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M Thickness (m + thickness)
Selected AbstractsNanodiamond Thin Film Electrodes: Metal Electro-Deposition and Stripping ProcessesELECTROANALYSIS, Issue 3 2003Hian, Lau Chi Abstract The properties of a nanodiamond thin film deposit formed on titanium substrates in a microwave-plasma enhanced CVD process, are investigated for applications in electroanalysis. The nanodiamond deposit consists of intergrown nano-sized platelets of diamond with a high sp2 carbon content giving it high electrical conductivity and electrochemical reactivity. Nanodiamond thin film electrodes (of approximately 2,,m thickness) are characterized by electron microscopy and electrochemical methods. First, for a reversible one electron redox system, Ru(NH3)63+/2+, nanodiamond is shown to give well-defined diffusion controlled voltammetric responses. Next, metal deposition processes are shown to proceed on nanodiamond with high reversibility and high efficiency compared to processes reported on boron-doped diamond. The nucleation of gold is shown to be facile at edge sites, which are abundant on the nanodiamond surface. For the deposition and stripping of both gold and copper, a stripping efficiency (the ratio of electro-dissolution charge to electro-deposition charge) of close to unity is detected even at low concentrations of analyte. The effect of thermal annealing in air is shown to drastically modify the electrode characteristics probably due to interfacial oxidation, loss of active sp2 sites, and loss of conductivity. [source] Geophysical exploration for interlayer slip breccia gold deposits: example from Pengjiakuang gold deposit, Shandong Province, ChinaGEOPHYSICAL PROSPECTING, Issue 2 2004Z. Qingdong ABSTRACT Interlayer slipping breccia-type gold deposit , a new type of gold deposit, defined recently in the northern margin of the Jiaolai Basin, Shandong Province, China , occurs in interlayer slip faults distributed along the basin margin. It has the features of large orebody thickness (ranging from 14 m to 46 m, with an average thickness of 30 m), shallow embedding (0,50 m thickness of cover), low tenor of gold ore (ranging from 3 g/t to 5 g/t), easy mining and ore dressing. This type of gold deposit has promising metallogenic forecasting and potential for economic exploitation. A ground gamma-ray survey in the Pengjiakuang gold-ore district indicates that the potassium/thorium ratio is closely related to the mineralization intensity, i.e. the larger the potassium/thorium ratio, the higher the mineralization. The gold mineralized alteration zone was defined by a potassium/thorium ratio of 0.35. A seismic survey confirms the location of the top and bottom boundaries and images various features within the Pengjiakuang gold mineralization belt. The gold-bearing shovel slipped belt dips to the south at an angle of 50,55° at the surface and 15,20° at depth. The seismic profile is interpreted in terms of a structural band on the seismic section characterized by a three-layered model. The upper layer is represented by weakly discontinuous reflections that represent the overlying conglomerates. A zone of stronger reflections representing the interlayer slip fault (gold-bearing mineralized zone) is imaged within the middle of the section, while the strongest reflections are in the lower part of the section and represent metamorphic rocks at depth. At the same time, the seismic reflection survey confirms the existence of a granite body at depth, indicating that ore-forming fluids may be related to the granite. A CSAMT survey showed that the gold-bearing mineralized zone is a conductive layer and contains a low-resistivity anomaly ranging from 2 ,m to 200 ,m. [source] Multilayer Construction with Various Ceramic Films for Electronic Devices Fabricated by Aerosol DepositionINTERNATIONAL JOURNAL OF APPLIED CERAMIC TECHNOLOGY, Issue 6 2006Hironori Hatono Aerosol deposition (AD) is applicable as a fabrication technology for microstructures comprising different materials. We used this method for electronic devices that consist of ceramic films and metal electrodes. Various ceramic thick films (5,50 ,m thickness), for example, Al2O3, 2MgO·SiO2, and BaTiO3, were deposited on substrates using room-temperature aerosol deposition. The dielectric constant of BaTiO3 was 78 at 1 MHz. Multilayer constructions with ceramic films and copper electrodes were obtained using aerosol deposition and sputtering. During deposition, photoresist film masks were applied to produce patterns of ceramic films and connections between upper and lower electrodes through the ceramic films. [source] Atmospheric circulation patterns related to heavy snowfall days in Andorra, PyreneesINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 3 2005Pere Esteban Abstract Heavy snowfalls over mountain regions are often a direct cause of avalanches. Specific synoptic-scale atmospheric situations are responsible for these kinds of extreme snowfall event, and this is indeed the case for Andorra, a small country located in the Pyrenees, between France and Spain. Based on days with an intensity of at least 30 cm of snow in a 24 h period, the present study uses principal component analysis (PCA) and clustering techniques to characterize the synoptic circulation patterns for these days during the winter season. The area of analysis encompasses the region 30,60°N by 30°W,15°E and the period covers the winter seasons from 1986,87 to 2000,01. The methodology proposed involves a preprocessing approach consisting of a spatial standardization of the data used for the PCA, an alternative approximation to decide the centroids and the number of groups for the K -means clustering, and the rejection of the iterations for this algorithm. This approach enables the synoptic classification of every heavy snowfall day, and composite maps were constructed for sea-level pressure, 500 hPa geopotential height, and 1000,500 m thickness (the 5270 m, 5400 m and 5520 m contour lines). The results show seven circulation patterns, most of them with an Atlantic component of the wind, and others with a clear Mediterranean advection that could be combined with cold continental air. The results, as weather charts, could be a useful tool to assist meteorological models in heavy snowfall forecasting, and the day's classification obtained opens up future possibilities for detailed meteorological and climatological analysis of the established types. Copyright © 2005 Royal Meteorological Society [source] Optical and thermo electrical properties of ZnO nano particle filled polystyreneJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010Mulayam S. Gaur Abstract The study of optical and thermally stimulated electrical properties such as optical band gap, refractive index, X-ray spectra, SEM spectra, thermally stimulated discharge current (TSDC), differential scanning calorimetry (DSC) have been undertaken in ZnO nanoparicle filled polystyrene nanocomposite thin film of 30 ,m thickness. The appearance of single TSDC peak at temperature 408 ± 5 K in nanocomposite samples shows the charge carriers injected from deeper trapping levels. It is due to the modification of surface and bulk properties of polystyrene by filling of ZnO nanoparticles. In other hand, the strong interaction of nanoparticles with polymer matrix is the expected reason of improvement of crystallite size, optical energy band gap, refractive index, TSDC, glass transition temperature, and charge storage. It is confirmed from SEM images that the modifications of these properties are caused by creation of clusters in amorphous,crystalline boundaries of pristine polystyrene. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Effects of membrane thickness and heat treatment on the gas transport properties of membranes based on P84 polyimideJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010Yi Shen Abstract P84 polyimide membranes with thicknesses ranging from 6 to 310 ,m were successfully fabricated by spin coating. The glass transition temperature of the P84 powder was found to be 315°C using differential scanning calorimetry, whereas its decomposition temperature was 536°C using thermogravimetric analysis. Scanning electron microscopy was used to examine the morphology of the membranes. The permeability of single gas (He, N2, O2, and CO2) and the ideal selectivity of gas pair (O2/N2, He/CO2, CO2/N2, and He/O2), as a function of membrane thickness, were determined. The results showed that the permeability of a single gas increased with increasing membrane thickness, whereas the selectivity of a given gas pair was nearly independent of the membrane thickness. The average selectivity of O2/N2, He/CO2, CO2/N2, and He/O2 were found to be 8.2, 10.0, 12.9, and 15.8, respectively. The effects of heat treatment on the membrane morphology and gas transport properties were investigated for three annealing temperatures, i.e., 80°C, 200°C, and 315°C. The membrane annealed at 315°C was cracked due to the stress sustained either during heating or cooling, thereby resulting in little or no selectivity. The permeabilities of P84-118 membrane (118 ,m thickness) annealed at 80°C were 16.2, 0.196, 1.20, and 2.01 Barrer for He, N2, O2, and CO2, respectively. The permeabilities of P84-118 membrane annealed at 200°C decreased by 9.75%, 47.96%, 25.83%, and 30.85% for He, N2, O2, and CO2, respectively, as compared with those at 80°C, whereas the ideal selectivities increased by 42.65%, 30.52%, 32.85%, and 21.63% for O2/N2, He/CO2, CO2/N2, and He/O2, respectively. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Modified Atmosphere Packaging of PomegranateJOURNAL OF FOOD SCIENCE, Issue 7 2000F. Artés ABSTRACT: Spanish ,Mollar de Elche' sweet pomegranates (Punica granatum L.) were stored at 2 or 5 °C for 12 wk in unperforated polypropylene (UPP) film of 25 ,m thickness in modified atmosphere packaging (MAP). Perforated polypropylene (PPP) film of 20 ,m thickness and conventional cold storage were applied as control treatments. Quality was evaluated after storage and after shelf life of 6 d at 15 °C and 75% RH. PPP at 5 °C was the best treatment for maintaining red skin-color of the arils at the end of storage. All treatments suffered a decrease in total anthocyanins content at the end of shelf life. After shelf life, UPP fruits had higher values of absorbance at 510 and 446 nm. MAP strongly reduced water loss and chilling injuries without incidence of decay. [source] Novel Fabrication of Ca-Doped LaNbO4 Thin-Film Proton-Conducting Fuel Cells by Pulsed Laser DepositionJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 7 2010Anna Magrasó Thin films of 0.5% Ca-doped La0.995Ca0.005NbO4,, (LCNO) proton-conducting electrolytes of ,2 ,m thickness were obtained by pulsed laser deposition on NiO,LaNbO4 composite substrates. The morphology of the films was granular after annealing at T,1000°C and evolved to spherical-like grains at 1100°C and above. The structure and composition of the films were characterized by X-ray diffraction and X-ray photoelectron spectrocopy. LCNO films showed the monoclinic fergusonite-type structure at room temperature. The area-specific resistance for a ,2-,m-thick electrolyte was in the order of 0.4 ,·cm2 at 600°C based on estimates of the electrode area. Temperature dependency of the electrical conductivity at 600°,700°C was comparable with that of bulk disks of the material. [source] Thin films of Co3O4, MnCo2O4 and their solid solution as electrocatalyst: study of their magnetic propertiesPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue S1 2004E. Ríos Abstract We present magnetic measurements performed on the MnxCo3,xO4 (0 , x , 1) solid solution, prepared by spray pyrolysis. Thin films of about 20 ,m thickness were obtained after depositing aqueous metal nitrates precursors on Ti or conducting glass substrates. Powder material scratched from the substrate's surface was used for physico-chemical characterization. Presence of two oxidation states for each metal ion (Mn3+,Mn4+; Co2+,Co3+) triggers specific conduction mechanisms and double-exchange magnetic interactions. The ferromagnetic components are enhanced when x(Mn) increases, in detriment of the antiferromagnetic interactions. The ordering temperature Tc changes with x (from 22 K up to room temperature, for x = 0 up to x = 1). Based in the paramagnetic moment ,eff obtained at T > Tc, we propose a cationic distribution which can be nicely compared to the one obtained from crystallographic analyses. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] UV curing behaviors and hydrophilic characteristics of UV curable waterborne hyperbranched aliphatic polyesters,POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 9 2003Anila Asif Abstract A series of waterborne hyperbranched polyesters (WBHPs) endcapped with methacrylic and salt-like groups in different ratios have been investigated as UV curable resins. The kinetic studies of the drying step and UV curing were carried out by FT-IR measurements. The drying of the film of 100,,m thickness was completed in less than 6,hr at 70°C or within 10,hr at 50°C in an oven. The influence of different photoinitiators and their concentrations, extent of unsaturation and acid content of WBHP on final unsaturation conversion was studied. The surface free energy is a critical character, which affects the surface properties of a cured film. So one method based on the measurement of contact angle of a pure liquid on a solid surface was applied to determine the polar and dispersive components of the surface energy of UV cured films. The investigations of surface energy of WBHPs illustrated that those with more acid content and thus higher polar component are more sensitive to water, while those containing less acid content and thus lower polar term are less water sensitive. Moreover, the UV cured films of WBHPs and their blends with commercial waterborne resins (trade name EB 210, EB 2002, EB 11 and IRR 160) have acceptable pendulum hardness varying from 55 to 180,sec. Copyright © 2003 John Wiley & Sons, Ltd. [source] Characteristics of Underground Water Flow at Different Water Levels in Tianshengan Karst Area, Yunnan, ChinaACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 1 2010Janja KOGOV Abstract: Three tracing tests from the same injection point executed at low, medium, and high water levels in the karst aquifer near Tianshengan village, Lunan Stone Forest, Yunnan Province, China, have revealed the basic properties of underground water flow. They showed the general directions of water flows; tracer concentrations were observed at six successive points allowing for the calculation of apparent dominant flow velocities at these sections towards the Dalongtan karst spring. For the high water level, the discharge between single sections was between two and 10 times greater than that at low water level. For the medium water level, the flow velocity at different sections was between 1.4 and 3.7 times faster than that at low water level; and for high water level, it was between 1.3 and 2.7 times faster than that at medium water level. The fastest water flow appeared at the first section (23 cm/s at medium water level); and the slowest (0.6 cm/s at low water level) appeared where water flow must cross the Tianshengan fault (north-south direction), and later, a layer of 20-30 m thickness of quartz sandstone and shale clay-stones. It was also possible to calculate the recovery of the tracer for point 4, Dakenyan, where discharge was measured. At the medium water level, 50% of the injected tracer was detected a half-day after its first appearance and at low water level after more than 3 days. The previously published research illustrates the transport velocities of possible contaminants and their solubilities in water at different hydrological conditions. [source] Histomorphologic and histomorphometric evaluation of various endosseous implant healing chamber configurations at early implantation times: a study in dogsCLINICAL ORAL IMPLANTS RESEARCH, Issue 6 2010Charles Marin Abstract Aim: The objective of this study was to evaluate the early healing of endosseous implants presenting various healing chamber configurations in a beagle dog mandible model. Methods: The four premolars of 12 beagle dogs were extracted and allowed to heal for a period of 8 weeks. Implants allowing six different healing chamber configurations were placed in each dog (three per side, six configurations per dog). The animals were sacrificed after 3 and 5 weeks in vivo (n=6 per time in vivo), and the implants were non-decalcified processed to slides of ,30 ,m thickness. Bone-to-implant contact (BIC) and bone area fraction occupied (BAFO) within the healing chamber were quantified. Statistical analysis was performed by a GLM ANOVA model at 5% significance level. Results: Osseointegration and healing with woven bone filling throughout all healing chambers was observed. Replacement of woven bone by lamellar bone showing primary osteonic structures was observed at 5 weeks. BIC was significantly affected by healing chamber configuration (P<0.001) and was not affected by time in vivo (P>0.42) at 3 and 5 weeks in vivo. BAFO was not affected by healing chamber configuration (P>0.14) however significantly increased over implantation time (P<0.001). Conclusion: Regardless of healing chamber design and dimensions considered, healing allowed the devices osseointegration. However, healing chamber configuration significantly affected osseointegration measurable parameters such as BIC. To cite this article: Marin C, Granato R, Suzuki M, Gil JN, Janal, MN Coelho PG. Histomorhpologic and histomorphometric evaluation of various endosseous implant healing chamber configurations at early implantation times: a study in dogs. Clin. Oral Impl. Res. 21, 2010; 577,583. doi: 10.1111/j.1600-0501.2009.01853.x [source] | ||||||||||||||||