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Marie-Alix Fauroux, Marie De Boutray, Eve Malthiéry, Jacques-Henri Torres
INTRODUCTION: Companies selling dental implant guided systems mostly offer similar surgical guides. The purpose of this paper is to present an innovative guided surgery system which originality lies in its guidance device, and to report the author's experience in using this system for dental implant surgery. TECHNICAL PROTOCOL: Two parallel tubes on either side of the drilling axis guide the successive drills and the implant placement. As a result of the lateral guidance, there is no friction of the drills on the surgical guide which would damage it or contaminate the drilling hole with particles torn out from the guide...
February 19, 2018: Journal of Stomatology, Oral and Maxillofacial Surgery
Daria Noferini, Michael M Koza, Seikh M H Rahman, Zach Evenson, Gøran J Nilsen, Sten Eriksson, Andrew R Wildes, Maths Karlsson
Acceptor-doped barium zirconates are currently receiving considerable interest because of their high proton conductivity at intermediate temperatures, making them applicable as electrolytes in various electrochemical devices, but the mechanism of proton conduction is unclear. Here, we investigate the role of the acceptor-dopant level in the localized proton motions, i.e. proton transfers between oxygens and O-H reorientations, in hydrated samples of the proton conducting, acceptor-doped, perovskites BaZr1-x Inx O3-x/2 with x = 0...
February 21, 2018: Physical Chemistry Chemical Physics: PCCP
Piyaporn Jaimeewong, Piyalak Ngernchuklin, Napatporn Promsawat, Soodkhet Pojprapai, Sukanda Jiansirisomboon, Methee Promsawat, Anucha Watcharapasorn
This work aims to study the effect of sintering temperature on properties of barium calcium zirconate titanate (BCZT) ceramics. The BCZT is a Pb-free material that shows excellent piezoelectric properties. In this study, BCZT ceramics were prepared from BCZT powders synthesized from barium nitrate, calcium nitrate, zirconium (IV) oxynitrate hydrate, titanium (IV) butoxide and citric acid precursors by the sol-gel auto-combustion method. The BCZT powder was calcined at the temperature ranging from 700 to 1000 °C...
June 1, 2018: Journal of Nanoscience and Nanotechnology
Sulgiye Park, Cameron L Tracy, Fuxiang Zhang, Changyong Park, Christina Trautmann, Sergey N Tkachev, Maik Lang, Wendy L Mao, Rodney C Ewing
The effects of swift heavy ion irradiation-induced disordering on the behavior of lanthanide zirconate compounds (Ln2Zr2O7 where Ln = Sm, Er, or Nd) at high pressures are investigated. After irradiation with 2.2 GeV 197Au ions, the initial ordered pyrochlore structure (Fd3[combining macron]m) transformed to a defect-fluorite structure (Fm3[combining macron]m) in Sm2Zr2O7 and Nd2Zr2O7. For irradiated Er2Zr2O7, which has a defect-fluorite structure, ion irradiation induces local disordering by introducing Frenkel defects despite retention of the initial structure...
February 12, 2018: Physical Chemistry Chemical Physics: PCCP
J Jacobs, G Paoli, S Rocchi, A K Ksienzyk, H Sirevaag, M A Elburg
We have traced the particle path of high-pressure metasedimentary rocks on Elba Island, Northern Apennines, with the help of a U-Pb-Hf detrital zircon study. One quarter of the analysed zircons are surprisingly young, 41-30 Ma, with a main age peak at ca. 32 Ma, indicating an unexpected early Oligocene maximum deposition age. These Oligocene ages with negative εHf indicate a volcanic source region in the central-southern Alps. Though young by geological means, these zircons record an extraordinary geodynamic history...
February 9, 2018: Scientific Reports
Jongsoo Choi, Xiyu Duan, Haijun Li, Thomas D Wang, Kenn R Oldham
Use of a thin-film piezoelectric microactuator for axial scanning during multi-photon vertical cross-sectional imaging is described. The actuator uses thin-film lead-zirconate-titanate (PZT) to generate upward displacement of a central mirror platform, micro-machined from a silicon-on-insulator (SOI) wafer to dimensions compatible with endoscopic imaging instruments. Device modeling in this paper focuses on existence of frequencies near device resonance producing vertical motion with minimal off-axis tilt even in the presence of multiple vibration modes and non-uniformity in fabrication outcomes...
October 2017: Journal of Microelectromechanical Systems
Anton V Ievlev, Marius Chyasnavichyus, Donovan Leondard, Joshua C Agar, Gabriel Velarde, Lane W Martin, Sergei V Kalinin, Petro Maksymovych, Olga Ovchinnikova
The ability to control thin-film growth has led to advances in our understanding of fundamental physics as well as to the emergence of novel technologies. However, common thin-film growth techniques introduce a number of limitations related to the concentration of defects on film interfaces and surfaces that limit the scope of systems that can be produced and studied experimentally. Here, we developed an ion-beam based subtractive fabrication process that enables creation and modification of thin films with pre-defined thicknesses...
February 2, 2018: Nanotechnology
Nan Zhang, Hiroko Yokota, A M Glazer, D A Keen, Semën Gorfman, P A Thomas, Wei Ren, Zuo-Guang Ye
Lead zirconate titanate (PZT) is one of the most widely studied piezoelectric materials, mainly because of its 'mysterious' relationship between the so-called morphotropic phase boundary (MPB) and its strong piezoelectric coupling factor. Using results from a pair distribution function analysis, this paper examines how the complex local structure in PZT affects the long-range average structure across the MPB. A monoclinic M C type structure is discovered in PZT. A first-order transformation between the monoclinic M A and M C components in both the average and local structures explains the sudden change in piezoelectric effect around these compositions...
January 1, 2018: IUCrJ
Yona Nebel-Jacobsen, Oliver Nebel, Martin Wille, Peter A Cawood
Plate tectonics and associated subduction are unique to the Earth. Studies of Archean rocks show significant changes in composition and structural style around 3.0 to 2.5 Ga that are related to changing tectonic regime, possibly associated with the onset of subduction. Whole rock Hf isotope systematics of black shales from the Australian Pilbara craton, selected to exclude detrital zircon components, are employed to evaluate the evolution of the Archean crust. This approach avoids limitations of Hf-in-zircon analyses, which only provide input from rocks of sufficient Zr-concentration, and therefore usually represent domains that already underwent a degree of differentiation...
January 17, 2018: Scientific Reports
Yu-Xiu Zhang, Xin Jin, Kai-Jun Zhang, Wei-Dong Sun, Jian-Ming Liu, Xiao-Yao Zhou, Li-Long Yan
The Triassic eclogite-bearing central Qiangtang metamorphic belt (CQMB) in the northern Tibetan Plateau has been debated whether it is a metamorphic core complex underthrust from the Jinsha Paleo-Tethys or an in-situ Shuanghu suture. The CQMB is thus a key issue to elucidate the crustal architecture of the northern Tibetan Plateau, the tectonics of the eastern Tethys, and the petrogenesis of Cenozoic high-K magmatism. We here report the newly discovered Baqing eclogite along the eastern extension of the CQMB near the Baqing town, central Tibet...
January 17, 2018: Scientific Reports
Xiaodong Jian, Biao Lu, Dandan Li, Yingbang Yao, Tao Tao, Bo Liang, Jin-Hong Guo, Yi-Jiang Zeng, Jia-Le Chen, Sheng-Guo Lu
Barium zirconate titanate (Ba(ZrxTi1-x)O3-BZT) ceramics with Zr4+ content x of 5, 10, 15, 20, 25 and 30 mol%, were prepared using a solid-state-reaction approach. The microstructures, morphologies, and electric properties were characterized using XRD, SEM and impedance analysis methods, respectively. The dielectric analyses indicate that the BZT bulk ceramics show characteristics of phase transition from a normal ferroelectric to a relaxor ferroelectric with the increasing Zr4+ ionic content. The electrocaloric effect (ECE) adiabatic temperature change decreases with the increasing Zr4+ content...
January 12, 2018: ACS Applied Materials & Interfaces
Markus Kratzer, Michael Lasnik, Sören Röhrig, Christian Teichert, Marco Deluca
Lead zirconate titanate (PZT) is one of the prominent materials used in polycrystalline piezoelectric devices. Since the ferroelectric domain orientation is the most important parameter affecting the electromechanical performance, analyzing the domain orientation distribution is of great importance for the development and understanding of improved piezoceramic devices. Here, vector piezoresponse force microscopy (vector-PFM) has been applied in order to reconstruct the ferroelectric domain orientation distribution function of polished sections of device-ready polycrystalline lead zirconate titanate (PZT) material...
January 11, 2018: Scientific Reports
Jilai Ding, Janakiraman Balachandran, Xiahan Sang, Wei Guo, Gabriel M Veith, Craig A Bridges, Christopher M Rouleau, Jonathan David Poplawsky, Nazanin Bassiri-Gharb, Panchapakesan Ganesh, Raymond R Unocic
Proton conducting perovskites have been widely studied due to their potential application as solid electrolytes in intermediate temperature solid oxide fuel cells. Structural and chemical heterogeneities can develop during synthesis, device fabrication or service, which can profoundly affect proton transport. Here, we use time-resolved Kelvin probe force microscopy, scanning transmission electron microscopy, atom probe tomography and density functional theory calculations to intentionally introduce Ba-deficient planar and spherical defects, and link the resultant atomic structure with proton transport behavior in both stoichiometric and non-stoichiometric epitaxial, yttrium doped barium zirconate thin films...
January 11, 2018: ACS Applied Materials & Interfaces
Thea H Heimdal, Henrik H Svensen, Jahandar Ramezani, Karthik Iyer, Egberto Pereira, René Rodrigues, Morgan T Jones, Sara Callegaro
The end-Triassic is characterized by one of the largest mass extinctions in the Phanerozoic, coinciding with major carbon cycle perturbations and global warming. It has been suggested that the environmental crisis is linked to widespread sill intrusions during magmatism associated with the Central Atlantic Magmatic Province (CAMP). Sub-volcanic sills are abundant in two of the largest onshore sedimentary basins in Brazil, the Amazonas and Solimões basins, where they comprise up to 20% of the stratigraphy. These basins contain extensive deposits of carbonate and evaporite, in addition to organic-rich shales and major hydrocarbon reservoirs...
January 9, 2018: Scientific Reports
Zheng Xu, Yong-Fei Zheng, Zi-Fu Zhao
Crustal components may be incorporated into continental basalts by either shallow contamination or deep mixing. While the former proceeds at crustal depths with common preservation of refractory minerals, the latter occurs at mantle depths with rare survival of relict minerals. Discrimination between the two mechanisms has great bearing to subcontinental mantle geochemistry. Here we report the occurrence of relict zircons in Cenozoic continental basalts from eastern China. A combined study of zircon U-Pb ages and geochemistry indicates that detrital zircons were carried by terrigenous sediments into a subcontinental subduction zone, where the zircon were transferred by fluids into the magma sources of continental basalts...
January 9, 2018: Scientific Reports
Mario A de Oliveira, Nelcileno V S Araujo, Rodolfo N da Silva, Tony I da Silva, Jayantha Epaarachchi
A considerable amount of research has focused on monitoring structural damage using Structural Health Monitoring (SHM) technologies, which has had recent advances. However, it is important to note the challenges and unresolved problems that disqualify currently developed monitoring systems. One of the frontline SHM technologies, the Electromechanical Impedance (EMI) technique, has shown its potential to overcome remaining problems and challenges. Unfortunately, the recently developed neural network algorithms have not shown significant improvements in the accuracy of rate and the required processing time...
January 8, 2018: Sensors
Xiuming Dou, Kun Ding, Baoquan Sun
Diamond anvil cell (DAC) technique is widely employed for the high pressure measurements in the field of physics, chemistry, and material research. The new designs of DAC and new techniques for applying pressure have been gradually developed. This paper introduces a piezoelectric driving DAC device to achieve tunable high pressure at low temperature down to 20 K by in situ continuous pressure tuning. The tuning range is about 2-4 GPa depending on the applied electric voltage to piezoelectric lead zirconic titanate ceramic stack...
December 2017: Review of Scientific Instruments
Ke-Jing Lee, Yu-Chi Chang, Cheng-Jung Lee, Li-Wen Wang, Yeong-Her Wang
A one-transistor and one-resistor (1T1R) architecture with a resistive random access memory (RRAM) cell connected to an organic thin-film transistor (OTFT) device is successfully demonstrated to avoid the cross-talk issues of only one RRAM cell. The OTFT device, which uses barium zirconate nickelate (BZN) as a dielectric layer, exhibits favorable electrical properties, such as a high field-effect mobility of 5 cm²/Vs, low threshold voltage of -1.1 V, and low leakage current of 10-12 A, for a driver in the 1T1R operation scheme...
December 9, 2017: Materials
Chao Liu, Andrew H Knoll, Robert M Hazen
The mineralogy and geochemistry associated with Rodinian assembly (~1.3-0.9 Ga) are significantly different from those of other supercontinents. Compared to other supercontinents, relatively more Nb-bearing minerals, Y-bearing minerals, and zircons formed during Rodinian assembly, with corresponding enrichments of Nb, Y, and Zr concentrations in igneous rocks. By contrast, minerals bearing many other elements (e.g., Ni, Co, Au, Se, and platinum group elements) are significantly less abundant, without corresponding depletion of Ni and Co concentrations in igneous rocks...
December 5, 2017: Nature Communications
Linsheng Huo, Xu Li, Hongnan Li, Zhijie Wang, Gangbing Song
Embedded Lead Zirconate Titanate (PZT) transducers have been widely used in research related to monitoring the health status of concrete structures. This paper presents a dynamic model of an embeddable PZT transducer with a waterproof layer and a protecting layer. The proposed model is verified by finite-element method (FEM). Based on the proposed model, the factors influencing the dynamic property of the embeddable PZT transducers, which include the material and thickness of the protecting layer, the material and thickness of the waterproof layer, and the thickness of the PZT, are analyzed...
December 5, 2017: Sensors
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