ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Excitation of electron Bernstein and ion Bernstein waves by extraordinary electromagnetic pump: Kinetic theory (1994)
    [S.l.] : American Institute of Physics (AIP)
    Physics of Plasmas 1 (1994), S. 522-527 
    Details
    ISSN: 1089-7674
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In the present paper, parametric decay instability of an extraordinary electromagnetic (EM) wave into a high-frequency electron Bernstein wave and a low-frequency ion Bernstein wave is studied. The guiding center formalism is followed to obtain the coupling coefficients including kinetic effects. The momentum space integrals in the coupling coefficients are solved in the dipole approximation of the pump wave and in the limits, k⊥ρe〈1 for electron Bernstein wave and k⊥ρi〈1 for ion Bernstein wave. Analytical expressions for homogeneous growth rate and threshold are given explicitly. Applications of the present investigation are pointed out to ionospheric modification experiment and fusion plasmas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.870796
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Some parametric decay instabilities of fast magnetosonic waves in the ion cyclotron harmonic frequency regime (1992)
    New York, NY : American Institute of Physics (AIP)
    Physics of Fluids 4 (1992), S. 79-85 
    Details
    ISSN: 1089-7666
    Source: AIP Digital Archive
    Topics: Physics
    Notes: In the present paper, some possible parametric decay instabilities of fast magnetosonic waves (FMSW) near the second harmonic of ion cyclotron frequency have been considered in one-ion species hydrogen plasmas. The decay channels of FMSW include an ion Bernstein wave as a high-frequency decay wave and a low-frequency decay wave either as an ion-acoustic wave or kinetic Alfvén wave. Applications have been pointed out to the ASDEX [Plasma Phys. Controlled Fusion 28, 235 (1986)] and ACT-1 [Rev. Sci. Instrum. 53, 4 (1982)] toroidal devices where parametric decay instabilities of FMSW near the second harmonic of ion cyclotron frequency have been observed in the scrape-off layer and near the edge plasma. It has been shown that the growth rate is sufficiently high at the edge and may thus contribute to the energy deposition to the edge plasma. A comparison between various decay processes has been discussed for different toroidal devices. Applications have also been pointed out to Earth's magnetospheric plasmas where some magnetic fluctuations have been observed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.860407
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Absorption edge determination of thick GaAs wafers using surface photovoltage spectroscopy (2002)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 73 (2002), S. 1835-1840 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: A procedure for choosing the appropriate chopping frequency (f) for the surface photovoltage spectroscopy (SPS) measurements in order to obtain the absorption related features is presented. We could obtain the absorption edge of thick n+ GaAs wafer (thickness (approximate)700 μm) by performing SPS measurements at f≥1 kHz at room temperature (300 K). The similar information for semi-insulating (SI) GaAs could not be obtained due to the carrier trapping at deep levels or surface states at 300 K. However, we could obtain the absorption edge of SI-GaAs by performing SPS measurements at 395 K at f=3 kHz. Here, we demonstrate the capability of the SPS technique to measure large absorption coefficient (α) values for thick wafers by performing SPS measurements and normalizing this with the reported α value at one wavelength in the above band gap region. For comparison, we also perform quasisimultaneous SPS and transmission spectroscopy (TS) measurements. The SPS technique could provide α values up to 104 cm−1 for 700-μm-thick GaAs wafers, whereas TS could only measure α values up to about 15 cm−1. An improved design of the sample holder for measuring the surface photovoltage in the chopped light geometry, which increases the signal strength by reducing the gap between the top electrode and the wafer in a controlled manner, is presented. This ensures that there is no sample damage or contamination. © 2002 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1449461
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Simulation of dynamic compaction of metal powders (1999)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 85 (1999), S. 767-775 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: This article presents numerical studies on the deformation of particles during dynamic compaction of metal powders. The analysis of the process is based on a micromechanics approach using multiple particle configurations. The material considered is elastoviscoplastic with interparticle friction. Two-dimensional studies on particles in close packed arrangement were carried out using plane strain conditions for deformation and thermal response. The finite element method using an explicit dynamic analysis procedure was used for the simulations. The influence of speed of compaction, strain hardening, strain rate dependency, interparticle friction and size of the powder particles on the final shape and temperature variations within the particles were analyzed. The studies offer useful information on the shape and temperature variations within the particles. The results provide a better understanding of the dynamic compaction process at the micromechanics level. © 1999 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.369158
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Dielectric relaxation in Ba0.96Bi0.04Ti0.96Fe0.04O3 (1998)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 84 (1998), S. 6811-6814 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Samples of Ba0.96Bi0.04Ti0.96Fe0.04O3 were prepared by a solid state reaction method. Data on the dielectric constant as a function of temperature and frequency were obtained in the temperature range 35–180 °C at 10 and 100 kHz. The material shows a diffuse phase transition. With increasing frequency, the transition temperature shifts towards lower temperature, resembling that of a relaxor ferroelectric with a negative shift in Tc. Impedance analysis confirms the relaxor behavior. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.368875
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    facet.materialart.
    Unknown
    Proof-of-concept experiment for on-line laser induced breakdown spectroscopy analysis of impurity layer deposited on optical window and other plasma facing components of Aditya tokamak (2015)
    American Institute of Physics (AIP)
    Details
    Publication Date: 2015-12-30
    Description: In the present manuscript, we demonstrate the design of an experimental setup for on-line laser induced breakdown spectroscopy (LIBS) analysis of impurity layers deposited on specimens of interest for fusion technology, namely, plasma-facing components (PFCs) of a tokamak. For investigation of impurities deposited on PFCs, LIBS spectra of a tokamak wall material like a stainless steel sample (SS304) have been recorded through contaminated and cleaned optical windows. To address the problem of identification of dust and gases present inside the tokamak, we have shown the capability of the apparatus to record LIBS spectra of gases. A new approach known as “back collection method” to record LIBS spectra of impurities deposited on the inner surface of optical window is presented.
    Print ISSN: 0034-6748
    Electronic ISSN: 1089-7623
    Topics: Electrical Engineering, Measurement and Control Technology , Physics
    Published by American Institute of Physics (AIP)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 7
    facet.materialart.
    Unknown
    Probing on green long persistent Eu2+/Dy3+ doped Sr3SiAl4O11 emerging phosphor for security applications (2015)
    American Institute of Physics (AIP)
    Details
    Publication Date: 2015-06-26
    Description: Herein, a novel green emitting long-persistent Sr 3 SiAl 4 O 11 :Eu 2+ /Dy 3+ phosphor was synthesized in a single phase form using facile solid state reaction method under the reducing atmosphere of 10% H 2 and 90% N 2 . The resulting phosphor exhibits hyper-sensitive strong broad green emission, peaking at 510 nm upon 340 nm excitation wavelength, which is attributed to the 4f 6 5d 1 -4f 7 transitions of emission center of europium (Eu 2+ ) ions. Moreover, the incorporation of dysprosium (Dy 3+ ) ions, which act as effective hole trap centers with appropriate depth, largely enhances the photoluminescence characteristics and greatly improves the persistent intense luminescence behavior of Sr 3 SiAl 4 O 11 :Eu 2+ /Dy 3+ phosphor under ultraviolet (UV) excitation. In addition, with the optimum doping concentration and sufficient UV excitation time period, the as-synthesized phosphor can be persisted afterglow for time duration ∼4 h with maximum luminescence intensity. Thus, these results suggest that this phosphor could be expected as an ultimate choice for next generation advanced luminescent materials in security applications such as latent finger-marks detection, photo-masking induced phosphorescent images, and security code detection.
    Print ISSN: 0021-8979
    Electronic ISSN: 1089-7550
    Topics: Physics
    Published by American Institute of Physics (AIP)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 8
    facet.materialart.
    Unknown
    Asymmetric bursting of Taylor bubble in inclined tubes (2016)
    American Institute of Physics (AIP)
    Details
    Publication Date: 2016-08-20
    Description: In the present study, experiments have been reported to explain the phenomenon of approach and collapse of an asymmetric Taylor bubble at free surface inside an inclined tube. Four different tube inclinations with horizontal (30°, 45°, 60° and 75°) and two different fluids (water and silicon oil) are considered for the experiment. Using high speed imaging, we have investigated the approach, puncture, and subsequent liquid drainage for re-establishment of the free surface. The present study covers all the aspects in the collapse of an asymmetric Taylor bubble through the generation of two films, i.e., a cap film which lies on top of the bubble and an asymmetric annular film along the tube wall. Retraction of the cap film is studied in detail and its velocity has been predicted successfully for different inclinations and fluids. Film drainage formulation considering azimuthal variation is proposed which also describes the experimental observations well. In addition, extrapolation of drainage velocity pattern beyond the experimental observation limit provides insight into the total collapse time of bubbles at different inclinations and fluids.
    Print ISSN: 1070-6631
    Electronic ISSN: 1089-7666
    Topics: Physics
    Published by American Institute of Physics (AIP)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 9
    facet.materialart.
    Unknown
    Absence of low temperature phase transitions and enhancement of ferroelectric transition temperature in highly strained BaTiO3 epitaxial films grown on MgO Substrates (2015)
    American Institute of Physics (AIP)
    Details
    Publication Date: 2015-04-03
    Description: Recently, a large enhancement in the ferroelectric transition temperature of several oxides is reported by growing the respective thin films on appropriate substrates. This phenomenon is correlated with high residual strain in thin films often leading to large increase in the tetragonality of their crystal structure. However, such an enhancement of transition temperature is usually limited to very thin films of ∼10 nm thickness. Here, we report growth of fully strained epitaxial thin films of BaTiO 3 of 400 nm thickness, which are coherently grown on MgO substrates by pulsed laser deposition technique. Conventional high resolution x-ray diffraction and also the reciprocal space map measurements confirm that the film is fully strained with in-plane tensile strain of 5.5% that dramatically increases the tetragonality to 1.05. Raman measurements reveal that the tetragonal to cubic structural phase transition is observed at 583 K, which results in an enhancement of ∼200 K. Furthermore, temperature dependent Raman studies on these films corroborate absence of all the low temperature phase transitions. Numerical calculations based on thermodynamical model predict a value of the transition temperature that is greater than 1500 °C. Our experimental results are therefore in clear deviation from the existing strain dependent phase diagrams.
    Print ISSN: 0021-8979
    Electronic ISSN: 1089-7550
    Topics: Physics
    Published by American Institute of Physics (AIP)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 10
    facet.materialart.
    Unknown
    Evidence for spin glass state of NdCo1−xNixO3 (x = 0.3−0.5) (2014)
    American Institute of Physics (AIP)
    Details
    Publication Date: 2014-08-21
    Description: Low-temperature magnetic properties of single phase NdCo 1−x Ni x O 3 (x = 0.3−0.5) have been studied using ac and dc magnetic susceptibility measurements. Nickel substituted samples have been found to exhibit a different magnetic state at low temperature as compared to pristine NdCoO 3 . The temperature dependent dc magnetization M ( T ) revealed the presence of a sharp cusp occurring at characteristic temperatures T P , for x = 0.3, 0.4, 0.5. Below T P , clear effect of magnetic field can be seen in M ( T ) curves and T P decreases with increasing magnetic field as well as Ni substitution content. The isothermal magnetization measurements at low temperatures shows small unsaturated hysteresis loop at lowest temperature (10 K). The ac susceptibility results show a clear frequency dependent feature. These results are analyzed to distinguish superparamagnetic and spin glass behavior by using Néel-Arrhennius, Vogel-Fulcher law, and power law fitting. This analysis ruled out the superparamagnet like state and suggests the presence of significant inter-cluster interactions, giving rise to spin-glass like cooperative freezing.
    Print ISSN: 0021-8979
    Electronic ISSN: 1089-7550
    Topics: Physics
    Published by American Institute of Physics (AIP)
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...