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The paper investigates the dynamic operation of novel control scheme for both Static Synchronous Compensator (STATCOM) and Static Synchronous Series Compensator (SSSC) based on a new full model comprising a 48-pulse Gate Turn-Off thyristor voltage source converter for combined reactive power compensation and voltage stabilization of the electric grid network. The complete digital simulation of the STATCOM and SSSC within the power system is performed in the MATLAB/Simulink environment using the Power System Blockset (PSB). The STATCOM scheme and the electric grid network are modeled by specific electric blocks from the power system blockset, while the control system is modeled using Simulink. Two novel controllers for the STATCOM and SSSC are presented in this paper based on a decoupled current control strategy. The performance of both STATCOM and SSSC schemes connected to the 230-kV grid are evaluated. The proposed novel control schemes for the STATCOM and SSSC are fully validated by digital simulation.

Alcoholism and alcohol abuse represent a significant medical and societal problem, and have been thoroughly investigated in humans as well as using animal models. A less well understood aspect of alcohol related disorders is the possible effect of this drug on offspring whose parents were exposed prior to conception. The zebrafish has been successfully employed in alcohol research, however, the effect of exposing the parents to alcohol before fertilization of the eggs on offspring has not been demonstrated in this species. In this proof of concept study, we attempt to address this hiatus. We exposed both adult male and female zebrafish to 0.0% (control) or 0.5% (vol/vol) alcohol chronically for 7 days, subsequently bred the fish within their respective treatment group, collected the fertilized eggs, allowed them to develop, and tested the behavior of free-swimming offspring at their age of 7-9 days post-fertilization. We conducted the analysis in two genetically distinct quasi-inbred strains of zebrafish, AB and TL. Although gross morphology and general activity of the fish appeared unaffected, we found significant behavioral alterations in offspring of alcohol exposed parents compared to offspring of control parents in both strains. These alterations included robustly increased duration and reduced frequency of immobility, increased turn angle, and increased intra-individual variance of turn angle in offspring of alcohol exposed parents in both strains. The mechanisms underlying these behavioral effects or whether the effects are due to exposure of the father, the mother, or both to alcohol are unknown. Nevertheless, our results now set the stage for future studies with zebrafish that will address these questions.

Abstract Supersonic separator is a new technology with applications in gas dehydration and hydrocarbon dew pointing. Many research studies have investigated the design, performance and efficiency, economic viability, and industrial applications of these separators. Experimental facilities, pilot plants, and full scale industrial platform applications along with theoretical, analytical, and numerical modelling are some of the tools used in these studies. This review has found that while several aspects of this study are well studied, considerable gaps within the published literature still exists in the areas such as study of supersonic flows containing microscopic liquid droplets and liquid wall film.

Abstract The accumulation of waste biomass and plastic and the inefficient combustion of low-quality coal is a major cause of energy loss and air pollution in rural China. This paper reports for the first time an experimental and multi-perspective analysis on an industrial scale co-pyrolysis of waste biomass and plastic. The results show that the resulting biochar product had a low calorific value of ≥21.0 MJ/kg, which meets the national standard for commercial solid fuel (GB/T 31862–2015). The calorific value of the produced gas was over 10 MJ/m3 and met the requirements of the national standard for residential heating and cooking (GB/T 13612–2006). The products of the co-pyrolysis can replace 1100 t of standard coal per annum, and reduce carbon dioxide emissions, sulfur dioxide emissions, smoke, and other contaminants at the rate of 1720 t, 5–6 t, and 320 kg, respectively, as well as reducing smoke pollution. In addition, through the recycling of 750 t of plastic waste per annum for use in the co-pyrolysis, this method can reduce the white pollution of 50–66.7 km2 of farmland in the local area. The present study can guide the optimization of such systems and lead to adequate flexibility in the co-pyrolysis of different wastes to generate economic and socioenvironmental benefits.

Abstract Morphological characteristics of poplar and willow clones were determined in order to identify main characteristics leading to superior growth under increased plant competition with low or high nitrogen (N) availability. Seven hybrid poplar ( Populus spp. including one hybrid aspen) and five willow ( Salix spp.) clones were grown under greenhouse conditions for 13 weeks at three spacings (20 × 20, 35 × 35, and 60 × 60 cm) and two N levels (20 and 200 mg kg −1 ). The decrease in spacing from 60 to 20 cm reduced leaf area by 50% but clones had similar aboveground biomass per tree under all spacings, with increasing their height per unit leaf area. More productive clones had greater leaf area (+102%), leaf area per unit plant biomass (+12%) and lower root-to-shoot ratios (−27%) compared to less productive clones. There were positive relationships between leaf area and above-ground biomass per tree for both more and less productive clones. Compared to low N level and 60 cm spacing, trees growing in high N level and 20 cm spacing reached similar root collar diameter, crown width, and leaf area values and even greater height, suggesting that an addition of N could help mitigate negative effects of tree competition.

Abstract Global environmental change is driven by food production. Biogas from food waste is a better source of clean energy. Ghana’s energy strategy targets a 10% increase in renewable energy and modern biomass in the national electricity generation mix. Studies on the assessment of electricity generation potential and economic feasibility of biogas to electricity projects in Ghana’s major cities are scarcely available. This study assesses the electricity generation potential of biogas from food waste through anaerobic digestion technology. The municipal solid waste generation potential of Accra and Kumasi was estimated from 2020 to 2039. The potential theoretical methane yield from food waste was calculated using Buswell’s equation. The study analyzed anaerobic digestion projects’ economic feasibility using the total life cycle cost, net present value, investment payback period, levelized cost of energy, and internal rate of return methods. A sensitivity analysis based on two scenarios (optimistic and pessimistic) was performed to analyze the influence of changes in the composition of food waste, per capita waste generation rate, population growth rate, per capita GDP growth rate, discount rate, capacity factor, electricity generation efficiency, waste collection efficiency, and methane production potential on the economic feasibility of the projects. The main findings indicate that the amount of waste generation in Accra during the project life cycle is 899,000 t/y to 3,359,000 t/y, while that of Kumasi is 915,000 t/y to 3,159,000 t/y. The power generation potential of the project in Accra ranges from 80.43 to 300.49 GWh/y, and in Kumasi ranges from 60.63 to 209.31 GWh/y. Economically, the project is feasible in Accra and Kumasi. The net present value of the project in Accra and Kumasi is $217,800,000 and $156,100,000. The sensitivity analysis shows that the project is infeasible in all the cities with a discount rate exceeding 20%. When the discount rate exceeds 20%, the project becomes highly infeasible in Accra compared to Kumasi. This study will offer itself as scientific guidance for investment in biogas to electricity projects in Ghana’s cities.

Abstract As a result of prodigious energy requirements, unprecedented demands are being placed on China's coal supply system. Since the railways bear the brunt of moving coal, they not only have to move large volumes but to carry these volumes over increasing distances. Moreover, as the amount of coal requiring transport grows, the railways must continually invest in network expansion by adding new lines and enlarging the capacity of existing ones. This paper traces these developments and assesses their adequacy in the light of the spatial mismatches between supply and demand for coal.

Abstract In the present work, effects of height, length, and width of a single-slope basin-type solar still on its distillate production was investigated. For this purpose, a radiation model was developed which accounts for the influences of all walls on quantities of received solar radiation by the base and saline water of the still. Moreover, in this radiation model, the side walls of the still were considered as the trapezoid and the diffuse as well as beam components of solar irradiance were separately taken into account for the first time. Abilities of the present model were compared with earlier ones. Furthermore, the predictions of the current model were compared with the present experimental results, and it was observed that the predicted and measured values are in a close agreement. The results of this study show that by increasing the height of still's walls, its efficiency decreases. The model suggests that the height of the front wall should be less than about 0.10 m. Moreover, it is illustrated that by extending the still length, the side walls shadow reduces and consequently, the system efficiency increases. In addition, the optimal width to length ratio was found to be about 0.4.

Abstract In this study, hydrogen production with activated sludge, a diverse bacterial source has been investigated and compared to microflora from anaerobic digester sludge, which is less diverse. Batch experiments were conducted at mesophilic (37 °C) and thermophilic (55 °C) temperatures. The hydrogen production yields with activated sludge at 37 °C and 55 °C were 0.56 and 1.32 mol H 2 /mol glucose consumed, respectively. While with anaerobically digested sludge hydrogen yield was 2.18 mol H 2 /mol glucose consumed at 37 °C and 1.25 mol H 2 /mol glucose consumed at 55 °C. The results of repeated batch experiments for 615 h resulted in average yields of 1.21 ± 0.62 and 1.40 ± 0.16 mol H 2 /mol glucose consumed for activated sludge and anaerobic sludge, respectively. The hydrogen production with activated sludge was not stable during the repeated batches and the fluctuation in hydrogen production was attributed to formation of lactic acid as the predominant metabolite in some batches. The presence of lactic acid bacteria in microflora was confirmed by PCR-DGGE.