Silver halide-containing photochromic powders of SiO2 sol–gel glass

In order to develop a photochromic powder, an SiO2-gel based on tetraethoxysilane (TEOS) was doped with AgNO3 or AgNO2. The dried gel pieces were pulverized and treated with aqueous or ethanolic halide solutions for growing silver halide microcrystals. Both the introduction of cuprous compounds such as CuBr, CuCl, Cu2O, Cu(CH3COO)2·H2O or sulphur-containing compounds and the formation of AgBrxCl1-x crystals lead to variations of photochromic properties. X-ray diffraction measurements indicate that the average diameters of silver halide microcrystals are limited to 70–110nm. Ultraviolet–visible spectroscopic investigations show the reversibility of the darkening/fading process. Cu+-containing samples exhibit a remarkable fading even at room temperature.     

Storage of Structured Beef Steakettes Produced with Algin/Calcium/Adipic Acid Gel

Binding properties and shelf-life characteristics of solid-muscle structured beef produced with algin/calcium/adipic acid binding gel were evaluated. Juncture binding strength and surface discoloration were not affected by refrigerated storage of meat blocks up to 35 days. Fresh steakettes had stronger muscle junctures than frozen steakettes in both raw and cooked forms. Rancidity development was greatest in steakettes stored in oxygen permeable packages. Results indicated structured meat products bound with algin/calcium/adipic acid gel maintained integrity following extended refrigerated and/or frozen storage.     

Cloud detection from thermal infrared images using a segmentation technique

In this paper, a fast and accurate method is proposed for two cloud detection tests on thermal infrared (IR) data obtained from satellite images over sea; an IR gross cloud test and a spatial coherence test. The proposed method is based on a regional segmentation technique. After the segmentation of an IR image, small regions were regarded as cloudy due to their high spatial variability in temperature. This technique preserved the spatial resolution of the detected cloud image which would be degraded by the conventional spatial coherence test. It also reduced the computation dramatically, compared to the conventional spatial coherence test. An accurate temperature threshold between clear sea and clouds was determined directly from the segmented image. This post-determined threshold was found to be more accurate than pre-determined temperature thresholds. Since this algorithm does not require any human interaction, it can be combined with other tests in an automatic cloud detection algorithm.     

Physical, Chemical and Sensory Characteristics of Four Types of Beef Steaks

Four types of beef forequarter steaks, rib eye roll steaks (RER), ser-ratus ventralis solid-muscle structured steaks (SRV), salt/phosphate comminuted structured steaks (NaCl/PO⁴) and algin/calcium comminuted structured steaks (Alg/Ca) were evaluated. Meat purchasers preferred the color, lack of surface discoloration and overall appearance of intact muscle steaks (RER and SRV) over the comminuted structured steaks (NaCl/PO⁴ and Alg/Ca). Purchasers perceived the fat content in SRV steaks to be less than in RER steaks. Sensory evaluations of juiciness and overall desirability were similar for all four types. Intact muscle steaks were lower in sensory tenderness ratings and higher in flavor desirability than comminuted structured steaks. Consumer acceptability was evident for all four types offering merchandising options to beef fabricators.     

Flame pyrolysis – a preparation route for ultrafine pure γ-Fe2O3 powders and the control of their particle size and properties

Highly dispersed γ-Fe2O3 powders with particle sizes down to 5 nm were directly synthesized by combustion of solutions of iron pentacarbonyl or iron(III) acetylacetonate in toluene in an oxyhydrogen flame. The particle size as well as other properties of the obtained powders can be controlled simply by varying the iron concentration in the starting solutions. Phase composition, morphological and magnetic properties of the powders were studied. The reasons for the formation of γ-Fe2O3 are discussed by means of structure–chemical/kinetic considerations. The materials are interesting as recording materials, or ferrofluids, or for colour imaging and bioprocessing. This revised version was published online in November 2006 with corrections to the Cover Date.     

单向,双向记忆合金的相变热测定

用ＤＳＣ－７研究了ＣｕＺｎＡｌ单向，双向记忆合金相变潜热，发现：单向，双向记忆合金相变过程的ＤＳＣ曲线形状各异，单向记忆合金的ＤＳＣ曲线为犬牙状，有多个峰；而双向记忆合金的ＤＳＣ曲线只有一个峰。在相变大小上，单向记忆合金的相变热比双向记忆合金约大１／４。     

Phase Equilibria in the Systems NiO-Cr2,O3,-O2, MgO-Cr2O3−O2, and CdO-Cr2,O3,-O2, at High Oxygen Pressures

Phase equilibria were determined for the systems NiO-Cr₂O₃−O₂, MgO-Cr₂O₃,-O₂, and CdO-Cr₂O₃−O₂ from 450° to above 850° C and at oxygen pressures of from 2 to 3500 atm. Only two intermediate phases were found in the nickel system: NiCrO., (CrVO₄ structure) and the spinel NiCr₂O₄. The magnesium and cadmium systems are similar in that they have three analogous phases: the low-temperature α-MgCrO₄ and α-CdCrO₄ (both with the CrVO₄ structure), the high-temperature β-MgCrO₄ and β-CdCrO₄ (both with the α-MnMoO₄ structure), and the spinels MgCr₂O₄ and CdCr₂O₄. The cadmium system contains an additional phase, Cd₂CrO₅, which is primitive monoclinic.     

STABILITY OF NONAQUEOUS ELECTROLYTES FOR AMBIENT TEMPERATURE RECHARGEABLE LITHIUM CELLS

Three tests have been used lo determine the stability of solutions of two nonaqueous solvents, propylene carbonate and 2-methyl-tetrahydrofuran and their solutions of LiAlCl₄. LiAsF₆ and LiClO₄ in contact with lithium. The procedures identify the effect of surface layers, open-circuit stand, anodic and cathodic polarization. They employ (1) contact with liquid Li amalgam and solid sheet Li; (2) open circuit potential measurements of cathodic deposits and (3) anodic dissolution of deposits with ramped potential. The stability of solvents is found to depend on the dissolved electrolyte. Polymeric materials containing other products of the reaction between metal and electrolytes have been identified by X-ray diffraction.     

Effect of Tannic Acid on a Low Tannin African Sorghum Variety in Relation to Carbohydrate and Amylase

The effect of concentrations of 0-3% tannic acid on root growth, starch, soluble carbohydrate and alpha and beta amylase was determined during germination of a low tannin sorghum variety. At higher concentrations of tannic acid root growth was suppressed. Starch degradation and accumulation of soluble carbohydrates were reduced and both alpha and beta amylase synthesis was decreased. This suggests that tannins retard starch degradation indirectly by inhibiting the synthesis of starch hydrolytic enzymes during germination.