Experimental evidence on molecular interaction in desorption and adsorption of CO molecules on metal surfaces

Adsorption and desorption of CO on Ni(100) and Pt(111) surfaces are presented. At the thermodynamic equilibrium, the site occupation between the terminal and the bridged sites are described with the free energy of the system, including the vibrational entropy. Adsorption of CO onto a cold surface as 20 K has also been studied by infrared reflection absorption spectroscopy (IRAS). The occupation ratio of bridged CO to terminal CO species on Ni(100) at 20 K ranges from ～ 2·8 to 0·7 at the total coverage from 0·003 to 0·15 ML. Such strong coverage dependence of the occupation ratio even at small coverages suggests that the interaction between CO molecules operates at relatively long range (> 10 Å). The isotope experiments suggest that there is substantial interaction between preadsorbed (accommodated) CO species and incoming (mobile) CO species. Desorption process is also affected by the interaction between the adsorbed CO and the incoming species. The effect of temporal bimolecular CO interaction on the desorption kinetics is also discussed.     

Development of confocal laser microscope system for examination of microscopic characteristics of radiophotoluminescence glass dosemeters

A confocal laser microscope system was developed for the measurement of radiophotoluminescence (RPL) photons emitted from a minute alpha-ray-irradiated area in an RPL glass dosemeter. The system was composed mainly of an inverted-type microscope, an ultraviolet laser, an XY movable stage and photon-counting circuits. The photon-counting circuits were effective in the reduction of the background noise level in the measurement of RPL photons. The performance of this microscope system was examined by the observation of standard RPL glass samples irradiated using (241)Am alpha rays. The spatial resolution of this system was ～ 3 μm, and with regard to the sensitivity of this system, a hit of more than four to five alpha rays in unit area produced enough amount of RPL photons to construct the image.     

Measurements of thermal conductivity and thermal diffusivity of alternative refrigerants in liquid phase with a transient short‐hot‐wire method

A transient short‐hot‐wire method has been proposed to simultaneously measure the thermal conductivity and thermal diffusivity of liquids. The method has been applied to the refrigerant HCFC‐22, alternative refrigerants HFC‐32, HFC‐125, HFC‐134a and refrigerant mixtures HFC‐32/125 [35/65, 50/50 (HFC‐410A), 68/32 wt%], HFC‐32/125/134a [23/25/52 (HFC‐407C) wt%]. From the present study, it is shown that the measured results agree well with the literature values on thermal conductivity and those on thermal diffusivity obtained from NIST's thermophysical property database, REFPROP Ver. 6.0. © 2004 Wiley Periodicals, Inc. Heat Trans Asian Res, 33(8): 540–552, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/htj.20032     

Survey of pesticide residues in imported frozen vegetables and fruits (1989.4~2008.3)

A survey of pesticide residues in 595 imported frozen products on the Tokyo market from April 1989 to March 2008 was carried out. Forty three kinds of pesticides, including organophosphorus, organochlorine, carbamate, pyrethroid and others, were detected between levels of trace (below 0.01 ppm) and 4.6 ppm from 162 samples. Chlorpyrifos, cypermethrin and omethoate were frequently detected in green vegetables (komatsuna leaf and spinach), cypermethrin and methamidophos were detected in pods and seeds (green soybean and string pea), chlorpropham (CIPC) was detected in potato, and captan and carbaryl were detected in berries (blueberry, raspberry and strawberry). The hydrophilic pesticide methamidophos was detected in flesh of lychee. Residue levels of these pesticides were calculated as between less than 0.5% and 30% of their ADI values according to the daily intake of frozen products. Therefore, these frozen products should be safe when they were eaten in customary amounts.     

Phase transformation and mechanical properties of si-free CMnAl transformation-induced plasticity-aided steel

Conventional CMnSi transformation-induced plasticity (TRIP)-aided steels are a promising solution for producing lighter, crash-resistant car bodies, due to their high-strength and large uniform elongation. The CMnSi TRIP-aided steels, with more than 1 mass pct Si, have the drawback of poor galvanizability due to the presence of complex Si-Mn oxides on the surface. The full substitution of the Si by Al in cold-rolled and intercritically annealed TRIP-aided steels, therefore, was evaluated in detail. The phase-transformation kinetics during the intercritical annealing and the isothermal bainitic transformation were investigated by means of dilatometry. The allotropic phase-boundary was determined both by thermodynamic calculations and the experimental determination of the C content in the retained austenite. The results imply that short isothermal bainitic transformation times are sufficient to obtain the TRIP microstructure and that the processing of CMnAl TRIP-aided steels in a continuous annealing line not equipped for overaging is possible. The mechanical properties were evaluated for CMnAl TRIP-aided steels obtained using an industrial thermal cycle: the properties matched those of the conventional CMnSi TRIP-aided steels, where it was found that the high-Al CMnAl TRIP-aided steel had a high strain-hardening coefficient of 0.25, which was stable up to a true strain of 0.25. on leave from the Yawata R&D Laboratory, Nippon Steel Corporation, Tobihata-cho, Japan. S. CLAESSENS, Product Research Manager, is with OCAS NV, Research Centre of the Sidmar Group, ARBED Group Flat Rolled Products Division, B-9060 Zelzate, Belgium.     

SDH network evolution in Japan

NTT has entered the second phase of its deployment of synchronous digital hierarchy (SDH)-based transmission systems, with a primary focus on creating a more reliable network with lower costs and improving network operation systems for these SDH-based network elements. This article describes the evolution of NTT's network from a plesiochronous digital hierarchy (PDH)-based network to an SDH-based network. First, we see the evolution from a network element point-of-view. Then, we focus on the network operation system, which has been unified to achieve flow-through operation     

Electrostatic fluctuation measurements in the periphery of reversed field pinch plasma

In this paper, the authors study the magnetic and electric properties of ferromagnetic substance/semimetal (Fe/Bi) system multilayered thin films prepared by ion beam sputtering. The multilayered thin film was prepared with 99.6% Fe and 99.99% Bi. The experimental results are summarized as follows. From XRD in the small‐degree region (2θ = 2 to 4^°), Fe/Bi system thin films for N = 3,4, and 5 Fe layers have formed multilayer structures. Coercive force H_c increased with increasing number of Fe layers. The maximum value was 4.522 kA/m at N = 6 Fe layers. The coercive force then decreased and its value was constant at more than 15 layers. Electrical resistivity, ρ, of Fe/Bi system multilayered thin films changed from conductivity to semiconductivity at temperatures in the range for T = 380 to 400 K. Magneto‐resistance (MR) ratio decreased with increasing applied field H when the current was parallel to an applied magnetic field (I‖H). MR ratio reached a maximum of 0.154% at N = 4 Fe layers at room temperature. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 151(1): 1–8, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20068     

Differences in cardiovascular mortality rates among hemodialysis patients in the United States and Japan: The importance of background cardiovascular mortality

Mortality rates among hemodialysis patients differ greatly among the United States, Europe, and Japan and it has been hypothesized that this is mainly due to differences in practice patterns. Results from the international DOPPS study, however, indicate that differences in practice patterns among the United States, Japan, and Europe are small and not alone explanatory for the differences in mortality rates. Ethnic variability in predisposition to atherosclerotic cardiovascular disease in the general population may lead to significant differences in background cardiovascular mortality in the United States, Japan, and Europe. It is our hypothesis that cardiovascular mortality in dialysis patients is to a great extent dependent on cardiovascular background mortality of the general population. We are currently studying the relationship between all‐cause and cardiovascular death rates in countries worldwide using the WHO database. Preliminary data from 35 countries show that all‐cause and cardiovascular death rates differ significantly among regions, with Eastern European countries reporting four‐ to sevenfold higher death rates than Asian countries. A strong linear relationship between cardiovascular and all‐cause death rates is observed among these countries. The next step of our study will be to compare country‐specific cardiovascular death rates of dialysis populations with those of the respective general populations. Ethnic differences in cardiovascular morbidity and mortality may be explained by genetic variability based upon polymorphism of genes involved in the pathogenesis of atherosclerosis and myocardial infarction.     

细化钢铁材料晶粒的原理与方法

细化晶粒是控制金属材料组织结构的最重要、最基本的方法，目前，实际应用的成块材料可获得的最细的铁素体晶粒约为5μm。获得细晶粒的方法有利用相变和再结晶的热处理（或形变热处理），钢液超速冷却，机械合金化，超细粒子烧结和非晶体结晶等。形变热处理对晶粒细化极为有效，已以实验室规模获得了具有小于或等于1μm的超细晶组织的成块材料。本文以形变热处理为中心，介绍了控制轧制、加速冷却的形变热处理（TMCP），以及形成微细双相组织、亚晶大角度化等细化晶粒的方法，从金相学角度阐述了细化晶粒的原理和方法的现状及最新进展。     

Optimizing three-dimensional gadolinium-enhanced magnetic resonance angiography. Original investigation

RATIONALE AND OBJECTIVES: This primarily theoretical work examines three-dimensional gadolinium-enhanced magnetic resonance angiography f8p4Gd-MRA) with the goal of understanding how to achieve the best possible images with respect to signal to noise ratio (SNR) and k-space induced artifacts. Patient variables, contrast injection schemes, and pulse sequence parameters are considered for this purpose. METHODS: A theoretical analysis, including computer simulation, describes how contrast material injection profiles influence 3D Gd-MRA images, both in terms of intravascular signal and resultant artifacts. Further theoretical analysis of the spoiled gradient refocused pulse sequence describes how to maximize SNR. Clinical imaging complements computer modeling. RESULTS: Equations were derived relating contrast injection parameters and pulse sequence variables to SNR and artifacts. For present imaging equipment, administering contrast material over a duration of 60% to 80% of the total imaging time and using fractional echo techniques gives the best SNR without significantly sacrificing image quality. CONCLUSIONS: Three-dimensional Gd-MRA can be tailored to a specific clinical situation and imaging system through the use of proper breath-holding, bolus timing, Gd administration, and pulse sequence design.