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Othmar Müntener, Tanya Ewing, Lukas P Baumgartner, Mélina Manzini, Thibaud Roux, Pierre Pellaud, Luc Allemann
The subduction system in southern Patagonia provides direct evidence for the variability of the position of an active continental arc with respect to the subducting plate through time, but the consequences on the arc magmatic record are less well studied. Here we present a geochemical and geochronological study on small plutons and dykes from the upper crust of the southern Patagonian Andes at ~ 51°S, which formed as a result of the subduction of the Nazca and Antarctic plates beneath the South American continent...
2018: Contributions to Mineralogy and Petrology. Beiträge Zur Mineralogie und Petrologie
Min-Su Kwon, Sung-Gap Lee, Kyeong-Min Kim
In this study, Barium Titanate (BT)/Lead Zirconate Titanate (PZT) multilayer thin films were fabricated by the spin-coating method on Pt (200 nm)/Ti (10 nm) SiO2 (100 nm)/P-Si (100) substrates using BaTiO3 and Pb(Zr0.90Ti0.10)O3 metal alkoxide solutions. The coating and heating procedure was repeated several times to form the multilayer thin films. All of BT/PZT multilayer thin films show X-ray diffraction patterns typical to a polycrystalline perovskite structure and a uniform and void free grain microstructure...
September 1, 2018: Journal of Nanoscience and Nanotechnology
Hyunki Kim, Pyungho Choi, Nayoung Lee, Soonkon Kim, Kwangjun Koo, Jaehyeong Lee, Byoungdeog Choi
Hafnium-silicate (HfSiO4, (HfO2)x(SiO2)1-x) and hafnium-zirconate (HfZrO4, (HfO2)x(ZrO2)1-x) films were employed as a gate dielectric to enhance the electrical properties of pure HfO2. (HfO2)x(SiO2)1-x and (HfO2)x(ZrO2)1-x films were formed onto p-Si substrates with varying degrees of Hf content x (x = 1, 0.9, 0.7, and 0.5) via solution processing. With regard to (HfO2)x(SiO2)1-x, the leakage current decreased from 1.94 × 10-8 to 4.29 × 10-9 A/cm2 at a gate voltage of VG = -1 V when the HfO2 content was reduced...
September 1, 2018: Journal of Nanoscience and Nanotechnology
L M Candido, L N Miotto, Lmg Fais, P F Cesar, Lap Pinelli
PURPOSE: This study compared monolithic zirconia with conventional ones based on mean roughness (Ra), Vickers hardness (VHN), topography, transmittance, grain size, flexural strength (FS), Weibull modulus, and fractographic behavior. METHODS AND MATERIALS: One monolithic (Prettau Zircon [PR group]) and two conventional (ICE Zirkon Transluzent [IZ group] and BloomZir [BL group]) zirconias were used. Specimens were tested using a profilometer, a microhardness tester, a scanning electron microscope, a spectrophotometer, and a Universal Testing Machine (EMIC DL 2000)...
May 2018: Operative Dentistry
Norihiro Suzuki, Minoru Osada, Motasim Billah, Yoshio Bando, Yusuke Yamauchi, Shahriar A Hossain
Barium titanate (BaTiO3, hereafter BT) is an established ferroelectric material first discovered in the 1940s and still widely used because of its well-balanced ferroelectricity, piezoelectricity, and dielectric constant. In addition, BT does not contain any toxic elements. Therefore, it is considered to be an eco-friendly material, which has attracted considerable interest as a replacement for lead zirconate titanate (PZT). However, bulk BT loses its ferroelectricity at approximately 130 °C, thus, it cannot be used at high temperatures...
March 27, 2018: Journal of Visualized Experiments: JoVE
Sukrit Ranjan, Zoe R Todd, John D Sutherland, Dimitar D Sasselov
A key challenge in origin-of-life studies is understanding the environmental conditions on early Earth under which abiogenesis occurred. While some constraints do exist (e.g., zircon evidence for surface liquid water), relatively few constraints exist on the abundances of trace chemical species, which are relevant to assessing the plausibility and guiding the development of postulated prebiotic chemical pathways which depend on these species. In this work, we combine literature photochemistry models with simple equilibrium chemistry calculations to place constraints on the plausible range of concentrations of sulfidic anions (HS- , HSO3 - , SO3 2- ) available in surficial aquatic reservoirs on early Earth due to outgassing of SO2 and H2 S and their dissolution into small shallow surface water reservoirs like lakes...
April 8, 2018: Astrobiology
Shiuh-Chuan Her, Han-Yung Chen
INTRODUCTION: Smart structures equipped with piezoelectric devices to sense and actuate the structure could be used in many engineering applications. To explore the smart structure further and apply it to more complex structures, some problems are critical to be concerned. Among them, delamination due to the high stress is an important issue since its serious effect on the strength and stiffness of the composite structure. METHOD: In this investigation, a piezoelectric layer is embedded into the host structure to form a sandwich composite structure...
January 2018: Journal of Applied Biomaterials & Functional Materials
Dou Zhang, Weiwei Liu, Ru Guo, Kechao Zhou, Hang Luo
Polymer-based capacitors with high energy density have attracted significant attention in recent years due to their wide range of potential applications in electronic devices. However, the obtained high energy density is predominantly dependent on high applied electric field, e.g., 400-600 kV mm-1 , which may bring more challenges relating to the failure probability. Here, a simple two-step method for synthesizing titanium dioxide/lead zirconate titanate nanowire arrays is exploited and a demonstration of their ability to achieve high discharge energy density capacitors for low operating voltage applications is provided...
February 2018: Advanced Science (Weinheim, Baden-Wurttemberg, Germany)
Jie Chen, Seung Kyu Oh, Haiyang Zou, Shahab Shervin, Weijie Wang, Sara Pouladi, Yunlong Zi, Zhong Lin Wang, Jae-Hyun Ryou
Piezoelectric generators (PEGs) are a promising power source for future self-powered electronics by converting ubiquitous ambient mechanical energy into electricity. However, most of the high-output PEGs are made from lead zirconate titanate (PZT), in which the hazardous lead could be a potential risk to both the human and environment, limiting their real applications. III-nitride (III-N) can be a potential candidate to make stable, safe, and efficient PEGs, due to its high chemical stability and piezoelectricity...
March 29, 2018: ACS Applied Materials & Interfaces
Zhen-Yu He, Reiner Klemd, Li-Li Yan, Tian-Yu Lu, Ze-Ming Zhang
We report in situ O and Hf isotope data of zircon grains from coeval Mesoproterozoic (ca. 1.4 Ga) igneous metamafic (amphibolite) and granitic rocks of the Chinese Central Tianshan microcontinent (CTM) in the southern Central Asian Orogenic Belt (CAOB). Zircon grains from amphibolite have mantle-like δ18 OVSMOW values of 4.7-5.6‰ and juvenile Hf isotopic compositions (εHf (t) = 8.4-15.3; TDMC  = 1.57-1.22 Ga), whereas those from granitic rocks have δ18 OVSMOW values of 5.6-7.0‰ and evolved Hf isotopic compositions (εHf (t) = -1...
March 22, 2018: Scientific Reports
Buket Ayna, Emrah Ayna, Sema Çelenk, Emine Göncü Başaran, Berivan Dündar Yılmaz, İbrahim Halil Tacir, Mehmet Cudi Tuncer
AIM: To compare the efficacy of resin composite restorations, retained with either polyethylene or zirconia-rich glass fiber posts. METHODS: Sixty-two single rooted maxillary and mandibular central incisor teeth in forty-four patients (15 males and 29 females; age range 15-32 years) were restored either with an ultrahigh molecular weight polyethylene (UHMWP) fiber post (Bondable Reinforcement Ribbon, DENSE, Ribbond, Seattle, WA, United States) or a zircon-rich glass fiber post (Snowpost, Lot H 040; Carbotech, Ganges, France)...
March 16, 2018: World Journal of Clinical Cases
Nor Ain Fathihah Abdullah, Lee Sin Ang
Density functional calculations were performed on the metal complexes formed during the synthesis of barium zirconate (BZY). This compound has been synthesized previously, but the molecular interactions present during the formation of the ligand-metal complexes are unknown. In this study, calculations were carried out to determine the preferred coordination sites for the metal complexes. The cations Ba2+, Y3+, and Zr4+ were modeled to interact with two deprotonated chelating agents (citric acid [CA] and ethylenediaminetetraacetic acid [EDTA]) at strategic positions...
March 2018: Acta Chimica Slovenica
J-P Suuronen, M Sayab
Zircon is the most widely used mineral in petrochronology and provides key information about magmatic and crustal differentiation history of plutonic rocks, transport paths of clastic material 'from source to sink' and significantly contributes in the reconstruction of enigmatic planetary-scale tectonic episodes since the Archaean. However, detailed textural analysis of this accessory mineral has always been hampered by two-dimensional (2D) analytical limitations. With the advancements in X-ray nanotomography technology, it is now possible to non-destructively, yet digitally, cut, visualize, compare and quantify internal textures within zircons, their growth and zoning patterns and chemical distribution of trace elements in three dimensions (3D)...
March 16, 2018: Scientific Reports
Hoa Thanh Phan, Thien Xuan Dinh, Phong Nhu Bui, Van Thanh Dau
In this paper, we report on the design, simulation, and experimental analysis of a miniaturized device that can generate multiple circulated jet flows. The device is actuated by a lead zirconate titanate (PZT) diaphragm. The flows in the device were studied using three-dimensional transient numerical simulation with the programmable open source OpenFOAM and was comparable to the experimental result. Each flow is verified by two hotwires mounted at two positions inside each consisting chamber. The experiment confirmed that the flow was successfully created, and it demonstrated good agreement with the simulation...
March 13, 2018: Sensors
Shruti B Seshadri, Michelle M Nolan, Goknur Tutuncu, Jennifer S Forrester, Eva Sapper, Giovanni Esteves, Torsten Granzow, Pam A Thomas, Juan C Nino, Tadej Rojac, Jacob L Jones
Large piezoelectric coefficients in polycrystalline lead zirconate titanate (PZT) are traditionally achieved through compositional design using a combination of chemical substitution with a donor dopant and adjustment of the zirconium to titanium compositional ratio to meet the morphotropic phase boundary (MPB). In this work, a different route to large piezoelectricity is demonstrated. Results reveal unexpectedly high piezoelectric coefficients at elevated temperatures and compositions far from the MPB. At temperatures near the Curie point, doping with 2 at% Sm results in exceptionally large piezoelectric coefficients of up to 915 pm/V...
March 7, 2018: Scientific Reports
Jonathan M Puder, Jeffrey S Pulskamp, Ryan Q Rudy, Ronald G Polcawich, Sunil A Bhave
This paper reports on a general analytical expression for the motional resistance ( ) of an arbitrary mode in a piezoelectric microelectromechanical system resonator with parallel plate electrode geometry. After applying simplifying assumptions and using analytical modes shapes, expressions for the of modes with out-of-plane flexure as the primary displacement are presented. These modes include free-free transverse beam flexure (TBF), unclamped disk flexure resonators (DFRs), and antisymmetric Lamb modes. For verification, is extracted from resonators fabricated in a lead zirconate titanate on silicon process...
March 2018: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
Huamin Zhao, Cunfu He, Lyu Yan, Haijun Zhang
It is necessary to develop a transducer that can quickly detect the inner and outer wall defects of thick-walled pipes, in order to ensure the safety of such pipes. In this paper, a flexible broadband Rayleigh-waves comb transducer based on PZT (lead zirconate titanate) for defect detection of thick-walled pipes is studied. The multiple resonant coupling theory is used to expand the transducer broadband and the FEA (Finite Element Analysis) method is used to optimize transducer array element parameters. Optimization results show that the best array element parameters of the transducer are when the transducer array element length is 30 mm, the thickness is 1...
March 2, 2018: Sensors
Nick M W Roberts, Qiong-Yan Yang, M Santosh
The mineral zircon through its isotopic and elemental signatures comprises the greatest archive recording the evolution of Earth's continental crust. Recognising primary from secondary zircon compositional signatures is thus important for the accurate interpretation of this archive. We report two examples of metasedimentary rocks from high-grade shear zones within the Southern Granulite Belt of India, where anomalously high and homogeneous oxygen isotope signatures indicate disturbance of this isotopic system...
February 26, 2018: Scientific Reports
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
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