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High Pressure Synthesis versus Calcination – Different Approaches to Crystallization of Zirconium Dioxide

Gutfeld, R.J. (1981). Investigation of laser enhanced electroplating mechanisms, J. Electrochem. Soc. 128, 2539–2545. DOI: 10.1149/1.2127287. 12. Kumar, A. & Roy., R. (1988). RESA—A wholly new process for fine oxide powder preparation, J. Mater. Res. 3(6), 1373–1377. DOI: 10.1557/JMR.1988.1373. 13. Ehrlich, H., Simon, P., Motylenko, M., Wysokowski, M., Bazhenov, V.V., Galli, R., Stelling, A.L., Stawski, D., Ilan, M., Stöcker, H., Abendroth, B., Born, R., Jesionowski, T., Kurzydłowski, K.J. & Meyer, D.C. (2013). Extreme Biomimetics: formation of zirconium dioxide

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Studies on magnetron-sputtered zirconium-silicide coatings deposited on zirconium alloy for the enhancement of their high-temperature oxidation resistance

.jnucmat.2015.10.019 . 17. Younker, M., & Fratoni, M. (2016) Neutronic evaluation of coating and cladding materials for accident tolerant fuels. Prog. Nucl. Energy , 88 , 10–18. http://dx.doi.org/10.1016/j.pnucene.2015.11.006 . 18. Tang, C., Stueber, M., Seifert, H. J., & Steinbruck, M. (2017). Protective coatings on zirconium-based alloys as accident-tolerant fuels (ATF) claddings. Corros. Rev. , 35 (3), 141–165. DOI: 10.1515/corrrev-2017-0010. 19. Starosta, W., Barlak, M., Buczkowski, M., Kosińska, A., Sartowska, B., Waliś, L., & Janiak, T. (2015

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Synthesis and formation process of zirconium dioxide nanorods

Abstract

Crystalline zirconium dioxide nanorods have been prepared by a simple hydrothermal process using zirconium hydroxide as the zirconium raw material. Zirconium dioxide nanorods are composed of monoclinic zirconium dioxide phase, which has been confirmed by the X-ray diffraction analysis. Electron microscopy observations show that the zirconium dioxide nanorods have a single crystal structure, with the rod diameter of less than 100 nm and length of 1–2 μm. Hydrothermal temperature and reaction time play essential roles in the formation and growth of the zirconium dioxide nanorods. Nucleation and crystal growth process are proposed to explain the formation and growth of the zirconium dioxide nanorods.

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Hydrogen degradation of pre-oxidized zirconium alloys

References 1. Steinbrück M., Böttcher M., Air oxidation of Zircaloy-4, M5_ and ZIRLO™ cladding alloys at high temperatures. J Nucl Mater 2011; 414:276-85. 2. Zielinski A., Sobieszczyk S., Hydrogen-enhanced degradation and oxide effects in zirconium alloys for nuclear applications. Intl J Hydrogen Energy 2011;36:8619-29. 3. Lelièvre G., Fruchart D., Convert P., Lefè`vre-Joud F., Characterisation by neutron diffraction in high temperature pressurized water of the surface corrosion and hydrogen embrittlement of

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Mini-Implants and Zirconium Crowns in Treating Congenitally Missing Maxillary Lateral Incisors: Case Report

Summary

Background/Aim: A problem of congenitally missing lateral incisors is frequently encountered in dentistry, with several available treatment modalities, the choice depending on each case. Case Report: A young female patient with bilateral missing lateral incisors was in need for dental treatment for esthetics. She had spacing among the upper anterior teeth with class I molar relationship. Orthodontic space creation was carried out followed by two-piece mini dental implant placement. Two-stage protocol was followed. After osseointegration, implants were exposed. Healing collars were installed to allow mucosal healing. Closed tray implant level impression was taken. Zirconium crowns were chosen for optimum esthetic results. Conclusions: Mini-implants can be used successfully for restoring congenitally missing lateral incisors after space opening. Esthetic results can be enhanced using Zirconium crowns

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Comparative Analysis of the Mechanical Properties between the Fiber-Reinforced Composite and Zirconium Posts

Abstract

Objectives: To make a comparative analysis of the mechanical properties between FRC and zirconium posts

Methods: The patients with FRC and zirconium posts were divided in two groups with three subgroups, each of them composed of 10 samples. Subgroup I with 1.2 mm; Subgroup II with 1.35 mm and Subgroup III with 1.5 mm post diameter. The fracture force, bending and tensile strength of each group were measured with Shimadzu Universal Testing Machine.

Results: The fracture force for the first group measured in the first, second and third subgroup was 34.80900N; 67.15390N; 46.53100N and for the second group, first, second and third subgroup was 34.80900N; 46.53100N; 67.15390N correspondingly. The bending strength for the first group measured in the first, second and third subgroup was 401.4420N; 444.6425N; 333.6828N and for the second group, first, second and third subgroup was 307.9352N; 289.1030N; 304.1649N correspondingly. The tensile strength for the first group measured in the first, second and third subgroup was 5.442267N; 4.350545N; 2.943465N and for the second group, first, second and third subgroup was 4.224141N; 3.751466N; 3.168756N correspondingly.

Conclusions: The longest diameter of the posts significantly increases the resistance to fracture in relation to the two smaller diameters. The larger diameter, the higher values of the bending strength, as well as the lowest values of the tensile strength of the material contribute to improved mechanical properties of the fiber and zirconium posts.

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in PRILOZI
Baddeleyite segregations in zircon of the Azov zirconium-rare-earth deposit (Ukrainian Shield)

Abstract

Baddeleyite as inclusions in zircon crystals is described for the first time from the ore zone of the Azov zirconium-rare-earth deposit in the Volodarsky (Pivdennokalchytsky) syenite Massif in the Ukrainian Shield. The main admixture in the zircon containing baddeleyite is hafnium (0.68 wt%). The baddeleyite occurs in a substance that fills cracks and that probably corresponds to glass. The chemical compositions of four baddeleyite segregations, and of the hosting glass, are presented. The baddeleyite formed as a result of interaction between zircon and silicate melt with a low SiO2 content. The silicate melt formed under the influence of highthermobaric CO2-fluid flows on the rock.

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Influence of pre-treatment on zirconium based conversion coating on AA2024

Abstract

A comparison of the influence of two alloy pre-treatments and temperature treatments on the formation and composition of zirconium based conversion coating on the AA2024 alloy has been performed. The investigation employed mass changes, atomic force microscopy (AFM), XRD dispersive spectroscopy (EDX), infrared spectroscopy (IR) and electrochemical tests by open circuit potential (OCP) measurements. Pre-treatment using only alkaline etching is called alkaline pre-treatment. When alkaline etching is followed by de-oxidization in a phosphoric acid solution the process is called acidic pre-treatment. Conversion coatings were formed in Pragokor BL. IR analysis revealed the formation of a phosphate on the alloy surface. EDX analysis showed Mg dissolution. The Zr content increased with the temperature of the conversion coating formation. Both pre-treatment methods provided a phosphate layer on the alloy surface.

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Chromium Coating as a Surface Protection of Zirconium Alloys

References 1. Große, M.; Lehmann, E.; Steinbrück, M.; Kühne, G.; Stuckert, J. Influence of oxide layer morphology on hydrogen concentration in tin and niobium containing zirconium alloys after high temperature steam oxidation. Journal of Nuclear Materials 2009, 385, 339-345. 2. Labib, A.; Harris, M.J. Learning how to learn from failures: The Fukushima nuclear disaster. Engineering Failure Analysis 2015, 47, 117-128. 3. Tsuruda, T.; Nuclear power plant explosions at Fukushima-Daiichi. Procedia Engineering 2015

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Oxidation and Hydrogen Behaviur in Zr-2Mn Alloy

REFERENCES 1. Bair J., Asle Zaeem M., Tonks M.: A review on hydride precipitation in zirconium alloys. J. Nucl. Mater. 466 (2015) 12–20. 2. Suman S., Khan M.K., Pathak M., Singh R.N., Chakravartty J.K.: Hydrogen in Zircaloy: Mechanism and its impacts. Intl. J. Hydrogen Energy 40 (2015) 5976–5994. 3. Zielinski A., Sobieszczyk S.: Hydrogen-enhanced degradation and oxide effects in zirconium alloys for nuclear applications. Intl. J. Hydrogen Energy 36 (2011) 8619–8629. 4. Baek J.H., Jeong Y.H.: Breakaway phenomenon of Zr-based alloys during a

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