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  • 1
    ISSN: 1398-9995
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background: It has been hypothesized that changes in heating systems and insulation of homes in developed countries have generated an indoor climate favorable to organisms that excrete allergens inducing sensitization and allergic disease. The purpose of this study was to determine the influence of the installation of highly insulated windows and central heating systems on indoor climate, and mite-allergen (Der f 1) and mold spore concentrations. Methods: The bedrooms of 98 apartments were examined before and 7 months (mean) after installation of insulated windows and central heating systems. The air-exchange rate, temperature, and humidity were measured. In settled dust on carpets and mattresses, the number of colony-forming mold spores and the Der f 1 concentration were determined. The inhabitants completed a questionnaire about their lifestyles and housing conditions. Results: The air-exchange rate decreased from geometric mean 0.73 to 0.52 per hour (P=0.029). Temperature (mean 13.4 vs 17.5°C, P〈0.001), and absolute humidity (mean 4.6 g vs 6.2 g H2O/kg air, P〈0.001) increased. Relative humidity remained nearly unchanged (mean 47.6 vs 49.1%). Der f 1 concentrations on carpets (geometric mean 0.65 vs 1.28 μg/g dust, P〈0.001) and mattresses (geometric mean 1.56 vs 2.40 μg/g, P=0.002) increased. Among the fungi that were analyzed, only the thermotolerant species Aspergillus fumigatus increased (geometric mean 20 vs 60 colony-forming units/g carpet dust, P=0.02). Conclusions: The findings of this study suggest that the installation of insulated windows and central heating systems is associated with an increase of Der f 1 concentrations in carpet and mattress dust and A. fumigatus in carpet dust in apartment bedrooms.
    Type of Medium: Electronic Resource
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  • 2
    Unknown
    Chapel Hill : University of North Carolina Press
    Keywords: Federal Writers' Project, History. ; United States, Civilization, 1918-1945. ; United States, Historiography. ; United States, Intellectual life, 20th century. ; National characteristics, American.
    Pages: xii, 293 p.
    ISBN: 0-8078-6166-9
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  • 3
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 112 (2000), S. 260-267 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Ab initio configuration interaction (Cl) calculations are carried out for the lowest-lying six 1,3Π and three 3Σ+ states. In addition, the first and second radial couplings 〈φi(R,r)|∂/∂R|φj(R,r)〉 and 〈φi(R,r)|∂2/∂R2|φj(R,r)〉, spin-orbit, and rotational couplings are also evaluated based on the resulting highly correlated wave functions. Energy positions and predissociation linewidths of rovibrational levels associated with the above electronic states are determined in the adiabatic representation by means of the complex scaling method employing a basis of complex scaled Hermite polynomials and Gauss–Hermite quadrature. The present treatment correctly reproduces a number of observed trends in energy and line broadening for individual rovibrational levels of the (4s)b 3Π and C 1Π states of HCl and DCl. The calculated linewidths for the v=0, J=2, and J=8 rovibrational levels of the (4s)C 1Π state of HCl are 1.2 and 2.1 cm−1, respectively, which is in good agreement with the recently observed rotational dependence of line broadening for the v=0 level of this state [M. H. Alexander et al., Chem. Phys. 231, 331 (1998)]. The present calculations find that the linewidths of the (4pσ)D 1Π state are greater than for the (4pσ)d 3Π state. The distinctive predissociation mechanisms of the D 1Π and the d 3Π states are discussed on the basis of the calculated radial couplings. The calculations predict very broad lines for the v=0 and 1 vibrational levels of the lowest adiabatic bound 3Σ+ state, consistent with the fact that the corresponding state has not yet been identified by spectroscopic means. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 72 (2001), S. 324-327 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: In a Doppler reflectometry experiment the line of sight is chosen to be nonperpendicular with respect to the reflecting layer. This type of diagnostic is able to probe density perturbations with the wave number in the reflecting layer selected by the tilt angle. The propagation velocity of the perturbations is calculated from the Doppler shift of the returning microwave signal whereas its intensity contains information about the perturbation amplitude. The diagnostic capability of Doppler reflectometry is demonstrated at the W7-AS stellarator using an antenna system with variable tilt angle. The measured values of the propagation velocity of density perturbations and its radial dependence are in good agreement with the E×B velocity of the plasma obtained from spectroscopy. Transient states can be followed with a temporal resolution less than 50 μs. Therefore Doppler reflectometry allows one to test the interdependence of sheared flow and turbulence on that timescale. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 88 (2000), S. 4953-4960 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We present results from a vacuum-ultraviolet (VUV) "photoabsorption imaging" technique based on the measurement of the time and space resolved absorption of a quasimonochromatic VUV beam from a laser plasma light source. The use of VUV radiation as a probe beam permits direct access to resonance lines of (singly and more highly charged) ions and also to the resonant and nonresonant continua of atoms and ions. In this experiment we have confined ourselves to measurements using the 3p–3d resonances of Ca, Ca+, and Ca2+ as markers of the temporal and spatial distribution of ground state atoms and ions in an expanding laser plasma plume. We show how time resolved column density maps may be extracted from such images. In addition we have extracted plasma plume velocities from the data, which compare well with an analytical laser ablation model. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 91 (2002), S. 6095-6098 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Metal–semiconductor–metal detectors have been fabricated based on AlGaN grown on Si by molecular beam epitaxy. Field distribution and collection efficiency were studied with the ion beam induced charge collection method. The results were explained by numerical two-dimensional calculations of the electric field distribution. The calculated field map and charge buildup at the electrodes are used to explain the bias and position dependence of the ion beam induced charge collection. The similarities and differences with the case of optical detection are discussed. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 90 (2001), S. 6066-6069 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The nitridation of GaAs, InAs, and InSb by low-energy N2+ ion bombardment at room temperature was studied by near-edge x-ray absorption fine structure (NEXAFS) and x-ray photoelectron spectroscopy measurements. The formation of thin surface nitride layers, consisting mostly of GaN or InN but also containing minor amounts of mixed nitrides, was observed. Besides the nitride-related features, sharp peaks in the NEXAFS due to π* resonance at 401.0 eV and correlated peaks at 403.8 eV in N 1s core level spectra were detected. Both spectral features could be assigned to the presence of interstitial nitrogen, most likely molecular nitrogen. It was found that the amount of interstitial nitrogen in the surface layer strongly depends on the AIII–BV semiconductor system and may be affected by modification of the conditions during low energy ion bombardment. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 29 (1907), S. 314-321 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 72 (2001), S. 1734-1741 
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A home-built spectrometer for solid-state nuclear magnetic resonance (NMR) spectroscopy with stochastic excitation is described. An overview of the instrument is given and selected components are explained in more detail. These are the control unit and the module for the pulse generation. Furthermore, a static probe with crossed coils for the transmitter and receiver circuits and the data processing part of the spectrometer software are described. The pulse unit can generate pulse trains with up to 219 pulses. Also, pulse-width-modulated sequences with automatic pulse centering can be produced. Using the crossed coil, probe decoupling between transmitter and receiver of more than 80 dB is possible. Several examples of NMR measurements are shown, which include selective excitation in solids and the acquisition of static 2H solid state NMR spectra with a spectral width of up to 185 kHz. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 8 (2001), S. 931-956 
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Magnetohydrodynamic (MHD) instabilities in the Wendelstein 7-AS stellarator (W7-AS) [G. Grieger et al., Phys. Fluids B 4, 2081 (1992)] are characterized experimentally in various plasma parameter regimes and heating scenarios. The observations are compared with theoretical predictions for particular cases. In the high-β range (〈β〉≤2%) no clear evidence of a stability β-limit could be found yet. In the lower β regime fast particle driven global Alfvén modes are the most important instabilities during neutral beam injection (NBI). Besides of coherent modes with almost no effect on the plasma performance additional Alfvén modes appear at higher frequencies up to 400 kHz, which show nonlinear phenomena-like bursting, frequency chirping, and MHD induced energy and fast particle losses. The activity of edge localized modes (ELMs) is investigated in NBI heated discharges. The issue of current driven instabilities and their potential stabilization by a stellarator field has been investigated with regard to the design of compact hybrid stellarator systems. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
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