The potential and feasibility of using ultrafast picosecond laser scanning pulses (1064 nm) for t... more The potential and feasibility of using ultrafast picosecond laser scanning pulses (1064 nm) for the removal of tarnish over metal threads of the gloves worn by king Charles I (1600 –1649, England) were investigated. Analytical techniques including optical microscope, SEM-EDX and Raman Spectroscopy were employed to characterize the constituent materials of the gloves and their condition, and to assess the cleaning results obtained. Following the trails of optimization tests of laser cleaning parameters, results suggest that satisfactory laser cleaning could be achieved for the removal of tarnish without damage the underlying metal threads substrate. Considerations for the application of ultrafast ps laser cleaning are presented which highlight the advantages of applying ultrashort laser processing for cleaning composite material with consideration of the limitations regarding the current practical application of ultrafast laser processing for the conservation of cultural heritage.
In this work the interaction of a pulsed Er:YAG (2940 nm) laser beam with mock-ups of poly(vinyl ... more In this work the interaction of a pulsed Er:YAG (2940 nm) laser beam with mock-ups of poly(vinyl alcohol) (PVOH) has been investigated. Online time resolved temperature peaks induced by single-pulse laser irradiations were measured for the first time through the development of a dedicated setup based on a fast IR detector. Tests were performed using fluences ranging between 1.1-2.8 J/cm2 and pulse durations of 160-430μs. A multiple heterojunction IR photovoltaic detector with bandwidth 2-12 μm and risetime <7 ns was used to study the surface temperature transient upon Er:YAG laser irradiation of PVOH. Tests and thermal modelling allowed to verify effectiveness and reliability of the novel sensor developed.
Abstract In this work, the potential applications of surface laser removal of biological crusts f... more Abstract In this work, the potential applications of surface laser removal of biological crusts from Carrara marble artefacts and in-depth microwave selective heating for treatment of possible endolithic growths have been evaluated. The investigations were carried out on seriously deteriorated marble fragments from the monumental tombs of the English Cemetery in Florence, Italy. The second harmonic (532 nm) of a Q-switched Nd:YAG laser was used for cleaning while a microwave system emitting at 2.45 GHz was tested for in-depth sterilization. As is well known, microwaves are strongly absorbed by water via dipolar energy dissipation, which permits selective heating of endolithic organisms. The effects of laser and microwave treatments were characterized using scanning electron microscopy (SEM) along with chlorophyll fluorescence with pulsed amplitude modulated imaging. The latter has allowed the quantification of the impairment effects to photosystem II of epilithic phototrophic organism residues by mapping the maximum quantum yield, while the damage to endolithic growths was evaluated by means of SEM following osmium tetroxide staining of cytoplasmic lipids. The results provide an early picture of the development and application perspectives of the combined laser and microwave treatments in the conservation of biodeteriorated stone artefacts.
Temperature rise during Raman spectroscopy can induce chemical alterations of the material under ... more Temperature rise during Raman spectroscopy can induce chemical alterations of the material under analysis and seriously affect its characterization. Thus, such photothermal side effects can represent a serious problem to be carefully controlled in order to safeguard the integrity of the material and its spectral features. In this work, an innovative probe for thermally controlled portable Raman spectroscopy (exc. 785 nm) equipped with infrared sensing lines was developed. It included an infrared source and two thermopile sensors, which allowed to perform real-time measurements of the local emissivity of the material surface under laser excitation. The emissivity, which is needed in order to monitor the temperature of the irradiated surface through infrared radiation measurements, represents the complementary component of the reflectance in the radiative energy balance. Thus, total reflectance, temperature measurements and Raman spectroscopy were integrated in the present probe. Afte...
Prospettiva-rivista Di Storia Dell Arte Antica E Moderna, 2016
The Fibula of Montieri. Archeological studies at the church of San Niccolo and the discovery of a... more The Fibula of Montieri. Archeological studies at the church of San Niccolo and the discovery of a medieval jewel. The fibula under examination in the present article was found during recent archeological excavations in the area of Canonica, near Montieri (Grosseto), carried out by the Medieval Archeology staff of Siena University. The parish church, dedicated to San Niccolo, was linked to the bishop of Volterra in the same way as the nearby castle of Montieri. The religious complex consisted of a church with six apses situated within an enclosure that incorporated an open space overlooked by two long buildings and a smaller construction. The church was built in the first half of the XIth century. In the layer of earth where the building's foundations were laid, a small circular hole was made where the fibula was deposited. The uniqueness of the archeological discovery is given by the fact of finding the fibula where it had originally been laid. The chronology of the church's...
The rapid in-situ characterization of limestones, dolomitic limestones and calcareous dolostones,... more The rapid in-situ characterization of limestones, dolomitic limestones and calcareous dolostones, might be crucial to speed up their recognition directly in the quarry. Therefore, the use of portable analytical techniques could be useful for this purpose. Among these, Raman spectroscopy is capable to identify and discriminate the presence of calcite and / or dolomite. The results obtained from the analyses carried out on carbonate rock samples show that Raman spectra obtained from a portable device lead to the identification of the main mineralogical components. Moreover, the intensity of the Raman signal appears to depend on the average size of the crystals constituting the carbonate rocks. In particular, it can be seen that the Raman spectra of rocks with an average crystal size of less than 50 µm show a worse signal/noise ratio. The purpose of this research is to study the correlation between Raman signal efficiency and average crystal size. In this respect, the portable Raman sp...
Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications XVI, 2016
In previous works a minimally invasive laser-assisted technique for vascular repair was presented... more In previous works a minimally invasive laser-assisted technique for vascular repair was presented. The technique rests on the photothermal adhesion of a biocompatible and bioresorbable patch containing Indocyanine Green that is brought into contact with the site to be repaired. Afterward the use of NIR millisecond-long light pulses generates a strong welding effect between the patch and the underlying tissue and in turn the repair of the wound. This technique was shown to be effective in animal model and provides several advantages over conventional suturing methods. Here we investigate and discuss the optical stability of the ICG-biopolymeric patches and the photothermal effects induced to the irradiated tissue.
Here, the potential of laser-induced breakdown spectroscopy (LIBS) in grading calcareous rocks fo... more Here, the potential of laser-induced breakdown spectroscopy (LIBS) in grading calcareous rocks for the lime industry was investigated. In particular, we developed a system equipped with non-intensified detectors operating in scanning mode, defined a suitable data acquisition protocol, and implemented quantitative data processing using both partial least squares regression (PLS-R) and a multilayer perceptron (MLP) neural network. Tests were carried out on 32 samples collected in various limestone quarries, which were preliminarily analyzed using traditional laboratory X-ray fluorescence (XRF); then, they were divided into two groups for calibration and validation. Particular attention was dedicated to the development of LIBS methodology providing a reliable basis for precise material grading. The congruence of the results achieved demonstrates the capability of the present approach to precisely quantify major and minor geochemical components of calcareous rocks, thus disclosing a con...
The potential and feasibility of using ultrafast picosecond laser scanning pulses (1064 nm) for t... more The potential and feasibility of using ultrafast picosecond laser scanning pulses (1064 nm) for the removal of tarnish over metal threads of the gloves worn by king Charles I (1600 –1649, England) were investigated. Analytical techniques including optical microscope, SEM-EDX and Raman Spectroscopy were employed to characterize the constituent materials of the gloves and their condition, and to assess the cleaning results obtained. Following the trails of optimization tests of laser cleaning parameters, results suggest that satisfactory laser cleaning could be achieved for the removal of tarnish without damage the underlying metal threads substrate. Considerations for the application of ultrafast ps laser cleaning are presented which highlight the advantages of applying ultrashort laser processing for cleaning composite material with consideration of the limitations regarding the current practical application of ultrafast laser processing for the conservation of cultural heritage.
In this work the interaction of a pulsed Er:YAG (2940 nm) laser beam with mock-ups of poly(vinyl ... more In this work the interaction of a pulsed Er:YAG (2940 nm) laser beam with mock-ups of poly(vinyl alcohol) (PVOH) has been investigated. Online time resolved temperature peaks induced by single-pulse laser irradiations were measured for the first time through the development of a dedicated setup based on a fast IR detector. Tests were performed using fluences ranging between 1.1-2.8 J/cm2 and pulse durations of 160-430μs. A multiple heterojunction IR photovoltaic detector with bandwidth 2-12 μm and risetime <7 ns was used to study the surface temperature transient upon Er:YAG laser irradiation of PVOH. Tests and thermal modelling allowed to verify effectiveness and reliability of the novel sensor developed.
Abstract In this work, the potential applications of surface laser removal of biological crusts f... more Abstract In this work, the potential applications of surface laser removal of biological crusts from Carrara marble artefacts and in-depth microwave selective heating for treatment of possible endolithic growths have been evaluated. The investigations were carried out on seriously deteriorated marble fragments from the monumental tombs of the English Cemetery in Florence, Italy. The second harmonic (532 nm) of a Q-switched Nd:YAG laser was used for cleaning while a microwave system emitting at 2.45 GHz was tested for in-depth sterilization. As is well known, microwaves are strongly absorbed by water via dipolar energy dissipation, which permits selective heating of endolithic organisms. The effects of laser and microwave treatments were characterized using scanning electron microscopy (SEM) along with chlorophyll fluorescence with pulsed amplitude modulated imaging. The latter has allowed the quantification of the impairment effects to photosystem II of epilithic phototrophic organism residues by mapping the maximum quantum yield, while the damage to endolithic growths was evaluated by means of SEM following osmium tetroxide staining of cytoplasmic lipids. The results provide an early picture of the development and application perspectives of the combined laser and microwave treatments in the conservation of biodeteriorated stone artefacts.
Temperature rise during Raman spectroscopy can induce chemical alterations of the material under ... more Temperature rise during Raman spectroscopy can induce chemical alterations of the material under analysis and seriously affect its characterization. Thus, such photothermal side effects can represent a serious problem to be carefully controlled in order to safeguard the integrity of the material and its spectral features. In this work, an innovative probe for thermally controlled portable Raman spectroscopy (exc. 785 nm) equipped with infrared sensing lines was developed. It included an infrared source and two thermopile sensors, which allowed to perform real-time measurements of the local emissivity of the material surface under laser excitation. The emissivity, which is needed in order to monitor the temperature of the irradiated surface through infrared radiation measurements, represents the complementary component of the reflectance in the radiative energy balance. Thus, total reflectance, temperature measurements and Raman spectroscopy were integrated in the present probe. Afte...
Prospettiva-rivista Di Storia Dell Arte Antica E Moderna, 2016
The Fibula of Montieri. Archeological studies at the church of San Niccolo and the discovery of a... more The Fibula of Montieri. Archeological studies at the church of San Niccolo and the discovery of a medieval jewel. The fibula under examination in the present article was found during recent archeological excavations in the area of Canonica, near Montieri (Grosseto), carried out by the Medieval Archeology staff of Siena University. The parish church, dedicated to San Niccolo, was linked to the bishop of Volterra in the same way as the nearby castle of Montieri. The religious complex consisted of a church with six apses situated within an enclosure that incorporated an open space overlooked by two long buildings and a smaller construction. The church was built in the first half of the XIth century. In the layer of earth where the building's foundations were laid, a small circular hole was made where the fibula was deposited. The uniqueness of the archeological discovery is given by the fact of finding the fibula where it had originally been laid. The chronology of the church's...
The rapid in-situ characterization of limestones, dolomitic limestones and calcareous dolostones,... more The rapid in-situ characterization of limestones, dolomitic limestones and calcareous dolostones, might be crucial to speed up their recognition directly in the quarry. Therefore, the use of portable analytical techniques could be useful for this purpose. Among these, Raman spectroscopy is capable to identify and discriminate the presence of calcite and / or dolomite. The results obtained from the analyses carried out on carbonate rock samples show that Raman spectra obtained from a portable device lead to the identification of the main mineralogical components. Moreover, the intensity of the Raman signal appears to depend on the average size of the crystals constituting the carbonate rocks. In particular, it can be seen that the Raman spectra of rocks with an average crystal size of less than 50 µm show a worse signal/noise ratio. The purpose of this research is to study the correlation between Raman signal efficiency and average crystal size. In this respect, the portable Raman sp...
Optical Fibers and Sensors for Medical Diagnostics and Treatment Applications XVI, 2016
In previous works a minimally invasive laser-assisted technique for vascular repair was presented... more In previous works a minimally invasive laser-assisted technique for vascular repair was presented. The technique rests on the photothermal adhesion of a biocompatible and bioresorbable patch containing Indocyanine Green that is brought into contact with the site to be repaired. Afterward the use of NIR millisecond-long light pulses generates a strong welding effect between the patch and the underlying tissue and in turn the repair of the wound. This technique was shown to be effective in animal model and provides several advantages over conventional suturing methods. Here we investigate and discuss the optical stability of the ICG-biopolymeric patches and the photothermal effects induced to the irradiated tissue.
Here, the potential of laser-induced breakdown spectroscopy (LIBS) in grading calcareous rocks fo... more Here, the potential of laser-induced breakdown spectroscopy (LIBS) in grading calcareous rocks for the lime industry was investigated. In particular, we developed a system equipped with non-intensified detectors operating in scanning mode, defined a suitable data acquisition protocol, and implemented quantitative data processing using both partial least squares regression (PLS-R) and a multilayer perceptron (MLP) neural network. Tests were carried out on 32 samples collected in various limestone quarries, which were preliminarily analyzed using traditional laboratory X-ray fluorescence (XRF); then, they were divided into two groups for calibration and validation. Particular attention was dedicated to the development of LIBS methodology providing a reliable basis for precise material grading. The congruence of the results achieved demonstrates the capability of the present approach to precisely quantify major and minor geochemical components of calcareous rocks, thus disclosing a con...
Abstract
Before restoring ancient and valuable ethnographic objects many aspects should be
taken ... more Abstract Before restoring ancient and valuable ethnographic objects many aspects should be taken into account, because lignocellulosic fibers-based materials undergo different and concomitant degrading reactions (oxidation, hydrolysis, depolimerization) over time. Basically, dry cleaning methods should be preferred, as they are potentially less invasive in the long term, especially for the easily hydrolysable components. Here, the fundamental and second harmonic of Q-Switch Nd:YAG laser, were comparatively investigated for dealing with the removal of soiling (soot, dirt, aluminum silicates, carbonaceous material) from a woven-fibers angarêb bed, which is preserved at Africa Hall of the National Geographic Society Museum (Cairo, Egypt). Besides fiber identification, laser induced-effects were assessed on angarêb fibers by means of stratigraphic examination, Vis-NIR fluorescence emission, Raman spectroscopy, ESEM-EDX analysis and optical microscopy observations. Irradiation at 532 nm negatively affects color appearance and structural integrity of fibers. Bond-breaking/depolymerization followed by bleaching, due to the significant absorption of lignin/phenolic-carbohydrate and lignin-quinonoid complexes, occur at this wavelength. The promising results achieved at 1064 nm, in term of chemical and structural integrity, highlight the possibility of using this wavelenghth for treating soiled and untreatable ethnographic material.
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Papers by Iacopo Osticioli
Before restoring ancient and valuable ethnographic objects many aspects should be
taken into account, because lignocellulosic fibers-based materials undergo different
and concomitant degrading reactions (oxidation, hydrolysis, depolimerization) over
time. Basically, dry cleaning methods should be preferred, as they are potentially less
invasive in the long term, especially for the easily hydrolysable components. Here, the
fundamental and second harmonic of Q-Switch Nd:YAG laser, were comparatively investigated
for dealing with the removal of soiling (soot, dirt, aluminum silicates, carbonaceous
material) from a woven-fibers angarêb bed, which is preserved at Africa
Hall of the National Geographic Society Museum (Cairo, Egypt). Besides fiber identification,
laser induced-effects were assessed on angarêb fibers by means of stratigraphic
examination, Vis-NIR fluorescence emission, Raman spectroscopy, ESEM-EDX analysis
and optical microscopy observations.
Irradiation at 532 nm negatively affects color appearance and structural integrity
of fibers. Bond-breaking/depolymerization followed by bleaching, due to the significant
absorption of lignin/phenolic-carbohydrate and lignin-quinonoid complexes, occur at
this wavelength.
The promising results achieved at 1064 nm, in term of chemical and structural
integrity, highlight the possibility of using this wavelenghth for treating soiled and untreatable
ethnographic material.