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High cell density Ni monolithic catalysts coated with a series of Ni–Re bimetallic surface layers (Re 0–38 at%) were synthesized and examined for application in methane steam reforming (MSR) under a steam-to-carbon ratio of 1.36 and a gas hourly space velocity of 6400 h−1 in the temperature range of 773–1173 K. The influence of mass and heat transport was verified to be minor below 973 K under the present experimental conditions. The catalytic activities of the Ni monolithic catalysts were effectively improved in the presence of a Ni–Re bimetallic surface layer coating, and the stability in terms of the catalyst activity was significantly enhanced below 973 K upon increasing the Re content to >24 at%. The Ni–Re surface layer was analyzed by using in situ X-ray absorption fine structure spectroscopy, synchrotron radiation X-ray diffraction, scanning electron microscopy, and density functional theory calculations. These results revealed that a Ni–Re alloy consisting of a Ni(Re) solid solution phase and a Re phase was formed during hydrogen pre-reduction and the subsequent MSR reaction. The Re atoms in the Ni–Re alloy promoted hydrogen adsorption on the surface, thereby suppressing the oxidation of the surface Ni atoms during MSR, and enhancing the stability of the monolithic catalysts.

The catalysis of methane steam reforming (MSR) by pure Ni honeycombs with high cell density of 2300 cells per square inch (cpsi) was investigated to develop efficient and inexpensive catalysts for hydrogen production. The Ni honeycomb catalyst was assembled using 30-μm-thick Ni foils, and showed much higher activity than that of a Ni honeycomb catalyst with cell density of 700 cpsi at a steam-to-carbon ratio of 1.36 and a gas hourly space velocity of 6400 h−1 in a temperature range of 873–1173 K. Notably, the activity increased approximately proportional to the increasing geometric specific surface area of the honeycombs. The turnover rate of the Ni honeycomb catalyst was higher than that of supported Ni catalysts. The changes in chemical state of the Ni catalyst during hydrogen reduction and MSR reaction were analyzed by in situ X-ray absorption fine structure spectroscopy, which revealed that deactivation was mainly due to oxidation of the surface Ni atoms. These results demonstrated that the high-cell-density Ni honeycomb catalyst exhibits good performance for MSR reaction, and easy regeneration of the deactivated Ni honeycomb catalyst is possible only via hydrogen reduction.

The effect of steam and hydrogen treatments on the catalytic properties of a high-cell-density pure Ni honeycomb catalyst for methane steam reforming was investigated. A pretreatment consisting of steam treatment and subsequent hydrogen reduction at 1173 K significantly enhanced the catalytic activity of the Ni honeycomb catalyst at low temperatures below 1073 K. In situ X-ray absorption fine structure spectroscopy analysis showed that during the steam treatment, the surface Ni atoms were oxidized, and then these oxides were completely reduced to metallic Ni during the subsequent hydrogen reduction. The evolution analysis in surface morphology during pretreatment showed that many fine Ni particles formed on the surface. This surface structure was considered to be catalytically active for the methane steam reforming which is known to be structure sensitive.

The initial oxidation behavior of a clean Ni 3 Al (210) surface was studied at 300 K using a supersonic O 2 molecular beam (O 2 SSMB) having an O 2 translational energy of 2.3 eV, and real-time photoemission spectroscopy performed with high-brilliance synchrotron radiation. The evolution behaviors of the O 1s, Ni 2p, Al 2p, and Ni 3p spectra were examined during irradiation with the O 2 SSMB. The spectral analysis revealed that both the Al atoms and the Ni atoms on the surface were oxidized; however, the oxidation of Al progressed much faster than that of Ni. The oxidation of Al began to occur and AlO x was formed at an oxygen coverage of 0.26 monolayer (ML) (1 ML was defined as the atomic density of the Ni 3 Al (210) surface) and saturated at an oxygen coverage of 2.5 ML. In contrast, the oxidation of Ni commenced a little late at an oxygen coverage of 1.6 ML and slowly progressed to saturation, which occurred at an oxygen coverage of 4.89 ML.

A pretreatment procedure consisting of water vapor oxidation followed by H2 reduction has been developed for enhancing the catalytic activity of as-rolled Ni3Al foils for steam reforming of methane. The catalytic activities of the as-rolled Ni3Al foils in the temperature range of 873–1023 K at a steam to carbon ratio of 1.0 were found to be significantly improved by the pretreatment procedure consisting of a water vapor oxidation at 873–923 K for 1 h followed by a H2 reduction at 873 K for 1 h. Surface characterization of the foils before and after the reactions revealed that many fine NiO particles were formed on the surface by the water vapor oxidation at 873–923 K, whereas much less NiO particles were formed by the water vapor oxidation at low temperatures ( 973 K). During the subsequent H2 reduction treatment at 873 K, These NiO particles were reduced to metallic Ni. It is supposed that the enhancement in catalytic activity is attributed to the fine metallic Ni particles formed on the foil surface by the pretreatment procedure.

The catalytic properties of single-phase Ni3Sn powder in the production of hydrogen via the decomposition of methanol were investigated in isothermal tests at 713, 793, and 873 K. The catalytic activity of Ni3Sn significantly increased with time at 793 and 873 K, but not at 713 K, suggesting that Ni3Sn is spontaneously activated at temperatures above 793 K. At these temperatures, Ni3Sn showed high selectivity for H2 and CO production and low selectivity for CH4, CO2, and H2O production, indicating that methanol decomposition was the main reaction, and that side reactions such as methanation and water–gas shift reaction were suppressed. Surface analysis revealed that fine Ni3Sn particles were formed during the reaction, accompanied by a small amount of deposited carbon. The formation of these particles was suggested to be the cause for the spontaneous activation of Ni3Sn.

Honeycomb catalysts were assembled, using only 30 μm-thick Ni foils, to develop genuine monolithic catalysts for hydrogen production via methane steam reforming. A high cell density (900 cpsi) and geometric surface area (59.4 cm2/cm3) were achieved on the honeycomb catalyst. The catalyst exhibited high CH4 conversion (over 97%) at 1073 K for a long period of up to 8321.1 h under low steam-to-carbon ratio (1.34) and space velocity (335 h−1) conditions. A H2 production rate of 74.2 ml/min was achieved, and carbon deposition was hardly detected in spite of the low steam-to-carbon ratio. The catalyst was gradually deactivated due to the oxidation of Ni, but was repeatedly regenerated by reduction in flowing hydrogen. These findings proved the high potential of the Ni honeycomb catalyst for application to a small-scale hydrogen production system. Monitoring the temperature profile along the axial direction showed good heat transfer between the catalyst and the surrounding gas, which was attributed to the high thermal conductivity of Ni and to the high cell density of the catalyst. The high geometric surface area and good heat transfer are considered responsible for the good performance of the catalyst.

The catalytic properties of Ni-25 at% Al (Ni25Al) nanoparticles fabricated by arc plasma evaporation toward methanol decomposition were studied at temperatures ranging from 513 to 753 K. The Ni25Al nanoparticles showed much higher activity than gas atomized Ni25Al powders. They showed a high degree of selectivity for methanol decomposition into H 2 and CO. Side reactions such as methanation and water-gas shift reaction were suppressed to a high temperature of 673 K, which is hardly achieved for common Ni catalysts. Detailed characterization of the Ni25Al nanoparticles showed that they were composed of Ni, Ni 3 Al, and Al 2 O 3 phases with Ni and Al oxides on the surface of the Ni and Ni 3 Al phases. The Ni oxides were reduced to Ni phase by a hydrogen reduction prior to methanol decomposition, while the Al oxides remained unchanged. It is supposed that the Ni phase provided the active sites for methanol decomposition, and the Ni 3 Al and Al 2 O 3 phases acted as supports for the Ni phase. Probably the Ni 3 Al and Al 2 O 3 phases provided good resistance to agglomeration of the Ni phase during the reaction, which might contribute to maintain the high catalytic performance of the nanoparticles for methanol decomposition.

The catalytic properties of Ni3Sn and Ni3Sn2 powders were investigated for producing hydrogen from decomposing methanol during 593–953 K. The activities of Ni3Sn and Ni3Sn2 both increased with increasing temperature, but Ni3Sn showed much higher activity than Ni3Sn2. Furthermore, Ni3Sn and Ni3Sn2 both showed a high degree of selectivity for methanol decomposition.

A two-step pretreatment, oxidation in air followed by reduction in hydrogen, was performed on Ni3Al foils to improve the catalytic activity for methanol decomposition. A two-layer structure, Ni/Al2O3, was formed over the foil surface which was oxidized at 973 K and reduced, whereas a three-layer structure, Ni/NiAl2O4/Al2O3, was formed over the foil surface that was oxidized at 1173 K and reduced. In both cases the outmost Ni layer consisted of polycrystals and continuously covered the underlying oxides. Both pretreated foils exhibited lower onset temperature and enhanced catalytic activity for methanol decomposition into H2 and CO, compared to the untreated foil, and the difference between them was very small. In addition, they exhibited a good stability in catalytic performance at 673 K. The results demonstrate that the oxidation–reduction pretreatment effectively improves the catalytic performance of Ni3Al foil by the formation of an outmost Ni layer on the foil surface.

We had, in a previous study, found that flat cold-rolled Ni3Al foil is spontaneously activated during the initial stage of catalytic methanol decomposition, and further, this is accompanied by the gradual formation of fine Ni particles. In this study, we investigate the evolution of the foil surface structure at the beginning of the spontaneous activation by using hard X-ray (hν = 5.95 keV) photoelectron spectroscopy. The core level spectra of Ni 2p, Ni 3p, Al 2p, O 1s, Al 1s, and C 1s have been analyzed in detail. Ni in the Ni3Al foil remained in the metallic state during the reaction, and neither Ni oxide nor Ni hydroxide was formed. In contrast, Al was found to react with the gaseous products of methanol decomposition to form two compounds in succession. At the beginning of the reaction, Al was oxidized to form an Al2O3 layer on the surface. The outer surface of the Al2O3 layer then hydroxylated to Al(OH)3, thereby forming an Al(OH)3/Al2O3 two-layer structure. Thus, it was found that an Al(OH)3/Al2O3 t...

Cold-rolled Ni3Al foils were found to be spontaneously activated up to a high level during methanol decomposition, forming Ni particles on the foil surface. Utilizing this characteristic phenomenon, we pre-activated the Ni3Al foils and subsequently examined the catalytic properties under steam addition to methanol (steam-to-carbon ratio (S/C) = 0–1.0). The pre-activated foils exhibited high catalytic activity for methanol decomposition from the beginning of the reaction under steam addition and sustained the activity during the entire reaction time. Surface analyses revealed that the Ni particles formed by the pre-activation treatment survived after the reaction at all S/Cs, attributing to the high catalytic activity. Ni3Al foils which were spontaneously pre-activated in pure methanol exhibited high catalytic activity for methanol decomposition from the beginning of the reaction under steam addition and sustained the activity during the entire reaction time.

The surface structure of the alkali-leached single-phase Ni 3 Al powder was investigated by X-ray diffraction, BET (Brunauer–Emmett–Teller) surface area analysis, electron microscopy, X-ray photoelectron spectroscopy, and temperature-programmed reduction. It was found that fine Ni particles of several nm in diameter were formed on the outer surface layer of the Ni 3 Al powder after the alkali leaching process. The surface of the Ni particles was covered with a thin layer of Ni oxides and hydroxide, Ni 2 O 3 , NiO and Ni(OH) 2 , and these Ni oxides and hydroxide can be easily reduced by hydrogen to the metallic nickel that is catalytically active. The inside of the Ni 3 Al powder remained as the original Ni 3 Al ordered structure after alkali leaching. Having heat resistant properties, the Ni 3 Al phase can serve as a support of the fine Ni particles and provide the structural and thermal stabilities to the fine Ni particles.

We previously found catalytic activity for methane steam reforming in atomized Ni3Al powder which was pretreated by acid and subsequent alkali leaching. In this study the catalytic stability of the pretreated Ni3Al powder was investigated by isothermal test in the temperature range of 873–1173 K for 10 h. The activity was relatively stable over time at low temperatures below 973 K, especially at 873 K, where it retained the initial activity even after 10 h. However, it rapidly decreased with time at temperatures above 1073 K. Fine Ni particles, which were produced on the outer surface of Ni3Al powder during the pretreatment and served as a catalyst, survived on the surface after tests at all the temperatures. They remained almost unchanged below 973 K, leading to the good stability, while sintering and oxidation occurred at high temperatures, leading to the rapid deactivation.

cis-[Ru(NO)(CH3CN)(pyca)2] and trans-[Ru(NO)(OH)(pyca)2] (pyca = 2-pyridinecarboxylato) were synthesized and characterized by X-ray crystallography. Electrochemical behaviors of cis-[Ru(NO)(CH3CN)(pyca)2] and cis-[Ru(NO)(CH3O)(pyca)2] in acetonitrile were studied. These complexes showed two reduction processes in CH3CN. The controlled potential electrolyses of cis-[Ru(NO)(CH3O)(pyca)2] in a methanol–acetonitrile mixed solution were performed at the potential of the first reduction process. trans-[Ru(NO)(CH3O)(pyca)2] was isolated from the electrolyzed solution and characterized by IR and CV. The cis–trans geometrical change reaction occurred in the electrochemical one-electron reduction of cis-[Ru(NO)(CH3O)(pyca)2].

The catalytic activity of Ni3Al for methane steam reforming was investigated for the first time using its atomized powder. It was found that the activity was significantly enhanced by the combined pretreatment of acid and alkali leaching, while it was quite low for the as-received powder. The high activity was attributed to the formation of fine Ni particles on the porous surface of the powder.

Hydrogen was produced by methanol decomposition over cold-rolled foils of intermetallic compound Ni3Al which is known as an excellent high-temperature structural material. We found high catalytic activity and selectivity for methanol decomposition in flat cold-rolled Ni3Al foils. The catalytic activity was enhanced above 713 K by the spontaneous formation of fine Ni particles dispersed on carbon nanofibers during the reaction, resulting in high catalytic performance. The results demonstrate that the Ni3Al foils can be used both as catalyst precursors and as structural materials of microreactors for hydrogen production.

The effects of titanium additions on A s temperature, phase transformation behavior and microstructure have been studied in β+γ ′ two-phase alloys. When the endothermic β ′ →β transformation appeared first during heating of martensite, a mesh type microstructure, which has no resemblance to the original martensite plates, was obtained.

The reaction of cis-[Ru(NO)(CH(3)CN)(bpy)(2)](3+) (bpy = 2,2'-bipyridine) in H(2)O at room temperature proceeded to afford two new nitrosylruthenium complexes. These complexes have been identified as nitrosylruthenium complexes containing the N-bound methylcarboxyimidato ligand, cis-[Ru(NO)(NH=C(O)CH(3))(bpy)(2)](2+), and methylcarboxyimido acid ligand, cis-[Ru(NO)(NH=C(OH)CH(3))(bpy)(2)](3+), formed by an electrophilic reaction at the nitrile carbon of the acetonitrile coordinated to the ruthenium ion. The X-ray structure analysis on a single crystal obtained from CH(3)CN-H(2)O solution of cis-[Ru(NO)(NH=C(O)CH(3))(bpy)(2)](PF(6))(3) has been performed: C(22)H(20.5)N(6)O(2)P(2.5)F(15)Ru, orthorhombic, Pccn, a = 15.966(1) A, b = 31.839(1) A, c = 11.707(1) A, V = 5950.8(4) A(3), and Z = 8. The structural results revealed that the single crystal consisted of 1:1 mixture of cis-[Ru(NO)(NH=C(O)CH(3))(bpy)(2)](2+) and cis-[Ru(NO)(NH=C(OH)CH(3))(bpy)(2)](3+) and the structural formula of this single crystal was thus [Ru(NO)(NH=C(OH(0.5))CH(3))(bpy)(2)](PF(6))(2.5). The reaction of cis-[Ru(NO)(CH(3)CN)(bpy)(2)](3+) in dry CH(3)OH-CH(3)CN at room temperature afforded a nitrosylruthenium complex containing the methyl methylcarboxyimidate ligand, cis-[Ru(NO)(NH=C(OCH(3))CH(3))(bpy)(2)](3+). The structure has been determined by X-ray structure analysis: C(25)H(29)N(8)O(18)Cl(3)Ru, monoclinic, P2(1)/c, a = 13.129(1) A, b = 17.053(1) A, c = 15.711(1) A, beta = 90.876(5) degrees, V = 3517.3(4) A(3), and Z = 4.

The single crystal of isotopically enriched silicon ( 28 Si) has been made by FZ method with 〈111〉 growth direction. The specific heat measurement at low temperature was performed at the temperature range of 1–140 K. The low-temperature specific heat of 28 Si diverges from Debye T 3 behavior from 14.5 K, and this is in contrast to natural silicon, where deviations from the T 3 behavior occur already at much lower temperature (7.2 K). In addition, the specific heat of 28 Si becomes obviously higher than that of natural silicon at T >20 K.

cis-[Ru(NO)Cl(pyca)2] (pyca = 2-pyridinecarboxylate) ([1]), reacts with nucleophiles such as OH− and N3− in H2O to generate the dimeric nitrosylruthenium complex, [{Ru(NO)(pyca)2}2(μ-H3O2)]PF6·2H2O ([2]PF6·2H2O). The bridging unit of [2]PF6 is a hydroxide hydrate anion (H3O2−) composed of a hydroxo and an aqua moiety. Coordinated to each of the ruthenium centers are two pyca ligands in the trans-form with the pyridyl nitrogen atoms and the carboxylic oxygen atoms being at the trans position to each other (trans-form; trans(N,N), trans(O,O)-configuration). [2]PF6 has also been isolated by the reaction of [1] with N3− in H2O. The reaction of [1] with CH3O− in CH3OH gives the trans-form nitrosylruthenium complex, trans-[Ru(NO)(OCH3)(pyca)2]·CH3OH (trans(N,N), trans(O,O)-configuration) ([3]·CH3OH). The rare cis–trans isomerizations have thus occurred during the reaction between [1] (cis-form; trans(N,N), cis(O,O)-configuration) and OH−, N3− or CH3O−.

The measurement of specific heat at low temperature for isotopically modified boron single crystals was performed between 0.5 and 100 K using a calorimetric technique known as the time-constant or relaxation method. The results indicate that the specific heat has obvious divergencies at 1.3 K

The changes in the contents of dietary fibers, minerals, and free amino acids, and the fatty acid compositions of dried “nori” Porphyra yezoensis were examined during processing such as by cutting, mincing, mixing, and softening. The amount of soluble dietary fiber in nori cultivated at Chiba Prefecture was larger than that in Hyogo Prefacture; however, insoluble dietary fiber was reversed in each manufacturing process. Sodium and calcium contents of nori cultivated in Hyogo were larger than those in Chiba. Free amino acid contents such as taurine, alanine, and glutamic acid were higher in Chiba than in Hyogo during processing. Fat contents and the rate of icosapentaenoic acid in total lipid in the nori from Chiba were high, when compared with the counterpart in the process. There were no significant changes in any of the components during processing, when the results were expressed as g or mg per 100g of dry matter in each process. Therefore, we concluded that the specified components of nori were not lost to any significant degree in laver fronds during the processing of dried nori.

The measurement of specific heat and thermal conductivity at low temperature for isotopically modified boron single crystals was performed between 0.5 and 100 K using relaxation method and steady heat flow method, respectively. The results indicate that the specific heat has obvious divergences at T

Ruthenium complexes bearing ethylbis(2-pyridylethyl)amine (ebpea), which has flexible -C(2)H(4)- arms between the amine and the pyridyl groups and coordinates to a metal center in facial and meridional modes, have been synthesized and characterized. Three trichloro complexes, fac-[Ru(III)Cl(3)(ebpea)] (fac-[1]), mer-[Ru(III)Cl(3)(ebpea)] (mer-[1]), and mer-[Ru(II)Cl(3){η(2)-N(C(2)H(5))(C(2)H(4)py)═CH-CH(2)py}] (mer-[2]), were synthesized using the Ru blue solution. Formation of mer-[2] proceeded via a C-H activation of the CH(2) group next to the amine nitrogen atom of the ethylene arm. Reduction reactions of fac- and mer-[1] afforded a triacetonitrile complex mer-[Ru(II)(CH(3)CN)(3)(ebpea)](PF(6))(2) (mer-[3](PF(6))(2)). Five nitrosyl complexes fac-[RuX(2)(NO)(ebpea)]PF(6) (X = Cl for fac-[4]PF(6); X = ONO(2) for fac-[5]PF(6)) and mer-[RuXY(NO)(ebpea)]PF(6) (X = Cl, Y = Cl for mer-[4]PF(6); X = Cl, Y = CH(3)O for mer-[6]PF(6); X = Cl, Y = OH for mer-[7]PF(6)) were synthesized and characterized by X-ray crystallography. A reaction of mer-[2] in H(2)O-C(2)H(5)OH at room temperature afforded mer-[1]. Oxidation of C(2)H(5)OH in H(2)O-C(2)H(5)OH and i-C(3)H(7)OH in H(2)O-i-C(3)H(7)OH to acetaldehyde and acetone by mer-[2] under stirring at room temperature occurred with formation of mer-[1]. Alternative C-H activation of the CH(2) group occurred next to the pyridyl group, and formation of a C-N bond between the CH moiety and the nitrosyl ligand afforded a nitroso complex [Ru(II)(N(3))(2){N(O)CH(py)CH(2)N(C(2)H(5))C(2)H(4)py}] ([8]) in reactions of nitrosyl complexes with sodium azide in methanol, and reaction of [8] with hydrochloric acid afforded a corresponding chloronitroso complex [Ru(II)Cl(2){N(O)CH(py)CH(2)N(C(2)H(5))C(2)H(4)py}] ([9]).

Dietary fiber and minerals were analyzed in dried nori Porphyra yezoensis which was cultivated in eight main prefectures, i.e. Miyagi, Chiba, Aichi, Mie, Hyogo, Kagawa, Saga, and Kumamoto, and classified by price at auction. Insoluble dietary fiber was distributed within the range of 14.6 ?? 38.9g per 100g dry matter, and soluble dietary fiber within the range of 3.1 ?? 32.4g. Therefore, the total dietary fiber ranged from 19.6 to 59.8g. Low price nori as well as the sample harvested in March tended to contain high amounts of total dietary fiber. There were considerable variations in the contents of potassium (1, 610 ?? 4, 100mg/100g dry matter), sodium (510 ?? 2, 790mg), magnesium (53 ?? 249mg), calcium (46 ?? 331mg), iron (2.1 ?? 11.5mg), zinc (0.9 ?? 6.7mg), manganese (0 ?? 4.1mg), and copper (0.1 ?? 0.8mg). Mineral levels in nori seemed not to be correlated with the mineral concentration in sea water. No adequate correlation between these contents and prices was estimated from the results of the calculations.

The stock of brown alga, kombu, is used for Japanese dishes. Makombu Laminaria japonica cut into 1×1cm squares was irradiated at dose levels of 1, 10, and 100kGy under moisture contents of 10 or 40%, and then boiled up to 30min. Nitrogen, glutamic acid, and sugars in the kombu extracts were determined. When kombu was irradiated with a dose of 10 and 100kGy at 10% moisture, the amounts of extractive nitrogen boiled for 2 and 5min were about 1.4 times as many as those of non-irradiated control. Glutamic acid, one of the main constituents of delicious taste in kombu, was also highly extracted during 2 and 5min boiling in comparison with that of non-irradiated kombu. However, there were no significant differences in the amounts of either extractive nitrogen or glutamic acid after 30min boiling in any of samples. Sugars which deteriorated the quality of the kombu stock due to viscosity were dissolved in high amounts at a dose level of 100kGy. The amount of solubilized sugars from irradiated samples of 40% moisture was higher than that of 10% moisture, but no significant change was observed in other extracted substances during heating. From these results, the irradiation dose level of 10kGy was appropriate to obtain good kombu stock as a result of increased extractability.

A two-step treatment, oxidation in air followed by reduction in hydrogen, was carried out to modify the smooth Ni3Al foil surface into Ni particles supported on the oxide structure. The surface structure significantly changed depending on the oxidation temperature. A layer of granular NiO formed on the outer surface and inner oxide zone (IOZ) over Ni3Al foil surface after oxidation at 973 K. The IOZ was a mixture of Al and Ni oxides. In contrast, a large amount of faceted NiO particles formed on the outer surface after oxidation at 1173 K. Beneath the NiO particles, NiAl2O4 thin layer formed on IOZ over Ni3Al foil surface. And then, these NiO was selectively reduced to Ni after reduction treatment, constituting an oxide supported Ni particles structure. These results suggest that it is possible to modify the surface structure of Ni3Al foils simply by oxidation-reduction treatment.

Single crystals of MoSi2 and WSi2 with a body-centred-tetragonal C 1 1b structure were fabricated using a floating-zone method. The elastic wave velocity was measured for samples with various orientations using a simple pulse echo method at room temperature, and six elastic stiffness constantsc ij were calculated. The stiffness constants were a little higher for WSi2 than for MoSi2.c 11 andc 33 of these compounds were approximately equal toc 11 of tungsten and molybdenum, respectively, althoughc ij (i ≠j) was a little higher for these compounds than for molybdenum and tungsten. Young's modulus 1/s 11 was the highest in the direction, and the lowest in the direction. The shear modulus 1/s 66 was high on the {0 0 1} plane and independent of shear direction. It was generally low on the close-packed {1 1 0} plane and largely dependent on shear direction. The elastic constants for the polycrystalline materials were estimated fromc ij ands ij . Poisson's ratiov was 0.15 for MoSi2 and for WSi2, and these values were much lower than for ordinary metals and alloys. The Debye temperature θD was estimated using the elastic-wave velocity of the polycrystalline materials via the elastic constants such as Young's modulus and shear modulus: it was 759 K for MoSi2 and 625 K for WSi2.

Metal/single‐crystal‐silicide interface evolution has been examined for Ti/MoSi2 (001) using high‐resolution synchrotron radiation and x‐ray photoemission. Reaction between Ti and Si was observed for temperatures 300≤T≤873 K. At 300 K, it was limited to Ti interaction with the single Si layer terminating the cleaved MoSi2 (001) surface. Analysis of the Si 2p core level line shape showed two different interfacial reaction products with bonding characteristics of TiSi and a disordered solution of Si in Ti. Interfacial development was dominated by Si outdiffusion at higher temperatures with Si enrichment of the overlayer but not conversion to a silicide.

Corrosion of the primary circuit materials is one of the serious problems in High Temperature Gas-cooled Reactors (HTGR). In the present work, the effect of gaseous impurities in the helium coolant on the corrosion behavior of Inconel 617 has been studied at 1000 °C and atmospheric pressure for 1000 h. The helium gases used contained several impurities; H2, H2O, CH4, CO, and CO2. The corrosion behavior of alloying elements (Cr, Mo, Si, C) was strongly affected by the impurity concentration in helium and the extent of corrosion could be explained on the basis of the oxygen and carbon potentials in the gases used.

White and dark meats of bigeye tuna were packed in retortable pouches and thermally processed at 120, 110, and 100°C so far as to reach the equal lethality of F0 4, and the changes in extractive components of both meats were studied. As compared with the short time of heating at high temperature; the long time of heating at low temperature produced more intense browning of the meat extract, decrease in trimethylamine oxide, creatine, and total sugar, and increase in trimethylamine, creatinine, gelatin, and non-protein nitrogen. The decomposition of histidine and anserine, and the formation of gelatin in the dark meat were much greater than those in the white meat.

The decomposition of carnosine, anserine, and balenine during storage of the big-eye tuna and the sei whale meats was studied with a view to ascertain the formation of methyl derivatives of histamine and β-alanyl-histamine. A chromatographic deteiination of these amines on a 15cm column of a cation exchange resin (JEOL, LCR-2) was achieved using a borate buffer of pH 10.2 having sodium concentration of 0.32N, at 52°C. When the big-eye tuna meats with and without addition of chopped sardine skin were stored at 5°C for 12 days or 20°C for 5 days, and when the sei whale meats with and without addition of mackerel slime at 25°C or 37°C for 3 days, the meats turned putrid in the late stages of the storage periods. The amounts of anserine in the big-eye tuna, and carnosine and balenine in the sei whale did not decrease. Although a lot of histidine was decarboxylated into hislamine in the big-eye tuna meat at 20°C, the methyl derivatives of histamine and β-alanyl-histamine were not detected.

Carburization and decarburization of superalloys due to the impurities in the High Temperature Gas-cooled Reactor (HTGR) helium influences the mechanical properties of the superalloys. The objective of this study is to investigate the carburization and decarburization behavior thermodynamically. The four commercial superalloys were exposed to the three simulated HTGR helium gases and the change in carbon concentration was examined. The following results were obtained: 1. (1) The carburization and decarburization depend strongly on the superalloys and the helium gases. 2. (2) The extent of the carburization or decarburization exhibits a linear relation against its thermodynamic driving force. The results make it possible to predict the carburization and decarburization in the HTGR helium environment.

Specimens of bigeye tuna and the Pacific halibut meats packed in retortable pouches were heated at 115°C up to F0 values of 8, 12, and 21, and the changes in extractive components were studied. The decrease of the total sugar content and increase in pH value, Hunter value, degree of browning of extract, and the non-protein nitrogen content were observed during thermal pro-cessing. Trimethylamine oxide and creatine changed into trimethylamine and creatinine, re-spectively, almost equivalently, Little changes were observed in the amounts of free amino acid and its related compounds, but only histidine decreased significantly.

The distribution of nitrogenous compounds in the hot water extracts of snapping turtles cultured with six different diets was investigated. Although the amounts of nitrogenous compounds fluctuated among the specimens examined, carnosine, taurine, glutamic acid, histidine, inosine monophosphate, adenosine monophosphate, creatine, and creatinine were found to be relatively in high concentrations. The main component was gelatin, where nitrogen accounted for 72-80% of the total nitrogen in the hot water extracts. The changes in level of free amino acids and related compounds in the hot water extracts of the animals obtained from a commercial source were also investigated during heating. Carnosine, histidine, and taurine, all of which were present initially in large quantities, decreased rapidly and their amounts were approximately halved after 48h of heating. The degree of browning of the hot water extracts increased rapidly after 12h, possibly relating to the decrease in levels of such nitrogenous compounds. Gelatin contents increased rapidly and reached a maximum level after 24h.

1. 1. Seminal plasma of the mature salmon Oncorhynchus keta , was analysed for major inorganic and organic constituents, and their changes accompanying freshwater adaptation were compared with those of the blood plasma. 2. 2. Potassium concentration of the seminal plasma exceeded greatly the plasma level, whereas sodium concentration and the osmolality were almost identical with those of the blood plasma. 3. 3. As compared with blood plasma, seminal plasma contained almost negligible amounts of glucose, cholesterol, protein and cortisol. 4. 4. Unlike the blood plasma, the osmolality of the seminal plasma calculated from sum of cations exceeded the measured value. 5. 5. On transfer from seawater to freshwater, marked decrease in the levels of sodium, chloride and osmolality was observed both in the blood plasma and in the seminal plasma, whereas the decrease was more marked in the seminal plasma than in the blood plasma.

1. 1. A large amount of coelomic fluid appears at the moment of ovulation in Salmonidae, and the ovulated eggs lie free in the body cavity. 2. 2. Ion composition and osmolality of the coelomic fluid of the mature female salmon, Oncorhynchus keta, were approximately the same as those of the blood plasma, although an excess of sodium chloride and low levels of organic constituents were noted in the coelomic fluid. 3. 3. On transfer from seawater to freshwater, a significant reduction in ion concentrations and osmolality of the coelomic fluid was observed in close association with the changes in the plasma values.