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  • 1
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: The atmospheric environmental exposure system for synchrotron radiation (SR) lithography has been integrated using the Photon Factory storage ring (2.5 GeV). The system, composed of a highly reliable beamline, an SR extracting chamber and a prototype SR stepper, aims at attaining higher accuracy and throughput. Based on a fail-safe mechanism notion, a double-vacuum protection system, in which two sets of a fast closing valve and acoustic delay line are installed in the main beamline and branch beamline, respectively, has been organized. Vacuum breakdown tests indicated that any vacuum breakdown, a beryllium (Be) window rupture in the worst case, exerts little influence on the storage ring ultrahigh vacuum. The SR extracting chamber, equipped with a Be window and an extraction window, is filled with helium at atmospheric pressure. Particularly, the 50-μm-thick, 35-mm-diam Be window, vacuum-sealed by a Viton O-ring, was preliminarily employed and, so far, has operated successfully, giving a 25-mm square exposure area. In terms of practical availability and simplicity, the SR stepper in an atmospheric environment has been constructed. A novel differential mode linear Fresnel zone plate alignment method, which can detect an alignment error between a mask and a wafer during exposure, was developed.
    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 59 (1988), S. 2539-2543 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A new magnetic densimeter for cryogenic fluids has been developed by adapting a magnetic levitation of a high-Tc superconductor. In this instrument, a superconducting material made of Y–Ba–Cu–O is sealed in a hollow glass buoy, and a stable levitation of the buoy is carried out with the Meissner effect of the superconductor simply by placing the buoy in the fluid above a ring-shaped permanent magnet. The fluid density is obtained from the magnetic force required to levitate the buoy in the fluid. To measure this force, the magnet is suspended from an electronic balance and the reaction force acting on the magnet is determined directly as a change of the apparent weight of the magnet. Details are given of the theoretical calculation of the force acting on the superconductor in the magnetic field and of the construction of the apparatus. The measurements of the saturated liquid density of nitrogen have shown a standard deviation of 0.014%. The total uncertainty of the measurements is estimated to be less than 0.06%. The results agree with reliable literature values within the experimental uncertainty.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Journal of oral rehabilitation 32 (2005), S. 0 
    ISSN: 1365-2842
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: summary  The purpose of this investigation was to examine the effects of light intensity on linear shrinkage of photo-activated composite resins during setting. The materials used were four commercially available photo-activated composite resins. Three light-irradiation instruments were selected and prepared so as to obtain four light intensities (200, 480, 800 and 1600 mW cm−2). The linear shrinkage during setting was examined 10 min after light irradiation using a trial balance plastometer, and the specimen thickness was 2·0 mm for all materials. The depth of cure was examined according to the test method described in the International Organization for Standardization (ISO/FDIS 4049: 2000(E)). In measuring the linear shrinkage 60 s from the start of light irradiation for 10 s, there was a significant correlation (r = 0·89–0·94) between the amount of linear shrinkage and the light intensity: an increase in light intensity produced a greater linear shrinkage. Furthermore, there was a significant correlation (r = 0·92–1·0) between the linear shrinkage and the irradiation time: an increase in irradiation time resulted in a greater linear shrinkage. Values of the depth of cure ranged from 1·69 to 3·75 mm.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Applied physics 48 (1989), S. 189-191 
    ISSN: 1432-0630
    Keywords: 72.20H ; 72.20M
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract The magnetic field dependence of spontaneous oscillation in n-InSb is investigated. We have observed two types of variation in the oscillation with increasing magnetic field. One is an abrupt appearance of the oscillation between 0.56 T and 0.68 T. The other is the appearance of bifurcation in the oscillation period above 0.79 T. This can be explained by the change of the number of levels in the electron system, according to the generation-recombination model of Schöll for the self-generated chaos. The magnitude of the current at the onset of the oscillation decreases linearly with increasing magnetic field.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 0942-0940
    Keywords: Balloon test occlusion ; internal carotid artery ; compressed spectral arrays (CSAs): electroencephalography (EEG) ; Matas test
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We used the compressed spectral arrays (CSAs) of the electroencephalogram (EEG) to monitor cerebral blood flow related events in balloon test occlusion of the internal carotid artery (balloon Matas test). Reliability of the CSAs was examined in 22 patients subjected to the test. Of 9 patients who underwent subsequent permanent carotid occlusion, in 6 there was no change on CSAs and/or in neurological conditions. In 2 patients, there was a slowing on CSAs prior to the appearance of neurological deterioration during clinical testing. CSAs transformed these EEG changes into a succinct graphic display. In 1 of the 2, for whom the Matas test was repeated 1 year later, there was a change from positive to negative and delayed cerebral infarction occurred after carotid occlusion. In the other patient, an ischaemic insult occurred during the balloon occlusive procedures. The third patient had a fatal delayed ischaemic complication 3 days after surgical ligation of the cervical carotid artery, despite the negative balloon Matas test. Complications in these 3 patients were presumably related to thromboembolic mechanisms. The balloon Matas test monitored by CSAs is useful for detecting change in brain functions attributed to an inadequate blood flow. However, this test is unreliable for predicting thrombo-embolic complications.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Acta neurochirurgica 101 (1989), S. 3-8 
    ISSN: 0942-0940
    Keywords: Children ; supratentorial astrocytoma ; treatment ; prognosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Forty-one patients with ages from 0 to 16 years harbouring Supratentorial astrocytic tumours were treated between 1964 and 1986. Twenty-four of them were located in the cerebral hemisphere or in the ventricle, and 17 were in the basal ganglia, thalamus, and/ or optico-hypothalamic region. There were nine glioblastomas multiforme, four anaplastic astrocytomas, 11 fibrillary astrocytomas, 12 pilocytic astrocytomas, two pleomorphic xanthoastrocytomas, two subependymal giant cell astrocytomas and one primitive astrocytic tumour. Low grade tumours tended to occur in young subjects near the midline, and high grade ones in older patients in the hemisphere. Initial treatment in most the patients was a resection or biopsy followed by radiation therapy. Eleven patients were retreated for their recurrent tumours with combinations of surgical removal of the tumour, radiotherapy, and/or chemotherapy. After a follow-up of 3 months to 17 years, 51% of the patients survived with a median survival of 7 years. Outcome of the patients with Supratentorial astrocytomas correlated mostly with the histological grade of malignancy of the tumour, and to a lesser degree with the tumour location. The biological behaviour and treatment of supratentorial astrocytomas in childhood are discussed.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 0942-0940
    Keywords: Moyamoya disease ; paediatric case ; surgical treatment ; indirect non-anastomotic EC-IC bypass
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Surgical results of paediatric patients with Moyamoya disease who were treated by indirect revascularization procedures are reported. Encephalo-duro-arterio-synangiosis (EDAS), encephalomyo-arterio-synangiosis (EMAS), and/or encephalo-myo-synangiosis (EMS) were performed on 47 sides of 29 children with Moyamoya disease. The results of those non-anastomotic EC-IC bypass procedures were evaluated clinically, angiographically, and by computed tomography (CT). Postoperative external carotid angiograms showed a good collateral formation through EDAS, EMAS, or EMS in about 70–80 percent of all surgically treated sides. The symptoms such as TIA, RIND, and/or involuntary movements disappeared in the cases with a good collateral formation but not in those with insufficient development of the collateral circulation. The indirect EC-IC bypass surgery seems effective for most of the children with Moyamoya disease who present with ischaemic signs.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1432-1920
    Keywords: Anterior inferior celebellar artery ; Aneurysm
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Two cases of extremely rare aneurysms of peripheral portions of the AICA are reported with a review of the pertinent literature. According to reported surgical findings, nearly all of the aneurysms originated from arterial loops near the internal acoustic meatus. These aneurysms can therefore, cause the cerebellopontine angle syndrome, with or without subarachnoid hemorrhage.
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    Springer
    International journal of thermophysics 7 (1986), S. 17-28 
    ISSN: 1572-9567
    Keywords: critical exponent ; critical parameter ; gravity effect ; laser interferometry ; sulfur hexafluoride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A laser interferometry has been applied, in the present study, for determination of the critical temperature and critical exponents of sulfur hexafluoride (SF6). By means of laser holographic technique by real-time method, a series of Fraunhofer diffraction patterns due to the density fluctuation of the sample fluid in the very vicinity of the critical point has been successively photographed and analyzed. A dual-thermostat system which was designed and constructed for the present purpose has made the sample temperature constant within 15 μK for several days. We have obtained 107 data for (ρ L−ρ v)/ρ c along the vapor-liquid coexistence curve in the reduced temperature range 10−6≦¦ΔT *¦≦7×10−5 and additional 34 data for the isothermal compressibility in the single phase region. By analyzing these measurements with the aid of the simple power law, the critical temperature and the critical exponents of SF6 have been determined as T c=318.708±0.001 K, β=0.350±0.004, and γ=1.24±0.02, respectively.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    International Journal for Numerical Methods in Fluids 8 (1988), S. 1319-1329 
    ISSN: 0271-2091
    Keywords: Numerical simulation ; Vortical flow ; Navier-Stokes and Euler equations ; Double-delta wing ; Vortex interaction ; Vortex breakdown ; Grid resolution ; Engineering ; Engineering General
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Extensive study on the numerical simulation of the vortical flow over a double-delta wing is carried out using the ‘thin layer’ Navier-Stokes and Euler equations. Two important flow characteristics, vortex interaction and vortex breakdown, are successfully simulated. Grid resolution is one of the most important factors associated with the vortex problem. Computations were performed on a series of grids with various levels of refinement, coarse, medium and fine. Computations using either the coarse or medium grids fail to capture the proper physical phenomena. The computed result using a fine grid shows flow unsteadiness once the vortex breakdown takes place. The CL-α characteristics are well predicted up to the breakdown angle of attack for all the grid distributions. The Euler solutions show fairly good agreement with experiment on the CL-α characteristics. However, other aspects of the solution at each angle of attack, such as the locus of the leading-edge separation vortex, are not consistent with experiment. Even for the fine grid Navier-Stokes computations, further grid resolution is required to obtain good quantitative agreement with experiment.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
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