Search

The marine genus of bacteria, Vibrio, includes several significant human and animal pathogens, highlighting the importance of defining the factors that govern their occurrence in the environment. To determine what controls large-scale spatial patterns among this genus, we examined the abundance and diversity of Vibrio communities along a 4000 km latitudinal gradient spanning the Australian coast. We used a Vibrio-specific amplicon sequencing assay to define Vibrio community diversity, as well as quantitative PCR and digital droplet PCR to identify patterns in the abundances of the human pathogens V. cholera, V. parahaemolyticus and V. vulnificus. The hsp60 amplicon sequencing analysis revealed significant differences in the composition of tropical and temperate Vibrio communities. Over 50% of Vibrio species detected, including the human pathogens V. parahaemolyticus and V. vulnificus, displayed significant correlations with either temperature, salinity, or both, as well as different species of phytoplankton. High levels of V. parahaemolyticus and V. vulnificus were detected in the tropical site at Darwin and the subtropical Gold Coast site, along with high levels of V. parahaemolyticus at the subtropical Sydney site. This study has revealed the key ecological determinants and latitudinal patterns in the abundance and diversity of coastal Vibrio communities, including insights into the distribution of human pathogens, within a region experiencing significant ecological shifts due to climate change.

Solar photovoltaic (PV) modules consist of solar cells connected in series to provide the required output power. The solar PV system is experiencing major challenges, which are mainly due to the partial shadows on the photovoltaic modules leading to mismatching power loss and hot spot problems. Hotspots have become a major cause of PV module failure. The Cell Partition Technique (CPT) is proposed to reduce hotspots and minimize mismatch losses caused by partial shadings. Specifically, each solar PV cell (Full cell) in a solar PV module is divided or partitioned into two half cells (known as Half-Cut Cells or HC) and three equal cells (known as Tri-Cut Cells or TC) in accordance with the proposed technique. The HC and TC types of cells are connected in a strings of series-parallel connection, and bypass diode is placed in middle of the solar PV module to ensure proper operation. The primary aim of this research is to model, evaluate, and investigate the performance of solar PV arrays using new PV modules are developed based on Cell Partition Technique (PVM-CPT), such as half-cut cell modules (HCM), and tri-cut cell modules (TCM) and compared with full-sized cell modules (FCM). These PVM-CPT are connected in Series–Parallel (SP), Total-Cross-Tied (TCT), and proposed static shade dispersion based TCT reconfiguration (SD-TCTR) for the array sizes of 3x4, 4x3 and 4x4, respectively. The purpose is to select the most appropriate solar PV array configurations in terms of the highest global maximum power and thus the lowest mismatch power losses under short and narrow, short and wide, long and narrow, long and wide type of cell level partial shadings. The Matlab/Simulink software is used to simulate and analyze all of the shading cases. The results show that, when compared to conventional module configurations under different shading conditions, the proposed static SD-TCTR arrangement with TC modules (SDTCTR-TCM) exhibits the lowest mismatch power losses and the greatest imp

Solar-based photovoltaic (SPV) cells produce power from sunlight through the photovoltaic effect. The yield voltage of a single PV cell is small, so the voltage is extended by interfacing PV cells in series arrangement known as PV module or panel. Solar PV array comprises of series and parallel connections of modules in the grid structure with a few columns and rows. The various kinds of SPV array configurations or topologies are shaped by changing the number of electrical connections between module to module in an array. This paper presents the mathematical examination of 6×6 size regular SPV array configurations, including Total-Cross-Tied, Parallel, Honey-Comb, Series-Parallel, Series, Bridge-Linked types beneath un-shading case, and different proposed shading cases (primarily short narrow, short wide, long narrow, and long wide shadings). The electrical proportionate circuit of the SPV array setups was analyzed by Kirchhoff’s laws at distinctive nodes and loops in a sun powered PV array. The location of global maximum power point (GMPP) was determined hypothetically and distinguished in Matlab/simulation software at various shading conditions.Citation: Raju, V.B., and Chengaiah, C. (2020). Mathematical Analysis of Solar Photovoltaic Array Configurations with Partial Shaded Modules. Trends in Renewable Energy, 6, 121-143. DOI: 10.17737/tre.2020.6.2.00115

The conventional Total-Cross-Tied (TCT) Solar photovoltaic (SPV) array configuration has the highest power output as compared to other configurations or topologies in most cases of partial shading. But the performance of TCT configuration is affected under shading conditions, resulting in multiple peaks occurring in the output PV characteristics. To improve the performance of TCT array configuration under different shading scenarios, it is only necessary to reposition or rearrange the PV modules in the TCT Solar PV array based on the arrangement of puzzle numbers, without altering the electrical contacts of the TCT array configuration. The main objective of this study is to investigate the performance of rearrangement of modules in SPV array based new TCT array configurations with shade dispersion technique and compare the global maximum peak power (GMPP) of SPV array, mismatch losses, Fill-Factor, efficiency and number of required electrical connections or ties between array modules with proposed optimal arrangement of modules under shading (non-uniform irradiance) conditions. For this study, one uniform irradiance case and total 14 partial shading patterns were considered. MATLAB/Simulink software was used for modeling and simulation of 6×6 size different rearrangement based TCT array and proposed optimal SPV array configurations.Citation: BALARAJU, V., and Chengaiah, C. (2020). A Comprehensive Study on Re-arrangement of Modules Based TCT Configurations of Partial Shaded PV Array with Shade Dispersion Method. Trends in Renewable Energy, 6, 37-60. DOI: 10.17737/tre.2020.6.1.00111

© 2016 Siboni, Balaraju, Carney, Labbate and Seymour. Vibrio are a genus of marine bacteria that have substantial environmental and human health importance, and there is evidence that their impact may be increasing as a consequence of changing environmental conditions. We investigated the abundance and composition of the Vibrio community within the Sydney Harbour estuary, one of the most densely populated coastal areas in Australia, and a region currently experiencing rapidly changing environmental conditions. Using quantitative PCR (qPCR) and Vibrio-specific 16S rRNA amplicon sequencing approaches we observed significant spatial and seasonal variation in the abundance and composition of the Vibrio community. Total Vibrio spp. abundance, derived from qPCR analysis, was higher during the late summer than winter and within locations with mid-range salinity (5-26 ppt). In addition we targeted three clinically important pathogens: Vibrio cholerae, V. Vulnificus, and V. parahaemolyticus. While toxigenic strains of V. cholerae were not detected in any samples, non-toxigenic strains were detected in 71% of samples, spanning a salinity range of 0-37 ppt and were observed during both late summer and winter. In contrast, pathogenic V. vulnificus was only detected in 14% of samples, with its occurrence restricted to the late summer and a salinity range of 5-26 ppt. V. parahaemolyticus was not observed at any site or time point. A Vibrio-specific 16S rRNA amplicon sequencing approach revealed clear shifts in Vibrio community composition across sites and between seasons, with several Vibrio operational taxonomic units (OTUs) displaying marked spatial patterns and seasonal trends. Shifts in the composition of the Vibrio community between seasons were primarily driven by changes in temperature, salinity and NO2, while a range of factors including pH, salinity, dissolved oxygen (DO) and NOx (Nitrogen Oxides) explained the observed spatial variation. Our evidence for the presence of