Quaternized poly(phenylene oxide) anion exchange membrane for alkaline direct methanol fuel cells in KOH‐free media

A series of anion exchange membrane (AEM) electrolytes with quaternary ammonium moiety are fabricated from poly (phenylene oxide) for its application in alkaline direct methanol fuel cells (ADMFCs). In the first step, poly(phenylene oxide) (PPO) is successfully chloromethylated by substituting chloromethyl groups in the aryl position of polymer. In the second step, the chloromethylated PPO (CPPO) is further homogeneously quaternized and ion‐exchanged to form an AEM. From the second step, series of AEMs are prepared by changing the mole ratio of amine in relation to CPPO. The presence of quaternary ammonium group in the membrane was confirmed by elemental analysis. The fabricated membranes are subjected to cell polarization studies in ADMFCs, wherein quaternized poly(2,6‐dimethyl‐1,4‐phenylene oxide) (CPPO:amine of 1:8) membrane exhibits higher peak power density of 3.5 mW cm^?2 when compared with the other ratios of CPPO:amine in the absence of KOH solution. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43693.     

EFFECT OF LIPASE ENZYME ON THE RIPENING OF WHITE PICKLED CHEESE

The effect of addition of pregastric lipase enzyme on the accelerated ripening of white pickled cheese was investigated. Commercial pregastric lipase was added to milk before rennet addition at a level of 0,5, 8, 11 g per 100 L of milk and cheeses were made from this milk. Total solids, fat, total nitrogen, salt, titratable acidity, pH and free fatty acids (C₂-C_18:1) were analysed in the samples during 1–90 days of ripening period at 15 days intervals. Total solids, fat, total nitrogen, salt, titratable acidity, and pH of cheeses slightly increased during the ripening period. Free fatty acids and volatile free fatty acid contents in cheeses made from pregastric lipase added milk were affected by pregastric lipase and their contents were increased significantly (P<0.01) during the ripening period. Particularly, when cheese had a high level (11 g per 100 L milk) pregastric lipase, the amounts of butyric, caproic and caprylic acids in white pickled cheese were quite high. The relative amounts of volatile free fatty acids varied with storage time and pregastric lipase levels.     

Enhanced visible green and 1.5 μm radiative emission of Er~(3+) ions in Li_2O-PbO-Al_2O_3-B_2O_3 glasses for photonic applications

A series of Er~(3+) ions doped lithium lead alumino borate(LiPbAlB) glasses were synthesized via melt quench method and their structural,physical and optical properties were studied.Judd-Ofelt theory in correlation with the emission and absorption profiles was performed for the measurement of various radiative parameters for different transitions of Er~(3+) doped glasses.The as-prepared glasses show deep green(550 nm) as well as NIR(1532 nm) emission at 380 and 980 nm excitation wavelengths,respectively.The intensity of emission spectra increases with Er~(3+) ions concentration up to 1.5 mol% and beyond quenching is observed.The Dexter theory applied to the emission profiles reveals the interaction between Er~(3+)ions as dipole-dipole in nature.CIE color coordinates are found to fall in the green region of the visible spectrum.It is observed that 1.5 mol% of Er~(3+) ions concentration is optimum to exhibit the maximum quantum efficiency,branching ratios,gain bandwidth,emission cross-section,gain crosssection and aptly suitable for visible and NIR photonic applications.     

Status of the ITER magnets

The first 2 years of the ITER IO has seen substantial progress towards the construction of the magnets, in three main areas. Firstly, the design has been developed under the conflicting constraints to minimise construction costs and to maximise plasma physics performance. Building construction momentum while updating the design to take account of new physics assessments of the coil requirements has been challenging. Secondly, with a stabilising design, it has been possible for the Domestic Agencies to launch the first industrial procurement contracts. And thirdly, critical R&D to confirm the performance of the Nb3Sn cable in conduit design is proceeding successfully.The design consolidation has been accompanied by design reviews involving the international community. The reviews conducted by magnet experts have enabled a consensus to be built on choosing between some of the design options in the original ITER basic design in 2001. The major design decisions were to maintain the circular Nb₃Sn conductor embedded in radial plates for the toroidal field (TF) coils and to maintain NbTi-based conductors for the PF coils. Cold testing, at low current, is also being introduced for quality control purposes for all coils.     

Nafion and modified-Nafion membranes for polymer electrolyte fuel cells: An overview

Polymer electrolyte fuel cells (PEFCs) employ membrane electrolytes for proton transport during the cell reaction. The membrane forms a key component of the PEFC and its performance is controlled by several physical parameters, viz. water up-take, ion-exchange capacity, proton conductivity and humidity. The article presents an overview on Nafion membranes highlighting their merits and demerits with efforts on modified-Nafion membranes. Energy security refers to various security measures that a given nation, or the global community as a whole, must carryout to maintain an adequate energy supply     

A neural network approach for prediction of discharge in straight compound open channel flow

Most natural rivers and streams consist of two stage channels known as main channel and flood plains. Accurate prediction of discharge in compound open channels is extremely important from river engineering point of view. It helps the practitioners to provide essential information regarding flood mitigation, construction of hydraulic structures and prediction of sediment load so as to plan for effective preventive measures. Discharge determination models such as the single channel method (SCM), the divided channel method (DCM), the coherence method (COHM) and the exchange discharge method (EDM) are widely used; however, they are insufficient to predict discharge accurately. Therefore, an attempt has been made in this work to predict the total discharge in compound channels with an artificial neural network (ANN) and compare with the above models. The mean absolute percentage error with artificial neural networks is found to be consistently low as compared to other models.     

Dielectric and Thermal Investigations on PbNb2O6 in Pure Piezoelectric Phase and Pure Non-Piezoelectric Phase

A high piezoelectric transition temperature is indicated for present orthorhombic samples of lead meta-niobate (PbNb₂O₆) by the high value of the temperature (T_m) at which the real part (?′) of electrical permittivity peaks. It is 573 to 580°C. The imaginary component (?″) increases sharply at these temperatures. Cooling run after heating to 700°C gives changed values of ?′ and ?″ and T_m. Present work reports impedance spectroscopy (up to 700°C over 20 Hz to 5.5 MHz) and Differential Scanning Calorimetry or DSC on the pure orthorhombic phase, and, for the first time, on the pure rhombohedral phase. DSC shows an endothermic dip across T_m during heating and an exothermic peak during cooling for the orthorhombic sample only.     

Growth rate characteristics of acoustic neuromas associated with neurofibromatosis type 2

Neurofibromatosis type 2 (NF2) is a dominantly inherited disorder characterized by the occurrence of bilateral acoustic neuromas (ANs and other central nervous system tumors. Magnetic resonance images and audiologic data on 22 patients with NF2 who underwent multiple studies at the National Institutes of Health between 1983 and 1993 were reviewed to determine the growth characteristics of ANs in these patients. The average growth rate of ANs in NF2 patients was 0.30 cm3 per year and was significantly higher in older patients (0.75 cm3 per year) than in younger ones (0.12 cm3 per year). Larger ANs were more commonly found in patients with concomitant spinal tumors or meningiomas. NF2 patients with spinal tumors but not meningiomas demonstrated faster growth rates than patients without additional tumor burden. The data from this study suggest that older patients or patients with associated spinal tumors have faster growing ANs and therefore should be followed closely and treated aggressively.