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  • 1
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 91 (1989), S. 5672-5678 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The homogeneous nucleation of three supersaturated alcohol vapors carried in argon is investigated experimentally. A gasdynamic shock tube method serves to subject the vapors to short supersaturation pulses. The growing nuclei are detected in number and size by Mie-light scattering. The results provide the supersaturation over a wide range of temperature for the nucleation rate of 108 cm−3 s−1. Comparison with the classical nucleation theory (CNT) exhibits increasing divergence with decreasing temperature.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 65 (1994), S. 1483-1485 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A very high current modulation efficiency of 5.7 GHz/(square root of)(mA) has been demonstrated in a low threshold (0.85 mA) InGaAs vertical-cavity surface-emitting laser. These top surface emission devices have been fabricated with intracavity contacts on semi-insulating substrates to realize their high speed potential. Data is presented for various laser diameters. Modulation bandwidths up to 9.3 GHz at a bias of only 4.5 mA have been measured for 7 μm diameter lasers. Derived parameters indicate that considerably higher bandwidths should be possible with better heat dissipation and modified cavity designs.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 63 (1993), S. 3411-3413 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We report on a technique of grading the heterobarrier interfaces of a p-type distributed Bragg reflector mirror to reduce the operating voltages of vertical-cavity surface-emitting lasers (VCSELs). We report VCSELs with lower operating voltages (2–3 V) and record continuous-wave room-temperature power-conversion efficiencies (17.3%). We experimentally demonstrate that by using a parabolic grading and modulating the doping correctly, a flat valence band is generated that provides low voltage hole transport. The low resistance mirrors are achieved using low Be doping, digital-alloy grading and 600 °C growth temperatures.
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  • 4
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Industrial & engineering chemistry 20 (1928), S. 74-76 
    ISSN: 1520-5045
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Process Engineering, Biotechnology, Nutrition Technology
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 47 (1925), S. 449-454 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 113 (2000), S. 6774-6781 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Homogeneous nucleation rates of n-pentanol in nitrogen are presented. They are obtained from a piston-expansion tube (pex-tube) involving the nucleation pulse method which generates a limited number of nuclei that grow into droplets. The detection of the droplets is achieved by a new counting method developed on the basis of a CCD camera in combination with a laser light sheet. Nucleation rates between 104 and 109 cm−3 s−1 are covered for three nucleation temperatures 250, 260, and 270 K. The rates are plotted as isotherms vs supersaturation. Influence of the initial expansion temperature and the nucleation pressure on the nucleation rate is identified. Comparison with results available in literature and classical nucleation theory (CNT) is provided. © 2000 American Institute of Physics.
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  • 7
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 91 (1987), S. 2487-2489 
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 105 (1996), S. 5168-5176 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Measurements of homogeneous nucleation rates of two binary vapor mixtures of water and alcohol carried in nitrogen have been performed with a new instrument for nucleation and droplet growth studies, the piston expansion tube (pex-tube). The pex-tube subjects the vapors to short supersaturation pulses generating a limited number of nuclei which grow into monodisperse droplets. The droplets are detected in number and size by Mie light scattering. The results provide nucleation rates between 105 and 109 cm−3 s−1 at constant temperature as a function of the vapor phase activities a1 and a2 of water and alcohol, respectively. Comparison with published experimental data exhibits good agreement. © 1996 American Institute of Physics.
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  • 9
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 116 (2002), S. 7617-7620 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Homogeneous nucleation rates of n-propanol in nitrogen are presented. They are obtained from a piston-expansion tube involving the nucleation pulse method which generates a limited number of nuclei that grow into droplets. The detection of the droplets is achieved by a counting method based on a digital charge coupled device camera in combination with a laser light sheet. Nucleation rates between 104 and 1010 cm−3 s−1 are covered for nucleation temperatures between 242 and 273 K. The rates are plotted as isotherms versus supersaturation. Best fit curves are provided for data representation. As in a previous case dealing with n-pentanol nucleation a weak influence of the initial expansion temperature on the nucleation rate is substantiated and explained. Comparison with literature data and classical nucleation theory is provided. © 2002 American Institute of Physics.
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  • 10
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 83 (1985), S. 6425-6431 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The onset of homogeneous condensation of binary vapors in the supersaturated state is studied by means of the unsteady expansion in a shock tube. The experiments are concerned with low temperatures down to 220 K which are of particular interest for atmospheric conditions. Two representative systems, ethanol/n-propanol and water/ethanol, are investigated since they allow a sufficient theoretical description. The first system forms a nearly ideal solution, whereas the latter one is an example of a strongly nonideal mixture. For either system vapor mixtures of various compositions are diluted in dry air at small mole fractions and expanded in the driver section from room temperature. The onset of homogeneous condensation is detected optically and the corresponding thermodynamic state is evaluated. The experimental results are compared with the binary nucleation theory and the particular problems of the theoretical evaluation at the low temperatures are discussed. The use of surface tension values derived for small binary droplets1 in the nucleation theory is mandatory to restore agreement between theory and experiment for the surface active system water/ethanol.
    Type of Medium: Electronic Resource
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