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  • 1
    Electronic Resource
    Electronic Resource
    Kinetic energies of Cn+ fragment ions (58≥n≥4) produced by electron impact on C60 (1998)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 108 (1998), S. 963-970 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: We used mass spectrometric techniques in conjunction with the ion deflection method to determine the kinetic energies of Cn+ fragment ions (58≥n≥4) produced by controlled electron impact on C60 under single collision conditions. The recorded ion beam profiles for the various fragment ions were analyzed using two independent methods. One method extracts the average kinetic energy of the fragment ion under study from the measured half-width of the ion beam profile (half-width method), whereas the second method analyzes the entire measured beam profile (profile method). For each Cn+ fragment ion, the kinetic energies obtained were interpreted assuming two possible formation pathways, (i) the fission of the excited parent C60+ ion in a single-step, two-fragment break-up, C60+→Cn++C60−n and (ii) the sequential decay of excited C60+ into Cn+ via the successive removal of Cm units (m=1, 2, or 3). Both the half-width method and the profile method yield very similar results for the kinetic energies of the Cn+ fragment ions for both formation mechanisms, viz., an average kinetic energy of roughly 0.45 eV in the case of the single-step fission and a linearly increasing average kinetic energy from 0.43 eV for the formation of C58+ to roughly 12 eV for the formation of C4+ in case of the sequential decay mechanism (in this case an essentially constant energy of also about 0.45 eV was obtained for the last fragmentation step in each case, which was confirmed by a third method using a fitting procedure). These results will be discussed in the context of the most likely fragmentation mechanism leading to the formation of the various fragment ions. © 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.475459
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  • 2
    Electronic Resource
    Electronic Resource
    Electron impact ionization of the SO2 molecule (1995)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 103 (1995), S. 211-218 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: We report measurements of the absolute cross sections for the electron-impact ionization of SO2 from threshold to 200 eV. Absolute cross sections for the formation of the SO+2 parent ions and of the SO+, S+, O+, and O+2 fragment ions were obtained independently in two different laboratories using two different experimental techniques with uncertainties ranging from ±18% to ±25%. The level of agreement between the absolute cross sections (at 70 eV) obtained by the two techniques ranges from about 10% for SO+2 and SO+ to 20% for (S++O+2) and O+, which in all cases is well within the combined error margins of the two measurements. The high resolution capability of the mass spectrometer employed in one experiment enabled the separation of the S+ and O+2 fragment ions, which are separated by only 0.017 76 atomic mass units (amu), for the first time. The single positive ion formation is the dominant process for all observed product ions. The total single SO2 ionization cross section obtained by the two techniques agreed to within 8%. A comparison of the experimentally determined total SO2 single ionization cross sections with calculated cross sections based on a modified additivity rule revealed agreement to within 20%. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.469634
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  • 3
    Electronic Resource
    Electronic Resource
    Side-cooled 1200 mm silicon x-ray mirrors with pneumatic benders : Proceedings of the 5th international conference on synchrotron radiation instrumentation (1995)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 66 (1995), S. 2177-2179 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: This paper reports the successful design, fabrication, and testing of several side-cooled silicon and SiC (graphite) synchrotron mirrors (flat, spherical, and cylindrical) with a length of up to 1200 mm. The mirrors are equipped with support structures which allow the mirrors to be bent meridionally to cylinders with radii from infinity to 5000 m. Detailed metrology results are presented for the mirrors and the bending system. All mirrors will be installed at ESRF beamlines 8, 15, and 19. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1145697
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  • 4
    Electronic Resource
    Electronic Resource
    Electron impact ionization of the SiDx (x=1–3) free radicals (1996)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 105 (1996), S. 6315-6321 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: We report measurements of absolute cross sections for the electron-impact ionization and dissociative ionization of the SiDx (x=1–3) free radicals from threshold to 200 eV using the fast-neutral-beam technique. The deuterated rather than the protonated target species were used in order to allow a better separation of the various product ions from a given parent in our apparatus. A common feature of all three radicals studied in this work is a dominant parent ionization cross section with essentially the same absolute value of roughly 3.7×10−16 cm2 at 70 eV. Dissociative ionization processes for all three targets are less significant with a single dissociative process dominating in each case, viz. the removal of a single D atom (SiDx+e−→SiD+x−1+D+2e−). The cross section for this dominant dissociative ionization channel also had the same maximum value of about 1.2×10−16 cm2 for all three targets. A comparison of the experimentally determined total single ionization cross sections with calculated cross sections using a modified additivity rule showed good to satisfactory agreement for all three targets in terms of the absolute values, but reveals some discrepancies in the cross section shapes. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.472484
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  • 5
    Electronic Resource
    Electronic Resource
    Electron-impact ionization of the SO free radical (1995)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 102 (1995), S. 770-773 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: We studied the electron-impact ionization of the SO free radical using the fast-neutral-beam technique. Absolute cross sections were measured for the formation of the SO+ parent ion as well as for the S+ and O+ fragment ions from threshold to 200 eV. At 70 eV, cross section values of 3.25±0.50×10−20 m2 (SO+), 1.32±0.23×10−20 m2 (S+), and 0.45±0.08×10−20 m2 (O+) were obtained. We found little evidence of the presence of vibrationally excited SO radicals in the incident target beams and only negligible contributions to the measured ion signal from excited SO radicals in Rydberg and/or metastable states were observed. The only significant pathway contributing to the formation of the observed SO+, S+, and O+ ions is the single positive ion formation. The measured partial ionization cross sections were combined to yield the absolute total single ionization cross section of SO which was compared to calculations using a recently introduced modified additivity rule. The agreement between measured and calculated cross sections was found to be very good. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.469190
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  • 6
    Electronic Resource
    Electronic Resource
    Absolute partial and total cross-section functions for the electron impact ionization of C60 and C70 (1996)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 105 (1996), S. 1880-1896 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Electron impact ionization of C60 and C70 was studied using a molecular/electron beam ion source in combination with a two sector field mass spectrometer operated in the ion beam deflection mode. Relative partial ionization cross sections for the production of singly and multiply charged parent ions (up to charge state z=4) and fragment ions (down to C+44 in the case of C60 and down to C2+50 in the case of C70) were determined from threshold up to 1000 eV electron energy. Absolute partial and total ionization cross sections are obtained using a novel approach for the absolute calibration involving an intercomparison of the cation with the anion yield. The results obtained reveal not only an anomalous large parent ion cross section as compared to other ionization channels [e.g., σ(C+60/C60) is more than a factor of 30 larger than σ(C+58/C60)] but also anomalies for the production of multiply charged parent and fragment ions. For instance, the maximum cross section for the formation of C2+60 amounts to 30% of the maximum C+60 cross section and that of C2+70 to about 50% of C+70. Moreover, for all fragment ions, the formation of the doubly charged fragment ions has a larger cross section than that of the respective singly charged fragment ion. These peculiar features of the kinetics of electron impact ionization of C60 and C70 are related to the specific electronic and geometric structures of these fullerenes. The present absolute cross-section data for the summed up partial cross sections are in good agreement with a recent semiclassical calculation from our laboratory. © 1996 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.472059
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  • 7
    Electronic Resource
    Electronic Resource
    Topical benzocaine anaesthesia lacks analgesic effects in painful non-acid oesophagitis (1997)
    Oxford, UK : Blackwell Science Ltd
    Alimentary pharmacology & therapeutics 11 (1997), S. 0 
    Details
    ISSN: 1365-2036
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: No established treatment exists for pain relief in symptomatic non-acid oesophagitis. One of the most common topical anaesthetics is benzocaine which has been demonstrated to produce excellent analgesia on oral mucous membranes.〈section xml:id="abs1-2"〉〈title type="main"〉MethodsIn a prospective, placebo-controlled, balanced, single-blinded study, 26 patients with retrosternal discomfort or odynophagia due to painful non-acid oesophagitis were treated either with oral benzocaine 0.75% solution (n = 14) or with benzocaine-free solvent (placebo, n = 12) at a daily dose of 20–40 mL, for up to 6 consecutive days (median 5.5 days). During the study period patients recorded subjective pain scores for both complaints on visual analogue scales.〈section xml:id="abs1-3"〉〈title type="main"〉ResultsBenzocaine did not affect pain scores for any of the two symptoms, nor did it alter global subjective or objective assessment of therapy outcome in treated compared to untreated subjects (P 〉 0.05). There was a non-significant tendency for placebo patients to stop prematurely their study medication more often, because of lack of analgesic efficacy (P = 0.098).〈section xml:id="abs1-4"〉〈title type="main"〉ConclusionsTopical benzocaine cannot be recommended for routine symptomatic pain relief in non-acid oesophagitis. By indirect evidence, it is assumed that pain perception of non-acid oesophagitis is not preferentially mediated by superficially located mucosal nociceptors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2036.1997.00213.x
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  • 8
    Electronic Resource
    Electronic Resource
    Kinetic Study of the NCO + C2H4 Reaction (1995)
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 99 (1995), S. 5986-5991 
    Details
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/j100016a039
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  • 9
    Electronic Resource
    Electronic Resource
    A note on the effects of L-carnitine on the energy metabolism of individually reared carp, Cyprinus carpio L. (1997)
    Oxford, UK : Blackwell Publishing Ltd
    Aquaculture nutrition 3 (1997), S. 0 
    Details
    ISSN: 1365-2095
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: Twelve carp, Cyprinus carpio L., were grown from 30 to 120 g live mass on four diets, control (405 g kg−1 crude protein, 20.6 MJ kg−1 gross energy) and control + 200, 400 or 600 mg kg−1L-carnitine. The diets were designated as CONT, C200, C400 and C600, respectively. Each diet was randomly assigned three fish kept in individual open-circuit respirometers. Fish that ate diets C400 and C600 grew faster than the controls, expended less energy and retained more energy per unit of food energy intake. Average energetic efficiency, expressed as energy retained per unit of energy expended, was 30% higher in the C400 group than in the controls. However, owing to the small number of fish in each group and the large variations in all these parameters, especially within the control group, none of these differences reached statistical significance at the P= 0.1 level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2095.1997.00044.x
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  • 10
    Electronic Resource
    Electronic Resource
    Individually reared female Nile tilapia (Oreochrornis niloticus) can grow faster than males (1998)
    Oxford, UK : Blackwell Publishing Ltd
    Journal of applied ichthyology 14 (1998), S. 0 
    Details
    ISSN: 1439-0426
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology , Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
    Notes: It has often been claimed that male tilapia appear to grow faster than females, which may be caused either by a sex-specific physiological growth capacity, female mouth-brooding or the more aggressive feeding behaviour of males. To test for differences in the physiological growth capacity of both sexes, 45 Oreochromis niloticus were reared individually for 109 days in aquaria or respirometric boxes connected to recirculating systems. During this time, body mass increased from 38.2 ± 6.5 g to 130.9 ± 39.5 g for males and 34.5 ± 5.5 g to 163.2 ± 29.8 g for females.In contrast to results for previous studies on group rearing reported in the literature, body mass gain, metabolic growth rate, feed conversion and productive protein value (PPV) were significantly (P 〈 0.05) better for females than for males in our experiment under individual rearing. Energy retention (K101), heat dissipation and non-utilized energy were also slightly more favorable for females than for males. The superior female growth performance in this study is due to lower metabolic costs, i.e. oxygen consumption is lower for females than for males. The growth superiority of males reported in other studies is therefore probably caused by behavioral rather than physiological factors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1439-0426.1998.tb00612.x
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