–Scholars have long discussed the introduction and spread of iron metallurgy in different civiliz... more –Scholars have long discussed the introduction and spread of iron metallurgy in different civilizations. The sporadic use of iron has been reported in the Eastern Mediterranean area from the late Neolithic period to the Bronze Age. Despite the rare existence of smelted iron, it is generally assumed that early iron objects were produced from meteoritic iron. Nevertheless, the methods of working the metal, its use, and diffusion are contentious issues compromised by lack of detailed analysis. Since its discovery in 1925, the meteoritic origin of the iron dagger blade from the sarcophagus of the ancient Egyptian King Tutankhamun (14th C. BCE) has been the subject of debate and previous analyses yielded controversial results. We show that the composition of the blade (Fe plus 10.8 wt% Ni and 0.58 wt% Co), accurately determined through portable x-ray fluorescence spectrometry, strongly supports its meteoritic origin. In agreement with recent results of metallographic analysis of ancient iron artifacts from Gerzeh, our study confirms that ancient Egyptians attributed great value to meteoritic iron for the production of precious objects. Moreover, the high manufacturing quality of Tutankhamun's dagger blade, in comparison with other simple-shaped meteoritic iron artifacts, suggests a significant mastery of ironworking in Tutankhamun's time.
Scholars have long discussed the introduction and spread of iron metallurgy in different civiliza... more Scholars have long discussed the introduction and spread of iron metallurgy in different civilizations. The sporadic use of iron has been reported in the Eastern Mediterranean area from the late Neolithic period to the Bronze Age. Despite the rare existence of smelted iron, it is generally assumed that early iron objects were produced from meteoritic iron. Nevertheless, the methods of working the metal, its use, and diffusion are contentious issues compromised by lack of detailed analysis. Since its discovery in 1925, the meteoritic origin of the iron dagger blade from the sarcophagus of the ancient Egyptian King Tutankhamun (14th C. BCE) has been the subject of debate and previous analyses yielded controversial results. We show that the composition of the blade (Fe plus 10.8 wt% Ni and 0.58 wt% Co), accurately determined through portable x-ray fluorescence spectrometry, strongly supports its meteoritic origin. In agreement with recent results of metallographic analysis of ancient iron artifacts from Gerzeh, our study confirms that ancient Egyptians attributed great value to meteoritic iron for the production of precious objects. Moreover, the high manufacturing quality of Tutankhamun’s dagger blade, in comparison with other simple-shaped meteoritic iron artifacts, suggests a significant mastery of ironworking in Tutankhamun’s time.
Synchrotron-based Fourier transform infrared micro-spectroscopy (SR-μFTIR) was used to map photo-... more Synchrotron-based Fourier transform infrared micro-spectroscopy (SR-μFTIR) was used to map photo-oxidative degradation of acrylonitrile-butadiene-styrene (ABS) and to investigate the presence and the migration of additives in historical samples from important Italian design objects. High resolution (3×3 μm(2)) molecular maps were obtained by FTIR microspectroscopy in transmission mode, using a new method for the preparation of polymer thin sections. The depth of photo-oxidation in samples was evaluated and accompanied by the formation of ketones, aldehydes, esters, and unsaturated carbonyl compounds. This study demonstrates selective surface oxidation and a probable passivation of material against further degradation. In polymer fragments from design objects made of ABS from the 1960s, UV-stabilizers were detected and mapped, and microscopic inclusions of proteinaceous material were identified and mapped for the first time.
Optics for Arts, Architecture, and Archaeology IV, 2013
ABSTRACT We present the non-invasive study of historical and modern Zn- and Cd-based pigments wit... more ABSTRACT We present the non-invasive study of historical and modern Zn- and Cd-based pigments with time-resolved fluorescence spectroscopy, fluorescence multispectral imaging and fluorescence lifetime imaging (FLIM). Zinc oxide and Zinc sulphide are semiconductors which have been used as white pigments in paintings, and the luminescence of these pigments from trapped states is strongly dependent on the presence of impurities and crystal defects. Cadmium sulphoselenide pigments vary in hue from yellow to deep red based on their composition, and are another class of semiconductor pigments which emit both in the visible and the near infrared. The Fluorescence lifetime of historical and modern pigments has been measured using both an Optical Multichannel Analyser (OMA) coupled with a Nd:YAG nslaser, and a streak camera coupled with a ps-laser for spectrally-resolved fluorescence lifetime measurements. For Znbased pigments we have also employed Fluorescence Lifetime Imaging (FLIM) for the measurement of luminescence. A case study of FLIM applied to the analysis of the painting by Vincent Van Gogh on paper - "Les Bretonnes et le pardon de Pont-Aven" (1888) is presented. Through the integration of complementary, portable and non-invasive spectroscopic techniques, new insights into the optical properties of Zn- and Cd-based pigments have been gained which will inform future analysis of late 19th] and early 20th C. paintings.
ABSTRACT Imaging and spectroscopy techniques that have been developed in our laboratory to suppor... more ABSTRACT Imaging and spectroscopy techniques that have been developed in our laboratory to support the conservation and monitoring of artworks will be presented along with some applications to mural paintings and sculptures.
Time and budget constraints have precluded the use of conventional mapping techniques for the US ... more Time and budget constraints have precluded the use of conventional mapping techniques for the US Bureau of Land Management to produce a comprehensive resource inventory of the California deserts region as mandated by the California Desert ...
ABSTRACT The influence of dibutyl phthalate (DBP) plasticizer on poly(vinyl acetate) (PVAc) degra... more ABSTRACT The influence of dibutyl phthalate (DBP) plasticizer on poly(vinyl acetate) (PVAc) degradation was investigated. A multi-analytical approach (combining FTIR and Fluorescence spectroscopy, NMR and DSC analyses) was used to study how thermal- and photo-oxidative ageing treatments act on the polymer and assess the role of the additive in the degradation pattern. Standard and plasticized PVAc films were artificially aged at 60 °C in a thermal regime and irradiated at wavelengths above 290 nm in a photo-oxidative ageing regime, with exposure between 100 and 2000 h. The two types of ageing differ mainly in the formation of CC double bonds along the polymer backbone, enhanced by thermal ageing, and the formation of aldehydic structures, following photo-oxidative treatment and in the degree to which plasticizer is lost. The integration of results from different analytical methods highlights the utility in combining complementary analyses for the study of PVAc degradation.
A noninvasive method to assess the local monomer concentration within a wooden matrix, post monom... more A noninvasive method to assess the local monomer concentration within a wooden matrix, post monomer impregnation, by time-resolved diffuse optical spectroscopy is demonstrated. A data analysis technique for improving accuracy, which takes account of changes in the refractive index during the monomer uptake, has been employed. This technique can be potentially applied in the wood industry for the study of polymer composites as well as in cultural heritage science for noninvasively monitoring the penetration of chemical compounds used for consolidation or conservation purposes.
ABSTRACT Surface-Enhanced Raman Spectroscopy (SERS), a powerful spectrochemical technique enablin... more ABSTRACT Surface-Enhanced Raman Spectroscopy (SERS), a powerful spectrochemical technique enabling highly sensitive analysis of organic and biological materials, is investigated for applications in the analysis of archaeological materials including in situ screening. In this work, a compact mobile Raman spectrometer is employed for acquiring Surface-Enhanced Raman spectra from natural amino acids (l-Arg, l-Phe, l-Met) and a tripeptide (Glutathione), adsorbed on silver colloids. The detection limits of the portable Raman spectrometer, together with an optimization of sample preparation and experimental parameters, are reported. The collection and interpretation of SER spectra of amino acids and peptides is a starting point for the optimization of the instrumentation and its application in the study of more complex biological molecules in the context of detection and analysis of archaeological materials and residues.
Low temperature carrier dynamics in the InGaAs/GaAs quantum dot-based tunnel injection structure ... more Low temperature carrier dynamics in the InGaAs/GaAs quantum dot-based tunnel injection structure is studied by the time resolved photoluminescence experiment. We observed strongly modified photoluminescence kinetics between tunnel injection and reference quantum dot structures. Slowing down of the photoluminescence rise time in the tunnel injection system under weak and moderate excitation powers, we attributed to a fingerprint of a feeding
... The identity and composition of a broad va-riety of materials including pigments and minerals... more ... The identity and composition of a broad va-riety of materials including pigments and minerals, metal alloys and jewelry, stone and glass, pottery and soil can be determined by the use of well-known elemental anal-ysis techniques including X-ray fluorescence (XRF) spec ...
... 1 INTRODUCTION The traditional methods for the conservation and consolidation of leather have... more ... 1 INTRODUCTION The traditional methods for the conservation and consolidation of leather have usually involved the ... 18.83 17.33 After Paraloid B-72 application 39.55 24.06 21.02 After aging of Paraloid B-72 38.38 26.10 ... FTIR-ATR spectra of Paraloid B72 over leather (Fig. ...
The exploration of Laser Induced Fluorescence (LIF) for the analysis of organic material found in... more The exploration of Laser Induced Fluorescence (LIF) for the analysis of organic material found in paintings is investigated. Protein-based materials have often been included as binding media and an understanding of their origin and behaviour is critical for conservation. Traditionally-used methods for protein analysis can provide specific information regarding composition of even complex mixtures of very small samples; however, protein
–Scholars have long discussed the introduction and spread of iron metallurgy in different civiliz... more –Scholars have long discussed the introduction and spread of iron metallurgy in different civilizations. The sporadic use of iron has been reported in the Eastern Mediterranean area from the late Neolithic period to the Bronze Age. Despite the rare existence of smelted iron, it is generally assumed that early iron objects were produced from meteoritic iron. Nevertheless, the methods of working the metal, its use, and diffusion are contentious issues compromised by lack of detailed analysis. Since its discovery in 1925, the meteoritic origin of the iron dagger blade from the sarcophagus of the ancient Egyptian King Tutankhamun (14th C. BCE) has been the subject of debate and previous analyses yielded controversial results. We show that the composition of the blade (Fe plus 10.8 wt% Ni and 0.58 wt% Co), accurately determined through portable x-ray fluorescence spectrometry, strongly supports its meteoritic origin. In agreement with recent results of metallographic analysis of ancient iron artifacts from Gerzeh, our study confirms that ancient Egyptians attributed great value to meteoritic iron for the production of precious objects. Moreover, the high manufacturing quality of Tutankhamun's dagger blade, in comparison with other simple-shaped meteoritic iron artifacts, suggests a significant mastery of ironworking in Tutankhamun's time.
Scholars have long discussed the introduction and spread of iron metallurgy in different civiliza... more Scholars have long discussed the introduction and spread of iron metallurgy in different civilizations. The sporadic use of iron has been reported in the Eastern Mediterranean area from the late Neolithic period to the Bronze Age. Despite the rare existence of smelted iron, it is generally assumed that early iron objects were produced from meteoritic iron. Nevertheless, the methods of working the metal, its use, and diffusion are contentious issues compromised by lack of detailed analysis. Since its discovery in 1925, the meteoritic origin of the iron dagger blade from the sarcophagus of the ancient Egyptian King Tutankhamun (14th C. BCE) has been the subject of debate and previous analyses yielded controversial results. We show that the composition of the blade (Fe plus 10.8 wt% Ni and 0.58 wt% Co), accurately determined through portable x-ray fluorescence spectrometry, strongly supports its meteoritic origin. In agreement with recent results of metallographic analysis of ancient iron artifacts from Gerzeh, our study confirms that ancient Egyptians attributed great value to meteoritic iron for the production of precious objects. Moreover, the high manufacturing quality of Tutankhamun’s dagger blade, in comparison with other simple-shaped meteoritic iron artifacts, suggests a significant mastery of ironworking in Tutankhamun’s time.
Synchrotron-based Fourier transform infrared micro-spectroscopy (SR-μFTIR) was used to map photo-... more Synchrotron-based Fourier transform infrared micro-spectroscopy (SR-μFTIR) was used to map photo-oxidative degradation of acrylonitrile-butadiene-styrene (ABS) and to investigate the presence and the migration of additives in historical samples from important Italian design objects. High resolution (3×3 μm(2)) molecular maps were obtained by FTIR microspectroscopy in transmission mode, using a new method for the preparation of polymer thin sections. The depth of photo-oxidation in samples was evaluated and accompanied by the formation of ketones, aldehydes, esters, and unsaturated carbonyl compounds. This study demonstrates selective surface oxidation and a probable passivation of material against further degradation. In polymer fragments from design objects made of ABS from the 1960s, UV-stabilizers were detected and mapped, and microscopic inclusions of proteinaceous material were identified and mapped for the first time.
Optics for Arts, Architecture, and Archaeology IV, 2013
ABSTRACT We present the non-invasive study of historical and modern Zn- and Cd-based pigments wit... more ABSTRACT We present the non-invasive study of historical and modern Zn- and Cd-based pigments with time-resolved fluorescence spectroscopy, fluorescence multispectral imaging and fluorescence lifetime imaging (FLIM). Zinc oxide and Zinc sulphide are semiconductors which have been used as white pigments in paintings, and the luminescence of these pigments from trapped states is strongly dependent on the presence of impurities and crystal defects. Cadmium sulphoselenide pigments vary in hue from yellow to deep red based on their composition, and are another class of semiconductor pigments which emit both in the visible and the near infrared. The Fluorescence lifetime of historical and modern pigments has been measured using both an Optical Multichannel Analyser (OMA) coupled with a Nd:YAG nslaser, and a streak camera coupled with a ps-laser for spectrally-resolved fluorescence lifetime measurements. For Znbased pigments we have also employed Fluorescence Lifetime Imaging (FLIM) for the measurement of luminescence. A case study of FLIM applied to the analysis of the painting by Vincent Van Gogh on paper - "Les Bretonnes et le pardon de Pont-Aven" (1888) is presented. Through the integration of complementary, portable and non-invasive spectroscopic techniques, new insights into the optical properties of Zn- and Cd-based pigments have been gained which will inform future analysis of late 19th] and early 20th C. paintings.
ABSTRACT Imaging and spectroscopy techniques that have been developed in our laboratory to suppor... more ABSTRACT Imaging and spectroscopy techniques that have been developed in our laboratory to support the conservation and monitoring of artworks will be presented along with some applications to mural paintings and sculptures.
Time and budget constraints have precluded the use of conventional mapping techniques for the US ... more Time and budget constraints have precluded the use of conventional mapping techniques for the US Bureau of Land Management to produce a comprehensive resource inventory of the California deserts region as mandated by the California Desert ...
ABSTRACT The influence of dibutyl phthalate (DBP) plasticizer on poly(vinyl acetate) (PVAc) degra... more ABSTRACT The influence of dibutyl phthalate (DBP) plasticizer on poly(vinyl acetate) (PVAc) degradation was investigated. A multi-analytical approach (combining FTIR and Fluorescence spectroscopy, NMR and DSC analyses) was used to study how thermal- and photo-oxidative ageing treatments act on the polymer and assess the role of the additive in the degradation pattern. Standard and plasticized PVAc films were artificially aged at 60 °C in a thermal regime and irradiated at wavelengths above 290 nm in a photo-oxidative ageing regime, with exposure between 100 and 2000 h. The two types of ageing differ mainly in the formation of CC double bonds along the polymer backbone, enhanced by thermal ageing, and the formation of aldehydic structures, following photo-oxidative treatment and in the degree to which plasticizer is lost. The integration of results from different analytical methods highlights the utility in combining complementary analyses for the study of PVAc degradation.
A noninvasive method to assess the local monomer concentration within a wooden matrix, post monom... more A noninvasive method to assess the local monomer concentration within a wooden matrix, post monomer impregnation, by time-resolved diffuse optical spectroscopy is demonstrated. A data analysis technique for improving accuracy, which takes account of changes in the refractive index during the monomer uptake, has been employed. This technique can be potentially applied in the wood industry for the study of polymer composites as well as in cultural heritage science for noninvasively monitoring the penetration of chemical compounds used for consolidation or conservation purposes.
ABSTRACT Surface-Enhanced Raman Spectroscopy (SERS), a powerful spectrochemical technique enablin... more ABSTRACT Surface-Enhanced Raman Spectroscopy (SERS), a powerful spectrochemical technique enabling highly sensitive analysis of organic and biological materials, is investigated for applications in the analysis of archaeological materials including in situ screening. In this work, a compact mobile Raman spectrometer is employed for acquiring Surface-Enhanced Raman spectra from natural amino acids (l-Arg, l-Phe, l-Met) and a tripeptide (Glutathione), adsorbed on silver colloids. The detection limits of the portable Raman spectrometer, together with an optimization of sample preparation and experimental parameters, are reported. The collection and interpretation of SER spectra of amino acids and peptides is a starting point for the optimization of the instrumentation and its application in the study of more complex biological molecules in the context of detection and analysis of archaeological materials and residues.
Low temperature carrier dynamics in the InGaAs/GaAs quantum dot-based tunnel injection structure ... more Low temperature carrier dynamics in the InGaAs/GaAs quantum dot-based tunnel injection structure is studied by the time resolved photoluminescence experiment. We observed strongly modified photoluminescence kinetics between tunnel injection and reference quantum dot structures. Slowing down of the photoluminescence rise time in the tunnel injection system under weak and moderate excitation powers, we attributed to a fingerprint of a feeding
... The identity and composition of a broad va-riety of materials including pigments and minerals... more ... The identity and composition of a broad va-riety of materials including pigments and minerals, metal alloys and jewelry, stone and glass, pottery and soil can be determined by the use of well-known elemental anal-ysis techniques including X-ray fluorescence (XRF) spec ...
... 1 INTRODUCTION The traditional methods for the conservation and consolidation of leather have... more ... 1 INTRODUCTION The traditional methods for the conservation and consolidation of leather have usually involved the ... 18.83 17.33 After Paraloid B-72 application 39.55 24.06 21.02 After aging of Paraloid B-72 38.38 26.10 ... FTIR-ATR spectra of Paraloid B72 over leather (Fig. ...
The exploration of Laser Induced Fluorescence (LIF) for the analysis of organic material found in... more The exploration of Laser Induced Fluorescence (LIF) for the analysis of organic material found in paintings is investigated. Protein-based materials have often been included as binding media and an understanding of their origin and behaviour is critical for conservation. Traditionally-used methods for protein analysis can provide specific information regarding composition of even complex mixtures of very small samples; however, protein
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