Structural Transition of C60 On Iodine Doping By Solid-Vapor Reaction

f.c.c. C60.     

Optimization of the electric power leveling system by using superconducting magnetic energy storage with genetic algorithm

A new optimization method of the electric power leveling system using an SMES is proposed. The SMES is parallelly connected with rolling mills in steel works. The leveling control is based on fuzzy reasoning. The SMES capacity and the scaling factors of the fuzzy controller will be optimized so that the power leveling control can be achieved and then the total cost of the added SMES cost and reduced contract electricity rate becomes lower. The optimization is carried out using a genetic algorithm and a cost reduction of 7.76 billion yen can be achieved. Power leveling simulation confirms that the proposed optimization method is very effective for designing the power leveling system. © 2004 Wiley Periodicals, Inc. Electr Eng Jpn, 150(3): 62–69, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20049     

Excellent effects of hydrogen postoxidation annealing on inversionchannel mobility of 4H-SiC MOSFET fabricated on (112¯0) face

Effects of hydrogen postoxidation annealing (H₂ POA) on 4H-silicon carbide (SiC) MOSFETs with wet gate oxide on the (112¯0) face have been investigated. As a result, an inversion channel mobility of 110 cm²/Vs was successfully achieved using H₂ POA at 800°C for 30 min. H₂ POA reduces the interface trap density by about one order of magnitude compared with that without H₂ POA, resulting in considerable improvement of the inversion channel mobility to 3.5 times higher than that without H₂ POA. In addition, 4H-SiC MOSFET with H₂ POA has a lower threshold voltage of 3.1 V and a wide gate voltage operation range in which the inversion channel mobility is more than 100 cm²/Vs     

Severe testotoxicosis phenotype associated with Asp578-->Tyr mutation of the lutrophin/choriogonadotrophin receptor gene

Testotoxicosis is a form of male precocious puberty caused by heterogeneous activating mutations in the gene for the lutrophin/choriogonadotrophin receptor (LHR). A patient with an unusually early and severe presentation of testotoxicosis, including profound Leydig cell hyperplasia, was found to have a sporadic mutation encoding Asp578-->Tyr. The severe testotoxicosis phenotype appears to be related to the strongly activating nature of the Tyr substitution.     

A method of evaluating local turbulent diffusivity of heat in a gridded fuel subassembly

In evaluating the turbulent diffusivity of heat associated with the coolant flow past a grid spacer within an FBR fuel subassembly, a heat diffusion technique is usually employed. However, measurement of subchannel bulk coolant temperature using thermocouples usually involves difficulty due to a steep and non-linear temperature gradient in the subchannels adjacent to a heater pin.A series solution of the heat conduction equation for the coolant flow in subchannels past a grid spacer and a heated section of a dummy fuel pin was derived under a slug flow approximation where the boundary conditions on dummy fuel pins were satisfied by means of the point-matching technique. The solution may be utilized in analyzing the turbulent diffusivity of heat within subchannel coolant flow as a function of distance from a grid spacer based on the measured temperature distribution on the wall of dummy fuel pins, which may be obtained without affecting the subchannel coolant temperature.In an illustrative example, the turbulent diffusivity of heat was most exaggerated at about 50 mm beyond a grid spacer and was approximately five times larger than the corresponding diffusivity without a grid spacer.     

Social responsibility and contribution: R & D for the construction industry in the twenty-first century

An authoritative account of current thinking in Japan by a distinguished contributor presented at the second Rinker International conference. Toshihiko Ota discusses the social responsibilities and contributions of the construction industry, drawing on the example of the effective performance of Japan's R & D and highlighting a number of responsibilities for the twenty-first century.     

A direct measure of the value of choice-freedom

The value of choice-freedom is a measurement of the variety of choice of an individual and is defined as the maximum amount a consumer would be willing to pay for the option which is infrequently or not at all used by the consumer. This paper shows that the value of choice-freedom can be derived from random utility theory and measured by an entropy defined by choice probabilities. In addition, the interrelationships among choice-freedom, average utility and indirect utility is unified into only one equation, called the choice equation, and its properties are examined.     

SiC matrix composites reinforced with internally synthesized TiB2

A new process of preparing particulate-reinforced ceramic composites by internal synthesis has been developed. SiC powder mixed with TiN and amorphous boron was hot-pressed above 2000° C in an argon atmosphere. The boron molar content in the mixture was designed to be more than twice that of TiN. In the process of hot-pressing, the following reaction took place between 1100 and 1700° C TiN+2B TiB₂+1/2N₂ The synthesis of TiB₂ was followed by the densification of SiC matrix with the aid of the excess boron. The new process provides SiC matrix composites in which fine TiB₂ particulates are dispersed. Compared with hot-pressed monolithic SiC, the composite containing 20 vol % TiB₂ exhibits a 80% increase in fracture toughness and about the same flexural strength of 490 MPa at 20° C in air and 750 MPa at 1400° C in a vacuum.     

Development of sulfur tolerant catalysts for the synthesis of high quality transportation fuels

In this paper, results concerning the development of sulfur tolerant catalysts for Fischer–Tropsch synthesis (FTS), C₂₊ alcohol synthesis, methanol and/or DME synthesis are presented. In the FTS reaction on Fe using H₂-rich syngas such as the biomass-derived syngas, the composition of catalyst pretreatment gas and the addition of MnO on Fe had strong impacts on its sulfur resistance as well as activity. Especially the Fe/MnO catalyst pretreated with CO showed a much lower deactivation rate and a higher FTS activity than an Fe/Cu/K catalyst in the presence of H₂S. For C₂₊ alcohol synthesis a novel preparation method was developed for a highly active MoS₂-based catalyst that is well known as the sulfur tolerant catalyst. Besides some metal sulfides were found to show higher CO hydrogenation activities than MoS₂. In particular, both Rh and Pd sulfides were active and selective for the methanol synthesis. Modified Pd sulfide catalyst, i.e. sulfided Ca/Pd/SiO₂, showed an activity that was about 60% of that of a Cu/ZnO/Al₂O₃ catalyst in the absence of H₂S. This catalyst preserved 35% of the initial activity even in the presence of H₂S. The sulfided Ca/Pd/SiO₂ mixed with γ-Al₂O₃ was also available for in situ DME synthesis in the presence of H₂S.