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  • 1
    Digitale Medien
    Digitale Medien
    STUDIES OF ROADWAY MODES IN A COAL SEAM BY DISPERSION AND POLARIZATION ANALYSIS: A CASE HISTORY (1987)
    Oxford, UK : Blackwell Publishing Ltd
    Geophysical prospecting 35 (1987), S. 0 
    Details
    ISSN: 1365-2478
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Geologie und Paläontologie , Physik
    Notizen: Field data from two-component in-seam seismic measurements are used to study roadway modes and their interaction with reflected seam waves. Using the multiple-filter technique to investigate the dispersion behaviour of the different waves, it can be shown that the roadway modes disperse very similarly to the related transmitted seam waves. However, because of the free surface of the coal face, the dispersion curves of the roadway modes show a velocity reduction and a slight shift to lower frequencies compared to those of the related transmitted seam waves. Polarization analysis using hodograms, rectilinearity and polarization angle confirms these results. The parameters found by polarization analysis can be used to design polarization filters which help to separate roadway modes and reflected events in the traveltime range of superposition in the presented field case.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-2478.1987.tb02257.x
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  • 2
    Digitale Medien
    Digitale Medien
    CALCULATION OF DISPERSION CURVES AND AMPLITUDE-DEPTH DISTRIBUTIONS OF LOVE CHANNEL WAVES IN HORIZONTALLY-LAYERED MEDIA (1985)
    Oxford, UK : Blackwell Publishing Ltd
    Geophysical prospecting 33 (1985), S. 0 
    Details
    ISSN: 1365-2478
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Geologie und Paläontologie , Physik
    Notizen: We present dispersion curves, and amplitude-depth distributions of the fundamental and first higher mode of Love seam waves for two characteristic seam models. The first model consists of four layers, representing a coal seam underlain by a root clay of variable thickness. The second model consists of five layers, representing coal seams containing a dirt band with variable position and thickness. The simple three-layer model is used for reference.It is shown that at higher frequencies, depending on the thickness of the root clay and the dirt band, the coal layers alone act as a wave guide, whereas at low frequencies all layers act together as a channel. Depending on the thickness, and position of the dirt band and the root clay, in the dispersion curves of the group velocity, secondary minima grow in addition to the absolute minima. Furthermore, the dispersion curves of the group velocity of the two modes can overlap. In all these cases, wave groups in addition to the Airy phase of the fundamental mode (propagating with minimum group velocity) occur on the seismograms recorded in in-seam seismic surveys, thus impeding their interpretation. Hence, we suggest the estimation of the dispersion characteristics of Love seam waves in coal seams under investigation preceding actual field surveys.All numerical calculations were performed using a fast and stable phase recursion algorithm.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1111/j.1365-2478.1985.tb00779.x
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  • 3
    Digitale Medien
    Digitale Medien
    Gonadal steroid receptors in meningiomas (1987)
    Springer
    Journal of neurology 234 (1987), S. 328-333 
    Details
    ISSN: 1432-1459
    Schlagwort(e): Oestrogen receptor ; Progesterone receptor ; Androgen receptor ; Monoclonal antibody ; Meningioma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Oestrogen receptor (ER) analysis was performed in 70 meningiomas with an enzyme immunoassay, using monoclonal antibodies against human oestrogen receptor protein (oestrophilin) and with a sensitive radioligand binding assay, using 125I-oestradiol as radioligand. Low levels of ER immunoreactivity were found in tumours from 51% of patients, whereas ER binding activity was demonstrated in 40% of the meningiomas examined. In 8 (11%) tissue samples multiple binding sites for oestradiol were observed. The immunoreactive binding sites corresponded to the classical, high-affinity ER. In ligand binding studies, however, measurement of classical ER was considerably influenced by a second low-affinity, high-capacity oestrogen binding component even at low ligand concentrations. 3H-methylpromegestone and 3H-methyltrienolone, a synthetic gestagen and androgen, were used for concurrent determination of the progesterone receptor (PR) and androgen receptor (AR) binding activity. High concentrations of PR were detected in 53 (76%), whereas moderate levels of AR binding sites were demonstrated in 33 (47%) tumours. A positive correlation between ER immunoreactivity and AR binding activity is indicative for an oestrogen regulation of AR via the ER system. The presence of gonadal steroid receptors in a large proportion of meningiomas and the tendency for a dependence of receptor concentrations on the histological subtype could have implications for tumour therapy.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00314289
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  • 4
    Digitale Medien
    Digitale Medien
    Neutrons produced by 1.22 GeV antiproton interactions with nuclei (2000)
    Springer
    The European physical journal 8 (2000), S. 197-204 
    Details
    ISSN: 1434-601X
    Schlagwort(e): PACS 25.43.+t Antiproton-induced reactions – 24.60.Dr Statistical compound nucleus reactions – 24.75.+i General properties of fission
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract: Inclusive neutron energy spectra were measured by time of flight using 1.22 GeV antiprotons from LEAR, CERN, as projectiles and targets from natural Al, Cu, Ag, Ho, Ta, Au, Pb, Bi, U. The sum of two Maxwellian distributions was fitted to the spectra obtained at several forward and backward angles yielding neutron multiplicities Mi and slope or temperature parameters T i for the low-energy (evaporative, i=1) and high-energy (pre-equilibrium,i=2) parts, respectively. M 1 increases with A, proportional to the nuclear volume, and M 2 is growing with A , proportional to the nuclear radius. The T parameters are nearly independent of A. The results are compared with previous multiplicity measurements with a neutron detector, intranuclear cascade calculations and neutron spectra from stopped antiproton annihilation on nuclei. With the measured proton spectra also the ratio of emitted neutrons to protons was determined for Au.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s100500070106
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  • 5
    Digitale Medien
    Digitale Medien
    Experiment to measure the Lamb shift in muonic hydrogen (2000)
    Springer
    Hyperfine interactions 127 (2000), S. 161-166 
    Details
    ISSN: 1572-9540
    Schlagwort(e): proton ; proton radius ; muon ; muonic hydrogen ; Lamb shift
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract The contribution of the root mean square (RMS) proton charge radius to the Lamb shift (2S–2P energy difference) in muonic hydrogen (μp) amounts to 2%. Apart from the uncertainty on this charge radius, theory predicts the Lamb shift with a precision on the ppm level. We are going to measure ΔE (2 S1/2(F=1)–2 P3/2(F=2)) in a laser resonance experiment to a precision of 30 ppm (i.e., 10% of the natural linewidth) and to deduce the RMS proton charge radius with 10−3 relative accuracy, 20 times more precise than presently known. The most important requirement for the feasibility of such an experiment, namely the availability of a sufficient amount of long lived metastable μp atoms in the 2S state, has been investigated in a recent experiment at PSI. Our analysis shows that in the order of one percent of all muons stopped in low pressure hydrogen gas form a long lived μp(2S) with a lifetime of the order of 1 μs. The technical realization of our experiment involves a new high intensity low energy muon beam, an efficient low energy muon entrance detector, a randomly triggered 3 stage laser system providing the 0.5 mJ, 7 ns laser pulses at 6.02 μm wavelength, and a combination of a xenon gas proportional scintillation chamber (GPSC) and a microstrip gas chamber (MSGC) with a CsI coated surface to detect the 2 keV X rays from theμp(2P → 1S) transition.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1012679114531
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  • 6
    Digitale Medien
    Digitale Medien
    Synthetische, dem Curcumin ähnliche Verbindungen (1927)
    New York, NY : Wiley-Blackwell
    Journal für Praktische Chemie/Chemiker-Zeitung 115 (1927), S. 281-291 
    Details
    ISSN: 0021-8383
    Schlagwort(e): Chemistry ; Organic Chemistry
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/prac.19271150122
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