Download or read book Etudes th orique et exp rimentale de plasmas produits par laser en vue de leur application a l analyse chimique des mat riaux en environnement complexe written by Guillaume Clair and published by . This book was released on 2011 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ce travail présente une étude originale de l'interaction laser-matière en régime nanoseconde à l'aide d'une double approche expériences-modélisation numérique. L'approche expérimentale vise à caractériser les plasmas produits par laser et l'empreinte laissée par le faisceau laser sur la cible. L'approche numérique s'appuie sur un modèle 1D qui permet de décrire le chauffage de la cible par le laser, l'ablation de matière et la formation d'un plasma dans cette matière ablatée dûe à l'interaction avec le laser. Des comparaisons des résultats obtenus par les deux approches permettent d'évaluer le degré de précision des résultats issus du modèle. Ces comparaisons se limitent aux 100 premières nanosecondes d'expansion du plasma. Nous montrons ainsi que le modèle décrit assez bien l'écrantage du faisceau laser par le plasma, l'expansion du plasma et la propagation de l'onde de choc dans le gaz ambiant. De plus, les valeurs des seuils d'ablation et de formation du plasma sont calculées avec une bonne précision. En revanche, des écarts sont constatés pour la modélisation des processus d'interaction entre le laser et la cible. Le degré de précision du modèle est au final suffisamment bon pour nous permettre d'étudier précisément l'effet du gaz ambiant sur les propriétés et la dynamique du plasma.
Download or read book ETUDE DE PLASMAS PRODUITS PAR LASER A PRESSION ATMOSPHERIQUE EN VUE DE L ANALYSE ELEMENTAIRE written by Nadine André (docteur en physique) and published by . This book was released on 1995 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: DANS LE CADRE DES ETUDES MENEES SUR L'APPLICATION DE LA SPECTROSCOPIE D'EMISSION SUR PLASMA PRODUIT PAR LASER (SEO-PPL) A L'ANALYSE ELEMENTAIRE DES SOLIDES, L'OBJECTIF QUE NOUS NOUS SOMMES FIXE, CONSISTE A ELABORER UNE METHODE DE QUANTIFICATION DES SIGNAUX OPTIQUES PERMETTANT DE S'AFFRANCHIR DE L'UTILISATION D'UN ETALON INTERNE. LA REALISATION DE CET OBJECTIF NECESSITE D'UNE PART, DE RECHERCHER LES PARAMETRES QUI FIXENT L'INTENSITE DES RAIES D'EMISSION ET D'AUTRE PART, DE TROUVER DES MOYENS DE DIAGNOSTIC DU PLASMA PERMETTANT LA PRISE EN COMPTE D'EVENTUELLES VARIATIONS DE CES PARAMETRES AU COURS DES MESURES. NOTRE PARTIE EXPERIMENTALE A DEBUTE PAR LE DEVELOPPEMENT D'UNE INSTRUMENTATION PERMETTANT DE CONTROLER LES PARAMETRES EXPERIMENTAUX (SURFACE D'INTERACTION ET PUISSANCE DU FAISCEAU LASER) ET DE DEFINIR UNE PROCEDURE DE MESURE. LE BON NIVEAU DE REPETABILITE DES SIGNAUX OPTIQUES MESURES SANS REFERENCE INTERNE A MONTRE QUE LE PLASMA EST MAITRISE DANS DES CONDITIONS EXPERIMENTALES CONTROLEES. LA SECONDE PARTIE EXPERIMENTALE A EU POUR OBJET LA MISE EN UVRE DES DIAGNOSTICS PLASMA PERMETTANT DE SUIVRE LA VARIATION DES PARAMETRES CLEFS DU PROCEDE D'ABLATION PAR LASER (VAPORISATION, ATOMISATION ET EXCITATION). NOUS AVONS MONTRE QUE LE SIGNAL ACOUSTIQUE, GENERE LORS DE L'EXPANSION DU PLASMA DANS LE MILIEU AMBIANT, EST CORRELE A LA QUANTITE DE MATIERE ATOMISEE. D'APRES NOTRE MODELE, CELA SIGNIFIE QUE LE SIGNAL ACOUSTIQUE ET LA TEMPERATURE D'EXCITATION RENDENT COMPTE DE L'ENSEMBLE DES PROCESSUS D'ABLATION. POUR VALIDER CETTE HYPOTHESE, NOUS AVONS COMPARE LES PENTES DE DROITES D'ETALONNAGE ETABLIES SUR PLUSIEURS MATERIAUX DE NATURE PHYSICO-CHIMIQUE DIFFERENTE. LES RESULTATS OBTENUS SUR LES ECHANTILLONS ETUDIES (ALLIAGES D'ALUMINIUM, DE NICKEL, ACIERS, VERRES) ONT MONTRE QU'IL N'EXISTE PAS D'EFFETS DE MATRICES POUR CES MATERIAUX ET QUE LES QUANTITES DE MATIERE ATOMISEE ET LA TEMPERATURE D'EXCITATION SONT IDENTIQUES. PAR CONTRE, NOUS AVONS OBSERVE DES EFFETS DE MATRICE ENTRE DEUX ALLIAGES D'ALUMINIUM (AL-CU ET AL-ZN) ET DE ZINC, QUI ONT PU ETRE CORRIGES PAR NOTRE METHODE DE NORMALISATION
Download or read book Health Effects of Environmental Pollution written by and published by . This book was released on 1973 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Radiation Protection Programmes for the Transport of Radioactive Material written by International Atomic Energy Agency and published by . This book was released on 2024-02-29 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Safety Guide provides recommendations on meeting the requirements established in IAEA Safety Standards Series No. SSR-6 (Rev. 1), Regulations for the Safe Transport of Radioactive Material, 2018 Edition, for a radiation protection programme for the transport of radioactive material. The objectives of a radiation protection programme for the transport of radioactive material are to provide for adequate consideration of radiation protection measures in transport; to ensure that the system of radiological protection is adequately applied; to enhance a safety culture in the transport of radioactive material; and to provide practical measures to meet these objectives. The recommendations provided in this Safety Guide are applicable to the transport of radioactive material by all modes on land, water, or in the air, including transport that is incidental to the use of the radioactive material. The intended audience for this Safety Guide includes competent authorities, consignors, carriers, consignees, and operators of ports (e.g. harbours, seaports and airports). It will also be of interest to the employees of public authorities (customs authorities, harbour authorities, port authorities) concerning activities associated with the transport of radioactive material that involve radiation exposure.
Download or read book Radiation Protection Practice written by International Radiation Protection Association. International Congress and published by Elsevier Science & Technology. This book was released on 1988 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Steady and Transient Performance Prediction of Gas Turbine Engines written by and published by . This book was released on 1991 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aircraft Fire Safety written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Propulsion and Energetics Panel. Symposium and published by . This book was released on 1997 with total page 344 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Progress in Chemical Toxicology written by Abraham Stolman and published by Elsevier. This book was released on 2013-10-22 with total page 406 pages. Available in PDF, EPUB and Kindle. Book excerpt: Progress in Chemical Toxicology, Volume 5 covers topics on the improved isolation and detection procedures and quantitation methods for volatile poisons, stimulants, hallucinogenic drugs, and marihuana. The book discusses the absorption, distribution, and excretion of drugs and poisons and their metabolites; the system for the toxicological analysis of drugs in biological specimens; and the isolation and analysis of phenothiazines. The text also describes the use of fluorescence in toxicology and the toxicology of new synthetic organic polymers used in containers for food, pharmaceutical compounds, and drinkable water. Some microcrystal tests for drugs and advances in polarography as applied to toxicological analysis are also considered. Biochemists, toxicologists, and scientists involved in the study of narcotics will find the book invaluable.
Download or read book NSWC TR written by Naval Surface Weapons Center and published by . This book was released on 1979 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Secondary Flows in Turbomachines written by Von Karman Institute for Fluid Dynamics and published by . This book was released on 1975 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book AGARD Conference Proceedings written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development and published by . This book was released on 1992 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Lead Poisoning in Childhood written by Siegfried M. Pueschel and published by Brookes Publishing Company. This book was released on 1996 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: This resource examines the causes and consequences of childhood lead poisoning, offers cost-effective prevention strategies, and explores crucial legislation that can and should protect children at risk. Information on screening tests, nutrition, treatment guidelines, and safe environmental abatement techniques will help pediatricians, physicians, social workers, and nurses understand, treat, and eliminate lead poisoning in children.
Download or read book Hypersonic Combined Cycle Propulsion written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Propulsion and Energetics Panel. Symposium and published by . This book was released on 1990 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transonic and Supersonic Phenomena in Turbomachines written by and published by . This book was released on 1987 with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heat Transfer and Cooling in Gas Turbines written by and published by . This book was released on 1985 with total page 350 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Application of Advanced Material for Turbomachinery and Rocket Propulsion written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Propulsion and Energetics Panel. Specialists' Meeting and published by . This book was released on 1989 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Inhaled Particles and Vapours written by British Occupational Hygiene Society and published by Pergamon. This book was released on 1961 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt:
