Search results for "YAG"
showing 10 items of 166 documents
Clinical evaluation of the Er:YAG laser in combination with an enamel matrix protein derivative for the treatment of intrabony periodontal defects: a…
2003
OBJECTIVES The aim of the present study was to compare the combination therapy of deep intrabony periodontal defects using an Er:YAG laser (ERL) and enamel matrix protein derivative (EMD) to scaling and root planing+ ethylenediaminetetraacetic acid (EDTA)+EMD. MATERIAL AND METHODS Twenty-two patients with chronic periodontitis, each of whom displayed 1 intrabony defect, were randomly treated with access flap surgery and defect debridement with an Er:YAG (160 mJ/pulse, 10 Hz) plus EMD (test) or with access flap surgery followed by scaling and root planing (SRP) with hand instruments plus EDTA and EMD (control). The following clinical parameters were recorded at baseline and at 6 months: plaq…
Comparison of three adhesive systems in class II composite restorations in endodontically treated teeth : influence of Er:YAG laser conditioning and …
2018
Background Dental surface conditioning by Er:YAG laser is currently being investigated, as not all of the mechanisms and effects of this technique have been clearly studied. Thus, the aim of the present study was to assess the cervical microleakage of Class II resin composite restorations in endodontically treated teeth following either the respective conventional conditioning or additional Er:YAG laser conditioning, in association with varied adhesives. Material and methods Standardized mesial-occlusal-distal cavities (two gingival walls positioned in dentin and enamel, respectively) were created in 60 extracted human premolar teeth. Following the completion of the endodontic therapy, the …
News about the Aragonese Botanist Martín Sessé Lacasta
2018
Se dan noticias del paso por la Universidad de Zaragoza y por América del médico y naturalista aragonés Martín Sessé Lacasta, que impulsó desde América la Expedición Botánica de Nueva España, así como la creación del Jardín botánico de México. Se trata de una de las personalidades que más han prestigiado la labor científica de España en América. / News about the stay of the Aragonese doctor and naturalist Martín Sessé Lacasta both in the Universidad de Zaragoza and Central America. He was part of the Botanical Expedition in Nueva España where he promoved Botanical studies and helped creating the Botanical Garden in Mexico. He is one of the most important Spanish scientist who spread Science…
Etalement urbain et consommation d'espace. Etude comparée de Besançon, Belfort et Montbéliard
2007
Urban sprawl constitutes a specific case of urbanization that is currently common in French cities. Arising from significant development of suburbs, it inevitably leads to the increase of built-up surfaces in every periurban area. At the same time, we can assume that urban sprawl induces over-consumption of space. This assumption is tested on the three main towns of Franche-Comté, that are associated with very different geographical, demographic and industrial characteristics (these characteristics are briefly described). The study confirms, in general, the reality of over-consumption of space, dependant on urban sprawl ; it seems generally independent of the individual characteristics of e…
Visioni dell’America. Viaggio, spazialità e narrazione in De Amicis e Amado
2021
Nella prospettiva della geografia culturale l’odeporica offre l’opportunità di studiare alcune dinamiche di (ri)produzione simbolica relative al modo di concepire e rappresentare concetti chiave quali lo spazio, il paesaggio e le interazioni umane. Questo lavoro, partendo dall’analisi di alcuni brani significativi di due raccolte di scritti, In America (1897) di Edmondo De Amicis e In giro per le Americhe (2001) di Jorge Amado, studia, con un approccio geografico-culturale e semiotico, le modalità di costruzione e descrizione dello spazio fisico e simbolico comprese le «frontiere», nonché le interazioni e la socialità attraverso la testualizzazione di esperienze diverse. La comparazione fra…
Gas protection optimization during Nd:YAG laser welding
2004
International audience; Many laser processes, such as welding or surface treatments are associated with an undesired phenomenon, which is oxidation. The solution commonly employed to solve this problem approaches the shielding gas and/or the shielding gas device. What we propose in this paper is a methodology with the goal to optimize the protection gas device design as well as the gas flow in the case of laser welding and surface treatments. The pressure created by the gas flow on the sample surface is recorded and analysed together with the operating parameters influence in order to reach the objectives. The nozzle system designed and presented below assures the protection against materia…
Experimental investigation and multi-scale modelling of the behavior of mechanically activated metallic powders : from binary systems to High Entropy…
2021
Generally, metal alloys consist of a main element associated with other elements present in smaller quantities such as iron, nickel, aluminum or copper alloys. The precise composition of an alloy is adjusted according to the required performance: high temperature behavior, corrosion resistance, mechanical properties, durability ... In 2004, a Taiwanese scientist, JW Yeh, had the idea of making an alloy base of several elements, at least 5, whose composition in the alloy varies between 5% and 30% at. Yeh invented the high entropy alloy (HEA). Mixed on a microscopic scale, the metals form a remarkably stable solid solution. The explanation is thermodynamic. An alloy is all the more stable as …
Microstructure-process relationship and reactivity at the nanoscale : a molecular dynamics study of Ni, Ni-Al, and Ti-Al metallic systems
2023
The process-microstructure relationship is central in materials science because the microstructure will determine the properties of the materials developed by the processes. In our work, we focused on different metallurgical processes by adopting a description at the atomic scale. This approach allows us to detect the elementary mechanisms that are at the origin of the observed microstructures without having to postulate macroscopic mechanisms or estimate the associated parameters. In this respect, molecular dynamics simulations provide a tool for "in-situ" observation of metallic systems as long as an atomic interaction potential is available. The originality of our approach consists in mo…
Du monnayage au crypto-monnayage
2020
Minting Techniques in Currencies and Cryptocurrencies. Over the past ten years, the creation of bitcoin and other cryptocurrencies has renewed the debate on the nature of money. This paper discusses the comparison between cryptocurrencies and coins : after describing their ideological and technical foundations, we explain the reasons why the reference to metals is often invoked. We then detail the techniques of minting, the processes of marking, and the question of seigniorage.
Bactericidal Effect of the Er:YAG Laser on Dental Implant Surfaces: An In Vitro Study
2002
The aim of the in vitro study was to examine the bactericidal effect of an Er:YAG laser on common dental implant surfaces.Seventy-two titanium platelets with 3 different surfaces--sandblasted and acid-etched (SA), titanium plasma-sprayed (TPS), and hydroxyapatite-coated (HA)--were incubated with a suspension of Streptococcus sanguinis (ATCC 10556). Irradiation at pulse energies of 60 and 120 mJ and a frequency of 10 pps was performed on a computer-controlled XY translation stage. After laser treatment the specimens were sonicated and the bacterial growth examined by counting colony forming units on blood agar plates. Temperature elevations during irradiation were investigated using K-type t…