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  • 1985-1989  (13)
  • 1965-1969
  • 1989  (5)
  • 1986  (8)
Material
Years
  • 1985-1989  (13)
  • 1965-1969
Year
  • 1
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 90 (1989), S. 4879-4891 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The electron attachment rate constants ka for SF6 have been measured in dilute mixtures of SF6 in high pressure (〉1 atm) N2, Ar, and Xe buffer gases at room temperature (T≈300 K) over a wide E/N range (electric field strength to gas number density ratio), corresponding to mean electron energies 〈ε〉 from near thermal electron energies (≈0.04 eV) to 〈ε〉≈4.3 eV. Particular attention has been paid to the effects of space charge distortion, molecular impurities, and changes in the electron energy distribution function on the measured electron attachment rate constant values at the lower E/N values in these mixtures. The present measured thermal electron attachment rate constants in SF6/N2 and SF6/Xe gas mixtures are in excellent agreement with recent accurate measurements of these parameters in several SF6/buffer gas mixtures. At higher 〈ε〉 values, the present SF6/N2 measurements are in fair agreement with previous measurements, while no previous measurements using Ar and Xe buffer gases have been published. These measurements have been used in numerical two term, spherical harmonic Boltzmann equation analyses of the electron motion in these gas mixtures to obtain the low energy (〈10 eV) nondissociative and dissociative electron attachment cross sections for SF6. The present derived electron attachment cross sections are compared with recently measured and derived nondissociative and dissociative electron attachment cross sections for SF6. The primary value of the present results is in the large and overlapping 〈ε〉 ranges of the present ka measurements for the three buffer gases compared with that for SF6/N2 gas mixtures alone, which in turn, makes these measurements ideal for testing cross-section sets in SF6 for use in many applied studies.
    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 60 (1986), S. 24-35 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: An improved pulsed Townsend technique for the measurement of electron transport parameters in gases is described. The accuracy and sensitivity of the technique have been investigated by performing, respectively, electron attachment coefficient measurements in pure O2 over a wide range of E/N at selected O2 pressures and by determining the electron attachment and ionization coefficients and electron drift velocity in CH4 over a wide E/N range. Good agreement has been obtained between the present and the previously published electron attachment coefficients in O2 and for the drift velocity measurements in CH4. The data on the electron attachment coefficient in CH4 (measured for the first time) showed that with the present improved pulsed Townsend method, electron attachment coefficients up to 10 times smaller than the ionization coefficients at a given E/N value can be accurately measured. Our measurements of the electron attachment and ionization coefficients in CH4 are in good agreement with a Boltzmann equation analysis of the electron gain and loss processes in CH4 using published electron scattering cross sections for this molecule.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 65 (1989), S. 1858-1865 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The drift velocity of electrons (w) in SiF4 and BF3 has been measured over the density-reduced electric field (E/N) range 0.5×10−17 V cm2 ≤E/N≤300×10−17 V cm2 using a pulsed Townsend experimental technique. The electron attachment (η/N) and ionization (α/N) coefficients have also been measured in SiF4 and BF3 over the E/N range 30×10−17 V cm2 ≤E/N≤300×10−17 V cm2 in the same experiment. The electron drift velocities in these two gases exhibit regions of negative differential conductivity (NDC) similar to but smaller in magnitude than those in CH4 and CF4 . The effective ionization coefficient (α¯/N) has been obtained from the η/N and α/N measurements in both gases, from which the high-voltage limiting electric field strengths (E/N)lim have been found to be 123×10−17 V cm2 for BF3 and 121×10−17 V cm2 for SiF4. The significance of these results in modeling gas discharges for a number of technological applications is indicated.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Environment and Resources 11 (1986), S. 451-469 
    ISSN: 0362-1626
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Plant, cell & environment 9 (1986), S. 0 
    ISSN: 1365-3040
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: Abstract Cold-acclimated stems of red-osier dogwood (Cornus sericea L.) were sampled in midwinter and early spring and subjected to the following low temperature treatments: (a)0 →−40 → 0°C; (b) 0 →−40 →− 196 → 0°C; (c) 0 →−40 →−196 →−269 →−196 → 0°C; (d) 0 →−40 →−269 →−196 → 0°C; (e) 0 →−196 → 0°C; (f) 0 →−269 →−196 →0°C. The cortical parenchyma cells of the outer stem layers survived exposure to −269°C when pre-frozen to −40°C and either transferred directly to −269°C or to −196°C and then to −269°C (treatments c and d). Acclimated stems transferred to a greenhouse (22°C) 2 weeks prior to the low temperature treatments deacclimated and were not able to survive freezing to −10°C. Cortical cells of stem samples taken in March, near the time when dogwood naturally deacclimates, survived −196°C (treatment b), but not −269°C (treatment cord). Thus, the freezing tolerance of dogwood varies seasonally from near −10°C to below −269°C.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Anaesthesia 41 (1986), S. 0 
    ISSN: 1365-2044
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: This report describes the successful use of ketanserin, a 5–HT2 receptor antagonist, for the acute control of systemic blood pressure in a patient with the carcinoid syndrome. undergoing hepatic artery embolisation. Serial measurements of plasma 5–hydroxyindoles. platelet 5–hydroxytryptamine and plasma cate–cholamines are also given.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Springer
    European journal of pediatrics 149 (1989), S. 124-125 
    ISSN: 1432-1076
    Keywords: Neonatal ; Thrombosis ; Protein C ; Streptokinase
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A newborn infant was diagnosed as having renal vein thrombosis due to heterozygous protein C deficiency and no other predisposing factor for thrombosis. He responded adequately to treatment with streptokinase, fresh frozen plasma and subsequent anticoagulation with heparin and warfarin (Coumadin). Four years from diagnosis he remains well with no recurrence of thrombosis and with normal renal function.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1434-6052
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We have studied the processpp→γγ+X at $$\sqrt s = 63 GeV$$ GeV in the central rapidity region. We report a positive signal at 96% C.L., a ratio γγ/e + e −=4.0±3.0 when the transverse momentum of each photon is above 2 GeV/c, and a cross-sectiondσ/dydM γγ=(5.5±2.7)×10−34 cm2/GeV when |y|〈0.5,4〈M γγ〈6 GeV.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1434-6052
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We present stdies of events triggered on two high-p T jets, produced inpp collisions at the CERN Intersecting Storage Rings (ISR) at $$\sqrt s $$ =63 GeV, using a large solid angle calorimeter. The cross-section for producing two jets is measured in the dijet mass range 17–50 GeV/c2. A high-statistics sample of dijet events, where each jet has transverse energy above 10 GeV, is used to study the structure of jets and the associated event. We find the longitudinal fragmentation function to be similar to that of jets emerging frome + e − collisions but considerably harder than that observed at the Super Proton Synchrotron (SPS) $$p\bar p$$ Collider. A steepening of the fragmentation function is observed when increasing the jet energy. Studies of the charge distribution in jets show that these predominantly originate from fragmenting valence quarks. The transverse energy and particle flows are presented as functions of the azimuthal distance from the jet axis.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1434-6052
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We have studiedpp collisions at the CERN ISR at $$\sqrt s = 63 GeV$$ using a jet trigger. We demonstrate that a sample of well-separated triple high-p T jet events can be described as due to the QCD bremsstrahlung process. The energy flow of these 3-jet events is well described by an independent fragmentation model, with a gluon-jet transverse width 33% greater than the quark-jet width. From the ratio of the 3- and 2-jet production crosssections the strong coupling is determined to lowest order in QCD. We find α s =0.18±0.03 (stat.) ±0.04 (stst.). The error does not include the theoretical uncertainty in the fragmentation scheme. We compare our results with measurements at the SPS Collider and discuss the different methods used.
    Type of Medium: Electronic Resource
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