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  • 1
    Electronic Resource
    Electronic Resource
    Terawatt fiber pinch experiments (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 70 (1991), S. 7261-7272 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Pinch formation in fiber pinch experiments has been investigated in the lower terawatt regime. The main results are: (1) there are upper limits of breakdown voltage (∼700 kV) and current rise rate (∼20 kA/ns) beyond which leak discharges develop within the vacuum feed of the pulseline KALIF; (2) there is a lower limit of fiber radius (∼10 μm) below which pinch disruptions take place at a pinch current of (approximately-greater-than)300 kA; (3) the hot (Te≤1 keV) inhomogeneous pinch plasma develops typically 10 ns after local collapses (micropinches) at a pinch current (approximately-greater-than)400 kA and lives for more than 50 ns; (4) neutron emission (yield of CD2 fibers ∼1010) appears mostly isotropic; (5) all fiber pinches show global expansion with velocities reaching from typically 10 μm/ns (initial expansion) to (approximately-greater-than)100 μm/ns; and (6) the power requirements for the fiber ablation process are contradictory to those for the final pinch phase.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.349773
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  • 2
    Electronic Resource
    Electronic Resource
    Observations of soft x-ray production in the speed 2 plasma focus (1991)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 69 (1991), S. 613-617 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A new soft x-ray source has been developed and investigated. Argon is injected into a plasma focus through a hole in the anode. The pinch emits several Joules per shot of soft x rays at λ〈0.5 nm from multiple micropinches well aligned along the axis of symmetry. When viewed end-on the pinch appears as a small source of 700 μm diam. The micropinches have the following characteristics: Range of size 40–250 μm (depending on radiation wavelength), density 1028 m−3, temperature 1.5 keV, and lifetime typically less than 1 ns. The helium-like emission from single micropinches lasts for 250 ps only, which is much shorter than previously reported.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.347394
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  • 3
    Electronic Resource
    Electronic Resource
    The dynamics of bifurcating bright-spots in fiber Z-pinch plasmas (1997)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 4 (1997), S. 2967-2971 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Results are presented from the diagnosis of the optical and x-ray emission from "bright-spots" in carbon fiber Z-pinch experiments using the MAGPIE (Mega-Ampere Generator for Plasma Implosion Experiments) generator [I. H. Mitchell et al., Rev. Sci. Instrum. 67, 1533 (1996)]. Inhomogeneities evolve very rapidly within the plasma with bright-spots becoming detectable after 15–20 ns. After a short (∼4 ns) duration formation phase, these bright-spots exhibit highly dynamic behavior. Bifurcation of the bright-spots is observed giving rise to rapid axial motion at 1–3×105 ms−1. The post-bifurcation bright-spots persist for up to 40 ns. Analysis of cross-filtered, time integrated, x-ray pinhole images yield bright-spot parameters during the formation phase (diameter ∼80 μm, temperature 250–300 eV, ion number densities ∼2×1026 m−3). With a spatial resolution of 175 μm, the strong temperature and density gradients within the post-bifurcation spots can be resolved in gated x-ray images with 2 ns exposure times. After the dynamic phase of bright-spot evolution, the pinch enters a quiescent phase where the time scale for evolution is much longer. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.872444
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  • 4
    Electronic Resource
    Electronic Resource
    A cryogenic fiber maker for continuous extrusion (1998)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 69 (1998), S. 2365-2368 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A cryogenic fiber maker that continuously extrudes fibers is presented. The design of the fiber maker is based on the use of two cooling stages maintained at different temperatures. The fiber maker consists of two copper reservoirs that are connected in series and are kept at different temperatures. The first reservoir is used to liquefy the gas coming in from an external gas line. The second reservoir is colder than the first; here, the liquid that comes from the first reservoir is frozen and later extruded using the pressure of the external line gas supply. A two-stage closed-cycle refrigerator (a Gifford–McMahon cooler), which uses helium as a working fluid, is used as a cooling system. The frozen gas is extruded through a stainless-steel capillary nozzle with internal diameters between 50 and 250 μm and a length of 2 mm. The temperature of the two reservoirs is set independently, which permits the extrusion rate of the fibers to be controlled and to produce the fibers continuously. Using this system, hydrogen, deuterium, nitrogen, and argon fibers of various diameters were extruded. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1148945
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  • 5
    Electronic Resource
    Electronic Resource
    Optimization of a high-voltage trigatron switch (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 78 (1995), S. 3659-3663 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Work has been carried out to optimize the operation of a high-voltage trigatron switch. It is demonstrated here that the trigatron can operate in two different modes depending on the route of the initial breakdown. This initial breakdown can occur either to the adjacent electrode or to the opposite electrode. It is shown here that, for a given switch, the mode of operation depends only on the ratio of trigger voltage to working voltage. The optimization was based upon the suggestion that the optimum operation of a trigatron would occur when the trigger pin breaks down simultaneously to both the adjacent and the opposite electrodes. This occurs for the trigger to working voltage ratio, which results in equal mean electric fields across the main gap and the trigger gap. The experiments were carried out with working voltages, Vg, between −1 and −2 MV and with trigger voltage to working voltage ratios of between −2% and −8%. It is shown that the minimum delay and jitter figures are indeed obtained with the trigger voltage closest to this optimum value, Vt*. For the switch used here, this corresponded to a ratio of Vt*/Vg=−3.4%. A single switch was operated for two hundred shots with a working voltage of −2 MV and the optimum trigger voltage and gave an average delay of 44 ns with an overall jitter of 4.4 ns. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.359943
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  • 6
    Electronic Resource
    Electronic Resource
    A high impedance mega-ampere generator for fiber z-pinch experiments (1996)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 67 (1996), S. 1533-1541 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: At Imperial College a mega-ampere generator for plasma implosion experiments has been designed, built, and commissioned. With a final line impedance of 1.25 Ω this terawatt class generator has been designed primarily to drive a maximum current of 1.8 MA with a rise time of 150 ns into high inductance z-pinch loads of interest to radiative collapse studies. This article describes the design and tests of the generator which has a novel configuration of lines and a new design of a magnetically insulated transmission line (MITL). In summary, the generator consists of four Marx generators each of the Hermes III type (2.4 MV, 84 kJ), each connected to 5 Ω pulse forming lines and trigatron gas switches. The power is fed into the matched 1.25 Ω vertical transfer line which feeds a diode stack and a short conical MITL in vacuum which concentrates the power into the z-pinch load. At 80% charge a current rising to 1.4 MA in 150 ns has been measured in a 15 nH inductive short. Similar results are obtained when using a plasma load. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1146884
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  • 7
    Electronic Resource
    Electronic Resource
    Something to chew over? (2003)
    Oxford, UK : Blackwell Science Ltd
    Anaesthesia 58 (2003), S. 0 
    Details
    ISSN: 1365-2044
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2044.2003.03543.x
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  • 8
    Electronic Resource
    Electronic Resource
    Lymphocyte Homing and Ig Secretion in the Murine Mammary Gland (2001)
    Oxford, UK : Blackwell Science Ltd
    Scandinavian journal of immunology 54 (2001), S. 0 
    Details
    ISSN: 1365-3083
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: In mice the majority of the immunoglobulins (Ig) in milk belongs to the IgA class. Prior to its transepithelial transportation into the milk, dimeric IgA (dIgA) is bound to the transmembrane form of the secretory component or polymeric Ig receptor (SC/pIgR). The latter is synthesized in the epithelial cells lining the ducts and alveoli of the mammary gland. A candidate for playing the role of adhesion molecule to primed lymphocytes present in the murine mammary gland might be the mucosal addressin cell adhesion molecule-1 (MAdCAM-1). We studied the correlation between the levels of IgA in colostrum and milk, the number of IgA producing plasma cells in the mammary gland and the expression of MAdCAM-1 in mammary gland endothelial cells during pregnancy and lactation. The relation between the IgA levels in the milk and the expression levels of pIgR in mammary gland epithelial cells was also investigated. We found that the expression of MAdCAM-1 and pIgR starts in early–mid pregnancy; the number of IgA-producing plasma cells and the IgA concentration in milk increase from early lactation onwards. The MAdCAM-1 expression declines during lactation whereas the pIgR levels and IgA-producing plasma cell numbers rise until the end of lactation. Because the MAdCAM-1 level starts to rise several days before the rise of the IgA-producing plasma cell level, MAdCAM-1 cannot be the rate determining factor governing extravasation of primed B cells to the mammary gland. We also conclude that the pIgR is present in sufficient amounts to enable increasing S-IgA secretion into the milk during lactation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-3083.2001.00933.x
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  • 9
    Electronic Resource
    Electronic Resource
    The crafts of the blacksmith - Edited by B. G. Scott & H. Cleere. 1987. 180 pp., numerous figs, plates and tables. Belfast: UISPP with the Ulster Museum. £31. ISBN 0-900761-202
    Amsterdam : Elsevier
    Journal of Archaeological Science 16 (1989), S. 447-448 
    Details
    ISSN: 0305-4403
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Archaeology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/0305-4403(89)90019-8
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  • 10
    Electronic Resource
    Electronic Resource
    Early vitreous materials - Edited by M. Bimsen & I. C. Freestone. 1987. 191 pp., numerous figures, plates and tables. London: British Museum (British Museum Occasional Paper No. 56). £10.00. ISBN 0-86159-056-2
    Amsterdam : Elsevier
    Journal of Archaeological Science 15 (1988), S. 213-214 
    Details
    ISSN: 0305-4403
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Archaeology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/0305-4403(88)90008-8
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