10 research outputs found

    Giant congenital left ventricular diverticulum associated with infective endocarditis: A diagnosis made by tissue Doppler echocardiography

    Get PDF
    Left ventricular (LV) diverticulum is a relatively rare condition, and it is important to differentiate it from pseudoaneurysm. The increasing use of noninvasive imaging modalities can help to demonstrate different types of ventricular outpouching structures. We report a case of congenital LV diverticulum that is much larger than the usual size and is diagnosed with tissue Doppler echocardiography and cardiac magnetic resonance imaging. Although a ventricular diverticulum is mostly asymptomatic, in the case of this particular patient, it has become complicated with infective endocarditis. © 2016 Japanese College of Cardiolog

    Elimination of impurity phase formation in FePt magnetic thin films prepared by pulsed laser deposition

    No full text
    The formation of impurity phases in FePt thin films severely degrades its magnetic properties. The X-ray diffraction patterns of FePt thin films, synthesized using pulsed laser deposition (PLD), showed peaks corresponding to impurity phases, resulting in softer magnetic properties. A systematic investigation was carried to determine the factors that might have led to impurity phase formation. The factors include (i) PLD target composition, (ii) substrate material, (iii) annealing parameters such as temperature, duration and ambience and (iv) PLD deposition parameters such as chamber ambience, laser energy fluence and target–substrate distance. Depositions on the different substrates revealed impurity phase formation only on Si substrates. It was found that the target composition, PLD chamber ambience, and annealing ambience were not the factors that caused the impurity phase formation. The annealing temperature and duration influenced the impurity phases, but are not the cause of their formation. A decrease in the laser energy fluence and increase of the target–substrate distance resulted in elimination of the impurity phases and enhancement in the magnetic and structural properties of FePt thin films. The energy of the ablated plasma species, controlled by the laser energy fluence and the target–substrate distance, is found to be the main factor responsible for the formation of the impurity phases

    Joint experiments on small tokamaks: edge plasma studies on CASTOR

    No full text
    The 1st Joint (Host Laboratory) Experiment on 'joint research using small tokamaks' was carried out using the IPP Prague experimental facility 'CASTOR tokamak'. The main experimental programme was aimed at characterizing the edge plasma in a tokamak by using different advanced diagnostic techniques. It is widely recognized that characterization of phenomena occurring at the plasma edge is essential for understanding the plasma confinement in a tokamak. The edge plasma in small and large scale experiments has many similar features, and the results obtained through detailed measurements in a small flexible device such as CASTOR are in many aspects still relevant to those in large tokamaks. Therefore, it is expected that the results of this joint experiment will have general validity. The radial and poloidal structure of electrostatic turbulence was characterized. The effects of edge biasing were analysed. Radiation fluctuations and profile measurements were performed using fast bolometry. Plasma position measurements were performed using novel Hall sensors

    High-precision half-life determination of 14^{14}O via direct ββ counting

    No full text
    The half-life of the superallowed Fermi β+\beta^+ emitter 14^{14}O was determined to high precision via a direct β\beta counting experiment performed at the Isotope Separator and Accelerator (ISAC) facility at TRIUMF. The result, T1/2T_{1/2}(14^{14}O) = 70619.2(76) ms, is consistent with, but is more precise than, the world average obtained from 11 previous measurements. Combining the 14^{14}O half-life deduced in the present work with the previous most precise measurements of this quantity leads to a reduction in the overall uncertainty, by nearly a factor of 2. The new world average is T1/2T_{1/2}(14^{14}O) = 70619.6(63) ms with a reduced χ2\chi^2 value of 0.87 obtained from 8 degrees of freedom

    Joint experiments on the tokamaks CASTOR and T-10

    No full text
    Small tokamaks may significantly contribute to the better understanding of phenomena in a wide range of fields such as plasma confinement and energy transport; plasma stability in different magnetic configurations; plasma turbulence and its impact on local and global plasma parameters; processes at the plasma edge and plasma-wall interaction; scenarios of additional heating and non-inductive current drive; new methods of plasma profile and parameter control; development of novel plasma diagnostics; benchmarking of new numerical codes and so on. Furthermore, due to the compactness, flexibility, low operation costs and high skill of their personnel small tokamaks are very convenient to develop and test new materials and technologies. Small tokamaks are suitable and important for broad international cooperation, providing the necessary environment and manpower to conduct dedicated joint research programmes. In addition, the experimental work on small tokamaks is very appropriate for the education of students, scientific activities of post-graduate students and for the training of personnel for large tokamaks. The first Joint (Host Laboratory) Experiment (JEI) has been carried out in 2005 on the CASTOR tokamak at the IPP Prague, Czech Republic. It was jointly organized by the IPP-ASCR and KFKI HAC, Budapest, involved 20 scientists from 7 countries and was supported through the IAEA and the ICTP, Trieste. The objective of JE1 was to perform studies of plasma edge turbulence and plasma confinement. Following the success of JE1, JE2 has been performed on T-10 at RRC "Kurchatov Institute" in Moscow; 30 scientists from 13 countries participated in this experiment. This experiment aimed to continue JEI turbulence studies, now extending them to the plasma core. Results of JEI and JE2 will be overviewed and compared

    Results of Joint Experiments and other IAEA activities on research using small tokamaks

    No full text
    This paper presents an overview of the results obtained during the Joint Experiments organized in the framework of the IAEA Coordinated Research Project on `Joint Research Using Small Tokamaks` that have been carried out on the tokamaks CASTOR at IPP Prague, Czech Republic (2005), T-10 at RRC `Kurchatov Institute`, Moscow, Russia (2006), and the most recent one at ISTTOK at IST, Lisbon, Portugal, in 2007. Experimental programmes were aimed at diagnosing and characterizing the core and the edge plasma turbulence in a tokamak in order to investigate correlations between the occurrence of transport barriers, improved confinement, electric fields and electrostatic turbulence using advanced diagnostics with high spatial and temporal resolution. On CASTOR and ISTTOK, electric fields were generated by biasing an electrode inserted into the edge plasma and an improvement of the global particle confinement induced by the electrode positive biasing has been observed. Geodesic acoustic modes were studied using heavy ion beam diagnostics on T-10 and ISTTOK and correlation reflectometry on T-10. ISTTOK is equipped with a gallium jet injector and the technical feasibility of gallium jets interacting with plasmas has been investigated in pulsed and ac operation. The first Joint Experiments have clearly demonstrated that small tokamaks are suitable for broad international cooperation to conduct dedicated joint research programmes. Other activities within the IAEA Coordinated Research Project on Joint Research Using Small Tokamaks are also overviewed.GACR Grant Agency of Academy of Sciences of the Czech Republic[KJB100430504]ROSATOM[RF 02.516.11.6068]ROSATOM[RFBR 0502-17016]ROSATOMROSATOM[07-02-01001]ROSATOM[INTAS 100008-8046]ROSATOM[NWO-RFBR 047.016.015]IAEAICT
    corecore