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  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 74 (1993), S. 6482-6487 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Emission life of small Ba-impregnated thermionic cathodes suitable for use in TV tubes is investigated systematically. Cathodes are covered with an Os layer to enhance the emissivity. They have an unusual emission life in that the emission current decreases gradually with time and then drops abruptly. The early gradual decrease in emission at high cathode temperatures is caused by the phase change of the Os layer to OsW2. A linear relationship is found to exist between the logarithm of the lifetime and the reciprocal of the cathode temperature. This life end is believed to happen after the end of the reduction reaction between BaO and the porous W body and after ceasing replenishment of the low work function Ba+-O− monolayer on the metal surface. A formula for the emission lifetime is derived from the assumption that the rate determining step is the Ba diffusion inside the pellet. Emission lifetime τ is shown to be given by τ=Ad2 exp(E/kT), where A is a constant, d is the pellet thickness, and E is the activation energy of Ba diffusion. This relation is confirmed experimentally.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 64 (1993), S. 2277-2284 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Laser blow-off neutral lithium beam probing with high temporal resolution has been developed to measure edge electron density profiles in a plasma. A new electron density reconstruction method, taking account of the transport of a laser blow-off beam in the plasma, improves the accuracy of the density measurement. The use of a camera system with a gate function makes it possible for us to measure the density profile with a high temporal resolution of 10–50 μs. The optimum condition for shutter timing and period to observe the Li i emission profile is discussed from the viewpoints of the beam penetration into the plasma and the accuracy of measurement. A rapid temporal evolution of the edge electron density profile during limiter biasing in a small tokamak HYBTOK-II was successfully obtained by this system.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 64 (1993), S. 1699-1704 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: Two different electron density reconstruction methods for 8-keV neutral lithium beam probing have been developed for the Compact Helical System (CHS). Density dependences on emission and ionization processes are included by using effective rate coefficients obtained from the collisional radiative model. Since the two methods differ in the way the local beam density in the plasma is determined, the methods have different applicable electron densities. The beam attenuation is calculated by iteration from the electron density profile in method I. In method II, the beam remainder at the observation point z is determined by integrating the Li i emission intensity from z toward the position of emission tail-off. At the emission tail-off, the fast lithium beam is completely attenuated. Selecting an appropriate method enables us to obtain edge electron density profile well inside the last closed flux surface for various ranges of plasma densities (1012–5×1013 cm−3). The electron density profiles reconstructed by these two different methods are in good agreement with each other and are consistent with results from ruby laser Thomson scattering.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 95 (1991), S. 2036-2040 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The Raman spectra of hydrogen-bonded molecular solid H2S have been measured up to 23 GPa at 300 K in a gasketed diamond-anvil cell. In the orientationally disordered phase I between 0.47 and 11 GPa, the symmetric stretching mode ν1 shows a red-shift in frequency (dν1/dP=−10.1 cm−1/GPa ) and a dramatic broadening with pressure. At about 11 GPa, the antisymmetric stretching band ν3 appears at the higher-frequency side of ν1. Near this same pressure five low-frequency vibrational modes also appear and show pressure-sensitive features. These results indicate a pressure-induced phase transition near 11 GPa. This new solid phase, which persists to at least 23 GPa at 300 K, seems to be the same phase as previously found above 3.3 GPa at 25 K.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Clinical and experimental pharmacology and physiology 18 (1991), S. 0 
    ISSN: 1440-1681
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: 1. Vasomotor pressor neurons in the subretrofacial nucleus of the rostral ventrolateral medulla receive afferent inputs from different sources that utilize different neurotransmitters. This paper briefly reviews recent studies on the role of inputs releasing: (i) GABA, and (ii) angiotensin II (AII) in the subretrofacial nucleus.2. There are two types of tonic GABAergic inhibitory inputs: one arises from peripheral baroreceptors, while the second is independent of peripheral baroreceptors.3. Blockade of receptors for AII elicits a decrease in blood pressure and sympathetic vasomotor activity, indicating that subretrofacial neurons are also tonically excited by AII. It is likely that the AII is released from nerve terminals in the subretrofacial nucleus, but the origin of the pathway is unknown.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Radiation and environmental biophysics 30 (1991), S. 205-207 
    ISSN: 1432-2099
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1432-2307
    Keywords: Amelogenin ; Odontogenic tumour ; Immunohistochemistry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Amelogenins, enamel proteins in odontogenic tumours, were detected immunohistochemically using a monoclonal antibody. They were strongly expressed in amyloid-like material, ghost cells, and the cells surrounding ghost cells of calcifying epithelial odontogenic tumours and cysts, whereas calcified bodies within the tumours and cysts showed negative staining. The expression of amelogenins was also positive in tumour cells of ameloblastoma, adenomatoid odontogenic tumour, squamous odontogenic tumour and ameloblastic fibroma. Peripheral tumour cells of the follicular ameloblastoma were positive with relatively intense staining. Undifferentiated or flattened tumour cells of adenomatoid odontogenic tumour and non-keratinized tumour cells of the squamous odontogenic tumour showed marked staining. Reduced ameloblasts in the odontoma displayed the strongest staining for amelogenins. The study suggests that biosynthesis of amelogenins may occur in the homogeneous materials of calcifying epithelial odontogenic tumours and cysts.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Acta crystallographica 49 (1993), S. 478-483 
    ISSN: 1600-5740
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Copenhagen : International Union of Crystallography (IUCr)
    Acta crystallographica 49 (1993), S. 780-781 
    ISSN: 1600-5740
    Source: Crystallography Journals Online : IUCR Backfile Archive 1948-2001
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    Acta neuropathologica 82 (1991), S. 295-301 
    ISSN: 1432-0533
    Keywords: Hyaline inclusions ; Motor neuron disease ; Amyotrophic lateral sclerosis ; Immunocytochemistry ; Ultrastructure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We investigated hyaline inclusion bodies (HI) immunocytochemically and ultrastructurally in six cases of sporadic motor neuron disease (MND). All HI contained large amounts of ubiquitin and some HI were stained at the core or the center with anti-neurofilament antibody, with the surrounding halo unstained. No HI were stained with antibodies raised against cytoskeletal proteins such as high-molecular weight microtubule-associated proteins and phosphorylated tau. Ultrastructurally, HI were chiefly composed of filaments measuring about 20 nm in diameter thicker than neurofilaments, and contained fine granules and frequently one or more of four characteristic profiles, i.e., small electron-dense materials resembling Bunina bodies, bundles of tubular filaments measuring approximately 20 nm in diameter, large electron-dense cores, and focal accumulations of randomly arranged neurofilaments. Hyaline inclusions can be regarded as one of the characteristic markers for sporadic MND as well as familial amyotrophic lateral sclerosis. Hyaline inclusions have a markedly heterogeneous ultrastructure and, therefore, differences in immunoreactivity with antineurofilament antibodies are not unexpected.
    Type of Medium: Electronic Resource
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