The passivation and oxidation process of tungsten and molybdenum narlopowders, produced by electrical explosion of wires was studied by means of FE-SEM, XPS. XRD, TEM, DIA-TGA and sire distribution analysis. In addition, the phase transformation of W and Mo nanopowders under oxidation in air was investigated. A chemical process is suggested for the oxidation of W and Mo nano-particles after a comprehensive testing of passivated and oxidized powders.

The oxidation behavior of 91 WC-9Co hardmetal in weight percentage has been studied in the present work as a part of the development of recycling process. The morphological and compositional changes of the WC-Co hardmetal with oxidation time at 90 were analyzed by using surface observation and X-ray diffraction. respective]y. As the oxidation time increased, the WC-Co hardmetal was continuously expanded to form porous oxide mixtures of and . The morphology of porous oxide mixture was basically dependent on initial shape of the WC-Co hardmetal. From thermo-gravimetric (TG) analysis, it was found that the oxidation rate was increased with increasing oxidation temperature and oxygen content in the flowing atmospheric gas. The fraction of oxidation versus time curves showed S-curve relationship at a given of oxidation temperature. These oxidation behaviors of the WC-Co hardmetal were discussed in terms of previously proposed kinetic models.

Structural changes of high modulus carbon fiber by oxidation in carbon dioxide gas using SEM, TEM, and XRD have been observed. It was shown that the originally high modulus carbon fiber is composed of highly ordered graphitic crystalline area and non-crystalline area. It was observed that the La increases during the whole oxidation process. It was shown that the oxidation of high modulus carbon fiber initiates at the non-crystalline area and at the ends of fiber. The large pores developed in fiber by direction of fiber length at high temperature (1,100℃), and the small pores developed on the fiber surface at low temperature (900℃). In conclusion, it is found that the oxidation of the carbon fiber was progressed through the imperfection.

The catalytic oxidation reaction of several cycloolefins in CH2Cl2 have been investigated using non-redox metalloporphyrin(M = Ga(III), In(III) and TI(III) complexes as a catalyst and sodium hypochlorite as a terminal oxidant. Porphyrins were (p-CH3O)TPP, (p-CH3)TPP, TPP, (p-F)TPP, (p-Cl)TPP and (F20)TPP (TPP=5,10,15,20-tetraphenyl-21H,23H-porphyrin) and olefins were cyclopentene, cyclohexene, cycloheptene and cyclooctene, The substrate conversion yield(%) was investigated according to the radius effect of non-redox metal ion, substituent effect and hindrance effect of metalloporphyrin. The conversion yield of cycloolefin was in the following order : C5 〈 C6 〈 C7 = C8.

The rapid growth of the food packaging field is powered by the ever growing health conscious consumers and demand for fresher and higher quality foods. Active packaging technologies provide solutions for extending products shelf life with specially altered packaging systems. Among the several shelf life enhancer systems, active packaging system for preventing oxidation is discussed in this paper. Oxidation is generally regarded as the main factor in the development of rancidity of fats and oils. The oxidative processes result in the food becoming unacceptable for consumers. Such oxidation is inhibited by exclusion of oxygen and by the presence of antioxidants. First of all, oxygen scavengers made up of substances which chemically or enzymically react with oxygen were developed to remove oxygen. The commercial oxygen scavengers such as “ageless sachet”, “platinum catalyst”, and “glucose/oxidase enzyme” have been greatly discussed in their action mechanisms and applications. The use of antioxidants in packaging manufacture has so far been limited to stabilizing the polymer during the processing or retarding the change of polymer's physical properties during storage when UV irradiated. However, a further benefit derived from incorporation of an antioxidant into the polymer is more interesting for its ability to retard lipid oxidation of the packaged food via slow migration of an antioxidant from the polymer to food. In view of which, in this paper we will review some oxygen scavenger systems as well as antioxidant-impregnated or antioxidant-coated polymer packaging material.

Two types of carbon fiber based high modulus- and isotropic-pitch were exposed to isothermal oxidation in air and CO2 gas and the weight change was measured by TGA apparatus. The kinetic equation was introduced f=1--(-atb) and the constant b was obtained in the range of 1.02~1.68 for the isotropic fiber and obtained 0.91~1.93 for the high modulus fiber respectively. In considering the effect of the atmosphere for isothermal oxidation, the value of the constant b obtained in the carbon dioxide was higher than that obtained in the air. Therefore, it was found that the pitch based carbon fiber shows sigmoidal characteristic when it is oxidized in the carbon dioxide. In addition, it was also found that kf = 0.5, which was reaction constant at f = 0.5, was a very useful parameter for evaluation of the oxidation reactivity of pitch based carbon fibers. According to the consideration, it is suggested that the conversion-time curves of the pitch based carbon fibers are correlated by normalized equation f=1--(-AτB), where τ=t/tf= 0.5.