Performance Evaluation of PV Panel Configurations Considering PSC’s for PV Standalone Applications

One of the major concerns for continuous solar photovoltaic (PV) generation is partial shading. The movement of clouds, shadow of buildings, trees, birds, litter and dust, etc., can lead to partial shadow conditions (PSCs). The PSCs have caused inconsistent power losses in the PV modules. This leads to a shortage of electricity production and the presence in the PV curve of several peaks. One of the simplest solutions to PSC’s is the PV configurations. The objective of this paper is modelling and simulation of solar PV system in various shading scenarios for KC200GT 200 W, 5 x 5 configurations that includes Series/Parallel (SP), Total-Cross-Tied (TCT), Triple-Tied (TT), Bridge-Link (BL) configurations. Real time PSC’s such as corner, center, frame, random, diagonal, right side end shading conditions are evaluated under all PV array configurations. A comparative analysis is carried out for the parameters such as open circuit voltage, short circuit current, maximum power point, panel mismatch losses, fill factor, efficiency under all PV configurations considering PSC’s. From the comparison analysis best configuration will be presented.

Deformation Source Revealed From Leveling Survey in Jigokudani Valley, Tateyama Volcano, Japan

We modeled vertical deformation detected from leveling survey in Jigokudani valley, Tateyama volcano, central Japan. In Jigokudani valley, uplift of 4 cm/year was previously detected during the period from 2007 to 2010 by Interferometric Synthetic Aperture Radar (InSAR). To confirm whether this inflation has continued to the present, we conducted leveling survey in Jigokudani valley since 2015. Most bench marks showed subsidence up to 5.6 cm during the four-year period from October 2016 to September 2020, while a bench mark locates at the center of the leveling route uniquely showed uplift of 1.6 cm. We applied a dislocation source model to the deformation using a grid search method. A crack with a length of 350 m, a width of 100 m, a strike of N117°E and a dip of 61° is located at a depth of 50 m near the center of Jigokudani valley (Koya jigoku and the new fumarolic area) where highly activating recently. Closing of the crack of 344 cm yields volume decreases of 120,400 m3. Striking direction of the crack is parallel to the line of which are old explosion craters (Mikurigaike and Midorigaike ponds) and corresponds to current maximum compressive stress field in the region of Hida Mountains including Tateyama volcano. The deformation source of the previous period from 2007 to 2010 detected from InSAR was estimated to be at a depth of 50 m and a gas chamber was correspondingly found from the audio-frequency magnetotelluric (AMT) survey. The estimated crack in this study is also located at a similar position of the gas chamber which was also identified from AMT survey. During the period from 2015 to 2016, the crack opened (i.e., inflated) and the inflation stopped during the next one-year period from 2016 to 2017. During the period from 2017 to 2020, the crack turned to closing (i.e., deflation), probably because of the increase in emission of volcanic fluid or gas with a formation of a new crater at the western side of Jigokudani valley (Yahata jigoku) during the period from 2017 to 2018.

Length-based assessment of southern brown shrimp stock from trawl fisheries on the Amazon Continental Shelf

Virtual Population Analysis (VPA) is a diagnostic tool that providing valuable input for management decisions to sustainable catches for marine fisheries. Industrial shrimp trawling produces one of the most valuable export commodities in the Brazilian fishery sector. Due to the profitability, there is pressure on government agencies to increase the number of fishing licenses. The present study used the body-length data available for the industrial southern brown shrimp trawling fleet of the Amazon Continental Shelf (ACS), Brazil, to estimate the current maximum sustainable yield and test the potential effects of increased effort on the sustainability of this fishery. The available data encompasses 13 years of onboard monitoring of shrimp trawling. The VPA was run in an Excel spreadsheet. The results indicate that the ACS shrimp stock has high fishing (F) mortality rates, although exploitation levels can be considered adequate below the MSY. An increase of up to 40% in fishery effort – including the expansion of the number of vessels – would not result in overfishing, although we would not recommend an increase in effort, as this may increase impacts on the bycatch fauna and eventual economic losses in the event of the failure of recruitment.

Genotoxicity and carcinogenicity of traditionally roasted meat using indicator polycyclic aromatic hydrocarbons (PAHs), Port Harcourt, Nigeria

This research is targeted to employ indicator like PAHs, mainly PAH4 and PAH8 to evaluate the genotoxicity and carcinogenicity of PAHs in traditionally roasted meat (Suya) in selected locations at Port Harcourt metropolis, Nigeria, since its estimation using toxicity equivalent factor (TEF) model is not convenient. Suya sample were obtained at designated locations in the metropolitan city and were analyzed for PAHs present in them by using GC-FID and Chemstation after the PAHs were extracted using USEPA 8270 method. The series of results clearly indicated that indicator PAHs, i.e., PAH4 gave the best outlook on genotoxicity and carcinogenicity potential of the Suya over PAH8, PAH2 and Bap indicator PAHs and also visibly showed peak loadings of 0.15131 μg/Kg, which indicates that the sample Suya meat is not genotoxic or carcinogenic especially when correlated with current maximum regulatory value of 12 μg/Kg for PAH4. Regular consumption of Suya is however risky and may expose consumers to cancer.

Genotoxicity and carcinogenicity of traditionally roasted meat using indicator polycyclic aromatic hydrocarbons (PAHs), Port Harcourt, Nigeria

This research is targeted to employ indicator like PAHs, mainly PAH4 and PAH8 to evaluate the genotoxicity and carcinogenicity of PAHs in traditionally roasted meat (Suya) in selected locations at Port Harcourt metropolis, Nigeria, since its estimation using toxicity equivalent factor (TEF) model is not convenient. Suya sample were obtained at designated locations in the metropolitan city and were analyzed for PAHs present in them by using GC-FID and Chemstation after the PAHs were extracted using USEPA 8270 method. The series of results clearly indicated that indicator PAHs, i.e., PAH4 gave the best outlook on genotoxicity and carcinogenicity potential of the Suya over PAH8, PAH2 and Bap indicator PAHs and also visibly showed peak loadings of 0.15131 μg/Kg, which indicates that the sample Suya meat is not genotoxic or carcinogenic especially when correlated with current maximum regulatory value of 12 μg/Kg for PAH4. Regular consumption of Suya is however risky and may expose consumers to cancer.

Environmental variability and fishing effects on the Pacific sardine fisheries in the Gulf of California

Small pelagic fish support some of the largest fisheries globally, yet there is an ongoing debate about the magnitude of the impacts of environmental processes and fishing activities on target species. We use a nonparametric, nonlinear approach to quantify these effects on the Pacific sardine (Sardinops sagax) in the Gulf of California. We show that the effect of fishing pressure and environmental variability are comparable. Furthermore, when predicting total catches, the best models account for both drivers. By using empirical dynamic programming with average environmental conditions, we calculated optimal policies to ensure long-term sustainable fisheries. The first policy, the equilibrium maximum sustainable yield, suggests that the fishery could sustain an annual catch of ∼2.16 × 105 tonnes. The second policy with dynamic optimal effort, reveals that the effort from 2 to 4 years ago impacts the current maximum sustainable effort. Consecutive years of high effort require a reduction to let the stock recover. Our work highlights a new framework that embraces the complex processes that drive fisheries population dynamics yet produces simple and robust advice to ensure long-term sustainable fisheries.

An Experimental Investigation on Photovoltaic Array Power Output Affected by the Different Partial Shading Conditions

This paper presents an experimental investigation on photovoltaic array (PV array) power output affected by partial shading conditions (PSCs). An experiment setup of a PV array with a series configuration using 2 × 4 photovoltaic modules (PV modules) was built. The power output loss due to the shading effect on the first photovoltaic cells (PV cell) connected with bypass diodes of each photovoltaic module, installed in the PV array in the horizontal direction, was evaluated. Depending on the direction of the sun relative to the PV array configuration, the shading percentage was measured during the test and recorded the current and voltage of the PV array. The performance evaluation of the PV array configurations is referred to with respect to the values of maximum power voltage, the maximum power current, maximum power output, power output losses and fill factor (FF). The experimental results show that 44% shading of the first PV cells affects PV array power output loss by more than 80%.

Research on the Influence of Dust and Ambient Temperature on the Power of Photovoltaic Cells Based on the Regression Method

Solar energy has huge potential and offers a solution to fulfill the demand for energy and reduce fossil fuel emissions. An effort had been made for assessing the effects of dust accumulation and ambient temperature on module conversion efficiency of 62 KWp grid connected rooftop solar plant. The performance parameters including open-circuit voltage, maximum voltage, short-circuit current, maximum current, etc. were collected and permitting for usual dust addition. These statistics were used for the estimation of the performance ratio (PR), capacity utilization factor (CUF), and power conversion efficiency. This work assesses the decrease in conversion efficiency of cell as a function of dust addition and ambient temperature. A multivariate linear regressions (MLR) model can forecast conversion efficiency closely, with R2 values close to 91%. It was employed in computing decrease in efficiency due to dust addition only. Result shows that the normal efficiency drops due to dust are 0.872%/day, energy harms are 9.935 kWh/m2 and Rs. 192.72 or 2.5 dollar per day by the MLR model.

Warming winters threaten peripheral Arctic charr populations of Europe

As the global climate warms, the fate of lacustrine fish is of huge concern, especially given their sensitivity as ectotherms to changes in water temperature. The Arctic charr (Salvelinus alpinus L.) is a salmonid with a Holarctic distribution, with peripheral populations persisting at temperate latitudes, where it is found only in sufficiently cold, deep lakes. Thus, warmer temperatures in these habitats particularly during early life stages could have catastrophic consequences on population dynamics. Here, we combined lake temperature observations, a 1-D hydrodynamic model, and a multi-decadal climate reanalysis to show coherence in warming winter water temperatures in four European charr lakes near the southernmost limit of the species’ distribution. Current maximum and mean winter temperatures are on average ~ 1 °C warmer compared to early the 1980s, and temperatures of 8.5 °C, adverse for high charr egg survival, have frequently been exceeded in recent winters. Simulations of winter lake temperatures toward century-end showed that these warming trends will continue, with further increases of 3–4 °C projected. An additional 324 total accumulated degree-days during winter is projected on average across lakes, which could impair egg quality and viability. We suggest that the perpetuating winter warming trends shown here will imperil the future status of these lakes as charr refugia and generally do not augur well for the fate of coldwater-adapted lake fish in a warming climate.

SiGMoiD: A superstatistical generative model for binary data

AbbstractIn modern biological physics, there is a great interest in building generative probabilistic models for ensembles of covarying binary variables. A popular approach is to use the maximum entropy principle. Here, one builds generative models that use as constraints lower level statistics estimated from the data. While extremely popular, maximum entropy models have conceptual as well as practical issues; they rely on the modelers’ choice of constraints and are computationally expensive to infer when the number of variables is large (n > 100). Here, we address both these issues with Superstastistical Generative Model for binary Data (SiGMoiD). SiGMoiD is a maximum entropy based framework where we imagine that the data as arising from superstatistical system; individual binary variables are coupled to the same bath whose intensive variables fluctuate from sample to sample. Moreover, instead of choosing the constraints, in SiGMoiD we choose only the number of constraints and let the algorithm infer them from the data itself. Notably, we show that SiGMoiD is orders of magnitude faster than current maximum entropy-based models and allows us to model collections of very large number of binary variables. We also discuss future directions.