The Ti (texas + instruments)

Distribution by Scientific Domains

Selected Abstracts

3D In-Vivo Optical Skin Imaging for Topographical Quantitative Assessment of Non-Ablative Laser Technology

Paul M. Friedman MD
background. A new method for treating facial rhytides and acne scars with nonablative laser and light source techniques has recently been introduced. Given the inherent limitations of photographic and clinical evaluation to assess subtle changes in rhytides and surface topography, a new noninvasive objective assessment is required to accurately assess the outcomes of these procedures. objective. The purpose of this study was to measure and objectively quantify facial skin using a novel, noninvasive, In-vivo method for assessing three-dimensional topography. This device was used to quantify the efficacy of five treatment sessions with the 1064 nm QS Nd:YAG laser for rhytides and acne scarring, for up to six months following laser treatment. methods. Two subjects undergoing facial rejuvenation procedures were analyzed before and after therapy using a 30-mm, three-dimensional microtopography imaging system (PRIMOS, GFM, Teltow, Germany). The imaging system projects light on to a specific surface of the skin using a Digital Micromirror Device (DMDÔ Texas Instruments, Irving, TX) and records the image with a CCD camera. Skin Surface microtopography is reconstructed using temporal phase shift algorithms to generate three-dimensional images. Measurements were taken at baseline, at various times during the treatment protocol, and then at three and six-month follow-up visits. Silicone skin replicas (FLEXICO, Herts, England) were also made before and after the laser treatment protocol for comparison to In-vivo acquisition. results. Skin roughness decreased by 11% from baseline after three treatment sessions in the wrinkles subject, while a 26% improvement of skin roughness was recorded by 3D In-vivo assessment six months following the fifth treatment session. The subject with acne scarring demonstrated a 33% decrease in roughness analysis after three treatment sessions by 3D In-vivo assessment. A 61% improvement in surface topography was recorded 3-months following the fifth treatment session, which was maintained at the 6-month follow-up. conclusion. Three-dimensional In-vivo optical skin imaging provided a rapid and quantitative assessment of surface topography and facial fine lines following multiple treatment sessions with a 1064-nm QS Nd:YAG laser, correlating with clinical and subjective responses. This imaging technique provided objective verification and technical understanding of nonablative laser technology. Wrinkle depth and skin roughness decreased at the three and six-month follow-up evaluations by 3D In-vivo assessment, indicating ongoing dermal collagen remodeling after the laser treatment protocol. Future applications may include comparison of nonablative laser technology, optimization of treatment regimens, and objective evaluation of other aesthetic procedures performed by dermatologists. [source]

Monitoring bird migration with a fixed-beam radar and a thermal-imaging camera

Sidney A. Gauthreaux Jr
ABSTRACT Previous studies using thermal imaging cameras (TI) have used target size as an indicator of target altitude when radar was not available, but this approach may lead to errors if birds that differ greatly in size are actually flying at the same altitude. To overcome this potential difficulty and obtain more accurate measures of the flight altitudes and numbers of individual migrants, we have developed a technique that combines a vertically pointed stationary radar beam and a vertically pointed thermal imaging camera (VERTRAD/TI). The TI provides accurate counts of the birds passing through a fixed, circular sampling area in the TI display, and the radar provides accurate data on their flight altitudes. We analyzed samples of VERTRAD/TI video data collected during nocturnal fall migration in 2000 and 2003 and during the arrival of spring trans-Gulf migration during the daytime in 2003. We used a video peak store (VPS) to make time exposures of target tracks in the video record of the TI and developed criteria to distinguish birds, foraging bats, and insects based on characteristics of the tracks in the VPS images and the altitude of the targets. The TI worked equally well during daytime and nighttime observations and best when skies were clear, because thermal radiance from cloud heat often obscured targets. The VERTRAD/TI system, though costly, is a valuable tool for measuring accurate bird migration traffic rates (the number of birds crossing 1609.34 m [1 statute mile] of front per hour) for different altitudinal strata above 25 m. The technique can be used to estimate the potential risk of migrating birds colliding with man-made obstacles of various heights (e.g., communication and broadcast towers and wind turbines),a subject of increasing importance to conservation biologists. SINOPSIS Estudios previos, en donde no se ha hecho uso de radar, han utilizado cámaras infrarojas de imagen termal (CIT) y el tamaño de individuos como indicador, para detereminar la altura de vuelo. Sin embargo, este método puede dar origen a errores si las aves que vuelan a una misma altura varían en tamaño. Para subsanar esta dificultad y tomar medidas más exactas de la altura de vuelo y el número de individuos en una bandada, desarrollamos una técnica que combina un radar de rayos fijos con antena parabólica (RRF) con una cámara infraroja de imagen termal (RRT/CIT). El CIT provee de un conteo preciso de las aves pasando por un área circular fija de muestreo y el radar provee el dato preciso de la altura de vuelo. Utilizando una videograbadora digital, analizamos las muestras tomadas con la combinación RRT/CIT durante la migración otoñal noctura en el 2000 y el 2003 y durante la migración primaveral diurna del 2003, a través del Golfo de México. Utilizamos la cámara de video para hacer exposiciones en lapsos de tiempo en lo tomado por el CIT y desarrollamos criterios para distinguir entre aves, murciélagos e insectos, usando la huella dejada en el video y la altura del objeto. El CIT trabajo de forma eficiente tanto de dia como de noche, pero aún mejor cuando el cielo estaba despejado (cuando esta ausente la interferencia por la irradiación de calor de parte de las nubes). El sistema RRT/CIT, aunque costoso, es una herramienta valiosa para medir con presición las rutas migratorias y el número de aves moviéndose a diferente altura. Dicho sistema es de gran utilidad para determinar el riesgo de coliciones de aves migratorias con obstáculos construidos por el hombre a diferentes alturas (ej. torres de comunicación o turbinas de viento), asuntos de gran relevancia e importancia para la conservación de aves. [source]

The Synthesis and Reactivity of Group 4 Zwitterionic Complexes of the Type Mt+CH2AlCl3,: One-Component Stereoselective Polymerization and Oligomerization Catalysts for Olefins and Acetylenes

John J. Eisch
Abstract A reinvestigation of the interaction of TiCl4 with 2 equiv. of Me3Al in toluene between ,78 °C and 25 °C over 24 h has now established that the ultimate black product obtained is an associated zwitterion of the type [Ti+,CH2,AlCl3,]n, supported by multinuclear NMR spectroscopy and mass spectrometric and gasometric analyses of the gases evolved (CH4, H2) upon its protolysis. Chemical reactions of the zwitterion have corroborated specific aspects of its proposed structure: 1) its methylene character, by its transformation of benzophenone into 1,1-diphenylethylene; 2) its divalent titanium content, by the substantial reductive dimerization of benzophenone to tetraphenylethylene, and 3) its Lewis acidic Ti center, by its catalytic isomerization of trans -stilbene oxide to 1,1-diphenylacetaldehyde. Similar individual reactions of ZrCl4 or HfCl4 with Me3Al have led to the analogous zwitterions [Zr+,CH2,AlCl3,]n and [Hf+,CH2,AlCl3,]n, respectively. These zwitterions of Ti, Zr and Hf have been proven to be capable of the cyclotrimerization and/or polymerization of acetylenes with varying facility, as evidenced by their catalytic action on 1-hexyne, phenylacetylene, di- n -butylacetylene, and diphenylacetylene. Furthermore, all three zwitterions were able to polymerize ethylene, without any added cocatalyst, with an activity following the order Zr > Ti > Hf. The Ti and Zr zwitterions effected the stereoselective polymerization of propylene to yield 50% of isotactic polymer, and all three catalysts induced the polymerization of 1-hexene to yield 85% (Zr, Hf) or 100% (Ti) of isotactic polymer. These oligomerizations and stereoselective polymerizations of acetylenes and olefins can be rationalized through a model for the active site resembling a three-membered metallacyclopropa(e)nium ion intermediate formed from the attack of the Group 4 metal zwitterion on the unsaturated hydrocarbon. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source]

Structure and metal type effects on cure kinetics of DGEBA with benzil bisthiosemicarbazone complexes

Mousa Ghaemy
Abstract The curing reaction kinetics of the diglycidyl ether of bisphenol A- (DGEBA) based epoxy was investigated according to the change of curing agents. Complex curing agents based on Ni(II) and Cu(II) chelates with benzil bisthiosemicarbazone (LH6) as a ligand was studied using differential scanning calorimetry. The curing reaction was characterized by high-activation energies (Ea), cure onset (Ti), and peak maximum (Tp) temperatures. Dynamic kinetic parameters were calculated by using Kissinger and Ozawa methods. For the NiLH6Cl2, CuLH6Cl2, and LH6 the average values of Ea were calculated to be 165.16, 165.92, and 115.75 kJ/mol, respectively. For the NiLH6Cl2 systems, their activation energies at 40 and 30 phr are equal. The Ti and Tp of the DGEBA/NiLH6Cl2 system are lower than those of DGEBA/CuLH6Cl2 system. These results indicate that NiLH6Cl2 has a higher reactivity toward epoxy resin at the beginning of the curing reaction. The effect of hardener concentration, heating rate, and type of metal ion on the cure kinetic parameters and the shape of DSC thermograms were investigated. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]

On The Ethical Significance Of The Ti,Yong Distinction

Antonio S. Cua

Improvement of Hardness and Toughness of TiAlN Coating by Nanoscale Multilayered Structurization with Si3N4

Jong-Keuk Park
Abstract The Ti(Al)-Si based nitride coating material has been studied due to its excellent mechanical properties such as hardness and oxidation resistance as in the Ti(Al)N/a-Si3N4 nanocomposites with high hardness over 50 GPa. In this study, the effect of microstructure, especially layer thickness of TiAlN and Si3N4 phase, on the mechanical properties of the TiAlN/Si3N4 nanoscale multilayered coating has been investigated. By nanoscale multilayered structurization with a thin Si3N4 layer (,0.3 nm), the hardness and toughness of TiAlN coating were greatly improved. It is known that for the TiAlN/Si3N4 nanoscale multilayered coatings, thickness of the Si3N4 layer is the most important factor and should be carefully controlled to obtain coatings with high hardness and toughness. [source]

Chlorido(,5 -cyclopentadienyl)bis(dimethylamido)titanium, [TiCl(,5 -C5H5)(NMe2)2]

Brette M. Chapin
The title complex, [Ti(C5H5)(C2H6N)2Cl], exhibits two nearly planar dimethylamide groups oriented approximately perpendicular to each other. The Ti,cyclopentadienyl centroid vector lies nearly in the plane of one of the dimethylamide groups. Long-range contacts between Ti,Cl and cyclopentadienyl H,C groups give rise to geometric ordering in the extended solid. [source]

A novel titanium,,-O,zirconium complex: bis(,-methyliminodiethanolato-1,3O,N,O,;1:2,2O)(methyliminodiethanolato-2,3O,N,O,)dipropanolato-1,O,2,O -titanium(IV)zirconium(IV)

Graeme J. Gainsford
The title compound, [TiZr(C5H11NO2)3(C3H7O)2], contains three methyl­imino­diethano­late ligands, two in different ,-oxo bridging coordination modes and one bound only to the Ti atom. The Ti and Zr atoms have distorted octahedral and pentagonal,bipyramidal coordinations, respectively, which share edges. As well as some conformational disorder in the carbon chains, there is chemical disorder at one Ti site, with a mix of n - and isopropanolate ligands. [source]

Petrography, mineralogy, and trace element geochemistry of lunar meteorite Dhofar 1180

Aicheng Zhang
Dhofar 1180 is predominantly composed of fine-grained matrix with abundant mineral fragments and a few lithic and glassy clasts. Lithic clasts show a variety of textures including cataclastic, gabbroic, granulitic, ophitic/subophitic, and microporphyritic. Both feldspathic and mafic lithic clasts are present. Most feldspathic lithic clasts have a strong affinity to ferroan anorthositic suite rocks and one to magnesian suite rocks. Mafic lithic clasts are moderately to extremely Fe-rich. The Ti/[Ti+Cr]-Fe/[Fe+Mg] compositional trend of pyroxenes in mafic lithic clasts is consistent with that of low-Ti mare basalts. Glasses display a wide chemical variation from mafic to feldspathic. Some glasses are very similar to those from Apollo 16 soils. KREEP components are essentially absent in Dhofar 1180. One glassy clast is rich in K, REE and P, but its Mg/[Mg+Fe] is very low (0.25). It is probably a last-stage differentiation product of mare basalt. Molar Fe/Mn ratios of both olivine and pyroxene are essentially consistent with a lunar origin. Dhofar 1180 has a LREE-enriched (La 18 × CI, Sm 14 × CI) pattern with a small positive Eu anomaly (Eu 15 × CI). Th concentration is 0.7 ppm in Dhofar 1180. Petrography, mineralogy, and trace element geochemistry of Dhofar 1180 are different from those of other lunar meteorites, indicating that Dhofar 1180 represents a unique mingled lunar breccia derived from an area on the lunar nearside but far away from the center of the Imbrium Basin. [source]

Monocyclopentadienyl Phenoxido,Amino and Phenoxido,Amido Titanium Complexes: Synthesis, Characterisation, and Reactivity of Asymmetric Metal Centre Derivatives

Giuseppe Alesso
Abstract Reduction of phenol,imine derivatives R,N=CH(3,5-R2C6H2 -2-OH) (R = tBu; R, = C6H51a, p -MeC6H41b, Cy 1c, tBu 1d, 2,6-Me2C6H31e; R = H; R, = p -MeC6H41f; Cy = cyclohexyl) with MBH4 (M = Li, Na) or AlLiH4 in ethyl ether or thf at room temperature affords the phenol,amine compounds R,NHCH2(3,5-R2C6H2 -2-OH) 2a,c and 2e,f. The N -R-[2,4-di- tert -butyl]benzo-1-oxa-3-azine species (R = tBu 2d1, 2,6-Me2C6H32e1) are obtained by Mannich reaction of 2,4-di- tert -butylphenol with RNH2 in refluxing methanol. Intermediate 2d1 is converted in ethanol at room temperature into N - tert -butyl[2-hydroxy-3,5-di- tert -butyl]benzylamine (2d), whereas 2e is not obtained from 2e1 by using this procedure.N -alkyl,N - tert -butyl[2-hydroxy-3,5-di- tert -butyl]benzylaminecompounds tBuN(R)CH2(3,5- tBu2C6H2 -2-OH) (R = Me 2g, Et 2h, nPr 2i, CH2Ph 2j) are also prepared by the appropriate synthetic method. Treatment of 2a,c with 1 equiv. of TiCpCl3 in the presence of 2.5 equiv. of NEt3 in hexane at room temperature gives the monocyclopentadienyl phenoxido,amido monochloride complexes TiCp[R,NCH2(3,5- tBu2C6H2 -2-O)]Cl (R, = C6H53a, R, = p -MeC6H43b, R, = Cy 3c). The analogous complex Ti(,5 -C5H4SiMe2Cl)[C6H5NCH2(3,5- tBu2C6H2 -2-O)]Cl (4a) results from the reaction of 2a with Ti(,5 -C5H4SiMe2Cl)Cl3. Nevertheless, 2d reacts with TiCpCl3 in hexane in the presence of NEt3 at room temperature yielding the monocyclopentadienyl phenoxido dichloride compound TiCp[tBuNHCH2(3,5- tBu2C6H2 -2-O)]Cl2 (5), whereas in ethyl ether and in the absence of NEt3 adduct 5·HCl is obtained, which is further converted into TiCp[tBuNCH2(3,5- tBu2C6H2 -2-O)]Cl (3d) by addition of a NEt3/ethyl ether solution. The reaction of TiCpCl3 with 2a in the presence of 2.5 equiv. of NEt3 in a polar solvent (thf, CH2Cl2 or toluene) at room temperature affords TiCp[Ph(H)NCH2(3,5- tBu2C6H2 -2-O)]Cl (6a) as a mixture of two stereoisomers. All the reported compounds were characterised by the usual analytical and spectroscopic methods and the molecular structures of 2a, 2d, 2e and 3d were determined by X-ray diffraction analysis from suitable single crystals. Preliminary studies of catalytic activity for ethylene polymerisation by using solid methylaluminoxane as cocatalyst were performed.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]

Magnetic fields and chemical peculiarities of the very young intermediate-mass binary system HD 72106

C. P. Folsom
ABSTRACT The recently discovered magnetic Herbig Ae and Be stars may provide qualitatively new information about the formation and evolution of magnetic Ap and Bp stars. We have performed a detailed investigation of one particularly interesting binary system with a Herbig Ae secondary and a late B-type primary possessing a strong, globally ordered magnetic field. 20 high-resolution Stokes V spectra of the system were obtained with the ESPaDOnS instrument mounted on the Canada,France,Hawaii Telescope. In these observations we see clear evidence for a magnetic field in the primary, but no evidence for a magnetic field in the secondary. A detailed abundance analysis was performed for both stars, revealing strong chemical peculiarities in the primary and normal chemical abundances in the secondary. The primary is strongly overabundant in Si, Cr and other iron-peak elements, as well as Nd, and underabundant in He. The primary therefore appears to be a very young Bp star. In this context, line profile variations of the primary suggest non-uniform lateral distributions of surface abundances. Interpreting the 0.639 95 ± 0.000 09 d variation period of the Stokes I and V profiles as the rotational period of the star, we have modelled the magnetic field geometry and the surface abundance distributions of Si, Ti, Cr and Fe using magnetic Doppler imaging. We derive a dipolar geometry of the surface magnetic field, with a polar strength Bd= 1230 G and an obliquity ,= 57°. The distributions Ti, Cr and Fe are all qualitatively similar, with an elongated patch of enhanced abundance situated near the positive magnetic pole. The Si distribution is somewhat different, and its relationship to the magnetic field geometry less clear. [source]

Thymic size in preterm neonates: a sonographic study

DL Jeppesen
Aim: To assess the variation in size of the thymus in vivo in preterm neonates and to identify relations between thymic size and gestational age (GA), birthweight, occurrence of postnatal infections and maternal alcohol and tobacco intake during pregnancy. Methods: Eighty preterm neonates with a GA between 24 and 36 wk, and a birthweight between 490 and 4110 g were examined between days 0 and 19 after birth. The thymic size was assessed by sonography as a volume estimate, the so-called thymic index (Ti). The median Ti was 5.2 (1.2,17.9). Ti was positively correlated with birthweight and GA and negatively correlated with occurrence of postnatal infection (p < 0.01, p= 0.03, p= 0.05, R2= 0.68). A correlation between thymic size and maternal alcohol and tobacco intake was not demonstrated. Conclusion: It is possible to assess the size of the thymus by sonography in very low-birthweight and preterm neonates. A normal range for Ti in preterm neonates has been established. The sonographic method is a safe and effective technique for measuring the size of the thymus in preterm infants. [source]