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  • 1
    Electronic Resource
    Electronic Resource
    Auger electron spectroscopy of molecules: Theory for spin polarization following photoabsorption in rotating linear molecules (1993)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 98 (1993), S. 5242-5258 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: This paper develops theoretical expressions to study angular distribution and spin polarization of those Auger electrons which are emitted in the decay of a vacancy created by the absorption of a photon in a rotating linear molecule. Identical expressions except, of course, for different decay amplitudes, in both the Hund's coupling schemes (a) and (b), are obtained for the differential Auger current emitted in the transition J→Jf measured by an electron spectrometer sensitive to spin detection. The structure of these angular distributions is exactly the same as that of the spin-resolved photoelectrons from unoriented atoms and molecules. The present paper thus puts the angle- and spin-resolved Auger and photoelectron spectroscopies on the same footing wherein identical geometrical and kinematical analysis is applicable. The four parameters needed to completely characterize such distributions depend, in the present case, on rotational orientation and/or alignment of the photoexcited molecule, in addition to its Auger decay amplitudes. The use of parity-adapted molecular states separates the Auger spectra into even and odd partial wave components of the ejected electron continuum in both of the coupling schemes. Our analysis shows that the integrated Auger current is spin resolved provided it is produced in the decay of oriented vacancies. We further find that Auger electrons which leave the molecular ion in Jf=0 state may have nonzero degree of spin polarization if they follow absorption of only circularly polarized light. In this case, both the angular distribution and spin polarization of emitted electrons become totally independent of Auger dynamics. Thus, angle- and spin-resolved Auger electron spectroscopy can be used to produce polarized electrons, to determine rotational orientation and alignment of linear molecules, to study their structure and dynamics, and to prepare ions of such molecules in selective ro-vibronic states.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.464924
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  • 2
    Electronic Resource
    Electronic Resource
    Energy levels of the SbGa heteroantisite defect in GaAs:Sb (1993)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 62 (1993), S. 2968-2970 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A transient capacitance study of antimony-doped bulk GaAs has led to the identification of two energy levels related to the SbGa heteroantisite defect. The levels with electron emission activation energies of 0.54 and 0.70 eV are typically overshadowed by omnipresent EL3 and EL2 traps related to oxygen defect and the arsenic antisite, respectively. Positive identification of the levels, and determination of their emission rate signatures, was made possible employing GaAs crystals with a defect structure especially engineered to achieve very low concentrations of background traps. Relationship of the levels to the SbGa defect is deduced from excellent agreement with previous electron paramagnetic resonance results.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.109159
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  • 3
    Electronic Resource
    Electronic Resource
    Clonal propagation of Virginia Pine (Pinus virginiana Mill.) by organogenesis (1991)
    Springer
    Plant cell reports 10 (1991), S. 131-134 
    Details
    ISSN: 1432-203X
    Keywords: cotyledons ; abscisic acid ; cytokinins ; organogenesis ; Pinus virginiana
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Clonal propagation of Virginia Pine (Pinus virginiana Mill.) was achieved by organogenesis on cotyledon explants. The influence of several cytokinins and abscisic acid on adventitious shoot production from cotyledon explants was investigated. Benzyladenine was more effective in shoot induction than three other cytokinins tested. Benzyladenine (22.2 μM) in combination with naphthaleneacetic acid(0.05 μM) in a Gresshoff and Doy (1972) medium was found to increase shoot bud production. Abscisic acid (7.6 μM) in combination with benzyladenine and naphthaleneacetic acid enhanced shoot formation by an additional 65%. Root initiation was achieved with 0.5 strength Gresshoff and Doy media amended with naphthaleneacetic acid (1.3 μM), indole-3-butyric acid (1.2 μM) and benzyladenine (0.4 μM). Over 2400 plantlets from 2 families survived and were transferred to a greenhouse in preparation for field planting. After ten months, the maximum number of surviving plantlets/seed explant from these two sources was 57 for family ALPV-38 and 41 for family ALPV-78, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00232043
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  • 4
    Electronic Resource
    Electronic Resource
    Plant regeneration through somatic embryogenesis from suspension culture-derived protoplasts of Paspalum scrobiculatum L. (1991)
    Springer
    Plant cell reports 10 (1991), S. 362-365 
    Details
    ISSN: 1432-203X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Protoplasts were released from embryogenic suspension culture of Paspalum scrobiculatum and cultured in either liquid or semisolid KM medium supplemented with 2,4-D in the dark at 24°C with or without a feeder layer. Cell wall formation was observed in 75% of the plated protoplasts. Microcolonies developed after 10 d of culture, which in turn formed callus upon transfer to M-2 medium (Nayak and Sen, 1989). The highest plating effeciency (ca 7%) was obtained in thin-layer liquid culture. The macrocalli formed somatic embryos which regenerated to plantlets. The plantlets were grown to flowering plants upon transfer to soil.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00193160
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  • 5
    Electronic Resource
    Electronic Resource
    The axial-vector symmetry: its effective restoration at high temperature and the massive pseudoscalar mesons (1993)
    Springer
    The European physical journal 59 (1993), S. 563-565 
    Details
    ISSN: 1434-6052
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract TheU L−R (1) symmetry breaking is shown to be associated with the emergence of the gluon enriched massive singlet mode. The possibility of the restoration of this symmetry at high temperature is studied and its phenomenological consequences are envisaged.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01562548
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  • 6
    Electronic Resource
    Electronic Resource
    Semiconduction properties of some polyene-iodine charge-transfer complexes and their application in solid-state batteries (1993)
    Springer
    Journal of materials science 28 (1993), S. 1367-1371 
    Details
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The conjugated polyenes β-carotene, lutein, retinoic acid and β-apo-8′-carotenal are shown to form charge-transfer (CT) complexes with the electron acceptor iodine. The conductivity increases by several orders of magnitude and the activation energy decreases on CT complex formation. Using these complexes as cathodic material, batteries with the configuration Mg/(polyene-iodine CT complex) /graphite are developed. Different battery parameters are evaluated. The effects of ambient temperature and humidity on battery performance are also studied. Results show that a β-apo-8′-carotenal-l2 based battery has the maximum power density and longest self-life and is suitable for use as a micro-electronic gadget energizer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01191979
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  • 7
    Electronic Resource
    Electronic Resource
    Chemical interactions between soil N and alkaline-hydrolysing N fertilizers (1993)
    Springer
    Nutrient cycling in agroecosystems 36 (1993), S. 239-248 
    Details
    ISSN: 1573-0867
    Keywords: Added nitrogen interaction ; alkaline hydrolysis ; ammonia fixation ; aqua ammonia ; di-ammonium phosphate ; fertilizer-induced deamination ; urea
    Source: Springer Online Journal Archives 1860-2000
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract Chemical interactions between soil N and alkaline-hydrolysing N fertilizers labelled with15N were studied in the laboratory using twelveγ-irradiated soils. Fertilizer was recovered in the soil organic N fraction via the process of NH3 fixation. NH3 fixation at day 7 varied from 1.8 to 4.6% of the N added as aqua ammonia at 1000 mg kg−1 soil. The amount of NH3 fixed increased with increasing rates of application of NH3(aq) and urea. The rate of NH3 fixation decreased with time, with more than 55% of the total NH3 fixation in 28 days occurring in the first week following application of 2000 mg urea-N kg−1 soil. Soil pH and NH3 fixation varied in response to N source, and increased in the order of di-ammonium phosphate 〈urea 〈 aqua ammonia at equivalent N concentrations. The alkaline hydrolysis of indigenous organic N occurred simultaneously with NH3 fixation, resulting in the release of unlabelled ammonium (deamination) and a real added nitrogen interaction in all but two of the soils studied. The release of NH 4 + initially increased up to a pH of 7.5, was inhibited between pH 8.5 and 9.0, but increased thereafter. The balance (Nbal) between NH3 fixation and deamination was either positive or negative, depending on the pH of the fertilized soil, which was directly related to N source and concentration for a given soil.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00748702
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  • 8
    Electronic Resource
    Electronic Resource
    Infrared spectra of jute stick and alkali-treated jute stick (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 42 (1991), S. 2943-2950 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Defatted jute stick was treated with sodium hydroxide solution (2% w/v) at ambient temperature (∼ 32∼C) and boiling water bath temperature (95-97°C). Infrared (IR) spectra of defatted jute stick and alkali-treated jute stick were studied. The IR spectra of the alkalitreated jute stick were conspicuous by the absence of the 1730 cm-1 band, as compared to that of jute stick. Another characteristic feature of the alkali treated jute sticks is the absence of the band at 1240 cm-1, which is replaced by the 1265 and 1225 cm-1 bands; other bands in the above samples also recorded significant changes.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1991.070421111
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  • 9
    Electronic Resource
    Electronic Resource
    Infrared spectra of jute stick bleached with sodium chlorite and hydrogen peroxide (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 43 (1991), S. 2187-2192 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Jute stick was bleached with sodium chlorite and alkaline hydrogen peroxide solutions. The infrared (IR) spectra of bleached samples and jute stick were analyzed and compared. The bleached samples were characterized by higher absorbance intensity ratios (Av/A2900) of the bands attributed to hemicellulose. Among the bleached samples the chlorite-bleached sample showed higher intensity for the bands mentioned. The bands attributed to lignin are either absent or very weak in the chlorite-bleached jute stick as compared to that of peroxide-bleached jute stick, although some residual lignin was present in the substrate. The 1635 cm-1 band attribute to the vibration of adsorbed water molecules in the noncrystalline regions in cellulose appears as a sharp peak in chlorite-bleached jute stick and as a shoulder in peroxide-bleached jute stick. This can be attributed to the difference in the nature of the two bleaching processes.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1991.070431205
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  • 10
    Electronic Resource
    Electronic Resource
    Characterization of grafted jute fiber by optical and scanning electron microscopy (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 49 (1993), S. 25-30 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Raw and partially delignified jute fibers were grafted with acrylonitrile and methyl meth-acrylate monomers, using the redox system of initiation with ceric ammonium sulfate. Grafting was also carried out in a mixed monomer system with acrylonitrile and methyl methacrylate monomers in different proportions. The optimum grafting condition depends on the duration of grafting treatment and proportion of grafting monomers. The monomers entered the fiber matrix with high add-on and, at still higher graft add-ons, the ultimate fibers suffered disintegration. The surfaces were increasingly covered with grafted materials and longitudinal cracks developed on the fiber surface with higher add-on. © 1993 John Wiley & Sons, Inc.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1993.070490104
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