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811.
Analyses of the molecular species of authentic triacylglycerols and of soybean triacylglycerols, which were separated on a
fused silica open-tubular column coated with a methylphenylsilicone gum stationary phase, were carried out by selective ion
monitoring mass spectrometry. It was determined that peak assignments could be made by selecting certain characteristic ions
with the same retention time on the SIM profile, that is, three ions of the type RCO+ corresponding to the fatty acyl residues (R1CO+, R2CO+ and R3CO+) and the corresponding three M-acyl ions ([M-OCOR1]+, [M-OCOR2]+ and [M-OCOR3]+ instead of the molecular ion. The yield of [RCO-1]+ and [RCO-2]+ and relating these to the unsaturated fatty acyl residues is inconvenient for an exact peak assignment. The SIM method was
further applied to the peak assignment of the triacylglycerols from palm, cottonseed and safflower oils and certain new fatty
acid combinations are proposed. 相似文献
812.
Toshiaki Yamaguchi Wataru Sakamoto Toshinobu Yogo Shin-ichi Hirano 《Journal of the American Ceramic Society》2002,85(4):909-914
The effects of the substitution of transition-metal ions and/or reductant gases on the catalytic properties of barium hexaaluminogallate were investigated. Transition-metal-substituted hexaaluminogallates (BaM(Al,Ga)11 O19 , M = transition metal, Al/Ga = 9/3) were synthesized from aqueous metal nitrates and ammonium carbonate by the coprecipitation followed by crystallization at 1100°C. The direct NO x reduction was observed over BaM(Al,Ga)11 O19 to be around 10%. The NO x removal activity of BaM(Al,Ga)11 O19 powders was improved by addition of C3 H6 as a reductant gas. Co-, Ni- and Cu-substituted BaM(Al,Ga)11 O19 catalysts exhibited about 40% NO x reduction with C3 H6 in excess oxygen at a high space velocity of 10 000 h−1 . The NO x reduction on Mn- and Fe-substituted BaM(Al,Ga)11 O19 catalysts was less than 10% even in the presence of C3 H6 . The temperature of the effective NO x reduction on BaM(Al,Ga)11 O19 catalysts could be adjusted from 350° to 500°C by the selection of the transition-metal substitution in the catalysts. The catalysts hold high activities for NO x reduction even at 500°C in water vapor produced in the combustion system of reductant gases. 相似文献
813.
A procedure for the preparation of solid formed coke of enough adhesion and anisotropic development for use in the blast furnace has been studied, using non-fusible and slightly fusible coals with petroleum cocarbonizing additives. The coke precursor was prepared through the copreheat-treatment of coal and a suitable additive in adequate quantity under stipulated conditions. The desired coke was produced by carbonization after forming with a press. The conditions for the copreheat-treatment have been carefully examined in terms of the temperature, time and heating devices. The behaviour of coals during copreheat-treatment and carbonization were discussed in terms of coal ranks, comparing this behaviour to the liquefaction reactivity and thermal stability of their liquefied product. 相似文献
814.
Kazuhiko Yamasaki Takahiro Chikazawa Yoshihisa Tamaki Toshiaki Kikuchi Masatoshi Hanzawa Yasuji Morita Yasuhisa Ikeda 《Progress in Nuclear Energy》2005,47(1-4):414-419
The simple reprocessing method based on precipitation using N-cyclohexyl-2- pyrrolidone (NCP) as a selective precipitant for U and Pu ions from dissolved solutions of spent FBR fuels has been developed. On the basis of fundamental studies on precipitation behaviors, we designed and built up the scaled-up laboratory equipments (1/20-scale of future plant capacity of 200 tHM/y) to evaluate technological and economical feasibility. This system, which mainly consists of a precipitator and a precipitate separator, should be operated continuously from economical reasons. From the experimental results, it was confirmed that the precipitator is capable of producing UO22+-NCP precipitate stably with stipulated residence time (approximately 30 min), and the precipitate separator has the highly efficient separation of precipitate from the slurry. Furthermore, the parametric experiments indicated that the rinsing operation increased the efficiency in decontamination of FP elements. 相似文献
815.
The combustion of polypropylene flame-retarded by the synergistic action between Sb2O3 and bromine-containing flame retardants has been studied. From the relationship between a number of the variables, a parameter quantatively reflecting the flame retardant effect has been found. With the addition of flame retardant, the rate of weight loss, the CO and CO2 emission rates and heat release all decrease while smoke density increases. These effects were considered to depend on the concentration of HBr gas in the pyrolysates released into the gas phase (i.e., dWHBr/dW, HBr flux ensity), and the following equations were obtained: η*(dW/dt)max, which approximately corresponds to the oxidation velocity of pyrolized hydrocarbon, is inversely proportional to the HBr flux density. As the conversion of CO to CO2 was almost independent of the amount of flame retardants added, the flame retardant effect of bromine-containing flame retardants was considered to be a retardant effect of the initial oxidation reaction at the gas liquid interface. Moreover, η* is almost proportional to the combustion efficiency η, which was obtained from the heat release measured in the flaming region. The heat release is therefore considered to be governed by the HBr flux density. 相似文献
816.
The oxidation behavior of cis-1,4-polyisoprene, emulsion polyisoprene, emulsion isoprene/styrene copolymers, and emulsion butadiene/styrene copolymers by heat aging or ultraviolet irradiation has been investigated from the change of gel fraction and molecular weight distribution. It was determined that the oxidation behavior of both isoprene and butadiene polymers is strongly dependent on the composition of the polymers as well as on the microstructure of the polymers. In the case of oxidation by heat aging, the probability ratio of chain scission to crosslinking of both isoprene and butadiene copolymers increases gradually with increasing styrene fraction. In the case of oxidation by ultraviolet irradiation, isoprene copolymers show a remarkable increase in the probability ratio of chain scission to crosslinking, whereas butadiene copolymers show substantially no change with increase in styrene fraction. It was also demonstrated that both isoprene and butadiene polymers show a greater tendency for crosslinking with oxidation by ultraviolet irradiation than with oxidation by heat aging. 相似文献
817.
Ken Terao Tomotake Karino Naotsugu Nagasawa Fumio Yoshii Miyoko Kubo Toshiaki Dobashi 《应用聚合物科学杂志》2004,91(5):3083-3087
A new type of gelatin microspheres was manufactured with the crosslinking method by using γ‐ray irradiation. Microspheres thus obtained were characterized by microscopic observation and enzymatic degradability. The mean diameter of the microspheres was in the range from 2.4 to 3.6 μm and the size distribution was quite small. The size decreased with increasing the shear rate of the emulsifier used in the preparation and was not affected by the radiation dose. The enzymatic degradability decreased with increasing the radiation dose and decreasing the gelatin concentration of the microsphere. In other words, the rate of the enzymatic decomposition of microspheres can be controlled by these two parameters. These trends were consistent with our previous results for the gel sheet made of gelatin. Their sorption of proteins was also investigated with the use of three types of proteins labeled by fluorescent pigment. From the fluorescence micrographs, it was observed that the gelatin microspheres adsorbed only proteins having the opposite charge. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3083–3087, 2004 相似文献
818.
Robert Chang David Rohindra Roselyn Lata Keiichi Kuboyama Toshiaki Ougizawa 《Polymer Engineering and Science》2019,59(Z2):E32-E41
Blends of poly(ε‐caprolactone) (PCL) with pine resin, an extract from the plant Pinus caribaea—Hondurensis was prepared by melt mixing in mass ratios from 90/10 to 50/50. The thermal, crystallization, morphological, and mechanical properties of the blends were studied by differential scanning calorimetry, Fourier transform infrared spectroscopy, polarized optical microscopy, scanning electron microscopy, and tensile test. Enzymatic degradation of the blends was investigated using porcine pancreatic and Candida rugosa lipase. Antimicrobial activity of the blends was tested against four strains of bacteria; Staphylococcus aureas, Escherichia coli, Bacillus subtilis, and Pseudomonas aeruginosa using the zone inhibition method. Miscibility of the blends was confirmed by the depression in the equilibrium melting temperature ( ) of PCL estimated from Hoffman–Weeks plot and the presence of extinction rings in the spherulites of blended PCL. Interactions between the two components involved the carbonyl and the C‐O‐C groups. The tensile strength of the blends with low pine resin content was comparable to PCL but decreased with higher pine gum content. Enzymatic degradation of the blends increased with increasing pine resin content. The blends showed antimicrobial property with all the bacteria except E. coli. The developed biomaterial shows promising candidacy in medical applications. POLYM. ENG. SCI., 59:E32–E41, 2019. © 2018 Society of Plastics Engineers 相似文献
819.
The effects of droplet size and emulsifiers on oxidative stability of polyunsaturated TAG in oil-in-water (o/w) emulsions
with droplet sizes of 0.806±0.0690, 3.28±0.0660, or 10.7±0.106 μm (mean ± SD) were investigated. Hydroperoxide contents in
the emulsion with a mean droplet size of 0.831 μm were significantly lower than those in the emulsion with a mean droplet
size of 12.8 μm for up to 120 h of oxidation time. Residual oxygen contents in the headspace air of the vials containing an
o/w emulsion with a mean droplet size of 0.831 μm were lower compared with those of the emulsion with a mean droplet size
of 12.8 μm. Hexanal developed from soybean oil TAG o/w emulsions with smaller droplet size showed significantly lower residual
oxygen contents than those of the larger droplet size emulsions. Consequently, oxidative stability of TAG in o/w emulsions
could be controlled by the size of oil droplet even though the origins of TAG were different. Spin-spin relaxation time of
protons of acyl residues on TAG in o/w emulsions measured by 1H NMR suggested that motional frequency of some acyl residues was shorter in o/w emulsions with a smaller droplet size. The
effect of the wedge associated with hydrophobic acyl residues of emulsifiers was proposed as a possible mechanism to explain
differences in oxidative stability between o/w emulsions with different droplet sizes. 相似文献
820.
Yukio Nakako Shinich Katsushima Shinich Oya Toshiaki Okui Tetsuo Matsumura Toshio Osawa Kaisaburo Saito Akihiro Mawashima Nobuo Tanaka 《Fuel》1982,61(10):953-958
Reaction kinetics of the liquefaction of Victorian brown coal in a process development unit (PDU) having three reactors in series have been studied at temperatures of 430–470°C, and pressures of 15–25 MPa. It is shown that the rate of hydrogen consumption can be expressed as a function of the concentrations of coal and catalyst, hydrogen partial pressure, reaction temperature and residence time, and is controlled by the rates of hydrogenation of polynuclear aromatic components, and the rates of formation and stabilization of radicals. The relative contribution of these reactions, at any temperature, determine the influence of the hydrogen partial pressure on the rate of the hydrogen consumption. The kinetics of the decomposition reactions of brown coal to preasphaltene, asphaltene and to oil also have been studied. The apparent activation energies determined are 25 kJ mol?1 for the brown coal to preasphaltene, 50 kJ mol?1 for preasphaltene to asphaltene, 76 kJ mol?1 for asphaltene to oil, and 184 kJ mole?1 for oil to gases. 相似文献