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  • 1
    Electronic Resource
    Electronic Resource
    Direct observation of preferential bond fission by excitation of a vibrational fundamental: Photodissociation of HOD (0,0,1) (1990)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 93 (1990), S. 2146-2148 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The 193 nm photodissociation of individual rotational levels of HOD molecules excited with one quantum of O–H stretching vibrational energy is described. Stimulated Raman excitation and coherent anti-Stokes Raman scattering are used to prepare and detect, respectively, the (0,0,1) vibrationally excited HOD. The OD and OH fragments are detected by laser induced fluorescence. The photodissociation of the HOD (0,0,1) molecules yields at least three times more OD than OH.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.459040
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  • 2
    Electronic Resource
    Electronic Resource
    Mode-selective bond fission: Comparison between the photodissociation of HOD (0,0,1) and HOD (1,0,0) (1991)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 95 (1991), S. 3341-3346 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The 193 nm photodissociation of individual rotational levels of HOD molecules excited with one quantum of O–H or O–D stretching vibrational energy is described. Stimulated Raman excitation and coherent anti-Stokes Raman scattering are used to prepare and detect, respectively, the (0,0,1) (O–H stretch) or (1,0,0) (O–D stretch) vibrationally excited HOD. The OD and OH fragments are detected by laser-induced fluorescence. In the photodissociation of HOD (0,0,1), the yield of both fragments is enhanced [relative to HOD (0,0,0)], but the yield of OD is increased 2.5±0.5 times more than that of OH. In the photodissociation of HOD (1,0,0), no enhancement of the yield of the fragments is obtained. Our results show that even the very lowest possible level of vibrational excitation can be "leveraged'' to effect selective bond breaking. Also, these results demonstrate that bond cleavage does not necessarily occur on the weakened bond and they agree with theoretical calculations indicating that the yield of OD and OH fragments depends on the Franck–Condon overlap of the vibrational wave function with the repulsive surface of the upper state.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.460839
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  • 3
    Electronic Resource
    Electronic Resource
    Recycling municipal wastes in the future: from organic to inorganic forms? (2005)
    Oxford, UK : Blackwell Publishing Ltd
    Soil use and management 21 (2005), S. 0 
    Details
    ISSN: 1475-2743
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract. This paper highlights the principal problems related to the recycling of municipal wastes to arable land and outlines future solutions. History reveals that transport of sewage with water was introduced early (2500 bc), but only some Asian societies, which did not utilize sewage flushing, redistributed toilet wastes to arable land effectively. Nutrient flow analyses in developed countries indicate a withdrawal of 20 kg N and 3kgP ha−1 yr−1 from arable land because of non-return of organic human wastes. Limited reuse of municipal organic wastes in agriculture in several European countries is often seen as a question of waste quality. However, we believe that despite acceptable quality levels only minor progress in recycling has been achieved. Higher water contents in organic wastes than in harvested crops and, consequently, high costs for drying or transportation of wastes, often in combination with non-optimal plant nutrient composition, will remain the bottleneck which restricts the recycling of nutrients in wastes. One solution is to extract nutrients out of organic wastes and thereby derive concentrated compounds similar to those in inorganic fertilizers that can be redistributed and applied to soil. The challenge for modern sewage treatment systems is to shift perspective from removal to recovery of nutrients.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1475-2743.2005.tb00419.x
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  • 4
    Electronic Resource
    Electronic Resource
    Recycling municipal wastes in the future: from organic to inorganic forms? (2005)
    Oxford, UK : Blackwell Publishing Ltd
    Soil use and management 21 (2005), S. 0 
    Details
    ISSN: 1475-2743
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Geosciences , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Abstract. This paper highlights the principal problems related to the recycling of municipal wastes to arable land and outlines future solutions. History reveals that transport of sewage with water was introduced early (2500 bc), but only some Asian societies, which did not utilize sewage flushing, redistributed toilet wastes to arable land effectively. Nutrient flow analyses in developed countries indicate a withdrawal of 20 kg N and 3 kg P ha−1 yr−1 from arable land because of non-return of organic human wastes. Limited reuse of municipal organic wastes in agriculture in several European countries is often seen as a question of waste quality. However, we believe that despite acceptable quality levels only minor progress in recycling has been achieved. Higher water contents in organic wastes than in harvested crops and, consequently, high costs for drying or transportation of wastes, often in combination with non-optimal plant nutrient composition, will remain the bottleneck which restricts the recycling of nutrients in wastes. One solution is to extract nutrients out of organic wastes and thereby derive concentrated compounds similar to those in inorganic fertilizers that can be redistributed and applied to soil. The challenge for modern sewage treatment systems is to shift perspective from removal to recovery of nutrients.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1475-2743.2005.tb00119.x
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  • 5
    Electronic Resource
    Electronic Resource
    Dynamic model of trapping-detrapping in SiO2 (1985)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 58 (1985), S. 2252-2261 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The field and time dependence of charge carriers trapping under different charge injection conditions, is studied in this work, using the dc hot electron injection technique. It is shown that the trapping characteristics converge to field-dependent quasisaturation values. Variation of the trapping levels, due to change of the oxide field magnitude, are obtained in both directions and exhibit complete reversibility. These results, which cannot be explained by the first-order conventional trapping model, are consistent with a dynamic trapping-detrapping model. According to this model, quasisaturation of trapping characteristics is obtained when the trapping and detrapping processes are balanced. The occupation of the traps under steady-state conditions is therefore field dependent. The same model also describes the generation of positive charge under high-field injection conditions. This phenomenon is shown to be related to ionization of localized states in the SiO2 forbidden gap. The implications of the dynamic model suggest the need for a reevaluation of the present characterization methods for trapping in oxide layers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.335942
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  • 6
    Electronic Resource
    Electronic Resource
    Trap generation and occupation dynamics in SiO2 under charge injection stress (1986)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 60 (1986), S. 2024-2035 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The effect of enduring charge injection on the physical properties of the SiO2 layer of a metal-oxide-semiconductor structure is studied by means of a novel characterization method. It is based on the observation reported previously, that under charge injection conditions the density of occupied oxide traps reaches a value which is only a fraction of the total trap density. This trap occupation level is strongly dependent on the oxide electric field. The oxide trap density can be evaluated by measuring this field dependence, using a relatively small amount of charge injection. This method is used to distinguish between the process of trap generation and electron trapping in the generated traps, under conditions of continuous charge injection up to levels of more than 50 C/cm2. The trap generation rate is found to be proportional to the flux of the injected charge, and to increase exponentially with the oxide electric field. At high oxide field only a small fraction of the newly generated traps are occupied; consequently, the measured oxide charge buildup does not reflect the actual increase in the density of generated traps. The density of the generated traps reaches high values of the order of 1020 cm−3. It is suggested that these high values of oxide traps may be the cause of the SiO2 "wear out'' type breakdown, by forming a new path of conductance by electron tunneling between closely spaced generated traps.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.337204
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  • 7
    Electronic Resource
    Electronic Resource
    SiO2-induced substrate current and its relation to positive charge in field-effect transistors (1986)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 59 (1986), S. 824-832 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Experimental data are presented for the substrate current (holes), which accompanies electron injection into the oxide of n-channel field-effect transistor structures, in the tunneling regime. Dependencies of the effect on oxide thickness and on the metal gate material were investigated. An inverse relation was found between the initial rise time of oxide current transients and both the electron and hole currents. It is shown that these initial current increases are related to positive charge, therefore a correlation exists between the positive charge and electron or hole currents. The strength of impact ionization in SiO2 is discussed on the basis of band-structure arguments and it is concluded that there are difficulties in explaining the substrate current by impact ionization. A technique for fast measurements of capacitance-voltage shifts at the end of an applied high field pulse is described.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.336605
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  • 8
    Electronic Resource
    Electronic Resource
    Use of high direct current bias to separate electrode from bulk impedance (1995)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 66 (1995), S. 706-708 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: It is shown that the electrode impedance can be separated from the bulk impedance in semiconductors and electrochemical cells using high dc biases. This is true both for two-point dc resistance measurements and for two-point ac impedance measurements. Experimental evidence on semiconductor thin films is presented. The dc biases required may be high, in the 50 V range, and can then be applied mainly to high resistance samples, in particular to thin films. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.114106
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  • 9
    Electronic Resource
    Electronic Resource
    Photodissociation of HOD (νOD=3): Demonstration of preferential O–D bond breaking (1995)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 102 (1995), S. 3612-3616 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: It has been predicted that photodissociation of vibrationally excited HOD may preferentially yield either OD+H or D+OH, depending on the vibrational mode and the dissociation wavelength. To date, only the former preference has experimentally been demonstrated. In the present work preferential O–D bond breaking has been achieved from the photolysis of HOD (νOD=3) at 193 nm. HOD was prepared in a specific rovibrational level of the second overtone of the O–D stretch via infrared excitation. The subsequent photolysis led to enhancement of both OH and OD production, the OH/OD branching ratio being 2.6±0.5. The results agree with the predictions of Imre and co-workers [J. Phys. Chem. 93, 1840 (1989)] on the enhancement of νOD≥3 photodissociation but differ in the branching ratio obtained at the specific photolysis wavelength. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.468589
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  • 10
    Electronic Resource
    Electronic Resource
    In Vivo 19F Nuclear Magnetic Resonance Brain Studies of Halothane, Isoflurane, and Desflurane (1991)
    Oxford, UK : Blackwell Publishing Ltd
    Annals of the New York Academy of Sciences 625 (1991), S. 0 
    Details
    ISSN: 1749-6632
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Natural Sciences in General
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1749-6632.1991.tb33904.x
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