Copper-Indium Alloy Transformations

Phase transformations of copper-indium alloy thin films are analyzed by hot-stage x-ray diffraction (XRD) over the temperature range from 30 to 425 °C in controlled ambient. Thin films of Cu/In with a molar ratio of approximately 0.9 were used. In situ experiments were carried out in a reducing hydrogen atmosphere to minimize oxide formation. The as-deposited Cu/In alloy transformed at 150 °C to form Cu₁₁In₉. Ramping the temperature to the upper limit of 425 °C revealed an additional transformation at 350 °C to form Cu₁₆In₉.     

Assessing the Health Risks of Sea Bathing

This paper considers the scientific basis of epidemiological research into marine bathing water quality in the UK, and places it in the context of policy development for the water industry and regulatory agencies in Europe. Results of the latest UK studies employing internationally recognized methods are reviewed, together with the output of other studies including those based on the use of healthy adult volunteers. It is concluded that methods based on captive volunteer populations may have merit in inland waters used by defined groups of recreational users. However, there is no epidemiologically defensible way of linking the output of such methods to the results of more conventional techniques for assessing risks in marine recreational waters. This observation may have implications for the formulation of new standards for bathing water quality in Europe.     

Contemporary approaches into obesity: drugs and genes

Obesity is a global epidemic effecting the health and life style of millions of people in both developed and developing countries. In this article, current medical treatments, recent scientific progresses toward understanding obesity, and future potentials in biotechnology applications in pharmaceutical research are reviewed in detail.     

Stabilization of Red Beet Pigments with Isoascorbic Acid

Isoascorbic acid was investigated as a stabilizer for red beet pigments. Sterilized samples of red beet juice containing 0.05–1.0% isoascorbic acid, with the pH adjusted to 3, 5, or 7, were stored under artificial light or in darkness at 25°C or at 5°C. The best pigment preservation was obtained with 0.1% added isoascorbic acid. After 30 days storage at 25°C, samples at pH 5 containing 0.1% isoascorbit acid retained 52% (under light) and 65% (in darkness) of the red beet pigments, whereas the controls faded to yellow within 6 days under the same conditions.     

Nutritional Effects of Fresh, Laboratory Heated, and Pressure Deep-Fry Fats

Cooking fats from a pressure deep-fat frying operation producing fried chicken, were compared with laboratory heated and fresh fats in the diets of animals. Included were corn oil (CO), peanut oil (PO), and partially hydrogenated soybean oil (HSBO). Weanling rats were fed diets containing 15% fat for 28 days. Laboratory heating reduced absorption of CO and PO, but not that of HSBO. Pressure deep-frying increased absorption of HSBO. Animals derived less metabolizable energy from diets containing heated or hydrogenated fats relative to fresh oil. Polar lipid fractions of liver changed due to heating. Pressure deep-frying with fats resulted in less deterioration than with laboratory heating, as shown by chemical analyses, coefficient of digestibility, and metabolizable energy studies.     

Clickable,versatile poly(2,5-dithienylpyrrole) derivatives

In this study a novel, clickable, azide containing conducting polymers based on 1-(2-azido-ethyl)-2,5-dithiophene-2-yl-1H-pyrrole (SNS-N₃) were synthesized and characterized. Optical and electronic properties of homopolymer (PSNS-N₃) were investigated and colorimetric studies were performed. The homopolymer has a band gap of 2.49 eV and it displays yellow to blue coloration upon doping. Electrochemically prepared copolymers of SNS-N₃ and 3,4-ethylenedioxythiophene (EDOT) formed multichromic, color tunable electrochromic materials with continuous color gradient from cinnamon, mustard, lime green, blue and dark blue. Spectroelectrochemical analyses revealed that the neutral copolymers possess two absorption maxima (～320 and 450 nm) where the relative intensity and position of the two depends on polymerization potential. Copolymer films could be fully switched between their neutral and oxidized forms in ～1.2 s with a percent transmittance of ～65% at 950 nm. Moreover, a PSNS-N₃ coated ITO electrode was subjected to click reaction using ethynylferrocene. CV and FTIR studies revealed that ferrocene could easily be attached onto the electrode surface without loss of electroactivity of both ferrocene and PSNS backbone. Our results suggest that electrochemically prepared PSNS-N₃ films offer a novel and multipurpose platform for simple, effective post-functionalization of poly(2,5-dithienylpyrrole)s under mild conditions.     

Sweetness concentration-response behavior of rebiana at room and refrigerator temperatures

Rebiana is a zero-calorie, natural, high-potency sweetener derived from Stevia rebaudiana Bertoni and comprising almost pure rebaudioside A. Reliable information on its sweetness concentration-response (C-R) behavior is fundamental to rebiana's use as an ingredient. The response curve of rebiana in room-temperature (21 °C) and refrigerated (5 °C) water was determined using 2-alternative forced choice discrimination tests with a minimum of 70 tasters. From a series of panels the proportion of tasters finding different sucrose concentrations sweeter than a fixed concentration of rebiana was plotted against sucrose concentration. The resultant sigmoid curves were linearized by transforming the ordinate axis to a probability scale. This aided experimental design and determination of isosweet concentrations. The latter were deemed to be the sucrose concentration at which 50% of tasters found it to be the sweeter of the pair. Isosweet concentrations of sucrose for seven rebiana concentrations up to 600 mg/L were used to construct a C-R curve for each temperature. Equations were derived for the resultant hyperbolic curves. Rebiana is significantly more potent in cold water. PRACTICAL APPLICATION: Rebiana is a new, zero-calorie, natural, high-potency sweetener derived from the Stevia plant. We have measured the sweetness of rebiana over a range of concentrations at room and refrigerator temperatures. This information will help developers of low-calorie products get the right sweetness level when replacing sugar with rebiana.     

Effects of geometry and PVP addition on mechanical behavior of PEI membranes for use in wastewater treatment

This study focuses on the mechanical behavior and design of membrane filters that are used in water and wastewater treatment. The aim of this study is, after characterizing the mechanical behavior of the membrane materials, to find a better shape in terms of mechanical parameters. As the first step, uniaxial tensile testing is applied to the produced polymeric membranes with certain contents of poly(ether imide), poly(vinylpyrrolidone), and N-methyl-2-pyrrolidone to get an understanding of the mechanical behavior of the membrane materials. The material data obtained from this experimental process are used as input to software where a finite element model of the membrane is built. Each geometry has the same boundary conditions and the same area, and the same pressure is applied to each geometry. Using these numerical models, the selected geometries are analyzed in terms of displacement, equivalent stress, and equivalent strain. The results are discussed based on these parameters. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47073.     

The Usability of Boric Acid as an Alternative Foaming Agent on the Fabrication of Al/Al<Subscript>2</Subscript>O<Subscript>3</Subscript> Composite Foams

Pure Al and alumina (2, 5, 10 wt.% Al₂O₃)-added Al composite foams were fabricated through powder metallurgy technique, where boric acid (H₃BO₃) is employed as a new alternative foaming agent. It is aimed to determine the effects of boric acid on the foaming behavior and cellular structure and also purposed to develop the mechanical properties of Al foams by addition of Al₂O₃. Al and Al composite foams with porosity fraction in the range of 46-53% were achieved by sintering at 620 °C for 2 h. Cell morphology was characterized using a combination of stereomicroscope equipped with image analyzer and scanning electron microscopy. Microhardness values were measured via using Vickers indentation technique. Quasi-static compression tests were performed at strain rate of 10^?3 s^?1. Compressive strength and energy absorption of the composite foams enhanced not only by the increasing weight fraction of alumina, but also by the usage of boric acid which leads to formation of boron oxide (B₂O₃) acting as a binder in obtaining dense cell walls. The results revealed that the boric acid has outstanding potential as foaming agent in the fabrication of Al and Al composite foams by providing improved mechanical properties.