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Abstract The increasing energy demand in developing countries has jeopardised energy security, necessitating the employment of solar energy to augment conventional energy sources. It is important to assess the annual performance parameters of solar power plants to understand its place in energy generation. This study analyses the performance and economic viability of a large-scale solar power park located in India. A 50 MWp Solar Photovoltaic Power Park (SPPP) located at Sakunala, in the State of Andhra Pradesh, is one of the largest solar power park in India, and the site receives an average solar radiation of 5.5–6.0 kWh/m2/day. The design, performance analysis, economic feasibility, and greenhouse gas mitigation of the 50 MWp SPPP is presented. The energy yields, performance ratio (PR), capacity utilization factor (CUF), and losses are assessed based on the IEC 61724 standards for two consecutive years (2018–2019 and 2019–2020). The performance results obtained are compared with the PVsyst simulation results. The PR, CUF, and energy yields are estimated as 0.779, 0.24, and 107,326.4 MWh in 2018–2019 and 0.691, 0.22, and 96,707.336 MWh in the year 2019–2020, respectively. The PVsyst simulator evaluates the PR, CUF, and energy yields as 0.80, 0.24, and 106,022 MWh, respectively. Further, the effect of power curtailment policies on solar PV projects is also discussed and the effect of curtailment policy on the economy of the solar power park in terms of payback period and emissions are analysed. The performance of the SPPP is also compared with those of other PV plants installed all over the world.

At present, Artemisia annua L. is the major source of artemisinin production. To control the outbreaks of malaria, artemisinin combination therapies (ACTs) are recommended, and hence an ample amount of artemisinin is required for ACTs manufacture to save millions of lives. The low yield of this antimalarial drug in A. annua L. plants (0.01-1.1%) ensues its short supply and high cost, thus making it a topic of scrutiny worldwide. In this study, the effects of root endophyte, Piriformospora indica strain DSM 11827 and nitrogen fixing bacterium, Azotobacter chroococcum strain W-5, either singly and/or in combination for artemisinin production in A. annua L. plants have been studied under poly house conditions. The plant growth was monitored by measuring parameters like height of plant, total dry weight and leaf yield with an increase of 63.51, 52.61 and 79.70% respectively, for treatment with dual biological consortium, as compared to that of control plants. This significant improvement in biomass was associated with higher total chlorophyll content (59.29%) and enhanced nutrition (especially nitrogen and phosphorus, 55.75 and 86.21% respectively). The concentration of artemisinin along with expression patterns of artemisinin biosynthesis genes were appreciably higher in dual treatment, which showed positive correlation. The study suggested the potential use of the consortium P. indica strain DSM 11827 and A. chroococcum strain W-5 in A. annua L. plants for increased overall productivity and sustainable agriculture.

The aim of this research is to find out suitable material for insulator and their flashover performance to withstand the high pollution degree in different environmental conditions. The experimental investigation was carried out on various insulating material like porcelain, glass, and rubber to find out the artificial effluence to examine alternate current flashover potentials. The result shows that the polluted flashover voltage is affected by equivalent salt deposit density and non soluble deposit density, the authorities of which are autonomous of each one on another. The correction formulae of the flashover voltage of various insulators at various salt deposit density and non soluble deposit density levels have pointed out by means of the flashover voltages examination. Also the dissimilarity existing between the flashover voltages of various types of polluted insulators. From this we are able to conclude which insulating material withstands the pollution degree better amongst the above three.

Abstract In arid areas, dry cooling technology is a preferable alternate of wet cooling mainly owing to the scarcity of abundant water supply. However, the supercritical CO2 power cycle still offers considerable thermal performance even at higher ambient temperature using dry cooling. The novelty of this work is the exhaustive designing of dry cooler for supercritical CO2 cycles (recompression and partial cooling) in concentrating solar power application. Prior to the design of tower, a preliminary analysis is conducted in achieving the optimum main compressor inlet temperature (33 °C-recompression and 40 °C-partial cooling) at which the cycle delivers the maximal efficiency. The comparison is performed at same higher and lower pressure and for the partial cooling, the intermediate pressure is optimized. At relatively higher compressor inlet temperatures (above 50 °C), the partial cooling achieves higher efficiency while at lower temperatures (30–49 °C), the recompression shows superior performance. An iterative nodal method is used for the air-cooled finned tube heat exchanger units that takes account of the dramatic variation in thermodynamic properties of CO2 with the bulk temperature. Kroger’s detailed methodology of designing dry cooler is adapted with the implementation of nodal approach for CO2 property variation. A dry cooling tower with 52.45 m height is essential for the recompression cycle, whereas the partial cooling requires two towers of the height of 35.4 m and 38.7 m. A thermal assessment is carried out on the dry cooler under various cycle fluid inlet temperatures and ambient temperatures. During hot and humid ambient conditions, lower compressor inlet temperatures (up to 53.1 °C) are obtained with the recompression cycle compared to partial cooling (up to 64.5 °C). In extreme climate condition of 50 °C air temperature, the recompression cycle provides superior thermal efficiency (46.5% against 45.5%). For future commercialization of dry cooled sCO2 power plant, the recompression cycle is preferred due to its superior performance and lower capital cost for cooling tower design and solar field. The work demonstrates the impact of dry cooling tower design strategy in the context of cycle thermal assessment under various working condition.

Abstract Comprehensive information about the concentrations, distribution, and modes of occurrence of elements in coal are important from the environmental and economic point of view. Although a great number of previous studies have investigated the geology of coalbed methane in the Qinshui Basin, only a few studies focused on the inorganic constituents in coal. More specifically, the mode of occurrences of valuable element Li in the No. 3 Coal is still unclear, although Li was found enriched. In this study, we present mineral characteristics, as well as multi-element data on the Permian No. 3 Coal from the Sucun and Gaohe Mines, Changzhi City, southern Qinshui Basin. The studied coals are characterized by low- to medium-ash yield (Ad = 5.72%- 28.18%, 12.34% on average), low volatile matter yield (Vdaf = 8.49–15.17%, 10.96% on average), suggesting a low volatile bituminous coal to semi-anthracite. NH4-illite and kaolinite are the main minerals in the coals detected by XRD, and trace amount of minerals calcite, dolomite, quartz, pyrite and diaspore can also be found. The major elements of the studied No. 3 coals are dominated by SiO2 and Al2O3, ranging 2.49–16.45 wt% and 2.13–12.9 wt% (on a whole-coal basis), respectively. Li is enriched in the No. 3 coals (5

Abstract Biodiesel has gained the forefront of our focus on renewable transportation fuels. This article provides a comprehensive review on the sources used as feedstock and their classification based on generation or type (edible, non-edible, waste resources and animal fats) along with a variety of classical and modern oil extraction techniques. The technical aspects of the various biodiesel production methods currently implemented to the best of our knowledge are discussed here, which include in-situ biodiesel production, both catalysed (homogeneous and heterogeneous systems) and uncatalysed classical production approaches, with emphasis on how each of these approaches are affected by their reaction parameters. The review also highlights the observed drawbacks of each process with a view to assessing the implementation of supercritical and superheated technologies as an alternative, economically feasible advancement. Supercritical process (SCP) has shown great prospect in the obtainment of high quality biodiesel from a wide range of high to low grade feedstock with minimal impacts on the presence of water or FFAs (free fatty acids). From available literature it is shown that these do not affect the process significantly, and various other supercritical fluids such as methyl acetate, tert-butyl methyl ether (MTBE) and dimethyl carbonate can also be used to avoid glycerol formation. The process however, suffers from high initial implementation cost being the most prominent drawback, among others like thermal degradation of the fuel. Another promising technique, the superheated vapour technology (SHV) has emerged as an alternative, with limited literature proving the superiority of either of these processes to be inconclusive. In future works, researchers need to look into various aspects such as developing a spiral reactor for heat recovery, using software based optimization for eliminating redundant experiments analysing production cost for industrial scale-up and improving the fuel’s oxidative stability by adding antioxidants for convenient long-term storage and use.

Abstract The trend of using biodiesels in compression ignition engines have been the focus in recent decades due to the promising environmental factors and depletion of fossil fuel reserves. This work presents the effect of Calophyllum inophyllum methyl ester on diesel engine performance, emission and combustion characteristics at different injection pressures. Experimental investigations with varying injection pressures of 200 bar, 220 bar and 240 bar have been carried out to analyse the parameters like brake thermal efficiency, specific fuel consumption, heat release rate and engine emissions of direct injection diesel engine fuelled with 100% biodiesel and compared with neat diesel. The experimental results revealed that brake specific fuel consumption of C. inophyllum methyl ester fuelled engine has been reduced to a great extent with higher injection pressure. Significant reduction in emissions of unburnt hydrocarbons, carbon monoxide and smoke opacity have been observed during fuel injection of biodiesel at 220 bar compared to other fuel injection pressures. However oxides of nitrogen increased with increase in injection pressures of C. inophyllum methyl ester and are always higher than that of neat diesel. In addition the combustion characteristics of biodiesel at all injection pressures followed a similar trend to that of conventional diesel.

Field study was conducted during winter seasons (November–March) of 2015–2016 and 2016–2017 at the Research Farm of Bidhan Chandra Krishi Viswavidyalaya, West Bengal, India, with an aim to investigate the crop productivity, energy and C budget, carbon footprint and economic sustainability of peanut cultivation fertilized with varied levels of nitrogen under polythene mulching. The experiment laid out in split-plot design comprised of two mulching practices as the main-plot treatments and seven doses of N with or without supplementation of Rhizobium bio-fertilizer as the sub-plot treatments. Fertilization with 100% recommended dose of nitrogen (RDN) + Rhizobium under polythene mulching brought about significant enhancement in pod yield over other nutrient management practices. The effects on yield attributing characters were similar to that of pod yield. Energy indices namely net energy gain, energy productivity, energy intensiveness and energy profitability were the highest with 100% RDN + Rhizobium, irrespective of mulching situations. However, the maximum values of specific energy and nutrient energy ratio were recorded when the crop received 50% RDN with and without Rhizobium, respectively, under mulching and non-mulching situations. Human energy profitability was always greater under mulching situations over non-mulching. Total estimated carbon footprints improved with increase in N level from 0 to 100% RDN with Rhizobium under polythene mulching over non-mulching situations. Highest value of C sustainability index was also observed with polythene covering particularly with the application of 100% RDN + Rhizobium. This treatment combination also proved its superiority with respect to economic benefits in peanut cultivation.

Biomass burning (BB) is one of the largest sources of carbonaceous aerosols with adverse impacts on air quality, visibility, health and climate. BB emits a few specific aromatic acids (p-hydroxybenzoic, vanillic, syringic and dehydroabietic acids) which have been widely used as key indicators for source identification of BB-derived carbonaceous aerosols in various environmental matrices. In addition, measurement of p-hydroxybenzoic and vanillic acids in snow and ice cores have revealed the historical records of the fire emissions. Despite their uniqueness and importance as tracers, our current understanding of analytical methods, concentrations, diagnostic ratios and degradation processes are rather limited and scattered in literature. In this review paper, firstly we have summarized the most established methods and protocols for the measurement of these aromatic acids in aerosols and ice cores. Secondly, we have highlighted the geographical variability in the abundances of these acids, their diagnostic ratios and degradation processes in the environments. The review of the existing data indicates that the concentrations of aromatic acids in aerosols vary greatly with locations worldwide, typically more abundant in urban atmosphere where biomass fuels are commonly used for residential heating and/or cooking purposes. In contrast, their concentrations are lowest in the polar regions which are avoid of localized emissions and largely influenced by long-range transport. The diagnostic ratios among aromatic acids can be used as good indicators for the relative amounts and types of biomass (e.g. hardwood, softwood and herbaceous plants) as well as photochemical oxidation processes. Although studies suggest that the degradation processes of the aromatic acids may be controlled by light, pH and hygroscopicity, a more careful investigation, including closed chamber studies, is highly appreciated.