WorldWideScience

Sample records for projekt az po

  1. Effect of (NaPO3)6 concentrations on corrosion resistance of plasma electrolytic oxidation coatings formed on AZ91D magnesium alloy

    International Nuclear Information System (INIS)

    Luo Haihe; Cai Qizhou; Wei Bokang; Yu Bo; Li Dingjun; He Jian; Liu Ze

    2008-01-01

    Different plasma electrolytic oxidation (PEO) coatings were prepared on AZ91D magnesium alloy in electrolytes containing various concentrations of (NaPO 3 ) 6 . The morphologies, chemical compositions and corrosion resistance of the PEO coatings were characterized by environmental scanning electron microscopy (ESEM), X-ray diffractometer (XRD), energy dispersive analysis of X-rays (EDAX), potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) test. The results showed that the PEO coatings were mainly composed of MgO, Mg 2 SiO 4 , MgAl 2 O 4 and amorphous compounds. As the (NaPO 3 ) 6 concentrations increased from 0 to 10 g/l, the thickness and surface roughness of the coatings approximately linearly increased; the MgO and Mg 2 SiO 4 phase increased within the concentration range of 0-3 and 0-5 g/l, and then decreased within the range of 3-10 and 5-10 g/l, respectively, while the MgAl 2 O 4 phase gradually decreased. Moreover, the corrosion resistance of the coatings increased within the range of 0-5 g/l and then decreased within the range of 5-10 g/l. The best corrosion resistance coating was obtained in electrolyte containing 5 g/l (NaPO 3 ) 6 , it had the most compact microstructure. Besides, a reasonable equivalent circuit was established, and the fitting results were consistent with the results of the EIS test

  2. Projekt EDI / Priit Põdra

    Index Scriptorium Estoniae

    Põdra, Priit, 1963-

    2000-01-01

    Projekt EDI töötab välja programmisüsteemi rahvusvaheliste kaubavedude korraldamiseks, dokumentide vormistamiseks ja firmade arvutiprogrammide koostöö korraldamiseks. Projekti tutvustab AS-i EDI VEKTOR juhatuse esimees Priit Põdra

  3. Projekt i innovation

    OpenAIRE

    Rasmussen, Dorte Sams Marstrand

    2017-01-01

    AbstraktProjektet ”Projekt i innovation”, tager afsæt i et HR-ledelsesperspektiv i organisationen Google, hvor det undersøges, hvordan innovation udspiller sig i praksis, hvilket sker gennem i en komparativ analyse, med en ansat medarbejder i organisationen. Projektet har til formål at undersøge, om der i organisationen eksisterer særlig tilgange til arbejdet, når det handler om at skabe innovation, og hvad der kræves af individet i ansættelsen. Da innovation kan opleves som et abstrakt begre...

  4. NOTAT - Projekt Cykeljakken

    DEFF Research Database (Denmark)

    Lahrmann, Harry; Madsen, Jens Christian Overgaard

    Dette notat er en del af afrapporteringen af Projekt Cykeljakken, hvor hypotesen var, at cyklisters sikkerhed kan forbedres ved at øge deres synlighed i trafikbilledet. I projektet undersøgte vi denne hypotese ved at teste, om en cykeljakke med høj synlighed (farve og reflekser) øger cyklisters...... sikkerhed. Projektet blev gennemført som et randomiseret forsøg, hvor vi gav en cykeljakke til 6.800 frivillige cyklister. Efter tilfældig udvælgelse fik halvdelen – testgruppen – cykeljakken med det samme, og lovede at køre med jakken, hver gang de cyklede i det år, projektet varede. Den anden halvdel...

  5. NOTAT - Projekt Cykeljakken

    DEFF Research Database (Denmark)

    Thedchannamoorthy, Shaline; Madsen, Tanja Kidholm Osmann; Araghi, Bahar Namaki

    Dette notat er en del af afrapporteringen af Projekt Cykeljakken, hvor hypotesen var, at cyklisters sikkerhed kan forbedres ved at øge deres synlighed i trafikbilledet. I projektet undersøgte vi denne hypotese ved at teste, om en cykeljakke med høj synlighed (farve og reflekser) øger cyklisters...... sikkerhed. Projektet blev gennemført som et randomiseret forsøg, hvor vi gav en cykeljakke til 6.800 frivillige cyklister. Efter tilfældig udvælgelse fik halvdelen – testgruppen – cykeljakken med det samme, og lovede at køre med jakken, hver gang de cyklede i det år, projektet varede. Den anden halvdel...... udgjorde en såkaldt kontrolgruppe, som først fik cykeljakken, da projektperioden var omme. Hver måned indrapporterede deltagerne uheld, som de havde været involverede i som cyklist i den forgangne måned, ligesom testgruppen en tilfældig dag i måneden blev spurgt, om de havde benyttet cykeljakken på deres...

  6. Das DELA-NOBA Projekt

    DEFF Research Database (Denmark)

    Daryai-Hansen, Petra; Meister, Maive; Tonello, Elisa

    2015-01-01

    in the English language classroom in Argentina and Denmark var et delprojekt under et større internationalt samarbejde, koordineret af Michael Byram, og belyste, hvordan interkulturelt medborgerskab kan styrkes i grundskolens læringsrum (Byram et al. under udgivelse). Grundidéen i interkulturelle......Artiklen præsenterer et udviklings- og forskningsprojekt på Randersgades Skole. I projektet deltog elever fra 7.v og en 5./6. klasse fra Argentina i et arrangeret kultur- og sprogmøde inden for rammerne af deres engelskundervisning. Projektet Green Kidz. Intercultural environmental citizenship...... langues-Ansatz noch weitreichend unbekannt. Das Projekt Developing the Language Awareness/ Éveil aux langues Approach in the Nordic and Baltic Countries (DELA- NOBA), das von 2013 bis 2016 von NordPlus Horizontal finanziert wird, etabliert eine Zusammenarbeit zwischen Universitäten und Pilotschulen aus...

  7. Film Presentation: Projekt Zukunft/Tomorrow Today

    CERN Multimedia

    Carolyn Lee

    2010-01-01

    Projekt Zukunft/Tomorrow Today, by Deutsche Welle (2009)   Deutsche Welle TV’s weekly science journal explores the LHC at CERN with host Ingolf Baur. Please note that we will show both the German and English versions of this broadcast. Each episode is about 27 minutes long. Projekt Zukunft/Tomorrow Today will be presented on Friday, 29 October from 13:00 to 14:00 in the Main Auditorium Language: German version followed by the English version      

  8. Outdoor i integrationsarbejde - et nyt EU projekt

    DEFF Research Database (Denmark)

    Kjeldsen, Lis Reinholdt

    2014-01-01

    Beskriver opstarten af det internationale projekt, hvor omgivelserne anvendes i læreprocesser for nytilkomne. Samarbejdspartnere er Linköbing Universitet i Sverige, Novia Yrkeshøgskola i Finland, Bologna Universitet i Italien. Projektet vil udvikle læreplan til anvendelse for undervisere af nytil...... nytilkomne, hvor Outdoor learning i naturen og de kulturelle omgivelser anvendes....

  9. Hans Küng: "Projekt Weltethos "

    OpenAIRE

    Altmanninger, Maria

    2002-01-01

    Bei dieser Arbeit werde ich mich vor Allem auf zwei Werke beziehen: Küng,Hans:Projekt Weltethos.Piper.München 1990. Küng,Hans;Kuschel,Karl-Josef (Hg.):Weltfrieden durch Religionsfrieden.Die unter Punkt Acht aufgeführte Stellungnahme wurde ausschließlich von mir verfasst.

  10. Experiental Civic Learning by using "Projekt: Aktive Bürger"

    Directory of Open Access Journals (Sweden)

    Klaus Koopmann

    2002-01-01

    Full Text Available Various social and political developments seem to sum up to a process of 'de-civilization' which impede - rather than facilitate - the project of a humane and democratic society. In order to make this project a successful one it is necessary to reclaim citizens as politically acting subjects. The ability to act as enlightened and autonomous citizens will be sustainably acquired by experiencing extensive participation in society and in politics. Civic education should foster this process of 'revi-talization of citizenship' by offering youth meaningful participatory experiences of social and po-litical relevance. That is: Civic education should create, organize and offer learning strategies that are oriented towards the notion of reflective acting as experiential learning. Experiential learning processes, aimed at the sustainable acquisition of competencies which are relevant in politics and civil society, will particularly unfold in the course of the (interactive dealing of the individual(s with the authentic political and social problems and processes that surround and concern them. This also includes reflection and co-operation. One example of how to practice an experiential and prob-lem-centred learning strategy is well being demonstrated by the civic education program "Projekt: Aktive Bürger", the German adaptation of "We the People ... Project Citizen" designed by the American Center for Civic Education.

  11. Emil Fahrenkamp : Bauten und Projekte für Berlin

    NARCIS (Netherlands)

    Jacob, B.

    2006-01-01

    Thema der vorliegenden Arbeit ist die umfassende Aufarbeitung und Dokumentation der Bauten und Projekte Emil Fahrenkamps (*1885, 1966) in Berlin und Potsdam-Babelsberg sowie die kritische Einordnung seiner Arbeiten in den Kontext der Baugeschichte des 20. Jahrhunderts. Den zentralen

  12. Projekt "RADAR" - teerajaja Setomaal / Ülo Kask, Martin Kikas

    Index Scriptorium Estoniae

    Kask, Ülo, 1952-

    2009-01-01

    RADAR projekt - taastuvate energiaallikate alase teadlikkuse tõstmine agro-energeetilise ahela mudelite arendamise abil. Projektis osales 7 riiki: Itaalia, Suurbritannia, Rootsi, Eesti, Läti, Horvaatia ja Bulgaaria

  13. Projekt READ - sammen om læsning

    DEFF Research Database (Denmark)

    Christensen, Mette Vedsgaard; Østerbye, Torkil

    2015-01-01

    Projekt READ er et et-årigt projekt gennemført i et samarbejde mellem TrygFondens Børneforskningscenter, Aarhus Universitet, Aarhus Kommune og VIA University College. Projektet undersøger, om læse- og skrivefærdigheder hos elever i 2. og 3. klasse kan løftes gennem en intervention, hvor forældre...

  14. Projekts Sporta kluba izveidošanai

    OpenAIRE

    Andrejevs, Jurijs

    2010-01-01

    Maģistra darba temats ir „PROJEKTS SPORTA KLUBA „URBAN GYM” IZVEIDOŠANA.” Uzņēmējdarbības vide Latvijā pēdējos gados sākusi stipri vien mainīties. No vienas puses, tā lēnām kļūst sakārtotāka, no otras puses, iezīmējas arvien lielāks konkurences pieaugums. Tirgus tiek piesātināts, un aizvien grūtāk kļūst darboties, nedomājot par konkurenci, darbības aktivitāti un rentabilitāti. Vadītājiem un īpašniekiem nemitīgi jādomā, ar ko uzņēmums īsti pelna naudu, kā varētu pelnīt vairāk. Bet neskatoti...

  15. Tõeliselt julge projekt = A brave project, indeed / Tarja Nurmi

    Index Scriptorium Estoniae

    Nurmi, Tarja

    2013-01-01

    Aidu püramiidid. Arhitekt: Kadarik Tüür Arhitektid (KTA). Autorid: Ott Kadarik, Mihkel Tüür. Projekt: 2011-2013. Vastavalt projektile on alale ette nähtud restoranid, veinikeldrid, ujumiskohad jm. Peapüramiid (130 m kõrge) lubab harrastada mägironimist

  16. Projekt "Baltenet - The Baltic Technology Network" / Leonid Pai

    Index Scriptorium Estoniae

    Pai, Leonid

    2005-01-01

    Baltenet - The Baltic Technology Network on projekt, mille alusel teevad koostööd tehniliste erialade koolituse arendamiseks Baltimere äärsetes riikides neli kutseõppeasutust Soomest, Rootsist, Lätis ja Eestist. Projekti rahastab Euroopa Liidu Leonardo da Vinci programm

  17. Forschungsdatenmanagement in DFG-Sonderforschungsbereichen: Teilprojekte Informationsinfrastruktur (INF-Projekte

    Directory of Open Access Journals (Sweden)

    Claudia Engelhardt

    2013-10-01

    Full Text Available Seit 2007 gibt es im Rahmen von DFG-Sonderforschungsbereichen die Möglichkeit, ein „Teilprojekt Informationsinfrastruktur” (kurz: INF-Projekt zu beantragen. Dieses dient dem Forschungsdatenmanagement innerhalb des Sonderforschungsbereiches, was sowohl die Konzeption des Datenmanagements als auch die Bereitstellung der erforderlichen Infrastruktur beinhalten kann. Das Konzept der INF-Projekte sieht dabei die Kooperation der Fachwissenschaft mit den Informationsinfrastruktureinrichtungen am Standort vor, beispielsweise mit der Bibliothek oder dem Rechenzentrum. In dieser Hinsicht können die INF-Projekte auch als ein spezifischer Anwendungsfall des Embedded Librarianship betrachtet werden. In dieser Arbeit werden die Ergebnisse einer Befragung und eines Workshops mit Vertretern der INF-Projekte vorgestellt, die interessante Einblicke in die Arbeit derselben gewähren. In 2007, ”Information Infrastructure” (INF projects were introduced within the context of the German Research Foundations Collaborative Research Centres. Their purpose is to facilitate research data management within the Collaborative Research Centres, which can include the approach to data management as well as the establishment of the necessary infrastructure. The concept of the INF projects is designed to encourage cooperation between researchers and their local infrastructure institutions, such as the library or the computing centre. In this regard, the INF projects can be viewed as examples of embedded librarianship. This article presents the results of a survey among and a workshop with members of the INF projects, providing interesting insights into their work.

  18. Systém pro management projektů

    OpenAIRE

    Špaček, Petr

    2009-01-01

    Tato bakalářská práce se zabývá problémem řízení projektů. Navržený software slouží k usnadnění řízení a plánování projektů ve firmě jednoduchým grafickým uživatelským rozhraním. K implementaci jsou zejména použity technologie Microsoft .NET, Microsoft SQL Server 2008. The work deals with project management.  The design software helps to manage and plan projects by using a simple graphic user interface. For implementation there are used technologies like Microsoft .NET, Microsoft SQL Serve...

  19. Projekt skal undersøge MRSA i danske mink

    DEFF Research Database (Denmark)

    Fertner, Mette Ely; Hansen, Julie Elvekjær; Larsen, Gitte

    2017-01-01

    MRSA blev for første gang isoleret fra to danske mink, som var indsendt til undersøgelse på DTU Veterinærinstituttet, i 2013. I løbet af 2017 gennemfører DTU Veterinærinstituttet et projekt, som har til formål at klarlægge MRSA-forekomsten og smitteoverførslen på danske minkgårde....

  20. Correlation between the surface chemistry and the atmospheric corrosion of AZ31, AZ80 and AZ91D magnesium alloys

    International Nuclear Information System (INIS)

    Feliu, S.; Pardo, A.; Merino, M.C.; Coy, A.E.; Viejo, F.; Arrabal, R.

    2009-01-01

    X-ray photoelectron spectroscopy (XPS) was used in order to investigate the correlation between the surface chemistry and the atmospheric corrosion of AZ31, AZ80 and AZ91D magnesium alloys exposed to 98% relative humidity at 50 deg. C. Commercially pure magnesium, used as the reference material, revealed MgO, Mg(OH) 2 and tracers of magnesium carbonate in the air-formed film. For the AZ80 and AZ91D alloys, the amount of magnesium carbonate formed on the surface reached similar values to those of MgO and Mg(OH) 2 . A linear relation between the amount of magnesium carbonate formed on the surface and the subsequent corrosion behaviour in the humid environment was found. The AZ80 alloy revealed the highest amount of magnesium carbonate in the air-formed film and the highest atmospheric corrosion resistance, even higher than the AZ91D alloy, indicating that aluminium distribution in the alloy microstructure influenced the amount of magnesium carbonate formed.

  1. Projekt EUth, platvorm OPIN ja noorte e-osalemine / Teo Gregov, Kerstin Franzi ; kommenteerinud Ivo Visak

    Index Scriptorium Estoniae

    Gregov, Teo

    2016-01-01

    Projekti EUth eesmärk on suurendada noorte huvi ja aktiivset osalemist nii kohalikes kui ka Euroopa poliitilistes institutsioonides ja organisatsioonides. Projekti tulemusena valmis veebiplatvorm OPIN (www.opin.me), mis aitab projekte kavandada ja hallata

  2. Kristian Smedsi projekt viib Brüsselisse Eesti näitlejad / Andres Laasik

    Index Scriptorium Estoniae

    Laasik, Andres, 1960-2016

    2008-01-01

    11. veebr. 2009 esietendub Brüsselis Kristian Smedsi rahvusvaheline projekt "Trans-Euroopa komöödia Pühast Vihast" (dramaturg Ivo Kuyl, kunstnik Jurate Paulekaite). Eestist osalevad projektis Juhan Ulfsak ja Eva Klemets

  3. Tallinna Sakala keskuse projekt kütab kirgi / Aivo Vahemets

    Index Scriptorium Estoniae

    Vahemets, Aivo

    2004-01-01

    Raine Karbi projekteeritud hoone ümberehituse projekt telliti Inglismaalt büroost Burrow&Cave, OÜ Arhitektuuriagentuuri projektist loobuti. Eesti Arhitektide Liidu esinaise Margit Mutso ja arhitektuurinõukogu esimehe Peep Aaviksoo kommentaar

  4. Viele Daten, hohe Hürden: eine Bilanz aus dem Projekt Open-Access-Statistik

    OpenAIRE

    Herb, Ulrich

    2018-01-01

    Dieser Artikel referiert die Ergebnisse des Projekts Open-Access-Statistik, dessen Ziel es war, standardisierte Nutzungszahlen für wissenschaftliche Dokumente zu erheben. Die gesammelten Nutzungsdaten sollten in erster Linie dazu dienen, Impact-Werte für Open-Access-Dokumente zu ermitteln. Das Projekt sah auch die Implementierung anspruchsvollerer Verfahren wie Netzwerk-Analysen vor, sah sich jedoch mit komplexen rechtlichen Anforderungen konfrontiert. Der Beitrag versucht überdies, Open-Acce...

  5. A Comparative Electrochemical Study of AZ31 and AZ91 Magnesium Alloy

    Directory of Open Access Journals (Sweden)

    S. A. Salman

    2010-01-01

    Full Text Available A comparative study has been carried out on AZ31 and AZ91 magnesium alloys in order to understand the electrochemical behavior in both alkaline and chloride containing solutions. The open circuit potential (OCP was examined in 1 M NaOH and 3.5 mass % NaCl solutions. AZ31 magnesium alloy shows several potential drops throughout the immersion in 1 M NaOH solution, though AZ91 does not show this phenomenon. The specimens were anodized at a constant potential of 3 V for 30 minutes at 298 K in 1 M NaOH solution. The anticorrosion behavior of the anodized specimens was better than those of nonanodized specimens. The anodized AZ91 has better corrosion resistance compared to nonanodized specimen and anodized AZ31 magnesium alloy.

  6. EnviroAtlas - Phoenix, AZ - Block Groups

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset is the base layer for the Phoenix, AZ EnviroAtlas area. The block groups are from the US Census Bureau and are included/excluded based on...

  7. The A-Z of electronuclear power

    International Nuclear Information System (INIS)

    Temmerman, G. de; Chedorge, D.

    1992-01-01

    Both a bilingual translation aid and a reference book, 'The A-Z of Electronuclear Power' covers the full range of electronuclear activities and the English and French terminology relating to the different phases of the modern industrial process

  8. Sada testů pro projekt OpenLDAP/NSS

    OpenAIRE

    Špůrek, David

    2011-01-01

    Cílem práce je vytvořit sadu testů pro projekt OpenLDAP/NSS. Práce objasňuje principy testování, možnosti automatizace testování v prostředí GNU/Linux a vysvětluje pojmy LDAP i NSS. Testy jsou navrženy pro distribuci Fedora/Red Hat Enterprise Linux a jsou automatizovány pomocí skriptování v shellu s využitím knihovny Beakerlib pro testování. Pro návrh testů je použita metoda black box. Testy se zaměřují na integraci OpenLDAP a NSS. V práci jsou navrhnuty a implementovány testy pro balíky open...

  9. Cold-Sprayed AZ91D Coating and SiC/AZ91D Composite Coatings

    Directory of Open Access Journals (Sweden)

    Yingying Wang

    2018-03-01

    Full Text Available As an emerging coating building technique, cold spraying has many advantages to elaborate Mg alloy workpieces. In this study, AZ91D coatings and AZ91D-based composite coatings were deposited using cold spraying. Coatings were prepared using different gas temperatures to obtain the available main gas temperature. Compressed air was used as the accelerating gas, and although magnesium alloy is oxidation-sensitive, AZ91D coatings with good performance were obtained. The results show that dense coatings can be fabricated until the gas temperature is higher than 500 °C. The deposition efficiency increases greatly with the gas temperature, but it is lower than 10% for all coating specimens. To analyze the effects of compressed air on AZ91D powder particles and the effects of gas temperature on coatings, the phase composition, porosity, cross-sectional microstructure, and microhardness of coatings were characterized. X-ray diffraction and oxygen content analysis clarified that no phase transformation or oxidation occurred on AZ91D powder particles during cold spraying processes with compressed air. The porosity of AZ91D coatings remained between 3.6% and 3.9%. Impact melting was found on deformed AZ91D particles when the gas temperature increased to 550 °C. As-sprayed coatings exhibit much higher microhardness than as-casted bulk magnesium, demonstrating the dense structure of cold-sprayed coatings. To study the effects of ceramic particles on cold-sprayed AZ91D coatings, 15 vol % SiC powder particles were added into the feedstock powder. Lower SiC content in the coating than in the feedstock powder means that the deposition efficiency of the SiC powder particles is lower than the deposition efficiency of AZ91D particles. The addition of SiC particles reduces the porosity and increases the microhardness of cold-sprayed AZ91D coatings. The corrosion behavior of AZ91D coating and SiC reinforced AZ91D composite coating were examined. The Si

  10. Weiterentwicklung Gruppenleiter/innen-Kurs: Ein Projekt in der Freiwilligenarbeit des CVJM/CVJF Regionalverband Basels: Projektbericht

    OpenAIRE

    Fankhauser, Miriam

    2016-01-01

    Im folgenden Bericht geht es um das Projekt «Weiterentwicklung Gruppenleiter/innen-Kurs – Ein Pro- jekt in der Freiwilligenarbeit des CVJM/CVJF Regionalverband Basels». Dieses Projekt wurde von der Studentin Miriam Fankhauser im Rahmen der Praxisausbildung an der Hochschule Luzern für Soziale Arbeit durchgeführt. In Auftrag gegeben wurde das Projekt vom CVJM/CVJF Regionalverband Basel. Beim eben genannten Projekt ging es darum, den Gruppenleiter/innen-Kurs weiterzuentwickeln. Der Kurs rich...

  11. Effects of sintering temperature on the corrosion behavior of AZ31 alloy with Ca–P sol–gel coating

    Energy Technology Data Exchange (ETDEWEB)

    Niu, Bo [School of Materials Science and Engineering, Liaoning University of Technology, Jinzhou, Liaoning Province, 121001 (China); Shi, Ping, E-mail: p_shi@sohu.com [School of Materials Science and Engineering, Liaoning University of Technology, Jinzhou, Liaoning Province, 121001 (China); Wei, Donghua [School of Materials Science and Engineering, Liaoning University of Technology, Jinzhou, Liaoning Province, 121001 (China); E, Shanshan [School of Mathematics and Physics, Bohai University, Jinzhou, Liaoning Province, 121013 (China); Li, Qiang; Chen, Yang [School of Materials Science and Engineering, Liaoning University of Technology, Jinzhou, Liaoning Province, 121001 (China)

    2016-04-25

    To slow down the initial biodegradation rate of magnesium alloy, calcium phosphate (Ca–P) coatings were prepared on AZ31 magnesium alloy by a sol–gel technique. To study the effects of sintering temperature on microstructure, bonding strength and corrosion behavior of the coatings, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and an adhesive strength test were used to characterize the coatings. The corrosion resistance of the coatings was investigated by immersion test and electrochemical corrosion techniques in simulated body fluid (SBF) solution. It shows that the sol–gel coatings consist of Ca{sub 2}P{sub 2}O{sub 7}, mixture of Ca{sub 2}P{sub 2}O{sub 7}, Ca{sub 3}(PO{sub 4}){sub 2} and hydroxyapatite, and hydroxyapatite, by sintering respectively at 300 °C, 400 °C and 500 °C. There are major cracks on the coatings. The crack area portion on the coating and the bonding strength at the interface between the calcium phosphate coating and the bare AZ31 increases, and the corrosion resistance of the coated AZ31 in SBF decreases with increasing sintering temperatures from 300 °C to 500 °C. Based on our investigations, the corrosion resistance of the coated AZ31 in SBF depends mainly on the crack area portion on the coatings, rather than on the coating phase stability. - Highlights: • Ca–P coating was prepared on AZ31 alloy by a sol–gel technique. • Crack area portion in the coating increases with temperatures. • Bonding strength between Ca–P coating and substrate increases with temperatures. • Corrosion resistance of the coated AZ31 in SBF decreases with temperatures. • Corrosion resistance of the coated AZ31 depends mainly on the crack area portion.

  12. The step from the project control to long-distance control; Von der Projekt- zur Fernkontrolle

    Energy Technology Data Exchange (ETDEWEB)

    Kaelin, W. [Ingenieurbuero Werner Kaelin, Schwyz (Switzerland)

    1995-12-31

    In chapter 8 of the anthology about building control the extension from project control to long-distance control is described. The following aspects are discussed: guidelines (operating concept, task anthology), project (implementation, control, documentation), realisation (initiation, example), operation (regional co-operation, characteristic numbers). (BWI) [Deutsch] Kapitel 8 des Sammelbandes ueber Building Control ist dem Ausbau von der Projekt- zur Fernkontrolle gewidmet. In diesem Zusammenhang werden folgende Themen angesprochen: Vorgaben (Betriebskonzept, Pflichtenheft), Projekt (Umsetzung, Kontrolle, Dokumentation), Ausfuehrung (Inbetriebsetzung, Beispiel); Betrieb (regionaler Zusammenschluss, Kennzahlen). (BWI)

  13. Nachlassverzeichnisse im Netz – Ein Projekt der Bayerischen Staatsbibliothek

    Directory of Open Access Journals (Sweden)

    Maximilian Schreiber

    2015-12-01

    Full Text Available Nachlässe rücken in der wissenschaftlichen Forschung immer mehr in den Fokus, wie etwa die stark gestiegenen Nutzerzahlen der Bayerischen Staatsbibliothek (BSB über die letzten Jahre hinweg deutlich zeigen. Umso wichtiger ist insbesondere für Bibliotheken mit umfangreichen und fachlich breit gestreuten Nachlassbeständen eine möglichst genaue Erschließung im Internet, um der wissenschaftlichen Forschung einen schnellen Zugriff auf diese unikalen Materialien zu ermöglichen. Bei der digitalen Bereitstellung und vernetzten Erschließung verfolgt die BSB mit ihren rund 1.100 Nachlässen eine doppelte Strategie. Einerseits wird versucht, ausgewählte Nachlässe im Verbundsystem Kalliope zu katalogisieren. Andererseits werden die Erschließungsdaten zu den bereits erschlossenen und den erst grob geordneten Nachlässen, die in Form von hand- oder maschinenschriftlichen Listen sowie als Wordlisten vorliegen, digitalisiert und über den Bibliothekskatalog online zur Verfügung gestellt, um den Nutzern die Möglichkeit zu geben, sich so über die vorhandenen Bestände zu informieren. Wie dieses Projekt genau durchgeführt wurde, ist Gegenstand des Artikels. Special collections and personal papers are becoming more and more important for academic research, as is shown clearly by the increasing usage numbers at the Bavarian State Library (BSB over the last couple of years. Especially for libraries with extensive and manifold collections of estates, it is important to present these unique materials in a well-indexed manner on the internet, in order to give the scientific community easy access. The Bavarian State Library, which keeps more than 1.100 estates of personal papers, pursues a double strategy: On the one hand, selected estates are fully cataloged in the database “Kalliope”. As this procedure is likely to take a long time, the library on the other hand has been digitizing older hand- or typewritten lists with information

  14. 77 FR 10649 - Modification of Class E Airspace; Douglas, AZ

    Science.gov (United States)

    2012-02-23

    ...-1313; Airspace Docket No. 11-AWP-17] Modification of Class E Airspace; Douglas, AZ AGENCY: Federal... Bisbee Douglas International Airport, Douglas, AZ. Decommissioning of the Cochise VHF Omni-Directional... Federal Register a notice of proposed rulemaking to amend controlled airspace at Douglas, AZ (76 FR 78180...

  15. Medienerziehung im Vorschulbereich - Zum Projekt Mediengarten der Wiener Medienpädagogik

    Directory of Open Access Journals (Sweden)

    Gudrun Kern

    2010-09-01

    Full Text Available Im Zuge des Projekts Mediengarten der Wiener Medienpädagogik wurde in Kooperation mit angehenden KindergartenpädagogInnen eine Medienerziehung im Sinne einer Auseinandersetzung über Medien im Vorschulbereich anhand konkreter Angebote in Kindergärten konzipiert. Im folgenden Artikel werden die Schwerpunktsetzungen dieses Konzepts vorgestellt und durch praktische Beispiele verdeutlicht.

  16. Projekt OK-NET-ARABLE : mahetootmiseks vajalik teave tuleb tuua praktikuteni / Airi Vetemaa

    Index Scriptorium Estoniae

    Vetemaa, Airi

    2015-01-01

    OK-NET-ARABLE, mida võiks tõlkida kui põllukultuuride kasvatuse alast maheteabe võrgustikku, on ELi teadusrahastu Horisont 2020 projekt, mille eesmärk on vahendada innovaatilist ja traditsioonilist teavet mahetootjate, nõustajate ja teadlaste vahel, suurendamaks mahepõllukultuuride produktiivsust ja kvaliteeti üle Euroopa

  17. Tank 241-AZ-101 tank characterization plan

    International Nuclear Information System (INIS)

    Schreiber, R.D.

    1995-01-01

    The Defense Nuclear Facilities Safety Board has advised the DOE to concentrate the near-term sampling and analysis activities on identification and resolution of safety issues. The Data Quality Objective (DQO) process was chosen as a tool to be used in the resolution of safety issues. As a result, A revision in the Federal Facilities Agreement and Consent Order (Tri-Party Agreement) milestone M-44 has been made, which states that ''A Tank Characterization Plan (TCP) will also be developed for each double-shell tank (DST) and single-shell tank (SST) using the DQO process. Development of TCPs by the DQO process is intended to allow users to ensure their needs will be met and that resources are devoted to gaining only necessary information''. This document satisfies that requirement for Tank 241-AZ-101 (AZ-101) sampling activities. Tank AZ-101 is currently a non-Watch List tank, so the only DQOs applicable to this tank are the safety screening DQO and the compatibility DQO, as described below. The contents of Tank AZ-101, as of October 31, 1994, consisted of 3,630 kL (960 kgal) of dilute non-complexed waste and aging waste from PUREX (NCAW, neutralized current acid waste). Tank AZ-101 is expected to have two primary layers. The bottom layer is composed of 132 kL of sludge, and the top layer is composed of 3,500 kL of supernatant, with a total tank waste depth of approximately 8.87 meters

  18. Tank 241-AZ-102 tank characterization plan

    International Nuclear Information System (INIS)

    Schreiber, R.D.

    1995-01-01

    The Defense Nuclear Facilities Safety Board has advised the DOE to concentrate the near-term sampling and analysis activities on identification and resolution of safety issues. The Data Quality Objective (DQO) process was chosen as a tool to be used in the resolution of safety issues. As a result, a revision in the Federal Facilities Agreement and Consent Order (Tri-Party Agreement) milestone M-44 has been made, which states that ''A Tank Characterization Plan (TCP) will also be developed for each double-shell tank (DST) and single-shell tank (SST) using the DQO process ... Development of TCPs by the DQO process is intended to allow users to ensure their needs will be met and that resources are devoted to gaining only necessary information''. This document satisfies that requirement for tank 241-AZ-102 (AZ-102) sampling activities. Tank AZ-102 is currently a non-Watch List tank, so the only DQOs applicable to this tank are the safety screening DQO and the compatibility DQO, as described below. The current contents of Tank AZ-102, as of October 31, 1994, consisted of 3,600 kL (950 kgal) of dilute non-complexed waste and aging waste from PUREX (NCAW, neutralized current acid waste). Tank AZ-102 is expected to have two primary layers. The bottom layer is composed of 360 kL of sludge, and the top layer is composed of 3,240 kL of supernatant, with a total tank waste depth of approximately 8.9 meters

  19. Friction welding of AZ31 magnesium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Tsujino, R.; Ochi, H. [Osaka Inst. of Tech., Osaka (Japan); Kawai, G. [Osaka Sangyo Univ., Osaka (Japan); Yamaguchi, H.; Ogawa, K. [Osaka Prefecture Univ., Osaka (Japan); Suga, Y. [Keio Univ., Kanagawa (Japan)

    2003-07-01

    In this paper, for an acceleration of utilization of magnesium alloy which is being interested in recent years, friction welding of AZ31 magnesium alloy was carried out, and the joint performance was discussed in relation to the deformation heat input in the upset stage and upset loss as a evaluation factor. Where, the deformation heat input in the upset stage is mechanical work represented by the product of upset speed and axial pressure. As a result, it was made clear that the friction welding of AZ31 magnesium alloy was easy in the atmosphere, and good welded joints without a non- adhesion area at the weld interface could de obtained. Moreover, the evaluation factors discussed were possible to evaluate to joint performance. (orig.)

  20. Det særlige ved at lave et projekt i Nationalt Videncenter for Læsning

    DEFF Research Database (Denmark)

    Lund, Henriette Romme

    2009-01-01

    Nationalt Videncenter for Læsnings kommunikationskonsulent har interviewet projektdeltagere om, hvor de så det særlige i at lave et projekt i regi af Nationalt Videncenter for Læsning......Nationalt Videncenter for Læsnings kommunikationskonsulent har interviewet projektdeltagere om, hvor de så det særlige i at lave et projekt i regi af Nationalt Videncenter for Læsning...

  1. Corrosion product layers on magnesium alloys AZ31 and AZ61: Surface chemistry and protective ability

    Science.gov (United States)

    Feliu, S.; Llorente, I.

    2015-08-01

    This paper studies the chemical composition of the corrosion product layers formed on magnesium alloys AZ31 and AZ61 following immersion in 0.6 M NaCl, with a view to better understanding their protective action. Relative differences in the chemical nature of the layers were quantified by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive analysis of X-ray (EDX) and low-angle X-ray diffraction (XRD). Corrosion behavior was investigated by Electrochemical Impedance Spectroscopy (EIS) and hydrogen evolution measurement. An inhibitive effect from the corrosion product layers was observed from EIS, principally in the case of AZ31, as confirmed by hydrogen evolution tests. A link was found between carbonate enrichment observed by XPS in the surface of the corrosion product layer, concomitant with the increase in the protective properties observed by EIS.

  2. Datu noliktavu projektējums mobilajām iekārtām

    OpenAIRE

    Grigore, Madara

    2014-01-01

    Bakalaura darbā „Datu noliktavu projektējums mobilajām iekārtām” tiek pētīti pētnieku piedāvātie risinājumi mobilas datu noliktavas izveidei. Darbā tiek izpētīts, kādas ir datu noliktavas pamata funkcijas, kas ir mobila vide, kas ir mobila BI un kādām īpašībām jāpiemīt iekrātai, lai to sauktu par mobilu iekārtu. Lasītāji tiek iepazīstināti ar trīs iespējamiem mobilas datu noliktas projektējumiem: Hand-OLAP, AMDB un FCLOS. Darba praktiskajā daļā tiek izmantotas MicroStrategy Desktop, Develop...

  3. MuSiK Projekt:Multimaterialdruck von C/Si/SiC-Keramiken

    OpenAIRE

    Marigo, Gloria; Wahl, Larissa; Nauditt, Gotthard

    2017-01-01

    Poster über den ersten 6 Monate von MuSiK Projekt. Additive Verfahren wurden ursprünglich zur effizienten Herstellung von Mustern und Prototypen entwickelt und bieten besondere Einsatzpotentiale, die mittlerweile auch für die Kleinserienproduktion hochinteressant sind. Im Bereich der keramischen Komponenten ist der Einsatz additiver Verfahren bislang nicht weit verbreitet. Ein Grund dafür ist unter anderem die eingeschränkte Verfügbarkeit der notwendigen Fertigungsanlagen und entsprech...

  4. GIMMS – Et EU-projekt om Gender, Innovation and Mentoring in Mathematics and Science

    DEFF Research Database (Denmark)

    Stougaard, Birgitte

    GIMMS projektet er et tværnationalt projekt, som giver mulighed for at ’gen-tænke’ undervisning og læring. Projektet involverer studerende, professionelle lærere og læreruddannere fra 6 lande: Irland, Tyskland, Østrig, Tjekkiet, Spanien og Danmark. GIMMS står for fokus på køn, innovation og mento...

  5. Radiochemical determination of 210Po

    International Nuclear Information System (INIS)

    Clarence, J.

    1961-04-01

    By spontaneous deposition of Po onto silver, and with the use of Po 208 as a tracer, the accurate spectrographic measurements are made possible. Quantitative recovery of Po 210 from radioactive cellulose filters is obtained by burning of samples in a golden lined calorimetric bomb. (author) [fr

  6. Joining of AZ31 and AZ91 Mg alloys by friction stir welding

    Directory of Open Access Journals (Sweden)

    B. Ratna Sunil

    2015-12-01

    Full Text Available Two dissimilar magnesium (Mg alloy sheets, one with low aluminium (AZ31 and another with high aluminium (AZ91 content, were successfully joined by friction stir welding (FSW. The effect of process parameters on the formation of hot cracks was investigated. A sound metallurgical joint was obtained at optimized process parameters (1400 rpm with 25 mm/min feed which contained fine grains and distributed β (Mg17Al12 phase within the nugget zone. An increasing trend in the hardness measurements has also confirmed more amount of dissolution of aluminium within the nugget zone. A sharp interface between nugget zone and thermo mechanical affected zone (TMAZ was clearly noticed at the AZ31 Mg alloy side (advancing but not on the AZ91 Mg alloy side (retreating. From the results it can be concluded that FSW can be effectively used to join dissimilar metals, particularly difficult to process metals such as Mg alloys, and hot cracking can be completely eliminated by choosing appropriate process parameters to achieve sound joint.

  7. The phase transition of the incommensurate phases β-Ln(PO3)3(Ln=Y,Tb...Yb), crystal structures of α-Ln(PO3)3(Ln=Y,Tb...Yb) and Sc(PO3)3

    International Nuclear Information System (INIS)

    Hoeppe, Hennig A.

    2009-01-01

    The incommensurately modulated room-temperature phases β-Ln(PO 3 ) 3 (Ln=Y,Tb...Yb) undergo a topotactic phase transition monitored by vibrational spectroscopy below 180 K leading to α-Ln(PO 3 ) 3 (Ln=Y,Dy...Yb), above 200 K the incommensurate phases are reobtained. The low-temperature phases exhibit a new structure type (α-Dy(PO 3 ) 3 ,P2 1 /c,Z=12,a=14.1422(6),b=20.0793(9),c=10.1018(4)A, β=127.532(3) 0 ). α-Tb(PO 3 ) 3 is isotypic with Gd(PO 3 ) 3 (α-Tb(PO 3 ) 3 ,I2/a,Z=16,a=25.875(6),b=13.460(3),c=10.044(2)A, β=119.13(3) 0 ). The symmetry relations between the involved phases of the phase transition are discussed. The crystal structure of Sc(PO 3 ) 3 is isotypic with that of Lu(PO 3 ) 3 and C-type phosphates. The polyphosphates consist of infinite zig-zag chains of corner-sharing PO 4 tetrahedra, the cations are coordinated sixfold in an almost octahedral arrangement. To confirm the quality of the determined crystal structures the deviation of the phosphate tetrahedra from ideal symmetry was determined and discussed. - Abstract: Basic structure from which all crystal structures of the late lanthanoids' polyphosphates at room temperature and below can be derived.

  8. The phase transition of the incommensurate phases β-Ln(PO3)3(Ln=Y,Tb…Yb), crystal structures of α-Ln(PO3)3(Ln=Y,Tb…Yb) and Sc(PO3)3

    Science.gov (United States)

    Höppe, Hennig A.

    2009-07-01

    The incommensurately modulated room-temperature phases β-Ln(PO3)3(Ln=Y,Tb…Yb) undergo a topotactic phase transition monitored by vibrational spectroscopy below 180 K leading to α-Ln(PO3)3(Ln=Y,Dy…Yb), above 200 K the incommensurate phases are reobtained. The low-temperature phases exhibit a new structure type (α-Dy(PO3)3, P21/c, Z=12,a=14.1422(6), b=20.0793(9),c=10.1018(4) A˚, β=127.532(3)∘). α-Tb(PO3)3 is isotypic with Gd(PO3)3(α-Tb(PO3)3, I2/a,Z=16,a=25.875(6), b=13.460(3), c=10.044(2) A˚, β=119.13(3)∘). The symmetry relations between the involved phases of the phase transition are discussed. The crystal structure of Sc(PO3)3 is isotypic with that of Lu(PO3)3 and C-type phosphates. The polyphosphates consist of infinite zig-zag chains of corner-sharing PO4 tetrahedra, the cations are coordinated sixfold in an almost octahedral arrangement. To confirm the quality of the determined crystal structures the deviation of the phosphate tetrahedra from ideal symmetry was determined and discussed.

  9. Tank 241-AZ-101 and tank 241-AZ-102, airlift circulator operation vapor sampling and analysis plan

    International Nuclear Information System (INIS)

    TEMPLETON, A.M.

    1999-01-01

    This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for vapor samples obtained during the operation of the tank 241-AZ-101 and 241-AZ-102 airlift circulators (ALCs). The purpose of the ALC operation is to support portions of the operational test procedure (OTP) for Project W-030 (OTP-W030-001) and to perform functional test in support of Project W-151. Project W-030 is the 241-A-702 ventilation upgrade project (241-AZ-702) and Project W-151 is the 241-AZ-101 Mixer Pump Test. The functional tests will check the operability of the tank 241-AZ-101 ALCs. Process Memo's No.2E98-082 and No.2E99-001 (LMHC 1999a, LMHC 1999b) direct the operation of the ALCs and the Industrial Hygiene monitoring respectively. A series of tests will be conducted in which the ALCs in tanks 241-AZ-101 and 241-AZ-102 will be operated at different air flow rates. Vapor samples will be obtained to determine constituents that may be present in the tank headspace during ALC operation at tanks 241-AZ-101 and 241-AZ-102 as the waste is disturbed. During the testing, vapor samples will be obtained from the headspace of tanks 241-AZ-101 and 241-AZ-102 via the unused port on the standard hydrogen monitoring system (SHMS). Results will be used to provide the waste feed delivery program with environmental air permitting data for tank waste disturbing activities. Because of radiological concerns, the samples will be filtered for particulates. It is recognized that this may remove some organic compounds

  10. Grain refinement of AZ31 magnesium alloy by electromagnetic ...

    Indian Academy of Sciences (India)

    Low-frequency electromagnetic field; AZ31 magnesium alloy; Al4C3; grain refinement. Abstract. The effects of electromagnetic stirring and Al4C3 grain refiner on the grain refinement of semicontinuously cast AZ31 magnesium alloy were discussed in this investigation. The results indicate that electromagnetic stirring has an ...

  11. ANALYSIS RESULTS FOR BUILDING 241 702-AZ A TRAIN

    Energy Technology Data Exchange (ETDEWEB)

    DUNCAN JB; FRYE JM; COOKE CA; LI SW; BROCKMAN FJ

    2006-12-13

    This report presents the analyses results for three samples obtained under RPP-PLAN-28509, Sampling and Analysis Plan for Building 241 702-AZ A Train. The sampling and analysis was done in response to problem evaluation request number PER-2004-6139, 702-AZ Filter Rooms Need Radiological Cleanup Efforts.

  12. 76 FR 18378 - Amendment of Class E Airspace; Taylor, AZ

    Science.gov (United States)

    2011-04-04

    ...-1189; Airspace Docket No. 10-AWP-19] Amendment of Class E Airspace; Taylor, AZ AGENCY: Federal Aviation Administration (FAA), DOT. ACTION: Final rule. SUMMARY: This action will amend Class E airspace at Taylor Airport, Taylor, AZ, to accommodate aircraft using the CAMBO One Departure, and the Area Navigation (RNAV...

  13. ANALYSIS RESULTS FOR BUILDING 241 702-AZ A TRAIN

    International Nuclear Information System (INIS)

    DUNCAN JB; FRYE JM; COOKE CA; LI SW; BROCKMAN FJ

    2006-01-01

    This report presents the analyses results for three samples obtained under RPP-PLAN-28509, Sampling and Analysis Plan for Building 241 702-AZ A Train. The sampling and analysis was done in response to problem evaluation request number PER-2004-6139, 702-AZ Filter Rooms Need Radiological Cleanup Efforts

  14. 702AZ aging waste ventilation facility year 2000 test procedure

    International Nuclear Information System (INIS)

    Winkelman, W.D.

    1998-01-01

    This test procedure was developed to determine if the 702AZ Tank Ventilation Facility system is Year 2000 Compliant. The procedure provides detailed instructions for performing the operations necessary and documenting the results. This verification procedure will document that the 702AZ Facility Systems are year 2000 compliant and will correctly meet the criteria established in this procedure

  15. Das EU-Projekt MOPEM – europaweite Nutzung elektronischer Lernpfade in der Marketing-Weiterbildung

    OpenAIRE

    Scholl, Margit; Tippe, Ulrike

    2008-01-01

    Im Projekt »Marketing 0nline – Path to Enter New Markets« wollen sieben Partnereinrichtungen aus fünf Ländern der defizitären europäischen Online- Ausbildung im Bereich des fortgeschrittenen Marketings begegnen. Die Lernkurse zum fortgeschrittenen Marketing für Europäische Märkte sollen anhand von Fallstudien praxisorientiert die kulturellen Unterschiede berücksichtigen, modulartig separierbar und wiederverwendbar sowie unabhängig vom konkreten Bildungssystem aufgebaut sein, sodass sie bei be...

  16. Corrosion product layers on magnesium alloys AZ31 and AZ61: Surface chemistry and protective ability

    International Nuclear Information System (INIS)

    Feliu, S.; Llorente, I.

    2015-01-01

    Highlights: • Surface chemistry of the corrosion product layers on magnesium alloys. • Influence of the type of alloy on the carbonate surface enrichment. • Relation between surface composition and protection properties. - Abstract: This paper studies the chemical composition of the corrosion product layers formed on magnesium alloys AZ31 and AZ61 following immersion in 0.6 M NaCl, with a view to better understanding their protective action. Relative differences in the chemical nature of the layers were quantified by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive analysis of X-ray (EDX) and low-angle X-ray diffraction (XRD). Corrosion behavior was investigated by Electrochemical Impedance Spectroscopy (EIS) and hydrogen evolution measurement. An inhibitive effect from the corrosion product layers was observed from EIS, principally in the case of AZ31, as confirmed by hydrogen evolution tests. A link was found between carbonate enrichment observed by XPS in the surface of the corrosion product layer, concomitant with the increase in the protective properties observed by EIS

  17. Corrosion product layers on magnesium alloys AZ31 and AZ61: Surface chemistry and protective ability

    Energy Technology Data Exchange (ETDEWEB)

    Feliu, S., E-mail: sfeliu@cenim.csic.es; Llorente, I.

    2015-08-30

    Highlights: • Surface chemistry of the corrosion product layers on magnesium alloys. • Influence of the type of alloy on the carbonate surface enrichment. • Relation between surface composition and protection properties. - Abstract: This paper studies the chemical composition of the corrosion product layers formed on magnesium alloys AZ31 and AZ61 following immersion in 0.6 M NaCl, with a view to better understanding their protective action. Relative differences in the chemical nature of the layers were quantified by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), energy dispersive analysis of X-ray (EDX) and low-angle X-ray diffraction (XRD). Corrosion behavior was investigated by Electrochemical Impedance Spectroscopy (EIS) and hydrogen evolution measurement. An inhibitive effect from the corrosion product layers was observed from EIS, principally in the case of AZ31, as confirmed by hydrogen evolution tests. A link was found between carbonate enrichment observed by XPS in the surface of the corrosion product layer, concomitant with the increase in the protective properties observed by EIS.

  18. Facebook Marketing - Fra A-Z

    DEFF Research Database (Denmark)

    Mortensen, Thomas Bøtker

    2009-01-01

    Facebook Marketing – Leverage Social Media to Grow Your Business af Steven Holzner er Facebook Marketing fra A-Z, som kan anbefales til virksomheder, som overvejer at bevæge sig ud i cyber space og afprøve mulighederne for at markedsføre sig dér. Bogen beskriver på hvilke væsentlige punkter...... marketing på Facebook adskiller sig fra traditionel marketing, og gennemgår trin for trin de fundamentale ting, som man skal vide for, at virksomheden kan agere med den tilsigtede effekt i et socialt netværk som Facebook. Og eftersom 34 % af den danske befolkning i dag er hoppet med på Facebook vognen og...... har oprettet en profil på Facebook, er potentialet åbenlyst....

  19. "Bildung für nachhaltige Entwicklung" - die Sicht der Kinder : Ergebnisse aus dem weltweiten OMEP-Projekt

    OpenAIRE

    Engdahl, Ingrid

    2017-01-01

    Während der UNESCO Dekade „Bildung für nachhaltige Entwicklung“ (BNE) führte die Weltorganisation für Frühe Bildung (OMEP) zwischen 2009-2014 ein umfangreiches Projekt zum Thema Nachhaltigkeit durch. Das übergeordnete Ziel des Projektes war das Bewußtsein der OMEP Mitglieder und der internationalen Fachgemeinde für die Bildung für nachhaltige Entwicklung (BNE) zu stärken. Dabei wurde ein besonderer Fokus auf die kindorientierte Perspektive gelegt.

  20. A comparative corrosion behavior of Mg, AZ31 and AZ91 alloys in 3.5% NaCl solution

    Directory of Open Access Journals (Sweden)

    I.B. Singh

    2015-06-01

    Full Text Available The corrosion behavior of Mg, AZ31 and AZ91 has been evaluated in 3.5% NaCl solution using weight loss, electrochemical polarization and impedance measurements. Corrosion rate derived from the weight losses demonstrated the occurrence of steeply fast corrosion reaction on AZ91 alloy after three hours of immersion, indicating the start of galvanic corrosion. An increase of corrosion rate with immersion time was also observed for AZ31 but with lesser extent than AZ91 alloy. Whereas Mg metals showed a decrease of corrosion rate with immersion time, suggesting the formation of a protective layer on their surfaces. In contrast, the corrosion current density (Icorr derived from the Tafel plots, exhibited their corrosion resistances in order of Mg > AZ91 > AZ31. Electrochemical charge transfer resistance (Rct and double layer capacitance measured by electrochemical impedance spectroscopy (EIS, are well in accordance with the measured Icorr. EIS measurements with time and microstructural examination of the corroded and uncorroded samples are helpful in elucidation of results measured by electrochemical polarization.

  1. Use of innovative projects in the Agenda procedure: Heating - ventilation - sanitary. Compilation of selected projects from data base of Deutsche Bundesstiftung Umwelt. CD-ROM of May 2000 as further added sources.; Nutzung innovativer Projekte im Agenda Prozess: Heizung - Lueftung - Sanitaer. Zusammenstellung ausgewaehlter Projekte aus der Datenbank der Deutschen Bundesstiftung Umwelt. CD-ROM vom Mai 2000 sowie weiterer hinzugezogene Quellen

    Energy Technology Data Exchange (ETDEWEB)

    Schefe, W. (comp.)

    2001-05-01

    Compilation of selected projects from data base of Deutsche Bundesstiftung Umwelt. (orig.) [German] Zusammenstellung ausgewaehlter Projekte aus der Datenbank der Deutschen Bundesstiftung Umwelt. (orig.)

  2. Urbane Projekter

    DEFF Research Database (Denmark)

    Andersen, Anne Juel

    2013-01-01

    of Chapter 1 ’problem and research questions’, Chapter 2 ’place, discourse and planning as a theoretical framework’ and Chapter 3 ’research design’. Part 2 ’urban practice locally, nationally and globally’ consisting of Chapter 4 ’background and context, urban trans- formations in Aalborg from 1950 to 2013...... of Chapter 9 with the same name. The analysis results and thus the conclusions are at 3 levels of knowledge: Historically specific development in terms of urban planning practices respectively in Aalborg and natio- nally/internationally The tools here have been a focus on different rationales or urban...... projects as a strategic tool in urban policy, development of place perceptions, the use of narratives in the planning processes, the functions of representations as discursive devised imagined realities, power structures and planning approaches - knowledge that can be used in the future practice of other...

  3. Projekt Sundterm

    DEFF Research Database (Denmark)

    Toft, Birthe

    2008-01-01

    terminologisk konsistent dansk klinisk terminologi, der accepteres af sundhedssektorens praktikere. Forfatteren er tilknyttet projektet som ekstern terminologikonsulent og beskriver i artiklen blandt andet arbejdet i projektets redaktionsgruppe, der godkender den oversatte terminologi samt fastlægger de...

  4. Recommendation Report: EJournals/EBooks A-Z Management System

    KAUST Repository

    Ramli, Rindra M.

    2014-01-01

    This is a recommendation report for KAUST Library on the Ejournals / EBooks AZ Management systems project. It briefly described the issues faced by the ERM Team, project plan overview and the project findings as well as the recommendation(s).

  5. Deutsche Bahn jätkab majanduskriisile vaatamata koostööprojekte Venemaal / Gebhard Hafer ; intervjueerinud Anna Nezhinskaya

    Index Scriptorium Estoniae

    Hafer, Gebhard

    2009-01-01

    Deutsche Bahni SRÜ riikide ja Ida-Euroopa rahvusvahelise osakonna direktor Gebhard Hafer vastab küsimustele, mis puudutavad majanduskriisi mõju ettevõtte tegevusele, töötajate koondamisest hoidumisest, päevakorras olevaid Saksa-Venemaa projekte ning transiidi arengut Hiinast

  6. 241-AZ-101 pump removal trough analysis

    International Nuclear Information System (INIS)

    Coverdell, B.L.

    1995-01-01

    As part of the current Hanford mission of environmental cleanup, various long length equipment must be removed from highly radioactive waste tanks. The removal of equipment will utilize portions of the Equipment Removal System for Project W320 (ERS-W320), specifically the 50 ton hydraulic trailer system. Because the ERS-W320 system was designed to accommodate much heavier equipment it is adequate to support the dead weight of the trough, carriage and related equipment for 241AZ101 pump removal project. However, the ERS-W320 components when combined with the trough and its' related components must also be analyzed for overturning due to wind loads. Two troughs were designed, one for the 20 in. diameter carriage and one for the 36 in. diameter carriage. A proposed 52 in. trough was not designed and, therefore is not included in this document. In order to fit in the ERS-W320 strongback the troughs were design with the same widths. Structurally, the only difference between the two troughs is that more material was removed from the stiffener plates on the 36 in trough. The reduction in stiffener plate material reduces the allowable load. Therefore, only the 36 in. trough was analyzed

  7. Caustic leaching of composite AZ-101/AZ-102 Hanford tank sludge

    International Nuclear Information System (INIS)

    Rapko, B.M.; Wagner, M.J.

    1997-07-01

    To reduce the quantity (and hence the cost) of glass canisters needed for disposing of high-level radioactive wastes from the Hanford tank farms, pretreatment processes are needed to remove as much nonradioactive material as possible. This report describes the results of a laboratory-scale caustic leaching test performed on a composite derived from a combination of 241-AZ-101 and 241-AZ-102 Hanford Tank sludges. The goals of this FY 1996 test were to evaluate the effectiveness of caustic leaching on removing key components from the sludge and to evaluate the effectiveness of varying the free-hydroxide concentrations by incrementally increasing the free hydroxide concentration of the leach steps up to 3 M free hydroxide. Particle-size analysis of the treated and untreated sludge indicated that the size and range of the sludge particles remained essentially unchanged by the caustic leaching treatment. Both before and after caustic leaching, a particle range of 0.2 microm to 50 microm was observed, with mean particle diameters of 8.5 to 9 microm based on the volume distribution and mean particle diameters of 0.3 to 0.4 microm based on the number distribution

  8. AZ91C magnesium alloy modified by Cd

    DEFF Research Database (Denmark)

    Shabadi, R.; Ambat, Rajan; Dwarakadasa, E.S.

    2014-01-01

    In the present work, the effect of Cd on the microstructure, mechanical properties and general corrosion behaviour of AZ91C alloys was investigated. Addition of Cd was found not to be efficient in modifying/refining the microstructure or β-phase. A morphology change in β-phase from fine continuous...... precipitates to discontinuous β-phase upon the addition of Cd was observed. A marginal increment in mechanical properties was observed. General corrosion behaviour was followed with weight loss measurements, potentiostatic polarisation studies and surface studies in 3.5% sodium chloride solution and 3.......5% sodium chloride with 2% potassium dichromate solution. Cd addition deteriorated the corrosion behaviour of AZ91C. This behaviour was attributed to the formation of chunks of β-phase upon the addition of Cd. AZ91C with refined β-phase distribution, performed rather better in the NaCl solutions....

  9. AZ-101 Mixer Pump Test Qualification Test Procedures (QTP)

    International Nuclear Information System (INIS)

    THOMAS, W.K.

    2000-01-01

    Describes the Qualification test procedure for the AZ-101 Mixer Pump Data Acquisition System (DAS). The purpose of this Qualification Test Procedure (QTP) is to confirm that the AZ-101 Mixer Pump System has been properly programmed and hardware configured correctly. This QTP will test the software setpoints for the alarms and also check the wiring configuration from the SIMcart to the HMI. An Acceptance Test Procedure (ATP), similar to this QTP will be performed to test field devices and connections from the field

  10. Corrosion Behavior of PEO Coatings Formed on AZ31 Alloy in Phosphate-Based Electrolytes with Calcium Acetate Additive

    Science.gov (United States)

    Ziyaei, E.; Atapour, M.; Edris, H.; Hakimizad, A.

    2017-07-01

    The PEO coating started on magnesium AZ31 using a unipolar DC power source. The coating was generated in the electrolyte based on Na3PO4·12H2O and KOH with calcium acetate as additive. The x-ray diffraction method showed some phases containing calcium and phosphate, which was created in the presence of additive. Also, the EDS tests of the sample's surfaces proved the existence of calcium on the surface. Based on the electrochemical tests results, the most corrosion resistance belongs to the sample with calcium acetate additive. In fact, the results of the EIS tests showed the coating with calcium acetate has the highest resistance but the lowest capacitance. However, this state belongs to the surface morphology, the lower porosity, and surface chemical composition.

  11. Der Ausbau des Hochrheins zur Schifffahrtsstraße - Die Geschichte eines gescheiterten Großprojekts

    OpenAIRE

    Steiner, Rudolf

    2006-01-01

    Die vorliegende Arbeit befasst sich mit Genese, Verfall und Scheitern eines der ehrgeizigsten technischen Großprojekte des 20. Jahrhunderts im süddeutschen Raum – dem Ausbau des Rheinabschnitts zwischen Basel und dem Bodensee zu einer schiffbaren Wasserstraße. Hatte es bereits seit dem Mittelalter mehrere erfolglose Versuche gegeben, die zahlreichen natürlichen Hindernisse auf dem Hochrhein, wie die genannte Strecke bezeichnet wird, zum Zwecke einer durchgängigen Schifffahrt bis zum Bodensee ...

  12. Dauerhafter Zugriff auf digitale Publikationen – das DFG-Projekt NatHosting

    Directory of Open Access Journals (Sweden)

    Hildegard Schäffler

    2015-12-01

    Full Text Available Das Arbeiten mit digitalen Veröffentlichungen und Daten in Forschung, Lehre und Studium erfordert eine kontinuierliche und möglichst störungsfreie Verfügbarkeit dieser Inhalte. Bei Publikationen, die von wissenschaftlichen Fachverlagen lizenzpflichtig vertrieben werden, können verschiedene Typen von Störungsfällen wie temporäre oder längerfristige Ausfälle von Verlagsservern, der Transfer von Zeitschriftentiteln zu anderen Verlagen, das komplette Ausscheiden von Verlagen aus dem Markt oder die Abbestellung der elektronischen Ressourcen durch die lizenznehmende Einrichtung zu Zugriffsunterbrechungen führen. Das DFG-Projekt „Nationales Hosting elektronischer Ressourcen“ (NatHosting untersucht, wie unter Berücksichtigung bereits existierender Lösungsansätze eine nationale Strategie zur Absicherung des dauerhaften Zugriffs auf digitale Publikationen entwickelt werden kann. Das vom Projekt erarbeitete Lösungskonzept umfasst eine zweigleisige Strategie der Teilnahme eines nationalen Konsortiums bei Portico bei gleichzeitigem Aufbau eines „Private LOCKSS Networks“ für die durch Portico nicht abgedeckten Inhalte. Weitere Komponenten sind der Aufbau eines rechnergestützten Rechtemanagements und die Einrichtung einer „Hosting-Agentur“ mit Koordinationsaufgaben für das nationale Hosting. In order to work with digital publications and data in a reliable and sustainable way, researchers need to be sure that access to and immediate availability of the content is provided continuously and free of faults. An interruption of access to licensed content can occur for various reasons such as temporary or long-term breakdown of publishers’ servers, the transfer of journals to another publisher, the withdrawal of publishers from the market or the termination of electronic resource subscriptions by the licensee. Against the background of existing solutions, the project NatHosting (National Hosting of Electronic Resources aims at

  13. 76 FR 78180 - Proposed Modification of Class E Airspace; Douglas, AZ

    Science.gov (United States)

    2011-12-16

    ...-1313; Airspace Docket No. 11-AWP-17] Proposed Modification of Class E Airspace; Douglas, AZ AGENCY... action proposes to modify Class E airspace at Bisbee Douglas International Airport, Douglas, AZ... feet above the surface at Douglas, AZ. Additional controlled airspace is necessary to accommodate...

  14. 75 FR 883 - Environmental Impact Statement; Maricopa County, AZ

    Science.gov (United States)

    2010-01-06

    ...; Maricopa County, AZ AGENCY: Federal Highway Administration (FHWA), DOT. ACTION: Notice of Intent. SUMMARY...: (602) 382-8998, e-mail: [email protected] SUPPLEMENTARY INFORMATION: The FHWA, in cooperation with the... reasonable alternatives will be considered including: (1) Taking no action; (2) using alternate travel modes...

  15. Mixer pump test plan for double shell tank AZ-101

    International Nuclear Information System (INIS)

    STAEHR, T.W.

    1999-01-01

    Mixer pump systems have been chosen as the method for retrieval of tank wastes contained in double shell tanks at Hanford. This document describes the plan for testing and demonstrating the ability of two 300 hp mixer pumps to mobilize waste in tank AZ-101. The mixer pumps, equipment and instrumentation to monitor the test were installed by Project W-151

  16. 75 FR 81190 - Television Broadcasting Services; Yuma, AZ

    Science.gov (United States)

    2010-12-27

    ... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 73 [DA 10-2365; MB Docket No. 02-151; RM-10453] Television Broadcasting Services; Yuma, AZ AGENCY: Federal Communications Commission. ACTION: Dismissal. SUMMARY: The Commission dismisses the petition for rulemaking filed by Arizona Western College, requesting...

  17. Projekts: SIA Ģimenes centrs" dibināšana

    OpenAIRE

    Mensaha, Elizabete

    2016-01-01

    Maģistra darba tēma ir projekts SIA „Ģimenes centrs” dibināšana. Ikviena cilvēka dzīvē ģimene ir pati svarīgākā. Ģimenē veidojas galvenie uzskati par to, kas ir labi vai slikti, pareizi vai nepareizi, godīgi vai negodīgi. Bērni, kuri jau no bērnības dzīvo labvēlīgās ģimenēs, zina, kā veidot labas attiecības savā un savu bērnu ģimenē, zina, kā pārvarēt sadzīviskas vai ikdienišķas problēmas, kuras bieži kļūst par ģimenes šķiršanās iemesliem. Laulības šķiršana ir viena no aktuālākajām mūsdienas ...

  18. Handlungsmuster von Lehrerinnen und Lehrern beim Einsatz neuer Medien. Grundlagen eines Projekts zur empirischen Unterrichtsforschung

    Directory of Open Access Journals (Sweden)

    Sigrid Blömeke

    2017-08-01

    Full Text Available Ziel des vorzustellenden Projekts ist es in einem ersten Schritt, Handlungsmuster von Lehrpersonen beim Einsatz von neuen Medien im Unterricht der Fächer Deutsch, Mathematik und Informatik der Sekundarstufe II zu identifizieren. Zu diesem Zweck werden Videoaufnahmen von 30 Unterrichtsstunden im Hinblick auf zugrunde liegende ‚Unterrichtsscripts’ (i.e. didaktische Routinen analysiert und die subjektiven Theorien der Lehrkräfte zum Lehren und Lernen erhoben. Bei der Zusammensetzung der Stichprobe findet neben der Variation der Fachzugehörigkeit der Expertisegrad der Lehrpersonen bezogen auf den Einsatz neuer Medien Berücksichtigung, und zwar in zwei Abstufungen (hoch – niedrig. Auf diese Weise wird ermöglicht, in einem zweiten Schritt begründet Hypothesen zu Zusammenhängen zwischen Handlungsmustern sowie Fach und Expertise als Kontextfaktoren zu generieren und mögliche Geltungsbereiche zu beschreiben. Über diese Grundlagenforschung hinausgehend sollen in einem dritten Schritt anhand der gewonnenen Erkenntnisse Interventionen entwickelt werden, die eine Weiterentwicklung von Lehrerhandeln beim Einsatz neuer Medien im Unterricht ermöglichen. Hier stellt sich allerdings die Frage, wie sich Handeln grundsätzlich verändern lässt.

  19. Rugby-metoden SCRUM: En ny måde at bedrive projekter

    DEFF Research Database (Denmark)

    Pries-Heje, Lene; Pries-Heje, Jan

    2012-01-01

    En ny måde at bedrive projekter på breder sig i disse år med overraskende fart. Selv om de første tanker om ”Scrum” – hvor navnet og fremgangsmåden er inspireret af Rugby-spillet – blev tænkt for mere end 10 år siden, så er det først nu at fremgangsmåden for alvor har vundet udbredelse i Danmark....... Denne artikel gennemgår metoden og fortæller om både positive resultater og udfordringer i tre danske organisationer: Et softwarehus, en bank, og et universitet. De tre cases illustrer meget forskellige anvendelsessituationer af Scrum set i forhold til projekternes størrelse, karakter og den...... organisatoriske kontekst. Artiklen slutter med at diskutere, hvad det er der gør, at Scrum er blevet så populær, og i dag fremstår som et reelt alternativ til klassisk plandreven projektledelse...

  20. Role of PO4 tetrahedron in LiFePO4 and FePO4 system.

    Science.gov (United States)

    Zeng, Yuewu

    2015-06-01

    Using high resolution transmission electron microscopy with image simulation and Fourier analysis, the Li1- x FePO4 (x < 0.01), Li1- x FePO4 (x ∼ 0.5), and FePO4 particles, prepared by charging or discharging the 053048 electrochemical cells (thickness: 5 mm, width: 30 mm, height: 48 mm) and dismantled inside an Ar-filled dry box, were investigated. The high resolution images reveal: (1) the solid solution of Li1- x FePO4 (x < 0.01) contains some missing Li ions leading PO4 group distorted around M1 tunnel of the unit cell; (2) the texture of the particles of Li1- x FePO4 (x ∼0.5) has homogeneously distributed compositional domains of LiFePO4 and FePO4 resulting from spinodal decomposition which promote Li ion easily getting into the particle due to uphill diffusion, (3) the particles of FePO4 formed in charging have heavily distorted lattice and contain some isolated LiFePO4 , (4) interface between LiFePO4 and FePO4 and between amorphous and crystal region provides the lattice distortion of small polarons. © 2015 Wiley Periodicals, Inc.

  1. Corrosion resistance of plasma-anodized AZ91D magnesium alloy by electrochemical methods

    International Nuclear Information System (INIS)

    Barchiche, C.-E.; Rocca, E.; Juers, C.; Hazan, J.; Steinmetz, J.

    2007-01-01

    Anodic coatings formed on magnesium alloys by plasma anodization process are mainly used as protective coatings against corrosion. The effects of KOH concentration, anodization time and current density on properties of anodic layers formed on AZ91D magnesium alloy were investigated to obtain coatings with improved corrosion behaviour. The coatings were characterized by scanning electron microscopy (SEM), electron dispersion X-ray spectroscopy (EDX), X-ray diffraction (XRD) and micro-Raman spectroscopy. The film is porous and cracked, mainly composed of magnesium oxide (MgO), but contains all the elements present in the electrolyte and alloy. The corrosion behaviour of anodized Mg alloy was examined by using stationary and dynamic electrochemical techniques in corrosive water. The best corrosion resistance measured by electrochemical methods is obtained in the more concentrated electrolyte 3 M KOH + 0.5 M KF + 0.25 M Na 3 PO 4 .12 H 2 O, with a long anodization time and a low current density. A double electrochemical effects of the anodized layer on the magnesium corrosion is observed: a large inhibition of the cathodic process and a stabilization of a large passivation plateau

  2. User Manual for the AZ-101 Data Acquisition System (AS-101 DAS)

    Energy Technology Data Exchange (ETDEWEB)

    BRAYTON, D.D.

    2000-02-17

    User manual for the TK AZ-101 Waste Retrieval System Data Acquisition System. The purpose of this document is to describe use of the AZ-101 Data Acquisition System (AZ-101 DAS). The AZ-101 DAS is provided to fulfill the requirements for data collection and monitoring as defined in Letters of Instruction (LOI) from Numatec Hanford Corporation (NHC) to Fluor Federal Services (FFS). For a complete description of the system, including design, please refer to the AZ-101 DAS System Description document, RPP-5572.

  3. User Manual for the AZ-101 Data Acquisition System (AS-101 DAS)

    International Nuclear Information System (INIS)

    BRAYTON, D.D.

    2000-01-01

    User manual for the TK AZ-101 Waste Retrieval System Data Acquisition System. The purpose of this document is to describe use of the AZ-101 Data Acquisition System (AZ-101 DAS). The AZ-101 DAS is provided to fulfill the requirements for data collection and monitoring as defined in Letters of Instruction (LOI) from Numatec Hanford Corporation (NHC) to Fluor Federal Services (FFS). For a complete description of the system, including design, please refer to the AZ-101 DAS System Description document, RPP-5572

  4. Influence of artificial biological fluid composition on the biocorrosion of potential orthopedic Mg-Ca, AZ31, AZ91 alloys

    International Nuclear Information System (INIS)

    Gu, X N; Zheng, Y F; Chen, L J

    2009-01-01

    The electrochemical behavior of potential orthopedic Mg-Ca, AZ31 and AZ91 alloys was studied in Hank's solution, Dulbecco's Modified Eagle's Medium (DMEM) and serum-containing medium (DMEM adding 10% fetal bovine serum (DMEM+FBS)) over a 7 day immersion period. The biocorrosion of the above three alloys for various immersion time intervals was investigated by linear polarization and electrochemical impedance spectroscopy (EIS). After 7 day immersion, potentiodynamic polarization tests were carried out and the surface morphologies of experimental samples were examined by scanning electron microscopy (SEM) observation complemented by energy-disperse spectrometer (EDS) analysis. It was shown that the corrosion of magnesium alloys was influenced by the composition of the solution. The results indicated that chloride ion could reduce the corrosion resistance and the hydrocarbonate ions could induce rapid surface passivation. The adsorbed amino acid on the experimental magnesium alloys' surface increased their polarization resistance and reduced current densities. The influence of the serum protein on corrosion was found to be associated with the magnesium alloy compositions. A Mg-Ca alloy exhibited an increased corrosion rate in the presence of serum protein. An AZ31 alloy showed an increased corrosion rate in DMEM+FBS in the initial 3 day immersion and the corrosion rate decreased thereafter. An AZ91 alloy, with high Al content, showed a reduced corrosion rate with the addition of FBS into DMEM.

  5. Influence of artificial biological fluid composition on the biocorrosion of potential orthopedic Mg-Ca, AZ31, AZ91 alloys.

    Science.gov (United States)

    Gu, X N; Zheng, Y F; Chen, L J

    2009-12-01

    The electrochemical behavior of potential orthopedic Mg-Ca, AZ31 and AZ91 alloys was studied in Hank's solution, Dulbecco's Modified Eagle's Medium (DMEM) and serum-containing medium (DMEM adding 10% fetal bovine serum (DMEM+FBS)) over a 7 day immersion period. The biocorrosion of the above three alloys for various immersion time intervals was investigated by linear polarization and electrochemical impedance spectroscopy (EIS). After 7 day immersion, potentiodynamic polarization tests were carried out and the surface morphologies of experimental samples were examined by scanning electron microscopy (SEM) observation complemented by energy-disperse spectrometer (EDS) analysis. It was shown that the corrosion of magnesium alloys was influenced by the composition of the solution. The results indicated that chloride ion could reduce the corrosion resistance and the hydrocarbonate ions could induce rapid surface passivation. The adsorbed amino acid on the experimental magnesium alloys' surface increased their polarization resistance and reduced current densities. The influence of the serum protein on corrosion was found to be associated with the magnesium alloy compositions. A Mg-Ca alloy exhibited an increased corrosion rate in the presence of serum protein. An AZ31 alloy showed an increased corrosion rate in DMEM+FBS in the initial 3 day immersion and the corrosion rate decreased thereafter. An AZ91 alloy, with high Al content, showed a reduced corrosion rate with the addition of FBS into DMEM.

  6. Influence of artificial biological fluid composition on the biocorrosion of potential orthopedic Mg-Ca, AZ31, AZ91 alloys

    Energy Technology Data Exchange (ETDEWEB)

    Gu, X N; Zheng, Y F [State Key Laboratory for Turbulence and Complex System and Department of Advanced Materials and Nanotechnology, College of Engineering, Peking University, Beijing 100871 (China); Chen, L J, E-mail: yfzheng@pku.edu.c [School of Material Science and Engineering, Shengyang University of Technology, Shenyang 110023 (China)

    2009-12-15

    The electrochemical behavior of potential orthopedic Mg-Ca, AZ31 and AZ91 alloys was studied in Hank's solution, Dulbecco's Modified Eagle's Medium (DMEM) and serum-containing medium (DMEM adding 10% fetal bovine serum (DMEM+FBS)) over a 7 day immersion period. The biocorrosion of the above three alloys for various immersion time intervals was investigated by linear polarization and electrochemical impedance spectroscopy (EIS). After 7 day immersion, potentiodynamic polarization tests were carried out and the surface morphologies of experimental samples were examined by scanning electron microscopy (SEM) observation complemented by energy-disperse spectrometer (EDS) analysis. It was shown that the corrosion of magnesium alloys was influenced by the composition of the solution. The results indicated that chloride ion could reduce the corrosion resistance and the hydrocarbonate ions could induce rapid surface passivation. The adsorbed amino acid on the experimental magnesium alloys' surface increased their polarization resistance and reduced current densities. The influence of the serum protein on corrosion was found to be associated with the magnesium alloy compositions. A Mg-Ca alloy exhibited an increased corrosion rate in the presence of serum protein. An AZ31 alloy showed an increased corrosion rate in DMEM+FBS in the initial 3 day immersion and the corrosion rate decreased thereafter. An AZ91 alloy, with high Al content, showed a reduced corrosion rate with the addition of FBS into DMEM.

  7. Concentration of 210Po in cigars

    International Nuclear Information System (INIS)

    Kelecom, Alphonse; Gouvea, Rita C.S.; Santos, Pedro L.

    2000-01-01

    210 Po concentrations have been determined in 57 different cigar brands manufactured in 11 countries. Cuban and American cigars showed the lowest 210 Po content. The mean levels of 210 Po in Brazilian cigars were almost equal to those of European and Dominican cigars, and somewhat lower than cigars from Central American countries. (author)

  8. LiHo(PO34

    Directory of Open Access Journals (Sweden)

    Mokhtar Férid

    2009-02-01

    Full Text Available Lithium holmium(III polyphosphate(V, LiHo(PO34, belongs to the type I of polyphosphates with general formula ALn(PO34, where A is a monovalent cation and Ln is a trivalent rare earth cation. In the crystal structure, the polyphosphate chains spread along the b-axis direction, with a repeat period of four tetrahedra and 21 internal symmetry. The Li and Ho atoms are both located on twofold rotation axes and are surrounded by four and eight O atoms, leading to a distorted tetrahedral and dodecahedral coordination, respectively. The HoO8 polyhedra are isolated from each other, the closest Ho...Ho distance being 5.570 (1 Å.

  9. Accumulation of 210Po in Baltic invertebrates

    International Nuclear Information System (INIS)

    Skwarzec, B.; Falkowski, L.

    1988-01-01

    This paper presents the results of an investigation of the 210 Po contents of Baltic marine invertebrates. The 210 Po concentrations fall within the range 11.3-78.9 Bq kg -1 (dry wt), the higher values relating to polychaeta, priapulida and malacostraca and the lower levels to bivalvia. It is demonstrated that 210 Po is non-uniformly distributed within the isopod Mesidotea entomon and the bivalve Mya arenaria. The 210 Po contents of the internal organs decreasing in the order-hepatopancreas > alimentary tract > gill > muscle. Moreover, the results indicate the dominant role of the digestive organs of these invertebrates in controlling absorption and elimination of 210 Po. (author)

  10. Das RADAR Projekt: Datenarchivierung und -publikation als Dienstleistung - disziplinübergreifend, nachhaltig, kostendeckend

    Directory of Open Access Journals (Sweden)

    Matthias Razum

    2014-12-01

    Full Text Available Die Nachvollziehbarkeit und Reproduzierbarkeit wissenschaftlicher Erkenntnisse basiert zunehmend auf digitalen Daten. Deren Publikation, Verfügbarkeit und Nachnutzung muss im Rahmen guter wissenschaftlicher Praxis gewährleistet werden. Das Projekt RADAR geht diese Herausforderung durch die Etablierung einer generischen Infrastruktur für die Archivierung und Publikation von Forschungsdaten an. Dafür vereinen fünf Projektpartner aus den Informations- und Naturwissenschaften (FIZ Karlsruhe, TIB in Hannover, KIT/SCC, LMU München und IPB Halle ihre Kompetenzen. Durch enge Kooperation mit Wissenschaftler/innen, Datenzentren, Fachgesellschaften und Verlagen wird eine bedarfsgerechte Entwicklung der Infrastruktur sichergestellt. RADAR richtet sich an zwei Zielgruppen: Projekte (d. h. Forscher/innen und Institutionen. Es verfolgt dabei einen zweistufigen Ansatz: ein disziplinübergreifendes Einstiegsangebot zur formatunabhängigen Datenarchivierung mit minimalem Metadatensatz und ein erweitertes Angebot mit integrierter Datenpublikation. Der thematische Schwerpunkt  liegt bei den wissenschaftlichen Disziplinen  im „long tail of science“, in denen Forschungsdateninfrastrukturen meist noch fehlen. RADAR erlaubt eine temporäre oder – im Falle einer Datenpublikation – eine zeitlich unbegrenzte Datenarchivierung. Das angestrebte Geschäftsmodell zielt auf einen sich selbst tragenden Betrieb mit einer Kombination aus Einmalzahlungen und institutionellen Angeboten ab. RADAR ist als Baustein der internationalen Informationsinfrastruktur geplant, der sich über Schnittstellen auch in weitere Datenmanagement-Dienste Dritter integrieren lässt. The transparency and reproducibility of scientific results are increasingly based on digital data. In compliance with good scientific practice data need to be published, accessible, and re-usable. The RADAR project aims to establish a generic infrastructure, which will provide archiving and publication

  11. Characterization of mussel H2A.Z.2: a new H2A.Z variant preferentially expressed in germinal tissues from Mytilus.

    Science.gov (United States)

    Rivera-Casas, Ciro; González-Romero, Rodrigo; Vizoso-Vazquez, Ángel; Cheema, Manjinder S; Cerdán, M Esperanza; Méndez, Josefina; Ausió, Juan; Eirin-Lopez, Jose M

    2016-10-01

    Histones are the fundamental constituents of the eukaryotic chromatin, facilitating the physical organization of DNA in chromosomes and participating in the regulation of its metabolism. The H2A family displays the largest number of variants among core histones, including the renowned H2A.X, macroH2A, H2A.B (Bbd), and H2A.Z. This latter variant is especially interesting because of its regulatory role and its differentiation into 2 functionally divergent variants (H2A.Z.1 and H2A.Z.2), further specializing the structure and function of vertebrate chromatin. In the present work we describe, for the first time, the presence of a second H2A.Z variant (H2A.Z.2) in the genome of a non-vertebrate animal, the mussel Mytilus. The molecular and evolutionary characterization of mussel H2A.Z.1 and H2A.Z.2 histones is consistent with their functional specialization, supported on sequence divergence at promoter and coding regions as well as on varying gene expression patterns. More precisely, the expression of H2A.Z.2 transcripts in gonadal tissue and its potential upregulation in response to genotoxic stress might be mirroring the specialization of this variant in DNA repair. Overall, the findings presented in this work complement recent reports describing the widespread presence of other histone variants across eukaryotes, supporting an ancestral origin and conserved role for histone variants in chromatin.

  12. Test Excavations at Painted Rock Reservoir: Sites AZ Z:1:7, AZ Z:1:8, and AZ S:16:36.

    Science.gov (United States)

    1981-11-01

    were dehydrated, trimmed to 12-mm squares, and 77 78 placed in catalyzed (0.05-percent benzoyl peroxide), deinhibited acrylic monomer (50-percent methyl ...refrigeration for 72 hours in partially polymerized ethyl- methyl methacrylate. The methacrylate was polymerized at 50 degrees C and 50 p.s.i. nitrogen...pollen types from fill of Feature 10, AZ Z:l:8 Pollen Type Percent Pinus spp. 0.5 Cheno-Am 92.0 Gramineae 2.0 Ambrosia spp. 0.5 Malvaceae 0.5 Zea spp. 2.0

  13. The Corrosion Protection of Magnesium Alloy AZ31B

    Science.gov (United States)

    Danford, M. D.; Mendrek, M. J.; Mitchell, M. L.; Torres, P. D.

    1997-01-01

    Corrosion rates for bare and coated Magnesium alloy AZ31B have been measured. Two coatings, Dow-23(Trademark) and Tagnite(Trademark), have been tested by electrochemical methods and their effectiveness determined. Electrochemical methods employed were the scanning reference electrode technique (SRET), the polarization resistance technique (PR) and the electrochemical impedance spectroscopy technique (EIS). In addition, general corrosion and stress corrosion methods were employed to examine the effectiveness of the above coatings in 90 percent humidity. Results from these studies are presented.

  14. Systems of Ba(PO3)2-Sr(Pu3)2, Cd(PO3)2-Ca(PO3)2

    International Nuclear Information System (INIS)

    Tokman, I.A.; Bukhalova, G.A.

    1977-01-01

    Phase diagrams of the Ba(PO 3 ) 2 -Sr(PO 3 ) 2 and Cd(PO 3 ) 2 -Ca(PO 3 ) 2 systems have been studied and plotted by the methods of differential-thermal analysis (DTA), visual-polythermal, X-ray phase and infrared spectroscopy. The Ba(PO 3 ) 2 -Sr(PO 3 ) 2 system is of the eutectic type. In the binary system Cd(PO 3 ) 2 -Ca(PO 3 ) 2 the existence of a continuous series of solid solutions with a minimum at 858 deg C and 27.5 mol.% Ca(PO 3 ) 2 has been established

  15. Enhancing Microstructure and Mechanical Properties of AZ31-MWCNT Nanocomposites through Mechanical Alloying

    Directory of Open Access Journals (Sweden)

    J. Jayakumar

    2013-01-01

    Full Text Available Multiwall carbon nanotubes (MWCNTs reinforced Mg alloy AZ31 nanocomposites were fabricated by mechanical alloying and powder metallurgy technique. The reinforcement material MWCNTs were blended in three weight fractions (0.33%, 0.66%, and 1% with the matrix material AZ31 (Al-3%, zinc-1% rest Mg and blended through mechanical alloying using a high energy planetary ball mill. Specimens of monolithic AZ31 and AZ31-MWCNT composites were fabricated through powder metallurgy technique. The microstructure, density, hardness, porosity, ductility, and tensile properties of monolithic AZ31 and AZ31-MWCNT nano composites were characterized and compared. The characterization reveals significant reduction in CNT (carbon nanoTube agglomeration and enhancement in microstructure and mechanical properties due to mechanical alloying through ball milling.

  16. Reorganization of Damaged Chromatin by the Exchange of Histone Variant H2A.Z-2

    Energy Technology Data Exchange (ETDEWEB)

    Nishibuchi, Ikuno [Department of Cellular Biology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima (Japan); Department of Radiation Oncology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima (Japan); Department of Radiation Oncology, Hiroshima Prefectural Hospital, Hiroshima (Japan); Suzuki, Hidekazu; Kinomura, Aiko; Sun, Jiying; Liu, Ning-Ang [Department of Cellular Biology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima (Japan); Horikoshi, Yasunori [Department of Cellular Biology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima (Japan); Research Center for Mathematics of Chromatin Live Dynamics, Hiroshima University, Hiroshima (Japan); Shima, Hiroki [Department of Biochemistry, Graduate School of Medical Sciences, Tohoku University, Sendai (Japan); Kusakabe, Masayuki; Harata, Masahiko [Laboratory of Molecular Biology, Graduate School of Agricultural Science, Tohoku University, Sendai (Japan); Fukagawa, Tatsuo [Department of Molecular Genetics, National Institute of Genetics and The Graduate University for Advanced Studies, Mishima (Japan); Ikura, Tsuyoshi [Laboratory of Chromatin Regulatory Network, Department of Mutagenesis, Radiation Biology Center, Kyoto University, Kyoto (Japan); Ishida, Takafumi [Department of Cardiovascular Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima (Japan); Nagata, Yasushi [Department of Radiation Oncology, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima (Japan); Tashiro, Satoshi, E-mail: ktashiro@hiroshima-u.ac.jp [Department of Cellular Biology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima (Japan); Research Center for Mathematics of Chromatin Live Dynamics, Hiroshima University, Hiroshima (Japan)

    2014-07-15

    Purpose: The reorganization of damaged chromatin plays an important role in the regulation of the DNA damage response. A recent study revealed the presence of 2 vertebrate H2A.Z isoforms, H2A.Z-1 and H2A.Z-2. However, the roles of the vertebrate H2A.Z isoforms are still unclear. Thus, in this study we examined the roles of the vertebrate H2A.Z isoforms in chromatin reorganization after the induction of DNA double-strand breaks (DSBs). Methods and Materials: To examine the dynamics of H2A.Z isoforms at damaged sites, we constructed GM0637 cells stably expressing each of the green fluorescent protein (GFP)-labeled H2A.Z isoforms, and performed fluorescence recovery after photobleaching (FRAP) analysis and inverted FRAP analysis in combination with microirradiation. Immunofluorescence staining using an anti-RAD51 antibody was performed to study the kinetics of RAD51 foci formation after 2-Gy irradiation of wild-type (WT), H2A.Z-1- and H2A.Z-2-deficient DT40 cells. Colony-forming assays were also performed to compare the survival rates of WT, H2A.Z-1-, and H2A.Z-2-deficient DT40 cells with control, and H2A.Z-1- and H2A.Z-2-depleted U2OS cells after irradiation. Results: FRAP analysis revealed that H2A.Z-2 was incorporated into damaged chromatin just after the induction of DSBs, whereas H2A.Z-1 remained essentially unchanged. Inverted FRAP analysis showed that H2A.Z-2 was released from damaged chromatin. These findings indicated that H2A.Z-2 was exchanged at DSB sites immediately after the induction of DSBs. RAD51 focus formation after ionizing irradiation was disturbed in H2A.Z-2-deficient DT40 cells but not in H2A.Z-1-deficient cells. The survival rate of H2A.Z-2-deficient cells after irradiation was lower than those of WT and H2A.Z-1- DT40 cells. Similar to DT40 cells, H2A.Z-2-depleted U2OS cells were also radiation-sensitive compared to control and H2A.Z-1-depleted cells. Conclusions: We found that vertebrate H2A.Z-2 is involved in the regulation of the DNA

  17. Reorganization of Damaged Chromatin by the Exchange of Histone Variant H2A.Z-2

    International Nuclear Information System (INIS)

    Nishibuchi, Ikuno; Suzuki, Hidekazu; Kinomura, Aiko; Sun, Jiying; Liu, Ning-Ang; Horikoshi, Yasunori; Shima, Hiroki; Kusakabe, Masayuki; Harata, Masahiko; Fukagawa, Tatsuo; Ikura, Tsuyoshi; Ishida, Takafumi; Nagata, Yasushi; Tashiro, Satoshi

    2014-01-01

    Purpose: The reorganization of damaged chromatin plays an important role in the regulation of the DNA damage response. A recent study revealed the presence of 2 vertebrate H2A.Z isoforms, H2A.Z-1 and H2A.Z-2. However, the roles of the vertebrate H2A.Z isoforms are still unclear. Thus, in this study we examined the roles of the vertebrate H2A.Z isoforms in chromatin reorganization after the induction of DNA double-strand breaks (DSBs). Methods and Materials: To examine the dynamics of H2A.Z isoforms at damaged sites, we constructed GM0637 cells stably expressing each of the green fluorescent protein (GFP)-labeled H2A.Z isoforms, and performed fluorescence recovery after photobleaching (FRAP) analysis and inverted FRAP analysis in combination with microirradiation. Immunofluorescence staining using an anti-RAD51 antibody was performed to study the kinetics of RAD51 foci formation after 2-Gy irradiation of wild-type (WT), H2A.Z-1- and H2A.Z-2-deficient DT40 cells. Colony-forming assays were also performed to compare the survival rates of WT, H2A.Z-1-, and H2A.Z-2-deficient DT40 cells with control, and H2A.Z-1- and H2A.Z-2-depleted U2OS cells after irradiation. Results: FRAP analysis revealed that H2A.Z-2 was incorporated into damaged chromatin just after the induction of DSBs, whereas H2A.Z-1 remained essentially unchanged. Inverted FRAP analysis showed that H2A.Z-2 was released from damaged chromatin. These findings indicated that H2A.Z-2 was exchanged at DSB sites immediately after the induction of DSBs. RAD51 focus formation after ionizing irradiation was disturbed in H2A.Z-2-deficient DT40 cells but not in H2A.Z-1-deficient cells. The survival rate of H2A.Z-2-deficient cells after irradiation was lower than those of WT and H2A.Z-1- DT40 cells. Similar to DT40 cells, H2A.Z-2-depleted U2OS cells were also radiation-sensitive compared to control and H2A.Z-1-depleted cells. Conclusions: We found that vertebrate H2A.Z-2 is involved in the regulation of the DNA

  18. Standortbasierte Online-Informationen vermitteln: cUBe, ein Projekt der Universitätsbibliothek Bern

    Directory of Open Access Journals (Sweden)

    Reto List

    2017-12-01

    Full Text Available Die Transformation der Bibliotheksangebote schreitet immer weiter voran. In vielen Bibliotheken wird der sichtbare Buchbestand mehr und mehr von Arbeitsplätzen und Gruppenräumen verdrängt, Bibliotheken unterliegen zunehmend Neudefinitionen unter dem Label von Lern- und Begegnungsorten. Daneben nimmt die Bedeutung von elektronischen Medienangeboten und webbasierten Dienstleistungen laufend zu. Gleichzeitig ist das umfangreiche elektronische Angebot, welches Bibliotheken teuer lizensieren oder kaufen, oft nicht in aller Breite und zielgruppenbezogen bekannt und erfährt keine adäquate Nutzung. Mit dem Projekt cUBe wurde in der im Frühsommer 2016 nach umfangreicher Sanierung neu eröffneten Bibliothek Münstergasse der Universitätsbibliothek Bern der Versuch unternommen, die reichhaltigen digitalen Nachweise und Bestände für das Bibliothekspublikum sichtbarer, besser zugänglich und damit bekannter zu machen. Dabei wurde auf Basis der neuen Technologien des physischen Webs die standortbasierte Verbindung von OnlineInformationen (Katalog, E-Medien, sonstige digitale Angebote mit den entsprechenden Räumen der Bibliothek und den vor Ort noch verfügbaren Beständen realisiert. The transformation of library services is constantly proceeding. In many libraries, print collections are replaced by space designated to learning. Increasingly, our libraries are defined by labels like learning or meeting space. In addition, the importance of electronic collections and web-based services is constantly growing. However, this extensive and expensive electronic material licenced or bought by libraries is often neither known in detail and to all target groups nor used appropriately. The project cUBe was launched in late spring 2016 after an extensive renovation of the newly opened Münstergasse Library. cUBe aims at improving visibility, access and publicity of the library’s comprehensive digital references and collections for its users. On the basis of

  19. Kinetics of neutralization of Po-218

    International Nuclear Information System (INIS)

    Chu, K.D.

    1987-01-01

    In a well-defined experimental system the neutralization of polonium-218 ions was investigated as a function of the physical and chemical properties of the controlled composition atmosphere. The mobilities of Po + and PoO 2 + are determined by combining experimental results with a computer model of the system. Three neutralization mechanisms were individually studied. The small ion recombination rate has been found to be proportional to the square root of radon concentration. The electron scavenging mechanism is responsible for the neutralization of Po + in NO 2 or H 2 O in nitrogen. When PoO 2 + is formed, the electron transfer mechanism dominates the neutralization process. The electron is transferred to PoO 2 + from molecules with lower ionization potentials. The ionization potential of PoO 2 + is also determined to be 10.44 +/- 0.05 eV

  20. Tank 241-AZ-102 Privatization Push Mode Core Sampling and Analysis Plan

    International Nuclear Information System (INIS)

    TEMPLETON, A.M.

    1999-01-01

    This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for samples obtained from tank 241-AZ-102

  1. Tank 241-AZ-102 Privatization Push Mode Core Sampling and Analysis Plan

    International Nuclear Information System (INIS)

    RASMUSSEN, J.H.

    2000-01-01

    This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for samples obtained from tank 241-AZ-102

  2. 241-AZ Tank Farm Construction Extent of Condition Review for Tank Integrity

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, Travis J.; Boomer, Kayle D.; Gunter, Jason R.; Venetz, Theodore J.

    2013-07-30

    This report provides the results of an extent of condition construction history review for tanks 241-AZ-101 and 241-AZ-102. The construction history of the 241-AZ tank farm has been reviewed to identify issues similar to those experienced during tank AY-102 construction. Those issues and others impacting integrity are discussed based on information found in available construction records, using tank AY-102 as the comparison benchmark. In the 241-AZ tank farm, the second DST farm constructed, both refractory quality and tank and liner fabrication were improved.

  3. Microstructural Characteristics and Mechanical Properties of 2205/AZ31B Laminates Fabricated by Explosive Welding

    Directory of Open Access Journals (Sweden)

    Yan Li

    2017-04-01

    Full Text Available A bimetal composite of 2205 duplex stainless steel and AZ31B magnesium alloy was cladded successfully through the method of explosive welding. The microstructural characteristics and mechanical properties of 2205/AZ31B bimetal composite are discussed. The interface of 2205/AZ31B bimetallic composite was a less regular wavy morphology with locally melted pockets. Adiabatic shear bands occurred only in the AZ31B side near explosive welding interface. The microstructure observed with EBSD showed a strong refinement near the interface zones. Line scan confirmed that the interface had a short element diffusion zone which would contribute to the metallurgical bonding between 2205 duplex stainless steel and AZ31B magnesium alloy. The value of micro-hardness near the bonding interface of composite plate increased because of work hardening and grain refinement. The tensile shear strength of bonding interface of 2205/AZ31B composite was 105.63 MPa. Tensile strength of 2205/AZ31B composite material was higher than the base AZ31B. There were two abrupt drops in stress in the stress–strain curves of the 2205/AZ31B composite materials.

  4. The Ca(PO3)2-Sr(PO3)2 system

    International Nuclear Information System (INIS)

    Bukhalova, G.A.; Tokman, I.A.

    1977-01-01

    Phase diagram of the system Ca(PO 3 ) 2 -Sr(PO 3 ) 2 has been studied and plotted with the aid of differential thermal, visual polythermal, X-ray analysis, and infrared spectroscopy. Continuous solid solutions are formed in the system with a minimum at 968 deg C and 25 mol.% of Sr(PO 3 ) 2 . Solid solutions decompose with the formation of about 30 mol.% of Sr(PO 3 ) 2

  5. Complex phosphates in the Li(Na)3PO4-InPO4 systems

    International Nuclear Information System (INIS)

    Potapova, A.M.; Zimina, G.V.; Smirnova, I.N.; Novoselov, A.V.; Spiridonov, F.M.; Stefanovich, S.Yu.

    2008-01-01

    Subsolidus sections in the systems Li 3 PO 4 -InPO 4 (950 deg C) and Na 3 PO 4 -InPO 4 (800, 900, and 1000 deg C) have been studied by X-ray powder diffraction. The compound Li 3 In(PO 4 ) 2 has been synthesized, and the NASICON-type solid solution Li 3(1-x) In 2+x (PO 4 ) 3 (0.67 ≤ x ≤ 0.80) has been found to exist. In the system Na 3 PO 4 -InPO 4 , the solid solution Na 3(1-x) In x/3 PO 4 (0 ≤ x ≤ 0.2) and two complex phosphates exist: Na 3 In(PO 4 ) 2 and Na 3 In 2 (PO 4 ) 3 . These complex phosphates are dimorphic, with the irreversible-transition temperature equal to 675 and 820 deg C, respectively. Na 3 In(PO 4 ) 2 degrades at 920 deg C. Ionic conductivity has been measured in some phases in the system [ru

  6. Determination of 210 Po in cigarettes

    International Nuclear Information System (INIS)

    Peres, Ana Claudia; Hiromoto, Goro

    1999-01-01

    A radiochemical procedure for the determination of 110 Po in cigarettes is presented. The method is based on solvent extraction, followed by spontaneous deposition on copper disks and counting by alpha spectrometry. Some commercial cigarette brands available in the national market were analysed, obtaining 210 Po concentrations ranging from 15 to 26 mBq per gram of dry tobacco. (author)

  7. Factory conversion, Tallinn : ARS Projekt converted a 20th-century factory into homes with a veneer of history / Triin Ojari

    Index Scriptorium Estoniae

    Ojari, Triin, 1974-

    2009-01-01

    Endise Tallinna vineeri- ja mööblivabriku hooned ehitati ümber korterelamuks. Projekteeris ARS Projekt (Eero Jürgenson, Rasmus Tamme, Jaanus Saarepera, Andrei Pleskatsjov, Evelin Eelma). Vabrik ehitati 1912. aastal vene arhitektide Aleksei Bubõri ja Nikolai Vassiljevi projekti järgi

  8. Evaluering af metoder til risikovurdering af kombinationseffekter og etablering af PBTK/TD modeller for pesticider - et ph.d.-projekt

    DEFF Research Database (Denmark)

    Reffstrup, Trine Klein

    2012-01-01

    I dette ph.d.-projekt ved DTU Fødevareinstituttet er den nuværende viden om metoder til risikovurdering af kombinationseffekter af kemiske stoffer med fokus på pesticider gennemgået. Endvidere undersøgtes, hvordan man kan implementere matematiske computermodeller som et værktøj i vurderingen af...

  9. In-beam spectroscopy of 198Po and 200Po nuclei

    International Nuclear Information System (INIS)

    Maj, A.

    1988-01-01

    The main purpose of this thesis is to answer the question whether any signs of collectivity or deformation are evident in 198 Po and 200 Po nuclei, situated on the border of the predicted new region of oblate deformation. Bearing this in mind spectroscopic investigations were performed. The level schemes of 198 Po and 200 Po were established, transition rates were determined and g-factors of isomeric states and, for 200 Po, the quadrupole moment of the 8 + - state were measured. The experimental techniques are described and the methods of evaluating the obtained data are presented. 74 refs., 7 figs., 9 tabs. (M.F.W.)

  10. Po-210 excretion and radon exposure

    International Nuclear Information System (INIS)

    Breuer, F.; Clemente, G.F.

    1979-01-01

    A mathematical model is given to describe the metabolism of the 210 Po introduced into the systemic compartiments of the human body. The model has been based on the experimental data referred to the 210 Pb- 210 Po intake, excretion and body burden of members of the general italian population. The model fits also very well the experimental data of 210 Pb- 210 Po intake and excretion reported by other authors. The retention function of 210 Po in total body, soft tissue and bone has been evaluated together with the urinary excretion function and the absorbed fraction by ingestion. The model is very valuable to evaluate the lung exposure to Radon decay products on the basis of the 210 Pb- 210 Po urinary excretions

  11. Aberrant PO2 values in proficiency testing.

    Science.gov (United States)

    Fonzi, C E; Clausen, J L; Mahoney, J

    1993-03-01

    We prospectively determined the frequency of aberrant vials of fluorocarbon/buffer used for proficiency testing of measurements of pH, PCO2, and PO2, using 20 duplicate vials from 12 lots of fluorocarbon/buffer and two arterial blood gas analyzers in eight reference laboratories. We defined aberrant vials as vials for which both duplicate measurements differed from the mean value of repeated measurements for the specific instrument (for each lot of testing materials) by > 0.04 for pH, > 10% of the mean or 3.0 mm Hg, whichever was greater, for PCO2; or > 10% of the mean or 6 mm Hg, whichever was greater, for PO2. Four of 1620 vials (0.25%) were aberrant, all based on PO2 measurements (range of mean values: pH, 7.181-7.631; PCO2, 12.7-65.9; PO2, 32.5-150.1) were 0.0055 for pH, 0.67 mm Hg for PCO2, and 1.65 mm Hg for PO2. Deliberate contamination of the fluorocarbon emulsion with room air, as might occur during sampling from the vial, indicated that only minor increases in PO2 (e.g., 1.0 mm Hg at PO2 of 56 mm Hg) occur when samples are aspirated. Larger increases in PO2 (mean 7.1 mm Hg at a PO2 of 66 mm Hg) occurred when the syringe samples were contaminated with room air. We conclude that isolated aberrant measurements of PO2 in blood gas proficiency testing attributable to vial contents can occur, but the frequency is very low.

  12. Metabolism of 210Po in rats: Volatile 210Po from faeces

    International Nuclear Information System (INIS)

    Sadi, B. B.; Li, C.; Wyatt, H.; Bugden, M.; Wilkinson, D.; Kramer, G.

    2011-01-01

    The metabolic formation of volatile 210 Po species in a rat that was intravenously administered with 210 Po-citrate was investigated in this study. A slurry of the faecal sample was prepared in water and was bubbled with nitrogen gas in a closed system. The discharged gas was passed through a trapping device filled with liquid scintillation cocktail in order to capture any volatile 210 Po species. The amount of 210 Po trapped in the scintillation cocktail was measured by a liquid scintillation analyser that provided evidence of the presence of volatile 210 Po species in the faeces. The presence of volatile 210 Po in the faeces indicates that the metabolic formation of volatile 210 Po is likely to occur in the gut due to bacterial activity. The amount of volatile 210 Po species was compared with the daily faecal excretion of 210 Po. After 2 h of bubbling, the volatile 210 Po collected from the faeces sample was found to be between 1.0 and 1.7 % of the daily faecal excretion for the 4 d following 210 Po-citrate administration. (authors)

  13. 76 FR 62144 - Environmental Impact Statement for Implementation of Passenger Rail Service Between Tucson, AZ...

    Science.gov (United States)

    2011-10-06

    ... impacts to the natural and built environment of those alternatives, and invite public participation in the... will provide programmatic assessment of environmental effects associated with the construction... Environmental Impact Statement for Implementation of Passenger Rail Service Between Tucson, AZ and Phoenix, AZ...

  14. 76 FR 30299 - Proposed Establishment of Class E Airspace; Kayenta, AZ

    Science.gov (United States)

    2011-05-25

    ...-0393; Airspace Docket No. 11-AWP-2] Proposed Establishment of Class E Airspace; Kayenta, AZ AGENCY... action proposes to establish Class E Airspace at Kayenta Airport, Kayenta, AZ. Controlled airspace is...) standard instrument approach procedures at Kayenta Airport. The FAA is proposing this action to enhance the...

  15. 76 FR 3570 - Proposed Amendment of Class E Airspace; Taylor, AZ

    Science.gov (United States)

    2011-01-20

    ...-1189; Airspace Docket No. 10-AWP-19] Proposed Amendment of Class E Airspace; Taylor, AZ AGENCY: Federal... proposes to modify Class E airspace at Taylor Airport, Taylor, AZ. Controlled airspace is necessary to accommodate aircraft using the CAMBO One Departure Area Navigation (RNAV) out of Taylor Airport. The FAA is...

  16. Influence of the Composition of the Hank’s Balanced Salt Solution on the Corrosion Behavior of AZ31 and AZ61 Magnesium Alloys

    Czech Academy of Sciences Publication Activity Database

    Tkacz, J.; Slouková, K.; Minda, J.; Drábiková, J.; Fintová, Stanislava; Doležal, P.; Wasserbauer, J.

    2017-01-01

    Roč. 7, č. 11 (2017), č. článku 465. ISSN 2075-4701 Institutional support: RVO:68081723 Keywords : magnesium alloy * AZ31 * AZ61 * HBSS * HBSS+ * EIS * potentiodynamic test Subject RIV: JK - Corrosion ; Surface Treatment of Materials OBOR OECD: Coating and films Impact factor: 1.984, year: 2016 http://www.mdpi.com/2075-4701/7/11/465

  17. Development of AZS refractories for the glass industry

    International Nuclear Information System (INIS)

    Guzman, A.M.; Rodriguez, P.

    2004-01-01

    Refractory materials can support high temperatures, thermal strength and the contact with aggressive environments, for this reason they are widely used in the cement, glass and steel industry. Commercial AZS (alumina-zirconia-silica) refractories are a good alternative in refractory materials for the glass industry' because they can support the aggressive conditions during liquid processing of glass. However, another problem encountered in glass industry is contamination by refractory' material that fall into the molten glass, which can produce a series of defects in the final product. This research was conducted to develop new formulations of AZS refractories with different amounts of ZrO 2 with the purpose of improving the characteristics, properties and the work conditions in the glass melting furnaces and, at the same time, lower the costs this type of refractories. The results obtained indicate that the composition with low content of ZrO 2 can provide better properties than the commercial product, with some modifications in the particle size distribution. Copyright (2004) AD-TECH - International Foundation for the Advancement of Technology Ltd

  18. Influence of the Composition of the Hank’s Balanced Salt Solution on the Corrosion Behavior of AZ31 and AZ61 Magnesium Alloys

    Directory of Open Access Journals (Sweden)

    Jakub Tkacz

    2017-11-01

    Full Text Available The electrochemical corrosion characteristics of AZ31 and AZ61 magnesium alloys were analyzed in terms of potentiodynamic tests and electrochemical impedance spectroscopy. The influence of the solution composition and material surface finish was examined also through the analysis of corrosion products created on the samples’ surface after electrochemical measurements in terms of scanning electron microscopy using energy-dispersive spectroscopy. Obtained data revealed the differences in the response of the magnesium alloys to enriched Hank’s Balanced Salt Solution—HBSS+ (with Mg2+ and Ca2+ ions and Hank’s Balanced Salt Solution—HBSS (without Mg2+ and Ca2+ ions. Both examined alloys exhibited better corrosion resistance from the thermodynamic and kinetic point of view in the enriched HBSS+. AZ61 magnesium alloy reached higher values of polarization resistance than AZ31 magnesium alloy in both the used corrosion solutions. Phosphate-based corrosion products were characteristic for the AZ31 and AZ61 alloys tested in the HBSS (without Mg2+ and Ca2+ ions. The combination of phosphate-based corrosion products and clusters of MgO and Mg(OH2 was typical for the surface of samples tested in the enriched HBSS+ (with Mg2+ and Ca2+ ions. Pitting corrosion attack was observed only in the case of enriched HBSS+.

  19. In Vitro Studies on the Degradability, Bioactivity, and Cell Differentiation of PRP/AZ31B Mg Alloys Composite Scaffold

    Directory of Open Access Journals (Sweden)

    Jian Zou

    2017-01-01

    Full Text Available In recent years, more and more methods have been developed to improve the bioactivity of the biodegradable materials in bone tissue regeneration. In present study, we used rat mesenchymal stem cells (rMSCs to evaluate the outcomes of Mg alloys (AZ31B, Magnesium, and Aluminum and Platelet-rich plasma (PRP/Mg alloys on rMSCs biocompatibility and osteogenic differentiation. Water absorption experiments indicated that both bare AZ31B and PRP/AZ31B were capable of absorbing large amounts of water. But the water absorption ratio for PRP/AZ31B was significantly higher than that for bare AZ31B. The degradability experiments implied that both samples degraded at same speed. rMSCs on the surface of AZ31B distributed more and better than those on the AZ31B scaffold. In ALP activity experiment, the activity of rMSCs on the PRP/AZ31B was markedly higher than that on the AZ31B scaffolds on the 7th day and 14th day. qRT-PCR also showed that OPN and OCN were expressed in both samples. OPN and OCN expression in PRP/AZ31B sample were higher than those in bare AZ31B samples. In summary, the in vitro study implied that AZ31B combined with PRP could remarkably improve cell seeding, attachment, proliferation, and differentiation.

  20. Dictionary of engines. The internal combustion engine from A-Z; Lexikon Motorentechnik. Der Verbrennungsmotor von A-Z

    Energy Technology Data Exchange (ETDEWEB)

    Schaefer, F. (ed.); Basshuysen, R. van

    2004-04-01

    This dictionary describes current engine technology and gives an outlook to the future. Cross-references, broader and narrower terms ensure optimal user guidance. Entries do not stand alone but provide content-oriented information. About 4,500 terms are included from A-Z, providing an outline of subjects like exhaust systems, acoustics, supercharging, combustion chamber, injection systems, control, flame propagation, mixing, catalytic converters, pistons, fuels, cooling, crank casing, stratified charging, lambda control, camshaft, oil, particulate filters, sensors/actuators, pollutants, valves, combustion processes, efficiency, ignition, cylinder head. The dictionary is for development engineers in the motor car industry, in component and system development in the supply industry, university teachers and students, foremen in motor car repair shops, etc. (orig.) [German] Das Lexikon Motorentechnik ist ein Nachschlagewerk, das die aktuelle Motorentechnik umfassend beschreibt und Ausblicke in der Zukunft ermoeglicht. Das ausgefeilte System aus Querverweisen fuehrt alle Unterbegriffe zum Hauptbegriff und ermoeglicht so eine optimale Benutzerfuehrung. Dadurch stehen die Stichwoerter nicht isoliert, sondern es werden inhaltlich zusammenhaengende Betrachtungen moeglich. Der Inhalt umfasst 4 500 Begriffe von A-Z wie z.B.: Abgastechnik, Akustik, Aufladung, Brennraum, Einspritzsysteme, Elektronische Motorsteuerung, Flammenausbreitung, Gemischbildung, Katalysator, Kolben, Kraftstoff, Kuehlung, Kurbelgehaeuse, Kurbeltrieb, Ladungswechsel, Lambda-Regelung, Nockenwelle, Oel, Partikelfilter, Sensoren/Aktuatoren, Schadstoffe, Ventiltrieb, Verbrennungsverfahren, Wirkungsgrad, Zuendung, Zylinderkopf. Die Zielgruppen waeren Ingenieure in Motoren- und Fahrzeugentwicklung der Automobilindustrie, Ingenieure in der Komponenten- und Systementwicklung der Zuliefererindustrie, Professoren und Studenten an Hochschulen mit Schwerpunkt Kraftfahrzeugtechnik, Meister in Kfz-Werkstaetten. (orig.)

  1. Superconducting Coil of Po Dipole

    CERN Multimedia

    1983-01-01

    The Po superconducting dipole was built as a prototype beam transport magnet for the SPS extracted proton beam P0. Its main features were: coil aperture 72 mm, length 5 m, room-temperature yoke, NbTi cable conductor impregnated with solder, nominal field 4.2 T at 4.7 K (87% of critical field). It reached its nominal field without any quench.After this successful test up to its nominal field of 4.2 T, the power was not raised to reach a quench. The magnet was not installed in a beam and had no other further use. Nevertheless its construction provided knowledges and experience which became useful in the design and construction of the LHC magnets. The photo shows a detail of the inner layer winding before superposing the outer layer to form the complete coil of a pole. Worth noticing is the interleaved glass-epoxy sheet (white) with grooved channels for the flow of cooling helium. See also 8211532X.

  2. Aspects on the analysis of 210Po.

    Science.gov (United States)

    Henricsson, F; Ranebo, Y; Holm, E; Roos, P

    2011-05-01

    There has been little development regarding analysis of polonium (Po) in environmental samples since the 1960 ies. This is due to the straightforward spontaneous deposition of this element on silver (Ag), nickel (Ni) or copper (Cu) without any radiochemical separation. For many years, no radiochemical yield determinant was used and it was generally supposed that the yield was 100% after two depositions. Counting was often done using ZnS scintillation counter coupled to a photomultiplier tube. However, the use of the yield determinants (208)Po and (209)Po and the development of alpha spectrometry showed that the yield was lower. Furthermore, the tendency of Po to volatilize at low temperatures constrains the sample preparation techniques; dry-ashing cannot be used. But during the wet-ashing procedure, there are still some losses. The aim of this study was to evaluate the Po losses during wet-ashing by the use of a double-tracer technique. We have found that the losses were about 30% when open glass beakers were used and about 17% when the samples were digested in microwave oven. When long-necked bottles (Kjeldahl flasks) were used, a loss of about 20% was registered. It has also been observed that (210)Pb to some extent is plating out together with its daughter nuclide Po during the electrochemical deposition. This will result in a systematic error since an unknown amount of supported (210)Po will be produced from the (210)Pb decay depending on the fraction of (210)Pb being deposited on the disc and the waiting time between deposition and measurement of the sample. A further consequence of this is that in the assessment of the (210)Pb content in the sample, very often the remaining liquid is stored after deposition for build-up of (210)Po. Since some (210)Pb is lost on the disc, the result for (210)Pb will be too low. Both these systematic errors give rise to a too high (210)Po/(210)Pb ratio. The fraction of (210)Pb which is plating out has been assessed in this

  3. Po2 temperature blood factor for blood gas apparatus.

    Science.gov (United States)

    Teisseire, B P; Hérigault, R A; Teisseire, L J; Laurent, D N

    1984-01-01

    PO2 temperature formulae supplied by manufacturers on automatic blood gas apparatus, PO2 corr. = PO2 37 degrees C X 10F X delta T were studied and compared to the experimental determination of the delta log PO2/delta T ratio (Hérigault et al. [10]). Acid-base status at 37 degrees C appeared to have a measurable influence on the PO2 temperature factor; alkalosis increased the delta log PO2/delta T ratio, and the contrary was found for acidosis in comparison with normal acid-base status at 37 degrees C. For the same PO2, measured at 37 degrees C, all the proposed formulae of commercial blood gas automatic apparatus did not give the same temperature corrected PO2. The observed difference between the corrected PO2 may be important and greater than the precision of the initial measurement. To correct the measured PO2 for temperature, a relationship between delta log PO2/delta T and PO2 is proposed, between PO2 zero and PO2 180 mmHg, which takes into account measured pH and PO2 values at 37 degrees C:delta log PO2/delta T = [(-0.35 pH + 0.658) X 10(-4) X PO2] + 0.035.

  4. Mixed phosphates of the Na3PO4 - LnPO4 systems

    International Nuclear Information System (INIS)

    Slivko, T.A.; Smirnova, I.N.; Zimina, G.V.; Spiridonov, F.M.; Chudinova, N.N.

    2002-01-01

    The phase relationships in the systems Na 3 PO 4 - LnPO 4 (subsolidus 950 Deg C cross-sections), where Ln=Sm, Eu, Tb, Dy, Ho, Tm, Yb, Lu, were studied by X-ray analysis. Reactions of the components were deduced, formed phases were separated and identified. The Na 6 Ln 3 (PO 4 ) 5 (Ln=Dy, Ho, Tm), Na 3 Ln 2 (PO 4 ) 3 (Ln=Tm, Yb, Lu) compounds and phases of the unstable composition Na 6+x Ln 3-x/3 (PO 4 ) 5 (Ln=Yb, Lu, 0 ≤ x ≤ 1.5) were detected for the first time. In all systems the existence of the Na 3-x Ln x/3 PO 4 unstable composition phase on the basis of the high temperature modification of sodium phosphate (sp. gr. Fm3m) is established, suggesting that stabilization of this modification by rare earth ions is possible [ru

  5. El lenguaje poético

    Directory of Open Access Journals (Sweden)

    Alfonso Hanssen

    1966-03-01

    Full Text Available Me parece absurdo pretender hallar la intención poética en cualesquiera rastros de la historia, por el solo hecho de que en ellos se afirma cierta reconditez que los hace misteriosos.

  6. 241-AY/AZ waste storage tanks: Supplemental gravity load analysis. Volume 1

    International Nuclear Information System (INIS)

    Baliga, R.

    1994-01-01

    An analysis of the 241SY tanks performed by ADVENT(1994b) to resolve dome overload issues indicated that the tank can sustain the dome loads resulting from additional soil overburden depth, increased soil density, and increased concentrated load. Similar issues exist for the 241AY/AZ tanks and therefore, an interim analysis of the 241AY/AZ tanks is presented herein. The scope of this effort is to review and compare all design drawings pertaining to the 241AY and 241AZ tanks with those pertaining to the 241SY tanks; to modify the axisymmetric model of the 241SY tanks to represent the 241AY/AZ tanks; and to evaluate the effect of additional dome load on the 241AY/AZ tanks by performing a structural analysis for gravity loads (dead load + live load). ADVENTS's additional scope of work is to perform a qualitative evaluation of the 241AY/AZ tanks for seismic and thermal loadings (Vollert 1982 and Blume 1971). This qualitative evaluation does not include any detailed finite element analysis of the tanks. The following design-based gravity loading conditions are used in this interim analysis of the 241AY/AZ tanks to determine a baseline for the tank stresses or section loads

  7. Histone H2A.Z is essential for estrogen receptor signaling

    Science.gov (United States)

    Gévry, Nicolas; Hardy, Sara; Jacques, Pierre-Étienne; Laflamme, Liette; Svotelis, Amy; Robert, François; Gaudreau, Luc

    2009-01-01

    Incorporation of H2A.Z into the chromatin of inactive promoters has been shown to poise genes for their expression. Here we provide strong evidence that H2A.Z is incorporated into the promoter regions of estrogen receptor (ERα) target genes only upon gene induction, and that, in a cyclic pattern. Moreover, members of the human H2A.Z-depositing complex, p400, also follow the same gene recruitment kinetics as H2A.Z. Importantly, cellular depletion of H2A.Z or p400 leads to a severe defect in estrogen signaling, including loss of estrogen-specific cell proliferation. We find that incorporation of H2A.Z within TFF1 promoter chromatin allows nucleosomes to adopt preferential positions along the DNA translational axis. Finally, we provide evidence that H2A.Z is essential to allow estrogen-responsive enhancer function. Taken together, our results provide strong mechanistic insight into how H2A.Z regulates ERα-mediated gene expression and provide a novel link between H2A.Z–p400 and ERα-dependent gene regulation and enhancer function. PMID:19515975

  8. About some corrosion mechanisms of AZ91D magnesium alloy

    International Nuclear Information System (INIS)

    Ballerini, Gaia; Bardi, Ugo; Bignucolo, Roberto; Ceraolo, Giuseppe

    2005-01-01

    The present work is dedicated to a study of the corrosion resistance of AZ91D (91% Mg) alloy in wet environments. Three industrial alloys obtained by die-casting or sand casting were subjected to salt spray corrosion tests (ASTM-B117 standard) and immersion tests. Weight loss kinetic curves were measured. Surface analysis was performed by X-ray photoelectron diffraction (XPS). After corrosion the sand cast alloy presents a surface mainly enriched in hydroxides and carbonates while the die-cast alloy presents a surface enriched also in mixed Mg-Al oxides. The quantitative analysis of the rate Mg/Al shows an enrichment in aluminium for the die-cast alloys in comparison to the sand cast alloy

  9. High speed cutting of AZ31 magnesium alloy

    Directory of Open Access Journals (Sweden)

    Liwei Lu

    2016-06-01

    Full Text Available Using LBR-370 numerical control lathe, high speed cutting was applied to AZ31 magnesium alloy. The influence of cutting parameters on microstructure, surface roughness and machining hardening were investigated by using the methods of single factor and orthogonal experiment. The results show that the cutting parameters have an important effect on microstructure, surface roughness and machine hardening. The depth of stress layer, roughness and hardening present a declining tendency with the increase of the cutting speed and also increase with the augment of the cutting depth and feed rate. Moreover, we established a prediction model of the roughness, which has an important guidance on actual machining process of magnesium alloy.

  10. commodity: el caso del mercado internacional del azúcar

    Directory of Open Access Journals (Sweden)

    Julio César Alonso

    2013-01-01

    Full Text Available Este trabajo estudia el comportamiento estacional de los precios internacionales del azúcar transados en Nueva York y Londres. Para este caso, empleando pruebas de raíces estacionales y una muestra mensual desde enero de 1989 hasta diciembre de 2010, se encuentra la existencia de un comportamiento estacional estocástico no estacionario. Dicha conducta implica que un “verano” se puede convertir en un “invierno”, resultado que no había sido documentado previamente en estos mercados. Por otro lado, empleando dicho hallazgo, los resultados muestran que es posible construir un modelo autorregresivo de media móvil que se comporta relativamente mejor al pronosticar el precio frente a un modelo que no tiene en cuenta dicho tipo de estacionalidad.

  11. Lifetime measurement in {sup 195}Po

    Energy Technology Data Exchange (ETDEWEB)

    Grahn, T.; Page, R.D. [University of Liverpool, Department of Physics, Oliver Lodge Laboratory, Liverpool (United Kingdom); Dewald, A.; Jolie, J.; Melon, B.; Pissulla, T. [Universitaet zu Koeln, Institut fuer Kernphysik, Koeln (Germany); Greenlees, P.T.; Jakobsson, U.; Jones, P.; Julin, R.; Juutinen, S.; Ketelhut, S.; Leino, M.; Nyman, M.; Peura, P.; Rahkila, P.; Saren, J.; Scholey, C.; Sorri, J.; Uusitalo, J. [University of Jyvaeskylae, Department of Physics, P.O. Box 35, Jyvaeskylae (Finland); Kroell, T.; Kruecken, R.; Maierbeck, P. [TU Muenchen, Physik-Department E12, Garching (Germany)

    2009-03-15

    The lifetime of the 17/2{sup +} yrast state in {sup 195}Po has been measured using the recoil distance Doppler-shift technique to be {tau}=43(11) ps. The lifetime was extracted from the singles {gamma}-ray spectra obtained by using the recoil-decay tagging method. The present work provides more information of the coupling schemes, shapes and configuration mixing in neutron-deficient odd-mass Po nuclei. (orig.)

  12. The onset collectivity in {sup 196}Po

    Energy Technology Data Exchange (ETDEWEB)

    Bernstein, L A; Cizewski, J A; Jin, H Q; Henry, R G; Farris, L P [Rutgers--the State Univ., New Brunswick, NJ (United States); Khoo, T L; Carpenter, M P; Janssens, R V.F.; Lauritsen, T [Argonne National Lab., IL (United States); Bearden, I G [Purdue Univ., Lafayette, IN (United States); Ye, D [Notre Dame Univ., IN (United States)

    1992-08-01

    We have studied the in-beam {gamma}-ray spectroscopy of {sup 196}Po, which is the first Po isotope to exhibit collective vibrational structure. The onset of collective motion occurs in this isotope because of the large overlap between valence protons in h{sub 9/2} and valence neutrons in i{sub 13/2} orbitals. (author). 7 refs., 2 tabs., 3 figs.

  13. Baltiiskije teatrõ smejutsja po-russki / Ksenia Repson

    Index Scriptorium Estoniae

    Repson, Ksenia

    2006-01-01

    14. ja 15. okt. esietendub kolme vene teatri - Riia, Tallinna ja Vilniuse - koostööprojekt, lavastus "Vene naer" Fjodor Dostojevski varasemate jutustuste põhjal. Projekti lavastaja on Roman Kozak, koreograaf Alla Sigalova, kunstnik Igor Popov ja valguskunstnik Gleb Felstinski

  14. Corrosion resistance of titanium ion implanted AZ91 magnesium alloy

    International Nuclear Information System (INIS)

    Liu Chenglong; Xin Yunchang; Tian Xiubo; Zhao, J.; Chu, Paul K.

    2007-01-01

    Degradable metal alloys constitute a new class of materials for load-bearing biomedical implants. Owing to their good mechanical properties and biocompatibility, magnesium alloys are promising in degradable prosthetic implants. The objective of this study is to improve the corrosion behavior of surgical AZ91 magnesium alloy by titanium ion implantation. The surface characteristics of the ion implanted layer in the magnesium alloys are examined. The authors' results disclose that an intermixed layer is produced and the surface oxidized films are mainly composed of titanium oxide with a lesser amount of magnesium oxide. X-ray photoelectron spectroscopy reveals that the oxide has three layers. The outer layer which is 10 nm thick is mainly composed of MgO and TiO 2 with some Mg(OH) 2 . The middle layer that is 50 nm thick comprises predominantly TiO 2 and MgO with minor contributions from MgAl 2 O 4 and TiO. The third layer from the surface is rich in metallic Mg, Ti, Al, and Ti 3 Al. The effects of Ti ion implantation on the corrosion resistance and electrochemical behavior of the magnesium alloys are investigated in simulated body fluids at 37±1 deg. C using electrochemical impedance spectroscopy and open circuit potential techniques. Compared to the unimplanted AZ91 alloy, titanium ion implantation significantly shifts the open circuit potential (OCP) to a more positive potential and improves the corrosion resistance at OCP. This phenomenon can be ascribed to the more compact surface oxide film, enhanced reoxidation on the implanted surface, as well as the increased β-Mg 12 Al 17 phase

  15. The determination of 210Po in urine

    International Nuclear Information System (INIS)

    Bale, W.F.; Helmkamp, R.W.; Hrynyszyn, V.; Contreras, M.A.

    1975-01-01

    To measure 210 Po present in normal human urine a technique was developed in which a 4.5 x 11cm silver foil was shaken at room temperature for 48-hr periods in each of two successive volumes of 1.7 l. of urine acidified to 0.5N with HCl. Alpha rays were counted with an ionization chamber, coupled to a vibrating reed electrometer, and capable of measuring α-ray pulses originating on both sides of the silver foil serving as a central electrode. The background α-count was less than 2/hr. Analyses of human urine spiked with 0.29 to 0.58pCi of 210 Po, together with studies of urine from dogs carrying significant body burdens of 210 Pb, indicated that the average recovery of added 210 Po from 1.7 l. volumes of spiked human urine was 72%. If it is assumed that the same percentage of 210 Po is extracted from non-spiked urine, then the average 210 Po concentration found in 13 analyses of 2 x 1.7 l. samples from 26 different pools of fresh human urine was 0.023pCi/l. Substantial additional 210 Po was generated on short aging of the urine through radioactive decay of excreted 210 Bi. (author)

  16. Corrosion properties and corrosion evolution of as-cast AZ91 alloy with rare earth yttrium

    International Nuclear Information System (INIS)

    Luo, T.J.; Yang, Y.S.

    2011-01-01

    Highlights: → Minor addition of Y will increase the corrosion resistance of AZ91 alloy, and 0.3 wt.% Y is the optimum addition. → A film composed of Mg(OH) 2 , MgCO 3 , Al(OH) 3 and Al 2 O 3 is formed on the surface of AZ91 alloy with rare earth Y free. → The film of AZ91 alloy with 0.3 wt.% Y is mainly composed of Mg(OH) 2 and MgCO 3 without any Al(OH) 3 and Al 2 O 3 . → The relative quantity of MgCO 3 in the surface film of AZ91 + 0.3 wt.% Y is bigger than that of AZ91 alloy with Y free. → Y 2 O 3 phase is found in the surface film of alloy III, which benefits to stabilize the surface film. -- Abstract: The corrosion resistance property and the corrosion evolution of as-cast AZ91 alloy with rare earth Y addition are investigated by using immersion tests, electrochemical impedance spectroscopy (EIS), and X-ray photoelectron spectroscopy (XPS). The results show that the proper amount of Y in the alloys can improve the corrosion resistance of AZ91 alloys effectively. With the increment of Y, the corrosion rate of the modified AZ91 alloys by Y addition was markedly less than that of AZ91 alloy. The corrosion rate of AZ91 alloy with 0.3 wt.% Y was the slightest, but further addition of Y content over 0.3 wt.% make the corrosion heavier. The XPS analysis suggests that the compound film of AZ91 alloy with 0.3 wt.% Y is mainly composed of Mg(OH) 2 and MgCO 3 without any Al(OH) 3 and Al 2 O 3 , in addition, Y 2 O 3 phase is found in the compound film of AZ91 alloy with 0.3 wt.% Y, which benefits to stabilize the surface film.

  17. Project W-211 Initial Tank Retrieval Systems (ITRS) Description of Operations for 241-AZ-102

    Energy Technology Data Exchange (ETDEWEB)

    BRIGGS, S.R.

    2000-02-25

    The primary purpose of the Initial Tank Retrieval Systems (ITRS) is to provide systems for retrieval of radioactive wastes stored in underground double-shell tanks (DSTs) for transfer to alternate storage, evaporation, pretreatment or treatment, while concurrently reducing risks associated with safety watch list and other DSTs. This Description of Operation (DOO) defines the control philosophy for the waste retrieval system for Tank 241-AZ-102 (AZ-102). This DOO provides a basis for the detailed design of the Project W-211 Retrieval Control System (RCS) for AZ-102 and also establishes test criteria for the RCS.

  18. Microstructure and Aging Behavior of Nonflammable AZ91D Mg Alloy

    OpenAIRE

    Seok Hong Min; Tae Kwon Ha

    2014-01-01

    Phase equilibria of AZ91D Mg alloys for nonflammable use, containing Ca and Y, were carried out by using FactSage® and FTLite database, which revealed that solid solution treatment could be performed at temperatures from 400 to 450oC. Solid solution treatment of AZ91D Mg alloy without Ca and Y was successfully conducted at 420oC and supersaturated microstructure with all beta phase resolved into matrix was obtained. In the case of AZ91D Mg alloy with some Ca and Y; howeve...

  19. Project W-211 Initial Tank Retrieval Systems (ITRS) Description of Operations for 241-AZ-102

    International Nuclear Information System (INIS)

    BRIGGS, S.R.

    2000-01-01

    The primary purpose of the Initial Tank Retrieval Systems (ITRS) is to provide systems for retrieval of radioactive wastes stored in underground double-shell tanks (DSTs) for transfer to alternate storage, evaporation, pretreatment or treatment, while concurrently reducing risks associated with safety watch list and other DSTs. This Description of Operation (DOO) defines the control philosophy for the waste retrieval system for Tank 241-AZ-102 (AZ-102). This DOO provides a basis for the detailed design of the Project W-211 Retrieval Control System (RCS) for AZ-102 and also establishes test criteria for the RCS

  20. Upconversion luminescence of Er3+/Yb3+ doped Sr5(PO4)3OH phosphor powders

    Science.gov (United States)

    Mokoena, P. P.; Swart, H. C.; Ntwaeaborwa, O. M.

    2018-04-01

    Sr5(PO4)3OH co-doped with Er3+and Yb3+ powder phosphors were synthesized by urea combustion method. The crystal structure was analyzed using X-ray diffraction (XRD). Particle morphology was analyzed using a Jeol JSM 7800F thermal field emission scanning electron microscope (FE-SEM) and the chemical composition analysis was carried out using an Oxford Instruments AzTEC energy dispersive spectrometer (EDS) attached to the FE-SEM. Upconversion emission was measured by using a FLS980 Spectrometer equipped with a 980 nm NIR laser as the excitation source, and a photomultiplier (PMT) detector. The XRD data of the Sr5(PO4)3OH powder exhibited characteristic diffraction patterns of the hexagonal structure referenced in the standard JCPDS card number 00-033-1348. The sharp peaks revealed the formation of crystalline Sr5(PO4)3OH. The powders were made up of hexagonal nanospheres. The enhanced red emission due to the 4F9/2 → 4I15/2 transitions of Er3+ was observed and was attributed to up conversion (UC) energy transfer from Yb3+. The upconversion energy transfer mechanism from Yb3+ to Er3+ is discussed.

  1. Fremlæggelse af projekt med Epworth søvnighedsskema, opgørelse af data fra 2009-2014: "Prevalence of excessive daytime sleepiness in patients treated with orthognathic surgery"

    DEFF Research Database (Denmark)

    Linderup, Mette Werner

    Fremlæggelse af projekt med Epworth søvnighedsskema, opgørelse af data fra 2009-2014: "Prevalence of excessive daytime sleepiness in patients treated with orthognathic surgery"......Fremlæggelse af projekt med Epworth søvnighedsskema, opgørelse af data fra 2009-2014: "Prevalence of excessive daytime sleepiness in patients treated with orthognathic surgery"...

  2. Sistem Informasi Pada Perusahaan Otobus (Po) Waspada Bengkulu Berbasis Web

    OpenAIRE

    -, Khairil; Koesoemanegara, Eddy

    2011-01-01

    Web Sistem Informasi pada PO. Waspada Bengkulu berguna sebagai pusat informasi dan sarana promosi untuk mempilkan profil Perusahaan dan juga untuk menawarkan produk dan pelayanan yang ditawarkan oleh PO. Waspada. Sistem informasi ini ditujukan agar PO. Waspada lebih dikenal oleh masyarakat dan akhirnya dapat meningkatkan jumlah penumpang yang menggunakan jasa PO. Waspada Bengkulu.Web Sistem Informasi PO. Waspada Bengkulu dikembangkan menggunakan web editor Adobe Dreamweaver dengan web promgra...

  3. EnviroAtlas - Phoenix, AZ - BenMAP Results by Block Group

    Data.gov (United States)

    U.S. Environmental Protection Agency — This EnviroAtlas dataset demonstrates the effect of changes in pollution concentration on local populations in 2,434 block groups in Phoenix, AZ. The US EPA's...

  4. EnviroAtlas - Phoenix, AZ - Meter-Scale Urban Land Cover (MULC) Data (2010)

    Data.gov (United States)

    U.S. Environmental Protection Agency — The EnviroAtlas Phoenix, AZ Meter-Scale Urban Land Cover (MULC) data and map were generated from USDA NAIP (National Agricultural Imagery Program) four band (red,...

  5. Development of a Ballistic Specification for Magnesium Alloy AZ31B

    National Research Council Canada - National Science Library

    Jones, Tyrone L; DeLorme, Richard D

    2008-01-01

    The U.S. Army Research Laboratory (ARL) and Magnesium Elektron North America (MENA) have conducted a joint effort to develop and evaluate rolled plate in commercially available magnesium alloy-temper AZ31B-H24...

  6. PO2 cycling reduces diaphragm fatigue by attenuating ROS formation.

    Science.gov (United States)

    Zuo, Li; Diaz, Philip T; Chien, Michael T; Roberts, William J; Kishek, Juliana; Best, Thomas M; Wagner, Peter D

    2014-01-01

    Prolonged muscle exposure to low PO2 conditions may cause oxidative stress resulting in severe muscular injuries. We hypothesize that PO2 cycling preconditioning, which involves brief cycles of diaphragmatic muscle exposure to a low oxygen level (40 Torr) followed by a high oxygen level (550 Torr), can reduce intracellular reactive oxygen species (ROS) as well as attenuate muscle fatigue in mouse diaphragm under low PO2. Accordingly, dihydrofluorescein (a fluorescent probe) was used to monitor muscular ROS production in real time with confocal microscopy during a lower PO2 condition. In the control group with no PO2 cycling, intracellular ROS formation did not appear during the first 15 min of the low PO2 period. However, after 20 min of low PO2, ROS levels increased significantly by ∼30% compared to baseline, and this increase continued until the end of the 30 min low PO2 condition. Conversely, muscles treated with PO2 cycling showed a complete absence of enhanced fluorescence emission throughout the entire low PO2 period. Furthermore, PO2 cycling-treated diaphragm exhibited increased fatigue resistance during prolonged low PO2 period compared to control. Thus, our data suggest that PO2 cycling mitigates diaphragm fatigue during prolonged low PO2. Although the exact mechanism for this protection remains to be elucidated, it is likely that through limiting excessive ROS levels, PO2 cycling initiates ROS-related antioxidant defenses.

  7. PO2 cycling reduces diaphragm fatigue by attenuating ROS formation.

    Directory of Open Access Journals (Sweden)

    Li Zuo

    Full Text Available Prolonged muscle exposure to low PO2 conditions may cause oxidative stress resulting in severe muscular injuries. We hypothesize that PO2 cycling preconditioning, which involves brief cycles of diaphragmatic muscle exposure to a low oxygen level (40 Torr followed by a high oxygen level (550 Torr, can reduce intracellular reactive oxygen species (ROS as well as attenuate muscle fatigue in mouse diaphragm under low PO2. Accordingly, dihydrofluorescein (a fluorescent probe was used to monitor muscular ROS production in real time with confocal microscopy during a lower PO2 condition. In the control group with no PO2 cycling, intracellular ROS formation did not appear during the first 15 min of the low PO2 period. However, after 20 min of low PO2, ROS levels increased significantly by ∼30% compared to baseline, and this increase continued until the end of the 30 min low PO2 condition. Conversely, muscles treated with PO2 cycling showed a complete absence of enhanced fluorescence emission throughout the entire low PO2 period. Furthermore, PO2 cycling-treated diaphragm exhibited increased fatigue resistance during prolonged low PO2 period compared to control. Thus, our data suggest that PO2 cycling mitigates diaphragm fatigue during prolonged low PO2. Although the exact mechanism for this protection remains to be elucidated, it is likely that through limiting excessive ROS levels, PO2 cycling initiates ROS-related antioxidant defenses.

  8. Crystal structure of 4-RbHo(PO3)4, 4-RbTm(PO3)4 and 4-CsEr(PO3)4

    International Nuclear Information System (INIS)

    Maksimova, S.I.; Palkina, K.K.; Chibiskova, N.T.

    1982-01-01

    X-ray structural study of 4-RbLn(PO 3 ) 4 (Ln=Mo, Tm) and 4-CsEr(PO 3 ) 4 is carried out. The compounds are crystallized in monoclinic crystal system, sp. gr P2 1 /n. Parameters of their unit cell, atom coordinates, anisotropic heat parameters, interatomic distances and valent angles are given. 4-RbHo(PO 3 ) 4 , 4-RbTm(PO 3 ) 4 , 4-CsEr(PO 3 ) 4 are isostructural to previously studied TlNd(PO 3 ) and 4-RbNd(PO 3 ) 4 . Using as an example the structural type 4-M 1 Ln(PO 3 ) 4 it is shown that the change of the shortest distances Ln-Ln, M 1 -M 1 and M 1 -Ln, as well as of degree of polymorphous chain corrugation to a higher extent depends on rare earth atom dimensions, than on monovalent metal ion dimensions [ru

  9. α-decay properties of 190Po and the identification of 191Po

    International Nuclear Information System (INIS)

    Batchelder, J.C.; Batchelder, J.C.; Zganjar, E.F.; Toth, K.S.; Bingham, C.R.; Bingham, C.R.; Wauters, J.; Brown, L.T.; Davids, C.N.; Seweryniak, D.; Brown, L.T.; Conticchio, L.F.; Seweryniak, D.; Conticchio, L.F.; Wood, J.L.

    1997-01-01

    The α-decay properties of 190 Po were investigated through the use of a fragment mass analyzer in conjunction with a double-sided Si strip detector. The isotope was produced via the 96 Mo( 96 Mo,2n) reaction, and its α-decay energy and T 1/2 were measured as 7529(10) keV and 2.4 -0.3 +0.4 ms, respectively. The resulting reduced width is nearly identical to that of the 192,194 Po isotopes. This is believed to result from significant mixing between the ground state π(2p) and the low-lying 0 + π(4p-2h) intruder state in the Po parent. The result provides further evidence for shape coexistence in the light Po isotopes. In addition, 191 Po was unambiguously identified, and the 186 Pb α-decay branch was determined experimentally for the first time. copyright 1997 The American Physical Society

  10. Radioactive {sup 210}Po in magnesium supplements

    Energy Technology Data Exchange (ETDEWEB)

    Struminska-Parulska, Dagmara Ida [Gdansk Univ. (Poland). Environmental Chemistry and Radiochemistry Chair

    2016-08-01

    The aim of this pioneer study was to determine polonium {sup 210}Po in the most popular magnesium supplements in Poland and estimate the possible related dose assessment to the consumers. The analyzed magnesium pharmaceutics contained organic or inorganic magnesium compounds; some from natural sources. The objectives of this research were to investigate the naturally occurring {sup 210}Po activity concentrations in magnesium supplements, find the correlations between {sup 210}Po concentration in medicament and magnesium chemical form, and calculate the effective radiation dose connected to analyzed magnesium supplement consumption. The highest {sup 210}Po activity concentrations were determined in mineral tablets made from sedimentary rocks, namely dolomite - 3.84 ± 0.15 mBq g{sup -1} (sample Mg17). The highest annual radiation dose from {sup 210}Po taken with 1 tablet of magnesium supplement per day or with 400 mg of pure Mg daily would come from sample Mg17 (dolomite) - 1.35 ± 0.5 and 8.44 ± 0.33 μSv year{sup -1} respectively.

  11. Radioactive 210Po in magnesium supplements

    International Nuclear Information System (INIS)

    Struminska-Parulska, Dagmara Ida

    2016-01-01

    The aim of this pioneer study was to determine polonium 210 Po in the most popular magnesium supplements in Poland and estimate the possible related dose assessment to the consumers. The analyzed magnesium pharmaceutics contained organic or inorganic magnesium compounds; some from natural sources. The objectives of this research were to investigate the naturally occurring 210 Po activity concentrations in magnesium supplements, find the correlations between 210 Po concentration in medicament and magnesium chemical form, and calculate the effective radiation dose connected to analyzed magnesium supplement consumption. The highest 210 Po activity concentrations were determined in mineral tablets made from sedimentary rocks, namely dolomite - 3.84 ± 0.15 mBq g -1 (sample Mg17). The highest annual radiation dose from 210 Po taken with 1 tablet of magnesium supplement per day or with 400 mg of pure Mg daily would come from sample Mg17 (dolomite) - 1.35 ± 0.5 and 8.44 ± 0.33 μSv year -1 respectively.

  12. Una poética del pliegue

    Directory of Open Access Journals (Sweden)

    Ana Porrúa

    2000-11-01

    Full Text Available La producción de Juan Gelman-de Violín y otras cuestiones a Relaciones- puede inscribirse dentro de la poética sesentista caracterizada por la hegemonía de la narración y la apertura del discurso poético al resto de los discursos sociales, pero también establece una compleja relación con las vanguardias históricas. La noción de pliegue permite revisar las articulaciones de este conflicto; como espacio el pliegue separa ambas poéticas, la "coloquialista" y vanguardista, que pueden leerse en el interior del corpus propuesto en estado puro, yuxtapuestas, o bajo la forma del cruce que instala la polémica entre libros o textos de un mismo libro. La idea depliegue como rasgo operatorio permite, por su parte, revisar la relación entre ambas poéticas en el interior de un poema, focalizando la materia, el lenguaje. En este caso la poética vanguardista funciona como cuestionamiento de la linealidad del texto sesentista.

  13. Una poética del pliegue

    Directory of Open Access Journals (Sweden)

    Ana Porrúa

    2001-11-01

    Full Text Available La producción de Juan Gelman-de Violín y otras cuestiones a Relaciones- puede inscribirse dentro de la poética sesentista caracterizada por la hegemonía de la narración y la apertura del discurso poético al resto de los discursos sociales, pero también establece una compleja relación con las vanguardias históricas. La noción de pliegue permite revisar las articulaciones de este conflicto; como espacio el pliegue separa ambas poéticas, la "coloquialista" y vanguardista, que pueden leerse en el interior del corpus propuesto en estado puro, yuxtapuestas, o bajo la forma del cruce que instala la polémica entre libros o textos de un mismo libro. La idea depliegue como rasgo operatorio permite, por su parte, revisar la relación entre ambas poéticas en el interior de un poema, focalizando la materia, el lenguaje. En este caso la poética vanguardista funciona como cuestionamiento de la linealidad del texto sesentista.

  14. Operational Test Report for the 241-AZ-101 Suspended Solids Profiler

    International Nuclear Information System (INIS)

    STENKAMP, D.M.

    2000-01-01

    This document comprises the Operational Test Report for the 241-AZ-101 Suspended Solids Profiler. This document presents the results of Operational Testing of the 241-AZ-101 Suspended Solids Profiler (SSP). Testing of the SSP was performed in accordance with OTP-260-005, ''SUSPENDED SOLIDS PROFILER OPERATIONAL TEST PROCEDURE''. The objective of the testing was to verify that all equipment and components functioned as designed, following construction completion and turnover to operations

  15. Microstructure and corrosion resistance of Ce–V conversion coating on AZ31 magnesium alloy

    International Nuclear Information System (INIS)

    Jiang, Xiao; Guo, Ruiguang; Jiang, Shuqin

    2015-01-01

    Highlights: • Through simple chemical conversion process, a Ce–V conversion coating is prepared on AZ31 magnesium alloy. The coating (∼2 μm thick) has a duplex structure and is composed of Mg, Al, Ce, V and O in the outer layer and Mg, Al, V, F and O in the inner layer. • The Ce–V conversion coating can increase the E corr by 157 mV and decrease the i corr by 80 times compared to AZ31 magnesium alloy substrate. Moreover, the performance of the Ce–V conversion coating excels the chromate conversion coating on AZ31 magnesium alloy. • The EIS results of Ce–V conversion coating indicate an increase of 10× in the corrosion resistance and a delay in the corrosion process kinetics compared to uncoated AZ31 magnesium alloy in 3.5 wt.% NaCl solution. • The ball cratering is a simple and effective technique of thickness measurement for chemical conversion coating. - Abstract: A Ce–V conversion coating was developed to improve the corrosion resistance of AZ31 magnesium alloy. Scanning electronic microscope (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectrometer (XPS), grazing incidence X-ray diffraction (GIXRD) and the ball cratering test were adopted to study the morphology, chemical composition, structure and thickness of the coating. The coating has duplex structure with network and its thickness is about 2 μm. The coating contains high contents of Ce and V, which exhibits amorphous structure. Potentiodynamic polarization shows the coating can increase the corrosion potential and reduce the corrosion current density of AZ31 magnesium alloy. Moreover, the electrochemical impedance spectra exhibit the coating significantly improves the corrosion resistance of AZ31 magnesium alloy. Results indicate that the Ce–V conversion coating can provide effective protection to AZ31 magnesium alloy

  16. Microstructure and corrosion resistance of Ce–V conversion coating on AZ31 magnesium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Xiao, E-mail: xiaoxiao217@126.com; Guo, Ruiguang; Jiang, Shuqin

    2015-06-30

    Highlights: • Through simple chemical conversion process, a Ce–V conversion coating is prepared on AZ31 magnesium alloy. The coating (∼2 μm thick) has a duplex structure and is composed of Mg, Al, Ce, V and O in the outer layer and Mg, Al, V, F and O in the inner layer. • The Ce–V conversion coating can increase the E{sub corr} by 157 mV and decrease the i{sub corr} by 80 times compared to AZ31 magnesium alloy substrate. Moreover, the performance of the Ce–V conversion coating excels the chromate conversion coating on AZ31 magnesium alloy. • The EIS results of Ce–V conversion coating indicate an increase of 10× in the corrosion resistance and a delay in the corrosion process kinetics compared to uncoated AZ31 magnesium alloy in 3.5 wt.% NaCl solution. • The ball cratering is a simple and effective technique of thickness measurement for chemical conversion coating. - Abstract: A Ce–V conversion coating was developed to improve the corrosion resistance of AZ31 magnesium alloy. Scanning electronic microscope (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectrometer (XPS), grazing incidence X-ray diffraction (GIXRD) and the ball cratering test were adopted to study the morphology, chemical composition, structure and thickness of the coating. The coating has duplex structure with network and its thickness is about 2 μm. The coating contains high contents of Ce and V, which exhibits amorphous structure. Potentiodynamic polarization shows the coating can increase the corrosion potential and reduce the corrosion current density of AZ31 magnesium alloy. Moreover, the electrochemical impedance spectra exhibit the coating significantly improves the corrosion resistance of AZ31 magnesium alloy. Results indicate that the Ce–V conversion coating can provide effective protection to AZ31 magnesium alloy.

  17. Final results of double-shell tank 241-AZ-101 ultrasonic inspection

    International Nuclear Information System (INIS)

    JENSEN, C.E.

    1999-01-01

    This document presents the results and documentation of the nondestructive ultrasonic examination of tank 241-AZ-101. A tank inspection supplier was retained to provide and use an ultrasonic examination system (equipment, procedures, and inspectors) to scan a limited area of double-shell tank 241-AZ-101 primary tank wall and welds. The inspection found one reportable indication of thinning and no reportable pitting, corrosion, or cracking

  18. System Description for Tank 241-AZ-101 Waste Retrieval Data Acquisition System

    International Nuclear Information System (INIS)

    ROMERO, S.G.

    2000-01-01

    The proposed activity provides the description of the Data Acquisition System for Tank 241-AZ-101. This description is documented in HNF-5572, Tank 241-AZ-101 Waste Retrieval Data Acquisition System (DAS). This activity supports the planned mixer pump tests for Tank 241-AZ-101. Tank 241-AZ-101 has been selected for the first full-scale demonstration of a mixer pump system. The tank currently holds over 960,000 gallons of neutralized current acid waste, including approximately 12.7 inches of settling solids (sludge) at the bottom of the tank. As described in Addendum 4 of the FSAR (LMHC 2000a), two 300 HP mixer pumps with associated measurement and monitoring equipment have been installed in Tank 241-AZ-101. The purpose of the Tank 241-AZ-101 retrieval system Data Acquisition System (DAS) is to provide monitoring and data acquisition of key parameters in order to confirm the effectiveness of the mixer pumps utilized for suspending solids in the tank. The suspension of solids in Tank 241-AZ-101 is necessary for pretreatment of the neutralized current acid waste and eventual disposal as glass via the Hanford Waste Vitrification Plant. HNF-5572 provides a basic description of the Tank 241-AZ-101 retrieval system DAS, including the field instrumentation and application software. The DAS is provided to fulfill requirements for data collection and monitoring. This document is not an operations procedure or is it intended to describe the mixing operation. This USQ screening provides evaluation of HNF-5572 (Revision 1) including the changes as documented on ECN 654001. The changes include (1) add information on historical trending and data backup, (2) modify DAS I/O list in Appendix E to reflect actual conditions in the field, and (3) delete IP address in Appendix F per Lockheed Martin Services, Inc. request

  19. Acceptance Test Report for the 241-AZ-101 Ultrasonic Interface Level Analyzer

    International Nuclear Information System (INIS)

    ANDREWS, J.E.

    2000-01-01

    This document comprises the Acceptance Test Report for the 241-AZ-101 Ultrasonic Interface Level Analyzer. This document presents the results of Acceptance Testing of the 241-AZ-101 Ultrasonic Interface Level Analyzers (URSILLAs). Testing of the URSILLAs was performed in accordance with ATP-260-001, ''URSILLA Pre-installation Acceptance Test Procedure''. The objective of the testing was to verify that all equipment and components function in accordance with design specifications and original equipment manufacturer's specifications

  20. Influence of boron addition on the grain refinement and mechanical properties of AZ91 Mg alloy

    International Nuclear Information System (INIS)

    Suresh, M.; Srinivasan, A.; Ravi, K.R.; Pillai, U.T.S.; Pai, B.C.

    2009-01-01

    This article reports the effect of boron addition on the grain refinement efficiency and mechanical properties of AZ91 magnesium alloy. The results show that the addition of boron in the form of Al-4B master alloy, significantly refines the grain size of AZ91 alloy. This refinement is due to the presence of AlB 2 particles, which act as potential nucleants for Mg grains. Improved mechanical properties are obtained with the addition of boron due to the finer grains.

  1. On thermal expansion of RbD2PO4, CsH2PO4 and CsDrPO4 crystals

    International Nuclear Information System (INIS)

    Vlokh, O.G.; Shchur, Ya.I.; Klymiv, I.M.

    1994-01-01

    Thermal expansion of RbD 2 PO 4 , CsH 2 PO 4 , CsD 2 PO 4 crystals in a wide range of temperatures embracing points of phase transitions was studied. An explanation of anomalous behaviour of thermal expansion factor along directions b and c in the course of RbD 2 PO 4 transfer into intermediate phase was suggested. 10 refs., 4 figs

  2. Electrochemical corrosion behavior of AZ91D alloy in ethylene glycol

    International Nuclear Information System (INIS)

    Fekry, A.M.; Fatayerji, M.Z.

    2009-01-01

    The effect of concentration on the corrosion behavior of Mg-based alloy AZ91D was investigated in ethylene glycol-water solutions using electrochemical techniques i.e. potentiodynamic polarization, electrochemical impedance measurements (EIS) and surface examination via scanning electron microscope (SEM) technique. This can provide a basis for developing new coolants for magnesium alloy engine blocks. Corrosion behavior of AZ91D alloy by coolant is important in the automotive industry. It was found that the corrosion rate of AZ91D alloy decreased with increasing concentration of ethylene glycol. For AZ91D alloy in chloride >0.05 M or fluoride 0.05 M for fluoride containing ethylene glycol solution, some inhibition effect has been observed. The corrosion of AZ91D alloy in the blank can be effectively inhibited by addition of 0.05 mM paracetamol that reacts with AZ91D alloy and forms a protective film on the surface at this concentration as confirmed by surface examination.

  3. Effect of mechanical vibrations on the wear behavior of AZ91 Mg alloy

    Science.gov (United States)

    Chaturvedi, V.; Pandel, U.; Sharma, A.

    2018-02-01

    AZ91 Mg alloy is the most promising alloy used for structural applications. The vibration induced methods are effective and economic viable in term of mechanical properties. Sliding wear tests were performed on AZ91 Mg alloy using a pin-on- disc configuration. Wear rates were measured at 5 N and 10N at a sliding velocity of 1m/s for varied frequency within the range of 5- 25Hz and a constant amplitude of 2mm. Microstructures of worn surfaces and wear debris were characterized by field emission scanning electron microscopy (FESEM). It is observed that wear resistance of vibrated AZ91 alloy at 15Hz frequency ad 2mm amplitude was superior than cast AZ91 Mg alloy. Finer grain size and equiaxed grain shape both are important parameters for better wear resistance in vibrated AZ91 Mg alloys. FESEM analysis revealed that wear is considerably affected due to frictional heat generated by the relative motion between AZ91 Mg alloy and EN31 steel surface. No single mechanism was responsible for material loss.

  4. Effect of aluminum coatings on corrosion properties of AZ31 magnesium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Chiu Liuho; Lin Hsingan; Chen Chunchin; Yang Chihfu [Dept. of materials engineering, Tatung Univ., Taipei (Taiwan); Chang Chiahua; Wu Jenchin [Physical chemistry section, chemical systems research div., Chung-Shan Inst. of Science and Technology, Tao-Yuan (Taiwan)

    2003-07-01

    This investigation aimed to increase the corrosion resistance of an AZ31 magnesium alloy by an aluminum arc spray coating and a post-treatment consisted of hot pressing and anodizing. It was found that the aluminum arc spraying alone was incapable of protection against corrosion due to the high amount of pores present in the coating layer. In order to solve the problem, densification of the Al arc-sprayed layer was carried out by hot pressing the coated AZ31 Mg alloy plate under an appropriate range of temperature, time and pressure. After hot pressing the Al coated AZ31 Mg alloy plate exhibited a much improved corrosion resistance. A final anodizing treatment applied to the AZ31 alloy with the dense Al coating further improved its resisting to corrosion. The results showed that, by adopting the Al arc spraying, hot pressing and anodizing process, the corrosion current density of the AZ31 alloy in a 3.5 wt% NaCl solution was from 2.1 x 10{sup -6} A/cm{sup 2} (original AZ31) to 3.7 x 10{sup -7} A/cm{sup 2} (after the surface treatment), which value is close to that of an anodized aluminum plate. (orig.)

  5. Electrochemical corrosion behavior of AZ91D alloy in ethylene glycol

    Energy Technology Data Exchange (ETDEWEB)

    Fekry, A.M. [Chemistry Department, Faculty of Science, Cairo University, Giza 12613 (Egypt)], E-mail: hham4@hotmail.com; Fatayerji, M.Z. [Chemistry Department, Faculty of Science, Cairo University, Giza 12613 (Egypt)

    2009-11-01

    The effect of concentration on the corrosion behavior of Mg-based alloy AZ91D was investigated in ethylene glycol-water solutions using electrochemical techniques i.e. potentiodynamic polarization, electrochemical impedance measurements (EIS) and surface examination via scanning electron microscope (SEM) technique. This can provide a basis for developing new coolants for magnesium alloy engine blocks. Corrosion behavior of AZ91D alloy by coolant is important in the automotive industry. It was found that the corrosion rate of AZ91D alloy decreased with increasing concentration of ethylene glycol. For AZ91D alloy in chloride >0.05 M or fluoride <0.05 M containing 30% ethylene glycol solution, they are more corrosive than the blank (30% ethylene glycol-70% water). However, at concentrations <0.05 for chloride or >0.05 M for fluoride containing ethylene glycol solution, some inhibition effect has been observed. The corrosion of AZ91D alloy in the blank can be effectively inhibited by addition of 0.05 mM paracetamol that reacts with AZ91D alloy and forms a protective film on the surface at this concentration as confirmed by surface examination.

  6. Effect of rare earth elements on high cycle fatigue behavior of AZ91 alloy

    International Nuclear Information System (INIS)

    Mokhtarishirazabad, M.; Boutorabi, S.M.A.; Azadi, M.; Nikravan, M.

    2013-01-01

    This article investigates effects of adding rare earth elements (RE) into a magnesium–aluminum–zinc alloy (the AZ91 alloy) on its high cycle fatigue (HCF) behavior. For this purpose, AZ91 and AZ91+1% RE (AZE911) alloys were gravity casted in a metallic die. RE elements were added to the AZ91 alloy in the form of mischmetals. Microscopic evaluations with the scanning electron microscopy (SEM) and mechanical tests include tensile, hardness and HCF behaviors, were performed on prepared samples. Rotary bending fatigue tests were carried out at a stress ratio (R) of −1 and a frequency of 125 Hz, at the room temperature, in the air. The microscopic investigation demonstrates that the addition of 1% RE elements leads to the formation of Al 11 RE 3 intermetallic particles which is associated to the reduction of β-(Mg 17 Al 12 ) phases. Results of mechanical experiments suggest a negligible effect of adding 1% RE elements on mechanical properties of the AZ91 alloy. Curves of stress-life (S–N) shows an increase in the fatigue strength at 10 5 cycles, from 100±10 MPa to 135±10 MPa, when RE elements were added to the AZ91 alloy

  7. Effect of rare earth elements on high cycle fatigue behavior of AZ91 alloy

    Energy Technology Data Exchange (ETDEWEB)

    Mokhtarishirazabad, M., E-mail: mehdi-mokhtari@hotmail.com [School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Boutorabi, S.M.A. [School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Azadi, M.; Nikravan, M. [Irankhodro Powertrain Company (IPCO), Tehran (Iran, Islamic Republic of)

    2013-12-10

    This article investigates effects of adding rare earth elements (RE) into a magnesium–aluminum–zinc alloy (the AZ91 alloy) on its high cycle fatigue (HCF) behavior. For this purpose, AZ91 and AZ91+1% RE (AZE911) alloys were gravity casted in a metallic die. RE elements were added to the AZ91 alloy in the form of mischmetals. Microscopic evaluations with the scanning electron microscopy (SEM) and mechanical tests include tensile, hardness and HCF behaviors, were performed on prepared samples. Rotary bending fatigue tests were carried out at a stress ratio (R) of −1 and a frequency of 125 Hz, at the room temperature, in the air. The microscopic investigation demonstrates that the addition of 1% RE elements leads to the formation of Al{sub 11}RE{sub 3} intermetallic particles which is associated to the reduction of β-(Mg{sub 17}Al{sub 12}) phases. Results of mechanical experiments suggest a negligible effect of adding 1% RE elements on mechanical properties of the AZ91 alloy. Curves of stress-life (S–N) shows an increase in the fatigue strength at 10{sup 5} cycles, from 100±10 MPa to 135±10 MPa, when RE elements were added to the AZ91 alloy.

  8. Karlsruhe Research Center, Nuclear Safety Research Project (PSF). Annual report 1994; Forschungszentrum Karlsruhe, Projekt Nukleare Sicherheitsforschung. Jahrsbericht 1994

    Energy Technology Data Exchange (ETDEWEB)

    Hueper, R. [ed.

    1995-08-01

    The reactor safety R and D work of the Karlsruhe Research Centre (FZKA) has been part of the Nuclear Safety Research Projet (PSF) since 1990. The present annual report 1994 summarizes the R and D results. The research tasks are coordinated in agreement with internal and external working groups. The contributions to this report correspond to the status of early 1995. An abstract in English precedes each of them, whenever the respective article is written in German. (orig.) [Deutsch] Seit Beginn 1990 sind die F+E-Arbeiten des Forschungszentrum Karlsruhe (FZKA) zur Reaktorsicherheit im Projekt Nukleare Sicherheitsforschung (PSF) zusammengefasst. Der vorliegende Jahresbericht 1994 enthaelt Beitraege zu aktuellen Fragen der Sicherheit von Leichtwasserreaktoren und innovativen Systemen sowie der Umwandlung von minoren Aktiniden. Die konkreten Forschungsthemen und -vorhaben werden mit internen und externen Fachgremien laufend abgestimmt. An den beschriebenen Arbeiten sind die folgenden Institute und Abteilungen des FZKA beteiligt: Institut fuer Materialforschung IMF I, II, III; Institut fuer Neutronenphysik und Reaktortechnik INR; Institut fuer Angewandte Thermo- und Fluiddynamik IATF; Institut fuer Reaktorsicherheit IRS; Hauptabteilung Ingenieurtechnik HIT; Hauptabteilung Versuchstechnik HVT sowie vom KfK beauftragte externe Institutionen. Die einzelnen Beitraege stellen den Stand der Arbeiten zum Fruehjahr 1995 dar und sind entsprechend dem F+E-Programm 1994 numeriert. Den in deutscher Sprache verfassten Beitraege sind Kurzfassungen in englischer Sprache vorangestellt. (orig.)

  9. VIP Project - Visual based intelligent process control. Final report; VIP Projekt - Visuell basierte intelligente Prozessfuehrung. Fachlicher Abschlussbericht

    Energy Technology Data Exchange (ETDEWEB)

    Moreno Rueda, R.

    2001-09-01

    This BMBF project comprised the development and testing of new process control strategies involving local resolution sensors and efficient simulation models. A system comprising a video section and a spectroscopic section is presented here. Further data can be processed in the master PC if desired. By analyzing every single burner, it is possible to analyze and optimize the complete combustion process. [German] Im Rahmen des BMBF-Projektes 'Visuell basierte Intelligente Prozessfuehrung fuer grosstechnische Feuerungsprozesse' wurden neuartige Prozessfuehrungsstrategien durch die Verbindung von ortsaufloesender Sensorik und leistungsfaehige Simulationsmodellen entwickelt und erprobt. Zur Loesung der gestellten Aufgaben wurde das hier dargestellte Gesamtsystem, bestehend aus Video- und Spektroskopie entwickelt. Ueber die Darstellung hinaus koennen im Master-PC auch die Daten weiterer Lanzen/Brenner verarbeitet werden. Die Vorortschraenke wie Kuehlmedien-Steuerschrank und Elektro-Steuerschrank koennen je nach Kesselabmassen auch fuer mehr als 2 Lanzen zusammengafasst werden. Durch die Betrachtung jedes einzelnen Brenners, wird es moeglich die Feuerung ganzheitlich und zeitgleich zu erfassen, zu beurteilen und zu optimieren. (orig.)

  10. RbCuFe(PO42

    Directory of Open Access Journals (Sweden)

    Mongi Ben Amara

    2013-08-01

    Full Text Available A new iron phosphate, rubidium copper(II iron(III bis(phosphate, RbCuFe(PO42, has been synthesized as single crystals by the flux method. This compound is isostructural with KCuFe(PO42 [Badri et al. (2011, J. Solid State Chem. 184, 937–944]. Its structure is built up from Cu2O8 units of edge-sharing CuO5 polyhedra, interconnected by FeO6 octahedra through common corners to form undulating chains that extend infinitely along the [011] and [01-1] directions. The linkage of such chains is ensured by the PO4 tetraedra and the resulting three-dimensional framework forms quasi-elliptic tunnels parallel to the [101] direction in which the Rb+ cations are located.

  11. UBV Photometry at the Outside Eclipse Phase of AZ Cassiopeiae

    Directory of Open Access Journals (Sweden)

    Il-Seong Nha

    1994-06-01

    Full Text Available VV Cep-type long period spectroscopic-eclipsing binary AZ Cas has been observed for five years, 1985 Oct ~ 1990 Feb, in UBV at the Ilsan Station of Yonsei University Observatory. A total of 431 observations (U=129, B=142 and V=160 are made for 86 nights. Instrumental differential UBV and B-V light curves made with these observations cover phases nearly a half of one period. There is no appreciable light variation in V but in other two passbands a gradual decrease of the brightness is clearly noticed. The loss of light in B resulted in a reddening in △(B-V by +0.06 at phases between 0.4~0.5 as compared with that of at phase ~0.1. This intrinsic reddening arouses a question why at the orbital phase of the transit of a hot star in front of a cool M supergiant the heating of the facing hemisphere of M supergiant by the strong radiation from the B star is absent. With regard to this unusual situation we propose a hypothesis that a large amount of gas stream of low temperature ejected from the surface of M supergiant component towards the B star dominates the brightness of B star and reflection effect.

  12. CYCLIC FATIGUE RESISTANCE OF AZ91 MAGNESIUM ALLOY

    Directory of Open Access Journals (Sweden)

    Aneta Němcová

    2009-11-01

    Full Text Available The paper deals with determination of principal mechanical properties and the investigation of fatigue behaviour of AZ91 magnesium alloy. The experimental material was made by squeeze casting technique and heat treated to obtain T4 state (solution annealing, when hard, brittle Mg17Al12 intermetallic phase is dissolved. The basic mechanical properties (Young’s modulus, ultimate tensile strength, yield strength, elongation to fracture and reduction of area were determined by static tensile test. Furthermore, fatigue parameters were investigated. The S-N curve on the basis of smooth test bars tested under symmetrical push-pull loading at room temperature was evaluated. The measured data were subsequently used for fitting with suitable regression functions (Kohout & Věchet and Stromeyer for determination of the fatigue parameters. Fatigue limit sigma-c of the studied alloy for 108 cycles is approaching 50 MPa. In addition, the fracture surfaces were observed by scanning electron microscopy. The failure analysis proved that the striations were observed in fatigue crack propagation area and in the area of static fracture was observed the transgranular ductile fracture. The structure of the studied alloy in the basic state and after heat treatment was observed by light and scanning electron microscopy.

  13. AzTEC on ASTE Survey of Submillimeter Galaxies

    Science.gov (United States)

    Kohno, K.; Tamura, Y.; Hatsukade, B.; Nakanishi, K.; Iono, D.; Takata, T.; Wilson, G. W.; Yun, M. S.; Perera, T.; Austermann, J. E.; Scott, K. S.; Hughes, H.; Aretxaga, I.; Tanaka, K.; Oshima, T.; Yamaguchi, N.; Matsuo, H.; Ezawa, H.; Kawabe, R.

    2008-10-01

    We have conducted an unprecedented survey of submillimeter galaxies (SMGs) using the 144 pixel bolometer camera AzTEC mounted on the ASTE 10-m dish in Chile. We have already obtained many (>20) wide (typically 12' × 12' or wider) and deep (1 σ sensitivity of 0.5-1.0 mJy) 1.1 mm continuum images of known blank fields and over-density regions/protoclusters across a wide range of redshifts with a spatial resolution of ˜ 30''. It has resulted in the numerous (˜ a few 100, almost equivalent to the total number of the previously known SMGs) new and secure detections of SMGs. In this paper, we present initial results of two selected fields, SSA 22 and AKARI Deep Field South (ADF-S). A significnat clustering of bright SMGs toward the density peak of LAEs is found in SSA 22. We derived the differential and cumulative number counts from the detected sources in ADF-S, which probe the faintest flux densities (down to ˜1 mJy) among 1-mm blank field surveys to date.

  14. The effects of alloying elements on microstructures and mechanical properties of tungsten inert gas welded AZ80 magnesium alloys joint

    Science.gov (United States)

    Li, Hui; Zhang, Jiansheng; Ding, Rongrong

    2017-11-01

    The effects of alloying elements on the macrostructures, microstructures and tensile strength of AZ80 Mg alloy weldments were studied in the present study. The results indicate that with the decrease of Al element content of filler wire, the welding defects of seam are gradually eliminated and the β-Mg17Al12 phases at α-Mg boundaries are refined and become discontinuous, which are beneficial to the improvement of tensile strength. With AZ31 Mg alloy filler wire, the maximum tensile strength of AZ80 weldment is 220 MPa and fracture occurs at the welding seam of joint. It is experimentally proved that robust AZ80 Mg alloy joints can be obtained by tungsten inert gas (TIG) welding process with AZ31 Mg alloy filler wire. However, further study is required to improve the microstructures and reduce welding defects of joint in order to further improve the joining strength of AZ80 Mg alloy joint.

  15. A study on the relationships between corrosion properties and chemistry of thermally oxidised surface films formed on polished commercial magnesium alloys AZ31 and AZ61

    International Nuclear Information System (INIS)

    Feliu, Sebastián; Samaniego, Alejandro; Barranco, Violeta; El-Hadad, A.A.; Llorente, Irene; Serra, Carmen; Galván, J.C.

    2014-01-01

    Highlights: • Surface chemistry of heat treated magnesium alloys. • Relation between heat treatment and aluminium subsurface enrichment. • Relation between surface composition and corrosion behaviour. - Abstract: This paper studies the changes in chemical composition of the thin oxide surface films induced by heating in air at 200 °C for time intervals from 5 min to 60 min on the freshly polished commercial AZ31 and AZ61 alloys with a view to better understanding their protective properties. This thermal treatment resulted in the formation of layers enriched in metallic aluminium at the interface between the outer MgO surface films and the bulk material. A strong link was found between the degree of metallic Al enrichment in the subsurface layer (from 10 to 15 at.%) observed by XPS (X-ray photoelectron spectroscopy) in the AZ61 treated samples and the increase in protective properties observed by EIS (electrochemical impedance spectroscopy) in the immersion test in 0.6 M NaCl. Heating for 5–60 min in air at 200 °C seems to be an effective, easy to perform and inexpensive method for increasing the corrosion resistance of the AZ61 alloy by approximately two or three times

  16. A study on the relationships between corrosion properties and chemistry of thermally oxidised surface films formed on polished commercial magnesium alloys AZ31 and AZ61

    Energy Technology Data Exchange (ETDEWEB)

    Feliu, Sebastián, E-mail: sfeliu@cenim.csic.es [Centro Nacional de Investigaciones Metalúrgicas CSIC, Avda. Gregorio del Amo 8, 28040 Madrid (Spain); Samaniego, Alejandro [Centro Nacional de Investigaciones Metalúrgicas CSIC, Avda. Gregorio del Amo 8, 28040 Madrid (Spain); Barranco, Violeta [Instituto de Ciencias de Materiales de Madrid, ICMM, Consejo Superior de Investigaciones Científicas, CSIC, Sor Juana Inés de la Cruz, 3, Cantoblanco, 28049, Madrid (Spain); El-Hadad, A.A. [Physics Department, Faculty of Science, Al-Azhar University, Nasr City 11884, Cairo (Egypt); Llorente, Irene [Centro Nacional de Investigaciones Metalúrgicas CSIC, Avda. Gregorio del Amo 8, 28040 Madrid (Spain); Serra, Carmen [Servicio de Nanotecnologia y Análisis de Superficies, CACTI, Universidade de Vigo, 36310 Vigo (Spain); Galván, J.C. [Centro Nacional de Investigaciones Metalúrgicas CSIC, Avda. Gregorio del Amo 8, 28040 Madrid (Spain)

    2014-03-01

    Highlights: • Surface chemistry of heat treated magnesium alloys. • Relation between heat treatment and aluminium subsurface enrichment. • Relation between surface composition and corrosion behaviour. - Abstract: This paper studies the changes in chemical composition of the thin oxide surface films induced by heating in air at 200 °C for time intervals from 5 min to 60 min on the freshly polished commercial AZ31 and AZ61 alloys with a view to better understanding their protective properties. This thermal treatment resulted in the formation of layers enriched in metallic aluminium at the interface between the outer MgO surface films and the bulk material. A strong link was found between the degree of metallic Al enrichment in the subsurface layer (from 10 to 15 at.%) observed by XPS (X-ray photoelectron spectroscopy) in the AZ61 treated samples and the increase in protective properties observed by EIS (electrochemical impedance spectroscopy) in the immersion test in 0.6 M NaCl. Heating for 5–60 min in air at 200 °C seems to be an effective, easy to perform and inexpensive method for increasing the corrosion resistance of the AZ61 alloy by approximately two or three times.

  17. A study on the relationships between corrosion properties and chemistry of thermally oxidised surface films formed on polished commercial magnesium alloys AZ31 and AZ61

    Science.gov (United States)

    Feliu, Sebastián; Samaniego, Alejandro; Barranco, Violeta; El-Hadad, A. A.; Llorente, Irene; Serra, Carmen; Galván, J. C.

    2014-03-01

    This paper studies the changes in chemical composition of the thin oxide surface films induced by heating in air at 200 °C for time intervals from 5 min to 60 min on the freshly polished commercial AZ31 and AZ61 alloys with a view to better understanding their protective properties. This thermal treatment resulted in the formation of layers enriched in metallic aluminium at the interface between the outer MgO surface films and the bulk material. A strong link was found between the degree of metallic Al enrichment in the subsurface layer (from 10 to 15 at.%) observed by XPS (X-ray photoelectron spectroscopy) in the AZ61 treated samples and the increase in protective properties observed by EIS (electrochemical impedance spectroscopy) in the immersion test in 0.6 M NaCl. Heating for 5-60 min in air at 200 °C seems to be an effective, easy to perform and inexpensive method for increasing the corrosion resistance of the AZ61 alloy by approximately two or three times.

  18. Electronic Properties of LiFePO4 and Li doped LiFePO4

    International Nuclear Information System (INIS)

    Zhuang, G.V.; Allen, J.L.; Ross, P.N.; Guo, J.-H.; Jow, T.R.

    2005-01-01

    The potential use of different iron phosphates as cathode materials in lithium-ion batteries has recently been investigated.1 One of the promising candidates is LiFePO4. This compound has several advantages in comparison to the state-of-the-art cathode material in commercial rechargeable lithium batteries. Firstly, it has a high theoretical capacity (170 mAh/g). Secondly, it occurs as mineral triphylite in nature and is inexpensive, thermally stable, non-toxic and non-hygroscopic. However, its low electronic conductivity (∼10-9 S/cm) results in low power capability. There has been intense worldwide research activity to find methods to increase the electronic conductivity of LiFePO4, including supervalent ion doping,2 introducing non-carbonaceous network conduction3 and carbon coating, and the optimization of the carbon coating on LiFePO4 particle surfaces.4 Recently, the Li doped LiFePO4 (Li1+xFe1-xPO4) synthesized at ARL has yield electronic conductivity increase up to 106.5 We studied electronic structure of LiFePO4 and Li doped LiFePO4 by synchrotron based soft X-ray emission (XES) and X-ray absorption (XAS) spectroscopies. XAS probes the unoccupied partial density of states, while XES the occupied partial density of states. By combining XAS and XES measurements, we obtained information on band gap and orbital character of both LiFePO4 and Li doped LiFePO4. The occupied and unoccupied oxygen partial density of states (DOS) of LiFePO4 and 5 percent Li doped LiFePO4 are presented in Fig. 1. Our experimental results clearly indicate that LiFePO4 has wideband gap (∼ 4 eV). This value is much larger than what is predicted by DFT calculation. For 5 percent Li doped LiFePO4, a new doping state was created closer to the Fermi level, imparting p-type conductivity, consistent with thermopower measurement. Such observation substantiates the suggestion that high electronic conductivity in Li1.05Fe0.95 PO4 is due to available number of charge carriers in the material

  19. Radiocesium in wheat of the Po plain

    International Nuclear Information System (INIS)

    Dominici, G.; Malvicini, A.

    1988-01-01

    The Cs-137 measurements of many wheat samples, which was cultivated in Po plain during 1986 and 1987, are reported. A relationship is also shown between the quantity of Cs-137, which is contained in total fall-out, and that in the wheat by direct deposition

  20. doped LiMgPO4 phosphor

    Indian Academy of Sciences (India)

    attention because of their remarkable luminescence proper- ties and .... Figure 1. (a) X-ray diffraction patterns of LiMgPO4:Tb3+ phosphor and (b) standard data. ICDD file. .... ground signal which affects the signal to noise ratio [17]. MDD was ...

  1. Study on fused/cast AZS refractories for deployment in vitrification of radioactive waste effluents

    Energy Technology Data Exchange (ETDEWEB)

    Sengupta, Pranesh, E-mail: praneshsengupta@gmail.com [Materials Science Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Mishra, R.K.; Soudamini, N. [Waste Management Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Sen, D.; Mazumder, S. [Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Kaushik, C.P. [Waste Management Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Ajithkumar, T.G. [Central NMR Facility, National Chemical Laboratory, Pune 411 008 (India); Banerjee, K. [Nuclear Recycle Group, Mumbai 400 085 (India)

    2015-12-15

    ‘Fused/cast Al{sub 2}O{sub 3}–ZrO{sub 2}–SiO{sub 2} (FC-AZS)’ is being considered as ‘glass contact refractory’ within ceramic melters, to be used for nuclear waste immobilization. Microstructural analyses reveal random distributions of baddeleyite (ZrO{sub 2}) within aluminosilicate (Al{sub 2}SiO{sub 5}) matrix. {sup 27}Al and {sup 29}Si NMR data suggest that within aluminosilicate matrix Al occurs in both 4- and 6-fold co-ordinations whereas Si prefers a 4-fold environment. Polydispersity of pores has been studied with small-angle neutron scattering (SANS) technique. Corrosion rates of FC-AZS within 6 M HNO{sub 3}, simulated wastes (500 h exposure), and borosilicate melt (975 °C, 800 h exposure) are found to be 0.38 × 10{sup 3} μmy{sup −1}, 0.13 × 10{sup 3} μmy{sup −1} and 4.75 × 10{sup 3} μmy{sup −1} respectively. A comparison of chemical interaction data clearly suggests that FC-AZS exhibits better chemical durability than AZC refractory (Al{sub 2}O{sub 3}–ZrO{sub 2}–Cr{sub 2}O{sub 3}, also used for similar purpose). Thermal cycling studies indicate that FC-AZS retains structural integrity (including compressive strength and density) even up to 20 cycles. - Highlights: • Vitrification of nuclear waste using AZS refractory within ceramic melter. • Microstructure of AZS refractory. • Interaction of AZS with simulated high level waste and glass.

  2. Rapid coating of AZ31 magnesium alloy with calcium deficient hydroxyapatite using microwave energy

    International Nuclear Information System (INIS)

    Ren, Yufu; Zhou, Huan; Nabiyouni, Maryam; Bhaduri, Sarit B.

    2015-01-01

    Due to their unique biodegradability, magnesium alloys have been recognized as suitable metallic implant materials for degradable bone implants and bioresorbable cardiovascular stents. However, the extremely high degradation rate of magnesium alloys in physiological environment has restricted its practical application. This paper reports the use of a novel microwave assisted coating technology to improve the in vitro corrosion resistance and biocompatibility of Mg alloy AZ31. Results indicate that a dense calcium deficient hydroxyapatite (CDHA) layer was uniformly coated on a AZ31 substrate in less than 10 min. Weight loss measurement and SEM were used to evaluate corrosion behaviors in vitro of coated samples and of non-coated samples. It was seen that CDHA coatings remarkably reduced the mass loss of AZ31 alloy after 7 days of immersion in SBF. In addition, the prompt precipitation of bone-like apatite layer on the sample surface during immersion demonstrated a good bioactivity of the CDHA coatings. Proliferation of osteoblast cells was promoted in 5 days of incubation, which indicated that the CDHA coatings could improve the cytocompatibility of the AZ31 alloy. All the results suggest that the CDHA coatings, serving as a protective layer, can enhance the corrosion resistance and biological response of magnesium alloys. Furthermore, this microwave assisted coating technology could be a promising method for rapid surface modification of biomedical materials. - Highlights: • A microwave assisted coating process for biodegradable Mg alloy. • CDHA coatings were successfully developed on AZ31 alloy in minutes. • The as-deposited CDHA coatings significantly reduced the degradation rate of AZ31 alloy. • The CDHA coated AZ31 alloy showed good bioactivity and biocompatibility in vitro. • The microwave assisted coating process can be used as rapid surface modification for bioimplants

  3. Rapid coating of AZ31 magnesium alloy with calcium deficient hydroxyapatite using microwave energy

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Yufu, E-mail: Yufu.Ren@rockets.utoledo.edu [Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH (United States); Zhou, Huan [Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH (United States); Institute of Biomedical Engineering and Health Sciences, Changzhou University, Changzhou, Jiangsu (China); Nabiyouni, Maryam [Department of Bioengineering, The University of Toledo, Toledo, OH (United States); Bhaduri, Sarit B. [Department of Mechanical, Industrial and Manufacturing Engineering, The University of Toledo, Toledo, OH (United States); Division of Dentistry, The University of Toledo, Toledo, OH (United States)

    2015-04-01

    Due to their unique biodegradability, magnesium alloys have been recognized as suitable metallic implant materials for degradable bone implants and bioresorbable cardiovascular stents. However, the extremely high degradation rate of magnesium alloys in physiological environment has restricted its practical application. This paper reports the use of a novel microwave assisted coating technology to improve the in vitro corrosion resistance and biocompatibility of Mg alloy AZ31. Results indicate that a dense calcium deficient hydroxyapatite (CDHA) layer was uniformly coated on a AZ31 substrate in less than 10 min. Weight loss measurement and SEM were used to evaluate corrosion behaviors in vitro of coated samples and of non-coated samples. It was seen that CDHA coatings remarkably reduced the mass loss of AZ31 alloy after 7 days of immersion in SBF. In addition, the prompt precipitation of bone-like apatite layer on the sample surface during immersion demonstrated a good bioactivity of the CDHA coatings. Proliferation of osteoblast cells was promoted in 5 days of incubation, which indicated that the CDHA coatings could improve the cytocompatibility of the AZ31 alloy. All the results suggest that the CDHA coatings, serving as a protective layer, can enhance the corrosion resistance and biological response of magnesium alloys. Furthermore, this microwave assisted coating technology could be a promising method for rapid surface modification of biomedical materials. - Highlights: • A microwave assisted coating process for biodegradable Mg alloy. • CDHA coatings were successfully developed on AZ31 alloy in minutes. • The as-deposited CDHA coatings significantly reduced the degradation rate of AZ31 alloy. • The CDHA coated AZ31 alloy showed good bioactivity and biocompatibility in vitro. • The microwave assisted coating process can be used as rapid surface modification for bioimplants.

  4. The system La(PO3)3-Ca(PO3)2-P2O5

    International Nuclear Information System (INIS)

    Jungowska, W.; Znamierowska, T.

    1993-01-01

    Ternary system La(PO 3 ) 3 -Ca(PO 3 ) 2 -P 2 O 5 has been studied by means of thermal and roentgenography analysis. The existence of single intermediate compound CaLa(PO 3 ) 5 has been observed. The phase diagrams for the ternary system as well as for two binary systems La(PO 3 ) 3 -Ca(PO 3 ) 2 and CaLa(PO 3 ) 5 -LaP 5 O 11 have been shown. 7 refs, 3 figs

  5. Effect of the chemistry and structure of the native oxide surface film on the corrosion properties of commercial AZ31 and AZ61 alloys

    Energy Technology Data Exchange (ETDEWEB)

    Feliu, Sebastian, E-mail: sfeliu@cenim.csic.es [Centro Nacional de Investigaciones Metalurgicas CSIC, Avda. Gregorio del Amo 8, 28040 Madrid (Spain); Maffiotte, C. [CIEMAT-DT edificio 30, Avda. Complutense, 22, 28040 Madrid (Spain); Samaniego, A.; Galvan, Juan Carlos [Centro Nacional de Investigaciones Metalurgicas CSIC, Avda. Gregorio del Amo 8, 28040 Madrid (Spain); Barranco, Violeta [Centro Nacional de Investigaciones Metalurgicas CSIC, Avda. Gregorio del Amo 8, 28040 Madrid (Spain); Instituto de Ciencias de Materiales de Madrid, ICMM, Consejo Superior de Investigaciones Cientificas, CSIC, Sor Juana Ines de la Cruz, 3, Cantoblanco, 28049, Madrid (Spain)

    2011-08-01

    The purpose of this study has been to advance in knowledge of the chemical composition, structure and thickness of the thin native oxide film formed spontaneously in contact with the laboratory atmosphere on the surface of freshly polished commercial AZ31 and AZ61 alloys with a view to furthering the understanding of protection mechanisms. For comparative purposes, and to more fully describe the behaviour of the native oxide film, the external oxide films formed as a result of the manufacturing process (as-received condition) have been characterised. The technique applied in this research to study the thin oxide films (thickness of just a few nanometres) present on the surface of the alloys has basically been XPS (X-ray photoelectron spectroscopy) in combination with ion sputtering. Corrosion properties of the alloys were studied in 0.6 M NaCl by measuring charge transfer resistance values, which are deduced from EIS (electrochemical impedance spectroscopy) measurements after 1 h of exposure. Alloy AZ61 generally showed better corrosion resistance than AZ31, and the freshly polished alloys showed better corrosion resistance than the alloys in as-received condition. This is attributed to a combination of (1) higher thickness of the native oxide film on the AZ61 alloy and (2) greater uniformity of the oxide film in the polished condition. The formation of an additional oxide layer composed by a mixture of spinel (MgAl{sub 2}O{sub 4}) and MgO seems to diminish the protective properties of the passive layer on the surface of the alloys in as-received condition.

  6. Effect of the chemistry and structure of the native oxide surface film on the corrosion properties of commercial AZ31 and AZ61 alloys

    International Nuclear Information System (INIS)

    Feliu, Sebastian; Maffiotte, C.; Samaniego, A.; Galvan, Juan Carlos; Barranco, Violeta

    2011-01-01

    The purpose of this study has been to advance in knowledge of the chemical composition, structure and thickness of the thin native oxide film formed spontaneously in contact with the laboratory atmosphere on the surface of freshly polished commercial AZ31 and AZ61 alloys with a view to furthering the understanding of protection mechanisms. For comparative purposes, and to more fully describe the behaviour of the native oxide film, the external oxide films formed as a result of the manufacturing process (as-received condition) have been characterised. The technique applied in this research to study the thin oxide films (thickness of just a few nanometres) present on the surface of the alloys has basically been XPS (X-ray photoelectron spectroscopy) in combination with ion sputtering. Corrosion properties of the alloys were studied in 0.6 M NaCl by measuring charge transfer resistance values, which are deduced from EIS (electrochemical impedance spectroscopy) measurements after 1 h of exposure. Alloy AZ61 generally showed better corrosion resistance than AZ31, and the freshly polished alloys showed better corrosion resistance than the alloys in as-received condition. This is attributed to a combination of (1) higher thickness of the native oxide film on the AZ61 alloy and (2) greater uniformity of the oxide film in the polished condition. The formation of an additional oxide layer composed by a mixture of spinel (MgAl 2 O 4 ) and MgO seems to diminish the protective properties of the passive layer on the surface of the alloys in as-received condition.

  7. Le corps poétique ou la poétique du corps

    Directory of Open Access Journals (Sweden)

    Yvonne Goga

    2007-05-01

    Full Text Available Les réflexions sur la poésie de Valéry sont illustrées dans deux volumes : Album de vers anciens et Charmes. Parmi les images les plus représentatives est celle du corps de la femme. Par l’analyse des images sur le corps de la femme, le but de notre étude est celui de souligner l’un des principes de la poétique de Valéry : la relation entre le monde extérieur, le corps et l’esprit, pour créer le poème et le poète.

  8. Luminescent properties of LuPO4-Pr and LuPO4-Eu nanoparticles

    International Nuclear Information System (INIS)

    Vistovskyy, V.; Malyi, T.; Vas’kiv, A.; Chylii, M.; Mitina, N.; Zaichenko, A.; Gektin, A.; Voloshinovskii, A.

    2016-01-01

    Spectral-luminescence parameters of LuPO 4 -Eu and LuPO 4 -Pr nanoparticles of different sizes are studied upon excitation by the synchrotron radiation with photon energies 4–40 eV. Influence of the nanoparticle size on Eu 3+ and Pr 3+ impurity luminescence is analyzed for intracenter and recombination excitation. It is shown that the luminescence intensity of impurities in the case of recombination excitation significantly stronger decreases with decreasing of nanoparticle size compared to intracenter excitation. This feature is explained by the influence of thermalization length to nanoparticle size ratio on the recombination luminescence. Electron recombination luminescence inherent for LuPO 4 -Eu nanoparticles shows a weaker dependence on the nanoparticle size than the hole one in LuPO 4 -Pr nanoparticles. The difference between energy states of praseodymium impurity ions in nanoparticles of different sizes is revealed.

  9. Fatigue life of the casting-magnesium alloy AZ91

    International Nuclear Information System (INIS)

    Eisenmeier, G.; Mughrabi, H.; Holzwarth, B.; Hoeppel, H.W.; Ding, H.Z.

    2000-01-01

    The cyclic deformation behaviour of the die-casting magnesium alloy AZ91 was investigated at constant total strain amplitudes between 1.4 x 10 -3 and 2 x 10 -2 at room temperature (20 C) and at 130 C. At low total strain amplitudes, a weak cyclic softening at the beginning of the fatigue tests is followed by cyclic hardening, whereas at high total strain amplitudes a strong cyclic hardening occurs throughout. The fatigue lives at 130 C are slightly longer at high strain amplitudes but shorter at low strain amplitudes than at room temperature. The fatigue life data for both temperatures can be described well by the laws of Manson-Coffin and Basquin. The microstructural investigations performed show the strong influence of several microstructural features on the initiation and propagation of fatigue cracks. In order to understand the fatigue crack propagation behaviour, fatigue tests were interrupted at certain numbers of cycles in order to make replicas of the surface of the samples. It could be verified that crack propagation occurs mainly by the coalescence of smaller cracks. Furthermore, unloading tests, performed within a closed cycle, were carried out in order to capture the changes of stiffness (compliance) during a closed cycle with the aim to ascertain the damage evolution occurring during the fatigue tests and to determine the stresses at which the cracks open and close. Finally, two-step fatigue tests were carried out with the objective to quantify deviations from the linear damage rule (LDR) of Palmgren and Miner. The results obtained in this study will be used to formulate a microstructurally based life-prediction concept for single-step as well as for two-step fatigue loading. (orig.)

  10. Dose rate analysis for Tank 101 AZ (Project W151)

    International Nuclear Information System (INIS)

    Schwarz, R.A.; Hillesland, K.E.; Carter, L.L.

    1994-11-01

    This document describes the expected dose rates for modification to tank 101 AZ including modifications to the steam coil, mixer pump, and temperature probes. The thrust of the effort is to determine dose rates from: modification of a steam coil and caisson; the installation of mixer pumps; the installation of temperature probes; and estimates of dose rates that will be encountered while making these changes. Because the dose rates for all of these configurations depend upon the photon source within the supernate and sludge, comparisons were also made between measured dose rates within a drywell and the corresponding calculated dose rates. The calculational tool used is a Monte Carlo (MCNP 2 ) code since complicated three dimensional geometries are involved. A summary of the most important results of the entire study is given in Section 2. The basic calculational geometry model of the tank is discussed in Section 3, along with a tabulation of the photon sources that were used within the supernate and the sludge, and a discussion of uncertainties. The calculated dose rates around the steam coil and caisson before and after modification are discussed in Section 4. The configuration for the installation of the mixer pumps and the resulting dose rates are given in Section 5. The predicted changes in dose rates due to a possible dilution of the supernate source are given in Section 6. The calculational configuration used to model the installation of temperature probes and the resulting predicted dose rates are discussed in Section 7. Finally, comparisons of measured to calculated dose rates within a drywell are summarized in Section 8. Extended discussions of calculational models and Monte Carlo optimization techniques used are included in Appendix A

  11. Long-term corrosion inhibition mechanism of microarc oxidation coated AZ31 Mg alloys for biomedical applications

    International Nuclear Information System (INIS)

    Gu, Yanhong; Bandopadhyay, Sukumar; Chen, Cheng-fu; Ning, Chengyun; Guo, Yuanjun

    2013-01-01

    Highlights: ► The corrosion behavior is significantly affected by the long-term immersion. ► The degradation is inhibited due to the corrosion product layer. ► The corrosion resistance is enhanced by optimized MAO electrolyte concentrations. ► The corrosion inhibition mechanism is presented by a Flash animation. - Abstract: This paper addresses the long-term corrosion behavior of microarc oxidation coated Mg alloys immersed in simulated body fluid for 28 days. The coatings on AZ31 Mg alloys were produced in the electrolyte of sodium phosphate (Na 3 PO 4 ) at the concentration of 20 g/L, 30 g/L and 40 g/L, respectively. Scanning electron microscope (SEM) and optical micrograph were used to observe the microstructure of the samples before and after corrosion. The composition of the MAO coating and corrosion products were determined by X-Ray Diffraction (XRD). Corrosion product identification showed that hydroxyapatite (HA) was formed on the surface of the corroded samples. The ratio of Ca/P in HA determined by the X-ray Fluorescence (XRF) technique showed that HA is an acceptable biocompatible implant material. The potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were employed to characterize the corrosion rate and the electrochemical impedance. The corrosion resistance of the coated Mg alloys can be enhanced by optimizing the electrolyte concentrations for fabricating samples, and is enhanced after immersing the coated samples in simulated body fluid for more than 14 days. The enhanced corrosion resistance after long-term immersion is attributed to a corrosion product layer formed on the sample surface. The inhibition mechanism of the corrosion process is discussed and presented with an animation

  12. Influence of cerium on passivity behavior of wrought AZ91 alloy

    International Nuclear Information System (INIS)

    Wang Henan; Li Ying; Wang Fuhui

    2008-01-01

    In this paper, more focus had been put on the passivity behavior of wrought AZ91 alloy with 1.5 mass% Ce. The passive current density of wrought AZ91 alloy increased with addition of Ce and the passive film became unstable. Structures and compositions of the passive films formed on wrought AZ91 alloy without and with Ce in 0.01 M NaOH aqueous solution were analyzed by potentiostatic polarization, potentiostatic-galvanostatic (P-G) transient technique and X-ray photoelectron spectroscopy (XPS). The results showed that Ce only accumulated in the inner layer of passive film in the form of CeO 2 . Further analysis revealed that there were two main effects of Ce on the passive process of wrought AZ91 alloy: first, the existence of CeO 2 in inner layer of passive film made mass transport through the passive film follow tangent hyperbolic (T) impedance instead of Warburg impedance (W); second, donor concentration (N d ) of the passive film increased by a factor 10 when 1.5 mass% Ce existed in wrought AZ91 alloy, which led to the higher passivity current density

  13. Informatische Pädagogik - pädagogische Informatik. Beispiele für fächerverbindende Projekte mit medienerzieherischem Anspruch

    Directory of Open Access Journals (Sweden)

    Michael Weigend

    2001-12-01

    Full Text Available Mit der Profilbildung der Schulen und mit der Entwicklung individueller schulinterner Lehrpläne, sind in zunehmendem Masse Kopplung von Oberstufenkursen und fächerverbindenes Unterrichten gefragt. In diesem Beitrag werden Projekte vorgestellt, die eine Kooperation der Fächer Informatik und Erziehungswissenschaft voraussetzen. Inhaltlich stellen die Neuen Medien den Bezugspunkt dar: multimediale und zum Teil interaktive Anwendungen, wie digitale Animationen, Spiele und Bildschirm-Experimente können von den Schüler/innen selbst entwickelt und als Medien eingesetzt werden, wobei technische und gesellschaftliche Fragen der Mediengestaltung und der Mediennutzung zu reflektieren sind.

  14. Results of the project 'combustion modelling' (BKM II); Ergebnisse des Projekts 'Brennkammermodellierung' (BKM II)

    Energy Technology Data Exchange (ETDEWEB)

    Noll, B.; Rachner, M.; Frank, P.; Schmitz, G.; Geigle, K.P.; Meier, W.; Schuetz, H.; Aigner, M. [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Stuttgart (Germany). Inst. fuer Verbrennungstechnik; Kessler, R. [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Goettingen (Germany). Inst. fuer Aerodynamik und Stroemungstechnik; Lehmann, B. [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Koeln (Germany). Inst. fuer Antriebstechnik; Forkert, T. [DLR Deutsches Zentrum fuer Luft- und Raumfahrt e.V., Koeln (Germany). Simulation und Softwaretechnik

    2002-07-01

    In the year 1996 the spheres of competence of several DLR-Institutes working in the areas of fluid dynamics, reaction kinetics, combustion, numerical methods and laser measuring techniques have been brought together while contributing to the internal DLR project 'combustion chamber modelling (BKM)', in order to proceed with the computational simulation of combustion processes in combustion chambers of gas turbines. The main issue was the development of a research code for numerical simulation of fluid flow in real combustion chambers. Here the development of computational models of physical and chemical processes was emphasized, among other processes the formation of soot was treated. Moreover, a worldwide outstanding database of measured data for the purpose of code validation has been created within the framework of the BKM project using the laboratory facilities of the DLR, which are in Germany unique for the experimental investigation of the various processes in combustion chambers of gas turbines. The project BKM is part of the specific DLR-programme 'energy'. With the successful completion of the first phase of the project in 1998, a second project phase of three years (BKM II) has been launched at the beginning of 1999. Here the work of the first phase continued and new topics were tackled. The second phase of the project was partly founded by the DLR-programme 'aeronautics'. (orig.) [German] Im Jahr 1996 wurden die Faehigkeiten mehrerer DLR-Institute auf den Gebieten Stroemungsmechanik, Reaktionskinetik, Verbrennung sowie Numerische Verfahren und Laser-Messverfahren in dem DLR-internen Projekt 'Brennkammermodellierung' (BKM) zusammengefuehrt, um die rechnerische Simulation der Verbrennungsvorgaenge in Gasturbinen-Brennkammern voranzutreiben. Dabei war die Entwicklung eines Forschungscodes zur numerischen Simulation von realen Brennkammerstroemungen das vorrangige Ziel der Arbeiten. Ein besonderes Schwergewicht lag

  15. Korozní odolnost tvářených hořčíkových slitin AZ31 a AZ61 v Hankovì roztoku

    Czech Academy of Sciences Publication Activity Database

    Tkacz, J.; Slouková, K.; Minda, J.; Drábiková, J.; Fintová, Stanislava; Doležal, P.; Wasserbauer, J.

    2016-01-01

    Roč. 60, č. 4 (2016), s. 101-106 ISSN 1804-1213 Institutional support: RVO:68081723 Keywords : corrosion * AZ31 magnesium alloy * AZ61 magnesium alloy Subject RIV: JK - Corrosion ; Surface Treatment of Materials https://www.degruyter.com/view/j/kom.2016.60.issue-4/kom-2016-0016/kom-2016-0016.xml?format=INT

  16. Effect of ultrasonic cold forging technology as the pretreatment on the corrosion resistance of MAO Ca/P coating on AZ31B Mg alloy

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Lingling, E-mail: daisy_chenlingling@163.com [College of Mechanical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617 (China); College of Mechanical and Electrical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Gu, Yanhong, E-mail: gu_yanhong@163.com [College of Mechanical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617 (China); Liu, Lu, E-mail: liulu@bipt.edu.cn [College of Mechanical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617 (China); Liu, Shujing, E-mail: liushujing@bipt.edu.cn [College of Mechanical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617 (China); Hou, Binbin, E-mail: sohu19880815@126.com [School of Engineering and Technology, China University of Geosciences, Beijing 100083 (China); Liu, Qi, E-mail: 13521196884@sina.cn [College of Mechanical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617 (China); Ding, Haiyang, E-mail: dinghaiyang@bipt.edu.cn [College of Mechanical Engineering, Beijing Institute of Petrochemical Technology, Beijing 102617 (China)

    2015-06-25

    Highlights: • Ultrasonic cold forging technology was used as the pretreatment for MAO coating. • Nano layer with the grain size of 30–80 nm was formed on the UCFT treated surface. • Calcium phosphate contained coating was obtained by MAO process. • The remained nano layer underlying MAO coating could impact the corrosion resistance greatly. - Abstract: A calcium phosphate contained (Ca/P) coating was obtained on AZ31B Mg alloy by micro-arc oxidation (MAO) process under the pretreatment of ultrasonic cold forging technology (UCFT). The surface nanograins were introduced after UCFT pretreatment on AZ31B Mg alloy. Optical microscope (OM) was employed to observe the microstructures of the untreated and UCFT treated samples. Transmission electron microscopy (TEM) and atomic force microscope (AFM) were employed to observe the microstructures of nanograins and the surface roughness of the UCFT treated Mg alloys. The grain size of the UCFT treated Mg alloy is 48.67 nm and the surface roughness is 17.03 nm. The microstructures and the phase compositions of MAO samples were observed and analyzed by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. The XRD results show that the coating include Ca/P phase, including hydroxyapatite (Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}), HA), tertiary calcium phosphate (Ca{sub 3}(PO{sub 4}){sub 2}, TCP) and calcium phosphate dehydrate (CaHPO{sub 4}⋅2H{sub 2}O, DCPD). The hardness of the samples was measured by the micro-hardness tester under the loads of 10 g, 25 g and 50 g. 3D topographies of hardness indenter were characterized by 3D profiler. The immersion tests and potentiodynamic polarization tests were used to evaluate the weight loss rate and corrosion current density in simulated body fluid (SBF). The results show that the corrosion resistance of Ca/P MAO coating on Mg alloy was improved greatly by the pretreatment of UCFT.

  17. Microstructures of friction welded joints of AZ31 to AM60 magnesium alloys

    Energy Technology Data Exchange (ETDEWEB)

    Fukumoto, S.; Ono, T.; Tanaka, S.; Tsubakino, H. [Graduate School of Engineering, Himeji Inst. of Tech., Hyogo (Japan); Tomita, T.; Aritoshi, M. [Hyogo Prefectural Inst. of Industrial Research, Kobe, Hyogo (Japan); Okita, K. [Inst. of Industrial Research, Osaka Sangyo Univ., Osaka (Japan)

    2003-07-01

    AZ31 magnesium alloy was friction-welded to AM60 and the microstructures and the friction welding process were studied. The microstructures changed near the weld interface. The AZ31 was refined to a grain size of several {mu}m near the weld interface. The nucleation occurred in the shear bands that were introduced during the welding process. On the other hand, the eutectic structure was deformed and the lamellar structure which was composed of {alpha}-Mg and Mg{sub 17}Al{sub 12} was formed near the weld interface in AM60 alloy. In the friction process, the adhesion and peel off occurred alternately between AZ31 and AM60. Eventually, bonding was completed during upset process. (orig.)

  18. Diffusion Bonding and Post-Weld Heat Treatment of Extruded AZ91 Magnesium Alloys

    Directory of Open Access Journals (Sweden)

    Fei LIN

    2015-11-01

    Full Text Available The grain size of as-extruded AZ91 magnesium alloys was refined to 12.31 μm from 21.41 μm by recrystallization annealing. The vacuum diffusion welding of as-annealed AZ91 magnesium alloys was researched. The results showed that the maximum shear strength of joints reached 64.70 MPa in the situation of 10 MPa bonding pressure, 18 Pa vacuum degree, 470 °C bonding temperature and 90 min bonding time; both bonding temperature and time are the main influence factors on as-extruded AZ91 magnesium alloys diffusion welding. Then the diffusion welded specimens were annealed, and the shear strength of joints was further improved to 76.93 MPa.DOI: http://dx.doi.org/10.5755/j01.ms.21.4.9699

  19. Influence of inorganic acid pickling on the corrosion resistance of magnesium alloy AZ31 sheet

    DEFF Research Database (Denmark)

    Nwaogu, Ugochukwu Chibuzoh; Blawert, C.; Scharnagl, N.

    2009-01-01

    Surface contaminants as a result of thermo-mechanical processing of magnesium alloys, e.g. sheet rolling, can have a negative effect on the corrosion resistance of magnesium alloys. Especially contaminants such as Fe, Ni and Cu, left on the surface of magnesium alloys result in the formation...... of micro-galvanic couples and can therefore increase corrosion attack on these alloys. Due to this influence they should be removed to obtain good corrosion resistance. In this study, the effect of inorganic acid pickling on the corrosion behaviour of a commercial AZ31 magnesium alloy sheet...... cleaning the AZ31 sheet. However, to obtain reasonable corrosion resistance at least 5 mu m of the surface of AZ31 magnesium alloy sheet have to be removed....

  20. Biodegradable behaviors of AZ31 magnesium alloy in simulated body fluid

    International Nuclear Information System (INIS)

    Song Yingwei; Shan Dayong; Chen Rongshi; Zhang Fan; Han Enhou

    2009-01-01

    Magnesium alloys have unique advantages to act as biodegradable implants for clinical application. The biodegradable behaviors of AZ31 in simulated body fluid (SBF) for various immersion time intervals were investigated by electrochemical impedance spectroscopy (EIS) tests and scanning electron microscope (SEM) observation, and then the biodegradable mechanisms were discussed. It was found that a protective film layer was formed on the surface of AZ31 in SBF. With increasing of immersion time, the film layer became more compact. If the immersion time was more than 24 h, the film layer began to degenerate and emerge corrosion pits. In the meantime, there was hydroxyapatite particles deposited on the film layer. The hydroxyapatite is the essential component of human bone, which indicates the perfect biocompatibility of AZ31 magnesium alloy.

  1. Tank 241-AZ-102 Privatization Push Mode Core Sampling and Analysis Plan; FINAL

    International Nuclear Information System (INIS)

    TEMPLETON, A.M.

    1999-01-01

    This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for samples obtained from tank 241-AZ-102. The purpose of this sampling event is to obtain information about the characteristics of the contents of 241-AZ-102. Push mode core samples will be obtained from risers 15C and 24A to provide sufficient material for the chemical analyses and tests required to satisfy these data quality objectives. The 222-S Laboratory will extrude core samples, composite the liquids and solids, perform chemical analyses, and provide subsamples to the Process Chemistry Laboratory. The Process Chemistry Laboratory will prepare test plans and perform process tests to evaluate the behavior of the 241-AZ-102 waste undergoing the retrieval and treatment scenarios defined in the applicable DQOs. Requirements for analyses of samples originating in the process tests will be documented in the corresponding test plan

  2. Tank 241-AZ-101 Mixer Pump Test Vapor Sampling and Analysis Plan

    International Nuclear Information System (INIS)

    TEMPLETON, A.M.

    2000-01-01

    This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for vapor samples obtained during the operation of mixer pumps in tank 241-AZ-101. The primary purpose of the mixer pump test (MPT) is to demonstrate that the two 300 horsepower mixer pumps installed in tank 241-AZ-101 can mobilize the settled sludge so that it can be retrieved for treatment and vitrification. Sampling will be performed in accordance with Tank 241-AZ-101 Mixer Pump Test Data Quality Objective (Banning 1999) and Data Quality Objectives for Regulatory Requirements for Hazardous and Radioactive Air Emissions Sampling and Analysis (Mulkey 1999). The sampling will verify if current air emission estimates used in the permit application are correct and provide information for future air permit applications

  3. Influence of The Arrangement of Materials and Microstructural Analysis During FSW of AZ80A

    Directory of Open Access Journals (Sweden)

    Sevvel P.

    2017-09-01

    Full Text Available The main objective of this paper is to produce defect free weldments with improved properties during friction stir welding of dissimilar Mg alloys. The influence of the anisotropic arrangement of materials when AZ80A Mg alloy is taken as advancing side and AZ91C Mg alloy as retreating side and vice versa with respect to their mechanical properties and microstructural characteristics were investigated. The effects of various FSW parameters on the quality of these joints were also analyzed and best optimized FSW parameters were suggested. Defect free sound joints with excellent mechanical properties were produced when AZ80A Mg alloy was positioned at retreating side. At the same time, it seems a little bit difficult to obtain good quality joints with the contrary arrangement of materials. These investigations revealed that materials having inferior plastic deformability must be kept at the advancing side to obtain sound joints during FSW of dissimilar alloys of Magnesium.

  4. Separation and electrodeposited of 210 Po

    International Nuclear Information System (INIS)

    Ordonez R, E.; Iturbe G, J.L.

    1991-12-01

    Presently work it was determined the selective separation of the 210 Po that is in an uraniferous mineral, by means of acid leaching of the mineral and the purification was carried out by means of partition chromatography whose stationary phase is 2-ethylhexyl phosphoric acid (D 2 EHPA), it has been possible to isolate the 210 Po of the rest of the radioactive elements that conform the family 4 N +2 , the optimal elutriation conditions of this element were settled down of manner of not dragging other radioelements. Another of the achievements presented in this communication has been the electrodeposition of this element has more than enough stainless steel discs with a superior yield to 95%. (Author)

  5. Corrosion behaviour and in vitro/in vivo biocompatibility of surface-modified AZ31 alloy; Comportamiento frente a la corrosion y biocompatibilidad in vitrolin vivo de la aleacion AZ31 modificada superficialmente

    Energy Technology Data Exchange (ETDEWEB)

    Carboneras, M.; Iglesias, C.; Perez-Maceda, B. T.; Valle, J. A. de; Garcia-Alonso, M. C.; Alobera, M. A.; Clemente, C.; Rubio, J. C.; Escudero, M. I.; Lozano, R. M.

    2011-07-01

    The present work evaluates the corrosion behaviour and the in vitro/in vivo biocompatibility of the AZ31 magnesium alloy, which fulfills the mechanical requirements of bone. The corrosion kinetic of as-received AZ31 alloy was not compatible with the cell growth. To improve its performance, the AZ31 alloy was surface modified by a chemical conversion treatment in hydrofluoric acid. The magnesium fluoride layer generated by the surface treatment of AZ31 alloy enhances its corrosion behaviour, allowing the in vitro growth of osteoblastic cells over the surface and the in vivo formation of a highly compact layer of new bone tissue. These results lead to consider the magnesium fluoride coating as necessary for potential use of the AZ31 alloy as biodegradable and absorbable implant for bone repair. (Author) 18 refs.

  6. Measurement of 210Po in vegetables of Gudalore

    International Nuclear Information System (INIS)

    Selvasekarapandian, S.; Sivakumar, R.; Mugunthamanikandan, N.; Ragunath, V.M.; Meenashisundaram, V.

    1999-01-01

    Intake of 210 Po with food was determined for the population in Gudalore taluka of Nilgiri district. The content of 210 Po in different vegetable samples was determined. The annual intake of 210 Po due different vegetables was estimated on the basis of their average annual consumption. The intake of 210 Po varied from 0.056 to 11.97 Bq/kg. The largest intake of 210 Po was with tapioca. From the intake annual effective dose was calculated. Effective dose equivalent due to polonium in different vegetables varied between 0.0121 to 2.872 μSv/Y. (author)

  7. Microstructure and corrosion behavior of electrodeposited nano-crystalline nickel coating on AZ91 Mg alloy

    Energy Technology Data Exchange (ETDEWEB)

    Zarebidaki, Arman, E-mail: arman.zare@iauyazd.ac.ir; Mahmoudikohani, Hassan, E-mail: hassanmahmoudi.k@gmail.com; Aboutalebi, Mohammad-Reza

    2014-12-05

    Highlights: • Activation, zincating, and Cu electrodeposition were used as pretreatment processes for electrodeposition of nickel coatings. • Nano-crystalline nickel coatings were successfully electrodeposited onto the AZ91 Mg alloys. • Effect of nickel electrodeposited coating on the corrosion resistance of AZ91 Mg alloy has been studied. - Abstract: In order to enhance the corrosion resistance, nickel coating was electrodeposited onto AZ91 Mg alloy. Activation, zincating, and Cu electrodeposition used as pretreatment processes for better adhesion and corrosion performance of the nickel over layer. The corrosion properties of the AZ91 Mg alloy, nickel electroplated AZ91 Mg alloy, and pure nickel was assessed via polarization and electrochemical impedance spectroscopy (EIS) methods in 3.5 wt% NaCl solution. Moreover, the structure of the coating was investigated by means of X-ray diffraction, whereas specimen’s morphology and elemental composition were analyzed using scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS). Measurements revealed that the coating has a nano-crystalline structure with the grain size of 95 nm. Corrosion results showed superior corrosion resistance for the coated AZ91 Mg alloy as the corrosion current density decreased from 2.5 × 10{sup −4} A cm{sup −2}, for the uncoated sample, to 1.5 × 10{sup −5} A cm{sup −2}, for coated specimen and the corrosion potential increased from −1.55 V to −0.98 V (vs. Ag/AgCl) at the same condition.

  8. Corrosion and mechanical performance of AZ91 exposed to simulated inflammatory conditions.

    Science.gov (United States)

    Brooks, Emily K; Der, Stephanie; Ehrensberger, Mark T

    2016-03-01

    Magnesium (Mg) and its alloys, including Mg-9%Al-1%Zn (AZ91), are biodegradable metals with potential use as temporary orthopedic implants. Invasive orthopedic procedures can provoke an inflammatory response that produces hydrogen peroxide (H2O2) and an acidic environment near the implant. This study assessed the influence of inflammation on both the corrosion and mechanical properties of AZ91. The AZ91 samples in the inflammatory protocol were immersed for three days in a complex biologically relevant electrolyte (AMEM culture media) that contained serum proteins (FBS), 150 mM of H2O2, and was titrated to a pH of 5. The control protocol immersed AZ91 samples in the same biologically relevant electrolyte (AMEM & FBS) but without H2O2 and the acid titration. After 3 days all samples were switched into fresh AMEM & FBS for an additional 3-day immersion. During the initial immersion, inflammatory protocol samples showed increased corrosion rate determined by mass loss testing, increased Mg and Al ion released to solution, and a completely corroded surface morphology as compared to the control protocol. Although corrosion in both protocols slowed once the test electrolyte solution was replaced at 3 days, the samples originally exposed to the simulated inflammatory conditions continued to display enhanced corrosion rates as compared to the control protocol. These lingering effects may indicate the initial inflammatory corrosion processes modified components of the surface oxide and corrosion film or initiated aggressive localized processes that subsequently left the interface more vulnerable to continued enhanced corrosion. The electrochemical properties of the interfaces were also evaluated by EIS, which found that the corrosion characteristics of the AZ91 samples were potentially influenced by the role of intermediate adsorption layer processes. The increased corrosion observed for the inflammatory protocol did not affect the flexural mechanical properties of the AZ91

  9. Blocking spinal CCR2 with AZ889 reversed hyperalgesia in a model of neuropathic pain

    Directory of Open Access Journals (Sweden)

    Vaillancourt François

    2010-12-01

    Full Text Available Abstract Background The CCR2/CCL2 system has been identified as a regulator in the pathogenesis of neuropathy-induced pain. However, CCR2 target validation in analgesia and the mechanism underlying antinociception produced by CCR2 antagonists remains poorly understood. In this study, in vitro and in vivo pharmacological approaches using a novel CCR2 antagonist, AZ889, strengthened the hypothesis of a CCR2 contribution to neuropathic pain and provided confidence over the possibilities to treat neuropathic pain with CCR2 antagonists. Results We provided evidence that dorsal root ganglia (DRG cells harvested from CCI animals responded to stimulation by CCL2 with a concentration-dependent calcium rise involving PLC-dependent internal stores. This response was associated with an increase in evoked neuronal action potentials suggesting these cells were sensitive to CCR2 signalling. Importantly, treatment with AZ889 abolished CCL2-evoked excitation confirming that this activity is CCR2-mediated. Neuronal and non-neuronal cells in the spinal cord were also excited by CCL2 applications indicating an important role of spinal CCR2 in neuropathic pain. We next showed that in vivo spinal intrathecal injection of AZ889 produced dose-dependent analgesia in CCI rats. Additionally, application of AZ889 to the exposed spinal cord inhibited evoked neuronal activity and confirmed that CCR2-mediated analgesia involved predominantly the spinal cord. Furthermore, AZ889 abolished NMDA-dependent wind-up of spinal withdrawal reflex pathway in neuropathic animals giving insight into the spinal mechanism underlying the analgesic properties of AZ889. Conclusions Overall, this study strengthens the important role of CCR2 in neuropathic pain and highlights feasibility that interfering on this mechanism at the spinal level with a selective antagonist can provide new analgesia opportunities.

  10. Electrochemical polymerization of pyrrole over AZ31 Mg alloy for biomedical applications

    International Nuclear Information System (INIS)

    Srinivasan, A.; Ranjani, P.; Rajendran, N.

    2013-01-01

    Highlights: ► Polymerization of pyrrole over AZ31 Mg was carried out using cyclic voltammetry. ► Pyrrole concentration was optimized to accomplish the adherent and uniform coating. ► Effect of monomer concentration on the surface morphology was discussed. ► Corrosion resistance of AZ31 Mg in SBF was studied as a function of Py concentration. ► PPy coated AZ31 Mg alloy exhibited enhanced corrosion resistance at 0.25 M of Py. -- Abstract: Electrochemical polymerization of pyrrole (Py) from aqueous salicylate solution over AZ31 Mg alloy was carried out using cyclic voltammetry (CV). The effect of monomer concentration on the surface and electrochemical corrosion in simulated body fluid (SBF) were analysed. Attenuated total reflection-infrared (ATR-IR) spectra showed the characteristic ring stretching peaks for polypyrrole (PPy). Scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies exhibited typical cauliflower morphology with rough surface for PPy coated AZ31 Mg alloy. Open circuit potential measurement and potentiodynamic polarization studies revealed that the coating prepared using 0.25 M of Py had positive shift of about 120 mV in corrosion potential and lower corrosion current density (0.03 mA/cm 2 ) compared to other concentrations and uncoated AZ31 Mg alloy (0.25 mA/cm 2 ). Electrochemical impedance spectroscopic (EIS) studies of uncoated and PPy coated Mg alloy in SBF revealed three-time constants behaviour with about one order of increment in impedance value for 0.25 M of Py

  11. Assessing the ecosystem service potential of Tucson AZ's urban forest

    Science.gov (United States)

    Pavao-Zuckerman, M.

    2011-12-01

    Urbanization is arguably one of the most dramatic forms of landscape change, and an important anthropogenic influence on the structure and function of ecosystems. Cities have obvious impacts on local ecologies and environments, such as shifts in species diversity and alteration of local microclimates. While scientists are now familiar with many of these localized impacts of urbanization, cities and suburban areas contribute to 10-15 % of surface land cover in the conterminous U.S., pointing to the potential, yet poorly understood, contribution of cities to regional, national, and global carbon (C) and energy budgets. As cities continue to expand urban ecologists place more emphasis on understanding the functions of urban ecosystems and the ecosystem services (e.g. habitat, air, and water quality) that cities provide. While studies demonstrate that the urban environment alters the structure and function of remnant patches of native ecosystems relative to their non-urban counterparts, the ability of restoration, planning, and design to improve the provision of ecosystem services is a new approach within ecology. One strategy involves green urban design, or using ecological principles for planning or reinvigorating certain ecological processes, in cities. Increasing the amount of vegetative cover can reduce this effect by reinforcing ecosystem services in cities, including shading of surfaces, promotion of cooling through evapotranspiration, and the sequestration of atmospheric CO2 in plant tissues and soils. However, the on-the-ground reality of such strategies is relatively unknown. A pilot study is being conducted in Tucson, AZ to investigate the impact of increasing the cover of trees in the urban landscape on local microclimates and the urban heat island. Trees (Velvet Mesquite, Chilean Mesquite, and Desert Willow) were planted in two neighborhoods in Tucson in 1990. We are collecting data during the summer 2011 monsoon (DBH, crown volume, and hemispherical

  12. 78 FR 34403 - Notice of Availability of the Record of Decision for the Quartzsite Solar Energy Project, AZ

    Science.gov (United States)

    2013-06-07

    ...; AZA34666] Notice of Availability of the Record of Decision for the Quartzsite Solar Energy Project, AZ... Solar Energy Project (QSEP). The Acting Assistant Secretary for Land and Minerals Management approved...: http://www.blm.gov/az/st/en/prog/energy/solar/quartzsite_solar_energy.html . FOR FURTHER INFORMATION...

  13. Differential deposition of H2A.Z in rice seedling tissue during the day-night cycle.

    Science.gov (United States)

    Zhang, Kang; Xu, Wenying; Wang, Chunchao; Yi, Xin; Su, Zhen

    2017-03-04

    Chromatin structure has an important role in modulating gene expression. The incorporation of histone variants into the nucleosome leads to important changes in the chromatin structure. The histone variant H2A.Z is highly conserved between different species of fungi, animals, and plants. However, dynamic changes to H2A.Z in rice have not been reported during the day-night cycle. In this study, we generated genome wide maps of H2A.Z for day and night time in harvested seedling tissues by combining chromatin immunoprecipitation and high-throughput sequencing. The analysis results for the H2A.Z data sets detected 7099 genes with higher depositions of H2A.Z in seedling tissues harvested at night compared with seedling tissues harvested during the day, whereas 4597 genes had higher H2A.Z depositions in seedlings harvested during the day. The gene expression profiles data suggested that H2A.Z probably negatively regulated gene expression during the day-night cycle and was involved in many important biologic processes. In general, our results indicated that H2A.Z may play an important role in plant responses to the diurnal oscillation process.

  14. An exponential material model for prediction of the flow curves of several AZ series magnesium alloys in tension and compression

    International Nuclear Information System (INIS)

    Fereshteh-Saniee, F.; Barati, F.; Badnava, H.; Fallah Nejad, Kh.

    2012-01-01

    Highlights: ► The exponential model can represent flow behaviors of AZ series Mg alloys very well. ► Strain rate sensitivities of AZ series Mg alloys in compression are nearly the same. ► Effect of zinc element on tensile activation energy is higher than on compressive one. ► Activation energies of AZ80 and AZ81 in tension were greater than in compression. ► Tensile and compressive rate sensitivities of AZ80 are not close to each other. -- Abstract: This paper is concerned with flow behaviors of several magnesium alloys, such as AZ31, AZ80 and AZ81, in tension and compression. The experiments were performed at elevated temperatures and for various strain rates. In order to eliminate the effect of inhomogeneous deformation in tensile and compression tests, the Bridgeman’s and numerical correction factors were respectively employed. A two-section exponential mathematical model was also utilized for prediction of flow stresses of different magnesium alloys in tension and compression. Moreover, based on the compressive flow model proposed, the peak stress and the relevant true strain could be estimated. The true stress and strain of the necking point can also be predicted using the corresponding relations. It was found that the flow behaviors estimated by the exponential flow model were encouragingly in very good agreement with experimental findings.

  15. PoET: Polarimeters for Energetic Transients

    Science.gov (United States)

    McConnell, Mark; Barthelmy, Scott; Hill, Joanne

    2008-01-01

    This presentation focuses on PoET (Polarimeters for Energetic Transients): a Small Explorer mission concept proposed to NASA in January 2008. The principal scientific goal of POET is to measure GRB polarization between 2 and 500 keV. The payload consists of two wide FoV instruments: a Low Energy Polarimeter (LEP) capable of polarization measurements in the energy range from 2-15 keV and a high energy polarimeter (Gamma-Ray Polarimeter Experiment - GRAPE) that will measure polarization in the 60-500 keV energy range. Spectra will be measured from 2 keV up to 1 MeV. The PoET spacecraft provides a zenith-pointed platform for maximizing the exposure to deep space. Spacecraft rotation will provide a means of effectively dealing with systematics in the polarization response. PoET will provide sufficient sensitivity and sky coverage to measure statistically significant polarization for up to 100 GRBs in a two-year mission. Polarization data will also be obtained for solar flares, pulsars and other sources of astronomical interest.

  16. Qualitative Research of AZ31 Magnesium Alloy Aircraft Brackets Produced by a New Forging Method

    Directory of Open Access Journals (Sweden)

    Dziubińska A.

    2016-06-01

    Full Text Available The paper reports a selection of numerical and experimental results of a new closed-die forging method for producing AZ31 magnesium alloy aircraft brackets with one rib. The numerical modelling of the new forming process was performed by the finite element method.The distributions of stresses, strains, temperature and forces were examined. The numerical results confirmed that the forgings produced by the new forming method are correct. For this reason, the new forming process was verified experimentally. The experimental results showed good agreement with the numerical results. The produced forgings of AZ31 magnesium alloy aircraft brackets with one rib were then subjected to qualitative tests.

  17. Influence of Zeolite Coating on the Corrosion Resistance of AZ91D Magnesium Alloy.

    Science.gov (United States)

    Banerjee, P Chakraborty; Woo, Ren Ping; Grayson, Sam Matthew; Majumder, Amrita; Raman, R K Singh

    2014-08-22

    The protective performance of zeolite coating on AZ91D magnesium alloy was evaluated using potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS) in 0.1 M sodium chloride solution (NaCl). Electrical equivalent circuit (EEC) was developed based upon hypothetical corrosion mechanisms and simulated to correspond to the experimental data. The morphology and the chemical nature of the coating were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. Post corrosion morphologies of the zeolite coated and the uncoated AZ91D alloy were investigated using SEM. The corrosion resistance of the zeolite coated specimen was at least one order of magnitude higher than the uncoated specimen.

  18. Augmenting the Energy-Saving Impact of IEEE 802.3az via the Control Plane

    OpenAIRE

    Thaenchaikun , Chakadkit; Jakllari , Gentian; Paillassa , Béatrice

    2015-01-01

    International audience; IEEE 802.3az, the recent standard for Energy Efficient Ethernet, is one of the main contributions of the ICT industry to the global quest for energy efficiency. Energy consumption reduction is accomplished by essentially replacing the continuous IDLE of legacy IEEE 802.3 cards with a Low Power Idle. While this is an important step in the right direction, studies have shown that the energy saving with IEEE 802.3az highly depends on the traffic load and stops for link ut...

  19. Anticorrosive magnesium hydroxide coating on AZ31 magnesium alloy by hydrothermal method

    International Nuclear Information System (INIS)

    Zhu Yanying; Wu Guangming; Xing Guangjian; Li Donglin; Zhao Qing; Zhang Yunhong

    2009-01-01

    Magnesium alloys are potential biodegradable biomaterials in orthopedic surgery. However, the rapid degradation rate has limited their application in biomedical field. A great deal of studies have been done to improve the resistance of magnesium alloys. In this article, An anticorrosive magnesium hydroxide coating with a thickness of approximately 100μm was formed on an AZ31 magnesium alloy by hydrothermal method. The morphology of the coatings were observed by an optical microscope and SEM. And the samples were soaked in hank's solution (37 deg. C) to investigate the corrosion resistance. Magnesium alloy AZ31 with magnesium hydroxide coatings present superior corrosion resistance than untreated samples.

  20. Effects of organic acid pickling on the corrosion resistance of magnesium alloy AZ31 sheet

    DEFF Research Database (Denmark)

    Nwaogu, Ugochukwu Chibuzoh; Blawert, C.; Scharnagl, N.

    2010-01-01

    mu m of the contaminated surface was required to reach corrosion rates less than 1 mm/year in salt spray condition. Among the three organic acids examined, acetic acid is the best choice. Oxalic acid can be an alternative while citric acid is not suitable for cleaning AZ31 sheet, because......Organic acids were used to clean AZ31 magnesium alloy sheet and the effect of the cleaning processes on the surface condition and corrosion performance of the alloy was investigated. Organic acid cleanings reduced the surface impurities and enhanced the corrosion resistance. Removal of at least 4...

  1. Structure of the AZ91 alloy pressure castings fabricated of home scrap containing charge

    Directory of Open Access Journals (Sweden)

    Z. Konopka

    2011-04-01

    Full Text Available The influence of the AZ91 alloy home scrap addition to the metal charge on both the structure and the selected mechanical propertiesof pressure castings was examined in this article. Two heats were made using different components, the first with only pure AZ91 alloyingots in the charge, and the second containing 30 wt % of home scrap. The hot chamber 3 MN machine was used for casting. Thestructures of the castings and their Brinell hardness were examined for both cases. A strong refinement of crystals was observed in castings made with the contribution of the recycled material. Any significant differences in castings hardness were not observed.

  2. Acceptance Test Report for the 241-AZ-101 Ultrasonic Interface Level Analyzer

    Energy Technology Data Exchange (ETDEWEB)

    ANDREWS, J.E.

    2000-01-27

    This document comprises the Acceptance Test Report for the 241-AZ-101 Ultrasonic Interface Level Analyzer. This document presents the results of Acceptance Testing of the 241-AZ-101 Ultrasonic Interface Level Analyzers (URSILLAs). Testing of the URSILLAs was performed in accordance with ATP-260-001, ''URSILLA Pre-installation Acceptance Test Procedure''. The objective of the testing was to verify that all equipment and components function in accordance with design specifications and original equipment manufacturer's specifications.

  3. Patrón de consumo e ingestas recomendadas de azúcar

    OpenAIRE

    Joan Quiles i Izquierdo

    2013-01-01

    Los azúcares son hidratos de carbono con sabor dulce que proveen energía al organismo. El cerebro adulto utiliza aproximadamente 140 g de glucosa al día, cantidad que puede representar hasta el 50% del total de hidratos de carbono que se consumen. En nuestro país el patrón de consumo de azúcar en alimentos permanece constante, mientras que el consumo de bebidas refrescantes presenta un aumento en los últimos cuatro años. La Encuesta Nacional de Ingesta Dietética de España (ENIDE, 2010-11) est...

  4. Radiochemical determination of 210 Po in tobacco and farm food

    International Nuclear Information System (INIS)

    Chung, K. H.; Lee, H. P.; Cho, Y. H.; Choi, G. S.; Kim, C. K.; Lee, C. W.

    2002-01-01

    A method for measuring 210 Po in tobacco (cigarette and leaf) and farm food has been studied by alpha- spectrometry. Polonium was separated from HCl solution in the presence of other radionuclides and ascorbic acid (reduction of Fe 3+ ) by spontaneous deposition onto a silver disc. To determine the optimum conditions for plating polonium on a disc, the effects of reducing agent, plating time etc. were investigated. In the method, the samples are spiked with 208 Po (or 209 Po) as a chemical yield tracer. Because the main sources of 210 Po in the human body are food and cigarette smoke, this procedure to determine 210 Po has been applied to tobacco and farm food samples. Analyses of 210 Po in tobacco leaves and farm food samples using this method are in progress. The concentrations of 210 Po in cigarettes were ranged from 17 to 21 mBq/g and compared with published data on this natural radionuclide

  5. Comportamiento mecánico de la aleación AZ31 reforzada con nanofibras de carbono

    Directory of Open Access Journals (Sweden)

    Adeva, P.

    2010-12-01

    Full Text Available The aim of this study is to investigate the effect of reinforcing AZ31 with carbon nanofibres. The materials AZ31, AZ31-1 % C y AZ31-2 % C were produced by a conventional powder metallurgy route consisting of mechanical mixing of nanofibres and powders of AZ31, cool compactation and extrusion at 350 °C. After extrusion the three materials exhibited a recrystallized microstructure of similar grain size, fine and rather inhomogeneous. Furthermore, they presented a weak fibre texture with basal plane parallel to the extrusion direction. The tensile properties were affected by the nanofibres presence only at 100 °C. At this temperature, yield strength and tensile strength were 30% higher than in the unreinforced alloy.

    En este trabajo se ha estudiado el efecto de la adición de nanofibras de carbono en las propiedades mecánicas de la aleación AZ31 procesada por una ruta pulvimetalúrgica convencional. Se prepararon tres materiales, AZ31, AZ31- 1 % C y AZ31-2 % C. Tras una mezcla mecánica de las nanofibras con los polvos de AZ31, se precompactaron en frío y se extruyeron a 350 °C. Los tres presentan una microestructura recristalizada con un tamaño de grano similar, fino aunque algo heterogéneo. Los tres materiales presentan una débil textura de fibra con el plano basal paralelo a la dirección de extrusión. Las propiedades mecánicas a tracción únicamente se ven afectadas por la presencia de nanofibras a 100 °C superando los materiales reforzados en un 30 % a los valores de límite elástico y resistencia de la aleación sin reforzar.

  6. Forenzika elektronske pošte

    Directory of Open Access Journals (Sweden)

    Milorad S. Markagić

    2013-10-01

    Full Text Available U najopštijem smislu digitalna forenzika može se definisati kao skup metoda za prikupljanje, analizu i prezentaciju digitalnih dokaza koji se mogu pronaći na računarima, serverima, u računarskim mrežama, bazama podataka, mobilnim uređajima i svim drugim elektronskim uređajima na kojima se čuvaju podaci. U ovom radu su opisane metode prikupljanja digitalnih dokaza u elektronskoj pošti i njihova analiza. Uvod Elektronska pošta se kao dokazni materijal pojavljuje u velikom broju kako građanskih tako i kriminalnih forenzičkih istraga. Elektronska pošta i elektronska pošta zasnovana na internet serverima  širi se veoma brzo, pa lako i brzo završi i na računaru korisnika kome nije namenjena. Prvu elektronsku poruku poslao je Ray Tomilson 1971. godine, a deset godina kasnije u kombinaciji sa personalnim računarima i internetom prerasta u globalni način komuniciranja i personalnog i poslovnog. Takođe se koristi i u svrhu zabave, načina razmene podataka, ali predstavlja i nezamenjiv izvor digitalnih dokaza, kada dodje do računarskog incidenta. Analiza elektronske pošte Svaka elektronska poruka sastoji se od dva dela: zaglavlja i teksta poruke. Iz zaglavlja je moguće saznati izvorišnu i odredišnu adresu, pošiljaoca i namenjenog primaoca, a telo poruke sadrži tekst poruke. Ekstenzije dokumenata elektronske pošte U slučajevima kada je potrebno otkriti samo dokumente potrebne za pregled elektronskih poruka, ili kopirati pojedinačni dokument sačuvan unutar elektronske pošte, moguće je koristiti sistem na istraživanom računaru ili specijalizovani softver kao što je Outlook Extract Pro ili Outlook Export. Mnogo ispravniji, sigurniji i jednostavniji način je korišćenje forenzičkih alata kao što su EnCase ili FTK, sa ugrađenim pregledačima koji omogućavaju pregled i snimanje sadržaja baze podataka kao i njihovo kopiranje na druge medije za dalju analizu. Forenzički alati automatizuju proces skidanja i kopiranja

  7. Half-life of 214Po and 212Po measured with CTF at LNGS

    International Nuclear Information System (INIS)

    Bellini, G.; Benziger, J.; Bick, D.

    2013-01-01

    Polonium isotopes 214 Po and 212 Po are part of the 238 U and 232 Th decay chains, respectively. There exist only a few measurements of these two mean lifetimes with precision better than one or two percent. Since we have been studying decay spectra of 214 Bi and 212 Bi with the purpose of experimentally constraining anti-neutrino spectral shape important for geoneutrino studies, we have a large statistics of decays of 214 Po and 212 Po collected with the Counting Test Facility (CTF), which was operational in the underground I.N.F.N. Gran Sasso National Laboratory. The apparatus consisted of an external cylindrical water tank (diameter ∼ 11 m, high ∼ 10 m; ∼ 1000 tons of water) serving as passive shielding for 4.8 m 3 of liquid organic scintillator contained in an inner spherical vessel with a diameter of ∼ 2 m. The inner vessel was realized with a nylon membrane (∼ 500 ?m thick), with excellent optical clarity, which allowed the effective transmission of the scintillation light to the 100 phototubes (PMTs) forming the optical read-out, anchored on a 7 m diameter support structure inside the water tank. The high purity and low background in CTF allows a favourable signal to background ratio for these measurements. More specifically the ratio of signal to background of the present measurements is more than three orders of magnitude larger than the best existing measurements. We have studied the decays of 214 Po into 210 Pb and of 212 Po into 208 Pb tagged by the coincidence with the previously decays from 214 Bi and 212 Bi by using 222 Rn, 232 Th and 220 Rn sources sealed inside quartz vials and inserted in the CTF

  8. Temporal changes of 210Po in temperate coastal waters

    International Nuclear Information System (INIS)

    Wildgust, M.A.; White, K.N.; McDonald, P.

    1998-01-01

    The temporal variation of Polonium-210 ( 210 Po) was examined in coastal sea water, the mussel Mytilus edulis, the winkle Littorina littorea and green algae Ulva lactuca in order to investigate the entry of 210 Po into the marine food chain. More than 99% of 210 Po in the water column occurred in the particulate phase. Dissolved 210 Po concentrations peaked during the spring phytoplankton bloom and it is suggested this is related to preferential scavenging of 210 Po by the increased numbers of bacteria, viruses and small dissolved particulates. Changes in L. Littorea 210 Po specific activity are thought not to be related to food, but to a drop in body weight following spawning. Much of the 210 Po accumulated by M. edulis was located in the digestive gland. The specific activity of 210 Po in the digestive gland of M. edulis was shown to be strongly correlated with changes in sea water suspended particulate specific activity. Examination of other trace metal (Ag, Al, As, Ca, Cd, Cr, Co, Cu, Fe, Hg, K, Mg, Mn, Na, Ni Sb, Se, Sn and Zn) variations in the digestive gland revealed that class B and borderline metals had a strong positive correlation with 210 Po. On-going work is investigating whether the accumulation and loss of 210 Po is affected by the presence of metallothioneins

  9. Temporal changes of 210Po in temperate coastal waters.

    Science.gov (United States)

    Wildgust, M A; McDonald, P; White, K N

    1998-06-18

    The temporal variation of Polonium-210 (210Po) was examined in coastal sea water, the mussel Mytilus edulis, the winkle Littorina littorea and green alga Ulva lactuca in order to investigate the entry of 210Po into the marine food chain. More than 99% of 210Po in the water column occurred in the particulate phase. Dissolved 210Po concentrations peaked during the spring phytoplankton bloom and it is suggested this is related to preferential scavenging of 210Po by the increased numbers of bacteria, viruses and small dissolved particulates. Changes in L. littorea 210Po specific activity are thought not to be related to food, but to a drop in body weight following spawning. Much of the 210Po accumulated by M. edulis was located in the digestive gland. The specific activity of 210Po in the digestive gland of M. edulis was shown to be strongly correlated with changes in sea water suspended particulate specific activity. Examination of other trace metal (Ag, Al, As, Ca, Cd, Cr, Co, Cu, Fe, Hg, K, Mg, Mn, Na, Ni, Sb, Se, Sn and Zn) variations in the digestive gland revealed that class B and borderline metals had a strong positive correlation with 210Po. On-going work is investigating whether the accumulation and loss of 210Po is affected by the presence of metallothioneins.

  10. Cesium Removal From Tanks 241-AN-103 and 241-SX-105 and 241-AZ-101 and 241-AZ-102 Composite For Testing In Bench Scale Steam Reformer

    International Nuclear Information System (INIS)

    Duncan, J.B.; Huber, H.J.

    2011-01-01

    This report documents the preparation of three actual Hanford tank waste samples for shipment to the Savannah River National Laboratory (SRNL). Two of the samples were dissolved saltcakes from tank 241-AN-103 (hereafter AN-103) and tank 241-SX-105 (hereafter SX-105); one sample was a supernate composite from tanks 241-AZ-101 and 241-AZ-102 (hereafter AZ-101/102). The preparation of the samples was executed following the test plans LAB-PLAN-10-00006, Test Plan for the Preparation of Samples from Hanford Tanks 241-SX-105, 241-AN-103, 241-AN-107, and LAB-PLN-l0-00014, Test Plan for the Preparation of a Composite Sample from Hanford Tanks 241-AZ-101 and 241-AZ-102 for Steam Reformer Testing at the Savannah River National Laboratory. All procedural steps were recorded in laboratory notebook HNF-N-274 3. Sample breakdown diagrams for AN-103 and SX-105 are presented in Appendix A. The tank samples were prepared in support of a series of treatability studies of the Fluidized Bed Steam Reforming (FBSR) process using a Bench-Scale Reformer (BSR) at SRNL. Tests with simulants have shown that the FBSR mineralized waste form is comparable to low-activity waste glass with respect to environmental durability (WSRC-STI-2008-00268, Mineralization of Radioactive Wastes by Fluidized Bed Steam Reforming (FBSR): Comparisons to Vitreous Waste Forms and Pertinent Durability Testing). However, a rigorous assessment requires long-term performance data from FBSR product formed from actual Hanford tank waste. Washington River Protection Solutions, LLC (WRPS) has initiated a Waste Form Qualification Program (WP-5.2.1-2010-001, Fluidized Bed Steam Reformer Low-level Waste Form Qualification) to gather the data required to demonstrate that an adequate FBSR mineralized waste form can be produced. The documentation of the selection process of the three tank samples has been separately reported in RPP-48824, Sample Selection Process for Bench-Scale Steam Reforming Treatability Studies Using

  11. CESIUM REMOVAL FROM TANKS 241-AN-103 & 241-SX-105 & 241-AZ-101 & 241AZ-102 COMPOSITE FOR TESTING IN BENCH SCALE STEAM REFORMER

    Energy Technology Data Exchange (ETDEWEB)

    DUNCAN JB; HUBER HJ

    2011-04-21

    This report documents the preparation of three actual Hanford tank waste samples for shipment to the Savannah River National Laboratory (SRNL). Two of the samples were dissolved saltcakes from tank 241-AN-103 (hereafter AN-103) and tank 241-SX-105 (hereafter SX-105); one sample was a supernate composite from tanks 241-AZ-101 and 241-AZ-102 (hereafter AZ-101/102). The preparation of the samples was executed following the test plans LAB-PLAN-10-00006, Test Plan for the Preparation of Samples from Hanford Tanks 241-SX-105, 241-AN-103, 241-AN-107, and LAB-PLN-l0-00014, Test Plan for the Preparation of a Composite Sample from Hanford Tanks 241-AZ-101 and 241-AZ-102 for Steam Reformer Testing at the Savannah River National Laboratory. All procedural steps were recorded in laboratory notebook HNF-N-274 3. Sample breakdown diagrams for AN-103 and SX-105 are presented in Appendix A. The tank samples were prepared in support of a series of treatability studies of the Fluidized Bed Steam Reforming (FBSR) process using a Bench-Scale Reformer (BSR) at SRNL. Tests with simulants have shown that the FBSR mineralized waste form is comparable to low-activity waste glass with respect to environmental durability (WSRC-STI-2008-00268, Mineralization of Radioactive Wastes by Fluidized Bed Steam Reforming (FBSR): Comparisons to Vitreous Waste Forms and Pertinent Durability Testing). However, a rigorous assessment requires long-term performance data from FBSR product formed from actual Hanford tank waste. Washington River Protection Solutions, LLC (WRPS) has initiated a Waste Form Qualification Program (WP-5.2.1-2010-001, Fluidized Bed Steam Reformer Low-level Waste Form Qualification) to gather the data required to demonstrate that an adequate FBSR mineralized waste form can be produced. The documentation of the selection process of the three tank samples has been separately reported in RPP-48824, Sample Selection Process for Bench-Scale Steam Reforming Treatability Studies Using

  12. Expression of P. falciparum var Genes Involves Exchange of the Histone Variant H2A.Z at the Promoter

    Science.gov (United States)

    Petter, Michaela; Lee, Chin Chin; Byrne, Timothy J.; Boysen, Katja E.; Volz, Jennifer; Ralph, Stuart A.; Cowman, Alan F.; Brown, Graham V.; Duffy, Michael F.

    2011-01-01

    Plasmodium falciparum employs antigenic variation to evade the human immune response by switching the expression of different variant surface antigens encoded by the var gene family. Epigenetic mechanisms including histone modifications and sub-nuclear compartmentalization contribute to transcriptional regulation in the malaria parasite, in particular to control antigenic variation. Another mechanism of epigenetic control is the exchange of canonical histones with alternative variants to generate functionally specialized chromatin domains. Here we demonstrate that the alternative histone PfH2A.Z is associated with the epigenetic regulation of var genes. In many eukaryotic organisms the histone variant H2A.Z mediates an open chromatin structure at promoters and facilitates diverse levels of regulation, including transcriptional activation. Throughout the asexual, intraerythrocytic lifecycle of P. falciparum we found that the P. falciparum ortholog of H2A.Z (PfH2A.Z) colocalizes with histone modifications that are characteristic of transcriptionally-permissive euchromatin, but not with markers of heterochromatin. Consistent with this finding, antibodies to PfH2A.Z co-precipitate the permissive modification H3K4me3. By chromatin-immunoprecipitation we show that PfH2A.Z is enriched in nucleosomes around the transcription start site (TSS) in both transcriptionally active and silent stage-specific genes. In var genes, however, PfH2A.Z is enriched at the TSS only during active transcription in ring stage parasites. Thus, in contrast to other genes, temporal var gene regulation involves histone variant exchange at promoter nucleosomes. Sir2 histone deacetylases are important for var gene silencing and their yeast ortholog antagonises H2A.Z function in subtelomeric yeast genes. In immature P. falciparum parasites lacking Sir2A or Sir2B high var transcription levels correlate with enrichment of PfH2A.Z at the TSS. As Sir2A knock out parasites mature the var genes are

  13. Tema og projekter

    DEFF Research Database (Denmark)

    Formålet med P2-projektenheden er at sætte de studerende i stand til på metodisk måde at gennemføre den problemorienterede og projektorganiserede læringsform i grupper, med tilhørende vurderinger af de opnåede resultater og en samlet konklusion....

  14. Das ATHENA-Projekt: [

    Directory of Open Access Journals (Sweden)

    Passenheim, Renate

    2006-02-01

    Full Text Available [english] Since the winter semester of 2002/03, the Medical Faculty of the University of Heidelberg has been using the electronic learning environment ATHENA. It is the "virtual bulletin board" for the exchange and provision of information on the study of medicine within the faculty. Since 2004/05, the platform has been operated using the open source system LRN. The system is used with the focus on document management. The use of the interactive learning contents and programme takes place as a web-based support of the required attendance classes and independent study. The tools available on the platform are used within the departments for the integration of computer-assisted examination concepts, and the conducting of online course evaluations. [german] Seit dem Wintersemester 2002/03 setzt die Medizinische Fakultät Heidelberg die elektronische Lernumgebung ATHENA ein. Sie ist das "Virtuelle Schwarze Brett" für den Austausch und die Bereitstellung von Informationen zum Medizinstudium an der Fakultät. Seit 2004/05 wird die Plattform mit dem Open-Source-System .LRN betrieben. Das System wird eingesetzt mit dem Schwerpunkt der Kurs- und Dokumentenverwaltung. Die Nutzung der interaktiven Lerninhalte und -programme erfolgt als webbasierte Unterstützung der Präsenzveranstaltungen sowie im Selbststudium. Die in der Plattform verfügbaren Tools werden in den Fachbereichen zur Integration computerunterstützter Prüfungskonzepte sowie zur Durchführung von Online-Kursevaluationen eingesetzt.

  15. El Sistema inspirerede projekter

    DEFF Research Database (Denmark)

    Holst, Finn; Chemi, Tatiana

    Rapporten er resultat af pilotprojektet ”Forundersøgelse El Sistema DK” gennemført af Ph.D. Finn Holst (DPU, Aarhus Universitet) og Ph.D. Tatiana Chemi (Aalborg Universitet) i 2015. I rapporten indgår desuden bidrag fra Sofie Holm, Sara Fink Søndergaard og Stine Møgelbjerg Johansen. Pilotprojektet...... er gennemført for DMKLs El Sistema-udvalg med støtte fra Statens Kunstfond, Projektstøtteudvalget for Musik....

  16. Projekt "Lasnamjae" / Jekaterina Rodina

    Index Scriptorium Estoniae

    Rodina, Jekaterina

    2006-01-01

    Lasnamäe arengukonverentsil esitatud perspektiividest aastateks 2006-2009: rajatakse tööstuspark, meelelahutuskompleks Tallink City, kiirtrammitee, uus elamurajoon Loopealse, õigeusukatedraal, rekonstrueeritakse Tallinn-Narva maantee Väo-Maardu teelõik. Sissejuhatus lk. 1 "Lasnamjäe - raion millionerov"

  17. Soome kunstniku melanhoolne projekt

    Index Scriptorium Estoniae

    2002-01-01

    9.-25. VIII Tallinna Linnagaleriis soome kunstniku Tuukka Kaila (sünd. 1975) näitus "Kena koht Põhjamaal". Väljas on installatsioon "Fuck Finland - pilte ja helisid riigist, mida kunagi polnud" ja fotoseeria "Rõõmsad"

  18. Arbejde, innovation og projekter

    DEFF Research Database (Denmark)

    Grex, Sara

    studies indicate that project management is not the best way to manage and support innovative work. Hence there was a need for looking further in to this in preparation for developing ways of organizing that can overcome problems within the project frame and contributing to support the process....... The objective of the project is to investigate the organizational possibilities for developing ways of organizing so that innovative processes in project-oriented companies can be supported. The problem is answered through a literature review of theories within innovation, project management, and project...... organizing and two qualitative studies. One study is a multiple case study based on qualitative interviews in four different companies focusing on problems and challenges that participants in innovative processes experience in relation to the way innovative work is organized in projects. The other study...

  19. 75 FR 11554 - Notice of Intent to Repatriate Cultural Items: Museum of Northern Arizona, Flagstaff, AZ

    Science.gov (United States)

    2010-03-11

    ... continue to be used by traditional Navajo religious practitioners. Based on the sacred esoteric knowledge... Northern Arizona, Flagstaff, AZ, that meet the definitions of ``sacred objects'' and ``objects of cultural... the area of Farmington, NM. The 29 cultural items are 4 watercolors of sacred Navajo Yei figures and...

  20. 241-AZ-101 Waste Tank Color Video Camera System Shop Acceptance Test Report

    International Nuclear Information System (INIS)

    WERRY, S.M.

    2000-01-01

    This report includes shop acceptance test results. The test was performed prior to installation at tank AZ-101. Both the camera system and camera purge system were originally sought and procured as a part of initial waste retrieval project W-151

  1. Fault-tolerant epoxy-silane coating for corrosion protection of magnesium alloy AZ31

    NARCIS (Netherlands)

    Lamaka, S.V.; Xue, H.B.; Meis, N.N.A.H.; Esteves, A.C.C.; Ferreira, M.G.S.

    2015-01-01

    In this work, a hybrid epoxy-silane coating was developed for corrosion protection of magnesium alloy AZ31. The average thickness of the film produced by dip-coating procedure was 14 µm. The adhesion strength of the epoxy-silane coating to the Mg substrate was evaluated by pull-off tests and was

  2. 241-AZ-101 Waste Tank Color Video Camera System Shop Acceptance Test Report

    Energy Technology Data Exchange (ETDEWEB)

    WERRY, S.M.

    2000-03-23

    This report includes shop acceptance test results. The test was performed prior to installation at tank AZ-101. Both the camera system and camera purge system were originally sought and procured as a part of initial waste retrieval project W-151.

  3. Laser cladding of Zr-based coating on AZ91D magnesium alloy for ...

    Indian Academy of Sciences (India)

    based coating made of Zr powder was fabricated on AZ91D magnesium alloy by laser cladding. The microstructure of the coating was characterized by XRD, SEM and TEM techniques. The wear resistance of the coating was evaluated under dry ...

  4. Flow mechanisms in creep of a short-fibre AZ91 alloy-based composite

    Czech Academy of Sciences Publication Activity Database

    Pahutová, Marie; Sklenička, Václav; Kuchařová, Květa; Svoboda, Milan; Langdon, T. G.

    43 2005, č. 1 (2005), s. 34-44 ISSN 0023-432X R&D Projects: GA ČR(CZ) GA106/03/0901 Institutional research plan: CEZ:AV0Z20410507 Keywords : AZ91 magnesium alloy * metal matrix composite * short fibre reinforcement Subject RIV: JG - Metallurgy Impact factor: 0.973, year: 2005

  5. Study on fused/cast AZS refractories for deployment in vitrification of radioactive waste effluents

    Science.gov (United States)

    Sengupta, Pranesh; Mishra, R. K.; Soudamini, N.; Sen, D.; Mazumder, S.; Kaushik, C. P.; Ajithkumar, T. G.; Banerjee, K.

    2015-12-01

    'Fused/cast Al2O3-ZrO2-SiO2 (FC-AZS)' is being considered as 'glass contact refractory' within ceramic melters, to be used for nuclear waste immobilization. Microstructural analyses reveal random distributions of baddeleyite (ZrO2) within aluminosilicate (Al2SiO5) matrix. 27Al and 29Si NMR data suggest that within aluminosilicate matrix Al occurs in both 4- and 6-fold co-ordinations whereas Si prefers a 4-fold environment. Polydispersity of pores has been studied with small-angle neutron scattering (SANS) technique. Corrosion rates of FC-AZS within 6 M HNO3, simulated wastes (500 h exposure), and borosilicate melt (975 °C, 800 h exposure) are found to be 0.38 × 103 μmy-1, 0.13 × 103 μmy-1 and 4.75 × 103 μmy-1 respectively. A comparison of chemical interaction data clearly suggests that FC-AZS exhibits better chemical durability than AZC refractory (Al2O3-ZrO2-Cr2O3, also used for similar purpose). Thermal cycling studies indicate that FC-AZS retains structural integrity (including compressive strength and density) even up to 20 cycles.

  6. 78 FR 23135 - Safety Zone; Blue Water Resort & Casino West Coast Nationals; Parker, AZ

    Science.gov (United States)

    2013-04-18

    ...-AA00 Safety Zone; Blue Water Resort & Casino West Coast Nationals; Parker, AZ AGENCY: Coast Guard, DHS... Water Resort & Casino West Coast Nationals. This temporary safety zone is necessary to provide for the....). RPM Racing Enterprises is sponsoring the Blue Water Resort & Casino West Coast Nationals, which is...

  7. 75 FR 11939 - DNS Electronics, Chandler, AZ; Notice of Termination of Investigation

    Science.gov (United States)

    2010-03-12

    ... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-70,654] DNS Electronics, Chandler, AZ; Notice of Termination of Investigation Pursuant to Section 223 of the Trade Act of 1974, as... on behalf of workers of DNS Electronics, Chandler, Arizona. The petitioning group of workers is...

  8. Laser cladding of Zr-based coating on AZ91D magnesium alloy for ...

    Indian Academy of Sciences (India)

    3Hubei Key Laboratory of Hydroelectric Machinery Design & Maintenance, ... To improve the wear and corrosion resistance of AZ91D magnesium alloy, Zr-based coating made of ... process that lead to inflammatory cascades which reduce bio- ... tions regarding their application as protective films on load- ... Experimental.

  9. 75 FR 5115 - Temporary Concession Contract for Lake Mead National Recreation Area, AZ/NV

    Science.gov (United States)

    2010-02-01

    ... National Recreation Area, AZ/NV AGENCY: National Park Service, Department of the Interior. ACTION: Notice of intention to award temporary concession contract for Lake Mead National Recreation Area. SUMMARY: Pursuant to 36 CFR 51.24, public notice is hereby given that the National Park Service intends to award a...

  10. Effect of Pr addition on microstructure and mechanical properties of AZ61 magnesium alloy

    Directory of Open Access Journals (Sweden)

    You Zhiyong

    2014-03-01

    Full Text Available To improve the strength, hardness and heat resistance of Mg-6Al-1Zn (AZ61 alloy, the effects of Pr addition on the as-cast microstructure and mechanical properties of AZ61 alloy were investigated at room and elevated temperatures by means of Brinell hardness measurement, optical microscope (OM, scanning electron microscope (SEM, energy dispersive spectroscopy (EDS, X-ray diffractometer (XRD and DNS100 electronic universal testing machine. The results show that the microstructures of Pr-containing AZ61 alloys were refined, with primary β-Mg17Al12 phase distributed homogeneously. When the addition of Pr is up to 1.2wt.%, the β phase becomes finer, and new needle-like or short-rod shaped Al11Pr3 phase and blocky AlPr phase appear. As a result, optimal tensile properties are obtained. However, greater than 1.2wt.% Pr addition leads to poorer mechanical properties due to the aggregation of the needle-like phase and large size of grains. The present research findings provide a new way for strengthening of magnesium alloys at room and elevated temperatures, and a method of producing thermally-stable AZ61 magnesium alloy.

  11. Mechanical properties of plasma-sprayed layers of aluminium and aluminium alloy on AZ 91

    Czech Academy of Sciences Publication Activity Database

    Kubatík, Tomáš František; Ctibor, Pavel; Mušálek, Radek; Janata, Marek

    2017-01-01

    Roč. 51, č. 2 (2017), s. 323-327 ISSN 1580-2949 R&D Projects: GA ČR(CZ) GP14-31538P Institutional support: RVO:61389021 Keywords : plasma spraying of aluminium * adhesion of coating * wear * magnesium alloy AZ91 Subject RIV: JG - Metallurgy OBOR OECD: Materials engineering Impact factor: 0.436, year: 2016

  12. Structural evaluation of thermocouple probes for 241-AZ-101 waste tank

    International Nuclear Information System (INIS)

    Kanjilal, S.K.

    1994-01-01

    This document reports on the structural analysis of the thermocouple probe to be installed in 241-AZ-101 waste tank. The thermocouple probe is analyzed for normal pump mixing operation and potential earthquake induced loads required by the Hanford Site Design Criteria SDC-4.1

  13. Structural evaluation of thermocouple probes for 241-AZ-101 waste tank

    Energy Technology Data Exchange (ETDEWEB)

    Kanjilal, S.K.

    1994-12-06

    This document reports on the structural analysis of the thermocouple probe to be installed in 241-AZ-101 waste tank. The thermocouple probe is analyzed for normal pump mixing operation and potential earthquake induced loads required by the Hanford Site Design Criteria SDC-4.1.

  14. Tank 241-AZ-101 steam bumping and settling Process Test report

    International Nuclear Information System (INIS)

    Winkler, C.M.

    1995-01-01

    This report summarizes the process test in which the airlift circulators in Tank 241-AZ-101 were shutdown. The test was successful, in that no extreme temperature excursions occurred. Only general data was obtianed through the use of a gamma energy probe

  15. Fatigue properties of magnesium alloy AZ91 processed by severe plastic deformation

    Czech Academy of Sciences Publication Activity Database

    Fintová, Stanislava; Kunz, Ludvík

    2015-01-01

    Roč. 42, FEB (2015), s. 219-228 ISSN 1751-6161 R&D Projects: GA ČR GAP108/10/2001 Institutional support: RVO:68081723 Keywords : AZ91 magnesium alloy * ECAP * Fatigue * Crack initiation Subject RIV: JL - Materials Fatigue, Friction Mechanics Impact factor: 2.876, year: 2015 http://www.sciencedirect.com/science/article/pii/S1751616114003713

  16. 77 FR 20356 - Foreign-Trade Zone 277-Western Maricopa County, AZ; Application for Manufacturing Authority...

    Science.gov (United States)

    2012-04-04

    ... Maricopa County, AZ; Application for Manufacturing Authority; Suntech Arizona, Inc., (Solar Panel... facility is used for the manufacture of 275 and 290 watt solar panels for industrial use. Components and... to solar panels (duty-free) for the foreign inputs noted above. Suntech would also be exempt from...

  17. Comparison of Electrochemical Methods for the Evaluation of Cast AZ91 Magnesium Alloy

    Czech Academy of Sciences Publication Activity Database

    Tkacz, J.; Minda, J.; Fintová, Stanislava; Wasserbauer, J.

    2016-01-01

    Roč. 9, č. 11 (2016), č. článku 925. ISSN 1996-1944 Institutional support: RVO:68081723 Keywords : AZ91 magnesium alloy * cathodic polarization curve * anodic polarization curve * linear polarization curve Subject RIV: JK - Corrosion ; Surface Treatment of Materials Impact factor: 2.654, year: 2016 http://www.mdpi.com/1996-1944/9/11/925

  18. In vitro corrosion of magnesium alloy AZ31 — a synergetic influence of glucose and Tris

    Science.gov (United States)

    Li, Ling-Yu; Liu, Bin; Zeng, Rong-Chang; Li, Shuo-Qi; Zhang, Fen; Zou, Yu-Hong; Jiang, Hongwei George; Chen, Xiao-Bo; Guan, Shao-Kang; Liu, Qing-Yun

    2018-05-01

    Biodegradable Mg alloys have generated great interest for biomedical applications. Accurate predictions of in vivo degradation of Mg alloys through cost-effective in vivo evaluations require the latter to be conducted in an environment close to that of physiological scenarios. However, the roles of glucose and buffering agents in regulating the in vivo degradation performance of Mg alloys has not been elucidated. Herein, degradation behavior of AZ31 alloy is investigated by hydrogen evolution measurements, pH monitoring and electrochemical tests. Results indicate that glucose plays a content-dependent role in degradation of AZ31 alloy in buffer-free saline solution. The presence of a low concentration of glucose, i.e. 1.0 g/L, decreases the corrosion rate of Mg alloy AZ31, whereas the presence of 2.0 and 3.0 g/L glucose accelerates the corrosion rate during long term immersion in saline solution. In terms of Tris-buffered saline solution, the addition of glucose increases pH value and promotes pitting corrosion or general corrosion of AZ31 alloy. This study provides a novel perspective to understand the bio-corrosion of Mg alloys in buffering agents and glucose containing solutions.

  19. Selectividad de caña de azúcar en bovinos

    Directory of Open Access Journals (Sweden)

    E. M. Aranda

    2009-01-01

    Full Text Available Se condujo este trabajo con el objetivo de conocer la aceptación del forraje de caña de azúcar integral en la dieta con base de pasto para bovinos adultos fistulados en rumen y duodeno estabulados; para ello, se ofreció pasto estrella africana (Cynodon plectostachyus y caña de azúcar (Saccharum officinarum mezclada con 1% de urea a voluntad, por separado. Se midió la composición de los alimentos, consumo de materia seca, pH ruminal y duodenal. Se utilizaron técnicas de la estadística descriptiva, como la media aritmética y error estándar. La proteína, paredes celulares y hemicelulosa fueron mayores para el pasto estrella. El consumo de MS fue de 46.6 y 38.1% para la caña de azúcar y el pasto, respectivamente; el pH ruminal tuvo valores de 7.3, disminuyendo a 6.7 a las 12 h.; y el pH de la digesta duodenal osciló de 3.7 a 4.7. Se concluye que hubo mayor aceptación por la caña de azúcar y el pH ruminal no indica valores que afecten la celulólisis ruminal.

  20. Corrosion behaviour of laser surface melted magnesium alloy AZ91D

    International Nuclear Information System (INIS)

    Taltavull, C.; Torres, B.; Lopez, A.J.; Rodrigo, P.; Otero, E.; Atrens, A.; Rams, J.

    2014-01-01

    A high power diode laser (HPDL) was used to produce laser surface melting (LSM) treatments on the surface of the Mg alloy AZ91D. Different treatments with different microstructures were produced by varying the laser-beam power and laser-scanning speed. Corrosion evaluation, using hydrogen evolution and electrochemical measurements, led to a relationship between microstructure and corrosion. Most corrosion rates for LSM treated specimens were within the scatter of the as-received AZ91D, whereas some treatments gave higher corrosion rates and some of the samples had corrosion rates lower than the average of the corrosion rate for AZ91D. There were differences in corroded surface morphology. Nevertheless laser treatments introduced surface discontinuities, which masked the effect of the microstructure. Removing these surface defects decreased the corrosion rate for the laser-treated samples. - Highlights: • Corrosion behavior of AZ91D Mg alloys is intimately related with its microstructure. • Laser surface melting treatments allows surface modification of the microstructure. • Different laser parameters can achieve different microstructures. • Controlling laser parameters can produce different corrosion rates and morphologies. • Increase of surface roughness due to laser treatment is relevant to the corrosion rate

  1. poCAMon personal online continuous airmonitor

    International Nuclear Information System (INIS)

    Streil, T.; Oeser, V.

    2015-01-01

    The poCAMon combines a very compact design with a high flow rate and long battery life. Its size and weight are still acceptable for carrying by one person. The unit measures long-lived aerosols as well as short-lived Radon/Thoron daughters by alpha spectroscopy and beta counting. The radioactive aerosols and particles are collected on the surface of a high resolution membrane filter. The alpha and beta decays on the filter are measured by a high-end semiconductor radiation detector (400 mm@). This allows a perfect separation of the different decay products. The increased pump rate (more than 3 l/ min) is suitable for lower detection limits. A sensor measures permanently the pressure drop on the filter in order to recognize an exhausted or perforated filter instantly. With the 3.8 Ah NiMH battery pack the poCAMon achieves an operation time of more than 30 hours. The quality control is a main issue of any radiation measurement. Therefore the poCAMon records a complete alpha spectrum for each measured value. This allows the monitoring of the device's perfect operation in each moment of the measurement. There are options for additional sensors for carbon monoxide and combustible gases as needed in underground mines. All measured data are stored in a 2GB memory card and can be accessed with a PC or laptop via a USB interface. Data transmission and device control can also be done via wireless ZigBee network or via a server for stationary operation with network access. A barometric pressure sensor and a GPS receiver are optional features of the device.

  2. Optimizacija razvoza po lastnih prodajalnah izbranega podjetja

    OpenAIRE

    Bagari, Jasmina

    2015-01-01

    V diplomskem delu obravnavamo problematiko optimizacije razvoza pekovskih izdelkov v lastne prodajalne. Reševanja problematike smo se lotili s pomočjo sledilnega sistema Trak 8. Najprej smo naredili posnetek stanja in nato analizirali pridobljene podatke. Prišli smo do zaključka, da lahko proge razvoza bolj racionalno in točno načrtujemo. S tem odpravimo podvojene kilometre, prazne kilometre in zmanjšamo stroške razvoza. Po prestrukturiranju vseh prog smo prišli do spoznanja, da lahko lastne ...

  3. Friction stir welded AM50 and AZ31 Mg alloys: Microstructural evolution and improved corrosion resistance

    Energy Technology Data Exchange (ETDEWEB)

    Templeman, Yael [Department of Materials Engineering, Ben Gurion University of the Negev, PO Box 653, Beer Sheva 84105 (Israel); Ben Hamu, Guy [Department of Mechanical Engineering, Sami Shamoon College of Engineering, Ashdod 77245 (Israel); Meshi, Louisa, E-mail: Louisa@bgu.ac.il [Department of Materials Engineering, Ben Gurion University of the Negev, PO Box 653, Beer Sheva 84105 (Israel)

    2017-04-15

    One of the major drawbacks of Mg alloys is poor weldability, caused by porosity formation during conventional fusion welding processes. Friction Stir Welding (FSW) is promising technique in this context since it is a solid state technique. Contradicting results were published in the literature regarding the FSWed Mg alloys joint's properties. Current research was performed in order to investigate the microstructure and corrosion properties of FSWed Mg alloys, studying representatives of two commercial families: wrought AZ31-H24 and die cast AM50. It was found that in both alloys recrystallization occurred during the FSW. In AM50 the mechanism of the recrystallization was continuous, manifested by dislocation rearrangement into sub grain boundaries. In AZ31 discontinuous recrystallization had occurred through grain boundaries migration - twins rotated with respect to the matrix, turning into low angle grain boundaries. Corrosion resistance has improved during the FSW in both alloys to different extents. In the AM50 alloy, the nugget exhibited significantly higher surface potential than the base metal mainly due to the higher Al concentration in the matrix of the nugget, resulting from the dissolution of Al-enrichment and β-Mg{sub 17}Al{sub 12} phase. In the AZ31 alloy, no change in Al concentration had occurred, and the surface potential measured in the nugget was only slightly higher than in the base metal. These results underline the appropriateness of the FSW for Mg alloys since during the conventional welding deterioration of the corrosion resistance occurs. - Highlights: • Following FSW, AZ31-H24 experienced discontinuous recrystallization. • In AZ31 grain boundaries migration occurred, thus twins rotated. • In die cast AM50 continuous recrystallization occurred during the FSW. • In AM50 - dislocations rearranged into sub grain boundaries. • Corrosion resistance has improved during the FSW in both alloys to different extent.

  4. Friction stir welded AM50 and AZ31 Mg alloys: Microstructural evolution and improved corrosion resistance

    International Nuclear Information System (INIS)

    Templeman, Yael; Ben Hamu, Guy; Meshi, Louisa

    2017-01-01

    One of the major drawbacks of Mg alloys is poor weldability, caused by porosity formation during conventional fusion welding processes. Friction Stir Welding (FSW) is promising technique in this context since it is a solid state technique. Contradicting results were published in the literature regarding the FSWed Mg alloys joint's properties. Current research was performed in order to investigate the microstructure and corrosion properties of FSWed Mg alloys, studying representatives of two commercial families: wrought AZ31-H24 and die cast AM50. It was found that in both alloys recrystallization occurred during the FSW. In AM50 the mechanism of the recrystallization was continuous, manifested by dislocation rearrangement into sub grain boundaries. In AZ31 discontinuous recrystallization had occurred through grain boundaries migration - twins rotated with respect to the matrix, turning into low angle grain boundaries. Corrosion resistance has improved during the FSW in both alloys to different extents. In the AM50 alloy, the nugget exhibited significantly higher surface potential than the base metal mainly due to the higher Al concentration in the matrix of the nugget, resulting from the dissolution of Al-enrichment and β-Mg 17 Al 12 phase. In the AZ31 alloy, no change in Al concentration had occurred, and the surface potential measured in the nugget was only slightly higher than in the base metal. These results underline the appropriateness of the FSW for Mg alloys since during the conventional welding deterioration of the corrosion resistance occurs. - Highlights: • Following FSW, AZ31-H24 experienced discontinuous recrystallization. • In AZ31 grain boundaries migration occurred, thus twins rotated. • In die cast AM50 continuous recrystallization occurred during the FSW. • In AM50 - dislocations rearranged into sub grain boundaries. • Corrosion resistance has improved during the FSW in both alloys to different extent.

  5. Tank 241-AZ-101 criticality assessment resulting from pump jet mixing: Sludge mixing simulation

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, Y.; Recknagle, K.

    1997-04-01

    Tank 241-AZ-101 (AZ-101) is one of 28 double-shell tanks located in the AZ farm in the Hanford Site`s 200 East Area. The tank contains a significant quantity of fissile materials, including an estimated 9.782 kg of plutonium. Before beginning jet pump mixing for mitigative purposes, the operations must be evaluated to demonstrate that they will be subcritical under both normal and credible abnormal conditions. The main objective of this study was to address a concern about whether two 300-hp pumps with four rotating 18.3-m/s (60-ft/s) jets can concentrate plutonium in their pump housings during mixer pump operation and cause a criticality. The three-dimensional simulation was performed with the time-varying TEMPEST code to determine how much the pump jet mixing of Tank AZ-101 will concentrate plutonium in the pump housing. The AZ-101 model predicted that the total amount of plutonium within the pump housing peaks at 75 g at 10 simulation seconds and decreases to less than 10 g at four minutes. The plutonium concentration in the entire pump housing peaks at 0.60 g/L at 10 simulation seconds and is reduced to below 0.1 g/L after four minutes. Since the minimum critical concentration of plutonium is 2.6 g/L, and the minimum critical plutonium mass under idealized plutonium-water conditions is 520 g, these predicted maximums in the pump housing are much lower than the minimum plutonium conditions needed to reach a criticality level. The initial plutonium maximum of 1.88 g/L still results in safety factor of 4.3 in the pump housing during the pump jet mixing operation.

  6. Tank 241-AZ-101 criticality assessment resulting from pump jet mixing: Sludge mixing simulation

    International Nuclear Information System (INIS)

    Onishi, Y.; Recknagle, K.

    1997-04-01

    Tank 241-AZ-101 (AZ-101) is one of 28 double-shell tanks located in the AZ farm in the Hanford Site's 200 East Area. The tank contains a significant quantity of fissile materials, including an estimated 9.782 kg of plutonium. Before beginning jet pump mixing for mitigative purposes, the operations must be evaluated to demonstrate that they will be subcritical under both normal and credible abnormal conditions. The main objective of this study was to address a concern about whether two 300-hp pumps with four rotating 18.3-m/s (60-ft/s) jets can concentrate plutonium in their pump housings during mixer pump operation and cause a criticality. The three-dimensional simulation was performed with the time-varying TEMPEST code to determine how much the pump jet mixing of Tank AZ-101 will concentrate plutonium in the pump housing. The AZ-101 model predicted that the total amount of plutonium within the pump housing peaks at 75 g at 10 simulation seconds and decreases to less than 10 g at four minutes. The plutonium concentration in the entire pump housing peaks at 0.60 g/L at 10 simulation seconds and is reduced to below 0.1 g/L after four minutes. Since the minimum critical concentration of plutonium is 2.6 g/L, and the minimum critical plutonium mass under idealized plutonium-water conditions is 520 g, these predicted maximums in the pump housing are much lower than the minimum plutonium conditions needed to reach a criticality level. The initial plutonium maximum of 1.88 g/L still results in safety factor of 4.3 in the pump housing during the pump jet mixing operation

  7. Characterization of the first core sample of neutralized current acid waste from double-shell tank 101-AZ

    International Nuclear Information System (INIS)

    Peterson, M.E.; Scheele, R.D.; Tingey, J.M.

    1989-09-01

    In FY 1989, Westinghouse Hanford Company (WHC) successfully obtained four core samples (totaling seven segments) of neutralized current acid waste (NCAW) from double-shell tanks (DSTs) 101-AZ and 102-AZ. A segment was a 19-in.-long and 1-in.-diameter cylindrical sample of waste. A core sample consisted of enough 19-in.-long segments to obtain the waste of interest. Three core samples were obtained from DST 101-AZ and one core sample from DST 102-AZ. Two DST 101-AZ core samples consisted of two segments per core, and the third core sample consisted of only one segment. The third core consisted of the solids from the bottom of the tank and was used to determine the relative abrasiveness of this NCAW. The DST 102-AZ core sample consisted of two segments. The core samples were transported to the Pacific Northwest Laboratory (PNL), where the waste was extruded from its sampler and extensively characterized. A characterization plan was followed that simulated the processing of the NCAW samples through retrieval, pretreatment and vitrification process steps. Physical, rheological, chemical and radiochemical properties were measured throughout the process steps. The characterization of the first core sample from DST 101-AZ was completed, and the results are provided in this report. The results for the other core characterizations will be reported in future reports. 3 refs., 13 figs., 10 tabs

  8. Leaching of 210Po in human saliva from smokeless tobacco

    International Nuclear Information System (INIS)

    Syed, U.F.; Bari, A.; Husain, L.; Husain, L.

    2009-01-01

    Use of smokeless tobacco (SLT) is associated with cancer of the oral cavity. 210 Po, a known carcinogen present in SLT may leach into the saliva when the snuff is held in the mouth. Alpha emission from leached 210 Po can cause oral tissue damage, especially in the presence of non healing ulcers seen frequently in snuff users' mouth. Leaching of 210 Po from SLT in human saliva was determined for six popular US snuff brands. 210 Po was leached into human saliva for 30 min, separated radiochemically and its activity was determined by α-counting. Approximately 2-10% of 210 Po present in SLT was observed to leach. Annual exposure from leached 210 Po, based on average daily consumption of 15 g of SLT, was calculated to range from 1.1 to 3.8 Bq year -1 . (author)

  9. Vibrational modes of deuterium in KD2PO4

    International Nuclear Information System (INIS)

    Mizoguchi, Kohji; Agui, Akane; Tominaga, Yasunori; Nakai, Yusuke; Ikeda, Susumu.

    1993-01-01

    In order to study the deuteration effect in hydrogen-bonded compounds such as KH 2 PO 4 , hydrogen and deuterium modes in KH 2 PO 4 and K(D x H 1-x ) 2 PO 4 (x = 95 %) were investigated by means of inelastic neutron-scattering measurements over a wide energy range. By comparing Raman spectra of KH 2 PO 4 and KD 2 PO 4 with neutron-scattering spectra, the vibrational modes of deuterium and those of PO 4 tetrahedrons in the energy range of 30 < ε < 150 meV have been investigated. At least two deuterium modes have been found at 87 meV and 106 meV. (author)

  10. Afprøvning af et sundhedspædagogisk koncept målrettet voksne med psykisk sygdom i region Syddanmark – fokus på kompetenceudvikling af professionelle. Projekt ’Livsstilsguide i praksis (2015-2017)’

    DEFF Research Database (Denmark)

    Folmann Hempler, Nana; Saurbrey Pals, Regitze; Oest, Lone

    2017-01-01

    Særlig læring/særlig succes Behovsafdækningen i projektet peger på, at der er behov for at styrke professionelles kompetencer til at samarbejde med voksne med psykisk sygdom om sundhed. Nærværende projekt viser, at professionelle kan styrke samarbejdskompetencer vha. undervisning. Baggrund Voksne...

  11. Projekt ArcLib - budování systému pro dlouhodobou archivaci digitálních dat v českých knihovnách

    Czech Academy of Sciences Publication Activity Database

    Melichar, M.; Hutař, J.; Růžička, M.; Hruška, Z.; Vašek, Z.; Bartošek, M.; Lhoták, Martin

    2016-01-01

    Roč. 20, č. 2 (2016), s. 13-17 ISSN 1335-793X R&D Projects: GA MK(CZ) DG16P02R044 Keywords : digital archiving * open source * OAIS Subject RIV: IN - Informatics, Computer Science http://itlib.cvtisr.sk/buxus/docs/13_projekt%20arclib.pdf

  12. Inovativní metody monitorování emisí z naftových motorů v reálném městském provozu (projekt MEDETOX.)

    Czech Academy of Sciences Publication Activity Database

    Topinka, Jan; Vojtíšek, M.; Gruntorád, P.

    2012-01-01

    Roč. 24, č. 5 (2012), s. 44-46 ISSN 1211-0337 Grant - others:Projekt MEDETOX(XE) LIFE10 ENV/CZ/651 Institutional research plan: CEZ:AV0Z50390703 Keywords : engine emissions * real traffic * biofuels toxicity of engine emissions Subject RIV: DN - Health Impact of the Environment Quality

  13. PO2 Cycling Reduces Diaphragm Fatigue by Attenuating ROS Formation

    OpenAIRE

    Zuo, Li; Diaz, Philip T.; Chien, Michael T.; Roberts, William J.; Kishek, Juliana; Best, Thomas M.; Wagner, Peter D.

    2014-01-01

    Prolonged muscle exposure to low PO2 conditions may cause oxidative stress resulting in severe muscular injuries. We hypothesize that PO2 cycling preconditioning, which involves brief cycles of diaphragmatic muscle exposure to a low oxygen level (40 Torr) followed by a high oxygen level (550 Torr), can reduce intracellular reactive oxygen species (ROS) as well as attenuate muscle fatigue in mouse diaphragm under low PO2. Accordingly, dihydrofluorescein (a fluorescent probe) was used to monito...

  14. Levels of 210 Pb and 210 Po in Brazilian cigarettes

    International Nuclear Information System (INIS)

    Santos, Pedro Lopes dos; Kelecom, Alphonse; Gouvea, Rita de Cassia dos Santos; Dutra, Iedo Ramos

    1996-01-01

    210 Po and 210 Pb concentrations have been determined in 18 Brazilian cigarette samples and compared with known data on U content. U is respectively 3-fold less and 4-fold less abundant than 210 Po or 210 Pb. No correlation could be observed between U concentration and those of Po or Pb. The mean concentration of 210 Pb is higher than that of 210 Pb observed in many other plants, even in plants frown in high background areas. (author)

  15. Assessment of 210Po in foodstuffs consumed in Korea

    International Nuclear Information System (INIS)

    Chang Woo Lee; Mun Ja Kang; Wanno Lee; Geun Sik Choi; Young Hyun Cho; Hee Reyoung Kim; Kun Ho Chung

    2009-01-01

    210 Po in the daily diet in Korea was analyzed and the ingestion dose from an intake of 210 Po was estimated by considering the dietary habit of a Korean person. The 210 Po concentrations of a leafy vegetable (0.36 Bq x kg -1 for lettuce) in the terrestrial food were higher than those of grain, whereas Chinese cabbage had a lesser 210 Po concentration (0.019 Bq x kg -1 ). The 210 Po concentration of the animal product was similar to those detected in the grain and vegetable. The 210 Po concentrations in the shell and crustaceous were high from 19.1 to 33.0 Bq x kg -1 , however, its value fell in the overall range of the reported values. The effective dose from 210 Po for an adult from the Korean population was about 269.4 μSv x y -1 . Nearly 80% of the ingestion dose from the intake of 210 Po was attributed to the consumption of seafood. It suggests that the marine food ingestion is a critical pathway for natural 210 Po to the Korean population. (author)

  16. Análisis del perfil de azúcares en la autentificación de zumos de frutas

    OpenAIRE

    Úbeda Gallego, Ana

    2013-01-01

    El objetivo general ha sido estudiar el perfil de azúcares por HPAEC-PAD para la autentificación de zumos de frutas de naranja, manzana y piña. Este objetivo general se ha dividido en los siguientes objetivos parciales: 1. Optimizar el método de análisis de azúcares por HPAEC-PAD. Para ello se han ensayado distintas concentraciones de NaOH en la fase móvil y distinta velocidad de flujo. Se han analizando muestras de azúcares, zumos concentrados y zumos comerciales. 2. Determinar el p...

  17. Crystal structure of polyphosphates NaCd(PO3)3 and NaMn(PO3)3

    International Nuclear Information System (INIS)

    Murashova, E.V.; Chudinova, N.N.

    1997-01-01

    Crystal structure of NaCd(PO 3 ) 3 (1) and NaMn(PO 3 ) 3 (2) isostructural polyphosphates was determined for twin samples. Rhombic lattice parameters of (1): a = 14.678, b = 14.669, c = 14.705 A, sp. gr. P2 1 2 1 2 1 , Z = 16. The structure of compounds is of frame type. Polyphosphate chain with repetition period of 24 PO 4 tetrahedrons contacts with NaO 6 and M 2 O 6 octahedrons by means of common oxygen vertices. Similarities and differences in structure of mentioned polyphosphates and earlier analyzed NaMg(PO 3 ) 3 polyphosphate are noted [ru

  18. Effect of excitation energy and angular momentum on the characteristics of 208Po and 210Po compound nucleus fission fragments

    International Nuclear Information System (INIS)

    Itkis, M.G.; Kalpakchieva, R.; Okolovich, V.N.; Penionzhkevich, Yu.Eh.; Tolstikov, V.N.

    1982-01-01

    To study characteristics of fissioning nucleus fragments, investigated were reactiiiiiiiiiiiiiiiH8Pt+ 12 C → 210 Po in the 12 C ion energy range of 86-110.5 MeV, of 192 Os+ 16 O → 208 Po in 90-131 MeV range, 204 Pb+ 3 He → 207 Po, 206 Pb+ 3 He → 209 Po, 207 Pb+ 3 He → 210 Po with 60 MeV 3 He ion energy. Using a correlation technique for measuring energies of two fragments mass and energy distributions of fission fragments of 208 Po and 210 Po compound nuclei produced in the reactions have been studied. Mass and energy distributions of fragments from fission of 208 Po and 210 Po in the reactions with ions 16 O, 12 C and 3 He were investigated in an ample energy range, using the correlational techniques for measurement of energies of two fragments. An increase in the total kinetic energy with rise of the angular momentum was observed, the fact indicating a weak coupling of one-particle and collective modes of motion in the fissile nucleus resulting in that the rolational energy is transfered mainly to translation energies of the fragments

  19. Neutralization of Na2PO4: Reaction between Na3PO4 and CaCL2

    International Nuclear Information System (INIS)

    Xia Shenglan; Wang Luning

    1990-01-01

    The results of reaction Na 3 PO 4 with CaCl 2 in water at ambient and higher temperature are described. The reaction rate of Na 3 PO 4 with CaCl 2 is slow at ambient temperature and the reaction is complete at 260 deg C after 2 h. The products are Ca(OH) 2 and Ca 5 (PO 4 ) 3 (OH). The quantity of them is dependent upon the quanity of Na 3 PO 4 and CaCl 2 contained in water, all of them control pH of water

  20. pO2 measurements in arteriolar networks.

    Science.gov (United States)

    Torres Filho, I P; Kerger, H; Intaglietta, M

    1996-03-01

    Previous studies from our laboratory have shown that the average arteriolar pO2 in the hamster skinfold preparation is lower than arterial systemic pO2. In the present work we tested the hypothesis that there is a longitudinal gradient of pO2 along precapillary vessels. Experiments were performed in Syrian golden hamsters bearing a dorsal skin chamber. The oxygen-dependent quenching of phosphorescence of palladium-porphyrin complexes was used to measure intravascular pO2 in the microcirculation. Arterioles were classified in four orders according to their position in the network, first-order vessels being the entrance points. Simultaneous determinations of diameter (D), red blood cell velocity, and systemic blood gases were also made. There was a significant fall of pO2 between vessels of different orders. First-order arterioles (mean D = 64 microns) had pO2 of 51.8 +/- 9.8 mm Hg (mean +/- SD) which was equivalent to approximately equal to 73% of the arterial systemic pO2. Within the arteriolar network, further decreases of intravascular pO2 were measured, leading to a pO2 of 34.0 +/- 7.9 mm Hg in terminal arterioles (mean D = 7.7 microns). In some vessels pO2 was measured in different positions of the same arteriole. The average longitudinal arteriolar oxygen saturation gradient was 3.4 +/- 0.4 delta %/mm (range 0.8-7.2). A significant and positive correlation was found between pO2 and microhemodynamic parameters when arterioles were grouped according to their order. This relation was not significant for venules which showed a mean pO2 of 30.8 +/- 10.8 mm Hg. Tissue pO2 averaged 24.6 +/- 5.8 mm Hg. We conclude that: (1) There is an oxygen loss in arterial vessels larger than 100 micrograms in diameter, (2) arteriolar pO2 in this preparation depends on the position of the vessel within the network, (3) a substantial portion of oxygen delivery to the hamster skin is provided by the arteriolar network, and (4) only a small pO2 gradient exists between terminal

  1. Studies of {sup 194,195,197}Po

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, M.P.; Ahmad, I.; Crowell, B. [and others

    1995-08-01

    The energy systematics of low-lying polonium states show sudden changes near N = 114. The observed drops in the low-lying levels of {sup 196,198}Po relative to the heavier isotopes indicate significant changes in the underlying structure of these nuclei. It is thought that this change is due to the onset of vibrational collectivity brought about by the quadrupole interaction between neutron and proton-pairs. In order to extend the Po systematics even further, we measured, for the first time, states in {sup 194,195,197}Po using the {sup 28}Si + {sup 170}Yb reaction at a beam energy of 142 MeV. The beam was supplied by ATLAS, and the data were taken with 10 Compton-suppressed Ge detectors placed at the target position of the Fragment Mass Analyzer. Preliminary level schemes were constructed for {sup 194,195,197}Po based on {gamma}-{gamma} and {gamma}-FMA coincidences. The results for {sup 194}Po show that the 2{sup +} - 0{sup +} transition energy decreased in energy by 140 keV relative to {sup 196}Po suggesting that this nucleus moved beyond the vibrational limit to more collective motion. An extrapolation of the systematics predicts that the 2{sup +} energy could drop another 140 keV between {sup 194}Po and {sup 192}Po which would indicate the onset of rotational motion. Currently, we have an approved experiment to investigate the decay of yrast isomers in {sup 194}Po which will allow us to (1) confirm our earlier level scheme of {sup 194}Po, and (2) assess the experimental conditions needed for a future study of {sup 192}Po.

  2. Research Report: Neue Formen der gesellschaftlichen Kommunikation von Wissen – Ein videografisches Projekt [New Social Forms of Knowledge Communication─A Videographic Project

    Directory of Open Access Journals (Sweden)

    Roman Pernack

    2008-11-01

    Full Text Available Hardly any conference talks are given without illustrative picture, tables and graphics. The entire conference culture has changed as a result of Powerpoint and similar programs. The talk has become the presentation. The body of the speaker plays an important role in communicating the content to an audience. To examine this new phenomenon of conference culture a video camera was used as an instrument of data collection in a project (http://www2.tu-berlin.de/~soziologie/AllgSoz/projekt/index2.htm supported by the German Research Foundation (Deutsche Forschungsgemeinschaft, DFG. Video analysis can be highly beneficial when examining the corporeality of interactive events. The film (2008, German/English, 15 min, Stereo 3:4, PAL introduces the method of videography and thereby shows some results of the research project. URN: urn:nbn:de:0114-fqs0803P16

  3. Controlling applied to information processing: quality management applied to IP projects and IP services; Informationsverarbeitungs-Controlling: Qualitaetsmanagement fuer IV-Projekte und fuer IV-Service

    Energy Technology Data Exchange (ETDEWEB)

    Becker, B. [Vereinigung Deutscher Elektrizitaetswerke e.V. (VDEW), Frankfurt am Main (Germany); Beckers, F. [Isar-Amperwerke AG, Muenchen (Germany); Dewald, N. [Bayernwerk AG, Muenchen (Germany); Hauffe, P. [Pfalzwerke AG, Ludwigshafen am Rhein (Germany); Hein, F. [EVS AG Stuttgart (Germany); Hoederath, M. [Vereinigte Elektrizitaetswerke Westfalen AG (VEW), Dortmund (Germany); Seyen, R. [Staedtische Werke Nuernberg GmbH (Germany)

    1998-01-12

    The working group on information processing (IP) basics (in German: `IV-Grundlagen`) has prepared this contribution dealing with controlling applied to information processing. This new report, on the one hand, takes into consideration the role of the organizational IP unit as one offering its services to all sections of a company. On the other hand, information processing as an operational infrastructure influencing all business processes becomes increasingly important with respect to the competitiveness of the EVU. Therefore, quality management applied to IP projects and IP services must support this development. (orig./RHM) [Deutsch] Der VDEW Arbeitskreis `IV-Grundlagen` hat einen Beitrag zum Controlling fuer die Informationsverarbeitung erstellt. Hier geht zum einen die Rolle der Organisationseinheit IV als Dienstleister fuer alle Unternehmensbereiche ein. Zum anderen gewinnt die Informationsverarbeitung als betriebliche Infrastruktur fuer alle Geschaeftsprozesse zunehmende Bedeutung fuer die Wettbewerbsfaehigkeit der EVU. Das Qualitaetsmanagement fuer IV-Projekte und fuer IV-Service muss dies unterstuetzen. (orig./RHM)

  4. The world's biggest dam construction project at the Yangtze river. The Three Gorges project; Weltweit groesster Staudamm entsteht am Jangtse. Three-Gorges-Projekt

    Energy Technology Data Exchange (ETDEWEB)

    Kreher, G.

    2002-02-11

    The author, having seen the Three Gorges Project model exhibited at the Expo 2000 in Hannover, went there to get an impression of the real dimensions of this gigantic project. His report also contains personal impressions but primarily gives a picture of the engineering, landscaping, and social aspects and implications, also referring to relevant technical information obtained on site.(orig./CB) [German] Der Autor hat den Stand der Arbeiten am Three-Gorges-Projekt (TGP) anhand eines im China-Pavillon auf der Expo 2000 in Hannover detailliert vorgestellten Planungsprojektes zum Anlass genommen, sich vor Ort vom Fortgang der Arbeiten zu ueberzeugen. Vor allem war das Interesse zum heute noch sichtbaren urspruenglichen Landschaftsbild und den sich danach in vielen Bereichen ergebenden Veraenderungen in der Region geweckt. Im Folgenden sollen ein Bild der persoenlichen Eindruecke, eine Einschaetzung des Verfassers zur Situation vor Ort und zeitnahe Aussagen von zugaenglichen Quellen widergespiegelt werden. (orig.)

  5. MEE-project: One year of public relations on the environment and energy. MEE-projekt: Een jaar voorlichten over milieu en energie

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1991-06-26

    A final overview is presented of the MEE-project ('Milieu- En Energie projekt' or Environmental and Energy project). The MEE-project was aimed at stimulating energy saving and improving the public attitude concerning energy and the environment. The project is also considered as an employment project for the unemployed. The main target group of the project was the households in the Dutch municipality Heerhugowaard. Five persons in search of employment offered interested private households options to save energy and the environment within their own surroundings by means of information and documentation. 5610 information packets were delivered. The costs did not exceed 115,000 Dutch guilders. The overall conclusion is positive: the people of the municipality are active in trying to save energy and the environment. Four of the five project members have new and better perspectives for a job.

  6. MEMS - Munich Energy Management System. FIA Project: Exchange of research information; MEMS - Muenchner Energiemanagement-System. FIA-Projekt - Forschungs-Informations-Austausch

    Energy Technology Data Exchange (ETDEWEB)

    Funk, H.; Fries, W.

    2001-10-01

    The City of Munich developed the project 'Munich Energy-Management-Systems (MEMS)' with financial support from the Federal Ministry of Economy and Technology. The project is based on a system of building automation using as many standard elements of hardware and software as possible. This will guarantee a high degree of independence from suppliers and subcontractors. The project has led to a reliable working base for the evaluation, measuring and control for ca. 150 municipal buildings. (orig.) [German] Mit dem Projekt 'Muenchner Energie-Management-System (MEMS)' erstellte die Landeshauptstadt Muenchen mit finanzieller Unterstuetzung des Bundesministeriums fuer Wirtschaft und Technologie ein auf der Leitzentrale Haustechnik (LZH) basierendes zentrales Energiemanagementsystem. Die Verwendung moeglichst vieler Standards in Hard- und Software ist dabei ein wesentlicher Gesichtspunkt. Dadurch wurde eine weitgehende Unabhaengigkeit von einem einzelnen Hersteller erreicht. Damit wurde ein Erfassungs-, Auswerte- und Steuerungssystem fuer derzeit rund 150 staedtische Gebaeude geschaffen. (orig.)

  7. Bioetanol de la caña de azúcar

    Directory of Open Access Journals (Sweden)

    N. Aguilar-Rivera

    2007-01-01

    Full Text Available La búsqueda de la viabilidad y desarrollo de la agroindustria de la caña de azúcar es ya una política imperativa. La producción de caña y azúcar constituyen la principal agroindustria del país, con presencia en 57 ingenios azucareros, localizados en 15 estados de la república. Sin embargo, la actual ineficiencia productiva, altos costos y otras causas —como la entrada de jarabe de maíz de alta fructosa (HFCS de menor costo— han desplazado el consumo interno de azúcar de caña, principalmente en bebidas embotelladas. Todos estos factores han contribuido a la actual y prolongada crisis del sector azucarero. Por lo tanto, la industria debe reestructurarse y reducir la producción de azúcar hacia la competitividad, con la alternativa del etanol combustible en la búsqueda de un futuro para la industria azucarera en México. Con la producción de etanol (EtOH a gran escala, por parte de los ingenios azucareros, es posible visualizar un nuevo y futuro mercado de uso de energías renovables en México, oportunidades para la exportación e incrementar los beneficios ambientales y económicos a través de su uso. La flexibilidad de la producción combinada, de azúcar y etanol en los ingenios, permitirá alcanzar esquemas y objetivos ambientales como nación. Para la industria azucarera, su mayor competidesafío, en este sentido, representa disminuir los costos actuales de producción de etanol a través del uso de la ingeniería genética, uso de diferentes materias primas y la totalidad de la planta de caña de azúcar e introducir mejoras tecnológicas.

  8. Desarrollo de las pequeñas industrias rurales de la caña de azúcar en iberoamerica: Melaza, Panela y Azúcar Moreno

    OpenAIRE

    Da Silva, Fabio César; Cesar, Marco; Hernández Díaz-Ambrona, Carlos Gregorio

    2010-01-01

    Los niveles de producción de azúcar en los últimos años crecen a un ritmo semejante al crecimiento poblacional. El fabricante debe estar atento a las características de calidad del producto que su mercado o comprador/consumidor exige y la facilidad de transporte al centro consumidor. La legislación debe especificar los requisitos mínimos pero el fabricante debe tener como desafío ofrecer un producto de calidad y reducir los riesgos ambientales en sus cultivos en función de la aptitud de la...

  9. AZ-101 Mixer Pump Demonstration Data Acquisition System and Gamma Cart Data Acquisition Control System Software Configuration Management Plan

    International Nuclear Information System (INIS)

    WHITE, D.A.

    1999-01-01

    This Software Configuration Management Plan (SCMP) provides the instructions for change control of the AZ1101 Mixer Pump Demonstration Data Acquisition System (DAS) and the Sludge Mobilization Cart (Gamma Cart) Data Acquisition and Control System (DACS)

  10. A biodegradable AZ91 magnesium alloy coated with a thin nanostructured hydroxyapatite for improving the corrosion resistance.

    Science.gov (United States)

    Mukhametkaliyev, T M; Surmeneva, M A; Vladescu, A; Cotrut, C M; Braic, M; Dinu, M; Vranceanu, M D; Pana, I; Mueller, M; Surmenev, R A

    2017-06-01

    The main aim of this study was to investigate the properties of an AZ91 alloy coated with nanostructured hydroxyapatite (HA) prepared by radio frequency (RF) magnetron sputtering. The bioactivity and biomineralization of the AZ91 magnesium alloy coated with HA were investigated in simulated body fluid (SBF) via an in vitro test. Scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD) analyses were performed. The samples were immersed in SBF to study the ability of the surface to promote the formation of an apatite layer as well as corrosion resistance and mass change of the HA-coated AZ91 alloy. Electrochemical tests were performed to estimate the corrosion behaviour of HA-coated and uncoated samples. The results revealed the capability of the HA coating to significantly improve the corrosion resistance of the uncoated AZ91 alloy. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Effect of Phosphate Salts (Na3PO4, Na2HPO4, and NaH2PO4) on Ag3PO4 Morphology for Photocatalytic Dye Degradation under Visible Light and Toxicity of the Degraded Dye Products

    NARCIS (Netherlands)

    Amornpitoksuk, P; Intarasuwan, K; Suwanboon, S; Baltrusaitis, Jonas

    2013-01-01

    Ag3PO4 was synthesized by the precipitation method using three different types of phosphate salts (Na3PO4, Na2HPO4, and NaH2PO4) as a precipitating agent. Hydrolysis of each phosphate salt gave a specific pH that affected the purity and morphology of the prepared Ag3PO4. The Ag3PO4 prepared from

  12. Volatilization of Po by microorganisms at laboratory culture experiments

    International Nuclear Information System (INIS)

    Momoshima, N.; Ishida, A.; Yoshinaga, C.; Fukuda, A.

    2005-01-01

    The previous experiments proved the volatility of polonium form culture medium in which microorganisms were propagated from seed of seawater, river water or pond water, therefore we did not know what kind of species are responsible to Po volatility. To search microorganisms, which concerned with Po emission we carried out culture experiments using known microorganisms. Three microorganisms were examined; Escherichia coli K-12, Bacillus subtilis and Chromobacterium violaceum. The microorganisms were pre-cultured in LB medium at 30 degree C and a small portion of the pre-cultured was transferred to a culture bottle in which LB medium and 208 Po tracer were contained. The culture was done at 30 degree C with shaking the culture bottle and air passed through a filter was introduced. The Po volatilized was transferred into the trap vials in which scintillator for liquid scintillation counting (LSC) was contained. The Po activity was measured by LSC. All of the microorganisms examined volatilized Po but their ability was quite different each other. Highest ability was observed on Chromobacterium violaceum and then Escherichia coli K-12 followed by Bacillus subtilis, the relative magnitude of the ability was 10 2 , 10, 1, respectively. Chromobacterium violaceum and Escherichia coli K-12 showed high volatility for the first 24 h but Escherichia coli K-12 showed a decrease thereafter. However high volatility was continued on Chromobacterium violaceum during the culture. The low culture temperature suppressed Po volatility, supporting biologically mediated Po emission from the culture.

  13. Separation and electrodeposited of {sup 210} Po; Separacion y electrodeposito de {sup 210} Po

    Energy Technology Data Exchange (ETDEWEB)

    Ordonez R, E.; Iturbe G, J.L

    1991-12-15

    Presently work it was determined the selective separation of the {sup 210} Po that is in an uraniferous mineral, by means of acid leaching of the mineral and the purification was carried out by means of partition chromatography whose stationary phase is 2-ethylhexyl phosphoric acid (D{sub 2}EHPA), it has been possible to isolate the {sup 210} Po of the rest of the radioactive elements that conform the family 4 N{sup +2}, the optimal elutriation conditions of this element were settled down of manner of not dragging other radioelements. Another of the achievements presented in this communication has been the electrodeposition of this element has more than enough stainless steel discs with a superior yield to 95%. (Author)

  14. Synthesis and crystal structure of hydrogen phosphites RbH2PO3, CsH2PO3, and TlH2PO3

    International Nuclear Information System (INIS)

    Kosterina, E.V.; Troyanov, S.I.; Kemnits, Eh.; Aslanov, L.A.

    2001-01-01

    The crystal acid phosphites RbH 2 PO 3 , CsH 2 PO 3 and TlH 2 PO 3 were separated during reaction of Rb, Cs and Tl carbonates with phosphorous acid solution. The crystal structure of the compounds was analyzed by X-ray diffraction method at 150 K. CsH 2 PO 3 has a monoclinic system, a = 7.930(2), b = 8.929(2), c = 13.163(3) A, β = 104.84(3) Deg, V = 900.9(4) A 3 , Z 8, sp. gr. P2 1 /c, R 1 = 0.239. In the structure hydrogen bonds integrate the PHO 3 tetrahedrons in the unlimited zigzag chains [HPHO 3 ] n n- laying at the layers, which are alternate to the layers of metal cations. The layers of anion chains have a wavy form [ru

  15. In vitro corrosion of pure magnesium and AZ91 alloy?the influence of thin electrolyte layer thickness

    OpenAIRE

    Zeng, Rong-Chang; Qi, Wei-Chen; Zhang, Fen; Li, Shuo-Qi

    2016-01-01

    In vivo degradation predication faces a huge challenge via in vitro corrosion test due to the difficulty for mimicking the complicated microenvironment with various influencing factors. A thin electrolyte layer (TEL) cell for in vitro corrosion of pure magnesium and AZ91 alloy was presented to stimulate the in vivo corrosion in the micro-environment built by the interface of the implant and its neighboring tissue. The results demonstrated that the in vivo corrosion of pure Mg and the AZ91 all...

  16. Levels of 210Po and 210Pb in cigars

    International Nuclear Information System (INIS)

    Kelecom, A.; Gouvea, R.C.S.; Santos, P.L.

    2002-01-01

    210 Po and 210 Pb concentrations have been determined in 58 cigar brands manufactured in 11 countries. Cuban and American cigars showed the lowest 210 Po content. The mean levels of 210 Po in Brazilian, European and Dominican cigars were almost identical and somewhat lower than the levels observed for cigars from other Latin American countries. Cuban, American and European cigars contained low levels of 210 Pb. Cigars from the remaining countries contained twice as much 210 Pb. The mean 210 Po/ 210 Pb ratio showed an excess of polonium. In the case of one cigar-a-day smoker, the calculated annual absorbed dose due to 210 Po is ∼16 μGy. (author)

  17. Evaluation of AY/AZ tank farm ventilation system during aging waste retrieval operations

    International Nuclear Information System (INIS)

    Wong, J.J.; Waters, E.D.

    1995-01-01

    Waste Management is currently planning to demonstrate mobilization of radioactive waste sludges in Tank 101-AZ beginning in October 1991. The retrieval system being designed will utilize mixer pumps that generate high-velocity, high-volume submerged liquid jets to mobilize settled solids. There is concern that these jets may also generate radioactive aerosols, some of which may be carried into the tank Ventilation system. The purpose of this study is to determine if the current AY/AZ ventilation system or the proposed ventilation system upgrade (Project W-030) will provide adequate deentrainment of liquid and solid aerosols during mixer pump operations, or if the radioactive aerosols will overload the HEPA filters

  18. Effect of alternating voltage treatment on corrosion resistance of AZ91D magnesium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, X. [Corrosion and Protection Laboratory, Key Laboratory of Superlight Materials and Surface Technology (Harbin Engineering University), Ministry of Education, Harbin (China); Zhang, T.; Shao, Y.; Meng, G.; Wang, F. [Corrosion and Protection Laboratory, Key Laboratory of Superlight Materials and Surface Technology (Harbin Engineering University), Ministry of Education, Harbin (China); State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, Shenyang (China)

    2012-06-15

    AZ91D magnesium alloy was treated by the alternating voltage (AV) treatment technique. The optimal AV-treatment parameters of the alloy were determined by orthogonal experiments. Polarization curve, electrochemical impedance spectroscopy (EIS), and scanning electrochemical microscopy (SECM) were used to understand the effect of AV-treatment on the corrosion resistance of the alloy. AFM, contact angle, and XPS were employed to investigate further the influence of AV-treatment on the properties of the surface film formed on the alloy after AV-treatment. The results showed that a uniform and stable film was formed and the corrosion resistance of AZ91D magnesium alloy was significantly improved after AV-treatment. This was caused by the noticeable change of the chemical structure and semi-conducting properties of the surface film after AV-treatment. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  19. Influence of Zeolite Coating on the Corrosion Resistance of AZ91D Magnesium Alloy

    Directory of Open Access Journals (Sweden)

    P. Chakraborty Banerjee

    2014-08-01

    Full Text Available The protective performance of zeolite coating on AZ91D magnesium alloy was evaluated using potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS in 0.1 M sodium chloride solution (NaCl. Electrical equivalent circuit (EEC was developed based upon hypothetical corrosion mechanisms and simulated to correspond to the experimental data. The morphology and the chemical nature of the coating were characterized by scanning electron microscopy (SEM and X-ray diffraction (XRD analysis. Post corrosion morphologies of the zeolite coated and the uncoated AZ91D alloy were investigated using SEM. The corrosion resistance of the zeolite coated specimen was at least one order of magnitude higher than the uncoated specimen.

  20. Project W-314 specific test and evaluation plan for AZ tank farm upgrades

    International Nuclear Information System (INIS)

    Hays, W.H.

    1998-01-01

    The purpose of this Specific Test and Evaluation Plan (STEP) is to provide a detailed written plan for the systematic testing of modifications made by the addition of the SN-631 transfer line from the AZ-O1A pit to the AZ-02A pit by the W-314 Project. The STEP develops the outline for test procedures that verify the system's performance to the established Project design criteria. The STEP is a lower tier document based on the W-314 Test and Evaluation P1 an (TEP). Testing includes Validations and Verifications (e.g., Commercial Grade Item Dedication activities, etc), Factory Tests and Inspections (FTIs), installation tests and inspections, Construction Tests and Inspections (CTIs), Acceptance Test Procedures (ATPs), Pre-Operational Test Procedures (POTPs), and Operational Test Procedures (OTPs). The STEP will be utilized in conjunction with the TEP for verification and validation

  1. Diffusion and solubility of Au implanted into the AZ1350 photoresist

    International Nuclear Information System (INIS)

    Soares, M.R.F.; Kaschny, J.R.A.; Santos, J.H.R. dos; Amaral, L.; Behar, M.; Fink, D.

    2000-01-01

    In the present paper we report diffusion and solubility results for Au into the photoresist AZ1350. Au was implanted into AZ1350 films at very low energy (E=20 keV) and fluences (PHI=10 12 and 5x10 12 Au/cm 2 ). In this way the radiation damage introduced by the implantation process was minimized and cluster formation was avoided. Annealing was performed in the 150-300 deg. C temperature range and the as implanted and thermal treated samples were analyzed using the Rutherford backscattering (RBS) technique. For the lowest implantation fluence the results have shown a regular atomic diffusion process characterized by an activation energy of E a =640 meV. Instead, for PHI=5x10 12 Au/cm 2 the diffusional mechanism has revealed the effects of the radiation damage. In addition solubility measurements indicate that the solubility limit at 250 deg. C is of the order 0.3 at.%

  2. Corrosion behavior of biodegradable material AZ31 coated with beeswax-colophony resin

    Science.gov (United States)

    Gumelar, Muhammad Dikdik; Putri, Nur Ajrina; Anggaravidya, Mahendra; Anawati, Anawati

    2018-05-01

    Magnesium (Mg) and its alloys are potential candidates for biodegradable implant materials owing to their ability to degrade spontaneously in a physiological environment. However, the degradation rate is still considered too fast in human body solution. A coating is typically applied to slowdown corrosion rate of Mg alloys. In this work, an organic coating of mixture beeswax-colophony with ratios of 40-60, 50-50, and 60-40 in wt% was synthesized and applied on commercial magnesium alloyAZ31. The coated specimens were then characterized with SEM and XRF. The corrosion behavior of the coated specimens was evaluated by immersion test in 0.9 wt% NaCl solution at 37°C for 14 days. The results indicated that the coating material improved the corrosion resistance of the AZ31 alloy.

  3. Surface roughness optimization in machining of AZ31 magnesium alloy using ABC algorithm

    Directory of Open Access Journals (Sweden)

    Abhijith

    2018-01-01

    Full Text Available Magnesium alloys serve as excellent substitutes for materials traditionally used for engine block heads in automobiles and gear housings in aircraft industries. AZ31 is a magnesium alloy finds its applications in orthopedic implants and cardiovascular stents. Surface roughness is an important parameter in the present manufacturing sector. In this work optimization techniques namely firefly algorithm (FA, particle swarm optimization (PSO and artificial bee colony algorithm (ABC which are based on swarm intelligence techniques, have been implemented to optimize the machining parameters namely cutting speed, feed rate and depth of cut in order to achieve minimum surface roughness. The parameter Ra has been considered for evaluating the surface roughness. Comparing the performance of ABC algorithm with FA and PSO algorithm, which is a widely used optimization algorithm in machining studies, the results conclude that ABC produces better optimization when compared to FA and PSO for optimizing surface roughness of AZ 31.

  4. Surface characterization and cytocompatibility evaluation of silanized magnesium alloy AZ91 for biomedical applications

    Directory of Open Access Journals (Sweden)

    Agnieszka Witecka, Akiko Yamamoto, Henryk Dybiec and Wojciech Swieszkowski

    2012-01-01

    Full Text Available Mg alloys with high Al contents have superior corrosion resistance in aqueous environments, but poor cytocompatibility compared to that of pure Mg. We have silanized the cast AZ91 alloy to improve its cytocompatibility using five different silanes: ethyltriethoxysilane (S1, 3-aminopropyltriethoxysilane (S2, 3-isocyanatopyltriethoxysilane (S3, phenyltriethoxysilane (S4 and octadecyltriethoxysilane (S5. The surface hydrophilicity/hydrophobicity was evaluated by water contact angle measurements. X-ray photoelectron analysis was performed to investigate the changes in surface states and chemical composition. All silane reagents increased adsorption of the albumin to the modified surface. In vitro cytocompatibility evaluation revealed that silanization improved cell growth on AZ91 modified by silane S1. Measurement of the concentration of Mg2+ ions released during the cell culture indicated that silanization does not affect substrate degradation.

  5. Evolution of twinning in extruded AZ31 alloy with bimodal grain structure

    Energy Technology Data Exchange (ETDEWEB)

    Garcés, G., E-mail: ggarces@cenim.csic.es [Department of Physical Metallurgy, National Centre for Metallurgical Research CENIM-CSIC, Av. De Gregorio del Amo 8, 28040 Madrid (Spain); Oñorbe, E. [CIEMAT, Division of Structural Materials, Avenida Complutense, 40, 28040 Madrid (Spain); Gan, W. [German Engineering Materials Science Centre at MLZ, Helmholtz-Zentrum Geesthacht, Lichtebergstr. 1, D-85747 Garching (Germany); Máthis, K. [Department of Physics of Materials, Faculty of Mathematics and Physics, Charles University, KeKarlovu 5, 121 16 Praha 2 (Czech Republic); Tolnai, D. [Institute of Materials Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Str. 1, 21502 Geesthacht (Germany); Horváth, K. [Department of Physics of Materials, Faculty of Mathematics and Physics, Charles University, KeKarlovu 5, 121 16 Praha 2 (Czech Republic); Pérez, P.; Adeva, P. [Department of Physical Metallurgy, National Centre for Metallurgical Research CENIM-CSIC, Av. De Gregorio del Amo 8, 28040 Madrid (Spain)

    2017-04-15

    Twinning in extruded AZ31 alloy with a bimodal grain structure is studied under compression along the extrusion direction. This study has combined in-situ measurements during the compression tests by Synchrotron Radiation Diffraction and Acoustic Emission techniques and the evaluation of the microstructure and texture in post-mortem compression samples deformed at different strains. The microstructure of the alloy is characterized by the coexistence of large areas of fine dynamic recrystallized grains and coarse non-recrystallized grains elongated along extrusion direction. Twinning occurs initially in large elongated grains before the macroscopic yield stress which is controlled by the twinning in equiaxed dynamically recrystallized grains. - Highlights: • The AZ31 extruded at low temperature exhibits a bimodal grains structure. • Twinning takes place before macroscopic yielding in coarse non-DRXed grains. • DRXed grains controls the beginning of plasticity in magnesium alloys with bimodal grain structure.

  6. Corrosion behavior of friction stir welded AZ31B Mg alloy - Al6063 alloy joint

    Directory of Open Access Journals (Sweden)

    B. Ratna Sunil

    2016-12-01

    Full Text Available In the present work, AZ31B Mg alloy and Al6063 alloy-rolled sheets were successfully joined by friction stir welding. Microstructural studies revealed a sound joint with good mechanical mixing of both the alloys at the nugget zone. Corrosion performance of the joint was assessed by immersing in 3.5% NaCl solution for different intervals of time and the corrosion rate was calculated. The joint has undergone severe corrosion attack compared with both the base materials (AZ31B and Al6063 alloys. The predominant corrosion mechanism behind the high corrosion rate of the joint was found to be high galvanic corrosion. From the results, it can be suggested that the severe corrosion of dissimilar Mg–Al joints must be considered as a valid input while designing structures intended to work in corroding environment.

  7. Effect of Rare Earth on Corrosion Products and Impedance Behavior of AZ91 Magnesium Alloy Under Dry-wet Cycles

    Directory of Open Access Journals (Sweden)

    ZHAO Xi

    2017-04-01

    Full Text Available The effect of mischmetal of lanthanum and cerium on the composition and structure of the corrosion products on the surface of AZ91 Mg alloy in deicing salt solution under dry-wet cycles was investigated by scanning electron microscopy (SEM, X-ray diffraction (XRD and energy dispersive spectrometer (EDS. The results show that the corrosion products of AZ91 Mg alloy without mischmetal addition (La,Ce are mainly composed of Mg(OH2, MgO, CaCO3 and Mg6Al2CO3(OH16·4H2O; and (La,CeAlO3 can be found in the products of AZ91 with mischmetal addition, meanwhile dense layer occurs in the corrosion products. Electrochemical impedance spectroscopy (EIS measurements show that the charge transfer resistance of AZ91 alloy with mischmetal addition tested in the same dry-wet cycles is much higher than that of AZ91 alloy, the addition of mischmetal helps to reduce the dispersing effect of impedance spectroscopy, indicating that the corrosion resistance of AZ91 Mg alloy and the stability of corrosion product films can be improved by mischmetal of La and Ce.

  8. TIP48/Reptin and H2A.Z requirement for initiating chromatin remodeling in estrogen-activated transcription.

    Directory of Open Access Journals (Sweden)

    Mathieu Dalvai

    2013-04-01

    Full Text Available Histone variants, including histone H2A.Z, are incorporated into specific genomic sites and participate in transcription regulation. The role of H2A.Z at these sites remains poorly characterized. Our study investigates changes in the chromatin environment at the Cyclin D1 gene (CCND1 during transcriptional initiation in response to estradiol in estrogen receptor positive mammary tumour cells. We show that H2A.Z is present at the transcription start-site and downstream enhancer sequences of CCND1 when the gene is poorly transcribed. Stimulation of CCND1 expression required release of H2A.Z concomitantly from both these DNA elements. The AAA+ family members TIP48/reptin and the histone variant H2A.Z are required to remodel the chromatin environment at CCND1 as a prerequisite for binding of the estrogen receptor (ERα in the presence of hormone. TIP48 promotes acetylation and exchange of H2A.Z, which triggers a dissociation of the CCND1 3' enhancer from the promoter, thereby releasing a repressive intragenic loop. This release then enables the estrogen receptor to bind to the CCND1 promoter. Our findings provide new insight into the priming of chromatin required for transcription factor access to their target sequence. Dynamic release of gene loops could be a rapid means to remodel chromatin and to stimulate transcription in response to hormones.

  9. Comparison of simulants to actual neutralized current acid waste: process and product testing of three NCAW core samples from Tanks 101-AZ and 102-AZ

    Energy Technology Data Exchange (ETDEWEB)

    Morrey, E.V.; Tingey, J.M.; Elliott, M.L.

    1996-10-01

    A vitrification plant is planned to process the high-level waste (HLW) solids from Hanford Site tanks into canistered glass logs for disposal in a national repository. Programs were established within the Pacific Northwest Laboratory Vitrification Technology Development (PVTD) Project to test and model simulated waste to support design, feed processability, operations, permitting, safety, and waste-form qualification. Parallel testing with actual radioactive waste was performed on a laboratory-scale to confirm the validity of using simulants and glass property models developed from simulants. Laboratory-scale testing has been completed on three radioactive core samples from tanks 101-AZ and 102-AZ containing neutralized current acid waste (NCAW), which is one of the first waste types to be processed in the high-level waste vitrification plant under a privatization scenario. Properties of the radioactive waste measured during process and product testing were compared to simulant properties and model predictions to confirm the validity of simulant and glass property ,models work. This report includes results from the three NCAW core samples, comparable results from slurry and glass simulants, and comparisons to glass property model predictions.

  10. Comparison of simulants to actual neutralized current acid waste: Process and product testing of three NCAW core samples from Tanks 101-AZ and 102-AZ

    Energy Technology Data Exchange (ETDEWEB)

    Morrey, E.V.; Tingey, J.M.

    1996-04-01

    A vitrification plant is planned to process the high-level waste (HLW) solids from Hanford Site tanks into canistered glass logs for disposal in a national repository. Programs have been established within the Pacific Northwest Laboratory Vitrification Technology Development (PVTD) Project to test and model simulated waste to support design, feed processability, operations, permitting, safety, and waste-form qualification. Parallel testing with actual radioactive waste is being performed on a laboratory-scale to confirm the validity of using simulants and glass property models developed from simulants. Laboratory-scale testing has been completed on three radioactive core samples from tanks 101-AZ and 102-AZ containing neutralized current acid waste (NCAW), which is one of the first waste types to be processed in the high-level waste vitrification plant under a privatization scenario. Properties of the radioactive waste measured during process and product testing were compared to simulant properties and model predictions to confirm the validity of simulant and glass property models work. This report includes results from the three NCAW core samples, comparable results from slurry and glass simulants, and comparisons to glass property model predictions.

  11. Mechanical properties of AZ31 alloy processed by a green metallurgy route; Propiedades mecanicas de la aleacion AZ31 procesada por una ruta eco-sostenible

    Energy Technology Data Exchange (ETDEWEB)

    D' Enrico, F.; Garces, G.; Hofer, M.; Kim, S. K.; Perez, P.; Cabeza, S.; Adeva, P.

    2013-07-01

    Recently it has been proved that molding of defect-free components of various commercial alloys of magnesium can be carried out successfully when small amounts of CaO are added to the melt, making unnecessary the use of SF{sub 6} coverage. In the case of AZ alloys, this process also remarkably improves their mechanical properties not only by the greater cleaning of alloys but also by the formation of CaAl{sub 2} phase. This work, part of the Green project Metallurgy (http://www.green-metallurgy.eu) funded by the European Union (LIFE+2009), studies the influence of different CaO additions on the microstructure and mechanical properties of AZ31 Eco-Mg alloy. The alloy was processed by a conventional route involving extrusion of as-cast rods as well as by a powder metallurgy route (PM) using chips as starting material. The objective was to analyze the viability of recycling machining chips to manufacture components for the automobile industry and transportation in general, because of its low cost and environmental impact. It has been demonstrated that alloys processed from chips exhibit the highest tensile stress values, close to 320 MPa. (Author)

  12. Comparison of simulants to actual neutralized current acid waste: process and product testing of three NCAW core samples from Tanks 101-AZ and 102-AZ

    International Nuclear Information System (INIS)

    Morrey, E.V.; Tingey, J.M.; Elliott, M.L.

    1996-10-01

    A vitrification plant is planned to process the high-level waste (HLW) solids from Hanford Site tanks into canistered glass logs for disposal in a national repository. Programs were established within the Pacific Northwest Laboratory Vitrification Technology Development (PVTD) Project to test and model simulated waste to support design, feed processability, operations, permitting, safety, and waste-form qualification. Parallel testing with actual radioactive waste was performed on a laboratory-scale to confirm the validity of using simulants and glass property models developed from simulants. Laboratory-scale testing has been completed on three radioactive core samples from tanks 101-AZ and 102-AZ containing neutralized current acid waste (NCAW), which is one of the first waste types to be processed in the high-level waste vitrification plant under a privatization scenario. Properties of the radioactive waste measured during process and product testing were compared to simulant properties and model predictions to confirm the validity of simulant and glass property ,models work. This report includes results from the three NCAW core samples, comparable results from slurry and glass simulants, and comparisons to glass property model predictions

  13. Comparison of simulants to actual neutralized current acid waste: Process and product testing of three NCAW core samples from Tanks 101-AZ and 102-AZ

    International Nuclear Information System (INIS)

    Morrey, E.V.; Tingey, J.M.

    1996-04-01

    A vitrification plant is planned to process the high-level waste (HLW) solids from Hanford Site tanks into canistered glass logs for disposal in a national repository. Programs have been established within the Pacific Northwest Laboratory Vitrification Technology Development (PVTD) Project to test and model simulated waste to support design, feed processability, operations, permitting, safety, and waste-form qualification. Parallel testing with actual radioactive waste is being performed on a laboratory-scale to confirm the validity of using simulants and glass property models developed from simulants. Laboratory-scale testing has been completed on three radioactive core samples from tanks 101-AZ and 102-AZ containing neutralized current acid waste (NCAW), which is one of the first waste types to be processed in the high-level waste vitrification plant under a privatization scenario. Properties of the radioactive waste measured during process and product testing were compared to simulant properties and model predictions to confirm the validity of simulant and glass property models work. This report includes results from the three NCAW core samples, comparable results from slurry and glass simulants, and comparisons to glass property model predictions

  14. Influence of Heat Treatment on the Corrosion Behavior of Purified Magnesium and AZ31 Alloy

    OpenAIRE

    Khalifeh, Sohrab; Burleigh, T. David

    2017-01-01

    Magnesium and its alloys are ideal for biodegradable implants due to their biocompatibility and their low-stress shielding. However, they can corrode too rapidly in the biological environment. The objective of this research was to develop heat treatments to slow the corrosion of high purified magnesium and AZ31 alloy in simulated body fluid at 37{\\deg}C. Heat treatments were performed at different temperatures and times. Hydrogen evolution, weight loss, PDP, and EIS methods were used to measu...

  15. Mechanical behaviour of biodegradable AZ31 magnesium alloy after long term in vitro degradation.

    Science.gov (United States)

    Adekanmbi, Isaiah; Mosher, Christopher Z; Lu, Helen H; Riehle, Mathis; Kubba, Haytham; Tanner, K Elizabeth

    2017-08-01

    Biodegradable magnesium alloys including AZ31 are exciting candidates for temporary implants as they eliminate the requirement for surgical removal, yet have higher mechanical properties than degradable polymers. However, the very long term mechanical properties and degradation of these alloys have not been fully characterized. The tensile, bending and corrosion behaviour of biodegradable AZ31 Mg alloy specimens have been investigated for up to 9months in vitro in phosphate buffered saline (PBS). Small AZ31 Mg specimens showed a significant drop in bend yield strength and modulus after 3months in vitro degradation and an average mass loss of 6.1%. Larger dumbbell specimens showed significant drops in tensile strength from 251.96±3.53MPa to 73.5±20.2MPa and to 6.43±0.9MPa and in modulus from 47.8±5.6GPa to 25.01±3.4GPa and 2.36±0.89GPa after 3 and 9months respectively. These reductions were accompanied by an average mass loss of 18.3% in 9months. Degradation rate for the small and large specimens followed similar profiles with immersion time, with peak degradation rates of 0.1747gm -2 h - 1 and 0.0881gm -2 h - 1 , and average rates of 0.1038gm -2 h - 1 and 0.0397gm -2 h - 1 respectively. SEM fractography and polished specimen cross-sections revealed corrosion pits, cracks and corrosion induced defects. These data indicate the potential of AZ31 Mg for use in implants that require medium term degradation with load bearing mechanical properties. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Influence of Zeolite Coating on the Corrosion Resistance of AZ91D Magnesium Alloy

    OpenAIRE

    Banerjee, P. Chakraborty; Woo, Ren Ping; Grayson, Sam Matthew; Majumder, Amrita; Raman, R. K. Singh

    2014-01-01

    The protective performance of zeolite coating on AZ91D magnesium alloy was evaluated using potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS) in 0.1 M sodium chloride solution (NaCl). Electrical equivalent circuit (EEC) was developed based upon hypothetical corrosion mechanisms and simulated to correspond to the experimental data. The morphology and the chemical nature of the coating were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD...

  17. Metallurgical bond between magnesium AZ91 alloy and aluminium plasma sprayed coatings

    Czech Academy of Sciences Publication Activity Database

    Kubatík, Tomáš František; Pala, Zdeněk; Neufuss, Karel; Vilémová, Monika; Mušálek, Radek; Stoulil, J.; Slepička, P.; Chráska, Tomáš

    2015-01-01

    Roč. 282, November (2015), s. 163-170 ISSN 0257-8972 R&D Projects: GA ČR(CZ) GP14-31538P Institutional support: RVO:61389021 Keywords : Plasma spraying * AZ91 magnesium alloy * Aluminium * Metallurgical bond * X-ray diffraction Subject RIV: JK - Corrosion ; Surface Treatment of Materials Impact factor: 2.139, year: 2015 http://www.sciencedirect.com/science/article/pii/S0257897215303297

  18. Effect of ECAP on microstructure and mechanical properties of cast AZ91 magnesium alloy

    International Nuclear Information System (INIS)

    Chung, C W; Gao, W; Ding, R G; Chiu, Y L

    2010-01-01

    An as-cast AZ91 magnesium alloy was processed by Equal Channel Angular Pressing (ECAP) at 320 0 C. The microstructure and mechanical properties were studied. It has been found that ECAP refines both the grains and precipitates, thus modifies the strength and ductility of the processed alloy. After the first pass of ECAP, the yield stress improves significantly from 71 MPa to 140 MPa.

  19. Hydroxyapatite coating on AZ91 magnesium alloy via sol-gel method

    OpenAIRE

    Albayrak, Sevda; Çinici, Hanifi; Çalın, Recep; Cömert, Canser

    2018-01-01

    Producinga material lighter than available biomaterials, having corrosion-resistance tobiological attacks and histocompatible similar to the bone structure in orderto use in biomedical applications is the purpose of this study. Lightness isextremely important in biomedical applications because stainless steel and manyof the similar heavy metallic alloys can lead to infection by causing harm totissues around the implant when it is used in the body. Although the lightnessof AZ91 Mg alloy is an ...

  20. Inelastic neutron scattering and lattice dynamics studies of AlPO4 and GaPO4

    International Nuclear Information System (INIS)

    Mittal, R.; Chaplot, S.L.; Kolesnikov, A.I.; Loong, C.-K.; Jayakumar, O.D.; Kulshreshtha, S.K.

    2006-01-01

    The compounds AlPO 4 and GaPO 4 show phase transitions at high pressure depending on the compressibility of the constituent tetrahedra. Semi-empirical interatomic potentials are available for AlPO 4 and GaPO 4 . Molecular dynamics simulations have been reported using these potentials to understand the nature of phase transitions in different polymorphs of these compounds. In order to check these potentials we have carried out lattice dynamical studies for AlPO 4 and GaPO 4 . The phonon density of states measurements from the polycrystalline samples of low-cristobalite phase of AlPO 4 and GaPO 4 are carried out using High-Resolution Medium-Energy Chopper Spectrometer at ANL in the energy transfer range 0-160 meV. The calculated phonon spectra for both the compounds using the available potentials show fair agreement with the experimental data. However, the agreement between the two is improved by including the polarizibility of the oxygen atoms in the framework of the shell model. The lattice dynamical model is used for the calculation of specific heat and thermal expansion

  1. Specific absorption spectra of hemoglobin at different PO2 levels: potential noninvasive method to detect PO2 in tissues.

    Science.gov (United States)

    Liu, Peipei; Zhu, Zhirong; Zeng, Changchun; Nie, Guang

    2012-12-01

    Hemoglobin (Hb), as one of main components of blood, has a unique quaternary structure. Its release of oxygen is controlled by oxygen partial pressure (PO2). We investigate the specific spectroscopic changes in Hb under different PO2 levels to optimize clinical methods of measuring tissue PO2. The transmissivity of Hb under different PO2 levels is measured with a UV/Vis fiber optic spectrometer. Its plotted absorption spectral curve shows two high absorption peaks at 540 and 576 nm and an absorption valley at 560 nm when PO2 is higher than 100 mm Hg. The two high absorption peaks decrease gradually with a decrease in PO2, whereas the absorption valley at 560 nm increases. When PO2 decreases to approximately 0 mm Hg, the two high absorption peaks disappear completely, while the absorption valley has a hypochromic shift (8 to 10 nm) and forms a specific high absorption peak at approximately 550 nm. The same phenomena can be observed in visible reflectance spectra of finger-tip microcirculation. Specific changes in extinction coefficient and absorption spectra of Hb occur along with variations in PO2, which could be used to explain pathological changes caused by tissue hypoxia and for early detection of oxygen deficiency diseases in clinical monitoring.

  2. 210Pb and 210Po in tobacco - with a special focus on estimating the doses of 210Po to man

    International Nuclear Information System (INIS)

    Takizawa, Y.; Zhang, L.; Zhao, L.

    1994-01-01

    Inhalation of tobacco smoke is ranked second to food as a source of 210 Pb and 210 Po exposure to man. assay of 210 Pb and 210 Po in commercially available tobacco collected from many countries have been carried out to assess the potential risk from 210 Po present in tobacco. The range of 210 Po contained in the tobacco grands varied from 10.08 to 15.0 mBq/tob or 13.0 to 20.1 mBq/g and the mean was 11.6 mBq/tob or 15.4 mBq/g. During the International Standard Smoking process about 50% of 210 Po present in tobaccos was transferred into the smoke and the other 50% remained in the ash and butt. About 10% of the total 210 Po of tobacco was inhaled by smoke through mainstream smoke. One pack-a-day smoker inhaled 24 mBq of 210 Po per day through smoking and the annual inhalation was 8.8 Bq. The risk of mortality from lung cancer caused by 210 Po in tobaccos was 18 per million persons for the above model. (author) 6 refs.; 1 fig.; 4 tabs

  3. Corrosion characterization of micro-arc oxidization composite electrophoretic coating on AZ31B magnesium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Congjie [School of Materials Science and Engineering, Xi’an University of Technology, Xi’an 710048 (China); Jiang, Bailing [School of Materials Science and Engineering, Nanjing Tech University, Nanjing 211816 (China); Liu, Ming [General Motors China Science Lab, Shanghai 201206 (China); Ge, Yanfeng [School of Materials Science and Engineering, Xi’an University of Technology, Xi’an 710048 (China)

    2015-02-05

    Highlights: • A new protective composite coatings were prepared on AZ31B Mg alloy. • The E-coat locked into MAO coat by discharge channels forming a smoother and compact surface without defects. • Comparing with MAO coat, the MAOE composite coat could provide an excellent barrier for bare Mg against corrosion attack. - Abstract: A two layer composite coating system was applied on the surface of AZ31B magnesium alloy by Micro-arc Oxidation (MAO) plus electrophoretic coat (E-coat) technique. The Mg sample coated with MAO plus E-coat (MAOE) was compared with bare Mg and Mg sample coated by MAO only. The surface microstructure and cross section of bare and coated Mg before and after corrosion were examined by Scanning Electron Microscopy (SEM). The corrosion performance of bare and coated Mg was evaluated using electrochemical measurement and hydrogen evolution test. The results indicated that the corrosion resistance of AZ31B Mg alloy was significantly improved by MAOE composite coating. The corrosion mechanism of bare and coated Mg is discussed.

  4. Nano grained AZ31 alloy achieved by equal channel angular rolling process

    International Nuclear Information System (INIS)

    Hassani, F.Z.; Ketabchi, M.

    2011-01-01

    Equal channel angular rolling (ECAR) is a severe plastic deformation process which is carried out on large, thin sheets. The grain size could be significantly decreased by this process. The main purpose of this study is to investigate the possibility of grain refinement of AZ31 magnesium alloy sheet by this process to nanometer. The effect of the number of ECAR passes on texture evolution of AZ31 magnesium alloy was investigated. ECAR temperature was controlled to maximize the grain refinement efficiency along with preventing cracking. The initial microstructure of as-received AZ31 sheet showed an average grain size of about 21 μm. The amount of grain refinement increased with increasing the pass number. After 10 passes of the process, significant grain refinement occurred and the field emission scanning electron microscopic (FESEM) micrographs showed that the size of grains were decreased significantly to about 14-70 nm. These grains were formed at the grain boundaries and inside some of the previous larger micrometer grains. Observation of optical microstructures and X-ray diffraction patterns (XRD) showed the formation of twins after ECAR process. Micro-hardness of material was studied at room temperature. There was a continuous enhancement of hardness by increasing the pass number of ECAR process. At the 8th pass, hardness values increased by 53%. At final passes hardness reduced slightly, which was attributed to saturation of strain in high number of passes.

  5. Formation and mechanism of nanocrystalline AZ91 powders during HDDR processing

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yafen; Fan, Jianfeng, E-mail: fanjianfeng@tyut.edu.cn; Zhang, Hua; Zhang, Qiang; Gao, Jing; Dong, Hongbiao, E-mail: hd38@leicester.ac.uk; Xu, Bingshe

    2017-03-15

    Grain sizes of AZ91 alloy powders were markedly refined to about 15 nm from 100 to 160 μm by an optimized hydrogenation-disproportionation-desorption-recombination (HDDR) process. The effect of temperature, hydrogen pressure and processing time on phase and microstructure evolution of AZ91 alloy powders during HDDR process was investigated systematically by X-ray diffraction, optical microscopy, scanning electron microscopy and transmission electron microscopy, respectively. The optimal HDDR process for preparing nanocrystalline Mg alloy powders is hydriding at temperature of 350 °C under 4 MPa hydrogen pressure for 12 h and dehydriding at 350 °C for 3 h in vacuum. A modified unreacted core model was introduced to describe the mechanism of grain refinement of during HDDR process. - Highlights: • Grain size of the AZ91 alloy powders was significantly refined from 100 μm to 15 nm. • The optimal HDDR technology for nano Mg alloy powders is obtained. • A modified unreacted core model of grain refinement mechanism was proposed.

  6. Wire Arc Additive Manufacturing of AZ31 Magnesium Alloy: Grain Refinement by Adjusting Pulse Frequency

    Directory of Open Access Journals (Sweden)

    Jing Guo

    2016-10-01

    Full Text Available Wire arc additive manufacturing (WAAM offers a potential approach to fabricate large-scale magnesium alloy components with low cost and high efficiency, although this topic is yet to be reported in literature. In this study, WAAM is preliminarily applied to fabricate AZ31 magnesium. Fully dense AZ31 magnesium alloy components are successfully obtained. Meanwhile, to refine grains and obtain good mechanical properties, the effects of pulse frequency (1, 2, 5, 10, 100, and 500 Hz on the macrostructure, microstructure and tensile properties are investigated. The results indicate that pulse frequency can result in the change of weld pool oscillations and cooling rate. This further leads to the change of the grain size, grain shape, as well as the tensile properties. Meanwhile, due to the resonance of the weld pool at 5 Hz and 10 Hz, the samples have poor geometry accuracy but contain finer equiaxed grains (21 μm and exhibit higher ultimate tensile strength (260 MPa and yield strength (102 MPa, which are similar to those of the forged AZ31 alloy. Moreover, the elongation of all samples is above 23%.

  7. Study on fluidity of squeeze cast AZ91D magnesium alloy with different wall thicknesses

    Directory of Open Access Journals (Sweden)

    Chen Yun

    2014-03-01

    Full Text Available Rectangular cross-section specimens with different section thicknesses were prepared to study the influences of pouring temperature, mould temperature and squeeze velocity on the fluidity of squeeze cast AZ91D magnesium alloy by means of orthogonal test design method. The results show that pouring temperature, mould temperature and squeeze velocity can significantly affect the fluidity of magnesium alloy specimens with wall thickness no more than 4 mm, and the pouring temperature is the most influential factor on the fluidity of specimens with wall thickness of 1, 2 and 3 mm, while mould temperature is the one for specimens with wall thickness of 4 mm. Increasing pouring temperature between 700 °C and 750 °C is beneficial to the fluidity of AZ91D magnesium alloy, and increasing mould temperature significantly enhances the filling ability of thick (3 and 4 mm section castings. The fluidity of squeeze cast magnesium alloy increases with the increase of wall thickness. It is not recommended to produce magnesium alloy casting with wall thickness of smaller than 3 mm by squeeze cast process due to the poor fluidity. The software DPS was used to generate the regression model, and linear regression equations of the fluidity of squeeze cast AZ91D with different wall thicknesses are obtained using the test results.

  8. The effect of PVD coatings on the corrosion behaviour of AZ91 magnesium alloy

    International Nuclear Information System (INIS)

    Altun, Hikmet; Sen, Sadri

    2006-01-01

    In this study, multilayered AlN (AlN + AlN + AlN) and AlN + TiN were coated on AZ91 magnesium alloy using physical vapour deposition (PVD) technique of DC magnetron sputtering, and the influence of the coatings on the corrosion behaviour of the AZ91 alloy was examined. A PVD system for coating processes, a potentiostat for electrochemical corrosion tests, X-ray difractometer for compositional analysis of the coatings, and scanning electron microscopy for surface examinations were used. It was determined that PVD coatings deposited on AZ91 magnesium alloy increased the corrosion resistance of the alloy, and AlN + AlN + AlN coating increased the corrosion resistance much more than AlN + TiN coating. However, it was observed that, in the coating layers, small structural defects e.g., pores, pinholes, cracks that could arise from the coating process or substrate and get the ability of protection from corrosion worsened were present

  9. Cerium Addition Improved the Dry Sliding Wear Resistance of Surface Welding AZ91 Alloy

    Directory of Open Access Journals (Sweden)

    Qingqiang Chen

    2018-02-01

    Full Text Available In this study, the effects of cerium (Ce addition on the friction and wear properties of surface welding AZ91 magnesium alloys were evaluated by pin-on-disk dry sliding friction and wear tests at normal temperature. The results show that both the friction coefficient and wear rate of surfacing magnesium alloys decreased with the decrease in load and increase in sliding speed. The surfacing AZ91 alloy with 1.5% Ce had the lowest friction coefficient and wear rate. The alloy without Ce had the worst wear resistance, mainly because it contained a lot of irregularly shaped and coarse β-Mg17Al12 phases. During friction, the β phase readily caused stress concentration and thus formed cracks at the interface between β phase and α-Mg matrix. The addition of Ce reduced the size and amount of Mg17Al12, while generating Al4Ce phase with a higher thermal stability. The Al-Ce phase could hinder the grain-boundary sliding and migration and reduced the degree of plastic deformation of subsurface metal. Scanning electron microscopy observation showed that the surfacing AZ91 alloy with 1.5% Ce had a total of four types of wear mechanism: abrasion, oxidation, and severe plastic deformation were the primary mechanisms; delamination was the secondary mechanism.

  10. Electrodeposition of Al-Mn alloy on AZ31B magnesium alloy in molten salts

    International Nuclear Information System (INIS)

    Zhang Jifu; Yan Chuanwei; Wang Fuhui

    2009-01-01

    The Al-Mn alloy coatings were electrodeposited on AZ31B Mg alloy in AlCl 3 -NaCl-KCl-MnCl 2 molten salts at 170 deg. C aiming to improve the corrosion resistance. However, in order to prevent AZ31B Mg alloy from corrosion during electrodeposition in molten salts and to ensure excellent adhesion of coatings to the substrate, AZ31B Mg alloy should be pre-plated with a thin zinc layer as intermediate layer. Then the microstructure, composition and phase constituents of the coatings were investigated by scanning electron microscopy (SEM), energy-dispersive X-ray spectrometry (EDX), and X-ray diffraction (XRD). It was indicated that, by adjusting the MnCl 2 content in the molten salts from 0.5 wt% to 2 wt%, the Mn content in the alloy coating was increased and the phase constituents were changed from f.c.c Al-Mn solid solution to amorphous phase. The corrosion resistance of the coatings was evaluated by potentiodynamic polarization measurements in 3.5% NaCl solution. It was confirmed that the Al-Mn alloy coatings exhibited good corrosion resistance with a chear passive region and significantly reduced corrosion current density at anodic potentiodynamic polarization. The corrosion resistance of the alloy coatings was also related with the microstructure and Mn content of the coatings.

  11. Characteristics of AZ31 Mg alloy joint using automatic TIG welding

    Science.gov (United States)

    Liu, Hong-tao; Zhou, Ji-xue; Zhao, Dong-qing; Liu, Yun-teng; Wu, Jian-hua; Yang, Yuan-sheng; Ma, Bai-chang; Zhuang, Hai-hua

    2017-01-01

    The automatic tungsten-inert gas welding (ATIGW) of AZ31 Mg alloys was performed using a six-axis robot. The evolution of the microstructure and texture of the AZ31 auto-welded joints was studied by optical microscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and electron backscatter diffraction. The ATIGW process resulted in coarse recrystallized grains in the heat affected zone (HAZ) and epitaxial growth of columnar grains in the fusion zone (FZ). Substantial changes of texture between the base material (BM) and the FZ were detected. The {0002} basal plane in the BM was largely parallel to the sheet rolling plane, whereas the c-axis of the crystal lattice in the FZ inclined approximately 25° with respect to the welding direction. The maximum pole density increased from 9.45 in the BM to 12.9 in the FZ. The microhardness distribution, tensile properties, and fracture features of the AZ31 auto-welded joints were also investigated.

  12. Stamping of Thin-Walled Structural Components with Magnesium Alloy AZ31 Sheets

    International Nuclear Information System (INIS)

    Chen, F.-K.; Chang, C.-K.

    2005-01-01

    In the present study, the stamping process for manufacturing cell phone cases with magnesium alloy AZ31 sheets was studied using both the experimental approach and the finite element analysis. In order to determine the proper forming temperature and set up a fracture criterion, tensile tests and forming limit tests were first conducted to obtain the mechanical behaviors of AZ31 sheets at various elevated temperatures. The mechanical properties of Z31 sheets obtained from the experiments were then adopted in the finite element analysis to investigate the effects of the process parameters on the formability of the stamping process of cell phone cases. The finite element simulation results revealed that both the fracture and wrinkle defects could not be eliminated at the same time by adjusting blank-holder force or blank size. A drawbead design was then performed using the finite element simulations to determine the size and the location of drawbead required to suppress the wrinkle defect. An optimum stamping process, including die geometry, forming temperature, and blank dimension, was then determined for manufacturing the cell phone cases. The finite element analysis was validated by the good agreement between the simulation results and the experimental data. It confirms that the cell phone cases can be produced with magnesium alloy AZ31 sheet by the stamping process at elevated temperatures

  13. Precipitation behavior and effect of new precipitated β phase in AZ80 magnesium alloy

    Institute of Scientific and Technical Information of China (English)

    TANG Wei; HAN En-hou; XU Yong-bo; LIU Lu

    2006-01-01

    Granular precipitate that was a new kind of β-Mg17Al12 phase found in aged AZ80 wrought Mg alloy at all aging temperature was studied. The structure and precipitation behavior of this granular β-Mg17Al12 precipitate were studied by environmental scanning electron microscopy (ESEM) and transmission electron microscopy (TEM). The effect of the granular precipitate on mechanical properties of AZ80 alloy was also studied. The new precipitate that was granular and nucleated both on grain boundaries (GBs) and twin boundaries, has the same crystal structure and lattice parameter as those of the continuous or discontinuous precipitated β-Mg17Al12. And the nucleation and growth of the granular precipitate are faster than those of the other two precipitates at higher temperatures (above 583 K), but are suppressed at lower temperatures (below 423 K). At lower temperatures, the discontinuous β-Mg17Al12 precipitates firstly and the granular β-Mg17Al12 precipitates after aged more than 40 h. The crack is easily nucleated on the phase boundaries of granular phase and matrix because of the weak binding force. As a result, the strength and ductility of AZ80 Mg alloy are decreased by the granular β-Mg17Al12 precipitate.

  14. Influence of heat treatment on the machinability and corrosion behavior of AZ91 Mg alloy

    Directory of Open Access Journals (Sweden)

    Swetha Chowdary V

    2018-03-01

    Full Text Available In the present study, AZ91 Mg alloy was heat treated at 410 °C for 6, 12 and 24 h to investigate the influence of heat treatment on machinability and corrosion behavior. The effect of soaking time on the amount and distribution of Mg17Al12 (β – phase was analyzed under the optical microscope. Microhardness measurements demonstrated the increased hardness with increased heat treatment soaking time, which can be attributed to the solid solution strengthening. The influence of super saturated α-grains on reducing the cutting force (Fz with respect to increased cutting speed was observed as prominent. The corrosion behavior of the heat treated specimens was studied by conducting electrochemical tests. Surprisingly, corrosion rate of heat treated samples was observed as increased compared with the base material. From the results, it is evident that the machinability of AZ91 Mg alloy can be improved by producing super saturated α-grains through heat treatment but at the cost of losing corrosion resistance. Keywords: AZ91 Mg alloy, Solid solution, Turning, Corrosion, Machinability

  15. Corrosion of AZ91D magnesium alloy with a chemical conversion coating and electroless nickel layer

    International Nuclear Information System (INIS)

    Huo Hongwei; Li Ying; Wang Fuhui

    2004-01-01

    A chemical conversion treatment and an electroless nickel plating were applied to AZ91D alloy to improve its corrosion resistance. By conversion treatment in alkaline stannate solution, the corrosion resistance of the alloy was improved to some extent as verified by immersion test and potentiodynamic polarization test in 3.5 wt.% NaCl solution at pH 7.0. X-ray diffraction patterns of the stannate treated AZ91D alloy showed the presence of MgSnO 3 · H 2 O, and SEM images indicated a porous structure, which provided advantage for the adsorption during sensitisation treatment prior to electroless nickel plating. A nickel coating with high phosphorus content was successfully deposited on the chemical conversion coating pre-applied to AZ91D alloy. The presence of the conversion coating between the nickel coating and the substrate reduced the potential difference between them and enhanced the corrosion resistance of the alloy. An obvious passivation occurred for the nickel coating during anodic polarization in 3.5 wt.% NaCl solution

  16. Flow behaviour of magnesium alloy AZ31B processed by equal-channel angular pressing

    International Nuclear Information System (INIS)

    Arun, M S; Chakkingal, U

    2014-01-01

    Magnesium alloys are characterised by their low density, high specific strength and stiffness. But, the potential application of Mg is limited by its low room-temperature ductility and formability. Formability can be improved by developing an ultrafine grained (UFG) structure. Equal channel angular pressing (ECAP) is a well known process that can be used to develop an ultrafine grained microstructure. The aim of this study was to investigate the flow behaviour of AZ31B magnesium alloy after ECAP. The specimen was subjected to three passes of ECAP with a die angle of 120° using processing route Bc. The processing temperature was 523 K for the first pass and 423 K for the subsequent two passes. The microstructure characterisation was done. Compression tests of ECAPed and annealed specimens were carried out at strain rates of 0.01 – 1s −1 and deformation temperatures of 200 – 300°C using computer servo-controlled Gleeble-3800 system. The value of activation energy Q and the empirical materials constants of A and n were determined. The equations relating flow stress and Zener-Hollomon parameter were proposed. In the case annealed AZ31, the activation energy was determined to be 154 kJ/mol, which was slightly higher than the activation energy of 144 kJ/mol for ECAPed AZ31

  17. Flow behaviour of magnesium alloy AZ31B processed by equal-channel angular pressing

    Science.gov (United States)

    Arun, M. S.; Chakkingal, U.

    2014-08-01

    Magnesium alloys are characterised by their low density, high specific strength and stiffness. But, the potential application of Mg is limited by its low room-temperature ductility & formability. Formability can be improved by developing an ultrafine grained (UFG) structure. Equal channel angular pressing (ECAP) is a well known process that can be used to develop an ultrafine grained microstructure. The aim of this study was to investigate the flow behaviour of AZ31B magnesium alloy after ECAP. The specimen was subjected to three passes of ECAP with a die angle of 120° using processing route Bc. The processing temperature was 523 K for the first pass and 423 K for the subsequent two passes. The microstructure characterisation was done. Compression tests of ECAPed and annealed specimens were carried out at strain rates of 0.01 - 1s-1 and deformation temperatures of 200 - 300°C using computer servo-controlled Gleeble-3800 system. The value of activation energy Q and the empirical materials constants of A and n were determined. The equations relating flow stress and Zener-Hollomon parameter were proposed. In the case annealed AZ31, the activation energy was determined to be 154 kJ/mol, which was slightly higher than the activation energy of 144 kJ/mol for ECAPed AZ31.

  18. Dry Sliding Wear Charactristics of Aluminum 6061-T6, Magnesium AZ31 and Rock Dust Composite

    Science.gov (United States)

    Balachandar, R.; Balasundaram, R.; Rajkumar, G.

    2018-02-01

    In recent years, the use of aluminum composite is gaining popularity in a wide range of applications like automobiles, aerospace and constructions (both interior & exterior) panels etc., due to its high strength, low density characteristics. Various reinforcing materials are used with aluminum 6061-T6 in order to have better mechanical properties. The addition of 0.3% of magnesium AZ31 will increase the ultimate tensile strength by 25 %. The reinforcement of rock dust will decrease the density. Hence, in order to have an advantages of magnesium AZ31 and rock dust, in this work, these two constitutes are varied from 1% to 2% on the base material of Al6061-T6 in stir casting. To evaluate the wear characteristics, Pin on disc is used in these composites. The input parameters are speed, time & load. The output response is wear. To minimize the number of experiments, L9 orthogonal array is used. The test results showed that a composite of 97% of Al (6061-T6), 1% Mg (AZ31) & 2 % of rock dust produced less wear. To find the best value of operating parameter for each sample, ANN-GA is used.

  19. Enrique Díaz and Present Phpotographies (From Graphic Notes to Photo-essays

    Directory of Open Access Journals (Sweden)

    Rebeca Monroy Nasr

    1998-10-01

    Full Text Available With "Enrique Díaz and Present Phpotographies (From Graphic Notes to Photo-essays ", the author presents part of our photo­graphic history, as well as some aspects of its development as a form of journalism and of art. She rescues the figure of Enrique Díaz Reyna as representative of the union of graphic journalists, due to his technical, formal and conceptual traits, all of them tools with which he opened important paths and innovative graphical and aesthetic proposals. This essay presents some aspects of the graphic journalist's work in Mexico City, from the twenties to the forties. As a guide to the photographer's extensi­ve work, the author reviews some of the proposals he made as his work became more mature: first, the graphic note, later, recrea­ting the photo-reportage, and finally, exploring with photoessays. Thus, attention is centered particularly on Díaz Reyna's visual language, where the signs of a distinctive modernity appro­priate of his time allow us to understand a substantial part of the transition towards a contemporary and  truly national photo-journalism.

  20. In vitro cell culture pO2 is significantly different from incubator pO2.

    Science.gov (United States)

    Bambrick, L L; Kostov, Y; Rao, G

    2011-07-01

    Continuous noninvasive monitoring of peri-cellular liquid phase pO2 in adherent cultures is described. For neurons and astrocytes, this approach demonstrates that there is a significant difference between predicted and observed liquid phase pO2. Particularly at low gas phase pO2s, cell metabolism shifts liquid phase pO2 significantly lower than would be predicted from the O2 gas/air equilibrium coefficient, indicating that the cellular oxygen uptake rate exceeds the oxygen diffusion rate. The results demonstrate the need for direct pO2 measurements at the peri-cellular level, and question the widely adopted current practice of relying on setting the incubator gas phase level as means of controlling pericellular oxygen tension, particularly in static culture systems that are oxygen mass transfer limited. Copyright © 2011 American Institute of Chemical Engineers (AIChE).

  1. Rhenium(V) and technetium(V) complexes of bis(o-hydroxyphenyl)phenylphosphine (PO22-) and (o-hydroxyphenyl)diphenylphosphine (PO-) ligands

    International Nuclear Information System (INIS)

    Luo, Hongyan; Setyawati, Ika; Rettig, S.J.; Orvig, C.

    1995-01-01

    The synthesis of several phosphine-based chelating compounds and chelates formed between these compounds and rhenium or technetium is discussed. Four categories of products result, (i) bis-(o-hydroxyphenyl) diphenylphosphine (PO) complexes, (ii) mono- (PO) complexes, (iii) bis-bis(o-hydroxyphenyl)-phenylphosphine (PO 2 ) complexes, and mixed-(PO) and (PO 2 ) complexes. Molecular structures of these compounds (including isomers) were probed by NMR, MS, and IR spectroscopies and by X-ray crystallography

  2. Mechanical and thermal-expansion characteristics of Ca10(PO46(OH2-Ca3(PO42 composites

    Directory of Open Access Journals (Sweden)

    Ruseska G.

    2006-01-01

    Full Text Available Three types of composites consisting of Ca10(PO46(OH2 and Ca3(PO42 with composition: 75% (wt Ca10(PO46(OH2: 25%(wt Ca3(PO42; 50%(wt Ca10(PO46(OH2: 50%(wtCa3(PO42 and 25 %(wt Ca10(PO46(OH2: 75%(wt Ca3(PO42 were the subject of our investigation. Sintered compacts were in thermal equilibrium, which was proved by the absence of hysteresis effect of the dependence ΔL/L=f(T during heating /cooling in the temperature interval 20-1000-200C. Sintered compacts with the previously mentioned composition possess 26-50% higher values of the E-modulus, G-modulus and K-modulus indicating the presence of a synergism effect. Several proposed model equations for predicting the thermal expansion coefficient in dependence of the thermal and elastic properties of the constitutive phases and their volume fractions, given by: Turner, Kerner, Tummala and Friedberg, Thomas and Taya, were used for making correlations between mechanical and thermal-expansion characteristics of the Ca10(PO46(OH2 - Ca3(PO42 composites. Application of the previously mentioned model equations to all kinds of composites leads to the conclusion that the experimentally obtained results for the thermal expansion coefficient are in an excellent agreement with the theoretical calculated values on account of the volume fraction of each constitutive phase and with all applied model equations, with a coefficient of correlation from 98.16-99.86 %.

  3. Tank 241-AZ-102 Privatization Push Mode Core Sampling and Analysis Plan

    International Nuclear Information System (INIS)

    RASMUSSEN, J.H.

    1999-01-01

    This sampling and analysis plan (SAP) identifies characterization objectives pertaining to sample collection, laboratory analytical evaluation, and reporting requirements for samples obtained from tank 241-AZ-102. The purpose of this sampling event is to obtain information about the characteristics of the contents of 241-AZ-102 required to satisfy the Data Quality Objectives For TWRS Privatization Phase I : Confirm Tank TIS An Appropriate Feed Source For High-Level Waste Feed Batch X(HLW DQO) (Nguyen 1999a), Data Quality Objectives For TWRS Privatization Phase 1: Confirm Tank TIS An Appropriate Feed Source For Low-Activity Waste Feed Batch X (LAW DQO) (Nguyen 1999b), Low Activity Waste and High Level Waste Feed Data Quality Objectives (L and H DQO) (Patello et al. 1999) and Characterization Data Needs for Development, Design, and Operation of Retrieval Equipment Developed through the Data Quality Objective Process (Equipment DQO) (Bloom 1996). The Tank Characterization Technical Sampling Basis document (Brown et al. 1998) indicates that these issues, except the Equipment DQO apply to tank 241-AZ-102 for this sampling event. The Equipment DQO is applied for shear strength measurements of the solids segments only. Poppiti (1999) requires additional americium-241 analyses of the sludge segments. Brown et al. (1998) also identify safety screening, regulatory issues and provision of samples to the Privatization Contractor(s) as applicable issues for this tank. However, these issues will not be addressed via this sampling event. Reynolds et al. (1999) concluded that information from previous sampling events was sufficient to satisfy the safety screening requirements for tank 241-AZ-102. Push mode core samples will be obtained from risers 15C and 24A to provide sufficient material for the chemical analyses and tests required to satisfy these data quality objectives. The 222-S Laboratory will extrude core samples, composite the liquids and solids, perform chemical analyses

  4. Lactancia materna, alimentación artificial y el primer contacto con azúcar

    Directory of Open Access Journals (Sweden)

    Fabian Calixto Fraiz

    2013-01-01

    Full Text Available Objetivo: Este estudio evaluó los cambios en el patrón de lactancia materna, alimentación artificial y en la introducción de azúcar en la dieta de niños de 0 a 36 meses, a través de dos estudios, con un intervalo de 13 años en la ciudad de Curitiba, Paraná, Brasil. Material y métodos: Poblaciones semejantes de una misma región geográfica fueron evaluadas a través de un cuestionario, en los años de 1993 y 2006, envolviendo, respectivamente, las madres de 180 y 94 niños. Introducción de azúcar en la dieta fue considerada precoz cuando ocurrió antes del 6º mes completo de vida. Los datos fueron analizados estadísticamente a través del test de qui-cuadrado y test exacto de Fisher (α= 0,05. Resultados: Hubo diferencias en la frecuencia del primer contacto con azúcar (p <0,001, que ocurrió en el primer mes de vida en 61,7% de los niños del primer estudio y en sólo 3,2% de los niños del segundo estudio. Hubo diferencias en el patrón de lactancia materna (p = 0,02, siendo la prevalencia de niños amamantados mayor en el segundo estudio. No fueron encontradas diferencias estadísticamente significativas en la prevalencia de uso de biberón, uso de biberón durante la noche y lactancia materna durante la noche, así como en el uso de biberón conteniendo azúcar. Conclusiones: Estos resultados indican que la lactancia materna puede, además de sus varias ventajas, también promover el aplazamiento de la introducción de azúcar en la dieta infantil. Nuevas investigaciones son necesarias para confirmar esta hipótesis.

  5. 210Po behaviour in terrestrial environment: a review

    International Nuclear Information System (INIS)

    Coppin, F.; Roussel-Debet, S.

    2004-01-01

    This bibliographical review illustrates the behaviour of 210 polonium in the terrestrial environment. Sources of 210 Po in the atmosphere vary especially with the geographical localization and the occurrence or the absence of mining activities. In soils, polonium, because of its atmospheric origin, is concentrated in the first upper centimeters. 210 Po is rather immobile and adsorbed on mineral surfaces; it can (co)precipitate with metallic (oxi)hydroxides or in the form of sulphide. The main transfer pathway of 210 Po to vegetation is foliar deposit, which is not, or only slightly, followed by incorporation or translocation. 210 Po is transferred to animals mainly by ingestion, with relatively high transfer factors. In fresh waters, 210 Po is generally immobile in the form of insoluble Po(IV) and/or associated with the particulate or colloidal phase. Plankton, invertebrates and fish concentrate the 210 Po, especially in soft tissues. Polonium, which is an omnipresent natural radionuclide, is likely to occasion a significant exposure to man, compared with other natural or artificial radioisotopes. Nearly all studies derive from in situ measurements and are very descriptive, therefore experimental work aiming at a better knowledge and modeling of its behaviour in the terrestrial environment would be useful. (author)

  6. Quantitative determination of 210Po in geochemical samples

    International Nuclear Information System (INIS)

    Dyck, W.; Bristow, Q.

    1984-01-01

    To test the usefulness of 210 Po in soils as a means of detecting buried U mineralization, methods for the determination of 210 Po were investigated and adapted for routine production of 210 Po data from geochemical samples. A number of conditions affecting autodeposition and detection of 210 Po were investigated. The optimum area of deposition with a 450 mm 2 solid state detector was found to be 300 mm 2 . Convenience dictated room temperature over-night deposition times, although increased temperature increased speed and efficiency of deposition. A clear inverse relationship was observed between volume of solution and deposition efficiency with stirring times of less than 2 hours. For routine analysis, soil and rock powders were dissolved by leaching 1 g samples in teflon beakers successively with conc. HNO 3 , HF, and HNO 3 -HClO 4 , evaporating the solution to dryness between leaches, and taking the residue up in 20 mL 0.5 M HCl. The 210 Po was deposited on 19 mm diameter Ni discs and counted with an alpha spectrometer system employing 450 mm 2 ruggedized surface barrier detectors. The method achieved 90 percent recovery of 210 Po from solution and a detection efficiency of 30 percent. With a counting time of 3 hours, the method is capable of detecting 0.2 pCi of 210 Po per gram of sample

  7. Concentration of Po-210 and Pb-210 in human tissues

    International Nuclear Information System (INIS)

    Zhao Lancai; Takizawa, Y.; Yamamoto, M.

    1990-01-01

    The levels of Pb-210 and Po-210 in human tissues of people in Japan were determined. Various tissue samples were obtained at autopsy from the cadavers of 22 oncologic cases, mainly in Niigata Prefecture in northern Japan during the period of 1986 to 1988. Wet ashing, followed by electrochemical deposition and alpha-ray spectrometry were used to separate and determine the Pb-210 and Po-210 presented. Among the tissues analyzed the highest concentrations of Pb-210 and Po-210 were observed in bone, liver and kidneys: 1.29, 1.69 and 1.22 Bq.kg -1 respectively for Po-210, and 1.27, 0.56 and 0.43 Bq/kg for Pb-210 respectively. The Po-210/Pb-210 ratios in liver and kidney are 3.0 and 2.9 respectively. Po-210/Pb-210 ratios in other tissues are close to one. The total body burden of Pb-210 and Po-210 was found to be approximately 15.8 Bq and 19.1 Bq respectively

  8. Spirit Pluralisme dalam Klenteng Sam Po Kong Semarang

    Directory of Open Access Journals (Sweden)

    Edi Nurwahyu Julianto

    2015-07-01

    Full Text Available Klenteng Sam Po Kong has very deep meaning as a symbol of multi cultural; multi ethnic and multi religious. Klenteng Sam Po Kong has a different function, not only used by people with background religious Tri Dharma (Budha, Tao and Konghuchu, but also used by Javanese ethnic with different religious backgrounds. Between ethnic China and Java, mutual respect and tolerance run beliefs and rituals of each. More over, Klenteng Sam Po Kong is a form of pluralism which reflected the fact Sino Javanese Muslim Culture is preserved to date both of sightings physical culture and system cultural in the form of religious rites performed by ethnic China and Java.

  9. Accumulation of 210Po by benthic marine algae

    International Nuclear Information System (INIS)

    Gouvea, R.C.; Branco, M.E.C.; Santos, P.L.

    1988-01-01

    The accumulation of polonium 210 Po by various species of benthic marine seaweeds collected from 4 different points on the coast of Rio de Janeiro, showed variations by species and algal groups. The highest value found was in red alga, Plocamium brasiliensis followed by other organisms of the same group. In the group of the brown alga, the specie Sargassum stenophylum was outstanding. The Chlorophyta presented the lowest content of 210 Po. The algae collected in open sea, revealed greater concentration factors of 210 Po than the same species living in bays. The siliceous residue remaining after mineralization of the algae did not interfere with the detection of polonium. (author)

  10. Biogeochemical factors affecting the presence of 210Po in groundwater

    International Nuclear Information System (INIS)

    Seiler, Ralph L.; Stillings, Lisa L.; Cutler, Nichole; Salonen, Laina; Outola, Iisa

    2011-01-01

    Research highlights: → 210 Po activities in numerous domestic wells in Fallon NV exceed 500 mBq/L. → 210 Po levels in sediment are not the primary determinant on levels in groundwater. → δ 34 S measurements indicate SO 4 reduction occurred in all 210 Po contaminated wells. → 210 Po contaminated wells are anoxic, have high pH and low Ca. → Po mobilization probably involves an anaerobic S cycle in which H 2 S dissolves MnO 2 . - Abstract: The discovery of natural 210 Po enrichment at levels exceeding 500 mBq/L in numerous domestic wells in northern Nevada, USA, led to a geochemical investigation of the processes responsible for its mobilization. 210 Po activities in 63 domestic and public-supply wells ranged from below 1 mBq/L to 6590 ± 590 mBq/L, among the highest reported levels in the USA. There is little spatial or depth variability in 210 Pb activity in study-area sediments and mobilization of a few percent of the 210 Po in the sediments would account for all of the 210 Po in water. Stable-isotope measurements indicate SO 4 reduction has occurred in all 210 Po contaminated wells. Sulfide species are not accumulating in the groundwater in much of Lahontan Valley, probably because of S cycling involving microbial SO 4 reduction, abiotic oxidation of H 2 S to S 0 by Mn(IV), followed by microbial disproportionation of S 0 to H 2 S and SO 4 . The high pH, Ca depletion, MnCO 3 saturation, and presence of S 0 in Lahontan Valley groundwater may be consequences of the anaerobic S cycling. Consistent with data from naturally-enriched wells in Florida, 210 Po activities begin to decrease when aqueous sulfide species begin to accumulate. This may be due to formation and precipitation of PoS, however, Eh-pH diagrams suggest PoS would not be stable in study-area groundwater. An alternative explanation for the study area is that H 2 S accumulation begins when anaerobic S cycling stops because Mn oxides are depleted and their reduction is no longer releasing 210 Po

  11. Effectiveness of Ti-micro alloying in relation to cooling rate on corrosion of AZ91 Mg alloy

    International Nuclear Information System (INIS)

    Candan, S.; Celik, M.; Candan, E.

    2016-01-01

    In this study, micro Ti-alloyed AZ91 Mg alloys (AZ91 + 0.5wt.%Ti) have been investigated in order to clarify effectiveness of micro alloying and/or cooling rate on their corrosion properties. Molten alloys were solidified under various cooling rates by using four stage step mold. The microstructural investigations were carried out by using scanning electron microscopy (SEM). Corrosion behaviors of the alloys were evaluated by means of immersion and electrochemical polarization tests in 3.5% NaCl solution. Results showed that the Mg 17 Al 12 (β) intermetallic phase in the microstructure of AZ91 Mg alloy formed as a net-like structure. The Ti addition has reduced the distribution and continuity of β intermetallic phase and its morphology has emerged as fully divorced eutectic. Compared to AZ91 alloy, the effect of the cooling rate in Ti-added alloy on the grain size was less pronounced. When AZ91 and its Ti-added alloys were compared under the same cooling conditions, the Ti addition showed notably high corrosion resistance. Electrochemical test results showed that while I corr values of AZ91 decrease with the increase in the cooling rate, the effect of the cooling rate on I corr values was much lower in the Ti-added alloy. The corrosion resistance of AZ91 Mg alloy was sensitive towards the cooling rates while Ti-added alloy was not affected much from the cooling conditions. - Highlights: • Effect the cooling rate on grain size was less pronounced in the Ti-added alloy. • The morphology of the β phase transformed into fully divorced eutectics. • Ti addition exhibited significantly higher corrosion resistance. • Ti micro alloying is more effective than faster cooling of the alloy on corrosion.

  12. The study of a Mg-rich epoxy primer for protection of AZ91D magnesium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Lu Xiangyu [School of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Zuo Yu, E-mail: zuoy@mail.buct.edu.c [School of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China); Zhao Xuhui; Tang Yuming; Feng Xingguo [School of Materials Science and Engineering, Beijing University of Chemical Technology, Beijing 100029 (China)

    2011-01-15

    Research highlights: {yields} A Mg-rich epoxy primer was prepared by adding pure magnesium particles in epoxy coating. Cross scratch testing results showed that in 3% NaCl solution the Mg-rich primer showed better protection for AZ91D magnesium alloy than the same epoxy primer without Mg addition. {yields} The open circuit potential of AZ91D alloy in NaCl solution decreased after coated with Mg-rich coating, suggesting that cathodic protection effect of the Mg-rich coating on AZ91D alloy was present. {yields} EIS studies showed that during the immersion tests of AZ91D alloy with Mg-rich coating the magnesium particles in coating dissolved with the charge-transfer resistance R{sub ct} at the magnesium particle/coating interface decreased and the double-layer capacitance Q{sub dl} increased. While the coating resistance remained stable for a long time and corrosion of the AZ91D alloy substrate was obviously delayed. - Abstract: A Mg-rich epoxy primer was prepared by adding pure magnesium particles to an epoxy coating. The coating properties were studied with electrochemical impedance spectroscopy (EIS), scanning electronic microscopy (SEM) and X-ray diffraction (XRD). The Mg-rich primer showed better protection for AZ91D magnesium alloy than the same epoxy primer without Mg addition. The open circuit potential measurements showed cathodic protection effect of the Mg-rich primer on AZ91D alloy. Cross scratch testing showed that the Mg-rich primer provided better protection for the substrate than original epoxy coating. The precipitation of Mg(OH){sub 2} in the coating also provided some degree of barrier protection.

  13. The study of a Mg-rich epoxy primer for protection of AZ91D magnesium alloy

    International Nuclear Information System (INIS)

    Lu Xiangyu; Zuo Yu; Zhao Xuhui; Tang Yuming; Feng Xingguo

    2011-01-01

    Research highlights: → A Mg-rich epoxy primer was prepared by adding pure magnesium particles in epoxy coating. Cross scratch testing results showed that in 3% NaCl solution the Mg-rich primer showed better protection for AZ91D magnesium alloy than the same epoxy primer without Mg addition. → The open circuit potential of AZ91D alloy in NaCl solution decreased after coated with Mg-rich coating, suggesting that cathodic protection effect of the Mg-rich coating on AZ91D alloy was present. → EIS studies showed that during the immersion tests of AZ91D alloy with Mg-rich coating the magnesium particles in coating dissolved with the charge-transfer resistance R ct at the magnesium particle/coating interface decreased and the double-layer capacitance Q dl increased. While the coating resistance remained stable for a long time and corrosion of the AZ91D alloy substrate was obviously delayed. - Abstract: A Mg-rich epoxy primer was prepared by adding pure magnesium particles to an epoxy coating. The coating properties were studied with electrochemical impedance spectroscopy (EIS), scanning electronic microscopy (SEM) and X-ray diffraction (XRD). The Mg-rich primer showed better protection for AZ91D magnesium alloy than the same epoxy primer without Mg addition. The open circuit potential measurements showed cathodic protection effect of the Mg-rich primer on AZ91D alloy. Cross scratch testing showed that the Mg-rich primer provided better protection for the substrate than original epoxy coating. The precipitation of Mg(OH) 2 in the coating also provided some degree of barrier protection.

  14. poCAMon personal online continuous airmonitor; poCAMon online Personen Aerosolmonitor

    Energy Technology Data Exchange (ETDEWEB)

    Streil, T.; Oeser, V. [SARAD GmbH, Dresden (Germany)

    2015-07-01

    The poCAMon combines a very compact design with a high flow rate and long battery life. Its size and weight are still acceptable for carrying by one person. The unit measures long-lived aerosols as well as short-lived Radon/Thoron daughters by alpha spectroscopy and beta counting. The radioactive aerosols and particles are collected on the surface of a high resolution membrane filter. The alpha and beta decays on the filter are measured by a high-end semiconductor radiation detector (400 mm@). This allows a perfect separation of the different decay products. The increased pump rate (more than 3 l/ min) is suitable for lower detection limits. A sensor measures permanently the pressure drop on the filter in order to recognize an exhausted or perforated filter instantly. With the 3.8 Ah NiMH battery pack the poCAMon achieves an operation time of more than 30 hours. The quality control is a main issue of any radiation measurement. Therefore the poCAMon records a complete alpha spectrum for each measured value. This allows the monitoring of the device's perfect operation in each moment of the measurement. There are options for additional sensors for carbon monoxide and combustible gases as needed in underground mines. All measured data are stored in a 2GB memory card and can be accessed with a PC or laptop via a USB interface. Data transmission and device control can also be done via wireless ZigBee network or via a server for stationary operation with network access. A barometric pressure sensor and a GPS receiver are optional features of the device.

  15. Att tillämpa återkommande mätning av kundnöjdhet i IT-projekt : En vidareutvecklad modell baserad på modellerna American Customer Satisfaction Index (ACSI) och SERVQUAL

    OpenAIRE

    Karlmats, Roberg; Karlsson, Daniel

    2015-01-01

    I dagens samhälle är det allt viktigare för företag att behålla sina existerande kunder då konkurrensen blir allt hårdare. Detta medför att företag försöker vidta åtgärder för att vårda relationer med sina kunder. Detta problem är även högst relevant inom IT-branschen. Inom IT-branschen är det vanligt att arbeta agilt i IT-projekt. Vår samarbetspartner har sett ett ökat behov av att mäta servicekvalitet på ett återkommande sätt inom IT-projekt, detta för att mäta relevanta variabler som sträc...

  16. ¿A qué Recorte Territorial Podemos Llamar Barrio?: el caso de Apipucos y Poço da Panela en Recife / What we call neighborhood?: the case of Apipucos and Poço da Panela, Recife

    Directory of Open Access Journals (Sweden)

    Leão Barros, Sandra A.

    2004-03-01

    Full Text Available La escala barrio hace mucho se hace presente en el paisaje urbano recifense. Desde los primeros ingenios de azúcar en la cuenca del río Capibaribe, pasando por las parroquias y pueblos, arrabales, hoy Regiones Político-Administrativas y barrios componentes. Esos contornos todavía parecen ser los mismos. Ingenios que viraron a barrios. Barrios que son verdaderos ‘genius loci’ del Recife. Apipucos y Casa Forte ‘ingenios’, Poço da Panela ‘parroquia’; Apipucos, Casa Forte y Poço da Panela ‘arrabales’; todos ‘barrios’ hoy. Es en esta escala donde hay más convergencia entre el espacio geométrico y el espacio social, donde es más fuerte el sentido de lugar urbano. Es un módulo espacio-social, otrora parroquial, asociado a un soporte físico que lo encierra. Además, presenta siempre tres características simultáneas e integrantes entre sí: una forma y un tamaño, un límite político-administrativo que lo representa frente al Estado y una carga histórico-cultural de la sociedad a que pertenencen. Así lo son Apipucos y Poço da Panela. Relacionar esas características con los barrios estudiados en un biés histórico-temporal es la propuesta de este artículo./For a long time, the district scale appears in the urban landscape from Recife. Since the first mills in Capibaribe’s valley, passing through the parishes and villages, suburbs, today Politic-Administrative Regions and components districts. Theses outlines still seem to be the same. Mills that became districts. Districts which are Recife’s true ‘genius loci’. Apipucos and Casa Forte ‘mills’; Poço da Panela ‘parish’; Apipucos, Casa Forte and Poço da Panela ‘suburbs’; all ‘districts’ today. It is in this scale where there is larger convergence between the geometric space and the social space, where the sense of urban place is stronger. It is a space-social module, formely parochial, associated to a physical support which concludes it

  17. Superacid univalent metal phosphites (MH2PO3)2·H3PO3 (M Rb, Tl+) and MH2PO3·H3PO3 (M = K, Cs): synthesis and structure

    International Nuclear Information System (INIS)

    Kosterina, E.V.; Troyanov, S.I.; Aslanov, L.A.; Kemnits, Eh.

    2001-01-01

    Crystal superacid phosphites α-CsH 2 PO 3 ·H 3 PO 3 (1) and β-CsH 2 PO 3 ·H 3 PO 3 (2) were prepared by means of interaction between cesium carbonate and phosphoric acid excess. The structure of the compounds, i.e.: 1-rhombic crystal system, sp.gr. P2 1 2 1 2 1 , a = 6.033 (1), b = 6.444 (1), c = 18.345 (4) A: 2-monoclinic crystal system, sp.gr. C2/c, a = 9.990 (3), b = 12.197 (4), c = 6.866 (2) A, β = 118.14 (3) deg, was determined by the method of X-ray diffraction analysis of monocrystals at 150 K. Comparative analysis of the crystal structure and hydrogen bond systems in acid phosphites of different composition was conducted [ru

  18. Electroweak Higgs production with HiggsPO at NLO QCD

    International Nuclear Information System (INIS)

    Greljo, Admir; Isidori, Gino; Zhang, Hantian; Lindert, Jonas M.; Marzocca, David

    2017-01-01

    We present the HiggsPO UFO model for Monte Carlo event generation of electroweak VH and VBF Higgs production processes at NLO in QCD in the formalism of Higgs pseudo-observables (PO). We illustrate the use of this tool by studying the QCD corrections, matched to a parton shower, for several benchmark points in the Higgs PO parameter space. We find that, while being sizable and thus important to be considered in realistic experimental analyses, the QCD higher-order corrections largely factorize. As an additional finding, based on the NLO results, we advocate to consider 2D distributions of the two-jet azimuthal-angle difference and the leading jet p T for new physics searches in VBF Higgs production. The HiggsPO UFO model is publicly available. (orig.)

  19. Electroweak Higgs production with HiggsPO at NLO QCD

    Science.gov (United States)

    Greljo, Admir; Isidori, Gino; Lindert, Jonas M.; Marzocca, David; Zhang, Hantian

    2017-12-01

    We present the HiggsPO UFO model for Monte Carlo event generation of electroweak VH and VBF Higgs production processes at NLO in QCD in the formalism of Higgs pseudo-observables (PO). We illustrate the use of this tool by studying the QCD corrections, matched to a parton shower, for several benchmark points in the Higgs PO parameter space. We find that, while being sizable and thus important to be considered in realistic experimental analyses, the QCD higher-order corrections largely factorize. As an additional finding, based on the NLO results, we advocate to consider 2D distributions of the two-jet azimuthal-angle difference and the leading jet p_T for new physics searches in VBF Higgs production. The HiggsPO UFO model is publicly available.

  20. Electroweak Higgs production with HiggsPO at NLO QCD

    Energy Technology Data Exchange (ETDEWEB)

    Greljo, Admir [Universitaet Zuerich, Physik-Institut, Zurich (Switzerland); Johannes Gutenberg-Universitaet Mainz, PRISMA Cluster of Excellence and Mainz Institute for Theoretical Physics, Mainz (Germany); University of Sarajevo, Faculty of Science, Sarajevo (Bosnia and Herzegovina); Isidori, Gino; Zhang, Hantian [Universitaet Zuerich, Physik-Institut, Zurich (Switzerland); Lindert, Jonas M. [Durham University, Department of Physics, Institute for Particle Physics Phenomenology, Durham (United Kingdom); Marzocca, David [Universitaet Zuerich, Physik-Institut, Zurich (Switzerland); INFN, Sezione di Trieste(Italy); SISSA, Trieste (Italy)

    2017-12-15

    We present the HiggsPO UFO model for Monte Carlo event generation of electroweak VH and VBF Higgs production processes at NLO in QCD in the formalism of Higgs pseudo-observables (PO). We illustrate the use of this tool by studying the QCD corrections, matched to a parton shower, for several benchmark points in the Higgs PO parameter space. We find that, while being sizable and thus important to be considered in realistic experimental analyses, the QCD higher-order corrections largely factorize. As an additional finding, based on the NLO results, we advocate to consider 2D distributions of the two-jet azimuthal-angle difference and the leading jet p{sub T} for new physics searches in VBF Higgs production. The HiggsPO UFO model is publicly available. (orig.)

  1. Study on the excretion of pb-210 and po-210

    Energy Technology Data Exchange (ETDEWEB)

    Okabayashi, Hiroyuki [National Inst. of Radiological Sciences, Chiba (Japan)

    1982-06-01

    The amount of Po-210 excreted in urine and feces was more influenced by Po-210 that was taken with food and drink than taken through inhalation. The amount of Pb-210 in urine of mining workers among uranium mine workers was higher than that of the non-uranium mine workers. It was thought that this fact was due to the working environment in uranium mine the amount of Pb-210 being a few tens times higher than that in normal environment. The activity ratios of Po-210 of faecal to urinary excretion are widely distributed, however, the average value of many samples approached to 10. Urinary excretion of Po-210 was highest after 24 hours of ingestion, but for faecal excretion, it was highest after 3 day.

  2. Prediction of Wind Energy Resources (PoWER) Users Guide

    Science.gov (United States)

    2016-01-01

    ARL-TR-7573● JAN 2016 US Army Research Laboratory Prediction of Wind Energy Resources (PoWER) User’s Guide by David P Sauter...manufacturer’s or trade names does not constitute an official endorsement or approval of the use thereof. Destroy this report when it is no longer needed. Do...not return it to the originator. ARL-TR-7573 ● JAN 2016 US Army Research Laboratory Prediction of Wind Energy Resources (PoWER

  3. Study about excretion of 210 Po in urine

    International Nuclear Information System (INIS)

    Fonseca Azeredo, A.M.G. da.

    1988-01-01

    The urine of mines's workers are analysed to detect the presence of 210 Po. The results was compared with the workers and with a control population. Cigarettes samples was analysed two and confirmed the 210 presence. The control population individuals were divided in smokers and non smokers and them urine was investigated the influence of the smoke in the 210 Po excretion. (L.M.J.)

  4. Po-210 distribution in uranium-mill circuits

    International Nuclear Information System (INIS)

    McKlveen, J.W.; Hubele, N.D.; McDowell, W.J.; Case, G.N.

    1983-01-01

    Greater than 99% of all incoming Po-210 reports to the tailing piles for both the acid and the alkaline leach uranium circuits. Leached Po-210 may be carried along on small particles rather than dissolved in solution. There does not appear to be any radiologically significant buildup or accumulation in the acid leach circuit, but there are noteworthy amounts in the molybdenum recovery solution

  5. Water quality in Italy: Po River and its tributaries

    International Nuclear Information System (INIS)

    Crosa, G.; Marchetti, R.

    1993-01-01

    For Italy's Po River hydrological basin, artificial reservoirs have a great importance; water reserve is about 1600 million cubic meters for the hydroelectric reservoirs and about 76 million cubic meters for irrigation. The principal factors determining the water quality of the Po River and its tributaries are examined. Organic micropollutants, metals and the microbial load are the principal parameters altering the quality of the waters; dilution is the prevailing factor reducing this contamination

  6. Syntheses and characterizations of LiFePO4 powders

    OpenAIRE

    Jugović, Dragana; Kuzmanović, Maja; Mitrić, Miodrag; Cvjetićanin, Nikola; Uskoković, Dragan

    2011-01-01

    The olivine type compositions LiMPO4 (M = Fe, Mn, Co) are among the most attractive materials for the positive electrode of lithium-ion battery. The benefits of using LiFePO4 are excellent cycle life, high structural stability, low cost and environmental friendliness. Here will be presented our efforts to obtain LiFePO4 powders through several synthesis methods. The differences in phase purity, microstructure, morphology, and electrochemical performances of synthesized powders were investigat...

  7. The Effects of Rare Earth Pr and Heat Treatment on the Wear Properties of AZ91 Alloy

    Directory of Open Access Journals (Sweden)

    Ning Li

    2018-06-01

    Full Text Available This paper investigated the influences of Pr addition and heat treatment (T6 on the dry sliding wear behavior of AZ91 alloy. The wear rates and friction coefficients were measured by using a pin-on-disc tribometer under loads of 30, 60 and 90 N at dry sliding speeds of 100 rpm, over a sliding time of 15 min. The worn surfaces were examined using a scanning electron microscope and was analyzed with an energy dispersive spectrometer. The experimental results revealed that AZ91-1.0%Pr magnesium alloy exhibited lower wear rate and friction coefficient than the other investigated alloys. As the applied load increased, the wear rate and friction coefficient increased. Compared with the as-cast AZ91-1.0%Pr magnesium alloy, the hardness and wear resistance of the alloy after solution treatment were reduced, and through the subsequent aging, the hardness and wear resistance of the alloy were improved and the hardness was 101.1 HB (compared to as-cast AZ91 magnesium alloy, it increased by 45%. The AZ91-1.0%Pr with T6 magnesium alloy exhibited best wear resistance. Abrasion was dominant at load of 30 N, delamination was dominant at load of 60 N and plastic deformation was dominant at load of 90 N. Oxidation was observed at all loads.

  8. Effect of thermal tempering on microstructure and mechanical properties of Mg-AZ31/Al-6061 diffusion bonding

    Energy Technology Data Exchange (ETDEWEB)

    Jafarian, Mojtaba [Young Researchers and Elite Club, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Rizi, Mohsen Saboktakin, E-mail: M.saboktakin@Pa.iut.ac.ir [Department of Materials Engineering, Isfahan University of Technology, Isfahan 8415683111 (Iran, Islamic Republic of); Department of Industrial Engineering, Lenjan Branch, Islamic Azad University, Isfahan (Iran, Islamic Republic of); Jafarian, Morteza [Young Researchers and Elite Club, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Honarmand, Mehrdad [Department of Mechanical Engineering, Tiran Branch, Islamic Azad University, Isfahan (Iran, Islamic Republic of); Javadinejad, Hamid Reza; Ghaheri, Ali [Department of Materials Engineering, Isfahan University of Technology, Isfahan 8415683111 (Iran, Islamic Republic of); Department of Industrial Engineering, Lenjan Branch, Islamic Azad University, Isfahan (Iran, Islamic Republic of); Bahramipour, Mohammad Taghi [Materials Engineering Department, Hakim Sabzevari University, Sabzevar, 397 (Iran, Islamic Republic of); Ebrahimian, Marzieh [Department of Materials Engineering, Isfahan University of Technology, Isfahan 8415683111 (Iran, Islamic Republic of); Department of Industrial Engineering, Lenjan Branch, Islamic Azad University, Isfahan (Iran, Islamic Republic of)

    2016-06-01

    The objective of this study is to investigate the effect of the types thermal tempering of aluminum alloy on microstructure and mechanical properties of AZ31-O Mg and Al 6061-T6 diffusion bonding. Using Optical Microscope (OM) and Scanning Electron Microscopes (SEM) equipped with EDS analysis and line scan the interfaces of joints were evaluated. The XRD analysis was carried out to characterize phase constitution near the interface zone. The mechanical properties of joints were measured using Vickers micro-hardness and shear strength. According to the results in bonding of AZ31-Mg/Al-6061-O, in less plastic deformation in magnesium alloy, diffusion rate of most magnesium atoms occurred to aluminum alloy and formation of diffusion zone with minimum micro-hardness (140 HV) and maximum shear strength (32 MPa) compared to Al 6061-T6/Mg-AZ31 bonding. Evaluation of fracture surfaces indicates an occurrence of failure from the brittle intermetallic phases. - Highlights: • Diffusion bonding AZ31 to Al-6061withoutany interlayer was successful. • Thermal tempered aluminum alloy plays a vital role in the mechanical properties of joint. • Less thickness of reaction layers and micro-hardness in bonding annealed Al- 6061 layers to AZ31 was achieved. • Fracture surfaces indicated that the onset of fracture from intermetallic compounds resulted in fracture of the cleavage.

  9. A biodegradable AZ91 magnesium alloy coated with a thin nanostructured hydroxyapatite for improving the corrosion resistance

    Energy Technology Data Exchange (ETDEWEB)

    Mukhametkaliyev, T.M.; Surmeneva, M.A. [National Research Tomsk Polytechnic University, 634050, Lenin Avenue 43, Tomsk (Russian Federation); Vladescu, A. [National Research Tomsk Polytechnic University, 634050, Lenin Avenue 43, Tomsk (Russian Federation); National Institute for Optoelectronics, 409 Atomistilor St., RO77125 Magurele (Romania); Cotrut, C.M. [National Research Tomsk Polytechnic University, 634050, Lenin Avenue 43, Tomsk (Russian Federation); Politehnica University of Bucharest, 313 Spl. Independentei, Bucharest (Romania); Braic, M.; Dinu, M. [National Institute for Optoelectronics, 409 Atomistilor St., RO77125 Magurele (Romania); Vranceanu, M.D. [Politehnica University of Bucharest, 313 Spl. Independentei, Bucharest (Romania); Pana, I. [National Institute for Optoelectronics, 409 Atomistilor St., RO77125 Magurele (Romania); Faculty of Physics, Bucharest University, 405 Atomistilor St., RO77125 Magurele (Romania); Mueller, M. [Fraunhofer Institute for Interfacial Engineering and Biotechnology IGB, 70569 Stuttgart (Germany); Surmenev, R.A., E-mail: rsurmenev@gmail.com [National Research Tomsk Polytechnic University, 634050, Lenin Avenue 43, Tomsk (Russian Federation)

    2017-06-01

    The main aim of this study was to investigate the properties of an AZ91 alloy coated with nanostructured hydroxyapatite (HA) prepared by radio frequency (RF) magnetron sputtering. The bioactivity and biomineralization of the AZ91 magnesium alloy coated with HA were investigated in simulated body fluid (SBF) via an in vitro test. Scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD) analyses were performed. The samples were immersed in SBF to study the ability of the surface to promote the formation of an apatite layer as well as corrosion resistance and mass change of the HA-coated AZ91 alloy. Electrochemical tests were performed to estimate the corrosion behaviour of HA-coated and uncoated samples. The results revealed the capability of the HA coating to significantly improve the corrosion resistance of the uncoated AZ91 alloy. - Highlights: • The nanostructured HA layer allows to control the degradation rate of the AZ91 alloy. • The HA coating significantly reduces the corrosion current density. • The HA coating significantly improves the polarization resistance in vitro. • The RF magnetron deposited HA coating promotes calcium-phosphate precipitation in SBF.

  10. Effect of thermal tempering on microstructure and mechanical properties of Mg-AZ31/Al-6061 diffusion bonding

    International Nuclear Information System (INIS)

    Jafarian, Mojtaba; Rizi, Mohsen Saboktakin; Jafarian, Morteza; Honarmand, Mehrdad; Javadinejad, Hamid Reza; Ghaheri, Ali; Bahramipour, Mohammad Taghi; Ebrahimian, Marzieh

    2016-01-01

    The objective of this study is to investigate the effect of the types thermal tempering of aluminum alloy on microstructure and mechanical properties of AZ31-O Mg and Al 6061-T6 diffusion bonding. Using Optical Microscope (OM) and Scanning Electron Microscopes (SEM) equipped with EDS analysis and line scan the interfaces of joints were evaluated. The XRD analysis was carried out to characterize phase constitution near the interface zone. The mechanical properties of joints were measured using Vickers micro-hardness and shear strength. According to the results in bonding of AZ31-Mg/Al-6061-O, in less plastic deformation in magnesium alloy, diffusion rate of most magnesium atoms occurred to aluminum alloy and formation of diffusion zone with minimum micro-hardness (140 HV) and maximum shear strength (32 MPa) compared to Al 6061-T6/Mg-AZ31 bonding. Evaluation of fracture surfaces indicates an occurrence of failure from the brittle intermetallic phases. - Highlights: • Diffusion bonding AZ31 to Al-6061withoutany interlayer was successful. • Thermal tempered aluminum alloy plays a vital role in the mechanical properties of joint. • Less thickness of reaction layers and micro-hardness in bonding annealed Al- 6061 layers to AZ31 was achieved. • Fracture surfaces indicated that the onset of fracture from intermetallic compounds resulted in fracture of the cleavage.

  11. Multivalent binding of PWWP2A to H2A.Z regulates mitosis and neural crest differentiation.

    Science.gov (United States)

    Pünzeler, Sebastian; Link, Stephanie; Wagner, Gabriele; Keilhauer, Eva C; Kronbeck, Nina; Spitzer, Ramona Mm; Leidescher, Susanne; Markaki, Yolanda; Mentele, Edith; Regnard, Catherine; Schneider, Katrin; Takahashi, Daisuke; Kusakabe, Masayuki; Vardabasso, Chiara; Zink, Lisa M; Straub, Tobias; Bernstein, Emily; Harata, Masahiko; Leonhardt, Heinrich; Mann, Matthias; Rupp, Ralph Aw; Hake, Sandra B

    2017-08-01

    Replacement of canonical histones with specialized histone variants promotes altering of chromatin structure and function. The essential histone variant H2A.Z affects various DNA-based processes via poorly understood mechanisms. Here, we determine the comprehensive interactome of H2A.Z and identify PWWP2A as a novel H2A.Z-nucleosome binder. PWWP2A is a functionally uncharacterized, vertebrate-specific protein that binds very tightly to chromatin through a concerted multivalent binding mode. Two internal protein regions mediate H2A.Z-specificity and nucleosome interaction, whereas the PWWP domain exhibits direct DNA binding. Genome-wide mapping reveals that PWWP2A binds selectively to H2A.Z-containing nucleosomes with strong preference for promoters of highly transcribed genes. In human cells, its depletion affects gene expression and impairs proliferation via a mitotic delay. While PWWP2A does not influence H2A.Z occupancy, the C-terminal tail of H2A.Z is one important mediator to recruit PWWP2A to chromatin. Knockdown of PWWP2A in Xenopus results in severe cranial facial defects, arising from neural crest cell differentiation and migration problems. Thus, PWWP2A is a novel H2A.Z-specific multivalent chromatin binder providing a surprising link between H2A.Z, chromosome segregation, and organ development. © 2017 The Authors.

  12. Correlative change of corrosion behavior with the microstructure of AZ91 Mg alloy modified with Y additions

    Energy Technology Data Exchange (ETDEWEB)

    Jia, Ruiling, E-mail: jrl014014@163.com [College of Materials Science and Engineering, Inner Mongolia University of Technology, Hohhot, Inner Mongolia 010051 (China); Zhang, Ming; Zhang, Lina [College of Materials Science and Engineering, Inner Mongolia University of Technology, Hohhot, Inner Mongolia 010051 (China); Zhang, Wei [Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Road, Shenyang 110016 (China); Guo, Feng [College of Materials Science and Engineering, Inner Mongolia University of Technology, Hohhot, Inner Mongolia 010051 (China)

    2015-06-15

    Highlights: • The effect of Y addition into the AZ91 Mg alloys was investigated. • Initial stage of corrosion was studied by in-situ 3D digital microscopy observation. • The potential difference was investigated by Kelvin probe force microscopy. • The effect of Y addition on the corrosion mechanisms of AZ91 alloy was studied. - Abstract: Microstructure characterization of the AZ91 magnesium alloys with or without rare earth element yttrium (Y) has been revealed by SEM, EDS and EPMA. Some Y-rich phases can be found in the magnesium alloys with Y additions. The fraction of β-Mg{sub 17}Al{sub 12} phase obvious decreases and turns into granular distribution with the increase of Y addition instead of original wet distribution along grain boundaries. The results of the potentiodynamic polarization tests show that the corrosion resistance of AZ91 alloy is improved with appropriate Y additions. But an in-situ observation of 3D digital microscopy for the initial stage of corrosion of the magnesium alloy with 0.9%Y addition shows that Y-rich phases act as cathodic effect and the α phases in the vicinity of them acting as anode are corroded. So the additions of Y have a beneficial effect that can depress the overall corrosion of AZ91 alloy, whereas its harmful effect is related to Y-rich phases because they present the highest Volta potential difference from the adjacent matrix and they can drive galvanic corrosion.

  13. Correlative change of corrosion behavior with the microstructure of AZ91 Mg alloy modified with Y additions

    International Nuclear Information System (INIS)

    Jia, Ruiling; Zhang, Ming; Zhang, Lina; Zhang, Wei; Guo, Feng

    2015-01-01

    Highlights: • The effect of Y addition into the AZ91 Mg alloys was investigated. • Initial stage of corrosion was studied by in-situ 3D digital microscopy observation. • The potential difference was investigated by Kelvin probe force microscopy. • The effect of Y addition on the corrosion mechanisms of AZ91 alloy was studied. - Abstract: Microstructure characterization of the AZ91 magnesium alloys with or without rare earth element yttrium (Y) has been revealed by SEM, EDS and EPMA. Some Y-rich phases can be found in the magnesium alloys with Y additions. The fraction of β-Mg 17 Al 12 phase obvious decreases and turns into granular distribution with the increase of Y addition instead of original wet distribution along grain boundaries. The results of the potentiodynamic polarization tests show that the corrosion resistance of AZ91 alloy is improved with appropriate Y additions. But an in-situ observation of 3D digital microscopy for the initial stage of corrosion of the magnesium alloy with 0.9%Y addition shows that Y-rich phases act as cathodic effect and the α phases in the vicinity of them acting as anode are corroded. So the additions of Y have a beneficial effect that can depress the overall corrosion of AZ91 alloy, whereas its harmful effect is related to Y-rich phases because they present the highest Volta potential difference from the adjacent matrix and they can drive galvanic corrosion

  14. A biodegradable AZ91 magnesium alloy coated with a thin nanostructured hydroxyapatite for improving the corrosion resistance

    International Nuclear Information System (INIS)

    Mukhametkaliyev, T.M.; Surmeneva, M.A.; Vladescu, A.; Cotrut, C.M.; Braic, M.; Dinu, M.; Vranceanu, M.D.; Pana, I.; Mueller, M.; Surmenev, R.A.

    2017-01-01

    The main aim of this study was to investigate the properties of an AZ91 alloy coated with nanostructured hydroxyapatite (HA) prepared by radio frequency (RF) magnetron sputtering. The bioactivity and biomineralization of the AZ91 magnesium alloy coated with HA were investigated in simulated body fluid (SBF) via an in vitro test. Scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray diffraction (XRD) analyses were performed. The samples were immersed in SBF to study the ability of the surface to promote the formation of an apatite layer as well as corrosion resistance and mass change of the HA-coated AZ91 alloy. Electrochemical tests were performed to estimate the corrosion behaviour of HA-coated and uncoated samples. The results revealed the capability of the HA coating to significantly improve the corrosion resistance of the uncoated AZ91 alloy. - Highlights: • The nanostructured HA layer allows to control the degradation rate of the AZ91 alloy. • The HA coating significantly reduces the corrosion current density. • The HA coating significantly improves the polarization resistance in vitro. • The RF magnetron deposited HA coating promotes calcium-phosphate precipitation in SBF.

  15. Assessment of Po-210 exposure for the Italian population

    International Nuclear Information System (INIS)

    Clemente, G.F.; Renzetti, A.; Santori, G.; Breuer, F.

    1980-01-01

    Most of the natural internal dose of the general population due to alpha particles is associated with 210 Po exposure. The experimental data obtained to evaluate the levels of 210 Po exposure to members of the general Italian population and to some critical population groups exposed to high radon and daughter air concentration are summarized. The 210 Po content was measured in the following: a) daily diets; b) urinary excretions from members of the general population, both non-smokers and smokers; c) urinary excretions from workers in radioactive spas and non-uranium mines; d) teeth and bone samples from the general population. In most samples the content of 210 Pb, was also measured to assess the behaviour of 210 Po in man. A mathematical model fitting the experimental data was developed to describe the metabolism of systemic 210 Po. Four different levels of 210 Po exposure were detected according to the internal burden measured in the considered subjects. The corresponding dose rate to cortical and trabecular bone and soft tissue was evaluated. The values of the mean dose to the skeleton (cortical bone) were found to range from about 70 μGy/year for non-smokers of the general population to about 2 mGy/year for individuals working inside radioactive spas. (H.K.)

  16. Relational Aggression in Children with Preschool Onset (PO) Psychiatric Disorders

    Science.gov (United States)

    Belden, Andy C.; Gaffrey, Michael S.; Luby, Joan L.

    2012-01-01

    Objective The role of preschool onset (PO) psychiatric disorders as correlates and/or risk factors for relational aggression during kindergarten or 1st grade was tested in a sample of N = 146 preschool-age children (3 to 5.11). Method Axis-I diagnoses and symptom scores were derived using the Preschool Age Psychiatric Assessment. Children’s roles in relational aggression as aggressor, victim, aggressive-victim, or non-aggressor/non-victim were determined at preschool and again 24 months later at elementary school entry. Results Preschoolers diagnosed with PO-psychiatric disorders were 3 times as likely as the healthy preschoolers to be classified aggressors, victims, or aggressive-victims. Children diagnosed with PO-disruptive, depressive, and/or anxiety disorders were at least 6 times as likely as children without PO-psychiatric disorders to become aggressive-victims during elementary school after covarying for other key risk factors. Conclusions Findings suggested that PO-psychiatric disorders differentiated preschool and school-age children’s roles in relational aggression based on teacher-report. Recommendations for future research and preventative intervention aimed at minimizing the development of relational aggression in early childhood by identifying and targeting PO-psychiatric disorders are made. PMID:22917202

  17. Assessment of 210Po exposure for the Italian population

    International Nuclear Information System (INIS)

    Clemente, G.F.; Renzetti, A.; Santori, G.; Breuer, F.

    1980-01-01

    A summary is given of the data required to evaluate the 210 Po internal burden and the relative dose given to the members of the Italian general public and to those groups of subjects who are exposed in non-uranium mines and spas to high radon and daughter product air concentrations. Data on the daily intake, daily excretion, total body burden and skeletal burden of 210 Pb and 210 Po for the general public provide the components of the 210 Pb- 210 Po metabolic balance. A mathematical model has been developed on the basis of this data and can be used to evaluate the 210 Pb- 210 Po body burden of subjects exposed to high levels of radon and daughter products on the basis of their 210 Pb- 210 Po daily excretion. Data is presented for the 210 Pb- 210 Po skeletal and soft tissue burden and the yearly dose rate to the skeleton in non-smokers, smokers, non-uranium miners and spa employees. (UK)

  18. Pengaruh waktu kontak terhadap kualitas sambungan hasil las gesek (Friction Welding Magnesium AZ-31

    Directory of Open Access Journals (Sweden)

    Solihin Solihin

    2018-01-01

    Full Text Available Abstrak: Pengelasan merupakan salah suatu proses penyambungan dua atau lebih bahan teknik, dengan atau tanpa peroses pencairan logam dasarnya. Teknologi Las Gesek (Friction Welding, FW merupakan salah satu teknik pengelasan padat atau pengelasan tanpa proses pencairan (solid-state welding. Pembangkitan panas dalam proses FW dihasilkan dengan cara menggesekkan permukaan material las (base metal hingga mencapai temperatur penyambungannya (semi-solid temperature atau sekitar 80% dari temperature cair bahan, dan dalam hal Magnesium AZ31 adalah sekitar temperatur 5500C. Setelah bahan mencapai temperatur semi-solid tersebut, kemudian diberi tekanan agar terjadi proses penyambungan. Penelitian ini bertujuan untuk mengetahui pengaruh variasi proses terhadap kualitas hasil pengelasan gesek, yang meliputi: kekuatan tarik, struktur makro, dan nilai kekerasan bahan hasil las. Parameter pengujiannya adalah variasi waktu kontak las, yaitu selama 3, 5, dan 10 menit. Kecepatan putar spindle selama proses pengelasan ditetapkan 1400 rpm. Hasil pengelasan menunjukkan bahwa waktu kontak gesek 3 menit menghasilkan kekuatan tarik tertinggi (16,78 MPa, bila dibandingkan dengan dua parameter lain. Hasil uji keras pada daerah las (stir zone menunjukkan angka kekerasan rata-rata yang relative konsisten, atau sebesar 60 HRE untuk semua parameter, sedangkan angka kekerasan rata-rata di daerah terpengaruh panas (heat affected zone, HAZ untuk waktu kontak gesek 3, 5 dan 10 menit secara berturut-turut adalah sebesar 69,6; 64,6; dan 60,6 HRE. Hasil penelitian awal ini memberikan potensi studi lanjutan pada berbagai parameter pengelasan lain agar didapatkan kualitas sambungan las gesek yang optimum untuk proses pengelasan gesek Magnesium AZ-31. Kata Kunci: Las gesek, Magnesium AZ-31, struktur makro, cacat void. Abstract: Welding is a process technology aiming to join two or more materials. Friction Welding (FW is including in a solid-state technology cluster, where the heat is

  19. Effect of the Strain Rate on the Tensile Properties of the AZ31 Magnesium Alloy

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Seunghun; Park, Jiyoun; Choi, Ildong [Korea Maritime University, Busan (Korea, Republic of); Park, Sung Hyuk [Korea Institute of Materials Science, Changwon (Korea, Republic of)

    2013-10-15

    The effect of the strain rate at a range of 10‒4 ⁓ 3 × 10{sup 2}s{sup -}1 on the tensile characteristics of a rolled AZ31 magnesium alloy was studied. The normal tensile specimens were tested using a high rate hydraulic testing machine. Specimens were machined from four sheets with different thicknesses, 1, 1.5, 2 and 3 mm, along three directions, 0°, 45°, and 90° to the rolling direction. The results revealed that all the specimens had a positive strain rate sensitivity of strength, that is, the strength increased with increasing strain rate. This is the same tendency as other automotive steels have. Our results suggest that the AZ31 magnesium alloy has better collision characteristics at high strain rates because of improved strength with an increasing strain rate. Ductility decreased with an increasing strain rate with a strain rate under 1 s{sup -}1, but it increased with an increasing strain rate over 1 s{sup -}1. The mechanical properties of the AZ31 magnesium alloy depend on the different microstructures according to the thickness. Two and 3 mm thickness specimens with a coarse and non-uniform grain structure exhibited worse mechanical properties while the 1.5 mm thickness specimens with a fine and uniform grain structure had better mechanical properties. Specimens machined at 0° and 45° to the rolling direction had higher absorbed energy than that of the 90° specimen. Thus, we demonstrate it is necessary to choose materials with proper thickness and machining direction for use in automotive applications.

  20. Effect of the Strain Rate on the Tensile Properties of the AZ31 Magnesium Alloy

    International Nuclear Information System (INIS)

    Jeong, Seunghun; Park, Jiyoun; Choi, Ildong; Park, Sung Hyuk

    2013-01-01

    The effect of the strain rate at a range of 10‒4 ⁓ 3 × 10"2s"-1 on the tensile characteristics of a rolled AZ31 magnesium alloy was studied. The normal tensile specimens were tested using a high rate hydraulic testing machine. Specimens were machined from four sheets with different thicknesses, 1, 1.5, 2 and 3 mm, along three directions, 0°, 45°, and 90° to the rolling direction. The results revealed that all the specimens had a positive strain rate sensitivity of strength, that is, the strength increased with increasing strain rate. This is the same tendency as other automotive steels have. Our results suggest that the AZ31 magnesium alloy has better collision characteristics at high strain rates because of improved strength with an increasing strain rate. Ductility decreased with an increasing strain rate with a strain rate under 1 s"-1, but it increased with an increasing strain rate over 1 s"-1. The mechanical properties of the AZ31 magnesium alloy depend on the different microstructures according to the thickness. Two and 3 mm thickness specimens with a coarse and non-uniform grain structure exhibited worse mechanical properties while the 1.5 mm thickness specimens with a fine and uniform grain structure had better mechanical properties. Specimens machined at 0° and 45° to the rolling direction had higher absorbed energy than that of the 90° specimen. Thus, we demonstrate it is necessary to choose materials with proper thickness and machining direction for use in automotive applications.

  1. Bohaterki, bojowniczki, przegrane? Hiszpańskie narracje o kobietach zaangażowanych w ruchy lewicowe pierwszej połowy XX wieku

    Directory of Open Access Journals (Sweden)

    Aránzazu Calderón Puerta

    2014-06-01

    , rozumienie własnej roli, poczucie wartości, słowem – obraz samych siebie; po drugie, wydobywają niedostrzeganą przez większość lewicowych projektów różnicę między możliwościami upodmiotowienia obywatelki i obywatela z powodu różnicy praktyk dotyczących płci oraz wynikające z tego nierówności i konflikty; po trzecie, opowiadają heroiczną historię emancypacji kobiet wewnątrz ruchów lewicowych, nierzadko wbrew ograniczeniom owych ruchów; po czwarte, sięgają po historie postaci z drugiego planu – kobiet tworzących sieci społeczne, dzięki którym możliwe było działanie lewicowych organizacji. Wszystkie te aspekty zasadniczo zmieniają obraz rewolucji i historii lewicy jako całości. Przedstawione narracje ujawniają tym samym niezauważane dotąd doświadczenia, które mogą okazać się interesujące w polskim kontekście. Hiszpańskie badaczki pokazały zderzenie kobiet walczących o emancypację z modelami płci dominującymi na prawicy i w ruchach lewicowych, uwikłanie rewolucjonistów i rewolucjonistek we wzory gender, wreszcie próby i strategie przezwyciężania patriarchalnych ograniczeń.

  2. Influence of mictrostructure features on the corrosion behaviourof AZ91 alloy in chloride media

    Directory of Open Access Journals (Sweden)

    Lenka Bukovinová

    2014-11-01

    Full Text Available The influence of the microstructure of as-cast AZ91 magnesium alloy, which applied to solution annealing treatment and ageing treatment respectively, was evaluated in terms of its corrosion behaviour in 0.1 M NaCl solution at room temperature. The corrosion process was monitored by electrochemical impedance spectroscopy (EIS and the surface was characterized by scanning Kelvin probe force microscopy (SKPFM. The extent of corrosion damage was dependent on the microstructure. Surface potential maps indicated that, the surface potential of α-matrix is more positive than surface potential of β phase.

  3. Evaluation of 241-AZ tank farm supporting phase 1 privatization waste feed delivery

    Energy Technology Data Exchange (ETDEWEB)

    CARLSON, A.B.

    1998-11-19

    This evaluation is one in a series of evaluations determining the process needs and assessing the adequacy of existing and planned equipment in meeting those needs at various double-shell tank farms in support of Phase 1 privatization. A number of tank-to-tank transfers and waste preparation activities are needed to process and feed waste to the private contractor in support of Phase 1 privatization. The scope of this evaluation is limited to process needs associated with 241-AZ tank farm during the Phase 1 privatization.

  4. Evaluation of microstructural effects on the corrosion behaviour of AZ91D magnesium alloy

    DEFF Research Database (Denmark)

    Ambat, Rajan; Aung, Naing Naing; Zhou, W.

    2000-01-01

    The effect of microconstituents on the corrosion and electrochemical behaviour of AZ91D alloy prepared by die-casting and ingot casting route has been investigated in 3.5% NaCl solution at pH 7.25. The experimental techniques used include constant immersion technique, in-situ corrosion monitoring....... The corrosion products for ingot consisted of Mg(OH)(2) with small amounts beta phase, magnesium-aluminum oxide and MgH2 while for die-cast, the product showed a highly amorphous structure. (C) 2000 Elsevier Science Ltd. All rights reserved....

  5. Conversion Coatings Produced on AZ61 Magnesium Alloy by Low-Voltage Process

    Directory of Open Access Journals (Sweden)

    Nowak M.

    2016-03-01

    Full Text Available The resultes of anodic oxide conversion coatings on wrought AZ61 magnesium alloy production are describe. The studies were conducted in a solution containing: KOH (80 g/l and KF (300 g/l using anodic current densities of 3, 5 and 10 A/dm2 and different process durations. The obtained coatings were examined under a microscope and corrosion tests were performed by electrochemical method. Based on these results, it was found that the low-voltage process produces coatings conferring improved corrosion resistance to the tested magnesium alloy.

  6. Microstructure of Magnesium alloy AZ91-HP cast in permanent and non-permanent moulds

    DEFF Research Database (Denmark)

    Tiedje, Niels; Sørensen, Rasmus Kirkegaard; Albachari, Sami

    2003-01-01

    Casting of different geometries were made with AZ91-HP in different moulding media, so that a range of cooling conditions were obtained. Cooling curves were measured and compared to the microstructures found in the castings. It was shown that segregation in the alloy is highly dependent on cooling...... rate. This leads to precipitation of varying amounts of intermetallic phases. The distribution of phases in the material is controlled both by interdendritic and intergranular segregation, leading to an inhomogeneous microstructure. It is shown that local solidification time, segregation and diffusion...

  7. Structure and Mechanical Properties of Friction Stir Weld Joints of Magnesium Alloy AZ31

    Science.gov (United States)

    Nagasawa, T.; Otsuka, M.; Yokota, T.; Ueki, T.

    The applicability of friction stir welding to hot rolled sheet of commercial magnesium alloy AZ31 plates has been investigated. Friction stir weld joint showed mechanical strength comparable to that of base material, though the ductility remained at one half of that of the latter. The results are consistent with the microstructure which is characterized by a fine grained bond layer bounded by-intermediate grained base metals. It is found that both anodizing treatment and insertion of aluminum foil between batting faces do not degrade the joint properties at all. The results suggest that friction stir welding can be potentially applied to magnesium alloy.

  8. Microstructural Effects on the Spall Properties of ECAE-Processed AZ31B Magnesium Alloy

    Science.gov (United States)

    2016-10-01

    stresses using 51 mm and 105 mm bore gas guns . The Hugoniot Elastic Limit (HEL) was measured to be approximately 181 ± 3 MPa. The spall strengths...MD 21218, USA b Institute of Shock Physics, Imperial College London, London SW7 2AZ, UK c U.S. Army Research Laboratory, Aberdeen Proving Ground, MD...21005, USA d Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA A R T I C L E I N F O Article history: Received

  9. Constituyentes volátiles del mango de azúcar

    OpenAIRE

    Bautista., Edgar; Duque, Carmenza; Torres, Rafael

    2010-01-01

    Empleando Extracción de Volátiles por Espacio de Cabeza Dinámico y Extracción Líquido-Líquido, se estudió el aroma del mango de azúcar (Mangifera indica L), variedad nativa Colombiana apreciada por su exquisito aroma y sabor. Estos dos métodos complementarios permifieron la identificación, por Cromatografía de Gases de Alta resolución y Cromatografía de Gases de Alta Resolución - Espectrometría de Masas, de 52 coinponentes, entre los cuales sobresalieron como mayoritarios el 3-careno, el b...

  10. Microstructure and properties of friction stir butt-welded AZ31 magnesium alloy

    International Nuclear Information System (INIS)

    Wang Xunhong; Wang Kuaishe

    2006-01-01

    Friction stir welding (FSW) is a relatively new joining technique particularly for magnesium and aluminum alloys that are difficult to fusion weld. In this paper, an excellent friction stir weld of AZ31 magnesium alloy was obtained at proper parameter. In the friction stir zone (FSZ), the microstructure of the base material (BM) is replaced by fine grains and small particles of intermetallic compounds. The average microhardness of the friction stir zone is higher than that of the base material. The maximum tensile strength of joint can reach 93% that of the base material. And the failure locations are almost at the heating affected zone

  11. Evaluation of 241-AZ tank farm supporting phase 1 privatization waste feed delivery

    International Nuclear Information System (INIS)

    CARLSON, A.B.

    1998-01-01

    This evaluation is one in a series of evaluations determining the process needs and assessing the adequacy of existing and planned equipment in meeting those needs at various double-shell tank farms in support of Phase 1 privatization. A number of tank-to-tank transfers and waste preparation activities are needed to process and feed waste to the private contractor in support of Phase 1 privatization. The scope of this evaluation is limited to process needs associated with 241-AZ tank farm during the Phase 1 privatization

  12. Organic coatings silane-based for AZ91D magnesium alloy

    International Nuclear Information System (INIS)

    Hu Junying; Li Qing; Zhong Xiankang; Li Longqin; Zhang Liang

    2010-01-01

    Organic coatings silane-based containing electron withdrawing group or electron donating group have been synthesized and evaluated as prospective surface treatments for AZ91D magnesium alloy by hydrolysis and condensation reaction of the different silanes. Electrochemical tests were employed to confirm the corrosion resistance ability of the two kinds of organic coatings. The results showed that the coating with electron donating group had better corrosion protection performance. On the basis of the spatial configuration and the density of charge of those silanes molecules which was obtained through Gaussian 03 procedure based on B3LYP and density functional theory, combining experiment results, the rational explanation was provided.

  13. El azúcar y el ejercicio físico: su importancia en los deportistas

    OpenAIRE

    Ana B. Peinado; Miguel A. Rojo-Tirado; Pedro J. Benito

    2013-01-01

    El glucógeno muscular, principal almacén de glucosa en el organismo, y la glucemia sanguínea constituyen uno de los principales sustratos energéticos para la contracción muscular durante el ejercicio. El azúcar (sacarosa) es un estupendo suplemento al suministrar tanto glucosa como fructosa. Por ello, es esencial que los deportistas cuiden su alimentación, para mantener y aumentar los depósitos de este combustible, ya que las reservas de glucógeno muscular constituyen un factor limitante de l...

  14. Personal monitoring of 218Po and 214Po radionuclide deposition onto individuals under normal environmental exposure conditions

    International Nuclear Information System (INIS)

    Eatough, J.P.; Worley, A.; Moss, G.R.

    1999-01-01

    Personal dosemeters have been utilized to monitor the deposition of the radon decay products 218 Po and 214 Po onto individuals under normal environmental exposure conditions. Each detector consists of TASTRAK alpha-sensitive plastic incorporated into an ordinary working wristwatch. Subsequent analysis provides energy discrimination of the detected alpha-particle decays, and allows events from the individual radon decay products 218 Po and 214 Po, attached to the detector surface, to be uniquely identified. Assuming similar deposition onto skin and detector surfaces, the activity per unit area of deposited radionuclides can be determined for exposed skin. Forty-one personal dosemeters were issued to volunteers selected through the hospital medical physics departments at Reading, Northampton, Exeter and Plymouth. Each volunteer was also issued with a personal radon dosemeter to determine their individual radon exposure. The volunteers wore the two dosemeters simultaneously and continuously for a period of around one month. Correlations were observed between the radon exposure of the individual and the activity per unit area of 218 Po and 214 Po on the detector surface. From these correlations it can be estimated that at the UK average radon exposure of 20 Bq m -3 , the number of decays/cm 2 /year on continuously exposed skin surface is between 3500 and 28 000 for 218 Po, and between 7000 and 21 000 for 214 Po. These results can be combined with theoretical modelling of the dose distribution in the skin to yield the alpha-particle radiation dose to any identified target cells. (author)

  15. The Flanitzhuette project - solar island electricity supply combined with comprehensive electricity saving measures; Projekt Flanitzhuette - solare Inselstromversorgung in Kombination mit umfassenden Stromsparmassnahmen

    Energy Technology Data Exchange (ETDEWEB)

    Eingartner, M. [Abt. Marketing, Energiedienstleistungen, Regenerative Energien, Bayernwerk AG, Muenchen (Germany); Knapp, R. [Abt. Marketing, Energiedienstleistungen, Regenerative Energien, Bayernwerk AG, Muenchen (Germany); Kranz, U. [Abt. Marketing, Energiedienstleistungen, Regenerative Energien, Bayernwerk AG, Muenchen (Germany)

    1995-10-02

    Since 1992, Bayernwerk AG has been operating a solar island network at Flanitzhuette in the Bavarian Forest, to supply a remote hamlet. The plant is based on a photo-electric system together with a battery and a gas unit. The plant was designed by the least cost planning (LCP) process, ie: The electricity demand was first reduced by economy measures on the customers` side (demand side management, DSM) and then largely coverd by photo-electric supply. In the case of the `Flanitzhuette solar island`, the application of LCP was able to contribute to minimising the supply costs. The authors report on the project and the results in the electricity generation and saving areas. (orig.) [Deutsch] Die Bayernwerk AG betreibt seit 1992 in Flanitzhuette im Bayerischen Wald ein solares Inselstromnetz zur Versorgung eines abgelegenen Weilers. Die Anlage basiert auf einem Photovoltaik-System in Verbindung mit einer Batterieanlage und einem Gasaggregat. Bei der Konzeption der Anlage wurde nach dem Verfahren des Least-Cost Planning (LCP) vorgegangen, d.h. der Strombedarf wurde zunaechst durch wirtschaftliche Massnahmen auf der Kundenseite (Demand-Side Management, DSM) reduziert und erst anschliessend weitgehend photovoltaisch gedeckt. Im Falle der `Solarinsel Flanitzhuette` konnte die Anwendung von LCP zu einer Minimierung der Versorgungskosten beitragen. Die Verfasser berichten ueber das Projekt und die Ergebnisse im Stromerzeugungs- und Stromsparbereich. (orig.)

  16. Effect of magnesium hydride on the corrosion behavior of an AZ91 magnesium alloy in sodium chloride solution

    International Nuclear Information System (INIS)

    Chen Jian; Dong Junhua; Wang Jianqiu; Han Enhou; Ke Wei

    2008-01-01

    The effect of magnesium hydride on the corrosion behavior of an as-cast AZ91 alloy in 3.5 wt.% NaCl solution was investigated using gas collection method and potentiostatic test. The Pourbaix diagram of Mg-H 2 O system was built using thermodynamic calculation. It was possible that magnesium hydride could form in the whole pH range in theory. The experimental results showed that at cathodic region, magnesium hydride formed on surface, which was the controlling process for the corrosion behavior of AZ91 alloy; at anodic region and free corrosion potential, magnesium hydride model and partially protective film model, monovalent magnesium ion model and particle undermining model were responsible for the corrosion process of AZ91 alloy

  17. In vitro corrosion of pure magnesium and AZ91 alloy—the influence of thin electrolyte layer thickness

    Science.gov (United States)

    Zeng, Rong-Chang; Qi, Wei-Chen; Zhang, Fen; Li, Shuo-Qi

    2016-01-01

    In vivo degradation predication faces a huge challenge via in vitro corrosion test due to the difficulty for mimicking the complicated microenvironment with various influencing factors. A thin electrolyte layer (TEL) cell for in vitro corrosion of pure magnesium and AZ91 alloy was presented to stimulate the in vivo corrosion in the micro-environment built by the interface of the implant and its neighboring tissue. The results demonstrated that the in vivo corrosion of pure Mg and the AZ91 alloy was suppressed under TEL condition. The AZ91 alloy was more sensitive than pure Mg to the inhibition of corrosion under a TEL thickness of less than 200 µm. The TEL thickness limited the distribution of current, and thus localized corrosion was more preferred to occur under TEL condition than in bulk solution. The TEL cell might be an appropriate approach to simulating the in vivo degradation of magnesium and its alloys. PMID:26816655

  18. A study of the deformation and failure mechanisms of protective intermetallic coatings on AZ91 Mg alloys using microcantilever bending

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Mingyuan; Mead, James; Wu, Yueqin; Russell, Hugh; Huang, Han, E-mail: han.huang@uq.edu.au

    2016-10-15

    In this study, a nanoindentation-based microcantilever bending technique was utilized to investigate the interfacial properties of a β-Mg{sub 17}Al{sub 12}/AZ91 Mg alloy film/substrate system under tensile loading conditions. Finite element analysis (FEA) was first undertaken to optimise the design of cantilever structures for inducing high tensile stresses at the interface. Cantilevers consisting of a necked region or notch at the interface were determined to be the most successful designs. Microcantilevers containing the β-Mg{sub 17}Al{sub 12}/AZ91 interface were then made using focused ion beam (FIB) milling technique. Necks were made in the cantilevers to intensify the tension at the interface and notches were used to introduce a stress concentration to the interface. During bending, the cantilevers were deflected to failure. Subsequent analysis of the deformed cantilevers using electron microscopies revealed that plastic deformation, and subsequent ductile rupture, of the AZ91 phase was the dominant failure mechanism. When the β-Mg{sub 17}Al{sub 12}/AZ91 film/substrate system was subjected to tension, the softer AZ91 phase failed prior to interfacial delamination, demonstrating that the strength of the interface exceeded the stresses that caused ductile failure in the substrate material. - Highlights: •Microcantilever bending was used to study the property of film/substrate interface. •FEA was used to optimise cantilever design for achieving high interfacial tension. •The intermetallic coatings on AZ91 substrate have strong interfacial adhesion.

  19. Conformal, planarizing and bridging AZ5214-E layers deposited by a 'draping' technique on non-planar III V substrates

    Science.gov (United States)

    Eliás, P.; Strichovanec, P.; Kostic, I.; Novák, J.

    2006-12-01

    A draping technique was tested for the deposition of positive-tone AZ5214-E photo-resist layers on non-planar (1 0 0)-oriented III-V substrates, which had a variety of three-dimensional (3D) topographies micromachined in them that consisted, e.g., of mesa ridges confined to side facets with variable tilt, inverted pyramidal holes and stubs confined to perpendicular side facets. All objects were sharp-edged. In each draping experiment, an AZ5214-E sheet was (1) formed floating on the water surface, (2) lowered onto a non-planar substrate and (3) draped over it during drying to form either self-sustained, or conformal, or planarizing layers over the non-planar substrates. The draping process is based on the depression of the glass transition temperature Tg of AZ5214-E material induced by penetrant water molecules that interact with AZ5214-E. During the process, the molecules are initially trapped under an AZ5214-E sheet and then transported out through the sheet via permeation. The water-AZ5214-E interaction modifies the stiffness κ of the sheet. The magnitude of the effect depends on temperature T and on partial water vapour pressure difference p(T, P, κ): the net effect is that Tg = f(C(T, P), p(T, P, κ)) is lowered as the concentration C of water increases with T and p, where P is the permeability of the sheet. The interaction depressed the Tg of the sheets as low as or lower than 53 °C for 6 µm thick sheets. At room temperature T Tg, the sheet becomes rubbery and mouldable by adhesion and capillary forces. As a result, it can either contour or planarize the topography depending on its geometry and thickness of the sheet.

  20. Les poèmes ragusains de Dejan Despic

    Directory of Open Access Journals (Sweden)

    Stefanović Ana

    2005-01-01

    Full Text Available (francuski Les œuvres de Dejan Despic (1930, inspirées par Dubrovnik: Jadranski soneti op. 17 (1951-1954, Dubrovacki divertimento op. 18 (1952 et Dubrovacki kanconijer op. 96 (1989, révèlent, outre leur thème commun, une parenté supplémentaire importante. Elles sont incitées et, d'une manière essentielle, médiatisées par la poésie: soit par les vers de Jovan Ducic (1871-1943, poète du Parnasse et symbolisme serbe, soit par la poésie pétrarquiste ragusaine. Or, ces compositions ne se montrent pas seulement en tant qu` issues de l`inspiration par la poésie sur Dubrovnik, mais aussi d'un conditionnement spirituel plus profond: de l`inspiration poétique du compositeur lui-même par Dubrovnik. C`est le sentiment poétique du monde, en tant que constante de la vision créatrice de Dejan Despic, qui provient de cette inspiration particulière. Ce monde ragusain du compositeur est le monde classique dans une signification universelle du concept, selon la nature même du milieu évoqué. Or, cela n implique pas une monochromie stylistique des compositions considérées. Au contraire, les perspectives musicales de l`impressionnisme, du néoclassicisme, voire, de la néorennaissance, varient ce cadre stylistique général, tout en marquant les traits distincts d'une poétique de composition très individualisée.

  1. CSER 96-014: criticality safety of project W-151, 241-AZ-101 retrieval system process test

    Energy Technology Data Exchange (ETDEWEB)

    Vail, T.S., Fluor Daniel Hanford

    1997-02-06

    This Criticality Safety Evaluation Report (CSER) documents a review of the criticality safety implications of a process test to be performed in tank 241-AZ-101 (101-AZ). The process test will determine the effectiveness of the retrieval system for mobilization of solids and the practicality of the system for future use in the underground storage tanks at Hanford. The scope of the CSER extends only to the testing and operation of the mixer pumps and does not include the transfer of waste from the tank. Justification is provided that a nuclear criticality is extremely unlikely, if not impossible, in this tank.

  2. PoV-GAME: PUNTOS DE VISTA MEDIANTE JUEGOS PoV-GAME: VIEWPOINTS THROUGH GAMES

    Directory of Open Access Journals (Sweden)

    Carlos Zapata-Jaramillo

    2012-06-01

    Full Text Available El desarrollo de proyectos de software considera importante la consistencia entre la información entregada por todos los interesados de una aplicación. En otras palabras, se procura llegar a acuerdos entre los diferentes puntos de vista de cada actor y llevarlos a cabo durante todo el proyecto. Con los métodos de enseñanza tradicionales se procura formar habilidades en este campo, pero no se afianzan mediante la práctica que, generalmente, se emplea para el aprendizaje en este campo. Por ello, en este artículo se propone ''PoV-GAME'', una nueva forma de ''jugar aprendiendo'', la cual busca fortalecer algunos conceptos básicos en la ingeniería de software como la consistencia en la información que se maneja a lo largo de un proyecto y afianzar la importancia de los puntos de vista en el desarrollo de un producto de software. Posteriormente, se analizan los resultados obtenidos luego de realizar el juego en diferentes grupos de estudiantes.Information for software applications is delivered by the stakeholders. Software development projects need consistency as an important aspect of such information. In other words, agreement among the different viewpoints must be reached in order to be implemented in the project. Well-known teaching methods try to create capabilities in this field, but they fail in reinforcing them in practice, which is commonly used for teaching in this field. Therefore, in this paper we propose ''PoV GAME'' a new way of ''play-to-learn''. We aim the reinforcement of some basic concepts about software engineering such as consistency in the information handled throughout the project, and the importance of viewpoints in the software product development. Subsequently, we analyze the results obtained after holding the game in several groups of students.

  3. Comparison of electrochemical performances of olivine NaFePO4 in sodium-ion batteries and olivine LiFePO4 in lithium-ion batteries.

    Science.gov (United States)

    Zhu, Yujie; Xu, Yunhua; Liu, Yihang; Luo, Chao; Wang, Chunsheng

    2013-01-21

    Carbon-coated olivine NaFePO(4) (C-NaFePO(4)) spherical particles with a uniform diameter of ∼80 nm are obtained by chemical delithiation and subsequent electrochemical sodiation of carbon-coated olivine LiFePO(4) (C-LiFePO(4)), which is synthesized by a solvothermal method. The C-NaFePO(4) electrodes are identical (particle size, particle size distribution, surface coating, and active material loading, etc.) to C-LiFePO(4) except that Li ions in C-LiFePO(4) are replaced by Na ions, making them ideal for comparison of thermodynamics and kinetics between C-NaFePO(4) cathode in sodium-ion (Na-ion) batteries and C-LiFePO(4) in lithium-ion (Li-ion) batteries. In this paper, the equilibrium potentials, reaction resistances, and diffusion coefficient of Na in C-NaFePO(4) are systematically investigated by using the galvanostatic intermittent titration technique (GITT), electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV), and compared to those of the well-known LiFePO(4) cathodes in Li-ion batteries. Due to the lower diffusion coefficient of Na-ion and higher contact and charge transfer resistances in NaFePO(4) cathodes, the rate performance of C-NaFePO(4) in Na-ion batteries is much worse than that of C-LiFePO(4) in Li-ion batteries. However, the cycling stability of C-NaFePO(4) is almost comparable to C-LiFePO(4) by retaining 90% of its capacity even after 100 charge-discharge cycles at a charge-discharge rate of 0.1 C.

  4. Comportamiento frente a la corrosión y biocompatibilidad in vitro/in vivo de la aleación AZ31 modificada superficialmente

    OpenAIRE

    Escudero, M. L.; Clemente, C.; Rubio, J. C.; Alobera, M. A.; García-Alonso, M. C.; del Valle, J. A.; Iglesias, C.; Pérez-Maceda, B. T.; Carboneras, M.; Lozano, R. M.

    2011-01-01

    The present work evaluates the corrosion behaviour and the in vitro/in vivo biocompatibility of the AZ31 magnesium alloy, which fulfills the mechanical requirements of bone. The corrosion kinetic of as-received AZ31 alloy was not compatible with the cell growth. To improve its performance, the AZ31 alloy was surface modified by a chemical conversion treatment in hydrofluoric acid. The magnesium fluoride layer generated by the surface treatment of AZ31 alloy enhances its corrosion behaviour, a...

  5. TiO2 Deposition on AZ31 Magnesium Alloy Using Plasma Electrolytic Oxidation

    Directory of Open Access Journals (Sweden)

    Leon White

    2013-01-01

    Full Text Available Plasma electrolytic oxidation (PEO has been used in the past as a useful surface treatment technique to improve the anticorrosion properties of Mg alloys by forming protective layer. Coatings were prepared on AZ31 magnesium alloy in phosphate electrolyte with the addition of TiO2 nanoparticles using plasma electrolytic oxidation (PEO. This present work focuses on developing a TiO2 functional coating to create a novel electrophotocatalyst while observing the surface morphology, structure, composition, and corrosion resistance of the PEO coating. Microstructural characterization of the coating was investigated by X-ray diffraction (XRD and scanning electron microscopy (SEM followed by image analysis and energy dispersive spectroscopy (EDX. The corrosion resistance of the PEO treated samples was evaluated with electrochemical impedance spectroscopy (EIS and DC polarization tests in 3.5 wt.% NaCl. The XRD pattern shows that the components of the oxide film include Mg from the substrate as well as MgO and Mg2TiO4 due to the TiO2 nanoparticle addition. The results show that the PEO coating with TiO2 nanoparticles did improve the corrosion resistance when compared to the AZ31 substrate alloy.

  6. Room Temperature Shear Band Development in Highly Twinned Wrought Magnesium AZ31B Sheet

    Science.gov (United States)

    Scott, Jon; Miles, Michael; Fullwood, David; Adams, Brent; Khosravani, Ali; Mishra, Raja K.

    2013-01-01

    Failure mechanisms were studied in wrought AZ31B magnesium alloy after forming under different strain paths. Optical micrographs were used to observe the shear band formation and regions of high twin density in samples strained under uniaxial, biaxial, and plane strain conditions. Interrupted testing at 4 pct effective strain increments, until failure, was used to observe the evolution of the microstructure. The results showed that shear bands, with a high percentage of twinned grains, appeared early in the samples strained under biaxial or plane strain tension. These bands are similar to those seen in uniaxial tension specimens just prior to failure where the uniaxial tensile ductility was much greater than that observed for plane strain or biaxial tension conditions. A forming limit diagram for AZ31B, which was developed from the strain data, showed that plane strain and biaxial tension had very similar limit strains; this contrasts with materials like steel or aluminum alloys, which typically have greater ductility in biaxial tension compared to plane strain tension.

  7. Near-liquidus forging, partial remelting and thixoforging of an AZ91D + Y magnesium alloy

    International Nuclear Information System (INIS)

    Zhao Zude; Chen Qiang; Hu Chuankai; Huang Shuhai; Wang Yuanqing

    2009-01-01

    A new route, near-liquidus forging plus partial remelting, has been developed for obtaining globular microstructures. Firstly, a material is formed by near-liquidus forging for obtaining a fine dendritic microstructure. Globular microstructure can be produced by reheating the material into the semi-solid temperature range for a period of time. In this paper, an AZ91D alloy with the addition of yttrium was prepared by near-liquidus forging. Microstructure evolution during partial remelting was studied at temperatures and for times. Tensile mechanical properties of thixoforged components were also determined. It is shown that the fine dendritic structure firstly evolves into a blocky structure during partial remelting. With prolonged holding time, the blocky structure disintegrates into polygonal solid particles. Prolonging time and increasing temperature promote a faster spheroidization. Good mechanical properties are obtained for the thixoforged AZ91D alloy with the addition of yttrium prepared by near-liquidus forging, with a yield strength of 160.9 MPa and a ultimate tensile strength of 301.7 MPa and a elongation to fracture of 9.734%.

  8. Microstructural characterization and finite element modeling of AZ31 magnesium alloys welded joints

    Directory of Open Access Journals (Sweden)

    José A. Segarra

    2018-03-01

    Full Text Available In this article, it has been studied how the microstructure of AZ31 magnesium alloy can be affected by the thermic cycles produced by welding processes, trying to modeling by element finite software the thermic cycles in this material. The AZ31 samples tested were welded using Gas Tugsten Arc Welding (GTAW and different filler materials. For this investigation, optic microscopy, scanning electronic microscopy, and finite elements method software has been used. This work indicates in one hand that in this type of alloys the microconstituyentes are Al-Mn o Al-Mn-Mg compounds, the presence of β-phase cannot be found at room temperature in this research at room, on the other hand the obtained simulation models indicate that the recrystallization takes place in the areas which reach maximum temperatures around 550 °C, this value is also the limit of the dissolution area for the Al-Mn o Al-Mn-Mg precipitated particles which are very likely to act as inhibitors of the corrosion in NaCl electrolytes.

  9. Mechanical properties of AZ31 alloy processed by a green metallurgy route

    International Nuclear Information System (INIS)

    D'Enrico, F.; Garces, G.; Hofer, M.; Kim, S. K.; Perez, P.; Cabeza, S.; Adeva, P.

    2013-01-01

    Recently it has been proved that molding of defect-free components of various commercial alloys of magnesium can be carried out successfully when small amounts of CaO are added to the melt, making unnecessary the use of SF 6 coverage. In the case of AZ alloys, this process also remarkably improves their mechanical properties not only by the greater cleaning of alloys but also by the formation of CaAl 2 phase. This work, part of the Green project Metallurgy (http://www.green-metallurgy.eu) funded by the European Union (LIFE+2009), studies the influence of different CaO additions on the microstructure and mechanical properties of AZ31 Eco-Mg alloy. The alloy was processed by a conventional route involving extrusion of as-cast rods as well as by a powder metallurgy route (PM) using chips as starting material. The objective was to analyze the viability of recycling machining chips to manufacture components for the automobile industry and transportation in general, because of its low cost and environmental impact. It has been demonstrated that alloys processed from chips exhibit the highest tensile stress values, close to 320 MPa. (Author)

  10. Sealing of PEO Coated AZ91 Magnesium Alloy Using La-Based Solutions

    Directory of Open Access Journals (Sweden)

    Luca Pezzato

    2017-01-01

    Full Text Available In this work, solutions containing lanthanum salts were used for a post-treatment of sealing to increase the corrosion resistance of PEO coated AZ91 alloy. PEO coatings were produced on samples of AZ91 magnesium alloy using an alkaline solution containing sodium hydroxide, sodium phosphates, and sodium silicates. The sealing treatment was performed in a solution containing 12 g/L of La(NO33 at pH 4 at different temperatures and for different treatment times. Potentiodynamic polarization test, an EIS test, showed that the sealing treatment with solution containing lanthanum nitrate caused a remarkable increase in the corrosion resistance. The corrosion behavior was correlated with the surface morphology and elemental composition evaluated with scanning electron microscope (SEM, X-ray diffraction (XRD, and X-ray photoelectron spectroscopy (XPS. In particular, the sealing treatment at 50°C for 30 min resulted in being the most promising to increase the corrosion properties of PEO treated samples because of the formation of a homogeneous sealing layer, mainly composed of La(OH3.

  11. Novel hybrid sol-gel coatings for corrosion protection of AZ31B magnesium alloy

    International Nuclear Information System (INIS)

    Lamaka, S.V.; Montemor, M.F.; Galio, A.F.; Zheludkevich, M.L.; Trindade, C.; Dick, L.F.; Ferreira, M.G.S.

    2008-01-01

    This work aims to develop and study new anticorrosion films for AZ31B magnesium alloy based on the sol-gel coating approach. Hybrid organic-inorganic sols were synthesized by copolymerization of epoxy-siloxane and titanium or zirconium alkoxides. Tris(trimethylsilyl) phosphate was also used as additive to confer additional corrosion protection to magnesium-based alloy. A sol-gel coating, about 5-μm thick, shows good adhesion to the metal substrate and prevents corrosion attack in 0.005 M NaCl solution for 2 weeks. The sol-gel coating system doped with tris(trimethylsilyl)-phosphate revealed improved corrosion protection of the magnesium alloy due to formation of hydrolytically stable Mg-O-P chemical bonds. The structure and the thickness of the sol-gel film were characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The corrosion behaviour of AZ31B substrates pre-treated with the sol-gel derived hybrid coatings was tested by electrochemical impedance spectroscopy (EIS). The chemical composition of the silylphosphate-containing sol-gel film at different depths was investigated by X-ray photoelectron spectroscopy (XPS) with depth profiling

  12. Environmental friendly anodizing of AZ91D magnesium alloy in alkaline borate-benzoate electrolyte

    Energy Technology Data Exchange (ETDEWEB)

    Liu Yan [Department of Chemistry, Zhejiang University, Hangzhou 310027 (China); Department of Chemistry, Tianshui Normal University, Tianshui 741000 (China); Wei Zhongling [Magnesium Technology Co., Ltd., Chinese Academy of Sciences, Jiaxing 314051 (China); Yang Fuwei [Department of Chemistry, Tianshui Normal University, Tianshui 741000 (China); Zhang Zhao, E-mail: eaglezzy@zjuem.zju.edu.cn [Department of Chemistry, Zhejiang University, Hangzhou 310027 (China); Key Laboratory for Light Alloy Materials Technology, Jiaxing 314051 (China)

    2011-06-02

    Highlights: > Environmental friendly PEO technology for AZ91 magnesium alloy is developed. > NaBz is used as new additive and it is low-cost and environmental friendly. > The effect of NaBz additive on the properties of the anodized film was studied. > Anodized film with excellent corrosion resistance is obtained. > The forming mechanism of anodized film in the presence of NaBz is approached. - Abstract: A kind of environmental friendly anodizing routine for AZ91D magnesium alloy, based on an alkaline borate-sodium benzoate electrolyte (NaBz) was studied. The effect of NaBz on the properties of the anodized film was investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive spectrometry (EDS), potentiodynamic polarization and electrochemical impedance spectroscopy (EIS), respectively. The results showed that the anodizing process, surface morphology, thickness, phase structure and corrosion resistance of the anodized film were strongly dependent on the concentration of NaBz. In the presence of adequate NaBz, a thick, compact and smoothing anodized film with excellent corrosion resistance was produced. Moreover, the forming mechanism of the anodized film in the presence of NaBz additive was also approached, which was a suppression of arc discharge process by the adsorption of Bz{sup -} on the surface of magnesium alloy substrate.

  13. Thermal Microstructural Stability of AZ31 Magnesium after Severe Plastic Deformation

    Energy Technology Data Exchange (ETDEWEB)

    Young, John P.; Askari, Hesam A.; Hovanski, Yuri; Heiden, Michael J.; Field, David P.

    2015-03-01

    Both equal channel angular pressing and friction stir processing have the ability to refine the grain size of twin roll cast AZ31 magnesium and potentially improve its superplastic properties. This work used isochronal and isothermal heat treatments to investigate the microstructural stability of twin roll cast, equal channel angular pressed and friction stir processed AZ31 magnesium. For both heat treatment conditions, it was found that the twin roll casted and equal channel angular pressed materials were more stable than the friction stir processed material. Calculations of the grain growth kinetics showed that severe plastic deformation processing decreased the activation energy for grain boundary motion with the equal channel angular pressed material having the greatest Q value of the severely plastically deformed materials and that increasing the tool travel speed of the friction stir processed material improved microstructural stability. The Hollomon-Jaffe parameter was found to be an accurate means of identifying the annealing conditions that will result in substantial grain growth and loss of potential superplastic properties in the severely plastically deformed materials. In addition, Humphreys’s model of cellular microstructural stability accurately predicted the relative microstructural stability of the severely plastically deformed materials and with some modification, closely predicted the maximum grain size ratio achieved by the severely plastically deformed materials.

  14. Improvement of high temperature fatigue lifetime in AZ91 magnesium alloy by heat treatment

    Energy Technology Data Exchange (ETDEWEB)

    Mokhtarishirazabad, Mehdi [School of Metallurgy and Materials Engineering, Iran University of Science and Technology, Tehran (Iran, Islamic Republic of); Azadi, Mohammad, E-mail: m_azadi@ip-co.com [Fatigue and Wear Workgroup, Irankhodro Powertrain Company (IPCO), Tehran (Iran, Islamic Republic of); Hossein Farrahi, Gholam [School of Mechanical Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Winter, Gerhard; Eichlseder, Wilfred [Chair of Mechanical Engineering, University of Leoben, Leoben (Austria)

    2013-12-20

    In the present paper, an improvement in high temperature fatigue properties of the AZ91 magnesium alloy with rare earth elements has been obtained by a typical heat treatment, denoted by T6. For this objective, out-of-phase thermo-mechanical fatigue, room temperature and high temperature low cycle fatigue tests are performed to compare lifetimes. Several rare earth elements are initially added to the AZ91 alloy during a gravity casting process in permanent molds. Also, the type of the heat treatment is examined. Results of specimens with only the solution (the T4 heat treatment) and the solution with the ageing process (the T6 heat treatment) are compared under isothermal fatigue loadings. Microstructural investigations are carried out, before and after fatigue experiments to demonstrate the heat treatment effect. Results showed that both low cycle fatigue and thermo-mechanical fatigue of the alloy at high temperatures increases tremendously after the T6 heat treatment. This behavior attributes to the variation of the ductility, which was a result of microstructural changes during the heat treatment and the varying temperature in fatigue tests.

  15. El medievalismo fértil de Paloma Díaz-Mas

    Directory of Open Access Journals (Sweden)

    Rafael M. Mérida Jiménez

    2001-01-01

    Full Text Available The author of this article is concerned with trying to understand why Paloma Díaz-Mas, the writer of such an excellent novel as La tierra fértil (1999, has not received much critical attention. He underlines three main reasons. First, she does not live in Madrid or Barcelona and so she is far away from the main centres of cultural power. Second, she teaches Spanish literature in the Basque Country, a political and linguistic community which significantly differs from that of many other writers. Third, she writes historical novels, which does not appear to be very fashionable in Spain these days. Moreover, Díaz-Mas is a woman writer who does not make use of the most commonly available feminine patterns, and she does not seem to offer a model easy to include in a given feminist methodology either. However, Mérida-Jiménez argues that Paloma provides an intelligent deconstruction of “male authority” through subtle rhetorical means, as well as a representation of the weakness of his “domination” in very innovative ways, such as those derived from the dialectics between history and fiction, centrality and marginality, heterosexuality and homosexuality, individual and society, dream and reason or tradition and modernity.

  16. Microstructure control during twin roll casting of an AZ31 magnesium alloy

    International Nuclear Information System (INIS)

    Huang, Y; Bayandorian, I; Fan, Z

    2012-01-01

    The existing twin roll casting technique for magnesium alloys suffers heterogeneity in both microstructure and chemistry and downstream processing is required to improve the strip quality, resulting in cost rise. In the present work, twin roll casting was carried out using an AZ31 magnesium alloy, with the application of intensive shearing melt conditioning prior to casting. The effect of process parameters such as pouring temperature and casting speed on microstructure control during casting and subsequent downstream processing was studied. Experimental results showed that the melt conditioning treatment allowed the production of AZ31 strips with uniform and refined microstructure free of centreline segregations. It was also shown that an optimized combination of pouring temperature and casting speed, in conjunction with a strip thickness control operation, resulted in uniformly distributed stored energies due to enhanced plastic deformation, which promoted recrystallization during casting and subsequent heat treatment. Strips prepared by twin roll casting and homogenization developed similar microstructural features to those prepared by twin roll casting followed by lengthy downstream processing by homogenization, hot rolling and annealing and displayed a weaker basal texture, exhibiting a potentially better formability.

  17. Investigation of the AZ 5214E photoresist by the laser interference, EBDW and NSOM lithographies

    Energy Technology Data Exchange (ETDEWEB)

    Škriniarová, J., E-mail: jaroslava.skriniarova@stuba.sk [Institute of Electronics and Photonics, Slovak University of Technology, Bratislava (Slovakia); Pudiš, D. [Department of Physics, University of Žilina, Žilina (Slovakia); Andok, R. [Department of E-Beam Lithography, Institute of Informatics, Slovak Academy of Sciences, Bratislava (Slovakia); Lettrichová, I. [Department of Physics, University of Žilina, Žilina (Slovakia); Uherek, F. [Institute of Electronics and Photonics, Slovak University of Technology, Bratislava (Slovakia)

    2017-02-15

    Highlights: • Applicability of the AZ 5214E photoresist for three different lithographies. • Useful for the fabrication of 1D and 2D periodic and irregular structures. • 2D structures with 260 nm period achieved by the laser interference lithography. • Structures with period below 500 nm achieved with the e-beam direct-write lithography. • Holes of 270 nm diameter made by the near-field scanning optical microscopy lithography. - Abstract: In this paper we show a comparison of chosen lithographies used for the AZ 5214E photoresist, which is normally UV sensitive but has also been investigated for its sensitivity to e-beam exposure. Three lithographies, the E-Beam Direct Write lithography (EBDW), laser Interference Lithography (IL) and the non-contact Near-field Scanning Optical Microscopy (NSOM) lithography, are discussed here and the results on exposed arrays of simple patterns are shown. With the EBDW and IL we achieved periods of the structures around half-micron, and we demonstrate attainability of dimensions smaller or comparable than usually achieved by a standard optical photolithography with the investigated photoresist. With the non-contact NSOM lithography structures with periods slightly above a micron were achieved.

  18. Corrosion behaviors in physiological solution of cerium conversion coatings on AZ31 magnesium alloy

    International Nuclear Information System (INIS)

    Cui Xiufang; Yang Yuyun; Liu Erbao; Jin Guo; Zhong Jinggao; Li Qingfen

    2011-01-01

    In this paper, a non-toxic Ce-based conversion coating was obtained on the surface of bio-medical AZ31 magnesium alloys. The micro-morphology of the coating prepared with optimal technical parameters and immersed in physiological solution (Hank's solution) in different time was observed by scanning electron microscopy (SEM), composition of the cerium conversion coating and corrosion products in Hank's solution were characterized by X-ray photoelectron spectroscopy (XPS) and energy dispersive spectroscopy (EDS), respectively. In addition, the corrosion property in Hank's solution was studied by electrochemical experiment and immersion test. The results show that the dense Ce-based conversion coating is obtained on the surface of AZ31 magnesium alloys in optimal technical parameters and the conversion coating consists of a mass of trivalent and tetravalent cerium oxides. The cerium conversion coating can provide obvious protection of magnesium alloys and can effectively reduce the degradation speed in Hank's solution. Also the degradation products have little influence on human body.

  19. Tailoring degradation of AZ31 alloy by surface pre-treatment and electrospun PCL fibrous coating

    Energy Technology Data Exchange (ETDEWEB)

    Hanas, T. [Medical Materials Laboratory, Indian Institute of Technology Madras, Chennai 600036 (India); School of Nano Science and Technology, National Institute of Technology Calicut, Calicut, Kerala 673601 (India); Sampath Kumar, T.S., E-mail: tssk@iitm.ac.in [Medical Materials Laboratory, Indian Institute of Technology Madras, Chennai 600036 (India); Perumal, Govindaraj; Doble, Mukesh [Department of Biotechnology - Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai 600036 (India)

    2016-08-01

    AZ31 magnesium alloy was coated with polycaprolactone (PCL) nano-fibrous layer using electrospinning technique so as to control degradation in physiological environment. Before coating, the alloy was treated with HNO{sub 3} to have good adhesion between the coating and substrate. To elucidate the role of pre-treatment and coating, samples only with PCL coating as well as HNO{sub 3} treatment only were prepared for comparison. Best coating adhesion of 4B grade by ASTM D3359–09 tape test was observed for pre-treated samples. The effect of coating on in vitro degradation and biomineralization was studied using supersaturated simulated body fluid (SBF 5 ×). The weight loss and corrosion results obtained by immersion test showed that the combination of HNO{sub 3} pre-treatment and PCL coating is very effective in controlling the degradation rate and improving bioactivity. Cytotoxicity studies using L6 cells showed that PCL coated sample has better cell adhesion and proliferation compared to uncoated samples. Nano-fibrous PCL coating combined with prior acid treatment seems to be a promising method to tailor degradation rate with enhanced bioactivity of Mg alloys. - Highlights: • PCL electrospun coating on HNO{sub 3} pre-treated AZ31 alloy controls biodegradation. • Acid pre-treatment stabilizes the substrate - coating interface. • Electrospun porous coating improves biomineralization. • Coating similar to extracellular matrix enhances cell adhesion.

  20. Environmental friendly anodizing of AZ91D magnesium alloy in alkaline borate-benzoate electrolyte

    International Nuclear Information System (INIS)

    Liu Yan; Wei Zhongling; Yang Fuwei; Zhang Zhao

    2011-01-01

    Highlights: → Environmental friendly PEO technology for AZ91 magnesium alloy is developed. → NaBz is used as new additive and it is low-cost and environmental friendly. → The effect of NaBz additive on the properties of the anodized film was studied. → Anodized film with excellent corrosion resistance is obtained. → The forming mechanism of anodized film in the presence of NaBz is approached. - Abstract: A kind of environmental friendly anodizing routine for AZ91D magnesium alloy, based on an alkaline borate-sodium benzoate electrolyte (NaBz) was studied. The effect of NaBz on the properties of the anodized film was investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive spectrometry (EDS), potentiodynamic polarization and electrochemical impedance spectroscopy (EIS), respectively. The results showed that the anodizing process, surface morphology, thickness, phase structure and corrosion resistance of the anodized film were strongly dependent on the concentration of NaBz. In the presence of adequate NaBz, a thick, compact and smoothing anodized film with excellent corrosion resistance was produced. Moreover, the forming mechanism of the anodized film in the presence of NaBz additive was also approached, which was a suppression of arc discharge process by the adsorption of Bz - on the surface of magnesium alloy substrate.

  1. Effects of filter materials on microstructure and mechanical properties of AZ91

    Directory of Open Access Journals (Sweden)

    Wu Guohua

    2010-11-01

    Full Text Available The present investigation studied the effects of different kinds of ceramic foam filters (CFF incorporating gas bubbling on the microstructure and mechanical properties of virgin AZ91 alloys, and the reactions between filters and Mg melt during filtration. The results show that the purification process of CFF incorporating gas bubbling process can obviously improve the Rm and A of AZ91 alloy, especially the A. Amongst the selected four kinds of CFF, the MgO filter is the most suitable for filtrating Mg melt, and the filtration effective sequence of four kinds of filtrating materials is as follows: MgO>Al2O3>ZrO2>SiC. With MgO filter incorporating gas bubbling treatment under Ar flow rate of 2 L/min and temperature of 730 °C, the ultimate tensile strength Rm and elongation A can be improved greatly from 175.3 MPa and 2.74% to 195.4 MPa and 4.54%, respectively. No inclusions are found on the fracture surface of the sample filtrated by MgO ceramic foam filter, and the fracture mode is quasi-cleavage crack.

  2. The surface chemistry of 3-mercaptopropyltrimethoxysilane films deposited on magnesium alloy AZ91

    International Nuclear Information System (INIS)

    Scott, A.; Gray-Munro, J.E.

    2009-01-01

    Magnesium and its alloys have desirable physical and mechanical properties for a number of applications. Unfortunately, these materials are highly susceptible to corrosion, particularly in the presence of aqueous solutions. The purpose of this study is to develop a uniform, non-toxic surface treatment to enhance the corrosion resistance of magnesium alloys. This paper reports the influence of the coating bath parameters and alloy microstructure on the deposition of 3-mercaptopropyltrimethoxysilane (MPTS) coatings on magnesium alloy AZ91. The surface chemistry at the magnesium/MPTS interface has also been explored. The results indicate that the deposition of MPTS onto AZ91 was influenced by both the pH and MPTS concentration in the coating bath. Furthermore, scanning electron microscopy results showed that the MPTS film deposited uniformly on all phases of the magnesium alloy surface. X-ray photoelectron spectroscopy studies revealed that at the magnesium/MPTS interface, the molecules bond to the surface through the thiol group in an acid-base interaction with the Mg(OH) 2 layer, whereas in the bulk of the film, the molecules are randomly oriented.

  3. Electrophoretic deposition of nanostructured hydroxyapatite coating on AZ91 magnesium alloy implants with different surface treatments

    Energy Technology Data Exchange (ETDEWEB)

    Rojaee, Ramin, E-mail: raminrojaee@aim.com [Biomaterials Research Group, Department of Materials Engineering, Isfahan University of Technology, Isfahan, 84156-83111 (Iran, Islamic Republic of); Fathi, Mohammadhossein [Biomaterials Research Group, Department of Materials Engineering, Isfahan University of Technology, Isfahan, 84156-83111 (Iran, Islamic Republic of); Dental Materials Research Center, Isfahan University of Medical Sciences, Isfahan (Iran, Islamic Republic of); Raeissi, Keyvan [Department of Materials Engineering, Isfahan University of Technology, Isfahan, 84156-83111 (Iran, Islamic Republic of)

    2013-11-15

    Bio-absorbable magnesium (Mg) based alloys have been introduced as innovative orthopedic implants during recent years. It has been specified that rapid degradation of Mg based alloys in physiological environment should be restrained in order to be utilized in orthopedic trauma fixation and vascular intervention. In this developing field of healthcare materials, micro-arc oxidation (MAO), and MgF{sub 2} conversion coating were exploited as surface pre-treatment of AZ91 magnesium alloy to generate a nanostructured hydroxyapatite (n-HAp) coating via electrophoretic deposition (EPD) method. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM) techniques were used to characterize the obtained powder and coatings. The potentiodynamic polarization tests were carried out to evaluate the corrosion behavior of the coated and uncoated specimens, and in vitro bioactivity evaluation were performed in simulated body fluid. Results revealed that the MAO/n-HAp coated AZ91 Mg alloy samples with a rough topography and lower corrosion current density leads to a lower Mg degradation rate accompanied by high bioactivity.

  4. Research on the drawing process with a large total deformation wires of AZ31 alloy

    International Nuclear Information System (INIS)

    Bajor, T; Muskalski, Z; Suliga, M

    2010-01-01

    Magnesium and their alloys have been extensively studied in recent years, not only because of their potential applications as light-weight engineering materials, but also owing to their biodegradability. Due to their hexagonal close-packed crystallographic structure, cold plastic processing of magnesium alloys is difficult. The preliminary researches carried out by the authors have indicated that the application of the KOBO method, based on the effect of cyclic strain path change, for the deformation of magnesium alloys, provides the possibility of obtaining a fine-grained structure material to be used for further cold plastic processing with large total deformation. The main purpose of this work is to present research findings concerning a detailed analysis of mechanical properties and changes occurring in the structure of AZ31 alloy wire during the multistage cold drawing process. The appropriate selection of drawing parameters and the application of multistep heat treatment operations enable the deformation of the AZ31 alloy in the cold drawing process with a total draft of about 90%.

  5. Characterization of fold defects in AZ91D and AE42 magnesium alloy permanent mold castings

    International Nuclear Information System (INIS)

    Bichler, L.; Ravindran, C.

    2010-01-01

    Casting premium-quality magnesium alloy components for aerospace and automotive applications poses unique challenges. Magnesium alloys are known to freeze rapidly prior to filling a casting cavity, resulting in misruns and cold shuts. In addition, melt oxidation, solute segregation and turbulent metal flow during casting contribute to the formation of fold defects. In this research, formation of fold defects in AZ91D and AE42 magnesium alloys cast via the permanent mold casting process was investigated. Computer simulations of the casting process predicted the development of a turbulent metal flow in a critical casting region with abrupt geometrical transitions. SEM and light optical microscopy examinations revealed the presence of folds in this region for both alloys. However, each alloy exhibited a unique mechanism responsible for fold formation. In the AZ91D alloy, melt oxidation and velocity gradients in the critical casting region prevented fusion of merging metal front streams. In the AE42 alloy, limited solubility of rare-earth intermetallic compounds in the α-Mg phase resulted in segregation of Al 2 RE particles at the leading edge of a metal front and created microstructural inhomogeneity across the fold.

  6. Geologie study off gravels of the Agua Fria River, Phoenix, AZ

    Science.gov (United States)

    Langer, W.H.; Dewitt, E.; Adams, D.T.; O'Briens, T.

    2010-01-01

    The annual consumption of sand and gravel aggregate in 2006 in the Phoenix, AZ metropolitan area was about 76 Mt (84 million st) (USGS, 2009), or about 18 t (20 st) per capita. Quaternary alluvial deposits in the modern stream channel of the Agua Fria River west of Phoenix are mined and processed to provide some of this aggregate to the greater Phoenix area. The Agua Fria drainage basin (Fig. 1) is characterized by rugged mountains with high elevations and steep stream gradients in the north, and by broad alluvial filled basins separated by elongated faultblock mountain ranges in the south. The Agua Fria River, the basin’s main drainage, flows south from Prescott, AZ and west of Phoenix to the Gila River. The Waddel Dam impounds Lake Pleasant and greatly limits the flow of the Agua Fria River south of the lake. The southern portion of the watershed, south of Lake Pleasant, opens out into a broad valley where the river flows through urban and agricultural lands to its confluence with the Gila River, a tributary of the Colorado River.

  7. Ultrasonic Examination of Double-Shell Tank 241-AZ-102 Examination Completed August 2003

    International Nuclear Information System (INIS)

    Pardini, Allan F.; Posakony, Gerald J.

    2003-01-01

    COGEMA Engineering Corporation (COGEMA), under a contract from CH2M Hill Hanford Group (CH2M Hill), has performed an ultrasonic nondestructive examination of selected portions of Double-Shell Tank 241-AZ-102. The purpose of this examination was to provide information that could be used to evaluate the integrity of the wall of the primary tank. The requirements for the ultrasonic examination of Tank 241-AZ-102 were to detect, characterize (identify, size, and locate), and record measurements made of any wall thinning, pitting, or cracks that might be present in the wall of the primary tank. Any measurements that exceed the requirements set forth in the Engineering Task Plat (ETP), RPP-11832 (Jensen 2002) and summarized on page 1 of this document, are reported to CH2M Hill and the Pacific Northwest National Laboratory (PNNL) for further evaluation. Under the contract with CH2M Hill, all data is to be recorded on disk and paper copies of all measurements are provided to PNNL for third-party evaluation. PNNL is responsible for preparing a report that describes the results of the COGEMA ultrasonic examinations

  8. Improvement of high temperature fatigue lifetime in AZ91 magnesium alloy by heat treatment

    International Nuclear Information System (INIS)

    Mokhtarishirazabad, Mehdi; Azadi, Mohammad; Hossein Farrahi, Gholam; Winter, Gerhard; Eichlseder, Wilfred

    2013-01-01

    In the present paper, an improvement in high temperature fatigue properties of the AZ91 magnesium alloy with rare earth elements has been obtained by a typical heat treatment, denoted by T6. For this objective, out-of-phase thermo-mechanical fatigue, room temperature and high temperature low cycle fatigue tests are performed to compare lifetimes. Several rare earth elements are initially added to the AZ91 alloy during a gravity casting process in permanent molds. Also, the type of the heat treatment is examined. Results of specimens with only the solution (the T4 heat treatment) and the solution with the ageing process (the T6 heat treatment) are compared under isothermal fatigue loadings. Microstructural investigations are carried out, before and after fatigue experiments to demonstrate the heat treatment effect. Results showed that both low cycle fatigue and thermo-mechanical fatigue of the alloy at high temperatures increases tremendously after the T6 heat treatment. This behavior attributes to the variation of the ductility, which was a result of microstructural changes during the heat treatment and the varying temperature in fatigue tests

  9. Cyclic deformation and fatigue of rolled AZ80 magnesium alloy along different material orientations

    Energy Technology Data Exchange (ETDEWEB)

    Xiong, Ying, E-mail: yxiong@zjut.edu.cn [Key Laboratory of Special Purpose Equipment and Advanced Processing Technology, Ministry of Education, Zhejiang University of Technology, Hangzhou, Zhejiang 310032 (China); College of Mechanical Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310032 (China); Jiang, Yanyao, E-mail: yjiang@unr.edu [University of Nevada, Reno, Department of Mechanical Engineering, Reno, NV 89557 (United States)

    2016-11-20

    The effect of material orientation on cyclic deformation and fatigue behavior of rolled AZ80 magnesium (Mg) alloy was experimentally investigated under fully reversed strain-controlled loading in ambient. The testing specimens were taken from a rolled AZ80 Mg plate at four orientations with respect to rolled plane: 0°(ND, normal direction), 30°(ND30), 60°(ND60), and 90°(RD, rolled direction). Fatigue fracture morphologies of specimens along different orientation were analyzed by scanning electron microscopy (SEM). Overall cyclic hardening was observed for the material loaded in different directions. For a given strain amplitude, the ND specimens had the lowest fatigue resistance among the specimens of all material orientations. The fatigue life of an ND30 specimens is similar to that of an ND60 specimen at a given strain amplitude and both are higher than that of an RD specimen when the strain amplitude is higher than 0.4%, whereas an RD specimen exhibits a better fatigue resistance when the strain amplitude is lower than 0.4%. A mixed fracture mode with transgranular and intergranular cracking related to lamellar-like features occurred during stable crack growth, and an intergranular fracture mode related to dimple-like features exhibited in the fast fracture region. A multiaxial fatigue model based on the strain energy density can correlate all the fatigue experiments of the material at different material orientations.

  10. Electrophoretic deposition of nanostructured hydroxyapatite coating on AZ91 magnesium alloy implants with different surface treatments

    International Nuclear Information System (INIS)

    Rojaee, Ramin; Fathi, Mohammadhossein; Raeissi, Keyvan

    2013-01-01

    Bio-absorbable magnesium (Mg) based alloys have been introduced as innovative orthopedic implants during recent years. It has been specified that rapid degradation of Mg based alloys in physiological environment should be restrained in order to be utilized in orthopedic trauma fixation and vascular intervention. In this developing field of healthcare materials, micro-arc oxidation (MAO), and MgF 2 conversion coating were exploited as surface pre-treatment of AZ91 magnesium alloy to generate a nanostructured hydroxyapatite (n-HAp) coating via electrophoretic deposition (EPD) method. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM) techniques were used to characterize the obtained powder and coatings. The potentiodynamic polarization tests were carried out to evaluate the corrosion behavior of the coated and uncoated specimens, and in vitro bioactivity evaluation were performed in simulated body fluid. Results revealed that the MAO/n-HAp coated AZ91 Mg alloy samples with a rough topography and lower corrosion current density leads to a lower Mg degradation rate accompanied by high bioactivity.

  11. Electrophoretic deposition of nanostructured hydroxyapatite coating on AZ91 magnesium alloy implants with different surface treatments

    Science.gov (United States)

    Rojaee, Ramin; Fathi, Mohammadhossein; Raeissi, Keyvan

    2013-11-01

    Bio-absorbable magnesium (Mg) based alloys have been introduced as innovative orthopedic implants during recent years. It has been specified that rapid degradation of Mg based alloys in physiological environment should be restrained in order to be utilized in orthopedic trauma fixation and vascular intervention. In this developing field of healthcare materials, micro-arc oxidation (MAO), and MgF2 conversion coating were exploited as surface pre-treatment of AZ91 magnesium alloy to generate a nanostructured hydroxyapatite (n-HAp) coating via electrophoretic deposition (EPD) method. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM) techniques were used to characterize the obtained powder and coatings. The potentiodynamic polarization tests were carried out to evaluate the corrosion behavior of the coated and uncoated specimens, and in vitro bioactivity evaluation were performed in simulated body fluid. Results revealed that the MAO/n-HAp coated AZ91 Mg alloy samples with a rough topography and lower corrosion current density leads to a lower Mg degradation rate accompanied by high bioactivity.

  12. Fatigue characteristics of sand-cast AZ91D magnesium alloy

    Directory of Open Access Journals (Sweden)

    Zhenming Li

    2017-03-01

    Full Text Available The fatigue characteristics of the AZ91D-T6 alloy samples taken from engine blocks have been investigated at 20 °C and elevated temperature (150 °C. The fatigue strength and cyclic stress amplitude of the alloy significantly decrease with the increase of the test temperature, although cyclic hardening occurs continuously until failure for both temperatures. With the increase of the temperature, the decreased fatigue life of the alloy tested at the same stress amplitude is mainly attributed to the decreased matrix strength and the increased hysteresis energies. Fatigue failure of the engine blocks made of AZ91D-T6 alloy is mainly controlled by casting defects. For the defect-free specimens, the crack initiation behavior is determined by the single-slip (20 °C and by environment-assisted cyclic slip (150 °C during fatigue, respectively. The low-cycle fatigue lives of the alloy can be predicted using the Coffin-Manson relation and Basquin laws, the three-parameter equation and the energy-based concepts, while the high-cycle fatigue lives of the alloy fitted well with the developed long crack life model and MSF life models.

  13. El blocao (y el bloqueo de José Díaz Fernández

    Directory of Open Access Journals (Sweden)

    Luis Fernando Bueno Morillas

    2015-06-01

    Full Text Available El blocao (1928 fue la primera novela de José Díaz Fernández. Supuso un éxito editorial insólito hasta entonces porque reunía tres características novedosas: una actitud crítica ante la guerra de Marruecos, una integración de las novedades vanguardistas en la que su autor llamó literatura de avanzada y un posicionamiento del intelectual al lado de las reivindicaciones del pueblo. Sin embargo, aunque publicó otra novela un año después (La Venus mecánica, un libro teórico en el que definía la literatura que él propugnaba y practicaba (El nuevo romanticismo y algunas narraciones breves, Díaz Fernández se bloqueó y dejó la literatura narrativa que tan buenas expectativas levantó. Analizaremos las posibles causas de ese bloqueo.

  14. Bernal Díaz del Castillo, la memoria y la representación

    Directory of Open Access Journals (Sweden)

    María Luisa Fischer

    2016-04-01

    Full Text Available En este trabajo se analizan los procedimientos narrativos que verosimilizan la versión de la historia que define Bernal Díaz del Castillo. Se analiza la función que en el total del relato cumplen los capítulos de largos listados que lo cierran y, especialmente, el capítulo CCVI, dedicado a los retratos indistinguibles de los capitanes españoles de la Nueva España. Se muestra cómo la memoria privilegiada del cronista está funcionando bajo el predicamento de una retórica -en este caso, la del retrato del héroe, de origen medieval- que disputa su lugar frente a la pretendida reconstrucción de la experiencia por la vía única de la memoria. This work analyse the narrative procedures which Bernal Díaz del Castillo uses to make his version of history appear to be probable. The function of the long lists at the end of the story and, especially of Chapter CCVI, containing the indistinguishable portraits of New Spain's Spanish capitains is explained. How the chronicler's privileged memory functions as a rhetorical category -in this case, that of the portrait of a medieval hero- who argues his case for the pretended reconstruction of an experience based only on memory is shown.

  15. Surface composite nanostructures of AZ91 magnesium alloy induced by high current pulsed electron beam treatment

    International Nuclear Information System (INIS)

    Li, M.C.; Hao, S.Z.; Wen, H.; Huang, R.F.

    2014-01-01

    High current pulsed electron beam (HCPEB) treatment was conducted on an AZ91 cast magnesium alloy with accelerating voltage 27 kV, energy density 3 J/cm 2 and pulse duration 2.5 μs. The surface microstructure was characterized by optical microscope (OM), X-ray diffraction (XRD), scanning electron microscope (SEM) equipped with energy dispersive spectrometer (EDS), and transmission electron microscope (TEM). The surface corrosion property was tested with electrochemical method in 3.5 wt.% NaCl solution. It is found that after 1 pulse of HCPEB treatment, the initial eutectic α phase and Mg 17 Al 12 particles started to dissolve in the surface modified layer of depth ∼15 μm. When using 15 HCPEB pulses, the Al content in surface layer increased noticeably, and the phase structure was modified as composite nanostructures consisted of nano-grained Mg 3.1 Al 0.9 domains surrounded by network of Mg 17 Al 12 phase. The HCPEB treated samples showed an improved corrosion resistance with cathodic current density decreased by two orders of magnitude as compared to the initial AZ91 alloy.

  16. Mechanical properties and microstructural evaluation of AA1100 to AZ31 dissimilar friction stir welds

    Energy Technology Data Exchange (ETDEWEB)

    Azizieh, M., E-mail: azizieh@gmail.com [Department of Materials Science and Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz (Iran, Islamic Republic of); Sadeghi Alavijeh, A. [School of Mechatronic Systems Engineering, Simon Fraser University, 250-13450 102 Avenue, Surrey, BC V3T 0A3 (Canada); Abbasi, M. [High Temperature Energy Materials, Korea Institute of Science and Technology, Seoul, 136-791 (Korea, Republic of); Balak, Z. [Department of Materials Science and Engineering, Ahvaz Branch, Islamic Azad University, Ahvaz (Iran, Islamic Republic of); Kim, H.S. [Department of Materials Science and Engineering, Pohang University of Science and Technology, Pohang, 790-784 (Korea, Republic of)

    2016-02-15

    In this paper, microstructure and mechanical properties of dissimilar friction stir welds of AA1100 and AZ31 were investigated to understand the effects of rotational and travel speed as well as pin position. The tensile results of welded samples revealed that the sound welds were formed when the stirring pin deviated from the centreline to the AZ31 side. The X-ray diffraction shows that Al{sub 3}Mg{sub 2} and Al{sub 12}Mg{sub 17} intermetallics formation occurs in the stir zone during the welding process. High hardness of these intermetallic phases increased the hardness of the stir zone to 110 Hv. The best tensile results were obtained in the sample processed in the range of 28–32 (rev/mm) rotational to travel speed ratio. - Highlights: • For Al to Mg friction stir welding, tool offset must be to Mg side. • There is an optimum rotational speed for obtain the highest strength. • Intermetallics form in any welding condition. • The volume fraction of intermetallic is directly related to FSW peak temperature.

  17. Influence of Friction Stir Welding on Mechanical Properties of Butt Joints of AZ61 Magnesium Alloy

    Directory of Open Access Journals (Sweden)

    Seung-Ju Sun

    2017-01-01

    Full Text Available In this study, the effect of heat input on the mechanical properties and fracture behaviors of AZ61 magnesium alloy joints has been studied. Magnesium alloy AZ61 plates with thickness of 5 mm were welded at different ratios of tool rotational speed to welding speed (ω/ν. The average ultimate tensile strength of all weld conditions satisfying a ω/ν ratio of 3 reached 100% of the strength of the base material. Fractures occurred at the interface between the thermomechanical affected zone at advancing side and the stir zone in all welded specimens. From the scanning electron microscope and electron backscatter diffraction analysis, it was determined that the interface between the thermomechanical affected zone and the stir zone, which is the region where the grain orientation changes, was the weakest part; the advancing side region was relatively weaker than the retreating side region because the grain orientation change occurred more dramatically in the advancing side region.

  18. Pathogen and nutrient pulsing and attenuation in "accidental" urban wetland networks along the Salt River in Phoenix, AZ

    Science.gov (United States)

    Palta, M. M.; Grimm, N. B.

    2013-12-01

    Increases in available nutrients and bacteria in urban streams are at the forefront of research concerns within the ecological and medical communities, and both pollutants are expected to become more problematic under projected changes in climate. Season, discharge, instream conditions (oxygen, water velocity), and weather conditions (antecedent moisture) all may influence loading rates to and the retention capabilities of wetlands fed by urban runoff and storm flow. The aim of this research was to examine the effect of these variables on nutrient (nitrogen, phosphorus) and Escherichia coli (E. coli) loading and attenuation along flow paths in urban wetland networks along the Salt River in Phoenix, AZ. Samples were collected for one year along flowpaths through wetlands that formed below six perennially flowing outfalls. Collection took place monthly during baseflow (dry season) conditions, and before and immediately following storm events, in the summer monsoon and winter rainy seasons. Water quality was assessed at the following points: immediately downstream of the outfall, mid-wetland, and downstream of the wetland. For determination of E. coli counts, samples were plated on coliform-selective media (Chromocult) and incubated for 24 hours. Plates were then used to enumerate E. coli. For determination of nutrient concentrations, samples were filtered and frozen until they could be analyzed by ion chromatography and automated wet chemistry. During both summer and winter, total discharge into the wetlands increased during storm events. Concentrations of PO43+, NH4+, and E. coli were significantly higher following storm events than during baseflow conditions, and post-storm peaks in concentration ('pulses') were higher during the summer monsoon than in winter storms. Pulses of pollutants during storms were highest when preceded by hot, dry conditions. NO3- was high in both base and stormflow. E. coli counts and nutrient concentrations dropped along flowpaths

  19. Natural levels of {sup 210}Po in human urine

    Energy Technology Data Exchange (ETDEWEB)

    Diaz-Frances, I.; Manjon, G.; Mantero, J.; Diaz, J. [Departament of Applied Phisic II, University of Seville, P.O. Box 41012 Seville (Spain); Garcia-Tenorio, R. [Departament of Applied Phisic II, University of Seville, P.O. Box 41012 Seville (Spain); National Accelerator Centre, P.O. Box 41092 Seville (Spain)

    2014-07-01

    Since the secret agent Alexander Litvinenko was murdered in 2006 by a {sup 210}Po lethal dose, presumably ingested, there is renovated interest on the toxicity of this radionuclide in humans. {sup 210}Po is a radioactive isotope naturally found in nature, mainly incorporated by humans via food and water ingestion, as well as inhaled through its progenitor, the {sup 222}Rn. The total amount of natural {sup 210}Po in the human body can vary from person to person depending on their lifestyle: dietary habits, drinking water source, place of residence (associated with exposure to {sup 222}Rn), etc- and therefore in the concentrations of this element to be found in urine. To analyze the influence of dietary habits on the amount of {sup 210}Po excreted in urine, two volunteers in Seville had a well-defined and time-varying diet for a month, following a daily collection of their urine and determination of the concentrations therein of this radionuclide. The results obtained and the conclusions derived from them form the core of this communication. {sup 210}Po determinations were performed daily in 200 ml aliquots of urine using the technique of high resolution alpha spectrometry. This has involved the application of a single radiochemical method for the concentration and isolation {sup 210}Po, followed by its auto-deposition on copper planchets for proper measure. Daily {sup 210}Po activity concentrations in voluntary urine analyzed during the month of study show high variability with a difference of up to an order of magnitude between maximum and minimum values obtained, and a clear dependence on the diet type followed in the various stages of the experiment. The lowest concentrations obtained are associated with a diet rich in carbohydrates and proteins 'terrestrial' (pork, beef,...), while the highest concentrations were obtained in the final phase of the experiment when the diet was enriched with presence of marine products in fair correspondence with the

  20. PoSSUM: Polar Suborbital Science in the Upper Mesosphere

    Science.gov (United States)

    Reimuller, J. D.; Fritts, D. C.; Thomas, G. E.; Taylor, M. J.; Mitchell, S.; Lehmacher, G. A.; Watchorn, S. R.; Baumgarten, G.; Plane, J. M.

    2013-12-01

    Project PoSSUM (www.projectpossum.org) is a suborbital research project leveraging imaging and remote sensing techniques from Reusable Suborbital Launch Vehicles (rSLVs) to gather critical climate data through use of the PoSSUM Observatory and the PoSSUM Aeronomy Laboratory. An acronym for Polar Suborbital Science in the Upper Mesosphere, PoSSUM grew from the opportunity created by the Noctilucent Cloud Imagery and Tomography Experiment, selected by the NASA Flight Opportunities Program as Experiment 46-S in March 2012. This experiment will employ an rSLV (e.g. the XCOR Lynx Mark II) launched from a high-latitude spaceport (e.g. Eielson AFB, Alaska or Kiruna, Sweden) during a week-long deployment scheduled for July 2015 to address critical questions concerning noctilucent clouds (NLCs) through flights that transition the cloud layer where the clouds will be under direct illumination from the sun. The 2015 Project PoSSUM NLC campaign will use the unique capability of rSLVs to address key under-answered questions pertaining to NLCs. Specifically, PoSSUM will answer: 1) What are the small-scale dynamics of NLCs and what does this tell us about the energy and momentum deposition from the lower atmosphere? 2) What is the seasonal variability of NLCs, mesospheric dynamics, and temperatures? 3) Are structures observed in the OH layer coupled with NLC structures? 4) How do NLCs nucleate? and 5) What is the geometry of NLC particles and how do they stratify? Instrumentation will include video and still-frame visible cameras (PoSSUMCam), infrared cameras, a mesospheric temperatures experiment, a depolarization LiDAR, a mesospheric density and temperatures experiment (MCAT), a mesospheric winds experiment, and a meteoric smoke detector (MASS). The instrument suite used on PoSSUM will mature through subsequent campaigns to develop an integrated, modular laboratory (the ';PoSSUM Observatory') that will provide repeatable, low cost, in-situ NLC and aeronomy observations as well

  1. 210Pb and 210Po activities in French foodstuffs

    International Nuclear Information System (INIS)

    Renaud, Ph.; Roussel-Debet, S.; Pourcelot, L.; Thebault, H.; Loyen, J.; Gurriaran, R.

    2015-01-01

    The data on 210 Pb and 210 Po activities in French foodstuffs acquired during the last 15 years are numerous enough to derive reference values which will be usable to assess the dose to the French population due to the intake of these two natural radionuclides. The means and ranges are close to those observed in various countries and are most often higher than the reference values proposed by UNSCEAR. Mussels and oysters exhibit the highest 210 Po activities of all kinds of foodstuffs, with a mean value of 27 Bq.kg -1 fresh weight, followed by crustaceans and small fish species (anchovies, mullets, sardines, etc.) with 210 Po activities in the order of 3 to 10 Bq.k -1 fresh weight; cephalopods and other fish species presenting activities around 1 to 3 Bq.kg -1 fresh, close to the UNSCEAR reference value. Below these highest 210 Po activities are those of 210 Po and 210 Pb in terrestrial kinds of foodstuffs, by decreasing order: meats (around 1 Bq.kg -1 fresh), cereals (0.4 Bq.kg -1 ), leafy vegetables (0.3 Bq.kg -1 ), other vegetables and fruits (0.1 Bq.kg -1 ), and milk (from 0.03 to 0.1 Bq.L -1 ). (authors)

  2. Histone variant H2A.Z antagonizes the positive effect of the transcriptional activator CPC1 to regulate catalase-3 expression under normal and oxidative stress conditions.

    Science.gov (United States)

    Dong, Qing; Wang, Yajun; Qi, Shaohua; Gai, Kexin; He, Qun; Wang, Ying

    2018-05-05

    In eukaryotes, deposition of the histone variant H2A.Z into nucleosomes through the chromatin remodeling complex, SWR1, is a crucial step in modulating gene transcription. Recently, H2A.Z has been shown to control the expression of responsive genes, but the underlying mechanism of how H2A.Z responds to physiological stimuli is not well understood. Here, we reveal that, in Neurospora crassa, H2A.Z is a negative regulator of catalase-3 gene, which is responsible for resistance to oxidative stress. H2A.Z represses cat-3 gene expression through direct incorporation at cat-3 locus in a SWR1 complex dependent pathway. Notably, loss of H2A.Z or SWR1 subunits leads to increased binding of a transcription factor, CPC1, at cat-3 locus. Additionally, introduction of plasmids containing gene encoding H2A.Z or SWR1 complex subunits into wild-type strains decreased CAT-3 expression, indicating that H2A.Z counteracts the positive effect of CPC1 to achieve low level cat-3 expression under non-inductive condition. Furthermore, upon oxidative stress, H2A.Z is rapidly evicted from cat-3 locus for the recruitment of CPC1, resulting in robust and full cat-3 gene expression in response to external stimuli. Collectively, this study strongly demonstrates that H2A.Z antagonizes the function of transcription factor to regulate responsive gene transcription under normal conditions and to poise for gene full activation under oxidative stress. Copyright © 2018. Published by Elsevier Inc.

  3. Development of mechanical properties in a CaO added AZ31 magnesium alloy processed by equal-channel angular pressing

    International Nuclear Information System (INIS)

    Bae, Seong-Hwan; Jung, Ki Ho; Shin, Young-Chul; Yoon, Duk Jae; Kawasaki, Megumi

    2016-01-01

    Processing through the application of equal-channel angular pressing (ECAP) is recognized as one of the attractive severe plastic deformation techniques where the processed bulk metals generally achieve ultrafine-grained microstructure leading to improved physical characteristics and mechanical properties. Magnesium has received much attention to date for its lightweight, high strength and excellent elasticity. Mg alloys with addition of CaO is reported to provide the successful casting procedure without usage of greenhouse gas, SF 6 , whereas it is generally used for preventing the oxidation of Mg during casting. In the present investigation, a CaO added AZ31 (AZ31-CaO) magnesium alloy was processed by ECAP at elevated temepratures with a few steps of reduction which result in significant grain refinement to ~ 1.5 μm after 6 passes. Compression testing at room temperature demonstrated the AZ31-CaO alloy after ECAP showed enhanced yield strength more than the as-processed commercial AZ31 alloy while both alloys maintained ductility in spite of significant reduction in grain size. The improved strength in the AZ31-CaO alloy was attributed to the formation of fine Al 2 Ca precipitates which experience breaking-up through ECAP and accelerate the microstructural refinement. Moreover, the preservation of ductility was attributed to the enhancement of strain hardening capability in the AZ31 alloy at room temperature. This study discusses the feasibility of using ECAP to improve both strength and ductility on magnesium alloys by applying the diagram describing the paradox of strength and ductility. - Highlights: • AZ31 and AZ31-CaO magnesium alloys were processed by ECAP up to 6 passes. • AZ31-CaO alloy after ECAP showed improved yield strength without losing ductility. • CaO in AZ31 forms fine Al 2 Ca accelerating microstructural refinement during ECAP. • Feasibility of using ECAP was shown to improve both strength and ductility in Mg.

  4. Influencia de compuestos azúcares y no azúcares en la calidad industrial de caña de azúcar en Tucumán (R. Argentina: Parte 1: caña limpia y despuntada Influence of sugar and nonsugar compounds on sugarcane industrial quality in Tucumán (Argentine Republic

    Directory of Open Access Journals (Sweden)

    B. Silvia Zossi

    Full Text Available Se estudió la concentración de compuestos azúcares y no azúcares, especialmente los que influyen en la formación del color y otros que inciden en el proceso industrial de producción de azúcar blanco directo, de las cuatro variedades comerciales de caña más difundidas en Tucumán (R. Argentina: TUCCP 77-42, LCP 85-384, CP 65-357 y RA 87-3. Estos ensayos fueron realizados durante las zafras 2004 a 2007 en caña limpia y despuntada. Los parámetros analizados fueron: extracción de jugo, Brix %, pol % en jugo y en caña, sacarosa y azúcar recuperable. Se estudiaron no azúcares inorgánicos, tales como cenizas, fosfato y sílice, y no azúcares orgánicos: fibra, almidón, compuestos antocianos y fenoles, nitrógeno amínico, ácidos cis y trans-aconítico, "indicator value" y color. De las cuatro variedades analizadas, la que mejor comportamiento presentó para producir azúcar blanco directo fue LCP 85-384, por su alto contenido en sacarosa y bajo contenido de componentes no azúcares. El segundo lugar le correspondió a la variedad RA 87-3, seguida por CP 65-357 y TUCCP 77-42.The concentration of sugar and nonsugar compounds, especially those which play a part in colour formation and others which affect direct white sugar manufacturing process, was studied in the four commercial cane varieties most widely grown in Tucumán (Argentine Republic: TUCCP 77-42, LCP 85-384, CP 65-357 and RA 87-3. Trials with clean cane were conducted during the 2004-2007 harvests. Analyzed parameters were: juice extraction, Brix %, pol % in juice and cane, sucrose and sugar recovery. Inorganic nonsugar compounds, such as ash, phosphate and silica, as well as organic ones, such as fibre, starch, anthocyanin and phenolic compounds, amino nitrogen, cis and trans-aconitic acids, indicator value and colour, were studied. Results showed that LCP 85-384 variety had the best factory performance to produce direct white sugar because of its high sucrose and low

  5. Analysis of the Deformability of Two-Layer Materials AZ31/Eutectic / Analiza Możliwości Odkształcania Plastycznego Materiału Dwuwarstwowego AZ31/Eutektyka

    Directory of Open Access Journals (Sweden)

    Mola R.

    2015-12-01

    Full Text Available The paper present the results of physical simulation of the deformation of the two-layered AZ31/eutectic material using the Gleeble 3800 metallurgical processes simulator. The eutectic layer was produced on the AZ31 substrate using thermochemical treatment. The specimens of AZ31 alloy were heat treated in contact with aluminium powder at 445°C in a vacuum furnace. Depending on the heating time, Al-enriched surface layers with a thickness of 400, 700 and 1100 μm were fabricated on a substrate which was characterized by an eutectic structure composed of the Mg17Al12 phase and a solid solution of aluminium in magnesium. In the study, physical simulation of the fabricated two-layered specimens with a varying thickness of the eutectic layer were deformed using the plane strain compression test at various values of strain rates. The testing results have revealed that it is possible to deform the two-layered AZ31/eutectic material at low strain rates and small deformation values.

  6. The extrusion of AZ-series magnesium alloys - extending the processing limits by hydrostatic extrusion; Erweiterung der Prozessgrenzen beim Strangpressen von Magnesiumknetlegierungen der AZ-Reihe durch das hydrostatische Strangpressverfahren

    Energy Technology Data Exchange (ETDEWEB)

    Swiostek, J. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Werkstofforschung

    2008-12-04

    The present study is concerned with the analysis of the influence of hydrostatic extrusion on the microstructural development and mechanical properties of extruded profiles of the AZ-series magnesium alloys. This work also deals with the correlation between the microstructure and resulting mechanical properties for the case extruded profiles. (orig.)

  7. Enhanced photo-stability and photocatalytic activity of Ag3PO4 via modification with BiPO4 and polypyrrole

    Science.gov (United States)

    Cai, Li; Jiang, Hui; Wang, Luxi

    2017-10-01

    Ag3PO4 photocatalysts modified with BiPO4 and polypyrrole (PPy) were successfully synthesized via a combination of co-precipitation hydrothermal technique and oxidative polymerization method. Their morphologies, structures and optical and electronic properties were characterized by means of scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscope (TEM), Brunauer-Emmett-Teller (BET) surface areas, X-ray diffraction (XRD), fourier transform infrared spectra (FT-IR), X-ray photo-electron spectroscopy (XPS), UV-vis diffuse reflection spectra (UV-vis DRS), photocurrent technique and electrochemical impedance spectra (EIS). The typical triphenylmethane dye (malachite green) was chosen as a target organic contaminants to estimate the photocatalytic activities and photo-stabilities of Ag3PO4-BiPO4-PPy heterostructures under visible light irradiation. The results indicated that the existence of BiPO4 and PPy not only showed great influences on the photocatalytic activity, but also significantly enhanced photo-stability of Ag3PO4 in repeated and long-term applications. The degradation conversion of Ag3PO4-BiPO4-PPy heterostructures (ABP-3) was 1.58 times of that of pure Ag3PO4. The photo-corrosion phenomenon of Ag3PO4 was effectively avoided. The photocatalytic activity of up to 87% in the Ag3PO4-BiPO4-PPy heterostructures (ABP-3) can be remained after five repeated cycles, while only about 33% of the degradation efficiency can be reserved in pure Ag3PO4. The possible mechanism of enhanced photo-stability and photocatalytic activity of Ag3PO4-BiPO4-PPy heterostructures was also discussed in this work.

  8. Les poèmes ragusains de Dejan Despic

    OpenAIRE

    Stefanović Ana

    2005-01-01

    (francuski) Les œuvres de Dejan Despic (1930), inspirées par Dubrovnik: Jadranski soneti op. 17 (1951-1954), Dubrovacki divertimento op. 18 (1952) et Dubrovacki kanconijer op. 96 (1989), révèlent, outre leur thème commun, une parenté supplémentaire importante. Elles sont incitées et, d'une manière essentielle, médiatisées par la poésie: soit par les vers de Jovan Ducic (1871-1943), poète du Parnasse et symbolisme serbe, soit par la poésie pétrarquiste ragusaine. Or, ces compositions ne se mon...

  9. Co3(PO42·4H2O

    Directory of Open Access Journals (Sweden)

    Yang Kim

    2008-10-01

    Full Text Available Single crystals of Co3(PO42·4H2O, tricobalt(II bis[orthophosphate(V] tetrahydrate, were obtained under hydrothermal conditions. The title compound is isotypic with its zinc analogue Zn3(PO42·4H2O (mineral name hopeite and contains two independent Co2+ cations. One Co2+ cation exhibits a slightly distorted tetrahedral coordination, while the second, located on a mirror plane, has a distorted octahedral coordination environment. The tetrahedrally coordinated Co2+ is bonded to four O atoms of four PO43− anions, whereas the six-coordinate Co2+ is cis-bonded to two phosphate groups and to four O atoms of four water molecules (two of which are located on mirror planes, forming a framework structure. In addition, hydrogen bonds of the type O—H...O are present throughout the crystal structure.

  10. 210Pb and 210Po in Finnish cereals

    International Nuclear Information System (INIS)

    Turtiainen, Tuukka; Kostiainen, Eila; Hallikainen, Anja

    2011-01-01

    A survey was carried out on the activity concentrations of 210 Pb and 210 Po in cereal grains produced in Finland. The cereal species were wheat (Triticum aestivum), rye (Secale cereale), oats (Avena sativa) and barley (Hordeum vulgare), which account for 90% of the Finnish consumption of cereal products. The survey consisted of 18 flour and 13 unprocessed cereal samples and one hulled grain sample from 22 flour mills. According to the results, the mean 210 Pb/ 210 Po concentrations in wheat grains, wheat flour, rye flour, oat grains and barley grains were 0.29, 0.12, 0.29, 0.36 and 0.36 Bq kg -1 , respectively. Combined with the consumption rates of the products, we assess that the mean effective doses from 210 Pb and 210 Po in cereal products for the adult male and female population are 22 and 17 μSv per year, respectively.

  11. 210Pb and 210Po in Finnish cereals.

    Science.gov (United States)

    Turtiainen, Tuukka; Kostiainen, Eila; Hallikainen, Anja

    2011-05-01

    A survey was carried out on the activity concentrations of (210)Pb and (210)Po in cereal grains produced in Finland. The cereal species were wheat (Triticum aestivum), rye (Secale cereale), oats (Avena sativa) and barley (Hordeum vulgare), which account for 90% of the Finnish consumption of cereal products. The survey consisted of 18 flour and 13 unprocessed cereal samples and one hulled grain sample from 22 flour mills. According to the results, the mean (210)Pb/(210)Po concentrations in wheat grains, wheat flour, rye flour, oat grains and barley grains were 0.29, 0.12, 0.29, 0.36 and 0.36 Bq kg(-1), respectively. Combined with the consumption rates of the products, we assess that the mean effective doses from (210)Pb and (210)Po in cereal products for the adult male and female population are 22 and 17 μSv per year, respectively. Copyright © 2010 Elsevier Ltd. All rights reserved.

  12. 210Po radiation dose due to cigarette smoking

    International Nuclear Information System (INIS)

    Godwin, Wesley S.; Subha, Vincila R.; Feroz, Khan M.

    2010-01-01

    The level of 210 Po in eight brands of cigarettes and four brands of bidis popular in and around Nagercoil town was determined to evaluate the annual effective dose. The 210 Po activity in a full cigarette ranged from 32.8±3.6 to 68.4±5.9 mBq and from 34.3±3.5 to 62.9±5.8 mBq in a bidi. In tobacco, the highest 210 Po content was recorded in the brand C4 (23.0±1.2 mBq) whereas for bidis it was the highest in the brand B2 (21.1±1.1 mBq). The activity in mainstream varied from 15.2±0.75 to 36.8±2.1 mBq in a cigarette and from 20.7±3.1 to 39.8±4.0 mBq in a bidi. With regard to 210 Po activity concentration, not much specificity was noted with respect to the tobacco brand. The data showed a relatively wide range of activity concentration of 210 Po in the different cigarette/bidi brands and even within the same brand. The bidis showed a higher activity when compared to cigarettes. The popular brands concentrated more activity than the fine brands. Smokers who smoke one pack (10 cigarettes/bidis) per day may inhale about 100-300 mBq d -1 (0.1-0.3 Bq d -1 ) of 210 Po. In this study, radiation dose values in the range of 153.5-372.9 μSv Y - '1 from cigarettes and from 209.2 to 402.7 μSvY -1 from bidis was estimated for the whole body. (author)

  13. Po-210 and other radionuclides in terrestrial and freshwater environments

    Energy Technology Data Exchange (ETDEWEB)

    Gjelsvik, Runhild; Brown, Justin [eds.; Norwegian Radiation Protection Authority (Norway); Holm, Elis [Univ. of Lund (Sweden); Roos, Per [Risoe DTU (Denmark); Saxen, Ritva; Outola, Iisa [STUK - Radiation and Nuclear Safety Authority (Finland)

    2009-01-15

    This report provides new information on Po-210 (and where appropriate its grandparent Pb-210) behaviour in environmental systems including humans. This has primarily been achieved through measurements of Po-210 in aquatic and terrestrial environments that has led to the derivation of information on the levels of this radioisotope in plants, animals and the biotic components of their habitat (i.e. water, soil) providing basic information on transfer where practicable. For freshwater environments, Po-210 concentration ratios derived for freshwater benthic fish and bivalve mollusc were substantially different to values collated from earlier review work. For terrestrial environments, activity concentrations of Po-210 in small mammals (although of a preliminary nature because no correction was made for ingrowth from Pb-210) were considerably higher than values derived from earlier data compilations. It was envisaged that data on levels of naturally occurring radionuclides would render underpinning data sets more comprehensive and would thus allow more robust background dose calculations to be performed subsequently. By way of example, unweighted background dose-rates arising from internal distributions of Po-210 were calculated for small mammals in the terrestrial study. The biokinetics of polonium in humans has been studied following chronic and acute oral intakes of selected Po radioisotopes. This work has provided information on gastrointestinal absorption factors and biological retention times thus improving the database upon which committed effective doses to humans are derived. The information generated in the report, in its entirety, should be of direct relevance for both human and non-human impact assessments. (au)

  14. Po-210 and other radionuclides in terrestrial and freshwater environments

    International Nuclear Information System (INIS)

    Gjelsvik, Runhild; Brown, Justin; Roos, Per; Saxen, Ritva; Outola, Iisa

    2009-01-01

    This report provides new information on Po-210 (and where appropriate its grandparent Pb-210) behaviour in environmental systems including humans. This has primarily been achieved through measurements of Po-210 in aquatic and terrestrial environments that has led to the derivation of information on the levels of this radioisotope in plants, animals and the biotic components of their habitat (i.e. water, soil) providing basic information on transfer where practicable. For freshwater environments, Po-210 concentration ratios derived for freshwater benthic fish and bivalve mollusc were substantially different to values collated from earlier review work. For terrestrial environments, activity concentrations of Po-210 in small mammals (although of a preliminary nature because no correction was made for ingrowth from Pb-210) were considerably higher than values derived from earlier data compilations. It was envisaged that data on levels of naturally occurring radionuclides would render underpinning data sets more comprehensive and would thus allow more robust background dose calculations to be performed subsequently. By way of example, unweighted background dose-rates arising from internal distributions of Po-210 were calculated for small mammals in the terrestrial study. The biokinetics of polonium in humans has been studied following chronic and acute oral intakes of selected Po radioisotopes. This work has provided information on gastrointestinal absorption factors and biological retention times thus improving the database upon which committed effective doses to humans are derived. The information generated in the report, in its entirety, should be of direct relevance for both human and non-human impact assessments. (au)

  15. Concentrations of 210Po in fish and shellfish from southern region of Japan and evaluation of 210Po intake from seafood for Japanese people

    International Nuclear Information System (INIS)

    Momoshima, N.; Sugihara, S.; Nakao, H.

    2012-01-01

    Concentrations of 210 Po in fish and shellfish, mostly collected from southern region of Japan were analyzed. Values ranged from 0.2 to 229 Bq/kg fresh weight and higher concentrations were observed in samples analyzed with viscera. Intake of 210 Po through fish and shellfish was evaluated at different Japanese cities based on statistical consumption data. Phytoplankton, Heterosigma akashiwo was collected during a harmful algal bloom and 210 Po was analyzed. The phytoplankton occupied only 4.4% of 210 Po in seawater and a large fraction of 210 Po was observed in the particulate form. (orig.)

  16. Po Superconducting Magnet:detail of the windings

    CERN Multimedia

    1982-01-01

    The Po superconducting dipole was built as a prototype beam transport magnet for the SPS extracted proton beam Po. Its main features were: coil aperture 72 mm, length 5 m, room-temperature yoke, NbTi cable conductor impregnated with solder, nominal field 4.2 T at 4.7 K (87% of critical field). It reached its nominal field without any quench. The photo shows a detail of the inner layer winding before superposing the outer layer to form the complete coil of a pole. Worth noticing is the interleaved glass-epoxy sheet (white) with grooved channels for the flow of cooling helium. See also 8307552X.

  17. Los 'Horizontes poéticos' (1881) de Francisca Sarasate

    OpenAIRE

    Mata-Induráin, C. (Carlos)

    1999-01-01

    Francisca Sarasate supone una excepción notable en el área de las letras navarras, por la escasez de mujeres en el ámbito literario. Cultivó, entre otros, la novela, el cuento, el teatro y la poesía. Destaca su obra 'Horizontes poéticos'. ------------------ Francisca Sarasate is a notable exception in the area of the letters of Navarra, by the scarcity of women in the literary field. She cultivated the novel, short stories, drama and poetry. She wrote, among others, 'Horizontes poéticos'....

  18. Thermal analysis of a LiFePo4 Battery

    OpenAIRE

    Balanguer Escolano, David

    2014-01-01

    The objective of this final thesis project was to study and test a 3,3V LiFePo4 battery in outer space conditions to be able to determine its working range, its limitations and its problems. To do so a measuring set-up to read and estimate the capacity of a battery was built and programmed. Then the LiFePo4 battery was tested at different temperatures between -20°C and 40°C in a vacuum chamber at a pressure under 100 microbars. The results showed that the battery can still operate prope...

  19. Warm Deep Drawing of Rectangular Parts of AZ31 Magnesium Alloy Sheet Adopting Variable Blank Holder Force

    International Nuclear Information System (INIS)

    Peng Yinghong; Chang Qunfeng; Li Dayong; Zeng Xiaoqin

    2007-01-01

    AZ31 magnesium alloy sheet with good shape and formability is fabricated by warm cross rolling. Uniaxial tensile tests are conducted using a Gleeble 3500 thermal - mechanical simulator, and the mechanical properties of AZ31 magnesium alloy sheet are analyzed. A warm deep drawing process of square part is also simulated by the finite element method. The influences of blank holder force on the formability are numerically investigated. A double-action hydraulic press that can realize adjustable blank holder forces is developed and its working principle and control system are introduced. Some warm deep drawing experiments of square parts of AZ31 magnesium alloy sheet are also performed. Different variation schemes of the blank holder force with the stroke of the punch are tested, and the experiment results are compared. Results show that the suitable blank holder force variation scheme is a ladder curve with the punch stroke. Adopting the variable blank holder force technique can improve 13.2% of the drawing depth of square parts of AZ31 magnesium alloy sheet

  20. Effect of Mucin and Bicarbonate Ion on Corrosion Behavior of AZ31 Magnesium Alloy for Airway Stents

    Directory of Open Access Journals (Sweden)

    Yongseok Jang

    2014-08-01

    Full Text Available The biodegradable ability of magnesium alloys is an attractive feature for tracheal stents since they can be absorbed by the body through gradual degradation after healing of the airway structure, which can reduce the risk of inflammation caused by long-term implantation and prevent the repetitive surgery for removal of existing stent. In this study, the effects of bicarbonate ion (HCO3− and mucin in Gamble’s solution on the corrosion behavior of AZ31 magnesium alloy were investigated, using immersion and electrochemical tests to systematically identify the biodegradation kinetics of magnesium alloy under in vitro environment, mimicking the epithelial mucus surfaces in a trachea for development of biodegradable airway stents. Analysis of corrosion products after immersion test was performed using scanning electron microscopy (SEM, energy dispersive X-ray spectroscopy (EDX and X-ray diffraction (XRD. Electrochemical impedance spectroscopy (EIS was used to identify the effects of bicarbonate ions and mucin on the corrosion behavior of AZ31 magnesium alloys with the temporal change of corrosion resistance. The results show that the increase of the bicarbonate ions in Gamble’s solution accelerates the dissolution of AZ31 magnesium alloy, while the addition of mucin retards the corrosion. The experimental data in this work is intended to be used as foundational knowledge to predict the corrosion behavior of AZ31 magnesium alloy in the airway environment while providing degradation information for future in vivo studies.

  1. Preparation and characterization of inorganic and organic coatings on AZ91D magnesium alloy with electroless plating pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, S.Y.; Li, Q.; Zhang, H.X.; Wang, S.Y.; Liu, F. [School of Chemistry and Chemical Engineering, Southwest University Chongqing, 400715 (China); Yang, X.K. [School of Materials Science and Engineering, Southwest University Chongqing, 400715 (China)

    2011-09-15

    In this paper, a protective coating scheme was applied for the corrosion protection of AZ91D magnesium alloy. Electroless Ni coating (EN coating) as bottom layer, electrodeposited Ni coating (ENN coating), and silane-based coating (ENS coating) as top layer, respectively, were successfully prepared on AZ91D magnesium alloy by combination techniques. Scanning electron microscopy and X-ray diffraction were employed to investigate the surface and phase structure of coatings, respectively. The electrochemical corrosion behaviors of coatings in neutral 3.5 wt% NaCl solution were evaluated by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization techniques. The corrosion testing showed that the three kinds of coatings all could provide corrosion protection for AZ91D magnesium alloy to a certain extent, and the corrosion resistance of ENN and ENS was superior to EN. In order to further study the corrosion protection properties of ENN and ENS, a comparative investigation on the evolution of EIS of ENN and ENS was carried out by dint of immersion test in neutral 3.5 wt% NaCl solution. The results indicated that, compared with ENN, the ENS could provide longer corrosion protection for AZ91D magnesium alloy. It is significant to determine the barrier effect of each coating, which could provide reference for industry applications. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  2. Effect of Mucin and Bicarbonate Ion on Corrosion Behavior of AZ31 Magnesium Alloy for Airway Stents.

    Science.gov (United States)

    Jang, Yongseok; Owuor, Daniel; Waterman, Jenora T; White, Leon; Collins, Boyce; Sankar, Jagannathan; Gilbert, Thomas W; Yun, Yeoheung

    2014-08-15

    The biodegradable ability of magnesium alloys is an attractive feature for tracheal stents since they can be absorbed by the body through gradual degradation after healing of the airway structure, which can reduce the risk of inflammation caused by long-term implantation and prevent the repetitive surgery for removal of existing stent. In this study, the effects of bicarbonate ion (HCO₃ - ) and mucin in Gamble's solution on the corrosion behavior of AZ31 magnesium alloy were investigated, using immersion and electrochemical tests to systematically identify the biodegradation kinetics of magnesium alloy under in vitro environment, mimicking the epithelial mucus surfaces in a trachea for development of biodegradable airway stents. Analysis of corrosion products after immersion test was performed using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). Electrochemical impedance spectroscopy (EIS) was used to identify the effects of bicarbonate ions and mucin on the corrosion behavior of AZ31 magnesium alloys with the temporal change of corrosion resistance. The results show that the increase of the bicarbonate ions in Gamble's solution accelerates the dissolution of AZ31 magnesium alloy, while the addition of mucin retards the corrosion. The experimental data in this work is intended to be used as foundational knowledge to predict the corrosion behavior of AZ31 magnesium alloy in the airway environment while providing degradation information for future in vivo studies.

  3. 75 FR 2133 - Construction and Operation of the Quartzsite Solar Energy Project, La Paz County, AZ (DOE/EIS-0440)

    Science.gov (United States)

    2010-01-14

    ... Quartzsite Solar Energy Project, La Paz County, AZ (DOE/EIS-0440) AGENCY: Western Area Power Administration... proposed Quartzsite Solar Energy Project (Project) in La Paz County, near Quartzsite, Arizona. Quartzsite Solar Energy, LLC (QSE) has applied to Western to interconnect the proposed Project to Western's power...

  4. Microstructure investigation and first-principle analysis of die-cast AZ91 alloy with calcium addition

    International Nuclear Information System (INIS)

    Lin, L.; Wang, F.; Yang, L.; Chen, L.J.; Liu, Z.; Wang, Y.M.

    2011-01-01

    Highlights: → Die-cast AZ91 with Ca addition was investigated experimentally and theoretically. → Precipitation sequence was confirmed with increasing Ca addition. → Phase stability difference was verified by first-principle calculation. → Valence configurations were associated with alloying effects of Al, Mg and Ca. - Abstract: In order to get improved mechanical properties of die-cast AZ91 alloy under elevated temperatures, Ca element was added as a cost-effective alloying constituent. It appeared that minor Ca addition less than 0.5 wt% would result in no apparent change in microstructure, but the tensile strength at elevated temperatures was improved considerably. When increasing Ca addition to more than 1.0 wt%, Al 2 Ca phase will precipitate during solidification, no Mg 2 Ca phase was discovered. Homogeneous microstructure and high temperature stability in tensile strength of die-cast AZ91 alloy with Ca addition was mainly attributed to the precipitation of Al 2 Ca phase, which considerably refined the bulky β-Mg 17 Al 12 phase distributed originally at the grain boundaries of die-cast AZ91 alloy with no Ca addition. The priority of Al 2 Ca phase compared to Mg 2 Ca phase in precipitation sequence was verified by first-principle calculation of their cohesive energy and formation enthalpy, and can also be associated with more bounding electrons between Al and Ca atoms.

  5. Influence of Sulfate-Reducing Bacteria on the Corrosion Residual Strength of an AZ91D Magnesium Alloy

    Science.gov (United States)

    Zhu, Xianyong; Liu, Yaohui; Wang, Qiang; Liu, Jiaan

    2014-01-01

    In this paper, the corrosion residual strength of the AZ91D magnesium alloy in the presence of sulfate-reducing bacteria is studied. In the experiments, the chemical composition of corrosion film was analyzed by a scanning electron microscope with energy dispersive X-ray spectroscopy. In addition, a series of instruments, such as scanning electronic microscope, pH-meter and an AG-10TA materials test machine, were applied to test and record the morphology of the corrosion product, fracture texture and mechanical properties of the AZ91D magnesium alloy. The experiments show that the sulfate-reducing bacteria (SRB) play an important role in the corrosion process of the AZ91D magnesium alloy. Pitting corrosion was enhanced by sulfate-reducing bacteria. Corrosion pits are important defects that could lead to a significant stress concentration in the tensile process. As a result, sulfate-reducing bacteria influence the corrosion residual strength of the AZ91D magnesium alloy by accelerating pitting corrosion. PMID:28788236

  6. ARSENIC REMOVAL FROM DRINKING WATER BY ADSORPTIVE MEDIA USEPA DEMONSTRATION PROJECT AT VALLEY VISTA, AZ SIX-MONTH EVALUATION REPORT

    Science.gov (United States)

    This report documents the activities performed and the results obtained from the first six months of the EPA arsenic removal technology demonstration project at the Arizona Water Company (AWC) facility in Sedona, AZ, commonly referred to as Valley Vista. The main objective of the...

  7. ARSENIC REMOVAL FROM DRINKING WATER BY ADSORPTIVE MEDIA, USEPA DEMONSTRATION PROJECT AT RIMROCK, AZ, SIX-MONTH EVALUATION REPORT

    Science.gov (United States)

    This report documents the activities performed during and the results obtained from the first six months of the arsenic removal treatment technology demonstration project at Rimrock, AZ. The objectives of the project are to evaluate the effectiveness of AdEdge Arsenic Package Uni...

  8. A Study on Compressive Anisotropy and Nonassociated Flow Plasticity of the AZ31 Magnesium Alloy in Hot Rolling

    Directory of Open Access Journals (Sweden)

    Guoqiang Wang

    2014-01-01

    Full Text Available Effect of anisotropy in compression is studied on hot rolling of AZ31 magnesium alloy with a three-dimensional constitutive model based on the quadratic Hill48 yield criterion and nonassociated flow rule (non-AFR. The constitutive model is characterized by compressive tests of AZ31 billets since plastic deformations of materials are mostly caused by compression during rolling processes. The characterized plasticity model is implemented into ABAQUS/Explicit as a user-defined material subroutine (VUMAT based on semi-implicit backward Euler's method. The subroutine is employed to simulate square-bar rolling processes. The simulation results are compared with rolled specimens and those predicted by the von Mises and the Hill48 yield function under AFR. Moreover, strip rolling is also simulated for AZ31 with the Hill48 yield function under non-AFR. The strip rolling simulation demonstrates that the lateral spread generated by the non-AFR model is in good agreement with experimental data. These comparisons between simulation and experiments validate that the proposed Hill48 yield function under non-AFR provides satisfactory description of plastic deformation behavior in hot rolling for AZ31 alloys in case that the anisotropic parameters in the Hill48 yield function and the non-associated flow rule are calibrated by the compressive experimental results.

  9. Pump Jet Mixing and Pipeline Transfer Assessment for High-Activity Radioactive Wastes in Hanford Tank 241-AZ-102

    Energy Technology Data Exchange (ETDEWEB)

    Y Onishi; KP Recknagle; BE Wells

    2000-08-09

    The authors evaluated how well two 300-hp mixer pumps would mix solid and liquid radioactive wastes stored in Hanford double-shell Tank 241-AZ-102 (AZ-102) and confirmed the adequacy of a three-inch (7.6-cm) pipeline system to transfer the resulting mixed waste slurry to the AP Tank Farm and a planned waste treatment (vitrification) plant on the Hanford Site. Tank AZ-102 contains 854,000 gallons (3,230 m{sup 3}) of supernatant liquid and 95,000 gallons (360 m{sup 3}) of sludge made up of aging waste (or neutralized current acid waste). The study comprises three assessments: waste chemistry, pump jet mixing, and pipeline transfer. The waste chemical modeling assessment indicates that the sludge, consisting of the solids and interstitial solution, and the supernatant liquid are basically in an equilibrium condition. Thus, pump jet mixing would not cause much solids precipitation and dissolution, only 1.5% or less of the total AZ-102 sludge. The pump jet mixing modeling indicates that two 300-hp mixer pumps would mobilize up to about 23 ft (7.0 m) of the sludge nearest the pump but would not erode the waste within seven inches (0.18 m) of the tank bottom. This results in about half of the sludge being uniformly mixed in the tank and the other half being unmixed (not eroded) at the tank bottom.

  10. 76 FR 15936 - Designation for the Owensboro, KY; Bloomington, IL; Iowa Falls, IA; Casa Grande, AZ; Fargo, ND...

    Science.gov (United States)

    2011-03-22

    ... DEPARTMENT OF AGRICULTURE Grain Inspection, Packers and Stockyards Administration Designation for the Owensboro, KY; Bloomington, IL; Iowa Falls, IA; Casa Grande, AZ; Fargo, ND; Grand Forks, ND; and Plainview, TX Areas AGENCY: Grain Inspection, Packers and Stockyards Administration, USDA. ACTION: Notice...

  11. 78 FR 43850 - Opportunity for Designation in Owensboro, KY; Bloomington, IL; Iowa Falls, IA; Casa Grande, AZ...

    Science.gov (United States)

    2013-07-22

    ... DEPARTMENT OF AGRICULTURE Grain Inspection, Packers and Stockyards Administration Opportunity for Designation in Owensboro, KY; Bloomington, IL; Iowa Falls, IA; Casa Grande, AZ; Fargo, ND; Grand Forks, ND and Plainview, TX; Areas; Request for Comments on the Official Agencies Servicing These Areas AGENCY: Grain...

  12. 77 FR 75144 - Foreign-Trade Zone 277-Western Maricopa County, AZ; Application for Expansion; (New Magnet Site...

    Science.gov (United States)

    2012-12-19

    ... Maricopa County, AZ; Application for Expansion; (New Magnet Site) Under Alternative Site Framework An... additional new magnet sites in western Maricopa County, Arizona and request usage-driven designation for an..., Arizona. The current zone project includes the following magnet sites: Site 1 (230.25 acres)--within the...

  13. Pump Jet Mixing and Pipeline Transfer Assessment for High-Activity Radioactive Wastes in Hanford Tank 241-AZ-102

    International Nuclear Information System (INIS)

    Onishi, Y.; Recknagle, K.P.; Wells, B.E.

    2000-01-01

    The authors evaluated how well two 300-hp mixer pumps would mix solid and liquid radioactive wastes stored in Hanford double-shell Tank 241-AZ-102 (AZ-102) and confirmed the adequacy of a three-inch (7.6-cm) pipeline system to transfer the resulting mixed waste slurry to the AP Tank Farm and a planned waste treatment (vitrification) plant on the Hanford Site. Tank AZ-102 contains 854,000 gallons (3,230 m 3 ) of supernatant liquid and 95,000 gallons (360 m 3 ) of sludge made up of aging waste (or neutralized current acid waste). The study comprises three assessments: waste chemistry, pump jet mixing, and pipeline transfer. The waste chemical modeling assessment indicates that the sludge, consisting of the solids and interstitial solution, and the supernatant liquid are basically in an equilibrium condition. Thus, pump jet mixing would not cause much solids precipitation and dissolution, only 1.5% or less of the total AZ-102 sludge. The pump jet mixing modeling indicates that two 300-hp mixer pumps would mobilize up to about 23 ft (7.0 m) of the sludge nearest the pump but would not erode the waste within seven inches (0.18 m) of the tank bottom. This results in about half of the sludge being uniformly mixed in the tank and the other half being unmixed (not eroded) at the tank bottom

  14. Role of manganese on the grain refining efficiency of AZ91D magnesium alloy refined by Al4C3

    International Nuclear Information System (INIS)

    Liu Shengfa; Zhang Yuan; Han Hui

    2010-01-01

    A novel Mg-50% Al 4 C 3 (hereafter in wt.%) master alloy has been developed by powder in situ synthesis process, the role of manganese on the grain refining efficiency of AZ91D magnesium alloy refined by this master alloy has been investigated. X-ray diffraction (XRD) and energy dispersive X-ray spectroscopy (EDS) results show the existence of Al 4 C 3 particles in this master alloy. After addition of 0.6% Al 4 C 3 or combined addition of 0.6% Al 4 C 3 and 0.27% Mn, the average grain size of AZ91D decreased dramatically from 360 μm to 210 μm, and from 360 μm to130 μm, respectively. However, no further refinement of grain size was achieved with additional amount of Mn exceeding 0.27% for AZ91D alloy refined by 0.6% Al 4 C 3 in the present investigation. Al-C-O-Mn-Fe-rich intermetallic particles with an Al-C-O-rich coating film, often observed in the central region of magnesium grains of the AZ91D alloy treated by the combination of Al 4 C 3 and Mn, are proposed to be the potent nucleating substrates for primary α-Mg.

  15. Microstructure characteristics and effect of aging process on the mechanical properties of squeeze-cast AZ91 alloy

    International Nuclear Information System (INIS)

    Han, G.M.; Han, Z.Q.; Luo, A.A.; Liu, B.C.

    2015-01-01

    Highlights: • Characterization of three-dimensional morphologies of precipitates using AFM. • Quantitative microstructure of aged squeeze-cast AZ91 alloy. • The non-uniform continuous precipitation during aging of squeeze-cast AZ91 alloy. • The relationship between microstructure and property of aged squeeze-cast AZ91 alloy. - Abstract: Quantitative microstructure information is critical to modeling and prediction of mechanical properties of structural components. In this study, the microstructure characteristics of aged squeeze-cast AZ91 alloy were investigated using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and atomic force microscopy (AFM) analyses. Particularly, a study of the three-dimensional morphology of continuous precipitation during heat treatment was carried out using a combination of TEM and AFM. The results showed that a typical precipitate consisted of three kinds of faces, namely, broad, side, and end faces. The precipitate also presented a lath-shaped morphology with lozenge ends. Combined SEM and TEM analyses revealed quantitative information on the sizes and area number densities of precipitates after aging at different temperatures with different times. In general, the length and width of precipitates increased more rapidly than thickness during aging. The area number density initially increased and then slowly decreased because of coarsening. Furthermore, a special microstructure characteristic of the non-uniform continuous precipitation during aging was investigated using electron probe microanalysis (EPMA). The relationship between hardness response and yield strength was established

  16. Structural and Electrochemical Characterization of Pure LiFePO4 and Nanocomposite C-LiFePO4 Cathodes for Lithium Ion Rechargeable Batteries

    Directory of Open Access Journals (Sweden)

    Arun Kumar

    2009-01-01

    Full Text Available Pure lithium iron phosphate (LiFePO4 and carbon-coated LiFePO4 (C-LiFePO4 cathode materials were synthesized for Li-ion batteries. Structural and electrochemical properties of these materials were compared. X-ray diffraction revealed orthorhombic olivine structure. Micro-Raman scattering analysis indicates amorphous carbon, and TEM micrographs show carbon coating on LiFePO4 particles. Ex situ Raman spectrum of C-LiFePO4 at various stages of charging and discharging showed reversibility upon electrochemical cycling. The cyclic voltammograms of LiFePO4 and C-LiFePO4 showed only a pair of peaks corresponding to the anodic and cathodic reactions. The first discharge capacities were 63, 43, and 13 mAh/g for C/5, C/3, and C/2, respectively for LiFePO4 where as in case of C-LiFePO4 that were 163, 144, 118, and 70 mAh/g for C/5, C/3, C/2, and 1C, respectively. The capacity retention of pure LiFePO4 was 69% after 25 cycles where as that of C-LiFePO4 was around 97% after 50 cycles. These results indicate that the capacity and the rate capability improved significantly upon carbon coating.

  17. AZ-101 Mixer Pump Demonstration and Tests Data Management Analysis Plan

    Energy Technology Data Exchange (ETDEWEB)

    DOUGLAS, D.G.

    2000-02-22

    This document provides a plan for the analysis of the data collected during the AZ-101 Mixer Pump Demonstration and Tests. This document was prepared after a review of the AZ-101 Mixer Pump Test Plan (Revision 4) [1] and other materials. The plan emphasizes a structured and well-ordered approach towards handling and examining the data. This plan presumes that the data will be collected and organized into a unified body of data, well annotated and bearing the date and time of each record. The analysis of this data will follow a methodical series of steps that are focused on well-defined objectives. Section 2 of this plan describes how the data analysis will proceed from the real-time monitoring of some of the key sensor data to the final analysis of the three-dimensional distribution of suspended solids. This section also identifies the various sensors or sensor systems and associates them with the various functions they serve during the test program. Section 3 provides an overview of the objectives of the AZ-101 test program and describes the data that will be analyzed to support that test. The objectives are: (1) to demonstrate that the mixer pumps can be operated within the operating requirements; (2) to demonstrate that the mixer pumps can mobilize the sludge in sufficient quantities to provide feed to the private contractor facility, and (3) to determine if the in-tank instrumentation is sufficient to monitor sludge mobilization and mixer pump operation. Section 3 also describes the interim analysis that organizes the data during the test, so the analysis can be more readily accomplished. Section 4 describes the spatial orientation of the various sensors in the tank. This section is useful in visualizing the relationship of the Sensors in terms of their location in the tank and how the data from these sensors may be related to the data from other sensors. Section 5 provides a summary of the various analyses that will be performed on the data during the test

  18. Effect of fiber laser parameters on laser welded AZ31B Magnesium alloys

    Directory of Open Access Journals (Sweden)

    Mat Salleh Naqiuddin

    2017-01-01

    Full Text Available Recently, the usage of Magnesium (Mg alloys has been hugely applied in the industrial application such as in automotive, marine, and electronic due to its advantages of recyclability and lightweight. This alloys required low heat input to be weld since it is easily evaporated due to the Magnesium Oxide (MgO at the surface and it also possesses lower melting point compared to steel. Laser welding is more convenient to weld Mg alloys due to its high power and lower heat input. AZ31B was selected since it has strong mechanical properties among others Mg alloys due to the major alloying elements; Aluminium (Al and Zinc (Zn. Low power fiber laser machine with wavelength of 900 nm was used in this experiment. The intention of this work was to investigate the effect of low power fiber laser parameters and effect of shielding gas on weld penetration and microstructure. Another aim in this work was to produce the joint for this thin sheets metal. Penetration depth and microstructure evaluation were emphasized in the analysis section. Bead-on-Plate (BOP and laser lap welding was conducted on AZ31B with thicknesses of 1.0 mm and 0.6 mm for feasibility study using pulsed wave (PW mode. Defocusing features was used in order to find better focal position, which has less occurrence of evaporation (underfill. The effect of different angle of irradiation was also investigated. Two types of shielding gases, Argon (Ar and Nitrogen (N2 were used in order to study the effect of shielding gas. Lastly, the effect of pulsed energy on penetration types and depth of BOP welded samples was investigated. Focus point was found at focal length of 156 mm with 393.75 μm. For BOP experiment, higher pulsed energy used contributes to melt through defect. Meanwhile, Ns shielding gas proved to be better shielding gas in laser welding the AZ31B. Higher angle of irradiation could reduce the underfill defect. Fillet Lap joint of similar metal was successfully done where 2.0 J of

  19. AZ-101 Mixer Pump Demonstration and Tests: Data Management (Analysis) Plan

    International Nuclear Information System (INIS)

    DOUGLAS, D.G.

    2000-01-01

    This document provides a plan for the analysis of the data collected during the AZ-101 Mixer Pump Demonstration and Tests. This document was prepared after a review of the AZ-101 Mixer Pump Test Plan (Revision 4) [1] and other materials. The plan emphasizes a structured and well-ordered approach towards handling and examining the data. This plan presumes that the data will be collected and organized into a unified body of data, well annotated and bearing the date and time of each record. The analysis of this data will follow a methodical series of steps that are focused on well-defined objectives. Section 2 of this plan describes how the data analysis will proceed from the real-time monitoring of some of the key sensor data to the final analysis of the three-dimensional distribution of suspended solids. This section also identifies the various sensors or sensor systems and associates them with the various functions they serve during the test program. Section 3 provides an overview of the objectives of the AZ-101 test program and describes the data that will be analyzed to support that test. The objectives are: (1) to demonstrate that the mixer pumps can be operated within the operating requirements; (2) to demonstrate that the mixer pumps can mobilize the sludge in sufficient quantities to provide feed to the private contractor facility, and (3) to determine if the in-tank instrumentation is sufficient to monitor sludge mobilization and mixer pump operation. Section 3 also describes the interim analysis that organizes the data during the test, so the analysis can be more readily accomplished. Section 4 describes the spatial orientation of the various sensors in the tank. This section is useful in visualizing the relationship of the Sensors in terms of their location in the tank and how the data from these sensors may be related to the data from other sensors. Section 5 provides a summary of the various analyses that will be performed on the data during the test

  20. Research Update: Retardation and acceleration of phase separation evaluated from observation of imbalance between structure and valence in LiFePO4/FePO4 electrode

    Directory of Open Access Journals (Sweden)

    Kazuya Tokuda

    2014-07-01

    Full Text Available LiFePO4 is a potential positive electrode material for lithium ion batteries. We have experimentally observed an imbalance between the valence change of Fe ions and the structure change from the LiFePO4 phase to the FePO4 phase during delithiation by simultaneous in situ XRD and XANES measurements in an LiFePO4/FePO4 electrode. The ratio of structure change to valence change clearly indicates that the phase separation from LiFePO4 to FePO4 is suppressed at the beginning of delithiation, while it is accelerated at the latter stage, which is due to the coherent strain caused by the lattice misfit between the two phases.

  1. Poétique de l’invective dans les Poèmes aristophanesques de Laurent Tailhade

    Directory of Open Access Journals (Sweden)

    Laurent Robert

    2012-04-01

    Full Text Available Parmi l’abondant corpus traité par Marc Angenot dans La Parole pamphlétaire, les ouvrages de Laurent Tailhade Au Pays du mufle et À travers les Grouins [sic] constituent les seuls recueils poétiques. L’essayiste y voit une illustration du genre de la satire poétique, revivifié dès la fin du xviiie siècle avec les Iambes d’André Chénier, puis au xixe notamment par Auguste Barbier et Victor Hugo. Tailhade pourrait ainsi, superficiellement, être considéré comme le poète satiriste de la Troisième...

  2. Systematic understanding of corrosion behavior of plasma electrolytic oxidation treated AZ31 magnesium alloy using a mouse model of subcutaneous implant.

    Science.gov (United States)

    Jang, Yongseok; Tan, Zongqing; Jurey, Chris; Collins, Boyce; Badve, Aditya; Dong, Zhongyun; Park, Chanhee; Kim, Cheol Sang; Sankar, Jagannathan; Yun, Yeoheung

    2014-12-01

    This study was conducted to identify the differences between corrosion rates, corrosion types, and corrosion products in different physiological environments for AZ31 magnesium alloy and plasma electrolytic oxidation (PEO) treated AZ31 magnesium alloy. In vitro and in vivo tests were performed in Hank's Balanced Salt Solution (HBSS) and mice for 12 weeks, respectively. The corrosion rates of both AZ31 magnesium alloy and PEO treated AZ31 magnesium alloy were calculated based on DC polarization curves, volume of hydrogen evolution, and the thickness of corrosion products formed on the surface. Micro X-ray computed tomography (Micro-CT), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD) were used to analyze morphological and chemical characterizations of corrosion products. The results show that there is more severe localized corrosion after in vitro test in HBSS; however, the thicknesses of corrosion products formed on the surface for AZ31 magnesium alloy and PEO treated AZ31 magnesium alloy in vivo were about 40% thicker than the thickness of corrosion products generated in vitro. The ratio of Ca and P (Ca/P) in the corrosion products also differed. The Ca deficient region and higher content of Al in corrosion product than AZ31 magnesium alloy were identified after in vivo test in contrast with the result of in vitro test. Copyright © 2014 Elsevier B.V. All rights reserved.

  3. Double fillet lap of laser welding of thin sheet AZ31B Mg alloy

    Science.gov (United States)

    Ishak, Mahadzir; Salleh, M. N. M.

    2018-05-01

    In this paper, we describe the experimental laser welding of thin sheet AZ31B using double fillet lap joint method. Laser welding is capable of producing high quality weld seams especially for small weld bead on thin sheet product. In this experiment, both edges for upper and lower sheets were subjected to the laser beam from the pulse wave (PW) mode of fiber laser. Welded sample were tested their joint strength by tensile-shear strength method and the fracture loads were studied. Strength for all welded samples were investigated and the effect of laser parameters on the joint strength and appearances were studied. Pulsed energy (EP) from laser process give higher effect on joint strength compared to the welding speed (WS) and angle of irradiation (AOI). Highest joint strength was possessed by sample with high EP with the same value of WS and AOI. The strength was low due to the crack defect at the centre of weld region.

  4. Laser assisted self-pierce riveting of AZ31 magnesium alloy strips

    International Nuclear Information System (INIS)

    Durandet, Y.; Deam, R.; Beer, A.; Song, W.; Blacket, S.

    2010-01-01

    Laser assisted self-piercing riveting (LSPR) is a new solid state process that enables low ductility materials to be mechanically joined without cracking. A simple but effective thermal analysis of LSPR is presented that enabled both the absorption of the laser radiation and heat transfer between plies to be determined. The approach was applied to experimental data for LSPR joining of AZ31B-H24 magnesium alloy sheets. It is shown that by using this analytical approach, the temperature at the onset of joining could be estimated and related to observations of joint quality. It was found that crack-free joints were produced at strip temperatures above 200 o C at the time of rivet insertion.

  5. A two-step superplastic forging forming of semi-continuously cast AZ70 magnesium alloy

    Directory of Open Access Journals (Sweden)

    Pan Wang

    2015-03-01

    Full Text Available A two-step technology combined forging with superplastic forming has been developed to enhance the forgeability of semi-continuously cast AZ70 magnesium alloy and realize the application of the as-cast magnesium alloy in large deformation bullet shell. In the first step, fine-grained microstructure preforms that are suitable for superplastic forming were obtained by reasonably designing the size of the initial blanks with the specific height-to-diameter ratio, upsetting the blanks and subsequent annealing. In the second step, the heat treated preforms were forged into the end products at the superplastic conditions. The end products exhibit high quality surface and satisfied microstructure. Consequently, this forming technology that not only avoids complicating the material preparation but also utilizes higher strain rate superplastic provides a near net-shaped novel method on magnesium forging forming technology using as-cast billet.

  6. Study on hybrid heat source overlap welding of magnesium alloy AZ31B

    International Nuclear Information System (INIS)

    Liang, G.L.; Zhou, G.; Yuan, S.Q.

    2009-01-01

    The magnesium alloy AZ31B was overlap welded by hybrid welding (laser-tungsten inert gas arc). According to the hybrid welding interaction principle, a new heat source model, hybrid welding heat source model, was developed with finite element analysis. At the same time, using a high-temperature metallographical microscope, the macro-appearance and microstructure characteristics of the joint after hybrid overlap welding were studied. The results indicate that the hybrid welding was superior to the single tungsten inert gas welding or laser welding on the aspects of improving the utilized efficiency of the arc and enhancing the absorptivity of materials to laser energy. Due to the energy characteristics of hybrid overlap welding the macro-appearance of the joint was cup-shaped, the top weld showed the hybrid welding microstructure, while, the lower weld showed the typical laser welding microstructure

  7. Study on hybrid heat source overlap welding of magnesium alloy AZ31B

    Energy Technology Data Exchange (ETDEWEB)

    Liang, G.L. [Department of Electromechanical Engineering, Tangshan College, Tangshan 063000 (China)], E-mail: guoliliang@sohu.com; Zhou, G. [School of Material Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China); Yuan, S.Q. [Department of Electromechanical Engineering, Tangshan College, Tangshan 063000 (China)

    2009-01-15

    The magnesium alloy AZ31B was overlap welded by hybrid welding (laser-tungsten inert gas arc). According to the hybrid welding interaction principle, a new heat source model, hybrid welding heat source model, was developed with finite element analysis. At the same time, using a high-temperature metallographical microscope, the macro-appearance and microstructure characteristics of the joint after hybrid overlap welding were studied. The results indicate that the hybrid welding was superior to the single tungsten inert gas welding or laser welding on the aspects of improving the utilized efficiency of the arc and enhancing the absorptivity of materials to laser energy. Due to the energy characteristics of hybrid overlap welding the macro-appearance of the joint was cup-shaped, the top weld showed the hybrid welding microstructure, while, the lower weld showed the typical laser welding microstructure.

  8. Evaluation of cracking in the 241-AZ tank farm ventilation line at the Hanford Site

    Energy Technology Data Exchange (ETDEWEB)

    ANANTATMULA, R.P.

    1999-10-20

    In the period from April to October of 1988, a series of welding operations on the outside of the AZ Tank Farm ventilation line piping at the Hanford Site produced unexpected and repeated cracking of the austenitic stainless steel base metal and of a seam weld in the pipe. The ventilation line is fabricated from type 304L stainless steel pipe of 24 inch diameter and 0.25 inch wall thickness. The pipe was wrapped in polyethylene bubble wrap and buried approximately 12 feet below grade. Except for the time period between 1980 and 1987, impressed current cathodic protection has been applied to the pipe since its installation in 1974. The paper describes the history of the cracking of the pipe, the probable cracking mechanisms, and the recommended future action for repair/replacement of the pipe.

  9. Chitosan coatings crosslinked with genipin for corrosion protection of AZ31 magnesium alloy sheets.

    Science.gov (United States)

    de Y Pozzo, Ludmila; da Conceição, Thiago F; Spinelli, Almir; Scharnagl, Nico; Pires, Alfredo T N

    2018-02-01

    In this study, coatings of chitosan crosslinked with genipin were prepared on sheets of AZ31 magnesium alloy and their corrosion protection properties were characterized by means of potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The coatings were also characterized by means of FTIR and XPS. It was observed that the crosslinking process decreases the corrosion current and shifts the corrosion potential of the alloy to less negative values. The EIS analysis demonstrated that the crosslinking process increases the maximum impedance after short and long exposure times. The superior performance of the crosslinked coatings is related to a lower degree of swelling, as observed in the swelling tests carried out on free-standing films. Copyright © 2017 Elsevier Ltd. All rights reserved.

  10. Semiconducting behavior of the anodically passive films formed on AZ31B alloy

    Directory of Open Access Journals (Sweden)

    A. Fattah-alhosseini

    2014-12-01

    Full Text Available This work includes determination of the semiconductor character and estimation of the dopant levels in the passive film formed on AZ31B alloy in 0.01 M NaOH, as well as the estimation of the passive film thickness as a function of the film formation potential. Mott–Schottky analysis revealed that the passive films displayed n-type semiconductive characteristics, where the oxygen vacancies and interstitials preponderated. Based on the Mott–Schottky analysis, it was shown that the calculated donor density increases linearly with increasing the formation potential. Also, the electrochemical impedance spectroscopy (EIS results indicated that the thickness of the passive film was decreased linearly with increasing the formation potential. The results showed that decreasing the formation potential offer better conditions for forming the passive films with higher protection behavior, due to the growth of a much thicker and less defective films.

  11. Microstructural evolution of AZ31 magnesium alloy subjected to sliding friction treatment

    Science.gov (United States)

    Zhang, Wei; Lu, Jinwen; Huo, Wangtu; Zhang, Yusheng; Wei, Q.

    2018-06-01

    Microstructural evolution and grain refinement mechanism in AZ31 magnesium alloy subjected to sliding friction treatment were investigated by means of transmission electron microscopy. The process of grain refinement was found to involve the following stages: (I) coarse grains were divided into fine twin plates through mechanical twinning; then the twin plates were transformed to lamellae with the accumulation of residual dislocations at the twin boundaries; (II) the lamellae were separated into subgrains with increasing grain boundary misorientation and evolution of high angle boundaries into random boundaries by continuous dynamic recrystallisation (cDRX); (III) the formation of nanograins. The mechanisms for the final stage, the formation of nanograins, can be classified into three types: (i) cDRX; (ii) discontinuous dynamic recrystallisation (dDRX); (iii) a combined mechanism of prior shear-band and subsequent dDRX. Stored strain energy plays an important role in determining deformation mechanisms during plastic deformation.

  12. Microstructure of AZ31 Magnesium Alloy deformed by indentation-flattening compound deformation technology

    Science.gov (United States)

    Wang, Minghao; Wang, Zhongtang; Yu, Xiaolin

    2018-03-01

    Characteristic of indentation-flattening compound deformation technology (IFCDT) is discussed, and the parameters of IFCDT are defined. Performance of magnesium alloy AZ31 sheet deformed by IFCDT is researched. The effect of IFCDT coefficient, temperature and reduction ratio on the microstructure of magnesium alloy sheet is analyzed. The research results show that the volume fraction of the twin crystal decreases gradually and the average grain size increases with increasing of coefficient of IFCDT. With increase of the reduction ratio, the volume fraction of the twin crystal gradually increases, and the average grain size also increases. With increase of deformation temperature, the volume fraction of the twin crystal decreases gradually, and the twin crystal grain size increases.

  13. Merging airborne and carborne radiometric data for surveying the Deir Az-Zor area, Syria

    International Nuclear Information System (INIS)

    Jubeli, Y.M.; Aissa, M.; Al-Hent, R.

    1997-01-01

    To complete the radiometric map of Syria, and to estimate the natural background radiation levels for environmental monitoring, a carborne survey was undertaken over the Deir Az-Zor area. This area was not covered by a previous airborne survey, except for peripheral regions in the south and west. To complete the radiometric map, results of the carborne and airborne surveys had to be merged. This paper presents the merging procedure which was used after normalizing the two data sets to match each other. No anomalies suitable for radioelement exploration were found. However, the overall radiometric maps resulting from the present work were consistent with the maps of the areas covered by the airborne survey. (author)

  14. Alelopatía en Saccharum spp. (caña de azúcar

    Directory of Open Access Journals (Sweden)

    R. A. Arévalo

    2011-01-01

    6 Aminoácidos no proteicos, 7 Lactonas no saturadas, 8 ácidos orgánicos, alcoholes alifáticos, aldehídos y cetonas, 9 ácidos grasos, naftoquinonas, antraquinonas, y complejos de quinonas, 10 Coumarina. Los mecanismos de acción en la mayoría de los aleloquímicos son aún desconocidos. Las plantas arvenses, como Cypro-Cyperus rotundus L.; Rooex-Rottboellia exaltata L. f. causan alelopatía en caña de azúcar. Las plantas de Cucsa- Cucumis sativus L. son afectadas por efectos alelopáticos de plantas de Rooex. Las coberturas utilizadas en la agricultura sostenible tienen propiedades alelopáticas. Las respuestas de las plantas cultivadas a los aleloquímicos pueden ser susceptibles, tolerantes o resistentes. La alelopatía tiene gran potencial para el manejo de plagas en la agricultura.

  15. Improving the corrosion properties of magnesium AZ31 alloy GTA weld metal using microarc oxidation process

    Institute of Scientific and Technical Information of China (English)

    M.Siva Prasad; M.Ashfaq; N.Kishore Babu; A.Sreekanth; K.Sivaprasad; V.Muthupandi

    2017-01-01

    In this work,the morphology,phase composition,and corrosion properties of microarc oxidized (MAO) gas tungsten arc (GTA) weldments of AZ31 alloy were investigated.Autogenous gas tungsten arc welds were made as full penetration bead-on-plate welding under the alternating-current mode.A uniform oxide layer was developed on the surface of the specimens with MAO treatment in silicate-based alkaline electrolytes for different oxidation times.The corrosion behavior of the samples was evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy.The oxide film improved the corrosion resistance substantially compared to the uncoated specimens.The sample coated for 10 min exhibited better corrosion properties.The corrosion resistance of the coatings was concluded to strongly depend on the morphology,whereas the phase composition and thickness were concluded to only slightly affect the corrosion resistance.

  16. Process of film formation by anodizing AZ91D magnesium alloy

    Energy Technology Data Exchange (ETDEWEB)

    Qian Jiangang; Li Di; Zhang Feng [School of Materials Science and Engineering, Beijing Univ. of Aeronautics and Astronautics (China)

    2005-07-01

    The kinetics of film-forming process by anodizing AZ91D Mg alloy has been studied by ways of voltage-time and thickness-time curve, and the surface morphology, structure, composition and valence of element, phase constituent of anodic films have been analyzed by SEM, EDS, XPS and XRD respectively. The results show that the film-forming course can be divided into four stages. Formation of dense layer before sparking is the first stage. Formation of porous layer accompanied with a bit of small sparking is the second stage. Porous layer fast growth along with middle sparking is the third stage. Porous layer slowly-growth along with bigger sparking is the fourth stage. The anodic films contains approximately Mg,O,Si and B, which is composed mainly of MgO, MgSiO{sub 3} and Mg{sub 3}B{sub 2}O{sub 6}. (orig.)

  17. Microstructure and mechanical property of dual-directional-extruded Mg alloy AZ31

    International Nuclear Information System (INIS)

    Lu Liwei; Liu Tianmo; Jiang Shan; Pan Fushen; Liu Qing; Wang Zhongchang

    2010-01-01

    We report microstructure evolution and mechanical property of Mg alloy AZ31 processed by a new deformation technique, dual-directional extrusion (DDE). Using optical microscopy, scanning electron microscopy, and electron back scatter diffraction technique, we attribute the significant refinement of original coarse grains in the DDE-processed alloy to the occurrence of dynamic recrystallization. Moreover, we find that low temperature is crucial for yielding fine grain, which consequently results in high micro-hardness and yield stress, large fracture strain, and enhanced elongation. The improved mechanical properties are comparable or even superior to those of the alloy subjected to other deformation techniques, rendering the DDE a promising way for further tailoring properties of Mg-based alloys.

  18. Modelling of peak temperature during friction stir processing of magnesium alloy AZ91

    Science.gov (United States)

    Vaira Vignesh, R.; Padmanaban, R.

    2018-02-01

    Friction stir processing (FSP) is a solid state processing technique with potential to modify the properties of the material through microstructural modification. The study of heat transfer in FSP aids in the identification of defects like flash, inadequate heat input, poor material flow and mixing etc. In this paper, transient temperature distribution during FSP of magnesium alloy AZ91 was simulated using finite element modelling. The numerical model results were validated using the experimental results from the published literature. The model was used to predict the peak temperature obtained during FSP for various process parameter combinations. The simulated peak temperature results were used to develop a statistical model. The effect of process parameters namely tool rotation speed, tool traverse speed and shoulder diameter of the tool on the peak temperature was investigated using the developed statistical model. It was found that peak temperature was directly proportional to tool rotation speed and shoulder diameter and inversely proportional to tool traverse speed.

  19. El legado psicológico de Rogelio Díaz-Guerrero

    OpenAIRE

    Reynaldo Alarcón

    2010-01-01

    O autor identifica quatro dimensões básicas na obra do psicólogo mexicano Rogelio Díaz-Guerrero (1918-2004): a) seu interesse pioneiro por construir uma psicología do mexicano se inicia com a publicação de Estudios de psicología del mexicano (1961) e culmina 42 anos depois com seu livro Bajo las garras de la cultura. Psicología del mexicano 2 (2003); b) a orientação culturalista de seu pensamento; c) sua adesão à psicologia transcultural, em reação ao etnocentrismo psicológico dominante em su...

  20. Effect of equal channel angular pressing on the strength and ductility of an AZ80 alloy

    International Nuclear Information System (INIS)

    Pereira, T S; Chung, C W; Ding, R; Chiu, Y L

    2009-01-01

    Equal channel angular pressing (ECAP) was applied to an extruded AZ80 Mg alloy in order to refine microstructure and enhance mechanical properties. The results show that the initial grain size of 20 μm of the as-extruded samples has been reduced by 75% after the first pass of ECAP, down to about 5 μm. Also as a result of the severe plastic deformation, the intermetallic compound Mg 17 Al 12 , which was distributed along grain boundaries and forms networks before the ECAP, has been re-arranged into a more homogeneous distribution and with a more spherical shape after the ECAP. Although no strengthening effect has been observed, the grain refinement and precipitate fragmentation caused by the ECAP has resulted in a 28% increase in the elongation to failure in tensile tests. Fractography observation and texture measurement have also been carried out.