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  • 1
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Journal of Analytical and Applied Pyrolysis 20 (1991), S. 253-261 
    ISSN: 0165-2370
    Keywords: Archaeology ; gas chromatography ; mass spectrometry ; organic substances ; pyrolysis
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Journal of Analytical and Applied Pyrolysis 24 (1993), S. 227-242 
    ISSN: 0165-2370
    Keywords: Ancient painting media ; gas chromatography ; mass spectrometry ; pyrolysis ; simultaneous pyrolysis-methylation.
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Geometric and functional analysis 5 (1995), S. 14-75 
    ISSN: 1420-8970
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mathematics
    Notes: Abstract Let (M, h) be an odd-dimensional compact spin manifold in whichH is an embedded hypersurface with quadratic defining functionx 2∈C ∞ (M). Let be the Dirac operator associated to the metric jhen where ∈〉0 is a parameter. The limiting metric,g 0, is an exact b-metric on the compact manifold with boundary $$\overline M $$ obtained by cuttingM alongH and compactifying as a manifold with boundary, i.e. it givesM/H asymptotically cylindrical ends with cross-section $$\partial \overline M $$ , a double cover ofH. Under the assumption that the induced Dirac operator on this double cover is invertible we show that where is the ‘b’ version of the eta invariant introduced in [Me1],r 1(∈) andr 2(∈) are smooth, vanish at ∈=0 and are integrals of local geometric data, and where $$\tilde \eta ( \in )$$ is the finite dimensional eta invariant, or signature, for the small eigenvalues of . If is invertible then $$\tilde \eta ( \in ) \equiv 0$$ and Even if is not invertible this holds in ℝ/ℤ. In fact the discussion takes place more naturally in the context of the generalized Dirac operators associated to Hermitian Clifford modules. These results are proved by analyzing the resolvent family of , uniformly away from the spectrum and near zero. This leads to a precise description of the behaviour of the small eigenvalues. The corresponding ‘heat calculus’ is also constructed. It contains, and hence describes rather precisely, the heat kernel for uniformly as ∈→0. This calculus is related to, but different from, the surgery pseudodifferential operator calculus of McDonald ([Mc]).
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 49 (1999), S. 35-41 
    ISSN: 1612-1112
    Keywords: Pyrolysis gas chromatography-mass spectrometry ; Outdoor bronze monuments ; Patinas
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary As opposed to inorganic composition, the characterization of organic content in patinas of bronze monuments has been neglected. Analytical pyrolysis coupled with gaschromatographyάss-spectrometry (Py/GC-MS) has been shown to be a valid and rapid technique to identify organic materials in corrosion patina of bronze monuments. In this paper six renaissance Italian outdoor bronze monuments were analyzed in order to determine organic composition of the patina. Results show the presence of both environmental organic compounds and chemicals coming from protective treatment.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 40 (1995), S. 594-600 
    ISSN: 1612-1112
    Keywords: Pyrolysis-gas chromatography-mass spectrometry ; Fourier-transform infrared spectroscopy ; Ancient Egyptian painting media ; Egyptian sarcophagus
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary An Egyptian wooden sarcophagus and a cartonnage (664–525 B.C.) were subjected to pyrolysis-gas chromatography-mass spectrometry (PY-GC-MS) and Fourier-transform infrared spectroscopy (FT-IR) in order to characterize pigments and organic binding media. The aim of these investigations is to acquire a better knowledge of the painting technique used in ancient Egypt. Results showed that PY-GC-MS offered a rapid tool to discriminate between wax-based- and animal protein-based binders and to recognize the use of mixtures of the two products. FT-IR corroborated the pyrolysis findings, but sometimes provided less unequivocal results than PY-GC-MS. As an additional benefit, PY-GC-MS allowed the identification of a yellow pigment as the arsenic sulphide orpiment by means of the volatile As4 among the pyrolysis fragments.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Chromatographia 49 (1999), S. 268-272 
    ISSN: 1612-1112
    Keywords: Gas chromatography ; Mass spectrometry ; Analytical pyrolysis ; Chinese art objects ; Mercury analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary A few samples of polychrome Chinese archaeological objects of art have undergone analytical pyrolysis coupled with GC-MS to evaluated the possibility of contemporary characterization of the pigments as well as the organic media used. The red pigment cinnabar (HgS) is easily media used. The red pigment cinnabar (HgS) is easily detected, whereas in the case of organic components positive results are only found where the matrices are resistant to archaeological environmental conditions.
    Type of Medium: Electronic Resource
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  • 7
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Biological Mass Spectrometry 11 (1984), S. 557-561 
    ISSN: 0306-042X
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Natural differences in 13C/12C ratios of various metabolic fuels can produce systematic changes in the 13C/12C ratio of breath CO2, and therefore introduce errors into 13CO2 breath tests. To gain insight into the potential problem, we compared 13C/12C ratios of plasma macronutrients to those of breath CO2 under conditions that should alter the percentages of carbohydrate and lipid being oxidized. In rats, 48 h of starvation decreased the 13C/12C ratio of breath CO2 by 3.5‰. At this time the 13C/12C ratio of breath CO2 was very similar to that of plasma lipids. In humans, 30 min of heavy exercise increased the breath 13CO2/12CO2 ratio by 1.3‰. These changes in breath 13C/12C ratios could be predicted from 13C/12C ratios of plasma macronutrients and the percentage of carbon dioxide derived from each macronutrient, but only when compared within the same populations. For example, the 13C/12C ratios of plasma macronutrients of residents of Chicago, Illinois (USA) and Tokyo (Japan) differed by 1-3‰. An empirical correction of 13CO2 breath test data is recommended when breath tests are run under conditions that will change metabolic fuel utilization.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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