bridge single phase inverters with an LC low pass filter appended at their output terminals. It has been found that full bridge inverter gives two times more output than half bridge inverter and this has certainly the advantage of using less valued step up transformer

Differences in lineage replacement dynamics of G1 and G2 rotavirus strains versus G9 strain over a period of 22 years in Bangladesh

Group A rotaviruses (RVAs) have been a major cause of severe gastroenteritis in Bangladesh, mainly in children below the age of five. At the icddr,b, RVA strains collection and characterization dates back for more than 20years. This sample collection was used to study the molecular evolution of the VP7 gene of G1, G2 and G9 RVA strains, which have been circulating in Bangladesh for most of this study period. The evolutionary rates (95% HPD) for G1, G2 and G9 were calculated to be 0.93×10 (0.68-1.18), 1.45×10 (1.12-1.78) and 1.07×10 (0.78-1.39), respectively, which is in line with previous data for the RVA VP7 outer capsid protein, which is under strong negative selective pressure. Bayesian analyses revealed that for the G1 and G2 genotypes, one or multiple lineages co-circulated for one or a few seasons, frequently followed by replacement with genetically different lineages. This can be explained by the existence of a large variety of G1 and G2 RVA lineages and the rapid dissemination of different lineages across the globe. In contrast, circulating G9 lineages were rather closely related to each other across the study period and they were usually derived from variants circulating in the previous season(s). This is consistent with the fact that G9 RVAs have circulated in the human population for less than 20years, and therefore their genetic diversity is much smaller, not resulting in the replacement of circulating G9 strains by highly divergent G9 lineages from abroad. Such different evolutionary dynamics for different RVA genotypes may alter their response to the selective pressure that might be exerted by the introduction of RVA vaccines and therefore a continued close monitoring is warranted

Differences in lineage replacement dynamics of G1 and G2 rotavirus strains versus G9 strain over a period of 22years in Bangladesh

Group A rotaviruses (RVAs) have been a major cause of severe gastroenteritis in Bangladesh, mainly in children below the age of five. At the icddr,b, RVA strains collection and characterization dates back for more than 20years. This sample collection was used to study the molecular evolution of the VP7 gene of G1, G2 and G9 RVA strains, which have been circulating in Bangladesh for most of this study period. The evolutionary rates (95% HPD) for G1, G2 and G9 were calculated to be 0.93×10(-)(3) (0.68-1.18), 1.45×10(-)(3) (1.12-1.78) and 1.07×10(-)(3) (0.78-1.39), respectively, which is in line with previous data for the RVA VP7 outer capsid protein, which is under strong negative selective pressure. Bayesian analyses revealed that for the G1 and G2 genotypes, one or multiple lineages co-circulated for one or a few seasons, frequently followed by replacement with genetically different lineages. This can be explained by the existence of a large variety of G1 and G2 RVA lineages and the rapid dissemination of different lineages across the globe. In contrast, circulating G9 lineages were rather closely related to each other across the study period and they were usually derived from variants circulating in the previous season(s). This is consistent with the fact that G9 RVAs have circulated in the human population for less than 20years, and therefore their genetic diversity is much smaller, not resulting in the replacement of circulating G9 strains by highly divergent G9 lineages from abroad. Such different evolutionary dynamics for different RVA genotypes may alter their response to the selective pressure that might be exerted by the introduction of RVA vaccines and therefore a continued close monitoring is warranted.publisher: Elsevier articletitle: Differences in lineage replacement dynamics of G1 and G2 rotavirus strains versus G9 strain over a period of 22years in Bangladesh journaltitle: Infection, Genetics and Evolution articlelink: http://dx.doi.org/10.1016/j.meegid.2014.10.002 content_type: article copyright: Copyright © 2014 Elsevier B.V. All rights reserved.status: publishe

A Novel Multiplex RT-PCR Assay for Simultaneous Detection of Dengue and Chikungunya Viruses

The goal of the study was to develop a specific, sensitive, and cost-effective molecular RT-PCR diagnostic assay for the rapid and simultaneous detection of the serotypes of dengue virus (DENV) and Chikungunya virus (CHIKV) from sera of suspected febrile patients. A single-tube, single-step multiplex RT-PCR (mRT-PCR) assay was designed for the detection of viral genomes from clinical and field samples. Specificity and sensitivity of the mRT-PCR assay were evaluated against six different combinations using two reverse transcriptases (AMV-RT and RT-Ace) and three DNA polymerases (LA-Taq, rTaq, and Tth). Among the six combinations, the AMV-RT and LA-Taq combination was more specific and sensitive than other enzyme combinations for detecting viral genomes of DENV-1, DENV-2, DENV-3, and DENV-4 (p < 0.01), and for detecting viral genomes of CHIKV (p < 0.05). The detection limits of the mRT-PCR were 10 focus forming units (FFU) for CHIKV and 1 FFU, 20 FFU, 0.1 FFU, and 10 FFU for DENV-1, DENV-2, DENV-3, and DENV-4, respectively. The primers used for the mRT-PCR did not show any cross-reactivity among the serotypes of DENV or CHIKV. Specificity and sensitivity of the newly developed mRT-PCR were validated using serum samples collected from febrile patients during dengue outbreaks in Bangladesh. The sensitivity for serotype detection of DENV and CHIKV was superior to the virus isolation method and the antigen detection method using the Dengue NS1-Ag assay. This novel mRT-PCR method can be used for molecular epidemiological surveillance of DENV and CHIKV in epidemic and endemic countries