Hydrogel membrane electrolyte for electrochemical capacitors

Polymer electrolytes are known to possess excellent physicochemical properties that are very useful for electrochemical energy systems. The mobility in polymer electrolytes is understood to be mainly due to the segmental motion of polymer chains and the ion transport is generally restricted to the amorphous phase of the polymer. Gel polymer electrolytes (GPE) that are formed using plastizicers and polymers along with ionic salts are known to exhibit liquid-like ionic conductivity while maintaining the dimensional stability of a solid matrix. In the present study, the preparation and characterization of poly(vinyl alcohol)-based hydrogel membranes (PHMEs) as electrolytes for electrochemical capacitors have been reported. Varying HClO4 dopant concentration leads to different characteristics of the capacitors. The EC comprising PHME doped with 2 M HClO4 and black pearl carbon (BPC) electrodes has been found to exhibit a maximum specific capacitance value of 97 F g–1, a phase angle value of 78°, and a maximum charge–discharge coulombic efficiency of 88%

On the performance of stabilized α-nickel hydroxide as a nickel-positive electrode in alkaline storage batteries

The internal resistance of a stabilized α-nickel hydroxide electrode is found to be lower than that of a β-nickel hydroxide electrode as shown from studies of the open-circuit potential-time transients at all states-of-charge. Nevertheless, the self-discharge rates of the former is higher. Gasometric studies reveal that the charging efficiency of the α-nickel hydroxide electrode is higher than that of the β-nickel hydroxide electrode. © 1995

Effect of ethrel spray on the ripening behaviour of mango (Mangifera indica L.) variety 'Dashehari'

An experiment was carried out to investigate the effect of post harvest spray of different concentrations (100, 200, 400, 600 and 800 ppm) of ethrel (2-chloroethyl phosphonic acid) on ripening and colour development in ‘Dashehari’ mango fruits harvested in second week of June, 2015. The treated fruits were assessed for physico-chemical parameters such as physiological loss in weight (%), firmness (Kg/cm2), TSS (°Brix), titrable acidity (%), total carotenoids (mg/100g) and peel chlorophyll (mg/100g) and observations were recorded at 2 days interval during 8 days storage at ambient temperature. Changes in total soluble solids (8.5 to 23.23° Brix), total carotenoids (0.807 to 7.12 mg/100g) and PLW (14.58%) showed increasing trends up to 8 days during storage whereas fruit firmness (8.5 to 0.68 Kg/cm2), titrable acidity (1.26 to 0.08%) and total peel chlorophyll (5.2 to 0.14 mg/100g) showed decreasing trends. At the end of the storage period for 8 days, Ethrel spray at 600 ppm induced uniform ripening with attractive yellow colour within 4 days while untreated control fruits failed to ripen uniformly and remain light green even after 8 days of storage. Ripening advances by 4 days in fruits sprayed with 600 ppm ethrel com-pared to unsprayed control fruits

Electrochemically Impregnated Aluminum-Stabilized α-Nickel Hydroxide Electrodes

Nickel-positive electrodes obtained by electrochemical impregnation of aluminum-substituted α-nickel hydroxide are found to deliver a reversible discharge capacity of ca. 450 mAh/g. This is much higher than the capacity of β-nickel hydroxide electrodes 200 mAh/g: this work; 225 mAh/g: Dixit et al., J. Power Sources, 63, 167 (1996) prepared under identical conditions and pasted electrodes comprising cobalt-doped nickel hydroxide 345 mAh/g: Faure et al., J. Power Sources, 36, 497 (1991). These observations suggest that the theoretical target-capacity for high-performance nickel-positive electrodes must be revised from the currently accepted value of 289 mAh/g (1e exchange) to 491 mAh/g 1.7e exchange: Corrigan and Knight, J. Electrochem. Soc., 136, 613 (1989). © 1999 The Electrochemical Society. S1099-0062(98)08-044-4. All rights reserved

The formation and ordering of local magnetic moments in Fe-Al alloys

With density functional theory, studied are the local magnetic moments in Fe-Al alloys depending on concentration and Fe nearest environment. At zero temperature, the system can be in different states: ferromagnetic, antiferromagnetic and spin-spiral waves (SSW) which has a minimum energy. Both SSW and negative moment of Fe atoms with many Al atoms around them agree with experiments. Magnetization curves taken from literature are analysed. Assumption on percolation character of size distribution of magnetic clusters describes well the experimental superparamagnetic behaviour above 150 K.Comment: 4 pages, 3 figures (presented in Third Seeheim Conference on Magnetism, 26-30 Aug. 2007, Frankfurt, Germany

Validity of the zero-thermodynamic law in off-equilibrium coupled harmonic oscillators

In order to describe the thermodynamics of the glassy systems it has been recently introduced an extra parameter also called effective temperature which generalizes the fluctuation-dissipation theorem (FDT) to systems off-equilibrium and supposedly describes thermal fluctuations around the aging state. Here we investigate the applicability of a zero-th law for non-equilibrium glassy systems based on these effective temperatures by studying two coupled subsystems of harmonic oscillators with Monte Carlo dynamics. We analyze in detail two types of dynamics: 1) sequential dynamics where the coupling between the subsystems comes only from the Hamiltonian and 2) parallel dynamics where there is a further coupling between the subsystems arising from the dynamics. We show that the coupling described in the first case is not enough to make asymptotically the effective temperatures of two interacting subsystems coincide, the reason being the too small thermal conductivity between them in the aging state. This explains why different interacting degrees of freedom in structural glasses may stay at different effective temperatures without never mutually thermalizing.Comment: 23 pages, REVTeX, 4 eps figure

Pathogenic diversity of Sclerotium rolfsii isolates, a potential biocontrol agent against Parthenium hysterophorus L.

Parthenium hysterophorus L. is a wide-spread weed creating problems for agriculture and public health. Microbes and their by products is now proved to be a worthy alternative to toxic chemicals used for weed management. We determined the relative pathogenicity of ten Sclerotium rolfsii isolates recovered from diseased parts of Parthenium collected during a survey of various habitats in Central India. There was a considerable diversity amongst various isolates. The isolate designated Par # 02 from Jabalpur showed the maximum disease incidence (80%) whereas isolate Par#10 also from Jabalpur showed the lowest infection rate against targeted hosts (30%). The wide range of pathogenicity among S. rolfsii support the view that strain breeding for biological control of P. hysterophorus L. is warranted.Key words: Parthenium hysterophorus, variability, pathogenicity, Sclerotium rolfsi

Assessment of in vitro Antifungal Prospective of Fungicides against Alternaria alternata, A Causal Organism of Potato Brown Spot and Early Blight Disease

Efficacy evaluation of three fungicides was undertaken against phytopathogenic fungi Alternariaalternata. Fungicide copper oxychloride was found to restrict the growth of fungi at 500ppmconcentration, whereas at 5000ppm concentration of benomyl and mancozeb growth of fungi was notoccurred. At 1000ppm concentration growth of fungi was fifty percent compare to control on PDAmedium. At 5000ppm concentration of copper oxychloride and mancozeb spore germination did notoccur. In case of both the fungicides at 1000ppm concentration percent germination was foundbetween 56 and 75 percent. Germination percent of spores was always lesser than control in all thetreatments. Similarly germ tube growth was not occurred in copper oxychloride and mancozeb treatedspores at 5000ppm concentration. Germ tube growth was found always influenced by the treatment offungicides. Inhibitory effect of fungicides was dose dependent and proportional to the concentration offungicides. Reduction in growth, spore germination and germ tube elongation increased on increasingthe concentration of fungicides.&nbsp

Modulation Instability of Ultrashort Pulses in Quadratic Nonlinear Media beyond the Slowly Varying Envelope Approximation

We report a modulational instability (MI) analysis of a mathematical model appropriate for ultrashort pulses in cascaded quadratic-cubic nonlinear media beyond the so-called slowly varying envelope approximation. Theoretically predicted MI properties are found to be in good agreement with numerical simulation. The study shows the possibility of controlling the generation of MI and formation of solitons in a cascaded quadratic-cubic media in the few cycle regimes. We also find that stable propagation of soliton-like few-cycle pulses in the medium is subject to the fulfilment of the modulation instability criteria

Some common fixed point results of three self-mappings in cone metric spaces

The aim of this paper is to present coincidence point and common fixed point results for three self mappings satisfying generalized contractive conditions.  The results presented in this paper generalize and extend several well-known results in the literature