Corrosion of carbon steel feeders during dilute chemical decontamination of primary heat transport system of PHWRs

Carbon steel feeders in the primary heat transport system of pressurized heavy water reactors (PHWRs) show significant wall thinning due to flow accelerated corrosion (FAC). This is of great concern, as the wear rate in certain locations exceeds the corrosion allowance by design. This necessitates periodic measurement of wall thickness and in some cases even mid course enmasse replacement of feeders. While analyzing the data on wall thicknesses and in arriving at the wall thinning rate during operation of the reactor, sufficient care has to be taken to account for the wall thinning occurring during full system chemical decontamination campaign which is carried out occasionally to reduce dose rates during reactor shut down. Chemical decontamination of primary heat transport system is carried out using a mixture of organic acids at a total concentration of about 0.1 g/L and at 85 °C. The results of experiments carried out under simulated conditions for estimating the wall thinning occurring in carbon steel feeder elbow during dilute chemical decontamination are described in this work. The corrosion rates are quantified.     

Synthesis,characterization, and electrochemical properties of poly(ethylene oxide)-based polyaniline electrolyte complex

The polymer electrolyte based poly(ethylene oxide) complexed with conducting polyaniline (PANI) has been prepared in different weight percentages. The complexation is confirmed by Fourier transform infrared spectroscopy (FTIR).The change in morphology is studied by using scanning electron microscopy. The DC conductivity measurements are carried out using Keithley digital multimeter. It is seen that DC conductivity shows exponential behavior for all PEO : PANI complexes. It is observed that among all the PEO : PANI complexes, 50 wt % of PEO in PANI shows highest conductivity. Electrochemical cell parameters for battery applications at room temperature also have been determined. The samples are fabricated for battery application in the configuration of Na:(PEO : PANI):(I₂ + C + sample), and their experimental data are measured using Wagner polarization technique. The cell parameters results in an open-circuit voltage of 0.4 V and a short-circuit current of 902 μA for PEO : PANI (50 : 50) composite. Hence, these composites can be better candidates for the polymer electrolyte studies. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

Preparation of a functional nanofibrous polymer membrane incorporated with poly(2-aminothio phenol) stabilized gold nanoparticles

Functional nanofibrous polymer membranes were prepared by incorporating poly(2-aminothio phenol) (P2AT) stabilized Au NPs onto electrospun polyvinylidene fluoride (PVdF) nanofibers (designated as P2AT-Au NPs@PVdF-NFM). The preparation of P2AT-Au NPs@PVdF-NFM involves two steps: loading of 2AT (monomer) into electrospun PVdF nanofibrous membrane and polymerization of 2AT by gold chloride. P2AT and Au NPs were simultaneously formed into the electrospun PVdF-NFM. Transmission electron microscope image of P2AT-Au NPs@PVdF-NFM informs the presence of Au NPs (with sizes ~10 nm) onto PVdF-NFM.     

Bio-oil extraction and physicochemical characterization of Caesalpinia pulcherrima plant seed oil

Dwarf Poinciana (Caesalpinia pulcherrima) seeds are studied for first time for the extraction of bio-oil. The dried and crushed seeds are optimized for maximum yield of bio-oil with a series of polar and nonpolar solvents and recovered by a simple distillation process. Methanol is found to yield the maximum bio-oil. The fatty acid analysis of bio-oil reveals the prevalence of linoleic acid (54.67%), followed by palmitic acid (16.9%), stearic acid (12.5%), and oleic acid (10.32%). Basic fuel properties like specific gravity, viscosity, refractive index, iodine value, saponification value, fire point, flash point, pour point, and calorific value are studied.     

Optimization of Lithium Content and Sintering Aid for Maximized Li+ Conductivity and Density in Ta‐Doped Li7La3Zr2O12

Ta‐doped cubic phase Li₇La₃Zr₂O₁₂ (LLZ) lithium garnet received considerable attention in recent times as prospective electrolyte for all‐solid‐state lithium battery. Although the conductivity has been improved by stabilizing the cubic phase with the Ta⁵⁺ doping for Zr⁴⁺ in LLZ, the density of the pellet was found to be relatively poor with large amount of pores. In addition to the high Li⁺ conductivity, density is also an essential parameter for the successful application of LLZ as solid electrolyte membrane in all‐solid‐state lithium battery. Systematic investigations carried out through this work indicated that the optimal Li concentration of 6.4 (i.e., Li_6.4La₃Zr_1.4Ta_0.6O₁₂) is required to obtain phase pure, relatively dense and high Li⁺ conductive cubic phase in Li_7?xLa₃Zr_2?xTa_xO₁₂ solid solutions. Effort has been also made in this work to enhance the density and Li⁺ conductivity of Li_6.4La₃Zr_1.4Ta_0.6O₁₂ further through the Li₄SiO₄ addition. A maximized room‐temperature (33°C) total (bulk + grain boundary) Li⁺ conductivity of 3.7 × 10^?4 S/cm and maximized relative density of 94% was observed for Li_6.4La₃Zr_1.4Ta_0.6O₁₂ added with 1 wt% of Li₄SiO₄.     

Entropy of Alloy Phases: A Macroscopic Perspective

This study presents a comprehensive analysis of the entropy of condensed phases, its temperature, pressure, and composition dependence on a macroscopic correlative platform. Two principal contributions to total nonconfiguration entropy (S_T) are outlined. They are: (i) the pure thermal (S_th) contribution arising from the isochoric temperature dependence of Gibbs energy (G_T) and (ii) the elastic contribution (S_el) representing the dilatational volume effects. It is then argued that entropy variation among a group of alloy phases can be exclusively related to molar volume, only when both thermal pressure (p_th) and thermal entropy terms assume common values for all members. This argument is extended to establish a linear relationship between transformation entropy (ΔS_tr) and transformation-induced volumetric strain (ΔV_tr/V). The temperature and pressure dependencies of entropy have been discussed in terms of the complementing roles of S_th and S_el and simple approximations to these effects are suggested. A macroscopic power law relation for systematizing the standard entropy variation using a composite scaling parameter (MV^2/3/T_m) has been proposed, and its validity is demonstrated for both solid and liquid metals. This power law correlation has been exploited to deduce the following outcome: (i) a simple approximation for the initial slope (dp/dT_m) of p–T_m melting curve, (ii) self-consistent correlation of entropy with specific heat and Debye temperature, (iii) estimation of entropy of metastable phases, and (iv) correlating dilute solution entropy with volume effects of alloying.

     

Application of Proteomics in Pancreatic Ductal Adenocarcinoma Biomarker Investigations: A Review

Pancreatic ductal adenocarcinoma (PDAC), a highly aggressive malignancy with a poor prognosis is usually detected at the advanced stage of the disease. The only US Food and Drug Administration-approved biomarker that is available for PDAC, CA 19-9, is most useful in monitoring treatment response among PDAC patients rather than for early detection. Moreover, when CA 19-9 is solely used for diagnostic purposes, it has only a recorded sensitivity of 79% and specificity of 82% in symptomatic individuals. Therefore, there is an urgent need to identify reliable biomarkers for diagnosis (specifically for the early diagnosis), ascertain prognosis as well as to monitor treatment response and tumour recurrence of PDAC. In recent years, proteomic technologies are growing exponentially at an accelerated rate for a wide range of applications in cancer research. In this review, we discussed the current status of biomarker research for PDAC using various proteomic technologies. This review will explore the potential perspective for understanding and identifying the unique alterations in protein expressions that could prove beneficial in discovering new robust biomarkers to detect PDAC at an early stage, ascertain prognosis of patients with the disease in addition to monitoring treatment response and tumour recurrence of patients.     

Pd-Decorated Tungsten as Pt-Free Bimetallic Catalysts for Hydrogen Oxidation Reaction in Alkaline Electrolyte

Developing Pt-free catalysts for hydrogen oxidation reaction (HOR) in alkaline solution is becoming a key challenge in the development of anion exchange membrane fuel cells and electrochemical reactors. Herein, we present the preparation, HOR activity, and stability of Pd-decorated tungsten (Pd-d-W) catalysts. The Pd-d-W catalysts were prepared by the chemically activated surface of tungsten nanoparticles by Pd ions. The resultant bimetallic catalysts consisted of crystalline phases of both Pd and W nanoparticles. The CO stripping voltammograms and H-desorption (H_des) peak potential of hydrogen desorption in Pd suggests that the enhancement of HOR catalytic activity observed in Pd-d-W catalyst can be ascribed to the modification of electronic property of Pd and availability of OH_ad near-surface Pd atoms.