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  • 1
    Electronic Resource
    Electronic Resource
    Photoacoustic and photoluminescence studies of porous silicon etched by low-concentration hydrofluoric acid (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 88 (2000), S. 6444-6450 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: We applied photoacoustic (PA), photoluminescence (PL), photoluminescence excitation (PLE), and atomic force microscopy (AFM) techniques on porous silicon (PS) layers to study the influence of chemical etching by low-concentration hydrofluoric acid. The chemical etching reveals the formation of PS layers of small dimensions by AFM observations, indicating the possibility of a strong quantum confinement effect. PA spectroscopy is useful to obtain the optical absorption characteristic for strongly scattering media such as PS and it helps to confirm the above speculation by indicating the blueshift of the fundamental absorption edge for the PS layer with chemical etching. PL spectroscopy also confirms the possibility of a quantum confinement effect by revealing the strong intensity and blueshift for the PS layer with chemical etching. PLE measurements suggest that the site for the radiative processes is different from that for the recombination of carriers and the PL of PS layers were dominated only by small crystallites in various size distributions. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1289220
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  • 2
    Electronic Resource
    Electronic Resource
    Suppression of secondary electrons from an endplate of a tandem mirror by use of a biased mesh (1995)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 2 (1995), S. 352-354 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Negative bias is applied to a mesh placed in front of an endplate of the GAMMA 10 tandem mirror [Phys. Rev. Lett. 55, 939 (1985)]. A bias voltage of around 10 V results in an increase of the potential difference by an order of kV in the end region. The increment is about two times the temperature of end-loss electrons and most of that stems from the sheath potential drop in front of the endplate. Provided that almost all the secondary electrons emitted from endplate are reflected, these results agree with the prediction of a potential model for the open magnetic field configuration [J. Phys Soc. Jpn. 61, 3153 (1992)]. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.871439
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  • 3
    Electronic Resource
    Electronic Resource
    Control of a global motion on field-reversed configuration (2002)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 9 (2002), S. 171-176 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: An n=1 mode global motion on a field-reversed configuration (FRC) plasma is observed by means of a newly developed optical system. The deviation of the FRC from the coil axis reaches 20%–40% of the plasma radius. In order to push back the FRC to the equilibrium position, a multipole field (quadrupole or hexapole field) is applied. The n=1 motion can be easily controlled by the quadrupole field, the critical field strength of which is required to be about 15% of the confinement field. It is found that the n=2 rotational instability can also be stabilized by strength of the same order. The critical strength for the n=1 motion is theoretically obtained from a model such that the driving energy of the motion given at the formation phase balances with the work done by the multipole field. The theoretical estimation agrees within a factor of 2 with the experimental results. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1416880
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  • 4
    Electronic Resource
    Electronic Resource
    Origin of transconductance oscillations in silicon-on-insulator metal–oxide–semiconductor field-effect transistors with an ultrathin 6-nm-thick active Si layer (2002)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 91 (2002), S. 5360-5364 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Transconductance oscillations were observed for silicon-on-insulator metal–oxide–semiconductor field-effect transistors with 50 nm channel length and 6 nm Si-layer thickness in the temperature range of 39–50 K. By investigating the temperature dependence of the oscillations it was found that the oscillations were caused by two reasons. One reason is the roughness at the Si/insulator interface responsible for the low-gate-voltage oscillations. The roughness results in different thicknesses of the Si layer along the channel, causing different quantized energy levels, which act as barriers for carriers moving in the channel. The other reason is the tunneling through the potential barrier at the p/n junctions between the contacts and the channel, which is responsible for the high-gate-voltage oscillations. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1459606
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  • 5
    Electronic Resource
    Electronic Resource
    Pinhole camera imaging of x rays and energetic neutral atoms for hot plasma diagnostics (1998)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 69 (1998), S. 2574-2575 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A compact pinhole camera is found to be useful for observation of a spatial distribution of hot ions by imaging energetic charge-exchange neutral atoms. One can obtain images of neutral atoms and of x rays in the same geometry only by selecting filtering foils at the pinhole opening of a single camera. Easy comparison between the images associated with distributions of ions and electrons is quite beneficial for physical analyses of plasmas. The imaging technique is expected also to be useful to determine space–time-resolved energy spectra of hot ions. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1148962
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  • 6
    Electronic Resource
    Electronic Resource
    In situ calibration of microchannel-plate-based x-ray pinhole camera for observation of magnetically trapped plasma (1997)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 68 (1997), S. 3421-3425 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: The electronic amplification gain of a microchannel plate (MCP), as employed for detector and image amplifier of an x-ray pinhole camera, tends to decrease as the output current increases, posing problems both in quantitative analyses and in construction of a three-dimensional emissivity distribution. We report that the output-current dependent MCP gain is described in a simple empirical formula that is determined by an in situ calibration experiment using a steady-state low-temperature discharge plasma. We examine the validity of the formula affirmatively in correcting raw data of x-ray images of magnetically trapped hot plasma. It is also demonstrated that the correction leads to a three-dimensional distribution of soft x-ray emissivity in a quadrupole-mirror-trapped hot plasma that is consistent with other indirect measurements. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1148303
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  • 7
    Electronic Resource
    Electronic Resource
    Thermographic temperature determination of gray materials with an infrared camera in different environments (1997)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 68 (1997), S. 2422-2427 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: In conventional infrared (IR) thermographic cameras it is normally assumed that the ambient temperatures of optical objects are the same as the temperature determined at the camera head. In increasing cases of application of thermography, this assumption is not always satisfied, and often leads to erroneous results. In this article, we propose a determination scheme of the true temperature of such objects in an explicit form of equation to be solved by combining the readout temperature of the camera with a response function of the camera to a blackbody. The equation can be used to determine optical properties of components in an IR system. It also works to evaluate the contribution coming from each element along the optical path. Though the scheme is written in a form applicable to a specific camera among commercial products, it can be modified so that conventional IR cameras are conveniently used for thermographic determination of the temperature of gray objects in exotic environments. © 1997 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1148127
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  • 8
    Electronic Resource
    Electronic Resource
    A new method of radial potential profile measurement utilizing magnetic field gradient near a mirror throat (1996)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 67 (1996), S. 1822-1828 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A gold neutral beam is perpendicularly injected into a plasma column along a main chord near an inner mirror throat of a plug/barrier cell in the tandem mirror GAMMA 10, in order to directly measure time evolution of the electrostatic radial potential profile during one shot. The new method pays attention to the fact that trajectories of the ions, which are ionized at each point on the path of the neutral beam in the plasma column, are shifted due to the magnetic field gradient and the electrostatic potential. After traveling about a half period of Larmor motion, ions are detected by a plate type of ion detector. The radial profiles of the plasma potential are determined analyzing positions of the ion beam spots on the detector plane. The main advantage of this method is that radial potential profiles in a strong magnetic field region can be measured as a function of time during one shot without sweeping incident beam angles. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1146981
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  • 9
    Electronic Resource
    Electronic Resource
    Procyanidin B-2, extracted from apples, promotes hair growth: a laboratory study (2002)
    Oxford, UK : Blackwell Science, Ltd
    British journal of dermatology 146 (2002), S. 0 
    Details
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Summary  Background  We have previously reported that several selective protein kinase C (PKC) inhibitors, including procyanidin B-2, promote hair epithelial cell growth and stimulate anagen induction.Objectives  We discuss the hypothesis that the hair-growing activity of procyanidin B-2 is related to its downregulation or inhibition of translocation of PKC isozymes in hair epithelial cells.Methods  We examined the effect of procyanidin B-2 on the expression of PKC isozymes in cultured murine hair epithelial cells as well as PKC isozyme localization in murine dorsal skin at different stages in the hair cycle.Results  We observed that procyanidin B-2 reduces the expression of PKC-α, -βΙ, -βΙΙ and -η in cultured murine hair epithelial cells and also inhibits the translocation of these isozymes to the particulate fraction of hair epithelial cells. Our immunohistochemical analyses demonstrated that PKC-α, -βΙ, -βΙΙ and -η are specifically expressed in the outer root sheaths of both anagen and telogen hair follicles. The hair matrix at the anagen stage showed no positive staining for these PKC isozymes. Moderate to intense staining for PKC-βΙ and -βΙΙ in the epidermis and hair follicles was observed in a telogen-specific manner; however, expression of PKC-α and -η during the telogen stage was not conspicuous. Gö 6976, an inhibitor of calcium-dependent (conventional) PKC, proved to promote hair epithelial cell growth.Conclusions  These results suggest that PKC isozymes, especially PKC-βΙ and -βΙΙ, play an important role in hair cycle progression and that the hair-growing mechanisms of procyanidin B-2 are at least partially related to its downregulation of PKC isozymes or its inhibition of translocation of PKC isozymes to the particulate fraction of hair epithelial cells.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.0007-0963.2001.04558.x
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  • 10
    Electronic Resource
    Electronic Resource
    Magnetic properties of Fe films deposited by Ar, Kr, and Xe ion beam sputtering : The 7th joint MMM-intermag conference on magnetism and magnetic materials (1998)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 83 (1998), S. 6667-6669 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Fe films have been deposited by ion beam sputtering using Ar, Kr, and Xe gases. The sputtering voltage VS was varied in the range of 900–1800 V. The magnetic properties of the films had the significant relationship with the element of the sputtering gas. The saturation magnetization 4πMS was 21 kG for Ar and 20 kG for Kr or Xe. The coercivity HC took the minimum value of 5 Oe at VS of 1200 V for Ar. The energy/the number of the energetic particles, such as the sputtered atoms and the recoiled ions bombarding to the substrate was calculated by Monte-Carlo simulation in the sputtering system with an amorphous Fe target. The average energy of the sputtered atoms ES was 40–60 eV for Ar, 30–34 eV for Kr and 24–34 eV for Xe. The average energy of the recoiled ions ER was 200–370 eV for Ar, 60–100 eV for Kr, and 25–50 eV for Xe. The energy was remarkably different among their sputtering gases with different atomic mass. The bombardment by the recoiled ions at the high energy reduced the coercivity HC of the Fe films. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.367705
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