Search results for "Titanium"

Influence of Operator's Experience on Root Canal Shaping Ability with a Rotary Nickel-Titanium Single-File Reciprocating Motion System

2013

The aim of this study was to evaluate the influence of the operator's experience on the shaping of double-curvature simulated root canals with a nickel-titanium single-file reciprocating motion system.Sixty double-curvature root canals simulated in methacrylate blocks were prepared by 10 students without any experience in endodontics and by 10 professionals who had studied endodontics at the postgraduate level. The Reciproc-VDW system's R25 file was used in the root canal preparation. The blocks were photographed before and after the instrumentation, and the time of instrumentation was also evaluated. Changes in root canal dimensions were analyzed in 6 positions.Significant differences (P.0…

Multinuclear Cytotoxic Metallodrugs: Physicochemical Characterization and Biological Properties of Novel Heteronuclear Gold-Titanium Complexes

2011

An unprecedented series of titanocene-gold bi- and trimetallic complexes of the general formula [[(η(5)-C(5)H(5))(μ-η(5):κ(1)-C(5)H(4)(CH(2))(n)PPh(2))TiCl(2)](m)AuCl(x)](q+) (n = 0, 2, or 4; m = 1, x = 1, q = 0 or m = 2, x = 0, q = 1) have been prepared and characterized spectroscopically. The luminescence spectroscopy and photophysics of one of the compounds, [[(η(5)-C(5)H(5))(μ-η(5):κ(1)-C(5)H(4)PPh(2))TiCl(2)](2)Au]PF(6), have been investigated in 2MeTHF solution and in the solid state at 77 and 298 K. Evidence for interfragment interactions based on the comparison of electronic band positions and emission lifetimes, namely, triplet energy transfer (ET) from the Au- to the Ti-containing…

Development of Bimetallic Titanocene−Ruthenium−Arene Complexes As Anticancer Agents: Relationships between Structural and Biological Properties

2010

A series of bimetallic titanium-ruthenium complexes of general formula [(η(5)-C(5)H(5))(μ-η(5):κ(1)-C(5)H(4)(CR(2))(n)PR'R'')TiCl(2)](η(6)-p-cymene)RuCl(2) (n = 0, 1, 2 or 4; R = H or Me; R' = H, Ph, or Cy; R'' = Ph or Cy) have been synthesized, including two novel compounds as well as two cationic derivatives of formula [(η(5)-C(5)H(5))(μ-η(5):κ(1)-C(5)H(4)(CH(2))(n)PPh(2))TiCl(2)] [(η(6)-p-cymene)RuCl](BF(4)) (n = 0 or 2). The solid state structure of two of these compounds was also established by X-ray crystallography. The complexes showed a cytotoxic effect on human ovarian cancer cells and were markedly more active than their Ti or Ru monometallic analogues titanocene dichloride and RA…

The Effects of the Electron-Phonon Interaction on the Vibrational Anomalies and Polymorphism in Titanium

1997

AbstractWe apply the frozen phonon and molecular dynamics methods within the semiempirical orthogonal tight-binding framework to study the anomalous behaviour of the (0001) optical longitudinal (LO) and transverse (TO) phonons in the low temperature hep phase of Ti, and the ⅔[111]L and ½[110]T1 phonons in the high temperature bec phase. We demonstrate that, in agreement with previous findings in Zr, the anomalous thermal frequency shifts in hep Ti are related to the strong coupling of the electron density of states (DOS) to the particular lattice distortions. The distortions along the bec ⅔[111]L and ½[110]T1 phonons also significantly affect the DOS, resulting in the instability of these m…

Synthesis and immobilization of molecular switches onto titaniumdioxide nanowires

2009

Abstract The precursor [Fe III (L)Cl (L =  N , N ′-bis(2′-hydroxy-3′-methyl-benzyliden)-1,7-diamino-4-azaheptane) is combined with [Mo(CN) 8 ] 4− yields a star shaped nona-nuclear cluster, [Mo IV {(CN)Fe III (L)} 8 ]Cl 4 . This Fe 8 Mo molecule is a high-spin system at room temperature. On cooling to 20 K some of the iron(III) centres in the molybdenum(IV)-star switch to the low-spin state as proven by Mossbauer spectroscopy. This molecule was deposited on TiO 2 nanowires by electrostatic interactions between the cluster cations and the surface functionalized titanium oxide nanowire. The synthesis and surface binding of the multistable molecular switch was demonstrated using IR and UV–Vis s…

Photo-electrochemical investigation of anodic oxide films on cast Ti–Mo alloys. I. Anodic behaviour and effect of alloy composition

2009

Abstract The anodic behaviour of cast Ti–Mo alloys, having different Mo contents (6–20 wt.%), was investigated in acidic and neutral aerated aqueous solutions. All sample showed a valve-metal behaviour, owing to formation and thickening of barrier-type anodic oxides displaying interference colours. Growth kinetics of passive films is influenced by both anodizing electrolyte and composition of the starting alloy. This last parameter was found to change also the solid-state properties of the films, explored by photoelectrochemical and impedance spectroscopy experiments. Thicker films ( U f  = 8 V/MSE) grown on alloys richer in Mo showed more resistive character and a photocurrent sign inversi…

Electroslag process for better titanium deposition morphology

2018

Porous titanium for biomedical applications : an experimental study on rabbits

2010

Made available in DSpace on 2013-08-12T18:44:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-03-01 Made available in DSpace on 2013-09-30T18:34:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-03-01 Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-20T14:04:32Z No. of bitstreams: 0 Made available in DSpace on 2014-05-20T14:04:32Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-03-01 Objective: The aim of this study was to carry out an in vivo assessment of bone ingrowth in two different types of porous titanium -the first being completely porous, and the second with a porous surface and dense nucleus, manufactured by powder metallu…

The role of water in the photocatalytic degradation of acetonitrile and toluene in gas-solid and liquid-solid regimes

2006

Photocatalytic degradation of acetonitrile and toluene was carried out both in gas-solid and in liquid-solid regimes by using commercialTiO2samples (Merck and Degussa P25). The investigation was mainly aimed to study the influence of water present in the reaction environment on the mechanism and degradation rate of two probe molecules. In gas-solid regime, the reacting mixture consisted of toluene or acetonitrile, oxygen, nitrogen, and water vapour. The main degradation product of toluene wasCO2with small amounts of benzaldehyde. In the presence of water vapour, the activity ofTiO2Merck remained stable but greatly decreased if water was absent.TiO2Degussa P25 continuously deactivated, even …

Magnetic hybrid TiO 2 /Alg/FeNPs triads for the efficient removal of methylene blue from water

2018

A new adsorbent material with combined adsorption, photocatalytic, and magnetic properties has been suc- cessfully synthesized and tested for the efficient dye removal from methylene blue (MB) contaminated water. A facile non-thermal method was applied to synthesize a hybrid nanocomposite consisting of TiO2/calcium algi- nate (TiO/Alg) and magnetite (Fe3O4) nanoparticles (FeNPs). The potential of the adsorbent Alg as a barrier to prevent direct contact between the magnetic core and TiO2 was experimented by varying the synthesis condi- tions. The performance of four differently synthesized TiO2/Alg/FeNPs samples (TiO2/Alg/FeNPs-1, TiO2/Alg/ FeNPs-2, TiO2/Alg/FeNPs-3, and TiO2/Alg/FeNPs-4) wa…