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The accumulation of dust on any given photovoltaic (PV) module surface depends on the type of dust, environment, surroundings, weather, module properties, and its installation design. In this research, equations were developed for the preliminary evaluation and comparison of the reduction in power from PV modules because of dust soiling. Use of these equations shows that dust accumulation decreases solar irradiance and thus the power output of modules, and that there is a linear relationship between the power output degradation and density or amount of accumulated dust. The equations can be used to conduct analysis of average photon energy and the PV module power output reduction from accumulated dust. The study also showed that type of PV module can also affect the degree of power output reduction. The amorphous silicon PV modules are more affected compared to poly crystalline silicon PV modules as the latter has a spectrum response which still has the range that can produce full energy and therefore, dust soiling has lesser impact on them. PV power plants should regularly clean the modules, if not, production of electricity decreases, and so too the revenue from selling electricity, making the payback of the power plant longer.

Growing concerns over the use of limited fossil fuels and their negative impacts on the ecological niches have facilitated the exploration of alternative routes. The use of conventional plastic material also negatively impacts the environment. One such green alternative is polyhydroxyalkanoates, which are biodegradable, biocompatible, and environmentally friendly. Recently, researchers have focused on the utilization of waste gases particularly those belonging to C1 sources derived directly from industries and anthropogenic activities, such as carbon dioxide, methane, and methanol as the substrate for polyhydroxyalkanoates production. Consequently, several microorganisms have been exploited to utilize waste gases for their growth and biopolymer accumulation. Methylotrophs such as Methylobacterium organophilum produced highest amount of PHA up to 88% using CH4 as the sole carbon source and 52–56% with CH3OH. On the other hand Cupriavidus necator, produced 71–81% of PHA by utilizing CO and CO2 as a substrate. The present review shows the potential of waste gas valorization as a promising solution for the sustainable production of polyhydroxyalkanoates. Key bottlenecks towards the usage of gaseous substrates obstructing their realization on a large scale and the possible technological solutions were also highlighted. Several strategies for PHA production using C1 gases through fermentation and metabolic engineering approaches are discussed. Microbes such as autotrophs, acetogens, and methanotrophs can produce PHA from CO2, CO, and CH4. Therefore, this article presents a vision of C1 gas into bioplastics are prospective strategies with promising potential application, and aspects related to the sustainability of the system.

Cryptomeria japonica (CJ) samples were heated in a thermogravimetric analyzer (TGA) with CO2 as agent to study the gasification kinetics in the isothermal process. The samples were torrefied at 250 and 350 °C for 1 h. before being tested in TGA. Three isothermal conditions of 750, 800, and 850 °C were tested in this study to estimate the kinetic parameters of the Arrhenius form with the proposed models. The homogeneous model (HM), shrinking core model (SCM), and linear model (LM) were used, and the predicted results obtained from these models were compared with experimental data. The reaction rate of gasification was enhanced as temperature was raised, and a correlation of kinetic parameters with temperature was obtained. The simulated results of the linear model (LM) fit well with experimental data. This work is useful for design gasification in downdraft gasifier.

Abstract Carbon-based counter electrodes of dye-sensitized solar cells (DSSCs) such as carbon black-graphite composite (CB/Gr) have received unprecedented interest in recent years due to their ease of fabrication, good corrosion resistance, and low cost compared to platinum (Pt) electrodes. However, the poor surface adherence between the carbon counter electrodes (CE) and FTO substrate, low surface area, and poor inter-particle connection between the carbon materials have consistently become a major challenge. In order to overcome these issues, we have fabricated CB/Gr by incorporating binders of titanium (IV) isopropoxide (TTIP), and zirconium (IV) dioxide (ZrO2) as the counter electrodes for the DSSC. The performance of the CE is characterized by four-point probe conductivity measurement, scanning electron microscopy (SEM) and energy dispersive X-ray (EDX), X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS), and current density voltage (J-V) characteristics. The results revealed that incorporating binders to the CB/Gr has improved the series resistance (RS) and charge transfer resistance (RCT), which enhances the short-circuit current density (JSC), fill factor (FF), and the power conversion efficiency (PCE) of the device. The TTIP binder in CB/Gr CE exhibited superior performance in DSSC is largely attributed to the formation of TiO2 in situ with small particle size of about 100 nm, leading to enhanced intimate contact between the carbon materials, high surface area, and better surface adherence between counter electrode and the FTO substrate. Our findings, thereby, offer the possibility to engineer and optimize the energy levels of CE in an effort to develop a high-performing DSSC counter electrode.

Nowadays, as environmental awareness is key issue among researchers, scientific community is looking for natural materials as they are biodegradable, low cost, eco-friendly and also safe for health. Researchers and academicians have found many natural fibers and studied their properties for their sustainable applications in various possible sectors, and studies are also going on. So, in that context several natural fiber like jute, sisal, banana, pineapple, flax, hemp, kenaf, bamboo, cornstalk waste, coir, etc. have been successfully utilized as a reinforcing material in polymer composites by replacing man made synthetic fiber. Apart from traditional natural fibers, scientific community is also looking for locally available natural fibers across the globe in different geographical locations for successful reinforcement in polymer matrix. This will not only decrease burden on traditional fibers and but also at the same time it would be helpful to enrich the rural economy. Natural fiber based composites can be used in different areas such as auto motive industry, construction industry, sports industry and food industry. This study is related with extraction, characterization, surface treatment thermal analysis and activation energy of different uncommon natural fibers available at different geographical locations worldwide. The purpose of this study is to provide a comprehensive knowledge on extraction techniques, treatment methodologies, and properties of these uncommon natural fibers so that these novel materials can be utilized efficiently as a reinforcing material in different polymer matrix. Discussions on traditional natural fibers like Bagasse, Wheat straw, Coir, Pineapple, Banana etc. have been compiled extensively in various review papers but compilation on these new uncommon natural fibers is rare. Thermal analysis along with activation energy evaluation is another aspect which has been given emphasis in discussion because this is also a very important examination to evaluate the thermal stability of these natural fibers.

The levels of production diseases (PD) and the cow replacement rate are high in dairy farming. They indicate excessive production demands on the cow and a poor state of animal welfare. This is the subject of increasing public debate. The purpose of this study was to assess the effect of production diseases on the economic sustainability of dairy farms. The contributions of individual culled cows to the farm’s economic performance were calculated, based on milk recording and accounting data from 32 farms in Germany. Cows were identified as ‘profit cows’ when they reached their individual ‘break-even point’. Data from milk recordings (yield and indicators for PD) were used to cluster farms by means of a principal component and a cluster analysis. The analysis revealed five clusters of farms. The average proportion of profit cows was 57.5%, 55.6%, 44.1%, 29.4% and 19.5%. Clusters characterized by a high proportion of cows with metabolic problems and high culling and mortality rates had lower proportions of profit cows, somewhat irrespective of the average milk-yield per cow. Changing the perception of PD from considering it as collateral damage to a threat to the farms’ economic viability might foster change processes to reduce production diseases.

With rising price of oil and other conventional fuels, world is turning towards renewable energy to enable it to meet the growing demand for electrical power requirements. As an option, solar photovoltaic (PV) is gaining popularity, though its high initial cost is a major barrier for its widespread use. It can supply electricity, as stand alone grid connected and isolated PV hybrid energy systems. This paper discusses the techno-financial feasibility study for an electrical power supply system for a rural (island) village. The design tool HOMER was used as the sizing and optimization tool. Solar radiation and related load information are the input data required, and the procedure has been applied to the island community of Kohjig, located in the gulf of Thailand.

Bioethanol from agricultural waste is an attractive way to turn waste into added value that will solve the problem of food competition and waste management. Napier grass is a highly productive and effective lignocellulosic biomass, which is an important substrate of the second-generation biofuels. In addition, several processes are required in the production of ethanol from lignocellulosic materials; thus, co-culture fermentation can shorten the production process. This experimental research utilizes Trichoderma reesei and Saccharomyces cerevisiae co-culture fermentation in the bioethanol production of Napier grass using simultaneous saccharification and fermentation technology. To improve ethanol yield, Napier grass was pretreated with 3% (w/w) sodium hydroxide. An orthogonal experimental design was employed to optimize the Napier grass content, mixed crude co-culture loading, and incubation time for maximum bioethanol production. The results showed that pretreatment increased cellulose contents from 52.85% to 82%. The optimal fermentation condition was 15 g Napier grass, 15 g mixed crude co-culture, and 7 days incubation time, which maximizes the bioethanol yield of 16.90 g/L. Furthermore, the fermentation was upscaled 20-fold, and experiments were performed with and without supplemented sugar using laboratory-scale optimal fermentation conditions. The novelty of this research lies in the use of a mixed crude co-culture of T. reesei and S. cerevisiae to produce bioethanol from Napier grass with the maximum bioethanol concentration of 25.02 and 33.24 g/L under unadded and added sugar conditions and to reduce operational step and capital costs.