Study on ultra-fine w-EDM with on-machine measurement-assisted

International Nuclear Information System (INIS)

Chen Shuntong; Yang Hongye

2011-01-01

The purpose of this study was to develop the on-machine measurement techniques so as to precisely fabricate micro intricate part using ultra-fine w-EDM. The measurement-assisted approach which employs an automatic optical inspection (AOI) is incorporated to ultra-fine w-EDM process to on-machine detect the machining error for next re-machining. The AOI acquires the image through a high resolution CCD device from the contour of the workpiece after roughing in order to further process and recognize the image for determining the residual. This facilitates the on-machine error detection and compensation re-machining. The micro workpiece and electrode are not repositioned during machining. A fabrication for a micro probe of 30-μm diameter is rapidly machined and verified successfully. Based on the proposed technique, on-machine measurement with AOI has been realized satisfactorily.

Deposition velocities to Sorbus aria, Acer campestre, Populus deltoides x trichocarpa 'Beaupre', Pinus nigra and x Cupressocyparis leylandii for coarse, fine and ultra-fine particles in the urban environment

International Nuclear Information System (INIS)

Freer-Smith, P.H.; Beckett, K.P.; Taylor, Gail

2005-01-01

Trees are effective in the capture of particles from urban air to the extent that they can significantly improve urban air quality. As a result of their aerodynamic properties conifers, with their smaller leaves and more complex shoot structures, have been shown to capture larger amounts of particle matter than broadleaved trees. This study focuses on the effects of particle size on the deposition velocity of particles (Vg) to five urban tree species (coniferous and broadleaved) measured at two field sites, one urban and polluted and a second more rural. The larger uptake to conifers is confirmed, and for broadleaves and conifers Vg values are shown to be greater for ultra-fine particles (Dp<1.0 μm) than for fine and coarse particles. This is important since finer particles are more likely to be deposited deep in the alveoli of the human lung causing adverse health effects. The finer particle fraction is also shown to be transported further from the emission source; in this study a busy urban road. In further sets of data the aqueous soluble and insoluble fractions of the ultra-fines were separated, indicating that aqueous insoluble particles made up only a small proportion of the ultra-fines. Much of the ultra-fine fraction is present as aerosol. Chemical analysis of the aqueous soluble fractions of coarse, fine and ultra-fine particles showed the importance of nitrates, chloride and phosphates in all three size categories at the polluted and more rural location

Preparation of Ultra-fine Calcium Carbonate by a Solvent-free ...

African Journals Online (AJOL)

The treatment of calcium chloride with sodium carbonate under solvent-free conditions with a supersonic airflow and at a low heating temperature leads to the synthesis of ultra-fine calcium carbonate. The reaction not only involves mild conditions, a simple operation, and high yields but also gives a high conversion rate.

Thermal insulator made of ultra fine particles of silica. Chobiryushi silica kei dannetsuzai

Energy Technology Data Exchange (ETDEWEB)

Eguchi, T.

1991-05-30

An overview was presented of properties and applications of thermal insulator made of ultra fine powder of silica, MICROTHERM. The thermal conductivity of MICROTHERM is as low as (1/3) - (1/4) of that of conventional thermal insulator, because it is mainly composed of fumed silica or aero gel and formed into porous structure. In addition, metal oxide of special particle size is added to it in order to reject the radiative heat. The thermal insulation property and the mechanical strength of MICROTHERM is not affected by a sudden change in temperature and moisture. The standard type of MICROTHERM can be used at a temperature up to 950 {degree}C, while the high temperature type MICROTHERM can stand a high temperature up to 1025 {degree}C for long period of time. The thickness of insulator can be reduced markedly by using MICROTHERM as compared with the use of conventional insulating materials. Many new products in which MICROTHERM is used came into market. New type kilt, Semi-cylindrical block, Super high temperature MICROTHERM are just a few examples. Variety of application and energy saving effect are attracting public attention. 11 figs.

Improvement of the electrochromic response of a low-temperature sintered dye-modified porous electrode using low-resistivity indium tin oxide nanoparticles

International Nuclear Information System (INIS)

Watanabe, Yuichi; Suemori, Kouji; Hoshino, Satoshi

2016-01-01

An indium tin oxide (ITO) nanoparticle-based porous electrode sintered at low temperatures was investigated as a transparent electrode for electrochromic displays (ECDs). The electrochromic (EC) response of the dye-modified ITO porous electrode sintered at 150 °C, which exhibited a generally low resistivity, was markedly superior to that of a conventional dye-modified TiO 2 porous electrode sintered at the same temperature. Moreover, the EC characteristics of the dye-modified ITO porous electrode sintered at 150 °C were better than those of the high-temperature (450 °C) sintered conventional dye-modified TiO 2 porous electrode. These improvements in the EC characteristics of the dye-modified ITO porous electrode are attributed to its lower resistivity than that of the TiO 2 porous electrodes. In addition to its sufficiently low resistivity attained under the sintering conditions required for flexible ECD applications, the ITO porous film had superior visible-light transparency and dye adsorption capabilities. We conclude that the process temperature, resistivity, optical transmittance, and dye adsorption capability of the ITO porous electrode make it a promising transparent porous electrode for flexible ECD applications.

Formation of ultra-fine grained SUS316L steels by ball-milling and their mechanical properties after neutron irradiation

International Nuclear Information System (INIS)

Zheng, Y.J.; Yamasaki, T.; Fukami, T.; Terasawa, M.; Mitamura, T.

2003-01-01

In order to overcome the irradiation embrittlement in austenitic stainless steels, ultra-fine grained SUS316L steels with very fine TiC particles have been developed. The SUS316L-TiC nanocomposite powders having 1.0 to 2.0 mass% TiC were prepared by ball-milling SUS316L-TiC powder mixtures for 125 h in an argon gas atmosphere. The milled powders were consolidated by hot isostatic pressing (HIP) under a pressure of 200 MPa at temperatures between 700 and 1000 C, and the bulk materials with grain sizes between 100 and 400 nm have been produced. The possibility of using fine-grained TiC particles to pin grain boundaries and thereby maintain the ultra-fine grained structures has been discussed. In order to clarify the effects of the neutron irradiation on mechanical properties of the ultra-fine grained SUS316L steels, Vickers microhardness measurements were performed before and after the irradiation of 1.14 x 10 23 n/m 2 and 1.14 x 10 24 n/m 2 . The hardness increased with increasing the dose of the irradiation. However, these increasing rates of the ultra-fine grained steels were much smaller than those of the coarse-grained SUS316L steels having grain sizes between 13 and 50 μm. (orig.)

Effect of shot peening using ultra-fine particles on fatigue properties of 5056 aluminum alloy under rotating bending

Energy Technology Data Exchange (ETDEWEB)

Kikuchi, Shoichi, E-mail: kikuchi@mech.kobe-u.ac.jp [Department of Mechanical Engineering, Graduate School of Engineering, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe-shi, Hyogo 657-8501 (Japan); Nakamura, Yuki [Department of Mechanical Engineering, National Institute of Technology, Toyota College, 2-1 Eisei-cho, Toyota-shi, Aichi 471-8525 (Japan); Nambu, Koichiro [Department of Mechanical Engineering, National Institute of Technology, Suzuka College, Shiroko-cho, Suzuka-shi, Mie 510-0294 (Japan); Ando, Masafumi [Innovation Team, IKK SHOT Co. Ltd., 412-4, Nunowari, Minami-Shibata-machi, Tokai-shi, Aichi 476-0001 (Japan)

2016-01-15

Shot peening using particles 10 μm in diameter (ultra-fine particle peening: Ultra-FPP) was introduced to improve the fatigue properties of 5056 aluminum alloy. The surface microstructures of the Ultra-FPP treated specimens were characterized using a micro-Vickers hardness tester, scanning electron microscopy (SEM), X-ray diffraction (XRD), non-contact scanning white light interferometry, and electron backscatter diffraction (EBSD). The Ultra-FPP treated specimen had higher hardness than the conventional FPP treated specimen with a short nozzle distance due to the high velocity of the ultra-fine particles. Furthermore, the surface hardness of the Ultra-FPP treated specimen tended to increase as the peening time decreased. Fatigue tests were performed in air at room temperature using a cantilever-type rotating bending fatigue testing machine. It was found that the fatigue life of the Ultra-FPP treated specimen tended to increase with decreasing peening time. Mainly, the Ultra-FPP improved the fatigue properties of 5056 aluminum alloy in the very high cycle regime of more than 10{sup 7} cycles compared with the un-peened specimens. This is because the release of the compressive residual stress is small during fatigue tests at low stress amplitudes.

New insights into the formation and resolution of ultra-fine anaphase bridges

DEFF Research Database (Denmark)

Chan, Kok Lung; Hickson, Ian D

2011-01-01

that are important for preventing Fanconi anemia (FA) in man. As part of an analysis of the roles of these proteins in mitosis, we identified a novel class of anaphase bridge structure, called an ultra-fine anaphase bridge (UFB). These UFBs are also defined by the presence of a SNF2 family protein called PICH...

Nanofiber Anisotropic Conductive Films (ACF) for Ultra-Fine-Pitch Chip-on-Glass (COG) Interconnections

Science.gov (United States)

Lee, Sang-Hoon; Kim, Tae-Wan; Suk, Kyung-Lim; Paik, Kyung-Wook

2015-11-01

Nanofiber anisotropic conductive films (ACF) were invented, by adapting nanofiber technology to ACF materials, to overcome the limitations of ultra-fine-pitch interconnection packaging, i.e. shorts and open circuits as a result of the narrow space between bumps and electrodes. For nanofiber ACF, poly(vinylidene fluoride) (PVDF) and poly(butylene succinate) (PBS) polymers were used as nanofiber polymer materials. For PVDF and PBS nanofiber ACF, conductive particles of diameter 3.5 μm were incorporated into nanofibers by electrospinning. In ultra-fine-pitch chip-on-glass assembly, insulation was significantly improved by using nanofiber ACF, because nanofibers inside the ACF suppressed the mobility of conductive particles, preventing them from flowing out during the bonding process. Capture of conductive particles was increased from 31% (conventional ACF) to 65%, and stable electrical properties and reliability were achieved by use of nanofiber ACF.

An ultra-fine group slowing down benchmark

International Nuclear Information System (INIS)

Ganapol, B. D.; Maldonado, G. I.; Williams, M. L.

2009-01-01

We suggest a new solution to the neutron slowing down equation in terms of multi-energy panels. Our motivation is to establish a computational benchmark featuring an ultra-fine group calculation, where the number of groups could be on the order of 100,000. While the CENTRM code of the SCALE code package has been shown to adequately treat this many groups, there is always a need for additional verification. The multi panel solution principle is simply to consider the slowing down region as sub regions of panels, with each panel a manageable number of groups, say 100. In this way, we reduce the enormity of dealing with the entire spectrum all at once by considering many smaller problems. We demonstrate the solution in the unresolved U3o8 resonance region. (authors)

Impact of superplasticizer concentration and of ultra-fine particles on the rheological behaviour of dense mortar suspensions

International Nuclear Information System (INIS)

Artelt, C.; Garcia, E.

2008-01-01

This work aims at investigating the impact of the addition of superplasticizer and of ultra-fine particles, namely of silica fume and of precipitated titania, on the rheological behaviour of water-lean mortar pastes. The pastes are characterised in terms of their spread, their flowing behaviour and by means of performing a shear test, giving access to viscosity/shear gradient correlations. Adding superplasticizer is shown to shift the onset of shear thickening of the referring pastes to higher shear rates and to attenuate its otherwise rapid evolution, possibly by means of favouring steric particle-particle interactions. The workability of these mortars, which is characterised in terms of spread values and draining, is also improved. For the case of fly ash based mortars, adding ultra-fine particles is another way of (slightly) 'retarding' shear thickening and of attenuating its evolution, possibly because of resulting in - on the average - lower hydrodynamic forces and reduced attractive Van der Waals interactions between particles. However, at the same time these mortars are characterised by a worsening in workability which is attributed to the huge amount of surface area provided by the ultra-fines

Development of ultra-fine grained W-TiC and their mechanical properties for fusion applications

Energy Technology Data Exchange (ETDEWEB)

Kurishita, H. [International Research Center for Nuclear Materials Science, Institute for Materials Research (IMR), Tohoku University, Oarai, Ibaraki 311-1313 (Japan)]. E-mail: kurishi@imr.tohoku.ac.jp; Amano, Y. [Department of Materials Science and Engineering, Ehime University, Matsuyama 790-8577 (Japan); Kobayashi, S. [Department of Materials Science and Engineering, Ehime University, Matsuyama 790-8577 (Japan); Nakai, K. [Department of Materials Science and Engineering, Ehime University, Matsuyama 790-8577 (Japan); Arakawa, H. [International Research Center for Nuclear Materials Science, Institute for Materials Research (IMR), Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Hiraoka, Y. [Okayama University of Science, 1-1 Ridai-cho, Okayama 700-0005 (Japan); Takida, T. [A.L.M.T. Corp., 2 Iwase-koshi-machi, Toyama 931-8371 (Japan); Takebe, K. [A.L.M.T. Corp., 2 Iwase-koshi-machi, Toyama 931-8371 (Japan); Matsui, H. [International Research Center for Nuclear Materials Science, Institute for Materials Research (IMR), Tohoku University, Oarai, Ibaraki 311-1313 (Japan)

2007-08-01

Effects of neutron irradiation on microstructural evolution and radiation hardening were examined for fine-grained W-0.3 wt%TiC (grain size of 0.9 {mu}m) and commercially available pure W (20 {mu}m). Both materials were neutron irradiated at 563 K to 9 x 10{sup 23} n/m{sup 2} (E > 1 MeV) in the Japan Materials Testing Reactor (JMTR). Post-irradiation examinations showed that the microstructural changes and the degree of hardening due to irradiation were significantly reduced for fine-grained W-0.3TiC compared with pure W, demonstrating the significance of grain refinement to improve radiation resistance. In order to develop ultra-fine grained W-TiC compacts with nearly full densification, the fabrication process was modified, so that W-(0.3-0.7)%TiC with 0.06-0.2 {mu}m grain size and 99% of relative density was fabricated. The achievable grain refinement depended on TiC content and milling atmosphere. The three-point bending fracture strength at room temperature for ultra-fine grained W-TiC compacts of powder milled in H{sub 2} reached approximately 1.6-2 GPa for composition near 0.5%TiC.

Ultra-high mechanical properties of porous composites based on regenerated cellulose and cross-linked poly(ethylene glycol).

Science.gov (United States)

Teng, Jian; Yang, Biao; Zhang, Liang-Qing; Lin, Sheng-Qiang; Xu, Ling; Zhong, Gan-Ji; Tang, Jian-Hua; Li, Zhong-Ming

2018-01-01

The ultra-high mechanical, biocompatible and biodegradable porous regenerated cellulose/poly(ethylene glycol) (RC/PEG) composites with double network structure were fabricated via an simple method to dissolve cellulose followed by UV irradiation. The porous structure of RC/PEG was sensitively altered by PEG contents, which led to the porous structure morphology transition from 3D fibrillar network to close-grained sheet-like-network with the loading of cross-linked PEG. The porous RC/PEG showed excellent mechanical properties, i.e., the compressive strength can reach 33 times higher than that of neat RC (0.07MPa) at the compressive strain of 30%. Porous RC/PEG also displayed outstanding properties with openly porous structure and structural stabilization. Besides, porous RC/PEG exhibited good water absorbency, which the water absorbency ratio at equilibrium state was 83% higher than that of porous RC. This work provides an environmentally friendly and simple pathway to prepare non-toxic and biocompatible porous regenerated cellulose-based composites with high strength, structural stabilization and good water absorbency, which could be useful for packaging, biomedical applications, sewage purification, etc. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ultra fine grained Ti prepared by severe plastic deformation

Science.gov (United States)

Lukáč, F.; Čížek, J.; Knapp, J.; Procházka, I.; Zháňal, P.; Islamgaliev, R. K.

2016-01-01

The positron annihilation spectroscopy was employed for characterisation of defects in pure Ti with ultra fine grained (UFG) structure. UFG Ti samples were prepared by two techniques based on severe plastic deformation (SPD): (i) high pressure torsion (HPT) and (ii) equal channel angular pressing (ECAP). Although HPT is the most efficient technique for grain refinement, the size of HPT-deformed specimens is limited. On the other hand, ECAP is less efficient in grain refinement but enables to produce larger samples more suitable for industrial applications. Characterisation of defects by positron annihilation spectroscopy was accompanied by hardness testing in order to monitor the development of mechanical properties of UFG Ti.

Study on influences of TiN capping layer on time-dependent dielectric breakdown characteristic of ultra-thin EOT high- k metal gate NMOSFET with kMC TDDB simulations

International Nuclear Information System (INIS)

Xu Hao; Yang Hong; Luo Wei-Chun; Xu Ye-Feng; Wang Yan-Rong; Tang Bo; Wang Wen-Wu; Qi Lu-Wei; Li Jun-Feng; Yan Jiang; Zhu Hui-Long; Zhao Chao; Chen Da-Peng; Ye Tian-Chun

2016-01-01

The thickness effect of the TiN capping layer on the time dependent dielectric breakdown (TDDB) characteristic of ultra-thin EOT high- k metal gate NMOSFET is investigated in this paper. Based on experimental results, it is found that the device with a thicker TiN layer has a more promising reliability characteristic than that with a thinner TiN layer. From the charge pumping measurement and secondary ion mass spectroscopy (SIMS) analysis, it is indicated that the sample with the thicker TiN layer introduces more Cl passivation at the IL/Si interface and exhibits a lower interface trap density. In addition, the influences of interface and bulk trap density ratio N it / N ot are studied by TDDB simulations through combining percolation theory and the kinetic Monte Carlo (kMC) method. The lifetime reduction and Weibull slope lowering are explained by interface trap effects for TiN capping layers with different thicknesses. (paper)

Administration of Oxygen Ultra-Fine Bubbles Improves Nerve Dysfunction in a Rat Sciatic Nerve Crush Injury Model

Directory of Open Access Journals (Sweden)

Hozo Matsuoka

2018-05-01

Full Text Available Ultra-fine bubbles (<200 nm in diameter have several unique properties and have been tested in various medical fields. The purpose of this study was to investigate the effects of oxygen ultra-fine bubbles (OUBs on a sciatic nerve crush injury (SNC model rats. Rats were intraperitoneally injected with 1.5 mL saline, OUBs diluted in saline, or nitrogen ultra-fine bubbles (NUBs diluted in saline three times per week for 4 weeks in four groups: (1 control, (sham operation + saline; (2 SNC, (crush + saline; (3 SNC+OUB, (crush + OUB-saline; (4 SNC+NUB, (crush + NUB-saline. The effects of the OUBs on dorsal root ganglion (DRG neurons and Schwann cells (SCs were examined by serial dilution of OUB medium in vitro. Sciatic functional index, paw withdrawal thresholds, nerve conduction velocity, and myelinated axons were significantly decreased in the SNC group compared to the control group; these parameters were significantly improved in the SNC+OUB group, although NUB treatment did not affect these parameters. In vitro, OUBs significantly promoted neurite outgrowth in DRG neurons by activating AKT signaling and SC proliferation by activating ERK1/2 and JNK/c-JUN signaling. OUBs may improve nerve dysfunction in SNC rats by promoting neurite outgrowth in DRG neurons and SC proliferation.

The Radiation Synthesis of Ultra-Fine Powdered Carboxylated Styrene-Butadiene Rubber (UFCSBR) and Property of Nylon 6/ UFCSBR Blends

International Nuclear Information System (INIS)

Xu, L.

2006-01-01

A serial of novel ultra-fine powdered carboxylated styrene-butadiene rubber (UFCSBR) were prepared by using radiation crosslinking and spray drying method. Thereafter, these powdered rubber particles were used as toughener of nylon 6.The radiation synthesis of ultra-fine powdered rubbers were studied, moreover, the mechanical and thermal property of nylon 6/UFCSBR blends were investigated. Finally, the toughening mechanism of nylon 6 modified with ultra-fine rubber particles was discussed. The UFCSBR could be dispersed well in nylon 6 as individual particles with a diameter of 150 nm by using melt blending. The Nylon 6/UFCSBR (80/20) blend possesses higher toughness and higher thermal stability than Nylon 6/POE-g-MAH (which is most often used elastomer in toughening nylon now). The deformation mechanism of nylon 6/UFCSBR blends includes shear deformation of nylon 6 and the formation of elongated rubber particles in matrix. In addition, the UFCSBR has good interfacial compatibility with nylon 6. Therefore, the nylon 6/UFCSBR blends with good mechanical performance could be prepared in this work

Formation of ultra-fine grained TiC-dispersed SUS316L by ball-milling and their consolidation by hot isostatic pressing

International Nuclear Information System (INIS)

Zheng, Yongjia; Yamasaki, Tohru; Fukami, Takeshi; Mitamura, Tohru; Terasawa, Mititaka

2003-01-01

In order to overcome the irradiation embrittlement in austenitic stainless steels, ultra-fine grained SUS316L steels with very fine TiC particles have been developed. The SUS316-TiC nanocomposite powders having 1.0 to 2.0 mass%TiC were prepared by ball-milling SUS316-TiC powder mixtures for 125h in an argon gas atmosphere. The milled powders were consolidated by hot isostatic pressing (HIP) under a pressure of 200 MPa at temperature between 700-1000degC, and the bulk materials with crystallite size ranging between 100-400 nm have been produced. The possibility of using fine-grained TiC particles for pinning grain boundaries and thereby to maintain the ultra-fine grained structures has been discussed. (author)

Study of reduction permeability for deposit of fine particles and bacteria in porous media

International Nuclear Information System (INIS)

Restrepo Restrepo, Dora Patricia; Cardona Bernal, Felipe Andres; Usta Diaz, Martha Lucia

2004-01-01

This work shows a theoretical and practical description of the main variables and physical principles that lead to the obstruction by fine particles and therefore a reduction in permeability for unconsolidated porous media with almost a length foot. The results were also adjusted to theoretical model for the obstruction by fine particles in the entrance face. A first study about bacteria plugging was also carried out in order to try to understand it when these bacteria are in the water of injection of a normal process of water flooding

Thin porous indium tin oxide nanoparticle films: effects of annealing in vacuum and air

International Nuclear Information System (INIS)

Ederth, J.; Hultaaker, A.; Niklasson, G.A.; Granqvist, C.G.; Heszler, P.; Doorn, A.R. van; Jongerius, M.J.; Burgard, D.

2005-01-01

Electrical and optical properties were investigated in porous thin films consisting of In 2 O 3 :Sn (indium tin oxide; ITO) nanoparticles. The temperature-dependent resistivity was successfully described by a fluctuation-induced tunneling model, indicating a sample morphology dominated by clusters of ITO nanoparticles separated by insulating barriers. An effective-medium model, including the effect of ionized impurity scattering, was successfully fitted to measured reflectance and transmittance. Post-deposition treatments were carried out at 773 K for 2 h in both air and vacuum. It is shown that vacuum annealing increases either the barrier width or the area between two conducting clusters in the samples and, furthermore, an extra optical absorption occurs close to the band gap. A subsequent air annealing then reduces the effect of the barriers on the electrical properties and diminishes the absorption close to the band gap. (orig.)

Elevated temperature mechanical properties of novel ultra-fine grained Cu–Nb composites

Energy Technology Data Exchange (ETDEWEB)

Primorac, Mladen-Mateo [Department of Materials Physics, Montanuniversität Leoben (Austria); Abad, Manuel David; Hosemann, Peter [Department of Nuclear Engineering, University of California, Berkeley (United States); Kreuzeder, Marius [Department of Materials Physics, Montanuniversität Leoben (Austria); Maier, Verena [Department of Materials Physics, Montanuniversität Leoben (Austria); Erich-Schmid Institute for Materials Science, Austrian Academy of Sciences, Leoben (Austria); Kiener, Daniel, E-mail: daniel.kiener@unileoben.ac.at [Department of Materials Physics, Montanuniversität Leoben (Austria)

2015-02-11

Ultra-fine grained materials exhibit outstanding properties and are therefore favorable for prospective applications. One of these promising systems is the composite assembled by the body centered cubic niobium and the face centered cubic copper. Cu–Nb composites show a high hardness and good thermal stability, as well as a high radiation damage tolerance. These properties make the material interesting for use in nuclear reactors. The aim of this work was to create a polycrystalline ultra-fine grained composite for high temperature applications. The samples were manufactured via a powder metallurgical route using high pressure torsion, exhibiting a randomly distributed oriented grain size between 100 and 200 nm. The mechanical properties and the governing plastic deformation behavior as a function of temperature were determined by high temperature nanoindentation up to 500 °C. It was found that in the lower temperature regions up to 300 °C the plastic deformation is mainly governed by dislocation interactions, such as dislocation glide and the nucleation of kink pairs. For higher temperatures, thermally activated processes at grain boundaries are proposed to be the main mechanism governing plastic deformation. This mechanistic view is supported by temperature dependent changes in hardness, strain rate sensitivity, activation volume, and activation energy.

Porous screen printed indium tin oxide (ITO) for NOx gas sensing

International Nuclear Information System (INIS)

Mbarek, H.; Saadoun, M.; Bessais, B.

2007-01-01

Tin-doped Indium Oxide (ITO) films were prepared by the screen printing method. Transparent and conductive ITO thin films were obtained from an organometallic based paste fired in an Infrared furnace. The Screen printed ITO films were found to be granular and porous. This specific morphology was found to be suitable for sensing different gaseous species. This work investigates the possibility of using screen printed (ITO) films as a specific material for efficient NO x gas sensing. It was found that screen printed ITO is highly sensitive and stable towards NO x , especially for gas concentration higher than 50 ppm and starting from a substrate working temperature of about 180 C. The sensitivity of the ITO films increases with increasing NO x concentration and temperature. The sensitivity and stability of the screen printed ITO based sensors were studied within time. The ITO crystallite grain size dimension was found to be a key parameter that influences the gas response characteristics. Maximum gas sensitivity and minimum response time were observed for ITO films having lower crystallite size dimensions. (copyright 2007 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

Comparative study of Ta, TaN and Ta/TaN bi-layer barriers for Cu-ultra low-k porous polymer integration

International Nuclear Information System (INIS)

Yang, L.Y.; Zhang, D.H.; Li, C.Y.; Foo, P.D.

2004-01-01

Tantalum (Ta), TaN and bilayer Ta/TaN barriers deposited on ultra-low-k porous polymer (ULKPP) and the thermal stability of their structures are comparatively investigated using various techniques. The Ta/ultra-low-k polymer shows the smallest sheet resistance, but the poorest thermal stability, while TaN on the ultra-low-k polymer shows the highest resistance but the best thermal stability. The bi-layer Ta/TaN barrier takes the advantage of both Ta and TaN barriers and gives reasonable resistance and thermal stability. The electrical tests indicate that the Cu lines with the TaN and bi-layer Ta/TaN barriers exhibit the smaller leakage current and higher breakdown voltage compared with the Cu lines with the Ta barrier. The better thermal stability of the TaN and the bi-layer Ta/TaN barriers is mainly due to the amorphous/nanostructure and less grain boundaries of the barriers. In addition, the texture discontinuity at the Ta/TaN interfaces in the bi-layers barrier also plays an important role in reducing mutual diffusion of Ta atoms in the Ta barrier and some atoms in the ultra-low-k porous polymer

Hierarchically porous, ultra-strong reduced graphene oxide-cellulose nanocrystal sponges for exceptional adsorption of water contaminants

DEFF Research Database (Denmark)

Yousefi, Nariman; Wong, Kerwin K.W.; Hosseinidoust, Zeinab

2018-01-01

Self-assembly of graphene oxide (GO) nanosheets into porous 3D sponges is a promising approach to exploit their capacity to adsorb contaminants while facilitating the recovery of the nanosheets from treated water. Yet, forming mechanically robust sponges with suitable adsorption properties presents...... a significant challenge. Ultra-strong and highly porous 3D sponges are formed using GO, vitamin C (VC), and cellulose nanocrystals (CNCs) - natural nanorods isolated from wood pulp. CNCs provide a robust scaffold for the partially reduced GO (rGO) nanosheets resulting in an exceptionally stiff nanohybrid....... The concentration of VC as a reducing agent plays a critical role in tailoring the pore architecture of the sponges. By using excess amounts of VC, a unique hierarchical pore structure is achieved, where VC grains act as soft templates for forming millimeter-sized pores, the walls of which are also porous...

Amenability of some Witbank bituminous ultra fine coals to binderless briquetting

CSIR Research Space (South Africa)

Mangena, SJ

2004-10-15

Full Text Available and briquetting Each of the Witbank ultra fine coals was air-dried and subsequently split into five homogeneous portions of 5 kg, respectively. Four portions from each sample were physically wetted to ca. 5%, 10%, 15% and 20% H2O, automatically mixed for 15 min... and long-distance haulage in uncovered trucks during the rainy season. In terms of compressive strength, the SJM1 coal studied was amenable to conventional binderless briquetting. 3.1.2. SJM2 coal The effect of moisture on the compressive strength...

The effect of the presence of fine YSZ particles on the performance of porous nickel electrodes

NARCIS (Netherlands)

de Boer, B.; de Boer, B.; Gonzalez, M.; Gonzalez Cuenca, M.M.; Bouwmeester, Henricus J.M.; Verweij, H.

2000-01-01

The electrochemical performance of a porous nickel electrode with its surface modified by deposition with fine yttria-stabilised zirconia (YSZ) powder is compared with that of the ‘bare’ electrode. Image analysis of the electrode microstructure yields values for the triple phase boundary (TPB)

Porous carbon with small mesoporesas an ultra-high capacity adsorption medium

Science.gov (United States)

Gao, Biaofeng; Zhou, Haitao; Chen, De; Yang, Jianhong

2017-10-01

Resins (732-type), abundant and inexpensive resources were used to prepare porous carbon with small mesopores (CSM) by carbonization and post-chemical-activation with potassium hydroxide (KOH). The N2 adsorption measurements revealed that CSM had high surface areas (1776.5 m2 g-1), large pore volumes (1.10 cm3 g-1), and nearly optimal narrow small mesopore sizes ranging from 2 to 7 nm. CSM was used as adsorbent to investigate the adsorption behavior for Rhodamine B (RhB). Due to the optimal pore size distributions (PSD), intensive-stacking interaction, S-doped, and electrostatic attraction, the CSM exhibited an ultra-high-capacity of 1590 mg g-1 for RhB in aqueous solutions.

Functionalized ultra-porous titania nanofiber membranes as nuclear waste separation and sequestration scaffolds for nuclear fuels recycle.

Energy Technology Data Exchange (ETDEWEB)

Liu, Haiqing; Bell, Nelson S; Cipiti, Benjamin B.; Lewis, Tom Goslee,; Sava, Dorina Florentina; Nenoff, Tina Maria

2012-09-01

Advanced nuclear fuel cycle concept is interested in reducing separations to a simplified, one-step process if possible. This will benefit from the development of a one-step universal getter and sequestration material so as a simplified, universal waste form was proposed in this project. We have developed a technique combining a modified sol-gel chemistry and electrospinning for producing ultra-porous ceramic nanofiber membranes with controllable diameters and porous structures as the separation/sequestration materials. These ceramic nanofiber materials have been determined to have high porosity, permeability, loading capacity, and stability in extreme conditions. These porous fiber membranes were functionalized with silver nanoparticles and nanocrystal metal organic frameworks (MOFs) to introduce specific sites to capture gas species that are released during spent nuclear fuel reprocessing. Encapsulation into a durable waste form of ceramic composition was also demonstrated.

Development and manufacture of ultra-fine NbTi filament wires at ALSTHOM

International Nuclear Information System (INIS)

Hoang, G.K.; Laumond, Y.; Sabrie, J.L.; Dubots, P.

1986-01-01

Ultra-fine NbTi filament wires have been developed and manufactured by ALSTHOM. It is now possible to produce industrial copper -copper-nickel matrix wires with 0.6 mu m NbTi filaments for use in 50 / 60 Hz machines. Smaller filaments with diameters down to 0.08 mu m have been obtained with 254 100 filament wire samples. Studies are now being carried out on copper matrix conductors to reduce the filament diameter. The first results show that it is possible to obtain submicron filaments even in copper matrix wires

Influence of high volumes of ultra-fine additions on self-compacting concrete[ACI SP-239

Energy Technology Data Exchange (ETDEWEB)

Cioffi, R. [Naples Univ., Naples (Italy). Faculty of Engineering; Colangelo, F. [Naples Univ., Naples (Italy). Dept. of Technologies; Caputo, D.; Liguori, B. [Naples Univ., Naples (Italy). Dept. of Materials and Production Engineering

2006-07-01

The addition of fine minerals can reduce water demand and increase the slump characteristics of concrete. This paper examined the influence of high volumes of ultra-fine fly ash, raw fly ash, silica fume and natural zeolites on the properties of self-compacting concrete (SCC). Three samples of SCC were prepared using various mineral additions to determine normal slump and J-ring slump flows of fresh concrete as well as the compressive strength and elastic modulus properties of hardened concrete. Cement and crushed limestone natural aggregates were used. The fly ash, silica fume and natural zeolites were subjected to wet high energy milling. The rotating speed, milling time, water-to-solid ratio, and size of milling media were optimized to obtain powders with varying qualities. Results of the study showed that values for the normal slump flow ranged between 604 and 785 mm, while the differences with the J-ring slump flow were less than 30 mm. The samples were then tested to evaluate the mechanical properties of the hardened concrete after 7 and 28 curing days. The modulus of elasticity and compressive strength showed improvements in the concretes containing the ultra-fine fly ash. No segregation phenomena were observed in the case of the cylindrical column specimens. It was concluded that all the specimens provided environmentally sustainable, high workability concretes which can be successfully prepared with the addition of high volumes of minerals. 17 refs., 5 tabs., 6 figs.

High temperature mechanical properties on multi stage blazed fin body with ultra fine off-set fin for compact heat exchanger

International Nuclear Information System (INIS)

Ishiyama, Shintaro; Muto, Yasushi

2003-01-01

Three stage blazed plate fin body with ultra fine off-set fin (thickness x height x pitch x off-set pitch = 0.22 mm x 1.2 mm x 1.6 mm x 5 mm) for 600 MWt High Temperature Gas Cooled Reactor Gas Turbin (HTGR-GT) system was fabricated and tested on its high temperature mechanical properties and the following results were derived. (1) tested body shows almost the same strength an fatigue behavior of SUS 304 as main structural material at elevated temperatures up to 873 K, (2) static and fatigue fracture mainly occurred at ultra fine off-set and (3) high temperature strength and fatigue life are improved by blazing technique to double side walls of the fin by Ni blaze material. (author)

Preparation of ultra-fine calcium carbonate by a solvent-free reaction using supersonic airflow and low temperatures

OpenAIRE

Cai, Yan-Hua; Ma, Dong-Mei; Peng, Ru-Fang; Chu, Shi-Jin

2008-01-01

The treatment of calcium chloride with sodium carbonate under solvent-free conditions with a supersonic airflow and at a low heating temperature leads to the synthesis of ultra-fine calcium carbonate. The reaction not only involves mild conditions, a simple operation, and high yields but also gives a high conversion rate.

Sulfur X-ray absorption fine structure in porous Li–S cathode films measured under argon atmospheric conditions

International Nuclear Information System (INIS)

Müller, Matthias; Choudhury, Soumyadip; Gruber, Katharina; Cruz, Valene B.; Fuchsbichler, Bernd; Jacob, Timo; Koller, Stefan; Stamm, Manfred; Ionov, Leonid; Beckhoff, Burkhard

2014-01-01

In this paper we present the first results for the characterization of highly porous cathode materials with pore sizes below 1 μm for Lithium Sulfur (Li–S) batteries by Near Edge X-ray Absorption Fine Structure (NEXAFS) spectroscopy. A novel cathode material of porous carbon films fabricated with colloidal array templates has been investigated. In addition, an electrochemical characterization has been performed aiming on an improved correlation of physical and chemical parameters with the electrochemical performance. The performed NEXAFS measurements of cathode materials allowed for a chemical speciation of the sulfur content inside the cathode material. The aim of the presented investigation was to evaluate the potential of the NEXAFS technique to characterize sulfur in novel battery material. The long term goal for the characterization of the battery materials is the sensitive identification of undesired side reactions, such as the polysulfide shuttle, which takes place during charging and discharging of the battery. The main drawback associated with the investigation of these materials is the fact that NEXAFS measurements can usually only be performed ex situ due to the limited in situ instrumentation being available. For Li–S batteries this problem is more pronounced because of the low photon energies needed to study the sulfur K absorption edge at 2472 eV. We employed 1 μm thick Si 3 N 4 windows to construct sealed argon cells for NEXAFS measurements under ultra high vacuum (UHV) conditions as a first step towards in situ measurements. The cells keep the sample under argon atmosphere at any time and the X-ray beam passes mainly through vacuum which enables the detection of the low energy X-ray emission of sulfur. Using these argon cells we found indications for the presence of lithium polysulfides in the cathode films whereas the correlations to the offline electrochemical results remain somewhat ambiguous. As a consequence of these findings one may

Determination of permeability of ultra-fine cupric oxide aerosol through military filters and protective filters

Science.gov (United States)

Kellnerová, E.; Večeřa, Z.; Kellner, J.; Zeman, T.; Navrátil, J.

2018-03-01

The paper evaluates the filtration and sorption efficiency of selected types of military combined filters and protective filters. The testing was carried out with the use of ultra-fine aerosol containing cupric oxide nanoparticles ranging in size from 7.6 nm to 299.6 nm. The measurements of nanoparticles were carried out using a scanning mobility particle sizer before and after the passage through the filter and a developed sampling device at the level of particle number concentration approximately 750000 particles·cm-3. The basic parameters of permeability of ultra-fine aerosol passing through the tested material were evaluated, in particular particle size, efficiency of nanoparticle capture by filter, permeability coefficient and overall filtration efficiency. Results indicate that the military filter and particle filters exhibited the highest aerosol permeability especially in the nanoparticle size range between 100–200 nm, while the MOF filters had the highest permeability in the range of 200 to 300 nm. The Filter Nuclear and the Health and Safety filter had 100% nanoparticle capture efficiency and were therefore the most effective. The obtained measurement results have shown that the filtration efficiency over the entire measured range of nanoparticles was sufficient; however, it was different for particular particle sizes.

Ultra-Fine Friction Grinding of Sunflower Kernels – Thereof Tahini and Halva Production and Rheological Characterization

Directory of Open Access Journals (Sweden)

Emil RACOLŢA

2016-11-01

Full Text Available Tahini is a paste obtained by milling the roasted sunflower kernel. Usually, a time and energy consuming two-steps process is involved, a three-roll refiner and a beating machine. The aim of this work was to identify and test a milling process for roasted sunflower kernels with lower time and energy consumption. Different particle size sunflower tahini and halva samples were produced by Ultra-Fine Friction Grinding machine Masuko Sangyo “Supermasscolloider” MKCA6-2 and compared to standard technology. The rheological properties of tahini and textural parameters of halva were assessed. Rheological analysis revealed that all tahini samples produced by “Supermasscolloider” showed a different viscosity profile, as compared to control, the sample milled with the gap set at 100µm being the most viscous and the one at 200µm being the most fluid. When testing the halva samples texture, the sample obtained from the tahini milled at 200µm was clearly highlighted as having the lowest hardness values, while the other samples showed similar texture profiles. The feasibility of using an Ultra-Fine Friction Grinding machine for obtaining sunflower tahini and thereof halva with improved textural properties, was assessed successfully.

Performance assessment of river sand versus ceramic grinding media on the Fimiston Ultra-fine Grinding application

International Nuclear Information System (INIS)

Blake, Guillaume; Clermont, Benoit; Gianatti, Christopher

2012-01-01

Ultra-fine grinding increases the amenability of the refractory concentrate to direct cyanide leaching. Low cost media such as silica river sand gives very fine product grind sizes, however the sand media is quite angular and is often supplied with a broad size distribution. It is generally accepted that the use of a ceramic grinding media will result in a finer product size or allow an increase in the mill throughput. The capacity of a mill is known to increase with decreasing grinding media diameter, the mill wear can be decreased and efficiency of grinding increased. Magotteaux Keramax-MTX Ceramic grinding media was purchased for a plant trial, to assess its' performance.

Improvement of transistor characteristics and stability for solution-processed ultra-thin high-valence niobium doped zinc-tin oxide thin film transistors

Energy Technology Data Exchange (ETDEWEB)

Jeng, Jiann-Shing, E-mail: jsjeng@mail.nutn.edu.tw

2016-08-15

Nb-doped Zinc tin oxide (NZTO) channel materials have been prepared by solution process in combination with the spin-coating method. All NZTO thin film transistors (TFTs) are n-type enhancement-mode devices, either without or with Nb additives. High-valence niobium ion (ionic charge = +5) has a larger ionic potential and similar ionic radius to Zn{sup 2+} and Sn{sup 4+} ions. As compared with the pure ZTO device, introducing Nb{sup 5+} ions into the ZTO channel layers can improve the electrical properties and bias stability of TFTs because of the reduction of the oxygen vacancies. This study discusses the connection among the material properties of the NZTO films and the electrical performance and bias stability of NZTO TFTs and how they are influenced by the Nb/(Nb + Sn) molar ratios of NZTO films. - Highlights: • Ultra-thin high-valence niobium doped zinc-tin oxide (NZTO) thin films are prepared using a solution process. • Nb dopants in ZTO films reduce the oxygen vacancy and subgap adsorption of the ZTO films. • The Nb-doping concentration of the NZTO channel layer has a strong influence on the TFT performance.

Luminescence properties of Si-containing porous matrix–PbS nanoparticle systems

International Nuclear Information System (INIS)

Tarasov, S. A.; Aleksandrova, O. A.; Lamkin, I. A.; Maksimov, A. I.; Maraeva, E. V.; Mikhailov, I. I.; Moshnikov, V. A.; Musikhin, S. F.; Nalimova, S. S.; Permyakov, N. V.; Spivak, Yu. M.; Travkin, P. G.

2015-01-01

The luminescence properties of systems that contain lead-sulfide nanoparticles deposited onto substrates fabricated from porous silicon, oxidized porous silicon, and porous (tin-oxide)–(silicon-oxide) layers are studied. It is shown that the structure and composition of the matrix induce a strong effect on the luminescence spectra of colloidal quantum dots, defining their emission wavelength

A multi-scale homogenization model for fine-grained porous viscoplastic polycrystals: II - Applications to FCC and HCP materials

Science.gov (United States)

Song, Dawei; Ponte Castañeda, P.

2018-06-01

In Part I of this work (Song and Ponte Castañeda, 2018a), a new homogenization model was developed for the macroscopic behavior of three-scale porous polycrystals consisting of random distributions of large pores in a fine-grained polycrystalline matrix. In this second part, the model is used to investigate both the instantaneous effective behavior and the finite-strain macroscopic response of porous FCC and HCP polycrystals for axisymmetric loading conditions. The stress triaxiality and Lode parameter are found to have significant effects on the evolution of the substructure, which in turn have important implications for the overall hardening/softening behavior of the porous polycrystal. The intrinsic effect of the texture evolution of the polycrystalline matrix is inferred by appropriate comparisons with corresponding results for porous isotropic materials, and found to be significant, especially at low triaxialities. In particular, the predictions of the model identify, for the first time, two disparate regimes for the macroscopic response of porous polycrystals: a porosity-controlled regime at high triaxialities, and a texture-controlled regime at low triaxialities. The transition between these two regimes is found to be quite sharp, taking place between triaxialities of 1 and 2.

Influence of Oxygen Concentration on the Performance of Ultra-Thin RF Magnetron Sputter Deposited Indium Tin Oxide Films as a Top Electrode for Photovoltaic Devices

Directory of Open Access Journals (Sweden)

Jephias Gwamuri

2016-01-01

Full Text Available The opportunity for substantial efficiency enhancements of thin film hydrogenated amorphous silicon (a-Si:H solar photovoltaic (PV cells using plasmonic absorbers requires ultra-thin transparent conducting oxide top electrodes with low resistivity and high transmittances in the visible range of the electromagnetic spectrum. Fabricating ultra-thin indium tin oxide (ITO films (sub-50 nm using conventional methods has presented a number of challenges; however, a novel method involving chemical shaving of thicker (greater than 80 nm RF sputter deposited high-quality ITO films has been demonstrated. This study investigates the effect of oxygen concentration on the etch rates of RF sputter deposited ITO films to provide a detailed understanding of the interaction of all critical experimental parameters to help create even thinner layers to allow for more finely tune plasmonic resonances. ITO films were deposited on silicon substrates with a 98-nm, thermally grown oxide using RF magnetron sputtering with oxygen concentrations of 0, 0.4 and 1.0 sccm and annealed at 300 °C air ambient. Then the films were etched using a combination of water and hydrochloric and nitric acids for 1, 3, 5 and 8 min at room temperature. In-between each etching process cycle, the films were characterized by X-ray diffraction, atomic force microscopy, Raman Spectroscopy, 4-point probe (electrical conductivity, and variable angle spectroscopic ellipsometry. All the films were polycrystalline in nature and highly oriented along the (222 reflection. Ultra-thin ITO films with record low resistivity values (as low as 5.83 × 10−4 Ω·cm were obtained and high optical transparency is exhibited in the 300–1000 nm wavelength region for all the ITO films. The etch rate, preferred crystal lattice growth plane, d-spacing and lattice distortion were also observed to be highly dependent on the nature of growth environment for RF sputter deposited ITO films. The structural, electrical

Controlling the competing magnetic anisotropy energies in FineMET amorphous thin films with ultra-soft magnetic properties

Directory of Open Access Journals (Sweden)

Ansar Masood

2017-05-01

Full Text Available Thickness dependent competing magnetic anisotropy energies were investigated to explore the global magnetic behaviours of FineMET amorphous thin films. A dominant perpendicular magnetization component in the as-deposited state of thinner films was observed due to high magnetoelastic anisotropy energy which arises from stresses induced at the substrate-film interface. This perpendicular magnetization component decreases with increasing film thickness. Thermal annealing at elevated temperature revealed a significant influence on the magnetization state of the FineMET thin films and controlled annealing steps leads to ultra-soft magnetic properties, making these thin films alloys ideal for a wide range of applications.

Fabrication of ultra-fine nanostructures using edge transfer printing.

Science.gov (United States)

Xue, Mianqi; Li, Fengwang; Cao, Tingbing

2012-03-21

The exploration of new methods and techniques for application in diverse fields, such as photonics, microfluidics, biotechnology and flexible electronics is of increasing scientific and technical interest for multiple uses over distance of 10-100 nm. This article discusses edge transfer printing--a series of unconventional methods derived from soft lithography for nanofabrication. It possesses the advantages of easy fabrication, low-cost and great serviceability. In this paper, we show how to produce exposed edges and use various materials for edge transfer printing, while nanoskiving, nanotransfer edge printing and tunable cracking for nanogaps are introduced. Besides this, different functional materials, such as metals, inorganic semiconductors and polymers, as well as localised heating and charge patterning, are described here as unconventional "inks" for printing. Edge transfer printing, which can effectively produce sub-100 nm scale ultra-fine structures, has broad applications, including metallic nanowires as nanoelectrodes, semiconductor nanowires for chemical sensors, heterostructures of organic semiconductors, plasmonic devices and so forth. This journal is © The Royal Society of Chemistry 2012

Acoustic Phonons and Mechanical Properties of Ultra-Thin Porous Low-k Films: A Surface Brillouin Scattering Study

Science.gov (United States)

Zizka, J.; King, S.; Every, A.; Sooryakumar, R.

2018-04-01

To reduce the RC (resistance-capacitance) time delay of interconnects, a key development of the past 20 years has been the introduction of porous low-k dielectrics to replace the traditional use of SiO2. Moreover, in keeping pace with concomitant reduction in technology nodes, these low-k materials have reached thicknesses below 100 nm wherein the porosity becomes a significant fraction of the film volume. The large degree of porosity not only reduces mechanical strength of the dielectric layer but also renders a need for non-destructive approaches to measure the mechanical properties of such ultra-thin films within device configurations. In this study, surface Brillouin scattering (SBS) is utilized to determine the elastic constants, Poisson's ratio, and Young's modulus of these porous low-k SiOC:H films (˜ 25-250 nm thick) grown on Si substrates by probing surface acoustic phonons and their dispersions.

A 2D Micromodel Study of Fines Migration and Clogging Behavior in Porous Media: Implications of Fines on Methane Extraction from Hydrate-Bearing Sediments

Science.gov (United States)

Cao, S. C.; Jang, J.; Waite, W. F.; Jafari, M.; Jung, J.

2017-12-01

Fine-grained sediment, or "fines," exist nearly ubiquitously in natural sediment, even in the predominantly coarse-grained sediments that host gas hydrates. Fines within these sandy sediments can play a crucial role during gas hydrate production activities. During methane extraction, several processes can alter the mobility and clogging potential of fines: 1) fluid flow as the formation is depressurized to release methane from hydrate; 2) pore-fluid chemistry shifts as pore-fluid brine freshens due to pure water released from dissociating hydrate; 3) the presence of a moving gas/water interface as gas evolves from dissociating hydrate and moves through the reservoir toward the production well. To evaluate fines migration and clogging behavior changes resulting from methane gas production and pore-water freshening during hydrate dissociation, 2D micromodel experiments have been conducted on a selection of pure fines, pore-fluids, and micromodel pore-throat sizes. Additionally, tests have been run with and without an invading gas phase (CO2) to test the significance of a moving meniscus on fines mobility and clogging. The endmember fine particles chosen for this research include silica silt, mica, calcium carbonate, diatoms, kaolinite, illite, and bentonite (primarily made of montmorillonite). The pore fluids include deionized water, sodium chloride brine (2M concentration), and kerosene. The microfluidic pore models, used as porous media analogs, were fabricated with pore-throat widths of 40, 60, and 100 µm. Results from this research show that in addition to the expected dependence of clogging on the ratio of particle-to-pore-throat size, pore-fluid chemistry is also a significant factor because the interaction between a particular type of fine and pore fluid influences that fine's capacity to cluster, clump together and effectively increase its particle "size" relative to the pore-throat width. The presence of a moving gas/fluid meniscus increases the clogging

Fine platinum nanoparticles supported on a porous ceramic membrane as efficient catalysts for the removal of benzene.

Science.gov (United States)

Liu, Hui; Li, Chengyin; Ren, Xiaoyong; Liu, Kaiqi; Yang, Jun

2017-11-29

It would be desirable to remove volatile organic compounds (VOCs) while we eliminate the dusts using silicon carbide (SiC)-based porous ceramics from the hot gases. Aiming at functionalizing SiC-based porous ceramics with catalytic capability, we herein report a facile strategy to integrate high efficient catalysts into the porous SiC substrates for the VOC removal. We demonstrate an aqueous salt method for uniformly distributing fine platinum (Pt) particles on the alumina (Al 2 O 3 ) layers, which are pre-coated on the SiC substrates as supports for VOC catalysts. We confirm that at a Pt mass loading as low as 0.176% and a weight hourly space velocity of 6000 mL g -1 h -1 , the as-prepared Pt/SiC@Al 2 O 3 catalysts can convert 90% benzene at a temperature of ca. 215 °C. The results suggest a promising way to design ceramics-based bi-functional materials for simultaneously eliminating dusts and harmful VOCs from various hot gases.

Elastocaloric effects in ultra-fine grained NiTi microwires processed by cold-drawing

Directory of Open Access Journals (Sweden)

Xuexi Zhang

2018-03-01

Full Text Available Efficient elastocaloric cooling in shape memory alloys requires a stable superelastic behavior in which high yield strength is needed. Here Ni50.4Ti49.6 microwires with diameter 130 μm and ultra-fine grains ∼30 nm were prepared by multi-step cold-drawing and low-temperature annealing. Enhanced cyclic stability of the elastocaloric effects induced by the superelastic training was demonstrated. The pre-trained microwire showed a stable ΔSe 43 J/(kg K with a broad working temperature range ΔT ∼ 70 K. The superelastic trained microwire, with giant and stable ΔSe over a wide working temperature window, may act as a promising elastocaloric cooling material for minor-sized devices.

Use of Unprocessed Coal Bottom Ash as Partial Fine Aggregate ...

African Journals Online (AJOL)

2012r

transportation applications such as structural fill, road base material, and as snow ... normal fine particles resulting in weak porous paste, modulus of elasticity is ..... with the porous structure and high absorptivity of fine particles of bottom ash.

Vacuum ultra-violet damage and damage mitigation for plasma processing of highly porous organosilicate glass dielectrics

Energy Technology Data Exchange (ETDEWEB)

Marneffe, J.-F. de, E-mail: marneffe@imec.be; Lukaszewicz, M.; Porter, S. B.; Vajda, F.; Rutigliani, V.; Verdonck, P.; Baklanov, M. R. [IMEC v.z.w., 3001 Leuven (Belgium); Zhang, L.; Heyne, M.; El Otell, Z.; Krishtab, M. [IMEC v.z.w., 3001 Leuven (Belgium); Department of Chemistry, KULeuven, 3001 Leuven (Belgium); Goodyear, A.; Cooke, M. [Oxford Instruments Plasma Technology, BS49 4AP Bristol (United Kingdom)

2015-10-07

Porous organosilicate glass thin films, with k-value 2.0, were exposed to 147 nm vacuum ultra-violet (VUV) photons emitted in a Xenon capacitive coupled plasma discharge. Strong methyl bond depletion was observed, concomitant with a significant increase of the bulk dielectric constant. This indicates that, besides reactive radical diffusion, photons emitted during plasma processing do impede dielectric properties and therefore need to be tackled appropriately during patterning and integration. The detrimental effect of VUV irradiation can be partly suppressed by stuffing the low-k porous matrix with proper sacrificial polymers showing high VUV absorption together with good thermal and VUV stability. In addition, the choice of an appropriate hard-mask, showing high VUV absorption, can minimize VUV damage. Particular processing conditions allow to minimize the fluence of photons to the substrate and lead to negligible VUV damage. For patterned structures, in order to reduce VUV damage in the bulk and on feature sidewalls, the combination of both pore stuffing/material densification and absorbing hard-mask is recommended, and/or the use of low VUV-emitting plasma discharge.

Tin

Science.gov (United States)

Kamilli, Robert J.; Kimball, Bryn E.; Carlin, James F.; Schulz, Klaus J.; DeYoung,, John H.; Seal, Robert R.; Bradley, Dwight C.

2017-12-19

Tin (Sn) is one of the first metals to be used by humans. Almost without exception, tin is used as an alloy. Because of its hardening effect on copper, tin was used in bronze implements as early as 3500 B.C. The major uses of tin today are for cans and containers, construction materials, transportation materials, and solder. The predominant ore mineral of tin, by far, is cassiterite (SnO2).In 2015, the world’s total estimated mine production of tin was 289,000 metric tons of contained tin. Total world reserves at the end of 2016 were estimated to be 4,700,000 metric tons. China held about 24 percent of the world’s tin reserves and accounted for 38 percent of the world’s 2015 production of tin.The proportion of scrap used in tin production is between 10 and 25 percent. Unlike many metals, tin recycling is relatively efficient, and the fraction of tin in discarded products that get recycled is greater than 50 percent.Only about 20 percent of the world’s identified tin resources occur as primary hydrothermal hard-rock veins, or lodes. These lodes contain predominantly high-temperature minerals and almost invariably occur in close association with silicic, peraluminous granites. About 80 percent of the world’s identified tin resources occur as unconsolidated secondary or placer deposits in riverbeds and valleys or on the sea floor. The largest concentration of both onshore and offshore placers is in the extensive tin belt of Southeast Asia, which stretches from China in the north, through Thailand, Burma (also referred to as Myanmar), and Malaysia, to the islands of Indonesia in the south. Furthermore, tin placers are almost always found closely allied to the granites from which they originate. Other countries with significant tin resources are Australia, Bolivia, and Brazil.Most hydrothermal tin deposits belong to what can be thought of as a superclass of porphyry-greisen deposits. The hydrothermal tin deposits are all characterized by a close spatial

State of the Art Power-in Tube Niobium-Tin Superconductors

Energy Technology Data Exchange (ETDEWEB)

Godeke, A.; Ouden, A. Den; Nijhuis, A.; ten Kate, H.H.J.

2008-06-01

Powder-in-Tube (PIT) processed Niobium-Tin wires are commercially manufactured for nearly three decades and have demonstrated a combination of very high current density (presently up to 2500 A mm{sup -2} non-Cu at 12 T and 4.2 K) with fine (35 {micro}m), well separated filaments. We review the developments that have led to the present state of the art PIT Niobium-Tin wires, discuss the wire manufacturing and A15 formation processes, and describe typical superconducting performance in relation to magnetic field and strain. We further highlight successful applications of PIT wires and conclude with an outlook on possibilities for further improvements in the performance of PIT Niobium-Tin wires.

Investigation of plasma etch damage to porous oxycarbosilane ultra low-k dielectric

International Nuclear Information System (INIS)

Bruce, R L; Engelmann, S; Purushothaman, S; Volksen, W; Frot, T J; Magbitang, T; Dubois, G; Darnon, M

2013-01-01

There has been much interest recently in porous oxycarbosilane (POCS)-based materials as the ultra-low k dielectric (ULK) in back-end-of-line (BEOL) applications due to their superior mechanical properties compared to traditional organosilicate-based ULK materials at equivalent porosity and dielectric constant. While it is well known that plasma etching and strip processes can cause significant damage to ULK materials in general, little has been reported about the effect of plasma damage to POCS as the ULK material. We investigated the effect of changing the gas discharge chemistry and substrate bias in the dielectric trench etch and also the subsequent effect of the cap-open etch on plasma damage to POCS during BEOL integration. Large differences in surface roughness and damage behaviour were observed by changing the fluorocarbon depositing conditions. These damage behaviour trends will be discussed and potential rationalizations offered based on the formation of pits and craters at the etch front that lead to surface roughness and microtrenching. (paper)

Porous TiNb2O7 Nanospheres as ultra Long-life and High-power Anodes for Lithium-ion Batteries

International Nuclear Information System (INIS)

Cheng, Qiushi; Liang, Jianwen; Lin, Ning; Guo, Cong; Zhu, Yongchun; Qian, Yitai

2015-01-01

Graphical abstract: Due to the combinative merits of porosity and nanostructure, porous TiNb 2 O 7 nanospheres exhibit ultra long cyclic life and excellent rate performance for lithium ion batteries. - Highlights: • Porous TiNb 2 O 7 nanospheres have been fabricated with the assistance of block copolymer P123. • The as-prepared TiNb 2 O 7 anodes present a reversible capacity of 160 mA h/g after 10000 cycles at 5 C with a capacity loss of only 0.0033% per cycle. • The TiNb 2 O 7 anodes show good rate performance of 167 mA h/g at 50C. • The TiNb 2 O 7 materials maintain the morphology of nanospheres and the porous structure even after 10000 cycles. - Abstract: Porous TiNb 2 O 7 nanospheres comprised of nanoparticles have been synthesized with the assistance of block copolymer P123 (EO 20 PO 70 EO 20 ). Such porous TiNb 2 O 7 nanospheres, with diameter of 500 nm, exhibit a BET surface area of 23.4 m 2 /g and pore volume of 0.155 cm 3 /g. As the anodes for lithium-ion batteries, the TiNb 2 O 7 nanospheres present a reversible capacity of 160 mA h/g after 10000 cycles at 5 C with a capacity loss of only 0.0033% per cycle, and good rate performance of 167 mA h/g at 50 C. Furthermore, the TiNb 2 O 7 materials still maintain the morphology of nanospheres and the porous structure even after 10000 cycles

Elaboration and test of the method of separation of alkaline metals ions with tin phosphate

International Nuclear Information System (INIS)

Smirnov, G.I.; Chernyak, A.S.; Kostromina, O.N.; Kachur, N.Ya.; Shpeyzer, B.G.

1986-01-01

Present work is devoted to elaboration and test of the method of separation of alkaline metals ions with tin phosphate. Thus, the isotherms of sorption of lithium, sodium, potassium, rubidium and cesium ions with amorphous tin phosphate depending on their concentration, ph of solution, sorbent quantity are obtained. The parameters of extraction of potassium microquantities from sodium salts are defined. Ultra pure sodium chloride, sodium iodide, sodium sulphate, sodium nitrate, sodium nitrite, sodium phosphate are synthesized.

Investigation of the effects of particle size on the mechanical properties of porous and tin infiltrated niobium rods fabricated by a thermoplastic-powder metallurgy technique

International Nuclear Information System (INIS)

Noman, A.

1978-12-01

An investigation was made of the influence of particle size on the properties of both porous and tin infiltrated niobium rods fabricated by a thermoplastic-powder metallurgy technique. The residual porosity, extrusion pressure, tensile strength, and ductility were found to be dependent on the particle size distribution. All of these parameters were found to increase with increasing particle size. The influence of sintering time at a temperature of 2250 0 C was also studied. With increasing sintering time, the residual porosity and tensile strength decreased, whereas the ductility increased. The procedures for fabricating infiltrated niobium rods and the various tests employed to determine their properties are described

NANODERM. Quality of skin as a barrier to ultra-fine particles

International Nuclear Information System (INIS)

Kiss, A.Z.; Kertesz, Zs.; Szikszai, Z.; Biro, T.; Czifra, G.; Toth, B.I.; Juhasz, I.; Kiss, B.; Hunyadi, J.

2007-01-01

Complete text of publication follows. The EU5 project carried out by a consortium of 12 European universities and research institutes under the leadership of the Faculty of Physics and Geosciences, University of Leipzig started in 2003 and ended with the publication of its final report in 2007. The main goal of the project was to get quantitative information on the penetration of ultra-fine particles in all strata of skin, on their penetration pathways as well as on their impact on human health. Details of the project can be found on the following website: http://www.uni-leipzig.de/"~nanoderm. The Hungarian team was lead by the Department of Dermatology, University of Debrecen, who provided human skin grafted on SCID (Severe Combined Immune Deficiency) mice as a suitable model for studying particle penetration. In the Institute of Physiology, University of Debrecen, the cellular effects of the nanoparticles were assessed. The ATOMKI group performed ion beam analytical investigations using proton induced x-ray emission and scanning transmission ion microscopy techniques to determine the particle distribution on porcine, SCID graft and human skin samples on which various nanoparticle (TiO 2 ) formulations including commercially available sunscreens were applied. Several pre-treatments of the skin were tested, too. The skin samples were cryofixed native specimens, reducing considerably the possibility of creating artefacts. Results Titanium was only detected in the stratum corneum for healthy skin. Penetration to layers consisting of living cells was not observed. No diffusion profile was present therefore we conclude that the penetration takes place through mechanical action. Deep penetration into hair follicles was also observed, but not into vital tissue. Clearance is expected via desquamation and sebum excretion respectively for corneocyte layers and hair follicles. In conclusion, the NANODERM group does not expect any harmful effects of sunscreens containing

Porous electrode preparation method

Science.gov (United States)

Arons, R.M.; Dusek, J.T.

1983-10-18

A porous sintered plaque is provided with a bimodal porosity that is especially well suited for use as an electrode within a molten carbonate fuel cell. The coarse porosity is sufficient for admitting gases into contact with the reaction surfaces while the fine porosity is wetted with and retains molten electrolyte on the reaction sites. The electrode structure is prepared by providing a very fine powder of such as nickel oxide and blending the powder with a suitable decomposable binder to form a solid mass. The mass is comminuted into agglomerate size particles substantially larger than the fine oxide particles and formed into a cohesive compact for subsequent sintering. Sintering is carried out at sufficient conditions to bind the agglomerates together into a porous structure having both coarse and fine porosity. Where lithiated nickel oxide cathodes are prepared, the sintering conditions can be moderate enough to retain substantial quantities of lithium within the electrode for adequate conductivity. 2 figs.

Tin dioxide sol-gel derived films doped with platinum and antimony deposited on porous silicon

NARCIS (Netherlands)

Savaniu, C.; Arnautu, A.; Cobianu, C.; Craciun, G.; Flueraru, C.; Zaharescu, M.; Parlog, C.; Paszti, F.; van den Berg, Albert

1999-01-01

SnO2 sol-gel derived thin films doped simultaneously with Pt and Sb are obtained and reported for the first time. The Sn sources were tin(IV) ethoxide or tin(II) ethylhexanoate, while hexachloroplatinic acid (H2PtCl6) and antimony chloride (SbCl3) were used as platinum and antimony sources,

Scalable Production of the Silicon-Tin Yin-Yang Hybrid Structure with Graphene Coating for High Performance Lithium-Ion Battery Anodes.

Science.gov (United States)

Jin, Yan; Tan, Yingling; Hu, Xiaozhen; Zhu, Bin; Zheng, Qinghui; Zhang, Zijiao; Zhu, Guoying; Yu, Qian; Jin, Zhong; Zhu, Jia

2017-05-10

Alloy anodes possessed of high theoretical capacity show great potential for next-generation advanced lithium-ion battery. Even though huge volume change during lithium insertion and extraction leads to severe problems, such as pulverization and an unstable solid-electrolyte interphase (SEI), various nanostructures including nanoparticles, nanowires, and porous networks can address related challenges to improve electrochemical performance. However, the complex and expensive fabrication process hinders the widespread application of nanostructured alloy anodes, which generate an urgent demand of low-cost and scalable processes to fabricate building blocks with fine controls of size, morphology, and porosity. Here, we demonstrate a scalable and low-cost process to produce a porous yin-yang hybrid composite anode with graphene coating through high energy ball-milling and selective chemical etching. With void space to buffer the expansion, the produced functional electrodes demonstrate stable cycling performance of 910 mAh g -1 over 600 cycles at a rate of 0.5C for Si-graphene "yin" particles and 750 mAh g -1 over 300 cycles at 0.2C for Sn-graphene "yang" particles. Therefore, we open up a new approach to fabricate alloy anode materials at low-cost, low-energy consumption, and large scale. This type of porous silicon or tin composite with graphene coating can also potentially play a significant role in thermoelectrics and optoelectronics applications.

A multi-scale homogenization model for fine-grained porous viscoplastic polycrystals: I - Finite-strain theory

Science.gov (United States)

Song, Dawei; Ponte Castañeda, P.

2018-06-01

We make use of the recently developed iterated second-order homogenization method to obtain finite-strain constitutive models for the macroscopic response of porous polycrystals consisting of large pores randomly distributed in a fine-grained polycrystalline matrix. The porous polycrystal is modeled as a three-scale composite, where the grains are described by single-crystal viscoplasticity and the pores are assumed to be large compared to the grain size. The method makes use of a linear comparison composite (LCC) with the same substructure as the actual nonlinear composite, but whose local properties are chosen optimally via a suitably designed variational statement. In turn, the effective properties of the resulting three-scale LCC are determined by means of a sequential homogenization procedure, utilizing the self-consistent estimates for the effective behavior of the polycrystalline matrix, and the Willis estimates for the effective behavior of the porous composite. The iterated homogenization procedure allows for a more accurate characterization of the properties of the matrix by means of a finer "discretization" of the properties of the LCC to obtain improved estimates, especially at low porosities, high nonlinearties and high triaxialities. In addition, consistent homogenization estimates for the average strain rate and spin fields in the pores and grains are used to develop evolution laws for the substructural variables, including the porosity, pore shape and orientation, as well as the "crystallographic" and "morphological" textures of the underlying matrix. In Part II of this work has appeared in Song and Ponte Castañeda (2018b), the model will be used to generate estimates for both the instantaneous effective response and the evolution of the microstructure for porous FCC and HCP polycrystals under various loading conditions.

Photoluminescence studies on porous silicon/polymer heterostructure

International Nuclear Information System (INIS)

Mishra, J.K.; Bhunia, S.; Banerjee, S.; Banerji, P.

2008-01-01

Hybrid devices formed by filling porous silicon with MEH-PPV or poly [2-methoxy-5(2-ethylhexyloxy-p-phenylenevinylene)] have been investigated in this work. Analyses of the structures by scanning electron microscopy (SEM) demonstrated that the porous silicon layer was filled by the polymer with no significant change of the structures except that the polymer was infiltrated in the pores. The photoluminescence (PL) of the structures at 300 K showed that the emission intensity was very high as compared with that of the MEH-PPV films on different substrates such as crystalline silicon (c-Si) and indium tin oxide (ITO). The PL peak in the MEH-PPV/porous silicon composite structure is found to be shifted towards higher energy in comparison with porous silicon PL. A number of possibilities are discussed to explain the observations

Spectroelectrochemical properties of ultra-thin indium tin oxide films under electric potential modulation

Energy Technology Data Exchange (ETDEWEB)

Han, Xue, E-mail: x0han004@louisville.edu; Mendes, Sergio B., E-mail: sbmend01@louisville.edu

2016-03-31

In this work, the spectroscopic properties of ultra-thin ITO films are characterized under an applied electric potential modulation. To detect minute spectroscopic features, the ultra-thin ITO film was coated over an extremely sensitive single-mode integrated optical waveguide, which provided a long pathlength with more than adequate sensitivity for optical interrogation of the ultra-thin film. Experimental configurations with broadband light and several laser lines at different modulation schemes of an applied electric potential were utilized to elucidate the nature of intrinsic changes. The imaginary component of the refractive index (absorption coefficient) of the ultra-thin ITO film is unequivocally shown to have a dependence on the applied potential and the profile of this dependence changes substantially even for wavelengths inside a small spectral window (500–600 nm). The characterization technique and the data reported here can be crucial to several applications of the ITO material as a transparent conductive electrode, as for example in spectroelectrochemical investigations of surface-confined redox species. - Highlights: • Optical waveguides are applied for spectroscopic investigations of ultra-thin films. • Ultra-thin ITO films in aqueous environment are studied under potential modulation. • Unique spectroscopic features of ultra-thin ITO films are unambiguously observed.

Synthesis and Mechanical Characterisation of an Ultra-Fine Grained Ti-Mg Composite

Directory of Open Access Journals (Sweden)

Markus Alfreider

2016-08-01

Full Text Available The importance of lightweight materials such as titanium and magnesium in various technical applications, for example aerospace, medical implants and lightweight construction is well appreciated. The present study is an attempt to combine and improve the mechanical properties of these two materials by forming an ultra-fine grained composite. The material, with a composition of 75 vol% (88.4 wt% Ti and 25 vol% (11.4 wt% Mg , was synthesized by powder compression and subsequently deformed by high-pressure torsion. Using focused ion beam machining, miniaturised compression samples were prepared and tested in-situ in a scanning electron microscope to gain insights into local deformation behaviour and mechanical properties of the nanocomposite. Results show outstanding yield strength of around 1250 MPa, which is roughly 200 to 500 MPa higher than literature reports of similar materials. The failure mode of the samples is accounted for by cracking along the phase boundaries.

Hydrolysis of bis(dimethylamido)tin to tin (II) oxyhydroxide and its selective transformation into tin (II) or tin (IV) oxide

KAUST Repository

Khanderi, Jayaprakash; Shi, Lei; Rothenberger, Alexander

2015-01-01

Sn6O4(OH)4, a hydrolysis product of Sn(NMe2)2, is transformed to tin (II) or tin (IV) oxide by solid and solution phase processing. Tin (II) oxide is formed by heating Sn6O4(OH)4 at ≤200 °C in air or under inert atmosphere. Tin (IV) oxide

Selective Recovery of Mushistonite from Gravity Tailings of Copper–Tin Minerals in Tajikistan

Directory of Open Access Journals (Sweden)

Lei Sun

2017-12-01

Full Text Available Tajikistan has abundant copper–tin resources. In this study, mineralogical analysis of copper–tin ores from the Mushiston deposit of Tajikistan indicates that tin mainly occurred in mushistonite, cassiterite, and stannite, while copper mainly occurred in mushistonite, malachite, azurite, and stannite. The total grades of tin (Sn and copper (Cu were 0.65% and 0.66%, respectively, and the dissemination size of copper–tin minerals ranged from 4 μm to over 200 μm. Coarse particles of copper–tin minerals were partially recovered by shaking table concentrators with a low recovery rate. Based on the mineralogical analysis, flotation recovery was used for the first time on the fine particles of copper–tin minerals, including mushistonite, from shaking table tailings. Single factor flotation experiments, open circuit flotation tests, and closed circuit flotation tests were performed to determine the optimized flotation conditions. Results indicated that benzohydroxamic acid (C6H5CONHOH and lead nitrate could effectively recover the mushistonite, cooperating with other depressants. The final concentrate contained 13.28% Sn, with a recovery rate of 61.56%, and 18.51% Cu, with a recovery rate of 86.52%. This method proved effective for the exploitation and use of this type of copper–tin resource in Tajikistan.

Proton microprobe study of tin-polymetallic deposits

Energy Technology Data Exchange (ETDEWEB)

Murao, S [Geological Survey of Japan, Tsukuba, Ibaraki (Japan); Sie, S H; Suter, G F [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience

1997-12-31

Tin-polymetallic vein type deposits are a complex mixture of cassiterite and sulfides and they are the main source of technologically important rare metals such as indium and bismuth. Constituent minerals are usually fine grained having wide range of chemical composition and often the elements of interest occur as trace elements not amenable to electron microprobe analysis. PIXE with a proton microprobe can be an effective tool to study such deposits by delineating the distribution of trace elements among carrier minerals. Two representative indium-bearing deposits of tin- polymetallic type, Tosham of India (Cu-ln-Bi-Sn-W-Ag), and Mount Pleasant of Canada (Zn-Cu-In-Bi-Sn-W), were studied to delineate the distribution of medical/high-tech rare metals and to examine the effectiveness of the proton probe analysis of such ore. One of the results of the study indicated that indium and bismuth are present in chalcopyrite in the deposits. In addition to these important rare metals, zinc, copper, arsenic, antimony, selenium, and tin are common in chalcopyrite and pyrite. Arsenopyrite contains nickel, copper, zinc, silver, tin, antimony and bismuth. In chalcopyrite and pyrite, zinc, arsenic, indium, bismuth and lead are richer in Mount Pleasant ore, but silver is higher at Tosham. Also thallium and gold were found only in Tosham pyrite. The Tosham deposit is related to S-type granite, while Mount Pleasant to A-type. It appears that petrographic character of the source magma is one of the factors to determine the trace element distribution in tin-polymetallic deposit. 6 refs., 2 figs.

Proton microprobe study of tin-polymetallic deposits

Energy Technology Data Exchange (ETDEWEB)

Murao, S. [Geological Survey of Japan, Tsukuba, Ibaraki (Japan); Sie, S.H.; Suter, G.F. [Commonwealth Scientific and Industrial Research Organisation (CSIRO), North Ryde, NSW (Australia). Div. of Exploration Geoscience

1996-12-31

Tin-polymetallic vein type deposits are a complex mixture of cassiterite and sulfides and they are the main source of technologically important rare metals such as indium and bismuth. Constituent minerals are usually fine grained having wide range of chemical composition and often the elements of interest occur as trace elements not amenable to electron microprobe analysis. PIXE with a proton microprobe can be an effective tool to study such deposits by delineating the distribution of trace elements among carrier minerals. Two representative indium-bearing deposits of tin- polymetallic type, Tosham of India (Cu-ln-Bi-Sn-W-Ag), and Mount Pleasant of Canada (Zn-Cu-In-Bi-Sn-W), were studied to delineate the distribution of medical/high-tech rare metals and to examine the effectiveness of the proton probe analysis of such ore. One of the results of the study indicated that indium and bismuth are present in chalcopyrite in the deposits. In addition to these important rare metals, zinc, copper, arsenic, antimony, selenium, and tin are common in chalcopyrite and pyrite. Arsenopyrite contains nickel, copper, zinc, silver, tin, antimony and bismuth. In chalcopyrite and pyrite, zinc, arsenic, indium, bismuth and lead are richer in Mount Pleasant ore, but silver is higher at Tosham. Also thallium and gold were found only in Tosham pyrite. The Tosham deposit is related to S-type granite, while Mount Pleasant to A-type. It appears that petrographic character of the source magma is one of the factors to determine the trace element distribution in tin-polymetallic deposit. 6 refs., 2 figs.

Proton microprobe study of tin-polymetallic deposits

International Nuclear Information System (INIS)

Murao, S.; Sie, S.H.; Suter, G.F.

1996-01-01

Tin-polymetallic vein type deposits are a complex mixture of cassiterite and sulfides and they are the main source of technologically important rare metals such as indium and bismuth. Constituent minerals are usually fine grained having wide range of chemical composition and often the elements of interest occur as trace elements not amenable to electron microprobe analysis. PIXE with a proton microprobe can be an effective tool to study such deposits by delineating the distribution of trace elements among carrier minerals. Two representative indium-bearing deposits of tin- polymetallic type, Tosham of India (Cu-ln-Bi-Sn-W-Ag), and Mount Pleasant of Canada (Zn-Cu-In-Bi-Sn-W), were studied to delineate the distribution of medical/high-tech rare metals and to examine the effectiveness of the proton probe analysis of such ore. One of the results of the study indicated that indium and bismuth are present in chalcopyrite in the deposits. In addition to these important rare metals, zinc, copper, arsenic, antimony, selenium, and tin are common in chalcopyrite and pyrite. Arsenopyrite contains nickel, copper, zinc, silver, tin, antimony and bismuth. In chalcopyrite and pyrite, zinc, arsenic, indium, bismuth and lead are richer in Mount Pleasant ore, but silver is higher at Tosham. Also thallium and gold were found only in Tosham pyrite. The Tosham deposit is related to S-type granite, while Mount Pleasant to A-type. It appears that petrographic character of the source magma is one of the factors to determine the trace element distribution in tin-polymetallic deposit. 6 refs., 2 figs

First-principles study of optical, elastic anisotropic and thermodynamic properties of TiN under high temperature and high pressure

Directory of Open Access Journals (Sweden)

R. Yang

2017-12-01

Full Text Available The optical, elastic anisotropic and thermodynamic properties of TiN in the NaCl (B1 structure are analyzed in detail in the temperature range from 0 to 2000 K and the pressure range from 0 to 20 GPa. From the calculated dielectric constants, a first order isostructural phase transition between 29 and 30 GPa is found for TiN. The absorption spectra exhibit high values ranging from the far infrared region to the ultra-violet one. The anisotropy value of Young's modulus of TiN is smaller than that of c-BN at 0 GPa and the anisotropy of TiN clearly increases with an increase of pressure. The effects of pressure and temperature on the bulk modulus, Grüneisen parameter, Gibbs free energy, and Debye temperature are significant. The Grüneisen parameter of TiN is much larger than that of c-BN. At temperatures below 1000 K, TiN's heat capacity is much larger than that of c-BN.

POC-scale testing of an advanced fine coal dewatering equipment/technique

Energy Technology Data Exchange (ETDEWEB)

Groppo, J.G.; Parekh, B.K. [Univ. of Kentucky, Lexington, KY (United States); Rawls, P. [Department of Energy, Pittsburgh, PA (United States)

1995-11-01

Froth flotation technique is an effective and efficient process for recovering of ultra-fine (minus 74 {mu}m) clean coal. Economical dewatering of an ultra-fine clean coal product to a 20 percent level moisture will be an important step in successful implementation of the advanced cleaning processes. This project is a step in the Department of Energy`s program to show that ultra-clean coal could be effectively dewatered to 20 percent or lower moisture using either conventional or advanced dewatering techniques. As the contract title suggests, the main focus of the program is on proof-of-concept testing of a dewatering technique for a fine clean coal product. The coal industry is reluctant to use the advanced fine coal recovery technology due to the non-availability of an economical dewatering process. in fact, in a recent survey conducted by U.S. DOE and Battelle, dewatering of fine clean coal was identified as the number one priority for the coal industry. This project will attempt to demonstrate an efficient and economic fine clean coal slurry dewatering process.

Hierarchical TiN nanoparticles-assembled nanopillars for flexible supercapacitors with high volumetric capacitance.

Science.gov (United States)

Qin, Ping; Li, Xingxing; Gao, Biao; Fu, Jijiang; Xia, Lu; Zhang, Xuming; Huo, Kaifu; Shen, Wenli; Chu, Paul K

2018-05-10

Titanium nitride (TiN) is an attractive electrode material in fast charging/discharging supercapacitors because of its excellent conductivity. However, the low capacitance and mechanical brittleness of TiN restricts its further application in flexible supercapacitors with high energy density. Thus, it is still a challenge to rationally design TiN electrodes with both high electrochemical and mechanical properties. Herein, the hierarchical TiN nanoparticles-assembled nanopillars (H-TiN NPs) array as binder free electrodes were obtained by nitriding of hierarchical titanium dioxide (TiO2) nanopillars, which was produced by a simple hydrothermal treatment of anodic TiO2 nanotubes (NTs) array in water. The porous TiN nanoparticles connected to each other to form ordered nanopillar arrays, effectively providing larger specific surface area and more active sites for charge storage. The H-TiN NPs delivered a high volumetric capacitance of 120 F cm-3 at 0.83 A cm-3, which is better than that of TiN NTs arrays (69 F cm-3 at 0.83 A cm-3). After assembling into all-solid-state devices, the H-TiN NPs based supercapacitors exhibited outstanding volumetric capacitance of 5.9 F cm-3 at 0.02 A cm-3 and a high energy density of 0.53 mW h cm-3. Our results reveal a new strategy to optimize the supercapacitive performance of metal nitrides.

Fundamental electrochemiluminescence characteristics of fluorine-doped tin oxides synthesized by sol-gel combustion.

Science.gov (United States)

Moon, B H; Chaoumead, A; Sung, Y M

2013-10-01

Fluorine-doped tin oxide (FTO) materials synthesized by sol-gel combustion method were investigated for electrochemical luminescence (ECL) application. Effects of sol-gel combustion conditions on the structures and morphology of the porous FTO (p-FTO) materials were studied. ECL efficiency of p-FTO-based cell was about 251 cd/m2 at 4 V bias, which is higher than the sell using only FTO electrodes (102.8 cd/m2). The highest intensity of the emitting light was obtained at the wavelength of about 610 nm. The porous FTO layer was effective for increasing ECL intensities.

Structural control of ultra-fine CoPt nanodot arrays via electrodeposition process

Energy Technology Data Exchange (ETDEWEB)

Wodarz, Siggi [Department of Applied Chemistry, Waseda University, Shinjuku, Tokyo 169-8555 (Japan); Hasegawa, Takashi; Ishio, Shunji [Department of Materials Science, Akita University, Akita City 010-8502 (Japan); Homma, Takayuki, E-mail: t.homma@waseda.jp [Department of Applied Chemistry, Waseda University, Shinjuku, Tokyo 169-8555 (Japan)

2017-05-15

CoPt nanodot arrays were fabricated by combining electrodeposition and electron beam lithography (EBL) for the use of bit-patterned media (BPM). To achieve precise control of deposition uniformity and coercivity of the CoPt nanodot arrays, their crystal structure and magnetic properties were controlled by controlling the diffusion state of metal ions from the initial deposition stage with the application of bath agitation. Following bath agitation, the composition gradient of the CoPt alloy with thickness was mitigated to have a near-ideal alloy composition of Co:Pt =80:20, which induces epitaxial-like growth from Ru substrate, thus resulting in the improvement of the crystal orientation of the hcp (002) structure from its initial deposition stages. Furthermore, the cross-sectional transmission electron microscope (TEM) analysis of the nanodots deposited with bath agitation showed CoPt growth along its c-axis oriented in the perpendicular direction, having uniform lattice fringes on the hcp (002) plane from the Ru underlayer interface, which is a significant factor to induce perpendicular magnetic anisotropy. Magnetic characterization of the CoPt nanodot arrays showed increase in the perpendicular coercivity and squareness of the hysteresis loops from 2.0 kOe and 0.64 (without agitation) to 4.0 kOe and 0.87 with bath agitation. Based on the detailed characterization of nanodot arrays, the precise crystal structure control of the nanodot arrays with ultra-high recording density by electrochemical process was successfully demonstrated. - Highlights: • Ultra-fine CoPt nanodot arrays were fabricated by electrodeposition. • Crystallinity of hcp (002) was improved with uniform composition formation. • Uniform formation of hcp lattices leads to an increase in the coercivity.

Enhanced photoconductivity and fine response tuning in nanostructured porous silicon microcavities

Energy Technology Data Exchange (ETDEWEB)

Urteaga, R; MarIn, O; Acquaroli, L N; Schmidt, J A; Koropecki, R R [INTEC-UNL-CONICET, Guemes 3450 - 3000 Santa Fe (Argentina); Comedi, D, E-mail: rkoro@intec.ceride.gov.a [CONICET y LAFISO, Departamento de Fisica, FACET, Universidad Nacional de Tucuman (Argentina)

2009-05-01

We used light confinement in optical microcavities to achieve a strong enhancement and a precise wavelength tunability of the electrical photoconductance of nanostructured porous silicon (PS). The devices consist of a periodic array of alternating PS layers, electrochemically etched to have high and low porosities - and therefore distinct dielectric functions. A central layer having a doubled thickness breaks up the symmetry of the one-dimensional photonic structure, producing a resonance in the photonic band gap that is clearly observed in the reflectance spectrum. The devices were transferred to a glass coated with a transparent SnO{sub 2} electrode, while an Al contact was evaporated on its back side. The electrical conductance was measured as a function of the photon energy. A strong enhancement of the conductance is obtained in a narrow (17nm FWHM) band peaking at the resonance. We present experimental results of the angular dependence of this photoconductance peak energy, and propose an explanation of the conductivity behaviour supported by calculations of the internal electromagnetic field. These devices are promising candidates for finely tuned photoresistors with potential application as chemical sensors and biosensors.

Atomic layer epitaxy of hematite on indium tin oxide for application in solar energy conversion

Science.gov (United States)

Martinson, Alex B.; Riha, Shannon; Guo, Peijun; Emery, Jonathan D.

2016-07-12

A method to provide an article of manufacture of iron oxide on indium tin oxide for solar energy conversion. An atomic layer epitaxy method is used to deposit an uncommon bixbytite-phase iron (III) oxide (.beta.-Fe.sub.2O.sub.3) which is deposited at low temperatures to provide 99% phase pure .beta.-Fe.sub.2O.sub.3 thin films on indium tin oxide. Subsequent annealing produces pure .alpha.-Fe.sub.2O.sub.3 with well-defined epitaxy via a topotactic transition. These highly crystalline films in the ultra thin film limit enable high efficiency photoelectrochemical chemical water splitting.

Effect of Tin, Copper and Boron on the Hot Ductility of 20CrMnTi Steel between 650 °C and 1100 °C

Science.gov (United States)

Peng, Hong-bing; Chen, Wei-qing; Chen, Lie; Guo, Dong

2015-02-01

The hot ductility of 20CrMnTi steel with x% tin, y% copper and z ppm boron (x = 0, 0.02; y = 0, 0.2; z = 0, 60) was investigated. The results show that tin and copper in 20CrMnTi steel are detrimental to its hot ductility while adding boron can eliminate the adverse effect and enhance hot ductility greatly. Tin is found to segregate to the boundaries tested by EPMA in 20CrMnTi steel containing tin and copper and tin-segregation is suppressed by adding boron, moreover, copper was found not to segregate to boundaries, however, fine copper sulfide was found from carbon extraction replicas using TEM. The adverse effect of tin and copper on the hot ductility was due mainly to tin segregation and fine copper sulfide in the steel. The proeutectoid ferrite film precipitating along the austenite grain boundary causes the ductility trough of the three examined steels. Tin and copper in 20CrMnTi steel can retard the occurrence of dynamic recrystallization (DRX) while boron-addition can compensate for that change. The beneficial effect of boron on 20CrMnTi steel containing tin and copper might be ascribed to the fact that boron segregates to grain boundaries, accelerates onset of DRX, retards austenite/ferrite transformation and promotes intragranular nucleation of ferrite.

Size-dependent characteristics of ultra-fine oxygen-enriched nanoparticles in austenitic steels

Energy Technology Data Exchange (ETDEWEB)

Miao, Yinbin, E-mail: ymiao@anl.gov [Argonne National Laboratory, Lemont, IL 60439 (United States); University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Mo, Kun [Argonne National Laboratory, Lemont, IL 60439 (United States); Zhou, Zhangjian [University of Science and Technology Beijing, Beijing 100082 (China); Liu, Xiang; Lan, Kuan-Che [University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Zhang, Guangming [University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); University of Science and Technology Beijing, Beijing 100082 (China); Miller, Michael K.; Powers, Kathy A. [Oak Ridge National Laboratory, Oak Ridge, TN 37830 (United States); Stubbins, James F. [University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); International Institute for Carbon-Neutral Energy Research (I2CNER), Kyushu University, Fukuoka 819-0395 (Japan)

2016-11-15

Here, a coordinated investigation of the elemental composition and morphology of ultra-fine-scale nanoparticles as a function of size within a variety of austenitic oxide dispersion-strengthened (ODS) steels is reported. Atom probe tomography was utilized to evaluate the elemental composition of these nanoparticles. Meanwhile, the crystal structures and orientation relationships were determined by high-resolution transmission electron microscopy. The nanoparticles with sufficient size (>4 nm) to maintain a Y{sub 2}Ti{sub 2−x}O{sub 7−2x} stoichiometry were found to have a pyrochlore structure, whereas smaller Y{sub x}Ti{sub y}O{sub z} nanoparticles lacked a well-defined structure. The size-dependent characteristics of the nanoparticles in austenitic ODS steels differ from those in ferritic/martensitic ODS steels. - Highlights: • The structural and chemical characteristics of nanoparticles are revealed. • Nanoparticles' crystal structure and elemental composition are size-dependent. • Characteristics of austenitic ODS steels are compared to that of an F/M ODS steel. • Hypothesis about the formation mechanism of nanoparticles is proposed accordingly.

Preparation of Ultra Low-κ Porous SiOCH Films from Ring-Type Siloxane with Unsaturated Hydrocarbon Side Chains by Spin-On Deposition

International Nuclear Information System (INIS)

Chun-Xiao, Yang; Chi, Zhang; Qing-Qing, Sun; Sai-Sheng, Xu; Li-Feng, Zhang; Yu, Shi; Shi-Jin, Ding; Wei, Zhang

2010-01-01

An ultra-low-dielectric-constant (ultra low-k, or ULK) porous SiOCH film is prepared using a single ring-type siloxane precursor of the 2,4,6,8-tetravinyl-2,4,6,8-tetramethylcyclotetrasiloxane by means of spin-on deposition, followed by crosslinking reactions between the precursor monomers under UV irradiation. The as-prepared film has an ultra low k of 2.41 at 1 MHz due to incorporation of pores and hydrocarbon crosslinkages, a leakage current density of 9.86 × 10 −7 A/cm 2 at 1 MV/cm, as well as a breakdown field strength of ∼1.5 MV/cm. Further, annealing at 300°C results in lower k (i.e., 1.94 at 1 MHz), smaller leakage current density (2.96 × 10 −7 A/cm 2 at 1 MV/cm) and higher breakdown field strength (about 3.5 MV/cm), which are likely caused by the short-ranged structural rearrangement and reduction of defects in the film. Finally, the mechanical properties and surface morphology of films are also evaluated after different temperature annealing. (condensed matter: electronic structure, electrical, magnetic, and optical properties)

Citrus pectin derived porous carbons as a superior adsorbent toward removal of methylene blue

International Nuclear Information System (INIS)

Zhang, Wenlin; Zhang, Lian Ying; Zhao, Xi Juan; Zhou, Zhiqin

2016-01-01

An adsorbent, citrus pectin derived porous carbons with ultra-high adsorption capacity, rapid adsorption rate and good reusability toward removal of methylene blue, was synthesized by a facile zinc chloride activation approach in this study. The materials hold a great potential for treatment of dye wastewater. - Graphical abstract: Citrus pectin derived porous carbons with ultra-high adsorption capacity, rapid adsorption rate and good reusability toward methylene blue removal. - Highlights: • Citrus pectin derived porous carbons (CPPCs) were synthesized a facile zinc chloride activation approach. • CPPCs had abundant macro/meso/micropores for trapping MB molecules. • CPPCs exhibited ultrahigh adsorption capacity, rapid adsorption rate and good reusability toward removal of MB.

Citrus pectin derived porous carbons as a superior adsorbent toward removal of methylene blue

Energy Technology Data Exchange (ETDEWEB)

Zhang, Wenlin [College of Horticulture and landscape Architecture, Southwest University, Chongqing 400716 (China); Zhang, Lian Ying [Institute for Clean Energy & Advanced Materials, Southwest University, Chongqing 400715 (China); Zhao, Xi Juan [College of Horticulture and landscape Architecture, Southwest University, Chongqing 400716 (China); Key Laboratory of Horticulture Science for Southern Mountainous Regions, Ministry of Education, Chongqing 400715 (China); Zhou, Zhiqin, E-mail: zhouzhiqin@swu.edu.cn [College of Horticulture and landscape Architecture, Southwest University, Chongqing 400716 (China); Key Laboratory of Horticulture Science for Southern Mountainous Regions, Ministry of Education, Chongqing 400715 (China)

2016-11-15

An adsorbent, citrus pectin derived porous carbons with ultra-high adsorption capacity, rapid adsorption rate and good reusability toward removal of methylene blue, was synthesized by a facile zinc chloride activation approach in this study. The materials hold a great potential for treatment of dye wastewater. - Graphical abstract: Citrus pectin derived porous carbons with ultra-high adsorption capacity, rapid adsorption rate and good reusability toward methylene blue removal. - Highlights: • Citrus pectin derived porous carbons (CPPCs) were synthesized a facile zinc chloride activation approach. • CPPCs had abundant macro/meso/micropores for trapping MB molecules. • CPPCs exhibited ultrahigh adsorption capacity, rapid adsorption rate and good reusability toward removal of MB.

Development of Dynamic Compaction Technology for Ultra High Strength Powder Products

International Nuclear Information System (INIS)

Rhee, Chang Kyu; Lee, M. K.; Uhm, Y. R.; Park, J. J.; Lee, J. G.; Ivanov, V. V.; Hong, S. J.

2007-04-01

A synthesis of ultra fine powder and its compaction have been considered as a new generation and high value added technology in various industrial fields such as automobile, machine tool, electronic chip, sensor and catalyst because of its special characteristics of high toughness, strength and wear resistance which are not shown in conventional process. In this study, ultra hard and fine powders, such as Fe-Si, CuNi and Al 2 O 3 , have been fabricated by the pulsed wire evaporation (PWE) method and mechanical alloying (MA) method. In addition, with ultra hard and fine powders, the magnetic core, diamond tool and water jet nozzle with high density were made by a uniaxial dynamic compaction for the purpose of the real industrial application

Radiation-induced copolymerization of styrene/n-butyl acrylate in the presence of ultra-fine powdered styrene-butadiene rubber

Energy Technology Data Exchange (ETDEWEB)

Yu Haibo [Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Peng Jing [Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)], E-mail: jpeng@pku.edu.cn; Zhai Maolin; Li Jiuqiang; Wei Genshuan [Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Qiao Jinliang [Department of Applied Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); SINOPEC Beijing Research Institute of Chemical Industry, Beijing 100013 (China)

2007-11-15

Styrene (St)/n-butyl acrylate (BA) copolymers were prepared by two-stage polymerization: St/BA was pre-polymerized to a viscous state by bulk polymerization with initiation by benzoyl peroxide (BPO) followed by {sup 60}Co {gamma}-ray radiation curing. The resultant copolymers had higher molecular weight and narrower molecular weight distribution than conventional methods. After incorporation of ultra-fine powdered styrene-butadiene rubber (UFSBR) with a particle size of 100 nm in the monomer, the glass transition temperature (T{sub g}) of St-BA copolymer increased at low rubber content. Both the St-BA copolymer and the St-BA copolymer/UFSBR composites had good transparency at BA content below 40%.

Novel microwave-assisted synthesis of porous g-C3N4/SnO2 nanocomposite for solar water-splitting

Science.gov (United States)

Seza, A.; Soleimani, F.; Naseri, N.; Soltaninejad, M.; Montazeri, S. M.; Sadrnezhaad, S. K.; Mohammadi, M. R.; Moghadam, H. Asgari; Forouzandeh, M.; Amin, M. H.

2018-05-01

Highly porous nanocomposites of graphitic-carbon nitride and tin oxide (g-C3N4/SnO2) were prepared through simple pyrolysis of urea molecules under microwave irradiation. The initial amount of tin was varied in order to investigate the effect of SnO2 content on preparation and properties of the composites. The synthesized nanocomposites were well-characterized by XRD, FE-SEM, HR-TEM, BET, FTIR, XPS, DRS, and PL. A homogeneous distribution of SnO2 nanoparticles with the size of less than 10 nm on the porous C3N4 sheets could be obtained, suggesting that in-situ synthesis of SnO2 nanoparticles was responsible for the formation of g-C3N4. The process likely occurred by the aid of the large amounts of OH groups formed on the surfaces of SnO2 nanoparticles during the polycondensation reactions of tin derivatives which could facilitate the pyrolysis of urea to carbon nitride. The porous nanocomposite prepared with initial tin amount of 0.175 g had high specific surface area of 195 m2 g-1 which showed high efficiency photoelectrochemical water-splitting ability. A maximum photocurrent density of 33 μA cm-2 was achieved at an applied potential of 0.5 V when testing this nanocomposite as photo-anode in water-splitting reactions under simulated visible light irradiation, introducing it as a promising visible light photoactive material.

3D visualization of ultra-fine ICON climate simulation data

Science.gov (United States)

Röber, Niklas; Spickermann, Dela; Böttinger, Michael

2016-04-01

Advances in high performance computing and model development allow the simulation of finer and more detailed climate experiments. The new ICON model is based on an unstructured triangular grid and can be used for a wide range of applications, ranging from global coupled climate simulations down to very detailed and high resolution regional experiments. It consists of an atmospheric and an oceanic component and scales very well for high numbers of cores. This allows us to conduct very detailed climate experiments with ultra-fine resolutions. ICON is jointly developed in partnership with DKRZ by the Max Planck Institute for Meteorology and the German Weather Service. This presentation discusses our current workflow for analyzing and visualizing this high resolution data. The ICON model has been used for eddy resolving (developed specific plugins for the free available visualization software ParaView and Vapor, which allows us to read and handle that much data. Within ParaView, we can additionally compare prognostic variables with performance data side by side to investigate the performance and scalability of the model. With the simulation running in parallel on several hundred nodes, an equal load balance is imperative. In our presentation we show visualizations of high-resolution ICON oceanographic and HDCP2 atmospheric simulations that were created using ParaView and Vapor. Furthermore we discuss our current efforts to improve our visualization capabilities, thereby exploring the potential of regular in-situ visualization, as well as of in-situ compression / post visualization.

Porous γ-TiAl Structures Fabricated by Electron Beam Melting Process

Directory of Open Access Journals (Sweden)

Ashfaq Mohammad

2016-01-01

Full Text Available Porous metal structures have many benefits over fully dense structures for use in bio-implants. The designs of porous structures can be made more sophisticated by altering their pore volume and strut orientation. Porous structures made from biocompatible materials such as titanium and its alloys can be produced using electron-beam melting, and recent reports have shown the biocompatibility of titanium aluminide (γ-TiAl. In the present work, we produced porous γ-TiAl structures by electron-beam melting, incorporating varying pore volumes. To achieve this, the individual pore dimensions were kept constant, and only the strut thickness was altered. Thus, for the highest pore volume of ~77%, the struts had to be as thin as half a millimeter. To accomplish such fine struts, we used various beam currents and scan strategies. Microscopy showed that selecting a proper scan strategy was most important in producing these fine struts. Microcomputed tomography revealed no major gaps in the struts, and the fine struts displayed compressive stiffness similar to that of natural bone. The characteristics of these highly-porous structures suggest their promise for use in bio-implants.

Characterization of tin films synthesized from ethaline deep eutectic solvent

International Nuclear Information System (INIS)

Ghosh, Swatilekha; Roy, Sudipta

2014-01-01

Highlights: • Tin deposition was achieved by galvanostatic method on the basic substrates from ethaline deep eutectic solvent without use of any additives. • The current potential behaviour of tin system changes with increase in concentration of hydrated tin chloride in ethaline. • The deposition rate in ethaline display three times lower value compared to aqueous electrolytes. • Fine grained crystals of 62 ± 10 nm were obtained for tin deposits. • The deposition process is economical and can be adapted for industrial applications. - Abstract: Tin (Sn) films were electrodeposited by galvanostatic method from ethaline deep eutectic solvent (DES), without any additives. The effect of various deposition parameters on the microstructure was studied. With increase in metal salt concentration from 0.01 to 0.1 M, changes in current–potential behaviour were observed in the polarization scans. This might be due to the existence of [SnCl 3 ] − , [Sn 2 Cl 5 ] − complexes in ethaline DES. Smooth and homogeneous deposits were obtained on a steel substrate surface by applying current density of 1.57 × 10 −3 A/cm 2 at 25 °C. Under these conditions the deposition rate was found to be 0.1 ± 10% μm/min and current efficiency was obtained as 84 ± 3%. XRD analysis of the deposit confirmed the polycrystalline tetragonal structure with mostly (2 0 0) orientation having a crystallite size about 62 ± 16% nm along with an internal strain of 0.0031 ± 22%. The present deposition method is simple, economical and can be adapted for industrial applications

Recovery of clean coal fines through a combination of gravity concentrator and flotation processes

Energy Technology Data Exchange (ETDEWEB)

Gupta, A.K.; Banerjee, P.K.; Dutta, A.; Mishra, A. [Tata Steel, Jamshedpur (India). Research & Development

2007-07-01

Flotation feed is a mixture of coarse and ultra-fine fractions. During conditioning of the flotation feed with collector and frother, the finer fraction consumes more reagents as compared to coarser particles. This is mainly due to more specific surface area of the ultra fine than the coarse fraction. This favors the adsorption of reagents toward ultra-finer fractions leads to less complete surface coverage of coarse particles and more entrainment of finer gangue particles. This results in the lower yield of coarse fractions from the flotation circuit and loss in selectivity. Hence, the major challenge is to improve the recovery of the coarser fraction and selectivity of ultra-fine fractions by improving flotation kinetics of all size fractions. This article deals with an approach to overcome the improper reagent adsorption by fine and coarse coal fractions in the flotation circuit through an innovative washing circuit containing gravity operation and flotation processes. Flotation performance between a new washing circuit having stub cyclone and flotation and normal single-stage reagent addition flotation process is compared in terms of selectivity, separation efficiency, rate constant, and size-wise recovery. The washing circuit having stub cyclone and flotation processes improves the fine clean coal yield by 10% and reduces the consumption of reagent compared to the normal single-stage reagent addition flotation process.

Epitaxial TiN(001) wetting layer for growth of thin single-crystal Cu(001)

Energy Technology Data Exchange (ETDEWEB)

Chawla, J. S.; Zhang, X. Y.; Gall, D. [Department of Materials Science and Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180 (United States)

2011-08-15

Single-crystal Cu(001) layers, 4-1400 nm thick, were deposited on MgO(001) with and without a 2.5-nm-thick TiN(001) buffer layer. X-ray diffraction and reflection indicate that the TiN(001) surface suppresses Cu-dewetting, yielding a 4 x lower defect density and a 9 x smaller surface roughness than if grown on MgO(001) at 25 deg. C. In situ and low temperature electron transport measurements indicate that ultra-thin (4 nm) Cu(001) remains continuous and exhibits partial specular scattering at the Cu-vacuum boundary with a Fuchs-Sondheimer specularity parameter p = 0.6 {+-} 0.2, suggesting that the use of epitaxial wetting layers is a promising approach to create low-resistivity single-crystal Cu nanoelectronic interconnects.

A new equation of state for porous materials with ultra-low densities

CERN Document Server

Geng Hua Yun; Wu Qiang

2002-01-01

A thermodynamic equation of state is derived which is appropriate for investigating the thermodynamic variations along isobaric paths to predict compression behaviours of porous materials. This equation-of-state model is tested on porous iron, copper, lead and tungsten with different initial densities. The calculated Hugoniots are in good agreement with the corresponding experimental data published previously. This shows that this model can satisfactorily predict the Hugoniots of porous materials with wide porosity and pressure ranges.

Structural, optical and electrical properties of tin oxide thin films for application as a wide band gap semiconductor

Energy Technology Data Exchange (ETDEWEB)

Sethi, Riti; Ahmad, Shabir; Aziz, Anver; Siddiqui, Azher Majid, E-mail: amsiddiqui@jmi.ac.in [Department of Physics, Jamia Millia Islamia, New Delhi-110025 (India)

2015-08-28

Tin oxide (SnO) thin films were synthesized using thermal evaporation technique. Ultra pure metallic tin was deposited on glass substrates using thermal evaporator under high vacuum. The thickness of the tin deposited films was kept at 100nm. Subsequently, the as-deposited tin films were annealed under oxygen environment for a period of 3hrs to obtain tin oxide films. To analyse the suitability of the synthesized tin oxide films as a wide band gap semiconductor, various properties were studied. Structural parameters were studied using XRD and SEM-EDX. The optical properties were studied using UV-Vis Spectrophotometry and the electrical parameters were calculated using the Hall-setup. XRD and SEM confirmed the formation of SnO phase. Uniform texture of the film can be seen through the SEM images. Presence of traces of unoxidised Sn has also been confirmed through the XRD spectra. The band gap calculated was around 3.6eV and the optical transparency around 50%. The higher value of band gap and lower value of optical transparency can be attributed to the presence of unoxidised Sn. The values of resistivity and mobility as measured by the Hall setup were 78Ωcm and 2.92cm{sup 2}/Vs respectively. The reasonable optical and electrical parameters make SnO a suitable candidate for optoelectronic and electronic device applications.

TIN-X

DEFF Research Database (Denmark)

Cannon, Daniel C; Yang, Jeremy J; Mathias, Stephen L

2017-01-01

between proteins and diseases, based on text mining data processed from scientific literature. In the current implementation, TIN-X supports exploration of data for G-protein coupled receptors, kinases, ion channels, and nuclear receptors. TIN-X supports browsing and navigating across proteins......Motivation: The increasing amount of peer-reviewed manuscripts requires the development of specific mining tools to facilitate the visual exploration of evidence linking diseases and proteins. Results: We developed TIN-X, the Target Importance and Novelty eXplorer, to visualize the association...

Thermal Transmittance of Porous Hollow Clay Brick by Guarded Hot Box Method

Science.gov (United States)

Kim, Joonsoo

2018-03-01

The thermal property of a porous hollow clay brick was determined by measuring the thermal transmittance of the wall made of porous hollow clay bricks. Prior to the production of porous hollow clay bricks, nonporous and porous tiny clay bricks were prepared to determine the physico-mechanical properties by modifying the amount of wood flour and firing temperature. The bricks were produced by uniaxial pressing and then fired in an electric furnace. Their physico-mechanical properties were measured by water absorption, apparent porosity, bulk density, and compressive strength. The porous tiny clay bricks were produced with three types of wood flour: coarse wood flour (1-0.36 mm), medium-sized wood flour (0.36-0.15 mm), and fine wood flour (cement bricks. The two walls had a thermal transmittance of 1.42 and 2.72 W\\cdot m^{-2}\\cdot K^{-1}, respectively. The difference in thermal transmittance was due to the pores created with fine wood flour (< 0.08 mm) as a pore-forming agent.

Characterization of porous materials by small-angle scattering

Indian Academy of Sciences (India)

With the availability of ultra small-angle scattering instruments, one can investigate porous materials in the sub-micron length scale. Because of the increased accessible length scale vis-a-vis the multiple scattering effect, conventional data analysis procedures based on single scattering approximation quite often fail.

Measuring the diffusion of Ti and Cu in low-k materials for microelectronic devices by EELS, EFTEM and EDX

International Nuclear Information System (INIS)

Barnes, J-P; Lafond, D; Guedj, C; Fayolle, M; Meininger, P; Maitrejean, S; David, T; Posseme, N; Bayle-Guillemaud, P; Chabli, Amal

2006-01-01

The need to reduce RC delay and cross talk in Cu interconnects means that ultra low-k dielectrics such as porous SiCOH are being integrated into microelectronic devices. Unfortunately porous materials lead to integration issues such as metal diffusion into the porosity of the dielectric, especially when chemical vapour deposition (CVD) methods are used for metal deposition. In our case, the copper anti-diffusion barrier used before Cu deposition is MOCVD TiN. Without an appropriate surface treatment (pore sealing) of the low-k the TiN may diffuse in the porosity. The presence of Ti or Cu in the low-k is deleterious as it can raise the dielectric constant and the leakage current. EFTEM EELS and EDX have been used to map Ti, Cu, O and C as a function of process conditions

On the electrochemistry of tin oxide coated tin electrodes in lithium-ion batteries

International Nuclear Information System (INIS)

Böhme, Solveig; Edström, Kristina; Nyholm, Leif

2015-01-01

As tin based electrodes are of significant interest in the development of improved lithium-ion batteries it is important to understand the associated electrochemical reactions. In this work it is shown that the electrochemical behavior of SnO_2 coated tin electrodes can be described based on the SnO_2 and SnO conversion reactions, the lithium tin alloy formation and the oxidation of tin generating SnF_2. The CV, XPS and SEM data, obtained for electrodeposited tin crystals on gold substrates, demonstrates that the capacity loss often observed for SnO_2 is caused by the reformed SnO_2 layer serving as a passivating layer protecting the remaining tin. Capacities corresponding up to about 80 % of the initial SnO_2 capacity could, however, be obtained by cycling to 3.5 V vs. Li"+/Li. It is also shown that the oxidation of the lithium tin alloy is hindered by the rate of the diffusion of lithium through a layer of tin with increasing thickness and that the irreversible oxidation of tin to SnF_2 at potentials larger than 2.8 V vs. Li"+/Li is due to the fact that SnF_2 is formed below the SnO_2 layer. This improved electrochemical understanding of the SnO_2/Sn system should be valuable in the development of tin based electrodes for lithium-ion batteries.

Effect of copper additions in tin molten pool on stability temperature and critical current of Nb3Sn

International Nuclear Information System (INIS)

Kruzliak, J.; Hutka, P.; Tomasich, M.

1979-01-01

Tested is the effect of 55 at% copper addition into the tin bath on the stability temperature and crytical current of Nb 3 Sn, prepared by the diffusion method. It is shown that copper presence in the tin bath transfers the stability temperature of NbSn 2 and Nb 6 Sn 5 phases below the annealing temperature of 700 deg C. It results in Nb 3 Sn appearance at the annealing temperatures above 600 deg C. The critical current increase is explained as follows: lower Nb 3 Sn appearance temperatures provide fine-grained structure of superconducting Nb 3 Sn layer with greater density of binning centers and with higher critical current in accordance with NbSn prepared by the diffusion of pure tin into niobium

Enhanced Inhibitory Effect of Ultra-Fine Granules of Red Ginseng on LPS-induced Cytokine Expression in the Monocyte-Derived Macrophage THP-1 Cells

Directory of Open Access Journals (Sweden)

Hong-Yeoul Kim

2008-08-01

Full Text Available Red ginseng is one of the most popular traditional medicines in Korea because its soluble hot-water extract is known to be very effective on enhancing immunity as well as inhibiting inflammation. Recently, we developed a new technique, called the HACgearshift system, which can pulverize red ginseng into the ultra-fine granules ranging from 0.2 to 7.0 μm in size. In this study, the soluble hot-water extract of those ultra-fine granules of red ginseng (URG was investigated and compared to that of the normal-sized granules of red ginseng (RG. The high pressure liquid chromatographic analyses of the soluble hot-water extracts of both URG and RG revealed that URG had about 2-fold higher amounts of the ginsenosides, the biologically active components in red ginseng, than RG did. Using quantitative RT-PCR, cytokine profiling against the Escherichia coli lipopolysaccharide (LPS in the monocyte-derived macrophage THP-1 cells demonstrated that the URG-treated cells showed a significant reduction in cytokine expression than the RG-treated ones. Transcription expression of the LPS-induced cytokines such as TNF-α, IL-1β, IL-6, IL-8, IL-10, and TGF-β was significantly inhibited by URG compared to RG. These results suggest that some biologically active and soluble components in red ginseng can be more effectively extracted from URG than RG by standard hot-water extraction.

Characterization of nanoparticle and porous ultra low-k using positron beam

International Nuclear Information System (INIS)

Xu, Jun; Moxom, J.; Suzuki, R.; Ohdaira, T.; Mills, A.P. Jr.

2003-01-01

Nanoparticle materials are important because they exhibit unique properties due to size effects, quantum tunneling, and quantum confinement. As particle sizes are reduced to the nanometer scale, presence of vacancy clusters is expected to affect properties of nanomaterials. A combination of positron lifetime spectroscopy, which tells size of vacancy clusters, and coincidence Doppler broadening of annihilation radiation, which tell where vacancy clusters are located was used to study defect structures on nanomaterials of Au nanoparticles embedded in MgO. Vacancy clusters were found on the surfaces of Au nanoparticles. When the packing density between multilevel interconnects in microelectronic devices increases, a low dielectric constant material is needed to minimize RC delay. Porous oxide films are some of these new low-k materials that have been actively studied by the microelectronics industry. An ideal porous material would consist of a network of closed, small pores with narrow size distribution. However, large and interconnected pores, so called 'killer pores', result in high current leakage and poor mechanical strength. Clearly, characterization and understanding of pore size and interconnectivity are important to optimize the design of porous materials. Using positron beam, we have found that pore percolation in porous methyl-silsesquioxane (MSQ) films strongly depends on the molecular mass of pore generators. (author)

The use of a hierarchically platinum-free electrode composed of tin oxide decorated polypyrrole on nanoporous copper in catalysis of methanol electrooxidation

Energy Technology Data Exchange (ETDEWEB)

Asghari, Elnaz, E-mail: elnazasghari@yahoo.com; Ashassi-Sorkhabi, Habib; Vahed, Akram; Rezaei-Moghadam, Babak; Charmi, Gholam Reza

2016-01-01

Tin oxide nanoparticles were synthesized through a galvanostatic pathway on polypyrrole, PPy, coated nanoporous copper. The morphology and surface analysis of the assemblies were evaluated by field emission scanning electron microscopy, FESEM, and energy dispersive X-ray, EDX, analysis, respectively. The electrocatalytic behavior of electrodes was studied by cyclic voltammetry and chronoamperometry tests in methanol solution. FESEM results showed that uniformly distributed nanoparticles with diameters of about 20–30 nm have been dispersed on PPy matrix. Cyclic voltammetry and chronoamperometry tests in methanol solution showed a significant enhancement in the catalytic action of PPy after decoration of tin oxide nanoparticles. Porous Cu/PPy/SnO{sub x} electrodes showed enhanced anodic peak current density for methanol oxidation compared to smooth Cu/PPy/SnO{sub x} and porous Cu/PPy. The effects of synthesis current density and time on the electrocatalytic behavior of the electrodes were evaluated. The significant enhancement of electrocatalytic behavior of the Cu/PPy electrode after decoration of SnO{sub x} overlayer was attributed to the effect of tin oxide on the adsorption of intermediates of methanol oxidation as well as oxidation of bi-products such as CO; huge tendency of tin oxides for dehydrogenation of the alcohols and the increase in microscopic surface area of the electrodes were introduced as other affecting factors. - Highlights: • Nanoporous copper–zinc substrates were formed by chemical leaching of zinc. • Polypyrrole thin film was electrodeposited on nanoporous copper. • Thin oxide nanoparticles were synthesized electrochemically on polypyrrole layer. • The catalytic performance of the electrodes was evaluated for methanol oxidation.

MAGNOLOL ENTRAPPED ULTRA-FINE FIBROUS MATS ELECTROSPUN FROM POLY(ETHYLENE GLYCOL)-b-POLY(L-LACTIDE) AND IN VITRO RELEASE

Institute of Scientific and Technical Information of China (English)

Hao Wang; Hong-rui Song; Yong Cui; Ying-jie Deng; Xue-si Chen

2011-01-01

Ultra-fine fibrous mats with magnolol entrapped have been prepared by electrospinning biodegradable copolymer poly(ethylene glycol) blocked poly(L-lactide). Drug entrapment was perfect which was confirmed by scanning electron microscopy and differential scanning calorimetry. According to in vitro drug release investigation by high performance liquid chromatography, it was found that fibers with 10％, 20％ and 30％ drug entrapped respect to polymer (mass ratio) presented dramatically different drug release behavior and degradation behavior under the effect of proteinase K. The reason may be that fibers with 10％ drug entrapped was more easily affected by enzyme while, to some degree, magnolol in fibers with 20％ and 30％ entrapped prevented polymer from being degraded by enzyme.

Properties of hard alloys on the basis of WC-Co with the additives of nanodisperse TiN

International Nuclear Information System (INIS)

Ordanyan, S.S.; Andronova, T.E.; Vladimirova, M.A.; Pantelejev, I.B.; Zalite, I.

2001-01-01

The addition of nanodisperse titanium nitride (specific surface area of 20 - 30 m 2 /g, medium diameter of grains of 50 - 100 nm) to the starting hard alloy WC-Co in the stage of wet grinding allows to get some advantages: the growth of WC grains is retarded by the nanoparticles of TiN, being as a barrier for the process of secondary crystallization, and the toughness of hard alloy is being increased due to the formation of finely dispersed structure; the exploitation characteristics of cutting instruments are increased due to the volume alloying by means of titanium nitride having a decreased adhesion to the treated metal and decreased coefficient of friction; the formation of diffusion porosity is being eliminated due to the small size of TiN during the unavoidable dissolution of WC in TiN. (author)

Comparative assessment of gastrointestinal irritant potency in man of tin(II) chloride and tin migrated from packaging.

Science.gov (United States)

Boogaard, Peter J; Boisset, Michel; Blunden, Steve; Davies, Scot; Ong, Teng Jin; Taverne, Jean-Pierre

2003-12-01

Tin is present in low concentrations in most canned foods and beverages, the highest levels being found in products packaged in unlacquered or partially lacquered tinplate cans. A limited number of case-reports of acute gastrointestinal disorders after consumption of food containing 100-500 mg/kg tin have been reported, but these reports suffer many insufficiencies. Controlled clinical studies on acute effects of tin migrated from packaging suggest a threshold concentration for adverse effects (AEs) of >730 mg/kg. Two separate randomised, single-centre, double-blind, crossover studies, enabling comparison of the tolerability of tin added as tin(II) chloride at concentrations of soup in 24 volunteers (Study 2) were carried out. Distribution studies were conducted to get insight in the acute AEs of low molecular weight (clear dose-response relationship was only observed when tin was added as tin(II) chloride in tomato juice. No clinically significant AEs were reported in Study 2 and comparison of the incidence of tin-related AEs showed no difference between the dose levels (including control). Tin species of low molecular weight in supernatant represented 31-32% of total tin in canned tomato soup versus 56-61% in juice freshly spiked with tin(II) chloride. Differences in the incidence of AEs following administration of tomato juice with 161 and 264 mg of tin per kg and tomato soup with 201 and 267 mg of tin per kg likely results from differences in the concentration of low molecular weight tin species and in the nature of tin complexes formed. The results of this work demonstrate that tin levels up to 267 mg/kg in canned food cause no AEs in healthy adults and support the currently proposed tin levels of 200 mg/kg and 250 mg/kg for canned beverages and canned foods, respectively, as safe levels for adults in the general population.

Comparison of gate dielectric plasma damage from plasma-enhanced atomic layer deposited and magnetron sputtered TiN metal gates

Energy Technology Data Exchange (ETDEWEB)

Brennan, Christopher J.; Neumann, Christopher M.; Vitale, Steven A., E-mail: steven.vitale@ll.mit.edu [Lincoln Laboratory, Massachusetts Institute of Technology, Lexington, Massachusetts 02420 (United States)

2015-07-28

Fully depleted silicon-on-insulator transistors were fabricated using two different metal gate deposition mechanisms to compare plasma damage effects on gate oxide quality. Devices fabricated with both plasma-enhanced atomic-layer-deposited (PE-ALD) TiN gates and magnetron plasma sputtered TiN gates showed very good electrostatics and short-channel characteristics. However, the gate oxide quality was markedly better for PE-ALD TiN. A significant reduction in interface state density was inferred from capacitance-voltage measurements as well as a 1200× reduction in gate leakage current. A high-power magnetron plasma source produces a much higher energetic ion and vacuum ultra-violet (VUV) photon flux to the wafer compared to a low-power inductively coupled PE-ALD source. The ion and VUV photons produce defect states in the bulk of the gate oxide as well as at the oxide-silicon interface, causing higher leakage and potential reliability degradation.

Hydrolysis of bis(dimethylamido)tin to tin (II) oxyhydroxide and its selective transformation into tin (II) or tin (IV) oxide

KAUST Repository

Khanderi, Jayaprakash

2015-03-01

Sn6O4(OH)4, a hydrolysis product of Sn(NMe2)2, is transformed to tin (II) or tin (IV) oxide by solid and solution phase processing. Tin (II) oxide is formed by heating Sn6O4(OH)4 at ≤200 °C in air or under inert atmosphere. Tin (IV) oxide nanoparticles are formed in the presence of a carboxylic acid and base in air at room temperature. IR spectroscopy, Raman spectroscopy, thermogravimetry (coupled with infrared spectroscopy), powder X-ray diffraction, high temperature X-ray diffraction, scanning electron and transmission electron microscopy are used for the characterization of Sn6O4(OH)4 and the investigation of its selective decomposition into SnO or SnO2. Spectroscopic and X-ray diffraction results indicate that SnO is formed by the removal of water from crystalline Sn6O4(OH)4. SEM shows octahedral morphology of the Sn6O4(OH)4, SnO and SnO2 with particle size from 400 nm-2 μm during solid state conversion. Solution phase transformation of Sn6O4(OH)4 to SnO2 occurs in the presence of potassium glutarate and oxygen. SnO2 particles are 15-20 nm in size.

Multi-band emission in a wide wavelength range from tin oxide/Au nanocomposites grown on porous anodic alumina substrate (AAO)

International Nuclear Information System (INIS)

Norek, Małgorzata; Michalska-Domańska, Marta; Stępniowski, Wojciech J.; Ayala, Israel; Bombalska, Aneta; Budner, Bogusław

2013-01-01

The photoluminescence (PL) properties of tin oxide nanostructures are investigated. Three samples of different morphology, induced by deposition process and various geometrical features of nanoporous anodic aluminum oxide (AAO) substrate, are analyzed. X-ray photoelectronic spectroscopy (XPS) analysis reveals the presence of two forms of tin oxide on the surface of all studied samples: SnO and SnO 2 . The former form is typical for reduced surface with bridging oxygen atoms and every other row of in-plane oxygen atoms removed. The oxygen defects give rise to a strong emission in visible region. Two intense PL peaks are observed centered at about 540 (band I) and 620 (band II) nm. The origin of these bands was ascribed to the recombination of electrons from the conduction band (band I) and shallow traps levels (band II) to the surface oxygen vacancy levels. Upon deposition of Au nanoparticles on the top of tin oxide nanostructures the emission at 540 and 620 nm disappears and a new band (band III) occurs in the range >760 nm. The PL mechanism operating in the studied systems is discussed. The tin oxide/Au nanocomposites can be used as efficient multi-band light emitters in a wide (from visible to near infrared) wavelength range.

Super-adiabatic combustion in Al2O3 and SiC coated porous media for thermoelectric power conversion

International Nuclear Information System (INIS)

Mueller, Kyle T.; Waters, Oliver; Bubnovich, Valeri; Orlovskaya, Nina; Chen, Ruey-Hung

2013-01-01

The combustion of ultra-lean fuel/air mixtures provides an efficient way to convert the chemical energy of hydrocarbons and low-calorific fuels into useful power. Matrix-stabilized porous medium combustion is an advanced technique in which a solid porous medium within the combustion chamber conducts heat from the hot gaseous products in the upstream direction to preheat incoming reactants. This heat recirculation extends the standard flammability limits, allowing the burning of ultra-lean and low-calorific fuel mixtures and resulting a combustion temperature higher than the thermodynamic equilibrium temperature of the mixture (i.e., super-adiabatic combustion). The heat generated by this combustion process can be converted into electricity with thermoelectric generators, which is the goal of this study. The design of a porous media burner coupled with a thermoelectric generator and its testing are presented. The combustion zone media was a highly-porous alumina matrix interposed between upstream and downstream honeycomb structures with pore sizes smaller than the flame quenching distance, preventing the flame from propagating outside of the central section. Experimental results include temperature distributions inside the combustion chamber and across a thermoelectric generator; along with associated current, voltage and power output values. Measurements were obtained for a catalytically inert Al 2 O 3 medium and a SiC coated medium, which was tested for the ability to catalyze the super-adiabatic combustion. The combustion efficiency was obtained for stoichiometric and ultra-lean (near the lean flammability limit) mixtures of CH 4 and air. - Highlights: • Design of a porous burner coupled with a thermoelectric module. • Super-adiabatic combustion in a highly-porous ceramic matrix was investigated. • Both alumina and silicon carbide ceramic surfaces were used as porous media. • Catalytic properties of Al 2 O 3 and SiC ceramic surfaces were studied

Development of laundry drainage treatment system with ceramic ultra filter

International Nuclear Information System (INIS)

Kanda, Masanori; Kurahasi, Takafumi

1995-01-01

A compact laundry drainage treatment system (UF system hereafter) with a ceramic ultra filter membrane (UF membrane hereafter) has been developed to reduce radioactivity in laundry drainage from nuclear power plants. The UF membrane is made of sintered fine ceramic. The UF membrane has 0.01 μm fine pores, resulting in a durable, heat-resistant, and corrosion-resistant porous ceramic filter medium. A cross-flow system, laundry drainage is filtrated while it flows across the UF membrane, is used as the filtration method. This method creates less caking when compared to other methods. The UF membrane is back washed at regular intervals with permeated water to minimize caking of the filter. The UF membrane and cross-flow system provides long stable filtration. The ceramic UF membrane is strong enough to concentrate suspended solids in laundry drainage up to a weight concentration of 10%. The final concentrated laundry drainage can be treated in an incinerator. The performance of the UF system was checked using radioactive laundry drainage. The decontamination factor of the UF system was 25 or more. The laundry drainage treatment capacity and concentration ratio of the UF system, as well as the service life of the UF membrane were also checked by examination using simulated non-radioactive laundry drainage. Even though laundry drainage was concentrated 1000 times, the UF system showed good permeated water quality and permeated water flux. (author)

X-ray and synchrotron studies of porous silicon

Energy Technology Data Exchange (ETDEWEB)

Sivkov, V. N., E-mail: svn@dm.komisc.ru [Russian Academy of Sciences, Komi Scientific Center, Ural Branch (Russian Federation); Lomov, A. A. [Russian Academy of Sciences, Physical-Technological Institute (Russian Federation); Vasil' ev, A. L. [Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation); Nekipelov, S. V. [Komi State Pedagogical Institute (Russian Federation); Petrova, O. V. [Russian Academy of Sciences, Komi Scientific Center, Ural Branch (Russian Federation)

2013-08-15

The results of comprehensive studies of layers of porous silicon of different conductivity types, grown by anodizing standard Si(111) substrates in an electrolyte based on fluoric acid and ethanol with the addition of 5% of iodine and kept in air for a long time, are discussed. Measurements are performed by scanning electron microscopy, high-resolution X-ray diffraction, and ultrasoft X-ray spectroscopy using synchrotron radiation. The structural parameters of the layers (thickness, strain, and porosity) and atomic and chemical composition of the porous-silicon surface are determined. It is found that an oxide layer 1.5-2.3-nm thick is formed on the surface of the silicon skeleton. The near-edge fine structure of the Si 2p absorption spectrum of this layer corresponds to the fine structure of the 2p spectrum of well coordinated SiO{sub 2}. In this case, the fine structure in the Si 2p-edge absorption region of the silicon skeleton is identical to that of the 2p absorption spectrum of crystalline silicon.

Characterization of SiC based composite materials by the infiltration of ultra-fine SiC particles

International Nuclear Information System (INIS)

Lee, J.K.; Lee, S.P.; Byun, J.H.

2010-01-01

The fabrication route of SiC materials by the complex compound of ultra-fine SiC particles and oxide additive materials has been investigated. Especially, the effect of additive composition ratio on the characterization of SiC materials has been examined. The characterization of C/SiC composites reinforced with plain woven carbon fabrics was also investigated. The fiber preform for C/SiC composites was prepared by the infiltration of complex mixture into the carbon fabric structure. SiC based composite materials were fabricated by a pressure assisted liquid phase sintering process. SiC materials possessed a good density higher than about 3.0 Mg/m 3 , accompanying the creation of secondary phase by the chemical reaction of additive materials. C/SiC composites also represented a dense morphology in the intra-fiber bundle region, even if this material had a sintered density lower than that of monolithic SiC materials. The flexural strength of SiC materials was greatly affected by the composition ratio of additive materials.

Porous-Nickel-Scaffolded Tin-Antimony Anodes with Enhanced Electrochemical Properties for Li/Na-Ion Batteries.

Science.gov (United States)

Li, Jiachen; Pu, Jun; Liu, Ziqiang; Wang, Jian; Wu, Wenlu; Zhang, Huigang; Ma, Haixia

2017-08-02

The energy and power densities of rechargeable batteries urgently need to be increased to meet the ever-increasing demands of consumer electronics and electric vehicles. Alloy anodes are among the most promising candidates for next-generation high-capacity battery materials. However, the high capacities of alloy anodes usually suffer from some serious difficulties related to the volume changes of active materials. Porous supports and nanostructured alloy materials have been explored to address these issues. However, these approaches seemingly increase the active material-based properties and actually decrease the electrode-based capacity because of the oversized pores and heavy mass of mechanical supports. In this study, we developed an ultralight porous nickel to scaffold with high-capacity SnSb alloy anodes. The porous-nickel-supported SnSb alloy demonstrates a high specific capacity and good cyclability for both Li-ion and Na-ion batteries. Its capacity retains 580 mA h g -1 at 2 A g -1 after 100 cycles in Li-ion batteries. For a Na-ion battery, the composite electrode can even deliver a capacity of 275 mA h g -1 at 1 A g -1 after 1000 cycles. This study demonstrates that combining the scaffolding function of ultralight porous nickel and the high capacity of the SnSb alloy can significantly enhance the electrochemical performances of Li/Na-ion batteries.

International strategic minerals inventory summary report; tin

Science.gov (United States)

Sutphin, D.M.; Sabin, A.E.; Reed, B.L.

1990-01-01

The International Strategic Minerals Inventory tin inventory contains records for 56 major tin deposits and districts in 21 countries. These countries accounted for 98 percent of the 10 million metric tons of tin produced in the period 1934-87. Tin is a good alloying metal and is generally nontoxic, and its chief uses are as tinplate for tin cans and as solder in electronics. The 56 locations consist of 39 lode deposits and 17 placers and contain almost 7.5 million metric tons of tin in identified economic resources (R1E) and another 1.5 million metric tons of tin in other resource categories. Most of these resources are in major deposits that have been known for over a hundred years. Lode deposits account for 44 percent of the R1E and 87 percent of the resources in other categories. Placer deposits make up the remainder. Low-income and middle-income countries, including Bolivia and Brazil and countries along the Southeast Asian Tin Belt such as Malaysia, Thailand, and Indonesia account for 91 percent of the R1E resources of tin and for 61 percent of resources in other categories. The United States has less than 0.05 percent of the world's tin R1E in major deposits. Available data suggest that the Soviet Union may have about 4 percent of resources in this category. The industrial market economy countries of the United States, Japan, Federal Republic of Germany, and the United Kingdom are major consumers of tin, whereas the major tin-producing countries generally consume little tin. The Soviet Union and China are both major producers and consumers of tin. At the end of World War II, the four largest tin-producing countries (Bolivia, the Belgian Congo (Zaire), Nigeria, and Malaysia) produced over 80 percent of the world's tin. In 1986, the portion of production from the four largest producers (Malaysia, Brazil, Soviet Union, Indonesia) declined to about 55 percent, while the price of tin rose from about $1,500 to $18,000 per metric ton. In response to tin shortages

Sol–gel synthesis of nanostructured indium tin oxide with controlled morphology and porosity

Energy Technology Data Exchange (ETDEWEB)

Kőrösi, László, E-mail: ltkorosi@gmail.com [Department of Biotechnology, Nanophage Therapy Center, Enviroinvest Corporation, Kertváros u. 2, H-7632 Pécs (Hungary); Scarpellini, Alice [Department of Nanochemistry, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genova (Italy); Petrik, Péter [Institute for Technical Physics and Materials Science, Konkoly-Thege út 29-33, H-1121 Budapest (Hungary); Papp, Szilvia [Department of Biotechnology, Nanophage Therapy Center, Enviroinvest Corporation, Kertváros u. 2, H-7632 Pécs (Hungary); Dékány, Imre [MTA-SZTE Supramolecular and Nanostructured Materials Research Group, University of Szeged, Dóm tér 8, H-6720 Szeged (Hungary)

2014-11-30

Graphical abstract: - Highlights: • Nanocrystalline ITO thin films and powders were prepared by a sol–gel method. • The nature of the compounds used for hydrolysis plays a key role in the morphology. • Hydrolysis of In{sup 3+}/Sn{sup 4+} with EA led to a rod-like morphology. • Monodisperse spherical ITO nanoparticles were obtained on the use of AC. • ITO{sub E}A was highly porous, while ITO{sub A}C contained densely packed nanocrystals. - Abstract: Nanostructured indium tin oxide (ITO) powders and thin films differing in morphology and porosity were prepared by a sol–gel method. In{sup 3+} and Sn{sup 4+} were hydrolyzed in aqueous medium through the use of ethanolamine (EA) or sodium acetate (AC). X-ray diffraction measurements demonstrated that both EA and AC furnished indium tin hydroxide, which became nanocrystalline after aging for one day. The indium tin hydroxide samples calcined at 550 °C afforded ITO with a cubic crystal structure, but the morphology differed significantly, depending on the agent used for hydrolysis. Electron microscopy revealed the formation of round monodisperse nanoparticles when AC was used, whereas the application of EA led to rod-like ITO nanoparticles. Both types of nanoparticles were suitable for the preparation of transparent and conductive ITO thin films. The influence of the morphology and porosity on the optical properties is discussed.

Organic photovoltaics using thin gold film as an alternative anode to indium tin oxide

International Nuclear Information System (INIS)

Haldar, Amrita; Yambem, Soniya D.; Liao, Kang-Shyang; Alley, Nigel J.; Dillon, Eoghan P.; Barron, Andrew R.; Curran, Seamus A.

2011-01-01

Indium Tin Oxide (ITO) is the most commonly used anode as a transparent electrode and more recently as an anode for organic photovoltaics (OPVs). However, there are significant drawbacks in using ITO which include high material costs, mechanical instability including brittleness and poor electrical properties which limit its use in low-cost flexible devices. We present initial results of poly(3-hexylthiophene): phenyl-C 61 -butyric acid methyl ester OPVs showing that an efficiency of 1.9% (short-circuit current 7.01 mA/cm 2 , open-circuit voltage 0.55 V, fill factor 0.49) can be attained using an ultra thin film of gold coated glass as the device anode. The initial I-V characteristics demonstrate that using high work function metals when the thin film is kept ultra thin can be used as a replacement to ITO due to their greater stability and better morphological control.

Chemistry of tin compounds and environment

International Nuclear Information System (INIS)

Ali, S.; Mazhar, M.; Mahmood, S.; Bhatti, M.H.; Chaudhary, M.A.

1997-01-01

Of the large volume of tin compounds reported in the literature, possible only 100 are commercially important. Tin compounds are a wide variety of purposes such as catalysts, stabilizers for many materials including polymer, biocidal agents, bactericides, insecticides, fungicides, wood preservatives, acaricides and anti fouling agents in paints, anticancer and antitumour agents, ceramic opacifiers, as textile additives, in metal finishing operations, as food additives and in electro conductive coating. All these applications make the environment much exposed to tin contamination. The application of organotin compounds as biocides account for about 30% of total tin consumption suggesting that the main environmental effects are likely to originate from this sector. Diorgano tins and mono-organo tins are used mainly in plastic industry which is the next big source for environmental pollution. In this presentation all environmental aspects of the use of tin compounds and the recommended preventive measures are discussed. (author)

Synthesising highly reactive tin oxide using Tin(II2- ethylhexanoate polynucleation as precursor

Directory of Open Access Journals (Sweden)

Alejandra Montenegro Hernández

2009-01-01

Full Text Available Tin oxide is a widely used compound in technological applications, particularity as a catalyst, gas sensor and in making varistors, transparent conductors, electrocatalytic electrodes and photovoltaic cells. An ethylhexanoate tin salt, a carboxylic acid and poly-esterification were used for synthesising highly reactive tin oxide in the present study. Synthesis was controlled by Fourier transform infrared (FTIR spectroscopy and recording changes in viscosity. The tin oxide characteristics so obtained were determined using FTIR spectroscopy, X-ray diffraction (XRD and scanning electron microscopy (SEM. The SnO2 dust synthesised and heat-treated at 550°C yielded high density aggregates, having greater than 50 μm particle size. This result demonstrates the high reactivity of the ceramic powders synthesised here.

Measuring the sustainability of tin in China.

Science.gov (United States)

Yang, Congren; Tan, Quanyin; Zeng, Xianlai; Zhang, Yuping; Wang, Zhishi; Li, Jinhui

2018-09-01

Tin is a component of many items used in daily activities, including solder in consumer electronics, tin can containing food and beverages, polyvinyl chloride stabilizers in construction products, catalysts in industrial processes, etc. China is the largest producer and consumer of refined tin, and more than 60% of this refined tin is applied in the electronics sector as solder. China is the leader in global economic growth; simultaneously, China is also a major producer and consumer of electrical and electronic equipment (EEE). Thus, future tin supply and demand in China are forecasted, based on the gross domestic product per capita and the average consumption of refined tin in past five years. Current tin reserves and identified resources in China can meet the future two decades of mine production, but import of tin will also be critical for China's future tin consumption. However, there will be a lot of uncertainty for import of tin from other countries. At the same time, virgin mining of geological ores is a process of high energy consumption and destruction of the natural environment. Hence recycling tin from Sn-bearing secondary resources like tailings and waste electrical and electronic equipment (WEEE) can not only address the shortage of tin mineral resources, but also save energy and protect the ecological environment. Copyright © 2018 Elsevier B.V. All rights reserved.

Fatigue properties of ultra-fine grain Cu–Cr alloy processed by equal-channel angular pressing

International Nuclear Information System (INIS)

Wang, Q.J.; Du, Z.Z.; Luo, L.; Wang, W.

2012-01-01

Highlights: ► The UFG Cu–Cr alloys processed by ECAP possess high strength and sufficient ductility. ► The ECAPed sample with UFG under strain controlled fatigue exhibited cyclic softening and lower fatigue limit compared to the unECAPed one. ► That cyclic softening of UFG Cu–Cr alloy is associated with some dislocation annihilation and the substructure recovery. ► Shear bands, microcracks and final fracture of UFG Cu–Cr fatigue samples occur predominantly along the shear plane corresponding to the last ECAP. - Abstract: A precipitation-hardening copper based alloy (Cu–0.6 wt.% Cr) was selected and the ultra-fine grain (UFG) microstructure was obtained by equal channel angular pressing (ECAP). The alloys tensile behaviors and fatigue properties were investigated experimentally, the results indicated that the Cu–Cr alloy processed by ECAP possessed high strength and sufficient ductility and the 12-passes ECAPed sample with UFG under strain controlled fatigue exhibited cyclic softening and lower fatigue limit compared to the unECAPed one. Moreover, the shear bands on the surface of cycled samples were also studied by scanning electron microscopy, the results showed that the oriented distribution of defects along the shear plane in the last ECAP processing was one of the major mechanisms of SBs formation.

Current status and application of fine screening technology in China

Science.gov (United States)

Chernova, E. V.; Chernov, D. V.

2017-10-01

The paper presents data on the design and technical parameters of high frequency vibrating screens, which are produced by Chinese manufacturer - company Landsky Tech Ltd. The technology of high frequency vibration is widely used at mining and metallurgical industries to separate fine and ultra-fine particles from the flow of dry material or pulp. The paper contains different types of screening systems, description, advantages and disadvantages of equipment and test results from mineral processing plants.

Low-temperature Synthesis of Tin(II) Oxide From Tin(II) ketoacidoximate Precursor

KAUST Repository

Alshankiti, Buthainah

2015-01-01

Sn (II) oxide finds numerous applications in different fields such as thin film transistors1, solar cells2 and sensors.3 In this study we present the fabrication of tin monoxide SnO by using Sn (II) ketoacid oximate complexes as precursors. Tin (II

The determination, by x-ray-fluorescence spectrometry, of tin and tungsten in scheelite and cassiterite ores and concentrates

International Nuclear Information System (INIS)

Tolmay, R.T.; Jacobs, J.J.

1980-01-01

A method of analysis is presented that is applicable to sample mixtures of cassiterite and scheelite in concentrations of 0,2 to 70 per cent. Matrix variations are compensated for by dilution and fine grinding with coarse river sand, potassium chloride being used as a binder. Residual matrix effects are corrected for by the use of zinc and antimony as internal standards for tungsten and tin respectively. Calibration graphs are obtained by the use of chemically analysed scheelite and cassiterite standards. For tin, the relative standard deviation at a concentration of 60 per cent is 0,0063, and, at 10 per cent, 0,028; for tungsten, it is 0,013 at a concentration of 40 per cent. The lower levels of detection for tungsten and tin are 0,26 and 0,23 per cent respectively, and the time required for the analysis of 10 samples and 5 calibration standards by this method is 5 hours. A detailed laboratory method is given in the appendix [af

Gradient porous hydroxyapatite ceramics fabricated by freeze casting method

International Nuclear Information System (INIS)

Zuo Kaihui; Zhang Yuan; Jiang Dongliang; Zeng Yuping

2011-01-01

By controlling the cooling rates and the composition of slurries, the gradient porous hydroxyapatite ceramics are fabricated by the freeze casting method. According to the different cooling rate, the pores of HAP ceramics fabricated by gradient freeze casting are divided into three parts: one is lamellar pores, another is column pore and the last one is fine round pores. The laminated freeze casting is in favour of obtaining the gradient porous ceramics composed of different materials and the ceramics have unclear interfaces.

Influence of Al sub 2 O sub 3 nanoparticles on the thermal stability of ultra-fine grained copper prepared by high pressure torsion

CERN Document Server

Cizek, J; Kuzel, R; Islamgaliev, R K

2002-01-01

Ultra-fine grained (UFG) Cu (grain size 80 nm) containing 0.5 wt.% Al sub 2 O sub 3 nanoparticles (size 20 nm) was prepared by high pressure torsion (HPT). Positron lifetime spectroscopy was employed to characterize the microstructure of this material, especially with respect to types and concentration of lattice defects. The evolution of microstructure with increasing temperature was studied by positron lifetime spectroscopy and x-ray diffraction measurements. The thermal stability of the Cu + 0.5 wt.% Al sub 2 O sub 3 nanocomposite was compared with that of pure UFG Cu prepared by the same technique. The processes taking place during thermal recovery of the initial nanoscale structure in both studied materials are described. (author)

Ultra-fine SnO2 nanoparticles doubly embedded in amorphous carbon and reduced graphene oxide (rGO) for superior lithium storage

International Nuclear Information System (INIS)

Sher Shah, Md. Selim Arif; Lee, Jooyoung; Park, A. Reum; Choi, Youngjin; Kim, Woo-Jae; Park, Juhyun; Chung, Chan-Hwa; Kim, Jaeyun; Lim, Byungkwon; Yoo, Pil J.

2017-01-01

SnO 2 is a well-studied anode material for lithium ion batteries (LIBs). However, it undergoes severe capacity fading because of a large volume change (∼300%) during cycling. Composites of SnO 2 with electro-conductive graphene would deliver improved capacity and rate performance. Nevertheless, achieving the theoretical capacity of SnO 2 is still elusive, mainly because of disintegration of the active material from graphene and severe aggregation of SnO 2 , or Sn nanoparticles produced upon cycling. To surmount these limitations, in this work, nanocomposites containing ultra-fine sized SnO 2 nanoparticles (UFSN) with reduced graphene oxide and amorphous carbon were synthesized in a single step at low temperature and environmentally benign way, in which ascorbic acid was employed as the carbon source and reducing agent. UFSN could decrease the lithium ion diffusion path length. As a result of effective buffering effect afforded by the mesoporous structure against volume change and improved lithium ion diffusivity, the ternary nanocomposite achieves ultra-high capacity of 1245 mAh g −1 after 210 cycles at 100 mA g −1 and excellent cycling stability. Since the proposed approach is facile, straightforward, and highly reproducible, it is anticipated that this system would be a potential alternative to the conventional graphite anode for LIBs.

Granular nanocrystalline zirconia electrolyte layers deposited on porous SOFC cathode substrates

International Nuclear Information System (INIS)

Seydel, Johannes; Becker, Michael; Ivers-Tiffee, Ellen; Hahn, Horst

2009-01-01

Thin granular yttria-stabilized zirconia (YSZ) electrolyte layers were prepared by chemical vapor synthesis and deposition (CVD/CVS) on a porous substoichiometric lanthanum-strontium-manganite (ULSM) solid oxide fuel cell cathode substrate. The substrate porosity was optimized with a screen printed fine porous buffer layer. Structural analysis by scanning electron microscopy showed a homogeneous, granular nanocrystalline layer with a microstructure that was controlled via reactor settings. The CVD/CVS gas-phase process enabled the deposition of crack-free granular YSZ films on porous ULSM substrates. The electrolyte layers characterized with impedance spectroscopy exhibited enhanced grain boundary conductivity.

Ultra-Fine Bubble Distributions in a Plant Factory Observed by Transmission Electron Microscope with a Freeze-Fracture Replica Technique

Directory of Open Access Journals (Sweden)

Tsutomu Uchida

2018-03-01

Full Text Available Water containing ultra-fine bubbles (UFB may promote plant growth. But, as UFBs are too small to distinguish from other impurities in a nutrient solution, it is not known if UFBs survive transport from the water source to the rhizosphere. Here we use the freeze-fracture replica method and a transmission electron microscope (TEM to observe UFBs in the nutrient solutions used in a crop-growing system known as a plant factory. In this factory, TEM images taken from various points in the supply line indicate that the concentration of UFBs in the nutrient solution is conserved, starting from their addition to the nutrient solution in the buffer tank, through the peat-moss layer, all the way to the rhizosphere. Measurements also show that a thin film formed on the surface of UFBs in the nutrient solution, with greater film thickness at the rhizosphere. This film is considered to be made from the accumulation of impurities coming from solute and the peat-moss layer.

Structural studies of supported tin catalysts

Science.gov (United States)

Nava, Noel; Viveros, Tomás

1999-11-01

Tin oxide was supported on aluminium oxide, titanium oxide, magnesium oxide and silicon oxide, and the resulting interactions between the components in the prepared samples and after reduction were characterized by Mössbauer spectroscopy. It was observed that in the oxide state, tin is present as SnO2 on alumina, magnesia and silica, but on titania tin occupies Ti sites in the structure. After hydrogen treatment at high temperatures, tin is reduced from Sn(4) to Sn(2) on alumina and titania; it is reduced from Sn(4) to Sn(0) on silica, and is practically not reduced on magnesia. These results reveal the degree of interaction between tin and the different supports studied.

Structural studies of supported tin catalysts

International Nuclear Information System (INIS)

Nava, Noel; Viveros, Tomas

1999-01-01

Tin oxide was supported on aluminium oxide, titanium oxide, magnesium oxide and silicon oxide, and the resulting interactions between the components in the prepared samples and after reduction were characterized by Moessbauer spectroscopy. It was observed that in the oxide state, tin is present as SnO 2 on alumina, magnesia and silica, but on titania tin occupies Ti sites in the structure. After hydrogen treatment at high temperatures, tin is reduced from Sn(4) to Sn(2) on alumina and titania; it is reduced from Sn(4) to Sn(0) on silica, and is practically not reduced on magnesia. These results reveal the degree of interaction between tin and the different supports studied

Utilization of Pebax 1657 as structure directing agent in fabrication of ultra-porous ZIF-8

Energy Technology Data Exchange (ETDEWEB)

Jomekian, A. [Gas Engineering Department, Ahvaz Faculty of Petroleum Engineering, Petroleum University of Technology (PUT), Post Office Box 63431, Ahvaz (Iran, Islamic Republic of); Faculty of Chemical Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran (Iran, Islamic Republic of); Behbahani, R.M., E-mail: behbahani@put.ac.ir [Gas Engineering Department, Ahvaz Faculty of Petroleum Engineering, Petroleum University of Technology (PUT), Post Office Box 63431, Ahvaz (Iran, Islamic Republic of); Mohammadi, T. [Faculty of Chemical Engineering, Iran University of Science and Technology (IUST), Narmak, Tehran (Iran, Islamic Republic of); Kargari, A. [Department of Petrochemical Engineering, Amirkabir University of Technology (AUT), Mahshahr (Iran, Islamic Republic of)

2016-03-15

Ultra porous ZIF-8 particles synthesized using PEO/PA6 based poly(ether-block-amide) (Pebax 1657) as structure directing agent. Structural properties of ZIF-8 samples prepared under different synthesis parameters were investigated by laser particle size analysis, XRD, N{sub 2} adsorption analysis, BJH and BET tests. The overall results showed that: (1) The mean pore size of all ZIF-8 samples increased remarkably (from 0.34 nm to 1.1–2.5 nm) compared to conventionally synthesized ZIF-8 samples. (2) Exceptional BET surface area of 1869 m{sup 2}/g was obtained for a ZIF-8 sample with mean pore size of 2.5 nm. (3) Applying high concentrations of Pebax 1657 to the synthesis solution lead to higher surface area, larger pore size and smaller particle size for ZIF-8 samples. (4) Both, Increase in temperature and decrease in molar ratio of MeIM/Zn{sup 2+} had increasing effect on ZIF-8 particle size, pore size, pore volume, crystallinity and BET surface area of all investigated samples. - Highlights: • The pore size of ZIF-8 samples synthesized with Pebax 1657 increased remarkably. • The BET surface area of 1869 m{sup 2}/gr obtained for a ZIF-8 synthesized sample with Pebax. • Increase in temperature had increasing effect on textural properties of ZIF-8 samples. • Decrease in MeIM/Zn{sup 2+} had increasing effect on textural properties of ZIF-8 samples.

Corrosion resistance characterization of porous alumina membrane supports

Energy Technology Data Exchange (ETDEWEB)

Dong Yingchao, E-mail: dongyc9@mail.ustc.edu.cn [Materials and Surface Science Institute (MSSI), University of Limerick, Limerick (Ireland); USTC Lab for Solid State Chemistry and Inorganic Membranes, Department of Materials Science and Engineering, University of Science and Technology of China (USTC) (China); Key Lab of Jiangxi Universities for Inorganic Membranes, National Engineering Research Center for Domestic and Building Ceramics, Jingdezhen Ceramic University (JCU) (China); Lin Bin [USTC Lab for Solid State Chemistry and Inorganic Membranes, Department of Materials Science and Engineering, University of Science and Technology of China (USTC) (China); Zhou Jianer [Key Lab of Jiangxi Universities for Inorganic Membranes, National Engineering Research Center for Domestic and Building Ceramics, Jingdezhen Ceramic University (JCU) (China); Zhang Xiaozhen [USTC Lab for Solid State Chemistry and Inorganic Membranes, Department of Materials Science and Engineering, University of Science and Technology of China (USTC) (China); Key Lab of Jiangxi Universities for Inorganic Membranes, National Engineering Research Center for Domestic and Building Ceramics, Jingdezhen Ceramic University (JCU) (China); Ling Yihan; Liu Xingqin; Meng Guangyao [USTC Lab for Solid State Chemistry and Inorganic Membranes, Department of Materials Science and Engineering, University of Science and Technology of China (USTC) (China); Hampshire, Stuart [Materials and Surface Science Institute (MSSI), University of Limerick, Limerick (Ireland)

2011-04-15

Tubular porous alumina ceramic membrane supports were fabricated by an extrusion-drying-sintering process and then characterized in detail in terms of corrosion resistance in both H{sub 2}SO{sub 4} and NaOH aqueous solutions. Variations in the properties of the alumina supports such as mass loss percent, mechanical strength, open porosity and pore size distribution were studied before and after corrosion under different conditions. In addition, the microstructures were analyzed using scanning electron microscopy, energy dispersive spectroscopy and X-ray diffraction before and after corrosion. The fabricated porous alumina supports offer possibilities for some potential applications as micro-filtration or ultra-filtration membrane supports, as well as in the pre-treatment of strongly acidic industrial waste-liquids. - Research highlights: {yields} Porous alumina membrane supports fabricated by extrusion-drying-sintering process. {yields} Corrosion resistance in 20 wt.% H{sub 2}SO{sub 4} and 1, 5, 10 wt.% NaOH aqueous solutions. {yields} Rapid mass loss and loss of flexural strength occurred in hot NaOH solution. {yields} Resistant to strong acid corrosion with low mass loss, low flexural strength loss. {yields} Porous alumina supports have potential for treatment of strong acid waste liquids.

Production ultra propre

CERN Document Server

Morvan, Gilles

2011-01-01

L'ultra propreté se caractérise par l'absence de particules et la maîtrise de la contamination dans un environnement défini. Largement appliquée dans diverses industries (pharmacie, cosmétiques, dispositifs médicaux, chimie fine, biotechnologies, électronique et secteurs de pointe, agroalimentaire, plasturgie…), la technicité dans ce domaine est élevée, car principalement liée à la maîtrise des différentes sources de contaminations (eau, air ambiant, fluides, etc.). Véritable guide pratique, cet ouvrage détaille les points techniques essentiels pour permettre à l’ingénieur de trouver des solutions adéquates à chaque type de projet. La démarche passe par la rédaction de spécifications rigoureuses pour : - l’eau, essentielle à toutes productions, - les équipements de production ultra propre, - la démarche qualité et environnementale, - la démarche de suivi du projet.

Effect of Nitrogen Content on Physical and Chemical Properties of TiN Thin Films Prepared by DC Magnetron Sputtering with Supported Discharge

Science.gov (United States)

Kavitha, A.; Kannan, R.; Gunasekhar, K. R.; Rajashabala, S.

2017-10-01

Amorphous titanium nitride (TiN) thin films have been prepared on silicon (Si) and glass substrates by direct-current (DC) reactive magnetron sputtering with a supported discharge (triode). Nitrogen gas (N2) at partial pressure of 0.3 Pa, 0.4 Pa, 0.5 Pa, and 0.6 Pa was used to prepare the TiN thin films, maintaining total pressure of argon and N2 of about 0.7 Pa. The chemical, microstructural, optical, and electrical properties of the TiN thin films were systematically studied. Presence of different phases of Ti with nitrogen (N), oxygen (O2), and carbon (C) elements was revealed by x-ray photoelectron spectroscopy characterization. Increase in the nitrogen pressure from 0.3 Pa to 0.6 Pa reduced the optical bandgap of the TiN thin film from 2.9 eV to 2.7 eV. Photoluminescence study showed that TiN thin film deposited at N2 partial pressure of 0.3 Pa exhibited three shoulder peaks at 330 nm, 335 nm, and 340 nm, which disappeared when the sample was deposited with N2 partial pressure of 0.6 Pa. Increase in the nitrogen content decreased the electrical resistivity of the TiN thin film from 3200 μΩ cm to 1800 μΩ cm. Atomic force microscopy studies of the TiN thin films deposited with N2 partial pressure of 0.6 Pa showed a uniform surface pattern associated with accumulation of fine grains. The results and advantages of this method of preparing TiN thin films are also reported.

Development of Ultra-Fine-Grained Structure in AISI 321 Austenitic Stainless Steel

Science.gov (United States)

Tiamiyu, A. A.; Szpunar, J. A.; Odeshi, A. G.; Oguocha, I.; Eskandari, M.

2017-12-01

Ultra-fine-grained (UFG) structure was developed in AISI 321 austenitic stainless steel (ASS) using cryogenic rolling followed by annealing treatments at 923 K, 973 K, 1023 K, and 1073 K (650 °C, 700 °C, 750 °C, and 800 °C) for different lengths of time. The α'-martensite to γ-austenite reversion behavior and the associated texture development were analyzed in the cryo-rolled specimens after annealing. The activation energy, Q, required for the reversion of α'-martensite to γ-austenite in the steel was estimated to be 80 kJ mol-1. TiC precipitates and unreversed triple junction α'-martensite played major roles in the development of UFG structure through the Zener pinning of grain boundaries. The optimum annealing temperature and time for the development of UFG structure in the cryo-rolled AISI 321 steel are (a) 923 K (650 °C) for approximately 28800 seconds and (b) 1023 K (750 °C) for 600 seconds, with average grain sizes of 0.22 and 0.31 µm, respectively. Annealing at 1023 K (750 °C) is considered a better alternative since the volume fraction of precipitated carbides in specimens annealed at 1023 K (750 °C) are less than those annealed at 923 K (650 °C). More so, the energy consumption during prolonged annealing time to achieve an UFG structure at 923 K (650 °C) is higher due to low phase reversion rate. The hardness of the UFG specimens is 195 pct greater than that of the as-received steel. The higher volume fraction of TiC precipitates in the UFG structure may be an additional source of hardening. Micro and macrotexture analysis indicated {110}〈uvw〉 as the major texture component of the austenite grains in the UFG structure. Its intensity is stronger in the specimen annealed at low temperatures.

Porous hydroxyapatite composite with alumina for bone repair

International Nuclear Information System (INIS)

Rusnah Mustaffa; Mohd Reusmaazran Mohd Yusof; Idris Besar

2010-01-01

Porous fabrications, a number of techniques were investigated using polyurethane foam as the scaffold. These techniques involve dipping of the foam into a slurry prepared by mixing of HA+Al 2 O 3 powder with PVA and Sago as binder and subjecting to burn off procedure to get the porous products. Sintering parameter was studied at 1100, 1200 and 1300 degree Celsius. Initially HA powder was prepared by the sol-gel precipitation method using calcium hydroxide and ortho-phosphoric acid meanwhile Al 2 O 3 powder from supplier (MERK). The fine HA powder, measuring 2 O 3 . These techniques also produce the uniformity pore shape. Characterization of the physical analysis, porosity, surface morphology by Scanning Electron Microscopy analysis (SEM) and compression strength were studied. Mechanical properties showing that the composite of porous HA+Al 2 O 3 gives higher maximum compression strength compared to the porous hydroxyapatite itself. Observation from this studied the increasing of temperature will increase the strength. (author)

Fiscal 1996 survey report. `Ultra high electronic technology development promotion project` under consignment from NEDO; 1996 nendo kenkyu seika hokokusho. Shin Energy Sangyo Gijutsu Sogo Kaihatsu Kiko itaku jigyo `chosentan denshi gijutsu kaihatsu sokushin jigyo`

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-05-01

For the purpose of establishing ultra high technology of a next next generation level which is a basic technology in the electronic information field, a key to the realization of the high grade information society and a common technology base giving marked influences to the wide range industrial field, the R and D was started of ultra fine processing process technology, technologies on limit measuring/analysis/control and new functional electronic materials. Themes of the R and D are electronic beam direct picture drawing system technology, ultra short wavelength electromagnetic radiation patterning/system technology, ultra fine sensitizing technology to draw pictures on metal and crystal surfaces using ultra short wavelength laser beams, shading system technology of shading mask to be used to the process of drawing ultra high accuracy and complicated figures, ultra high tech plasma reactive measuring/analysis/control technologies which become the base of ultra thin films and ultra fine etching using plasma, ultra high tech cleaning base technology, ultra high sensitivity medium technology, new functional element/film formation technology, etc. 137 refs., 358 figs., 38 tabs.

In situ TEM study of the effect of M/A films at grain boundaries on crack propagation in an ultra-fine acicular ferrite pipeline steel

International Nuclear Information System (INIS)

Zhong Yong; Xiao Furen; Zhang Jingwu; Shan Yiyin; Wang Wei; Yang Ke

2006-01-01

Microstructural refinement of structural materials generally improves their tensile properties but deteriorates their fatigue properties. However, pipeline steels with ultra-fine acicular ferrite (UFAF) possess not only high strength and toughness, but also a low fatigue-crack-growth rate (FCGR) and long fatigue-propagation life. In this paper, the micro-fracture mechanisms of an UFAF pipeline steel are investigated by in situ tensile testing in a transmission electron microscope. The results indicate that a grain-boundary-film structure composed of martensite/austenite could significantly influence the crack propagating behavior in the UFAF steel, consequently lowering the FCGR by enhancing roughness-induced crack closure during cyclic loading

Optimized ultra-thin manganin alloy passivated fine-pitch damascene compatible bump-less Cu-Cu bonding at sub 200 °C for three-dimensional Integration applications

Science.gov (United States)

Panigrahi, Asisa Kumar; Hemanth Kumar, C.; Bonam, Satish; Ghosh, Tamal; Rama Krishna Vanjari, Siva; Govind Singh, Shiv

2018-02-01

Enhanced Cu diffusion, Cu surface passivation, and smooth surface at the bonding interface are the key essentials for high quality Cu-Cu bonding. Previously, we have demonstrated optimized 3 nm thin Manganin metal-alloy passivation from oxidation and also helps to reduce the surface roughness to about 0.8 nm which substantially led to high quality Cu-Cu bonding. In this paper, we demonstrated an ultra fine-pitch (indication of high quality bonding for future multilayer integrations. Furthermore, electrical characterization of the bonded structure was performed under various robust conditions as per International Technology Roadmap for Semiconductors (ITRS Roadmap) in order to satisfy the stability of the bonded structure.

A flexible 3D nitrogen-doped carbon foam@CNTs hybrid hosting TiO2 nanoparticles as free-standing electrode for ultra-long cycling lithium-ion batteries

Science.gov (United States)

Yuan, Wei; Wang, Boya; Wu, Hao; Xiang, Mingwu; Wang, Qiong; Liu, Heng; Zhang, Yun; Liu, Huakun; Dou, Shixue

2018-03-01

Free-standing electrodes have stood out from the electrode pack, owing to their advantage of abandoning the conventional polymeric binder and conductive agent, thus increasing the specific capacity of lithium-ion batteries. Nevertheless, their practical application is hampered by inferior electrical conductivity and complex manufacturing process. To this end, we report here a facile approach to fabricate a flexible 3D N-doped carbon foam/carbon nanotubes (NCF@CNTs) hybrid to act as the current collector and host scaffold for TiO2 particles, which are integrated into a lightweight free-standing electrode (NCF@CNTs-TiO2). In the resulting architecture, ultra-fine TiO2 nanoparticles are homogeneously anchored in situ into the N-doped NCF@CNTs framework with macro- and meso-porous structure, wrapped by a dense CNT layer, cooperatively enhances the electrode flexibility and forms an interconnected conductive network for electron/ion transport. As a result, the as-prepared NCF@CNTs-TiO2 electrode exhibits excellent lithium storage performance with high specific capacity of 241 mAh g-1 at 1 C, superb rate capability of 145 mAh g-1 at 20 C, ultra-long cycling stability with an ultra-low capacity decay of 0.0037% per cycle over 2500 cycles, and excellent thermal stability with ∼94% capacity retention over 100 cycles at 55 °C.

Current status of ultra-fine grained W-TiC development for use in irradiation environments

Energy Technology Data Exchange (ETDEWEB)

Kurishita, H [International Research Center for Nuclear Materials Science, Institute for Materials Research (IMR), Tohoku University, Oarai-machi, Ibaraki-ken 311-1313 (Japan); Kobayashi, S [Department of Materials Science and Biotechnology, Ehime University, Matsuyama-shi 790-8577 (Japan); Nakai, K [Department of Materials Science and Biotechnology, Ehime University, Matsuyama-shi 790-8577 (Japan); Arakawa, H [International Research Center for Nuclear Materials Science, Institute for Materials Research (IMR), Tohoku University, Oarai-machi, Ibaraki-ken 311-1313 (Japan); Matsuo, S [International Research Center for Nuclear Materials Science, Institute for Materials Research (IMR), Tohoku University, Oarai-machi, Ibaraki-ken 311-1313 (Japan); Takida, T [ALMT. Corp., 2 Iwase-koshi-machi, Toyama 931-8371 (Japan); Takebe, K [ALMT. Corp., 2 Iwase-koshi-machi, Toyama 931-8371 (Japan); Kawai, M [Institute of Material Structure Science, High Energy Accelerator Research Organization (KEK), Tsukuba-shi, Ibaraki-ken 305-0801 (Japan)

2007-03-15

Ultra-fine grained (UFG) W-TiC with a high purity matrix of low dislocation density is expected to exhibit improve resistance to irradiation with neutrons and helium ions and the room temperature mechanical properties. Aiming at such UFG W-TiC with the desired microstructure, powders of W with 0.25-0.8 wt% TiC additions were subjected to mechanical alloying (MA) and hot isostatic pressing (HIP), where purified H{sub 2} and Ar were used as the MA atmosphere. Microstructural observations and room- and high-temperature mechanical tests were performed for UFG W-TiC before and after neutron irradiation to a fluence of 2x10{sup 24} n m{sup -2} at 873 K. It is shown that the MA atmosphere significantly affects grain refinement, room-temperature strength and high-temperature tensile plasticity of UFG W-TiC. W-0.5TiC with H{sub 2} in MA (W-0.5TiC-H{sub 2}) shows a larger strain rate sensitivity of flow stress, m, of 0.5{approx}0.6 at temperatures from 1673 to 1973 K, which is a feature of superplastic materials. Whereas W-0.5TiC-Ar shows a smaller m value of approximately 0.2. No radiation hardening is recognized in UFG W-0.5TiC-H{sub 2} and W-0.5TiC-Ar.

Current status of ultra-fine grained W-TiC development for use in irradiation environments

International Nuclear Information System (INIS)

Kurishita, H; Kobayashi, S; Nakai, K; Arakawa, H; Matsuo, S; Takida, T; Takebe, K; Kawai, M

2007-01-01

Ultra-fine grained (UFG) W-TiC with a high purity matrix of low dislocation density is expected to exhibit improve resistance to irradiation with neutrons and helium ions and the room temperature mechanical properties. Aiming at such UFG W-TiC with the desired microstructure, powders of W with 0.25-0.8 wt% TiC additions were subjected to mechanical alloying (MA) and hot isostatic pressing (HIP), where purified H 2 and Ar were used as the MA atmosphere. Microstructural observations and room- and high-temperature mechanical tests were performed for UFG W-TiC before and after neutron irradiation to a fluence of 2x10 24 n m -2 at 873 K. It is shown that the MA atmosphere significantly affects grain refinement, room-temperature strength and high-temperature tensile plasticity of UFG W-TiC. W-0.5TiC with H 2 in MA (W-0.5TiC-H 2 ) shows a larger strain rate sensitivity of flow stress, m, of 0.5∼0.6 at temperatures from 1673 to 1973 K, which is a feature of superplastic materials. Whereas W-0.5TiC-Ar shows a smaller m value of approximately 0.2. No radiation hardening is recognized in UFG W-0.5TiC-H 2 and W-0.5TiC-Ar

Effect of various additives on morphological and structural characteristics of pulse electrodeposited tin coatings from stannous sulfate electrolyte

Energy Technology Data Exchange (ETDEWEB)

Sharma, Ashutosh, E-mail: stannum.ashu@gmail.com [Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Kharagpur 721302 (India); Das, Karabi [Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Kharagpur 721302 (India); Fecht, Hans-J. [Institut für Mikro- und Nanomaterialien, Universität Ulm, D-89081 Ulm (Germany); Das, Siddhartha [Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Kharagpur 721302 (India)

2014-09-30

Graphical abstract: - Highlights: • PEG and thiourea act as grain refiners, and Triton X-100 acts as brightener in bath. • Additives refine the crystallite size and modify the orientation of lattice planes. • Dendritic and nodular growths are reduced when additives are used in combination. - Abstract: The pulse electrodeposited tin coatings are synthesized from an acidic electrolyte (stannous sulfate, SnSO{sub 4}30 g/L and sulfuric acid, H{sub 2}SO{sub 4}—200 g/L) containing various additives (polyethylene glycol (PEG), thiourea and Triton X-100). The effect of the additives on surface morphology, preferred orientation of grains, grain size, and surface roughness has been studied. The final coatings are characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and surface profilometry. In the absence of additives, tin deposition is associated with prominent hydrogen evolution reaction giving rise to rough deposits. Both PEG and thiourea act as grain refiner while Triton X-100 acts as a brightener in the electrolyte. The cathodic polarization on the reduction of the tin (II) ions is more pronounced when a combination of additives is used and further, fine-grained, smooth and shiny electrodeposits of tin are obtained due to a synergistic effect of the adsorbed species.

Identification of ultra-fine Ti-rich precipitates in V-Cr-Ti alloys irradiated below 300 deg. C by using positron CDB technique

International Nuclear Information System (INIS)

Fukumoto, Ken-ichi; Matsui, Hideki; Ohkubo, Hideaki; Tang, Zheng; Nagai, Yasuyoshi; Hasegawa, Masayuki

2008-01-01

Irradiation-induced Ti-rich precipitates in V-Ti and V-4Cr-4Ti alloys are studied by TEM and positron annihilation methods (positron lifetime, and coincidence Doppler broadening (CDB)). The characteristics of small defect clusters formed in V alloys containing Ti at irradiation temperatures below 300 deg. C have not been identified by TEM techniques. Strong interaction between vacancy and Ti solute atoms for irradiated V alloys containing Ti at irradiation temperatures from 220 to 350 deg. C are observed by positron lifetime measurement. The vacancy-multi Ti solute complexes in V-alloys containing Ti are definitely identified by using CDB measurement. It is suggested that ultra-fine Ti-rich precipitates or Ti segregation at periphery of dislocation loops are formed in V alloys containing Ti at irradiation temperatures below 300 deg. C

Additive manufacturing technologies of porous metal implants

Directory of Open Access Journals (Sweden)

Yang Quanzhan

2014-06-01

Full Text Available Biomedical metal materials with good corrosion resistance and mechanical properties are widely used in orthopedic surgery and dental implant materials, but they can easily cause stress shielding due to the significant difference in elastic modulus between the implant and human bones. The elastic modulus of porous metals is lower than that of dense metals. Therefore, it is possible to adjust the pore parameters to make the elastic modulus of porous metals match or be comparable with that of the bone tissue. At the same time, the open porous metals with pores connected to each other could provide the structural condition for bone ingrowth, which is helpful in strengthening the biological combination of bone tissue with the implants. Therefore, the preparation technologies of porous metal implants and related research have been drawing more and more attention due to the excellent features of porous metals. Selective laser melting (SLM and electron beam melting technology (EBM are important research fields of additive manufacturing. They have the advantages of directly forming arbitrarily complex shaped metal parts which are suitable for the preparation of porous metal implants with complex shape and fine structure. As new manufacturing technologies, the applications of SLM and EBM for porous metal implants have just begun. This paper aims to understand the technology status of SLM and EBM, the research progress of porous metal implants preparation by using SLM and EBM, and the biological compatibility of the materials, individual design and manufacturing requirements. The existing problems and future research directions for porous metal implants prepared by SLM and EBM methods are discussed in the last paragraph.

Progress of admixtures and quality of concrete. 2. ; Approaches to ultra-high-strength concrete. Konwa zairyo no shinpo to concrete no hinshitsu. 2. ; Chokokyodo concrete eno approach

Energy Technology Data Exchange (ETDEWEB)

Kawai, T. (Shimizu Construction Co. Ltd., Tokyo (Japan)); Abe, M. (Building Research Institute, Tsukuba (Japan))

1994-02-15

Ultra-high-strength concrete of 600 kgf/cm[sup 2] or more is reviewed. MDF (macro defect free) cement, spheroidal cement and mechanically stabilized cement have been developed for ultra-high-strength concrete, however, in general, DSP (densified system containing homogeneously arranged ultra-fine particles) technique is now usual in which a water-cement ratio is reduced by use of advanced air entraining and water reducing agents and cured concrete is densified by use of ultra-fine particles as admixture. Four kinds of substances such as naphthalene system and polycarboxylic acid system are used as air entraining and water reducing agents, and silica fume is used as ultra-fine particle admixture which can be effectively replaced with blast furnace slag or fly ash. Various use examples of ultra-high-strength concrete such as an ocean platform are found in the world, however, only some examples such as a PC truss bridge and the main tower of a PC cable stayed bridge in Japan. 22 refs., 10 figs., 2 tabs.

1.9 μm superficially porous packing material with radially oriented pores and tailored pore size for ultra-fast separation of small molecules and biomolecules.

Science.gov (United States)

Min, Yi; Jiang, Bo; Wu, Ci; Xia, Simin; Zhang, Xiaodan; Liang, Zhen; Zhang, Lihua; Zhang, Yukui

2014-08-22

In this work, 1.9 μm reversed-phase packing materials with superficially porous structure were prepared to achieve the rapid and high efficient separation of peptides and proteins. The silica particles were synthesized via three steps, nonporous silica particle preparation by a modified seeded growth method, mesoporous shell formation by a one pot templated dissolution and redeposition strategy, and pore size expansion via acid-refluxing. By such a method, 1.9 μm superficially porous materials with 0.18 μm shell thickness and tailored pore diameter (10 nm, 15 nm) were obtained. After pore enlargement, the formerly dense arrays of mesoporous structure changed, the radially oriented pores dominated the superficially porous structure. The chromatographic performance of such particles was investigated after C18 derivatization. For packing materials with 1.9 μm diameter and 10 nm pore size, the column efficiency could reach 211,300 plates per m for naphthalene. To achieve the high resolution separation of peptides and proteins, particles with pore diameter of 15 nm were tailored, by which the baseline separation of 5 peptides and 5 intact proteins could be respectively achieved within 1 min, demonstrating the superiority in the high efficiency and high throughput analysis of biomolecules. Furthermore, BSA digests were well separated with peak capacity of 120 in 30 min on a 15 cm-long column. Finally, we compared our columns with a 1.7 μm Kinetex C18 column under the same conditions, our particles with 10nm pore size demonstrated similar performance for separation of the large intact proteins. Moreover, the particles with 15 nm pore size showed more symmetrical peaks for the separation of large proteins (BSA, OVA and IgG) and provided rapid separation of protein extracts from Escherichia coli in 5 min. All these results indicated that the synthesized 1.9 μm superficially porous silica packing materials would be promising in the ultra-fast and high

Electrochemical dissolution of tin in methanesulphonic acid solutions

NARCIS (Netherlands)

de Greef, R.A.T.; Janssen, L.J.J.

2001-01-01

High-rate electroplating of tin on a moving steel strip is generally carried out in cells with dimensionally stable anodes. To obtain a matt tin deposit a concentrated acidic tin methanesulphonate solution containing a small concentration of sulphuric acid is used. The concentrated tin

Fine and hyperfine structure spectra of the ultra-violet 23S → 53P transition in 4He and 3He with a frequency doubled CW ring laser, detected via associative ionization

International Nuclear Information System (INIS)

Runge, S.; Pesnelle, A.; Perdrix, M.; Sevin, D.; Wolffer, N.; Watel, G.

1982-01-01

High resolution laser spectroscopy coupled to a sensitive method of detection via mass analysis of He + 2 ions produced in He(5 3 P) + He(1 1 S) collisions, is used to obtain the fine and hyperfine spectra of the ultra-violet He 2 3 S → 5 3 P transition. A cw tunable UV radiation around 294.5 nm is generated by intracavity frequency doubling a Rhodamine 6G single mode ring dye laser using an ADA crystal. Both spectra enable fine and hyperfine structures to be determined within a few MHz. The magnetic dipole coupling constant A of the 5 3 P term of 3 He is found to be -4326 +- 9 MHz (-0.1443 +- 0.0003 cm -1 ). (orig.)

Tracking Single DNA Nanodevices in Hierarchically Meso-Macroporous Antimony-Doped Tin Oxide Demonstrates Finite Confinement.

Science.gov (United States)

Mieritz, Daniel; Li, Xiang; Volosin, Alex; Liu, Minghui; Yan, Hao; Walter, Nils G; Seo, Dong-Kyun

2017-06-27

Housing bio-nano guest devices based on DNA nanostructures within porous, conducting, inorganic host materials promise valuable applications in solar energy conversion, chemical catalysis, and analyte sensing. Herein, we report a single-template synthetic development of hierarchically porous, transparent conductive metal oxide coatings whose pores are freely accessible by large biomacromolecules. Their hierarchal pore structure is bimodal with a larger number of closely packed open macropores (∼200 nm) at the higher rank and with the remaining space being filled with a gel network of antimony-doped tin oxide (ATO) nanoparticles that is highly porous with a broad size range of textual pores mainly from 20-100 nm at the lower rank. The employed carbon black template not only creates the large open macropores but also retains the highly structured gel network as holey pore walls. Single molecule fluorescence microscopic studies with fluorophore-labeled DNA nanotweezers reveal a detailed view of multimodal diffusion dynamics of the biomacromolecules inside the hierarchically porous structure. Two diffusion constants were parsed from trajectory analyses that were attributed to free diffusion (diffusion constant D = 2.2 μm 2 /s) and to diffusion within an average confinement length of 210 nm (D = 0.12 μm 2 /s), consistent with the average macropore size of the coating. Despite its holey nature, the ATO gel network acts as an efficient barrier to the diffusion of the DNA nanostructures, which is strongly indicative of physical interactions between the molecules and the pore nanostructure.

Investigation of a thermoplastic-powder metallurgy process for the fabrication of porous niobium rods

International Nuclear Information System (INIS)

Nordin, D.R.

1978-06-01

The feasibility of using a thermoplastic-powder metallurgy technique for the fabrication of porous niobium rods was investigated. Some early problems were overcome to successfully extrude the polymer coated niobium powder into long lengths. The effects of certain process variables were investigated. Residual porosity and extrusion pressure were found to be regulated by the polymer fraction. The procedures for taking the extruded polystyrene--niobium rods through the heat treatments to the final, tin infiltrated stage are explained

Tin-antimony oxide oxidation catalysts

Energy Technology Data Exchange (ETDEWEB)

Berry, Frank J. [Open University, Department of Chemistry (United Kingdom)

1998-12-15

Tin-antimony oxide catalysts for the selective oxidation of hydrocarbons have been made by precipitation techniques. The dehydration of the amorphous dried precipitate by calcination at increasingly higher temperatures induces the crystallisation of a rutile-related tin dioxide-type phase and the segregation of antimony oxides which volatilise at elevated temperatures. The rutile-related tin dioxide-type phase contains antimony(V) in the bulk and antimony(III) in the surface. Specific catalytic activity for the oxidative dehydrogenation of butene to butadiene is associated with materials with large concentrations of antimony(III) in the surface.

One pot synthesis of multi-functional tin oxide nanostructures for high efficiency dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Wali, Qamar; Fakharuddin, Azhar; Yasin, Amina; Ab Rahim, Mohd Hasbi; Ismail, Jamil; Jose, Rajan, E-mail: rjose@ump.edu.my

2015-10-15

Photoanode plays a key role in dye sensitized solar cells (DSSCs) as a scaffold for dye molecules, transport medium for photogenerated electrons, and scatters light for improved absorption. Herein, tin oxide nanostructures unifying the above three characteristics were optimized by a hydrothermal process and used as photoanode in DSSCs. The optimized morphology is a combination of hollow porous nanoparticles of size ∼50 nm and micron sized spheres with BET surface area (up to 29 m{sup 2}/g) to allow large dye-loading and light scattering as well as high crystallinity to support efficient charge transport. The optimized morphology gave the highest photovoltaic conversion efficiency (∼7.5%), so far achieved in DSSCs with high open circuit voltage (∼700 mV) and short circuit current density (∼21 mA/cm{sup 2}) employing conventional N3 dye and iodide/triiodide electrolyte. The best performing device achieved an incident photon to current conversion efficiency of ∼90%. The performance of the optimized tin oxide nanostructures was comparable to that of conventional titanium based DSSCs fabricated at similar conditions. - Graphical abstract: Tin oxide hollow nanostructure simultaneously supporting improved light scattering, dye-loading, and charge transport yielded high photovoltaic conversion efficiency in dye-sensitized solar cells. - Highlights: • Uniformly and bimodelly distributed tin oxide hollow nanospheres (HNS) are synthesized. • Uniform HNS are of size ∼10 nm; bimodel HNS has additional size up to ∼800 nm. • They are evaluated as photoelectrodes in dye-sensitized solar cells (DSSCs). • The uniform HNS increase dye-loading and the larger increase light scattering in DSSCs. • Photo conversion efficiency ∼7.5% is achieved using bimodel HNS.

Synthesis and synchrotron characterisation of novel dual-template of hydroxyapatite scaffolds with controlled size porous distribution

Energy Technology Data Exchange (ETDEWEB)

Lima, Thiago A. R. M.; Ilavsky, Jan; Hammons, Joshua; Sarmento, Victor H. V.; Rey, José F. Q.; Valerio, Mário E. G.

2017-03-01

Hydroxyapatite (HAP) scaffolds with a hierarchical porous architecture were prepared by a new dual-template (corn starch and cetyltrimethylammonium bromide (CTAB) surfactant) used to cast HAP nanoparticles and development scaffolds with size hierarchical porous distribution. The Powder X-Ray diffraction (XRD) results showed that only the HAP crystalline phase is present in the samples after calcination; the Scanning Electron Microscopy (SEM) combined with Small Angle (SAXS) and Ultra-Small Angle X-ray Scattering (USAXS) techniques showed that the porous arrangement is promoted by needle-like HAP nanoparticles, and that the pore size distributions depend on the drip-order of the calcium and the phosphate solutions during the template preparation stage.

Preparation of ultra-fine powders from polysaccharide-coated solid lipid nanoparticles and nanostructured lipid carriers by innovative nano spray drying technology.

Science.gov (United States)

Wang, Taoran; Hu, Qiaobin; Zhou, Mingyong; Xue, Jingyi; Luo, Yangchao

2016-09-10

In this study, five polysaccharides were applied as natural polymeric coating materials to prepare solid lipid nanoparticles (SLN) and nanostructure lipid carriers (NLC), and then the obtained lipid colloidal particles were transformed to solid powders by the innovative nano spray drying technology. The feasibility and suitability of this new technology to generate ultra-fine lipid powder particles were evaluated and the formulation was optimized. The spray dried SLN powder exhibited the aggregated and irregular shape and dimension, but small, uniform, well-separated spherical powder particles of was obtained from NLC. The optimal formulation of NLC was prepared by a 20-30% oleic acid content with carrageenan or pectin as coating material. Therefore, nano spray drying technology has a potential application to produce uniform, spherical, and sub-microscale lipid powder particles when the formulation of lipid delivery system is appropriately designed. Copyright © 2016 Elsevier B.V. All rights reserved.

Process metallurgical evaluation and application of very fine bubbling technology

Energy Technology Data Exchange (ETDEWEB)

Catana, C.; Gotsis, V.S.; Dourdounis, E.; Angelopoulos, G.N.; Papamantellos, D.C. [Lab. of Metallurgy, Univ. of Patras, Rio (Greece); Mavrommatis, K. [IEHK, RWTH Aachen, Aachen (Germany)

2002-12-01

The potential of VFB (Very Fine Bubbling)-technology in steelmaking, developed for the production of super clean steels, was investigated. Recent R and D work has proven that with very fine argon bubbling through a developed Special Porous Plug (SPP) at low flow rates, the total oxygen content of low carbon steel grades can be lowered to a level of 6 ppm under industrial vacuum conditions and to a level of 10 ppm under argon protective atmosphere. The perspective of industrial application of the VFB technology to a 56-t ladle furnace of Helliniki Halyvourgia S.A., Greece, in order to improve steel cleanliness, requires additional R and D efforts. It is important to define the limits of VFB technology in respect of alloys dissolution, mixing time and homogenisation of steel and slag/metal reactions. In this work, a gas driven bubble aqueous reactor model simulating the bottom gas stirred ladle by means of gas injection through a SPP and a conventional porous plug was studied. Various operating conditions as well as different positions for the porous plug with and without a top oil layer were simulated. Tests concerning mixing time, solid-liquid mass transfer and critical gas flow rate, liquid/liquid mass transfer, using the SPP and a conventional porous plug have been performed. The evaluation of experimental results delivered important information for the design and operation of steel ladles, applying VFB-technology. Experimental results with SPP bubbles' agitated steel (1600 C) in laboratory and technical scale experiments in IF and VIF are presented and discussed. (orig.)

Geochemistry of ultra-fine and nano-compounds in coal gasification ashes: A synoptic view

Energy Technology Data Exchange (ETDEWEB)

Kronbauer, Marcio A. [Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS (Brazil); Universidade Federal do Rio Grande do Sul, Escola de Engenharia, Departamento de Metalurgia, Centro de Tecnologia, Av. Bento Gonçalves, 9500, Bairro Agronomia, CEP: 91501-970, Porto Alegre, RS (Brazil); Izquierdo, Maria [School of Applied Sciences, Cranfield University, Bedfordshire MK43 0AL (United Kingdom); Dai, Shifeng [State Key Laboratory of Coal Resources and Safe Mining, China University of Mining and Technology, Beijing 100083 (China); Waanders, Frans B. [School of Chemical and Minerals Engineering, North West University (Potchefstroom campus), Potchefstroom 2531 (South Africa); Wagner, Nicola J. [School of Chemical and Metallurgical Engineering, University of the Witwatersrand, Johannesburg (South Africa); Mastalerz, Maria [Indiana Geological Survey, Indiana University, Bloomington, IN 47405-2208 (United States); Hower, James C. [University of Kentucky Center for Applied Energy Research, 2540 Research Park Drive, Lexington, KY 40511 (United States); Oliveira, Marcos L.S. [Environmental Science and Nanotechnology Department, Catarinense Institute of Environmental Research and Human Development, IPADHC, Capivari de Baixo, Santa Catarina (Brazil); Taffarel, Silvio R.; Bizani, Delmar [Centro Universitário La Salle, Mestrado em Avaliação de Impactos Ambientais em Mineração, Victor Barreto, 2288 Centro, 92010-000 Canoas, RS (Brazil); and others

2013-07-01

The nano-mineralogy, petrology, and chemistry of coal gasification products have not been studied as extensively as the products of the more widely used pulverized-coal combustion. The solid residues from the gasification of a low- to medium-sulfur, inertinite-rich, volatile A bituminous coal, and a high sulfur, vitrinite-rich, volatile C bituminous coal were investigated. Multifaceted chemical characterization by XRD, Raman spectroscopy, petrology, FE-SEM/EDS, and HR-TEM/SEAD/FFT/EDS provided an in-depth understanding of coal gasification ash-forming processes. The petrology of the residues generally reflected the rank and maceral composition of the feed coals, with the higher rank, high-inertinite coal having anisotropic carbons and inertinite in the residue, and the lower rank coal-derived residue containing isotropic carbons. The feed coal chemistry determines the mineralogy of the non-glass, non-carbon portions of the residues, with the proportions of CaCO{sub 3} versus Al{sub 2}O{sub 3} determining the tendency towards the neoformation of anorthite versus mullite, respectively. Electron beam studies showed the presence of a number of potentially hazardous elements in nanoparticles. Some of the neoformed ultra-fine/nano-minerals found in the coal ashes are the same as those commonly associated with oxidation/transformation of sulfides and sulfates. - Highlights: • Coal waste geochemisty can provide increased environmental information in coal-mining areas. • Oxidation is the major process for mineral transformation in coal ashes. • The electron bean methodology has been applied to investigate neoformed minerals.

Effect of Source/Drain Electrodes on the Electrical Properties of Silicon–Tin Oxide Thin-Film Transistors

Directory of Open Access Journals (Sweden)

Xianzhe Liu

2018-05-01

Full Text Available Ultra-high definition displays have become a trend for the current flat plane displays. In this study, the contact properties of amorphous silicon–tin oxide thin-film transistors (a-STO TFTs employed with source/drain (S/D electrodes were analyzed. Ohmic contact with a good device performance was achieved when a-STO was matched with indium-tin-oxide (ITO or Mo electrodes. The acceptor-like densities of trap states (DOS of a-STO TFTs were further investigated by using low-frequency capacitance–voltage (C–V characteristics to understand the impact of the electrode on the device performance. The reason of the distinct electrical performances of the devices with ITO and Mo contacts was attributed to different DOS caused by the generation of local defect states near the electrodes, which distorted the electric field distribution and formed an electrical potential barrier hindering the flow of electrons. It is of significant importance for circuit designers to design reliable integrated circuits with SnO2-based devices applied in flat panel displays.

A Two-Scale Reduced Model for Darcy Flow in Fractured Porous Media

KAUST Repository

Chen, Huangxin

2016-06-01

In this paper, we develop a two-scale reduced model for simulating the Darcy flow in two-dimensional porous media with conductive fractures. We apply the approach motivated by the embedded fracture model (EFM) to simulate the flow on the coarse scale, and the effect of fractures on each coarse scale grid cell intersecting with fractures is represented by the discrete fracture model (DFM) on the fine scale. In the DFM used on the fine scale, the matrix-fracture system are resolved on unstructured grid which represents the fractures accurately, while in the EFM used on the coarse scale, the flux interaction between fractures and matrix are dealt with as a source term, and the matrix-fracture system can be resolved on structured grid. The Raviart-Thomas mixed finite element methods are used for the solution of the coupled flows in the matrix and the fractures on both fine and coarse scales. Numerical results are presented to demonstrate the efficiency of the proposed model for simulation of flow in fractured porous media.

Ultra-low reflection porous silicon nanowires for solar cell applications

OpenAIRE

Najar , Adel; Charrier , Joël; Pirasteh , Parastesh; Sougrat , R.

2012-01-01

International audience; High density vertically aligned Porous Silicon NanoWires (PSiNWs) were fabricated on silicon substrate using metal assisted chemical etching process. A linear dependency of nanowire length to the etching time was obtained and the change in the growth rate of PSiNWs by increasing etching durations was shown. A typical 2D bright-field TEM image used for volume reconstruction of the sample shows the pores size varying from 10 to 50 nm. Furthermore, reflectivity measuremen...

Ultra-fine CuO Nanoparticles Embedded in Three-dimensional Graphene Network Nano-structure for High-performance Flexible Supercapacitors

International Nuclear Information System (INIS)

Li, Yanrong; Wang, Xue; Yang, Qi; Javed, Muhammad Sufyan; Liu, Qipeng; Xu, Weina; Hu, Chenguo; Wei, Dapeng

2017-01-01

High conductivity, large specific surface area and excellent performance redox materials are urgently desired for improving electrochemical energy storage. However, with single redox material it is hard to achieve these properties. Herein, we develop ultra-fine CuO nanoparticles embedded in three-dimensional graphene network grown on carbon cloth (CuO/3DGN/CC) to construct a novel electrode material with advantages of high conductivity, large specific area and excellent redox activity for supercapacitor application. The CuO/3DGN/CC with different CuO mass ratios are utilized to fabricate supercapacitors and the optimized mass loading achieves the high areal capacitance of 2787 mF cm"−"2 and specific capacitance of 1539.8 F g"−"1 at current density of 6 mA cm"−"2 with good stability. In addition, a high-flexible solid-state symmetric supercapacitor is also fabricated by using this CuO/3DGN/CC composite. The device shows excellent electrochemical performance even at various bending angles indicating a promising application for wearable electronic devices, and two devices with area 2 × 4 cm"2 in series can light nine light emitting diodes for more than 3 minutes.

Embedding nano-Li{sub 4}Ti{sub 5}O{sub 12} in hierarchical porous carbon matrixes derived from water soluble polymers for ultra-fast lithium ion batteries anodic materials

Energy Technology Data Exchange (ETDEWEB)

Lan, Chun-Kai; Bao, Qi; Huang, Yao-Hui; Duh, Jenq-Gong, E-mail: jgd@mx.nthu.edu.tw

2016-07-15

Li{sub 4}Ti{sub 5}O{sub 12}/hierarchical porous carbon matrixes composites are successfully prepared by a facile and fast polymers assisted sol–gel method, aiming to promote both electronic and ionic conductivity. As indicated by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analysis, three less expensive cost and available water soluble polymers (e.g. PAA, CMC, and SA) can homogeneously react with Li–Ti–O precursor to incorporate into interior of nano-scale lithium titanate and provide a continues conductive network after pyrolysis. In addition, the results of scanning electron microscopy and transmission electron microscopy also prove that the Li{sub 4}Ti{sub 5}O{sub 12} nanoparticles are firmly embedded in porous carbon matrix with no obvious agglomeration. EIS measurement and cyclic voltammetry further reveal that the facilitated electrode kinetics and better ionic transport of Li{sub 4}Ti{sub 5}O{sub 12}/hierarchical porous carbon matrixes composites than that of Li{sub 4}Ti{sub 5}O{sub 12}. The c-CMC-LTO exhibits a superior capacity of 92 mAh g{sup −1} and retains its initial value with no obviously capacity decay over 200 cycles under an ultra-high C rate (50 C). - Graphical abstract: Schematic illustrations of the formation process of embedding LTO into Carbon matrixes derived from water soluable polymers (upper) and the electrochemical reaction paths in LTO/Carbon composites during charging/discharging processes (lower). - Highlights: • Hierarchical porous carbon matrixes were used to improve the Li{sub 4}Ti{sub 5}O{sub 12} anodes. • Carbon matrixes could suppress the agglomeration of Li{sub 4}Ti{sub 5}O{sub 12} nanoparticles. • meso-nanoporous carbon structure was beneficial for filtration of electrolyte. • The c-CMC-LTO exhibited superior high rate capability and cycling durability.

Ultra-Thin Atomic Layer Deposited TiN Films: Non-Linear I–V Behaviour and the Importance of Surface Passivation

NARCIS (Netherlands)

Van Hao, B.; Aarnink, Antonius A.I.; Kovalgin, Alexeij Y.; Wolters, Robertus A.M.

2011-01-01

We report the electrical resistivity of atomic layer deposited TiN thin films in the thickness range 2.5-20 nm. The measurements were carried out using the circular transfer length method structures. For the films with thickness in the range of 10-20 nm, the measurements exhibited linear

Microstructure and mechanical properties of a Ti-microalloyed low-carbon stainless steel treated by quenching-partitioning-tempering process

Energy Technology Data Exchange (ETDEWEB)

Xie, S.T., E-mail: xst-2007@163.com [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Liu, Z.Y. [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China); Wang, Z. [Research Institute, Baoshan Iron & Steel Co. Ltd., Shanghai 201900 (China); Wang, G.D. [State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110819 (China)

2016-06-15

Quenching-partitioning-tempering (Q-P-T) process was used to treat a Ti-microalloyed low-carbon stainless steel after cold rolling. In addition to martensite, ferrite and retained austenite, TiN, coarse TiC, fine TiC, (Fe,Cr){sub 3}C and ultra-fine TiC precipitates were formed after the Q-P-T treatment. Based on field emission-scanning electron microscope (FESEM) and transmission electron microscope (TEM) observations, thermodynamic, crystallographic and statistical analyses were used to reveal the precipitation behaviors of these particles. The effects of partitioning-tempering (P-T) temperature and time on the microstructure and mechanical properties of Q-P-T treated specimens were specially studied. The coarsening and spheroidization of (Fe,Cr){sub 3}C particles during P-T stage were obviously retarded by large Cr addition. The retained austenite was obtained significantly with appropriate P-T parameters. The precipitation of ultra-fine TiC particles in the martensite during the P-T stage at 500 °C induced a secondary hardening. - Highlights: • Some fine TiC with 30–70 nm precipitated in austenite during partial austenization. • A part of fine TiC had K-S OR with martensite after Q-P-T treatment. • A part of fine TiC had a OR specially deviating from K-S OR with martensite. • Coarsening and spheroidization of (Fe,Cr){sub 3}C were retarded during P-T stage. • Ultra-fine TiC with < 10 nm precipitated in martensite during P-T stage at 500 °C.

Conversion electron Moessbauer spectroscopic studies on the chemical states of surface layers of corroded tin plates and tin-coated iron plates

International Nuclear Information System (INIS)

Kato, Akinori; Endo, Kazutoyo; Sano, Hirotoshi

1980-01-01

By means of the conversion electron Moessbauer spectroscopy (CEMS), we studied surface layers of ''tin'' plates and tin-coated iron plates corroded by various acids. Transmission Moessbauer spectra and X-ray diffraction patterns were also measured. Metastannic acid was formed, when the ''tin'' plate was corroded by nitric acid solution. In corrosion by phosphoric acid solution, the X-ray diffractometry revealed the formation of tin(IV) pyrophosphate. In corrosion by various organic acid solutions, the formation of oxides was identified by the 119 Sn CEMS, but not by the X-ray diffractometry because of the too thin corrosion layer. In corrosion of tin-coated iron plates, maleic acid, malonic acid, formic acid, and oxalic acid were used. It was determined by CEMS that the corrosion products caused by these acids were tin(IV) oxides, although they could not be identified by the X-ray diffractometry. CEMS also confirmed that the surface of uncorroded tin-coated iron plate was already oxidized by air. Colorimetric determinations of Sn and Fe dissolved from tin-coated iron plates to various acid solutions confirmed that maleic acid had the strongest corrosion effect among the organic acids studied. (author)

Screen-printed Tin-doped indium oxide (ITO) films for NH3 gas sensing

International Nuclear Information System (INIS)

Mbarek, Hedia; Saadoun, Moncef; Bessais, Brahim

2006-01-01

Gas sensors using metal oxides have several advantageous features such as simplicity in device structure and low cost fabrication. In this work, Tin-doped indium oxide (ITO) films were prepared by the screen printing technique onto glass substrates. The granular and porous structure of screen-printed ITO are suitable for its use in gas sensing devices. The resistance of the ITO films was found to be strongly dependent on working temperatures and the nature and concentration of the ambient gases. We show that screen-printed ITO films have good sensing properties toward NH 3 vapours. The observed behaviors are explained basing on the oxidizing or the reducer nature of the gaseous species that react on the surface of the heated semi-conducting oxide

Deposition of indium tin oxide thin films by cathodic arc ion plating

International Nuclear Information System (INIS)

Yang, M.-H.; Wen, J.-C.; Chen, K.-L.; Chen, S.-Y.; Leu, M.-S.

2005-01-01

Indium tin oxide (ITO) thin films have been deposited by cathodic arc ion plating (CAIP) using sintered oxide target as the source material. In an oxygen atmosphere of 200 deg. C, ITO films with a lowest resistivity of 2.2x10 -4 Ω-cm were obtained at a deposition rate higher than 450 nm/min. The carrier mobility of ITO shows a maximum at some medium pressures. Although morphologically ITO films with a very fine nanometer-sized structure were observed to possess the lowest resistivity, more detailed analyses based on X-ray diffraction are attempted to gain more insight into the factors that govern electron mobility in this investigation

Directly smelted lead-tin alloys: A historical perspective

Science.gov (United States)

Dube, R. K.

2010-08-01

This paper discusses evidence related to the genesis and occurrence of mixed lead-tin ore deposit consisting of cassiterite and the secondary minerals formed from galena. These evidences belong to a very long time period ranging from pre-historic to as late as the nineteenth century a.d. This type of mixed ore deposits was smelted to prepare lead-tin alloys. The composition of the alloy depended on the composition of the starting ore mixture. A nineteenth century evidence for the production of directly smelted lead-tin alloys in southern Thailand is discussed. A unique and rather uncommon metallurgical terminology in Sanskrit language— Nāgaja—was introduced in India for the tin recovered from impure lead. This suggests that Indians developed a process for recovering tin from lead-tin alloys, which in all probability was based on the general principle of fire refining. It has been shown that in the context of India the possibility of connection between the word Nāgaja and the directly smelted lead-tin alloys cannot be ruled out.

High performance supercapacitor using catalysis free porous carbon nanoparticles

International Nuclear Information System (INIS)

Ali, Gomaa A M; Manaf, Shoriya Aruni Bt Abdul; Chong, Kwok Feng; Hegde, Gurumurthy; Kumar, Anuj

2014-01-01

Very high supercapacitance values are obtained using catalyst free porous carbon nanoparticles (PCNs). The obtained PCNs have a porous structure with fine particles 35 nm in size. The specific capacitance of PCNs is 343 F g −1 and 309 F g −1 at 5 mV s −1 and 0.06 A g −1 , respectively. PCNs shows a high cyclic stability of about 90% and high columbic efficiency of 95% over 2500 cycles at 1 A g −1 . Impedance spectra show low resistance of PCNs, supporting their suitability for supercapacitor electrode application. (paper)

TRANSFORMATIONS IN NANO-DIAMONDS WITH FORMATION OF NANO-POROUS SILICON CARBIDE AT HIGH PRESSURE

Directory of Open Access Journals (Sweden)

V. N. Kovalevsky

2010-01-01

Full Text Available The paper contains investigations on regularities of diamond - silicon carbide composite structure formation at impact-wave excitation. It has been determined that while squeezing a porous blank containing Si (SiC nano-diamond by explosive detonation products some processes are taking place such as diamond nano-particles consolidation, reverse diamond transition into graphite, fragments formation from silicon carbide. A method for obtaining high-porous composites with the presence of ultra-disperse diamond particles has been developed. Material with three-dimensional high-porous silicon-carbide structure has been received due to nano-diamond graphitation at impact wave transmission and plastic deformation. The paper reveals nano-diamonds inverse transformation into graphite and its subsequent interaction with the silicon accompanied by formation of silicon-carbide fragments with dimensions of up to 100 nm.

Infiltration Behavior Of Mechanical Alloyed 75 wt% Cu-25 wt% WC Powders Into Porous WC Compacts

Directory of Open Access Journals (Sweden)

Şelte A.

2015-06-01

Full Text Available In this work infiltration behavior of mechanical alloyed 75 wt% Cu – 25 wt% WC powders into porous WC compacts were studied. Owing to their ductile nature, initial Cu powders were directly added to mechanical alloying batch. On the other hand initial WC powders were high energy milled prior to mechanical alloying. Contact infiltration method was selected for densification and compacts prepared from processed powders were infiltrated into porous WC bodies. After infiltration, samples were characterized via X-Ray diffraction studies and microstructural evaluation of the samples was carried out via scanning electron microscopy observations. Based on the lack of solubility between WC and Cu it was possible to keep fine WC particles in Cu melt since solution reprecipitation controlled densification is hindered. Also microstructural characterizations via scanning electron microscopy confirmed that the transport of fine WC fraction from infiltrant to porous WC skeleton can be carried out via Cu melt flow during infiltration.

Toxicology of inorganic tin

International Nuclear Information System (INIS)

Burba, J.V.

1982-01-01

Tin(II) or stannous ion as a reducing agent is important in nuclear medicine because it is an essential component and common denominator for many in vivo radiodiagnostic agents, commonly called kits for the preparation of radiopharmaceuticals. This report is intended to alert nuclear medicine community regarding the wide range of biological effects that the stannous ion is capable of producing, and is a review of a large number of selected publications on the toxicological potential of tin(II)

An effective anisotropic poroelastic model for elastic wave propagation in finely layered media

NARCIS (Netherlands)

Kudarova, A.; van Dalen, K.N.; Drijkoningen, G.G.

2016-01-01

Mesoscopic-scale heterogeneities in porous media cause attenuation and dispersion at seismic frequencies. Effective models are often used to account for this. We have developed a new effective poroelastic model for finely layered media, and we evaluated its impact focusing on the angledependent

Characterization of tin selenides synthesized by high-energy milling

Directory of Open Access Journals (Sweden)

Marcela Achimovičová

2011-12-01

Full Text Available Tin selenides SnSeX (x=1,2 were synthesized from tin and selenium powder precursors by high-energy milling in the planetary ballmill Pulverisette 6 (Fritsch, Germany. The orthorhombic tin selenide SnSe and the hexagonal tin diselenide SnSe2 phases were formed after4 min and 5 min of milling, respectively. Specific surface area of both selenides increased with increasing time of mechanochemicalsynthesis. The particle size distribution analysis demonstrated that the synthesized products contain agglomerated selenide particlesconsisting of numerous idiomorphic tin selenide crystals, measuring from 2 to more than 100 nm in diameter, which were also documentedby TEM. UV-Vis spectrophotometry confirmed that tin selenide particles do not behave as quantum dots.

Upscaling of flow in porous media from a tracer perspective

NARCIS (Netherlands)

Berentsen, C.W.J.

2003-01-01

Most of our knowledge of flow in porous media is obtained at the pore and the macro scale. For reservoir scale modelling it is not practical to model the flow at these fine scales. Considering the usual objectives (e.g. large scale flow pattern and production forecast) it is undesirable to have to

Investigation of thermal transfers in super-fluid helium in porous media

International Nuclear Information System (INIS)

Allain, H.

2009-10-01

Particle accelerators are requiring increased magnetic fields for which niobium tin superconducting magnets are considered. This entails electric insulation and cooling problems. Porous ceramic insulations are potential candidates for cable insulation. As they are permeable to helium, they could allow a direct cooling by super-fluid helium. Therefore, this research thesis deals with the investigation of thermal transfers in superfluid helium in porous media. After a description of an accelerator's superconducting magnet, of its thermodynamics and its various cooling modes, the author describes the physical properties of super-fluid helium, its peculiarities with respect to conventional fluids as well as its different phases (fluid and super-fluid), its dynamics under different regimes (the Landau regime which is similar to the laminar regime for a conventional fluid, and the Gorter-Mellink regime which is the super-fluid turbulent regime). He determines the macroscopic equations governing the He II dynamics in porous media by applying the volume averaging method developed by Whitaker. Theoretical results are validated by comparison with a numerical analysis performed with a numerical code. Then, the author presents the various experimental setups which have been developed for the measurement of the intrinsic permeability, one at room temperature and another at high temperature. Experimental results are discussed, notably with respect to pore size and porosity

Fatigue behavior and damage characteristic of ultra-fine grain low-purity copper processed by equal-channel angular pressing (ECAP)

Energy Technology Data Exchange (ETDEWEB)

Xu Changzheng; Wang Qingjuan [School of Materials Science and Engineering, Xian Jiaotong University, Xian 710049 (China); Zheng Maosheng [Institute of Condensed Matter Physics and Materials, Northwest University, Xian 710069 (China)], E-mail: mszhengnw@sohu.com; Li Jindou; Huang Meiquan; Jia Qingming; Zhu Jiewu [School of Materials Science and Engineering, Xian Jiaotong University, Xian 710049 (China); Kunz, Ludvik; Buksa, Michal [Institute of Physics of Materials, Academy of Sciences of the Czech Republic, Brno 61662 (Czech Republic)

2008-02-25

The S-N and Coffin-Manson plot, cyclic stress-strain response, changes of microstructure, and the surface morphology of ultra-fine grain (UFG) low-purity copper processed by ECAP were tested and observed in present study. And the formation mechanism of shear bands was discussed in detail. The results show that the UFG Cu represents longer lifetime under stress-controlled fatigue, but lower fatigue resistance under strain-controlled fatigue when compared with the coarse grain counterpart. Cyclic stress-strain responses of UFG Cu under stress-controlled fatigue alter from cyclic softening to cyclic hardening as stress amplitude decreases. But the responses always show cyclic softening under strain-controlled fatigue in present testing. By electron back scattering diffraction and transmission electron microscope technique, the shear bands were discovered on the surface of all cycled samples and no grain coarsening was discovered near the shear bands, which indicated that there was no inevitable relationship between formation of SBs and cyclic softening/grain coarsening. The discovery should be related to impurities in copper. The oriented distribution of defects along the shear plane in the last ECAP processing is one of the major mechanisms of SBs formation.

Fatigue behavior and damage characteristic of ultra-fine grain low-purity copper processed by equal-channel angular pressing (ECAP)

International Nuclear Information System (INIS)

Xu Changzheng; Wang Qingjuan; Zheng Maosheng; Li Jindou; Huang Meiquan; Jia Qingming; Zhu Jiewu; Kunz, Ludvik; Buksa, Michal

2008-01-01

The S-N and Coffin-Manson plot, cyclic stress-strain response, changes of microstructure, and the surface morphology of ultra-fine grain (UFG) low-purity copper processed by ECAP were tested and observed in present study. And the formation mechanism of shear bands was discussed in detail. The results show that the UFG Cu represents longer lifetime under stress-controlled fatigue, but lower fatigue resistance under strain-controlled fatigue when compared with the coarse grain counterpart. Cyclic stress-strain responses of UFG Cu under stress-controlled fatigue alter from cyclic softening to cyclic hardening as stress amplitude decreases. But the responses always show cyclic softening under strain-controlled fatigue in present testing. By electron back scattering diffraction and transmission electron microscope technique, the shear bands were discovered on the surface of all cycled samples and no grain coarsening was discovered near the shear bands, which indicated that there was no inevitable relationship between formation of SBs and cyclic softening/grain coarsening. The discovery should be related to impurities in copper. The oriented distribution of defects along the shear plane in the last ECAP processing is one of the major mechanisms of SBs formation

Preparation of textural lamellar tin deposits via electrodeposition

Science.gov (United States)

Wen, Xiaoyu; Pan, Xiaona; Wu, Libin; Li, Ruinan; Wang, Dan; Zhang, Jinqiu; Yang, Peixia

2017-06-01

Lamellar tin deposits were prepared by galvanostatical electroplating from the aqueous acidic-sulfate bath, with gelatin and benzalacetone dissolved in ethanol (ABA+EtOH) as additive, and their morphologies were investigated by scanning electron microscopy. Cathodic polarization curves revealed that the absorbability of ABA+EtOH on the cathode surface was higher than that of gelatin. X-ray diffraction analysis indicated preferred orientations of tin growth led to the formation of lamellar structure and distortion of tin lattice. The growth mechanism of lamellar tin was also discussed.

Co-formation of hydroperoxides and ultra-fine particles during the reactions of ozone with a complex VOC mixture under simulated indoor conditions

DEFF Research Database (Denmark)

Fan, Z.H.; Weschler, Charles J.; Han, IK

2005-01-01

In this study we examined the co-formation of hydrogen peroxide and other hydroperoxides (collectively presented as H2O2*) as well as submicron particles, including ultra-fine particles (UFP), resulting from the reactions of ozone (O-3) with a complex mixture of volatile organic compounds (VOCs...... higher than typical indoor levels. When O-3 was added to a 25-m(3) controlled environmental facility (CEF) containing the 23 VOC mixture, both H2O2* and submicron particles were formed. The 2-h average concentration of H2O2* was 1.89 +/- 0.30ppb, and the average total particle number concentration was 46...... to achieve saturated concentrations of the condensable organics. When the 2 terpenes were removed from the O-3/23 VOCs mixture, no H2O2* or particles were formed, indicating that the reactions of O-3 With the two terpenes were the key processes contributing to the formation of H2O2* and submicron particles...

A Modified Porous Titanium Sheet Prepared by Plasma-Activated Sintering for Biomedical Applications

Directory of Open Access Journals (Sweden)

Yukimichi Tamaki

2010-01-01

Full Text Available This study aimed to develop a contamination-free porous titanium scaffold by a plasma-activated sintering within an originally developed TiN-coated graphite mold. The surface of porous titanium sheet with or without a coated graphite mold was characterized. The cell adhesion property of porous titanium sheet was also evaluated in this study. The peak of TiC was detected on the titanium sheet processed with the graphite mold without a TiN coating. Since the titanium fiber elements were directly in contact with the carbon graphite mold during processing, surface contamination was unavoidable event in this condition. The TiC peak was not detectable on the titanium sheet processed within the TiN-coated carbon graphite mold. This modified plasma-activated sintering with the TiN-coated graphite mold would be useful to fabricate a contamination-free titanium sheet. The number of adherent cells on the modified titanium sheet was greater than that of the bare titanium plate. Stress fiber formation and the extension of the cells were observed on the titanium sheets. This modified titanium sheet is expected to be a new tissue engineering material in orthopedic bone repair.

Optimization of operating variables for production of ultra-fine talc in a stirred mill. Specific surface area investigations

Directory of Open Access Journals (Sweden)

Toraman Oner Yusuf

2016-01-01

Full Text Available Due to its properties such as chemical inertness, softness, whiteness, high thermal conductivity, low electrical conductivity and adsorption properties talc has wide industrial applications in paper, cosmetics, paints, polymer, ceramics, refractory materials and pharmaceutical. The demand for ultra-fine talc is emerging which drives the mineral industry to produce value added products. In this study, it was investigated how certain grinding parameters such as mill speed, ball filling ratio, powder filling ratio and grinding time of dry stirred mill affect grindability of talc ore (d97=127 μm. A series of laboratory experiments using a 24 full factorial design was conducted to determine the optimal operational parameters of a stirred mill in order to minimize the specific surface area. The main and interaction effects on the volume specific surface area (SV, m2.cm−3 of the ground product were evaluated using the Yates analysis. Under the optimal conditions at the stirrer speed of 600 rpm, grinding time of 20 min, sample mass of 5% and ball ratio of 70%, the resulting talc powder had larger volume specific surface area (i.e., 3.48 m2.cm−3 than the starting material (i.e., 1.84 m2.cm−3.

Liquid tin limiter for FTU tokamak

Energy Technology Data Exchange (ETDEWEB)

Vertkov, A., E-mail: avertkov@yandex.ru [JSC “Red Star”, Moscow (Russian Federation); Lyublinski, I. [JSC “Red Star”, Moscow (Russian Federation); NRNU MEPhI, Moscow (Russian Federation); Zharkov, M. [JSC “Red Star”, Moscow (Russian Federation); Mazzitelli, G.; Apicella, M.L.; Iafrati, M. [Associazione EURATOM-ENEA sulla Fusione, C. R. Frascati, Frascati, Rome, Italy, (Italy)

2017-04-15

Highlights: • First steady state operating liquid tin limiter TLL is under study on FTU tokamak. • The cooling system with water spray coolant for TLL has been developed and tested. • High corrosion resistance of W and Mo in molten Sn confirmed up to 1000 °C. • Wetting process with Sn has been developed for Mo and W. - Abstract: The liquid Sn in a matrix of Capillary Porous System (CPS) has a high potential as plasma facing material in steady state operating fusion reactor owing to its physicochemical properties. However, up to now it has no experimental confirmation in tokamak conditions. First steady state operating limiter based on the CPS with liquid Sn installed on FTU tokamak and its experimental study is in progress. Several aspects of the design, structural materials and operation parameters of limiter based on tungsten CPS with liquid Sn are considered. Results of investigation of corrosion resistance of Mo and W in Sn and their wetting process are presented. The heat removal for limiter steady state operation is provided by evaporation of flowing gaswater spray. The effectiveness of such heat removal system is confirmed in modelling tests with power flux up to 5 MW/m2.

Influence of curing regimes on compressive strength of ultra high

Indian Academy of Sciences (India)

The present paper is aimed to identify an efficient curing regime for ultra high performance concrete (UHPC), to achieve a target compressive strength more than 150 MPa, using indigenous materials. The thermal regime plays a vital role due to the limited fineness of ingredients and low water/binder ratio. By activation of the ...

IMPEDANCE SPECTROSCOPY OF POLYCRYSTALLINE TIN DIOXIDE FILMS

Directory of Open Access Journals (Sweden)

D. V. Adamchuck

2016-01-01

Full Text Available The aim of this work is the analysis of the influence of annealing in an inert atmosphere on the electrical properties and structure of non-stoichiometric tin dioxide films by means of impedance spectroscopy method. Non-stoichiometric tin dioxide films were fabricated by two-step oxidation of metallic tin deposited on the polycrystalline Al2O3 substrates by DC magnetron sputtering. In order to modify the structure and stoichiometric composition, the films were subjected to the high temperature annealing in argon atmosphere in temperature range 300–800 °С. AC-conductivity measurements of the films in the frequency range 20 Hz – 2 MHz were carried out. Variation in the frequency dependencies of the real and imaginary parts of the impedance of tin dioxide films was found to occur as a result of high-temperature annealing. Equivalent circuits for describing the properties of films with various structure and stoichiometric composition were proposed. Possibility of conductivity variation of the polycrystalline tin dioxide films as a result of аnnealing in an inert atmosphere was demonstrated by utilizing impedance spectroscopy. Annealing induces the recrystallization of the films, changing in their stoichiometry as well as increase of the sizes of SnO2 crystallites. Variation of electrical conductivity and structure of tin dioxide films as a result of annealing in inert atmosphere was confirmed by X-ray diffraction analysis. Analysis of the impedance diagrams of tin dioxide films was found to be a powerful tool to study their electrical properties. 

A Novel Non-Planar Transverse Stretching Process for Micro-Porous PTFE Membranes and Resulting Characteristics

KAUST Repository

Chang, Y.-H.; Chen, S.-C.; Wang, T.-J.; Guo, J.

2018-01-01

Polytetrafluoroethylene (PTFE) micro-porous membranes were prepared from PTFE fine powder through extruding, rolling, and uniaxial longitudinally stretching. In contrast to conventional planar transverse stretching, a novel 3D mold design of non

Mitigating tin whisker risks theory and practice

CERN Document Server

Handwerker, Carol A; Bath, Jasbir

2016-01-01

Discusses the growth mechanisms of tin whiskers and the effective mitigation strategies necessary to reduce whisker growth risks. This book covers key tin whisker topics, ranging from fundamental science to practical mitigation strategies. The text begins with a review of the characteristic properties of local microstructures around whisker and hillock grains to identify why these particular grains and locations become predisposed to forming whiskers and hillocks. The book discusses the basic properties of tin-based alloy finishes and the effects of various alloying elements on whisker formation, with a focus on potential mechanisms for whisker suppression or enhancement for each element. Tin whisker risk mitigation strategies for each tier of the supply chain for high reliability electronic systems are also described.

Luminescence evolution of porous GaN thin films prepared via UV-assisted electrochemical etching

International Nuclear Information System (INIS)

Cheah, S.F.; Lee, S.C.; Ng, S.S.; Yam, F.K.; Abu Hassan, H.; Hassan, Z.

2015-01-01

Porous gallium nitride (GaN) thin films with different surface morphologies and free carriers properties were fabricated from Si-doped GaN thin films using ultra-violet assisted electrochemical etching approach under various etching voltages. Fluctuation of luminescence signals was observed in the photoluminescence spectra of porous GaN thin films. Taking advantage of the spectral sensitivity of infrared attenuated total reflection spectroscopy on semiconductor materials, roles of free carriers and porous structure in controlling luminescence properties of GaN were investigated thoroughly. The results revealed that enhancement in luminescence signal is not always attained upon porosification. Although porosification is correlated to the luminescence enhancement, however, free carrier is the primary factor to enhance luminescence intensity. Due to unavoidable significant reduction of free carriers from Si-doped GaN in the porosification process, control of etching depth (i.e., thickness of porous layer formed from the Si-doped layer) is critical in fabricating porous GaN thin film with enhanced luminescence response. - Highlights: • Various pore morphologies with free carrier properties are produced by Si-doped GaN. • Free carriers are important to control the luminescence signal of porous GaN. • Enhancement of luminescence signal relies on the pore depth of Si-doped layer

Ultra-Fine Scale Spatially-Integrated Mapping of Habitat and Occupancy Using Structure-From-Motion.

Directory of Open Access Journals (Sweden)

Philip McDowall

Full Text Available Organisms respond to and often simultaneously modify their environment. While these interactions are apparent at the landscape extent, the driving mechanisms often occur at very fine spatial scales. Structure-from-Motion (SfM, a computer vision technique, allows the simultaneous mapping of organisms and fine scale habitat, and will greatly improve our understanding of habitat suitability, ecophysiology, and the bi-directional relationship between geomorphology and habitat use. SfM can be used to create high-resolution (centimeter-scale three-dimensional (3D habitat models at low cost. These models can capture the abiotic conditions formed by terrain and simultaneously record the position of individual organisms within that terrain. While coloniality is common in seabird species, we have a poor understanding of the extent to which dense breeding aggregations are driven by fine-scale active aggregation or limited suitable habitat. We demonstrate the use of SfM for fine-scale habitat suitability by reconstructing the locations of nests in a gentoo penguin colony and fitting models that explicitly account for conspecific attraction. The resulting digital elevation models (DEMs are used as covariates in an inhomogeneous hybrid point process model. We find that gentoo penguin nest site selection is a function of the topography of the landscape, but that nests are far more aggregated than would be expected based on terrain alone, suggesting a strong role of behavioral aggregation in driving coloniality in this species. This integrated mapping of organisms and fine scale habitat will greatly improve our understanding of fine-scale habitat suitability, ecophysiology, and the complex bi-directional relationship between geomorphology and habitat use.

Ti Porous Film-Supported NiCo₂S₄ Nanotubes Counter Electrode for Quantum-Dot-Sensitized Solar Cells.

Science.gov (United States)

Deng, Jianping; Wang, Minqiang; Song, Xiaohui; Yang, Zhi; Yuan, Zhaolin

2018-04-17

In this paper, a novel Ti porous film-supported NiCo₂S₄ nanotube was fabricated by the acid etching and two-step hydrothermal method and then used as a counter electrode in a CdS/CdSe quantum-dot-sensitized solar cell. Measurements of the cyclic voltammetry, Tafel polarization curves, and electrochemical impedance spectroscopy of the symmetric cells revealed that compared with the conventional FTO (fluorine doped tin oxide)/Pt counter electrode, Ti porous film-supported NiCo₂S₄ nanotubes counter electrode exhibited greater electrocatalytic activity toward polysulfide electrolyte and lower charge-transfer resistance at the interface between electrolyte and counter electrode, which remarkably improved the fill factor, short-circuit current density, and power conversion efficiency of the quantum-dot-sensitized solar cell. Under illumination of one sun (100 mW/cm²), the quantum-dot-sensitized solar cell based on Ti porous film-supported NiCo₂S₄ nanotubes counter electrode achieved a power conversion efficiency of 3.14%, which is superior to the cell based on FTO/Pt counter electrode (1.3%).

Strategies to Reduce Tin and Other Metals in Electronic Cigarette Aerosol.

Directory of Open Access Journals (Sweden)

Monique Williams

Full Text Available Metals are present in electronic cigarette (EC fluid and aerosol and may present health risks to users.The objective of this study was to measure the amounts of tin, copper, zinc, silver, nickel and chromium in the aerosol from four brands of EC and to identify the sources of these metals by examining the elemental composition of the atomizer components.Four brands of popular EC were dissected and the cartomizers were examined microscopically. Elemental composition of cartomizer components was determined using integrated energy dispersive X-ray microanalysis, and the concentrations of the tin, copper, zinc silver, nickel, and chromium in the aerosol were determined for each brand using inductively coupled plasma optical emission spectroscopy.All filaments were made of nickel and chromium. Thick wires were copper coated with either tin or silver. Wires were joined to each other by tin solder, brazing, or by brass clamps. High concentrations of tin were detected in the aerosol when tin solder joints were friable. Tin coating on copper wires also contributed to tin in the aerosol.Tin concentrations in EC aerosols varied both within and between brands. Tin in aerosol was reduced by coating the thick wire with silver rather than tin, placing stable tin solder joints outside the atomizing chamber, joining wires with brass clamps or by brazing rather than soldering wires. These data demonstrate the feasibility of removing tin and other unwanted metals from EC aerosol by altering designs and using materials of suitable quality.

Effect of porous silicon layer on the performance of Si/oxide photovoltaic and photoelectrochemical cells

International Nuclear Information System (INIS)

Badawy, Waheed A.

2008-01-01

Photovoltaic and photoelectrochemical systems were prepared by the formation of a thin porous film on silicon. The porous silicon layer was formed on the top of a clean oxide free silicon wafer surface by anodic etching in HF/H 2 O/C 2 H 5 OH mixture (2:1:1). The silicon was then covered by an oxide film (tin oxide, ITO or titanium oxide). The oxide films were prepared by the spray/pyrolysis technique which enables doping of the oxide film by different atoms like In, Ru or Sb during the spray process. Doping of SnO 2 or TiO 2 films with Ru atoms improves the surface characteristics of the oxide film which improves the solar conversion efficiency. The prepared solar cells are stable against environmental attack due to the presence of the stable oxide film. It gives relatively high short circuit currents (I sc ), due to the presence of the porous silicon layer, which leads to the recorded high conversion efficiency. Although the open-circuit potential (V oc ) and fill factor (FF) were not affected by the thickness of the porous silicon film, the short circuit current was found to be sensitive to this thickness. An optimum thickness of the porous film and also the oxide layer is required to optimize the solar cell efficiency. The results represent a promising system for the application of porous silicon layers in solar energy converters. The use of porous silicon instead of silicon single crystals in solar cell fabrication and the optimization of the solar conversion efficiency will lead to the reduction of the cost as an important factor and also the increase of the solar cell efficiency making use of the large area of the porous structures

Effect of Graphene Addition on Mechanical Properties of TiN

International Nuclear Information System (INIS)

Shon, In-Jin; Yoon, Jin-Kook; Hong, Kyung-Tae

2017-01-01

Despite of many attractive properties of TiN, the current concern about the TiN focuses on its low fracture toughness below the ductile-brittle transition temperature. To improve its mechanical properties, the approach generally utilized has been the addition of a second phase to form composites and to make nanostructured materials. In this respect, highly dense nanostructured TiN and TiN-graphene composites were obtained within two min at 1250 ℃. The grain size of TiN was reduced remarkably by the addition of graphene. The addition of graphene to TiN simultaneously improved the fracture toughness and hardness of TiN-graphene composite due to refinement of TiN and deterring crack propagation by graphene. This study demonstrates that the graphene can be an effective reinforcing agent for improved hardness and fracture toughness of TiN composites.

Effect of Graphene Addition on Mechanical Properties of TiN

Energy Technology Data Exchange (ETDEWEB)

Shon, In-Jin [Chonbuk National University, Jeonju (Korea, Republic of); Yoon, Jin-Kook; Hong, Kyung-Tae [Korea Institute of Science and Technology, Seoul (Korea, Republic of)

2017-03-15

Despite of many attractive properties of TiN, the current concern about the TiN focuses on its low fracture toughness below the ductile-brittle transition temperature. To improve its mechanical properties, the approach generally utilized has been the addition of a second phase to form composites and to make nanostructured materials. In this respect, highly dense nanostructured TiN and TiN-graphene composites were obtained within two min at 1250 ℃. The grain size of TiN was reduced remarkably by the addition of graphene. The addition of graphene to TiN simultaneously improved the fracture toughness and hardness of TiN-graphene composite due to refinement of TiN and deterring crack propagation by graphene. This study demonstrates that the graphene can be an effective reinforcing agent for improved hardness and fracture toughness of TiN composites.

Microwave plasma CVD of NANO structured tin/carbon composites

Science.gov (United States)

Marcinek, Marek [Warszawa, PL; Kostecki, Robert [Lafayette, CA

2012-07-17

A method for forming a graphitic tin-carbon composite at low temperatures is described. The method involves using microwave radiation to produce a neutral gas plasma in a reactor cell. At least one organo tin precursor material in the reactor cell forms a tin-carbon film on a supporting substrate disposed in the cell under influence of the plasma. The three dimensional carbon matrix material with embedded tin nanoparticles can be used as an electrode in lithium-ion batteries.

Microstructural and Optical Properties of Porous Alumina Elaborated on Glass Substrate

Science.gov (United States)

Zaghdoudi, W.; Gaidi, M.; Chtourou, R.

2013-03-01

A transparent porous anodized aluminum oxide (AAO) nanostructure was formed on a glass substrate using the anodization of a highly pure evaporated aluminum layer. A parametric study was carried out in order to achieve a fine control of the microstructural and optical properties of the elaborated films. The microstructural and surface morphologies of the porous alumina films were characterized by x-ray diffraction and atomic force microscopy. Pore diameter, inter-pore separation, and the porous structure as a function of anodization conditions were investigated. It was then found that the pores density decreases with increasing the anodization time. Regular cylindrical porous AAO films with a flat bottom structure were formed by chemical etching and anodization. A high transmittance in the 300-900 nm range is reported, indicating a fulfilled growth of the transparent sample (alumina) from the aluminum metal. The data showed typical interference oscillations as a result of the transparent characteristics of the film throughout the visible spectral range. The thickness and the optical constants ( n and k) of the porous anodic alumina films, as a function of anodizing time, were obtained using spectroscopic ellipsometry in the ultraviolet-visible-near infrared (UV-vis-NIR) regions.

Temperature measurement of tin under shock compression

International Nuclear Information System (INIS)

Hereil, Pierre-Louis; Mabire, Catherine

2002-01-01

The results of pyrometric measurements performed at the interface of a tin target with a LiF window material are presented for stresses ranging from 38 to 55 GPa. The purpose of the study is to analyze the part of the interface in the temperature measurement by a multi-channel pyrometric device. The results show that the glue used at target/window interface remains transparent under shock. The values of temperature measured at the tin/LiF interface are consistent with the behavior of tin under shock

Strategies to Reduce Tin and Other Metals in Electronic Cigarette Aerosol

Science.gov (United States)

Williams, Monique; To, An; Bozhilov, Krassimir; Talbot, Prue

2015-01-01

Background Metals are present in electronic cigarette (EC) fluid and aerosol and may present health risks to users. Objective The objective of this study was to measure the amounts of tin, copper, zinc, silver, nickel and chromium in the aerosol from four brands of EC and to identify the sources of these metals by examining the elemental composition of the atomizer components. Methods Four brands of popular EC were dissected and the cartomizers were examined microscopically. Elemental composition of cartomizer components was determined using integrated energy dispersive X-ray microanalysis, and the concentrations of the tin, copper, zinc silver, nickel, and chromium in the aerosol were determined for each brand using inductively coupled plasma optical emission spectroscopy. Results All filaments were made of nickel and chromium. Thick wires were copper coated with either tin or silver. Wires were joined to each other by tin solder, brazing, or by brass clamps. High concentrations of tin were detected in the aerosol when tin solder joints were friable. Tin coating on copper wires also contributed to tin in the aerosol. Conclusions Tin concentrations in EC aerosols varied both within and between brands. Tin in aerosol was reduced by coating the thick wire with silver rather than tin, placing stable tin solder joints outside the atomizing chamber, joining wires with brass clamps or by brazing rather than soldering wires. These data demonstrate the feasibility of removing tin and other unwanted metals from EC aerosol by altering designs and using materials of suitable quality. PMID:26406602

Tensile behavior of porous scaffolds made from poly(para phenylene) - biomed 2013.

Science.gov (United States)

Dirienzo, Amy L; Yakacki, Christopher M; Safranski, David L; Frick, Carl P

2013-01-01

The goal of this study was to fabricate and mechanically characterize a high-strength porous polymer scaffold for potential use as an orthopedic device. Poly(para-phenylene) (PPP) is an excellent candidate due to its exceptional strength and stiffness and relative inertness, but has never been explicitly investigated for use as a biomedical device. PPP has strength values 3 to 10 times higher and an elastic modulus nearly an order of magnitude higher than traditional polymers such as poly(methyl methacrylate) (PMMA), polycaprolactone (PCL), ultra-high molecular weight polyethylene (UHMWPE), and polyurethane (PU) and is significantly stronger and stiffer than polyetheretherketone (PEEK). By utilizing PPP we can overcome the mechanical limitations of traditional porous polymeric scaffolds since the outstanding stiffness of PPP allows for a highly porous structure appropriate for osteointegration that can match the stiffness of bone (100-250 MPa), while maintaining suitable mechanical properties for soft-tissue fixation. Porous samples were manufactured by powder sintering followed by particle leaching. The pore volume fraction was systematically varied from 50–80 vol% for a pore sizes from150-500 µm, as indicated by previous studies for optimal osteointegration. The tensile modulus of the porous samples was compared to the rule of mixtures, and closely matches foam theory up to 70 vol%. The experimental modulus for 70 vol% porous samples matches the stiffness of bone and contains pore sizes optimal for osteointegration.

Diffuse scattering in metallic tin polymorphs

International Nuclear Information System (INIS)

Wehinger, Björn; Bosak, Alexeï; Piccolboni, Giuseppe; Krisch, Michael; Refson, Keith; Chernyshov, Dmitry; Ivanov, Alexandre; Rumiantsev, Alexander

2014-01-01

The lattice dynamics of the metallic tin β and γ polymorphs has been studied by a combination of diffuse scattering, inelastic x-ray scattering and density functional perturbation theory. The non-symmorphic space group of the β -tin structure results in unusual asymmetry of thermal diffuse scattering. Strong resemblance of the diffuse scattering intensity distribution in β and γ-tin were observed, reflecting the structural relationship between the two phases and revealing the qualitative similarity of the underlying electronic potential. The strong influence of the electron subsystem on inter-ionic interactions creates anomalies in the phonon dispersion relations. All observed features are described in great detail by the density functional perturbation theory for both β - and γ-tin at arbitrary momentum transfers. The combined approach delivers thus a complete picture of the lattice dynamics in harmonic description. (paper)

Global-local nonlinear model reduction for flows in heterogeneous porous media

KAUST Repository

AlOtaibi, Manal; Calo, Victor M.; Efendiev, Yalchin R.; Galvis, Juan; Ghommem, Mehdi

2015-01-01

In this paper, we combine discrete empirical interpolation techniques, global mode decomposition methods, and local multiscale methods, such as the Generalized Multiscale Finite Element Method (GMsFEM), to reduce the computational complexity associated with nonlinear flows in highly-heterogeneous porous media. To solve the nonlinear governing equations, we employ the GMsFEM to represent the solution on a coarse grid with multiscale basis functions and apply proper orthogonal decomposition on a coarse grid. Computing the GMsFEM solution involves calculating the residual and the Jacobian on a fine grid. As such, we use local and global empirical interpolation concepts to circumvent performing these computations on the fine grid. The resulting reduced-order approach significantly reduces the flow problem size while accurately capturing the behavior of fully-resolved solutions. We consider several numerical examples of nonlinear multiscale partial differential equations that are numerically integrated using fully-implicit time marching schemes to demonstrate the capability of the proposed model reduction approach to speed up simulations of nonlinear flows in high-contrast porous media.

Global-local nonlinear model reduction for flows in heterogeneous porous media

KAUST Repository

AlOtaibi, Manal

2015-08-01

In this paper, we combine discrete empirical interpolation techniques, global mode decomposition methods, and local multiscale methods, such as the Generalized Multiscale Finite Element Method (GMsFEM), to reduce the computational complexity associated with nonlinear flows in highly-heterogeneous porous media. To solve the nonlinear governing equations, we employ the GMsFEM to represent the solution on a coarse grid with multiscale basis functions and apply proper orthogonal decomposition on a coarse grid. Computing the GMsFEM solution involves calculating the residual and the Jacobian on a fine grid. As such, we use local and global empirical interpolation concepts to circumvent performing these computations on the fine grid. The resulting reduced-order approach significantly reduces the flow problem size while accurately capturing the behavior of fully-resolved solutions. We consider several numerical examples of nonlinear multiscale partial differential equations that are numerically integrated using fully-implicit time marching schemes to demonstrate the capability of the proposed model reduction approach to speed up simulations of nonlinear flows in high-contrast porous media.

Densely Packed, Ultra Small SnO Nanoparticles for Enhanced Activity and Selectivity in Electrochemical CO2 Reduction.

Science.gov (United States)

Gu, Jun; Héroguel, Florent; Luterbacher, Jeremy; Hu, Xile

2018-03-05

Controlling the selectivity in electrochemical CO 2 reduction is an unsolved challenge. While tin (Sn) has emerged as a promising non-precious catalyst for CO 2 electroreduction, most Sn-based catalysts produce formate as the major product, which is less desirable than CO in terms of separation and further use. Tin monoxide (SnO) nanoparticles supported on carbon black were synthesized and assembled and their application in CO 2 reduction was studied. Remarkably high selectivity and partial current densities for CO formation were obtained using these SnO nanoparticles compared to other Sn catalysts. The high activity is attributed to the ultra-small size of the nanoparticles (2.6 nm), while the high selectivity is attributed to a local pH effect arising from the dense packing of nanoparticles in the conductive carbon black matrix. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Telomere dysfunction and cell survival: roles for distinctTIN2-containing complexes

Energy Technology Data Exchange (ETDEWEB)

Kim, Sahn-Ho; Davalos, Albert R.; Heo, Seok-Jin; Rodier, Francis; Beausejour, Christian; Kaminker, Patrick; Campisi, Judith

2006-11-07

Telomeres are maintained by three DNA binding proteins, TRF1, TRF2 and POT1, and several associated factors. One factor, TIN2, binds TRF1 and TRF2 directly and POT1 indirectly. These and two other proteins form a soluble complex that may be the core telomere-maintenance complex. It is not clear whether subcomplexes exist or function in vivo. Here, we provide evidence for two TIN2 subcomplexes with distinct functions in human cells. TIN2 ablation by RNA interference caused telomere uncapping and p53-independent cell death in all cells tested. However, we isolated two TIN2 complexes from cell lysates, each selectively sensitive to a TIN2 mutant (TIN2-13, TIN2-15C). In cells with wild-type p53 function, TIN2-15C was more potent than TIN2-13 in causing telomere uncapping and eventual growth arrest. In cells lacking p53 function, TIN215C more than TIN2-13 caused genomic instability and cell death. Thus, TIN2 subcomplexes likely have distinct functions in telomere maintenance, and may provide selective targets for eliminating cells with mutant p53.

Analysis and estimation on composition and property change in atomic level due to radiation damage of materials

International Nuclear Information System (INIS)

Furuya, Kazuo; Son Menhi; Mitsuishi Kazuki; Yashihara, Kazuhiro; Sito, Tetsuya

1999-01-01

Porous silicon was analyzed by an analytical high-resolution ultra high voltage transmission electron microscope, which could in situ observation under electron beam radiation and the microanalysis. This study was carried out as the fundamental investigation of the relation between the local chemical bonding state and the optical transition. When p-type silicon wafer was obtained by the anodic oxidation, PL intensity increased with increasing the current of anodic oxidation and the lifetime increased a little with the current. The porous silicon layer constructed a tree structure. The more the current was large, the more fine the structure became. The fact showed the fine tree structure was of advantage to light emission. SiO 2 coexisted in the porous silicon and the amount of them was proportional to the emission intensity. These facts indicated that PL process was strongly related to the defects in the SiO 2 or the boundary between SiO 2 and Si crystal. (S.Y.)

One step synthesis of porous graphene by laser ablation: A new and facile approach

Science.gov (United States)

Kazemizadeh, Fatemeh; Malekfar, Rasoul

2018-02-01

Porous graphene (PG) was obtained using one step laser process. Synthesis was carried out by laser ablation of nickel-graphite target under ultra-high flow of argon gas. The field emission scanning electron microscopy (FE-SEM) results showed the formation of a porous structure and the transmission electron microscopy (TEM) revealed that the porosity of PGs increase under intense laser irradiation. Structural characterization study using Raman spectroscopy, X-ray powder diffraction (XRD) and selected area electron diffraction (SAED) technique showed that the obtained PGs display high crystalline structure in the form of few layer rhombohedral graphitic arrangement that can be interpreted as the phase prior to the formation of other carbon nanostructures.

Pilot Demonstration of Technology for the Production of High Value Materials from the Ultra-Fine (PM2.5) Fraction of Coal Combustion Ash

Energy Technology Data Exchange (ETDEWEB)

T. L. Robl; J. G. Groppo; R. Rathbone; B. Marrs; R. Jewell

2008-07-18

The overall objective of this research was to determine the feasibility of recovering a very fine fraction of fly ash, that is 5 microns in diameter or less and examining the characteristics of these materials in new or at least less traditional applications. These applications included as a polymer filler or as a 'super' pozzolanic concrete additive. As part of the effort the ash from 6 power plants was investigated and characterized. This work included collection from ESP Hoppers and ponds. The ash was thoroughly characterized chemically and physically. Froth flotation was used to reduce the carbon and testing showed that flotation could effectively reduce carbon to acceptable levels (i.e. 0.5% LOI) for most of the substrates tested. in order to enable eventual use as fillers. Hydraulic classification was used in the separation of the fine ash from the coarse ash. Hydraulic classification requires the ash to be dispersed to be effective and a range of dispersants were tested for adsorption as well as sedimentation rate. A wide range of dosages were required (0.3 to 10 g/kg). In general the ponded ash required less dispersant. A model was developed for hydraulic classification. A pilot-scale hydraulic classifier was also designed and operated for the project. Product yields of up to 21% of feed solids were achieved with recoveries of <5 {micro}m particles as high as 64%. Mean particle sizes (D{sub 50}) of the ultra fine ash (UFA) products varied from 3.7 to 10 {micro}m. A patent was filed on the classifier design. A conceptual design of a Process Demonstration Unit (PDU) with a feed rate of 2 tons of raw ash feed per hour was also completed. Pozzolanic activity was determined for the UFA ashes in mortars. In general the overall strength index was excellent with values of 90% achieved in 3 days and {approx}100% in 7 days. Three types of thermoplastic polymers were evaluated with the UFA as a filler: high density polyethylene, thermoplastic elastomer and

Telomere dysfunction and cell survival: Roles for distinct TIN2-containing complexes

Energy Technology Data Exchange (ETDEWEB)

Kim, Sahn-ho; Davalos, Albert R.; Heo, Seok-Jin; Rodier, Francis; Zou, Ying; Beausejour, Christian; Kaminker, Patrick; Yannone, Steven M.; Campisi, Judith

2007-10-02

Telomeres are maintained by three DNA binding proteins (TRF1, TRF2 and POT1), and several associated factors. One factor, TIN2, binds TRF1 and TRF2 directly and POT1 indirectly. Along with two other proteins, TPP1 and hRap1, these form a soluble complex that may be the core telomere maintenance complex. It is not clear whether sub-complexes also exist in vivo. We provide evidence for two TIN2 sub-complexes with distinct functions in human cells. We isolated these two TIN2 sub-complexes from nuclear lysates of unperturbed cells and cells expressing TIN2 mutants TIN2-13, TIN2-15C, which cannot bind TRF2 or TRF1, respectively. In cells with wild-type p53 function, TIN2-15C was more potent than TIN2-13 in causing telomere uncapping and eventual growth arrest. In cells lacking p53 function, TIN2-15C was more potent than TIN2-13 in causing telomere dysfunction and cell death. Our findings suggest that distinct TIN2 complexes exist, and that TIN2-15C-sensitive subcomplexes are particularly important for cell survival in the absence of functional p53.

Characterization of a porous nano-electrospray capillary emitter at ultra-low flow rates

Czech Academy of Sciences Publication Activity Database

Járvás, G.; Fonslow, B.; Yates III, J. R.; Foret, František; Guttman, A.

2017-01-01

Roč. 55, č. 1 (2017), s. 47-51 ISSN 0021-9665 R&D Projects: GA ČR(CZ) GBP206/12/G014 Institutional support: RVO:68081715 Keywords : nano-electrospray * ion suppression * porous joint Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 0.984, year: 2016

Microstructures and photocatalytic properties of porous ZnO films synthesized by chemical bath deposition method

International Nuclear Information System (INIS)

Wang Huihu; Dong, Shijie; Chang Ying; Zhou Xiaoping; Hu Xinbin

2012-01-01

Different porous ZnO film structures on the surface of alumina substrates were prepared through a simple chemical bath deposition method in the methanolic zinc acetate solution. The surface morphology and phase structure of porous ZnO film were determined by scanning electron microscopy (SEM) and X-ray diffraction (XRD), respectively. Both initial zinc acetate concentration and sintering temperature have great impact on the final film structures. With the increase of initial zinc acetate concentration, the porous structures can be finely tuned from circular nest like assemblies composed film into successive nest like film, and finally to globular aggregates composed film. By increasing the sintering temperature, the porous structure of successive nest like film can be further controlled. Furthermore, the crystallinity of photocatalysts also can be greatly improved. The photodegradation results of Methyl Orange revealed that porous ZnO film with successive nest like structure sintered at 500 °C exhibited the highest photocatalytic activity under UV illumination.

Preliminary study of tin slag concrete mixture

Science.gov (United States)

Hashim, Mohd Jamil; Mansor, Ishak; Pauzi Ismail, Mohamad; Sani, Suhairy; Azmi, Azhar; Sayuti, Shaharudin; Zaidi Ibrahim, Mohd; Adli Anuar, Abul; Rahim, Abdul Adha Abdul

2018-01-01

The study focuses on practices to facilitate tin smelting industry to reduce radioactive waste product (Tin Slag) by diluting its radioactivity to a safe level and turning it to a safer infrastructural building product. In the process the concrete mix which include Portland cement, sand, tin slag, water and plasticizer are used to produce interlocking brick pavements, piles and other infrastructural products. The mixing method follows DOE (UK) standard method of mixing targeted at in selected compressive strength suitable for its function and durability. A batching machine is used in the mixing and six test cubes are produced for the test. The testing equipment used are a compressional machine, ultrasonic measurement and a Geiger Muller counter to evaluate of the concrete mix to find the lowest emission of radiation surface dose without compromising the strength of concrete mix. The result obtained indicated the radioactivity of tin slag in the mixing process has reduced to background level that is 0.5μSv/h while the strength and workability of the concrete has not been severely affected. In conclusion, the concrete mix with tin slag has shown the potential it can be turned into a safe beneficial infrastructural product with good strength.

Porous nanostructured ZnO films deposited by picosecond laser ablation

International Nuclear Information System (INIS)

Sima, Cornelia; Grigoriu, Constantin; Besleaga, Cristina; Mitran, Tudor; Ion, Lucian; Antohe, Stefan

2012-01-01

Highlights: ► We deposite porous nanostructured ZnO films by picoseconds laser ablation (PLA). ► We examine changes of the films structure on the experimental parameter deposition. ► We demonstrate PLA capability to produce ZnO nanostructured films free of particulates. - Abstract: Porous nanostructured polycrystalline ZnO films, free of large particulates, were deposited by picosecond laser ablation. Using a Zn target, zinc oxide films were deposited on indium tin oxide (ITO) substrates using a picosecond Nd:YVO 4 laser (8 ps, 50 kHz, 532 nm, 0.17 J/cm 2 ) in an oxygen atmosphere at room temperature (RT). The morpho-structural characteristics of ZnO films deposited at different oxygen pressures (150–900 mTorr) and gas flow rates (0.25 and 10 sccm) were studied. The post-deposition influence of annealing (250–550 °C) in oxygen on the film characteristics was also investigated. At RT, a mixture of Zn and ZnO formed. At substrate temperatures above 350 °C, the films were completely oxidized, containing a ZnO wurtzite phase with crystallite sizes of 12.2–40.1 nm. At pressures of up to 450 mTorr, the porous films consisted of well-distinguished primary nanoparticles with average sizes of 45–58 nm, while at higher pressures, larger clusters (3.1–14.7 μm) were dominant, leading to thicker films; higher flow rates favored clustering.

Ultra-high density aligned Carbon-nanotube with controled nano-morphology for supercapacitors

Science.gov (United States)

Ghaffari, Mehdi; Zhao, Ran; Liu, Yang; Zhou, Yue; Cheng, Jiping; Guzman de Villoria, Roberto; Wardle, B. L.; Zhang, Q. M.

2012-02-01

Recent advances in fabricating controlled-morphology vertically aligned carbon nanotubes (VA-CNTs) with ultrahigh volume fractioncreate unique opportunities for developing unconventional supercapacitors with ultra-high energy density, power density, and long charge/discharge cycle life.Continuous paths through inter-VA-CNT channels allow fast ion transport, and high electrical conduction of the aligned CNTs in the composite electrodes lead to fast discharge speed. We investigate the charge-discharge characteristics of VA-CNTs with >20 vol% of CNT and ionic liquids as electrolytes. By employing both the electric and electromechanical spectroscopes, as well as nanostructured materials characterization, the ion transport and storage behaviors in porous electrodes are studied. The results suggest pathways for optimizing the electrode morphology in supercapacitorsusing ultra-high volume fraction VA-CNTs to further enhance performance.

Fiscal 1997 report on the development of an energy use rationalization ultra-high tech liquid crystal technology. Project of development/promotion of ultra-high tech electronic technology / technology of design/control/analysis of new functional electronic materials; 1997 nendo kenkyu seika hokokusho energy shiyo gorika chosentan ekisho gijutsu kaihatsu. Chosentan denshi gijutsu kaihatsu sokushin jigyo / shinkino denshi zairyo sekkei seigyo bunseki gijutsu

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-05-01

A research was conducted with the aim of developing an ultra-low power consuming type information display which supports the next next generation informatizing society. As to the function combined type fine structure formation technology, a formation technology of fine structure supporting multi-layer pixel by organic polymer materials was established to confirm a possibility of adopting it to high functional liquid crystal display. Concerning the high functional fine structure formation technology, a study was proceeded with on holographic PDLC which is an interference reflection coloring method. In relation to the low temperature film formation technology of ferroelectric thin films, a film formation device was introduced to obtain basic data, and at the same time a possibility was studied of improving film characteristics by laser annealing conducted after the film formation. Moreover, concerning the new functional material technology, studies were made of optical interference/high light-scattering control materials, light alignment elements, ultra-high purity/ultra-reliable optical materials, ultra-anisotropy optical materials, etc. About the light reflection characteristics control technology, studied were new liquid crystal molucular orientaion control technology, multi-dimensional anisotropy structure formation technology, etc. 100 refs., 273 figs., 58 tabs.

The effect of native Al2O3 skin disruption on properties of fine Al powder compacts

International Nuclear Information System (INIS)

Balog, Martin; Poletti, Cecilia; Simancik, Frantisek; Walcher, Martin; Rajner, Walter

2011-01-01

Research highlights: → The effect of various powder metallurgy compaction routes on the microstructures and properties of ultra-fine atomized Al powder compacts. → Applied compaction route affects the deformation and fracture of native Al 2 O 3 layer present on the surface of as-atomized powder. → Distribution, morphology and interconnectivity of in situ introduced Al 2 O 3 dispersoids distinctly determine the compacts properties. - Abstract: In the presented study we characterize how various powder metallurgical routes (extrusion, forging, and HIP/sintering) affect the fracture of native Al 2 O 3 layer present on the surface of ultra-fine atomized Al powders. It is shown that the different distribution, morphology and interconnectivity of in situ introduced Al 2 O 3 dispersoids strongly affect the thermal stability and mechanical and thermal properties of subsequent powder compacts.

Correlation between stress-induced leakage current and dielectric degradation in ultra-porous SiOCH low-k materials

Energy Technology Data Exchange (ETDEWEB)

Wu, C., E-mail: Chen.Wu@imec.be; De Wolf, I. [imec, Kapeldreef 75, 3001 Leuven (Belgium); Department of Materials Engineering, KU Leuven, 3000 Leuven (Belgium); Li, Y.; Leśniewska, A.; Varela Pedreira, O.; Marneffe, J.-F. de; Ciofi, I.; Verdonck, P.; Baklanov, M. R.; Bömmels, J.; Tőkei, Zs.; Croes, K. [imec, Kapeldreef 75, 3001 Leuven (Belgium)

2015-10-28

Stress-Induced Leakage Current (SILC) behavior during the dielectric degradation of ultra-porous SiOCH low-k materials was investigated. Under high voltage stress, SILC increases to a critical value before final hard breakdown. This SILC increase rate is mainly driven by the injected charges and is negligibly influenced by temperature and voltage. SILC is found to be transient and shows a t{sup −1} relaxation behavior, where t is the storage time at low voltages. This t{sup −1} transient behavior, described by the tunneling front model, is caused by both electron charging of neutral defects in the dielectric close to the cathode interface and discharging of donor defects close to the anode interface. These defects have a uniform density distribution within the probed depth range, which is confirmed by the observed flat band voltage shift results collected during the low voltage storage. By applying an additional discharging step after the low voltage storage, the trap energies and spatial distributions are derived. In a highly degraded low-k dielectric, the majority of defects have a trap depth between 3.4 eV and 3.6 eV and a density level of 1 × 10{sup 18 }eV{sup −1 }cm{sup −3}. The relation between the defect density N and the total amount of the injected charges Q is measured to be sub-linear, N ∼ Q{sup 0.45±0.07}. The physical nature of these stress-induced defects is suggested to be caused by the degradation of the Si-O based skeleton in the low-k dielectric.

Health impact of exposure to fine particles. Epidemiology of short-term effects

International Nuclear Information System (INIS)

Peters, Annette; Wichmann, H.-Erich; Univ. Muenchen; Heinrich, Joachim

2002-01-01

Epidemiological studies on short-term effects of fine particles are investigating whether morbidity or mortality increase on days with high particle concentrations. Multi-center studies have shown on a daily basis that there is an increase in morbidity and/or mortality in association with particle concentrations. Studies on the effects of particles on the respiratory tract have indicated that there is an impact of particles at their place of deposition. In addition, numerous studies have revealed that particles also have effects on the cardiovascular system, including acute-phase reactions, increased hospital admissions, and also an increase in cardiovascular disease mortality in association with elevated particle concentrations. For PM 10 consistent effects were found. Furthermore, the analyses showed that no threshold value could be established, but a linear dose-effect relation. Studies measuring PM 2.5 point to fine particles being mainly responsible for these effects. Current studies show that in addition to fine particles, ultra-fine particles can cause further health effects. (orig.) [de

Ultra-High Density Single Nanometer-Scale Anodic Alumina Nanofibers Fabricated by Pyrophosphoric Acid Anodizing

Science.gov (United States)

Kikuchi, Tatsuya; Nishinaga, Osamu; Nakajima, Daiki; Kawashima, Jun; Natsui, Shungo; Sakaguchi, Norihito; Suzuki, Ryosuke O.

2014-12-01

Anodic oxide fabricated by anodizing has been widely used for nanostructural engineering, but the nanomorphology is limited to only two oxides: anodic barrier and porous oxides. Therefore, the discovery of an additional anodic oxide with a unique nanofeature would expand the applicability of anodizing. Here we demonstrate the fabrication of a third-generation anodic oxide, specifically, anodic alumina nanofibers, by anodizing in a new electrolyte, pyrophosphoric acid. Ultra-high density single nanometer-scale anodic alumina nanofibers (1010 nanofibers/cm2) consisting of an amorphous, pure aluminum oxide were successfully fabricated via pyrophosphoric acid anodizing. The nanomorphologies of the anodic nanofibers can be controlled by the electrochemical conditions. Anodic tungsten oxide nanofibers can also be fabricated by pyrophosphoric acid anodizing. The aluminum surface covered by the anodic alumina nanofibers exhibited ultra-fast superhydrophilic behavior, with a contact angle of less than 1°, within 1 second. Such ultra-narrow nanofibers can be used for various nanoapplications including catalysts, wettability control, and electronic devices.

Hierarchical micro-lamella-structured 3D porous copper current collector coated with tin for advanced lithium-ion batteries

Energy Technology Data Exchange (ETDEWEB)

Park, Hyeji [School of Materials Science and Engineering, Kookmin University, Seoul 136-702 (Korea, Republic of); Um, Ji Hyun [School of Chemical and Biological Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of); Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 151-742 (Korea, Republic of); Choi, Hyelim [School of Materials Science and Engineering, Kookmin University, Seoul 136-702 (Korea, Republic of); Yoon, Won-Sub [Department of Energy Science, Sungkyunkwan University, Suwon, 440-746 (Korea, Republic of); Sung, Yung-Eun [School of Chemical and Biological Engineering, Seoul National University, Seoul 151-742 (Korea, Republic of); Center for Nanoparticle Research, Institute for Basic Science (IBS), Seoul 151-742 (Korea, Republic of); Choe, Heeman, E-mail: heeman@kookmin.ac.kr [School of Materials Science and Engineering, Kookmin University, Seoul 136-702 (Korea, Republic of); Cellmotive Co. Ltd., #518, Engineering Building, Kookmin University, Seoul 136-702 (Korea, Republic of)

2017-03-31

Highlights: • Sn-Cu scaffold anode fabricated by freeze-casting and electroless plating. • Sn-Cu scaffold architecture shows superior capacity and cyclic stability at high current density. • Sn-Cu scaffold electrode is commercially promising. - Abstract: A Novel 3D porous Sn-Cu architecture is prepared as an anode material for use in an advanced lithium-ion battery. Micro-lamellar-structured 3D porous Cu foam, which is electroless-plated with Sn as an active material, is used as anode current collector. Compared to Sn-coated Cu foil, the 3D Sn-Cu foam exhibits superior Li-ion capacity and stable capacity retention, demonstrating the advantage of 3D porous architecture by preserving its structural integrity. In addition, the effect of heat-treatment after Sn plating is investigated. Sn/Sn{sub 6}Cu{sub 5} and SnO{sub 2}/Cu{sub 10}Sn{sub 3} were formed on and in the 3D Sn-Cu foam under the heat-treatment at 150 °C and 500 °C, respectively. The development of Cu{sub 10}Sn{sub 3} in the 3D Sn-Cu foam heat-treated at 500 °C can be a key factor for the enhanced cyclic stability because the Cu{sub 10}Sn{sub 3} inactively reacts with Li-ion and alleviates the volume expansion of SnO{sub 2} as an inactive matrix.

Microstructure and growth mechanism of tin whiskers on RESn3 compounds

International Nuclear Information System (INIS)

Li Caifu; Liu Zhiquan

2013-01-01

Graphical abstract: Large amount of intact tin whiskers were firstly prepared without post handling, and their microstructures were investigated systematically with TEM. A growth model was proposed to explain the observed growth characteristics from Sn–RE alloys. - Abstract: An exclusive method was developed to prepare intact tin whiskers as transmission electron microscope specimens, and with this technique in situ observation of tin whisker growth from RESn 3 (RE = Nd, La, Ce) film specimen was first achieved. Electron irradiation was discovered to have an effect on the growth of a tin whisker through its root. Large quantities of tin whiskers with diameters from 20 nm to 10 μm and lengths ranging from 50 nm to 500 μm were formed at a growth rate of 0.1–1.8 nm s −1 on the surface of RESn 3 compounds. Most (>85%) of these tin whiskers have preferred growth directions of 〈1 0 0〉, 〈0 0 1〉, 〈1 0 1〉 and 〈1 0 3〉, as determined by statistics. This kind of tin whisker is single-crystal β-Sn even if it has growth striations, steps and kinks, and no dislocations or twin or grain boundaries were observed within the whisker body. RESn 3 compounds undergo selective oxidation during whisker growth, and the oxidation provides continuous tin atoms for tin whisker growth until they are exhausted. The driving force for whisker growth is the compressive stress resulting from the restriction of the massive volume expansion (38–43%) during the oxidation by the surface RE(OH) 3 layer. Tin atoms diffuse and flow to feed the continuous growth of tin whiskers under a compressive stress gradient formed from the extrusion of tin atoms/clusters at weak points on the surface RE(OH) 3 layers. A growth model was proposed to discuss the characteristics and growth mechanism of tin whiskers from RESn 3 compounds.

High temperature tensile properties and their application to toughness enhancement in ultra-fine grained W-(0-1.5)wt% TiC

Energy Technology Data Exchange (ETDEWEB)

Kurishita, H. [International Research Center for Nuclear Materials Science, Institute for Materials Research (IMR), Tohoku University, Oarai, Ibaraki 311-1313 (Japan)], E-mail: kurishi@imr.tohoku.ac.jp; Matsuo, S.; Arakawa, H.; Narui, M.; Yamazaki, M. [International Research Center for Nuclear Materials Science, Institute for Materials Research (IMR), Tohoku University, Oarai, Ibaraki 311-1313 (Japan); Sakamoto, T.; Kobayashi, S.; Nakai, K. [Department of Materials Science and Biotechnology, Ehime University, Matsuyama, Ehime 790-8577 (Japan); Takida, T.; Takebe, K. [A.L.M.T. Corp., 2 Iwase-koshi-machi, Toyama, Toyama 931-8543 (Japan); Kawai, M. [Institute of Material Structure Science, KEK, Tsukuba, Ibaraki 305-0801 (Japan); Yoshida, N. [Institute for Applied Mechanics, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan)

2009-04-30

Ultra-fine grained (UFG) W-TiC consolidates are very promising for use as divertors in fusion reactors, however, the assurance of room-temperature ductility of UFG W-TiC remains unsettled. The assurance requires a sufficient degree of plastic working for the consolidates and thus overcoming of poor plastic workability in UFG W-TiC by applying superplasticity. Therefore, the magnitudes of elongation to fracture and flow stress which are important measures for plastic working were examined for UFG W-(0-1.5)%TiC (in wt%) at 1673-1973 K where superplasticity occurs without appreciable grain growth. It is shown that the elongation and flow stress are strongly dependent on TiC addition and atmosphere (Ar, H{sub 2}) during mechanical alloying (MA). As the TiC addition increases, the elongation significantly increases without appreciable increase in the flow stress level. W-TiC fabricated with MA in H{sub 2} exhibits larger elongation and larger strain rate sensitivity of flow stress than W-TiC with MA in Ar. These results were applied to perform plastic working and the room-temperature bend test results for plastic worked W-1.0%TiC are shown.

NASA GSFC Tin Whisker Homepage http://nepp.nasa.gov/whisker

Science.gov (United States)

Shaw, Harry

2000-01-01

The NASA GSFC Tin Whisker Homepage provides general information and GSFC Code 562 experimentation results regarding the well known phenomenon of tin whisker formation from pure tin plated substrates. The objective of this www site is to provide a central repository for information pertaining to this phenomenon and to provide status of the GSFC experiments to understand the behavior of tin whiskers in space environments. The Tin Whisker www site is produced by Code 562. This www site does not provide information pertaining to patented or proprietary information. All of the information contained in this www site is at the level of that produced by industry and university researchers and is published at international conferences.

Fiscal 1997 survey report. `Ultra high electronic technology development promotion project` under consignment from NEDO; 1997 nendo kenkyu seika hokokusho. Shin Energy Sangyo Gijutsu Sogo Kaihatsu Kiko itaku jigyo `Chosentan denshi gijutsu kaihatsu sokushin jigyo`

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-05-01

For the purpose of establishing ultra high technology of a next next generation level, the R and D was conducted of ultra fine processing process technology, technologies on limit measuring/analysis/control and new functional electronic materials. Themes of the R and D are electronic beam direct picture drawing system technology, ultra short wavelength electromagnetic radiation patterning/system technology, ultra fine sensitizing technology, ultra high accuracy shading system technology, ultra high tech plasma reactive measuring/analysis/control technology, ultra high tech cleaning basic technology, ultra high sensitivity medium technology, new functional element/film formation technology, etc. This R and D is a greatly influential basic research in the whole industrial field, and therefore, it is necessary that researchers standing foremost in each field of industry/university/government join the project and that various R and D infrastructures are made the most of. For this, the concentrated joint research method and the dispersed joint research method are combined, and the R and D is being conduced by equal partnership of each researcher. 421 refs., 823 figs., 91 tabs.

The electronic fine structure of 4-nitrophenyl functionalized single-walled carbon nanotubes

International Nuclear Information System (INIS)

Chakraborty, Amit K; Coleman, Karl S; Dhanak, Vinod R

2009-01-01

Controlling the electronic structure of carbon nanotubes (CNTs) is of great importance to various CNT based applications. Herein the electronic fine structure of single-walled carbon nanotube films modified with 4-nitrophenyl groups, produced following reaction with 4-nitrobenzenediazonium tetrafluoroborate, was investigated for the first time. Various techniques such as x-ray and ultra-violet photoelectron spectroscopy, and near edge x-ray absorption fine structure studies were used to explore the electronic structure, and the results were compared with the measured electrical resistances. A reduction in number of the π electronic states in the valence band consistent with the increased resistance of the functionalized nanotube films was observed.

POROUS STRUCTURE OF ROAD CONCRETE

Directory of Open Access Journals (Sweden)

M. K. Pshembaev

2016-01-01

Full Text Available Having a great number of concrete structure classifications it is recommended to specify the following three principal types: microstructure – cement stone structure; mesostructure – structure of cement-sand mortar in concrete; macrostucture – two-component system that consists of mortar and coarse aggregate. Every mentioned-above structure has its own specific features which are related to the conditions of their formation. Thus, microstructure of cement stone can be characterized by such structural components as crystal intergrowth, tobermorite gel, incompletely hydrated cement grains and porous space. The most important technological factors that influence on formation of cement stone microstructure are chemical and mineralogical cement composition, its grinding fineness, water-cement ratio and curing condition. Specific cement stone microstructure is formed due to interrelation of these factors. Cement stone is a capillary-porous body that consists of various solid phases represented predominantly by sub-microcrystals of colloidal dispersion. The sub-microcrystals are able adsorptively, osmotically and structurally to withhold (to bind some amount of moisture. Protection of road concrete as a capillary-porous body is considered as one of the topical issues. The problem is solved with the help of primary and secondary protection methods. Methods of primary protection are used at the stage of designing, preparation and placing of concrete. Methods of secondary protection are applied at the operational stage of road concrete pavement. The paper considers structures of concrete solid phase and characteristics of its porous space. Causes of pore initiation, their shapes, dimensions and arrangement in the concrete are presented in the paper. The highest hazard for road concrete lies in penetration of aggressive liquid in it and moisture transfer in the cured concrete. Water permeability of concrete characterizes its filtration factor which

Organic derivatives of tin (II/IV): Investigation of their structure

Energy Technology Data Exchange (ETDEWEB)

Szirtes, L., E-mail: szirtes@iki.kfki.h [Institute of Isotopes of the Hungarian Academy of Sciences, Budapest H-1525, P.O. Box 77 (Hungary); Megyeri, J., E-mail: megyeri@iki.kfki.h [Institute of Isotopes of the Hungarian Academy of Sciences, Budapest H-1525, P.O. Box 77 (Hungary); Kuzmann, E. [Laboratory of Nuclear Chemistry, CRC of the Hungarian Academy of Science at Eoetvoes University, H-1518 Budapest, P.O. Box 32 (Hungary); Beck, A. [Institute of Isotopes of the Hungarian Academy of Sciences, Budapest H-1525, P.O. Box 77 (Hungary)

2011-07-15

The structures of tin(II)-oxalate, tin(IV)Na-EDTA and tin(IV)Na{sub 8}-inositol hexaphosphate were investigated using XRD analysis. Samples were identified using the Moessbauer study, thermal analysis and FTIR spectrometry. The Moessbauer study determined two different oxidation states of tin atoms, and consequently two different tin surroundings in the end products. The tin oxalate was found to be orthorhombic with space group Pnma, a=9.2066(3) A, b=9.7590(1) A, c=13.1848(5) A, V=1184.62 A{sup 3} and Z=8. SnNa-EDTA was found to be monoclinic with space group P2{sub 1}/c{sub 1}, a=10.7544(3) A, b=10.1455(3) A, c=16.5130(6) A, {beta}=98.59(2){sup o}, V=1781.50(4) A{sup 3} and Z=4. Sn(C{sub 6}H{sub 6}Na{sub 8}O{sub 24}P{sub 6}) was found to be amorphous.

Proton transport properties of tin phosphate, chromotropic acid ...

Indian Academy of Sciences (India)

The functionalized materials of tin (IV) phosphate (SnP) like chromotropic acid anchored tin ... elemental analysis (ICP–AES), thermal analysis, X-ray analysis and FTIR spectroscopy. .... nal level below 1 V, interfaced to a minicomputer for data.

Studies on Nanocrystalline TiN Coatings Prepared by Reactive Plasma Spraying

Directory of Open Access Journals (Sweden)

Dong Yanchun

2008-01-01

Full Text Available Titanium nitride (TiN coatings with nanostructure were prepared on the surface of 45 steel (Fe-0.45%C via reactive plasma spraying (denoted as RPS Ti powders using spraying gun with self-made reactive chamber. The microstructural characterization, phases constitute, grain size, microhardness, and wear resistance of TiN coatings were systematically investigated. The grain size was obtained through calculation using the Scherrer formula and observed by TEM. The results of X-ray diffraction and electron diffraction indicated that the TiN is main phase of the TiN coating. The forming mechanism of the nano-TiN was characterized by analyzing the SEM morphologies of surface of TiN coating and TiN drops sprayed on the surface of glass, and observing the temperature and velocity of plasma jet using Spray Watch. The tribological properties of the coating under nonlubricated condition were tested and compared with those of the AISI M2 high-speed steel and Al2O3 coating. The results have shown that the RPS TiN coating presents better wear resistance than the M2 high-speed steel and Al2O3 coating under nonlubricated condition. The microhardness of the cross-section and longitudinal section of the TiN coating was tested. The highest hardness of the cross-section of TiN coating is 1735.43HV100 g.

Networks of ultra-fine Ag nanocrystals in a Teflon AF (registered) matrix by vapour phase e-beam-assisted deposition

International Nuclear Information System (INIS)

Biswas, A; Bayer, I S; Marken, B; Pounds, T D; Norton, M G

2007-01-01

We have fabricated nanocomposite thin films comprising silver (Ag) nanoparticles dispersed in a Teflon AF (registered) polymer matrix using electron-beam-assisted physical vapour deposition. Four different Ag nanoparticle volume fillings (20%, 35%, 70% and 75%) were achieved by varying the relative metal-polymer evaporation rates with the formation of highly crystalline Ag nanoparticles regardless of the filling ratio. The present fabrication technique allowed full control over dispersion uniformity of nanoparticles in the polymer network. At 20% and 35% metal volume fillings, the nanocomposite film morphology consists of a uniformly dispersed assembly of equiaxed isolated Ag nanoparticles. At higher metal volume fractions the nanocomposite structures displayed two different and unique Ag nanoparticle arrangements within the polymer matrix. In particular, at 70% metal filling, the formation of irregularly shaped clusters of individually assembled nanocrystals was observed. At a slightly higher volume filling (75%), larger irregularly shaped Ag nanocrystals that appeared to be the result of coalescence and grain growth were observed. Finally, a composite theory developed by Tandon and Weng was used to estimate various elastic properties of the nanocomposite films. At high metal filling, the reinforcing effect of the Ag nanoparticles was reflected as approximately a sixfold increase in the elastic modulus compared to the virgin polymer film. Possible applications of such ultra-fine metal nanoparticles networks are discussed

Ultra-fine metal gate operated graphene optical intensity modulator

Science.gov (United States)

Kou, Rai; Hori, Yosuke; Tsuchizawa, Tai; Warabi, Kaori; Kobayashi, Yuzuki; Harada, Yuichi; Hibino, Hiroki; Yamamoto, Tsuyoshi; Nakajima, Hirochika; Yamada, Koji

2016-12-01

A graphene based top-gate optical modulator on a standard silicon photonic platform is proposed for the future optical telecommunication networks. On the basis of the device simulation, we proposed that an electro-absorption light modulation can be realized by an ultra-narrow metal top-gate electrode (width less than 400 nm) directly located on the top of a silicon wire waveguide. The designed structure also provides excellent features such as carrier doping and waveguide-planarization free fabrication processes. In terms of the fabrication, we established transferring of a CVD-grown mono-layer graphene sheet onto a CMOS compatible silicon photonic sample followed by a 25-nm thick ALD-grown Al2O3 deposition and Source-Gate-Drain electrodes formation. In addition, a pair of low-loss spot-size converter for the input and output area is integrated for the efficient light source coupling. The maximum modulation depth of over 30% (1.2 dB) is observed at a device length of 50 μm, and a metal width of 300 nm. The influence of the initial Fermi energy obtained by experiment on the modulation performance is discussed with simulation results.

Ultra-Low-Power Smart Electronic Nose System Based on Three-Dimensional Tin Oxide Nanotube Arrays.

Science.gov (United States)

Chen, Jiaqi; Chen, Zhuo; Boussaid, Farid; Zhang, Daquan; Pan, Xiaofang; Zhao, Huijuan; Bermak, Amine; Tsui, Chi-Ying; Wang, Xinran; Fan, Zhiyong

2018-06-04

In this work, we present a high-performance smart electronic nose (E-nose) system consisting of a multiplexed tin oxide (SnO 2 ) nanotube sensor array, read-out circuit, wireless data transmission unit, mobile phone receiver, and data processing application (App). Using the designed nanotube sensor device structure in conjunction with multiple electrode materials, high-sensitivity gas detection and discrimination have been achieved at room temperature, enabling a 1000 times reduction of the sensor's power consumption as compared to a conventional device using thin film SnO 2 . The experimental results demonstrate that the developed E-nose can identify indoor target gases using a simple vector-matching gas recognition algorithm. In addition, the fabricated E-nose has achieved state-of-the-art sensitivity for H 2 and benzene detection at room temperature with metal oxide sensors. Such a smart E-nose system can address the imperative needs for distributed environmental monitoring in smart homes, smart buildings, and smart cities.

Hydrothermal self-assembly of novel porous flower-like SnO_2 architecture and its application in ethanol sensor

International Nuclear Information System (INIS)

Jiang, X.H.; Ma, S.Y.; Sun, A.M.; Zhang, Z.M.; Jin, W.X.; Wang, T.T.; Li, W.Q.; Xu, X.L.; Luo, J.; Cheng, L.; Mao, Y.Z.; Zhang, M.

2015-01-01

Graphical abstract: - Highlights: • We have fabricated porous SnO_2 nanoflowers using a simple hydrothermal route. • The sensitivity of porous SnO_2 nanoflowers is about 208 for 500 ppm ethanol at 300 °C. • The porous SnO_2 nanoflowers could be a good candidate for fabricating effective ethanol sensor. - Abstract: Different morphologies of tin dioxide (SnO_2) architectures were prepared by increasing reaction time (12, 18, 24 and 48 h) under a facile hydrothermal process and followed by calcination. The crystal structures and morphologies of the hierarchical architecture were characterized in detail by means of powder X-ray diffraction (XRD), energy dispersive X-ray detector (EDX), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results showed that the porous flower-like SnO_2 architecture was obtained by 24 h hydrotherm treatment. Most importantly, the sensors based on porous flower-like SnO_2 architecture exhibited perfect sensing performance toward ethanol with excellent selectivity, high response and fast response-recovery capability compared with other SnO_2 nanoflowers for the same ethanol concentration at 300 °C. The response value was about 208 and the response-recovery time was around 8 and 7 s for 500 ppm ethanol, respectively. The enhancement in gas sensing properties was attributed to the unique structures, including the flower-like structure and porous feature, which provided more gas active center and diffusion pathways. The results indicated that porous flower-like SnO_2 architecture was a potential candidate for fabricating effective ethanol sensor. Furthermore, the possible growth mechanism and the ethanol sensing mechanism of the architecture were discussed, too.

Efficiency in supercritical fluid chromatography with different superficially porous and fully porous particles ODS bonded phases.

Science.gov (United States)

Lesellier, E

2012-03-09

The chromatographic efficiency, in terms of plate number per second, was dramatically improved by the introduction of sub-two microns particles with ultra-high pressure liquid chromatography (UHPLC). On the other hand, the recent development of superficially porous particles, called core-shell or fused-core particles, appears to allow the achievement of the same efficiency performances at higher speed without high pressure drops. CO₂-based mobile phases exhibiting much lower viscosities than aqueous based mobile phases allow better theoretical efficiencies, even with 3-5 μm particles, but with relative low pressure drops. They also allow much higher flow rates or much longer columns while using conventional instruments capable to operate below 400 bar. Moreover, the use of superficially porous particles in SFC could enhance the chromatographic performances even more. The kinetic behavior of ODS phases bonded on these particles was studied, with varied flow rates, outlet (and obviously inlet) pressures, temperatures, by using a homologous series (alkylbenzenes) with 10% modifier (methanol or acetonitrile) in the carbon dioxide mobile phase. Results were also compared with classical fully porous particles, having different sizes, from 2.5 to 5 μm. Superior efficiency (N) and reduced h were obtained with these new ODS-bonded particles in regards to classical ones, showing their great interest for use in SFC. However, surprising behavior were noticed, i.e. the increase of the theoretical plate number vs. the increase of the chain length of the compounds. This behavior, opposite to the one classically reported vs. the retention factor, was not depending on the outlet pressure, but on the flow rate and the temperature changes. The lower radial trans-column diffusion on this particle types could explain these results. This diffusion reduction with these ODS-bonded superficially porous particles seems to decrease with the increase of the residence time of compounds

Preparation of porous titania film and its application in solar cells.

Science.gov (United States)

Zhang, Tianhui; Zhao, Suling; Piao, Lingyu; Xu, Zheng; Liu, Xiaodong; Kong, Chao; Xu, Xurong

2011-11-01

Polymer/nanocrystal bulk heterojunction photovoltaic cells have attracted substantial interest because the hybrid active layer combines the advantages of inorganic materials and polymers. In this work, a porous TiO2 was prepared via the sol-gel method with a polyethylene glycol 2000 (PEG2000) template. A kind of polymer/inorganic solar cell based on poly (3-hexylthiophene) (P3HT)/TiO2 was fabricated on the indium-tin-oxide (ITO) glass substrate and the structure of device was ITO/TiO2/P3HT/Au. The device showed the performance with a short circuit current (J(SC)) of 1.29 mA/cm2, an open circuit voltage (V(OC)) of 0.55 V and a fill factor (FF) of 28.7%.

Dissolution of copper, tin, and iron from sintered tungsten-bronze spheres in a simulated avian gizzard, and an assessment of their potential toxicity to birds

International Nuclear Information System (INIS)

Thomas, Vernon G.; McGill, Ian R.

2008-01-01

The rates of dissolution of copper, tin, and iron from sintered tungsten-bronze spheres (51.1%W, 44.4%Cu, 3.9%Sn, 0.6%Fe, by mass) were measured in an in vitro simulated avian gizzard at pH 2.0, and 42C. Most of the spheres had disintegrated completely to a fine powder by day 14. Dissolution of copper, tin, and iron from the spheres was linear over time; all r > 0.974; all P < 0.001. The mean rate of release of copper, tin, and iron was 30.4 mg, 2.74 mg, and 0.38 mg per g tungsten-bronze per day, respectively. These rates of metal release were compared to those in published studies to determine whether the simultaneous ingestion of eight spheres of 3.48 mm diameter would pose a toxic risk to birds. The potential absorption rates of iron and tin (0.54 mg Fe/day, and 3.89 mg Sn/day) from eight tungsten-bronze spheres of total mass 1.42 g would not prove toxic, based on empirical studies of tin and iron ingestion in waterfowl. The release of 43.17 mg copper/day from eight tungsten-bronze spheres, while exceeding the daily copper requirements of domesticated birds, is far below the levels of copper known to cause copper toxicosis in birds. We conclude that sintered tungsten-bronze material made into gunshot, fishing weights, or wheel balance weights, would not pose a toxic risk to wild birds when ingested

Upscaled Lattice Boltzmann Method for Simulations of Flows in Heterogeneous Porous Media

Directory of Open Access Journals (Sweden)

Jun Li

2017-01-01

Full Text Available An upscaled Lattice Boltzmann Method (LBM for flow simulations in heterogeneous porous media at the Darcy scale is proposed in this paper. In the Darcy-scale simulations, the Shan-Chen force model is used to simplify the algorithm. The proposed upscaled LBM uses coarser grids to represent the average effects of the fine-grid simulations. In the upscaled LBM, each coarse grid represents a subdomain of the fine-grid discretization and the effective permeability with the reduced-order models is proposed as we coarsen the grid. The effective permeability is computed using solutions of local problems (e.g., by performing local LBM simulations on the fine grids using the original permeability distribution and used on the coarse grids in the upscaled simulations. The upscaled LBM that can reduce the computational cost of existing LBM and transfer the information between different scales is implemented. The results of coarse-grid, reduced-order, simulations agree very well with averaged results obtained using a fine grid.

Upscaled Lattice Boltzmann Method for Simulations of Flows in Heterogeneous Porous Media

KAUST Repository

Li, Jun

2017-02-16

An upscaled Lattice Boltzmann Method (LBM) for flow simulations in heterogeneous porous media at the Darcy scale is proposed in this paper. In the Darcy-scale simulations, the Shan-Chen force model is used to simplify the algorithm. The proposed upscaled LBM uses coarser grids to represent the average effects of the fine-grid simulations. In the upscaled LBM, each coarse grid represents a subdomain of the fine-grid discretization and the effective permeability with the reduced-order models is proposed as we coarsen the grid. The effective permeability is computed using solutions of local problems (e.g., by performing local LBM simulations on the fine grids using the original permeability distribution) and used on the coarse grids in the upscaled simulations. The upscaled LBM that can reduce the computational cost of existing LBM and transfer the information between different scales is implemented. The results of coarse-grid, reduced-order, simulations agree very well with averaged results obtained using a fine grid.

Selective Recovery of Mushistonite from Gravity Tailings of Copper–Tin Minerals in Tajikistan

OpenAIRE

Lei Sun; Yuehua Hu; Wei Sun; Zhiyong Gao; Mengjie Tian

2017-01-01

Tajikistan has abundant copper–tin resources. In this study, mineralogical analysis of copper–tin ores from the Mushiston deposit of Tajikistan indicates that tin mainly occurred in mushistonite, cassiterite, and stannite, while copper mainly occurred in mushistonite, malachite, azurite, and stannite. The total grades of tin (Sn) and copper (Cu) were 0.65% and 0.66%, respectively, and the dissemination size of copper–tin minerals ranged from 4 μm to over 200 μm. Coarse particles of copper–tin...

Preparation of ultra-light magnetic nanocomposites using highly concentrated emulsions

Energy Technology Data Exchange (ETDEWEB)

Ghosh, Goutam; Vilchez, Alejandro; Esquena, Jordi; Solans, Conxita [Instituto de Quimica Avanzada de Cataluna, Consejo Superior de Investigaciones Cientificas (IQAC-CSIC), Jordi Girona 18-26, 08034 Barcelona (Spain); Rodriguez-Abreu, Carlos, E-mail: carlos.rodriguez@inl.int [Instituto de Quimica Avanzada de Cataluna, Consejo Superior de Investigaciones Cientificas (IQAC-CSIC), Jordi Girona 18-26, 08034 Barcelona (Spain); International Iberian Nanotechnology Laboratory (INL), Av. Mestre Jose Veiga, 4715-330 Braga (Portugal)

2011-10-17

Highlights: {yields} Polystyrene-divinylbenzene-iron oxide nanocomposites. {yields} Porous magnetic nanocomposites from highly concentrated emulsions. {yields} Ultralight materials with relatively high magnetic moment. - Abstract: Hybrid inorganic-organic ultra-light magnetic solid foams with iron oxide nanoparticles embedded in a divinylbenzene-polystyrene matrix were prepared using a highly concentrated emulsion polymerization method. Iron oxide nanoparticles with diameters of 3 and 10 nm were synthesized using two different methods. For comparison purposes, nanocomposites with magnetite nanoparticles dispersed in a non-porous polymeric matrix obtained by bulk polymerization were also investigated. Materials were characterized using several techniques such as dynamic light scattering (DLS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), small angle X-ray scattering (SAXS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and magnetization measurements. SEM and TEM images showed that solid foams are made of well-defined macro pores with nanoparticles embedded in the walls. The density of the solid foams was ca. 50-70 kg m{sup -3}, which is about 20 times lighter than the non-porous monoliths. The magnetic measurements show that both nanocomposites are superparamagnetic, and that there are differences regarding the interparticle interactions depending on matrix porosity. The synthesized materials may find applications in adsorbents, tissue reparation, enzyme supports, microreactors, or in water decontamination.

Preparation of ultra-light magnetic nanocomposites using highly concentrated emulsions

International Nuclear Information System (INIS)

Ghosh, Goutam; Vilchez, Alejandro; Esquena, Jordi; Solans, Conxita; Rodriguez-Abreu, Carlos

2011-01-01

Highlights: → Polystyrene-divinylbenzene-iron oxide nanocomposites. → Porous magnetic nanocomposites from highly concentrated emulsions. → Ultralight materials with relatively high magnetic moment. - Abstract: Hybrid inorganic-organic ultra-light magnetic solid foams with iron oxide nanoparticles embedded in a divinylbenzene-polystyrene matrix were prepared using a highly concentrated emulsion polymerization method. Iron oxide nanoparticles with diameters of 3 and 10 nm were synthesized using two different methods. For comparison purposes, nanocomposites with magnetite nanoparticles dispersed in a non-porous polymeric matrix obtained by bulk polymerization were also investigated. Materials were characterized using several techniques such as dynamic light scattering (DLS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), small angle X-ray scattering (SAXS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR) and magnetization measurements. SEM and TEM images showed that solid foams are made of well-defined macro pores with nanoparticles embedded in the walls. The density of the solid foams was ca. 50-70 kg m -3 , which is about 20 times lighter than the non-porous monoliths. The magnetic measurements show that both nanocomposites are superparamagnetic, and that there are differences regarding the interparticle interactions depending on matrix porosity. The synthesized materials may find applications in adsorbents, tissue reparation, enzyme supports, microreactors, or in water decontamination.

Synthesis and characterization of porous structured ZnO thin film for dye sensitized solar cell applications

Energy Technology Data Exchange (ETDEWEB)

Marimuthu, T.; Anandhan, N., E-mail: anandhan-kn@rediffmail.com; Mummoorthi, M. [School of Physics, Alagappa University, Karaikudi – 630 003 (India); Dharuman, V. [Department of Bioelectronics and Biosensors, Alagappa University, Karaikudi – 630 003 (India)

2016-05-23

Zinc oxide (ZnO) and zinc oxide/eosin yellow (ZnO/EY) thin films were potentiostatically deposited onto fluorine doped tin oxide (FTO) glass substrate. Effect of eosin yellow dye on structural, morphological and optical properties was studied. X-ray diffraction patterns, micro Raman spectra and photoluminescence (PL) spectra reveal hexagonal wurtzite structure with less atomic defects in 101 plane orientation of the ZnO/EY film. Scanning electron microscopy (SEM) images show flower for ZnO and porous like structure for ZnO/EY thin film, respectively. DSSC was constructed and evaluated by measuring the current density verses voltage curve.

The Hydrolytic Stability and Degradation Mechanism of a Hierarchically Porous Metal Alkylphosphonate Framework

Directory of Open Access Journals (Sweden)

Kai Lv

2018-03-01

Full Text Available To aid the design of a hierarchically porous unconventional metal-phosphonate framework (HP-UMPF for practical radioanalytical separation, a systematic investigation of the hydrolytic stability of bulk phase against acidic corrosion has been carried out for an archetypical HP-UMPF. Bulk dissolution results suggest that aqueous acidity has a more paramount effect on incongruent leaching than the temperature, and the kinetic stability reaches equilibrium by way of an accumulation of a partial leached species on the corrosion conduits. A variation of particle morphology, hierarchical porosity and backbone composition upon corrosion reveals that they are hydrolytically resilient without suffering any great degradation of porous texture, although large aggregates crack into sporadic fractures while the nucleophilic attack of inorganic layers cause the leaching of tin and phosphorus. The remaining selectivity of these HP-UMPFs is dictated by a balance between the elimination of free phosphonate and the exposure of confined phosphonates, thus allowing a real-time tailor of radionuclide sequestration. Moreover, a plausible degradation mechanism has been proposed for the triple progressive dissolution of three-level hierarchical porous structures to elucidate resultant reactivity. These HP-UMPFs are compared with benchmark metal-organic frameworks (MOFs to obtain a rough grading of hydrolytic stability and two feasible approaches are suggested for enhancing their hydrolytic stability that are intended for real-life separation protocols.

The kinetics of ice-lens growth in porous media

KAUST Repository

Style, Robert W.

2012-01-09

Abstract We analyse the growth rate of segregated ice (ice lenses) in freezing porous media. For typical colloidal materials such as soils we show that the commonly employed Clapeyron equation is not valid macroscopically at the interface between the ice lens and the surrounding porous medium owing to the viscous dynamics of flow in premelted films. The flow in these films gives rise to an \\'interfacial resistance\\' to flow towards the growing ice which causes a significant drop in predicted ice-growth (heave) rates. This explains why many previous models predict ice-growth rates that are much larger than those seen in experiments. We derive an explicit formula for the ice-growth rate in a given porous medium, and show that this only depends on temperature and on the external pressures imposed on the freezing system. This growth-rate formula contains a material-specific function which can be calculated (with knowledge of the geometry and material of the porous medium), but which is also readily experimentally measurable. We apply the formula to plate-like particles, and show that the results can be matched with previous experimental data. Finally we show how the interfacial resistance explains the observation that the maximum heave rate in soils occurs in medium-grained particles such as silts, while heave rates are smaller for fine-and coarse-grained particles. © 2012 Cambridge University Press.

Mechanical and frictional behaviour of nano-porous anodised aluminium

Energy Technology Data Exchange (ETDEWEB)

Tsyntsaru, N., E-mail: tintaru@phys.asm.md [Institute of Applied Physics of ASM, 5 Academy str., Chisinau, MD 2028 (Moldova, Republic of); Kavas, B., E-mail: bkavas@ford.com.tr [Istanbul Technical University, Department of Metallurgical and Materials Engineering, 34469 Maslak (Turkey); Ford Otomotiv San A.S., Istanbul (Turkey); Sort, J., E-mail: jordi.sort@uab.cat [Institució Catalana de Recerca i Estudis Avançats (ICREA) and Departament de Física, Universitat Autònoma de Barcelona, E-08193 Bellaterra (Spain); Urgen, M., E-mail: urgen@itu.edu.tr [Istanbul Technical University, Department of Metallurgical and Materials Engineering, 34469 Maslak (Turkey); Celis, J.-P., E-mail: jean-pierre.celis@mtm.kuleuven.be [KU Leuven, Dept. MTM, Kasteelpark Arenberg 44, B-3001 (Belgium)

2014-12-15

The porous structure of anodic aluminium oxide (AAO) can be used in versatile applications such as a lubricant reservoir in self-lubricating systems. Such systems are subjected to biaxial loading, which can induce crack formation and propagation, ultimately leading to catastrophic mechanical failure. In this study, the mechanical and tribological behaviour of AAO, prepared from two different types of electrolytes (sulphuric and oxalic acids), are studied in detail. The electrolytic conditions are adjusted to render highly tuneable average pore diameters (between 16 and 75 nm), with porosity levels ranging from 9% to 65%. Well-ordered porous AAO are produced by two-step anodization at rather low temperatures. Mechanical properties, mainly hardness and Young's modulus, are investigated using nanoindentation. Both the porosity degree and the composition of the electrolytic baths used to prepare the AAO have an influence on the mechanical properties. Ball-on-flat configuration was used to estimate the tribological behaviour under dry conditions. No major cracks were observed by scanning electron microscopy, neither after indentation or fretting tests. In the running-in period of tribology experiments the pores were filled with debris. This was followed by the formation of a highly adherent tribolayer – a third body consisting of fine worn particles originated from both the sample and the counterbody. Pore diameter and porosity percentage are found to strongly affect hardness and Young's modulus, but they do not have a major effect on the frictional behaviour. - Highlights: • Well-ordered porous AAO with pore diameters between 16 and 75 nm were produced. • Porosity and composition of electrolytic baths influence the mechanical properties. • Ball-on-flat configuration was used in tribological testing under dry conditions. • Adherent tribolayer consisting of fine worn particles prevents AAO from cracking. • Testing parameters are moreover essential

Variational Multiscale Finite Element Method for Flows in Highly Porous Media

KAUST Repository

Iliev, O.; Lazarov, R.; Willems, J.

2011-01-01

We present a two-scale finite element method (FEM) for solving Brinkman's and Darcy's equations. These systems of equations model fluid flows in highly porous and porous media, respectively. The method uses a recently proposed discontinuous Galerkin FEM for Stokes' equations by Wang and Ye and the concept of subgrid approximation developed by Arbogast for Darcy's equations. In order to reduce the "resonance error" and to ensure convergence to the global fine solution, the algorithm is put in the framework of alternating Schwarz iterations using subdomains around the coarse-grid boundaries. The discussed algorithms are implemented using the Deal.II finite element library and are tested on a number of model problems. © 2011 Society for Industrial and Applied Mathematics.

Variational Multiscale Finite Element Method for Flows in Highly Porous Media

KAUST Repository

Iliev, O.

2011-10-01

We present a two-scale finite element method (FEM) for solving Brinkman\\'s and Darcy\\'s equations. These systems of equations model fluid flows in highly porous and porous media, respectively. The method uses a recently proposed discontinuous Galerkin FEM for Stokes\\' equations by Wang and Ye and the concept of subgrid approximation developed by Arbogast for Darcy\\'s equations. In order to reduce the "resonance error" and to ensure convergence to the global fine solution, the algorithm is put in the framework of alternating Schwarz iterations using subdomains around the coarse-grid boundaries. The discussed algorithms are implemented using the Deal.II finite element library and are tested on a number of model problems. © 2011 Society for Industrial and Applied Mathematics.

Heat Removal from Bipolar Transistor by Loop Heat Pipe with Nickel and Copper Porous Structures

Science.gov (United States)

Smitka, Martin; Malcho, Milan

2014-01-01

Loop heat pipes (LHPs) are used in many branches of industry, mainly for cooling of electrical elements and systems. The loop heat pipe is a vapour-liquid phase-change device that transfers heat from evaporator to condenser. One of the most important parts of the LHP is the porous wick structure. The wick structure provides capillary force to circulate the working fluid. To achieve good thermal performance of LHP, capillary wicks with high permeability and porosity and fine pore radius are expected. The aim of this work was to develop porous structures from copper and nickel powder with different grain sizes. For experiment copper powder with grain size of 50 and 100 μm and nickel powder with grain size of 10 and 25 μm were used. Analysis of these porous structures and LHP design are described in the paper. And the measurements' influences of porous structures in LHP on heat removal from the insulated gate bipolar transistor (IGBT) have been made. PMID:24959622

Influence of ultra-thin TiN thickness (1.4 nm and 2.4 nm) on positive bias temperature instability (PBTI) of high-k/metal gate nMOSFETs with gate-last process

International Nuclear Information System (INIS)

Qi Lu-Wei; Yang Hong; Ren Shang-Qing; Xu Ye-Feng; Luo Wei-Chun; Xu Hao; Wang Yan-Rong; Tang Bo; Wang Wen-Wu; Yan Jiang; Zhu Hui-Long; Zhao Chao; Chen Da-Peng; Ye Tian-Chun

2015-01-01

The positive bias temperature instability (PBTI) degradations of high-k/metal gate (HK/MG) nMOSFETs with thin TiN capping layers (1.4 nm and 2.4 nm) are systemically investigated. In this paper, the trap energy distribution in gate stack during PBTI stress is extracted by using ramped recovery stress, and the temperature dependences of PBTI (90 °C, 125 °C, 160 °C) are studied and activation energy (E a ) values (0.13 eV and 0.15 eV) are extracted. Although the equivalent oxide thickness (EOT) values of two TiN thickness values are almost similar (0.85 nm and 0.87 nm), the 2.4-nm TiN one (thicker TiN capping layer) shows better PBTI reliability (13.41% at 0.9 V, 90 °C, 1000 s). This is due to the better interfacial layer/high-k (IL/HK) interface, and HK bulk states exhibited through extracting activation energy and trap energy distribution in the high-k layer. (paper)

Tribological characterization of TiN coatings prepared by magnetron sputtering

Science.gov (United States)

Makwana, Nishant S.; Chauhan, Kamlesh V.; Sonera, Akshay L.; Chauhan, Dharmesh B.; Dave, Divyeshkumar P.; Rawal, Sushant K.

2018-05-01

Titanium nitride (TiN) coating deposited on aluminium and brass pin substrates using RF reactive magnetron sputtering. The structural properties and surface morphology were characterized by X-ray diffraction (XRD), atomic force microscope (AFM) and field emission scanning electron microscope (FE-SEM). There was formation of (101) Ti2N, (110) TiN2 and (102) TiN0.30 peaks at 3.5Pa, 2Pa and 1.25Pa sputtering pressure respectively. The tribological properties of coating were inspected using pin on disc tribometer equipment. It was observed that TiN coated aluminium and brass pins demonstrated improved wear resistance than uncoated aluminium and brass pins.

Characterization of tin oxide nanoparticles synthesized via oxidation from metal

International Nuclear Information System (INIS)

Abruzzi, R.C.; Dedavid, B.A.; Pires, M.J.R.; Streicher, M.

2014-01-01

The tin oxide (SnO_2) is a promising material with great potential for applications such as gas sensors and catalysts. This oxide nanostructures show higher activation efficiency due to its larger effective surface. This paper presents the synthesis and characterization of the tin oxide in different conditions, via oxidation of pure tin with nitric acid. Results obtained from the characterization of SnO_2 powder by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Spectroscopy (EDX), Particle size by Dynamic Light Scattering (DLS) and Infrared Spectroscopy (FTIR) indicated that the conditions were suitable for the synthesis to obtain manometric tin oxide granules with crystalline structure of rutile. (author)

Structural study and fabrication of nano-pattern on ultra thin film of Ag grown by magnetron sputtering

International Nuclear Information System (INIS)

Banerjee, S.; Mukherjee, S.; Kundu, S.

2001-01-01

We present the structural study of ultra thin Ag films using grazing incidence x-ray reflectivity and the modification of these films with the tip of an atomic force microscope. Ag thin films are deposited using dc magnetron sputtering on a Si(001) substrate. Initially, the growth of the film is carpet like and above a certain thickness (∼42 A) the film structure changes to form mounds. This ultra thin film of Ag having carpet-like growth can be modified by the tip of an atomic force microscope, which occurs due to the porous nature of the film. A periodic pattern of nanometer dimensions has been fabricated on this film using the atomic force microscope tip. (author)

Direct growth of Ge1-xSnx films on Si using a cold-wall ultra-high-vacuum chemical-vapor-deposition system

Directory of Open Access Journals (Sweden)

Aboozar eMosleh

2015-04-01

Full Text Available Germanium tin alloys were grown directly on Si substrate at low temperatures using a cold-wall ultra-high vacuum chemical vapor deposition system. Epitaxial growth was achieved by adopting commercial gas precursors of germane and stannic chloride without any carrier gases. The X-ray diffraction analysis showed the incorporation of Sn and that the Ge1-xSnx films are fully epitaxial and strain relaxed. Tin incorporation in the Ge matrix was found to vary from 1% to 7%. The scanning electron microscopy images and energy dispersive X-ray spectra maps show uniform Sn incorporation and continuous film growth. Investigation of deposition parameters shows that at high flow rates of stannic chloride the films were etched due to the production of HCl. The photoluminescence study shows the reduction of bandgap from 0.8 eV to 0.55 eV as a result of Sn incorporation.

Tin and tin-titanium as catalyst components for reversible hydrogen storage of sodium aluminium hydride

Energy Technology Data Exchange (ETDEWEB)

Qi Jia Fu; Shik Chi Tsang [University of Reading, Reading (United Kingdom). Surface and Catalysis Research Centre, School of Chemistry

2006-10-15

This paper is concerned with the effects of adding tin and/or titanium dopant to sodium aluminium hydride for both dehydrogenation and re-hydrogenation reactions during their reversible storage of molecular hydrogen. Temperature programmed decomposition (TPD) measurements show that the dehydrogenation kinetics of NaAlH{sub 4} are significantly enhanced upon doping the material with 2 mol% of tributyltin hydride, Sn(Bu)3H but the tin catalyst dopant is shown to be inferior than titanium. On the other hand, in this preliminary work, a significant synergetic catalytic effect is clearly revealed in material co-doped with both titanium and tin catalysts which shows the highest reversible rates of dehydrogenation and re-hydrogenation (after their hydrogen depletion). The re-hydrogenation rates of depleted Sn/Ti/NaAlH{sub 4} evaluated at both 9.5 and 140 bars hydrogen are also found to be favourable compared to the Ti/NaAlH{sub 4}, which clearly suggest the importance of the catalyst choice. Basing on these results some mechanistic insights for the catalytic reversible dehydrogenation and re-hydrogenation processes of Sn/Ti/NaAlH{sub 4} are therefore made. 31 refs., 8 figs., 2 tabs.

Ultra-wideband spectral analysis using S2 technology

International Nuclear Information System (INIS)

Krishna Mohan, R.; Chang, T.; Tian, M.; Bekker, S.; Olson, A.; Ostrander, C.; Khallaayoun, A.; Dollinger, C.; Babbitt, W.R.; Cole, Z.; Reibel, R.R.; Merkel, K.D.; Sun, Y.; Cone, R.; Schlottau, F.; Wagner, K.H.

2007-01-01

This paper outlines the efforts to develop an ultra-wideband spectrum analyzer that takes advantage of the broad spectral response and fine spectral resolution (∼25 kHz) of spatial-spectral (S2) materials. The S2 material can process the full spectrum of broadband microwave transmissions, with adjustable time apertures (down to 100 μs) and fast update rates (up to 1 kHz). A cryogenically cooled Tm:YAG crystal that operates on microwave signals modulated onto a stabilized optical carrier at 793 nm is used as the core for the spectrum analyzer. Efforts to develop novel component technologies that enhance the performance of the system and meet the application requirements are discussed, including an end-to-end device model for parameter optimization. We discuss the characterization of new ultra-wide bandwidth S2 materials. Detection and post-processing module development including the implementation of a novel spectral recovery algorithm using field programmable gate array technology (FPGA) is also discussed

Ultra-wideband spectral analysis using S2 technology

Energy Technology Data Exchange (ETDEWEB)

Krishna Mohan, R. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States)]. E-mail: krishna@spectrum.montana.edu; Chang, T. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Tian, M. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Bekker, S. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Olson, A. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Ostrander, C. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Khallaayoun, A. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Dollinger, C. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Babbitt, W.R. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Cole, Z. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); S2 Corporation, Bozeman, MT 59718 (United States); Reibel, R.R. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); S2 Corporation, Bozeman, MT 59718 (United States); Merkel, K.D. [Spectrum Lab, Montana State University, Bozeman, MT 59717 (United States); S2 Corporation, Bozeman, MT 59718 (United States); Sun, Y. [Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Cone, R. [Department of Physics, Montana State University, Bozeman, MT 59717 (United States); Schlottau, F. [University of Colorado, Boulder, CO 80309 (United States); Wagner, K.H. [University of Colorado, Boulder, CO 80309 (United States)

2007-11-15

This paper outlines the efforts to develop an ultra-wideband spectrum analyzer that takes advantage of the broad spectral response and fine spectral resolution ({approx}25 kHz) of spatial-spectral (S2) materials. The S2 material can process the full spectrum of broadband microwave transmissions, with adjustable time apertures (down to 100 {mu}s) and fast update rates (up to 1 kHz). A cryogenically cooled Tm:YAG crystal that operates on microwave signals modulated onto a stabilized optical carrier at 793 nm is used as the core for the spectrum analyzer. Efforts to develop novel component technologies that enhance the performance of the system and meet the application requirements are discussed, including an end-to-end device model for parameter optimization. We discuss the characterization of new ultra-wide bandwidth S2 materials. Detection and post-processing module development including the implementation of a novel spectral recovery algorithm using field programmable gate array technology (FPGA) is also discussed.

Electrodeposition, characterization and corrosion investigations of galvanic tin-zinc layers from pyrophosphate baths

OpenAIRE

STOPIC MILENA D.; FRIEDRICH BERND G.

2016-01-01

Tin-zinc alloy deposits are recognized as a potential alternative to toxic cadmium as corrosion resistant coatings. Tin-zinc alloy layers offer outstanding corrosion protection for steel by combining the barrier protection of tin with the galvanic protection of zinc. Tin-zinc coatings have been used on the chassis of electrical and electronic apparatus and on critical automotive parts such as fuel and brake line components. In this study, tin-zinc alloy deposits were successfully prepared fro...

Determination of tin in cassiterite ores by colorimetry of iodometry

International Nuclear Information System (INIS)

Rodriguez Hernandez, B.

1972-01-01

The analytical methods are described far the determination of tin in cassiterite ores. The gallein-colorimetric method is described for determining small amounts of tin, covering the 0,01-0,5 per cent range. The sample is decomposed by heating with ammonium iodide, and tin is analyzed colorimetrically by means of it s complex with gallein. The final measure may be brought about either visually or spectrophotometrically at 525 nm. (Author)

Wafer-level hermetic vacuum packaging by bonding with a copper-tin thin film sealing ring

Science.gov (United States)

Akashi, Teruhisa; Funabashi, Hirofumi; Takagi, Hideki; Omura, Yoshiteru; Hata, Yoshiyuki

2018-04-01

A wafer-level hermetic vacuum packaging technology intended for use with MEMS devices was developed based on a copper-tin (CuSn) thin film sealing ring. To allow hermetic packaging, the shear strength of the CuSn thin film bond was improved by optimizing the pretreatment conditions. As a result, an average shear strength of 72.3 MPa was obtained and a cavity that had been hermetically sealed using wafer-level packaging (WLP) maintained its vacuum for 1.84 years. The total pressures in the cavities and the partial pressures of residual gases were directly determined with an ultra-low outgassing residual gas analyzer (RGA) system. Hermeticity was evaluated based on helium leak rates, which were calculated from helium pressures determined with the RGA system. The resulting data showed that a vacuum cavity following 1.84 years storage had a total pressure of 83.1 Pa, contained argon as the main residual gas and exhibited a helium leak rate as low as 1.67  ×  10-17 Pa · m3 s-1, corresponding to an air leak rate of 6.19  ×  10-18 Pa · m3 s-1. The RGA data demonstrate that WLP using a CuSn thin film sealing ring permits ultra-high hermeticity in conjunction with long-term vacuum packaging that is applicable to MEMS devices.

Hierarchically porous nitrogen-doped carbon derived from the activation of agriculture waste by potassium hydroxide and urea for high-performance supercapacitors

Science.gov (United States)

Zou, Kaixiang; Deng, Yuanfu; Chen, Juping; Qian, Yunqian; Yang, Yuewang; Li, Yingwei; Chen, Guohua

2018-02-01

Nitrogen-doped carbon with an ultra-high specific surface area and a hierarchically interconnected porous structure is synthesized in large scale from a green route, that is, the activation of bagasse via a one-step method using KOH and urea. KOH and urea play a synergistic effect for the enhancement of the specific surface area and the modification of pore size of the as-prepared material. Benefiting from the multiple synergistic roles originated from an ultra-high specific area (2905.4 m2 g-1), a high porous volume (2.05 mL g-1 with 75.6 vol% micropores, which is an ideal proportion of micropores for obtaining high specific capacitance), a suitable nitrogen content (2.63 wt%), and partial graphitization, the hierarchically interconnected porous N-doped carbon exhibits an excellent electrochemical performance with a high specific capacitance (350.8, 301.9, and 259.5 F g-1 at 1.0 A g-1 in acidic, alkaline, and neutral electrolytes, respectively), superior rate capability and excellent cycling stability (almost no capacitance loss up to 5000 cycles). Furthermore, the symmetric device assembled by this material achieves high energy densities of 39.1 and 23.5 Wh kg-1 at power densities of 1.0 and 20 kW kg-1, respectively, and exhibits an excellent long-term cycling stability (with capacitance retention above 95.0% after 10 000 cycles).

The recovery of tin, and the production of niobium pentoxide and potassium tantalum fluoride, from a tin slag

International Nuclear Information System (INIS)

Iorio, G.; Tyler, M.S.

1987-01-01

This report describes the results of testwork on the recovery of tin, niobium, and tantalum from a tin slag. The slag, which consisted mainly of amorphous silica, with varying amounts of calcuim, magnesium, manganese, iron, and aluminium, contained an average of 8,8 per cent niobium pentoxide and 6,2 per cent tantalum pentoxide. The metallic tin-ion phase was removed from the crushed slag by magnetic separation. The slag was then leached with hydrochloric acid to remove magnesium, calcium, aluminium, iron, manganese, and the remainder of the tin. Leaching with sodium hydroxide for the removal of silica and phosphorous was followed by a final leach with hydrochloric acid for the removal of sodium. The upgraded concentrate thus obtained was purified by leaching with hydrofluoric acid, solvent extraction of niobium and tantalum into tri-n-butyl phosphate and methyl isobutyl ketone, and selective stripping of niobium with sulphuric acid and tantalum with ammonium floride. Niobium pentoxide and potassium tantalum fluoride were then precipitated by the addition of ammonium hydroxide and potassium fluoride to the respective strip liquors. The overall recoveries in the upgraded concentrate were 98 per cent for tantalum and 92 per cent for niobium. Dissolutions and recoveries of over 99 per cent were obtained for both tantalum and niobium in the purification steps. The niobium pentoxide and potassium tantalum fluoride precipitates obtained were of high purity

Analysis of Thomsen parameters for finely layered VTI media

International Nuclear Information System (INIS)

Berryman, J.G.; Berge, P.A.

1997-01-01

The range of Thomsen's anisotropy parameters ε and δ for vertical transversely isotropic (VTI) media when the anisotropy is due to fine layering of isotropic elas-tic materials is considered. We show that ε lies in the range -3/8 ≤ ε ≤ 1/2 v p 2 > p-2 >-1 for finely layered media having constant density; smaller positive and all negative values of ε occur for media with large fluctuations in the Lamacute e parameter λ We show that sign(δ) = sign ( p -2 > - s -2 > s 2 /v p 2 >) for constant density media, so δ can be either positive or negative. Among all theoretically possible random media, posi-tive and negative δ are equally likely in finely layered media limited to two types of constituent layers. Lay-ered media having large fluctuations in Lamacute e λ are the ones most likely to have positive δ. Since Gassmann's results for fluid-saturated porous media show that the effects of fluids influence only the λ Lamacute e constant, not the shear modulus μ, these results suggest that positive δ occurring together with positive but small ε may be indicative of changing fluid content in layered earth

Studies on tin based inorganic ion exchangers for fission products separation

International Nuclear Information System (INIS)

Dash, A.; Balasubramanian, K.R.; Murthy, T.S.

1993-01-01

Tin(IV) antimonate and hydrous tin(IV) oxide have been prepared and their characteristics are evaluated. A new method has been finalized for the separation of 95 Zr- 95 Nb from irradiated uranium using hydrous tin(IV) oxide. In this process, the irradiated sample is dissolved in concentrated HNO 3 , evaporated to near dryness and taken up in 0.5 M HNO 3 . The solution is passed over tin(IV) oxide column and the isotope eluted with 10 M HNO 3 . The product is obtained in pure nitrate form which is generally preferred for different applications. A method has been finalized for the separation of 106 Ru from fission product solution using tin(IV) antimonate. In this method fission product solution is adjusted to 2 M with respect to nitric acid, 137 Cs is separated on a column of ammonium phosphomolybdate, the effluent after adjustment of acidity to 0.2 M is then passed over a column of tin(IV) antimonate where the effluent contains pure 106 Ru. (author). 14 refs., 6 figs., 2 tabs

Assembly of [Cu2(COO)4] and [M3(μ3-O)(COO)6] (M = Sc, Fe, Ga, and In) building blocks into porous frameworks towards ultra-high C2H2/CO2 and C2H2/CH4 separation performance.

Science.gov (United States)

Zhang, Jian-Wei; Hu, Man-Cheng; Li, Shu-Ni; Jiang, Yu-Cheng; Qu, Peng; Zhai, Quan-Guo

2018-02-20

A porous MOF platform (SNNU-65s) formed by creatively combining paddle-wheel-like [Cu 2 (COO) 4 ] and trigonal prismatic [M 3 (μ 3 -O)(COO) 6 ] building blocks was designed herein. The mixed and high-density open metal sites and the OH-functionalized pore surface promote SNNU-65s to exhibit ultra-high C 2 H 2 uptake and separation performance. Impressively, SNNU-65-Cu-Ga stands out for the highest C 2 H 2 /CO 2 (18.7) and C 2 H 2 /CH 4 (120.6) selectivity among all the reported MOFs at room temperature.

PREPARATION OF ULTRA-LOW VOLUME WEIGHT AUTOCLAVED AERATED CONCRETE

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Ondrej Koutny

2016-12-01

Full Text Available Autoclaved aerated concrete is a modern construction material that gains its popularity especially due to its thermal insulation performance resulting from low volume weight and porous structure with sufficient mechanical strength. Nowadays, there are attempts to use this material for thermal insulation purposes and to replace current systems, which have many disadvantages, mainly concerning durability. The key for improvement of thermal insulation properties is therefore obtaining a material based on autoclaved aerated concrete with extremely low volume weight (below 200 kg/m ³ ensuring good thermal isolation properties, but with sufficient mechanical properties to allow easy manipulation. This material can be prepared by foaming very fine powder materials such as silica fume or very finely ground sand. This paper deals with the possibilities of preparation and summarizes the basic requirements for successful preparation of such a material.

Tin electrodeposition from sulfate solution containing a benzimidazolone derivative

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Said BAKKALI

2016-11-01

Full Text Available Tin electrodeposition in an acidic medium in the presence of N,N’-1,3-bis-[N-3-(6-deoxy-3-O-methyl-D-glucopyranose-6-yl-2-oxobenzimidazol-1-yl]-2-tetradecyloxypropane as an additive was investigated in this work. The adequate current density and the appropriate additive concentration were determined by gravimetric measurements. Chronopotentiometric curves showed that the presence of the additive caused an increase in the overpotential of tin reduction. The investigations by cyclic voltammetry technique revealed that, in the presence and in absence of the additive, there were two peaks, one in the cathodic side attributed to the reduction of Sn2+ and the other one in the anodic side assigned to the oxidation of tin previously formed during the cathodic scan. The surface morphology of the tin deposits was studied by scanning electron microscopy (SEM and XRD.

Modified composite material developed on the basis of no-fines asphalt concrete

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Mikhasek Andrey

2017-01-01

Full Text Available Being a composite material, asphalt concrete is widely used in hydraulic engineering and road construction. The paper proves one of asphalt concrete modification, which includes first creating a skeleton of no-fines concrete and then its washing-down with bituminous materials by a hot procedure, can be successfully used in hydraulic structures Modified composite material based on no-fines asphalt concrete has a harder skeleton because of links from cement stone and has a technological advantage, as through the proposed technology it allows to reduce the cost of filling porous spaces. This technology allows to conclude that concrete aggregate with size fractions of 120 mm or less and frost resistance of 50 cycles and less can be recommended for fastening of slopes.

Multilayer porous structures of HVPE and MOCVD grown GaN for photonic applications

Science.gov (United States)

Braniste, T.; Ciers, Joachim; Monaico, Ed.; Martin, D.; Carlin, J.-F.; Ursaki, V. V.; Sergentu, V. V.; Tiginyanu, I. M.; Grandjean, N.

2017-02-01

In this paper we report on a comparative study of electrochemical processes for the preparation of multilayer porous structures in hydride vapor phase epitaxy (HVPE) and metal organic chemical vapor phase deposition (MOCVD) grown GaN. It was found that in HVPE-grown GaN, multilayer porous structures are obtained due to self-organization processes leading to a fine modulation of doping during the crystal growth. However, these processes are not totally under control. Multilayer porous structures with a controlled design have been produced by optimizing the technological process of electrochemical etching in MOCVD-grown samples, consisting of five pairs of thin layers with alternating-doping profiles. The samples have been characterized by SEM imaging, photoluminescence spectroscopy, and micro-reflectivity measurements, accompanied by transfer matrix analysis and simulations by a method developed for the calculation of optical reflection spectra. We demonstrate the applicability of the produced structures for the design of Bragg reflectors.

The Moessbauer effect in binary tin chalcogenides of tin 119

International Nuclear Information System (INIS)

Ortalli, I.; Fano, V.

1975-01-01

The values of the isomer shift, quadrupole splitting, Moessbauer coefficient, Debye temperature for the tin chalcogenides SnS. SnSe, SnTe are tabulated for the temperatures 80 and 300 K. Temperature dependences of the Moessbauer coefficient and of the effective Debye temperature for SnS, SnSe and SnTe in a temperature range of 78 to 300 K are presented. (Z.S.)

Research into tin and arsenical copper artefacts using nuclear analytical techniques

International Nuclear Information System (INIS)

Grant, M.R.

1995-01-01

This study includes the chemical analysis, sourcing and historical metallurgy of tin and arsenical copper artefacts discovered at Rooiberg and elsewhere in the Northern Transvaal and at Great Zimbabwe. A complete chemical analysis method for tin and cassiterite is presented, based on INAA (instrumental neutron activation analysis) and supplemented by PIXE or AAS for elements such as lead, bismuth and niobium. This is apparently the first study in which tin artefacts were analysed by INAA without chemical processing of the samples. INAA and PIXE returned the same results when a homogenized tin alloy block was analysed, but the structure and distribution of hardhead phases appear to produce an iron quantification problem in ancient tin. Ores and slags were analysed for light matrix elements by XRF or PIXE and INAA for the heavy trace metals. 108 refs., 24 figs., 130 tabs

Tin-based anode materials with well-designed architectures for next-generation lithium-ion batteries

Science.gov (United States)

Liu, Lehao; Xie, Fan; Lyu, Jing; Zhao, Tingkai; Li, Tiehu; Choi, Bong Gill

2016-07-01

Tin (Sn) has long been considered to be a promising replacement anode material for graphite in next-generation lithium-ion batteries (LIBs), because of its attractive comprehensive advantages of high gravimetric/volumetric capacities, environmental benignity, low cost, high safety, etc. However, Sn-based anodes suffer from severe capacity fading resulting mainly from their large volume expansions/contractions during lithiation/delithiation and subsequent pulverization, coalescence, delamination from current collectors, and poor Li+/electron transport. To circumvent these issues, a number of extraordinary architectures from nanostructures to anchored, layered/sandwich, core-shell, porous and even integrated structures have been exquisitely constructed to enhance the cycling performance. To cater for the rapid development of Sn-based anodes, we summarize the advances made in structural design principles, fabrication methods, morphological features and battery performance with focus on material structures. In addition, we identify the associated challenges and problems presented by recently-developed anodes and offer suggestions and perspectives for facilitating their practical implementations in next-generation LIBs.

A novel processing approach for free-standing porous non-oxide ceramic supports from polycarbosilane and polysilazane precursors

OpenAIRE

Konegger, Thomas; Patidar, Rajesh; Bordia, Rajendra K.

2015-01-01

In this contribution, a low-pressure/low-temperature casting technique for the preparation of novel free-standing macrocellular polymer-derived ceramic support structures is presented. Preceramic polymers (polycarbosilane and poly(vinyl)silazane) are combined with sacrificial porogens (ultra-high molecular weight polyethylene microbeads) to yield porous ceramic materials in the Si?C or Si?C?N systems, exhibiting well-defined pore structures after thermal conversion. The planar-disc-type speci...

Estimating the Probability of Electrical Short Circuits from Tin Whiskers. Part 2

Science.gov (United States)

Courey, Karim J.; Asfour, Shihab S.; Onar, Arzu; Bayliss, Jon A.; Ludwig, Larry L.; Wright, Maria C.

2010-01-01

To comply with lead-free legislation, many manufacturers have converted from tin-lead to pure tin finishes of electronic components. However, pure tin finishes have a greater propensity to grow tin whiskers than tin-lead finishes. Since tin whiskers present an electrical short circuit hazard in electronic components, simulations have been developed to quantify the risk of said short circuits occurring. Existing risk simulations make the assumption that when a free tin whisker has bridged two adjacent exposed electrical conductors, the result is an electrical short circuit. This conservative assumption is made because shorting is a random event that had an unknown probability associated with it. Note however that due to contact resistance electrical shorts may not occur at lower voltage levels. In our first article we developed an empirical probability model for tin whisker shorting. In this paper, we develop a more comprehensive empirical model using a refined experiment with a larger sample size, in which we studied the effect of varying voltage on the breakdown of the contact resistance which leads to a short circuit. From the resulting data we estimated the probability distribution of an electrical short, as a function of voltage. In addition, the unexpected polycrystalline structure seen in the focused ion beam (FIB) cross section in the first experiment was confirmed in this experiment using transmission electron microscopy (TEM). The FIB was also used to cross section two card guides to facilitate the measurement of the grain size of each card guide's tin plating to determine its finish .

Porous Nb-Ti based alloy produced from plasma spheroidized powder

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Qijun Li

Full Text Available Spherical Nb-Ti based alloy powder was prepared by the combination of plasma spheroidization and mechanical alloying. Phase constituents, microstructure and surface state of the powder, and pore characteristics of the resulting porous alloy were investigated. The results show that the undissolved W and V in the mechanically alloyed powder is fully alloyed after spheroidization, and single β phase is achieved. Particle size of the spheroidized powder is in the range of 20–110 μm. With the decrease of particle size, a transformation from typical dendrite solidification structure to fine cell microstructure occurs. The surface of the spheroidized powder is coated by a layer of oxides consisting mainly of TiO2 and Nb2O5. Probabilities of sinter-neck formation and particle coalescence increases with increasing sintering temperature. Porous skeleton with relatively homogeneous pore distribution and open pore channel is formed after vacuum sintering at 1700 °C, and the porosity is 32%. The sintering kinetic analysis indicates that grain boundary diffusion is the primary mass transport mechanism during sintering process. Keywords: Powder metallurgy, Nb-Ti based alloy, Porous material, Mechanical alloying, Plasma spheroidizing, Solidification microstructure

A strategy for fast screening and identification of sulfur derivatives in medicinal Pueraria species based on the fine isotopic pattern filtering method using ultra-high-resolution mass spectrometry

International Nuclear Information System (INIS)

Yang, Min; Zhou, Zhe; Guo, De-an

2015-01-01

Sulfurous compounds are commonly present in plants, fungi, and animals. Most of them were reported to possess various bioactivities. Isotopic pattern filter (IPF) is a powerful tool for screening compounds with distinct isotope pattern. Over the past decades, the IPF was used mainly to study Cl- and Br-containing compounds. To our knowledge, the algorithm was scarcely used to screen S-containing compounds, especially when combined with chromatography analyses, because the "3"4S isotopic ion is drastically affected by "1"3C_2 and "1"8O. Thus, we present a new method for a fine isotopic pattern filter (FIPF) based on the separated M + 2 ions ("1"2C_x"1H_y"1"6O_z"3"2S"1"3C_2"1"8O, "1"2C_x_+_2"1H_y"1"6O_z_+_1"3"4S, tentatively named M + 2OC and M + 2S) with an ultra-high-resolution mass (100,000 FWHM @ 400 m/z) to screen sulfur derivatives in traditional Chinese medicines (TCM).This finer algorithm operates through convenient filters, including an accurate mass shift of M + 2OC and M + 2S from M and their relative intensity compared to M. The method was validated at various mass resolutions, mass accuracies, and screening thresholds of flexible elemental compositions. Using the established FIPF method, twelve S-derivatives were found in the popular medicinal used Pueraria species, and 9 of them were tentatively identified by high-resolution multiple stage mass spectrometry (HRMS"n). The compounds were used to evaluate the sulfurous compounds' situation in commercially purchased Pueraria products. The strategy presented here provides a promising application of the IPF method in a new field. - Highlights: • We provide a new strategy for specifically screening of sulfurous compounds. • The fine isotopic pattern filter (FIPF) bases on separation of "1"3C_2+"1"8O and "3"4S. • Ultra high resolution mass (100,000 FWHM @ 400 m/z) is essential for FIPF. • IPF is applied to study the unique components of TCM for the first time. • New sulfurous components

Robust non-carbon titanium nitride nanotubes supported Pt catalyst with enhanced catalytic activity and durability for methanol oxidation reaction

International Nuclear Information System (INIS)

Xiao, Yonghao; Zhan, Guohe; Fu, Zhenggao; Pan, Zhanchang; Xiao, Chumin; Wu, Shoukun; Chen, Chun; Hu, Guanghui; Wei, Zhigang

2014-01-01

By the combination of solvothermal alcoholysis and post-nitriding method, titanium nitride nanotubes (TiN NTs), with high surface area, hollow and interior porous structure are prepared successfully and used at a support for Pt nanoparticles. The TiN NTs supported Pt (Pt/TiN NTs) catalyst displays enhanced activity and durability towards methanol oxidation reaction (MOR) compared with the commercial Pt/C (E-TEK) catalyst. X ray diffraction (XRD), nitrogen adsorption/desorption, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS) measurements are performed to investigate the physicochemical properties of the synthesized catalyst. SEM and TEM images reveal that the wall of the TiN NTs is porous and Pt nanoparticles supported on the dendritic TiN nanocrystals exhibit small size and good dispersion. Effects of inherent corrosion-resistant, tubular and porous nanostructures and electron transfer due to the strong metal–support interactions of TiN NTs contribute to the enhanced catalytic activity and stability of Pt/TiN NTs towards the MOR

Synthesis, characterization and photoluminescence of tin oxide nanoribbons and nanowires

Energy Technology Data Exchange (ETDEWEB)

Duraia, El-Shazly M.A., E-mail: duraia_physics@yahoo.co [Suez Canal University, Faculty of Science, Physics Department, Ismailia (Egypt); Al-Farabi Kazakh National University, Almaty (Kazakhstan); Institute of Physics and Technology, 11 Ibragimov Street, 050032 Almaty (Kazakhstan); Mansorov, Z.A. [Al-Farabi Kazakh National University, Almaty (Kazakhstan); Tokmolden, S. [Institute of Physics and Technology, 11 Ibragimov Street, 050032 Almaty (Kazakhstan)

2009-11-15

In this work we report the successful formation of tin oxide nanowires and tin oxide nanoribbons with high yield and by using simple cheap method. We also report the formation of curved nanoribbon, wedge-like tin oxide nanowires and star-like nanowires. The growth mechanism of these structures has been studied. Scanning electron microscope was used in the analysis and the EDX analysis showed that our samples is purely Sn and O with ratio 1:2. X-ray analysis was also used in the characterization of the tin oxide nanowire and showed the high crystallinity of our nanowires. The mechanism of the growth of our1D nanostructures is closely related to the vapor-liquid-solid (VLS) process. The photoluminescence PL measurements for the tin oxide nanowires indicated that there are three stable emission peaks centered at wavelengths 630, 565 and 395 nm. The nature of the transition may be attributed to nanocrystals inside the nanobelts or to Sn or O vacancies occurring during the growth which can induce trapped states in the band gap.

Nanocrystalline Tin Oxide Nanofibers Deposited by a Novel Focused Electrospinning Method. Application to the Detection of TATP Precursors

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José Pedro Santos

2014-12-01

Full Text Available A new method of depositing tin dioxide nanofibers in order to develop chemical sensors is presented. It involves an electrospinning process with in-plane electrostatic focusing over micromechanized substrates. It is a fast and reproducible method. After an annealing process, which can be performed by the substrate heaters, it is observed that the fibers are intertwined forming porous networks that are randomly distributed on the substrate. The fiber diameters oscillate from 100 nm to 200 nm and fiber lengths reach several tens of microns. Each fiber has a polycrystalline structure with multiple nano-grains. The sensors have been tested for the detection of acetone and hydrogen peroxide (precursors of the explosive triacetone triperoxide, TATP in air in the ppm range. High and fast responses to these gases have been obtained.

Nanocrystalline tin oxide nanofibers deposited by a novel focused electrospinning method. Application to the detection of TATP precursors.

Science.gov (United States)

Santos, José Pedro; Fernández, Maria Jesús; Fontecha, José Luis; Matatagui, Daniel; Sayago, Isabel; Horrillo, Maria Carmen; Gracia, Isabel

2014-12-16

A new method of depositing tin dioxide nanofibers in order to develop chemical sensors is presented. It involves an electrospinning process with in-plane electrostatic focusing over micromechanized substrates. It is a fast and reproducible method. After an annealing process, which can be performed by the substrate heaters, it is observed that the fibers are intertwined forming porous networks that are randomly distributed on the substrate. The fiber diameters oscillate from 100 nm to 200 nm and fiber lengths reach several tens of microns. Each fiber has a polycrystalline structure with multiple nano-grains. The sensors have been tested for the detection of acetone and hydrogen peroxide (precursors of the explosive triacetone triperoxide, TATP) in air in the ppm range. High and fast responses to these gases have been obtained.

Influence of Microstructure on the Electrical Properties of Heteroepitaxial TiN Films

Science.gov (United States)

Xiang, Wenfeng; Liu, Yuan; Zhang, Jiaqi

2018-03-01

Heteroepitaxial TiN films were deposited on Si substrates by pulse laser deposition at different substrate temperature. The microstructure and surface morphology of the films were investigated by X-ray diffraction (θ-2θ scan, ω-scan, and ϕ-scan) and atomic force microscopy. The electrical properties of the prepared TiN films were studied using a physical property measurement system. The experimental results showed that the crystallinity and surface morphology of the TiN films were improved gradually with increasing substrate temperature below 700 °C. Specially, single crystal TiN films were prepared when substrate temperature is above 700 °C; However, the quality of TiN films gradually worsened when the substrate temperature was increased further. The electrical properties of the films were directly correlated to their crystalline quality. At the optimal substrate temperature of 700 °C, the TiN films exhibited the lowest resistivity and highest mobility of 25.7 μΩ cm and 36.1 cm2/V s, respectively. In addition, the mechanism concerning the influence of substrate temperature on the microstructure of TiN films is discussed in detail.

Electrochemical reduction of trinitrotoluene on core-shell tin-carbon electrodes

International Nuclear Information System (INIS)

Grigoriants, Irena; Markovsky, Boris; Persky, Rachel; Perelshtein, Ilana; Gedanken, Aharon; Aurbach, Doron; Filanovsky, Boris; Bourenko, Tatiana; Felner, Israel

2008-01-01

In this work, we studied the electrochemical process of 2,4,6-trinitrotoluene (TNT) reduction on a new type of electrodes based on a core-shell tin-carbon Sn(C) structure. The Sn(C) composite was prepared from the precursor tetramethyl-tin Sn(CH 3 ) 4 , and the product contained a core of submicron-sized tin particles uniformly enveloped with carbon shells. Cyclic voltammograms of Sn(C) electrodes in aqueous sodium chloride solutions containing TNT show three well-pronounced reduction waves in the potential range of -0.50 to -0.80 V (vs. an Ag/AgCl/Cl - reference electrode) that correspond to the multistep process of TNT reduction. Electrodes containing Sn(C) particles annealed at 800 deg. C under argon develop higher voltammetric currents of TNT reduction (comparing to the as-prepared tin-carbon material) due to stabilization of the carbon shell. It is suggested that the reduction of TNT on core-shell tin-carbon electrodes is an electrochemically irreversible process. A partial oxidation of the TNT reduction products occurred at around -0.20 V. The electrochemical response of TNT reduction shows that it is not controlled by the diffusion of the active species to/from the electrodes but rather by interfacial charge transfer and possible adsorption phenomena. The tin-carbon electrodes demonstrate significantly stable behavior for TNT reduction in NaCl solutions and provide sufficient reproducibility with no surface fouling through prolonged voltammetric cycling. It is presumed that tin nanoparticles, which constitute the core, are electrochemically inactive towards TNT reduction, but Sn or SnO 2 formed on the electrodes during TNT reduction may participate in this reaction as catalysts or carbon-modifying agents. The nitro-groups of TNT can be reduced irreversibly (via two possible paths) by three six-electron transfers, to 2,4,6-triaminotoluene, as follows from mass-spectrometric studies. The tin-carbon electrodes described herein may serve as amperometric sensors

Fabrication of Porous Ceramic-Geopolymer Based Material to Improve Water Absorption and Retention in Construction Materials: A Review

Science.gov (United States)

Jamil, N. H.; Ibrahim, W. M. A. W.; Abdullah, M. M. A. B.; Sandu, A. V.; Tahir, M. F. M.

2017-06-01

Porous ceramic nowadays has been investigated for a variety of its application such as filters, lightweight structural component and others due to their specific properties such as high surface area, stability and permeability. Besides, it has the properties of low thermal conductivity. Various formation techniques making these porous ceramic properties can be tailored or further fine-tuned to obtain the optimum characteristic. Porous materials also one of the good candidate for absorption properties. Conventional construction materials are not design to have good water absorption and retention that lead to the poor performance on these criteria. Temperature is a major driving force for moisture movement and influences sorption characteristics of many constructions materials. The effect of elevated temperatures on the water absorption coefficient and retention remain as critical issue that need to be investigated. Therefore, this paper will review the process parameters in fabricating porous ceramic for absorption properties.

Electrochemical properties of porous carbon black layer as an electron injector into iodide redox couple

International Nuclear Information System (INIS)

Kim, Jung-Min; Rhee, Shi-Woo

2012-01-01

Highlights: ► Carbon black (CB) porous layer for triiodide (I 3 − ) ion reduction is coated with spray coating method at 120 °C on the fluorine-doped tin oxide glass. ► The electrochemical impedance spectroscopy is analyzed for a symmetric cell and a new circuit model is applied to identify electrochemical parameters. ► Decreased particle size and increased thickness improve the catalytic activity because of the increase in the surface area and the conductivity of the CB layer. - Abstract: Electrochemical properties of carbon black (CB) porous layer as a counter electrode in dye-sensitized solar cells (DSC) are studied. CB electrode for triiodide (I 3 − ) ion reduction is coated with spray coating method on the fluorine-doped tin oxide glass at 120 °C. The CB particle size is varied from 20 nm to 90 nm and the CB electrode thickness is controlled from 1 μm to 9 μm by controlling the spraying time. The electrochemical impedance spectroscopy is analyzed for a symmetric cell and a new circuit model is applied to identify electrochemical parameters. As the CB particle size is decreased, the catalytic activity is improved because of the increase in the surface area and the conductivity of the CB layer. Increased CB electrode thickness also improves the catalytic activity and leads to the low charge transfer resistance at the electrolyte/CB electrode interface. The CB counter electrode with the particle size of 20 nm and the thickness of 9 μm for DSC shows the energy conversion efficiency of 7.2% with the highest fill factor (FF) of 65.6%, which is similar to the Pt counter electrode with FF of 65.8% and the efficiency of 7.6%.

Heat Removal from Bipolar Transistor by Loop Heat Pipe with Nickel and Copper Porous Structures

Directory of Open Access Journals (Sweden)

Patrik Nemec

2014-01-01

Full Text Available Loop heat pipes (LHPs are used in many branches of industry, mainly for cooling of electrical elements and systems. The loop heat pipe is a vapour-liquid phase-change device that transfers heat from evaporator to condenser. One of the most important parts of the LHP is the porous wick structure. The wick structure provides capillary force to circulate the working fluid. To achieve good thermal performance of LHP, capillary wicks with high permeability and porosity and fine pore radius are expected. The aim of this work was to develop porous structures from copper and nickel powder with different grain sizes. For experiment copper powder with grain size of 50 and 100 μm and nickel powder with grain size of 10 and 25 μm were used. Analysis of these porous structures and LHP design are described in the paper. And the measurements’ influences of porous structures in LHP on heat removal from the insulated gate bipolar transistor (IGBT have been made.

Shanghai Futures Exchange Published Draft of Tin and Nickel Futures Contract

Institute of Scientific and Technical Information of China (English)

2015-01-01

Shanghai Futures Exchange published draft for soliciting opinions for tin and nickel futures contract on its official website on January 19,which implies the marketing time of the long awaited tin and nickel futures is drawing near.According to the draft for soliciting opinions,the transaction unit of tin futures contract is 1tonne/lot,minimum variation unit is 10 yuan/tonne,daily maximum price fluctuation shall

VO2 /TiN Plasmonic Thermochromic Smart Coatings for Room-Temperature Applications.

Science.gov (United States)

Hao, Qi; Li, Wan; Xu, Huiyan; Wang, Jiawei; Yin, Yin; Wang, Huaiyu; Ma, Libo; Ma, Fei; Jiang, Xuchuan; Schmidt, Oliver G; Chu, Paul K

2018-03-01

Vanadium dioxide/titanium nitride (VO 2 /TiN) smart coatings are prepared by hybridizing thermochromic VO 2 with plasmonic TiN nanoparticles. The VO 2 /TiN coatings can control infrared (IR) radiation dynamically in accordance with the ambient temperature and illumination intensity. It blocks IR light under strong illumination at 28 °C but is IR transparent under weak irradiation conditions or at a low temperature of 20 °C. The VO 2 /TiN coatings exhibit a good integral visible transmittance of up to 51% and excellent IR switching efficiency of 48% at 2000 nm. These unique advantages make VO 2 /TiN promising as smart energy-saving windows. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Highly efficient fully flexible indium tin oxide free organic light emitting diodes fabricated directly on barrier-foil

International Nuclear Information System (INIS)

Bocksrocker, Tobias; Hülsmann, Neele; Eschenbaum, Carsten; Pargner, Andreas; Höfle, Stefan; Maier-Flaig, Florian; Lemmer, Uli

2013-01-01

We present a simple method for the fabrication of highly conductive and fully flexible metal/polymer hybrid anodes for efficient organic light emitting diodes (OLEDs). By incorporating ultra-thin metal grids into a conductive polymer, we fabricated anodes with very low sheet resistances and high transparency. After optimizing the metallic grid, OLEDs with these hybrid anodes are superior to OLEDs with standard indium tin oxide (ITO) anodes in luminous efficacy by a factor of ∼ 2. Furthermore, the sheet resistance can be reduced by up to an order of magnitude compared to ITO on polyethylene terephthalate (PET). The devices show a very low turn-on voltage and the hybrid anodes do not change the emissive spectra of the OLEDs. In addition, we fabricated the anodes directly on a barrier foil, making the double sided encapsulation of a typically used PET-substrate unnecessary

Experimental Study of Hysteresis behavior of Foam Generation in Porous Media

OpenAIRE

Kahrobaei, S.; Vincent-Bonnieu, S.; Farajzadeh, R.

2017-01-01

Foam can be used for gas mobility control in different subsurface applications. The success of foam-injection process depends on foam-generation and propagation rate inside the porous medium. In some cases, foam properties depend on the history of the flow or concentration of the surfactant, i.e., the hysteresis effect. Foam may show hysteresis behavior by exhibiting multiple states at the same injection conditions, where coarse-textured foam is converted into strong foam with fine texture at...

Tinned fish with radioprotective ingredients

International Nuclear Information System (INIS)

Chaneva, M.; Minkova, M.; Zajko, G.

1992-01-01

A survey of food ingredients with pronounced radioprotective properties is made. The protective effect of fish proteins and some vegetable oils is mentioned. As suitable additives to tinned fish during the manufacturing process the β carotene, anthocyans and apple pectin are pointed out. β-carotene possesses the ability to absorb radiations. It can be added either as a pure crystalline substance or dissolved in the vegetable oil. Anthocyans have an antimutagen effect due to their ability to inhibit free radical reactions. Some vegetable polyphenols can be added with wine. The Bulgarian anthocyan concentrate Enobagrin (made by extraction of marc and wine) is also proposed. A combination of Enobagrin, β-tocopherol and pyracetam decreases the postradiation hypoplasia. Special attention is paid to the importance of the pectin in intoxication with heavy radioactive metals. It is thought that the pectin forms unsoluble complex compounds with Fe, Zn, Cd, Co, Pb, Hg, Mn, Cr. The binding energy depends on the available carboxylic groups. Some experiments showing the interaction of the pectin with 90 Sr are mentioned. In the tinned fish the pectin can be introduced with tomato paste. Vegetables rich in pectin and carotene - carrots and tomato concentrate - can be added as well. Proposed enriched tinned fish can be used as a preventive radioprotective food under conditions of increased radiation risk. 19 refs

Ground Glass Pozzolan in Conventional, High, and Ultra-High Performance Concrete

OpenAIRE

Tagnit-Hamou Arezki; Zidol Ablam; Soliman Nancy; Deschamps Joris; Omran Ahmed

2018-01-01

Ground-glass pozzolan (G) obtained by grinding the mixed-waste glass to same fineness of cement can act as a supplementary-cementitious material (SCM), given that it is an amorphous and a pozzolanic material. The G showed promising performances in different concrete types such as conventional concrete (CC), high-performance concrete (HPC), and ultra-high performance concrete (UHPC). The current paper reports on the characteristics and performance of G in these concrete types. The use of G pro...

Separation of substandard tin ores by x-ray fluorescence method

International Nuclear Information System (INIS)

Kotler, N.I.; Konovalov, V.M.; Kamenskij, Yu.V.; Neverov, A.D.; Ogorodnikov, Yu.V.

1987-01-01

Analysis of pure tin ores on X-ray fluorescence separation (XFS) is carried out. The volumes of lump sampling are substantiated; several variants of technical and economical efficiency of XFS application have been calculated. It is shown that at XFS of -400+25 mm classes conditional as to tin content intermediate product with high efficiency factor may be prepared. Separation of -25+10 mm class is unsuitable, as it doesn't allow to increase tin content to conditional, and the process efficiency is low

Tin - an unlikely ally for silicon field effect transistors?

KAUST Repository

Hussain, Aftab M.

2014-01-13

We explore the effectiveness of tin (Sn), by alloying it with silicon, to use SiSn as a channel material to extend the performance of silicon based complementary metal oxide semiconductors. Our density functional theory based simulation shows that incorporation of tin reduces the band gap of Si(Sn). We fabricated our device with SiSn channel material using a low cost and scalable thermal diffusion process of tin into silicon. Our high-κ/metal gate based multi-gate-field-effect-transistors using SiSn as channel material show performance enhancement, which is in accordance with the theoretical analysis. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dynamic fragmentation of laser shock-melted tin: experiment and modelling

Energy Technology Data Exchange (ETDEWEB)

De Resseguier, T. [CNRS ENSMA, Lab Combust and Deton, F-86961 Futuroscope (France); Signor, L.; Dragon, A. [CNRS ENSMA, Mecan and Phys Mat Lab, F-86961 Futuroscope (France); Signor, L.; Roy, G. [CEA Valduc, 21 - Is-sur-Tille (France)

2010-07-01

Dynamic fragmentation of shock-loaded metals is an issue of considerable importance for both basic science and a variety of technological applications, such as pyrotechnics or inertial confinement fusion, the latter involving high energy laser irradiation of thin metallic shells. Whereas spall fracture in solid materials has been extensively studied for many years, little data can be found yet about the evolution of this phenomenon after partial or full melting on compression or on release. Here, we present an investigation of dynamic fragmentation in laser shock-melted tin, from the 'micro-spall' process (ejection of a cloud of fine droplets) occurring upon reflection of the compressive pulse from the target free surface, to the late rupture observed in the un-spalled melted layer (leading to the formation of larger spherical fragments). Experimental results consist of time-resolved velocity measurements and post-shock observations of recovered targets and fragments. They provide original information regarding the loss of tensile strength associated with melting, the cavitation mechanism likely to occur in the melted metal, the sizes of the subsequent fragments and their ejection velocities. A theoretical description based on an energetic approach adapted to the case of a liquid metal is implemented as a failure criterion in a one-dimensional hydro-code including a multi-phase equation of state for tin. The resulting predictions of the micro-spall process are compared with experimental data. In particular, the use of a new experimental technique to quantify the fragment size distributions leads to a much better agreement with theory than previously reported. Finally, a complementary approach focused on cavitation is proposed to evaluate the role of this phenomenon in the fragmentation of the melted metal. (authors)

Microstructure development of in situ porous TiO/Cu composites

International Nuclear Information System (INIS)

Qin, Q.D.; Huang, B.W.; Li, W.; Shao, F.

2016-01-01

An in situ porous TiO/Cu composite is successfully prepared using powder metallurgy by the reaction of Ti_2CO and Cu powder. Ti_2CO powder is produced by the carbothermic reduction of titanium dioxide (TiO_2) at 1000 °C. Morphological examination of the composite shows that the porosity of composites lies in the range between 10.2% and 35.2%. As the volume fraction of TiO increases, the size of TiO becomes more fine. Scanning electron microscopy (SEM) of the fracture morphology indicates that TiO particles and the Cu matrix are connected by a Cu–Ti phase. - Highlights: • An porous TiO/Cu composite is successfully prepared by powder metallurgy technology. • The porosity of composites lies in the range between 10.2% and 35.2%. • The TiO particles and the Cu matrix are connected by a Cu-Ti phase.

Tin Whisker Formation — A Stress Relieve Phenomenon

Science.gov (United States)

Dittes, M.; Oberndorff, P.; Crema, P.; Su, P.

2006-02-01

With the move towards lead-free electronics also the solderable finish of electronic components' terminations are converted. While the typical finish was containing 5 % to 20 % lead (Pb) and thus was almost whisker free, lead (Pb)-free finishes such as pure tin or high tin alloys are rather prone to grow whisker. These whiskers are spontaneous protrusions that grow to a significant length of up to millimeters with a typical diameter in the range of few microns and are suspect to cause shorts in electronic assemblies. The latest details of the mechanisms are not yet understood. However it appears to be well established that the driving force for tin whisker growth is a compressive stress in the tin layer and that this stress is released by whisker formation. Besides the mechanism for whisker growth therefore the mechanism of the stress induction is of interest. The origin of that stress may have multiple sources. Among others the most important one is the volume increase within the tin layer due the formation of intermetallics at the interface to the base material. This applies to all copper based material. For base materials with a coefficient of thermal expansion (cte) significantly different from the tin finish another mechanism plays the dominant role. This is the induction of stress during thermal cycling due to the different expansion of the materials with every temperature change. Another mechanism for stress induction may be the oxidation of the finish, which also leads to a local volume increase. Based on the knowledge of stress induction various mitigation strategies can be deducted. Most common is the introduction of a diffusion barrier (e.g. Ni) in order to prevent the growth of the Cu-Sn intermetallics, the controlled growth of Cu-Sn intermetallics in order to prevent their irregularity or the introduction of a mechanical buffer material targeting at the minimisation of the cte mismatch between base and finish material. With respect to the stress

Actual problems of exposure risk assessment of finely dispersed aerosols and aerosols of nanoparticles

Directory of Open Access Journals (Sweden)

A. I. Sevalnev

2018-04-01

Full Text Available Purpose of the study – analysis of the scientific literature on generalization of the data on domestic and foreign experience in risk assessment due to exposure to finely dispersed aerosols and aerosols of nanoparticles (NPs. The article summarizes data of long-term studies on the effect of nanomaterials and nanoparticles on the quality of human habitat and health. The domestic and foreign experience of harm health assessment, safety of new types of nanomaterials for the environment and work-related conditions have been analyzed. There are numerous studies of foreign and domestic scientists on the biological activity of nanoparticles and their effect on experimental animals, namely, on the specificity of their effect on various organs and systems of the body. Classification of nanomaterials, depending on their chemical composition, is presented. Attention is paid to the problems of nanosafety, namely, to the evaluation of nanotoxicity of substances and to the definition of the concept of a “dose” for nanoparticles. The data on the presence of finely dispersed and ultra-fine particles in the atmospheric air, which increase risk of respiratory system diseases among residents of large megacities, is given. There is special importance on assessing work conditions and occupational risks in production and use of materials which contain nanoparticles as well as in production processes with formation of the fine dust and nanoparticles indicated in the article. Due to the lack of a clear system for assessing health risks related to the action of nanoparticles, lack of common criteria of harmfulness and maximum allowable concentrations for most nanoparticles and uniform methods of their control, it is suggested to strictly adhere to protective measures in contact with nanomaterials and active improvement of nanosecurity measures. Conclusions. High toxicity and health hazards of finely dispersed and ultra-fine particles confirm need to control their

Adaptive mesh refinement and multilevel iteration for multiphase, multicomponent flow in porous media

Energy Technology Data Exchange (ETDEWEB)

Hornung, R.D. [Duke Univ., Durham, NC (United States)

1996-12-31

An adaptive local mesh refinement (AMR) algorithm originally developed for unsteady gas dynamics is extended to multi-phase flow in porous media. Within the AMR framework, we combine specialized numerical methods to treat the different aspects of the partial differential equations. Multi-level iteration and domain decomposition techniques are incorporated to accommodate elliptic/parabolic behavior. High-resolution shock capturing schemes are used in the time integration of the hyperbolic mass conservation equations. When combined with AMR, these numerical schemes provide high resolution locally in a more efficient manner than if they were applied on a uniformly fine computational mesh. We will discuss the interplay of physical, mathematical, and numerical concerns in the application of adaptive mesh refinement to flow in porous media problems of practical interest.

Electrochemical migration of tin in electronics and microstructure of the dendrites

DEFF Research Database (Denmark)

Minzari, Daniel; Grumsen, Flemming Bjerg; Jellesen, Morten Stendahl

2011-01-01

The macro-, micro-, and nano-scale morphology and structure of tin dendrites, formed by electrochemical migration on a surface mount ceramic chip resistor having electrodes consisting of tin with small amounts of Pb (∼2wt.%) was investigated by scanning electron microscopy and transmission electr...... by the dehydration of the hydrated oxide originally formed in solution ex-situ in ambient air.......The macro-, micro-, and nano-scale morphology and structure of tin dendrites, formed by electrochemical migration on a surface mount ceramic chip resistor having electrodes consisting of tin with small amounts of Pb (∼2wt.%) was investigated by scanning electron microscopy and transmission electron...... microscopy including Energy dispersive X-ray spectroscopy and electron diffraction. The tin dendrites were formed under 5 or 12V potential bias in 10ppm by weight NaCl electrolyte as a micro-droplet on the resistor during electrochemical migration experiments. The dendrites formed were found to have...

Trace hydrogen extraction from liquid lithium tin alloy

International Nuclear Information System (INIS)

Xie Bo; Hu Rui; Xie Shuxian; Weng Kuiping

2010-01-01

In order to finish the design of tritium extraction system (TES) of fusion fission hybrid reactor (FFHR) tritium blanket, involving the dynamic mathematical model of liquid metal in contact with a gaseous atmosphere, approximate mathematical equation of tritium in lithium tin alloy was deduced. Moreover, carrying process used for trace hydrogen extraction from liquid lithium tin alloy was investigated with hydrogen being used to simulate tritium in the study. The study results indicate that carrying process is effective way for hydrogen extraction from liquid lithium tin alloy, and the best flow velocity of carrier gas is about 4 L/min under 1 kg alloy temperatures and carrying numbers are the main influencing factors of hydrogen number. Hydrogen extraction efficiency can reach 85% while the alloy sample is treated 6 times at 823 K. (authors)

Ultra-fine structures of Pd-Ag-HAp nanoparticle deposition on protruded TiO2 barrier layer for dental implant

Science.gov (United States)

Jang, Jae-Myung; Kim, Seung-Dai; Park, Tae-Eon; Choe, Han-Cheol

2018-02-01

The biocompatibility structure of an implant surface is of great importance to the formation of new bone tissue around the dental implant and also has a significant chemical reaction in the osseointegration process. Thus, ultra-fine Pd-Ag-HAp nanoparticles have been electrodeposited on protruded TiO2 barrier layer in mixed electrolyte solutions. Unusual protrusions patterns, which are assigned to Pd-Ag-HAp nanoparticles, can be clearly differentiated from a TiO2 nanotube oxide layer formed by an anodizing process. In the chemical bonding state, the surface characteristics of Pd/Ag/HAp compounds have been investigated by FE-SEM, EDS mapping analysis, and XPS analysis. The mapping dots of the elements including Ti, Ca, Pd, Ag, and P showed a homogeneous distribution throughout the entire surface when deposited onto the protruded TiO2 barrier layer. The XPS spectra of Ti-2p, O-1S, Pd-3d, and Ag-3d have been investigated, with the major XPS peak indicating Pd-3d. The Ag-3d level was clearly observed with further scanning of the Ca-2p region. Based on the results of the chemical states, the structural properties of the protrusion patterns were also examined after being deposited onto the barrier oxide film, resulting in the representative protrusion patterns being mainly composed of Pd-Ag-HAp compounds. The results of the soaking evaluation showed that the protrusion patterns and the protruded TiO2 barrier layer were all effective in regards to biocompatibility.

Optimization of nanoparticulate indium tin oxide slurries for the manufacture of ultra-thin indium tin oxide coatings with the slot-die coating process

International Nuclear Information System (INIS)

Wegener, M.; Riess, K.; Roosen, A.

2016-01-01

This paper deals with the optimization of colloidal processing to achieve suitable nanoparticulate indium tin oxide (ITO) slurries for the production of sub-μm-thin ITO coatings with the slot die coating process. For application in printed electronics these ITO coatings, which are composite films consisting of nanoparticulate ITO and a polymeric binder, should offer high flexibility, transparency and electrical conductivity. To preserve their flexibility, the composite films are not subject to any heat treatment, instead they are used as deposited and dried. To achieve very good transparency and electrical conductivity at the same time, the slurries must exhibit excellent dispersivity to result in a dense particle packing during film formation and drying. To reduce materials costs, films with thicknesses of several 100 nm are of interest. Therefore, the slot-die technique was applied as a fast, pre-dosing technique to produce sub-μm-thin ITO/binder composite films. The resulting ITO/binder films were characterized with regard to their key properties such as total transmission and specific electrical resistance. With the colloidal optimization of ethanol- and water-based nanoparticulate ITO slurries using PVP and PVB as binders, it was possible to achieve films of 250 nm in thickness exhibiting high total transmission of ∝ 93 % and a low specific electrical resistance of ∝ 10 Ω.cm.

Optimization of nanoparticulate indium tin oxide slurries for the manufacture of ultra-thin indium tin oxide coatings with the slot-die coating process

Energy Technology Data Exchange (ETDEWEB)

Wegener, M.; Riess, K.; Roosen, A. [Erlangen-Nuremberg Univ., Erlangen (Germany). Dept. of Materials Science, Glass and Ceramics

2016-07-01

This paper deals with the optimization of colloidal processing to achieve suitable nanoparticulate indium tin oxide (ITO) slurries for the production of sub-μm-thin ITO coatings with the slot die coating process. For application in printed electronics these ITO coatings, which are composite films consisting of nanoparticulate ITO and a polymeric binder, should offer high flexibility, transparency and electrical conductivity. To preserve their flexibility, the composite films are not subject to any heat treatment, instead they are used as deposited and dried. To achieve very good transparency and electrical conductivity at the same time, the slurries must exhibit excellent dispersivity to result in a dense particle packing during film formation and drying. To reduce materials costs, films with thicknesses of several 100 nm are of interest. Therefore, the slot-die technique was applied as a fast, pre-dosing technique to produce sub-μm-thin ITO/binder composite films. The resulting ITO/binder films were characterized with regard to their key properties such as total transmission and specific electrical resistance. With the colloidal optimization of ethanol- and water-based nanoparticulate ITO slurries using PVP and PVB as binders, it was possible to achieve films of 250 nm in thickness exhibiting high total transmission of ∝ 93 % and a low specific electrical resistance of ∝ 10 Ω.cm.

Determination of total tin in canned food using inductively coupled plasma atomic emission spectroscopy

Energy Technology Data Exchange (ETDEWEB)

Perring, Loic; Basic-Dvorzak, Marija [Department of Quality and Safety Assurance, Nestle Research Centre, P.O. Box 44, Vers chez-les-Blanc, 1000, Lausanne (Switzerland)

2002-09-01

Tin is considered to be a priority contaminant by the Codex Alimentarius Commission. Tin can enter foods either from natural sources, environmental pollution, packaging material or pesticides. Higher concentrations are found in processed food and canned foods. Dissolution of the tinplate depends on the of food matrix, acidity, presence of oxidising reagents (anthocyanin, nitrate, iron and copper) presence of air (oxygen) in the headspace, time and storage temperature. To reduce corrosion and dissolution of tin, nowadays cans are usually lacquered, which gives a marked reduction of tin migration into the food product. Due to the lack of modern validated published methods for food products, an ICP-AES (Inductively coupled plasma-atomic emission spectroscopy) method has been developed and evaluated. This technique is available in many laboratories in the food industry and is more sensitive than atomic absorption. Conditions of sample preparation and spectroscopic parameters for tin measurement by axial ICP-AES were investigated for their ruggedness. Two methods of preparation involving high-pressure ashing or microwave digestion in volumetric flasks were evaluated. They gave complete recovery of tin with similar accuracy and precision. Recoveries of tin from spiked products with two levels of tin were in the range 99{+-}5%. Robust relative repeatabilities and intermediate reproducibilities were <5% for different food matrices containing >30 mg/kg of tin. Internal standard correction (indium or strontium) did not improve the method performance. Three emission lines for tin were tested (189.927, 283.998 and 235.485 nm) but only 189.927 nm was found to be robust enough with respect to interferences, especially at low tin concentrations. The LOQ (limit of quantification) was around 0.8 mg/kg at 189.927 nm. A survey of tin content in a range of canned foods is given. (orig.)

Interaction of a tin-based capillary porous structure with ITER/DEMO relevant plasma conditions

Energy Technology Data Exchange (ETDEWEB)

Morgan, T.W., E-mail: t.w.morgan@differ.nl; Bekerom, D.C.M. van den; De Temmerman, G.

2015-08-15

Sn filled capillary porous structures were exposed to high flux low temperature plasma conditions at the Pilot-PSI linear device. Enhanced erosion above that expected classically was investigated via spectroscopic observation of Sn{sup 0} emission from the plasma in front of the target surface while the surface temperature was monitored by both thermography and pyrometry. An anomalous erosion flux was observed as temperature increases, with onset for this occurrence varying strongly between different ion species. The results appear incompatible with existing ‘adatom’ models for the anomalous erosion flux. Further targets were exposed in turn to increasing heat fluxes and the heat removed determined from cooling water calorimetry, which was then compared to a solid Mo reference target. At high powers the total energy of the cooling water is reduced, indicating a shielding of the surface from the plasma heat flux by the vapour cloud in front.

Inductively coupled plasma atomic emission spectrometric determination of tin in canned food.

Science.gov (United States)

Sumitani, H; Suekane, S; Nakatani, A; Tatsuka, K

1993-01-01

Various canned foods were digested sequentially with HNO3 and HCl, diluted to 100 mL, and filtered, and then tin was determined by inductively coupled plasma atomic emission spectrometry (ICP/AES). Samples of canned Satsuma mandarin, peach, apricot, pineapple, apple juice, mushroom, asparagus, evaporated milk, short-necked clam, spinach, whole tomato, meat, and salmon were evaluated. Sample preparations did not require time-consuming dilutions, because ICP/AES has wide dynamic range. The standard addition method was used to determine tin concentration. Accuracy of the method was tested by analyzing analytical standards containing tin at 2 levels (50 and 250 micrograms/g). The amounts of tin found for the 50 and 250 micrograms/g levels were 50.5 and 256 micrograms/g, respectively, and the repeatability coefficients of variation were 4.0 and 3.8%, respectively. Recovery of tin from 13 canned foods spiked at 2 levels (50 and 250 micrograms/g) ranged from 93.9 to 109.4%, with a mean of 99.2%. The quantitation limit for tin standard solution was about 0.5 microgram/g.

Optical performance of hybrid porous silicon-porous alumina multilayers

Science.gov (United States)

Cencha, L. G.; Antonio Hernández, C.; Forzani, L.; Urteaga, R.; Koropecki, R. R.

2018-05-01

In this work, we study the optical response of structures involving porous silicon and porous alumina in a multi-layered hybrid structure. We performed a rational design of the optimal sequence necessary to produce a high transmission and selective filter, with potential applications in chemical and biosensors. The combination of these porous materials can be used to exploit its distinguishing features, i.e., high transparency of alumina and high refractive index of porous silicon. We assembled hybrid microcavities with a central porous alumina layer between two porous silicon Bragg reflectors. In this way, we constructed a Fabry-Perot resonator with high reflectivity and low absorption that improves the quality of the filter compared to a microcavity built only with porous silicon or porous alumina. We explored a simpler design in which one of the Bragg reflectors is replaced by the aluminium that remains bound to the alumina after its fabrication. We theoretically explored the potential of the proposal and its limitations when considering the roughness of the layers. We found that the quality of a microcavity made entirely with porous silicon shows a limit in the visible range due to light absorption. This limitation is overcome in the hybrid scheme, with the roughness of the layers determining the ultimate quality. Q-factors of 220 are experimentally obtained for microcavities supported on aluminium, while Q-factors around 600 are reached for microcavities with double Bragg reflectors, centred at 560 nm. This represents a four-fold increase with respect to the optimal porous silicon microcavity at this wavelength.

Effective adsorption and collection of cesium from aqueous solution using graphene oxide grown on porous alumina

Science.gov (United States)

Entani, Shiro; Honda, Mitsunori; Shimoyama, Iwao; Li, Songtian; Naramoto, Hiroshi; Yaita, Tsuyoshi; Sakai, Seiji

2018-04-01

Graphene oxide (GO) with a large surface area was synthesized by the direct growth of GO on porous alumina using chemical vapor deposition to study the Cs adsorption mechanism in aqueous solutions. Electronic structure analysis employing in situ near-edge X-ray absorption fine structure spectroscopy and X-ray photoelectron spectroscopy measurements clarifies the Cs atoms bond via oxygen functional groups on GO in the aqueous solution. The Cs adsorption capacity was found to be as high as 650-850 mg g-1, which indicates that the GO/porous alumina acts as an effective adsorbent with high adsorption efficiency for radioactive nuclides in aqueous solutions.

Quadtree of TIN: a new algorithm of dynamic LOD

Science.gov (United States)

Zhang, Junfeng; Fei, Lifan; Chen, Zhen

2009-10-01

Currently, Real-time visualization of large-scale digital elevation model mainly employs the regular structure of GRID based on quadtree and triangle simplification methods based on irregular triangulated network (TIN). TIN is a refined means to express the terrain surface in the computer science, compared with GRID. However, the data structure of TIN model is complex, and is difficult to realize view-dependence representation of level of detail (LOD) quickly. GRID is a simple method to realize the LOD of terrain, but contains more triangle count. A new algorithm, which takes full advantage of the two methods' merit, is presented in this paper. This algorithm combines TIN with quadtree structure to realize the view-dependence LOD controlling over the irregular sampling point sets, and holds the details through the distance of viewpoint and the geometric error of terrain. Experiments indicate that this approach can generate an efficient quadtree triangulation hierarchy over any irregular sampling point sets and achieve dynamic and visual multi-resolution performance of large-scale terrain at real-time.

Multifunctional porous solids derived from tannins

Science.gov (United States)

Celzard, Alain; Fierro, Vanessa; Pizzi, Antonio; Zhao, Weigang

2013-03-01

Tannins are extremely valuable, non toxic, wood extractives combining reactivity towards aldehydes, low cost, natural origin and easy handling. When polymerized in the presence of suitable chemicals including blowing agent, ultra lightweight rigid tannin-based foams are obtained. If pyrolyzed under inert gas, reticulated carbon foams having the same pore structure and the same density are obtained. The most remarkable features of tannin-based foams are the following: mechanical resistance similar to, or higher than, that of commercial phenolic foams, tuneable pore size and permeability, infusibility, very low thermal conductivity, cheapness, ecological character, high resistance to flame and to chemicals. Carbon foams have even better properties and are also electrically conducting. Consequently, various applications are suggested for organic foams: cores of sandwich composite panels, sound and shock absorbers and thermal insulators, whereas carbon foams can be used as porous electrodes, filters for molten metals and corrosive chemicals, catalyst supports and adsorbents.

Defects in fine-grained and porous materials characterized by positron annihilation

International Nuclear Information System (INIS)

Staab, T.E.M.; Krause-Rehberg, R.; Kieback, B.

2003-01-01

We investigate the annihilation parameters (lifetimes and intensities) for positrons becoming trapped at grain boundaries and at inner surfaces (pores), examining fine-grained nickel powder compacts (effective powder particle size 1 - 10 μm with grains in or even below the micron size). Furthermore, we can monitor grain growth and sintering (volume shrinkage) during successive heat treatment of powder compacts. To reach this aim, we correlate the annihilation parameters with results of a Monte-Carlo simulation and analytical solutions of the positron diffusion. We find that it is possible to determine an effective average powder particle size as well as grain sizes by positron lifetime spectroscopy. (author)

Research of the photovoltaic properties of anodized films of Sn

Science.gov (United States)

Afanasyev, D. A.; Ibrayev, N. Kh; Omarova, G. S.; Smagulov, Zh K.

2015-04-01

The results of studies of photovoltaic properties of solar cells based on porous tin oxide films, sensitized with an organic dye are presented. Porous films were prepared by electrochemical anodization of tin in alkaline electrolytes based on aqueous solution of NaOH and aqueous ammonia NH4OH. It was found that the time of anodizing of the Sn films affects on conversion efficiency of light energy into electrical energy. Increasing of the sorption time leads to an increase of the number of molecules on the surface of the porous film. For the solar cell based on tin oxide there is a strong dark current, which significantly reduces the efficiency of conversion of light energy into electrical energy.

Effect of glutinous rice flour and dried egg white in fabrication of porous cordierite by gel casting method

Directory of Open Access Journals (Sweden)

A. Kamil Fakhruddin

Full Text Available Abstract In this study, cordierite was produced using MgO, SiO2 and Al2O3 as raw materials through glass route method. The raw materials were mixed for 6 h and the mixture was melted at 1550 °C and then water quenched. The glass produced was milled for 5 h to obtain fine powder, which was used to prepare porous cordierite through gel casting method. The effect of addition of different natural binders, glutinous rice flour (GRF and dried egg white (DEW, on porous cordierite was investigated. GRF and DEW were added to the slurry during mixing. The synthesized cordierite powder was analyzed by X-ray diffraction. Porous cordierite was characterized through Archimedes method, morphological analysis, and compression test. The porosity level varied from 60.6% to 78.7% depending on the amount of natural binder added. Compression test results showed that the compressive strength of porous cordierite increased with increasing amount of natural binder added.

Properties of Polydisperse Tin-doped Dysprosium and Indium Oxides

Directory of Open Access Journals (Sweden)

Malinovskaya Tatyana

2017-01-01

Full Text Available The results of investigations of the complex permittivity, diffuse-reflectance, and characteristics of crystal lattices of tin-doped indium and dysprosium oxides are presented. Using the methods of spectroscopy and X-ray diffraction analysis, it is shown that doping of indium oxide with tin results in a significant increase of the components of the indium oxide complex permittivity and an appearance of the plasma resonance in its diffuse-reflectance spectra. This indicates the appearance of charge carriers with the concentration of more than 1021 cm−3 in the materials. On the other hand, doping of the dysprosium oxide with the same amount of tin has no effect on its optical and electromagnetic properties.

Evaluation of the suitability of tin slag in cementitious materials: Mechanical properties and Leaching behaviour

Science.gov (United States)

Rustandi, Andi; Wafa' Nawawi, Fuad; Pratesa, Yudha; Cahyadi, Agung

2018-01-01

Tin slag, a by-product of tin production has been used in cementitious application. The present investigation focuses on the suitability of tin slag as primary component in cement and as component that substitute some amount of Portland Cement. The tin slags studied were taken from Bangka, Indonesia. The main contents of the tin slag are SiO2, Al2O3, and Fe2O3 according to the XRF investigation. The aim of this article was to study the mechanical behaviour (compressive strength), microstructure and leaching behaviour of tin slag blended cement. This study used air-cooled tin slag that had been passed through 400# sieve to replace Portland Cement with ratio 0, 10, 20, 30, 40 by weight. Cement pastes and tin slag blended cement pastes were prepared by using water/cement ratio (W/C) of 0.40 by weight and hydrated for various curing ages of 3, 7, 14 days The microstructure of the raw tin slag was investigated using Scanning Electron Microscope (SEM). The phase composition of each cement paste was investigated using X-ray Diffraction (XRD). The aim of the leachability test was to investigate the environmental impacts of tin slag blended cement product in the range 4-8 pH by using static pH-dependent leaching test. The result show that the increase of the tin slag content decreasing the mortar compressive strength at early ages. The use of tin slag in cement provide economic benefits for all related industries.

Enhanced cooling in mono-crystalline ultra-thin silicon by embedded micro-air channels

KAUST Repository

Ghoneim, Mohamed T.; Fahad, Hossain M.; Hussain, Aftab M.; Rojas, Jhonathan Prieto; Sevilla, Galo T.; Alfaraj, Nasir; Lizardo, Ernesto B.; Hussain, Muhammad Mustafa

2015-01-01

In today’s digital world, complementary metal oxide semiconductor (CMOS) technology enabled scaling of bulk mono-crystalline silicon (100) based electronics has resulted in their higher performance but with increased dynamic and off-state power consumption. Such trade-off has caused excessive heat generation which eventually drains the charge of battery in portable devices. The traditional solution utilizing off-chip fans and heat sinks used for heat management make the whole system bulky and less mobile. Here we show, an enhanced cooling phenomenon in ultra-thin (>10 μm) mono-crystalline (100) silicon (detached from bulk substrate) by utilizing deterministic pattern of porous network of vertical “through silicon” micro-air channels that offer remarkable heat and weight management for ultra-mobile electronics, in a cost effective way with 20× reduction in substrate weight and a 12% lower maximum temperature at sustained loads. We also show the effectiveness of this event in functional MOS field effect transistors (MOSFETs) with high-κ/metal gate stacks.

Enhanced cooling in mono-crystalline ultra-thin silicon by embedded micro-air channels

KAUST Repository

Ghoneim, Mohamed T.

2015-12-11

In today’s digital world, complementary metal oxide semiconductor (CMOS) technology enabled scaling of bulk mono-crystalline silicon (100) based electronics has resulted in their higher performance but with increased dynamic and off-state power consumption. Such trade-off has caused excessive heat generation which eventually drains the charge of battery in portable devices. The traditional solution utilizing off-chip fans and heat sinks used for heat management make the whole system bulky and less mobile. Here we show, an enhanced cooling phenomenon in ultra-thin (>10 μm) mono-crystalline (100) silicon (detached from bulk substrate) by utilizing deterministic pattern of porous network of vertical “through silicon” micro-air channels that offer remarkable heat and weight management for ultra-mobile electronics, in a cost effective way with 20× reduction in substrate weight and a 12% lower maximum temperature at sustained loads. We also show the effectiveness of this event in functional MOS field effect transistors (MOSFETs) with high-κ/metal gate stacks.

Tuning the band gap in hybrid tin iodide perovskite semiconductors using structural templating.

Science.gov (United States)

Knutson, Jeremy L; Martin, James D; Mitzi, David B

2005-06-27

Structural distortions within the extensive family of organic/inorganic hybrid tin iodide perovskite semiconductors are correlated with their experimental exciton energies and calculated band gaps. The extent of the in- and out-of-plane angular distortion of the SnI4(2-) perovskite sheets is largely determined by the relative charge density and steric requirements of the organic cations. Variation of the in-plane Sn-I-Sn bond angle was demonstrated to have the greatest impact on the tuning of the band gap, and the equatorial Sn-I bond distances have a significant secondary influence. Extended Hückel tight-binding band calculations are employed to decipher the crystal orbital origins of the structural effects that fine-tune the band structure. The calculations suggest that it may be possible to tune the band gap by as much as 1 eV using the templating influence of the organic cation.

ULTRA-LIGHTWEIGHT CEMENT

International Nuclear Information System (INIS)

Fred Sabins

2001-01-01

The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Issues, Task 2: Review Russian Ultra-Lightweight Cement Literature, Task 3: Test Ultra-Lightweight Cements, and Task 8: Develop Field ULHS Cement Blending and Mixing Techniques. Results reported this quarter include: preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; summary of pertinent information from Russian ultra-lightweight cement literature review; laboratory tests comparing ULHS slurries to foamed slurries and sodium silicate slurries for two different applications; and initial laboratory studies with ULHS in preparation for a field job

NASA Goddard Space Flight Center Tin Whisker (and Other Metal Whisker) Homepage

Science.gov (United States)

Brusse, Jay; Sampson, Mike; Leidecker, Henning; Kadesch, Jong

2004-01-01

This website provides information about tin whiskers and related research. The independent research performed during the past 50+ years is so vast that it is impractical to cover all aspects of tin whiskers in this one resource. Therefore, the absence of information in this website about a particular aspect of tin whiskers should NOT be construed as evidence of absence.

Commercialization of Ultra-Hard Ceramics for Cutting Tools Final Report CRADA No. TC0279.0

Energy Technology Data Exchange (ETDEWEB)

Landingham, R. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Neumann, T. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

2017-08-15

This was a collaborative effort between Lawrence Livermore National Security, LLC as manager and operator of Lawrence Livermore National Laboratory (LLNL) and Greenleaf Corporation (Greenleaf) to develop the technology for forming unique precursor nano-powders process that can be consolidated into ceramic products for industry. LLNL researchers have developed a solgel process for forming nano-ceramic powders. The nano powders are highly tailorable, allowing the explicit design of desired properties that lead to ultra hard materials with fine grain size. The present CRADA would allow the two parties to continue the development of the sol-gel process and the consolidation process in order to develop an industrially sound process for the manufacture of these ultra-hard materials.

The Influences of Iron Ore Tailings as Fine Aggregate on the Strength of Ultra-High Performance Concrete

Directory of Open Access Journals (Sweden)

Zhigang Zhu

2015-01-01

Full Text Available The present study looks for the feasibility of preparing UHPC with iron ore tailings (IOT for short as fine aggregate. To enhance outstanding high performances, some influences on UHPC mortars were investigated such as different kinds of sands, different mix ratio of sands, and different largest particle size of fine aggregate. The results show that IOT have negligible poorer aggregate performance than silica sands but better than river sands. The strength of UHPC reaches the highest point when silica sands were instead 60% by IOT. As the largest particle size of fine aggregate is decreasing, the strength and frost resistance of UHPC were improved, but the liquidity was decreased. Micropowder of IOT affects the strength and the optimal content was 4%.

Tin in canned food: a review and understanding of occurrence and effect.

Science.gov (United States)

Blunden, Steve; Wallace, Tony

2003-12-01

Tinplate is light gauge, steel sheet or strip, coated on both sides with commercially pure tin and has been used for well over a hundred years as a robust form of food packaging. Altogether, about 25,000 million food cans are produced and filled in Europe per annum, about 20% of these having plain internal (unlacquered) tin-coated steel bodies. Worldwide, the total for food packaging is approximately 80,000 million cans. Tinplate is also extensively used for the production of beverage cans. Europe produces and fills over 15,000 million tinplate beverage cans per annum all of which are internally lacquered. The use of tinplate for food and beverage packaging, will result in some tin dissolving into the food content, particularly when plain uncoated internal surfaces are used. The Provisional Tolerable Weekly Intake for tin is 14 mg/kg body weight and recommended maximum permissible levels of tin in food are typically 250 mg/kg (200 mg/kg UK) for solid foods and 150 mg/kg for beverages. However, the question arises as to whether evidence exists that such elevated levels of tin in food in any way constitute a risk to human health. This review considers the factors affecting the dissolution of tin, the reported measurements/surveys of actual levels of tin in canned foods and the studies and reports of acute (short term) toxicity relating to the ingestion of elevated levels of tin in food products. Chronic studies are mentioned, but are not covered in detail, since the review is mainly concerned with possible effects from the ingestion of single high doses. From published data, there appears to be a small amount of evidence suggesting that consumption of food or beverages containing tin at concentrations at or below 200 ppm has caused adverse gastrointestinal effects in an unknown but possibly small proportion of those exposed. However, the evidence supporting this assertion is derived from reports of adverse effects which offer data that are limited, incomplete or of

Ultra-Stable, New Generation Q-Switched Monolithic Laser Cleaners for Fine Art Conservation

Science.gov (United States)

Brioschi, F.; Salvadeo, P.

The increasing use of laser cleaners in fine art conservation boosts the demand on improvements of the laser performances. More power and more wavelengths are required by the current applications, while laser should be more reliable, rugged and compact. The characteristics and performances of a new generation of laser cleaners are presented as a result of a dedicated research and development program.

Scalable preparation of porous micron-SnO2/C composites as high performance anode material for lithium ion battery

Science.gov (United States)

Wang, Ming-Shan; Lei, Ming; Wang, Zhi-Qiang; Zhao, Xing; Xu, Jun; Yang, Wei; Huang, Yun; Li, Xing

2016-03-01

Nano tin dioxide-carbon (SnO2/C) composites prepared by various carbon materials, such as carbon nanotubes, porous carbon, and graphene, have attracted extensive attention in wide fields. However, undesirable concerns of nanoparticles, including in higher surface area, low tap density, and self-agglomeration, greatly restricted their large-scale practical applications. In this study, novel porous micron-SnO2/C (p-SnO2/C) composites are scalable prepared by a simple hydrothermal approach using glucose as a carbon source and Pluronic F127 as a pore forming agent/soft template. The SnO2 nanoparticles were homogeneously dispersed in micron carbon spheres by assembly with F127/glucose. The continuous three-dimensional porous carbon networks have effectively provided strain relaxation for SnO2 volume expansion/shrinkage during lithium insertion/extraction. In addition, the carbon matrix could largely minimize the direct exposure of SnO2 to the electrolyte, thus ensure formation of stable solid electrolyte interface films. Moreover, the porous structure could also create efficient channels for the fast transport of lithium ions. As a consequence, the p-SnO2/C composites exhibit stable cycle performance, such as a high capacity retention of over 96% for 100 cycles at a current density of 200 mA g-1 and a long cycle life up to 800 times at a higher current density of 1000 mA g-1.

Excitation of epsilon-near-zero resonance in ultra-thin indium tin oxide shell embedded nanostructured optical fiber.

Science.gov (United States)

Minn, Khant; Anopchenko, Aleksei; Yang, Jingyi; Lee, Ho Wai Howard

2018-02-05

We report a novel optical waveguide design of a hollow step index fiber modified with a thin layer of indium tin oxide (ITO). We show an excitation of highly confined waveguide mode in the proposed fiber near the wavelength where permittivity of ITO approaches zero. Due to the high field confinement within thin ITO shell inside the fiber, the epsilon-near-zero (ENZ) mode can be characterized by a peak in modal loss of the hybrid waveguide. Our results show that such in-fiber excitation of ENZ mode is due to the coupling of the guided core mode to the thin-film ENZ mode. We also show that the phase matching wavelength, where the coupling takes place, varies depending on the refractive index of the constituents inside the central bore of the fiber. These ENZ nanostructured optical fibers have many potential applications, for example, in ENZ nonlinear and magneto-optics, as in-fiber wavelength-dependent filters, and as subwavelength fluid channel for optical and bio-photonic sensing.

Microstructure development of in situ porous TiO/Cu composites

Energy Technology Data Exchange (ETDEWEB)

Qin, Q.D., E-mail: 58124812@qq.com [Department of Materials & Metallurgy Engineering, Guizhou Institute of Technology, No.1 Caiguan Road, Guiyang 550003 (China); 2011 Special Functional Materials Collaborative Innovation Center of Guizhou Province, No.1 Caiguan Road, Guiyang 550003 (China); Huang, B.W. [Department of Materials & Metallurgy Engineering, Guizhou Institute of Technology, No.1 Caiguan Road, Guiyang 550003 (China); 2011 Special Functional Materials Collaborative Innovation Center of Guizhou Province, No.1 Caiguan Road, Guiyang 550003 (China); Li, W. [Department of Materials Engineering, Zhengzhou Technology College, No. 81 Zhengshang Road, Zhengzhou, 450051 (China); Shao, F. [2011 Special Functional Materials Collaborative Innovation Center of Guizhou Province, No.1 Caiguan Road, Guiyang 550003 (China)

2016-07-05

An in situ porous TiO/Cu composite is successfully prepared using powder metallurgy by the reaction of Ti{sub 2}CO and Cu powder. Ti{sub 2}CO powder is produced by the carbothermic reduction of titanium dioxide (TiO{sub 2}) at 1000 °C. Morphological examination of the composite shows that the porosity of composites lies in the range between 10.2% and 35.2%. As the volume fraction of TiO increases, the size of TiO becomes more fine. Scanning electron microscopy (SEM) of the fracture morphology indicates that TiO particles and the Cu matrix are connected by a Cu–Ti phase. - Highlights: • An porous TiO/Cu composite is successfully prepared by powder metallurgy technology. • The porosity of composites lies in the range between 10.2% and 35.2%. • The TiO particles and the Cu matrix are connected by a Cu-Ti phase.

In situ bioremediation: A network model of diffusion and flow in granular porous media

Energy Technology Data Exchange (ETDEWEB)

Griffiths, S.K.; Nilson, R.H.; Bradshaw, R.W.

1997-04-01

In situ bioremediation is a potentially expedient, permanent and cost- effective means of waste site decontamination. However, permeability reductions due to the transport and deposition of native fines or due to excessive microorganism populations may severely inhibit the injection of supplemental oxygen in the contamination zone. To help understand this phenomenon, we have developed a micro-mechanical network model of flow, diffusion and particle transport in granular porous materials. The model differs from most similar models in that the network is defined by particle positions in a numerically-generated particle array. The model is thus widely applicable to computing effective transport properties for both ordered and realistic random porous media. A laboratory-scale apparatus to measure permeability reductions has also been designed, built and tested.

Analysis of an Internal Combustion Engine Using Porous Foams for Thermal Energy Recovery

Directory of Open Access Journals (Sweden)

Mehdi Ali Ehyaei

2016-03-01

Full Text Available Homogeneous and complete combustion in internal combustion engines is advantageous. The use of a porous foam in the exhaust gas in an engine cylinder for heat recovery is examined here with the aim of reducing engine emissions. The internal combustion engine with a porous core regenerator is modeled using SOPHT software, which solved the differential equations for the thermal circuit in the engine. The engine thermal efficiency is observed to increase from 43% to 53% when the porous core regenerator is applied. Further, raising the compression ratio causes the peak pressure and thermal efficiency to increase, e.g., increasing the compression ratio from 13 to 15 causes the thermal efficiency and output work to increase from 53% to 55% and from 4.86 to 4.93 kJ, respectively. The regenerator can also be used as a catalytic converter for fine particles and some other emissions. The regenerator oxidizes unburned hydrocarbons. Meanwhile, heat recovered from the exhaust gases can reduce fuel consumption, further reducing pollutant emissions from the internal combustion engine.

A comparative study of TiN and TiC: Oxidation resistance and retention of xenon at high temperature and under degraded vacuum

International Nuclear Information System (INIS)

Gavarini, S.; Bes, R.; Millard-Pinard, N.; Peaucelle, C.; Perrat-Mabilon, A.; Gaillard, C.; Cardinal, S.; Garnier, V.

2011-01-01

Dense TiN and TiC samples were prepared by hot pressing using micrometric powders. Xenon species (simulating rare gas fission products) were then implanted into the ceramics. The samples were annealed for 1 h at 1500 deg. C under several degraded vacuums with P O 2 varying from 10 -6 to 2x10 -4 mbars. The oxidation resistance of the samples and their retention properties with respect to preimplanted xenon species were analyzed using scanning electron microscopy, grazing incidence x-ray diffraction, Rutherford backscattering spectrometry, and nuclear backscattering spectrometry. Results indicate that TiC is resistant to oxidation and does not release xenon for P O 2 ≤6x10 -6 mbars. When P O 2 increases, geometric oxide crystallites appear at the surface depending on the orientation and size of TiC grains. These oxide phases are Ti 2 O 3 , Ti 3 O 5 , and TiO 2 . Apparition of oxide crystallites is associated with the beginning of xenon release. TiC surface is completely covered by the oxide phases at P O 2 =2x10 -4 mbars up to a depth of 3 μm and the xenon is then completely released. For TiN samples, the results show a progressive apparition of oxide crystallites (Ti 3 O 5 mainly) at the surface when P O 2 increases. The presence of the oxide crystallites is also directly correlated with xenon release, the more oxide crystallites are growing the more xenon is released. TiN surface is completely covered by an oxide layer at P O 2 =2x10 -4 mbars up to 1 μm. A correlation between the initial fine microstructure of TiN and the properties of the growing layer is suggested.

Determination of tungsten and tin ions after preconcentration by flotation

International Nuclear Information System (INIS)

Dietze, U.; Kunze, S.

1990-01-01

A highly sensitive and selective combined method of flotation followed by spectrophotometry/d.c. polarography for the determination of tungsten and tin ions in acid and alkaline waste waters and hydrometallurgical solutions is presented here. Both kinds of ions are coprecipitated in the analyte solution with zirconium hydroxide after addition of ZrOCl 2 solution and ammonia. Afterwards, the collector precipitate is separated from the aqueous phase and preconcentrated by flotation for which sodium oleate and a frother are added. The precipitate is dissolved in a small amount of acid, with the organic reagents being destroyed by oxidation. The enrichment factor of the proposed technique is 100, with variations possible. Recovery is 94 % for tungsten and 99 % for tin. Spectrophotometry of the thiocyanate complex and d.c. polarography are applied as determination techniques for tungsten and tin, respectively. Detection limits attainable by this technique are 6 ng.ml -1 for tungsten and 5 ng.ml -1 for tin for the initial sample. (Authors)

Multiscale modeling of high contrast brinkman equations with applications to deformable porous media

KAUST Repository

Brown, Donald

2013-06-18

Simulating porous media flows has a wide range of applications. Often, these applications involve many scales and multi-physical processes. A useful tool in the analysis of such problems in that of homogenization as an averaged description is derived circumventing the need for complicated simulation of the fine scale features. In this work, we recall recent developments of homogenization techniques in the application of flows in deformable porous media. In addition, homogenization of media with high-contrast. In particular, we recall the main ideas of the homogenization of slowly varying Stokes flow and summarize the results of [4]. We also present the ideas for extending these techniques to high-contrast deformable media [3]. These ideas are connected by the modeling of multiscale fluid-structure interaction problems. © 2013 American Society of Civil Engineers.

Characterization and Gas Sensing Properties of Copper-doped Tin Oxide Thin Films Deposited by Ultrasonic Spray Pyrolysis

Directory of Open Access Journals (Sweden)

Zhaoxia ZHAI

2016-05-01

Full Text Available Tin oxide-based thin films are deposited by ultrasonic spray pyrolysis technology, in which Cu addition is introduced to enhance the gas sensing performance by H2S detection. The thin films are porous and comprise nano-sized crystallites. One of the Cu-containing thin film sensors demonstrates a fast and significant response to H2S gas. The values of power law exponent n are calculated to discuss the sensitivity of the sensors, which is significantly promoted by Cu additive. The sensitivity of Cu-doped SnO2 gas sensors is determined by two mechanisms. One is the normal gas sensing mechanism of SnO2 grains, and the other is the promoted mechanism caused by the transformation between CuO and CuS in the H2S detection. DOI: http://dx.doi.org/10.5755/j01.ms.22.2.12917

Punção Aspirativa por Agulha Fina Orientada por Ultra-Sonografia em Lesões Não-palpáveis Fine Needle Aspiration Cytology Guided by Ultrasound in Nonpalpable Lesions

Directory of Open Access Journals (Sweden)

Cláudio Kemp

2001-06-01

Full Text Available Objetivo: correlacionar os achados citológicos obtidos por punção com agulha fina dirigida pela ultra-sonografia de lesões não-palpáveis da mama, císticas ou sólidas, os aspectos ultra-sonográficos e os respectivos resultados histopatológicos das lesões que foram submetidas a cirurgia. Métodos: foram analisadas 617 lesões não-palpáveis visualizadas ao ultra-som. Realizou-se a punção aspirativa por agulha fina (PAAF orientada pela ultra-sonografia, com análise citológica do material, diferenciando-as em cistos ou nódulos sólidos. Estes tiveram seu resultado citológico confrontado com o resultado histopatológico, nos casos em que foi realizada a biópsia cirúrgica. Resultados: das 617 lesões não-palpáveis, 471 eram cistos, sendo 451 cistos simples que apresentaram citologia negativa em todos os casos e 20 casos foram considerados cistos complexos. Destes, 3 (15% tiveram resultado citológico positivo ou suspeito e em 2 casos confirmou-se malignidade. Dos 105 nódulos sólidos, 63 apresentaram citologia negativa, sendo 59 concordantes com a biópsia e houve 4 casos (0,3% de resultado falso-negativo pela citologia. Todos, porém, apresentavam discordância entre imagem e citologia. Em 14 nódulos sólidos (13%, a citologia foi suspeita e, destes, 5 foram diagnosticados como carcinoma. Em outros 14 (13%, o material foi insatisfatório e 1 era carcinoma. Em 51 casos, o tríplice diagnóstico foi concordante e optou-se por seguimento clínico. Conclusão: a análise citológica do material dos cistos mamários simples é desnecessária, porém quando são complexos, a citologia é imperativa. Nas lesões sólidas não-palpáveis, é fundamental a correlação da citologia com o aspecto ultra-sonográfico e mamográfico; caso sejam discordantes, deve-se sempre prosseguir a investigação da lesão.Purpose: to determine the relationship between fine needle aspiration cytology guided by ultrasound of nonpalpable breast lesions

STM study on surface relief, ultra-fine structure and transformation mechanism of bainite in steels

International Nuclear Information System (INIS)

Fang, H.S.; Yang, Z.G.; Wang, J.J.; Zheng, Y.K.

1995-01-01

The surface reliefs accompanying lower bainite transformation in steels have been studied by scanning tunneling microscopy (STM). With the exclusive vertical resolution of STM, we observed that the surface relief associated with bainite is a group of surface reliefs related to subplates, subunits and sub-subunits. From the bainite plate to the sub-subunit in it, the reliefs are in a tent shape, not of invariant plane strain (IPS) type. The fine structure of bainite in a steel has also been shown by STM and TEM that bainite plate is composed of subplates, subunits and sub-subunits. On the basis of the fine structure inside a bainitic ferrite plate observed under STM, sympathetic-ledgewise mechanism of bainite formation is proposed. (orig.)

Radiation levels and countermeasure research on radiological protection in tin mine in china

International Nuclear Information System (INIS)

Yang Fengfang; Yuan Yongling

2010-01-01

Objective: To study the distribution of radiation level in our nation's tin mine, therefore comes up with proposals on radiological protection and provide scientific evidence on how to protect lives and health of worker underground in tin mine. Methods: To get the radiation level of the underground workplaces in tin mine by analysis of research papers and the measuring results from on-scene investigations. Results: Majority of the absorbed dose rates of γ radiation in the air of underground workplaces in tin mine falls within the range of radiation levels of normal background. Earlier, the typical values of radon concentration and potential alpha energy concentration of radon daughters in the air of underground workplaces in tin mine are 3.12 kBq/m 3 and 5.61 μJ/m 3 respectively. Now, radon concentration and potential alpha energy concentration of radon daughters in the air of underground workplaces in majority of tin mine are lower than 1000 Bq/m 3 and 3.57 μJ/m 3 . Conclusion: For these tin mine workers with an average of annual effective dose greater than 1 mSv or these of their specific activity for natural uranium in materials are greater than 1 Bq/g need to have regulation of radiological protection. The control limits for the radon concentration and the potential alpha energy concentration of radon daughters and the absorbed dose rates of γ radiation in the air of underground workplaces in tin mine are 1000 Bq/m3, 3.57 μJ/m 3 and 1 μGy/h respectively. The administrative individual dose for workers working under the ground of tin mine is 10 mSv/a. If a worker's total annual effective dose is greater than 10 mSv, he/she should be considered as radioactive worker. (authors)

PCBs with immersion tin finish - some experiences with lead-free reflow process

Energy Technology Data Exchange (ETDEWEB)

Bukat, K.; Koziol, G.; Sitek, J.; Borecki, J.; Hackiewicz, H. [Tele and Radio Research Inst., Warsaw (Poland); Merkle, H.; Schroeder, S. [Ormecon Chemie GmbH and Co. KG, Ammersbek (Germany); Girulska, A.; Gardela, K. [Eldos Sp. z o.o., Wroclaw (Poland)

2004-07-01

Substitution of lead-free solders in electronic assemblies requires changes in the conventional SnPb finishes of PCBs. The Craft project ''PRINT'' objectives respond to this challenge. Its main goal is to develop and implement the new technology of high solderability immersion tin for printed circuit boards at small and medium enterprises. The subject of the research was organic based immersion tin coating which would fulfil demands of SMT. In the paper the results of reflow soldering process on PCBs covered by Ormecon registered immersion tin finish with using lead-free solder pastes will be described. Solderability of tin coating as well as wettability of lead-free solder paste will be presented. (orig.)

A strategy for fast screening and identification of sulfur derivatives in medicinal Pueraria species based on the fine isotopic pattern filtering method using ultra-high-resolution mass spectrometry

Energy Technology Data Exchange (ETDEWEB)

Yang, Min [National Engineering Laboratory for TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 501 Haike Road, Shanghai 201203 (China); Zhou, Zhe [ThermoFisher Scientific China Co., Ltd, No 6 Building, 27 Xinjinqiao Road, Shanghai 201206 (China); Guo, De-an, E-mail: daguo@simm.ac.cn [National Engineering Laboratory for TCM Standardization Technology, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 501 Haike Road, Shanghai 201203 (China)

2015-09-24

Sulfurous compounds are commonly present in plants, fungi, and animals. Most of them were reported to possess various bioactivities. Isotopic pattern filter (IPF) is a powerful tool for screening compounds with distinct isotope pattern. Over the past decades, the IPF was used mainly to study Cl- and Br-containing compounds. To our knowledge, the algorithm was scarcely used to screen S-containing compounds, especially when combined with chromatography analyses, because the {sup 34}S isotopic ion is drastically affected by {sup 13}C{sub 2} and {sup 18}O. Thus, we present a new method for a fine isotopic pattern filter (FIPF) based on the separated M + 2 ions ({sup 12}C{sub x}{sup 1}H{sub y}{sup 16}O{sub z}{sup 32}S{sup 13}C{sub 2}{sup 18}O, {sup 12}C{sub x+2}{sup 1}H{sub y}{sup 16}O{sub z+1}{sup 34}S, tentatively named M + 2OC and M + 2S) with an ultra-high-resolution mass (100,000 FWHM @ 400 m/z) to screen sulfur derivatives in traditional Chinese medicines (TCM).This finer algorithm operates through convenient filters, including an accurate mass shift of M + 2OC and M + 2S from M and their relative intensity compared to M. The method was validated at various mass resolutions, mass accuracies, and screening thresholds of flexible elemental compositions. Using the established FIPF method, twelve S-derivatives were found in the popular medicinal used Pueraria species, and 9 of them were tentatively identified by high-resolution multiple stage mass spectrometry (HRMS{sup n}). The compounds were used to evaluate the sulfurous compounds' situation in commercially purchased Pueraria products. The strategy presented here provides a promising application of the IPF method in a new field. - Highlights: • We provide a new strategy for specifically screening of sulfurous compounds. • The fine isotopic pattern filter (FIPF) bases on separation of {sup 13}C{sub 2}+{sup 18}O and {sup 34}S. • Ultra high resolution mass (100,000 FWHM @ 400 m/z) is essential

Electrochemical migration of tin in electronics and microstructure of the dendrites

Energy Technology Data Exchange (ETDEWEB)

Minzari, Daniel, E-mail: dmin@mek.dtu.d [Section for Materials and Surface Technology, Department for Mechanical Engineering, Technical University of Denmark (Denmark); Grumsen, Flemming Bjerg; Jellesen, Morten S.; Moller, Per; Ambat, Rajan [Section for Materials and Surface Technology, Department for Mechanical Engineering, Technical University of Denmark (Denmark)

2011-05-15

Graphical abstract: The electrochemical migration of tin in electronics forms dendritic structures, consisting of a metallic tin core, which is surrounded by oxide layers having various thickness. Display Omitted Research highlights: Electrochemical migration occurs if two conductors are connected by condensed moisture. Metallic ions are dissolved and grow in a dendritic structure that short circuit the electrodes. The dendrite consists of a metallic tin core with oxide layers of various thickness surrounding. Detailed microstructure of dendrites is investigated using electron microscopy. The dendrite microstructure is heterogeneous along the growth direction. - Abstract: The macro-, micro-, and nano-scale morphology and structure of tin dendrites, formed by electrochemical migration on a surface mount ceramic chip resistor having electrodes consisting of tin with small amounts of Pb ({approx}2 wt.%) was investigated by scanning electron microscopy and transmission electron microscopy including Energy dispersive X-ray spectroscopy and electron diffraction. The tin dendrites were formed under 5 or 12 V potential bias in 10 ppm by weight NaCl electrolyte as a micro-droplet on the resistor during electrochemical migration experiments. The dendrites formed were found to have heterogeneous microstructure along the growth direction, which is attributed to unstable growth conditions inside the micro-volume of electrolyte. Selected area electron diffraction showed that the dendrites are metallic tin having sections of single crystal orientation and lead containing intermetallic particles embedded in the structure. At certain areas, the dendrite structure was found to be surrounded by an oxide crust, which is believed to be due to unstable growth conditions during the dendrite formation. The oxide layer was found to be of nanocrystalline structure, which is expected to be formed by the dehydration of the hydrated oxide originally formed in solution ex-situ in ambient air.

Study on the removal of iron impurities in methanesulfonic acid tin plating bath

Science.gov (United States)

Hou-li, LIU; Jian-Jun, CHEN; Hong-Liang, PAN

2018-03-01

This thesis investigated the the influence of sodium sulfite as reducing agent on the recovery rate of tin ion. The approach is that HZ016 type cation exchange resin was used to adsorb Sn2+ and Fe2+ in electroplated tin solution first. After adsorption, the resin was removed by sulfuric acid, which was added with NaOH to adjust pH value to form precipitation and separate tin. X-ray diffraction (XRD) and energy spectrum (EDS) method were used to analyze the composition of the precipitates adjusted by pH. The results show that when the mass ratio of resin to bath is 1:2, the adsorption efficiency of resin reaches 98.3% and 97.1% respectively, and the elution efficiency of tin and iron reaches 95.1% and 94% respectively when the mass ratio of resin to eluent sulfuric acid is 1:4. Sodium sulfite was added to increase the efficiency of tin recovery by 8.1%. EDS and XRD atlas showed that after pH regulation, the main composition of the filtration precipitation was the hydroxides of tin.

Electrical Properties of Electrospun Sb-Doped Tin Oxide Nanofibers

International Nuclear Information System (INIS)

Leon-Brito, Neliza; Melendez, Anamaris; Ramos, Idalia; Pinto, Nicholas J; Santiago-Aviles, Jorge J

2007-01-01

Transparent and conducting tin oxide fibers are of considerable interest for solar energy conversion, sensors and in various electrode applications. Appropriate doping can further enhance the conductivity of the fibers without loosing optical transparency. Undoped and antimony-doped tin oxide fibers have been synthesized by our group in previous work using electrospinning and metallorganic decomposition techniques. The undoped tin oxide fibers were obtained using a mixture of pure tin oxide sol made from tin (IV) chloride : water : propanol : isopropanol at a molar ratio of 1:9:9:6, and a viscous solution made from poly(ethylene oxide) (PEO) and chloroform at a ratio of 200 mg PEO/10 mL chloroform. In this work, antimony doped fibers were obtained by adding a dopant solution of antimony trichloride and isopropanol at a ratio of 2.2812 g antimony trichloride/10 ml isopropanol to the original tin oxide precursor solution. The Sb concentration in the precursor solution is 1.5%. After deposition, the fibers were sintered 600deg. C in air for two hours. The electrical conductivity of single fibers measured at room temperature increases by up to three orders of magnitude when compared to undoped fibers prepared using the same method. The resistivity change as a function of the annealing temperature can be attributed to the thermally activated formation of a nearly stoichoimetric solid. The resistivity of the fibers changes monotonically with temperature from 714Ω-cm at 2 K to 0.1Ω-cm at 300 K. In the temperature range from 2 to 8 K the fibers have a positive magnetoresistance (MR) with the highest value of 155 % at 2 K and ±9 T. At temperatures of 10 and 12 K the sign of MR changes to negative values for low magnetic fields and positive for high magnetic fields. For higher temperatures (15 K and above) the MR becomes negative and its magnitude decreases with temperature

Combined TiN- and TaN temperature compensated thin film resistors

International Nuclear Information System (INIS)

Malmros, Anna; Andersson, Kristoffer; Rorsman, Niklas

2012-01-01

The opposite signs of the temperature coefficient of resistance (TCR) of two thin film materials, titanium nitride (TiN) and tantalum nitride (TaN), were used to form temperature compensated thin film resistors (TFRs). The principle of designing temperature compensated TFRs by connecting TFRs of each compound in series or in parallel was demonstrated. TiN, TaN, and combined TiN and TaN TFRs for monolithic microwave integrated circuits (MMICs) were fabricated by reactive sputtering. DC characterization was performed over the temperature range of 30–200 °C. The TiN TFRs exhibited an increase in resistivity with temperature with TCRs of 540 and 750 ppm/°C. The TaN TFR on the other hand exhibited a negative TCR of − 470 ppm/°C. The shunted TFRs were fabricated by serial deposition of TiN and TaN to form a bilayer component. The TCRs of the series- and shunt configurations were experimentally reduced to − 60 and 100 ppm/°C, respectively. The concept of temperature compensation was used to build a Wheatstone bridge with an application in on-chip temperature sensing.

Synthesis, Spectral Characterization and Antioxidant Activity of Tin(II-Morin Complex

Directory of Open Access Journals (Sweden)

Shahabuddin Memon

2012-12-01

Full Text Available The study focuses on the interaction between morin and Tin(II and the resulting complex was characterized through various analytical techniques by comparing it with morin. The complexation was confirmed at first by UV-Vis study, which shows that addition of Tin(II to morin may produce bathochromic shifts indicative of complex formation. IR spectral studies indicated that carbonyl has involved in coordination with Tin(II. Moreover, 1H-NMR studies validated that in conjunction with carbonyl, 3-OH of morin is more appropriate to be involved in complexation by replacement of its proton. Scavenging activities of morin and its Tin(II complex on DPPH• radical showed the inhibitory rates of 65% and 49%, respectively. In addition, the reducing capacity of morin was outstanding at 0.5 and 2.0 mg/ml concentrations relative to Tin(II complex. Overall, the study potentially shows the strong impact in order to design the anticancer drugs jointly from its cytotoxic potential and antioxidant activities, thereby selectively targeting the cancerous cells in result increasing their therapeutic index as well as extra advantages over other anticancer drugs.

Fracture Mechanisms of Zirconium Diboride Ultra-High Temperature Ceramics under Pulse Loading

Science.gov (United States)

Skripnyak, Vladimir V.; Bragov, Anatolii M.; Skripnyak, Vladimir A.; Lomunov, Andrei K.; Skripnyak, Evgeniya G.; Vaganova, Irina K.

2015-06-01

Mechanisms of failure in ultra-high temperature ceramics (UHTC) based on zirconium diboride under pulse loading were studied experimentally by the method of SHPB and theoretically using the multiscale simulation method. The obtained experimental and numerical data are evidence of the quasi-brittle fracture character of nanostructured zirconium diboride ceramics under compression and tension at high strain rates and the room temperatures. Damage of nanostructured porous zirconium diboride -based UHTC can be formed under stress pulse amplitude below the Hugoniot elastic limit. Fracture of nanostructured ultra-high temperature ceramics under pulse and shock-wave loadings is provided by fast processes of intercrystalline brittle fracture and relatively slow processes of quasi-brittle failure via growth and coalescence of microcracks. A decrease of the shear strength can be caused by nano-voids clusters in vicinity of triple junctions between ceramic matrix grains and ultrafine-grained ceramics. This research was supported by grants from ``The Tomsk State University Academic D.I. Mendeleev Fund Program'' and also N. I. Lobachevski State University of Nizhny Novgorod (Grant of post graduate mobility).

Do ultra-orphan medicinal products warrant ultra-high prices? A review

Directory of Open Access Journals (Sweden)

Picavet E

2013-06-01

Full Text Available Eline Picavet,1 David Cassiman,2 Steven Simoens1 1Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium; 2Department of Hepatology, University Hospital Leuven, Leuven, Belgium Abstract: Ultra-orphan medicinal products (ultra-OMPs are intended for the treatment, prevention, or diagnosis of ultra-rare diseases, ie, life-threatening or chronically debilitating diseases that affect less than one per 50,000 individuals. Recently, high prices for ultra-OMPs have given rise to debate on the sustainability and justification of these prices. The aim of this article is to review the international scientific literature on the pricing of ultra-OMPs and to provide an overview of the current knowledge on the drivers of ultra-OMP pricing. The pricing process of ultra-OMPs is a complex and nontransparent issue. Evidence in the literature seems to indicate that ultra-OMPs are priced according to rarity and what the manufacturer believes the market will bear. Additionally, there appears to be a trend between the price of an ultra-OMP and the number of available alternatives. Patients, third-party payers, and pharmaceutical companies could benefit from more transparent pricing strategies. With a view to containing health care costs, it is likely that cost-sharing strategies, such as performance-based risk sharing arrangements, will become increasingly more important. However, it is vital that any measures for price control are consistent with the intended goals of the incentives to promote the development of new OMPs. Ideally, a balance must be struck between attaining affordable prices for ultra-OMPs and securing a realistic return on investment for the pharmaceutical industry. Keywords: ultra-orphan medicinal product, ultra-rare disease, pricing

Colorimetric visualization of tin corrosion: A method for early stage corrosion detection on printed circuit boards

DEFF Research Database (Denmark)

Verdingovas, Vadimas; Jellesen, Morten Stendahl; Ambat, Rajan

2017-01-01

A majority of printed circuit board surfaces are covered with tin, therefore tin corrosion under humid conditions and movement of tin ions under the influence of an electric field plays an important role in the corrosion failure development. Tracking tin corrosion products spread on the printed c...

Porous organic cages

Science.gov (United States)

Tozawa, Tomokazu; Jones, James T. A.; Swamy, Shashikala I.; Jiang, Shan; Adams, Dave J.; Shakespeare, Stephen; Clowes, Rob; Bradshaw, Darren; Hasell, Tom; Chong, Samantha Y.; Tang, Chiu; Thompson, Stephen; Parker, Julia; Trewin, Abbie; Bacsa, John; Slawin, Alexandra M. Z.; Steiner, Alexander; Cooper, Andrew I.

2009-12-01

Porous materials are important in a wide range of applications including molecular separations and catalysis. We demonstrate that covalently bonded organic cages can assemble into crystalline microporous materials. The porosity is prefabricated and intrinsic to the molecular cage structure, as opposed to being formed by non-covalent self-assembly of non-porous sub-units. The three-dimensional connectivity between the cage windows is controlled by varying the chemical functionality such that either non-porous or permanently porous assemblies can be produced. Surface areas and gas uptakes for the latter exceed comparable molecular solids. One of the cages can be converted by recrystallization to produce either porous or non-porous polymorphs with apparent Brunauer-Emmett-Teller surface areas of 550 and 23m2g-1, respectively. These results suggest design principles for responsive porous organic solids and for the modular construction of extended materials from prefabricated molecular pores.

The tin mining and heavy mineral processing industry in the Kinta Valley, Perak, Malaysia

International Nuclear Information System (INIS)

Lee Swee Ching

1994-01-01

Overview of the tin mining and heavy mineral processing in the Kinta Valley, Perak, Malaysia was presented. Amang, a mixture composed of tin ore, sand, ilmenite, monazite, zircon, xenotime, struvite, etc , as a product from tin mining activities was discussed too in this paper

Ultra-low reflection porous silicon nanowires for solar cell applications

KAUST Repository

Najar, Adel

2012-01-01

High density vertically aligned Porous Silicon NanoWires (PSiNWs) were fabricated on silicon substrate using metal assisted chemical etching process. A linear dependency of nanowire length to the etching time was obtained and the change in the growth rate of PSiNWs by increasing etching durations was shown. A typical 2D bright-field TEM image used for volume reconstruction of the sample shows the pores size varying from 10 to 50 nm. Furthermore, reflectivity measurements show that the 35% reflectivity of the starting silicon wafer drops to 0.1% recorded for more than 10 μm long PSiNWs. Models based on cone shape of nanowires located in a circular and rectangular bases were used to calculate the reflectance employing the Transfert Matrix Formalism (TMF) of the PSiNWs layer. Using TMF, the Bruggeman model was used to calculate the refractive index of PSiNWs layer. The calculated reflectance using circular cone shape fits better the measured reflectance for PSiNWs. The remarkable decrease in optical reflectivity indicates that PSiNWs is a good antireflective layer and have a great potential to be utilized in radial or coaxial p-n heterojunction solar cells that could provide orthogonal photon absorption and enhanced carrier collection. ©2012 Optical Society of America.

77 FR 34938 - Certain Tin Mill Products From Japan: Continuation of Antidumping Duty Order

Science.gov (United States)

2012-06-12

... DEPARTMENT OF COMMERCE International Trade Administration [A-588-854] Certain Tin Mill Products... duty order on certain tin mill products from Japan would likely lead to continuation or recurrence of...: Background On August 28, 2000, the Department published the antidumping duty order on certain tin mill...

Interesterification of rapeseed oil catalyzed by tin octoate

International Nuclear Information System (INIS)

Galia, Alessandro; Centineo, Alessio; Saracco, Guido; Schiavo, Benedetto; Scialdone, Onofrio

2014-01-01

The interesterification of rapeseed oil was performed for the first time by using tin octoate as Lewis acid homogeneous catalysts and methyl or ethyl acetate as acyl acceptors in a batch reactor, within the temperature range 393–483 K. The yields in fatty acid ethyl esters (FAEE) and triacetin (TA) after 20 h of reaction time increased from 8% and 2%–to 61% and 22%, respectively, when the reaction temperature increased from 423 to 483 K. An optimum value of 40 for the acyl acceptor to oil molar ratio was found to be necessary to match good fatty acid alkyl ester yields with high enough reaction rate. The rate of generation of esters was significantly higher when methyl acetate was used as acyl acceptor instead of its ethyl homologue. The collected results suggest that tin octoate can be used as effective catalyst for the interesterification of rapeseed oil with methyl or ethyl acetate being highly soluble in the reaction system, less expensive than enzymes and allowing the operator to work under milder conditions than supercritical interesterification processes. - Highlights: • We study the interesterification of rapeseed oil catalyzed by tin(II) octoate. • Tin(II) octoate is an effective homogeneous catalyst at 483 K. • The acyl acceptor to oil molar ratio must be optimized. • Higher rate of reaction is obtained with methyl acetate as acyl acceptor

Highly conducting and transparent sprayed indium tin oxide

Energy Technology Data Exchange (ETDEWEB)

Rami, M.; Benamar, E.; Messaoudi, C.; Sayah, D.; Ennaoui, A. (Faculte des Sciences, Rabat (Morocco). Lab. de Physique des Materiaux)

1998-03-01

Indium tin oxide (ITO) has a wide range of applications in solar cells (e.g. by controlling the resistivity, we can use low conductivity ITO as buffer layer and highly conducting ITO as front contact in thin films CuInS[sub 2] and CuInSe[sub 2] based solar cells) due to its wide band gap (sufficient to be transparent) in both visible and near infrared range, and high carrier concentrations with metallic conduction. A variety of deposition techniques such as reactive electron beam evaporation, DC magnetron sputtering, evaporation, reactive thermal deposition, and spray pyrolysis have been used for the preparation of undoped and tin doped indium oxide. This latter process which makes possible the preparation of large area coatings has attracted considerable attention due to its simplicity and large scale with low cost fabrication. It has been used here to deposit highly transparent and conducting films of tin doped indium oxide onto glass substrates. The electrical, optical and structural properties have been investigated as a function of various deposition parameters namely dopant concentrations, temperature and nature of substrates. X-ray diffraction patterns have shown that deposited films are polycrystalline without second phases and have preferred orientation [400]. INdium tin oxide layers with small resistivity value around 7.10[sup -5] [omega].cm and transmission coefficient in the visible and near IR range of about 85-90% have been easily obtained. (authors) 13 refs.

XPS investigations of tribolayers formed on TiN and (Ti,Re)N coatings

Energy Technology Data Exchange (ETDEWEB)

Oktay, Serkan; Kahraman, Zafer; Urgen, Mustafa; Kazmanli, Kursat, E-mail: kursat@itu.edu.tr

2015-02-15

Graphical abstract: - Highlights: • The (Ti,Re)N coating (8 ± 1.9 at.% Re) consisted of TiN and ReNx (x > 1.33) phases. • TiO{sub 2} provided low friction coefficient to TiN coating at 150 °C. • Re addition to TiN drastically dropped the friction coefficients to 0.17–0.22. • Re{sub 2}O{sub 7} provided very low friction coefficient to (Ti,Re)N coating. • Re addition to TiN improved the wear behavior. - Abstract: TiN and (Ti,Re)N coatings were deposited on high-speed-steel substrates by a hybrid coating system composed of cathodic arc PVD and magnetron sputtering techniques. In order to keep rhenium content low (8 ± 1.9 at.%) in the coating, magnetron sputtering technique was utilized to evaporate rhenium. The (Ti,Re)N coating consisted of TiN and ReN{sub x} (x > 1.33) phases. The hardness of TiN and (Ti,Re)N were 31 GPa and 29 GPa ( ± 2 GPa), respectively. Tribological behaviors of the samples were tested against Al{sub 2}O{sub 3} balls at 21 °C (RT) and 150 °C (HT) by reciprocating wear technique. The tribolayers were analyzed by XPS technique. Friction coefficients of TiN were 0.56, 0.35 for 21 °C and 150 °C tests, respectively. Rhenium addition to TiN drastically dropped the friction coefficients to 0.22 and 0.17 for RT and HT samples. Rhenium addition also improved the wear resistance of the coating at both test temperatures. For TiN, main oxide component of the tribolayers was Ti{sub 2}O{sub 3} for RT tests and TiO{sub 2} for HT tests. The oxide layer formed on (Ti,Re)N were the mixture of TiO{sub 2}, Ti−O−N, ReO{sub 2} and Re{sub 2}O{sub 7} for both test temperatures. Re{sub 2}O{sub 7} provided very low friction coefficient to (Ti,Re)N. The findings are consistent with the crystal chemistry approach.

Porous SnO2-CuO nanotubes for highly reversible lithium storage

Science.gov (United States)

Cheong, Jun Young; Kim, Chanhoon; Jung, Ji-Won; Yoon, Ki Ro; Kim, Il-Doo

2018-01-01

Facile synthesis of rationally designed structures is critical to realize a high performance electrode for lithium-ion batteries (LIBs). Among different candidates, tin(IV) oxide (SnO2) is one of the most actively researched electrode materials due to its high theoretical capacity (1493 mAh g-1), abundance, inexpensive costs, and environmental friendliness. However, severe capacity decay from the volume expansion and low conductivity of SnO2 have hampered its use as a feasible electrode for LIBs. Rationally designed SnO2-based nanostructures with conductive materials can be an ideal solution to resolve such limitations. In this work, we have successfully fabricated porous SnO2-CuO composite nanotubes (SnO2-CuO p-NTs) by electrospinning and subsequent calcination step. The porous nanotubular structure is expected to mitigate the volume expansion of SnO2, while the as-formed Cu from CuO upon lithiation allows faster electron transport by improving the low conductivity of SnO2. With a synergistic effect of both Sn and Cu-based oxides, SnO2-CuO p-NTs deliver stable cycling performance (91.3% of capacity retention, ∼538 mAh g-1) even after 350 cycles at a current density of 500 mA g-1, along with enhanced rate capabilities compared with SnO2.

Positioning performance of a maglev fine positioning system

Energy Technology Data Exchange (ETDEWEB)

Wronosky, J.B.; Smith, T.G.; Jordan, J.D.; Darnold, J.R.

1996-12-01

A wafer positioning system was recently developed by Sandia National Laboratories for an Extreme Ultraviolet Lithography (EUVL) research tool. The system, which utilizes a magnetically levitated fine stage to provide ultra-precise positioning in all six degrees of freedom, incorporates technological improvements resulting from four years of prototype development experience. System enhancements, implemented on a second generation design for an ARPA National Center for Advanced Information Component Manufacturing (NCAICM) project, introduced active structural control for the levitated structure of the system. Magnetic levitation (maglev) is emerging as an important technology for wafer positioning systems in advanced lithography applications. The advantages of maglev stem from the absence of physical contact. The resulting lack of friction enables accurate, fast positioning. Maglev systems are mechanically simple, accomplishing full six degree-of-freedom suspension and control with a minimum of moving parts. Power-efficient designs, which reduce the possibility of thermal distortion of the platen, are achievable. Manufacturing throughput will be improved in future systems with the addition of active structural control of the positioning stages. This paper describes the design, implementation, and functional capability of the maglev fine positioning system. Specifics regarding performance design goals and test results are presented.

Upscaling of Large-Scale Transport in Spatially Heterogeneous Porous Media Using Wavelet Transformation

Science.gov (United States)

Moslehi, M.; de Barros, F.; Ebrahimi, F.; Sahimi, M.

2015-12-01

Modeling flow and solute transport in large-scale heterogeneous porous media involves substantial computational burdens. A common approach to alleviate this complexity is to utilize upscaling methods. These processes generate upscaled models with less complexity while attempting to preserve the hydrogeological properties comparable to the original fine-scale model. We use Wavelet Transformations (WT) of the spatial distribution of aquifer's property to upscale the hydrogeological models and consequently transport processes. In particular, we apply the technique to a porous formation with broadly distributed and correlated transmissivity to verify the performance of the WT. First, transmissivity fields are coarsened using WT in such a way that the high transmissivity zones, in which more important information is embedded, mostly remain the same, while the low transmissivity zones are averaged out since they contain less information about the hydrogeological formation. Next, flow and non-reactive transport are simulated in both fine-scale and upscaled models to predict both the concentration breakthrough curves at a control location and the large-scale spreading of the plume around its centroid. The results reveal that the WT of the fields generates non-uniform grids with an average of 2.1% of the number of grid blocks in the original fine-scale models, which eventually leads to a significant reduction in the computational costs. We show that the upscaled model obtained through the WT reconstructs the concentration breakthrough curves and the spreading of the plume at different times accurately. Furthermore, the impacts of the Hurst coefficient, size of the flow domain and the orders of magnitude difference in transmissivity values on the results have been investigated. It is observed that as the heterogeneity and the size of the domain increase, better agreement between the results of fine-scale and upscaled models can be achieved. Having this framework at hand aids

Reversible storage of lithium in a rambutan-like tin-carbon electrode.

Science.gov (United States)

Deng, Da; Lee, Jim Yang

2009-01-01

Fruity electrodes: A simple bottom-up self-assembly method was used to fabricate rambutan-like tin-carbon (Sn@C) nanoarchitecture (see scheme, green Sn) to improve the reversible storage of lithium in tin. The mechanism of the growth of the pear-like hairs is explored.

Studies in group IV organometallic chemistry XXX. Synthesis of compounds containing tin---titanium and tin---zirconium bonds

NARCIS (Netherlands)

Creemers, H.M.J.C.; Verbeek, F.; Noltes, J.G.

1968-01-01

Starting from the tetrakis(diethylamino) derivatives of titanium and zirconium and pheyltin hydrides six intermetalic compounds contianing up to nine tin and titanium(or zirconium) atoms have been obtained by hydrostannolysis type reactions.

Effect of pulsed voltage on electrochemical migration of tin in electronics

DEFF Research Database (Denmark)

Verdingovas, Vadimas; Jellesen, Morten Stendahl; Ambat, Rajan

2015-01-01

formation and increases the charge transferred between the electrodes over time. With increase of duty cycle, increases the anodic dissolution of tin, which was visualized using a tin ion indicator applied on the components prior to applying the voltage. The anodic dissolution of tin significantly...... respectively at 10 and 5 V, while the duty cycle and the pulse width were varied in the range of ms. The results showed that varying of pulse width at fixed duty cycle has a minor effect under investigated conditions, whereas increasing duty cycle significantly reduces the time to short due to dendrite...

Hydrothermal synthesis of tungsten doped tin dioxide nanocrystals

Science.gov (United States)

Zhou, Cailong; Li, Yufeng; Chen, Yiwen; Lin, Jing

2018-01-01

Tungsten doped tin dioxide (WTO) nanocrystals were synthesized through a one-step hydrothermal method. The structure, composition and morphology of WTO nanocrystals were characterized by x-ray diffraction, x-ray photoelectron spectroscopy, energy dispersive x-ray spectroscopy, UV-vis diffuse reflectance spectra, zeta potential analysis and high-resolution transmission electron microscopy. Results show that the as-prepared WTO nanocrystals were rutile-type structure with the size near 13 nm. Compared with the undoped tin dioxide nanocrystals, the WTO nanocrystals possessed better dispersity in ethanol phase and formed transparent sol.

Thermal interaction for molten tin dropped into water

Energy Technology Data Exchange (ETDEWEB)

Arakeri, V.H.; Catton, I.; Kastenberg, W.E.; Plesset, M.S.

1978-03-01

Multiflash photography with extremely short duration exposure times per flash was used to observe the interaction of molten tin dropped into a water bath. Detailed photographic evidence is presented which demonstrates that transition, or nucleate boiling, is a possible triggering mechanism for vapor explosions. It was also found that the thermal constraints required to produce vapor explosions could be relaxed by introducing a stable thermal stratification within the coolant. In the present work, the threshold value of the initial tin temperature required for vapor explosion was reduced from about 500 to 343/sup 0/C.

Investigation of Surface Phenomena in Shocked Tin in Converging Geometry

Energy Technology Data Exchange (ETDEWEB)

Rousculp, Christopher L. [Los Alamos National Laboratory; Oro, David Michael [Los Alamos National Laboratory; Griego, Jeffrey Randall [Los Alamos National Laboratory; Turchi, Peter John [Los Alamos National Laboratory; Reinovsky, Robert Emil [Los Alamos National Laboratory; Bradley, Joseph Thomas [Los Alamos National Laboratory; Cheng, Baolian [Los Alamos National Laboratory; Freeman, Matthew Stouten [Los Alamos National Laboratory; Patten, Austin Randall [Los Alamos National Laboratory

2016-03-21

There is great interest in the behavior of the free surface of tin under shock loading. While it is known that meso-scale surface imperfections can seed the Richtmyer- Meshkov Instability (RMI) for a surface that is melted on release, much less is known about a tin surface that is solid, but plastically deforming. Here material properties such as shear and yield strength come into play especially in converging geometry. Previous experiments have been driven by direct contact HE. Usually a thin, flat target coupon is fielded with various single-mode, sinusoidal, machined, profiles on the free surface. The free surface is adjacent to either vacuum or an inert receiver gas. Most of these previous driver/target configurations have been nominal planer geometry. With modern HE it has been straightforward to shock tin into melt on release. However it has been challenging to achieve a low enough pressure for solid state on release. Here we propose to extend the existing base of knowledge to include the behavior of the free surface of tin in cylindrical converging geometry. By shock loading a cylindrical tin shell with a magnetically driven cylindrical liner impactor, the free surface evolution can be diagnosed with proton radiography. With the PHELIX capacitor bank, the drive can easily be varied to span the pressure range to achieve solid, mixed, and liquid states on release. A conceptual cylindrical liner and target is shown in Figure 1.

Recovery Of Valuable Metals In Tin-Based Anodic Slimes By Carbothermic Reaction

OpenAIRE

Han Chulwoong; Kim Young-Min; Son Seong Ho; Choi Hanshin; Kim Tae Bum; Kim Yong Hwan

2015-01-01

This study investigated the recovery of anodic slimes by carbothermic reaction in the temperature range of 973~1,273K and amount of carbon as a function of time. Tin anodic slime samples were collected from the bottom of the electrolytic cells during the electro-refining of tin. The anodic slimes are consisted of high concentrated tin, silver, copper and lead oxides. The kinetics of reduction were determined by means of the weight-loss measurement technique. In order to understand in detail o...

Investigation of micro burner performance during porous media combustion for surface and submerged flames

Science.gov (United States)

Janvekar, Ayub Ahmed; Abdullah, M. Z.; Ahmad, Z. A.; Abas, Aizat; Hussien, Ahmed A.; Kataraki, Pramod S.; Mohamed, Mazlan; Husin, Azmi; Fadzli, Khairil

2018-05-01

Porous media combustion is considered to be one of the popular choice due to its tremendous advantages. Such type of combustion liberates not only super stable flame but also maintains emissions parameters below thresholds level. Present study incorporates reaction and preheat layer with discrete and foam type of materials respectively. Burner was made to run in ultra-lean mode. Optimum equivalence ratio was found out to be 0.7 for surface flame, while 0.6 during submerged flame condition. Maximum thermal efficiency was noted to be 81%. Finally, emissions parameters where recorded continuously to measure NOx and CO, which were under global limits.

[Synthesis and characteristics of porous hydroxyapatite bioceramics].

Science.gov (United States)

Niu, Jinlong; Zhang, Zhenxi; Jiang, Dazong

2002-06-01

The macroporous structure of human bone allows the ingrowth of the soft tissues and organic cells into the bone matrix, profits the development and metabolism of bone tissue, and adapts the bone to the change of load. There is great requirement for artificial biomimic porous bioactive ceramics with the similar structure of bone tissue that can be used clinically for repairing lost bone. Fine hydroxyapatite (HAp) powder produced by wet chemical reaction was mixed with hydrogen peroxide (H2O2), polyvinyl alcohol, methyl cellulose or other pores-making materials to form green cake. After drying at low temperature (below 100 degrees C) and decarbonizing at about 300 degrees C-400 degrees C, the spongy ceramic block was sintered at high temperature, thus, macroporous HAp bioceramic with interconnected pores and reasonable porosity and pore-diameter was manufactured. This kind of porous HAp bioceramics were intrinsically osteoinductive to a certain degree, but its outstanding property was that they can absorb human bone morphogenetic proteins and other bone growth factors to form composites, so that the macroporous HAp bioactive ceramic has appropriate feasibility for clinical application. From the point of biomedical application, the recent developments in synthesis and characteristics investigation of macroporous HAp are reviewed in this paper.

Emission characteristics of dispenser cathodes with a fine-grained tungsten top layer

Science.gov (United States)

Kimura, S.; Higuchi, T.; Ouchi, Y.; Uda, E.; Nakamura, O.; Sudo, T.; Koyama, K.

1997-02-01

In order to improve the emission stability of the Ir-coated dispenser cathode under ion bombardment, a fine-grained tungsten top layer was applied on the substrate porous tungsten plug before Ir coating. The emission characteristics were studied after being assembled in a CRT gun. Cathode current was measured under pulse operation in a range of 0.1-9% duty. Remarkable anti-ion bombardment characteristics were observed over the range of 1-6% duty. The improved cathode showed 1.5 times higher emission current than that of a conventional Ir-coated dispenser cathode at 4% duty. AES analysis showed that the recovering rates of surface Ba and O atoms after ion bombardment were 2.5 times higher. From these results it is confirmed that the Ir coated cathode with a fine-grained tungsten top layer is provided with a good tolerance against the ion bombardment.

NMR as a tool for kinetic studies: application to the assessment of organo tin reactivity

Energy Technology Data Exchange (ETDEWEB)

Fouquet, E.; Roulet, T. [Bordeaux-1 Univ., 33 - Talence (France); Pianet, I. [Bordeaux-1 Univ., 33 -Talence (France) CNRS, Centre d`Etudes Structurales et d`Analyse des Molecules Organiques; Willem, R. [Brussels University (VUB), Brussels (Belgium)

1998-02-01

There is a growing interest for the research of an answer to the environmental problems related to the industrial use of tetra organo tins. An interesting alternative would be to develop the chemistry of mono organo tins because of their lower toxicity and of the easy removal of ``inorganic`` tin side products. In this work, halogen exchange rates are measured for various mono organo tins with NMR techniques (EXSY spectra and 1 D {sup 119} Sn NMR), and an exchange mechanism is proposed. A correlation between kinetic data and the reactivity of the mono organo tins is then exemplified with radical allylic transfer and palladium catalyzed coupling reactions. (authors) 14 refs.

Determination of total tin in silicate rocks by graphite furnace atomic absorption spectrometry

Science.gov (United States)

Elsheimer, H.N.; Fries, T.L.

1990-01-01

A method is described for the determination of total tin in silicate rocks utilizing a graphite furnace atomic absorption spectrometer with a stabilized-temperature platform furnace and Zeeman-effect background correction. The sample is decomposed by lithium metaborate fusion (3 + 1) in graphite crucibles with the melt being dissolved in 7.5% hydrochloric acid. Tin extractions (4 + 1 or 8 + 1) are executed on portions of the acid solutions using a 4% solution of tricotylphosphine oxide in methyl isobutyl ketone (MIBK). Ascorbic acid is added as a reducing agent prior to extraction. A solution of diammonium hydrogenphosphate and magnesium nitrate is used as a matrix modifier in the graphite furnace determination. The limit of detection is > 10 pg, equivalent to > 1 ??g l-1 of tin in the MIBK solution or 0.2-0.3 ??g g-61 in the rock. The concentration range is linear between 2.5 and 500 ??g l-1 tin in solution. The precision, measured as relative standard deviation, is < 20% at the 2.5 ??g l-1 level and < 7% at the 10-30 ??g l-1 level of tin. Excellent agreement with recommended literature values was found when the method was applied to the international silicate rock standards BCR-1, PCC-1, GSP-1, AGV-1, STM-1, JGb-1 and Mica-Fe. Application was made to the determination of tin in geological core samples with total tin concentrations of the order of 1 ??g g-1 or less.

Occupational irritant contact folliculitis associated with triphenyl tin fluoride (TPTF) exposure

DEFF Research Database (Denmark)

Andersen, Klaus Ejner; Petri, M

1982-01-01

Triphenyl tin fluoride (TPTF) is a bioactive organo-tin compound used in concentrations 2-12% as anti-foulants in boat paints. The chemical is moderately toxic to the skin. An occupational irritant contact folliculitis from TPTF in a marine paint plant worker is described. Contact allergy...

EXAFS study on dynamic structural property of porous morph-genetic SiC

International Nuclear Information System (INIS)

Ding, J.; Sun, B.H.; Fan, T.X.; Zhang, D.; Kamada, M.; Ogawa, H.; Guo, Q.X.

2005-01-01

Novel porous morph-genetic silicon carbide has been fabricated through sintering treatment, after infiltrating the methyl organic silicone resin to the bio-template. Its dynamic transition of structure during sintering process is investigated by extended X-ray absorption fine structure (EXAFS) for the first time. By analyzing Si K-edge EXAFS, it is found that the coordination number of the nearest C shell remains almost unchanged while that of the nearest Si shell dramatically changes when the structure is transformed from amorphous into crystalline state

Numerical Simulation of Wave Propagation and Phase Transition of Tin under Shock-Wave Loading

International Nuclear Information System (INIS)

Hai-Feng, Song; Hai-Feng, Liu; Guang-Cai, Zhang; Yan-Hong, Zhao

2009-01-01

We undertake a numerical simulation of shock experiments on tin reported in the literature, by using a multiphase equation of state (MEOS) and a multiphase Steinberg Guinan (MSG) constitutive model for tin in the β, γ and liquid phases. In the MSG model, the Bauschinger effect is considered to better describe the unloading behavior. The phase diagram and Hugoniot of tin are calculated by MEOS, and they agree well with the experimental data. Combined with the MEOS and MSG models, hydrodynamic computer simulations are successful in reproducing the measured velocity profile of the shock wave experiment. Moreover, by analyzing the mass fraction contour as well as stress and temperature profiles of each phase for tin, we further discuss the complex behavior of tin under shock-wave loading. (condensed matter: structure, mechanical and thermal properties)

Effects on stress rupture life and tensile strength of tin additions to Inconel 718

Science.gov (United States)

Dreshfield, R. L.; Johnson, W.

1982-01-01

Because Inconel 718 represents a major use of columbium and a large potential source of columbium for aerospace alloys could be that of columbium derived from tin slags, the effects of tin additions to Inconel 718 at levels which might be typical of or exceed those anticipated if tin slag derived columbium were used as a melting stock were investigated. Tin was added to 15 pound Inconel 718 heats at levels varying from none added to approximately 10,000 ppm (1 wt%). Limited 1200 F stress rupture testing was performed at stresses from 68,000 to 115,000 psi and a few tensile tests were performed at room temperature, 800 and 1200 F. Additions of tin in excess of 800 ppm were detrimental to ductility and stress rupture life.

Enhanced cooling in mono-crystalline ultra-thin silicon by embedded micro-air channels

Directory of Open Access Journals (Sweden)

Mohamed T. Ghoneim

2015-12-01

Full Text Available In today’s digital world, complementary metal oxide semiconductor (CMOS technology enabled scaling of bulk mono-crystalline silicon (100 based electronics has resulted in their higher performance but with increased dynamic and off-state power consumption. Such trade-off has caused excessive heat generation which eventually drains the charge of battery in portable devices. The traditional solution utilizing off-chip fans and heat sinks used for heat management make the whole system bulky and less mobile. Here we show, an enhanced cooling phenomenon in ultra-thin (>10 μm mono-crystalline (100 silicon (detached from bulk substrate by utilizing deterministic pattern of porous network of vertical “through silicon” micro-air channels that offer remarkable heat and weight management for ultra-mobile electronics, in a cost effective way with 20× reduction in substrate weight and a 12% lower maximum temperature at sustained loads. We also show the effectiveness of this event in functional MOS field effect transistors (MOSFETs with high-κ/metal gate stacks.

Formation of Ti-N graded bioceramic layer by DC hollow-cathode plasma nitriding

Institute of Scientific and Technical Information of China (English)

ZHENG Chuan-lin

2004-01-01

Ti-N graded ceramic layer was formed on titanium by using DC hollow-cathode plasma nitriding technique. The structure of Ti-N layer was analyzed using X-ray diffractometry(XRD) with Cu Kα radiation, and the microhardness( HV0.1) was measured from the surface to inner along the cross section of Ti-N layer. The results indicate that the Ti-N graded layer is composed of ε-Ti2 N, δ-TiN and α-Ti(N) phases. Mechanism discussion shows that hollow-cathode discharge can intensify gas ionization, increase current density and enhance the nitriding potential, which directly increases the thickness of the diffusion coatings compared with traditional nitriding methods.

Silica Gel Coated Spherical Micro resonator for Ultra-High Sensitivity Detection of Ammonia Gas Concentration in Air.

Science.gov (United States)

Mallik, Arun Kumar; Farrell, Gerald; Liu, Dejun; Kavungal, Vishnu; Wu, Qiang; Semenova, Yuliya

2018-01-26

A silica gel coated microsphere resonator is proposed and experimentally demonstrated for measurements of ammonia (NH 3 ) concentration in air with ultra-high sensitivity. The optical properties of the porous silica gel layer change when it is exposed to low (parts per million (ppm)) and even ultra-low (parts per billion (ppb)) concentrations of ammonia vapor, leading to a spectral shift of the WGM resonances in the transmission spectrum of the fiber taper. The experimentally demonstrated sensitivity of the proposed sensor to ammonia is estimated as 34.46 pm/ppm in the low ammonia concentrations range from 4 ppm to 30 ppm using an optical spectrum analyser (OSA), and as 800 pm/ppm in the ultra-low range of ammonia concentrations from 2.5 ppb to 12 ppb using the frequency detuning method, resulting in the lowest detection limit (by two orders of magnitude) reported to date equal to 0.16 ppb of ammonia in air. In addition, the sensor exhibits excellent selectivity to ammonia and very fast response and recovery times measured at 1.5 and 3.6 seconds, respectively. Other attractive features of the proposed sensor are its compact nature, simplicity of fabrication.

High-performance lithium storage of Co3O4 achieved by constructing porous nanotube structure

International Nuclear Information System (INIS)

Cui, Zhentao; Wang, Shuguang; Zhang, Yihe; Cao, Minhua

2015-01-01

Graphical abstract: The porous Co 3 O 4 nanotubes (P-Co 3 O 4 -NTs) are prepared by coaxial electrospinning method followed by a fine annealing treatment. The resultant P-Co 3 O 4 -NTs exhibit excellent lithium storage performance in terms of specific capacity, rate capability, and cycling stability when used as an anode material for rechargeable lithium ion batteries (LIBs). - Abstract: Co 3 O 4 has been investigated intensively for its high specific capacity which makes it a promising candidate anode for high-performance lithium ion batteries (LIBs). However, rational design of Co 3 O 4 electrode that is beneficial for its electrochemical performance is still a great challenge. Herein, we designed and fabricated porous Co 3 O 4 nanotubes (P-Co 3 O 4 -NTs) by coaxial electrospinning method followed by a fine annealing treatment, which display one dimensional tubular structure with porous wall and hollow interior. The uniqueness of this strategy is that the morphologies of the P-Co 3 O 4 -NTs could be tuned by adjusting the mass ratio of reactants. The resultant P-Co 3 O 4 -NTs exhibit excellent lithium storage performance in terms of specific capacity, rate capability, and cycling stability, when used as an anode material for rechargeable LIBs. This unique structure endows a high reversible specific capacity of 1826.2 mA g −1 at a current density of 0.3 A g −1 after 100 cycles. Even at high current densities of 2 and 5 A g −1 , the P-Co 3 O 4 -NTs electrode still could deliver remarkable discharge capacities of 1506.2 and 1145.1 mAh g −1 , respectively. The excellent electrochemical performance can be attributed to the unique tubular and porous structure of P-Co 3 O 4 -NTs, which not only can accommodate the large volume change but also can provide an excellent ion diffusion and electronic conduction pathway. Therefore, the P-Co 3 O 4 -NTs have the potential for use as a high performance anode material in LIBs.

Metalorganic atomic layer deposition of TiN thin films using TDMAT and NH3

International Nuclear Information System (INIS)

Kim, Hyo Kyeom; Kim, Ju Youn; Park, Jin Yong; Kim, Yang Do; Kim, Young Do; Jeon, Hyeong Tag; Kim, Won Mok

2002-01-01

TiN films were deposited by using the metalorganic atomic layer deposition (MOALD) method using tetrakis-dimethyl-amino-titanium (TDMAT) as the titanium precursor and ammonia (NH 3 ) as the reactant gas. Two saturated TiN film growth regions were observed in the temperature ranges from 175 and 190 .deg. C and from 200 and 210 .deg. C. TiN films deposited by the MOALD technique showed relatively lower carbon content than films deposited by metalorganic chemical vapor deposition (MOCVD) method. TiN films deposited at around 200 .deg. C under standard conditions showed the resistivity values as low as 500 μΩ-cm, which is about one order lower than the values for TiN films deposited by MOCVD using TDMAT or TDMAT with NH 3 . Also, the carbon incorporation and the resistivity were further decreased with increasing Ar purge time and flow rate. TiN films deposited at temperature below 300 .deg. C showed amorphous characteristics. TiN film deposited on contact holes, about 0.4-μm wide and 0.8-μm deep, by using the MOALD method showed excellent conformal deposition with almost 100% step coverage. This study demonstrates that the processing parameters need to be carefully controlled to optimize the film properties that the processing parameters need to be carefully controlled to optimize the film properties when using the ALD technique and that TiN films deposited by using the MOALD method exhibited excellent film properties compared to those of films deposited by using other CVD methods

Stability of tinned food from pigs radiated with various doses of ionizing rays

International Nuclear Information System (INIS)

Kossakowska, A.; Kossakowski, S.; Widenska, T.; Wojton, B.

1978-01-01

The examinations were carried out on 347 tinned food made of meat from pigs exposed to radiation of 300 and 600 R. The animals were irradiated with 60 Co. The pigs irradiated with 300 R were slaughtered after 7 and 14 days, and these with 600 R after 7 and 12 days; the control animals were killed after 14 days. Post-slaughter visual and microbiological examinations were performed by seeding the samples of the blood, muscles, lymphnodes and internal organs for the presence of Salmonella sp. Meat was pickled and heated up to 67-68 0 C (in the center of tinned food). The lowest stability showed the tinned food made of pigs irradiated with 600 R and killed after 12 days. Chemical examinations of the tinned food stored at 6 0 C revealed the prevalence of oxydative processes in fat over hydrolitic ones. The difference in acid number between tinned food under test and controls appeared after 6 months. Peroxides occurred in the control after 6 months and in these under examination after 3 months, and the level was 4.00-5.80 apart from the tins made of meat of pigs irradiated with 300 R and slaughtered after 7 days. (author)

Understanding the gas sensing properties of polypyrrole coated tin oxide nanofiber mats

Science.gov (United States)

Bagchi, Sudeshna; Ghanshyam, C.

2017-03-01

Tin oxide-polypyrrole composites have been widely studied for their enhanced sensing performance towards ammonia vapours, but further investigations are required for an understanding of the interaction mechanisms with different target analytes. In this work, polypyrrole coated tin oxide fibers have been synthesized using a two-step approach of electrospinning and vapour phase polymerization for the sensing of ammonia, ethanol, methanol, 2-propanol and acetone vapours. The resistance variation in the presence of these vapours of different nature and concentration is investigated for the determination of sensor response. A decrease in resistance occurred on interaction of tin oxide-polypyrrole with ammonia, as opposed to previous reported works. Partial reduction of polypyrrole due to interfacial interaction with tin oxide has been proposed to explain this behavior. High sensitivity of 7.45 is achieved for 1 ppm ammonia concentration. Furthermore, the sensor exhibited high sensitivity and a faster response towards ethanol vapours although methanol has the highest electron donating capability. The catalytic mechanism has been discussed to explain this interesting behavior. The results reveal that interaction between tin oxide and polypyrrole is crucial to control the predominant sensing mechanism.

Heavy metal content of tinned soup as a function of storage time

Energy Technology Data Exchange (ETDEWEB)

Stelte, W.

1983-01-01

Samples were taken from soups prior to their preservation in tins. None of the samples showed an increased content of the investigated heavy metals lead and mercury exceeding the amounts normally found in food. Thus it may be considered as certain that the heavy metal content of soups is not adversely affected by technical processes during their preparation. Increase in heavy metal content by metallic residues from tin manufacture is slight and mainly due to tin, whose content is on average increased in the soup by 0.4 mg/kg. For lead the influence is smaller and for mercury it is not significantly demonstrable. The metallic residues from tin manufacture are an irrelevant quantity in terms of nutrition physiology. Within the investigated 4-year storage-period the lead content shows a tendency to increase towards saturation. Cadmium remains essentially constant, the content of mercury has a downward tendency and reaches zero after 2 to 4 years. Consumers' exposure is in a range known for the consumption of other foodstuffs as well. The use of varnished tins to package industrial soups involves no exposure of consumers to heavy metals justifying any apprehension even after prolonged storage.

Broad spectral response photodetector based on individual tin-doped CdS nanowire

Directory of Open Access Journals (Sweden)

Weichang Zhou

2014-12-01

Full Text Available High purity and tin-doped 1D CdS micro/nano-structures were synthesized by a convenient thermal evaporation method. SEM, EDS, XRD and TEM were used to examine the morphology, composition, phase structure and crystallinity of as-prepared samples. Raman spectrum was used to confirm tin doped into CdS effectively. The effect of impurity on the photoresponse properties of photodetectors made from these as-prepared pure and tin-doped CdS micro/nano-structures under excitation of light with different wavelength was investigated. Various photoconductive parameters such as responsivity, external quantum efficiency, response time and stability were analyzed to evaluate the advantage of doped nanowires and the feasibility for photodetector application. Comparison with pure CdS nanobelt, the tin-doped CdS nanowires response to broader spectral range while keep the excellect photoconductive parameters. Both trapped state induced by tin impurity and optical whispering gallery mode microcavity effect in the doped CdS nanowires contribute to the broader spectral response. The micro-photoluminescence was used to confirm the whispering gallery mode effect and deep trapped state in the doped CdS nanowires.

Film condensation on a porous vertical surface in a porous media

International Nuclear Information System (INIS)

Ebinuma, C.D.; Liu, C.Y.; Ismail, K.A.R.

1983-01-01

The problem of dry saturated steam film condensation by natural convection on a porous surface in a porous medium is presented. Through the classical Darcy law for flow in porous medium and the approximations considered in the Boundary layer theory, it is shown that the analytical solution exists only when the normal velocity to the porous wall is inversly proportional to the square root of the distance along the plate. (E.G.) [pt

Demonstration of high-performance p-type tin oxide thin-film transistors using argon-plasma surface treatments

Science.gov (United States)

Bae, Sang-Dae; Kwon, Soo-Hun; Jeong, Hwan-Seok; Kwon, Hyuck-In

2017-07-01

In this work, we investigated the effects of low-temperature argon (Ar)-plasma surface treatments on the physical and chemical structures of p-type tin oxide thin-films and the electrical performance of p-type tin oxide thin-film transistors (TFTs). From the x-ray photoelectron spectroscopy measurement, we found that SnO was the dominant phase in the deposited tin oxide thin-film, and the Ar-plasma treatment partially transformed the tin oxide phase from SnO to SnO2 by oxidation. The resistivity of the tin oxide thin-film increased with the plasma-treatment time because of the reduced hole concentration. In addition, the root-mean-square roughness of the tin oxide thin-film decreased as the plasma-treatment time increased. The p-type oxide TFT with an Ar-plasma-treated tin oxide thin-film exhibited excellent electrical performance with a high current on-off ratio (5.2 × 106) and a low off-current (1.2 × 10-12 A), which demonstrates that the low-temperature Ar-plasma treatment is a simple and effective method for improving the electrical performance of p-type tin oxide TFTs.

77 FR 32998 - Tin- and Chromium-Coated Steel Sheet From Japan

Science.gov (United States)

2012-06-04

...-Coated Steel Sheet From Japan Determination On the basis of the record \\1\\ developed in the subject five... order on tin- and chromium-coated steel sheet from Japan would be likely to lead to continuation or... USITC Publication 4325 (May 2012), entitled Tin- and Chromium-Coated Steel Sheet from Japan...

Porous Nb-Ti based alloy produced from plasma spheroidized powder

Science.gov (United States)

Li, Qijun; Zhang, Lin; Wei, Dongbin; Ren, Shubin; Qu, Xuanhui

Spherical Nb-Ti based alloy powder was prepared by the combination of plasma spheroidization and mechanical alloying. Phase constituents, microstructure and surface state of the powder, and pore characteristics of the resulting porous alloy were investigated. The results show that the undissolved W and V in the mechanically alloyed powder is fully alloyed after spheroidization, and single β phase is achieved. Particle size of the spheroidized powder is in the range of 20-110 μm. With the decrease of particle size, a transformation from typical dendrite solidification structure to fine cell microstructure occurs. The surface of the spheroidized powder is coated by a layer of oxides consisting mainly of TiO2 and Nb2O5. Probabilities of sinter-neck formation and particle coalescence increases with increasing sintering temperature. Porous skeleton with relatively homogeneous pore distribution and open pore channel is formed after vacuum sintering at 1700 °C, and the porosity is 32%. The sintering kinetic analysis indicates that grain boundary diffusion is the primary mass transport mechanism during sintering process.

Tailored Porous Materials

Energy Technology Data Exchange (ETDEWEB)

BARTON,THOMAS J.; BULL,LUCY M.; KLEMPERER,WALTER G.; LOY,DOUGLAS A.; MCENANEY,BRIAN; MISONO,MAKOTO; MONSON,PETER A.; PEZ,GUIDO; SCHERER,GEORGE W.; VARTULI,JAMES C.; YAGHI,OMAR M.

1999-11-09

Tailoring of porous materials involves not only chemical synthetic techniques for tailoring microscopic properties such as pore size, pore shape, pore connectivity, and pore surface reactivity, but also materials processing techniques for tailoring the meso- and the macroscopic properties of bulk materials in the form of fibers, thin films and monoliths. These issues are addressed in the context of five specific classes of porous materials: oxide molecular sieves, porous coordination solids, porous carbons, sol-gel derived oxides, and porous heteropolyanion salts. Reviews of these specific areas are preceded by a presentation of background material and review of current theoretical approaches to adsorption phenomena. A concluding section outlines current research needs and opportunities.

Tin-Silver Alloys for Flip-Chip Bonding Studied with a Rotating Cylinder Electrode

DEFF Research Database (Denmark)

Tang, Peter Torben; Pedersen, E.H.; Bech-Nielsen, G.

1999-01-01

Electrodeposition of solder for flip-chip bonding is studied in the form of a pyrophosphate/iodide tin-silver alloy bath. The objective is to obtain a uniform alloy composition, with 3.8 At.% silver, over a larger area. This specific alloy will provide an eutectic solder melting at 221°C (or 10°C...... photoresist, have shown a stable and promising alternative to pure tin and tin-lead alloys for flip-chip bonding applications....

Synthesis of antimony-doped tin oxide (ATO) nanoparticles by the nitrate-citrate combustion method

International Nuclear Information System (INIS)

Zhang Jianrong; Gao Lian

2004-01-01

Antimony-doped tin oxide (ATO) nanoparticles having rutile structure have been synthesized by the combustion method using citric acid (CA) as fuel and nitrate as an oxidant, the metal sources were granulated tin and Sb 2 O 3 . The influence of citric acid (fuel) to metal ratio on the average crystallite size, specific surface area and morphology of the nanoparticles has been investigated. X-ray diffraction showed the tin ions were reduced to elemental tin during combustion reaction. The average ATO crystallite size increased with the increase of citric acid (fuel). Powder morphology and the comparison of crystallite size and grain size shows that the degree of agglomeration of the powder decreased with an increase of the ratio. The highest specific surface area was 37.5 m 2 /g when the citric acid to tin ratio was about 6

Graded/Gradient Porous Biomaterials

Directory of Open Access Journals (Sweden)

Xigeng Miao

2009-12-01

Full Text Available Biomaterials include bioceramics, biometals, biopolymers and biocomposites and they play important roles in the replacement and regeneration of human tissues. However, dense bioceramics and dense biometals pose the problem of stress shielding due to their high Young’s moduli compared to those of bones. On the other hand, porous biomaterials exhibit the potential of bone ingrowth, which will depend on porous parameters such as pore size, pore interconnectivity, and porosity. Unfortunately, a highly porous biomaterial results in poor mechanical properties. To optimise the mechanical and the biological properties, porous biomaterials with graded/gradient porosity, pores size, and/or composition have been developed. Graded/gradient porous biomaterials have many advantages over graded/gradient dense biomaterials and uniform or homogenous porous biomaterials. The internal pore surfaces of graded/gradient porous biomaterials can be modified with organic, inorganic, or biological coatings and the internal pores themselves can also be filled with biocompatible and biodegradable materials or living cells. However, graded/gradient porous biomaterials are generally more difficult to fabricate than uniform or homogenous porous biomaterials. With the development of cost-effective processing techniques, graded/gradient porous biomaterials can find wide applications in bone defect filling, implant fixation, bone replacement, drug delivery, and tissue engineering.

Thermal interaction for molten tin dropped into water

International Nuclear Information System (INIS)

Arakeri, V.H.; Catton, I.; Kastenberg, W.E.; Plesset, M.S.

1978-01-01

Multiflash photography with extremely short duration exposure times per flash has been used to observe the interaction of molten tin dropped into a water bath. Detailed photographic evidence is presented which demonstrates that transition, or nucleate boiling, is a possible triggering mechanism for vapour explosions. It was also found that the thermal constraints required to produce vapour explosions could be relaxed by introducing a stable thermal stratification within the coolant. In the present work, the threshold value of the initial tin temperature required for vapour explosion was reduced from about 500 to 343 0 C. (author)

A Novel Non-Planar Transverse Stretching Process for Micro-Porous PTFE Membranes and Resulting Characteristics

KAUST Repository

Chang, Y.-H.

2018-02-26

Polytetrafluoroethylene (PTFE) micro-porous membranes were prepared from PTFE fine powder through extruding, rolling, and uniaxial longitudinally stretching. In contrast to conventional planar transverse stretching, a novel 3D mold design of non-planar transverse stretching process was employed in this study to produce micro-porous structure. The morphology, membrane thickness, mean pore size, and porosity of the PTFE membrane were investigated. The results show that the non-planar transverse stretched membranes exhibit more uniform average pore diameter with thinner membrane thickness. Morphological changes induced by planar and non-planar transverse stretching for pore characteristics were investigated. The stretching conditions, stretching temperature and rate, affect the stretched membrane. Increasing temperature facilitated the uniformity of pore size and uniformity of membrane thickness. Moreover, increase in stretching rate resulted in finer pore size and thinner membrane.

Ultrafast excited state deactivation of doped porous anodic alumina membranes

International Nuclear Information System (INIS)

Makhal, Abhinandan; Sarkar, Soumik; Pal, Samir Kumar; Yan, Hongdan; Wulferding, Dirk; Cetin, Fatih; Lemmens, Peter

2012-01-01

Free-standing, bi-directionally permeable and ultra-thin anodic aluminum oxide (AAO) membranes establish attractive templates (host) for the synthesis of nano-dots and rods of various materials (guest). This is due to their chemical and structural integrity and high periodicity on length scales of 5–150 nm which are often used to host photoactive nano-materials for various device applications including dye-sensitized solar cells. In the present study, AAO membranes are synthesized by using electrochemical methods and a detailed structural characterization using FEG-SEM, XRD and TGA confirms the porosity and purity of the material. Defect-mediated photoluminescence quenching of the porous AAO membrane in the presence of an electron accepting guest organic molecule (benzoquinone) is studied by means of steady-state and picosecond/femtosecond-resolved luminescence measurements. Using time-resolved luminescence transients, we have also revealed light harvesting of complexes of porous alumina impregnated with inorganic quantum dots (Maple Red) or gold nanowires. Both the Förster resonance energy transfer and the nano-surface energy transfer techniques are employed to examine the observed quenching behavior as a function of the characteristic donor–acceptor distances. The experimental results will find their relevance in light harvesting devices based on AAOs combined with other materials involving a decisive energy/charge transfer dynamics. (paper)

Ultrafast excited state deactivation of doped porous anodic alumina membranes

Science.gov (United States)

Makhal, Abhinandan; Sarkar, Soumik; Pal, Samir Kumar; Yan, Hongdan; Wulferding, Dirk; Cetin, Fatih; Lemmens, Peter

2012-08-01

Free-standing, bi-directionally permeable and ultra-thin anodic aluminum oxide (AAO) membranes establish attractive templates (host) for the synthesis of nano-dots and rods of various materials (guest). This is due to their chemical and structural integrity and high periodicity on length scales of 5-150 nm which are often used to host photoactive nano-materials for various device applications including dye-sensitized solar cells. In the present study, AAO membranes are synthesized by using electrochemical methods and a detailed structural characterization using FEG-SEM, XRD and TGA confirms the porosity and purity of the material. Defect-mediated photoluminescence quenching of the porous AAO membrane in the presence of an electron accepting guest organic molecule (benzoquinone) is studied by means of steady-state and picosecond/femtosecond-resolved luminescence measurements. Using time-resolved luminescence transients, we have also revealed light harvesting of complexes of porous alumina impregnated with inorganic quantum dots (Maple Red) or gold nanowires. Both the Förster resonance energy transfer and the nano-surface energy transfer techniques are employed to examine the observed quenching behavior as a function of the characteristic donor-acceptor distances. The experimental results will find their relevance in light harvesting devices based on AAOs combined with other materials involving a decisive energy/charge transfer dynamics.

Ultrafast excited state deactivation of doped porous anodic alumina membranes

Energy Technology Data Exchange (ETDEWEB)

Makhal, Abhinandan; Sarkar, Soumik; Pal, Samir Kumar [Department of Chemical, Biological and Macromolecular Sciences, S N Bose National Centre for Basic Sciences, Block JD, Sector III, Salt Lake, Kolkata 700 098 (India); Yan, Hongdan; Wulferding, Dirk; Cetin, Fatih; Lemmens, Peter [Institute for Condensed Matter Physics, TU Braunschweig, Mendelssohnstrasse 3, 38106 Braunschweig (Germany)

2012-08-03

Free-standing, bi-directionally permeable and ultra-thin anodic aluminum oxide (AAO) membranes establish attractive templates (host) for the synthesis of nano-dots and rods of various materials (guest). This is due to their chemical and structural integrity and high periodicity on length scales of 5-150 nm which are often used to host photoactive nano-materials for various device applications including dye-sensitized solar cells. In the present study, AAO membranes are synthesized by using electrochemical methods and a detailed structural characterization using FEG-SEM, XRD and TGA confirms the porosity and purity of the material. Defect-mediated photoluminescence quenching of the porous AAO membrane in the presence of an electron accepting guest organic molecule (benzoquinone) is studied by means of steady-state and picosecond/femtosecond-resolved luminescence measurements. Using time-resolved luminescence transients, we have also revealed light harvesting of complexes of porous alumina impregnated with inorganic quantum dots (Maple Red) or gold nanowires. Both the Foerster resonance energy transfer and the nano-surface energy transfer techniques are employed to examine the observed quenching behavior as a function of the characteristic donor-acceptor distances. The experimental results will find their relevance in light harvesting devices based on AAOs combined with other materials involving a decisive energy/charge transfer dynamics. (paper)

77 FR 5767 - Certain Tin Mill Products From Japan: Rescission of Antidumping Duty Administrative Review

Science.gov (United States)

2012-02-06

... DEPARTMENT OF COMMERCE International Trade Administration [A-588-854] Certain Tin Mill Products... duty order covering certain tin mill products from Japan. The period of review is August 1, 2010... parties to request an administrative review of the antidumping duty order on certain tin mill products...

76 FR 14902 - Certain Tin Mill Products From Japan: Rescission of Antidumping Duty Administrative Review

Science.gov (United States)

2011-03-18

... DEPARTMENT OF COMMERCE International Trade Administration [A-588-854] Certain Tin Mill Products... duty order covering certain tin mill products from Japan. The period of review is August 1, 2009... parties to request an administrative review of the antidumping duty order on certain tin mill products...

Corrosion Behavior of Carbon Steel in Concrete Material Composed of Tin Slag Waste in Aqueous Chloride Solution

Science.gov (United States)

Rustandi, Andi; Cahyadi, Agung; Taruli Siallagan, Sonia; Wafa' Nawawi, Fuad; Pratesa, Yudha

2018-01-01

Tin slag is a byproduct of tin ore smelting process which is rarely utilized. The main purpose of this work is to investigate the use of tin slag for concrete cement material application compared to the industrial Ordinary Portland Cement (OPC). Tin slag composition was characterized by XRD and XRF analysis. The characterization results showed the similar chemical composition of tin slag and OPC. It also revealed the semi crystalline structure of tin slag sample. Several electrochemical tests were performed to evaluate corrosion behavior of tin slag, OPC and various mixed composition of both materials and the addition of CaO. The corrosion behavior of OPC and tin slag were evaluated by using Cyclic Polarization, Electrochemical Impedance Spectroscopy (EIS) and Electrochemical Frequency Modulation (EFM) methods. Aqueous sodium chloride (NaCl) solution with 3.5% w.t concentration which similar to seawater was used as the electrolyte in this work. The steel specimen used as the reinforce bar (rebar) material of the concrete was carbon steel AISI 1045. The rebar was embedded in the concrete cement which composed of OPC and the various composition of tin slag including slag without addition of CaO and slag mixed with addition of 50 % CaO. The electrochemical tests results revealed that tin slag affected its corrosion behavior which becoming more active and increasing the corrosion rate as well as decreasing the electrochemical impedance.

Discovery of the calcium, indium, tin, and platinum isotopes

International Nuclear Information System (INIS)

Amos, S.; Gross, J.L.; Thoennessen, M.

2011-01-01

Currently, twenty-four calcium, thirty-eight indium, thirty-eight tin, and thirty-nine platinum isotopes have been observed and the discovery of these isotopes is discussed here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented. - Highlights: Documentation of the discovery of all calcium, indium, tin and platinum isotopes. → Summary of author, journal, year, place and country of discovery for each isotope. → Brief description of discovery history of each isotope.

Wear of tin coating and Al-Si alloy substrate against carburized steel under mixed lubrication

Science.gov (United States)

Wang, Q.; Cheng, H. S.; Fine, M. E.

1994-04-01

Tin coatings on Al-Si alloys are widely used in the automotive industries. The soft tin coating and the harder substrate alloy form a tribological system with the advantages of low friction and reasonably high load-bearing capacity. Wear tests of tin coated Al-Si Z332 alloy in conformal contact against carburized 1016 steel have been carried out under mixed lubrications with SAE 10W30 oil to study the wear mechanisms. Two major wear mechanisms, uniform wear of the tin coating due to micro-plowing and spall pitting related to the substrate are found to contribute to the bearing material loss when the fluid lubrication film is relatively thick (Lambda about 1.6). Under conditions of thinner films (Lambda approximately = 0.8), some local coating debonding occurs. The pitting and local coating debounding are closely related to fracture in the substrate. The bonding between silicon and tin seems to be weaker than between aluminum and tin. During wear, oxidation occurs.

Gas-exfoliated porous monolayer boron nitride for enhanced aerobic oxidative desulfurization performance

Science.gov (United States)

Wu, Yingcheng; Wu, Peiwen; Chao, Yanhong; He, Jing; Li, Hongping; Lu, Linjie; Jiang, Wei; Zhang, Beibei; Li, Huaming; Zhu, Wenshuai

2018-01-01

Hexagonal boron nitride has been regarded to be an efficient catalyst in aerobic oxidation fields, but limited by the less-exposed active sites. In this contribution, we proposed a simple green liquid nitrogen gas exfoliation strategy for preparation of porous monolayer nanosheets (BN-1). Owing to the reduced layer numbers, decreased lateral sizes and artificially-constructed pores, increased exposure of active sites was expected, further contributed to an enhanced aerobic oxidative desulfurization (ODS) performance up to ˜98% of sulfur removal, achieving ultra-deep desulfurization. This work not only introduced an excellent catalyst for aerobic ODS, but also provided a strategy for construction of some other highly-efficient monolayer two-dimensional materials for enhanced catalytic performance.

Nickel-Tin Electrode Materials for Nonaqueous Li-Ion Cells

Science.gov (United States)

Ehrlich, Grant M.; Durand, Christopher

2005-01-01

Experimental materials made from mixtures of nickel and tin powders have shown promise for use as the negative electrodes of rechargeable lithium-ion electrochemical power cells. During charging (or discharging) of a lithium-ion cell, lithium ions are absorbed into (or desorbed from, respectively) the negative electrode, typically through an intercalation or alloying process. The negative electrodes (for this purpose, designated as anodes) in state-of-the-art Li-ion cells are made of graphite, in which intercalation occurs. Alternatively, the anodes can be made from metals, in which alloying can occur. For reasons having to do with the electrochemical potential of intercalated lithium, metallic anode materials (especially materials containing tin) are regarded as safer than graphite ones; in addition, such metallic anode materials have been investigated in the hope of obtaining reversible charge/discharge capacities greater than those of graphite anodes. However, until now, each of the tin-containing metallic anode formulations tested has been found to be inadequate in some respect.

Electroluminescence of organic light-emitting diodes with an ultra-thin layer of dopant

Energy Technology Data Exchange (ETDEWEB)

Li Weizhi [State Key Lab of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054 (China); Yu Junsheng [State Key Lab of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054 (China)], E-mail: jsyu@uestc.edu.cn; Wang, Tao [State Key Lab of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054 (China); Jiang, Yadong [State Key Lab of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054 (China)], E-mail: jiangyd@uestc.edu.cn; Wei, Bangxiong [State Key Lab of Electronic Thin Films and Integrated Devices, School of Optoelectronic Information, University of Electronic Science and Technology of China (UESTC), Chengdu 610054 (China)

2008-03-15

Conventional fluorescent dyes, i.e., 4-(dicyanomethylene)-2-t-butyl-6(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB), 5,12-dihydro-5,12-dimethylquino [2,3-b]acridine-7,14-dione (DMQA) and 5,6,11,12-tetraphenylnaphthacene (Rubrene), were used to investigate the performance of organic light-emitting diodes (OLEDs) based on indium tin oxide (ITO)/N,N'-bis-(1-naphthyl)-N,N'-diphenyl-1,1'-biphenyl-4,4'-diamine (NPB)/tris-(8-hydroxyquinolate)-aluminum (Alq{sub 3})/MgAg. The dyes were either inserted into devices as an ultra-thin film at the NPB/Alq{sub 3} interface by sequential evaporation, or doped into the Alq{sub 3} emission layer by co-evaporation with the doping ratio about 2%. Electroluminescence (EL) spectra of devices indicated that concentration quenching effect (CQE) of the dye-dopant was slightly bigger in the former than in the latter, while the degrees of CQE for three dopants are in the order of DMQA > DCJTB > Rubrene suggested by the difference in EL spectra and performances of devices. In addition, EL process of device with an ultra-thin layer of dopant is dominated by direct carrier trapping (DCT) process due to almost no holes recombine with electrons in Alq{sub 3}-host layer.

Flexible suspended gate organic thin-film transistors for ultra-sensitive pressure detection

Science.gov (United States)

Zang, Yaping; Zhang, Fengjiao; Huang, Dazhen; Gao, Xike; di, Chong-An; Zhu, Daoben

2015-03-01

The utilization of organic devices as pressure-sensing elements in artificial intelligence and healthcare applications represents a fascinating opportunity for the next-generation electronic products. To satisfy the critical requirements of these promising applications, the low-cost construction of large-area ultra-sensitive organic pressure devices with outstanding flexibility is highly desired. Here we present flexible suspended gate organic thin-film transistors (SGOTFTs) as a model platform that enables ultra-sensitive pressure detection. More importantly, the unique device geometry of SGOTFTs allows the fine-tuning of their sensitivity by the suspended gate. An unprecedented sensitivity of 192 kPa-1, a low limit-of-detection pressure of <0.5 Pa and a short response time of 10 ms were successfully realized, allowing the real-time detection of acoustic waves. These excellent sensing properties of SGOTFTs, together with their advantages of facile large-area fabrication and versatility in detecting various pressure signals, make SGOTFTs a powerful strategy for spatial pressure mapping in practical applications.

Sun Ultra 5

CERN Multimedia

1998-01-01

The Sun Ultra 5 is a 64-bit personal computer based on the UltraSPARC microprocessor line at a low price. The Ultra 5 has been declined in several variants: thus, some models have a processor with less cache memory to further decrease the price of the computer.

Photocatalytic activity of tin-doped TiO{sub 2} film deposited via aerosol assisted chemical vapor deposition

Energy Technology Data Exchange (ETDEWEB)

Chua, Chin Sheng, E-mail: cschua@simtech.a-star.edu.sg [School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore); Singapore Institute of Manufacturing Technology, 71 Nanyang Drive, 638075 (Singapore); Tan, Ooi Kiang; Tse, Man Siu [School of Electrical and Electronic Engineering, Nanyang Technological University, 50 Nanyang Avenue, 639798 (Singapore); Ding, Xingzhao [Singapore Institute of Manufacturing Technology, 71 Nanyang Drive, 638075 (Singapore)

2013-10-01

Tin-doped TiO{sub 2} films are deposited via aerosol assisted chemical vapor deposition using a precursor mixture composing of titanium tetraisopropoxide and tetrabutyl tin. The amount of tin doping in the deposited films is controlled by the volume % concentration ratio of tetrabutyl tin over titanium tetraisopropoxide in the mixed precursor solution. X-ray diffraction analysis results reveal that the as-deposited films are composed of pure anatase TiO{sub 2} phase. Red-shift in the absorbance spectra is observed attributed to the introduction of Sn{sup 4+} band states below the conduction band of TiO{sub 2}. The effect of tin doping on the photocatalytic property of TiO{sub 2} films is studied through the degradation of stearic acid under UV light illumination. It is found that there is a 10% enhancement on the degradation rate of stearic acid for the film with 3.8% tin doping in comparison with pure TiO{sub 2} film. This improvement of photocatalytic performance with tin incorporation could be ascribed to the reduction of electron-hole recombination rate through charge separation and an increased amount of OH radicals which are crucial for the degradation of stearic acid. Further increase in tin doping results in the formation of recombination site and large anatase grains, which leads to a decrease in the degradation rate. - Highlights: ► Deposition of tin-doped TiO{sub 2} film via aerosol assisted chemical vapor deposition ► Deposited anatase films show red-shifted in UV–vis spectrum with tin-dopants. ► Photoactivity improves at low tin concentration but reduces at higher concentration. ► Improvement in photoactivity due to bandgap narrowing from Sn{sup 4+} band states ► Maximum photoactivity achieved occurs for films with 3.8% tin doping.

Multi - pulse tea CO2 laser beam interaction with the TiN thin films

International Nuclear Information System (INIS)

Gakovic, B.; Trtica, M.; Nenadovic, T.; Pavlicevic, B.

1998-01-01

The interaction of various types of energetic beams including a laser beam with the high-hardness coatings is of great fundamental and technological interest. The Nd:YAG, excimer and CO 2 are frequently used laser beams for this purpose. The interaction of a laser beam with low thickness coatings, deposited on austenitic stainless steel, is insufficiently known in the literature. Titanium nitride (TiN) possess the excellent physico-chemical characteristics. For this reason TiN films/coatings are widely used. The purpose of this article is a consideration of the effect of TEA C0 2 laser radiation on the TiN film deposited on austenitic stainless steel substrate (AISI 316). Investigation of TiN morphological changes, after multipulse laser irradiation, shown dependence on laser fluence, number of laser pulses and the laser pulse shape. Subsequently fast heating and cooling during multi-pulse laser bombardment cause the grain growth of TiN layer. Both laser pulses (pulses with tail and tail-free pulses) produced periodical wave like structure on polished substrate material. Periodicity is observed also on AISI 316 protected with TiN layer, but only with laser pulse with tail. (author)

Release path temperatures of shock-compressed tin from dynamic reflectance and radiance measurements

Energy Technology Data Exchange (ETDEWEB)

La Lone, B. M., E-mail: lalonebm@nv.doe.gov; Stevens, G. D.; Turley, W. D. [National Security Technologies, LLC, Special Technologies Laboratory, Santa Barbara, California 93111 (United States); Holtkamp, D. B. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Iverson, A. J. [National Security Technologies, LLC, Los Alamos Operations, Los Alamos, New Mexico 87544 (United States); Hixson, R. S.; Veeser, L. R. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); National Security Technologies, LLC, Los Alamos Operations, Los Alamos, New Mexico 87544 (United States)

2013-08-14

Dynamic reflectance and radiance measurements were conducted for tin samples shock compressed to 35 GPa and released to 15 GPa using high explosives. We determined the reflectance of the tin samples glued to lithium fluoride windows using an integrating sphere with an internal xenon flashlamp as an illumination source. The dynamic reflectance (R) was determined at near normal incidence in four spectral bands with coverage in visible and near-infrared spectra. Uncertainties in R/R{sub 0} are <2%, and uncertainties in absolute reflectance are <5%. In complementary experiments, thermal radiance from the tin/glue/lithium fluoride interface was recorded with similar shock stress and spectral coverage as the reflectance measurements. The two sets of experiments were combined to obtain the temperature history of the tin surface with an uncertainty of <2%. The stress at the interface was determined from photonic Doppler velocimetry and combined with the temperatures to obtain temperature-stress release paths for tin. We discuss the relationship between the experimental release paths and release isentropes that begin on the principal shock Hugoniot.

Assessment of organotin and tin-free antifouling paints contamination in the Korean coastal area.

Science.gov (United States)

Lee, Mi-Ri-Nae; Kim, Un-Jung; Lee, In-Seok; Choi, Minkyu; Oh, Jeong-Eun

2015-10-15

Twelve organotins (methyl-, octyl-, butyl-, and phenyl-tin), and eight tin-free antifouling paints and their degradation products were measured in marine sediments from the Korean coastal area, and Busan and Ulsan bays, the largest harbor area in Korea. The total concentration of tin-free antifouling paints was two- to threefold higher than the total concentration of organotins. Principal component analysis was used to identify sites with relatively high levels of contamination in the inner bay area of Busan and Ulsan bays, which were separated from the coastal area. In Busan and Ulsan bays, chlorothalonil and DMSA were more dominant than in the coastal area. However, Sea-Nine 211 and total diurons, including their degradation products, were generally dominant in the Korean coastal area. The concentrations of tin and tin-free compounds were significantly different between the east and west coasts. Copyright © 2015 Elsevier Ltd. All rights reserved.

Synthesis of Nanoscale Lithium-Ion Battery Cathode Materials Using a Porous Polymer Precursor Method

KAUST Repository

Deshazer, H.D.

2011-01-01

Fine particles of metal oxides with carefully controlled compositions can be easily prepared by the thermal decomposition of porous polymers, such as cellulose, into which solutions containing salts of the desired cations have been dissolved. This is a simple and versatile method that can be used to produce a wide variety of materials with a range of particle sizes and carefully controlled chemical compositions. Examples of the use of this method to produce fine particles of LiCoO2 and Li(NiMnCo)1/3O2, which are used in the positive electrodes of lithium-ion batteries, are shown. Experiments have demonstrated that materials made using this method can have electrochemical properties comparable to those typically produced by more elaborate procedures. © 2011 The Electrochemical Society.

Anomalous growth of whisker-like bismuth-tin extrusions from tin-enriched tin-Bi deposits

International Nuclear Information System (INIS)

Hu, C.-C.; Tsai, Y.-D.; Lin, C.-C.; Lee, G.-L.; Chen, S.-W.; Lee, T.-C.; Wen, T.-C.

2009-01-01

This article shows the first finding that the anomalous growth of Bi-Sn extrusions from tin-enriched alloys (Sn-xBi with x between 20 and 10 wt.%) can be induced by post-plating annealing in N 2 between 145 and 260 deg. C for 10 min although metal whiskers were commonly formed on the surface of pure metals or alloys of the enriched component. From SEM observations, very similar to Sn whiskers, Bi-Sn extrusions vary in size, shape, length, and diameter with changing the annealing temperature, which are highly important in regarding the potential for failure of electronic products. Annealing resulting in thermal expansion of Sn grains is believed to squeeze the Bi-Sn alloys with relatively low melting points to form whisker-like extrusions although the exact mechanism is unclear

An Empirical Model for Estimating the Probability of Electrical Short Circuits from Tin Whiskers. Part 2

Science.gov (United States)

Courey, Karim; Wright, Clara; Asfour, Shihab; Onar, Arzu; Bayliss, Jon; Ludwig, Larry

2009-01-01

In this experiment, an empirical model to quantify the probability of occurrence of an electrical short circuit from tin whiskers as a function of voltage was developed. This empirical model can be used to improve existing risk simulation models. FIB and TEM images of a tin whisker confirm the rare polycrystalline structure on one of the three whiskers studied. FIB cross-section of the card guides verified that the tin finish was bright tin.

Moessbauer study of the lattice dynamics of tin atoms in antimony

International Nuclear Information System (INIS)

Sitek, J.

1975-01-01

The Moessbauer effect probability f was investigated for tin impurity atoms in the SnSb solution (the impurity varied from 3 at% to 15 at%). The absolute value of the Moessbauer effect probability was determined from Moessbauer absorption spectra by the area method using a calibration absorber of a β-tin foil with known f. (Z.S.)

Fast, versatile x-ray fluorescence method for measuring tin in impregnated wood

DEFF Research Database (Denmark)

Drabæk, I.; Christensen, Leif Højslet

1985-01-01

The present paper describes an energy-dispersive x-ray fluorescence method for measuring tin in bis(tri-n-butyl)tin-oxide impregnated wood. The proposed method is of the backscatter/fundamental parameter type. Its versatility, precision, and accuracy is demonstrated by analyses of eleven samples...

Synthesis and electrochemical properties of tin oxide-based composite by rheological technique

International Nuclear Information System (INIS)

He Zeqiang; Li Xinhai; Xiong Lizhi; Wu Xianming; Xiao Zhuobing; Ma Mingyou

2005-01-01

Novel rheological technique was developed to synthesize tin oxide-based composites. The microstructure, morphology, and electrochemical performance of the materials were investigated by X-ray diffraction, scanning electron microscopy and electrochemical methods. The particles of tin oxide-based materials form an inactive matrix. The average size of the particles is about 150 nm. The material delivers a charge capacity of more than 570 mAh g -1 . The capacity loss per cycle is about 0.15% after being cycled 30 times. The good electrochemical performance indicates that this kind of tin oxide-based material is promising anode for lithium-ion battery

Tin Whisker Electrical Short Circuit Characteristics. Part 2

Science.gov (United States)

Courey, Karim J.; Asfour, Shihab S.; Onar, Arzu; Bayliss, Jon A.; Ludwig, Lawrence L.; Wright, Maria C.

2009-01-01

Existing risk simulations make the assumption that when a free tin whisker has bridged two adjacent exposed electrical conductors, the result is an electrical short circuit. This conservative assumption is made because shorting is a random event that has an unknown probability associated with it. Note however that due to contact resistance electrical shorts may not occur at lower voltage levels. In our first article we developed an empirical probability model for tin whisker shorting. In this paper, we develop a more comprehensive empirical model using a refined experiment with a larger sample size, in which we studied the effect of varying voltage on the breakdown of the contact resistance which leads to a short circuit. From the resulting data we estimated the probability distribution of an electrical short, as a function of voltage. In addition, the unexpected polycrystalline structure seen in the focused ion beam (FIB) cross section in the first experiment was confirmed in this experiment using transmission electron microscopy (TEM). The FIB was also used to cross section two card guides to facilitate the measurement of the grain size of each card guide's tin plating to determine its finish.

Microstructural evolution by heating at 1673-2373 K in ultra-fine grained W-(0.25-1.5)%TiC consolidates

International Nuclear Information System (INIS)

Hidaka, M.; Sakamoto, T.; Kobayashi, S.; Nakai, K.; Kurishita, H.; Arakawa, H.

2007-01-01

Full text of publication follows: Ultra-fine grained (UFG) W-TiC consolidates with nearly full densification are expected to be very promising for their use as divertors and structural materials exposed to irradiation environments because they exhibit good resistance to irradiations with fast neutrons, helium-ions and hydrogen-ions. In view of exposure to high heat loading on divertors, it is necessary to examine microstructural evolution due to high temperature heating in UFG W-TiC consolidates, which is closely related to recrystallization embrittlement. The objective of this study is to clarify how the microstructures in UFG W-TiC consolidates change with annealing at 1673-2373 K, with emphasis on the effects of TiC additions and nano-sized Ar bubbles retained in UFG W-TiC consolidates fabricated by mechanical alloying (MA) in an Ar atmosphere. UFG W-(0.25, 0.5, 0.8, 1.1, 1.5)%TiC (in wt%) consolidates were fabricated by powder metallurgical methods utilizing MA with 3MPDA (three mutually perpendicular directions agitation) bail mill in an atmosphere of purified H 2 (MA-H 2 ) or Ar (MA-Ar), followed by hot isostatic pressing (HIP) at 1623 K. Thin foils for transmission electron microscopy (TEM) observations were prepared from each of the as-HIPed consolidates and subjected to annealing in vacuum at temperatures from 1673 to 2373 K for 3.6 ks by radio-frequency induction heating. TEM examinations and EDX analyses were made using a JEM-2000FX and JEM-4000FX operating at 200 and 400 kV, respectively. It is shown that the as-HIPed specimens exhibit equiaxed grain sizes of 40 to 200 nm which decrease with increasing TiC addition, but the grain size tends to saturate around 1 wt% TiC addition. The nano-sized Ar bubbles in W-TiC with MA-Ar are observed in approximately half of the grains and provide a significant grain refinement effect: The grain size in W-TiC with MA-Ar is approximately half of that with MA-H 2 . Such Ar bubbles are retained even after heating at

Vanadocene reactions with mixed acylates of silicon, germanium and tin

International Nuclear Information System (INIS)

Latyaeva, V.N.; Lineva, A.N.; Zimina, S.V.; Gordetsov, A.S.; Dergunov, Yu.I.

1981-01-01

Vanadocene interaction with di-and tri-alkyl (aryl)-derivatives of silicon, tin and germanium is studied. Dibutyltin dibenzoate under mild conditions (20 deg C, toluene) oxidates vanadocene to [CpV(OCOC 6 H 5 ) 2 ] 2 , at that, the splitting off of one Cp group in the form of cyclopentadiene and formation of the products of tin-organic fragment disproportionation (tributyltin benzoate, dibutyltin, metallic tin) take place. Tributyltin benzoate oxidates vanadocene at the mole ratio 2:1 and during prolong heating (120 deg C) in the absence of the solvent, [CpV(OCOC 6 H 5 ) 2 ] 2 and hexabutyldistannate are the products of the reaction. Acetates R 3 SnOCOCH 3 react in the similar way. The reactivity of mono- and diacylates of germanium and silicon decreases in the series of derivatives Sn>Ge>Si [ru

Cyclic voltammetric study of tin hexacyanoferrate for aqueous battery applications

Directory of Open Access Journals (Sweden)

Denys Gromadskyi

2016-09-01

Full Text Available A hybrid composite containing 65 mass % of tin hexacyanoferrate mixed with 35 mass % of carbon nanotubes has been synthesized and its electrochemical behavior as a negative electrode in alkali metal-ion batteries has been studied in 1 mol L-1 aqueous solution of sodium sulfate. The specific capacity of pure tin hexacyanoferrate is 58 mAh g-1, whereas the specific capacity normalized per total electrode mass of the composite studied reaches 34 mAh g-1. The estimated maximal specific power of an aqueous alkali-metal ion battery with a tin hexacyanoferrate electrode is ca. 3.6 kW kg-1 being comparable to characteristics of industrial electric double-layer capacitors. The maximal specific energy accumulated by this battery may reach 25.6 Wh kg-1 at least three times exceeding the specific energy for supercapacitors.

Recovery of antimony-125 from tin-124 irradiated by neutrons

International Nuclear Information System (INIS)

Baluev, A.V.; Mityakhina, V.S.; Krasnikov, L.V.; Galkin, B.Ya.; Besnosyuk, V.I.

2003-01-01

Separation of 125 Sb from tin using highly basic, medium-basic, and weakly basic ion-exchangers was studied. The best results were obtained for AN-31 weakly basic anion exchanger. The yield of 125 Sb was 95 -98 % of the initial activity, the yield of tin, 98 ± 0.5% of the initial amount. The separation coefficient is 10 6 -10 7 for one cycle. A procedure based on ion exchange was developed. Extraction procedures of separation of 125 Sb from tin were studied. Isoamyl alcohol, ethyl acetate, and di-n-butyl ether were used as extracting agents. The most efficient extracting agent is di-n-butyl ether. Carrier-free radiochemically pure sample of 125 Sb was produced. More than 20 mCi of the target product was recovered. The extraction recovery procedure of 125 Sb has been developed. (author)

Technical problems associated with the production of technetium Tc 99m tin(II) pyrophosphate kits

International Nuclear Information System (INIS)

Kowalsky, R.J.; Dalton, D.R.

1981-01-01

The amount of tin(II) required for adequate reduction, complexation, and stability of technetium Tc 99m pertechnetate in radiopharmaceutical kits, and methods of preventing the loss of tin(II) during formulation of these lyophilized kits are investigated. Tin(II) loss from stannous chloride solutions was studied under several conditions, including room air versus nitrogen atmospheres, during vial filling in a laminar-flow hood with samples frozen on dry ice versus samples at room temperature, during lyophilization, and during storage under refrigerated, ambient, and elevated temperatures. Various amounts of stannous chloride, ranging from 5 to 1000 microgram/ml, were used in formulating sodium pertechnetate Tc 99m kits containing 100 mCi technetium Tc 99m and 0.4 microgram total technetium. Samples were removed at various times; hydrolyzed technetium, pertechnetate, and technetium Tc 99m pyrophosphate were isolated on instant thin-layer chromatography-silica gel and quantified with a scintillation counter. The time necessary to deoxygenate distilled water by nitrogen purging was measured. Several sources of stannous chloride were assayed for tin(II) content. Tin(II) loss occurs rapidly in solution (15% in one hour) unless continuously protected with nitrogen, and during vial filling in a laminar-flow hood unless frozen with dry ice. No substantial loss of tin(II) was detected during lyophilization or during storage of lyophilized product at any of the three temperatures. A minimum of 400 microgram tin(II) was required to provide 90% technetium Tc 99m pyrophosphate at six hours after preparation. Adequate deoxygenation of small quantities (450 ml) of water was accomplished in less than one hour. Some stannous chloride salts were highly oxidized in the dry state, and only high-purity elemental tin wire gave acceptable yields of tin

UV-visible spectroscopic estimation of photodegradation of rhodamine-B dye using tin(IV) oxide nanoparticles.

Science.gov (United States)

Sangami, G; Dharmaraj, N

2012-11-01

Nanocrystalline, tin(IV) oxide (SnO(2)) particles has been prepared by thermal decomposition of tin oxalate precursor obtained from the reactions of tin(IV) chloride and sodium oxalate using eggshell membrane (ESM). The as-prepared SnO(2) nanoparticles were characterized by thermal studies, transmission electron microscopy (TEM), powder X-ray diffraction (XRD), Raman, FT-IR and UV-visible studies and used as a photocatalyst for the degradation of rhodamine-B (Rh-B) dye. The size of the prepared nanoparticles was in the range of 5-12nm as identified from the TEM images. Powder XRD data revealed the presence of a tetragonal, rutile crystalline phase of the tin(IV) oxide nanoparticles. Thermal analysis showed that the decomposition of tin oxalate precursor to yield the titled tin(IV) oxide nanoparticles was completed below 500°C. The extent of degradation of Rh-B in the presence of SnO(2) monitored by absorption spectral measurements demonstrated that 94.48% of the selected dye was degraded upon irradiation with UV light for 60 min. Copyright © 2012 Elsevier B.V. All rights reserved.

Preparation of tin -heparin complex to be applied for myocardial infarct diagnosis

International Nuclear Information System (INIS)

Badi, J. M.; Al-Azzawi, H. A.; Resen, H. M.; Abed, I. G.; Owiad, H.; Manji, A. N.

2012-12-01

Tin-heparin complex has been prepared (liquid form) to be labeled with technetium-99 can be applied for diagnosis of myocardial infarcts vascular diseases and deep vein thrombosis. The preparation contents are 0.1mg tin chloride dehydrate and 1250 1.U of heparin. The results of the pH effect on the labeling yield indicated that high percentage of labeling yield (96.1%) was obtained in the optimal pH (5.50). The obtained results showed that the quantity of reducing agent (tin chloride dehydrate) and chelating agent (heparin) has no effect on the labeling yield. Results of radio analytical studies by paper chromatography technique wear confirmed by data obtained by Gel chromatography column scanning techniques. These techniques showed the high labeling yield of the tin-heparin complex. The persistence of high labeling yield for 8 hours is a good indication for its stability and efficiency for radio diagnosis examination in nuclear medicine centers. (Author)

Fabrication et applications des reseaux de Bragg ultra-longs

Science.gov (United States)

Gagne, Mathieu

This thesis presents the principal accomplishments realized during the PhD project. The thesis is presented by publication format and is a collection of four published articles having fiber Bragg gratings as a central theme. First achieved in 1978, UV writing of fiber Bragg gratings is nowadays a common and mature technology being present in both industry and academia. The property of reflecting light guided by optical fibers lead to diverse applications in telecommunication, lasers as well as several types of sensors. The conventional fabrication technique is generally based on the use of generally expensive phase masks which determine the obtained characteristics of the fiber Bragg grating. The fiber being photosensitive at those wavelengths, a periodic pattern can be written into it. The maximal length, the period, the chirp, the index contrast and the apodisation are all characteristics that depend on the phase mask. The first objective of the research project is to be able to go beyond this strong dependance on the phase mask without deteriorating grating quality. This is what really sets apart the technique presented in this thesis from other long fiber Bragg grating fabrication techniques available in the literature. The fundamental approach to obtain ultra long fiber Bragg gratings of arbitrary profile is to replace the scheme of scanning a UV beam across a phase mask to expose a fixed fiber by a scheme where the UV beam and phase mask are fixed and where the fiber is moving instead. To obtain a periodic index variation, the interference pattern itself must be synchronized with the moving fiber. Two variations of this scheme were implanted: the first one using electro-optical phase modulator placed in each arm of a Talbot interferometer and the second one using a phase mask mounted on a piezo electric actuator. A new scheme that imparts fine movements of the interferometer is also implemented for the first time and showed to be essential to achieve high

X-ray radiometric separation of low-grade tin ores

Energy Technology Data Exchange (ETDEWEB)

Kotler, N.I.; Neverov, A.D.; Konovalov, V.M.; Mironov, I.I.; Zakharov, S.N.

1984-10-01

The investigations on evaluation of X-ray radiometric separation of off-grade tin ores of one of the deposits are carried out. The experiments have been performed at loboratory and pilot-commerical plants. /sup 241/Am has been used as a radiation source. In the course of facility commercial the ore has been separated by means of a device comprising a separator and gate separatin device. The results of X-ray radiometric separation have shown its high productive efficiency. Concentrates with higher tin content at high extraction from ores are obtained.

X-ray radiometric separation of low-grade tin ores

International Nuclear Information System (INIS)

Kotler, N.I.; Neverov, A.D.; Konovalov, V.M.; Mironov, I.I.; Zakharov, S.N.

1984-01-01

The investigations on evaluation of X-ray radiometric separation of off-grade tin ores of one of the deposits are carried out. The experiments have been performed at loboratory and pilot-commerical plants. 241 Am has been used as a radiation source. In the course of facility commercial the ore has been separated by means of a device comprising a separator and gate separatin device. The results of X-ray radiometric separation have shown its high productive efficiency. Concentrates with higher tin content at high extraction from ores are obtained

Tin- and Lead-Based Perovskite Solar Cells under Scrutiny: An Environmental Perspective

DEFF Research Database (Denmark)

Serrano-Luján, Lucía; Espinosa Martinez, Nieves; Larsen-Olsen, Thue Trofod

2015-01-01

The effect of substituting lead with tin in perovskite-based solar cells (PSCs) has shows that lead is preferred over tin by a lower cumulative energy demand. The results, which also include end-of-life management, show that a recycling scenario that carefully handles emission of lead enables use...

The relationship between critical current and microstructure of internal tin wire

International Nuclear Information System (INIS)

Dietderich, D.R.; Hassenzahl, W.V.; Morris, J.W. Jr.

1986-01-01

Prior work on internal tin wire has shown that an increase in critical current results when the Nb 3 Sn reaction temperatures (650-730 0 C) are preceded by low temperature diffusion heat treatments that distribute the tin. These heat treatments produce a more uniform tin distribution through the niobium filament array before substantial Nb 3 Sn formation has occurred. Heat treatments as long as 19 days have been proposed as the optimal heat treatment for the conductor. However, it is possible to substantially reduce the low temperature heat treatment time while retaining the same high critical current. The success of shortened heat treatments may be interpreted on the basis of the Cu-Sn reaction, diffusion kinetics and the Nb 3 Sn growth kinetics

Isotope Dilution - Thermal Ionisation Mass Spectrometric Analysis for Tin in a Fly Ash Material

International Nuclear Information System (INIS)

Hernandez, C.; Fernandez, M.; Quejido, A. L.

2006-01-01

Isotope dilution-thermal ionisation mass spectrometry (ID-TIMS) analysis has been applied to the determination of tin in a fly ash sample supplied by the EC Joint Research Centre (Ispra, Italy). The proposed procedure includes the silica gel/phosphoric acid technique for tin thermal ionisation activation and a strict heating protocol for isotope ratio measurements. Instrumental mass discrimination factor has been previously determined measuring a natural tin standard solution. Spike solutions has been prepared from 112Sn-enriched metal and quantified by reverse isotope dilution analysis. Two sample aliquots were spiked and tin was extracted with 4,5 M HCI during 25 min ultrasound esposure time. Due to the complex matrix of this fly ash material, a two-steps purification stage using ion-exchange chromatography was required prior TIMS analysis. Obtained results for the two sample-spike blends (10,10 + - 0,55 y 10,50 + - 0,64 imolg-1) are comprarable, both value and uncertainty. Also a good reproducibility is observed between measurements. The proposed ID-TIMS procedure, as a primary method and due to the lack of fly ash reference material certified for tin content, can be used to validate more routine methodologies applied to tin determination in this kind of materials. (Author) 75 refs

Antimony Doped Tin Oxides and Their Composites with Tin pyrophosphates as Catalyst Supports for Oxygen Evolution Reaction in Proton Exchange Membrane Water Electrolysis

DEFF Research Database (Denmark)

Xu, Junyuan; Li, Qingfeng; Christensen, Erik

2012-01-01

Proton exchange membrane water electrolysers operating at typically 80 °C or at further elevated temperatures suffer from insufficient catalyst activity and durability. In this work, antimony doped tin oxide nanoparticles were synthesized and further doped with an inorganic proton conducting phase...... based on tin pyrophosphates as the catalyst support. The materials showed an overall conductivity of 0.57 S cm−1 at 130 °C under the water vapor atmosphere with a contribution of the proton conduction. Using this composite support, iridium oxide nanoparticle catalysts were prepared and characterized...

Electronegativity-dependent tin etching from thin films

Energy Technology Data Exchange (ETDEWEB)

Pachecka, M., E-mail: m.pachecka@utwente.nl; Sturm, J. M.; Kruijs, R. W. E. van de; Lee, C. J.; Bijkerk, F. [Industrial Focus Group XUV Optics, MESA+ Institute for Nanotechnology, University of Twente, Drienerlolaan 5, Enschede (Netherlands)

2016-07-15

The influence of a thin film substrate material on the etching of a thin layer of deposited tin (Sn) by hydrogen radicals was studied. The amount of remaining Sn was quantified for materials that cover a range of electronegativities. We show that, for metals, etching depends on the relative electronegativity of the surface material and Sn. Tin is chemically etched from surfaces with an electronegativity smaller than Sn, while incomplete Sn etching is observed for materials with an electronegativity larger than Sn. Furthermore, the amount of remaining Sn increases as the electronegativity of the surface material increases. We speculate, that, due to Fermi level differences in the material’s electronic structure, the energy of the two conduction bands shift such that the availability of electrons for binding with hydrogen is significantly reduced.

Design of decoupled dual servo stage with voice coil motor and linear motor for XY long stroke ultra-precision scanning system

Science.gov (United States)

Kim, Ki-Hyun; Choi, Young-Man; Gweon, Dae-Gab; Hong, Dong-Pyo; Kim, Koung-Suk; Lee, Suk-Won; Lee, Moon-Gu

2005-12-01

A decoupled dual servo (DDS) stage for ultra-precision scanning system is introduced in this paper. The proposed DDS consists of a 3 axis fine stage for handling and carrying workpieces and a XY coarse stage. Especially, the DDS uses three voice coil motors (VCM) as a planar actuation system of the fine stage to reduce the disturbances due to any mechanical connections with its coarse stage. VCMs are governed by Lorentz law. According to the law and its structure, there are no mechanical connections between coils and magnetic circuits. Moreover, the VCM doesn't have force ripples due to imperfections of commutation components of linear motor systems - currents and flux densities. However, due to the VCM's mechanical constraints the working range of the fine is about 5mm2. To break that hurdle, the coarse stage with linear motors is used for the fine stage to move about 200mm2. Because of the above reasons, the proposed DDS can achieve higher precision scanning than other stages with only one servo. Using MATLAB's Sequential Quadratic Programming (SQP), the VCMs are optimally designed for the highest force under conditions and constraints such as thermal dissipations due to its coil, its size, and so on. For linear motors, Halbach magnet linear motor is proposed and optimally designed in this paper. In addition, for their smooth movements without any frictions, guide systems of the DDS are composed of air bearings. And then, precisely to get their positions, linear scales with 0.1um resolution are used for the coarse's XY motions and plane mirror laser interferometers with 20nm for the fine's XYθz. On scanning, the two stages have same trajectories and are controlled. The control algorithm is Parallel method. The embodied ultra-precision scanning system has about 100nm tracking error and in-positioning stability.

IMPROVEMENT OF FATIGUE STRENGTH OF TIN BABBITT BY REINFORCING WITH NANO ILMENITE

Directory of Open Access Journals (Sweden)

M. V. S. BABU

2017-08-01

Full Text Available Tin Babbitt is an idle journal bearing material, its fatigue strength limits and its usage. To enhance its fatigue strength, in this paper a Tin Babbitt metal matrix is reinforced with nano Ilmenite. The metal matrix nanocomposite was fabricated by using ultrasonic assisted stir casting technique. ASTM standards in statistical planning for fatigue testing were employed in planning the fatigue tests. Fatigue tests were conducted at three stress levels, i.e., 0.9 UTS, 0.7 UTS and 0.5 UTS. Tests were conducted on a rotating-beam type fatigue testing machine. It was observed that the nano Ilmenite reinforcement enhanced the fatigue strength of Tin Babbitt.

High-energy green supercapacitor driven by ionic liquid electrolytes as an ultra-high stable next-generation energy storage device

Science.gov (United States)

Thangavel, Ranjith; Kannan, Aravindaraj G.; Ponraj, Rubha; Thangavel, Vigneysh; Kim, Dong-Won; Lee, Yun-Sung

2018-04-01

Development of supercapacitors with high energy density and long cycle life using sustainable materials for next-generation applications is of paramount importance. The ongoing challenge is to elevate the energy density of supercapacitors on par with batteries, while upholding the power and cyclability. In addition, attaining such superior performance with green and sustainable bio-mass derived compounds is very crucial to address the rising environmental concerns. Herein, we demonstrate the use of watermelon rind, a bio-waste from watermelons, towards high energy, and ultra-stable high temperature green supercapacitors with a high-voltage ionic liquid electrolyte. Supercapacitors assembled with ultra-high surface area, hierarchically porous carbon exhibits a remarkable performance both at room temperature and at high temperature (60 °C) with maximum energy densities of ∼174 Wh kg-1 (25 °C), and 177 Wh kg-1 (60 °C) - based on active mass of both electrodes. Furthermore, an ultra-high specific power of ∼20 kW kg-1 along with an ultra-stable cycling performance with 90% retention over 150,000 cycles has been achieved even at 60 °C, outperforming supercapacitors assembled with other carbon based materials. These results demonstrate the potential to develop high-performing, green energy storage devices using eco-friendly materials for next generation electric vehicles and other advanced energy storage systems.

An Investigation of the Electrical Short Circuit Characteristics of Tin Whiskers

Science.gov (United States)

Courey, Karim J.

2008-01-01

Existing risk simulations make the assumption that when a free tin whisker has bridged two adjacent exposed electrical conductors, the result is an electrical short circuit. This conservative assumption is made because shorting is a random event that has a currently unknown probability associated with it. Due to contact resistance electrical shorts may not occur at lower voltage levels. In this experiment, we study the effect of varying voltage on the breakdown of the contact resistance which leads to a short circuit. From this data we can estimate the probability of an electrical short, as a function of voltage, given that a free tin whisker has bridged two adjacent exposed electrical conductors. Also, three tin whiskers grown from the same Space Shuttle Orbiter card guide used in the aforementioned experiment were cross-sectioned and studied using a focused ion beam (FIB). The rare polycrystalline structure seen in the FIB cross section was confirmed using transmission electron microscopy (TEM). The FIB was also used to cross section two card guides to facilitate the measurement of the grain size to determine that the tin plating on the card guides had a bright finish.

Experimental study on TiN coated racetrack-type ceramic pipe

Science.gov (United States)

Wang, Jie; Xu, Yan-Hui; Zhang, Bo; Wei, Wei; Fan, Le; Pei, Xiang-Tao; Hong, Yuan-Zhi; Wang, Yong

2015-11-01

TiN film was coated on the internal surface of a racetrack-type ceramic pipe by three different methods: radio-frequency sputtering, DC sputtering and DC magnetron sputtering. The deposition rates of TiN film under different coating methods were compared. The highest deposition rate was 156 nm/h, which was obtained by magnetron sputtering coating. Based on AFM, SEM and XPS test results, the properties of TiN film, such as film roughness and surface morphology, were analyzed. Furthermore, the deposition rates were studied with two different cathode types, Ti wires and Ti plate. According to the SEM test results, the deposition rate of TiN/Ti film was about 800 nm/h with Ti plate cathode by DC magnetron sputtering. Using Ti plate cathode rather than Ti wire cathode can greatly improve the film deposition rate. Supported by National Nature Science Foundation of China (11075157)

Process for Making a Noble Metal on Tin Oxide Catalyst

Science.gov (United States)

Davis, Patricia; Miller, Irvin; Upchurch, Billy

2010-01-01

To produce a noble metal-on-metal oxide catalyst on an inert, high-surface-area support material (that functions as a catalyst at approximately room temperature using chloride-free reagents), for use in a carbon dioxide laser, requires two steps: First, a commercially available, inert, high-surface-area support material (silica spheres) is coated with a thin layer of metal oxide, a monolayer equivalent. Very beneficial results have been obtained using nitric acid as an oxidizing agent because it leaves no residue. It is also helpful if the spheres are first deaerated by boiling in water to allow the entire surface to be coated. A metal, such as tin, is then dissolved in the oxidizing agent/support material mixture to yield, in the case of tin, metastannic acid. Although tin has proven especially beneficial for use in a closed-cycle CO2 laser, in general any metal with two valence states, such as most transition metals and antimony, may be used. The metastannic acid will be adsorbed onto the high-surface-area spheres, coating them. Any excess oxidizing agent is then evaporated, and the resulting metastannic acid-coated spheres are dried and calcined, whereby the metastannic acid becomes tin(IV) oxide. The second step is accomplished by preparing an aqueous mixture of the tin(IV) oxide-coated spheres, and a soluble, chloride-free salt of at least one catalyst metal. The catalyst metal may be selected from the group consisting of platinum, palladium, ruthenium, gold, and rhodium, or other platinum group metals. Extremely beneficial results have been obtained using chloride-free salts of platinum, palladium, or a combination thereof, such as tetraammineplatinum (II) hydroxide ([Pt(NH3)4] (OH)2), or tetraammine palladium nitrate ([Pd(NH3)4](NO3)2).

Characterization of enzymatically induced aggregation of casein micelles in natural concentration by in situ static light scattering and ultra low shear viscosimetry

DEFF Research Database (Denmark)

Lehner, D.; Worning, Peder; G, Fritz

1999-01-01

of multiple scattering whenthe transmission is above 0.85. Due to the very complex and porous structure of the casein aggregates theRayleigh-Debye-Gans scattering theory has been used in the data analysis. Measurements with a newinstrument using ultra low shear showed good agreement with theory. Copyright......The aggregation of casein micelles in undiluted skim milk after the addition of chymosin was studied bystatic light scattering and ultra low shear viscometry. The static light scattering measurements were madewith two different sample thicknesses, 72 and 16 mum. The scattering data were analyzed...... by indirect Fouriertransformation and by the polydispersity inversion technique which led to pair distance distributionfunctions and size distribution function, respectively. The minimum scattering angle was 1 degrees, whichallows for the determination of particle sizes up to a maximum diameter of 12 mum...

Evaluation of Biofuel Cells with Hemoglobin as Cathodic Electrocatalysts for Hydrogen Peroxide Reduction on Bare Indium-Tin-Oxide Electrodes

Directory of Open Access Journals (Sweden)

Yusuke Ayato

2013-12-01

Full Text Available A biofuel cell (BFC cathode has been developed based on direct electron transfer (DET of hemoglobin (Hb molecules with an indium-tin-oxide (ITO electrode and their electrocatalysis for reduction of hydrogen peroxide (H2O2. In this study, the ITO-coated glass plates or porous glasses were prepared by using a chemical vapor deposition (CVD method and examined the electrochemical characteristics of the formed ITO in pH 7.4 of phosphate buffered saline (PBS solutions containing and not containing Hb. In half-cell measurements, the reduction current of H2O2 due to the electrocatalytic activity of Hb increased with decreasing electrode potential from around 0.1 V versus Ag|AgCl|KCl(satd. in the PBS solution. The practical open-circuit voltage (OCV on BFCs utilizing H2O2 reduction at the Hb-ITO cathode with a hydrogen (H2 oxidation anode at a platinum (Pt electrode was expected to be at least 0.74 V from the theoretical H2 oxidation potential of −0.64 V versus Ag|AgCl|KCl(satd. in pH 7.4. The assembled single cell using the ITO-coated glass plate showed the OCV of 0.72 V and the maximum power density of 3.1 µW cm−2. The maximum power per single cell was recorded at 21.5 µW by using the ITO-coated porous glass.

Gap enhancement in phonon-irradiated superconducting tin films

International Nuclear Information System (INIS)

Miller, N.D.; Rutledge, J.E.

1982-01-01

We have measured the current-voltage (I-V) characteristics of tin-tin tunnel junctions driven out of equilibrium by a flux of near-thermal phonons from a heater. The reduced ambient temperature was T/T/sub c/ = 0.41. The nonequilibrium I-V curves are compared to equilibrium thermal I-V curves at an elevated temperature chosen to match the total number of quasiparticles. The nonequilibrium curves show a smaller current near zero bias and a larger gap than the thermal curves. This is the first experimental evidence of phonon-induced gap enhancement far below T/sub c/. The results are discussed in terms of the coupled kinetic equations of Chang and Scalapino

TDPAC characterization of tin oxides using 181Ta

International Nuclear Information System (INIS)

Moreno, M.S.; Desimoni, J.; Requejo, F.G.; Renteria, M.; Bibiloni, A.G.

1991-01-01

In connection with a general study of the evolution of tin-oxygen thin films, we report here on the hyperfine interactions of 181 Ta substitutionally replacing tin in the isolated phases SnO and SnO 2 . For this purpose, pure SnO pressed powder and a thin SnO 2 film were implanted with 181 Hf. In both cases, unique quadrupole frequencies were found after thermal annealing treatments. The results indicate that the following hyperfine parameters: ν Q =740.6(2.1) MHz, η=0.07(2) and ν Q =971.5(1.9) MHz, η=0.72(1) characterize 181 Ta and SnO and SnO 2 , respectively. (orig.)

Rosé Wine Fining Using Polyvinylpolypyrrolidone: Colorimetry, Targeted Polyphenomics, and Molecular Dynamics Simulations.

Science.gov (United States)

Gil, Mélodie; Avila-Salas, Fabian; Santos, Leonardo S; Iturmendi, Nerea; Moine, Virginie; Cheynier, Véronique; Saucier, Cédric

2017-12-06

Polyvinylpolypyrrolidone (PVPP) is a fining agent polymer used in winemaking to adjust rosé wine color and to prevent organoleptic degradations by reducing polyphenol content. The impact of this polymer on color parameters and polyphenols of rosé wines was investigated, and the binding specificity of polyphenols toward PVPP was determined. Color measured by colorimetry decreased after treatment, thus confirming the adsorption of anthocyanins and other pigments. Phenolic composition was determined before and after fining by targeted polyphenomics (Ultra Performance Liquid Chromatography (UPLC)-Electrospray Ionization(ESI)-Mass Spectrometry (MS/MS)). MS analysis showed adsorption differences among polyphenol families. Flavonols (42%) and flavanols (64%) were the most affected. Anthocyanins were not strongly adsorbed on average (12%), but a specific adsorption of coumaroylated anthocyanins was observed (37%). Intermolecular interactions were also studied using molecular dynamics simulations. Relative adsorptions of flavanols were correlated with the calculated interaction energies. The specific affinity of coumaroylated anthocyanins toward PVPP was also well explained by the molecular modeling.

Moessbauer and NMR study of novel Tin(IV)-lactames

Energy Technology Data Exchange (ETDEWEB)

Kuzmann, Erno; Szalay, Roland; Homonnay, Zoltan, E-mail: homonnay@ludens.elte.hu; Nagy, Sandor [Eoetvoes Lorand University, Institute of Chemistry (Hungary)

2012-03-15

N-tributylstannylated 2-pyrrolidinone was reacted with tributyltin triflate in different molar ratios and the complex formation monitored using {sup 1}H-NMR, {sup 13}C-NMR and {sup 119}Sn Moessbauer spectroscopy. Comparing the carbon NMR and tin Moessbauer results, a reaction scheme is suggested for the complexation which assumes the formation of a simultaneously O- and N-tributylstannylated pyrrolidinone cation. The formation of the only O-stannylated pyrrolidinone is also assumed to account for the non-constant Moessbauer parameters of the two tin environments in the distannylated pyrrolidinone cation when the ratio of tributyltin triflate is increased in the reaction.

Comparative Analysis of Data Structures for Storing Massive Tins in a Dbms

Science.gov (United States)

Kumar, K.; Ledoux, H.; Stoter, J.

2016-06-01

Point cloud data are an important source for 3D geoinformation. Modern day 3D data acquisition and processing techniques such as airborne laser scanning and multi-beam echosounding generate billions of 3D points for simply an area of few square kilometers. With the size of the point clouds exceeding the billion mark for even a small area, there is a need for their efficient storage and management. These point clouds are sometimes associated with attributes and constraints as well. Storing billions of 3D points is currently possible which is confirmed by the initial implementations in Oracle Spatial SDO PC and the PostgreSQL Point Cloud extension. But to be able to analyse and extract useful information from point clouds, we need more than just points i.e. we require the surface defined by these points in space. There are different ways to represent surfaces in GIS including grids, TINs, boundary representations, etc. In this study, we investigate the database solutions for the storage and management of massive TINs. The classical (face and edge based) and compact (star based) data structures are discussed at length with reference to their structure, advantages and limitations in handling massive triangulations and are compared with the current solution of PostGIS Simple Feature. The main test dataset is the TIN generated from third national elevation model of the Netherlands (AHN3) with a point density of over 10 points/m2. PostgreSQL/PostGIS DBMS is used for storing the generated TIN. The data structures are tested with the generated TIN models to account for their geometry, topology, storage, indexing, and loading time in a database. Our study is useful in identifying what are the limitations of the existing data structures for storing massive TINs and what is required to optimise these structures for managing massive triangulations in a database.

21 CFR 189.301 - Tin-coated lead foil capsules for wine bottles.

Science.gov (United States)

2010-04-01

... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Tin-coated lead foil capsules for wine bottles. 189... SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) SUBSTANCES PROHIBITED FROM USE IN HUMAN FOOD... lead foil capsules for wine bottles. (a) Tin-coated lead foil is composed of a lead foil coated on one...

Tin( ii ) ketoacidoximates: synthesis, X-ray structures and processing to tin( ii ) oxide

KAUST Repository

Khanderi, Jayaprakash

2015-10-21

Tin(ii) ketoacidoximates of the type [HONCRCOO]Sn (R = Me 1, CHPh 2) and (MeONCMeCOO)Sn] NH·2HO 3 were synthesized by reacting pyruvate- and hydroxyl- or methoxylamine RONH (R = H, Me) with tin(ii) chloride dihydrate SnCl·2HO. The single crystal X-ray structure reveals that the geometry at the Sn atom is trigonal bipyramidal in 1, 2 and trigonal pyramidal in 3. Inter- or intramolecular hydrogen bonding is observed in 1-3. Thermogravimetric (TG) analysis shows that the decomposition of 1-3 to SnO occurs at ca. 160 °C. The evolved gas analysis during TG indicates complete loss of the oximato ligand in one step for 1 whereas a small organic residue is additionally removed at temperatures >400 °C for 2. Above 140 °C, [HONC(Me)COO]Sn (1) decomposes in air to spherical SnO particles of size 10-500 nm. Spin coating of 1 on Si or a glass substrate followed by heating at 200 °C results in a uniform film of SnO. The band gap of the produced SnO film and nanomaterial was determined by diffuse reflectance spectroscopy to be in the range of 3.0-3.3 eV. X-ray photoelectron spectroscopy indicates surface oxidation of the SnO film to SnO in ambient atmosphere.

Nanostructured antistatic and antireflective thin films made of indium tin oxide and silica over-coat layer

Science.gov (United States)

Cho, Young-Sang; Hong, Jeong-Jin; Yang, Seung-Man; Choi, Chul-Jin

2010-08-01

Stable dispersion of colloidal indium tin oxide nanoparticles was prepared by using indium tin oxide nanopowder, organic solvent, and suitable dispersants through attrition process. Various comminution parameters during the attrition step were studied to optimize the process for the stable dispersion of indium tin oxide sol. The transparent and conductive films were fabricated on glass substrate using the indium tin oxide sol by spin coating process. To obtain antireflective function, partially hydrolyzed alkyl silicate was deposited as over-coat layer on the pre-fabricated indium tin oxide film by spin coating technique. This double-layered structure of the nanostructured film was characterized by measuring the surface resistance and reflectance spectrum in the visible wavelength region. The final film structure was enough to satisfy the TCO regulations for EMI shielding purposes.

Determination of tin, chromium, cadmium and lead in canned fruits from the Czech market

Directory of Open Access Journals (Sweden)

Pavel Diviš

2017-01-01

Full Text Available The global production of metal cans is more than 300 billion cans. Benefits of metal packaging consist mainly from the great strenght, excellent barrier properties and good thermal conductivity. The main problem of used metal packaging are the corrosion processes. The corrosion of metal container causes dissolution of tin which is used as a protective layer of the steel shell of the can and other metallic elements used in the manufacture of cans. In this work 31 samples of canned fruit was analysed and the concentration of tin, chromium, cadmium and lead was determined in fruit and in syrup using ICP-OES and ICP-MS techniques. The results showed no difference between the concentration of analysed elements in fruit and in syrup. In none of the analyzed samples the permitted maximum concentration of tin 200 mg.kg-1 was exceeded. Maximum concentration of tin was measured in canned grepfruit (59.8 ±1.9 mg.kg-1. The age of cans had no significant effect on the concentration of tin in canned fruit. The concentration of tin in fruit packaged in cans with protective layer of lacquer was significantly lower than the concentration of tin in fruit packaged in cans without protective layer of lacquer. Concentration of chromium, cadmium and lead in the analysed samples was very low at the natural levels of occurrence of these metals in fruit and it was impossible to determine unequivocally that the measured concentrations of these metals in canned fruit originate from the corrosion of can. The corrosion of the tinplate was studied using scanning electron microscopy with an energy dispersive spectrometer. By analyzing the SEM pictures and EDS spectra, critical areas of tin plate corrosion were observed. Based on the measured results it can be concluded that the consumption of fresh canned fruit is not a major problem for the inhabitants of the Czech Republic in terms of intake of potentially hazardous metals.

Partial oxidation of TiN coating by hydrothermal treatment and ozone treatment to improve its osteoconductivity

International Nuclear Information System (INIS)

Shi, Xingling; Xu, Lingli; Le, Thi Bang; Zhou, Guanghong; Zheng, Chuanbo; Tsuru, Kanji; Ishikawa, Kunio

2016-01-01

Dental implants made of pure titanium suffer from abrasion and scratch during routine oral hygiene procedures. This results in an irreversible surface damage, facilitates bacteria adhesion and increases risk of peri-implantitis. To overcome these problems, titanium nitride (TiN) coating was introduced to increase surface hardness of pure titanium. However, the osteoconductivity of TiN is considered to be similar or superior to that of titanium and its alloys and therefore surface modification is necessary. In this study, TiN coating prepared through gas nitriding was partially oxidized by hydrothermal (HT) treatment and ozone (O 3 ) treatment in pure water to improve its osteoconductivity. The effects of HT treatment and O 3 treatment on surface properties of TiN were investigated and the osteoconductivity after undergoing treatment was assessed in vitro using osteoblast evaluation. The results showed that the critical temperature for HT treatment was 100 °C since higher temperatures would impair the hardness of TiN coating. By contrast, O 3 treatment was more effective in oxidizing TiN surfaces, improving its wettability while preserving its morphology and hardness. Osteoblast attachment, proliferation, alkaline phosphatase (ALP) expression and mineralization were improved on oxidized specimens, especially on O 3 treated specimens, compared with untreated ones. These effects seemed to be consequences of partial oxidation, as well as improved hydrophilicity and surface decontamination. Finally, it was concluded that, partially oxidized TiN is a promising coating to be used for dental implant. - Highlights: • TiN coating surface was oxidized by hydrothermal or ozone treatment while preserving its hardness. • Improved wettability, decontamination and interstitial N promoted osteoblast responses. • Partial oxidation makes TiN a promising coating for dental implant with good osteoconductivity.

Partial oxidation of TiN coating by hydrothermal treatment and ozone treatment to improve its osteoconductivity

Energy Technology Data Exchange (ETDEWEB)

Shi, Xingling [School of Material Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003 (China); Department of Biomaterials, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582 (Japan); Jiangsu Provincial Key Laboratory for Interventional Medical Devices, Huaiyin Institute of Technology, Huaian 223003 (China); Xu, Lingli, E-mail: linly311@163.com [School of Material Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003 (China); Le, Thi Bang [Department of Mechanical Engineering, University of Malaya, 50603 Kuala Lumpur (Malaysia); Zhou, Guanghong [Jiangsu Provincial Key Laboratory for Interventional Medical Devices, Huaiyin Institute of Technology, Huaian 223003 (China); Zheng, Chuanbo, E-mail: zjust316@163.com [School of Material Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003 (China); Tsuru, Kanji; Ishikawa, Kunio [Department of Biomaterials, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582 (Japan)

2016-02-01

Dental implants made of pure titanium suffer from abrasion and scratch during routine oral hygiene procedures. This results in an irreversible surface damage, facilitates bacteria adhesion and increases risk of peri-implantitis. To overcome these problems, titanium nitride (TiN) coating was introduced to increase surface hardness of pure titanium. However, the osteoconductivity of TiN is considered to be similar or superior to that of titanium and its alloys and therefore surface modification is necessary. In this study, TiN coating prepared through gas nitriding was partially oxidized by hydrothermal (HT) treatment and ozone (O{sub 3}) treatment in pure water to improve its osteoconductivity. The effects of HT treatment and O{sub 3} treatment on surface properties of TiN were investigated and the osteoconductivity after undergoing treatment was assessed in vitro using osteoblast evaluation. The results showed that the critical temperature for HT treatment was 100 °C since higher temperatures would impair the hardness of TiN coating. By contrast, O{sub 3} treatment was more effective in oxidizing TiN surfaces, improving its wettability while preserving its morphology and hardness. Osteoblast attachment, proliferation, alkaline phosphatase (ALP) expression and mineralization were improved on oxidized specimens, especially on O{sub 3} treated specimens, compared with untreated ones. These effects seemed to be consequences of partial oxidation, as well as improved hydrophilicity and surface decontamination. Finally, it was concluded that, partially oxidized TiN is a promising coating to be used for dental implant. - Highlights: • TiN coating surface was oxidized by hydrothermal or ozone treatment while preserving its hardness. • Improved wettability, decontamination and interstitial N promoted osteoblast responses. • Partial oxidation makes TiN a promising coating for dental implant with good osteoconductivity.

Obtainment of SnO2 for utilization of sensors by coprecipitation of tin salts

International Nuclear Information System (INIS)

Masetto, S.R.; Longo, E.

1990-01-01

Niobia doped tin dioxide was prepared by precipitation of tin dioxide II and IV using ammonium hydroxide. The powders were characterized by X-ray diffraction, particle size distribution and infra-red spectroscopy. (author) [pt

Atomic-layer chemical-vapor-deposition of TiN thin films on Si(100) and Si(111)

CERN Document Server

Kim, Y S; Kim, Y D; Kim, W M

2000-01-01

An atomic-layer chemical vapor deposition (AL-CVD) system was used to deposit TiN thin films on Si(100) and Si(111) substrates by cyclic exposures of TiCl sub 4 and NH sub 3. The growth rate was measured by using the number of deposition cycles, and the physical properties were compared with those of TiN films grown by using conventional deposition methods. To investigate the growth mechanism, we suggest a growth model for TiN n order to calculate the growth rate per cycle with a Cerius program. The results of the calculation with the model were compared with the experimental values for the TiN film deposited using the AL-CVD method. The stoichiometry of the TiN film was examined by using Auger electron spectroscopy, and the chlorine and the oxygen impurities were examined. The x-ray diffraction and the transmission electron microscopy results for the TiN film exhibited a strong (200) peak and a randomly oriented columnar microstructure. The electrical resistivity was found to decrease with increasing deposit...

The effect of tin sulfide quantum dots size on photocatalytic and photovoltaic performance

Energy Technology Data Exchange (ETDEWEB)

Cheraghizade, Mohsen [Young Researchers and Elite Club, Ahvaz Branch, Islamic Azad University, Ahvaz (Iran, Islamic Republic of); Jamali-Sheini, Farid, E-mail: faridjamali@iauahvaz.ac.ir [Advanced Surface Engineering and Nano Materials Research Center, Department of Physics, Ahvaz Branch, Islamic Azad University, Ahvaz (Iran, Islamic Republic of); Yousefi, Ramin [Department of Physics, Masjed-Soleiman Branch, Islamic Azad University (I.A.U), Masjed-Soleiman (Iran, Islamic Republic of); Niknia, Farhad [Young Researchers and Elite Club, Ahvaz Branch, Islamic Azad University, Ahvaz (Iran, Islamic Republic of); Mahmoudian, Mohammad Reza [Department of Chemistry, Shahid Sherafat, University of Farhangian, 15916, Tehran (Iran, Islamic Republic of); Sookhakian, Mehran [Centre for Ionic Liquids, Department of Chemistry, Faculty of Science, University of Malaya, Kuala Lumpur 50603 (Malaysia)

2017-07-01

In the current study, tin sulfide Quantum Dots (QDs) was successfully synthesized through sonochemical synthesis method by applying sonication times of 10, 15, and 20 min. Structural studies showed an orthorhombic phase of SnS and Sn{sub 2}S{sub 3}, and hexagonal phase of SnS{sub 2}. The particle size of tin sulfide QDs prepared through sonication time of 20 min was smaller than other QDs. According to TEM images, an increase in sonication time resulted in smaller spherical shaped particles. According to the results of Raman studies, five Raman bands and a shift towards the lower frequencies were observed by enhancing the sonication time. Based on the outcomes of photocatalytic activity, higher this property was observed for tin sulfide QDs, which are prepared through longer sonication time. Solar cell devices manufactured using tin sulfide QDs have a greater performance for the samples with more sonication time. Considering the obtained outcomes, the sonication time seems probable to be a factor affecting synthesis process of SnS QDs as well as its optical and electrical, photocatalytic, and photovoltaic conversion features. - Highlights: • Tin sulfide quantum dots (QDs) synthesized using a sonication method. • The sonication time was selected as a synthesis parameter. • The photocatalytic and photovoltaic performance were depended on synthesis parameter.

The effect of tin sulfide quantum dots size on photocatalytic and photovoltaic performance

International Nuclear Information System (INIS)

Cheraghizade, Mohsen; Jamali-Sheini, Farid; Yousefi, Ramin; Niknia, Farhad; Mahmoudian, Mohammad Reza; Sookhakian, Mehran

2017-01-01

In the current study, tin sulfide Quantum Dots (QDs) was successfully synthesized through sonochemical synthesis method by applying sonication times of 10, 15, and 20 min. Structural studies showed an orthorhombic phase of SnS and Sn_2S_3, and hexagonal phase of SnS_2. The particle size of tin sulfide QDs prepared through sonication time of 20 min was smaller than other QDs. According to TEM images, an increase in sonication time resulted in smaller spherical shaped particles. According to the results of Raman studies, five Raman bands and a shift towards the lower frequencies were observed by enhancing the sonication time. Based on the outcomes of photocatalytic activity, higher this property was observed for tin sulfide QDs, which are prepared through longer sonication time. Solar cell devices manufactured using tin sulfide QDs have a greater performance for the samples with more sonication time. Considering the obtained outcomes, the sonication time seems probable to be a factor affecting synthesis process of SnS QDs as well as its optical and electrical, photocatalytic, and photovoltaic conversion features. - Highlights: • Tin sulfide quantum dots (QDs) synthesized using a sonication method. • The sonication time was selected as a synthesis parameter. • The photocatalytic and photovoltaic performance were depended on synthesis parameter.

Developing an Empirical Model for Estimating the Probability of Electrical Short Circuits from Tin Whiskers. Part 2

Science.gov (United States)

Courey, Karim J.; Asfour, Shihab S.; Onar, Arzu; Bayliss, Jon A.; Ludwig, Larry L.; Wright, Maria C.

2009-01-01

To comply with lead-free legislation, many manufacturers have converted from tin-lead to pure tin finishes of electronic components. However, pure tin finishes have a greater propensity to grow tin whiskers than tin-lead finishes. Since tin whiskers present an electrical short circuit hazard in electronic components, simulations have been developed to quantify the risk of said short circuits occurring. Existing risk simulations make the assumption that when a free tin whisker has bridged two adjacent exposed electrical conductors, the result is an electrical short circuit. This conservative assumption is made because shorting is a random event that had an unknown probability associated with it. Note however that due to contact resistance electrical shorts may not occur at lower voltage levels. In our first article we developed an empirical probability model for tin whisker shorting. In this paper, we develop a more comprehensive empirical model using a refined experiment with a larger sample size, in which we studied the effect of varying voltage on the breakdown of the contact resistance which leads to a short circuit. From the resulting data we estimated the probability distribution of an electrical short, as a function of voltage. In addition, the unexpected polycrystalline structure seen in the focused ion beam (FIB) cross section in the first experiment was confirmed in this experiment using transmission electron microscopy (TEM). The FIB was also used to cross section two card guides to facilitate the measurement of the grain size of each card guide's tin plating to determine its finish.

Hydrothermal treatment for TiN as abrasion resistant dental implant coating and its fibroblast response

International Nuclear Information System (INIS)

Shi, Xingling; Xu, Lingli; Munar, Melvin L.; Ishikawa, Kunio

2015-01-01

Dental implant made of pure titanium (Ti) is prone to scratch and abrasion during routine oral hygiene procedures. This results an increase in surface roughness and therefore, facilitates the adhesion of bacteria. In severe cases, this could lead to peri-implantitis. To overcome this problem, surface modification of Ti is necessary to improve its abrasion resistance. Besides, a strong implant–gingiva interface should also be guaranteed to prevent the adhesion of bacteria. In this study, titanium nitride (TiN) coating was first prepared with gas nitriding to increase surface hardness of pure the substrate. Then, the TiN was hydrothermally treated in CaCl 2 solution in order to improve its soft tissue biocompatibility. The effect of hydrothermal treatment temperature on surface properties of TiN was investigated and its biocompatibility was assessed in vitro using NIH3T3 fibroblast cell. It was determined that 120 °C was the critical temperature for the hydrothermal treatment condition. Treatment below 120 °C could incorporate Ca into TiN surface, oxidize TiN surface partially and then improve the wettability while preserving its morphology and hardness. Fibroblast cell attachment and proliferation were improved and cell spreading was enhanced on hydrothermally treated specimens compared with untreated ones. Improved wettability, Ca incorporation and negative surface due to interstitial N were believed to be the main reasons. Hydrothermal treatment is expected to make TiN a promising dental implant coating with excellent abrasion resistance and good soft tissue affinity. - Highlights: • Ca was incorporated into TiN surface while not sacrificing its hardness. • Interstitial N due to oxidation promoted Ca adsorption and cell adhesion. • Hydrothermal treatment makes TiN a promising coating for dental implant

Hydrothermal treatment for TiN as abrasion resistant dental implant coating and its fibroblast response

Energy Technology Data Exchange (ETDEWEB)

Shi, Xingling, E-mail: shixingling1985@hotmail.com [School of Material Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003 (China); Department of Biomaterials, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582 (Japan); Jiangsu Provincial Key Laboratory for Interventional Medical Devices, Huaiyin Institute of Technology, Huaian 223003 (China); Xu, Lingli [School of Material Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003 (China); Munar, Melvin L.; Ishikawa, Kunio [Department of Biomaterials, Faculty of Dental Science, Kyushu University, Fukuoka 812-8582 (Japan)

2015-04-01

Dental implant made of pure titanium (Ti) is prone to scratch and abrasion during routine oral hygiene procedures. This results an increase in surface roughness and therefore, facilitates the adhesion of bacteria. In severe cases, this could lead to peri-implantitis. To overcome this problem, surface modification of Ti is necessary to improve its abrasion resistance. Besides, a strong implant–gingiva interface should also be guaranteed to prevent the adhesion of bacteria. In this study, titanium nitride (TiN) coating was first prepared with gas nitriding to increase surface hardness of pure the substrate. Then, the TiN was hydrothermally treated in CaCl{sub 2} solution in order to improve its soft tissue biocompatibility. The effect of hydrothermal treatment temperature on surface properties of TiN was investigated and its biocompatibility was assessed in vitro using NIH3T3 fibroblast cell. It was determined that 120 °C was the critical temperature for the hydrothermal treatment condition. Treatment below 120 °C could incorporate Ca into TiN surface, oxidize TiN surface partially and then improve the wettability while preserving its morphology and hardness. Fibroblast cell attachment and proliferation were improved and cell spreading was enhanced on hydrothermally treated specimens compared with untreated ones. Improved wettability, Ca incorporation and negative surface due to interstitial N were believed to be the main reasons. Hydrothermal treatment is expected to make TiN a promising dental implant coating with excellent abrasion resistance and good soft tissue affinity. - Highlights: • Ca was incorporated into TiN surface while not sacrificing its hardness. • Interstitial N due to oxidation promoted Ca adsorption and cell adhesion. • Hydrothermal treatment makes TiN a promising coating for dental implant.

Colloidal Photoluminescent Amorphous Porous Silicon, Methods Of Making Colloidal Photoluminescent Amorphous Porous Silicon, And Methods Of Using Colloidal Photoluminescent Amorphous Porous Silicon

KAUST Repository

Chaieb, Sahraoui

2015-04-09

Embodiments of the present disclosure provide for a colloidal photoluminescent amorphous porous silicon particle suspension, methods of making a colloidal photoluminescent amorphous porous silicon particle suspension, methods of using a colloidal photoluminescent amorphous porous silicon particle suspension, and the like.

Colloidal Photoluminescent Amorphous Porous Silicon, Methods Of Making Colloidal Photoluminescent Amorphous Porous Silicon, And Methods Of Using Colloidal Photoluminescent Amorphous Porous Silicon

KAUST Repository

Chaieb, Saharoui; Mughal, Asad Jahangir

2015-01-01

Embodiments of the present disclosure provide for a colloidal photoluminescent amorphous porous silicon particle suspension, methods of making a colloidal photoluminescent amorphous porous silicon particle suspension, methods of using a colloidal photoluminescent amorphous porous silicon particle suspension, and the like.

In-Situ Growth and Characterization of Indium Tin Oxide Nanocrystal Rods

Directory of Open Access Journals (Sweden)

Yan Shen

2017-11-01

Full Text Available Indium tin oxide (ITO nanocrystal rods were synthesized in-situ by a vapor-liquid-solid (VLS method and electron beam evaporation technique. When the electron-beam gun bombarded indium oxide (In2O3 and tin oxide (SnO2 mixed sources, indium and tin droplets appeared and acted as catalysts. The nanocrystal rods were in-situ grown on the basis of the metal catalyst point. The nanorods have a single crystal structure. Its structure was confirmed by X-ray diffraction (XRD and transmission electron microscopy (TEM. The surface morphology was analyzed by scanning electron microscopy (SEM. During the evaporation, a chemical process was happened and an In2O3 and SnO2 solid solution was formed. The percentage of doped tin oxide was calculated by Vegard’s law to be 3.18%, which was in agreement with the mixture ratio of the experimental data. The single crystal rod had good semiconductor switch property and its threshold voltage of single rod was approximately 2.5 V which can be used as a micro switch device. The transmission rate of crystalline nanorods ITO film was over 90% in visible band and it was up to 95% in the blue green band as a result of the oxygen vacancy recombination luminescence.

Grazing incidence x-ray diffraction analysis of zeolite NaA membranes on porous alumina tubes.

Science.gov (United States)

Kyotani, Tomohiro

2006-07-01

Zeolite NaA-type membranes hydrothermally synthesized on porous alumina tubes, for dehydration process, were characterized by grazing incidence 2 theta scan X-ray diffraction analysis (GIXRD). The fine structure of the membrane was studied fractionally for surface layer and for materials embedded in the porous alumina tube. The thickness of the surface layer on the porous alumina tube in the membranes used in this study was approximately 2-3 microm as determined from transmission electron microscopy with focused ion beam thin-layer specimen preparation technique (FIB-TEM). To discuss the effects of the membrane surface morphology on the GIXRD measurements, CaA-type membrane prepared by ion exchange from the NaA-type membrane and surface-damaged NaA-type membrane prepared by water leaching were also studied. For the original NaA-type membrane, 2 theta scan GIXRD patterns could be clearly measured at X-ray incidence angles (alpha) ranging from 0.1 to 2.0 deg in increments of 0.1 deg. The surface layers of the 2 - 3 microm on the porous alumina tube correspond to the alpha values up to ca. 0.2 deg. For the CaA-type and the surface-damaged NaA-type membranes, however, diffraction patterns from the surface layer could not be successfully detected and the others were somewhat broad. For all the three samples, diffraction intensities of both zeolite and alumina increased with depth (X-ray incidence angle, alpha) in the porous alumina tube region. The depth profile analysis of the membranes based on the GIXRD first revealed that amount of zeolite crystal embedded in the porous alumina tube is much larger than that in the surface layer. Thus, the 2 theta scan GIXRD is a useful method to study zeolite crystal growth mechanism around (both inside and outside) the porous alumina support during hydrothermal synthesis and to study water permeation behavior in the dehydration process.

Porous carbons

Indian Academy of Sciences (India)

R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

Abstract. Carbon in dense as well as porous solid form is used in a variety of applications. Activated porous carbons are made through pyrolysis and activation of carbonaceous natural as well as synthetic precursors. Pyrolysed woods replicate the structure of original wood but as such possess very low surface areas and ...

[Simultaneous determination of 33 primary aromatic amines of free state in fine pigments by ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry].

Science.gov (United States)

Man, Zhengyin; Wang, Quanlin; Li, Hesheng; Zhang, Aizhi

2014-12-01

A comprehensive analytical method based on ultra-performance liquid chromatography coupled with triple quadrupole mass spectrometry (UPLC-MS/MS) has been developed for the simultaneous determination of 33 primary aromatic amines (PAAs) in fine pigments such as gouache paint, oil painting pigment and acrylic paint. The primary aromatic amines in samples were extracted with acetonitrile. Then the extract was concentrated by centrifugation and nitrogen blow, finally diluted to 2 mL with methanol-water (1:9, v/v) and filtered through 0. 22 im membrane before UPLC-MS/MS analysis. The analytes were separated on a BEH Phenyl column (100 mm x 2. 1 mm, 1. 7 1µm) with 0. 07% (v/v) formic acid in methanol-water as mobile phases in gradient elution. The PAAs were detected by UPLC-MS/MS under multiple reaction monitoring (MRM) mode and quantified by the internal standard method. The separation conditions, fragment voltages and collision energies were optimized. The impacts of extraction times, extraction solvents and concentration methods on recoveries were studied. The limits of detection and limits of quantitation for the 33 primary aromatic amines were 5-50 µg/kg and 15-150 µg/kg respectively. The mean recoveries of three different dye products at three spiked levels were 70. 1% - 115. 8%. The relative standard deviations were 2. 1% - 15%. The expenmental results indicated that the method is simple, rapid, sensitive, accurate and can meet the requirements for the determination.

Structural analysis of a coating of TiN over a Cu-Ti-Cr alloy: Study of the Cu-Ti interphase

International Nuclear Information System (INIS)

Villegas Vejar, C; Suazo, A; Radtk, H; Carrasco, C

2004-01-01

The crystalline structure of a thin film of TiN deposited by DC planar magnetron sputtering over a ternary copper alloy was studied. A fine film of titanium was deposited between the coating and the substrate for better adherence. The samples were analyzed with a transmission electron microscope to determine the structure of each of the components as well as the network distortion in the Cu-Ti interphase. The results were complemented with previous X-ray diffraction analyses to identify the network parameter for each of the study components and the respective residual tensions. This study shows the agreement between the network distortion and the residual tensions that were measured, and also relates the theory of crystalline coherence with the experimentally calculated break down by electron diffraction in the Cu-Ti interphase (CW)

Classical and quantum chaotic scattering in a muffin tin potential

International Nuclear Information System (INIS)

Brandis, S.

1995-05-01

In this paper, we study the classical mechanics, the quantum mechanics and the semi-classical approximation of the 2-dimensional scattering from a muffin tin potential. The classical dynamical system for Coulombic muffin tins is proven to be chaotic by explicit construction of the exponentially increasing number of periodic orbits. These are all shown to be completely unstable (hyperbolic). By methods of the thermodynamic formalism we can determine the Hausdorff dimension, escape rate and Kolmogorov-Sinai-entropy of the system. An extended KKR-method is developed to determine the quantum mechanical S-matrix. We compare a few integrable scattering examples with the results of the muffin tin scattering. Characteristic features of the spectrum of eigenphases turn out to be the level repulsion and long range rigidity as compared to a completely random spectrum. In the semiclassical analysis we can rederive the regularized Gutzwiller trace formula directly from the exact KKR-determinant to prove that no further terms contribute in the case of the muffin tin potential. The periodic orbit sum allows to draw some qualitative conclusions about the effects of classical chaos on the quantum mechanics. In the context of scaling systems the theory of almost periodic functions is discussed as a possible mathematical foundation for the semiclassical periodic orbit sums. Some results that can be obtained from this analysis are developed in the context of autocorrelation functions and distribution functions for chaotic scattering systems. (orig.)

Ultra low-K shrinkage behavior when under electron beam in a scanning electron microscope

Energy Technology Data Exchange (ETDEWEB)

Lorut, F.; Imbert, G. [ST Microelectronics, 850 rue Jean Monnet, 38926 Crolles Cedex (France); Roggero, A. [Centre National d' Etudes Spatiales, 18 Avenue Edouard Belin, 31400 Toulouse (France)

2013-08-28

In this paper, we investigate the tendency of porous low-K dielectrics (also named Ultra Low-K, ULK) behavior to shrink when exposed to the electron beam of a scanning electron microscope. Various experimental electron beam conditions have been used for irradiating ULK thin films, and the resulting shrinkage has been measured through use of an atomic force microscope tool. We report the shrinkage to be a fast, cumulative, and dose dependent effect. Correlation of the shrinkage with incident electron beam energy loss has also been evidenced. The chemical modification of the ULK films within the interaction volume has been demonstrated, with a densification of the layer and a loss of carbon and hydrogen elements being observed.

Carbon materials-functionalized tin dioxide nanoparticles toward robust, high-performance nitrogen dioxide gas sensor.

Science.gov (United States)

Zhang, Rui; Liu, Xiupeng; Zhou, Tingting; Wang, Lili; Zhang, Tong

2018-08-15

Carbon (C) materials, which process excellent electrical conductivity and high carrier mobility, are promising sensing materials as active units for gas sensors. However, structural agglomeration caused by chemical processes results in a small resistance change and low sensing response. To address the above issues, structure-derived carbon-coated tin dioxide (SnO 2 ) nanoparticles having distinct core-shell morphology with a 3D net-like structure and highly uniform size are prepared by careful synthesis and fine structural design. The optimum carbon-coated SnO 2 nanoparticles (SnO 2 /C)-based gas sensor exhibits a low working temperature, excellent selectivity and fast response-recovery properties. In addition, the SnO 2 /C-based gas sensor can maintain a sensitivity to nitrogen dioxide (NO 2 ) of 3 after being cycled 4 times at 140 °C for, suggesting its good long-term stability. The structural integrity, good synergistic properties, and high gas-sensing performance of SnO 2 /C render it a promising sensing material for advanced gas sensors. Copyright © 2018 Elsevier Inc. All rights reserved.

Preparation of transparent conductive indium tin oxide thin films from nanocrystalline indium tin hydroxide by dip-coating method

International Nuclear Information System (INIS)

Koroesi, Laszlo; Papp, Szilvia; Dekany, Imre

2011-01-01

Indium tin oxide (ITO) thin films with well-controlled layer thickness were produced by dip-coating method. The ITO was synthesized by a sol-gel technique involving the use of aqueous InCl 3 , SnCl 4 and NH 3 solutions. To obtain stable sols for thin film preparation, as-prepared Sn-doped indium hydroxide was dialyzed, aged, and dispersed in ethanol. Polyvinylpyrrolidone (PVP) was applied to enhance the stability of the resulting ethanolic sols. The transparent, conductive ITO films on glass substrates were characterized by X-ray diffraction, scanning electron microscopy and UV-Vis spectroscopy. The ITO layer thickness increased linearly during the dipping cycles, which permits excellent controllability of the film thickness in the range ∼ 40-1160 nm. After calcination at 550 o C, the initial indium tin hydroxide films were transformed completely to nanocrystalline ITO with cubic and rhombohedral structure. The effects of PVP on the optical, morphological and electrical properties of ITO are discussed.

Effects of heat treatment on microstructure and mechanical behaviour of additive manufactured porous Ti6Al4V

Science.gov (United States)

Ahmadi, S. M.; Jain, R. K. Ashok Kumar; Zadpoor, A. A.; Ayas, C.; Popovich, V. A.

2017-12-01

Titanium and its alloys such as Ti6Al4V play a major role in the medical industry as bone implants. Nowadays, by the aid of additive manufacturing (AM), it is possible to manufacture porous complex structures which mimic human bone. However, AM parts are near net shape and post processing may be needed to improve their mechanical properties. For instance, AM Ti6Al4V samples may be brittle and incapable of withstanding dynamic mechanical loads due to their martensitic microstructure. The aim of this study was to apply two different heat treatment regimes (below and above β-transus) to investigate their effects on the microstructure and mechanical properties of porous Ti6Al4V specimens. After heat treatment, fine acicular α‧ martensitic microstructure was transformed to a mixture of α and β phases. The ductility of the heat-treated specimens, as well as some mechanical properties such as hardness, plateau stress, and first maximum stress changed while the density and elastic gradient of the porous structure remained unchanged.

Effects of curing type, silica fume fineness, and fiber length on the mechanical properties and impact resistance of UHPFRC

Directory of Open Access Journals (Sweden)

Hasan Şahan Arel

Full Text Available The effects of silica fume fineness and fiber aspect ratio on the compressive strength and impact resistance of ultra high-performance fiber-reinforced concrete (UHPFRC are investigated experimentally. To this end, UHPFRC mixtures are manufactured by combining silica fumes with different fineness (specific surface areas: 17,200, 20,000, and 27,600 m2/kg and hooked-end steel fibers with various aspect ratios (lengths: 8, 13, and 16 mm. The samples are subjected to standard curing, steam curing, and hot-water curing. Compressive strength tests are conducted after 7-, 28-, 56-, and 90-day curing periods, and an impact resistance experiment is performed after the 90th day. A steam-cured mixture of silica fumes with a specific surface area of 27,600 m2/kg and 16-mm-long fibers produce better results than the other mixtures in terms of mechanical properties. Moreover, impact resistance increases with the fiber aspect ratio. Keywords: Curing, Fineness, UHPFRC, Mechanical properties, Fiber

Effect of gas ratio on tribological properties of sputter deposited TiN coatings

Energy Technology Data Exchange (ETDEWEB)

Chavda, Mahesh R., E-mail: maheshchavda1990@gmail.com [Department of Mechanical Engineering, Dr. Jivraj Mehta Institute of Technology, Mogar-388340 (India); Chauhan, Kamlesh V.; Rawal, Sushant K., E-mail: sushantrawal.me@charusat.ac.in [CHAMOS Matrusanstha Department of Mechanical Engineering, Chandubhai S. Patel Institute of Technology, Charotar University of Science and Technology (CHARUSAT), Changa-388421 (India)

2016-05-06

Titanium nitride (TiN) coatings were deposited on Si, corning glass, pins of mild steel (MS, ϕ3mm), aluminium (Al, ϕ4mm) and brass (ϕ6mm) substratesby DC magnetron sputtering. The argon and nitrogen (Ar:N{sub 2})gas ratio was precisely controlled by Mass Flow Controller (MFC) and was varied systematically at diffract values of 10:10,12:08, 16:04 and 18:02sccm. The structural properties of TiN coatings were characterized by X-ray diffraction (XRD) and its surface topography was studied using field emission scanning electron microscopy (FE-SEM). The tribological properties of TiN coatings were investigated using pin-on-disc tribometer.

Determination of trace amounts of tin in geological materials by atomic absorption spectrometry

Science.gov (United States)

Welsch, E.P.; Chao, T.T.

1976-01-01

An atomic absorption method is described for the determination of traces of tin in rocks, soils, and stream sediments. A dried mixture of the sample and ammonium iodide is heated to volatilize tin tetraiodide -which is then dissolved in 5 % hydrochloric acid, extracted into TOPO-MIBK, and aspirated into a nitrous oxide-acetylene flame. The limit of determination is 2 p.p.m. tin and the relative standard deviation ranges from 2 to 14 %. Up to 20 % iron and 1000 p.p.m. Cu, Pb, Zn, Mn, Hg, Mo, V, or W in the sample do not interfere. As many as 50 samples can be easily analyzed per man-day. ?? 1976.

Sputtered tin oxide and titanium oxide thin films as alternative transparent conductive oxides

Energy Technology Data Exchange (ETDEWEB)

Boltz, Janika

2011-12-12

Alternative transparent conductive oxides to tin doped indium oxide have been investigated. In this work, antimony doped tin oxide and niobium doped titanium oxide have been studied with the aim to prepare transparent and conductive films. Antimony doped tin oxide and niobium doped titanium oxide belong to different groups of oxides; tin oxide is a soft oxide, while titanium oxide is a hard oxide. Both oxides are isolating materials, in case the stoichiometry is SnO{sub 2} and TiO{sub 2}. In order to achieve transparent and conductive films free carriers have to be generated by oxygen vacancies, by metal ions at interstitial positions in the crystal lattice or by cation doping with Sb or Nb, respectively. Antimony doped tin oxide and niobium doped titanium oxide films have been prepared by reactive direct current magnetron sputtering (dc MS) from metallic targets. The process parameters and the doping concentration in the films have been varied. The films have been electrically, optically and structurally analysed in order to analyse the influence of the process parameters and the doping concentration on the film properties. Post-deposition treatments of the films have been performed in order to improve the film properties. For the deposition of transparent and conductive tin oxide, the dominant parameter during the deposition is the oxygen content in the sputtering gas. The Sb incorporation as doping atoms has a minor influence on the electrical, optical and structural properties. Within a narrow oxygen content in the sputtering gas highly transparent and conductive tin oxide films have been prepared. In this study, the lowest resistivity in the as deposited state is 2.9 m{omega} cm for undoped tin oxide without any postdeposition treatment. The minimum resistivity is related to a transition to crystalline films with the stoichiometry of SnO{sub 2}. At higher oxygen content the films turn out to have a higher resistivity due to an oxygen excess. After post