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The HYPER-II device has been constructed in Kyushu University to investigate the flow structure formation in an ion-unmagnetized plasma, which is an intermediate state of plasma and consists of unmagnetized ions and magnetized electrons. High density plasmas are produced by electron cyclotron resonance heating, and the flow field structure in an inhomogeneous magnetic field is investigated with a directional Langmuir probe method and a laser-induced fluorescence method. The experimental setup has been completed and the diagnostic systems have been installed to start the experiments. A set of coaxial electrodes will be introduced to control the azimuthal plasma rotation, and the effect of plasma rotation to generation of rectilinear flow structure will be studied. The HYPER-II experiments will clarify the overall flow structure in the inhomogeneous magnetic field and contribute to understanding characteristic feature of the intermediate state of plasma.
The correlation of stress in Silicon Carbide (SiC) crystal and frequency shift in micro- Raman spectroscopy was determined by an experimental method. We applied uniaxial stress to 4H- and 6H-SiC single crystal square bar specimen shaped with (0001) and (11-20) faces by four point bending test, under measuring the frequency shift in micro-Raman spectroscopy. The results revealed that the linearity coefficients between stress and Raman shift were -1.96 cm-1/GPa for FTO(2/4)E2 on 4H-SiC (0001) face, -2.08 cm-1/GPa for FTO(2/4)E2 on 4H-SiC (11-20) face and -2.70 cm-1/GPa for FTO(2/6)E2 on 6H-SiC (0001) face. Determination of these coefficients has made it possible to evaluate the residual stress in SiC crystal quantitatively by micro-Raman spectroscopy. We evaluated the residual stress in SiC substrate that was grown in our laboratory by utilizing the results obtained in this study. The result of estimation indicated that the SiC substrate with a diameter of 6 inch remained residual stress as low as ±15 MPa.
The aim of this study was to estimate genetic correlations between milk yield, somatic cell score (SCS), mastitis, and claw and leg disorders (CLDs) during first lactation in Holstein cows by using a threshold–linear random regression test-day model. We used daily records of milk, fat and protein yields; somatic cell count (SCC); and mastitis and CLD incidences from 46 771 first-lactation Holstein cows in Hokkaido, Japan, that calved between 2000 and 2009. A threshold animal model for binary records (mastitis and CLDs) and linear animal model for yield traits were applied in our multiple trait analysis. For both liabilities and yield traits, additive genetic effects were used as random regression on cubic Legendre polynomials of days on milk. The highest positive genetic correlations between yields and disease incidences (0.36 for milk and mastitis, 0.56 for fat and mastitis, 0.24 for protein and mastitis, 0.32 for milk and CLD, 0.44 for fat and CLD and 0.31 for protein and CLD) were estimated at about the time of peak milk yield (36 to 65 days in milk). Selection focused on early lactation yield may therefore increase the risk of mastitis and CLDs. The positive genetic correlations of SCS with mastitis or CLD incidence imply that selection to reduce SCS in the early stages of lactation would decrease the incidence of both mastitis and CLD.
We investigated the relationships between conception rates (CRs) at first service in Japanese Holstein heifers (i.e. animals that had not yet had their first calf) and cows and their test-day (TD) milk yields. Data included records of artificial insemination (AI) for heifers and cows that had calved for the first time between 2000 and 2008 and their TD milk yields at 6 through 305 days in milk (DIM) from first through third lactations. CR was defined as a binary trait for which first AI was a failure or success. A threshold-linear animal model was applied to estimate genetic correlations between CRs of heifers or cows and TD milk yield at various lactation stages. Two-trait genetic analyses were performed for every combination of CR and TD milk yield by using the Bayesian method with Gibbs sampling. The posterior means of the heritabilities of CR were 0.031 for heifers, 0.034 for first-lactation cows and 0.028 for second-lactation cows. Heritabilities for TD milk yield increased from 0.324 to 0.433 with increasing DIM but decreased slightly after 210 DIM during first lactation. These heritabilities from the second and third lactations were higher during late stages of lactation than during early stages. Posterior means of the genetic correlations between heifer CR and all TD yields were positive (range, 0.082 to 0.287), but those between CR of cows and milk yields during first or second lactation were negative (range, −0.121 to −0.250). Therefore, during every stage of lactation, selection in the direction of increasing milk yield may reduce CR in cows. The genetic relationships between CR and lactation curve shape were quite weak, because the genetic correlations between CR and TD milk yield were constant during the lactation period.
Iodine filters expended after nuclear fuel reprocessing contain radioactive iodine (I-129), almost all of which exists as silver iodide (AgI). The synthetic rock technique is a solidification treatment technique using hot isostatic press (HIP), in which the alumina adsorbent base material is synthesized to form a dense solidified material (synthetic rock), and I-129 is physically confined in the form of AgI in the alumina matrix. Thus, it is necessary to understand the matrix dissolution behavior to evaluate the iodine release behavior.
Experiments involving the dissolution of the matrix were carried out under various temperatures (35–70 °C) and pH values (10–12.5) that reflect the disposal conditions. The results of the experiments showed that the dissolution rate of Al visibly increases with temperature and pH. The dissolution rate constant was calculated from the initial data assuming the dissolution of the matrix as a primary reaction. The logarithmic rate constant showed a good linear correlation with the pH and the reciprocal of temperature. The 27Al-NMR analysis of the solutions of the dissolved matrix showed that the major chemical species present in the solutions was Al(OH)4-. This indicated that the dissolution of the matrix can be described by the following equation: Al2O3 + 2OH- + 3H2O → 2Al(OH)4-. Subsequently, the empirical equation of the rate of dissolution of the matrix as a function of the temperature and pH was derived. It will be used to evaluate the iodine release behavior from the synthetic rock.
During neck dissection, the current practice is to preserve the internal jugular vein in the majority of cases. However, sacrifice of bilateral internal jugular veins is required in rare cases. Simultaneous excision of both internal jugular veins is known to frequently cause fatal complications. Even if staged, bilateral internal jugular vein sacrifice still occasionally leads to fatal complications (in 2 per cent). We report two different methods of unilateral internal jugular vein reconstruction, in two cases requiring excision of bilateral internal jugular veins, and we review the significance of this reconstruction procedure.
The first patient underwent conventional type A reconstruction (using Katsuno's classification): end-to-end anastomosis of the internal jugular vein to the external jugular vein. For the second patient, we anastomosed the internal jugular vein to the anterior jugular vein, preserving the flow of the external jugular vein. This method, termed type K, had two main expected benefits: facial drainage via the preserved external jugular vein; and provision of a built-in safeguard in the case of occlusion (via the preserved venous networks between the internal jugular vein and the external jugular vein, e.g. the facial vein).
In both cases, the reconstructed internal jugular vein was patent and the post-operative course was uneventful, with no severe complications.
The current and previous findings strongly indicate that the reconstruction of at least one internal jugular vein is highly recommended for patients requiring bilateral internal jugular vein sacrifice. Our type K method may represent a useful technique for this procedure.
Patients suspected of having cervical tuberculous lymphadenitis are diagnosed using investigations such as fine needle aspiration cytology and the polymerase chain reaction for Mycobacterium tuberculosis. However, these investigations are intended for primary tuberculosis infection. The majority of cervical tuberculous lymphadenitis cases in the elderly are thought to be caused by reactivation.
The aims of this study were (1) to examine the efficacy of fine needle aspiration cytology, polymerase chain reaction and blood tests in the diagnosis of cervical tuberculous lymphadenitis caused by reactivation, and (2) to clarify any differences when compared with primarily infected cervical tuberculous lymphadenitis cases.
Materials and methods:
Thirty-three elderly patients with neck lumps underwent excisional biopsy from 2003 to 2008. The efficacy of fine needle aspiration cytology was examined by comparing the results of excisional biopsy with those of fine needle aspiration cytology performed at the initial medical examination for cases of suspected tuberculous disease. Furthermore, the leucocyte count and C-reactive protein concentration were compared for cases of cervical tuberculous lymphadenitis versus cases of malignant lymphoma.
Although nine cases were diagnosed with cervical tuberculous lymphadenitis using excisional biopsy, only one of these had been suspected based on fine needle aspiration cytology results. Three cases with tuberculous lymphadenitis were suspected of having malignant lymphoma on initial examination. There was no significant difference in the leucocyte count and C-reactive protein concentration, comparing cases of tuberculous lymphadenitis versus malignant lymphoma.
Unlike the primary infection often seen in endemic areas, the diagnosis of early stage tuberculous lymphadenitis of the swelling type caused by reactivation in elderly people is difficult to confirm unless excisional biopsy is performed. In elderly patients with neck lumps, cervical tuberculous lymphadenitis should be included in the differential diagnosis.
To investigate two clusters of diarrhoea cases observed in our geriatric hospital wards, the faecal specimens were analysed. Reversed passive latex agglutination assay revealed that 63·2% and 41·7% of the faecal specimens from each cluster were positive for Clostridium perfringens enterotoxin. PCR assay revealed that 71·4% and 68·8% of C. perfringens isolates from each cluster were positive for the enterotoxin gene (cpe). These observations suggested that both the clusters were outbreaks caused by enterotoxigenic C. perfringens. Subsequent pulsed-field gel electrophoresis analysis revealed that the two outbreaks were caused by different C. perfringens isolates. However, these outbreak isolates as well as other sporadic diarrhoea isolates shared a 75-kb plasmid on which the cpe gene and the tcp locus were located. The 75-kb plasmid had horizontally spread to various C. perfringens isolates and had caused outbreaks and sporadic infections. However, the site and time of the plasmid transfer are unclear.
The Microlensing Observations in Astrophysics (MOA) is a microlensing survey conducted at Mt. John Observatory in New Zealand. We searched transiting planet candidates from the MOA-I Galactic bulge data, which have been obtained with a 61cm B&C telescope from 2000 to 2005 for a microlensing search. Although this survey data were dedicated to microlensing, they are also quite useful for searching transiting objects because of the large number of stars monitored (~7 million) and the long span of the survey (~6 years). From our analysis, we found 58 transiting planet candidates. We are planning to follow up these candidates with high-precision spectroscopic and photometric observations for further selection, toward the detection of planets by radial velocity observations.
A smooth affine surface
defined over the complex field
surface if the Makar–Limanov invariant
is trivial. In this paper we study the topology and geometry of
surfaces. Of particular interest is the question: Is every curve
which is isomorphic to the affine line a fiber component of an
? We shall show that the answer is affirmative if the Picard number
, but negative in case
$\rho (X)\,\ge \,1$
. We shall also study the ascent and descent of the
property under proper maps.
The ideal strengths of metals and alloys at finite temperatures have been studied using the statistical moment method. The tensile and shear strengths of the body-centered cubic (bcc) transition metals like Mo and W (refractory metals), and ordered FeAl (B2) and Fe3Al (DO3) alloys are calculated as a function of the temperature. The orthogonal tight-binding method is used for bcc transition elements, while the universal binding-energy relation (UBER)-type of pairwise potentials, derived from ab initio density-functional theory, is used for the FeAl and Fe3Al alloys. We discuss the temperature dependence of the tensile and shear strengths of the metals and alloys in conjunction with those of the second-order elastic constants.
The propagation of intense laser pulses and the generation of high-energy electrons from underdense plasmas are investigated using two-dimensional particle-in-cell simulations. It is shown that quasi-monoenergetic electron beams are generated in the regime where the laser pulse length is much longer than the plasma wavelength, when the condition of the focusing is appropriately controlled.
Three-dimensional electron motion in a linearly polarized tightly focused laser field is numerically calculated. A high-intensity laser pulse focused on the free electrons in vacuum generates relativistic electron bunches whose length is shorter than the laser wavelength. The extremely short electron bunches with low-energy spread less than 1% are generated for a wide range of the laser parameters.
We have demonstrated the acceleration of a monoenergetic electron beam
by a laser-produced wakefield. Experiments were performed by focusing 2-TW
laser pulses of 50 fs on supersonic gas-jet targets. The focused intensity
was 5 × 1018 W/cm2 (a0
= 1.5). At an electron density of 1.5 × 1020
cm−3, the clear monoenergetic electron beam from the
plasma was obtained at 7 to 15 MeV. The Stokes satellite peak in the
forward scattering explained the energy spectra of electrons at various
plasma densities well. Although the wakefield propagated 500 microns,
which was far beyond the dephasing length, monoenergetic electron beams
Experiments and numerical simulations are carried out to verify the existence of the acoustic solitary wave in an air-filled tube with an array of Helmholtz resonators connected. Following up previous work (Sugimoto et al. 1999), the experiments are improved by using a newly designed piston driver to launch an initially plane pressure pulse and also by extending the tube length from 7.4 m to 10.6 m. To highlight the effect of the array of resonators, the case with no array is also examined in parallel. Direct and indirect checks are made to verify the existence of the solitary wave. The former compares the profiles and propagation speeds of pulses measured experimentally to the solitary-wave solution. The latter checks the validity of nonlinear wave equations in describing real wave evolution in the tube. Solving an initial-value problem numerically with weakly lossy effects of boundary layers and jet loss at the throat of the resonator, comparison is made between measured and simulated evolution. The validity of the equations in the lossy case is necessary to maintain the existence of the solitary wave in the lossless limit. It is revealed that nonlinear wave equations originally derived for unidirectional propagation in the tube can provide a good description of the real evolution, with some allowance for phase shifts on reflection at both ends of the tube. In particular, it turns out that the lossy effects are described quantitatively well. By establishing the validity of the equations, it is concluded that the acoustic solitary wave exists.
More than 4000 stars observed in both MOA and DENIS projects showing periodic or quasi-periodic light curves are studied. Almost all Mira stars are located on the classical period-luminosity relation, and the multiplicity of the period-luminosity relation is confirmed for small-amplitude stars. The colour-magnitude diagrams based on the MOA red band, Rm, and Ks constructed for the sequences, form a single strip with small successive shifts.
A room temperature scanning micro-Hall probe microscope (RT-SHPM) was used for imaging stray magnetic field fluctuations at the surfaces of strontium ferrite permanent magnets (SFM) in the presence of external bias fields. The RT-SHPM enables the extremely fast, non-invasive, and quantitative measurement of localized surface magnetic fields on the sub-micron-scale. A 0.8 × 0.8 μm2 GaAs/AlGaAs micro-Hall probe (300K Hall coefficient =0.3ω/G; field sensitivity=0.04 G/√Hz ) with an integrated STM tip for precise vertical positioning was used as a magnetic field sensor. External bias fields (Hex) of up to 2700 Oe were applied parallel to the easy and hard axes of thermally demagnetized SFMs. Sample areas of up to 50×50 μm were imaged at a height of 0.3 μm above the SFM surface for each Hex, with scan speeds of approximately one frame/second (128×128 pixels) enabling quasi-real time imaging in synchronization with bias field changes. RT-SHPM images of surfaces normal to the easy axis of demagnetized samples at Hex=0, clearly showed the presence of 8-15 μm sized domains and stray magnetic field fluctuations of ±200G; images of surfaces normal to the hard axis showed 20 μm sized domains with magnetic field fluctuations of ±100G. Pronounced domain movement and rotation was observed for surfaces normal to the easy axis at bias fields above 700 Oe applied along the easy axis. A good correlation was found between domain movement and vibrating sample magnetometer hysteresis measurements. The RT-SHPM system was demonstrated to be a valuable tool for the direct and non-invasive study of micro-magnetic phenomena in ferromagnetic materials.
The Co/Pd and Co/Pd artificial lattice films have attracted much interest by their special magnetization properties. We discussed the effect of the Pt, Pd layer thickness on the magnetic anisotropy, and we showed the effect of the hydrogen ion implantation on the magnetic properties of multi-layered films. The Co/Pt and Co/Pd multi-layered films were formed on Si(111) substrates with molecular beam epitaxy. We did structure analysis, magnetic domain analysis and magnetic properties evaluation with XRD, MFM and VSM, respectively. Among the series of films of 0.4nm Co layer, XRD showed that the film of 1.0nm Pt layer had a highest periodicity and that they had (111) plane orientation completely. The magnetic domain size reduced with the increase of the thickness of Pt layer. We found out that the coercivity decreased linearly as a function of the length of magnetic domain wall in the unit area. The result of VSM showed that the multi-layered films of Pt thickness of less than 2.8nm had perpendicular magnetic anisotropy. The perpendicular anisotropy energy changed by the nonmagnetic layer thickness and had a maximum value for 0.4nm Co 0.4nm/ nonmagnetic metal 1.0nm multi-layered film. After hydrogen implantation into the films, XRD showed that the lattice spacing was swelled with hydrogen dose. Also, MFM observed that the magnetic domain size reduced with the increase of the hydrogen dose. The easy axis of magnetization changed from perpendicular to parallel in the plane with the increase of the hydrogen dose. After evacuation of hydrogen at 473K, perpendicular anisotropy was partially recovered. This phenomenon suggested that the origin of magnetic anisotropy was mainly the lattice mismatch and distortion in the layer interface. But Co/Pd film was not recovered by this thermal treatment. This means that Pd made stable hydride and did not evacuate hydrogen at this temperature.