PERIODATE OXIDATION OF PEG–600, AN ESSENTIAL PHARMACEUTICAL POLYMER

Objective: To study the kinetics of periodate oxidation of polyethylene glycol-600 (PEG-600), a familiar non-toxic polymer used in pharmaceutical and other fields of industry. Methods: Reactions were carried out in alkaline medium and measured the kinetics by iodometry. One oxygen atom loss or two electrons transfer was observed per each molecule of periodate i.e., the rate of reaction was measured periodate converts to iodate because the formed iodate species is unable to oxidize the substrate molecules. Results: Based on log (a-x) versus t plots, order w. r. t. oxidant (periodate) is unity. Reactions were found to be independent of substrate (PEG-600) concentration. A decrease in rate with an increase in alkali concentration [OH–] was found and order was inverse fractional. Temperature dependence of reaction rate was studied and then calculated the corresponding Arrhenius parameters. Conclusion: An appropriate rate law was proposed by considering the above experimental results

Simulated projections for summer monsoon climate over India by a high-resolution regional climate model (PRECIS)

Impact of global warming on the Indian monsoon climate is examined using Hadley Centre’s highresolution regional climate model, PRECIS (Providing REgional Climates for Impact Studies). Three simulations from a 17-member Perturbed Physics Ensemble generated using Hadley Center Coupled Model (HadCM3) for the Quantifying Uncertainty in Model Predictions (QUMP) project, are used to drive PRECIS. The PRECIS simulations corresponding to the IPCCSRES A1B emission scenario are carried out for a continuous period of 1961–2098. The model shows reasonable skill in simulating the monsoon climate over India. The climate projections are examined over three time slices, viz. short (2020s, i.e. 2011–2040), medium (2050s, i.e. 2041–2070) and long (2080s, i.e. 2071–2098). The model projections indicate significant warming over India towards the end of the 21st century. The summer monsoon precipitation over India is expected to be 9–16% more in 2080s compared to the baseline (1970s, i.e. 1961–1990) under global warming conditions. Also, the rainy days are projected to be less frequent and more intense over central India

Switched-resistor passive balancing of Li-ion battery pack and estimation of power limits for battery management system

DATA AVAILABILITY : No underlying data was collected or produced in this study.The battery pack performance and expected lifespan are crucial in electric vehicle applications. Balancing the charge on a battery pack connected in series and parallel is crucial due to manufacturing discrepancies and distinct performance of each cell in a standard battery pack. In this paper, a switched-resistor passive balancing-based method is proposed for balancing cells in a battery management system (BMS). The value of the available voltage at the battery cell terminals is balanced using resistors in an electrical circuit, and the excess voltage is eliminated. The cell balancing outcome demonstrates that the electrical circuit can maintain an even voltage across each cell. The procedure of balancing involves individually adjusting each cell’s level of charge. Passive balancing releases energy as heat by draining charge from cells that have too much charge. A passive cell balancer is a cost-effective solution and easy to install, but due to thermal loss from a resistor, it has a low energy efficiency for cell balancing and necessitates a lengthy balancing process. This passive cell balancer is an effective and reliable method for low-power devices and portable applications such as electrical vehicles. The power limits during charging and discharging are estimated using the bisection method.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1099-114Xam2024Electrical, Electronic and Computer EngineeringSDG-07:Affordable and clean energySDG-09: Industry, innovation and infrastructur

Surface morphology, electrical and optical properties of gallium antimonide layers grown by liquid phase epitaxy

Abstract Liquid phase epitaxial (LPE) growth of gallium antimonide has been carried out employing equilibrium cooling, step cooling, supercooling and two phase solution growth techniques. An optimum temperature range of 500-550°C was found to be suitable for the growth of high quality layers. The morphology of layers grown by the first three techniques improved with increase in layer thickness. In contrast, better morphology was obtained for thin layers when grown from the two phase solution technique. While the equilibrium cooling technique gave a diffuse substrate-epilayer interface, sharp interfaces were obtained by the step cooling, supercooling, and two phase solution growth techniques. Photoluminescence spectroscopy and current-voltage measurements carried out on the grown layers revealed that the layers grown from Ga-rich melts exhibit superior optical and electrical properties as compared to those grown from Sb-rich melts

Prevalence of Aspergillus flavus Infection and Aflatoxin Contamination of Groundnut in Telangana and Andhra Pradesh

Aflatoxin contamination is a qualitative problem in groundnut (Arachis hypogaea L.) occurring at both pre-and post-harvest stages. These aflatoxins are secondary metabolites produced by Aspergillus flavus and A. parasiticus and have carcinogenic, hepatotoxic, teratogenic and immuno-suppressive effects. To evaluate the prevalence of A. flavus infection and aflatoxin contamination in groundnut oil mills/traders’ of Telangana and Andhra Pradesh (AP) pod samples were collected from eight selected oil mills/traders’ in Mahaboobnagar, Rangareddy, Nizamabad, Karimnagar (Telangana); and Anantapur (AP) districts. A total of 24 pod samples were collected (Three samples from the each selected oil mill). Aflatoxin contamination in kernels was estimated by indirect competitive ELISA. In Telangana, kernel infection ranged from 42 (Mahaboobnagar) to 90.7% (Nizamabad). In AP, Tadimarri mandal recorded kernel infection up to 29.3% whereas Tadipatri recorded up to 59.3%. Aflatoxins in kernels from these mills in Telangana were highest in Rangareddy (1205.2 µg kg-1 ) followed by Karimnagar (365.5 µg kg-1 ). Oil mills of Nizamabad and Mahaboobnagar have recorded aflatoxins to a tune of 4.9 and 11.5 µg kg-1 in Telangana. In AP, aflatoxins in pod samples were 2.8 µg kg-1 (Tadipatri) and 6148.4 µg kg-1 (Tadimarri)

Pt/CdTe/Pt asymmetric nano-Schottky diodes from colloidal quantum dots

We have fabricated nano-Schottky diodes of CdTe QDs with platinum metal electrodes in metal-semiconductor-metal planar configuration by drop-casting. The observed high value of ideality factor (13.3) of the diode was possibly due to the presence of defects in colloidal QDs. We observed asymmetry and non-linear nature of I-V characteristics between forward and reverse directions, which has been explained in terms of size distributions of quantum dots due to coffee ring effect

Comparison of modification strategies towards enhanced charge carrier separation and photocatalytic degradation activity of metal oxide semiconductors (TiO2, WO3 and ZnO)

Metal oxide semiconductors (TiO2, WO3 and ZnO) finds unparalleled opportunity in wastewater purification under UV/visible light, largely encouraged by their divergent admirable features like stability, non-toxicity, ease of preparation, suitable band edge positions and facile generation of active oxygen species in the aqueous medium. However, the perennial failings of these photocatalysts emanates from the stumbling blocks like rapid charge carrier recombination and meager visible light response. In this review, tailoring the surface-bulk electronic structure through the calibrated and veritable approaches such as impurity doping, deposition with noble metals, sensitizing with other compounds (dyes, polymers, inorganic complexes and simple chelating ligands), hydrogenation process (annealing under hydrogen atmosphere), electronic integration with other semiconductors, modifying with carbon nanostructures, designing with exposed facets and tailoring with hierarchical morphologies to overcome their critical drawbacks are summarized. Taking into account the materials intrinsic properties, the pros and cons together with similarities and striking differences for each strategy in specific to TiO2, WO3 & ZnO are highlighted. These subtlety enunciates the primacy for improving the structure-electronic properties of metal oxides and credence to its fore in the practical applications. Future research must focus on comparing the performances of ZnO, TiO2 and W03 in parallel to get insight into their photocatalytic behaviors. Such comparisons not only reveal the changed surface-electronic structure upon various modifications, but also shed light on charge carrier dynamics, free radical generation, structural stability and compatibility for photocatalytic reactions. It is envisioned that these cardinal tactics have profound implications and can be replicated to other semiconductor photocatalysts like CeO2, In2O3, Bi2O3, Fe2O3, BiVO4, AgX, BiOX (X = CI, Br & I), Bi2WO6, Bi2MoO6, etc., to improve their competence for various environmental applications. (C) 2016 Elsevier B.V. All rights reserved