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Sequential exposures of W surfaces to steady-state and pulsed (∼0.5 ms) plasmas have been performed in a linear divertor plasma simulator and a magnetized coaxial plasma gun to investigate ...

Surface damage of carbon fiber composite (CFC) and tungsten (W) due to repetitive ELM-like pulsed plasma irradiation has been investigated by using a magnetized coaxial plasma gun. CX2002U CFC and stress-relieved W samples were exposed to repetitive pulsed deuterium plasmas with duration of ∼0.5 ms, incident ion energy of ∼30 eV, and surface absorbed energy density of ∼0.3–0.7 MJ/m 2 . Bright spots on a CFC surface during pulsed plasma exposures were clearly observed with a high-speed camera, indicating a local surface heating. No melting of a W surface was observed under a single plasma pulse exposure at energy density of ∼0.7 MJ/m 2 , although cracks were formed. Cracking of the W surface grew with repetitive pulsed plasma exposures. Subsequently, the surface melted due to localized heat absorption.

In-situ powder-in-tube MgB2 tapes have been prepared through a hot pressing process. Magnesium hydride MgH2 and amorphous B powders were mixed to synthesize MgB2 superconductor. The mixed powder was encased in a steel tube and rolled into a monocore tape of about 4 mm in width and 0.5 mm in thickness. Nano-sized SiC and TiC powders were added to the MgB2 core. The tapes were hot-pressed under 100 MPa during the heat treatment in Ar gas atmosphere. The Ic for the hot-pressed tapes with 5 mass% SiC addition exceeds 300 A at 4.2 K and 5 T, which corresponds to a core Jc of nearly 1,000 A/mm2. The core Jc is enhanced by more than a factor of two compared to that of tapes without pressing during the heat treatment. The higher Jc in hot pressed tapes results from the improvement of the denser MgB2 structures with less voids and better linkage among MgB2 grains.

The ion cyclotron range of frequencies (ICRF) heating with 3 MHz and ∼10 kW is being prepared in RT-1. The operation regime for electron cyclotron resonance (ECR) heating is surveyed as the target plasmas. ECRH with 8.2 GHz and ∼50 kW produces the plasmas with high energy electrons in the range of a few ten keV, but the ions still remain cold at a few ten eV. Ion heating is expected to access high ion beta state and to change the aspect of plasma confinement theoretically. The ICRF heating is applied to the target plasma as an auxiliary heating. The preliminary result of ICRF heating is reported.

Temperature anisotropy in broad component of H$\alpha$ line was found in the ring trap 1 (RT-1) device by Doppler spectroscopy. Since hot hydrogen neutrals emitting a broad component are mainly produced by charge exchange between neutrals and protons, the anisotropy in the broad component is the evidence of proton temperature anisotropy generated by betatron acceleration.

A compact-sized MCPG with a single discharge stage is developed so as to simulate transient heat loads such as type I ELMs in ITER. The MCPG produces H 2 plasma with the electron density of 1-4×1021 m−3, the ion energy of 15 eV and the pulse width of 0.5 ms. It is found that the absorbed energy density measured by a calorimeter reaches 0.9 MJ/m2 which is comparable to transient heat load of type I ELMs expected in ITER. Erosion of tungsten due to the plasma irradiation produced by the MCPG was confirmed only at the edge parts of the specimen.

Wavefront correction until Zernike polynomial of degree three by a phase conjugate plate has been demonstrated in a high-energy Nd:YLF amplifier system. 108 amplification of 380 mj has been achieved with a near-diffraction-limited beam quality.

Powder‐in‐tube PIT MgB2 tapes have been prepared through an in‐situ process using a steel sheath. Magnesium hydride MgH2 and amorphous boron powders were mixed to synthesize MgB2 superconductor. The mixed powder was encased in a steel tube and rolled into a monocore tape of about 5mm in width and 0.5mm in thickness. Different kinds of ceramic powder, i.e., SiC, TiC, WC and Si3N4 were added to the core. The addition of nanopowder, e.g. SiC and TiC, has been found to enhance appreciably the Jc in MgB2 tapes. The Ic for the 5 wt% SiC or 10 wt% TiC addition tapes reaches 100 A at 4.2 K and 7 T, which corresponds to the core Jc of higher than 10 kA/cm2. The improvement of the core Jc in higher magnetic field may results from the increase of upper critical field Hc2 due to an incorporation of ceramic nanopowder such as SiC and TiC. Furthermore, the core Jc for the hot‐pressed MgB2 tapes with SiC addition reached 40 kA/cm2 at 7 T, which is enhanced by a factor of 4 compared to that without pressing during the heat treatment.

Summary form only given. There are several reports of visible luminescence from bismuth-doped glasses and crystals. The spectra of these crystalline and glassy materials were very wide, and the absorption and the fluorescence peaks exist around 240 nm and 380 nm, respectively, however, these emissions from Bi/sup 3+/ are no use for optical communication. We found a new infrared emission at 1.25 /spl mu/m from the bismuth doped silica glass. We report a new infrared fluorescence of bismuth-doped silica glass.

Summary form only given. Diode-pumped solid-state laser (DPSSL) is one of promising candidates as reactor driver for IFE. We have been developing a 10-J output class of diode-pumped water-cooled Nd:glass zig-zag slab laser amplifier module as a smallest-scale test-version of our conceptually designed 4-MJ DPSSL driver. We will show the experimental confirmation of our conceptual design through the investigation of 10-J/spl times/10-Hz module on the key issues such as small signal gain, energy extraction, stored energy, pumping efficiency, thermal effects, beam quality and heat flow in the system.

Apoptosis in neurons can be induced by mild cerebral ischemia. We developed a rat model of subarachnoid hemorrhage that caused mild ischemic stress to the brain and detected expression of apoptosis-related genes in the hippocampus. Intracranial carotid bifurcation of the rat was perforated by a 3–0 nylon and subarachnoid hemorrhage induced. The intracranial pressure rose immediately to a level similar to systemic arterial pressure for 30 s to 1 min and returned to baseline by 20 min. We detected mRNA expression of bax, bcl-2, bcl-x, ice, p53 and p21 (Waf1) using an in situ hybridization technique. With this model, about one-third of the CA1 neurons were TUNEL-positive at 48 h after perforation, and histological findings were compatible with apoptotic cell changes. The bax, bcl-2, and bcl-x mRNA were expressed transiently at CAl pyramidal neurons, with a peak at 12 h. The bax tended to be expressed for a longer period than bcl-2. The CA3 pyramidal neurons showed bax, bcl-2, and bcl-x mRNA expression as well, but transiently and with an intensity that was about half that at CAl. The ice mRNA, the key enzyme for protease cascade, was upregulated at CA1 neurons with a peak at 12–18 h. The p53 mRNA expression was transient with maximum levels at 12 h, indicating that p53 is located upstream of bax expression. The p2l(Waf1) expression, however, reached maximum levels at 48 h and lasted until 120 h, suggesting no relation to bax or bcl-2 expression. The results may relate to delayed ischemic neurological deficit, which is often observed as a result of subarachnoid hemorrhage and vasospasm.

Kynureninase is the most important enzyme in tryptophan metabolism. In the main pathway of tryptophan metabolism, kynureninase forms 3-OH-anthranilic acid from 3-OH-kynurenine. In this reaction vitamin B6 is a co-enzyme. An important relationship between -SH groups and liver kynureninase apoenzyme has been reported by Takeuchi8, 9 and Izuta1. We have experimented on kynureninase and S-involved compounds as follows: (i) Kynureninase activity was inhibited in vitamin B6-deficient rats and in streptozotocin (STZ)-induced diabetic rats; (ii) Following tryptophan administration, in rats given taurine or oysters (rich in taurine), the excretion of xanthurenic acid (an index of vitamin B6 deficiency) decreased compared with an excess methionine-administered group; and (iii) The active center of kynureninase apoenzyme (464 amino acid residues) is located near cysteine.

Prof. H. Tornita of the Department of Otorhinolaryngology, Nihon University, has been carrying out experiments to determine the relationship between Zn2+ and taste abnormality in diabetes mellitus. Normal taste capacity was recovered by the administration of ZnSO4 to these patients. K. Okamoto of Kinki University [1] discovered oxine (8-hydroxy quinoline) diabetes; its mechanism might be due to chelation with Zn2+.

Deuterium (D) retention in tungsten (W) subjected to pulsed D plasma bombardment (surface absorbed energy density Q ~0.5–0.7 MJ m−2 at ~0.3–0.5 ms) has been investigated in a magnetized coaxial plasma gun. A high temperature desorption peak of D2 appears at ~1000–1100 K following transients at ~0.5 MJ m−2. At a higher Q ~0.7 MJ m−2, the total amount of D retained in W is significantly reduced. Nano-sized helium (He) bubbles, created by steady-state He plasma pre-exposure at ~573 K, slightly lower D retention, while a significant reduction is observed for a W fuzzy surface formed by steady-state high temperature (~1100 K) He plasma pre-exposure.

In 1952, Yahito Kotake et al. reported that xanthurenic acid (XA) might be a diabetogenic agent in vitamin B6 (B6)-deficient rats. From that time, many studies have been performed in B6-deficient rats and in diabetic (DM) patients. The results are as follows: 1) The pyridoxal phosphate/pyridoxal ratio in plasma decreased in DM patients compared with the control group [DM group: 0.54 (N = 9); control group: 3.84 (N = 8)], suggesting that pyridoxal kinase activity may be inhibited in DM patients (Hattori et al., 1984).

Molybdenum specimens having bare and carbon-evaporated surfaces have been irradiated in air using a high-powered short-pulsed glass laser. The laser-induced surface damage and dislocation substructure ace observed at power densities > 2 × 108 W cm−2, while the formation of thin surface films are observed at power densities > 10111 cm−2. In the laser-induced surface damage, in particular, damage ripples have been found to be initiated and propagated from surface irregularities such as pits and grain boundaries. The thin surface film formed on the bare surface of molybdenum exhibits a fine duplex amorphous-crystalline structure. From the diffraction pattern of the crystalline phase, the film has been found to be composed of Mo2N. Such a nitride film has been detected not only on molybdenum but also on aluminium. Therefore, the formation of nitride films is thought to be a general phenomenon which may occur when metal surfaces arc irradiated in air by a short-pulsed laser beam at a power density whi...

Characteristics of TEA CO2 laser oscillation are reported.The pressure region of laser oscillation was about from 10 torr to 700 torr. Maximum out put power was obtained when nitrogen gas is mixed to CO2 gas with ratio of PN2/PCO2= 1-1.5 The peak power of about 5KW per pulse was obtained and it was confirmed that laser output power is proportional to the square of gas pressure. Delay time between dischaege current pulse and laser oscillation was measured. Under short delay time condition condition, it was found that self Q-switching was responsible for the increase of laser output power.

The immunopharmacological activities of chemically synthesized lipid A-subunit analogs, 4-O-phosphono-D-glucosamine derivatives carrying different N- and 3-O-linked acyl groups, were investigated. None of the synthetic compounds tested exhibited any detectable pyrogenicity at a dose of 10 micrograms/kg. Weaker lethal toxicity in galactosamine-sensitized mice was detected at 1 microgram per mouse for all the synthetic compounds except GLA-58. Among (RS) stereoisomers of 4-O-phosphono-D-glucosamine derivatives carrying a 3-O-tetradecanoyl (C14) group with different N-linked acyloxyacyl groups, i.e., 3-dodecanoyloxytetradecanoyl [C14-O-(C12)], 3-tetradecanoyloxytetradecanoyl [C14-O-(C14)], and 3-hexadecanoyloxytetradecanoyl [C14-O-(C16)] groups (termed GLA-57, GLA-27, and GLA-58, respectively), GLA-27 exhibited significant colony-stimulating factor-inducing and tumor necrosis factor-inducing activities, mitogenicity, polyclonal B-cell activation activity, macrophage activation, and adjuvanticity. The activities of GLA-57, which had an N-linked C14-O-(C12) group, were equivalent to or somewhat weaker than those of GLA-27 with a C14-O-(C14) group. Significant immunopharmacological activities were not observed for GLA-58, carrying a C14-O-(C16) group bound to the amino group. GLA-59, carrying 3-O-linked 3-hydroxytetradecanoyl (C14OH) and N-linked C14-O-(C14) groups, showed much higher activities than GLA-27, GLA-60, a compound which possesses the same fatty acid substituents as GLA-59 but with reversed binding sites, showed the strongest B-cell activation and adjuvant activities among the synthetic compounds. Among stereoisomers of GLA-59 and GLA-60 composed of fatty acid substituents with the (RR) and (SS) configuration, compounds with the (RR) configuration elicited stronger activities than the (SS) stereoisomers. The importance of fatty acid substituents, including stereospecificity for the expression of immunopharmacological activities of 4-O-phosphono-D-glucosamine derivatives, was demonstrated.

Taurine, the main component of oyster, recovered the glucose tolerance in alloxan diabetic rats, and also have an important effect to V.B6 deficiency. In recent experiment, the action of many purine derivertives in oyster to platelet aggregation were studied. These substances, for example, adenosine, hypoxanthine and also 3-hydroxy anthranilic acid, the precursor of xanthurenic acid that is main product of tryptophan metabolism in V.B6 deficiency showed the same suppresive action to platelet aggregation. Reference On the effect of oyster components to platelet aggregation to some metabolites of amino acids T.Ohta et al The Fourth Symposium on Trace Nutrients Research, Kyoto 1987 Japan Trace Nutrients Research Society