Effect of gamma-ray irradiation on the sorption property of hydrous ferric oxide and ferric phosphate

The equilibirum sorption capacity of hydrous ferric oxide and ferric phosphate has been observed to increase on irradiation with γ-rays by 5.2 and 6.6%, respectively. The rate of sorption increases differently in the irradiated exchanger materials depending upon their characteristics nature; e.g., when the concentration of the Zn(ammine) solution is 0.10M, increase in the F-values, caused by irradiation is significantly more striking in the case of hydrous ferric oxide than in ferric phosphate. On the other hand, at lower external concentration of the Zn(ammine) ion (0.01M), the increase in F-values is more significant in the case of ferric phosphate.     

Techno‐economic analysis of three different substrate removal and reuse strategies for III‐V solar cells

The high cost of wafers suitable for epitaxial deposition of III‐V solar cells has been a primary barrier to widespread use of these cells in low‐concentration and one‐sun terrestrial solar applications. A possible solution is to reuse the substrate many times, thus spreading its cost across many cells. We performed a bottom‐up techno‐economic analysis of three different strategies for substrate reuse in high‐volume manufacturing: epitaxial lift‐off, spalling, and the use of a porous germanium release layer. The analysis shows that the potential cost reduction resulting from substrate reuse is limited in all three strategies––not by the number of reuse cycles achievable, but by the costs that are incurred in each cycle to prepare the substrate for another epitaxial deposition. The dominant substrate‐preparation cost component is different for each of the three strategies, and the cost‐ranking of these strategies is subject to change if future developments substantially reduce the cost of epitaxial deposition. Copyright © 2016 John Wiley & Sons, Ltd.     

Effect of physical wear and triboelectric interaction on surface charge as measured by Kelvin probe microscopy

Surface charge of human hair has a significant effect on manageability, feel, and appearance. For this reason, controlling charge buildup to improve these factors is an important issue in the commercial hair care industry. Physical wear has been shown to cause surface potential change in conductors and semiconductors, and it is of interest whether or not physical wear alone can cause a surface potential change on hair and other insulating materials. It is known that interaction of hair with dissimilar materials, such as plastic combs, hands, and latex balloons, creates a charge on hair, and determining the mechanisms of this phenomenon is the purpose of this study. In this study the surface potential of human hair is measured using the Kelvin probe method with an atomic force microscope (AFM). A variety of samples are worn with a diamond tip to study the effect of physical wear on surface potential. Hair samples are rubbed with latex to study the effect of triboelectric charging on the microscale. The potential on the sample surface is then measured with a conductive tip. Caucasian virgin (undamaged), chemically damaged, and mechanically damaged hair samples are studied to determine the effect of damaging treatments on surface charge properties. Samples treated with PDMS silicone conditioner as well as those treated with an amino silicone conditioner are also studied to determine the effect of conditioner treatment. Mechanisms for the given results are discussed and recommendations given.     

Xylopyrine-A and xylopyrine-B, two new peptide alkaloids from Zizyphus xylopyra

Two new 13-membered cyclopeptide alkaloids, xylopyrine-A and xylopyrine-B have been isolated from Zizyphus xylopyra, and their structures established by spectral and chemical evidences.     

Liquid chromatographic analysis of certain commercial formulations for non-opioid analgesics

A simple and sensitive method for separation and quantitative determination of non-opioid analgesics from pharmaceutical preparations has been developed and validated. Commercial formulations of three non-opioid analgesics, viz. paracetamol, ibuprofen and diclofenac, were chosen for present studies. These were extracted, isolated, purified and recrystallized and were characterized by melting point, lambda(max) and IR. Quantitative determination was carried out using HPLC and TLC supplemented with UV spectrophotometry.     

Reversed-phase high-performance liquid chromatographic, size exclusion chromatographic and polyacrylamide gel electrophoretic studies of glycinin: evidence for molecular species and their association-dissociation

Isolation and purification of glycinin and its molecular species from an Indian soybean variety (JS-335) was achieved using polyacrylamide gel electrophoresis (PAGE), size exclusion chromatography (SEC) and reversed-phase high-performance liquid chromatography (RP-HPLC). Glycinin was found to have two molecular species (glycinin I and II), and only glycinin I underwent reversible dissociation-association system into alpha and beta species. Glycinin I and II were not found to constitute a dissociation-association system. Glycinin II also did not dissociate under varying conditions of time, pH and ionic strength of buffer. Various species so dissociated were isolated, purified and characterized.     

Radiation-controlled enhancement of electroluminescence in Calcium Sulphide Electroluminors

Enhancement and quenching effects in electroluminescent emission from CaS:Cu, Er and CaS:Cu, Sm electroluminors under the concurrent action of electric field (a.c. or d.c.) and radiation (3650 Å) has been investigated. Variation of the ration R defined by R = (B_E+/B_E + B_L) has been studied as a function of voltage (a.c. or d.c.) and frequency (a.c.) of the applied field. The net effect is found as combination of enhancement and quenching. Sometimes peaks (one or more than one) are also found. With the increase in frequency of a.c. field higher value of R is found. No regular variation with increase in intensity of uv radiation is found.     

Thermoluminescence of ZnO:Cu,La under UV and γ-ray irradiation

Thermoluminescence (TL) glow curves of ZnO: Cu, La have been recorded under UV and γ-ray irradiations. These consist of a pronounced peak at 600°K alongwith some sharp transitions. The higher temperature peak has been studied by a number of methods namely heating rate, initial rise, isothermal decay and peak shape methods and activation energy (E), escape frequency factor (s) and the order of kinetics (l) have been determined and their nature has been discussed. E is found to be ∼1.63 eV and the order of kinetics l = 2 for this peak.     

DC Electroluminescence in (ZnS,ZnO): Cu,Cl Electroluminors

Some interesting oberservations on the DC electroluminescence of (ZnS, ZnO):Cu, Cl electroluminors are reported. A burst of emission is observed at the time of switching on (also at switching off) the field which very slowly decays to a saturation value. The time for saturated emission decreases with increasing temperature. The emission colours of bursts and the saturated light are different. The intensities of the bursts are dependent upon the polarity of the electrodes and the temperature. Possible explanations to these effects are proposed.