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  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 3001-3011 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Secondary ion mass spectrometry has become the preferred tool for impurity profiling primarily due to its excellent depth resolution and high detection sensitivity. Prerequisite in obtaining high detection sensitivity for positive secondary ions is the use of oxygen as primary ions. This leads to a high degree of oxidation of the sample surface, which is essential for a high secondary ion ionization efficiency. Unfortunately, this oxygen bombardment not only leads to the transformation of the original target surface into an oxidized layer but, as the latter requires a certain fluence before stationary state is reached, inherently causes some nonlinearities and transients in the secondary ion signal and the fluence-eroded depth relation. In this work a computer code implantation, sputtering, replacement/relocation, and diffusion (ISRD) has been optimized to predict the compositional changes of the sample surface (or altered layer formation), the sputter yields and the surface regression as a result of the interaction of oxygen beams with Si-targets. This article describes a careful reevaluation of the previously used version of ISRD (and the parameters contained in the program) in order to obtain a systematic agreement with experimental data on sputter yields, altered layer formation, and surface recession, and with other theoretical predictions. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 91 (2002), S. 178-182 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Gallium nitride layers grown by molecular beam epitaxy on c axis oriented sapphire substrates were implanted with 180 keV magnesium ions with ion doses between 1×1014 and 1×1016 cm−2. The implantation induced defect states were investigated by temperature dependent conductivity (TDC) as well as by thermal and optical admittance spectroscopy (TAS, OAS) measurements. Dominant carrier emissions having thermal activation energies between 360 and 800 meV were found in TAS and TDC. These states are assigned to implantation induced electron traps since they do not appear in the nonimplanted reference sample. Defect states with similar transition energies were also observed in OAS resulting in an enhancement of defect-to-band transitions in the near band-gap region around 3.45 eV, in the blue band around 3.0 eV, as well as in the midgap range for photon energies between 2.5 and 1.80 eV, respectively. In addition, new transitions were found at 2.1 and 1.95 eV. Furthermore, transitions from implantation induced shallow states were observed, i.e., the magnesium acceptor as well as a new donor level at about 70 meV, tentatively discussed as nitrogen vacancy. The critical ion dose for amorphization was determined to be between 5×1015 and 1×1016 Mg+ cm−2 using x-ray diffraction. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 77 (2000), S. 546-548 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In GaN layers grown by molecular beam epitaxy and metalorganic vapor phase epitaxy on c-axis oriented sapphire, a defect-to-band transition at a photon energy of 0.44 eV was found by optical admittance spectroscopy. This transition was investigated as a function of temperature and modulation frequency. The height of the corresponding optical admittance peak shows a thermally activated quenching with an activation energy of 0.4±0.1 eV caused by a thermal carrier emission from the same defect state to the conduction band at higher temperatures. Based on this thermal quenching, the 0.44 eV level is assigned to an electron trap located in the upper half of the gap. The spectral photoionization cross section was determined, resulting in a photoionization energy at 80 K estimated to be below 0.425 eV. The omnipresence of the 0.44 eV electron trap in GaN layers grown by various epitaxial techniques and in different reactors implicates its intrinsic nature. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Industrial and engineering chemistry 8 (1969), S. 145-149 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    International orthopaedics 24 (2000), S. 191-193 
    ISSN: 1432-5195
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Résumé  6 cadavres ont été examinés après implantation d’une prothèse totale du genou avec et sans implants de restructuration de la surface rotulienne. Les mesures de la pression et de la surface de contact ont été réalisées avec une flexion du genou à un angle de 60°. En comparant les résultats de genoux sans implants et genoux avec implants de la rotule de taille ”petite”, on remarque que ces derniers ont causé une diminution significative de la surface de contact rétro-rotulienne. Les pressions moyenne et maximum n’ont pas changé de manière déterminante. Les implants de taille ”moyenne” ont conduit à une augmentation considérable de la pression maximum et à une diminution significative de la force alors que la surface de contact et la pression moyenne ont elles, légèrement augmenté. Après la pose des deux types d’implants de la rotule on a constatée une réduction significative de la surface de contact, mais ne pas de la pression rétro-rotulienne.
    Notes: Abstract  Total knee replacement with and without patellar resurfacing was performed in 6 cadaver specimens. The contact pressure and contact area between femur and patella was measured at 60° of flexion. In comparison to specimens without resurfacing the specimens with small size resurfacing showed a significant decrease in contact area, whereas average and maximum pressure were unchanged. In specimens with medium size resurfacing, contact area and average pressure increased slightly, whereas maximum pressure increased significantly. Patellar resurfacing did not change the retropatellar pressure, but was associated with reduced contact area.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Solid state phenomena Vol. 76-77 (Jan. 2001), p. 43-46 
    ISSN: 1662-9779
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Physics
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    s.l. ; Stafa-Zurich, Switzerland
    Solid state phenomena Vol. 76-77 (Jan. 2001), p. 153-156 
    ISSN: 1662-9779
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Physics
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Springer
    Lung 131 (1965), S. 221-229 
    ISSN: 1432-1750
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Summary In official statistics urogenital-tuberculosis is being registered only since 1956. Compared with the total number of extrapulmonal tuberculosis, the frequency in Schleswig-Holstein rose from 6.2 per cent in 1956 to 24.8 per cent in 1963. Regarding the increase of genital-tuberculosis, especially kidney-tuberculosis which have been clinically registered, two reasons are discussed: 1st: Advanced diagnostic due to the extending number of freely practicing urologists. 2nd: The long latent period of kidney-tuberculosis of which the pathogenetic background so far was undiscovered and which was firstly observed bySteiger. Out of 503 cases of kidney-tuberculosis which have been dealt with here, the latent period could be made out in 238 cases, i. e. in 47.3 per cent, and amounted in 55 per cent to 1–10 years 31 per cent to 10–20 years and even 8 per cent to 20–30 years. This may explain the increasing number of kidney-tuberculosis which has been observed since 1956. This clinical manifestation is the result of the hematogenous dissemination of new consumptions within the kidney region and which took place in the first years after the war. The phenomenon of the latent period can be explained through functional and biochemical qualifications of the kidney parenchyma. The way and period of treatment as well as the prognosis of the 503 treated patients with kidney tuberculosis can be followed up by means of statistic figures. Of great importance is the newly introduced therapy with corticosteroids.
    Notes: Zusammenfassung In der offiziellen Statistik wird die Urogenitaltuberkulose erst seit 1956 registriert. Berechnet auf die Gesamtzahl der extrapulmonalen Tuberkulosen ist die Urogenitaltuberkulose in Schleswig-Holstein von 6,2% im Jahre 1956 auf 24,8% im Jahre 1963 angestiegen. Im gleichen Zeitraum hat die Belegung der extrapulmonalen Abteilung unseres Krankenhauses mit isolierten Nierentuberkulosen ständig zugenommen, nämlich von 12% auf 47% der Gesamtbelegung. Zwei Gründe werden für die Zunahme der Nierentuberkulosen diskutiert: 1. Verbesserte Diagnostik, seit sich mehr Urologen in der freien Praxis niedergelassen haben. 2. Die ungewöhnlich lange Latenzzeit der Nierentuberkulose. Von 503 Nierentuberkulosen, die bei uns behandelt wurden, konnte die Latenzzeit in 238 Fällen ermittelt werden. Sie erstreckte sich in 55% von 1 bis 10 Jahren in 31% von 10 bis 20 Jahren und noch in 8% von 20 bis 30 Jahren. Die Zunahme der Nierentuberkulosen werten wir als Ausdruck später klinischer Manifestation jener in den ersten Nachkriegsjahren von 1945 bis 1950 stattgefundenen hämatogenen Aussaat frischer Lungentuberkulosen im Bereich der Nieren. Für das Phänomen der Latenzzeit dürften funktionelle und biochemische Besonderheiten des Nierenparenchyms verantwortlich sein, die kurz umrissen werden. Über Behandlung und kontinuierlich kontrollierten Heilungsverlauf von 503 Nierentuberkulosen wird ausführlich berichtet. Tuberkulöse Ureterstenosen sind häufige Folgen der intensiven tuberkulostatischen Therapie. Ihre Behandlung mit Corticosteroiden ist in manchen Fällen erfolgversprechend.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract. A new high-spin isomer in 215Bi, with a half-life of 36.9(6) s, has been identified at the PSB-ISOLDE on-line mass separator using the pulsed-release technique combined with the element selective RILIS source. A decay scheme of $^{215{\rm m}}$ Bi was constructed and complemented with the low-spinstructure observed in $^{215{\rm g}}$ Bi decay. The population of a cascade on top of the $\left( \nu g_{9/2} \right)^5_{9/2+}$ level in 215Poprovides evidence for Gamow-Teller $\beta$ -decay of the high-spin 215Bi isomer.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1434-601X
    Keywords: PACS. 27.70.+q 150 ?A? 189 – 23.60.+e Alpha decay – 32.10.Dk Electric and magnetic moments, polarizability – 32.10.Fn Fine and hyperfine structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract: Alpha-decay properties of the neutron-deficient isotope 185Pb were studied at the PSB-ISOLDE (CERN) on-line mass separator using the resonance ionisation laser ion source (RILIS). The nuclei of interest were produced in a 1.4 GeV proton-induced spallation reaction of a uranium graphite target. In contrast to previous studies, two α-decaying isomeric states were identified in 185Pb. The relative production of the isomers, monitored by their α-counting rates, could be significantly changed when a narrow-bandwidth laser at the RILIS setup was used to scan through the atomic hyperfine structure. Based on the atomic hyperfine structure measurements, along with the systematics for heavier odd-mass lead isotopes, the spin and the parity of these states were interpreted as 3/2- and 13/2+ and their nuclear magnetic moments were deduced. The α-decay energy and half-life value for the I π = 13/2+ isomer are E α = 6408(5) keV, T 1/2 = 4.3(2) s, respectively; while for the I π = 3/2- isomer ( T 1/2 = 6.3(4) s) two α-decays with E α1 = 6288(5) keV, I α1 = 56(2)% and E α2 = 6486(5) keV, I α2 = 44(2)% were observed. By observing prompt α-γ coincidences new information on the low-lying states in the daughter isotope 181Hg was obtained.
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