In this work, the results of a study of laser ablation cleaning process on ceramic artifacts are presented. The experiments were conducted on a ＂Carosello＂, a structural hollow element made of clay, placed in arches...In this work, the results of a study of laser ablation cleaning process on ceramic artifacts are presented. The experiments were conducted on a ＂Carosello＂, a structural hollow element made of clay, placed in arches, in domes or even in the walls of buildings such as churches and houses. Our results show that laser ablation techniques is able to remove the surface impurity patina from artifacts surface without changes the chemical composition and the optical properties of ceramic. Moreover, because the laser cleaning heats only locally the surface of the sample, this method don＇t preclude the possibility to apply on artifact the thermo-luminescence dating process.展开更多
Abstract： In this work, the authors present a study of growth and characterization of composite based on AI and CNT （carbon nanotubes. The composites were prepared by a chemical mixing method and characterized by SE...Abstract： In this work, the authors present a study of growth and characterization of composite based on AI and CNT （carbon nanotubes. The composites were prepared by a chemical mixing method and characterized by SEM analysis, energy dispersed X-ray measurements, X-ray photoelectron spectroscopy and cathodoluminescence spectroscopy. The analysis showed that the composites are formed by macro-cluster of aluminum oxide on a network of CNT without formation of chemical bonds at interface between particles. The results are compared with those obtained for a sample of CNT with AI traces （〈 0.5%）. They show that only the presence of metal traces changes the nanotubes optical properties, with a luminescence signal centered at about 380 nm. These luminescence signals are caused by the adhesion between CNT and AI micro-clusters that promote the formation of band gap with some local energy levels.展开更多
This work is a study of effect of laser ablation in different medium on silver artifacts. The effectiveness of laser ablation cleanness methods was evaluated in air, water and vacuum condition. The samples were subjec...This work is a study of effect of laser ablation in different medium on silver artifacts. The effectiveness of laser ablation cleanness methods was evaluated in air, water and vacuum condition. The samples were subjected to HC1 treatment for several hours to simulate the formation of chloride patina on marine archeological artifacts. Laser ablation removes the patina in all medium, reducing its thickness from 300 to few microns in air and water and eliminating completely the chlorine in vacuum conditions. However, it was observed the formation, during cleanness of a white patina in air and water and an increasing of oxygen amount on surface. This indicate that in ambient reach in oxygen laser ablation favorite the oxygen absorbance on surface and the formation of a thin layer of AgO which dulls the surface. This hypothesis is confirmed by the results of laser ablation in vacuum conditions where surface tarnishing was not observed. So, laser ablation in vacuum condition was indicated as the most effective procedure to clean silver artifacts.展开更多
文摘In this work, the results of a study of laser ablation cleaning process on ceramic artifacts are presented. The experiments were conducted on a ＂Carosello＂, a structural hollow element made of clay, placed in arches, in domes or even in the walls of buildings such as churches and houses. Our results show that laser ablation techniques is able to remove the surface impurity patina from artifacts surface without changes the chemical composition and the optical properties of ceramic. Moreover, because the laser cleaning heats only locally the surface of the sample, this method don＇t preclude the possibility to apply on artifact the thermo-luminescence dating process.
文摘Abstract： In this work, the authors present a study of growth and characterization of composite based on AI and CNT （carbon nanotubes. The composites were prepared by a chemical mixing method and characterized by SEM analysis, energy dispersed X-ray measurements, X-ray photoelectron spectroscopy and cathodoluminescence spectroscopy. The analysis showed that the composites are formed by macro-cluster of aluminum oxide on a network of CNT without formation of chemical bonds at interface between particles. The results are compared with those obtained for a sample of CNT with AI traces （〈 0.5%）. They show that only the presence of metal traces changes the nanotubes optical properties, with a luminescence signal centered at about 380 nm. These luminescence signals are caused by the adhesion between CNT and AI micro-clusters that promote the formation of band gap with some local energy levels.
文摘This work is a study of effect of laser ablation in different medium on silver artifacts. The effectiveness of laser ablation cleanness methods was evaluated in air, water and vacuum condition. The samples were subjected to HC1 treatment for several hours to simulate the formation of chloride patina on marine archeological artifacts. Laser ablation removes the patina in all medium, reducing its thickness from 300 to few microns in air and water and eliminating completely the chlorine in vacuum conditions. However, it was observed the formation, during cleanness of a white patina in air and water and an increasing of oxygen amount on surface. This indicate that in ambient reach in oxygen laser ablation favorite the oxygen absorbance on surface and the formation of a thin layer of AgO which dulls the surface. This hypothesis is confirmed by the results of laser ablation in vacuum conditions where surface tarnishing was not observed. So, laser ablation in vacuum condition was indicated as the most effective procedure to clean silver artifacts.
