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Showing 1 to 20 of 601 for “"Impurity"”.
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Impurity transport studies on MAST
Impurity transport is a subject of fundamental importance in plasma physics in general and in tokamak physics in particular. The behaviour of the various impurity species and the evolution of their concentration determines, among other things, the fuel dilution and the fusion reaction rate, the …
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Optimum impurity concentration in semiconductor thermoelements
Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering, 1961.
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Fast impurity diffusion in hcp Zr
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1996.
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Alternate configurations for blocked impurity band detectors
Silicon Blocked Impurity Band (BIB) detectors are highly efficient, radiation-hardened photodetectors that operate in the range of 5-40 æm. To further extend BIB coverage to 40-350 æm, Ge and GaAs BIB detectors are under development; however, these new detectors face fabrication issues that have …
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Impurity Induced Raman Scattering in Alkali-Halides
Made available in DSpace on 2015-05-12T22:38:42Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 7121187.PDF: 4307589 bytes, checksum: a16c61f853cf6f2cca136e5672a8f867 (MD5) Previous issue date: 1971
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Impurity induced Raman scattering in alkali halides
… polarization effects in the interaction of the impurity with its surroundings is demonstrated. A weak peak of A1g symmetry has been observed at about 95 cm-1 in KI:H-. It is attributed to the gap mode previously seen in infrared sideband measurements. Raman scattering in NaCl:Ag+ is primarily …
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Magnetic Studies of Impurity Configurations in Metals
Submitted by Jesse Garrison (jagarris@illinois.edu) on 2011-07-06T19:57:35Z No. of bitstreams: 1 1972_rigert.pdf: 4759390 bytes, checksum: 16a1a37c713fb1732f4954d87f6a384b (MD5)
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Defect reactions and impurity control in silicon
… by Him, r,, and the background dopant and impurity concentrations. The model supports the defect assignments by DLTS. The model can be improved by including pair breakup processes and large interstitial clusters.
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Impurity analysis of MDA synthesized from unrestricted compounds
… laboratories. This thesis examines the impurity profile of two synthetic pathways to MDA, from helional and piperonal, both of which involve few restricted compounds and would therefore be ideal to clandestine chemists. Helional is a fragrant oil available for wholesale purchase for home …
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Effects of a single magnetic impurity on superconductivity
… in the vicinity of a single, iso- lated magnetic impurity has been probed experimentally with scanning tunneling spectroscopy by Yazdani et al.. Motivated by their experiment, we study the ef- fects of a single magnetic impurity on superconductivity by means of the mean-¯eld Bogoliubov-de Gennes …
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Local excitons in insulators and impurity doped metals
… spectra of some alkali-halide insulators and impurity doped lithium metal are calculated using atomic clusters to simulate the bulk solid. The calculations are ab initio and use unrestricted Hartree-Fock and second order many body perturbation techniques. Accurate results are obtained for …
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Temperature dependence of impurity resonances in cuprate superconductors
… by single atom scatterers. First, I report that impurity resonance peaks, near zero bias in the excitation spectrum, continue to exist above the superconducting transition temperature and prove that the impurity resonance peak is unchanged through the superconducting transition. I also show that …
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Low Impurity Content GaN Prepared via OMVPE for Use in Power Electronic Devices: Connection Between Growth Rate, Ammonia Flow, and Impurity Incorporation
… purity bulk substrates. However, unintentional impurity incorporation needs to be reduced. This reduction can be accomplished by reducing the source of contamination and exploration of extreme growth conditions which reduce the incorporation of these contaminants. Newly available bulk substrates …
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Luminescence of Impurity-Activated Alkali-Halides Under High Pressure
Made available in DSpace on 2015-05-13T15:21:56Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 7606750.PDF: 9580470 bytes, checksum: b7a638dd0f5a53b78dbd9617504ee389 (MD5) Previous issue date: 1975
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Interstitial-Impurity Trapping in Aluminum - Iron and Aluminum - Zinc
Made available in DSpace on 2015-05-13T15:22:17Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 8004194.PDF: 3284804 bytes, checksum: 3ca8cdba5173dd4fdbb68ef5ae8c53b2 (MD5) Previous issue date: 1979
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Effect of Antimony Impurity on Self-Diffusion of Silver
Made available in DSpace on 2015-05-12T17:11:54Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 0011544.PDF: 2246747 bytes, checksum: 8c6c2376a4c33f5a61b26a87ad1cb52e (MD5) Previous issue date: 1955
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Luminescence of impurity-activated alkali halides under high pressure
The effects of high pressure on the luminescence from Tl -, In -, and Ga+ -doped alkali halide phosphors excited in the A-absorption band were studied at room temperature for a number of materials in both the fcc and sc crystal structures. An emission spectrometer was constructed for use in the …
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Interstitial-impurity trapping in Al-Fe and Al-Zn
Ultrasonic attenuation and velocity measurements were made as a function of polarization, temperature, frequency and annealing before and after electron irradiation near 65K of A1-Fe and A1-Zn dilute alloys. Multiple relaxation processes were observed in both alloys. In the case of A1-Zn, the …
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AI-assisted reaction impurity prediction and inverse structure elucidation
… out possible-low-level impurities and performing impurity propagation, inverse structure elucidation – that is, identifying unknown impurities post hoc from analytical data, such as mass spectrometry data – presents a significant challenge. In this work, impurity prediction was established by …
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Study of recycling impurity retention in Alcator C-mod
… was aimed at reproducing experimental results in impurity compression of Ar, as well as the screening of recycling and non-recycling impurities from reaching the core plasma. As part of the study the code was upgraded in order to track the impurity flow from source till it reaches the core, …
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