Lithium-ion batteries (LIBs) are employed when high energy and power density are required. Howeve... more Lithium-ion batteries (LIBs) are employed when high energy and power density are required. However, under electrical, mechanical, or thermal abuse conditions a thermal runaway can occur resulting in an uncontrollable increase in pressure and temperature that can lead to fire and/or explosion, and projection of fragments. In this work, the behavior of LIBs under thermal abuse conditions is analyzed. To this purpose, tests on NCA 18,650 cells are performed in a cone calorimeter by changing the radiative heat flux of the conical heater and the State of Charge (SoC) of the cells from full charge to deep discharge. The dependence of SoC and radiative heat flux on the thermal runaway onset is clearly revealed. In particular, a deep discharge determines an earlier thermal runaway of the cell with respect to those at 50% and 100% of SoC when exposed to high radiative heat flux (50 kW/m2). This is due to a mechanism such as an electrical abuse. Cell components before and after tests are inve...
An improvement of a mathematical model of the galvanic iron corrosion, previously presented by on... more An improvement of a mathematical model of the galvanic iron corrosion, previously presented by one of the authors, is here proposed. The iron(III)-hydroxide formation is, now, considered in addition to the redox reaction. The PDE system, assembled on the basis of the fundamental holding electro-chemistry laws, is numerically solved by a locally refined FD method. For verification purpose we have assembled an experimental galvanic cell; in the present work, we report two tests cases, with acidic and neutral electrolitical solution, where the computed electric potential compares well with the measured experimental one
This paper presents the results of a study conducted by ISCR and Sapienza University of Rome in o... more This paper presents the results of a study conducted by ISCR and Sapienza University of Rome in order to restore a mosaic of the Roman Villa of Silin. Detached after the discovery and relayed on reinforced concrete panels with iron net, it presented complex conservation conditions due the vicinity of the sea. The restoration interventions provide the lifting and disassembling of the mosaic panels, the removal of the metal, the partial removal of the concrete. An extensive study has been carried out in order to select the reliable support of the panels and the in situ replacement.
Native asphalt is composed of an organic fraction (bi-tumen) and an inorganic fraction. Bitumen i... more Native asphalt is composed of an organic fraction (bi-tumen) and an inorganic fraction. Bitumen is a viscoelastic substance composed of a mixture of hy-drocarbon molecules of different molecular mass. Bi-tumen may be subdivided into four organic fractions: saturated, aromatics, ...
Sandstones, limestones, and marble stones with different porosity were used as building materials... more Sandstones, limestones, and marble stones with different porosity were used as building materials for thousands of years. In the last century these materials have become vulnerable to atmospheric pollutants; the reaction of sulphur dioxide with calcareous (and decorated) surfaces is well known to form gypsum and black crusts. More recently, some mathematical models used for civil works have been applied to study the evolution of degradation phenomena; however, they did not fit sufficiently for artistic and historical hand-works, ...
Conservation and Management of Archaeological Sites, 2001
Many Roman monuments made of opus caementicium are subjected to wetting and drying phenomena caus... more Many Roman monuments made of opus caementicium are subjected to wetting and drying phenomena caused by water or/and humidity from the ground. The action of water impregnation on the hypothetical dimensional changes in this Roman concrete has not been considered in the literature ...
Conservation and Management of Archaeological Sites, 2002
Page 1. Published by Maney Publishing (c) WS Maney & Son Limited CO:\SERVATIO:\ AT\D MA]\... more Page 1. Published by Maney Publishing (c) WS Maney & Son Limited CO:\SERVATIO:\ AT\D MA]\;AGEME]\;T OF ARCHAEOLOGICAL SITES (2002) volume 5 pages 231-240 ARTICLE Stabilityand conservation of the Maxentius Basilica in the Roman Forum ...
Organic semiconductors hold the promise of simple, large area solution deposition, low thermal bu... more Organic semiconductors hold the promise of simple, large area solution deposition, low thermal budgets as well as compatibility with flexible substrates, thus emerging as viable alternatives for cost-effective (opto)-electronic devices. In this study, we report the optimized synthesis and characterization of a helically shaped polycyclic aromatic compound, namely benzo[i]pentahelicene-3,6-dione, and explored its use in the fabrication of organic field effect transistors. In addition, we investigated its thermal, optical absorption, and electrochemical properties. Finally, the single crystal X-ray characterization is reported.
Salt inhibitors have been receiving increasing attention as potential innovative systems to count... more Salt inhibitors have been receiving increasing attention as potential innovative systems to counteract salt damage by preventing crystallisation of the salts within the natural stone structure—and related disruptive action—of built heritage. Especially, we focus on biomass-derived inhibitor systems featuring complete solubility in water or alcohol and intrinsic non-toxicity. Moving from the promising results obtained, the present study aims to develop research concerning the possibility of rationalizing the collected data sets and making them amenable to statistical analysis. This paper reports on an exploratory application of one of the most powerful methods in chemometrics, i.e., principal component analysis (PCA), in this area. It will be seen that this method is a promising tool to extract information from a series of tests to optimize them and to reduce the level of “noise” present in the data collected, i.e., unnecessary information or experimental errors, and to suggest new d...
The use of inhibition chemicals holds the prospect of an efficient strategy to control crystalliz... more The use of inhibition chemicals holds the prospect of an efficient strategy to control crystallization in porous materials, thereby potentially contributing to the prevention or mitigation of the salt decay phenomenon in modern as well as historical building materials in a more sustainable manner. In this review, we first provide an essential background on the mechanism of salt crystallization and on the factors influencing this phenomenon; next, we illustrate the mechanism at the basis of the action of crystal growth inhibitors, and critically discuss the major advances in the development of different families of inhibitors, particularly focusing on their influence on salt transport and crystallization within the structure of porous media. Specifically, correlations between the crystallization inhibition processes in porous materials and variables, such as porous substrate composition and properties, contaminant salt type and concentrations, microclimatic conditions, inhibiting sol...
The colonization of microorganisms and their subsequent interaction with stone substrates under d... more The colonization of microorganisms and their subsequent interaction with stone substrates under different environmental conditions encourage deterioration of materials by multiple mechanisms resulting in changes in the original color, appearance and durability. One of the emerging alternatives to remedy biodeterioration is nanotechnology, thanks to nanoparticle properties such as small size, no-toxicity, high photo-reactivity, and low impact on the environment. This study highlighted the effects of ZnO-based nanomaterials of two bacteria genera isolated from the Temple of Concordia (Agrigento’s Valley of the Temples in Sicily, Italy) that are involved in biodeterioration processes. The antimicrobial activities of ZnO-nanorods (Zn-NRs) and graphene nanoplatelets decorated with Zn-NRs (ZNGs) were evaluated against the Gram positive Arthrobacter aurescens and two isolates of the Gram negative Achromobacter spanius. ZNGs demonstrated high antibacterial and antibiofilm activities on seve...
Parchment is the primary writing medium of the majority of documents with cultural importance. Un... more Parchment is the primary writing medium of the majority of documents with cultural importance. Unfortunately, this material suffers of several mechanisms of degradation that affect its chemical-physical structure and the readability of text. Due to the unique and delicate character of these objects, the use of nondestructive techniques is mandatory. In this work, three partially degraded handwritten parchments dating back to the XIV-XV centuries were analyzed by means of X-ray fluorescence spectroscopy, µ-ATR Fourier transform infrared spectroscopy, and reflectance and UV-induced fluorescence spectroscopy. The elemental and molecular results provided the identification of the inks, pigments, and superficial treatments. In particular, all manuscripts have been written with iron gall inks, while the capital letters have been realized with cinnabar and azurite. Furthermore, multispectral UV fluorescence imaging and multispectral VIS-NIR imaging proved to be a good approach for the digi...
The application of coating polymers to building materials is a simple and cheap way to preserve a... more The application of coating polymers to building materials is a simple and cheap way to preserve and protect surfaces from weathering phenomena. Due to its environmentally friendly character, waterborne coating is the most popular type of coating, and improving its performance is an important key of research. The study presents the results regarding the mechanical and photo-oxidation resistance of some water-based acrylic coatings containing SiO2 nanoparticles obtained by batch miniemulsion polymerization. Coating materials have been characterized in terms of hydrophobic/hydrophilic behavior, mechanical resistance and surface morphology by means of water-contact angle, and scrub resistance and atomic force microscopy (AFM) measurements depending on silica-nanoparticle content. Moreover, accelerated weathering tests were performed to estimate the photo-oxidation resistance of the coatings. The chemical and color changes were assessed by Fourier-transform infrared spectroscopy (FTIR) a...
The effects of an enzymatic treatment with cellulase and mannanase on the properties of marine mi... more The effects of an enzymatic treatment with cellulase and mannanase on the properties of marine microalgae Nannochloropsis sp. were investigated. The combined use of these enzymes synergistically promoted the recovery of lipids from the microalgae, increasing the extraction yield from 40.8 to over 73%. Untreated and enzymatically treated microalgae were characterized by chemical analysis and by TGA/DTG, FTIR, XRD and SEM. Significant changes were observed in the chemical composition and thermal behavior of the microalgae. The enzymatic treatment also resulted in an increase of the crystalline-to-amorphous cellulose ratio. SEM images revealed dramatic changes in cell morphology, extensive cell damage and release of intracellular material. Overall, the results obtained indicate that the enzymes used are capable of disrupting the microalgal cell wall and that a combination of common analytical techniques can be used to assess the enzyme-induced damage.
Earth Resources and Environmental Remote Sensing/GIS Applications IV, 2013
ABSTRACT Early diagnostics and documentation fulfill an essential role for an effective planning ... more ABSTRACT Early diagnostics and documentation fulfill an essential role for an effective planning of conservation and restoration of cultural heritage assets. In particular, remote sensing techniques that do not require the use of scaffolds or lifts, such as fluoresence lidar, can provide useful information to obtain an overall assessment of the status of the investigated surfaces and can be exploited to address analytical studies in selected areas. Here we present the results of a joint Italian-Swedish project focused on documenting and recording the status of some sections of the part closed to the public by using fluorescence hyperspectral imaging lidar. The lidar used a tripled-frequency Nd:YAG laser emitting at 355 nm as excitation source and an intensified, gated 512x512-pixel CCD as detector. The lidar had imaging capabilities thanks to a computer-controlled scanning mirror. The fluorescence characteristics of fresco wall paintings were compared to those of fresco fragments found at the same archaeological site and separately examined in the lab using FT-IR and Raman techniques for the identification of pigments. The fluorescence lidar was also used to remotely detect the growth of phototrophic biodeteriogens on the walls. The fluorescence lidar data were compared with results from biological sampling, cultivation and laboratory analysis by molecular techniques.
Lithium-ion batteries (LIBs) are employed when high energy and power density are required. Howeve... more Lithium-ion batteries (LIBs) are employed when high energy and power density are required. However, under electrical, mechanical, or thermal abuse conditions a thermal runaway can occur resulting in an uncontrollable increase in pressure and temperature that can lead to fire and/or explosion, and projection of fragments. In this work, the behavior of LIBs under thermal abuse conditions is analyzed. To this purpose, tests on NCA 18,650 cells are performed in a cone calorimeter by changing the radiative heat flux of the conical heater and the State of Charge (SoC) of the cells from full charge to deep discharge. The dependence of SoC and radiative heat flux on the thermal runaway onset is clearly revealed. In particular, a deep discharge determines an earlier thermal runaway of the cell with respect to those at 50% and 100% of SoC when exposed to high radiative heat flux (50 kW/m2). This is due to a mechanism such as an electrical abuse. Cell components before and after tests are inve...
An improvement of a mathematical model of the galvanic iron corrosion, previously presented by on... more An improvement of a mathematical model of the galvanic iron corrosion, previously presented by one of the authors, is here proposed. The iron(III)-hydroxide formation is, now, considered in addition to the redox reaction. The PDE system, assembled on the basis of the fundamental holding electro-chemistry laws, is numerically solved by a locally refined FD method. For verification purpose we have assembled an experimental galvanic cell; in the present work, we report two tests cases, with acidic and neutral electrolitical solution, where the computed electric potential compares well with the measured experimental one
This paper presents the results of a study conducted by ISCR and Sapienza University of Rome in o... more This paper presents the results of a study conducted by ISCR and Sapienza University of Rome in order to restore a mosaic of the Roman Villa of Silin. Detached after the discovery and relayed on reinforced concrete panels with iron net, it presented complex conservation conditions due the vicinity of the sea. The restoration interventions provide the lifting and disassembling of the mosaic panels, the removal of the metal, the partial removal of the concrete. An extensive study has been carried out in order to select the reliable support of the panels and the in situ replacement.
Native asphalt is composed of an organic fraction (bi-tumen) and an inorganic fraction. Bitumen i... more Native asphalt is composed of an organic fraction (bi-tumen) and an inorganic fraction. Bitumen is a viscoelastic substance composed of a mixture of hy-drocarbon molecules of different molecular mass. Bi-tumen may be subdivided into four organic fractions: saturated, aromatics, ...
Sandstones, limestones, and marble stones with different porosity were used as building materials... more Sandstones, limestones, and marble stones with different porosity were used as building materials for thousands of years. In the last century these materials have become vulnerable to atmospheric pollutants; the reaction of sulphur dioxide with calcareous (and decorated) surfaces is well known to form gypsum and black crusts. More recently, some mathematical models used for civil works have been applied to study the evolution of degradation phenomena; however, they did not fit sufficiently for artistic and historical hand-works, ...
Conservation and Management of Archaeological Sites, 2001
Many Roman monuments made of opus caementicium are subjected to wetting and drying phenomena caus... more Many Roman monuments made of opus caementicium are subjected to wetting and drying phenomena caused by water or/and humidity from the ground. The action of water impregnation on the hypothetical dimensional changes in this Roman concrete has not been considered in the literature ...
Conservation and Management of Archaeological Sites, 2002
Page 1. Published by Maney Publishing (c) WS Maney & Son Limited CO:\SERVATIO:\ AT\D MA]\... more Page 1. Published by Maney Publishing (c) WS Maney & Son Limited CO:\SERVATIO:\ AT\D MA]\;AGEME]\;T OF ARCHAEOLOGICAL SITES (2002) volume 5 pages 231-240 ARTICLE Stabilityand conservation of the Maxentius Basilica in the Roman Forum ...
Organic semiconductors hold the promise of simple, large area solution deposition, low thermal bu... more Organic semiconductors hold the promise of simple, large area solution deposition, low thermal budgets as well as compatibility with flexible substrates, thus emerging as viable alternatives for cost-effective (opto)-electronic devices. In this study, we report the optimized synthesis and characterization of a helically shaped polycyclic aromatic compound, namely benzo[i]pentahelicene-3,6-dione, and explored its use in the fabrication of organic field effect transistors. In addition, we investigated its thermal, optical absorption, and electrochemical properties. Finally, the single crystal X-ray characterization is reported.
Salt inhibitors have been receiving increasing attention as potential innovative systems to count... more Salt inhibitors have been receiving increasing attention as potential innovative systems to counteract salt damage by preventing crystallisation of the salts within the natural stone structure—and related disruptive action—of built heritage. Especially, we focus on biomass-derived inhibitor systems featuring complete solubility in water or alcohol and intrinsic non-toxicity. Moving from the promising results obtained, the present study aims to develop research concerning the possibility of rationalizing the collected data sets and making them amenable to statistical analysis. This paper reports on an exploratory application of one of the most powerful methods in chemometrics, i.e., principal component analysis (PCA), in this area. It will be seen that this method is a promising tool to extract information from a series of tests to optimize them and to reduce the level of “noise” present in the data collected, i.e., unnecessary information or experimental errors, and to suggest new d...
The use of inhibition chemicals holds the prospect of an efficient strategy to control crystalliz... more The use of inhibition chemicals holds the prospect of an efficient strategy to control crystallization in porous materials, thereby potentially contributing to the prevention or mitigation of the salt decay phenomenon in modern as well as historical building materials in a more sustainable manner. In this review, we first provide an essential background on the mechanism of salt crystallization and on the factors influencing this phenomenon; next, we illustrate the mechanism at the basis of the action of crystal growth inhibitors, and critically discuss the major advances in the development of different families of inhibitors, particularly focusing on their influence on salt transport and crystallization within the structure of porous media. Specifically, correlations between the crystallization inhibition processes in porous materials and variables, such as porous substrate composition and properties, contaminant salt type and concentrations, microclimatic conditions, inhibiting sol...
The colonization of microorganisms and their subsequent interaction with stone substrates under d... more The colonization of microorganisms and their subsequent interaction with stone substrates under different environmental conditions encourage deterioration of materials by multiple mechanisms resulting in changes in the original color, appearance and durability. One of the emerging alternatives to remedy biodeterioration is nanotechnology, thanks to nanoparticle properties such as small size, no-toxicity, high photo-reactivity, and low impact on the environment. This study highlighted the effects of ZnO-based nanomaterials of two bacteria genera isolated from the Temple of Concordia (Agrigento’s Valley of the Temples in Sicily, Italy) that are involved in biodeterioration processes. The antimicrobial activities of ZnO-nanorods (Zn-NRs) and graphene nanoplatelets decorated with Zn-NRs (ZNGs) were evaluated against the Gram positive Arthrobacter aurescens and two isolates of the Gram negative Achromobacter spanius. ZNGs demonstrated high antibacterial and antibiofilm activities on seve...
Parchment is the primary writing medium of the majority of documents with cultural importance. Un... more Parchment is the primary writing medium of the majority of documents with cultural importance. Unfortunately, this material suffers of several mechanisms of degradation that affect its chemical-physical structure and the readability of text. Due to the unique and delicate character of these objects, the use of nondestructive techniques is mandatory. In this work, three partially degraded handwritten parchments dating back to the XIV-XV centuries were analyzed by means of X-ray fluorescence spectroscopy, µ-ATR Fourier transform infrared spectroscopy, and reflectance and UV-induced fluorescence spectroscopy. The elemental and molecular results provided the identification of the inks, pigments, and superficial treatments. In particular, all manuscripts have been written with iron gall inks, while the capital letters have been realized with cinnabar and azurite. Furthermore, multispectral UV fluorescence imaging and multispectral VIS-NIR imaging proved to be a good approach for the digi...
The application of coating polymers to building materials is a simple and cheap way to preserve a... more The application of coating polymers to building materials is a simple and cheap way to preserve and protect surfaces from weathering phenomena. Due to its environmentally friendly character, waterborne coating is the most popular type of coating, and improving its performance is an important key of research. The study presents the results regarding the mechanical and photo-oxidation resistance of some water-based acrylic coatings containing SiO2 nanoparticles obtained by batch miniemulsion polymerization. Coating materials have been characterized in terms of hydrophobic/hydrophilic behavior, mechanical resistance and surface morphology by means of water-contact angle, and scrub resistance and atomic force microscopy (AFM) measurements depending on silica-nanoparticle content. Moreover, accelerated weathering tests were performed to estimate the photo-oxidation resistance of the coatings. The chemical and color changes were assessed by Fourier-transform infrared spectroscopy (FTIR) a...
The effects of an enzymatic treatment with cellulase and mannanase on the properties of marine mi... more The effects of an enzymatic treatment with cellulase and mannanase on the properties of marine microalgae Nannochloropsis sp. were investigated. The combined use of these enzymes synergistically promoted the recovery of lipids from the microalgae, increasing the extraction yield from 40.8 to over 73%. Untreated and enzymatically treated microalgae were characterized by chemical analysis and by TGA/DTG, FTIR, XRD and SEM. Significant changes were observed in the chemical composition and thermal behavior of the microalgae. The enzymatic treatment also resulted in an increase of the crystalline-to-amorphous cellulose ratio. SEM images revealed dramatic changes in cell morphology, extensive cell damage and release of intracellular material. Overall, the results obtained indicate that the enzymes used are capable of disrupting the microalgal cell wall and that a combination of common analytical techniques can be used to assess the enzyme-induced damage.
Earth Resources and Environmental Remote Sensing/GIS Applications IV, 2013
ABSTRACT Early diagnostics and documentation fulfill an essential role for an effective planning ... more ABSTRACT Early diagnostics and documentation fulfill an essential role for an effective planning of conservation and restoration of cultural heritage assets. In particular, remote sensing techniques that do not require the use of scaffolds or lifts, such as fluoresence lidar, can provide useful information to obtain an overall assessment of the status of the investigated surfaces and can be exploited to address analytical studies in selected areas. Here we present the results of a joint Italian-Swedish project focused on documenting and recording the status of some sections of the part closed to the public by using fluorescence hyperspectral imaging lidar. The lidar used a tripled-frequency Nd:YAG laser emitting at 355 nm as excitation source and an intensified, gated 512x512-pixel CCD as detector. The lidar had imaging capabilities thanks to a computer-controlled scanning mirror. The fluorescence characteristics of fresco wall paintings were compared to those of fresco fragments found at the same archaeological site and separately examined in the lab using FT-IR and Raman techniques for the identification of pigments. The fluorescence lidar was also used to remotely detect the growth of phototrophic biodeteriogens on the walls. The fluorescence lidar data were compared with results from biological sampling, cultivation and laboratory analysis by molecular techniques.
A passionate team of research assistants and graduate students from La Sapienza University are di... more A passionate team of research assistants and graduate students from La Sapienza University are digging in a magnificent archeological site full of Roman history on the slope of the Palatine Hill and in the Valley of the Colosseum. Lingering in the walls and monuments of this site are the forgotten stories of an ancient society. The research and excavation proposed for this project will use next-generation materials and technology to unlock information, allowing us to see back in time. Identification of more specific historical periods and the significance of materials and structures will be our bridge to a better understanding of Ancient Rome. We want these secrets known not only to our scientific community, but to people all over the world.
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http://crowdfunding.loveitaly.org/projects/21-excavating-in-ancient-rome-valley-of-the-colosseum-and-palatine-hill