89 research outputs found

    Determination of the Bulk and Local Diffusion-Length Values of Charge Carriers in MCT Films and in the Absorber Layers of MCT-Based Photovoltaic IR FPA Detectors

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    In the present chapter, we describe two new photoelectric-measurement-based methods that can be used for characterization of the diffusion process of charge carriers either in mercury-cadmium-tellurium (MCT) films intended for fabrication of infrared focal plane array (IR FPA) detectors or in the absorber layers of ready MCT-based photovoltaic IR FPA detectors. First-type measurements are photocurrent measurements to be performed on special test structures involving round photodiodes provided with coaxial light-shielding cap metal contacts. Second-type measurements are spot-scan measurements of MCT photovoltaic 2D IR FPA detectors traditionally used for measuring the crosstalk value of such detectors yet implemented at low and high levels of registered diode photocurrents. Both methods permit the determination of the bulk diffusion length of minority charge carriers in MCT material. The second method, in addition, permits the determination of the local effective diffusion length of minority charge carriers in the absorber-layer region under FPA diodes. The values of the bulk diffusion length of minority carriers obtained in MCT films and in the MCT absorber material of the examined middle-wave and long-wave IR FPA detectors were found to be in good agreement with previously reported relevant data. The estimated value of the local effective diffusion length of minority carriers in the film region under back-biased FPA diodes proved to be consistent with a theoretical estimate of this length

    Energy levels and lifetimes of Gd IV and enhancement of the electron dipole moment

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    We have calculated energy levels and lifetimes of 4f7 and 4f6 5d configurations of Gd IV using Hartree-Fock and configuration interaction methods. This allows us to reduce significantly the uncertainty of the theoretical determination of the electron electric dipole moment (EDM) enhancement factor in this ion and, correspondingly, in gadolinium-containing garnets for which such measurements were recently proposed. Our new value for the EDM enhancement factor of Gd+3 is -2.2 +- 0.5. Calculations of energy levels and lifetimes for Eu~III are used to control the accuracy.Comment: Submitted to Phys. Rev. A 6 pages, 0 figures, 3 table

    Component efficient solutions in line-graph games with applications

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    Recently, applications of cooperative game theory to economic allocation problems have gained popularity. We investigate a class of cooperative games that generalizes some economic applications with a similar structure. These are the so-called line-graph games being cooperative TU-games in which the players are linearly ordered. Examples of situations that can be modeled like this are sequencing situations and water distribution problems. We define four properties with respect to deleting edges that each selects a unique component efficient solution on the class of line-graph games. We interpret these solutions and properties in terms of dividend distributions, and apply them to economic situations. Ā© 2006 Springer-Verlag

    Enhancement of the electron electric dipole moment in gadolinium garnets

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    Effects caused by the electron electric dipole moment (EDM) in gadolinium garnets are considered. Experimental studies of these effects could improve current upper limit on the electron EDM by several orders of magnitude. We suggest a consistent theoretical model and perform calculations of observable effects in gadolinium gallium garnet and gadolinium iron garnet. Our calculation accounts for both direct and exchange diagrams.Comment: 9 page

    Features of the Restoration of Arterial Circulation in Liver Transplantation

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    Objectives. Violations of tissue blood supply remain one of the most serious complications after liver transplantation. Design. To improve the surgical technique of performing reconstructive interventions on the arteries of the donor and the recipient in order to reduce the frequency of its thrombosis after liver transplantation. We studied 25 donors, 20 men and 5 women, the mean age was 56Ā± 4 years, eighteen of them had left aberrant supplementary artery, which in fifteen departed from the left gastric artery and in three from the aorta above the ventricular stem. Seventeen had the right aberrant artery moving away from the upper mesenteric artery. Twenty recipients with liver cirrhosis (eleven with primary biliary cirrhosis, five with primary sclerosing cholangitis, five with viral etiology C cirrhosis, and three of the lower cirrhosis-cirrhosis disseminated within the Milan criteria. All recipients had standard anatomical branching of the arteries of the liver. The average age was 50Ā±6. All recipients had standard anatomical branching of the liver arteries. Patients underwent liver transplantation with new methods of reconstructive interventions on the donor and recipient arteries. The developed technique provides the shortest pathway of the recipient's arterial blood to the liver transplant, through the superior mesenteric artery provides an alternative source of arterial blood supply from the aorta in which this transplant additionally needs. Presented method of blood circulation restoration at liver transplantation at abnormal structure of arterial channel of the liver transplant is performed inside the recipient's abdominal cavity. At first, blood flow is restored along the reconstructed common hepatic artery, after the right or left aberrant arteries liver transplant. Such technique provides the shortest route of the recipient's arterial blood to the liver transplant, through the upper mesenteric artery provides an alternative source of arterial blood supply from the aorta for which the transplant is additionally needed. This new method of blood circulation restoration provides an opportunity to avoid the formation of "kinking" syndrome, in the occurrence of which the blood vessels are lengthened, the angulation and location of the blood vessel in relation to the grafts and other abdominal organs. This reduces the risk of thrombosis of the arteries of the transplanted liver

    Recent advances in neutrinoless double beta decay search

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    Even after the discovery of neutrino flavour oscillations, based on data from atmospheric, solar, reactor, and accelerator experiments, many characteristics of the neutrino remain unknown. Only the neutrino square-mass differences and the mixing angle values have been estimated, while the value of each mass eigenstate still hasn't. Its nature (massive Majorana or Dirac particle) is still escaping. Neutrinoless double beta decay (0Ī½0\nu-DBD) experimental discovery could be the ultimate answer to some delicate questions of elementary particle and nuclear physics. The Majorana description of neutrinos allows the 0Ī½0\nu-DBD process, and consequently either a mass value could be measured or the existence of physics beyond the standard should be confirmed without any doubt. As expected, the 0Ī½0\nu-DBD measurement is a very difficult field of application for experimentalists. In this paper, after a short summary of the latest results in neutrino physics, the experimental status, the R&D projects, and perspectives in 0Ī½0\nu-DBD sector are reviewed.Comment: 36 pages, 7 figures, To be publish in Czech Journal of Physic

    Possibilities of low-field NMR spectrometers in screening the content of medicinal substances

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