The Effect of Zinc on Human Taste Perception

Zinc salts are added as a nutritional or functional ingredient in food and oral care products. The 1st experiment in this study investigated the taste and somatosensory effect of zinc salts (chloride, iodide, sulfate, bromide, acetate). The zinc salts had very little taste (bitter, salty, savory, sour, sweet), and the taste that was present was easily washed away with water rinses. The major oral quality of zinc was astringency, and the astringency lingered beyond expectoration. The 2nd experiment combined zinc salts with prototypical stimuli eliciting basic tastes. Zinc was a potent inhibitor of sweetness and bitterness (>70% reduction in taste) but did not affect salt, savory, or sour taste.     

Changes in the proportions of soluble and insoluble calcium during the ripening of cheddar cheese

In cheese, the concentration and form of residual Ca greatly influences texture. Two methods were used to determine the proportions of soluble (SOL) and insoluble (INSOL) Ca in Cheddar cheese during 4 mo of ripening. The first method was based on the acid-base buffering curves of cheese and the second was based on the extraction of the aqueous phase ("juice") of cheese under high pressure and determining the concentration of SOL Ca in the juice using atomic absorption spectroscopy. When cheese was acidified there was a strong buffering peak at pH approximately 4.8, which was due to the solubilization of residual colloidal calcium phosphate (CCP) of milk that remained in cheese as INSOL Ca phosphate. The area of this buffering peak in cheese was expressed as a percentage of the original area of this peak in milk and was used to estimate the concentration of residual INSOL Ca phosphate in cheese. There were no significant differences between the 2 methods. The proportions of INSOL Ca in cheese decreased from approximately 73 to approximately 58% between d 1 and 4 mo. These methods will be useful techniques to study the role of Ca in cheese texture and functionality.     

无机盐对十二烷基苯磺酸钠微乳液体系相行为的影响

通过Winsor相图和ε-β鱼状相图研究不同无机盐对十二烷基苯磺酸钠-正辛烷-水-正丁醇微乳液体系相行为的影响规律。实验结果表明,随无机盐盐度或醇量的增加,微乳液体系均会发生从WinsorⅠ→WinsorⅢ→WinsorⅡ的相转变,但具有不同阳离子或阴离子的无机盐对微乳液体系相行为的影响不同;无机盐对微乳液体系起主要作用的是表面活性剂的反离子,对阴离子表面活性剂配成的微乳液体系,阳离子的作用比较强,且价态越高、水合离子半径越小,对微乳液相态的影响越大;阴离子的作用比较弱,同价态阴离子的作用基本相同,且随阴离子价态的增加其作用越弱。     

Separation of chitin from shrimp shells enabled by transition metal salt aqueous solution and ionic liquid

Chitin is a widely used important industrial polymer mainly from shrimp shells, but its commercial preparation is under the great challenge of serious pollution due to the requirement of HCl and Na OH.Herein, we demonstrated that high purity chitin can be obtained from waste shrimp shells(WSSs) by cascade separation with transition metal salt aqueous solution and ionic liquid(IL). Firstly, calcium carbonate of WSSs was effectively removed in the metal salt aqueous solution driven by the ion exch...     

Addition of an aerated iron‐rich waste‐activated sludge to control the soluble sulphide concentration in sewage

Hydrogen sulphide emission in sewers is associated with toxicity, corrosion and odour and also yields considerable costs. The purpose of this study was to evaluate whether the soluble sulphide concentration in raw sewage can be controlled by dosing an iron‐rich waste‐activated sludge (WAS) or an iron‐rich aerated waste‐activated sludge (AWAS). An average soluble sulphide elimination of 99% was achieved at an iron‐rich AWAS to sewage ratio (v/v) of 16%, whereas dosage of iron‐poor AWAS at the same ratio decreased the soluble sulphide in the raw sewage by only 53%. Our lab‐scale tests suggest that dosing iron‐rich AWAS to sewage did not affect the chemical oxygen demand (COD) and total ammonia nitrogen (TAN) removal as well as the nitrification efficiency in the receiving activated sludge system. The results indicate that iron‐rich AWAS dosage is a feasible technique to remediate the sulphide problem in sewers.     

Effect of AlInGaN barrier layers with various TMGa flows on optoelectronic characteristics of near UV light-emitting diodes grown by atmospheric pressure metalorganic vapor phase epitaxy

Near ultraviolet light-emitting diodes (LEDs) with quaternary AlInGaN quantum barriers (QBs) are grown by atmospheric pressure metalorganic vapor phase epitaxy. The indium mole fraction of AlInGaN QB could be enhanced as we increased the TMG flow rate. Both the wavelength shift in EL spectra and forward voltage at 20 mA current injection were reduced by using AlInGaN QB. Under 100 mA current injection, the LED output power with Al_0.089In_0.035Ga_0.876N QB can be enhanced by 15.9%, compared to LED with GaN QB. It should be attributed to a reduction of lattice mismatch induced polarization mismatch in the active layer.     

某黄金冶炼厂水系硫酸根浓度升高原因分析及处理探索

在某黄金冶炼厂的生产过程中发现,含氰水系统中的硫酸根浓度逐渐升高。当气温降低时,产生的硫酸钠结晶严重时影响正常生产。本文分析了冶炼厂水系中硫酸根升高原因,采用冷冻结晶和化学沉淀法使硫酸根浓度降低,进而避免了结晶的生成。     

Surface active and thermodynamic properties of some surfactants derived from locally linear and heavy alkyl benzene in relation to corrosion inhibition efficiency

Linear and heavy alkyl benzene (HAB) were sulfonated with fuming sulfuric acid (oleum) and the sulfonated products were esterified with tri and poly ethanolamine (d = 4 and 6). The prepared three esters from each series were quaternized with n‐butyl bromide. The resulted six quaternized ester of linear and HAB sulfonate were named as (L1Q, L2Q, L3Q, H1Q, H2Q, and H3Q). The surface and thermodynamic properties of these compounds have been investigated. From the data obtained, it was found that surface tension and surface active properties for the HAB derivatives were better than which obtained from linear alkyl benzene (LAB) derivatives. From the results obtained from the surface activity, the best performance compound from each group was selected to study the corrosion inhibition efficiency of them relative to the surface activity. The obtained results show that the LAB derivative L3Q exhibited inhibition efficiency (93.1%) at 1000 ppm but H3Q exhibited (97%) at 600 ppm. The diversity of the resulted data obtained was discussed in the light of chemical structure of the alkyl benzene sulfonate.