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著者人数: 51名, Accepted: 2004-03-24, 資料番号: SA1003408000

著者人数: 51名, 資料番号: SA1003983000

The modification of JT-60 was programmed to be a superconducting tokamak (JT-60SC) that has superconducting toroidal field (TF) and poloidal field coils. The Nb 3 Al superconductor was developed in order to apply to the TF coil system in JT-60SC. The TF coil conductor was designed with a cable-in-conduit (CIC) type. This conductor was Nb 3 Al cable jacketed into stainless steel (SS) conduit. As the first step of SS conduit production, the 10 m long round-in-square type tubes were successfully fabricated within eccentricity tolerance of the tube hole ( 3 Al CIC conductor was successfully fabricated, so that a feasibility of mass-producing CIC conductor applied to the real machine was obtained.

Recent progress in the physics and engineering design study for the modification programme of JT-60 is presented. In order to achieve a steady state high-β plasma operation, which is the dominant issue of this programme, physics design for the MHD control and the stability analysis is investigated. Engineering design and the R & D for the superconducting coils, irradiation shield are performed well towards the mission of programme.

The real-time feedback control of the plasma stored energy has been developed for control of the plasma MHD stability in the JT-60U tokamak. The plasma stored energy can be detected with high accuracy in real-time by a function parameterization method for various plasmas available in JT-60U, such as Ohmic plasmas, the L-mode, the H-mode, the high poloidal beta mode and the reversed shear mode over a wide range of the plasma parameters. By manipulating the neutral beam injection power, the plasma stored energy has been successfully controlled along the preprogrammed reference waveform. Especially in the reversed shear mode, this feedback control scheme has improved the reproducibility of the formation of the internal transport barrier, and MHD activities could be suppressed keeping the normalized beta in a stable region. A DT equivalent fusion amplification gain of 0.5 was sustained for 0.8 s in a reversed shear plasma by employing this feedback control scheme.

Modification of JT-60 as a full superconducting tokamak (JT-60SC) is planned. The objectives of the JT-60SC programme are to establish scientific and technological bases for steady-state operation of high performance plasmas and utilization of reduced-activation materials in an economically and environmentally attractive DEMO reactor. Advanced fusion technologies relevant to the DEMO reactor have been developed for the superconducting magnet technology and plasma facing components of the JT-60SC design. To achieve a high current density in a superconducting strand, Nb3Al strands with a high copper ratio of 4 have been newly developed for the toroidal field coils (TFCs) of JT-60SC. The R&D to demonstrate the applicability of the Nb3Al conductor to TFCs by a react-and-wind technique has been carried out using a full-size Nb3Al conductor. A full-size NbTi conductor with low ac loss using Ni-coated strands has been successfully developed. A forced cooling divertor component with high heat transfer using screw tubes has been developed for the first time. The heat removal performance of the carbon fibre composite target was successfully demonstrated on an electron beam irradiation stand.

Comparisons are made from data acquired by four multi-spectral sensors (Landsat/ETM+, Terra/ASTER, Terra/MODIS, and NOAA/AVHRR) over Kushiro Marsh in Hokkaido, Japan, on September 26, 2001. There is good agreement in the spectral characteristics of the Digital Numbers (DNs) between ETM+ and ASTER. Equations relating the Landsat/ETM+ digital number to that of the Terra/ASTER are developed. To eliminate various environmental effects, the Normalized Difference Vegetation Index (NDVI) is computed from the data of the four sensors. Typical values of the NDVI for several land cover types are obtained. The NDVI values for broad-leaf forest indicate the NDVI derived from MODIS is the largest followed by those of ETM, ASTER and AVHRR. The ranges of respective NDVIs reflect the spatial resolution. To reveal the effect of the sensors' spatial resolution, simulated data are generated from the higher spatial resolution (small size pixel) data to match the lower spatial resolution (larger size pixel) data. Comparisons of NDVIs for the simulated pixels indicate that the MODIS NDVI has the largest minimum, mean, and maximum numerical values while the ASTER NDVI indicates the opposite characteristics.

The imaging spectrometer with a tunable filter, which can select the observing wavelength arbitrarily, is useful for the remote sensing of the earth. The LCTF (Liquid Crystal Tunable Filter) has a capability of selecting the observing wavelength instantaneously with high spectral resolution. Taking advantage of this filter we have developed an LCTF spectro-polarimetryr system with a polarimetry function, which can be realized by rotating the LCTF itself. Thus this LCTF spectro-polarimetryr system can acquire valuable image information of the earth's environments by continuously changing both wavelength and polarization angle in response to the observation requirements. The details of the configuration and performance of the LCTF spectro-polarimeter are presented in this paper.

Landsat-7 ETM+ (Enhanced Thematic Mapper Plus) simultaneously acquires multispectral image data with three different spatial resolutions; 30 meters for Band 1–5 and 7 (visible, near infrared and short wave infrared bands), 60 meters for Band 6 (thermal band) and 15 meters for Band 8 (panchromatic band). The spectral range of Band 8 is 520–900 rum and those of Bands 2, 3, and 4 are 530–610, 630–690 and 780–900 run respectively. Multispectral Band 2, 3 and 4 data at a 15 meter spatial resolution were generated by fusing with the higher resolution Band 8 data. Four methods are tested i.e. HSI (Hue, Saturation, Intensity) transformation, Brovey transformation and two proposed methods which utilize the statistical features of the multispectral and panchromatic data. The result indicates that in HSI and Brovey transformations the fusion of Band 8 data has reduced the numerical values of the average and the standard deviations of the original data while the proposed methods have generated the data of almost same color tone with nearly same values of average and standard deviations of the original data.

Through the research on the application of the multi temporal data acquired with Landsat-5 TM and Landsat-7 ETM+ to monitoring of rice field the following features are clarified Two vegetation indices NDVI (Normalized Difference Vegetation Index) and EVI (Extended Vegetation Index) obtained from Landsat-5 TM data of 7 July 2000 and that from Landsat-7 ETM+ data of 6 July 2000 show almost the same feature proving the validity of calibration of both sensors. NDVI computed from satellite data increases corresponding to the growth of rice plants until the flowering stage while EVI further continues to increase until the fructification stage. The vegetation indices computed from the in situ survey data with a portable multispectral radiometer do not coincide with those computed from satellite data. This is because that the reflectance of the background such as soil and water is included in the satellite data.

Heart failure developed 9 years after Fontan takedown with systemic-pulmonary artery shunt in a 12-year-old girl with pulmonary atresia, intact ventricular septum, and obstruction in the proximal pulmonary artery. Surgical scar after multiple operations complicated direct repair of the pulmonary artery, and thus she was not eligible for definitive palliation. Left innominate vein-to-left pulmonary artery shunt using an expanded polytetrafluoroethylene conduit in association with Glenn anastomosis functionally established an unobstructive superior cavopulmonary connection without direct repair of the central pulmonary artery, later facilitating one and a half ventricle repair. Use of an extraanatomical shunt may functionally relieve central pulmonary artery obstruction in candidates for Fontan-like circulation.

Lithium titanate (Li2TiO3) has attracted the attention of many researchers because of good tritium recovery at low temperature, chemical stability, low tritium inventory, etc. In this work, the effects of TiO2 doping of Li2TiO3 on the resistance to the environmental attack in air and hydrogen reduction under Ar+0.1%H2 flow were examined. Based on the results, the TiO2 doping (from 3.7 to 30 wt%) was found to improve the resistance to the environmental attack for very long exposure times in air at room temperature. The hydrogen reaction rates of Li2TiO3 and Li4Ti5O12 were almost similar up to 800 °C and that of Li4Ti5O12 was higher in the temperature range from 800 to 950 °C.

Li 2 TiO 3 is a candidate material for the tritium breeder blanket in the fusion reactor. The knowledge of Li 2 TiO 3 pebble bed properties is necessary to design the fusion blanket. In this study, the effective thermal diffusivity of Li 2 TiO 3 pebble bed under the neutron irradiation was evaluated. According to the irradiation test conducted in the Japan Materials Testing Reactor (JMTR), the effective thermal diffusivity of Li 2 TiO 3 pebble bed decreased with increasing the irradiation temperature and the thermal neutron fluence. However, horizontal temperature difference (DT) was almost constant at 400 °C under neutron irradiation up to 1×10 24 n/m 2 . Therefore, we can conclude that the effective thermal conductivity of Li 2 TiO 3 pebble bed is constant for thermal neutron fluence up to 1×10 24 n/m 2 at least.

The application of Li2TiO3 pebbles (diameter: 0.2–2 mm, density: 80–85%T.D., grain size

The design of an advanced solid breeding blanket in a DEMO reactor requires a tritium breeder and a neutron multiplier that can withstand high temperatures and high neutron fluences, and the development of such advanced blanket materials has been carried out by collaboration between JAERI, universities and industries in Japan. The Li2TiO3 pebble fabricated by a wet process is a reference material as a tritium breeder, but its stability at high temperatures has to be improved for its application in a DEMO blanket. One of these improved materials, TiO2-doped Li2TiO3 pebbles, was successfully fabricated and studied. For the advanced neutron multiplier, beryllides that have a high melting point and good chemical stability have been studied. Some characterization of Be12Ti was conducted, and it became clear that it had lower swelling and tritium inventory than beryllium metal. Pebble fabrication study for Be12Ti was also performed and Be12Ti pebbles were successfully fabricated. These activities have shown that there is a bright prospect in realizing a DEMO blanket by the application of TiO2-doped Li2TiO3 and beryllides.

著者人数: 46名, Accepted: 2003-05-20, 資料番号: SA1003406000

We are developing a new type of wiggler with a strong focusing force, named the edge-focusing wiggler. It is a Halbach-type wiggler made with permanent magnet blocks with an edge angle φ. An application is given for SASE in the shorter wavelength region. The characteristics of the wiggler are studied in detail using a three-dimensional magnetic field calculation program with the magnetic charge method.

The modification of JT-60 is programmed to be a superconducting tokamak (JT-60SC) that has superconducting toroidal field (TF) and poloidal field coils. The TF coil system, which consists of 18 D-shaped coils, makes the field of 3.8 T at plasma center (R = 2.8 m). The stored magnetic energy in total is 1.7 GJ. A squared Nb/sub 3/Al cable-in-conduit (CIC) conductor using SS316LN jacket allows us to fabricate the TFC by a react-and-wind (R&W) technique because of low strain sensitivity of Nb/sub 3/Al J/sub c/ characteristic. In order to support TF coils against the centering force, the inboard side of the TF coil case is wedged. Shear panels and keys between the TF coils are placed against the overturning force induced by poloidal fields. Stress analysis of the TF coil support structure was carried out. In the case of the maximum displacement caused by overturning force, the maximum stress was lower than the allowable stress of SS316LN at 4 K. The stress analysis of insulator and conduit at the inboard side of the TF coil with zooming model was also carried out. It is clear from zooming analysis that the stresses of conduit and insulator are within the allowable stress. Regarding a progress of R&D, demonstration of R&W technique using a D-shaped double layer coil with the full-scale CIC conductor is planned in this year in order to confirm its designed performance.

A new method for calculating indicated mean effective pressure (i.m.e.p.) was derived from harmonic analysis of pressure waveform in working space, instead of conventional numerical integration of the pressure-volume (P-V) diagram. The method is applicable to a number of displacement-type machines including engines. This paper first introduces a generalized i.m.e.p. equation, then derives the specific i.m.e.p. equations for various mechanisms such as the piston-crank, swash plate, etc. The proposed i.m.e.p. equations introduced show that i.m.e.p. is determined by very low frequency components, of less than several hundred Hz, included in the pressure waveform. The reason is that the amplitude of volumetric variation becomes rapidly smaller as the order of its harmonics increases. This means that the i.m.e.p. equations proposed are more accurate where the number n of sam-pling pressure data per cycle is decreased and allow highspeed calculation as compared with the conventional method. The error of the i.m.e.p. equation for internal combustion engines with a piston-crank driving mechanism is less than ±0.1 per cent. For a Stirling engine with a Ross yoke drving mechanism the erros is less than 0.4 per cent, even if n is decreased until four per cycle because the pressure waveform is close or similar to the sinusoidal wave. The digital i.m.e.p. meter developed as an application of the i.m.e.p. equation is also described, and its validation is discussed.

ZnGeN2, one of the II–IV–N2 compounds, has been grown directly on r-plane sapphire by remote-plasma enhanced metalorganic vapor phase epitaxy. Single crystalline ZnGeN2 was obtained at growth temperature of 775 °C. Epitaxial relationship is ZnGeN2(010)/α-Al2O3(10–12), ZnGeN2[100] ∥α-Al2O3[11–20], and ZnGeN2[001] ∥α-Al2O3[10–11]. Band structure of ZnGeN2 is direct transition type from absorption spectrum. From photoluminescence measurements, sharp emission peaks related to band-edge, were observed at around 3.3 eV. Band gap energy of ZnGeN2 is 3.3 eV at room temperature by considering absorption and photoluminescence spectrum together. Temperature dependence of band gap was estimated from the photoluminescence peak positions for the first time.

Lithium titanate (Li 2 TiO 3 ) is one of the candidate materials as tritium breeder in the breeding blanket of fusion reactors, and it is necessary to show the tritium release behavior of Li 2 TiO 3 pebble beds. Therefore, a blanket in-pile mockup was developed and in situ tritium release experiments with the Li 2 TiO 3 pebble bed were carried out in the Japan Materials Testing Reactor. In this study, the relationship between tritium release behavior from Li 2 TiO 3 pebble beds and effects of various parameters were evaluated. The ( R / G ) ratio of tritium release ( R ) and tritium generation ( G ) was saturated when the temperature at the outside edge of the Li 2 TiO 3 pebble bed became 300 °C. The tritium release amount increased cycle by cycle and saturated after about 20 pulse operations.

The diagnostic system of JT-60U (JT-60upgrade) is composed of about 50 individual diagnostic devices. Recently, the detailed radial profile measurements of plasma parameters have been improved, so ...

Fusion plasma performance and confinement studies on JT-60 and JT-60U are reviewed. With the main aim of providing a physics basis for ITER and the steady-state tokamak reactors, JT-60/JT-60U has b...

Epidermal growth factor (EGF) comprises a structurally related family of proteins containing heparin-binding EGF-like growth factor (HB-EGF) and transforming growth factor alpha (TGFalpha) that regulates the development of dopaminergic neurons as well as monoamine metabolism. We assessed the contribution of EGF to schizophrenia by measuring EGF family protein levels in postmortem brains and in fresh serum of schizophrenic patients and control subjects. EGF protein levels were decreased in the prefrontal cortex and striatum of schizophrenic patients, whereas the levels of HB-EGF and TGFalpha were not significantly different in any of the regions examined. Conversely, EGF receptor expression was elevated in the prefrontal cortex. Serum EGF levels were markedly reduced in schizophrenic patients, even in young, drug-free patients. Chronic treatment of animals with the antipsychotic drug haloperidol had no influence on EGF levels in the brain or serum. These findings suggest that there is abnormal EGF production in various central and peripheral tissues of patients with both acute and chronic schizophrenia. EGF might thus provide a molecular substrate for the pathologic manifestation of the illness, although additional studies are required to determine a potential link between impaired EGF signaling and the pathology/etiology of schizophrenia.

This paper aims to investigate experimentally steady state excavation performance under a constant cutting depth, especially the specific cutting energy of a disk cutter bit in the free edge part of a mortar specimen. Here, the tangential, lateral and normal forces acting on a disk cutter bit having three tip angles and the amount of debris were measured for several cutting spaces and cutting depths. As a result, it was observed that the specific cutting energy, i.e. the ratio of the excavation power of the disk cutter bit to the amount of debris, showed a minimum value of the ratio of cutting space to cutting depth of five, at which ratio the most efficient excavation could be attained.

A substantial reduction of the L-H transition threshold power was observed under the W-shaped divertor in JT-60U, in comparison with the open divertor. Radiation power in the main region was also decreased in this case. These differences of radiation power from the main plasma between open and W-shaped divertor were not large enough to account for the apparent reduction of threshold power. In this paper, the emphasis is on the edge plasma parameters which relate to the L-H transition. It was found that edge plasma pressure just before the L-H transition in the W-shaped divertor case became smaller than that in the open divertor case. After the modification of divertor geometry, edge ion collisionality just before the L-H transition also became lower and it was established with lower auxiliary power input. It was suggested that reduction of edge ion collisionality arose from neutral particles near the X-point by the analysis of poloidal profile of neutral density. Therefore, neutral particles near the X-point prevented the threshold power for the L-H transition from more reduction at low plasma density, and caused the shift of plasma density which gave minimum threshold power.

Protons with energies up to approximately 10(15) eV are the main component of cosmic rays, but evidence for the specific locations where they could have been accelerated to these energies has been lacking. Electrons are known to be accelerated to cosmic-ray energies in supernova remnants, and the shock waves associated with such remnants, when they hit the surrounding interstellar medium, could also provide the energy to accelerate protons. The signature of such a process would be the decay of pions (pi(0)), which are generated when the protons collide with atoms and molecules in an interstellar cloud: pion decay results in gamma-rays with a particular spectral-energy distribution. Here we report the observation of cascade showers of optical photons resulting from gamma-rays at energies of approximately 10(12) eV hitting Earth's upper atmosphere, in the direction of the supernova remnant RX J1713.7-3946. The spectrum is a good match to that predicted by pion decay, and cannot be explained by other mechanisms.

Two types of cable-in-conduit conductors (CICCs) for the JT-60 toroidal field coil (TFC) have been developed. The operational conditions of this conductor are 7.4 T in a maximum magnetic field and 19.4 kA in operational current. Each conductor consists of a stainless steel conduit (17 mm in inner diameter) containing 216 high performance superconducting strand (Nb/sub 3/Al or Nb/sub 3/Sn) and 108 copper wires. The diameter of strand is 0.74 mm including 2-/spl mu/m Cr plating. In order to attain a compact and stable coil, strands with high Cu/non-Cu ratio and high critical current density (Jc) were developed. The Cu/non-Cu ratio of Nb/sub 3/Al and Nb/sub 3/Sn strands are 4.1 and 3.6, respectively. The noncopper J/sub c/ of developed Nb/sub 3/Al and Nb/sub 3/Sn strands were 1914 A/mm/sup 2/ and 1843 A/mm/sup 2/ at 7.4 T, 4.2 K, respectively. Measurements of critical current (I/sub c/) of full size conductors showed that the I/sub c/ of Nb/sub 3/Al and Nb/sub 3/Sn CICCs were 98% and 79% of I/sub c/ estimated from I/sub c/ in strands. These values exceed the target values indicating that the developed conductors are quite appropriate for TFC of JT-60.

The full-size samples of 20-kA Nb/sub 3/Sn and NbTi cable-in-conduit conductors for the superconducting poloidal field coils of the fusion experimental tokamak JT-60 were manufactured. Since these coils operate in pulse mode, reduction of ac losses is one of the key issues. For the Nb/sub 3/Sn conductor, in order to separate the strands sintered with Cr coat after heat treatment, bending strains were applied on it. As a result, ac loss was effectively reduced, and it was found that 0.2% bending strain is enough to realize the design value level of 60 ms. Its critical current was also measured, and it was estimated that the compression strain due to the difference between thermal contractions of the stranded wire and stainless steel jacket was -0.6 %. For the NbTi conductor, comparison between the ac losses of the SnAg- and Cr-coated conductors was carried out. The measured coupling time constant of the Cr-coated conductor satisfied the design requirement of 50 ms, however the SnAg-coated conductor was more than five times that of the Cr-coated one.

At JAERI a plan of remodeling JT-60 tokamak fusion device by using superconducting coil system is being considered to investigate performance of break-even plasma in long pulse operation. The coil system are composed of Toroidal Field (TF), Central Solenoid (CS) and Equilibrium Field (EF) coils. The TF coil is designed to have a maximum field of 7.4 T at winding with a nominal current of 19.4 kA and a magnetic stored energy of 1.7 GJ which is larger than that of every superconducting coil constructed so far. The coil uses a cable-in-conduit conductor that a Nb/sub 3/Al (or Nb/sub 3/Sn) strand cable is inserted into a square stainless steel conduit with a circular hole and is wound with a react-and-wind technique. The design operating temperature is 4.6 K. The CS which consists of 4 modules is operated with a maximum field of 7.4 T and a maximum ramp up rate of 1.0 T/s. For the conductor, a square Nb/sub 3/Sn cable-in-conduit conductor with stainless steel conduit is used. The EF coil consists of 6 coils that the maximum size coil has an outer diameter of 11 in. The EF4 coil which has a maximum field of 7.4 T and a ramp up rate of 2.2 T/s uses the same conductor as CS and other field coils use a NbTi cable-in-conduit conductor.

CANGAROO-III is an Imaging Atmospheric Cherenkov Telescope (IACT) array of four 10 m telescopes for very high energy (sub-TeV) gamma-ray astronomy. A design study of the CANGAROO-III telescope system was carried out using the Monte Carlo technique in order to optimize the pixel size and the telescope spacing. Studies were also made of observations at low elevation angles.

Reduction in oocyte quality is a major factor responsible for declining fertility with age. The abnormal fertilization rate of oocytes from aged cows was reportedly higher than that of oocytes from young cows (Iwata et al. 2011. Reprod. Fertil. Dev. 23, 424–432). We hypothesised that assisted fertilization by intracytoplasmic sperm injection (ICSI) might improve the developmental abilities of oocytes collected from aged females. The aims of the study were (1) to determine the effect of maternal aging on the ability of bovine oocytes to undergo cytoplasmic maturation, fertilization, and further embryo development; and (2) to determine whether ICSI would improve the efficiency of embryo production in aged cows. Cows aged 30 to 50 months or >120 months were defined as young or aged, respectively. Cumulus-oocyte complexes were harvested from abattoir-derived ovaries of young (40 ± 7 months, n = 89) and aged (136 ± 12 months, n = 55) Holstein cows and matured for 23 h in TCM-199 supplemented with 5% fetal bovine serum (FBS) at 38.5°C under 5% CO2 with saturated humidity. Then, surrounding cumulus cells were removed, and cortical granules in the oocyte were stained with Lens culinaris–fluorescein isothiocyanate to evaluate the cytoplasmic maturation. Matured oocytes were inseminated by IVF or ICSI. At 15 h post-insemination, the numbers of pronuclei were determined to evaluate the fertilization rates. Presumptive IVF- or ICSI-derived zygotes were cultured for 5 days in CR1aa medium with 2% FBS and subsequently in USU6 with 5% FBS for 3 days at 38.5°C in 5% O2, 5% CO2, and 90% N2 with saturated humidity. Chromosome numbers of blastocysts were counted to evaluate the effect of maternal aging on ploidy. All experiments were performed with more than 4 independent runs, and data were analysed using chi-square tests. The distribution of matured oocytes into different cortical granule classes was affected by age, with a significantly lower (P

The influence of thermal boundary conditions was numerically clarified on the melting behaviour of an Ag nanowire mesh induced by Joule heating. The isotherm of the maximum temperature in the mesh, dependent on thermal boundary conditions, determines the melting behaviour. If such isotherm is a curve, global unstable melting happens where several nanowires melt simultaneously until the mesh is broken. The corresponding relationship of melting current and voltage becomes a data point. However, if the isotherm is a point, stable melting happens where only one nanowire melts at a time. The relationship of melting current and voltage becomes a curve.

This retrospective study assessed the treatment of 91 cases of carpal tunnel syndrome in long-term haemodialysis patients. One group of patients underwent an enlargement reconstruction of the flexor retinaculum with synovectomy and the other group was treated with a conventional carpal tunnel release. There were no major changes or differences between the outcomes of the two groups. However, there was an earlier functional recovery of grip strength and a lower recurrence rate in the enlargement plasty with synovectomy group.

Two hundred and four unrelated Japanese patients with rheumatoid arthritis (RA) were typed for HLA by serological typing and DNA typing. The serological typing revealed that frequencies of HLA-A11, DR4, DR53 and DQ4 were increased and those of DR8 and DQ1 were decreased in the patients. The DNA typing has precisely defined the disease-associated HLA class II alleles; DRB1 * 0405, DQA1 * 03 and DQB1 * 0401 showed positive associations, while negative associations were found with DRB1 * 0803, DQA1 * 0103 and DQB1 * 0601. The risk for RA was found to be closely associated with particular amino acid sequences of DR-beta chain, including glycine residue at the 86th position in addition to those between 70 and 74, which are known to confer binding specificity and affinity to antigenic peptides. The observation that the frequency of HLA-A11 was increased in the DRB1 * 0405-positive patients suggested the interaction of these two alleles in the susceptibility to RA. On the other hand, the frequency of DPB1 * 0201 was increased in the DRB1 * 0405-negative patients and the frequency of HLA-A2 was increased in the DPB1 * 0201-positive patients, especially in the younger onset group. These findings suggested that the combination of HLA-A2 and DPB1 * 0201 may confer the susceptibility in the DRB1 * 0405-negative patients. Our results suggested the possibility that the susceptibility to RA is controlled by the interaction of HLA-A and DRB1 genes or by that of HLA-A and DPB1 genes in different patient subgroups.

The engineering data on neutron irradiation performance of fusion blanket are indispensable to design the fusion blanket. In this study, an in-situ irradiation test of the Li 2 TiO 3 pebble bed was carried out at the J apan M aterials T esting R eactor (JMTR), and the effects of various parameters, i.e. sweep gas flow rate, irradiation temperature and hydrogen content in sweep gas on tritium release were evaluated.

The present paper describes the design concept and manufacturing of a new compact laminar flow heat exchanger with stainless-steel micro-tubes for helium refrigerators. In the temperature range of less than 20 K, aluminum plate fin type heat exchangers exhibit a remarkable fall of performance characteristics as a compact heat exchanger. We presented in a previous paper that some compact heat exchangers with good performance in the temperature range of less than 4 K are required for a subcooled He II refrigerator cycle to be worked with 3He turbo-compressors (F. Doty, et al., A new look at the closed brayton cycle, Proceedings, IECEC-90 Reno, NV, 1991, p. 116). For this requirement, we developed a micro-tube strip counter flow type heat exchanger, which consists of 12 elements with a total of 4800 stainless steel micro-tubes. Each element is formed with 400 tubes and a newly developed vacuum brazing method was applied for the bonding to the side plate. Each tube has an inner diameter of 0.5 mm, an outer diameter of 0.7 mm and is 310 mm long. We developed a cladding plate with two layers of gold brazing sheet sandwiched inside. In aerodynamic and thermal design of the element, the laminar flow conditions were adopted for the flows of inner and outer tubes to keep a high heat transfer rate and a low pressure loss.

The dependence of edge stability on plasma shape and local pressure gradients P' in the DIII-D and JT-60U tokamaks is studied. The stronger plasma shaping in DIII-D allows the edge region of DIII-D discharges with type I (giant) ELMs to have access to the second region of stability for ideal ballooning modes and a larger edge pedestal pressure gradient P' than JT-60U type I ELM discharges. These JT-60U discharges are near the ballooning mode first regime stability limit. The DIII-D results support an ideal stability based working model of type I ELMs as low to intermediate toroidal mode number, n, MHD modes. The results from a stability analysis of JT-60U type I ELM discharges indicate that the predictions of this model are also consistent with JT-60U edge stability observations.

When Kasba (Chuzan) virus (an orbivirus) was injected intracerebrally into 1-, 2- or 4-week-old mice, non-purulent necrotizing encephalitis developed and the mice showed nervous symptoms and became moribund. The necrotic lesions were more severe in younger animals. In 1-week-old mice, viral titres rose until 7 days post-infection, while in 2- and 4-week-old animals the titres reached a peak on day 3 and then declined gradually. Glial fibrillary acidic protein-positive astrocytes increased in the white matter, hippocampus and subpial area of the cerebral cortex of infected animals, and lectin-RCA-1-positive cells, thought to be microglial cells, increased in the necrotic lesions. The number of these glial cells increased even after viral titres had declined. In this study there were no survivors in any age group, but survival time increased with age.

Through the research on the application of the multi-temporal data acquired with Landsat-5 TM, SPOT-2 HRV, SPOT-4 HRVIR and RADARSAT-1 SAR to monitoring of rice field following features are clarified. Vegetation indices NDVI (Normalized Difference Vegetation Index) and EVI (Extended Vegetation Index) derived from different optical sensors TM, HVR, HRVIR indicate nearly same characteristics suggesting validity of calibration of respective sensors. It was found that by combined use of multi-temporal vegetation indices NDVI and EVI together with SAR (Synthetic Aperture Radar) data it was found that rice planted area can be estimated with the error less than 2%.

Both males and females of the species of spinous country-rats (Tokudaia osimensis osimensis, T. o. o., Rodentia: Muridae), which live on Amami Oshima Island, a southern Japanese island, have 25 chromosomes. Another species of spinous country-rats (Tokudaia osimensis spp., T. o. spp., which live on Tokunoshima Island 40 km south of Amami Oshima Island, also have an odd number of chromosomes, 45. Karyotypes of males and females by the G-band method were indistinguishable in both populations. The lesser number of chromosomes (25) of T. o. o. is likely to be a result of Robertsonian fusions of 45 chromosomes of T. o. spp. that seem to be the offspring of another spinous country-rat Tokudaia osimensis muenninki (T. o. m.), which live on Okinawa Island and have 44 chromosomes including the X and Y Chrs. The lengths of the non-paired, putative X-Chr of T. o. o. and T. o. spp. occupied roughly 3.2% and 1.7% of the total lengths, respectively, hinting at translocation or exchange of a part of the X Chr and thus in violation of Ohno's Law. Southern blot analysis with murine Sry as a probe indicated that these two animals do not have Sry. When Zfx from T. o. spp. was used as a probe, both males and females of T. o. o. and T. o. spp. showed two bands, suggesting possible translocation of Zfy from the Y Chr. Comparison of physical characteristics, constituents of chromosomes, and sex-determination methods of these three Tokudaia country-rat populations suggests that each is endemic to each island and constitutes an independent species. These specialized species would provide us with clues to elucidate the mechanisms of primary sex determination and karyotype evolution in mammals.

Lithium titanate (Li2TiO3) is one of the candidate tritium breeding materials for breeding blanket of the fusion reactor. Therefore, tritium release experiments from Li2TiO3 packing region were carried out to evaluate the effects of various parameters, i.e. sweep gas flow rate, irradiation temperature, and hydrogen content in sweep gas, etc. on tritium release. As for the shape of the Li2TiO3, a small spherical form (pebbles) is preferred to reduce the induced thermal stress in the breeding material. The diameter and total weight of Li2TiO3 pebbles were 1 mm and ∼135 g, respectively. And the integrated experiment of blanket in-pile mockup with Li2TiO3 pebble bed was carried out at the Japan Materials Testing Reactor (JMTR). The tritium released from Li2TiO3 pebble bed was swept by the helium gas with hydrogen. The total tritium concentration (HT+HTO) and gaseous tritium concentration (HT) of tritium released from Li2TiO3 pebbles were measured, and HT/(HT+HTO) ratio was evaluated under various conditions.

A remarkable reduction of the L-H threshold power was observed in JT-60U under the W-shaped pumped divertor geometry, in comparison with the results for the previous open divertor. The density range was extended to 0.6nGWL ( = Ip/πa2), where a stronger than linear density dependence was found. A reduction of the radiation power and edge temperature as well as a nonlinear increase in edge density were also observed. The poloidal distribution of the neutral particle density was first examined in this work, and it was found that compression of neutral particles near the X-point or loss of homogeneity on a flux surface produced by the modification of the divertor geometry may be an influential determinant of the L-H threshold power.

In JT-60U H-mode plasmas, giant (type I) ELMs disappear and minute grassy ELMs appear when triangularity δ, edge safety factor q95 and βp are high enough. Complete suppression of giant ELMs was observed at δ0.45, q956 and βp1.6. At higher δ (0.54), giant ELMs can disappear at a lower q95 (~4.0). In the grassy ELMy H-mode, edge temperature and pressure can be higher than those in giant ELMy H-mode and a favourable confinement can be sustained without an increase of the impurity concentration. An edge stability analysis suggests that the edge plasma is accessing the second stability regime of the high n ballooning mode in the grassy ELMy discharges.

Polymorphisms in the 5'-flanking promoter/enhancer region of the tumor necrosis factor (TNF)-a gene were examined to study the genetic background of rheumatoid arthritis (RA). Four variant alleles, -1,031C/ -863A, -1,031C/-238A, -857T and -308A, were identified and examined in 387 RA patients and 575 healthy Japanese controls. The frequency of the -857T allele in RA patients was significantly higher than that in the controls. However, the HLA-DRB1 analysis in the same subjects showed that the DRB1*0405 allele, which is in linkage disequilibrium with the -857T, was more strongly associated with the disease susceptibility than the -857T allele. These results suggest that the susceptible gene to RA is more closely linked to the HLA-DRB1 locus than to the TNF-alpha locus.