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In a study of the electrochemical behavior of low-cyanide silver plating baths and of the properties of the deposits obtained, it was found that the current-potential curve obtained with a solid electrode showed a two-step reduction wave, the height of the first being 1/5 that of the second. Analysis of the results of polarographic and rotating disk electrode measurmenents sugests that the rate-controlling steps wereAgCN+e-_??_Ag+CN-……(1)Ag(CN)2-+e-_??_Ag+2CN-……(2)for the first and second waves respectively. The Tafel plots of the two waves showed linear relationships at their rising portions, and the reactions are accordingly concluded to be slow chargetransfer controlled.In baths to which selenocyanate ion was added, the increase in current was markedly greater for the second wave than for the first, and the wave was shifted to the positive side. Potential decay curves for the baths containing selenocyanate ion obtained by the current interrupter method showed lower differential capacities than those for baths that were free of selenocyanate ion. This indicates that the selenocyanate ions were adsorbed preferentially at the electrode, suppress the adsorption of cyanide ions and enhancing the silver deposition reaction.Deposits obtained by jet plating were matt at current densities lower than 50A/dm2, and their appearance was not affected by the addition of selenocyanate ion. At above 50A/dm2, deposits obtained from selenocyanate-free baths were burnt, but deposits obtained from baths with selenocyanate ion added were mirror-bright with a strong (200) orientation up to around 150A/dm2.

Rainfed agriculture (1.25 billion hectares out of 1.55 billion hectares arable area) plays an important role globally in improving livelihoods and food security as it covers 63 per cent of total agriculture in Asia and 97 per cent in Africa. These areas are not only the hotspots of poverty but are also food insecure, hotspots of malnutrition, water scarcity, prone to severe land degradation and more vulnerable to the impacts of climate change.1 With increasing demand for food production to meet the needs of the growing population (9 billion by 2050), growing incomes and changing food habits, water scarcity will also intensify. The per-capita availability of water has declined considerably; for example, in India water availability was 1,820 cubic metres per person in 2001 compared to 5,177 cubic metres in 1951, and it is expected to decrease further to 1,341 cubic metres by 2025 and 1140 cubic metres by 2050.

AbstractRecently, modern power systems depend heavily on MicroGrids (MGs), which can accommodate Distributed Energy Resources (DERs) economically and with high flexibility. MGs integrated with DERs can assist in enhancing energy security, significant cost savings, and reduction in emission of greenhouse gases. In this paper, the assessment of operating performance of proposed MG system with DERs is employed to investigate the multi‐objective problems of cost optimization and economic scheduling. A grid‐connected Micro‐grid (MG) combined with solar photovoltaic (PV), wind turbine (WT), fuel cell (FC), and Battery Energy Storage System (BESS) is implemented to model the problem. This proposed model is considered as a test system for cost optimization and battery charging/discharging optimization. The developed framework is presented as multi‐objective function with constraints that can be tackled using an effective optimization technique. The above stochastic multi‐objective problem is optimized using various commonly used Physics based Meta‐heuristic techniques such as Simulated Annealing (SA), Harmony Search (HS), Slime Mold Algorithm (SMA), Gravitational Search Algorithm (GSA), Black Hole Optimization (BHO), Sine Cosine Algorithm (SCA), Multiverse optimization (MVO) and Lightning Search Algorithm (LSA). The assessment of the aforementioned physics‐based optimization techniques used on the proposed MG test system is compared using the results. According to the analysis, Black Hole Optimization (BHO) and Lightning Search Algorithm (LSA) both provide greater cost savings overall and for battery charging, respectively. The suggested optimization methods will take the BESS charging/discharging pattern and total cost savings into account.

The Energy Information Administration (EIA) of the U.S. Department of Energy has projected net electricity generation through 2040 for ten selected countries and the world. These ten countries including China and the U.S. are projected to produce 70% of the world electricity generation. Some of the past projections by EIA have been rated too conservative. Using a simple experience curve, we produce alternative projections for comparison. Our projections are significantly higher for eight out of the ten countries. Utilities operating in these eight countries may need to reexamine their plan for future net electricity generation.

Abstract A polymer-based flexible pulsating heat pipe (FPHP) as a flexible heat spreader was developed, and a series of experiments were conducted to evaluate the thermal performance and the long-term reliability of the FPHP. The FPHP consisted of a multilayer laminated film and a low-density polyethylene (LDPE) sheet. HFE-7000 was used as the working fluid, and the width, length, and thickness of the FPHP were 53.4 mm, 85.5 mm, and 1 mm, respectively. To minimize the permeation of non-condensable gases (NCGs) in a lateral direction, the heat-sealed flanges were covered with the indium coating. Owing to the indium-coated flanges, the long-term reliability of the FPHP drastically increased. The lifetime of the FPHP was defined to evaluate the long-term reliability. The FPHP had a lifetime of 18.2 days in the acceleration test environment, which was equivalent to 306 days in a standard atmosphere and 17 times longer than the previous polymer-based PHP. The FPHP had the thermal resistance of 2.41 K/W, which is 37% lower than that of the copper reference sample in a vertical orientation. Under bending conditions as well as in a horizontal orientation, the FPHP still operated well as a PHP, but the thermal resistance increased slightly. The fabrication method of the FPHP is effective in minimizing the permeation of NCGs in a lateral direction and can pave the way for fabricating a thin flexible heat spreader that has high flexibility, high thermal performance, and long-term reliability.

Abstract This paper presents numerical optimization results for the thermal and effective efficiencies of a solar air heater duct as a function of various roughness geometries on the heated plate. A methodology for the prediction of thermal and effective efficiency of the SAH has been developed on the basis of heat transfer and friction factor correlations. Among the roughness geometries considered, the discrete multiple V-shaped rib results in the best thermal and effective efficiencies over the entire range of design conditions. This work also addresses the scope for future research in the area of roughened SAH ducts and will be helpful for researchers investigating new artificial shapes for SAH ducts to enhance the heat transfer.

Abstract Zr Silicate (ZrxSi1 -xO4) films with a cation ratio of Zr:Si = 3:1 were deposited by atomic layer deposition (ALD) using trimethylsilylcyclopentadienyl tris(dimethylamino)zirconium (SCTDMAZ) and ozone as a single-source metal precursor and oxidant, respectively. The resultant films showed low residual impurity concentration as well as excellent conformality over complex structures, implying that the growth is controlled by a surface-limited reaction and hence proper ALD growth behavior. The Zr-silicate films exhibited amorphous characteristics as deposited and after post-deposition annealing (PDA) up to temperatures of 800 °C. After PDA the electrical properties of the amorphous Zr-silicate showed standard output values in the metal–insulator–semiconductor structure, with a low hysteresis of 0.04 V and moderate dielectric constant of ~ 10. Accordingly, these experimental results suggest that SCTDMAZ is indeed a viable option as a single-source metal precursor for the ALD of Zr-silicate thin films.

Polymer-based multicolor emissive materials have growing demand due to their potential applications in various fields such as full-color displays, bioimaging, and light sources because of their processability and high stability. Herein, we report dual-color emissive hybrid materials based on biocompatible poly(l-lactide) and polyethylene glycol-modified two-dimensional layered double hydroxide quantum dots (PEG-LDHQDs). The morphology of polymer films tunes the spatial distribution of QDs within the polymer matrix, modulating the energy transfer between the QDs and affording the dual emission behavior in the aggregated states. The amorphous hybrid films show single emission (blue) from the finely dispersed QDs (mostly isolated) within the polymer matrix. In contrast, dual emission (blue and red) was observed when the polymer was crystallized due to the possible accumulation of QDs at the interface of crystalline and amorphous phases in the lamellar structure. Furthermore, the dual emission could be enhanced by the aggregation of QDs on the pores of the breath figure pattern constructed on the surface of the hybrid film.

AbstractIn the present study, effect of internals and other hydrodynamic variables on pressure drop and expansion ratio were examined. The parameters studied include inlet air flow rate, bed height, spacing of internal, column diameter and percentage open area. Disc promoters of three different percentages of open area (48.03%, 55.15%, 66.26%) were used. The pressure drop was found to increase significantly with increase in bed height and decrease with open area of internals. As the spacing was decreased, the pressure drop increased first and then decreased due to effective breaking of bubbles in the presence of internals. The expansion ratio was seen to decrease significantly with decrease in the internal spacing and decrease in open area of internals. Correlations for pressure drop and expansion ratio have been found using dimensional analysis. The calculated values of pressure drop and expansion ratio were compared with experimental values. Several models have been developed using the Artificial Neural...