Effect of heat treatment on microstructure and mechanical properties of Ti-5wt-%Ni alloys for use as biomaterial

Titanium alloys are among the most important and frequently used class of biomaterials. In addition to biocompatibility, it is important that an implant material present satisfactory mechanical properties that allow long term use in the body. To improve such properties, different heat treatments are used, as well as doping with oxygen. The presence of interstitial oxygen in the crystal lattice causes deformation, increases the hardness, and causes modifications in anelasticity, thereby decreasing the elastic modulus. In this study, an alloy was prepared by arc melting precursor metals, heat and mechanically treated, and doped with oxygen, resulting in samples with different processing conditions. In each condition, the alloy was characterised in terms of amount of oxygen, X-ray diffraction, and optical microscopy. In addition, properties of the alloy, such as hardness and elastic modulus, were analysed.

Laska a smrt; tragedie o pěti jednáních.

At head of title: Dramaticka díla Jaroslava Vrchlického. XVIII.

Extrauagantes viginti Ioannis vigesimisecundi vna cum elega[n]ti apparatu domini zenzelini de cassanis ..., necnon regulis Cancellarie et decsionibus rote e pluribus Iacobi Fontani ... Adiecte sunt praetera vtilissime apostille D. Francisci de pauinis in easdem extrauagantes cum glosa dicti d[omi]ni zenzelini, quibus succesit vita d[omi]ni Ioannis vigesimisecu[n]di ...

Mode of access: Internet.

Libro nuevo cuyo titulo Nuevo, y natural modo de auxiliar à las mugeres en los lances peligrosos de los partos sin operacion de mano ni instrumentos /

Mode of access: Internet.

Pami︠a︡ti M.I. Glinki. Po sluchai︠u︡ 50-tiliet-ni︠a︡go i︠u︡bilei︠a︡ "Ruslan i Li︠u︡dmila" 1842-1892. 27. noi︠a︡bria.

Mode of access: Internet.

Taʻlīqāt : ḥāshiyah li-baḥr al-ʻulūm wa-kanz al-maʻārif wa-al-fuhūm dhī al-janāḥayn fī ʻilmay al-ẓāhir wa-al-bāṭin Mawlānā Ḍiyāʼ al-Dīn al-Shaykh Khālid al-Baghdādī al-Sulaymānī al-ʻUthmānī ... ʻalá Ḥāshiyat Mawlānā al-Siyālkūtī ʻalá al-Khayālī.

Mode of access: Internet.

Sbornik stateĭ v chestʹ Dmitrīi︠a︡ Aleksandrovicha Korsakova : po povodu sorokali︠e︡tīi︠a︡ ego uchenoĭ i pi︠a︡tidesi︠a︡tili︠e︡tīi︠a︡ ucheno-literaturnoĭ di︠e︡i︠a︡telʹnosti : istorīi︠a︡, istorīi︠a︡ literatury, arkheologīi︠a︡, i︠a︡zykovi︠e︡di︠e︡nīe filosofīi︠a︡, pedagogike = Mélanges Korsakoff : recueil de travaux, offert à M-r Dmitry Korsakoff, d-r et prof. émer. de l'Université de Kazan, à l'occasion du XL anniversaire de son professorat et de L ans d'activité comme savant et écrivain.

By D.V. Aĭnalov et al.

"Ėfemeridy" : statʹi po voprosamʺ iskusstva, teatra i literatuyry, kriticheskīe ėti︠u︡dy, literaturnye ocherki, nabroski, vpechatli︠e︡nīi︠a︡ /

With: Rystenko, A. V. (Aleksandr Vasilʹi︠e︡vich), 1881?-1915. Skazanīe o dvi︠e︡nadt︠s︡ati snakhʺ t︠s︡ari︠a︡ Mamera : vʺ slavi︠a︡no-russkoĭ literaturi︠e︡ / A.V. Rystenko. Odessa : "Ėkonomicheskai︠a︡" tipografīi︠a︡, 1904. -- Nevskīĭ, V. A. (Vladimir Aleksandrovich). Khudozhestvennye vystavki i oznakomlenie shirokikh narodnykh mass s zhivopisʹi︠u︡ / V.A. Nevskiĭ. Kostroma : Sovetskai︠a︡ tipografii︠a︡, 1920. -- Vsepolʹskai︠a︡ revoli︠u︡t︠s︡īonnai︠a︡ partīi︠a︡ : ocherkʺ sovremennykhʺ stremlenīĭ vsepolʹskoĭ partīi / sostavilʺ Azʺ. Lʹvovʺ : Vʺ tipografīi Stavropigīĭskago Instituta, 1903. -- Gurko, Vasiliĭ Iosifovich, b. 1864. Borba truda i kapitala : ego neizbi︠e︡zhnyi︠a︡ posli︠e︡dstvīi︠a︡ / Generalʺ V. Gurko. Berlin : Wosroschednje Rossii/ Die Wiedergeburt Russlands, 1919. -- Samokvasov, D. (Dmitrīĭ), 1843-1911. Paskopki drevnikhʺ mogilʺ i opisanīe, khranenīe i izdanē mogilʹnykhʺ drevnosteĭ / D.I︠A︡. Samokvasova. Moskva : Sinodalʹnai︠a︡ Tipografīi︠a︡, 1908.

Superplasticity and superplastic forming ability of a Zr-Ti-Ni-Cu-Be bulk metallic glass in the supercooled liquid recgion

The superplastic deformation behavior and superplastic forming ability of the Zr41.25Ti13.75Ni10Cu12.5Be22.5 (at.%) bulk metallic glass (BMG) in the supercooled liquid region were investigated. The isothermal tensile results indicate (hat the BMG exhibits a Newtonian behavior at low strain rates but a non-Newtonian behavior at hiqh-strain rates in the initial deformation stage. The maximum elongation reaches as high as 1624% at 656 K. and nanocrystallization was found to occur during the deformation process. Based cm the analysis on tensile deformation. a gear-like micropart is successfully die-forged via a superplastic forgings process. demonstrating that the BMG has excellent workability in the supercooled liquid region. (C) 2004 Elsevier B.V. All rights reserved.

Influência do número de refundições da liga Ni-Cr-Mo-Ti sobre as propriedades de próteses metalocerâmicas

A frequently encountered difficulty in oral prosthetics is associated with the loss of metallic alloys during the melting stage of the production of metal-ceramic replacement systems. Remelting such materials could impar their use in oral rehabilitation due to loss in esthetics, as well as in the chemical, physical, electrochemical and mechanical properties. Nowadays, the Ni-Cr-Mo-Ti alloy is widely used in metal-ceramic systems. Manufacturers state that this material can be remelted without significant alterations in its behavior, however little has been established as to the changes in the performance of this alloy after successive remelting, which is common practice in oral prosthetics. Therefore, the objective of this study was to evaluate possible changes in the esthetics and associated properties of metalceramic samples consisting of Ni-Cr-Mo-Ti and dental porcelain. Three to five remelting steps were carried out. The results revealed that Ni-Cr-Mo-Ti can be safely used even after three remelting steps. Further remelting significantly affect the characteristics of the alloys and should not be recommended for the manufacture of metal-ceramic systems

Caracterização Microestrutural e Tribocorrosiva de Sistemas Metalocerâmicos Odontológicos do Tipo Ni-Cr/Porcelana E Ni-Cr/Ti/Porcelana

The partial fixed prosthodontics restoration is used to rehabilitate form and function of partial or total compromised teeth, having to remain permanently joined to remainder tooth. The most useful material on prosthodontics is the feldspar porcelain, commercialized as aluminosilicate powders. Dental porcelains are presented with limited mechanical properties to rehabilitate extensive spaces. The association with Ni-Cr metallic systems (metal-ceramic system) allows that the metallic substructure compensates the fragile porcelain nature, preserving the thermal insulation and aesthetics desirable, as well as reducing the possibility of cracking during matication efforts. Cohesive flaws by low mechanical strength connect the metallic substructure to the oral environment, characterized by a electrolytic solution (saliva), by aggressive temperature, pH cyclic changes and mechanical requests. This process results on ionic liberation that could promote allergic or inflammatory responses, and/or clinical degradation of ceramometal system. The aim of this study was to evaluate the presence of an intermediate titanium layer on the microscopic fracture behavior of porcelains on ceramometal systems. Plasma deposition of titanium films result in regular passivating oxide layers which act as barriers to protect the metallic substrate against the hazardous effects of corrosive saliva. Tribocorrosion tests were performed to simulate the oral environment and mechanical stress, making it possible the early detection of crack formation and growth on metal-ceramic systems, which estimate the adherence between the compounds of this system. Plain samples consisting of dental feldspar porcelain deposited either onto metallic substrates or titanium films were fired and characterized by scanning electron microscopy. The result showed that the titanium film improved the adherence of the system compared to conventional metal-ceramic interfaces, thus holding crack propagation

Nuevos instrumentos de política ambiental

El propósito de este papel es describir los principales instrumentos económicos que pueden utilizarse en la política medio ambiental. Se examinan críticamente las soluciones clásicas, sin olvidar las espurias. Se introduce el tiempo en el análisis, se examina la importancia de la tasa de descuento en el cálculo económico y se presenta el concepto de economías de duración, para estudiar el conflicto entre los intereses individuales y el social y generar propuestas de solución. Se presta especial atención al conflicto entre los intereses de las generaciones presentes y las futuras, apuntando algunas vías para solventarlo.

Justificaciones e instrumentos de la intervención pública en la política de sanidad

El objetivo del trabajo es entrar a valorar los argumentos que justificaran la actuación de los poderes públicos en la política pública de sanidad para, en el caso de encontrarlos, entrar a valorar qué instrumentos de las políticas públicas pueden dar una mejor respuesta al problema sanitario. Aunque no se descarta llegar a obtener una respuesta definitiva de un modelo claramente mejor que los demás, se presentarán las diversas opciones posibles las cuáles dependerán principalmente de qué justificación se dio a la intervención pública en un inicio.