Effect of Pressure on the Curie Temperature of CrTe and MnSb Compounds of the Nickel Arsenide Type

The effect of the pressure on the Curie temperature of CrTe and MnSb compounds of the nickel arsenide type structure were studied up to 4, 000 kg/cm^2. The rate of change of the Curie temperature was -5.5×10^℃ kg^cm^2 for CrTe and (-3.2±0.5)×10^℃ kg^cm^2 for MnSb. From the result of the present experiment, the critical pressure and temperature to realize a first kind transition from a ferromagnetic to a paramagnetic state in CrTe are evaluated to be 41, 000 kg/cm^2 and 107°K, respectively

Impurity Effects on the Energy Gap in Fe-doped Bi2212

We performed scanning tunnelling microscopy/spectroscopy (STM/STS) on Fe-doped Bi2212. The Fe substitution for Cu causes a strong spatial inhomogeneity in STS spectra. The energy gap (Δ1 ∼80mV) has a sub-gap (Δ2 ∼70mV) in some distinct locations on the sample surface. We find that the gap edge peaks are largely depressed and only the sub-gap survives across the region where the spatial modulation of the local density of states is stronger. This indicates, that Δ1 anti-correlates with Δ2.Conference : 20th International Conference on Magnetism, ICM 2015Location : Barcelona, SPAINDate : JUL 05-10, 201

Brain Metastasis from Gastrointestinal Stromal Tumor: A Case Report and Review of the Literature

Metastasis of gastrointestinal stromal tumor (GIST) into the central nervous system is extremely rare. We report a patient with synchronous GIST and brain metastasis. At disease onset, there was left hemiplegia and ptosis of the right eyelids. Resection cytology of the brain tumor was reported as metastasis of GIST. After positron emission tomography examination, another tumor in the small bowel was discovered, which suggested a small bowel GIST associated with intracranial metastasis. Immunohistochemical analysis of the intestinal tumor specimen obtained by double balloon endoscopy showed a pattern similar to the brain tumor, with the tumors subsequently identified as intracranial metastases of jejunal GIST. After surgical resection of one brain tumor, the patient underwent whole brain radiation therapy followed by treatment with imatinib mesylate (Gleevec; Novartis Pharma, Basel, Switzerland). Mutational analysis of the original intestinal tumor revealed there were no gene alterations in KIT or PDGFRα. Since the results indicated the treatment had no apparent effect on either of the tumors, and because ileus developed due to an intestinal primary tumor, the patient underwent surgical resection of the intestinal lesion. However, the patient's condition gradually worsen and she subsequently died 4 months after the initial treatment

Bremsstrahlung X-ray Spectra for Enhanced K-edge Angiography

Energy-selective enhanced K-edge angiography utilizing a conventional x-ray generator is described. The x-ray generator is SOFRON NST-1005, and the maximum tube voltage and current are 100 kV and 5 mA, respectively. In the present research, the tube voltage ranged from 45 to 65kV, and the tube current was regulated to optimum values. The exposure time is controlled in order to obtain optimum x-ray intensity. At a charging voltage of 60 kV, the x-ray intensity rate obtained using an aluminum and a barium sulfate filters were 58.4 and 51.6 μGy/s at 0.7m per pulse, respectively, and the dimensions of the focal spot were approximately 1×1 mm. Angiography was performed using both the aluminum and the barium sulfate filters with a charging voltage of 60 kV

Development of an extremely soft x-ray generator

The development of an extremely soft x-ray generator with a tungsten-target tube and its applications including radiography are described. This generator consists of a high-voltage transformer, a filament power supply, and an x-ray tube. Negative high voltages are applied to the cathode electrode in the x-ray tube, and the tube voltage and current are regulated by the input voltage of the transformer and the filament voltage, respectively. The x-ray tube is a glass-enclosed double-focus diode with a tungsten target and a 0.2 mm-thick beryllium window. The maximum tube voltage and the electric power were 60 kV and 400 W, respectively. The focal-spot sizes were 4×4 (large) and 1×1 mm (small), respectively. Radiography was performed with a computed radiography system. In angiography using iodine-based microspheres, we observed fine blood vessels of about 50 μm or less with high contrasts. Using this generator, we designed an experimental setup for disinfection achieved with extremely soft x rays

Quasi-monochromatic x-ray irradiation from weakly ionized linear nickel plasma

In the plasma flash x-ray generator, a high-voltage main condenser of approximately 200 nF is charged up to 50 kV by a power supply, and electric charges in the condenser are discharged to an x-ray tube after triggering the cathode electrode. Flash x rays are then produced. The x-ray tube is a demountable triode connected to a turbo molecular pump with a pressure of approximately 1 mPa. As electrons from the cathode electrode are roughly focused onto a rod nickel target of 3.0 mm in diameter by the electric field in the x-ray tube, a weakly ionized linear plasma consisting of nickel ions and electrons forms by target evaporation. At a charging voltage of 50 kV, the maximum tube voltage was almost equal to the charging voltage of the main condenser, and the peak current was about 17 kA. When the charging voltage was increased, the linear plasma formed, and the intensities of K-series characteristic x rays increased. The K-series lines were quite sharp and intense, and hardly any bremsstrahlung rays were detected. The x-ray pulse widths were approximately 700 ns, and the time-integrated x-ray intensity had a value of approximately 30 μC/kg at 1.0 m from the x-ray source at a charging voltage of 50 kV

Cerium X-ray Spectra without Filtering and their Application to High-contrast Angiography

The cerium-target x-ray tube is useful in order to perform cone-beam K-edge angiography because K-series characteristic x rays from the cerium target are absorbed effectively by iodine-based contrast media. The x-ray generator consists of a main controller, an x-ray tube unit with a high-voltage circuit and an insulation transformer, and a personal computer. The tube is a glass-enclosed diode with a cerium target and a 0.5-mm-thick beryllium window. The maximum tube voltage and current were 65 kV and 0.4 mA, respectively, and the focal-spot sizes were 1.2×0.8 mm. Sharp cerium K-series characteristic x rays were observed without using a filter, and the x-ray intensity was 209μGy/s at 1.0 m from the source with a tube voltage of 60 kV and a current of 0.40 mA. Angiography was performed with a computed radiography system using iodine-based microspheres 15 μm in diameter. In angiography of non-living animals, we observed fine blood vessels of approximately 100 μm with high contrasts

Recent Results from LHD Experiment with Emphasis on Relation to Theory from Experimentalist’s View

he Large Helical Device (LHD) has been extending an operational regime of net-current free plasmas towardsthe fusion relevant condition with taking advantage of a net current-free heliotron concept and employing a superconducting coil system. Heating capability has exceeded 10 MW and the central ion and electron temperatureshave reached 7 and 10 keV, respectively. The maximum value of β and pulse length have been extended to 3.2% and 150 s, respectively. Many encouraging physical findings have been obtained. Topics from recent experiments, which should be emphasized from the aspect of theoretical approaches, are reviewed. Those are (1) Prominent features in the inward shifted configuration, i.e., mitigation of an ideal interchange mode in the configuration with magnetic hill, and confinement improvement due to suppression of both anomalous and neoclassical transport, (2) Demonstration ofbifurcation of radial electric field and associated formation of an internal transport barrier, and (3) Dynamics of magnetic islands and clarification of the role of separatrix