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A simulation-aided defect reconstruction method using an ultrasonic time-reversal approach that uses elastic constants determined by ultrasonic field data is proposed. Scattered waves from a defect are recorded using an array probe on a polystyrene wedge and the time-reversed waves are re-emitted in a finite element simulation. The target defect in these experiments is an electrical discharge machined slit in unidirectionally solidified SUS316L stainless steel. For the timereversal analysis, two kinds of elastic constant of SUS316L derived from an electromagnetic acoustic resonance (EMAR) method and a laser scanning ultrasonic visualisation method are used. The through-wall extent of the electrical discharge machined slit can be visually estimated from the focal point of the ultrasonic wave in the numerical model using the elastic constants determined by the laser ultrasonic method. This provides a proof of principle that the method is working. [ABSTRACT FROM AUTHOR]

Plasma turbulence tomography is now working to show a two dimensional structure and dynamics of plasma turbulence in a cylindrical plasma device, PANTA. A new method, the Stokes parameter analysis on moment vectors, is being developed to treat the image of plasma turbulence and extract hidden characteristics of polarization or rotation of spatial patterns created in turbulent plasmas. The article presents the explanation of the method and the application results obtained from a PANTA plasma. [ABSTRACT FROM AUTHOR]

Fourier-rectangular function (FRF) transform [K. Yamasaki et al., J. Appl. Phys. 126, 043304 (2019)] is used to analyze the structure and dynamics of plasma with cylindrical symmetry. In this article, a new technique based on FRF transform is proposed to elucidate the polarization characteristics of azimuthal modes and fluctuations. The application results are shown for a two-dimensional tomography image of linear cylindrical plasma. The method successfully resolves the polarization characteristics of azimuthal modes and attributes the intermittent behavior of the m = 1 mode to its polarization characteristics. [ABSTRACT FROM AUTHOR]

A Rogowski probe consisting of a small multi-layer Rogowski coil, five magnetic pick-up coils, and a Langmuir probe was developed to measure the local current density and its direction. It can be moved along the major radius and can be turned around its axis. This probe was used to measure the current density profile near the last closed flux surface of Ohmic plasmas in Tokyo Spherical Tokamak-2. The current density profile was measured successfully with a signal to noise ratio of greater than 20. [ABSTRACT FROM AUTHOR]

This article presents a method to estimate the rotational velocity of a cylindrical plasma from its two-dimensional images by an extended use of the Fourier-rectangular function transform, which was proposed to analyze the structure and dynamics of a cylindrical plasma [K. Yamasaki e t a l., J. Appl. Phys. 126 , 043304 (2019)]. The proposed method is applied to tomography images of plasmas produced in a linear cylindrical device and succeeds in obtaining the radial distribution of rotational velocity and its fluctuations, providing an interesting finding, that is, the existence of flow modulation associated with m = 1 mode fluctuations. [ABSTRACT FROM AUTHOR]

A letter to the editor is presented which discusses the case of a 75-year-old woman with one month history of yellowish rhinorrhoea, nasal stuffiness, and nasal epistaxis who was diagnosed with lipid-rich carcinoma.

Multipoint detection is an essential requirement for investigating plasma turbulence which is a highly nonlinear phenomenon in space and time. We have fabricated an array of 64-channel poloidal probes surrounding the linear cylindrical plasma named LMD-U in order to study turbulence properties, particularly the nonlinear mode couplings, in the domain of poloidal wave number and frequency. However, misalignments of probe tips produce spurious modes, which do not exist in the real plasma, to distort the precise wave number measurements. The paper presents the description of the 64-channel poloidal probe array with means to adjust the probe positions, with discussion on the effects of the misalignments on the wave number measurements. [ABSTRACT FROM AUTHOR]

A liquid chromatography/electrospray ionization-single quadrupole mass spectrometry (LC/ESI-MS) method was developed to quantify seven arsenic compounds: arsenate (As(V)), monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenobetaine (AB), trimethylarsine oxide (TMAO), arsenocholine (AC) and tetramethylarsonium ion (TEMA), widely found in seafood. The arsenicals separated by anion- or cation-exchange LC were all readily identified under the optimized ESI-MS conditions. Linear calibration curves constructed by plotting the peak area counts of molecular ions against the arsenic concentrations were obtained for all seven arsenic compounds. The limits of quantification (S/N = 10) were 800, 600, 50, 10, 5, 5 and 5 ng ml-1 for As(V), MMA, DMA, AB, TMAO, AC and TEMA, respectively. The LC/ESI-MS method was found to be useful to quantify arsenic compounds in seafood by model experiments using the mid-gut gland and muscle of a shellfish (Buccinid whelks). Spiking experiments verified the accuracy of the method. [ABSTRACT FROM AUTHOR]

A convergence study of bispectral analysis on toroidal plasma turbulence is presented with a theoretical estimate of bicoherence for the system of the drift wave and zonal flow. Examples are chosen from the analysis of floating potential fluctuation in the edge region of the JFT-2M tokamak. The convergence properties of the bispectral functions are clarified for an oscillatory branch of zonal flow (or geodesic acoustic mode) and drift waves. The total squared bicoherence or the biphase converges inversely proportional to the realization number or to the square root of the realization number, respectively. The numbers of realizations to qualitatively converge and obtain a quantitatively significant value of bicoherence are discussed for the drift wave fluctuations and for the zonal flow. [ABSTRACT FROM AUTHOR]

The bicoherence of fluctuations in a system of drift waves and zonal flows is discussed. In strong drift-wave turbulence, where broadband fluctuations are excited, the bicoherence is examined. A Langevin equation formalism of turbulent interactions allows us to relate the bicoherence coefficient to the projection of nonlinear force onto the test mode. The dependence of the summed bicoherence on the amplitude of zonal flows is clarified. The importance of observing biphase is also stressed. The results provide a basis for measurement of nonlinear interaction in a system of drift waves and zonal flow. [ABSTRACT FROM AUTHOR]

An analysis method is developed for imaging measurement systems, such as the tomography system or fast camera imaging, in order to extract the spatial structure properties of fluctuation. In this analysis method, rectangular functions and Fourier series are adopted for the basis functions of the radial and azimuthal coordinates, respectively. The examples of this analysis method show that this method is useful for quantifying the spatial structure of the 2D image such as the radial profile of the power and the rotation angle of each azimuthal mode. The method proposed in this article allows us to elucidate the features of the 2D spatial structure of phenomena in magnetized plasma. [ABSTRACT FROM AUTHOR]

36Cl is a long-lived radioisotope, which, because it is created mainly through a thermal neutron capture process by 35Cl, may be used to estimate the strength of thermal neutron flux from A-bombs or nuclear fuel facilities. The 36Cl contents in granite samples from the Hiroshima A-bomb site have been measured by the Cl-36 accelerator mass spectrometry (AMS) system at the University of Tsukuba. The 36Cl/Cl ratios deduced from the 36Cl measurements are compared with independent evaluations based upon the Dosimetry System 2002 (DS02) of the radiation doses received by the survivors of the Hiroshima A-bomb. The measurements corresponded well up to a ground distance of 1100 m, which proved the effectiveness of the DS02. Measurements of the 36Cl/Cl ratio of unexposed granite samples were 1.92 × 10-13 on average, and because the measured ratio for samples at a ground distance of 1163 m was 2.50 × 10-13, the assessment of the neutron flux by the 36Cl measurements of samples beyond about 1100 m is not practical. This limitation arises from the inability to distinguish bomb-induced Cl-36 from activation due to ambient sources. [Copyright &y& Elsevier]

An antibacterial protein in the skin secretion of rockfish (Sebastes schlegeli) was purified by lectin affinity chromatography on Con A-Sepharose and gel filtration on TSKgel G3000SW. The antibacterial protein featured the high molecular mass and selective action against Gram-negative bacteria. The molecular mass of the protein was estimated to be approximately 150 kDa in gel filtration and approximately 75 kDa by SDS-PAGE, suggesting that it is dimeric. The antibacterial principle was an acidic glycoprotein with pI 4.5, 3.4% reducing sugar and 2.8% amino sugar. Its sugar chains had N-type (high mannose-type) oligosaccharide and sialic acid components. It inhibited strongly the growth of Aeromonas salmonicida, Photobacterium damselae and Shewanella putrefaciens with a minimum inhibitory concentration (MIC) of approximately 3 μg/ml, and moderately the growth of Vibrio parahaemolyticus and A. hydrophila with a MIC of 12.5 μg/ml and 25 μg/ml, respectively. The values of the minimum bactericidal concentration were almost equivalent to those of MIC. The potent sensitivity against virulent pathogens such as A. hydrophila, A. salmonicida and P. damselae may contribute considerably to the innate host defense mechanism to combat microbes on the mucosal surfaces of the rockfish. [Copyright &y& Elsevier]

A new electron Bemstein wave emission diagnostic consisting of a heterodyne radiometer and a reflectometer was installed on TST-2. The instrument has a frequency range from 5 to 12 GHz which covers partially the fundamental and fully covers the second and third harmonic emissions. X-mode emission perpendicular to the flux surface, generated by B-X-FX mode-conversion scenario, is measured. The mode-conversion efficiency is calculated using a one-dimensional full-wave code with the density profile obtained simultaneously from the reflectometer, and the electron temperature (T[sub e]) is estimated. The levels corresponding to the 100-150 eV range are measured from the plasma core region, and the mode-conversion efficiency is calculated to be 0.5-0.8, leading to T[sub e] of approximately 200 eV. In addition, it is found that the reflectivity measured by the reflectometer is consistent with the calculated mode-conversion efficiency. This property can be used for a direct measurement of the mode-conversion efficiency. [ABSTRACT FROM AUTHOR]

A new positron lifetime spectrometer has been constructed and tested. It consists of a state-of-the-art digital oscilloscope (LeCroy Wavepro 960) and scintillation detectors based on Hamamatsu H3378 (R2083Q) photomultiplier tubes and BaF2 scintillators. A very good time resolution is obtained with scintillators of commonly used sizes (28 mm in diameter, 10–20 mm thick) and wide energy window settings (40–50%). The time resolution of 144 ps full-width at half-maximum (FWHM) is achieved for the positron lifetime measurement, in which time differences are measured between the arrivals of a 1.27 MeV γ-ray from 22Na and one of the two positron annihilation γ-rays of 0.511 MeV. The time resolution is further improved with a ‘double-stop’ setup, where timing information carried by the positron annihilation γ-ray pair is combined to determine the time of the annihilation. The time resolution with this setup is 119 ps FWHM. This improvement is interpreted in terms of the energy deposit in the scintillation detectors by γ-rays. Applications of the new spectrometer to other scintillation timing measurements are also described. [Copyright &y& Elsevier]

Abstract: Ionization cross sections for Cu K-shell by positron impact in the energy range between 10 and 30keV have been calculated using the three-body classical trajectory Monte Carlo method and the binary encounter model. We have found that the classical treatment of the collision describes reasonably well the ionization cross sections measured recently. [Copyright &y& Elsevier]

The domain structure and magnetization process of Nd-Cu-diffused magnets prepared from hydrogenation-disproportionation-desorption-recombination (HDDR)-processed powders and Nd-Cu powders were examined with a high-resolution Kerr microscope using an ultraviolet light source. We found that the coercivity of the HDDR magnet depends on the volume of magnetically coupled grains that simultaneously reverse their magnetization. In a magnet that has no Nd-Cu, and in which the Nd-rich phase along the grain boundaries is absent, magnetization reversal simultaneously occurs in several grains. In contrast, in a Nd-Cu-diffused magnet that contains adequate Nd-rich phases along the grain boundaries, magnetization reversal occurs independently in each grain. It follows that the change in microstructure caused by the presence of Nd-Cu leads to a decoupled magnetization reversal, and domain wall pinning is an important coercivity mechanism of an HDDR magnet compacted by hot-pressing. [ABSTRACT FROM AUTHOR]

Four types of composite torsion antennas for low-frequency gravitational radiation have been developed and tested at low temperature. They exhibited high quality factors comparable with that of a single-piece antenna. These experiments suggest a large-scale composite antenna may be built and retain a high quality factor. [ABSTRACT FROM AUTHOR]

The conditional average is a technique to extract a typical waveform from bursty or quasi-periodic phenomena regarded as a combination of deterministic trend and residual fluctuations (or probabilistic part). The article proposes a new conditional average technique that is an extension from what is called the template method that allows automatic selection, using the correlation analysis, of the identical events of the phenomena. The proposed method is applied on a quasi-periodic oscillation observed in a linear magnetized plasma, and successfully divides the phenomenon into the deterministic trend and residual fluctuations. Moreover, the statistical error analysis on the power of the residual fluctuations discloses the presence of mutual interactions between the deterministic trend and the residual fluctuations. [ABSTRACT FROM AUTHOR]

The synchronization of geodesic acoustic modes (GAMs) and magnetic fluctuations is identified in the edge plasmas of the HL-2A tokamak. Mesoscale electric fluctuations (MSEFs) having components of a dominant GAM, and m/n=6/2 potential fluctuations are found at the same frequency as that of the magnetic fluctuations of m/n=6/2 (m and n are poloidal and toroidal mode numbers, respectively). The temporal evolutions of the MSEFs and the magnetic fluctuations clearly show the frequency entrainment and the phase lock between the GAM and the m/n=6/2 magnetic fluctuations. The results indicate that GAMs and magnetic fluctuations can transfer energy through nonlinear synchronization. Such nonlinear synchronization may also contribute to low-frequency zonal flow formation, reduction of turbulence level, and thus confinement regime transitions. [ABSTRACT FROM AUTHOR]

A tomography system is developed for observing local fluctuations, pursuing higher spatial resolution, over the entire plasma of a linear cylindrical plasma. The system is equipped with totally 126 lines-of-sight that are distributed equally to six sets of light guide arrays placed around the plasma. The system has succeeded in measuring the two-dimensional structure of plasma emission and resolving coherent fluctuation structures, with spatial resolution comparable to the ion Larmor radius. [ABSTRACT FROM AUTHOR]

It is a critical issue to find the best set of fitting function bases in mode structural analysis of two dimensional images like plasma emission profiles. The paper proposes a method to optimize a set of the bases in the case of Fourier-Bessel function series, using their orthonormal property, for more efficient and precise analysis. The method is applied on a tomography image of plasma emission obtained with the Maximum-likelihood expectation maximization method in a linear cylindrical device. The result demonstrates the excellency of the method that realizes the smaller residual error and minimum Akaike information criterion using smaller number of fitting function bases. [ABSTRACT FROM AUTHOR]

Measurements of edge plasma parameters such as current density, electron density, and electron temperature were performed during internal reconnection events in TST-2 Ohmic plasmas. The measured current density consists of two components: a slowly varying component and a spiky bipolar component. The magnitude of the slowly varying component is comparable to the mean current density averaged over the poloidal cross section, and it seems to represent the global transport from the core to the edge. The spiky bipolar component is about an order of magnitude larger than the slowly varying component, but the spatial structure seems to be localized and its effect on plasma confinement is not catastrophic. [ABSTRACT FROM AUTHOR]

A heavy ion beam probe (HIBP) has been designed for the QUEST spherical tokamak to measure plasma turbulence and the profiles of electric potential profiles. Using a cesium ion beam with an energy of several 10 keV, the observable region covers most of the upper half of the plasma. Although the probe beam is deflected by the poloidal magnetic field produced by plasma current and poloidal coil currents, it can be detected under plasma current up to 150 kA by modifying the trajectories with two electrostatic sweepers. According to the numerical estimation of the intensity of the detected beam, sufficient signal intensity for measuring plasma turbulence can be obtained over almost the measurable area when the electron density is up to 1 × 1019 m−3, which is larger than the cut-off density of electron cyclotron heating in QUEST. The performance of the designed HIBP is sufficient to explore the mechanisms of heat and particle transport in magnetically confined plasmas, including the influence of plasma wall interactions, which is a goal of the QUEST project. [ABSTRACT FROM AUTHOR]

In TST-2 Ohmic discharges, local current is measured using a Rogowski probe by changing the angle between the local magnetic field and the direction of the hole of the Rogowski probe. The angular dependence shows a peak when the direction of the hole is almost parallel to the local magnetic field. The obtained width of the peak was broader than that of the theoretical curve expected from the probe geometry. In order to explain this disagreement, we consider the effect of sheath in the vicinity of the Rogowski probe. A sheath model was constructed and electron orbits were numerically calculated. From the calculation, it was found that the electron orbit is affected by E × B drift due to the sheath electric field. Such orbit causes the broadening of the peak in the angular dependence and the dependence agrees with the experimental results. The dependence of the broadening on various plasma parameters was studied numerically and explained qualitatively by a simplified analytical model. [ABSTRACT FROM AUTHOR]

We have investigated the positron-stimulated desorption of ions from a TiO2(l10) surface. Desorbed O+ ions were detected in coincidence with the emission of annihilation γ rays. The energy dependence of the ion yields shows that the O+ ions were detected at energies much lower than the previously reported threshold for electron impact desorption corresponding to the excitation energy of Ti(3p) core electrons. These results provide evidence that core-hole creation by positron annihilation with electrons in the core levels leads to ion desorption. [ABSTRACT FROM AUTHOR]

This paper presents the experimental identification of the dynamic interaction between three fluctuations excited by different thermodynamical forces in a linear plasma. The observed fluctuations are characterized as an axial symmetric mode, a drift wave, and an azimuthally symmetric potential fluctuation from the spatiotemporal structures measured with Langmuir probe arrays. The intermittent burst of the axial symmetric mode is observed by the instantaneous wave number spectrum. The energy transfer analysis revealed that the axially symmetric mode gains energy from the other mode during the burst while the drift wave loses energy. The intermittent burst synchronizes with the azimuthal symmetric potential fluctuation. [ABSTRACT FROM AUTHOR]

A self-nonlinear process involving the geodesic acoustic mode (GAM) was analyzed. GAMs nonlinearly excite higher harmonics as quasimodes. In the fluid picture, the Reynolds stress is modeled by the drift wave action. Other nonlinear terms such as the coupling between parallel velocity and vorticity, and between density and vorticity, were also considered, and evaluated using linear eigenmodes. We considered nonlinearities up to the third order. Analytic expressions for the amplitude of the second harmonic GAM and the saturation level of the fundamental GAM were derived. The validity of the theory is discussed based on a comparison of experimental results with theoretical predictions. [ABSTRACT FROM AUTHOR]

Abstract: We have measured the 36Cl/Cl ratio of uncultivated surface soil samples collected from 11 areas distributed throughout Japan to determine the undisturbed value of the ratio. The ratio was found to be on the order of 10−13 except for the Tokai-mura area, where four research reactors, two commercial nuclear power plants and a nuclear fuel reprocessing plant have been operated. The observed ratio in the Tokai-mura area was higher than 10−12. Notably, soil samples collected from a site of commercial BWR nuclear power plants in Fukushima prefecture showed no significant increase in 36Cl/Cl ratio. The 36Cl/Cl ratio depth profiles of soil samples collected at both of Makabe-town and Tokai-mura were also measured. Since Makabe-town is located about 50km apart from Tokai-mura, we do not expect it to be affected by the nuclear facilities. No large variations were observed in the Makabe depth profile; the measured ratios ranged from ∼3 to ∼5×10−13. The result obtained for Tokai-mura is significantly different in that from the surface to about 80cm depth, the measured ratios, ∼10−12, are much higher than any at Makabe. At depth below 80cm, the Tokai-mura ratios are lower and become indistinguishable from those at Makabe. The 36Cl/Cl ratio in unaffected areas of Japan is estimated to be 3–4×10−13. [Copyright &y& Elsevier]

Abstract: Heated extracts prepared from the mantle muscles (for decapods) or leg muscles (for octapods) of nine species of cephalopods were shown to be all reactive with serum IgE in crustacean-allergic patients. No marked difference in the reactivity with IgE was recognized among the cephalopods, suggesting that they are almost equally allergenic. Immunoblotting and inhibition immunoblotting data revealed that the major allergen is tropomyosin in common with the nine species of cephalopods and that the cephalopod tropomyosins are cross-reactive with one another and also with crustacean tropomyosins. Molecular cloning experiments first elucidated the primary structures of tropomyosins from five species of cephalopods. The cephalopod tropomyosins show high sequence identity (more than 92% identity) with one another, being the molecular basis for their cross-reactivity. Although the sequence identity between cephalopod and crustacean topomyosins is only about 63–64%, some of the IgE-binding epitopes proposed for brown shrimp Penaeus aztecus tropomyosin (Pen a 1) are well conserved in the cephalopod tropomyosins, supporting the cross-reactivity between cephalopod and crustacean tropomyosins. [Copyright &y& Elsevier]

Abstract: The mystery of 26Al origin has made the nuclide important in the astrophysics. It was proposed that the reaction, 14N(16O,α)26Al, may be one of the origin of the source of 26Al in the cosmic. In his work, the 26Al was measured with AMS by using full-stripping method, and the cross-sections of these reactions for around sub-barrier energies were deduced. The experiment details are described and the results represented. [Copyright &y& Elsevier]

Positronium emission from wurtzite GaN(0001) and AlN(0001) surfaces was observed by positronium time-of-flight spectroscopy. The positronium energy spectra contained two positronium components distinguished by their energies. Through detailed analyses based on Monte Carlo simulations, these two components were attributed to positronium formed from valence and conduction electrons. The obtained results augment the previous arguments regarding the contribution of conduction electrons to positronium emission from 4H SiC(0001) and Si(111) surfaces. [ABSTRACT FROM AUTHOR]

Heme oxygenase-1 (HO-1) is an inducible heat shock protein that regulates heme metabolism to form bilirubin, ferritin and carbon monoxide. Based on recent evidence that HOI is involved in the resolution of inflammation by modulating apoptotic cell death or cytokine expression, the present study examined whether overexpression of exogenous HO1 gene transfer provides a therapeutic effect on a murine model of acute lung injury caused by the type A influenza virus. We demonstrate herein that the transfer of HO-1 cDNA resulted in (1) suppression of both pathological changes and intrapulmonary hemorrhage; (2) enhanced survival of animals; and (3) a decrease of inflammatory cells in the lung. TUNEL analysis revealed that HO-1 gene transfer reduced the number of respiratory epithelial cells with DNA damage, and caspase assay suggested that HO-1 suppressed lung injury via a caspase-8-mediated pathway. These findings suggest the feasibility of HO-1 gene transfer to treat lung injury induced by a pathogen commonly seen in the clinical setting. Since oxidative stress and lung injury are involved in many lung disorders, such as pneumonia induced by a variety of microorganisms and pulmonary fibrosis, HO-1 may be useful for wider clinical applications in gene therapy targeting lung disorders including acute pneumonia and pulmonary fibrosis. [ABSTRACT FROM AUTHOR]

Heavy ion beam probe (HIBP) systems have been designed for the new tokamak, PLATO [A. Fujisawa, AIP Conf. Proc. 1993, 020011 (2018)]. The designs have been completed, and the installations are in progress. Two HIBPs are being installed in toroidal sections 180° apart to investigate long-range correlations in the toroidal direction. Each HIBP consists of an injection beamline and a detection beamline as usual. Yet, one of the HIBPs is equipped with an additional detection beamline; the measurement positions of its two detection beamlines can be placed on almost the same magnetic surface yet at poloidal angles that differ by ∼180°. The use of three detection beamlines allows us to investigate spatial asymmetry and long-range correlations in both the toroidal and poloidal directions, simultaneously. The detected beam intensity is expected to be enough for turbulence measurements in almost the entire plasma region when the electron density is up to 1 × 1019 m−3 by selecting appropriate ion species for the probe beam. Each detector has three channels 10 mm apart, allowing measurement of local structures of micro-scale turbulence. Therefore, using the HIBPs on the PLATO tokamak will enable both local and global properties of plasma turbulence to be investigated, simultaneously. [ABSTRACT FROM AUTHOR]

Long-lived chlorine, 36Cl (T1/2 = 301,000 y) in environmental samples has been measured by the AMS system installed in Tandem Accelerator Center, University of Tsukuba. A tri-carbon-molecular 12C3- pilot beam method is used to stabilize the terminal voltage of the tandem. A small amount of pure carbon graphite is well mixed into a AgCl target material for creating Cl- and 12C3- in the ion source. A 36S isobaric interference in the system is eliminated to determine 36Cl in environmental samples by chemical procedure. Some samples containing chlorine such as soil, chemical reagents and table salt have been collected in the JCO criticality accident site and analyzed to detect neutron-induced 36Cl. The experimental result has been compared with a theoretical calculation. [ABSTRACT FROM AUTHOR]

A Kerr microscope that uses UV light for high-resolution observation of magnetic domains was developed, and the domain structure and magnetization process of hot-pressed magnets prepared from hydrogenation-disproportionation-desorption-recombination (HDDR) processed powders were examined. This microscope is capable of distinguishing nanometer-sized domain patterns. The coercivity of the hot-pressed HDDR magnet depends on the area of magnetization reversal during a reversal process. Magnetization reversal occurs simultaneously in a few grains in a low-coercivity magnet because the Nd-rich phase along the grain boundaries is absent. In contrast, in a high-coercivity magnet, magnetization reversal in a grain independently occurs because of an adequate Nd-rich phase along the grain boundaries. It follows that the high coercivity of an HDDR powder compacted by hot pressing is due to domain wall pinning at the grain boundaries. [ABSTRACT FROM AUTHOR]

• Plasma current seems to flow in the open magnetic surface in the outside of the closed magnetic surface in the low-field region. • Considering the toroidal rotation, the equilibrium is fitted within nested magnetic surfaces by SU-EFIT. • Sum of contributions from toroidal rotation and pressure gradient to plasma current density is constant. In the EC-driven (8.2 GHz) steady-state plasma on QUEST, plasma current seems to flow in the open magnetic surface in the outside of the closed magnetic surface in the low-field region according to plasma current fitting method without taking equilibrium into account. In our previous work, plasma equilibrium solution was fitted assuming all plasma current is flowing in the inside of the Last Closed Flux Surface (LCFS). It was solved within isotropic pressure profile by EFIT code. Opposite-polarity current density region appeared in the high-field region. Here in this article, considering the toroidal rotation, the equilibrium is fitted within nested magnetic surfaces by SU-EFIT. Though the plasma magnetic axis shifts outward due to the centrifugal force, the opposite polarity current does not disappear in the high-field region. And relation between the toroidal rotation speed and the poloidal beta value will be discussed. [ABSTRACT FROM AUTHOR]

• New high voltage power supply (PS) for a klystron has been developed. • This PS is used for the electron cyclotron heating (ECH). • 8.56 GHz-RF with the PS will be a promising ECH system in QUEST spherical tokamak. • An IGBT and a reactor can shut down the PS quickly to protect the klystron. • AC switching has been set up for the overload and overheat of the PS. A high voltage DC power supply for the cathode of the 8.56 GHz CW klystron has been set up for electron cyclotron heating (ECH) in steady state tokamak operation on QUEST spherical tokamak. The power supply is equipped with an IGBT array and a reactor for fast shutoff of the voltage in 10 μs, where the influx of electric energy at the short circuit is limited to 5 J. AC switches also have been installed in the three-phase power lines. High voltage relays are useful to save electric energy consumption. Fast three-phase AC switching by IGBT-stack is applicable to reduce the electric load of the components of the klystron power supply. [ABSTRACT FROM AUTHOR]

New polarizer and launcher systems on a 28-GHz electron-cyclotron (EC) heating and current drive (HCD) system have been developed for non-inductive second-harmonic EC-plasma-current ramp-up in the QUEST spherical tokamak. A launcher system with two quasi-optical mirrors providing beam steering capability was designed to focus the incident beam to a small-sized waist of ∼0.05 m at the second-harmonic EC resonance layer. A relatively large focusing mirror was designed based on a Kirchhoff integral code developed to derive wave solutions. The focusing property of the launched beam was first confirmed with a 3-dimensional (3D) electromagnetic-wave simulator. Focusing characteristics were also checked at low-power test facilities, together with the steering capability. The performance of this launcher system was demonstrated to work as designed, and assembled in the QUEST device. The system was applied to the non-inductive second-harmonic EC plasma ramp-up experiments with no optimization required regarding the incident polarization. The results obtained for the non-inductive plasma ramp-up are also presented. [ABSTRACT FROM AUTHOR]

Purpose: Incisional hernia is a major complication after stoma closure and can cause uncomfortable symptoms. In this study, we evaluated the risk factors for hernia formation with the aim of reducing the incidence of incisional hernia.Methods: A total of 134 oncology patients underwent closure of a temporary loop ileostomy between May 2004 and December 2013. The incidence of incisional hernia was determined by routine follow-up computed tomography scanning every 6 months. The relationships between patients' characteristics, including age, sex, obesity, diabetes mellitus, surgical site infection, chronic obstructive pulmonary disease, hypertension, hypoalbuminemia, smoking, and presence of a midline hernia and the occurrence of incisional hernia were retrospectively evaluated.Results: The median follow-up time was 47 months (range 8-130). Hernias occurred in 23.9% of patients (32/134). The median time to detection of hernias was 8 months (range 2-39). The Chi-squared test revealed significant differences in obesity (P = 0.0003), hypertension (P = 0.0057), and incisional hernia history (P = 0.0000) between patients with and without incisional hernia. Multivariable analysis and univariate analysis revealed that hypertension and the presence of midline incisional hernia were risk factors for incisional hernia.Conclusions: Hypertension and the presence of a midline incisional hernia were the major risk factors for incisional hernia after loop ileostomy closure. These risk factors can be addressed before planning surgery. [ABSTRACT FROM AUTHOR]

We experimentally investigate the roles of drift wave type fluctuations interacting with zonal flow. The drift wave type fluctuations examined in this paper are characterized by nonlinear solitary wave, splash, and solitary eddy [Arakawa et al., Sci. Rep. 6, 33371 (2016)]. Compared to the nonlinear solitary wave, splash has a short lifetime, while solitary eddy has a long lifetime. Excitation/damping of the splash and the solitary eddy are synchronized with zonal perturbation. The roles of the splash and the solitary eddy in transport processes are also discussed. Solitary eddy contributes to momentum transport and accelerates zonal flow. The particle flux driven by the solitary eddy and the splash is in the inward and outward directions, respectively, with similar magnitudes. [ABSTRACT FROM AUTHOR]