Partial oxidation of ethane to synthesis gas over Co-loaded catalysts

Attention has been increasingly paid to the partial oxidation of lower alkanes to synthesis gas, due to its intrinsic energy saving process. We studied the partial oxidation of ethane (POE) on Co loaded on various supports. The POE performance varied as follows: Y₂O₃, CeO₂, ZrO₂, La₂O₃  SiO₂, Al₂O₃, TiO₂ > MgO. Comparing Y₂O₃ and CeO₂, the carbon deposition during the POE was negligible on CeO₂ and therefore CeO₂ was the most preferable support. By changing space velocity and O₂ partial pressure, reaction mechanism of POE was studied and it was revealed that two-step mechanism was prevailing; combustion of ethane to H₂O and CO₂ and subsequent reforming of ethane with H₂O and CO₂ to synthesis gas. Co/CeO₂ catalyst exhibited high and stable catalytic activity for 10 h; high ethane conversion of 18% (maximum ethane conversion 20% at O₂/C₂H₆ = 0.2) with H₂ and CO selectivities of 93 and 84%, respectively.     

Accretion of titanium carbide by electrical discharge machining with powder suspended in working fluid

A surface modification method by electrical discharge machining (EDM) with a green compact electrode has been studied to make thick TiC or WC layer. Titanium alloy powder or tungsten powder is supplied from the green compact electrode and adheres on a workpiece by the heat caused by discharge. To avoid the production process of the green compact electrode, a surface modification method by EDM with powder suspended in working fluid is proposed in this paper. After considering flow of working fluid in EDM process, the use of a thin electrode and a rotating disk electrode are expected to keep powder concentration high in the gap between a workpiece and an electrode and to accrete powder material on the workpiece. The accretion machining is tried under various electrical conditions. Titanium powder is suspended in working oil like kerosene. TiC layer grows a thickness of 150 μm with a hardness of 1600 Hv on carbon steel with an electrode of 1 mm in diameter. When a disk placed near a plate rotates in viscous fluid, the disk drags the fluid into the gap between the disk and the plate. Therefore, the powder concentration in the gap between a workpiece and a rotational disk electrode can be kept high. A wider area of the accretion can be obtained by using the rotational electrode with a gear shape.     

Conversion of allylic hydroxy oleate to conjugated linoleic acid and methoxy oleate by acid-catalyzed methylation procedures

Conjugated linoleic acid (CLA), a term describing a group of conjugated octadecadienoic acids that are both naturally occurring and formed during food processing, is the subject of considerable current research because of the recently reported antioxidant and anticarcinogenic properties of these compounds. Allylic hydroxy oleates (AHOs), secondary products of lipid autoxidation, have also been found in foods. By means of high-performance liquid chromatography with ultraviolet detection, gas chromatography/mass spectrometry and gas chromatography/matrix isolation/Fourier transform infrared spectroscopy, we determined that currently used acid-catalyzed methylation procedures convert AHOs to CLA and other products that potentially yield high values in determination of CLA in foods. A mixture of AHOs, containing mainly (8- and 11-)hydroxy-9-octadecadecenoates, was synthesized and tested by methylation procedures with the following catalysts: BF₃, HCl, NaOMe and tetramethylguanidine. Both the BF₃ and the HCl procedures converted AHOs to CLA. The base-catalyzed procedures did not convert AHOs to CLA.     

Protective effects of lemon flavonoids on oxidative stress in diabetic rats

The effects of lemon flavonoids, as crude flavonoids prepared from lemon juice, were investigated in diabetic rats. The oxidative stress of eriocitrin (eriodictyol 7-O-β-rutinoside) and hesperidin (hesperetin 7-O-β-rutinoside) on streptozotocin-induced diabetic rats was investigated. Diabetic rats were given a diet which contained 0.2% crude flavonoids, 0.2% eriocitrin, and 0.2% hesperidin. After the 28-d feeding period, the concentration of the thiobarbituric acid- reactive substance in the serum, liver, and kidney of diabetic rats administered crude flavonoids, eriocitrin, and hesperidin significantly decreased as compared with that of the diabetic group. The levels of 8-hydroxydeoxyguanosine, which is exchanged from deoxyguanosine owing to oxidative stress, in the urine of diabetic rats administered eriocitrin and hesperidin significantly decreased as compared with that of the diabetic rat group. Crude flavonoids, eriocitrin, and hesperidin suppressed the oxidative stress in the diabetic rats. These results demonstrated that dietary lemon flavonoids of eriocitrin and hesperidin play a role as antioxidant in vivo.     

Transport in the highly polarized Fermi system—A mixture of degenerate and classical fluids

It is shown that, at low temperature and high polarization, a spin-1/2 Fermi system becomes a mixture of a degenerate fluid (up spins) and a fluid described by Boltzmann statistics (down spins). The down spins become classical when the polarization is so high that their Fermi energy becomes much less thankT. For weakly interacting systems the coefficients of thermal conductivity, viscosity, and spin diffusion are computed by kinetic theory arguments and from the Boltzmann equation. Comparisons are made with coefficients of the fully degenerate systems at zero and high polarization; altered temperature and magnetic field dependences result.     

用于发动机动力系统的32位MCU

亚太地区特别是中国、印度和韩国的特大城市中，车辆保有量的迅猛增加，不可避免地带来了严重的空气污染，同时也导致了对自然资源的巨大需求。原油价格最近连创新高，环境质量持续恶化，这些事实迫使亚洲新兴市场国家从法律上做出日益严格的规定，要求降低排放并提高燃油的经济性。为确保亚洲汽车工业行业达到期望的发展水平，必须为客车、轻型和重型商用车辆及摩托车开发出更加智能化的发动机和传动控制系统。因此，控制系统中目前采用的8位和16位MCU，将逐渐被更先进的32位MCU所取代，以便未来的汽车设计师在确保汽车性能和安全性的前提下，降低燃料消耗，同时最大限度地减少有害物质的排放。     

Room temperature CW operation ofGa0.3In0.7As/GaInAsP/InP strained MQW lasers withwire active region

A room temperature CW operation of Ga_0.3In_0.7As/GaInAsP/InP GRINSCH compressive strained MQW lasers with 30~60 nm wide wire active region was achieved. This device was fabricated by two-step LP-OMVPE growths on p-type InP substrate and wet chemical etching. Threshold current as low as 53 mA ( L=910 μm, J_th=2.9 kA/cm²) was obtained at RT-CW condition. The spontaneous emission peak and the lasing wavelength of strained MQW wire lasers exhibited approximately 20-meV blue shift from those of MQW film lasers cut out from the same wafer     

Primary biliary cirrhosis associated with idiopathic thrombocytopenic purpura

A case of primary biliary cirrhosis (PBC) associated with idiopathic thrombocytopenic purpura (ITP) is reported. The patient is a 59-year-old man. When he was 49 years old, he was diagnosed with ITP and received steroid therapy that successfully increased platelet numbers. However, the steroid therapy failed to normalize the elevated gamma-glutamyl transpeptidase. Ten years after this episode, he suffered from general itching and malaise and exhibited a gradual increase of serum biliary enzyme levels. Immunologically, IgM was increased and anti-mitochondrial antibody was positive. Histological findings of liver needle biopsy showed chronic non-suppurative destructive cholangitis, confirming the diagnosis of PBC. To date, very few PBC cases associated with ITP have been reported. Our case is the second one in Japan. PBC and ITP in our patient seemed to develop simultaneously, but the effect of steroid therapy on the two conditions was different. This result suggests that the autoimmune process may have been different in PBC and ITP in the present patient.     

Preparation of amorphous Ni-Pd-P particles by melt ejection

Amorphous spherical particles with diameters of 0.5 to 1.4 mm have been prepared by melt ejecting Ni-rich Ni-Pd-P alloys into stirred cold water with 1 vol pct surfactive agent. The sphericity of the amorphous particles defined by the difference in diameter was better than 98 pct. Particle diameters (d) are 2 to 3 times larger than the orifice diameter (2r) of the quartz nozzle. The size ratio has been interpreted by the Raplace’s relation (d = 4r) derived from the assumption that an internal pressure of molten alloy is equal between cylindrical stream and spherical droplet. From the result that no spherical amorphous particles are formed in the cold water without surfactive agent, a significant decrease in the surface tension of coolant by the addition of surfactive agent is essential in the formation of spherical liquid particles from the ejected melt stream. The amorphous particles with diameters below about 1.0 mm exhibit hardness, crystallization temperature, and heat of crys-tallization similar to those from the amorphous ribbon with about 40 μm thickness. However, the onset temperature and heat of relaxation are lower by 16 K (4.2 pct) and larger by 130 J/mol (13 pct), respectively, for the particles. It is thus concluded that the amorphous spherical particles have the same thermal stability as that of the amorphous ribbon and its structure is in a more disordered state as compared with the ribbon sample.