EFFECTS OF OIL DROPLETS ON PHYSICAL AND SENSORY PROPERTIES OF O/W EMULSION AGAR GEL

Effects of oil droplets in an agar gel matrix were investigated by mechanical analyses and sensory evaluation. The results for compressive and puncture properties were expressed in terms of relative values. All compressive properties; stress, strain and compressive energy of emulsion gels, as obtained by compression tests, decreased with both increases of oil droplet size and oil volume fraction. The stress, strain and energy of the emulsion gels obtained by puncture tests did not change with an increase in oil droplet size. Results of sensory evaluation showed that the sample containing small oil droplets was harder than that with large oil droplets. On the other hand, the large oil droplet sample was oilier than that with small oil droplets. The sensory evaluations for hardness and oiliness of emulsion gels did not exhibit significant relations to most of the properties of mechanical analyses.     

Theoretical Concept of Hydrogen Redox Electric Power Generation

This paper demonstrates the electric power generator with both zero energy input and zero matter input and emission without violating the laws of thermodynamics. The hydrogen redox power generation system is a combined energy cycle consisting of the H₂O reduction by the electrostatic induction hydrogen electrolytic cell for the synthesis of pure stoichiometric H₂‐O₂ fuel and the H₂ oxidation to H₂O by the fuel cell. The electrostatic induction potential superposed hydrogen electrolytic cell works on the mechanism in which, on the theoretical base, power used is 17% of the total electrical energy required, while the remaining 83% can be provided by the electrostatic energy free of power. Part of the power delivered by the fuel cell is returned to the electrolytic cell, and the remainder represents the net power output. For high‐power applications, the cycle power efficiency defined as the ratio of net power output outside the generator to power delivered by the H₂‐O₂ fuel cell is of primary interest. According to calculations using the operational data of alkaline water electrolysis in industries, the cycle power efficiencies exceed 70%.     

ISO/IEC、美日中氢能技术标准化体系比较与建议

技术标准在技术进步、国际贸易中具有重要作用。全景式梳理、比较氢能技术标准化体系发展与现状,对于促进技术进步、规范国际贸易至关重要。本文综述了ISO/IEC、美国、日本和中国等5个主体氢能技术标准化体系：介绍了上述5个主体的氢能标准化机构,详细梳理了ISO/IEC氢能国际标准与美日中氢能国家标准/行业标准的层级结构比例,并按标准具体内容将其归类到8个技术类别中,分析了各主体在8个技术类别中的分布与特征。文中指出相比于美国和日本,中国氢能技术标准化体系存在行业标准数量较少、氢能产业联盟在行业标准制定中主导性弱和部分技术类别覆盖度低的不足。针对上述不足,文章对中国氢能技术标准体系提出两条发展建议：增加行业标准数量,以发挥其对标准体系补充、完善的作用,为此需赋予中国氢能产业联盟制定行业标准的权限;优化中国氢能技术标准分布,提高氢储运与加注以及氢能应用等技术类别的覆盖度,保障氢能产业从定点示范运营到城市群大规模推广的顺利升级。     

焊接顺序对厚板焊接残余应力分布的影响

采用试验手段和数值模拟方法研究了不锈钢厚板多道焊的残余应力分布特征．通过比较数值模拟结果和试验测量值，验证了基于Quick Welder软件开发的用于多道焊的热一弹一塑性有限元计算方法．同时，通过数值模拟澄清了焊接顺序对最终残余应力的影响．结果表明，焊接顺序对纵向和横向残余应力有明显影响．焊接顺序不仅显著影响峰值应力的...     

A new methodology to guarantee the structural integrity of Al2O3/SiC composite using crack healing and a proof test

Structural ceramics are brittle and sensitive to flaws. As a result, the structural integrity of a ceramic component may be seriously affected by inherent flaws. Self-crack-healing is an excellent answer to this problem. At the moment, however, there is no technique to heal embedded flaws. Therefore, a technique to guarantee the reliability of ceramic components is demanded, and thus a technique using crack healing followed by proof test was developed by K. Ando et al. to accomplish this. With this technique, testing the mechanical behaviour of the crack-healed zone is very important for ensuring the structural integrity of a ceramic component. In this study, first Al₂O₃/SiC composite with an excellent crack-healing ability was sintered. Second, a crack was introduced on the sample (3 mm × 4 mm × 36 mm), which reduced the bending strength by about 80%, and subsequently the crack was healed. Third, a proof test was carried out on the crack-healed sample. Last, using the crack-healed and proof-tested sample, a fracture test was carried out up to 1373 K. The measured minimum fracture stress (σ_Fmin) was compared with the theoretical minimum strength (σ_G) from room temperature (R.T.) to 1373 K. It was concluded that σ_G showed good agreement with σ_Fmin up to 1373 K and that the crack healing followed by proof test was an excellent technique to increase the survival probability by administering a proof test and to guarantee the reliability of Al₂O₃/SiC composite.     

On the controllability of systems with a time-varying delay†

This paper is concerned with the controllability of a system with a time-varying delay. The system to be considered here is described by a linear differential-difference equation of a retarded type, where a time-varying delay is a certain class of a time-varying function. First, the concepts of controllability for linear differential-difference systems with a constant delay, introduced by Weiss (1987), are developed to the system with a time-varying delay. Second, necessary and sufficient conditions for controllability are obtained. Finally, the controllability of a stationary system with a constant delay is treated, including the results of Chyung and Lee (1966).     

EFFECTS OF OIL DROPLET AND AGAR CONCENTRATION ON GEL STRENGTH AND MICROSTRUCTURE OF O/W EMULSION GEL

The effects of oil droplet size and agar concentration on gel strength and microstructure of emulsion gels were investigated by compression test and cryoscanning electron microscope (Cryo-SEM). At all agar concentrations, the compressive stress values of emulsion gels were lower than those of the oil-free gels. Compressive stress and energy were significantly affected by oil droplet size and agar concentration, but compressive strain was not. SEM observation revealed that the overall volume of void spaces decreased and strand compactness increased with increasing agar concentration. Gels containing oil droplets had some void spaces between the gel network and the oil droplets. The strands of emulsion gels did not cover the oil globules completely, a phenomenon which was also observed for the gel with high agar concentration.     

Impact of Sodium Ascorbate and Sodium Erythorbate Used in Meat Processing on the Vitamin B12 Contents of Cured Ham

Effects of sodium ascorbate (Na ascorbate) and sodium erythorbate (Na erythorbate) on vitamin B_]2 content of cured, cooked ham were investigated. Paired hams were injected with cure solution containing no curing accelerators or with cure solution containing Na ascorbate or Na erythorbate (3.28, 6.56, 9.84 g/L). There were no differences between vitamin B₁₂ contents of hams containing added curing accelerators and paired controls, indicating that B₁₂ was not destroyed by either Na ascorbate or Na erythorbate. Analysis of ascorbate, dehy-droascorbate, isoascorbate and dehydroisoascorbate showed ascorbate to be the only substance present in Na ascorbate-treated hams and isoascorbic acid to be the only substance present in Na erythorbate-treated hams.     

Assessment of Methodologies for Calorimetric Cholesterol Assay of Meats

The objective of this study was to assess the critical factors influencing the values for meat cholesterol determined colorimetrically. Procedure variations tested included: no saponification of total lipid extract before color development; with 15 min saponification at 80°C, with or without antioxidant protection; and with 60 min saponification at 80°C, with or without antioxidant protection. Without the saponification step, meat cholesterol values were overestimated. Samples with a large percentage of unsaturated fatty acids yielded higher cholesterol values when lipid extracts were saponified without antioxidant protection than with. Meat cholesterol values obtained by the procedure involving 15 min saponification with antioxidant protection were similar to those obtained by a commonly used gas chromatographic procedure.