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Summary Background & aims The associations between dietary magnesium intake and stroke and coronary heart disease (CHD) incidences are inconsistent and not established in Asian. We aimed to determine the association between dietary magnesium intake and the risk of stroke and CHD in a Japanese population. Subjects/Methods We studied 85,293 Japanese subjects by questionnaire at baseline (age 45–74 years, without cardiovascular disease or cancer in 1995 and 1998 for Cohorts I and II, respectively). The participants were followed until the end of 2009 and 2010 in Cohorts I and II, respectively. Dietary magnesium intake was estimated from a self-administered 138-item food-frequency questionnaire. Results After 1,305,738 person-years of follow-up, 4110 strokes and 1283 cases of CHD were documented. The multivariable-adjusted hazard ratios (HRs, 95% confidence intervals, 95%CIs) of CHD for the fourth and fifth quintiles of dietary magnesium intake were 0.70 (0.50–0.99) and 0.66 (0.44–0.97) in men (P for trend = 0.036), respectively, and third quintile of dietary magnesium intake was 0.61 (0.39–0.96) in women (P for trend = 0.241), compared with the lowest quintile in men and women. We observed no decreased risks of incident stroke in men or women with higher dietary magnesium intakes. Conclusions Higher dietary magnesium intake was associated with a reduced risk of CHD in Japanese men.

Published data on Factor C activity at various LPS and Lipid A concentrations (Nakamura et al. in Eur J Biochem 176:89, 1988; Kobayashi et al. in J Biol Chem 37:25987, 2014) were rearranged to show that Factor C exhibited its maximum activity at a specific concentration of LPS. A statistical model was proposed for examining whether a single LPS molecule binding activates Factor C (monomeric activation) or dimerization of Factor C is necessary for the activation (dimeric activation). In the monomeric activation model the plots of the relative activity of Factor C against the molar ratio of LPS to Factor C were different from those in the published data. The plots in the dimeric activation model lie on a bell-shaped curve, whatever the Factor C concentration, matching the published data and indicating the appropriateness of that model. We suggest that Factor C is activated by multiple molecular interactions of Factor C with LPS aggregates on which it dimerises and that this explains why larger aggregates are less effective at activating Factor C than smaller ones.

The crystallization behaviors of safflower and olive oils were investigated according to changes in volume and transmitted light intensity during isothermal storage at low temperature. The changes between the oils were significantly different even though their fatty acid compositions were similar, with oleic acid accounting for more than 75% (w/w) of the total oil. It was expected that minor components with high melting points would affect the crystallization behaviors of these oils. The crystallization processes of the oils were then analyzed using a kinetic model in which the oil crystallizes through two different processes. It is suggested that although the crystallization behaviors were apparently different, the crystallization mechanisms of these oils are essentially the same. Se estudiaron los comportamientos durante la cristalización de aceites de cártamo y oliva en función de los cambios en el volumen y la intensidad de la luz transmitida durante el almacenamiento isotérmico a baja temperatura. Los cambios fueron significativamente diferentes entre los dos aceites, aunque su composición en ácidos grasos era similar, con el ácido oleico en una proporción superior al 75% (p/p). Se esperaba que los componentes menores con altos puntos de fusión afectarían a los comportamientos de cristalización de estos aceites. Los procesos de cristalización de los aceites se analizaron utilizando un modelo cinético en el que el aceite cristaliza a través de dos procesos diferentes. Se sugiere que, aunque los comportamientos de cristalización fueron aparentemente diferentes, los mecanismos de cristalización de estos aceites serían esencialmente los mismos.

ery and prevention of early breakthrough. From CCUS point of views, the delay of gas breakthrough has a significant advantage in underground storage of industry-originated CO2. The reviews highlighted that various types of nano-additives have been investigated to develop further advanced foam technology. Key points to be focused on are how achieving more robust foam stability. Even a conventional CO2 foam generated with surfactant agents might be deteriorated in short period, those additives can extend foam half-life time. As additives, the recent researches have paid attention to nano-particles, polymer, viscoelastic surfactant, etc. The investigation measured half-life, viscosity, and differential pressure in core flood as key performance indicators. In addition, “high temperature (HT)” and “high salinity (HS)” are keywords in their researches. Namely, screening criteria of experimental conditions are aiming to more harsh conditions. However, the reviewed reports have not covered up to our target conditions in typical Middle East region. Thus, we have been concentrating to develop nano-additive enhancing CO2 foam technology in HTHS.

CO2 enhanced oil recovery (EOR) has been commercially applied all over the world to produce more oil. The CO2 function is to attain minimum miscibility pressures at reasonably low pressure compared with reservoir pressure. This generates CO2 miscible flooding leading to more preferable oil recovery. Even under such a preferable condition, 100% oil recovery is rarely seen in laboratory experiments: coreflood and slimtube tests. However, compositional simulation of gas-injection sometimes predicted zero oil saturation in certain grids. To decrease a gap between practical and numerical phenomenon, Hiraiwa et al. (2007) developed a method of incorporating residual oil saturation obtained in laboratory coreflood experiments. The concept of Sorm was defined as the residual oil saturation that did not decrease less than user-prescribed values. To evaluate CO2 EOR more practically, the laboratory results were used to estimate Sorm in core scale for numerical modelling. This paper presents extensive laboratory results of unsteady state oil displacement by 15PV CO2 much more than usual CO2 coreflood experiments of 2-3 PV. By properly considering such on-site reality into account for laboratory core flooding design, a core scale Sorm can be obtained. Based on the Sorm, CO2-penetrating pore throat size was discussed in this study.

Aims Coping strategies may be significantly associated with health outcomes. This is the first study to investigate the association between baseline coping strategies and cardiovascular disease (CVD) incidence and mortality in a general population cohort. Methods and results The Japan Public Health Center-based prospective Study asked questions on coping in its third follow-up survey (2000–04). Analyses on CVD incidence and mortality included 57 017 subjects aged 50–79 without a history of CVD and who provided complete answers on approach- and avoidance-oriented coping behaviours and strategies. Cox regression models, adjusted for confounders, were used to determine hazard ratios (HRs) according to coping style. Mean follow-up time was 7.9 years for incidence and 8.0 years for mortality. The premorbid use of an approach-oriented coping strategy was inversely associated with incidence of stroke (HR = 0.85; 95% CI, 0.73–1.00) and CVD mortality (HR = 0.74; 95% CI, 0.55–0.99). Stroke subtype analyses revealed an inverse association between the approach-oriented coping strategy and incidence of ischaemic stroke (HR = 0.79; 95% CI, 0.64–0.98) and a positive association between the combined coping strategy and incidence of intra-parenchymal haemorrhage (HR = 2.03; 95% CI, 1.01–4.10). Utilizing an avoidance coping strategy was associated with increased mortality from ischaemic heart disease (IHD) only in hypertensive individuals (HR = 3.46; 95% CI, 1.07–11.18). The coping behaviours fantasizing and positive reappraisal were associated with increased risk of CVD incidence (HR = 1.24; 95% CI, 1.03–1.50) and reduced risk of IHD mortality (HR = 0.63; 95% CI, 0.40–0.99), respectively. Conclusion An approach-oriented coping strategy, i.e. proactively dealing with sources of stress, may be associated with significantly reduced stroke incidence and CVD mortality in a Japanese population-based cohort.

Background and aims Higher intake of fish or n-3 polyunsaturated fatty acids (PUFAs) has been associated with reduced risk of coronary heart disease (CHD). However, it is unclear whether increased blood levels of n-3 PUFAs are associated with reduced risk of CHD in the Japanese population. Methods The relationship between circulating levels of n-3 PUFAs (eicosapentaenoic acid + docosapentaenoic acid + docosahexaenoic acid) and risk of CHD was examined in a nested case-control study among participants in the Japan Public Health Center (JPHC)-based Study Cohort. Plasma n-3 PUFA phospholipid levels were measured at baseline by gas chromatography in 209 cases with CHD and 418 controls matched for sex, age, date of blood draw, time elapsed since last meal before blood collection, and study location. The CHD cases (n = 209) comprised 168 cases of myocardial infarction and 41 of sudden cardiac death, otherwise classified as 157 non-fatal and 52 fatal coronary events, respectively. Mean duration of follow-up was 13.5 years. Results Multivariate conditional logistic analysis showed no significant association between n-3 PUFAs and risk of total CHD. The odds ratio (OR) for the highest versus lowest quartiles of plasma n-3 PUFAs was 0.79 (95% confidence interval [95% CI]: 0.41–1.51, p for trend = 0.51). Subtype analysis of CHD revealed that the multivariate ORs for the highest versus lowest quartiles for n-3 PUFAs were 0.91 (95% CI: 0.43–1.89, p for trend = 0.90) for myocardial infarction, 0.08 (95% CI: 0.01–0.88, p for trend = 0.04) for sudden cardiac death, 0.89 (95% CI: 0.42–1.89, p for trend = 0.97) for nonfatal coronary events, and 0.12 (95% CI: 0.02–0.75, p for trend = 0.03) for fatal coronary events. Conclusions Plasma n-3 PUFA levels were not associated with risk of total CHD but were inversely associated with risks of sudden cardiac death and fatal coronary events among middle-aged Japanese individuals.

Seafood/fish intake has been regarded as a protective factor for coronary heart disease (CHD), while smoking is a strong risk factor. To examine whether associations between smoking and risk of CHD are modified by seafood/fish intake, we studied 72,012 Japanese men and women aged 45-74 years who completed 2 food frequency questionnaires, 5 years apart, during the period 1995-2009. After 878,163 person-years of follow-up, 584 incident cases of CHD (101 fatal and 483 nonfatal), including 516 myocardial infarctions, were documented. There was a clear dose-response association between smoking and CHD risk among subjects with a low seafood/fish intake (

The aim of this study was to evaluate the effects of intra-arterial administration of edaravone after superior mesenteric artery (SMA) thromboembolism in a rabbit model. 24 Japanese white rabbits were randomly allocated to a urokinase group (group U) and a urokinase with edaravone group (group E). A further three rabbits, which were administered an autologous blood clot alone, served as a control group (group C). A 4-Fr sheath was inserted into an SMA. An autologous blood clot was administered to an SMA (group C). After 45 min, urokinase (6000 IU) and heparin (250 IU) were administered through the catheter, either alone (group U) or in conjuction with edaravone (0.5 mg kg(-1)) (group E). In eight rabbits from each of groups U and E, 6 h after reperfusion, the small intestine was harvested and divided into five equal parts. The degree of intestinal tissue injury in each part was rated on a scale of 0-8. After 1 week, survival times and blood biochemistry data were compared among rabbits in group U (four rabbits), group E (four rabbits) and group C (three rabbits), and significant differences (p0.05) were recorded. Intestinal mucosal damage was significantly greater in group U (5.8 +/- 1.5) than in group E (2.9 +/- 0.7). Survival time tended to be longer in group E (p0.4, not significant compared with group U). Liver and kidney function showed signs of deterioration over time whether or not edaravone was administered, but administration of edaravone reduced intestinal mucosal damage. An increase in survival rate requires improvements in evaluation methods to enable identification of ischaemic areas.

New materials often force modification in a metal–oxide–semiconductor field-effect transistor (MOSFET) fabrication process and a device structure. In our investigation, a high-stress silicon nitride (SiN) contact etch stopper layer (CESL), which improves device performance by straining the Si lattice, was used as the modified structure. A portion of its gate surround was cut to fabricate a fully silicided (FUSI) metal gate. FET characteristics of a polycrystalline silicon (poly-Si) gate and a Ni-FUSI gate MOSFET with a discontinuous CESL were compared with those of a poly-Si gate MOSFET with an ordinary continuous CESL for several SiN-stress conditions. It was found that the removal of a gate-top CESL diminishes mobility modulation effects of a high-stress CESL. It was also demonstrated that stress due to a FUSI gate compensates the effect of gate-top CESL removal. Mobility enhancement utilizing a high-stress SiN film was still effective for a FUSI gate process.

The plasma behavior around multiple objects has been simulated for the case of plasma immersion ion implantation (PIII) using the particle-in-cell module of the software “PEGASUS”. Simulations were performed for three types of negative pulse voltage application methods to the objects: (A) a single negative voltage pulse, (B) a negative voltage pulse after a negative voltage pulse, (C) a negative voltage pulse after a positive voltage pulse. The chamber wall was grounded. A cylindrical coordinate system was used. Effects of gas pressure and secondary electron emission by ion impact on the plasma (especially on the density and sheath shape) were studied. The gases were N 2 gas and C 2 H 2 gas. The time evolution of the spatial distribution of densities of electrons, N 2 + ions, N 2 ⁎ radicals, and N atoms in the N 2 plasma, and C 2 H 2 + , C 2 H 2 2+ , C 2 H + , CH + , H + , C 2 H 2 , C 2 H, CH 2 , CH, H in the C 2 H 2 gas plasma, was obtained. The time evolution of flux and energy distribution of electrons and ions at the object surface were also obtained. These results were compared for three types of pulsed voltage application methods, and it was concluded that the C-type was superior for obtaining conformal plasma at the objects.

In the present study, the thermal stability and tribological properties of silicon-incorporated diamond-like carbon (DLC) films were investigated. The DLC films were deposited using a bipolar-type plasma based ion implantation and deposition (PBII&D) technique, and the Si contents in the films were varied from 0 to 29 at.%. The deposited DLC films were annealed at 500 °C for 30 min in ambient air. The structure and mechanical properties of the Si-DLC films with a high Si content (≥ 21 at.%) were not affected by the thermal annealing. The 21 at.% Si-DLC film annealed at 500 °C shows low wear as well as low friction, whereas the 29 at.% Si-DLC film exhibited a high friction due to the creation of cracks on the worn surface related to the SiC-like nature. The 11 at.% Si-DLC film annealed at 500 °C shows the lowest friction coefficient at the cost of significant wear in the graphitized film. The formation of a thick silicon oxide layer on the Si-DLC film could be favorable for low friction and wear.

Diamond-like carbon (DLC) films were prepared on Si substrates using a variety of positively and negatively pulsed voltages ( V p and V n ), by a bipolar-type plasma based ion implantation system, and adhesion strength and toughness of the samples were examined in terms of the higher critical load ( L c2 ) and the scratch crack propagation resistance (CPRs) by a micro-scratch test. Cross sectional transmission electron microscopy (TEM) and Raman spectroscopy were also carried out to examine the microstructure of the samples. The L c2 and CPRs were increased by increasing V p and V n . TEM observation showed that a graphite-like form, such as turbostratic structure, is increased by increasing V p and V n . Raman spectra also indicated that the clustering of aromatic rings is enhanced at high V p and V n . From these results, it is suggested that the increase of the graphite-like form at high V p and V n should reduce the internal stress. In addition, it may act as a lubricant, resulting in the enhancement of the adhesion strength and the toughness of the films. The I D / I G obtained from Raman spectra measured at the different points of the pre-scratched region, the cracking region and the partial destruction region was varied, and a tentative explanation was made on the basis of a 3 stage model.

Some research has been carried out on DLC coating of inner walls of PET bottles because the DLC coating can reduce the oxygen transmission rate through the wall of the bottles drastically. Existing techniques for DLC formation on the inner wall of PET bottles require rather complicated coating systems. In this study, we propose a simple way to coat DLC on the inner walls using a modified PBII technique. The configuration is that the outer wall is covered by an outer electrode connected to a grounded vacuum chamber and an inner electrode, which is connected to a positive high voltage pulsed power supply, is inserted inside the bottle. In the coating process, the bottle is filled with C 2 H 2 gas at a suitable pressure. Using this approach we have succeeded in coating DLC on the inner walls of bottles. Oxygen and nitrogen gas transmission rates were examined for 20-s, 1-min and 5-min coating times on 50-μm thick PET films. We found that the DLC coatings reduce the rates drastically, and a 1-min coating time is enough to form a gas barrier. The results of micro-scratch tests for the DLC-coated PET films show good adhesion of the DLC coating and reduction of friction. The Meyer hardness and Young's modulus of the DLC-coated PET films were also estimated from the penetration depth–load relationship obtained by a depth sensing indenter with a diamond spherical indenter 200 μm in radius. It is revealed that for the 5-min coated film the apparent Meyer hardness at 5-mN load and Young's modulus were about 1.4 and 1.2 times larger than those of the uncoated film, respectively.

Diamond like carbon (DLC) films were prepared by the bipolar-type plasma based ion implantation, and the microstructure was examined as a function of positively and negatively pulsed voltages (Vp and Vn) by transmission electron microscopy (TEM) and Raman spectroscopy. Densities of the films were obtained from Rutherford backscattering spectrometry, elastic recoil detection analysis and surface profilemeter measurements. It was found that the density of the film was approximately 2.0 g/cm3 and slightly decreased with increasing Vp and Vn. TEM observation revealed that DLC films were amorphous structure and small size disordered graphite structure appeared as Vp increased. With increasing Vn, however, turbostratic structure was clearly developed. Raman spectra were fitted by 4 peaks (D1: 1190 cm− 1, D2: 1380 cm− 1, G1: around 1550 cm− 1 and G2: 1590 cm− 1). The G1 peak shifted to higher wave numbers and the intensity of G2 peak was increased with increasing Vp. In addition, the intensity ratio of D (D1 + D2) to G (G1 + G2) peaks was also increased. These results suggested that graphite structure was formed as Vp increased. With increasing Vn, on the other hand, the G1 peak did not shift so much and the intensity of G2 peak was decreased. This corresponds to the development of the turbostratic form (t-DLC). The influence of electron and ion bombardment induced by Vp and Vn on the microstructure was discussed.

Silicon incorporated diamond-like carbon (DLC) films were deposited using a bipolar-type plasma based ion implantation technique, and the effect of the positive pulse voltage on the thermal stability of the DLC films was investigated. The positive pulse voltage was varied from 2.0 to 6.3 kV while the negative pulse voltage was maintained at − 5.0 kV. The deposited DLC films were annealed in air for 1 h at constant temperatures of 500 and 600 °C. As a result, an optimum positive pulse voltage exists for the high deposition rate and thermal stability of the DLC films, which correlates with the surface temperature during the film deposition. The DLC film deposited at a positive pulse of 4.0 kV, whose surface temperature during deposition was 300 °C, showed a typical DLC Raman spectrum even though the annealing temperature increased to 600 °C, and exhibited good friction properties. This high thermal stability is attributed to the effect of pre-annealing during the deposition and the formation of a stable and thick silicon oxide layer on the DLC surface when annealed in air. On the other hand, the thermal stability of the DLC film deposited at 2.0 kV, whose surface temperature during deposition was 150 °C, quickly deteriorated when the film was annealed at 600 °C.

The relationship between the minority carrier lifetime and bulk defects and between this lifetime and the interface states due to 2 MeV electron irradiation were investigated using deep-level transient spectroscopy (DLTS) and the charge separation technique, respectively. There seems to be a correlation between the change in lifetime and the interface traps generated due to electron irradiation. For the same level of interface trap density after a fluence of 1×1014 e/cm2 electron irradiation due to Fowler–Nordheim (FN) high electric field stress, the lifetime did not changed. Due to the creation of a deeper state, which is probably a defect including V2 and H with increasing electron fluence, the lifetime decreases further. It is thought that the Si–H bonds at the Si–SiO2 interface are broken and dissociated hydrogen is introduced in the silicon bulk during the electron irradiation.

The plasma behavior inside of a PET bottle has been simulated under the condition of plasma immersed ion implantation and deposition (PIII&D) using the simulation software “PEGASUS”. The software uses the “PIC–MCCM” module for the plasma analysis and the “DSMCM” module for the gas flow field analysis. DSMCM gives densities, velocities, fluxes, temperatures and pressures of each neutral species such as the fed gas species and radicals. By coupling PIC–MCCM with DSMCM simulation, the plasma behavior in the flowing Ar gas and N2 gas has been simulated. The gas was injected from the tip of the gas inlet which was inserted into the center of the bottle. The base gas pressure was 1–50 Pa and a positive pulse voltage (maximum voltage = 0.1–1 kV) was applied to the center rod. A two-dimensional cylindrical coordinate system was used. Time evolution of the spacial distribution was obtained for densities of electrons, N 2 + ions, N 2 ∗ radicals and N atoms in N2 gas, and Ar+ ions, Ar∗ and Ar∗(4s) radicals in Ar gas. Time evolution of the particle flux and the energy flux of electrons and ions on the target surface was also obtained.

Plasma behavior inside of a PET bottle together with the gas flow has been analyzed under plasma-based ion implantation (PBII) conditions. The software "PEGASUS" with the cylindrical coordinate system was used for the simulation. PEGASUS uses the particle-in-cell (PIC) method for the movement of charged particles in the electromagnetic field and the Monte Carlo method for collisions of ions, electrons, and neutrals in the plasma in a low-pressure gas. The gas flow is analyzed by the Monte Carlo method. It gives spatial distributions of densities, velocities, fluxes, temperatures and pressures of each neutral species. The plasma simulation was coupled with the gas flow simulation, and the plasma behavior in the flowing N 2 gas was analyzed. The gas pressure was 10 and 50 Pa; a positive pulse voltage (maximum voltage = 500 V) was applied to the center rod from where the gas flows. Time evolutions of spatial distributions of the potential and the densities of ions, electrons and radicals in the coating system were obtained together with the flux of ions and electrons on the target surface.

A high-density plasma is generated inside a cylindrical target as a result of the hollow cathode discharge effect under a proper condition. The hollow cathode discharge plasma can be applied to the inner coating of the target. In order to analyze the plasma behavior near a cylindrical target, simulations have been carried out using the simulation software “PEGASUS” with a cylindrical coordinate system. The gas pressure was 0.1–600 Pa and a negative pulse or DC voltage (−30 eV∼−20 kV) was applied to the target. RF (13.56 MHz) and a superposed voltage of DC and RF were also applied. Effects of gas pressure, secondary electron emission coefficient, and length and inner diameter on the plasma generation were studied, and Paschen-like curves for a hollow cathode discharge were obtained for both centimeter-sized and millimeter-sized pipes. Plasma generation in the surroundings of a pipe with a grounded rod on the axis was also simulated. It was found that a hollow cathode discharge plasma works only for a short pipe of length vs. diameter less than 5. For a pipe of higher aspect ratio, a glow discharge plasma between the inside wall and a rod on the axis works well regardless of the length.

Diamondlike carbon (DLC) has been well known as a very hard and very low-friction material. The most critical issue of DLC is to improve its adhesion. To improve the adhesion, some other elements, such as Si, have been included in DLC films. We have studied the effects of Si content on friction and wear properties of DLC films made by our bipolar pulse PBII system. The content of Si was changed by varying the flow rates of tetramethylsilane (TMS) from 0.0 to 3.5 sccm while the flow rate of toluene and the total pressure was kept constant. Friction coefficients (FCs) were measured with a JIS-SUJ2 (AISI 52100) ball of 3-mm diameter. The length of sliding was 2 mm, the speed was 10 mm/s, and the load was 4.9 N for 40-min tests. Without TMS flow, the friction coefficients (FCs) were the largest, 0.35, and the DLC film came off easily. With the increase of TMS flow up to 1.0 sccm, the FC decreased to 0.14, and there was almost no peeling off. For 2.0 sccm, the FC was 0.18, and there was a lot of debris on the DLC surface. Hardness gradually decreased with the increase of TMS flow up to 1.0 sccm, and it decreased drastically for high flow rates or high Si content. Internal stress (compressive) of the films decreased with the increase of TMS flow. Si content in the film corresponded almost linearly to the TMS flow rate. One to two percent of Si doping is very suitable for improving the adhesion of films and reducing internal stress while maintaining the surface hardness of DLC films.

In order to analyze the plasma behavior in the plasma immersion ion implantation and deposition (PIII&D) process, a simulation has been carried out using the simulation software “PEGASUS”. The software uses a particle in cell method for the movement of charged particles in the electromagnetic field and a Monte Carlo method for collisions of ions, electrons, and neutrals in the plasma. The spatial distributions of potential, density, average temperature, velocity and flux of ions and electrons in the surroundings of a trench shaped target and a cylindrical target which is immersed in Ar plasma have been calculated together with the flux of ions and electrons on the target surface. The gas pressure was 0.01–600 Pa and a negative pulse, DC, RF, and RF+DC voltage (up to −20 kV) was applied to the target. The time dependence of the sheath length on the outer surface of the target agreed with the analytical values obtained by the Child–Langmuir method. In order to show the effectiveness of a bipolar pulse PIII/D process, a glow discharge plasma generation by a positive and a negative pulse voltage (± kV) application to a target were simulated and compared. The plasma generated by a positive pulse voltage was about two orders more intense than a negative pulse voltage. Furthermore, a hollow cathode discharge plasma can be applied to the inner coating of the target. The effects of gas pressure, secondary electron emission coefficient, and the length and the inner diameter of target on the plasma generation in the surroundings of a cylindrical target were studied. Paschen-like curves for a hollow cathode discharge were obtained for both centimeter-size pipe and millimeter-size pipe.

In order to analyze the plasma behavior under the plasma immersion ion implantation and deposition (PIIID when a negative pulse voltage is applied to a target, a weak plasma is generated around the target. In contrast, when a positive pulse voltage is applied, a more intense plasma is generated under the same conditions. The results obtained by simulation of the behavior of ions and electrons near a trench-shaped target are presented.

Four ring-probes were pasted on the inner surface of a pipe via an insulator sheet and the ion current was separately measured at each position by applying a negative pulse voltage in order to obtain the current distribution on the inner wall of the pipe, which was immersed in a cathodic arc plasma with a current of 80 A dc produced in a nitrogen gas at a pressure of 8 Pa. The probe current inside the pipe decreases rapidly, because the ion sheath thickness increases with time to arrive at the center of the pipe, which causes extinction of the plasma during the application of the pulse voltage to the pipe. Not only multiple setting of the arc sources but also the operation of a high frequency with a short pulse duration are necessary to realize a uniform treatment by a cathodic arc plasma-based ion implantation and deposition.

We have applied dynamic Monte Carlo simulations to the synthesis of a-C:H films by PBII. Like our previous model, we assumed a surface reaction layer consisted of one or two monolayers of a-C:H, in which very low threshold displacement energies are used, so atoms are knocked on by the collisions with energetic ions much easier than in the bulk substrate. Only atoms with energy higher than the barrier can penetrate into the subsurface. The change from the previous model is in the treatment of sp 3 state forming. Our new model is based on the subplantation model proposed by J. Robertson [1] . The sp 3 state formation was assumed resulted from the density increase. In the subsurface, among the penetrated C atoms, only atoms with low energy which is not enough to induce collision cascade form sp 3 state together with the surrounding C atoms and the other C atoms with higher energy form sp 2 state because of the density relaxation induced by the dense collision cascades. In addition to the above assumption, release of the displaced H atom after the subsequent collision cascade is assumed. The calculation is centered on how the sp 3 fraction and the H concentration, and the growth rate depend on the incident energy, the ion/neutral ratio, threshold energy of sp 3 formation. The energy dependence obtained for both sp 3 fraction and H concentration agreed well with the experimental data.

Amorphous alumina films, approximately 600 nm in thickness, prepared on Si(100) substrates by RF magnetron sputtering were irradiated with 2.0 MeV Si + ions at a dose of 1×10 17 ions/cm 2 and the influence on the composition, microstructure, and mechanical properties was examined by Rutherford backscattering, X-ray diffraction and nano-indentation measurements. It was found that the O/Al ratio in the films was approximately 1.5, and there was no significant alteration in this ratio after ion irradiation. However, a structural change from amorphous to the crystalline γ-alumina was observed. Hardness and elastic modulus of the irradiated film were significantly increased from approximately 11 and 181 GPa up to approximately 25 and 246 GPa, respectively.

A computer code, ‘Simulation of Atom Scattering in Amorphous MAterials based on Liquid model (dynamic-SASAMAL)’ has been developed to simulate the dose dependence of composition profile and sputtering yield of a non-crystalline target under ion implantation, which uses the binary collision model. Among many kinds of binary collision programs, the program TRIM and its derivatives have spread widely. In addition, there are some TRIM derivatives that can treat the dose dependence, i.e. TRIDYN and EVOLVE. However, these dynamic programs are not so obtainable as TRIM. Authors have studied many dose-dependent phenomena under ion implantation by the dynamic-SASAMAL code. Recently, we made the code easy to operate. At first, by using the periodic table, we are requested to input the atomic number of the implanted ion species and the target structure, the number of layers, and the maximum dose and the dose step. After the first calculation, if we need to continue the calculation by changing the energy or the ion species, we can. During the calculation, the depth profiles of atomic composition, vacancies and interstitial atoms, and the angle dependence of number and energy of sputtered atoms are shown on the display. We can set the concentration limit for a high-dose implantation of a reactive ion to a metal, such as 50% for N implantation to Ti. The outline of the software is presented together with the dose-dependent phenomena, which have been studied by using the dynamic-SASAMAL.

Dynamic Monte Carlo simulations have been applied to the synthesis of diamond-like carbon films by plasma-based ion implantation (PBII). The direct chemical incorporation of the radicals, like CH 3 reacting with a diamond surface, is too low for the deposition of DLC films, so that the other reaction mechanisms should be responsible. We assumed a surface reaction layer consisted of several radical layers, in which radicals are dissociated by the collisions with energetic ions and some H and C atoms are released out and some H and C atoms are stitched into the subsurface and the stitched C atoms are assumed to form the sp 3 states. In the subsurface, it was assumed that sp 3 states atoms are released to the sp 2 state and H atoms are released out of the surface as a results of collision cascades induced by the energetic ions. The following was obtained by the simulation: the C atom stitching probability, which related with sp 3 state formation, has a maximum of near 500 eV independent of the dissociation energy of radicals, number of monolayers in the surface reaction layer, or ion/radical arrival ratio. It agrees with the experimental result. The stitching probability increases with the decrease of the dissociation energy and the increase of number of monolayers in the surface reaction layer and ion/radical ratio. The H concentration shows a maximum of near 300 eV. It also agrees with the experimental result.

Plasma based ion implantation (PBII) with bipolar pulses has been proposed to improve a dose uniformity in an ion implantation on a three-dimensional target. A pulsed glow discharge plasma is produced around the target by a positive pulse at a gas pressure less than ∼0.5 Pa, and then ions are implanted into the target from all sides by the subsequent negative high-voltage pulse. It has been shown that ions produced by the positive pulse have been implanted effectively with the negative pulse. The PBII with bipolar pulses is applied to DLC coatings. A carbon mixing layer in the substrate surface is formed by the implantation to improve the adhesion of DLC films. Internal stress of DLC films slightly decreases with increasing frequencies of positive pulse. Moreover, it is shown that the PBII with bipolar pulses is possible to use for inner coating of DLC films on a stainless-steel pipe.

Sapphire (0 0 1) substrates were implanted with 1.0 MeV O ions and 2.1 MeV Cu ions and subsequently annealed at different temperatures in vacuum, and recovery of radiation damage and redistribution of Cu in the sapphire substrate were examined by Rutherford backscattering spectrometry measurements with channeling technique. In addition, the formation of copper oxide nanoparticles has also been examined by X-ray diffraction (XRD) measurements. It is found that radiation damage in the sample is almost retained up to 800 °C. Further increase of annealing temperature causes significant recovery of radiation damage. Concurrently, annealing temperatures higher than 800 °C cause the enhancement of Cu diffusion. The results of XRD measurements show that nanoparticles are grown above 800 °C. These results suggest that the recovery of radiation damage gives rise to the redistribution of Cu and the formation of copper oxide nanoparticles.

Amorphous strontium titanate (STO) films deposited on Si substrates by magnetron sputtering at room temperature were irradiated with 2 MeV Si ions at doses of 5×10 16 –1.5×10 17 Si + /cm 2 and post-annealed at 450 °C in vacuum. The compositional and structural changes of STO films after the ion irradiation were examined by Rutherford backscattering spectrometry, scanning electron microscopy and X-ray diffraction measurements. The Sr:Ti:O ratio of the as-deposited films was found to be approximately 0.8:1:3. Ion irradiation did not affect the amount of Sr and Ti significantly and the films remained amorphous. After annealing, however, the formation of STO crystals was observed and Sr and O were slightly lost from the films. As compared to the un-irradiated STO films, the ion-irradiated ones showed significantly enhanced crystallization behaviors upon vacuum annealing.

We have simulated off-lattice 2-dimensional diffusion-limited aggregation (DLA) and have made the growth of the DLA discrete by introducing a discrete time, defined as the time when a new longer branch appears for the first time. From our analysis, we have found that the fractal dimension of DLA can be represented by log 2/ log (3/2)=1.71 . This result implies that the contraction rate of 2-dimensional DLA is 2/3.

Amorphous alumina films prepared on Si(1 0 0) substrates by RF magnetron sputtering were irradiated with 1.0 MeV Si + ions at different doses of 5×10 16 –1.5×10 17 ions/cm 2 . The structural changes of the films were examined by Rutherford backscattering spectrometry, atomic force microscopy and X-ray diffraction measurements. It was found that the ratio of O and Al in the films was approximately 1.5, although Ar atoms were included in the films. After ion irradiation, there was no significant change in the amount of O, Al and Ar atoms even at a high dose. However, the smooth surface of the amorphous film was metamorphosed to the granular one and the transformation from amorphous to crystalline was observed after ion irradiation. A (1 0 0) highly oriented θ-Al 2 O 3 was grown at a dose of 5×10 16 ions/cm 2 and then γ-Al 2 O 3 was also grown at a dose above 1×10 17 ions/cm 2 .

We examined the association between green tea consumption and mortality due to all causes, cancer, heart disease, cerebrovascular disease, respiratory disease, injuries, and other causes of death in a large-scale population-based cohort study in Japan.We studied 90,914 Japanese (aged between 40 and 69 years) recruited between 1990 and 1994. After 18.7 years of follow-up, 12,874 deaths were reported. The association between green tea consumption and risk of all causes and major causes of mortality was assessed using the Cox proportional hazards regression model with adjustment for potential confounders.Hazard ratios for all-cause mortality among men who consumed green tea compared with those who drank less than 1 cup/day were 0.96 (0.89-1.03) for 1-2 cups/day, 0.88 (0.82-0.95) for 3-4 cups/day, and 0.87 (0.81-0.94) for more than 5 cups/day (P for trend.001). Corresponding hazard ratios for women were 0.90 (0.81-1.00), 0.87 (0.79-0.96), and 0.83 (0.75-0.91; P for trend.001). Green tea was inversely associated with mortality from heart disease in both men and women and mortality from cerebrovascular disease and respiratory disease in men. No association was found between green tea and total cancer mortality.This prospective study suggests that the consumption of green tea may reduce the risk of all-cause mortality and the three leading causes of death in Japan.

The neutrophil bactericidal/permeability-increasing protein (BPI) has both bactericidal and lipopolysaccharide-neutralizing activities. The present study suggests that BPI also plays an important role in phagocytosis of Escherichia coli by neutrophils through promotion of complement activation on the bacterial surface. Flow cytometric analysis indicated that fluorescein-labelled E. coli treated with BPI were phagocytosed in the presence of serum at two- to five-fold higher levels than phagocytosis of the bacteria without the treatment. In contrast, phagocytosis of the fluoresceined bacteria with or without treatment by BPI did not occur at all in the absence of serum. The phagocytosis stimulated by BPI and serum was dose-dependent. The effect of BPI on phagocytosis in the presence of serum was not observed on Gram-positive bacteria (Staphylococcus aureus). Interestingly, the complement C3b/iC3b fragments were deposited onto the bacterial surface also as a function of the BPI concentration under conditions similar to those for phagocytosis. Furthermore, the BPI-promoted phagocytosis was blocked completely by anti-C3 F(ab')(2) and partially by anti-complement receptor (CR) type 1 and/or anti-CR type 3. These findings suggest that BPI accelerates complement activation to opsonize bacteria with complement-derived fragments, leading to stimulation of phagocytosis by neutrophils via CR(s).

A flywheel rotor having a main shaft, two flywheel disks and one permanent magnet for a SMB (superconducting magnetic bearing) was designed and manufactured. The flywheel was made of CFRP material which is light weight and has high tensile strength. The permanent magnet was hooped by CPRP in order to prevent centrifugal bursting. The rotor was levitated by a SMB in the axial direction. The radial vibration of the rotor was damped by active magnetic bearings. The superconducting magnetic bearing was made of YBa/sub 2/Cu/sub 3/O/sub 7-X/ which had a strong pinning force. The whole rotor system was stably accelerated up to 30000 rpm by an induction motor in a vacuum chamber, and then its energy storage value reached 479 Wh. In this paper, the rotor design, bearing and rotational properties of the rotor are discussed.

As the demand for electric power has been increasing steadily, the introduction of a flywheel energy storage system (FESS) using a superconducting magnetic bearing (SMB) is needed to level daily load as much as possible (daily load-leveling). We have studied rotation loss characteristics of SMBs with high Tc superconductors (YBCO) and permanent magnets (PM) for supporting a flywheel in FESS. We have designed and manufactured a testing machine for measuring rotation loss characteristics of SMBs. The rotor is suspended by two sets of radial active magnetic bearings (RaAMBs), a set of axial active magnetic bearings (AxAMB) and a set of SMB. Then, we obtained rotation loss characteristics of the rotor levitated by RaAMBs, AxAMB and SMB on this testing machine.

The exposure of HfN thin films sputter-deposited on silicon-substrate to the irradiation with carbon ions of moderate energy ( E =100 and 150 keV) and different fluences resulted in a relaxation of compressive internal stresses (from −5 to −4 GPa). The stress-reduction has been confirmed by measurements of the substrate deflection and X-ray diffraction method. The structural changes induced in the ion modified HfN-film/silicon-substrate system were studied by means of Auger electron spectroscopy, electron microscopy and X-ray diffraction. The relative softening of HfN after bombardment with an energy of 150 keV was found to be caused by amorphization of the silicon substrate right under the film, while the depth-sensing indentation results proved that in the case of nitride films modified with lower energy (100 keV) the amorphization does not occur. We ascribed the registered post-deposition stress-release to a transport of interstitial defects within thermal spikes induced by the applied ion-treatment.

Energetic electrons and ions, which were induced by positive and negative pulses in C7H8 plasma, respectively, were bombarded alternately on a substrate in PBII/D process. The effects of pulsed negative bias voltage on the electrical conductivity of DLC films were studied. Conductivity and hardness of DLC films were measured by a four-point-probe method and microindentation method. Hydrogen concentration, sp2/sp3 ratio, Raman I(D)/I(G) ratio were also measured by ERD, XPS, Raman spectroscopy and the structure of the films was observed by HRTEM. As a result, the resistivity of the film decreased with negative pulse voltage and reached to 1 mΩ cm at −20 kV, and the hardness was 5.4 GPa. It has been shown that the electrically conductive DLC films are composed with cluster of graphite-like aggregate. The technique can be applied for conductive DLC coatings on three-dimensional substrate with high adhesion strength.

In the present study, diamond-like carbon (DLC) films were deposited on steel and silicon substrates using a plasma based ion implantation (PBII) with bipolar pulses, and the effect of the positive pulse power on the properties of DLC films was investigated. The positive pulse voltage was varied from 2.0 to 6.3 kV while the negative pulse voltage was maintained at 5.0 kV. We obtained DLC films with a very low internal stress less than 0.5 GPa and a relatively high hardness greater than 22 GPa. The optimum deposition conditions for high deposition rate due to high plasma density and low friction exist, which are determined by the bipolar pulse power and surface temperature of substrate.

The post-deposition bombardment of reactively sputtered HfN thin films with energetic (1, 2.5 and 5 MeV) gold ions to a fluence of 10 14 cm −2 resulted in a considerable reduction of high internal stresses which were estimated from the measurements of the surface curvature. The higher the energy of the gold species the lower degree of relaxation was registered. The observed phenomena are attributed here to the transport of the interstitial defects within the thermal spikes induced by bombarding HfN with Au ions. An alternative explanation of stress-reduction caused by an increase in vacancy concentration is also presented. Significant softening of HfN films after ion-beam treatment was registered by the high accuracy depth-sensing indentation method and attributed to the formation of an inter-layer of amorphous silicon, directly under the film. A structural analysis has been carried out using thin film X-ray diffraction. Nitride film resistivity was found to be slightly enhanced by bombardment with Au ions.