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  • 1
    Digitale Medien
    Digitale Medien
    Absolute measurement of spatial and spectral characteristics of bremsstrahlung using the photoexcitation of nuclear isomers (1993)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 64 (1993), S. 2298-2305 
    Details
    ISSN: 1089-7623
    Quelle: AIP Digital Archive
    Thema: Physik , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: A method of obtaining absolute, direct measurements of the spatial and spectral characteristics of bremsstrahlung is discussed. This technique, called x-ray activation of nuclei (XAN) is based on the use of well-known photonuclear reactions which populate long-lived nuclear isomers. These populations sample incident photon continua at discrete excitation energies and effectively store this information for convenient retrieval following the irradiation of gram-sized targets. Recently a series of experiments has been conducted which has significantly expanded the available data for the photoexcitation of a wide range of isomers at higher energies. Thus it has become feasible to extend the use of XAN to energies approaching 4 MeV. The utility of this technique is demonstrated by the characterization of bremsstrahlung from the newly installed research linac at the University of Texas at Dallas.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1143925
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  • 2
    Digitale Medien
    Digitale Medien
    High intensity electron channeling and perspectives for a bright tunable x-ray source (1990)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 57 (1990), S. 2956-2958 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: Using the continuous wave electron beam of the new Darmstadt superconducting electron accelerator and high intensity axial channeling in a diamond crystal, the possibility for the production of an intense tunable photon source in the x-ray region is investigated. Due to low emittance of the machine and its high current it has become possible, for the first time, to produce channeling radiation in the energy region of a few keV with an intensity of up to 2×1010 photons/s in an x-ray energy window of 10%. This is six orders of magnitude more than what has been observed previously.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.103738
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  • 3
    Digitale Medien
    Digitale Medien
    Elastase α1 proteinase inhibitor complex, granulocyte count, ratio of immature to total granulocyte count, and C-reactive protein in neonatal septicaemiaproteinase inhibitor complex, granulocyte count, ratio of immature to total granulocyte count, and C-reactive protein in neonatal septicaemia (1992)
    Springer
    European journal of pediatrics 151 (1992), S. 353-356 
    Details
    ISSN: 1432-1076
    Schlagwort(e): Neonatal septicaemia ; Elastase α1 proteinase inhibitor ; Granulocyte ; C-reactive protein
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract In a prospective study elastase α1-proteinase inhibitor (Eα1PI), polymorphonuclear (PMN) count, the immature to total neutrophil count ratio (I/T ratio), and C-reactive protein (CRP) were analysed in 74 patients (76 cases) with neonatal septicaemia at the time of initial clinical symptoms. At that early stage of the disease, 94% of the patients had abnormal values for Eα1PI, 71% for I/T ratio, 61% for PMN count, and only 54% for CRP. PMN count was a poor indicator of septicaemia. Neutropenia, present in 26% of all patients, was related to normal Eα1PI in only 4 patients. The combined use of Eα1 and I/T ratio was the most sensitive indicator. In all patients irrespective of causative bacteria or disease onset at least one of these parameters was elevated. In early-onset septicaemia (n=31), normal CRP values occurred significantly more often (63%) than in late-onset sepsis (33%). Even in five of the seven fatal cases, initial CRP measurements were normal. The sensitivity of PMN count and I/T ratio did not differ significantly between early-and late-onset septicaemia. Laboratory changes observed in 18 newborns during the first 3 days of the septic episode show that the rate of pathological values for Eα1PI and I/T ratio was highest at the time of initial clinical symptoms and decreased on days 2 and 3. In contrast, CRP reached maximal values as late as day 2 (88% abnormal values), followed by a decrease on day 3. We conclude that the use of Eα1PI may improve the laboratory detection of neonatal septicaemia especially if used in combination with I/T ratio.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02113257
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  • 4
    Digitale Medien
    Digitale Medien
    Electroexcitation of magnetic dipole and other modes in46Ti and48Ti (1990)
    Springer
    The European physical journal 336 (1990), S. 159-178 
    Details
    ISSN: 1434-601X
    Schlagwort(e): 21.60.-n ; 25.30.Dh ; 27.40.+z
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract With high-resolution inelastic electron scattering measurements on46Ti and48Ti the excitation mechanism of the transition into low lying Jπ=1+ states is investigated. The experimental evidence of considerable contribution of the orbital part of theM1 operator to the total transition strength is given by a model dependent analysis of form factors. The possibility of physical relationship to low lying Jπ=1+ states in the rare earth nuclei is discussed in various models. MoreoverE2 form factors and good candidates forM3 form factors are presented.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01290617
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  • 5
    Digitale Medien
    Digitale Medien
    Model-independent separation of structure functions over an extended kinematical region (1994)
    Springer
    The European physical journal 349 (1994), S. 161-168 
    Details
    ISSN: 1434-601X
    Schlagwort(e): 25.30.Fj ; 21.10.Pc ; 02.60.Ed
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract A method for the separation of structure functions in (e, e′ p) experiments is proposed, which is an extension of the traditional Rosenbluth-type techniques of [1,2]. In our approach, we use a very flexible Ansatz to describe the structure functions within an extended kinematical regionG and determine its free parameters with a x2 minimization. The procedure is tested by pseudo data (12C(e, e′p)11Bg.s.) in the quasi-free region.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01291175
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  • 6
    Digitale Medien
    Digitale Medien
    Phenomenological wave functions for the massA=14 system and a consistent description of beta decay observables (1991)
    Springer
    The European physical journal 341 (1991), S. 9-24 
    Details
    ISSN: 1434-601X
    Schlagwort(e): 21.60.−n ; 23.40.−s ; 25.30.−c
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract A set of phenomenological wave functions has been derived to describe the14N ground state and the isospin triplet consisting of the14C ground state, the first excited state of14N at 2.313 MeV and the14O ground state. Elastic and inelastic electron scattering form factors, the magnetic moment of the14N ground state and the shape factors in theβ ± decay have been employed in a multiparameter fitting procedure to determine the amplitudes of the wave functions inL-S coupling. The inclusion of the beta decay observables in the fit has become possible for the first time since exact formulas for the shape factor in higher order do exist. The set of wave functions deduced exhibit predominately anL=0 contribution for the 0+; 1 states andL=1 and 2 contributions of nearly equal weight for the 1+; 0 state. It was observed that the inclusion of the shape factors allowed a more stringent determination of the amplitudes compared to previous attempts reported in the literature and led in the case of the 0+; 1 states to wave functions that show a small but noticeable difference within the isospin triplet. Besides the observables used for the fit, the radiative widthΓ γ (M1) of the 2.313 MeV state in14N can be described quite well with the derived wave functions, and in addition it has become possible to predict the pathological largeft − value of the14C decay and theft + value of the14O decay precisely. The wave functions are also applied to calculate the14N(γ,π +) cross section.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01281270
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  • 7
    Digitale Medien
    Digitale Medien
    Admixture of the giant dipole resonance to low lying 1−-states in heavy nuclei (1992)
    Springer
    The European physical journal 341 (1992), S. 489-490 
    Details
    ISSN: 1434-601X
    Schlagwort(e): 21.10-k ; 23.20.-g
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract An investigation of E1 transitions from low lying Jπ=1− states detected in (e,e′) and (γ,γ′) measurements is presented. The B(E1) strengths are discussed in terms of the admixture of the giant dipole resonance to the low lying octupole states. We show that the spreading widths Γ ↓ are around 20–50 keV in the examined A=142–238 nuclei and compare this result with spreading widths extracted from isospin mixing matrix elements of isobaric analog resonances.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01301394
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  • 8
    Digitale Medien
    Digitale Medien
    Air embolism and pulmonary interstitial emphysema in a preterm infant with hyaline membrane disease (1991)
    Springer
    Pediatric radiology 21 (1991), S. 521-522 
    Details
    ISSN: 1432-1998
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract A preterm infant with severe hyaline membrane disease requiring extreme mechanical ventilation developed pulmonary air leaks with consecutive shock. The chest roentgenogram showed bilateral pulmonary interstitial emphysema and gas within the heart silhouette as well as in the hepatic veins, inferior v.cava, portal vein, and many abdominal vessels. The respiratory and circulatory failure by massive systemic gas embolism resulted in death.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02011730
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  • 9
    Digitale Medien
    Digitale Medien
    Super-allowed beta decay of nuclei at the drip-line (1991)
    Springer
    The European physical journal 340 (1991), S. 255-261 
    Details
    ISSN: 1434-601X
    Schlagwort(e): 23.40.Hc ; 21.60.−n ; 27.20.+n
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract We have investigated the continuous particle spectra following the beta decay of the neutron-rich nuclei that terminate the mass 6, 8, 9 and 11 isobaric chains. Strong beta transitions feeding the very top of the spectrum are found systematically. The favoured states are within a few MeV of the energy of the initial state. This phenomenon seems to be linked to the occurrence of a di-neutron structure or neutron halo in the drip-line nuclei.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01294673
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  • 10
    Digitale Medien
    Digitale Medien
    Susceptibility ofHeliothis zea (Boddie) larvae toNomuraea rileyi (Farlow) Samson (1990)
    Springer
    Journal of chemical ecology 16 (1990), S. 1751-1759 
    Details
    ISSN: 1573-1561
    Schlagwort(e): Heliothis zea ; Lepidoptera ; Noctuidae ; Nomuraea rileyi ; Deuteromycotina ; fungi ; α-tomatine ; allelochemical ; third trophic level
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract To determine the impact of α-tomatine at the third trophic level, the following model was developed:Nomuraea rileyi (Farlow) Samson, the secondary consumer, acting onHeliothis zea (Boddie), the primary consumer, fed an artificial diet modified with α-tomatine. In vitro, the allelochemical inhibited colony formation and growth of the fungus. The in vivo test revealed that larval growth and developmental time were affected by α-tomatine andN. rileyi. Detrimental effects on pupal development were observed in larvae fed diet containing α-tomatine and also treated withN. rileyi (LC90). The fungus was detected in the hemolymph and tissue of larvae treated with two lethal concentrations (LC50 and LC90) ofN. rileyi, including those fed α-tomatine. At the LC50, α-tomatine protected larvae againstN. rileyi and increased survivorship; at the LC90, it inhibited the development ofN. rileyi, thereby reducing production of conidia. Thus, the allelochemical α-tomatine retains its antifungal qualities beyond the second trophic level, inhibiting the development ofN. rileyi inH. zea.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01020492
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