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Sample records for high sn content

  1. Process modules for GeSn nanoelectronics with high Sn-contents

    Science.gov (United States)

    Schulte-Braucks, C.; Glass, S.; Hofmann, E.; Stange, D.; von den Driesch, N.; Hartmann, J. M.; Ikonic, Z.; Zhao, Q. T.; Buca, D.; Mantl, S.

    2017-02-01

    This paper systematically studies GeSn n-FETs, from individual process modules to a complete device. High-k gate stacks and NiGeSn metallic contacts for source and drain are characterized in independent experiments. To study both direct and indirect bandgap semiconductors, a range of 0-14.5 at.% Sn-content GeSn alloys are investigated. Special emphasis is placed on capacitance-voltage (C-V) characteristics and Schottky-barrier optimization. GeSn n-FET devices are presented including temperature dependent I-V characteristics. Finally, as an important step towards implementing GeSn in tunnel-FETs, negative differential resistance in Ge0.87Sn0.13 tunnel-diodes is demonstrated at cryogenic temperatures. The present work provides a base for further optimization of GeSn FETs and novel tunnel FET devices.

  2. High-Reliability Low-Ag-Content Sn-Ag-Cu Solder Joints for Electronics Applications

    Science.gov (United States)

    Shnawah, Dhafer Abdulameer; Said, Suhana Binti Mohd; Sabri, Mohd Faizul Mohd; Badruddin, Irfan Anjum; Che, Fa Xing

    2012-09-01

    Sn-Ag-Cu (SAC) alloy is currently recognized as the standard lead-free solder alloy for packaging of interconnects in the electronics industry, and high- Ag-content SAC alloys are the most popular choice. However, this choice has been encumbered by the fragility of the solder joints that has been observed in drop testing as well as the high cost of the Ag itself. Therefore, low-Ag-content SAC alloy was considered as a solution for both issues. However, this approach may compromise the thermal-cycling performance of the solders. Therefore, to enhance the thermal-cycling reliability of low-Ag-content SAC alloys without sacrificing their drop-impact performance, alloying elements such as Mn, Ce, Ti, Bi, In, Sb, Ni, Zn, Al, Fe, and Co were selected as additions to these alloys. However, research reports related to these modified SAC alloys are limited. To address this paucity, the present study reviews the effect of these minor alloying elements on the solder joint reliability of low-Ag-content SAC alloys in terms of thermal cycling and drop impact. Addition of Mn, Ce, Bi, and Ni to low-Ag-content SAC solder effectively improves the thermal-cycling reliability of joints without sacrificing the drop-impact performance. Taking into consideration the improvement in the bulk alloy microstructure and mechanical properties, wetting properties, and growth suppression of the interface intermetallic compound (IMC) layers, addition of Ti, In, Sb, Zn, Al, Fe, and Co to low-Ag-content SAC solder has the potential to improve the thermal-cycling reliability of joints without sacrificing the drop-impact performance. Consequently, further investigations of both thermal-cycling and drop reliability of these modified solder joints must be carried out in future work.

  3. Strain engineering in epitaxial Ge1‑ x Sn x : a path towards low-defect and high Sn-content layers

    Science.gov (United States)

    Margetis, Joe; Yu, Shui-Qing; Bhargava, Nupur; Li, Baohua; Du, Wei; Tolle, John

    2017-12-01

    The plastic strain relaxation of CVD-grown Ge1‑x Sn x layers was investigated in x = 0.09 samples with thicknesses of 152, 180, 257, 570, and 865 nm. X-ray diffraction-reciprocal space mapping was used to determine the strain, composition, and the nature of defects in each layer. Secondary ion mass spectrometry was used to examine the evolution of the compositional profile. These results indicate that growth beyond the critical thickness results in the spontaneous formation of a relaxed and highly defective 9% Sn layer followed by a low defect 12% Sn secondary layer. We find that this growth method can be used to engineer thick, strain-relaxed, and low defect density layers. Furthermore we utilize this strain-dependent Sn incorporation behavior to achieve Sn compositions of 17.5%. Photoluminesence of these layers produces light emission at 3.1 μm.

  4. The Effect of Increasing Sn Content on High-Temperature Mechanical Deformation of an Mg-3%Cu-1%Ca Alloy

    Directory of Open Access Journals (Sweden)

    Georgios S.E. Antipas

    2013-11-01

    Full Text Available Chill casting of magnesium alloy samples with secondary alloying elements of Cu, Ca and Sn at % w.t. concentrations in the range 1–5, 0.1–5 and 0.1–3 respectively, gave rise to appreciably enhanced resistance to high-temperature creep, while maintaining good heat conductivity. The latter was considered to be driven by Cu and Mg-Cu intermetallics while it was clear that Sn mediated the high-temperature performance, mainly via networks of Mg2Sn and MgCaSn precipitates along the Mg matrix grain boundaries. It was postulated that Sn formed intermetallics by preferential substitution of Ca atoms and, thus, did not degrade the heat conductivity by retaining Cu. The % w.t. stoichiometry with the optimum combination of heat conductivity and resistance to high-temperature creep was found to be Mg-3Cu-1Ca-0.1Sn.

  5. Optical critical points of Si x Ge1‑x‑y Sn y alloys with high Si content

    Science.gov (United States)

    Fischer, Inga A.; Berrier, Audrey; Hornung, Florian; Oehme, Michael; Zaumseil, Peter; Capellini, Giovanni; von den Driesch, Nils; Buca, Dan; Schulze, Jörg

    2017-12-01

    We extend the analysis of optical transition energies above 1.5 eV in ternary Si x Ge1‑x‑y Sn y alloys grown by molecular beam epitaxy to a composition range in which 1‑x‑y is as low as 0.405. Simple models for transition energies assume a quadratic dependence on material content. Comparing our results to existing predictions of the transition energies based on results obtained from samples with much lower Si and Sn content, however, we find a significant disagreement between experiment and theory, indicating that the assumption of a quadratic dependence might not be valid for the entire composition range of the ternary alloy.

  6. Structural reconstruction: a milestone in the hydrothermal synthesis of highly active Sn-Beta zeolites.

    Science.gov (United States)

    Zhu, Zhiguo; Xu, Hao; Jiang, Jingang; Wu, Haihong; Wu, Peng

    2017-11-21

    A novel structural reconstruction strategy is proposed to prepare an active Sn-Beta catalyst with high Sn contents and a hydrophobic nature. Compared with post-synthesized Sn-Beta and state-of-the-art classic fluoride-mediated Sn-Beta-F, this Sn-Beta zeolite exhibits unparalleled active site-based turnover frequency for desirable products and in particular catalyst weight-based space-time-yields in various redox reactions of ketones.

  7. Controlling the antibacterial activity of CuSn thin films by varying the contents of Sn

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Yujin; Park, Juyun; Kim, Dong-Woo; Kim, Hakjun; Kang, Yong-Cheol, E-mail: yckang@pknu.ac.kr

    2016-12-15

    Highlights: • We deposit CuSn thin films on a Si substrate with various Cu/Sn ratio. • Antibacterial activities of CuSn thin films increased as the ratio of Cu and the contact time increased. • XPS was utilized to assign the chemical environment of CuSn thin films before and after antibacterial test. - Abstract: We investigated antibacterial activity of CuSn thin films against Gram positive Staphylococcus aureus (S. aureus). CuSn thin films with different Cu to Sn ratios were deposited on Si(100) by radio frequency (RF) magnetron sputtering method using Cu and Sn metal anodes. The film thickness was fixed at 200 nm by varying the sputtering time and RF power on the metal targets. The antibacterial test was conducted in various conditions such as different contact times and Cu to Sn ratios in the CuSn films. The antibacterial activities of CuSn thin films increased as the ratio of Cu and the contact time between the film and bacteria suspension increased execpt in the case of CuSn-83. The oxidation states of Cu and Sn and the chemical composition of CuSn thin films before and after the antibacterial test were investigated by X-ray photoelectron spectroscopy (XPS). When the contact time was fixed, the Cu species was further oxidized as the RF power on Cu target increased. The intensity of Sn 3d decreased with increasing Cu ratio. When the sample was fixed, the peak intensity of Sn 3d decreased as the contact time increased due to the permeation of Sn into the cell.

  8. Growth of Cu2ZnSnSe4 Film under Controllable Se Vapor Composition and Impact of Low Cu Content on Solar Cell Efficiency.

    Science.gov (United States)

    Li, Jianjun; Wang, Hongxia; Wu, Li; Chen, Cheng; Zhou, Zhiqiang; Liu, Fangfang; Sun, Yun; Han, Junbo; Zhang, Yi

    2016-04-27

    It is a challenge to fabricate high quality Cu2ZnSnSe4 (CZTSe) film with low Cu content (Cu/(Zn + Sn) photovoltaic performance of the corresponding CZTSe solar cells has shown that the roughness of the CZTSe absorber film increases when Cu content decreases. As a consequence, the reflection loss of CZTSe solar cells reduces dramatically and the short circuit current density of the cells improve from 34.7 mA/cm(2) for Cu/(Zn + Sn) = 0.88 to 38.5 mA/cm(2) for Cu/(Zn + Sn) = 0.75. In addition, the CZTSe solar cells with low Cu content show longer minority carrier lifetime and higher open circuit voltage than the high Cu content devices. A champion performance CZTSe solar cell with 10.4% efficiency is fabricated with Cu/(Zn + Sn) = 0.75 in the CZTSe film without antireflection coating.

  9. Characterisation of Fecal Soap Fatty Acids, Calcium Contents, Bacterial Community and Short-Chain Fatty Acids in Sprague Dawley Rats Fed with Different sn-2 Palmitic Triacylglycerols Diets.

    Science.gov (United States)

    Wan, Jianchun; Hu, Songyou; Ni, Kefeng; Chang, Guifang; Sun, Xiangjun; Yu, Liangli

    2016-01-01

    The structure of dietary triacylglycerols is thought to influence fatty acid and calcium absorption, as well as intestinal microbiota population of the host. In the present study, we investigated the impact of palmitic acid (PA) esterified at the sn-2 position on absorption of fatty acid and calcium and composition of intestinal microorganisms in rats fed high-fat diets containing either low sn-2 PA (12.1%), medium sn-2 PA (40.4%) or high sn-2 PA (56.3%), respectively. Fecal fatty acid profiles in the soaps were measured by gas chromatography (GC), while fecal calcium concentration was detected by ICP-MS. The fecal microbial composition was assessed using a 16S rRNA high-throughput sequencing technology and fecal short-chain fatty acids were detected by ion chromatograph. Dietary supplementation with a high sn-2 PA fat significantly reduced total fecal contents of fatty acids soap and calcium compared with the medium or low sn-2 PA fat groups. Diet supplementation with sn-2 PA fat did not change the entire profile of the gut microbiota community at phylum level and the difference at genera level also were minimal in the three treatment groups. However, high sn-2 PA fat diet could potentially improve total short-chain fatty acids content in the feces, suggesting that high dietary sn-2 PA fat might have a beneficial effect on host intestinal health.

  10. Monodisperse and inorganically capped Sn and Sn/SnO2 nanocrystals for high-performance Li-ion battery anodes.

    Science.gov (United States)

    Kravchyk, Kostiantyn; Protesescu, Loredana; Bodnarchuk, Maryna I; Krumeich, Frank; Yarema, Maksym; Walter, Marc; Guntlin, Christoph; Kovalenko, Maksym V

    2013-03-20

    We report a facile synthesis of highly monodisperse colloidal Sn and Sn/SnO2 nanocrystals with mean sizes tunable over the range 9-23 nm and size distributions below 10%. For testing the utility of Sn/SnO2 nanocrystals as an active anode material in Li-ion batteries, a simple ligand-exchange procedure using inorganic capping ligands was applied to facilitate electronic connectivity within the components of the nanocrystalline electrode. Electrochemical measurements demonstrated that 10 nm Sn/SnO2 nanocrystals enable high Li insertion/removal cycling stability, in striking contrast to commercial 100-150 nm powders of Sn and SnO2. In particular, reversible Li-storage capacities above 700 mA h g(-1) were obtained after 100 cycles of deep charging (0.005-2 V) at a relatively high current of 1000 mA h g(-1).

  11. High-pressure high-temperature crystal growth of equiatomic rare earth stannides RENiSn and REPdSn

    Energy Technology Data Exchange (ETDEWEB)

    Heymann, Gunter [Institut für Allgemeine, Anorganische und Theoretische Chemie, Leopold-Franzens-Universität Innsbruck, Innrain 80-82, A-6020 Innsbruck (Austria); Heying, Birgit; Rodewald, Ute Ch.; Janka, Oliver [Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstraße 30, 48149 Münster (Germany); Huppertz, Hubert, E-mail: Hubert.Huppertz@uibk.ac.at [Institut für Allgemeine, Anorganische und Theoretische Chemie, Leopold-Franzens-Universität Innsbruck, Innrain 80-82, A-6020 Innsbruck (Austria); Pöttgen, Rainer, E-mail: pottgen@uni-muenster.de [Institut für Anorganische und Analytische Chemie, Universität Münster, Corrensstraße 30, 48149 Münster (Germany)

    2016-04-15

    The two series of equiatomic rare earth (RE) stannides RENiSn and REPdSn were systematically studied with respect to high-pressure modifications. The normal-pressure (NP) low-temperature (LT) modifications were synthesized by arc-melting and subsequently treated under high-pressure (P{sub max}=11.5 GPa) and high-temperature (T{sub max}=1570 K) conditions in a Walker-type multi-anvil press. The pressure and temperature conditions were systematically varied in order to improve the crystallization conditions. The new ZrNiAl-type high-pressure modifications HP-RENiSn (RE=Sc, Y, La, Gd–Lu) and HP-REPdSn (RE=Y, Sm–Dy) were obtained in 80 mg quantities, several of them in X-ray pure form. Some of the REPdSn stannides with the heavy rare earth elements show high-temperature (HT) modifications. The structures of HP-ScNiSn, HP-GdNiSn, HP-DyNiSn (both ZrNiAl-type), NP-YbNiSn, and HT-ErPdSn (both TiNiSi-type) were refined from single crystal diffractometer data, indicating full ordering of the transition metal and tin sites. TiNiSi-type NP-EuPdSn transforms to MgZn{sub 2}-type HP-EuPdSn: P6{sub 3}/mmc, a=588.5(2), c=917.0(3) pm, wR2=0.0769, 211 F{sup 2} values, 11 variables. The structure refinement indicated statistical occupancy of the palladium and tin sites on the tetrahedral network. The X-ray pure high-pressure phases were studied with respect to their magnetic properties. HP-YPdSn is a Pauli paramagnet. The susceptibility data of HP-TbNiSn, HP-DyNiSn, HP-GdPdSn, and HP-TbPdSn show experimental magnetic moments close to the free ion values of RE{sup 3+} and antiferromagnetic ordering at low temperature with the highest Néel temperature of 15.8 K for HP-TbPdSn. HP-SmPdSn shows the typical Van Vleck type behavior along with antiferromagnetic ordering at T{sub N}=5.1 K. HP-EuPdSn shows divalent europium and antiferromagnetic ordering at 8.9 K followed by a spin reorientation at 5.7 K. - Graphical abstract: Packing of the polyhedra in the high-pressure phase of EuPdSn

  12. SnTe-TiC-C composites as high-performance anodes for Li-ion batteries

    Science.gov (United States)

    Son, Seung Yeon; Hur, Jaehyun; Kim, Kwang Ho; Son, Hyung Bin; Lee, Seung Geol; Kim, Il Tae

    2017-10-01

    Intermetallic SnTe composites dispersed in a conductive TiC/C hybrid matrix are synthesized by high-energy ball milling (HEBM). The electrochemical performances of the composites as potential anodes for Li-ion batteries are evaluated. The structural and morphological characteristics of the SnTe-TiC-C composites with various TiC contents are investigated by X-ray diffraction (XRD) and high-resolution transmission electron microscopy, which reveal that SnTe and TiC are uniformly dispersed in a carbon matrix. The electrochemical performance is significantly improved by introducing TiC to the SnTe-C composite; higher TiC contents result in better performances. Among the prepared composites, the SnTe-TiC (30%)-C and SnTe-TiC (40%)-C electrodes exhibit the best electrochemical performance, showing the reversible capacities of, respectively, 652 mAh cm-3 and 588 mAh cm-3 after 400 cycles and high rate capabilities with the capacity retentions of 75.4% for SnTe-TiC (30%)-C and 82.2% for SnTe-TiC (40%)-C at 10 A g-1. Furthermore, the Li storage reaction mechanisms of Te or Sn in the SnTe-TiC-C electrodes are confirmed by ex situ XRD.

  13. Pulse number controlled laser annealing for GeSn on insulator structure with high substitutional Sn concentration

    Energy Technology Data Exchange (ETDEWEB)

    Moto, Kenta; Sadoh, Taizoh; Miyao, Masanobu, E-mail: miyao@ed.kyushu-u.ac.jp [Department of Electronics, Kyushu University, 744 Motooka, Fukuoka 819-0395 (Japan); Matsumura, Ryo [Department of Electronics, Kyushu University, 744 Motooka, Fukuoka 819-0395 (Japan); JSPS, 5-3-1 Kojimachi, Chiyoda-ku, Tokyo 102-0083 (Japan); Ikenoue, Hiroshi [Department of Gigaphoton Next GLP, Kyushu University, 744 Motooka, Fukuoka 819-0395 (Japan)

    2016-06-27

    Crystalline GeSn-on-insulator structures with high Sn concentration (>8%), which exceeds thermal equilibrium solid-solubility (∼2%) of Sn in Ge, are essential to achieve high-speed thin film transistors and high-efficiency optical devices. We investigate non-thermal equilibrium growth of Ge{sub 1−x}Sn{sub x} (0 ≤ x ≤ 0.2) on quartz substrates by using pulsed laser annealing (PLA). The window of laser fluence enabling complete crystallization without film ablation is drastically expanded (∼5 times) by Sn doping above 5% into Ge. Substitutional Sn concentration in grown layers is found to be increased with decreasing irradiation pulse number. This phenomenon can be explained on the basis of significant thermal non-equilibrium growth achieved by higher cooling rate after PLA with a lower pulse number. As a result, GeSn crystals with substitutional Sn concentration of ∼12% are realized at pulse irradiation of single shot for the samples with the initial Sn concentration of 15%. Raman spectroscopy and electron microscopy measurements reveal the high quality of the grown layer. This technique will be useful to fabricate high-speed thin film transistors and high-efficiency optical devices on insulating substrates.

  14. Epitaxial Technologies for SiGeSn High Performance Optoelectronic Devices

    Science.gov (United States)

    2015-04-29

    includes i) Growth of mid-IR GeSn/SiGeSn materials using Ultra-high- vacuum Chemical Vapor Deposition , ii) In-depth characterizations of GeSn materials...shrinkage has been observed in heavily doped n-type samples. GeSn samples have been fabricated into photoconductive detectors, avalanche photo diodes, and...low temperatures using two different Sn precursors (SnCl4 and SnD4) via a cold-wall ultra-high-vacuum chemical-vapor- deposition system (UHV- CVD

  15. Influence of Sn content on microstructural and mechanical properties of centrifugal cast Ti-Nb-Sn biomedical alloys; Efeitos da adicao de Sn na evolucao microestrutural e em propriedades mecanicas de ligas Ti-Nb-Sn biomedicas fundidas por centrifugacao

    Energy Technology Data Exchange (ETDEWEB)

    Lopes, E.S.N.; Contieri, R.J.; Caram, R., E-mail: ederlopes@fem.unicamp.b [Universidade Estadual de Campinas (DEMA/FEM/UNICAMP), SP (Brazil). Fac. de Engenharia Mecanica. Dept. de Engenharia de Materiais; Moraes, P.E.L. [FATEC Artur Azevedo, Mogi Mirim, SP (Brazil); Costa, A.M.S. [Universidade de Sao Paulo (DEMAR/EEL/USP), Lorena, SP (Brazil). Escola de Engenharia. Dept. de Engenharia de Materiais

    2010-07-01

    The arc voltaic centrifugal casting is an interesting alternative in terms of economic and technological development in the production of components based on materials with high reactivity and high melting point, such as titanium alloys. In this work, Ti-30Nb (wt. %) with additions of Sn (2, 4, 6, 8 and 10 wt. %) were formed by casting process. Characterization of the samples included optical microscopy, scanning electron microscopy, X-ray diffraction, Vickers hardness and elastic modulus measures by acoustic techniques. It was observed that the microstructure of the samples investigated is composed by dendritic structures, with clear segregation of alloying elements. The Vickers hardness and the elastic modulus decreased with the addition of Sn. The results show that the mechanical behavior of Ti-Nb alloys can be controlled within certain limits, by adding Sn. (author)

  16. Synthesis and high sensing properties of a single Pd-doped SnO2 nanoribbon

    OpenAIRE

    Ma, Jiang; Liu, Yingkai; Zhang, Heng; Ai, Peng; Gong, Nailiang; Zhang, Ying

    2014-01-01

    Monocrystal SnO2 and Pd-SnO2 nanoribbons have been successfully synthesized by thermal evaporation, and novel ethanol sensors based on a single Pd-SnO2 nanoribbon and a single SnO2 nanoribbon were fabricated. The sensing properties of SnO2 nanoribbon (SnO2 NB) and Pd-doped SnO2 nanoribbon (Pd-SnO2 NB) sensors were investigated. The results indicated that the SnO2 NB showed a high sensitivity to ethanol and the Pd-SnO2 NB has a much higher sensitivity of 4.3 at 1,000 ppm of ethanol at 230°C, w...

  17. Graphene-SnO2 composites for highly efficient photocatalytic degradation of methylene blue under sunlight.

    Science.gov (United States)

    Seema, Humaira; Christian Kemp, K; Chandra, Vimlesh; Kim, Kwang S

    2012-09-07

    Graphene sheets decorated with SnO(2) nanoparticles (RGO-SnO(2)) were prepared via a redox reaction between graphene oxide (GO) and SnCl(2). Graphene oxide (GO) was reduced to graphene (RGO) and Sn(2+) was oxidized to SnO(2) during the redox reaction, leading to a homogeneous distribution of SnO(2) nanoparticles on RGO sheets. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images show uniform distribution of the nanoparticles on the RGO surface and high-resolution transmission electron microscopy (HRTEM) shows an average particle size of 3-5 nm. The RGO-SnO(2) composite showed an enhanced photocatalytic degradation activity for the organic dye methylene blue under sunlight compared to bare SnO(2) nanoparticles. This result leads us to believe that the RGO-SnO(2) composite could be used in catalytic photodegradation of other organic dyes.

  18. Microstructure Evolution of Cu-Cored Sn Solder Joints Under High Temperature and High Current Density

    Science.gov (United States)

    Sa, Xianzhang; Wu, Ping

    2013-08-01

    This work investigated the microstructure evolution of Cu-cored Sn solder joints under high temperature and high current density. The Cu6Sn5 phase formed at both the Cu core/Sn interface and Cu wire/Sn interface right after reflow and grew with increasing annealing time, while the Cu3Sn phase formed and grew at the Cu/Cu6Sn5 interfaces. Intermetallic compound (IMC) growth followed a linear relationship with the square root of annealing time due to a diffusion-controlled mechanism. Under high current density, the thickness of the interfacial IMCs of the Cu core/Sn interface at the cathode side increased and the Cu core/Sn interface at the anode side exhibited an irregular and serrated morphology with prolonged current stressing time. Finite-element simulation was carried out to obtain the distribution of current density in the solder joint. Since Cu has lower resistivity, the electrical current primarily selected the Cu core as its electrical path, resulting in current crowding at the Cu core and the region between the Cu core and Cu wire. Compared with the conventional solder joint, the electromigration (EM) lifetime of the Cu-cored solder joint was much longer.

  19. A facile one-pot reduction method for the preparation of a SnO/SnO2/GNS composite for high performance lithium ion batteries.

    Science.gov (United States)

    Chen, Xiao-Ting; Wang, Kai-Xue; Zhai, Yu-Bo; Zhang, Hao-Jie; Wu, Xue-Yan; Wei, Xiao; Chen, Jie-Sheng

    2014-02-28

    A SnO/SnO2/GNS composite with controlled oxidation states and composition has been prepared through simple one-pot reduction of an EG suspension of SnCl2 and graphene oxide. The as-prepared composite was characterized by XRD, FT-IR, XPS, SEM, TEM and BET. SnO and SnO2 nanoparticles are uniformly distributed on the surface of the graphene. Taking advantage of the high electron conductivity of graphene and the large theoretical capacity of SnO, this SnO/SnO2/GNS composite exhibits high charge/discharge capacity, good cycling stability and good rate capability. A specific discharge capacity of approximately 464.2 mA h g(-1) is retained after being charged/discharged at a current density of 1000 mA g(-1) for 30 cycles.

  20. CoSn-graphite electrode material prepared by using the polyol method and high-intensity ultrasonication

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Jose R. [Laboratorio de Quimica Inorganica, Universidad de Cordoba, Edificio C3, Campus de Rabanales, 14071 Cordoba (Spain); Alcantara, Ricardo, E-mail: iq2alror@uco.es [Laboratorio de Quimica Inorganica, Universidad de Cordoba, Edificio C3, Campus de Rabanales, 14071 Cordoba (Spain); Nacimiento, Francisco; Tirado, Jose L. [Laboratorio de Quimica Inorganica, Universidad de Cordoba, Edificio C3, Campus de Rabanales, 14071 Cordoba (Spain)

    2011-11-30

    Highlights: > New anode materials are prepared by combined polyol and ultrasonication methods. > Highly-dispersed, amorphous nano-CoSn/ultrathin graphite composites can be obtained. > Ultrasonication under Ar-flow and LiPAA-binder leads to high Coulombic efficiency. - Abstract: Composite electrode materials containing nanoparticles of nearly amorphous CoSn and ultrathin layers of graphite are prepared here. For this purpose, Sn(II) and Co(II) ions in tetraethyleneglycol are reduced with NaBH{sub 4} in the presence of ball-milled graphite while high-intensity ultrasonication is continuously applied. The followed preparative route is a combination of the polyol and sonochemical methods. The observed capacity value for CoSn-ball milled graphite is over 400 mAh/g after 40 cycles (this is superior to graphite). The good electrochemical cycling behavior is connected to the small particle size of CoSn, the low crystallinity of CoSn and the dispersion of the CoSn particles in an optimized carbon matrix. The selected binder (polyvinylidene fluoride or lithium polyacrylate) also can contribute to improve the cycling behavior. The low electrochemical efficiency, particularly in the first cycles, may be related to the spontaneous oxidation of the metallic particles surface and irreversible electrolyte consumption. The use of inert atmosphere (Ar-flow) results in a decrease of the tin oxide content, as determined by using {sup 119}Sn Moessbauer spectroscopy, an increase of the initial electrochemical efficiency up to a maximum of 90.4%, and higher capacities (507 mAh/g after 40 cycles).

  1. Microstructural Aspects of Fatigue Parameters of Lead-Free Sn-Zn Solders with Various Zn Content

    Directory of Open Access Journals (Sweden)

    Pietrzak K.

    2017-03-01

    Full Text Available The study includes the results of research conducted on selected lead-free binary solder alloys designed for operation at high temperatures. The results of qualitative and quantitative metallographic examinations of SnZn alloys with various Zn content are presented. The quantitative microstructure analysis was carried out using a combinatorial method based on phase quanta theory, per which any microstructure can be treated as an array of elements disposed in the matrix material. Fatigue tests were also performed using the capabilities of a modified version of the LCF method hereinafter referred to in short as MLCF, which is particularly useful in the estimation of mechanical parameters when there are difficulties in obtaining many samples normally required for the LCF test. The fatigue life of alloys was analyzed in the context of their microstructure. It has been shown that the mechanical properties are improved with the Zn content increasing in the alloy. However, the best properties were obtained in the alloy with a chemical composition close to the eutectic system, when the Zn-rich precipitates showed the most preferred morphological characteristics. At higher content of Zn, a strong structural notch was formed in the alloy because of the formation in the microstructure of a large amount of the needle-like Zn-rich precipitates deteriorating the mechanical characteristics. Thus, the results obtained during previous own studies, which in the field of mechanical testing were based on static tensile test only, have been confirmed. It is interesting to note that during fatigue testing, both significant strengthening and weakening of the examined material can be expected. The results of fatigue tests performed on SnZn alloys have proved that in this case the material was softened.

  2. Powder-in-tube (PIT) $Nb_{3}Sn$ conductors for high-field magnets

    CERN Document Server

    Lindenhovius, J L H; den Ouden, A; Wessel, W A J; ten Kate, H H J

    2000-01-01

    New Nb/sub 3/Sn conductors, based on the powder-in-tube (PIT) process, have been developed for application in accelerator magnets and high-field solenoids. For application in accelerator magnets, SMI has developed a binary 504 filament PIT conductor by optimizing the manufacturing process and adjustment of the conductor lay-out. It uniquely combines a non-copper current density of 2680 A/mm/sup 2/@10 T with an effective filament diameter of about 20 mu m. This binary conductor may be used in a 10 T, wide bore model separator dipole magnet for the LHC, which is being developed by a collaboration of the University of Twente and CERN. A ternary (Nb/7.5wt%Ta)/sub 3/Sn conductor containing 37 filaments is particularly suited for application in extremely high-field superconducting solenoids. This wire features a copper content of 43%, a non-copper current density of 217 A/mm/sup 2/@20 T and a B/sub c2/ of 25.6 T. The main issues and the experimental results of the development program of PIT Nb/sub 3/Sn conductors a...

  3. Highly fluorescent peptide nanoribbon impregnated with Sn-porphyrin as a potent DNA sensor.

    Science.gov (United States)

    Parayil, Sreenivasan Koliyat; Lee, Jooran; Yoon, Minjoong

    2013-05-01

    Highly fluorescent and thermo-stable peptide nanoribbons (PNRs) were fabricated by solvothermal self-assembly of a single peptide (D,D-diphenyl alanine peptides) with Sn-porphyrin (trans-dihydroxo[5,10,15,20-tetrakis(p-tolyl)porphyrinato] Sn(IV) (SnTTP(OH)2)). The structural characterization of the as-prepared nanoribbons was performed by transmitting electron microscopy (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM), FT-IR and Raman spectroscopy, indicating that the lipophilic Sn-porphyrins are impregnated into the porous surface formed in the process of nanoribbon formation through intermolecular hydrogen bonding of the peptide main chains. Consequently the Sn-porphyrin-impregnated peptide nanoribbons (Sn-porphyrin-PNRs) exhibited typical UV-visible absorption spectrum of the monomer porphyrin with a red shifted Q-band, and their fluorescence quantum yield was observed to be enhanced compared to that of free Sn-porphyrin. Interestingly the fluorescence intensity and lifetimes of Sn-porphyrin-PNRs were selectively affected upon interaction with nucleotide base sequences of DNA while those of free Sn-porphyrins were not affected by binding with any of the DNA studied, indicating that DNA-induced changes in the fluorescence properties of Sn-porphyrin-PNRs are due to interaction between DNA and the PNR scaffold. These results imply that Sn-porphyrin-PNR will be useful as a potent fluorescent protein analogue and as a biocompatible DNA sensor.

  4. 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.

  5. Characterization of nanostructured alpha-Fe2O3-SnO2 solid solutions prepared by high energy ball milling

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Lin, R.; Mørup, Steen

    1998-01-01

    Solid solutions of SnO2 in alpha-Fe2O3 with SnO2 contents up to 20+-4 mol% have been prepared by mechanical alloying of alpha-Fe2O3 and SnO2 powder blends. X-ray diffraction and Mossbauer spectroscopy investigations show that the mechanical milling results in alloying on an atomic scale...... and that true solid solution formation occurs. We suggest that the high defect concentration and the chemical enthalpy of Fe3+ -O2- -Sn4+ interfaces between nanostructured alpha-Fe2O3 and SnO2 regions may serve as a driving force for the formation of a solid solution in the immiscible ceramic system....

  6. Dominant effect of high anisotropy in β-Sn grain on electromigration-induced failure mechanism in Sn-3.0Ag-0.5Cu interconnect

    Energy Technology Data Exchange (ETDEWEB)

    Huang, M.L., E-mail: huang@dlut.edu.cn; Zhao, J.F.; Zhang, Z.J.; Zhao, N.

    2016-09-05

    The effect of high diffusivity anisotropy in β-Sn grain on electromigration behavior of micro-bumps was clearly demonstrated using Sn-3.0Ag-0.5Cu solder interconnects with only two β-Sn grains. The orientation of β-Sn grain (θ is defined as the angle between the c-axis of β-Sn grain and the electron flow direction) is becoming the most crucial factor to dominate the different electromigration-induced failure modes: 1) the excessive dissolution of the cathode Cu, blocking at the grain boundary and massive precipitation of columnar Cu{sub 6}Sn{sub 5} intermetallic compounds (IMCs) in the small angle θ β-Sn grain occur when electrons flow from a small angle θ β-Sn grain to a large one; 2) void formation and propagation occur at the cathode IMC/solder interface and no Cu{sub 6}Sn{sub 5} IMCs precipitate within the large angle θ β-Sn grain when electrons flow in the opposite direction. The EM-induced failure mechanism of the two β-Sn grain solder interconnects is well explained in viewpoint of atomic diffusion flux in β-Sn. - Highlights: • High anisotropy in β-Sn dominates different electromigration-induced failure mode. • Excessive dissolution of cathode Cu occurs if electrons flow in forward direction. • Voids initiate and propagate at cathode if electrons flow in reverse direction. • Failure modes are well explained in viewpoint of atomic diffusion flux in β-Sn.

  7. Synthesis and high sensing properties of a single Pd-doped SnO2 nanoribbon.

    Science.gov (United States)

    Ma, Jiang; Liu, Yingkai; Zhang, Heng; Ai, Peng; Gong, Nailiang; Zhang, Ying

    2014-01-01

    Monocrystal SnO2 and Pd-SnO2 nanoribbons have been successfully synthesized by thermal evaporation, and novel ethanol sensors based on a single Pd-SnO2 nanoribbon and a single SnO2 nanoribbon were fabricated. The sensing properties of SnO2 nanoribbon (SnO2 NB) and Pd-doped SnO2 nanoribbon (Pd-SnO2 NB) sensors were investigated. The results indicated that the SnO2 NB showed a high sensitivity to ethanol and the Pd-SnO2 NB has a much higher sensitivity of 4.3 at 1,000 ppm of ethanol at 230°C, which is the highest sensitivity for a SnO2-based NB. Pd-SnO2 NB can detect ethanol in a wide range of concentration (1 ~ 1,000 ppm) with a relatively quick response (recovery) time of 8 s (9 s) at a temperature from 100°C to 300°C. In the meantime, the sensing capabilities of the Pd-SnO2 NB under 1 ppm of ethanol at 230°C will help to promote the sensitivity of a single nanoribbon sensor. Excellent performances of such a sensor make it a promising candidate for a device design toward ever-shrinking dimensions because a single nanoribbon device is easily integrated in the electronic devices.

  8. Synthesis of SnO2 versus Sn crystals within N-doped porous carbon nanofibers via electrospinning towards high-performance lithium ion batteries.

    Science.gov (United States)

    Wang, Hongkang; Lu, Xuan; Li, Longchao; Li, Beibei; Cao, Daxian; Wu, Qizhen; Li, Zhihui; Yang, Guang; Guo, Baolin; Niu, Chunming

    2016-04-14

    The design of tin-based anode materials (SnO2 or Sn) has become a major concern for lithium ion batteries (LIBs) owing to their different inherent characteristics. Herein, particulate SnO2 or Sn crystals coupled with porous N-doped carbon nanofibers (denoted as SnO2/PCNFs and Sn/PCNFs, respectively) are fabricated via the electrospinning method. The electrochemical behaviors of both SnO2/PCNFs and Sn/PCNFs are systematically investigated as anodes for LIBs. When coupled with porous carbon nanofibers, both SnO2 nanoparticles and Sn micro/nanoparticles display superior cycling and rate performances. SnO2/PCNFs and Sn/PCNFs deliver discharge capacities of 998 and 710 mA h g(-1) after 140 cycles (at 100, 200, 500 and 1000 mA g(-1) each for 10 cycles and then 100 cycles at 100 mA g(-1)), respectively. However, the Sn/PCNF electrodes show better cycling stability at higher current densities, delivering higher discharge capacities of 700 and 550 mA h g(-1) than that of SnO2/PCNFs (685 and 424 mA h g(-1)) after 160 cycles at 200 and 500 mA g(-1), respectively. The different superior electrochemical performance is attributed to the introduction of porous N-doped carbon nanofibers and their self-constructed networks, which, on the one hand, greatly decrease the charge-transfer resistance due to the high conductivity of N-doped carbon fibers; on the other hand, the porous carbon nanofibers with numerous voids and flexible one-dimensional (1D) structures efficiently alleviate the volume changes of SnO2 and Sn during the Li-Sn alloying-dealloying processes. Moreover, the discussion of the electrochemical behaviors of SnO2vs. Sn would provide new insights into the design of tin-based anode materials for practical applications, and the current strategy demonstrates great potential in the rational design of metallic tin-based anode materials.

  9. Fabrication of ternary reduced graphene oxide/SnS2/ZnFe2O4composite for high visible-light photocatalytic activity and stability.

    Science.gov (United States)

    Deng, Fang; Lu, Xiaoying; Pei, Xule; Luo, Xubiao; Luo, Shenglian; Dionysiou, Dionysios D

    2017-06-15

    Metal sulfides are promising photocatalysts for efficient removal of organic pollutants in wastewater. However, the practical application of these catalysts is limited due to the fast recombination of charge carriers and poor catalyst stability. In this study, ternary reduced graphene oxide/SnS 2 /ZnFe 2 O 4 (rGO/SnS 2 /ZnFe 2 O 4 ) composites were synthesized by a hydrothermal process, and rGO content was optimized. The surface morphology, crystal structure, optical and electrochemical properties of rGO/SnS 2 /ZnFe 2 O 4 composites were characterized. The adsorption capacity and visible-light photocatalytic activity of rGO/SnS 2 /ZnFe 2 O 4 were influenced by rGO content with results revealing an optimal rGO content of 7wt.%. The 7% rGO/SnS 2 /ZnFe 2 O 4 composite demonstrated the highest visible-light photocatalytic activity with almost 100% 2-nitrophenol removal, which could be attributed to the efficient charge separation, and the formation of O 2 - , h + and a few OH radicals. The possible photocatalytic mechanism of rGO/SnS 2 /ZnFe 2 O 4 composites was also provided based on the role of rGO and the energy bands of SnS 2 and ZnFe 2 O 4 . Moreover, rGO/SnS 2 /ZnFe 2 O 4 composites exhibit excellent reusability without an obvious decline in the photocatalytic activity after four degradation-regeneration cycles. The results indicate that ternary rGO/SnS 2 /ZnFe 2 O 4 composites have good prospect in practical removal of organic pollutants in wastewater due to high efficiency and excellent stability. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. High-mobility BaSnO3 grown by oxide molecular beam epitaxy

    Directory of Open Access Journals (Sweden)

    Santosh Raghavan

    2016-01-01

    Full Text Available High-mobility perovskite BaSnO3 films are of significant interest as new wide bandgap semiconductors for power electronics, transparent conductors, and as high mobility channels for epitaxial integration with functional perovskites. Despite promising results for single crystals, high-mobility BaSnO3 films have been challenging to grow. Here, we demonstrate a modified oxide molecular beam epitaxy (MBE approach, which supplies pre-oxidized SnOx. This technique addresses issues in the MBE of ternary stannates related to volatile SnO formation and enables growth of epitaxial, stoichiometric BaSnO3. We demonstrate room temperature electron mobilities of 150 cm2 V−1 s−1 in films grown on PrScO3. The results open up a wide range of opportunities for future electronic devices.

  11. High-mobility BaSnO{sub 3} grown by oxide molecular beam epitaxy

    Energy Technology Data Exchange (ETDEWEB)

    Raghavan, Santosh; Schumann, Timo; Kim, Honggyu; Zhang, Jack Y.; Cain, Tyler A.; Stemmer, Susanne, E-mail: stemmer@mrl.ucsb.edu [Materials Department, University of California, Santa Barbara, California 93106-5050 (United States)

    2016-01-01

    High-mobility perovskite BaSnO{sub 3} films are of significant interest as new wide bandgap semiconductors for power electronics, transparent conductors, and as high mobility channels for epitaxial integration with functional perovskites. Despite promising results for single crystals, high-mobility BaSnO{sub 3} films have been challenging to grow. Here, we demonstrate a modified oxide molecular beam epitaxy (MBE) approach, which supplies pre-oxidized SnO{sub x}. This technique addresses issues in the MBE of ternary stannates related to volatile SnO formation and enables growth of epitaxial, stoichiometric BaSnO{sub 3}. We demonstrate room temperature electron mobilities of 150 cm{sup 2} V{sup −1} s{sup −1} in films grown on PrScO{sub 3}. The results open up a wide range of opportunities for future electronic devices.

  12. 3D Flower-Like Hierarchitectures Constructed by SnS/SnS2 Heterostructure Nanosheets for High-Performance Anode Material in Lithium-Ion Batteries

    Directory of Open Access Journals (Sweden)

    Zhiguo Wu

    2015-01-01

    Full Text Available Sn chalcogenides, including SnS, Sn2S3, and SnS2, have been extensively studied as anode materials for lithium batteries. In order to obtain one kind of high capacity, long cycle life lithium batteries anode materials, three-dimensional (3D flower-like hierarchitectures constructed by SnS/SnS2 heterostructure nanosheets with thickness of ~20 nm have been synthesized via a simple one-pot solvothermal method. The obtained samples exhibit excellent electrochemical performance as anode for Li-ion batteries (LIBs, which deliver a first discharge capacity of 1277 mAhg−1 and remain a reversible capacity up to 500 mAhg−1 after 50 cycles at a current of 100 mAg−1.

  13. Development of immobilized Sn(4+) affinity chromatography material for highly selective enrichment of phosphopeptides.

    Science.gov (United States)

    Lin, Haizhu; Deng, Chunhui

    2016-11-01

    In this work, we first immobilized tin(IV) ion on polydopamine-coated magnetic graphene (magG@PDA) to synthesize Sn(4+) -immobilized magG@PDA (magG@PDA-Sn(4+) ) and successfully applied the material to highly selective enrichment of phosphopeptides. The material gathered the advantages of large surface area of graphene, superparamagnetism of Fe3 O4 , good hydrophilicity and biocompatibility of polydopamine, and strong interaction between Sn(4+) and phosphopeptides. The enrichment performance of magG@PDA-Sn(4+) toward phosphopeptides from digested β-casein at different concentrations, with and without added digested BSA was investigated and compared with magG@PDA-Ti(4+) . The results showed high selectivity and sensitivity of the Sn(4+) -IMAC material toward phosphopeptides, as good as the Ti(4+) -IMAC material. Finally, magG@PDA-Sn(4+) was applied to the analysis of endogenous phosphopeptides from a real sample, human saliva, with both MALDI-TOF MS and nano-LC-ESI-MS/MS. The results indicated that the as-synthesized Sn(4+) -IMAC material not only has good enrichment performance, but also could serve as a supplement to the Ti(4+) -IMAC material and expand the phosphopeptide coverage enriched by the single Ti(4+) -IMAC material, demonstrating the broad application prospects of magG@PDA-Sn(4+) in phosphoproteome research. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Magnetization Measurements of High-Jc Nb3Sn strands

    CERN Document Server

    Bordini, B; Alknes, P; Ballarino, A; Bottura, L; Oberli, L

    2013-01-01

    High critical current density Nb3Sn wires (Jc > 2500 A/mm2 at 4.2 K and 12 T) are the conductors considered for next generation accelerator magnets. At present, the large magnetization of these strands is a concern within the scientific community because of the impact it might have on the magnet field quality. In order to characterize the magnetic behavior of these wires, an extensive campaign of magnetization measurements was launched at CERN. Powder In Tube (PIT) strands by Bruker-EAS and Restacked Rod Process (RRP®) strands by Oxford Superconducting Technology (OST) were measured between 0 T and 10.5 T at different temperatures (ranging from 1.9 K to 14.5 K). The samples, based on strands with different sub-elements dimensions (35 to 80 μm), were measured with a Vibrating Sample Magnetometer (VSM). The experimental data were analyzed to: 1) calculate the effective filament size and the optimal parameters for the pinning force scaling law; 2) define the field-temperature region where there are flux...

  15. Calcination Method Synthesis of SnO2/g-C3N4 Composites for a High-Performance Ethanol Gas Sensing Application

    Science.gov (United States)

    Cao, Jianliang; Qin, Cong; Wang, Yan; Zhang, Bo; Gong, Yuxiao; Zhang, Huoli; Sun, Guang; Bala, Hari; Zhang, Zhanying

    2017-01-01

    The SnO2/g-C3N4 composites were synthesized via a facile calcination method by using SnCl4·5H2O and urea as the precursor. The structure and morphology of the as-synthesized composites were characterized by the techniques of X-ray diffraction (XRD), the field-emission scanning electron microscopy and transmission electron microscopy (SEM and TEM), energy dispersive spectrometry (EDS), thermal gravity and differential thermal analysis (TG-DTA), and N2-sorption. The analysis results indicated that the as-synthesized samples possess the two dimensional structure. Additionally, the SnO2 nanoparticles were highly dispersed on the surface of the g-C3N4nanosheets. The gas-sensing performance of the as-synthesized composites for different gases was tested. Moreover, the composite with 7 wt % g-C3N4 content (SnO2/g-C3N4-7) SnO2/g-C3N4-7 exhibits an admirable gas-sensing property to ethanol, which possesses a higher response and better selectivity than that of the pure SnO2-based sensor. The high surface area of the SnO2/g-C3N4 composite and the good electronic characteristics of the two dimensional graphitic carbon nitride are in favor of the elevated gas-sensing property. PMID:28468245

  16. Research Update: Prediction of high figure of merit plateau in SnS and solid solution of (Pb,SnS

    Directory of Open Access Journals (Sweden)

    Shiqiang Hao

    2016-10-01

    Full Text Available Direct conversion between thermal and electrical energy can be achieved by thermoelectric materials, which provide a viable route for power generation and solid state refrigeration. Here, we use a combination of energetic, electronic, and vibrational first-principles based results to predict the figure of merit performance in hole doped single crystals of SnS and (Pb,SnS. We find high ZT values for both materials, specifically for (Pb,SnS along the b-axis. Both SnS and (Pb,SnS have excellent power factors when doped, due to a combination of increased electrical conductivity (due to doping and a significantly enhanced Seebeck coefficient obtained by a doping-induced multiband effect. Anharmonic phonon calculations combined with a Debye-Calloway model show that the lattice thermal conductivity of both compounds is low, due to intrinsic anharmonicity, and is lowered further by the random, solid solution nature of the cation sublattice of (Pb,SnS. (Pb,SnS exhibits a high ZT plateau ranging from 1.3 at 300 K to 1.9 at 800 K. The overall ZT of the hole doped (Pb,SnS crystals is predicted to outperform most of the current state-of-the-art thermoelectric sulfide materials.

  17. Preparation of highly dispersed Ru-Sn bimetallic supported catalysts from the single source precursors Cp(PPh32Ru-SnX3 (X = Cl or Br

    Directory of Open Access Journals (Sweden)

    Ana Cláudia Bernardes Silva

    2003-06-01

    Full Text Available In this work highly dispersed Ru-Sn bimetallic catalysts have been prepared from organobimetallic Cp(PPh32Ru-SnX3 (X = Cl or Br complexes. These single source precursors can be easily impregnated in high surface area supports, such as activated carbon and sol-gel SiO2, and upon controlled thermal treatment the ligands are released as volatile products resulting in the formation of the bimetallic system Ru-Sn. Catalytic reactions, such as hydrodechlorination of CCl4 and chlorobenzene and TPR (Temperature Programmed Reduction experiments carried out with these RuSn catalysts suggested a strong interaction between Ruthenium and Tin. Mössbauer measurements showed that these materials when exposed to air are immediately oxidized to form Sn (IV. It was shown that upon controlled reduction conditions with H2 it is possible to reduce selectively Sn to different oxidation states and different phases. The Sn oxidation state showed significant effect on the catalytic hydrogenation of 1,5-cyclooctadiene. The use of these single source precursors with a controlled decomposition/reduction procedure allows the preparation of unique catalysts with an intimate interaction between the components ruthenium and tin and the possibility of varying the Sn oxidation state around the Ru metal.

  18. Influence of dipping time on cracking during bending of hot dip galvanized coatings with Sn and Ti contents

    Directory of Open Access Journals (Sweden)

    L. Zortea

    2010-10-01

    Full Text Available In the last years, the attention to environmental topics led a new approach solution in classical protection techniques, introducing innovative way oriented to optimize different coating properties. Hot-dip galvanizing is a classical process aimed to generate coatings on iron-based surfaces, used unchanged since 200 years: some chemical elements are added in the bath with different aims (e.g., Pb is really important for its fluidizing properties, sometimes replaced by Sn but sometimes these elements are dangerous for human health (e.g. … Pb!.In this work, the influence of dipping time and coatings chemical compositions on damaging micromechanisms was investigated considering different Sn and Ti contents. Main damaging micromechanisms in hot dip zinc coated ipersandelin steel specimens were investigated by means of bending tests. Longitudinal sections of bended specimens were observed by means of a LOM (Light Optical Microscope: main damage micromechanisms were identified as longitudinal and radial cracks.

  19. Wet Chemical Synthesis of SnS/Graphene Nanocomposites for High Performance Supercapacitor Electrodes

    Science.gov (United States)

    Ravuri, Syamsai; Pandey, Chandan Abhishek; Ramchandran, R.; Jeon, Soon Kwan; Grace, Andrews Nirmala

    A series of SnS/Graphene (SnS/G) nanocomposites at various concentrations of graphene were synthesized by a wet chemical route and the prepared composites were analyzed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), High Resolution Transmission Electron Microscopy (HRTEM) for its structural and morphological investigation. Results show that the prepared SnS nanoparticles in the composite are ˜30nm sized and uniformly dispersed on graphene sheets. To test the supercapacitance behavior, electrochemical measurements were carried out in 6M KOH electrolyte. A maximum specific capacitance of 984F/g was observed for SnS/G-c at 5mVs‑1 scan rate. Galvanostatic charge/discharge curves showed an excellent cyclic stability with higher charge/discharge duration, and hence could be used for high performance supercapacitor applications.

  20. High capacity, microporous Cu{sub 6}Sn{sub 5}-Sn anodes for Li-Ion batteries.

    Energy Technology Data Exchange (ETDEWEB)

    Trahey, L.; Vaughey, J. T.; Kung, H. H.; Thackeray, M. M. (Chemical Sciences and Engineering Division); ( PSC-USR); (Northwestern Univ.)

    2009-03-16

    Three-dimensional, microporous Cu{sub 6}Sn{sub 5}-Sn architectures were created by electrodeposition of copper and tin onto sintered copper foam substrates and evaluated as anodes for lithium-ion batteries. The electrodes were characterized before and after cycling by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectrometry. Before cycling, the electrochemically deposited films consisted of a combination of crystalline Cu{sub 6}Sn{sub 5} and Sn, whereas after cycling, the films appeared amorphous to X-rays. When evaluated in coin cells against metallic lithium, the composite Cu{sub 6}Sn{sub 5}-Sn electrodes delivered a reversible capacity of 670 mAh/g, which is significantly greater than the capacity achieved previously from powdered (ballmilled) and thin-film (sputtered) Cu{sub 6}Sn{sub 5} electrodes, typically 200-350 mAh/g.

  1. The Effect of Sb Addition on Sn-Based Alloys for High-Temperature Lead-Free Solders: an Investigation of the Ag-Sb-Sn System

    Science.gov (United States)

    Li, D.; Delsante, S.; Watson, A.; Borzone, G.

    2012-01-01

    Today there is renewed interest in alloys belonging to the Sb-Sn-X (X = Cu, Ag, Bi) ternary systems and their phase equilibria, phase transformations, and thermodynamic properties because of their possible use as high-temperature lead-free solders in the electronics industry. The integral mixing enthalpy of Ag-Sb-Sn liquid alloys has been measured along five different sections (Ag0.25Sn0.75, Ag0.50Sn0.50, Sb0.30Sn0.70, Sb0.50Sn0.50, and Sb0.70Sn0.30) at 530°C, 600°C, and 630°C, using a high-temperature Calvet calorimeter by dropping pure elements (Ag or Sb) in the binary alloy liquid bath. The ternary extrapolation models of Muggianu and Toop were used to calculate the integral enthalpy of mixing and to compare measured and extrapolated values. Selected ternary alloys have been prepared for thermal investigation by using a differential scanning calorimeter at different heating/cooling rates in order to clarify the temperature of the invariant reactions and the crystallization path.

  2. Topological Dirac line nodes and superconductivity coexist in SnSe at high pressure

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xuliang; Lu, Pengchao; Wang, Xuefei; Zhou, Yonghui; An, Chao; Zhou, Ying; Xian, Cong; Gao, Hao; Guo, Zhaopeng; Park, Changyong; Hou, Binyang; Peng, Kunling; Zhou, Xiaoyuan; Sun, Jian; Xiong, Yimin; Yang, Zhaorong; Xing, Dingyu; Zhang, Yuheng

    2017-10-01

    We report on the discovery of a pressure-induced topological and superconducting phase of SnSe, a material which attracts much attention recently due to its superior thermoelectric properties. In situ high-pressure electrical transport and synchrotron x-ray diffraction measurements show that the superconductivity emerges along with the formation of a CsCl-type structural phase of SnSe above around 27 GPa, with a maximum critical temperature of 3.2 K at 39 GPa. Based on ab initio calculations, this CsCl-type SnSe is predicted to be a Dirac line-node (DLN) semimetal in the absence of spin-orbit coupling, whose DLN states are protected by the coexistence of time-reversal and inversion symmetries. These results make CsCl-type SnSe an interesting model platform with simple crystal symmetry to study the interplay of topological physics and superconductivity.

  3. Multiwalled carbon nanotubes@C@SnO2 quantum dots and SnO2 quantum dots@C as high rate anode materials for lithium-ion batteries

    Science.gov (United States)

    Jin, Rencheng; Meng, Yanfeng; Li, Guihua

    2017-11-01

    The SnO2 quantum dots anchored on amorphous carbon coated multiwalled carbon nanotubes (CNTs@C@SnO2) and SnO2 quantum dots embedded in amorphous carbon network (SnO2@C) have been designed and fabricated by a solvothermal process accompanied by a high temperature calcination treatment. Such unique structured electrodes exhibit excellent cycle stability and high rate capability. At the current density of 5 A g-1, the capacities of 515 and 364 mAh g-1 are achieved after 300 cycles for CNTs@C@SnO2 and SnO2@C, respectively.

  4. Synthesis and characterization of low temperature Sn nanoparticles for the fabrication of highly conductive ink.

    Science.gov (United States)

    Jo, Yun Hwan; Jung, Inyu; Choi, Chung Seok; Kim, Inyoung; Lee, Hyuck Mo

    2011-06-03

    To fabricate a low cost, highly conductive ink for inkjet printing, we synthesized a gram scale of uniformly sized Sn nanoparticles by using a modified polyol process and observed a significant size-dependent melting temperature depression from 234.1 °C for bulk Sn to 177.3 °C for 11.3 nm Sn nanoparticles. A 20 wt% of Sn nanoparticles was dispersed in the 50% ethylene glycol: 50% isopropyl alcohol mixed solvent for the appropriate viscosity (11.6 cP) and surface tension (32 dyn cm(-1)). To improve the electrical property, we applied the surface treatments of hydrogen reduction and plasma ashing. The two treatments had the effect of diminishing the sheet resistance from 1 kΩ/sq to 50 Ω/sq. In addition, conductive patterns (1 cm × 1 cm) were successfully drawn on the Si wafer using an inkjet printing instrument with conductive Sn ink. The maximum resistivity for an hour of sintering at 250 °C was 64.27 µΩ cm, which is six times higher than the bulk Sn resistivity (10.1 µΩ cm).

  5. Effect of Cu content and temperature on the properties of Cu2ZnSnSe4 solar cells

    Directory of Open Access Journals (Sweden)

    Sahayaraj Sylvester

    2016-01-01

    Full Text Available The complexity involved in obtaining pure Kesterite Cu2ZnSnSe4 (CZTSe thin film primarily arises due to its narrow region of stability, leading to the presence of unavoidable binary selenides of the constituent metals. This study offers an insight on the formation of Cu selenides when the amount of Cu is varied in the precursor from Cu poor to Cu rich. The amount of Cu selenides was found to decrease when the composition of CZTSe absorber approached Cu rich conditions but functional devices were not obtained. Detailed characterizations also showed that the Cu and Sn binary phases were present at the backside interface of CZTSe solar cells. However with an increase in the selenization temperature it was found that the amount of Cu selenides and other secondary phases could be drastically minimized or even eliminated leading to high efficiency devices.

  6. Reaction properties and interfacial intermetallics for Sn-xAg-0.5Cu solders as a function of Ag content

    Science.gov (United States)

    Lee, Jong-Hyun; Yu, A.-Mi; Kim, Jeong-Han; Kim, Mok-Soon; Kang, Namhyun

    2008-10-01

    Wetting and interfacial reactions were investigated for Sn-xAg-0.5Cu alloys, in which the Ag content had a variation from x=1.0 to x=4.0. Differential scanning calorimetry (DSC) was used to investigate the range of the melting temperature and the solidification temperature by measuring the endothermic and the exothermic heat flow, respectively. Low Ag contents increased the melting temperature ranges and deteriorated the wetting properties such as zero cross time and wetting force measured at two seconds. The extent of undercooling increased and the thickness of intermetallic compounds (IMC) decreased as the Ag content decreased. As the Ag content decreased, the initial IMC thickness decreased due to the large undercooling and, during the solid aging at 170°C, the IMC growth slightly decelerated because of the small diffusion coefficient. For the application of good drop shock reliability, Sn-Ag-Cu solder of low Ag content should be beneficial due to the restraint of the IMC growth (Cu6Sn5 and Cu3Sn) and of the coarse plate-like IMC (Ag3Sn).

  7. A facile hydrothermal strategy for synthesis of SnO2 nanorods-graphene nanocomposites for high performance photocatalysis.

    Science.gov (United States)

    Chen, Lu-Ya; Zhang, Wei-De; Xu, Bin; Yu, Yu-Xiang

    2012-09-01

    In this study, we report a facilely hydrothermal process for synthesizing SnO2 nanorods-graphene (SnO2 nanorods-GR) composite using graphite oxide and SnCl4 as raw materials. The SnO2 nanorods-GR composite was characterized by X-ray diffraction, electron microscopy, Xray photoelectron spectroscopy, and thermogravimetric analysis. Compared to commercial TiO2 nanoparticles P25 and neat SnO2 nanorods, the SnO2 nanorods-GR composite exhibits higher photocatalytic activity under UV light irradiation. The mechanism of its high photocatalytic activity is mainly ascribed to the synergy effect between SnO2 and graphene, in which graphene acts as an adsorbent and electron acceptor due to its large structure of pi-pi conjugation from sp2 hybrid carbon atoms. The results demonstrated in this study provide a promising way to enhance the photocatalytic activity by compounding semiconductive nanocrystals with graphene.

  8. Electronic characteristics of p-type transparent SnO monolayer with high carrier mobility

    Energy Technology Data Exchange (ETDEWEB)

    Du, Juan [College of Physics and Materials Science, Henan Normal University, Xinxiang, Henan 453007 (China); Xia, Congxin, E-mail: xiacongxin@htu.edu.cn [College of Physics and Materials Science, Henan Normal University, Xinxiang, Henan 453007 (China); Liu, Yaming [Henan Institute of Science and Technology, Xinxiang 453003 (China); Li, Xueping [College of Physics and Materials Science, Henan Normal University, Xinxiang, Henan 453007 (China); Peng, Yuting [Department of Physics, University of Texas at Arlington, TX 76019 (United States); Wei, Shuyi [College of Physics and Materials Science, Henan Normal University, Xinxiang, Henan 453007 (China)

    2017-04-15

    Graphical abstract: SnO monolayer is a p-type transparent semiconducting oxide with high hole mobility (∼641 cm{sup 2} V{sup −1} s{sup −1}), which is much higher than that of MoS{sub 2} monolayer, which indicate that it can be a promising candidate for high-performance nanoelectronic devices. Display Omitted - Highlights: • SnO monolayer is a p-type transparent semiconducting oxide. • The transparent properties can be still maintained under the strain 8%. • It has a high hole mobility (∼641 cm{sup 2} V{sup −1} s{sup −1}), which is higher than that of MoS{sub 2} monolayer. - Abstract: More recently, two-dimensional (2D) SnO nanosheets are attaching great attention due to its excellent carrier mobility and transparent characteristics. Here, the stability, electronic structures and carrier mobility of SnO monolayer are investigated by using first-principles calculations. The calculations of the phonon dispersion spectra indicate that SnO monolayer is dynamically stable. Moreover, the band gap values are decreased from 3.93 eV to 2.75 eV when the tensile strain is applied from 0% to 12%. Interestingly, SnO monolayer is a p-type transparent semiconducting oxide with hole mobility of 641 cm{sup 2} V{sup −1} s{sup −1}, which is much higher than that of MoS{sub 2} monolayer. These findings make SnO monolayer becomes a promising 2D material for applications in nanoelectronic devices.

  9. Low-temperature (<200 oC solid-phase crystallization of high substitutional Sn concentration (∼10% GeSn on insulator enhanced by weak laser irradiation

    Directory of Open Access Journals (Sweden)

    Kenta Moto

    2017-07-01

    Full Text Available Low temperature (8% on insulating substrates is essential to realize next generation flexible electronics. To achieve this, a growth method of high quality GeSn films on insulating substrates by combination of laser irradiation and subsequent thermal annealing is developed. Here, the laser fluence is chosen as weak, which is below the critical fluence for crystallization of GeSn. It is clarified that for samples irradiated with weak laser fluence, complete crystallization of GeSn films is achieved by subsequent thermal annealing at ∼170 oC without incubation time. In addition, the quality of GeSn films obtained by this method is higher compared with conventional growth techniques such as melting growth by pulsed laser annealing or solid-phase crystallization (SPC without pre-laser irradiation. Substitutional Sn concentrations in the grown layers estimated by Raman spectroscopy measurements are 8-10%, which far exceed thermal equilibrium solid-solubility of Sn in Ge (∼2%. These phenomena are explained by generation of a limited number of nuclei by weak laser irradiation and lateral SPC by subsequent thermal annealing. This method will facilitate realization of next-generation high performance devices on flexible insulating substrates.

  10. High Gradient $Nb_3Sn$ Quadrupole Demonstrator MKQXF Engineering Design

    CERN Document Server

    Kokkinos, C; Karppinen, Mikko; CERN. Geneva. ATS Department

    2016-01-01

    A new mechanical design concept for the $Nb_3Sn$ quadrupoles has been developed with a goal of an accelerator quality magnet that can be industrially produced in large series. This concept can easily be extended to any length and applied on both 1-in-1 and 2-in-1 configurations. It is based on the pole-loading concept and collared coils using dipole-type collars. Detailed design optimisation of a demonstrator magnet based on present base-line HL-LHC IR quadrupole QXF coil geometry has been carried out including the end regions. This report describes the design concept and the fully parametric multi-physics finite element (FE) models that were used to determine the optimal assembly parameters including the effects of the manufacturing tolerances.

  11. Synthesis of High-Purity SnO2 Nanobelts by Using Exothermic Reaction

    Directory of Open Access Journals (Sweden)

    Guodong Zhang

    2011-01-01

    Full Text Available This paper presents a new method to synthesize high-purity single-crystalline SnO2 nanobelts with rutile structure. The purity, morphology, crystal structure, and sizes of the as-grown SnO2 nanobelts are characterized by X-ray diffraction, energy-dispersive X-ray analysis, scanning electron microscopy, transmission electron microscopy, and Raman-scattering spectroscopy. The scanning electron microscopy and transmission electron microscopy reveal tetragonal SnO2 nanobelts of 50–120 nm in width, 20–50 nm in thickness, and 2–10 μm in length. The three observed Raman peaks at 475, 633, and 774 cm−1 indicate the typical rutile structure of the SnO2, which is in agreement with the X-ray diffraction results, and other peaks of impurity are not found. High-resolution transmission electron microscopy demonstrates that the nanobelts have a high degree of crystallinity, without typical imperfects in it. And the growth mechanism of the SnO2 nanobelts is discussed.

  12. Interfacial Reaction and Mechanical Properties of Sn-Bi Solder joints.

    Science.gov (United States)

    Wang, Fengjiang; Huang, Ying; Zhang, Zhijie; Yan, Chao

    2017-08-09

    Sn-Bi solder with different Bi content can realize a low-to-medium-to-high soldering process. To obtain the effect of Bi content in Sn-Bi solder on the microstructure of solder, interfacial behaviors in solder joints with Cu and the joints strength, five Sn-Bi solders including Sn-5Bi and Sn-15Bi solid solution, Sn-30Bi and Sn-45Bi hypoeutectic and Sn-58Bi eutectic were selected in this work. The microstructure, interfacial reaction under soldering and subsequent aging and the shear properties of Sn-Bi solder joints were studied. Bi content in Sn-Bi solder had an obvious effect on the microstructure and the distribution of Bi phases. Solid solution Sn-Bi solder was composed of the β-Sn phases embedded with fine Bi particles, while hypoeutectic Sn-Bi solder was composed of the primary β-Sn phases and Sn-Bi eutectic structure from networked Sn and Bi phases, and eutectic Sn-Bi solder was mainly composed of a eutectic structure from short striped Sn and Bi phases. During soldering with Cu, the increase on Bi content in Sn-Bi solder slightly increased the interfacial Cu₆Sn₅ intermetallic compound (IMC)thickness, gradually flattened the IMC morphology, and promoted the accumulation of more Bi atoms to interfacial Cu₆Sn₅ IMC. During the subsequent aging, the growth rate of the IMC layer at the interface of Sn-Bi solder/Cu rapidly increased from solid solution Sn-Bi solder to hypoeutectic Sn-Bi solder, and then slightly decreased for Sn-58Bi solder joints. The accumulation of Bi atoms at the interface promoted the rapid growth of interfacial Cu₆Sn₅ IMC layer in hypoeutectic or eutectic Sn-Bi solder through blocking the formation of Cu₆Sn₅ in solder matrix and the transition from Cu₆Sn₅ to Cu₃Sn. Ball shear tests on Sn-Bi as-soldered joints showed that the increase of Bi content in Sn-Bi deteriorated the shear strength of solder joints. The addition of Bi into Sn solder was also inclined to produce brittle morphology with interfacial fracture, which

  13. Highly Efficient Gas Sensor Using a Hollow SnO2 Microfiber for Triethylamine Detection.

    Science.gov (United States)

    Zou, Yihui; Chen, Shuai; Sun, Jin; Liu, Jingquan; Che, Yanke; Liu, Xianghong; Zhang, Jun; Yang, Dongjiang

    2017-07-28

    Triethylamine (TEA) gas sensors having excellent response and selectivity are in great demand to monitor the real environment. In this work, we have successfully prepared a hollow SnO2 microfiber by a unique sustainable biomass conversion strategy and shown that the microfiber can be used in a high-performance gas sensor. The sensor based on the hollow SnO2 microfiber shows a quick response/recovery toward triethylamine. The response of the hollow SnO2 microfiber is up to 49.5 when the concentration of TEA gas is 100 ppm. The limit of detection is as low as 2 ppm. Furthermore, the sensor has a relatively low optimal operation temperature of 270 °C, which is lower than those of many other reported sensors. The excellent sensing properties are largely attributed to the high sensitivity provided by SnO2 and the good permeability and conductivity of the one-dimensional hollow structure. Thus, the hollow SnO2 microfiber using sustainable biomass as a template is a significant strategy for a unique TEA gas sensor.

  14. Heat treatment study of $Nb_{3}Sn$ strands for the Fermilab's high field dipole model

    CERN Document Server

    Barzi, E; Limon, P J; Ozelis, J P; Yamada, R; Zlobin, A V; Gregory, E; Pyon, T; Wake, M

    2000-01-01

    Fermilab is developing high field superconducting dipole magnets based on Nb/sub 3/Sn for a post-LHC very large hadron collider (VLHC) . The first prototype is a 1 meter long two-layer shell-type (cos- theta) coil with a nominal field of 11 T. A keystoned Rutherford-type cable made of 28 Nb/sub 3/Sn strands of 1 mm in diameter is used. The development of high J/sub c/ multifilamentary Nb/sub 3/Sn strands with low magnetization is an important step of this program. To achieve this goal, strand R&D is actively pursued by Fermilab and IGC using the internal tin process. Conductor designs, heat treatment studies, and results of measurements, including I/sub c/, n-value, RRR, magnetization, and chemical analyses, are presented. (4 refs).

  15. submitter Optimization of Nb$_{3}$Sn Rutherford Cables Geometry for the High Luminosity LHC

    CERN Document Server

    Fleiter, Jerome; Bonasia, Angelo; Bordini, Bernardo; Richter, David

    2017-01-01

    The quadrupole and dipole magnets for the LHC High Luminosity (HL-LHC) upgrade will be based on Nb3Sn Rutherford cables that operate at 1.9 K and experience magnetic fields of up to about 12 T. An important step in the design of these magnets is the development of the high aspect ratio Nb3Sn cables to achieve the nominal field with sufficient margin. The strong plastic deformation of unreacted $Nb_3Sn$ strands during the Rutherford cabling process may induce non negligible $I_c$ and RRR degradation. In this paper, the cabling degradation is investigated as a function of the cable geometry for both PIT and RRP conductors. Based on this analysis, new baseline geometries for both 11 T and QXF magnets of HL-LHC are proposed.

  16. Nb3Sn High Field Magnets for the High Luminosity LHC Upgrade Project

    Energy Technology Data Exchange (ETDEWEB)

    Ambrosio, Giorgio

    2015-06-01

    The High Luminosity upgrade of the Large Hadron Collider at CERN requires a new generation of high field superconducting magnets. High field large aperture quadrupoles (MQXF) are needed for the low-beta triplets close to the ATLAS and CMS detectors, and high field two-in-one dipoles (11 T dipoles) are needed to make room for additional collimation. The MQXF quadrupoles, with a field gradient of 140 T/m in 150 mm aperture, have a peak coil field of 12.1 T at nominal current. The 11 T dipoles, with an aperture of 60 mm, have a peak coil field of 11.6 T at nominal current. Both magnets require Nb3Sn conductor and are the first applications of this superconductor to actual accelerator magnets.

  17. High White Light Photosensitivity of SnSe Nanoplate-Graphene Nanocomposites

    Science.gov (United States)

    Liu, Jinyang; Huang, Qingqing; Zhang, Kun; Xu, Yangyang; Guo, Mingzhu; Qian, Yongqiang; Huang, Zhigao; Lai, Fachun; Lin, Limei

    2017-04-01

    The multi-functional nanomaterial constructed with more than one type of materials has gained a great attention due to its promising application. Here, a high white light photodetector prototype established with two-dimensional material (2D) and 2D nanocomposites has been fabricated. The 2D-2D nanocomposites were synthesized with SnSe nanoplate and graphene. The device shows a linear I-V characterization behavior in the dark and the resistance dramatically decreases under the white light. Furthermore, the photosensitivity of the device is as large as 1110% with a rapid response time, which is much higher than pristine SnSe nanostructure reported. The results shown here may provide a valuable guidance to design and fabricate the photodetector based on the 2D-2D nanocomposites even beyond the SnSe nanoplate-graphene nanocomposites.

  18. Highly sensitive nanostructure SnO2 based gas sensor for environmental pollutants

    Science.gov (United States)

    Korgaokar, Sushil; Moradiya, Meet; Prajapati, Om; Thakkar, Pranav; Pala, Jay; Savaliya, Chirag; Parikh, Sachin; Markna, J. H.

    2017-05-01

    A major quantity of pollutants are produced from industries and vehicles in the form of gas. New approaches are needed to solve well-known environmental pollutants like CO, CO2, NO2, SOx. Therefore detection with effective gas sensors is a vital part of pollution prevention efforts. There is a need to develop fast, rapid, cost-effective, highly sensitive, low power, and non-intrusive rugged sensors that can be easily installed. In the present study, nanostructured SnO2 used as a sensitive material in the devices and synthesized using hydrothermal process. The detailed development of the fabrication of SnO2 nanostructures gas sensor is described, which shows the remarkable change in the sensing properties with varying particle size. Additionally, we have used X-ray diffraction, scanning electron microscopy (SEM) for characterization and carefully examined the relative parameters like response magnitude (sensitivity) and selectivity of SnO2 nano structures with different particle size.

  19. Improvement of stability of Nb3Sn superconductors by introducing high specific heat substances

    Energy Technology Data Exchange (ETDEWEB)

    Xu, X. [Fermilab; Li, P. [Fermilab; Zlobin, A. V. [Fermilab; Peng, X. [Unlisted, US, OH

    2018-01-08

    High-J c Nb3Sn conductors have low stability against perturbations, which accounts for the slow training rates of high-field Nb3Sn magnets. While it is known that adding substances with high specific heat (C) into Nb3Sn wires can increase their overall specific heat and thus improve their stability, there has not been a practical method that is compatible with the fabrication of long-length conductors. In this work, we put forward a scheme to introduce such substances to distributed-barrier Nb3Sn wires, which adds minimum difficulty to the wire manufacturing process. Multifilamentary wires using a mixture of Cu and high-C Gd2O3 powders have been successfully fabricated along this line. Measurements showed that addition of Gd2O3 had no negative effects on residual resitivity ratio or non-Cu J c, and that flux jumps were remarkably reduced, and minimum quench energy values at 4.2 K, 14 T were increased by a factor of three, indicating that stability was significantly improved. We also discussed the influences of the positioning of high-C substances and their thermal diffusivity on their effectiveness in reducing the superconductor temperature rise against perturbations. Based on these results, we proposed an optimized conductor architecture to maximize the effectiveness of this approach.

  20. Electrical conductivity of molten SnCl{sub 2} at temperature as high as 1314 K

    Energy Technology Data Exchange (ETDEWEB)

    Salyulev, Alexander B.; Potapov, Alexei M. [Ural Branch of RAS, Ekaterinburg (Russian Federation). Inst. of High-Temperature Electrochemistry

    2015-07-01

    The electrical conductivity of molten SnCl{sub 2} was measured in a wide temperature range (ΔT=763 K), from 551 K to temperature as high as 1314 K, that is, 391 above the boiling point of the salt. The specific electrical conductance was found to reach its maximum at 1143 K, after that it decreases with the temperature rising.

  1. Ir/Sn dual-reagent catalysis towards highly selective alkylation of ...

    Indian Academy of Sciences (India)

    A catalytic combination of [Ir(COD)Cl]2-SnCl4 efficiently promotes the reactions of arenes and heteroarenes with 1°/2°/3° benzyl alcohols as the alkylating agents to afford the corresponding diarylmethane and triarylmethane derivatives in high yields. The scope and limitation of the reaction with respect to catalyst and ...

  2. Ir/Sn dual-reagent catalysis towards highly selective alkylation of ...

    Indian Academy of Sciences (India)

    Wintec

    *For correspondence. Ir/Sn dual-reagent catalysis towards highly selective alkylation of arenes and heteroarenes with benzyl alcohols. SUJIT ROY*, SUSMITA PODDER and JOYANTA CHOUDHURY. Organometallics and Catalysis Laboratory, Department of Chemistry, Indian Institute of Technology,. Kharagpur 721 302.

  3. Application of Nb3Sn superconductors in high-field accelerator magnets

    NARCIS (Netherlands)

    den Ouden, A.; Wessel, Wilhelm A.J.; Krooshoop, Hendrikus J.G.; ten Kate, Herman H.J.

    1997-01-01

    Last year a record central field of 11 T at first excitation at 4.4 K has been achieved with the experimental LHC model dipole magnet MSUT by utilising a high Jc powder-in-tube Nb3Sn conductor. This is the first real breakthrough towards fields well above 10 T at 4 K. The clear influence of

  4. The Effect of Eu Doping on Microstructure, Morphology and Methanal-Sensing Performance of Highly Ordered SnO2 Nanorods Array

    Directory of Open Access Journals (Sweden)

    Yanping Zhao

    2017-11-01

    Full Text Available Layered Eu-doped SnO2 ordered nanoarrays constructed by nanorods with 10 nm diameters and several hundred nanometers length were synthesized by a substrate-free hydrothermal route using alcohol and water mixed solvent of sodium stannate and sodium hydroxide at 200 °C. The Eu dopant acted as a crystal growth inhibitor to prevent the SnO2 nanorods growth up, resulting in tenuous SnO2 nanorods ordered arrays. The X-ray diffraction (XRD revealed the tetragonal rutile-type structure with a systematic average size reduction and unit cell volume tumescence, while enhancing the residual strain as the Eu-doped content increases. The surface defects that were caused by the incorporation of Eu ions within the surface oxide matrix were observed by high-resolution transmission electron microscope (HRTEM. The results of the response properties of sensors based on the different levels of Eu-doped SnO2 layered nanoarrays demonstrated that the 0.5 at % Eu-doped SnO2 layered nanorods arrays exhibited an excellent sensing response to methanal at 278 °C. The reasons of the enhanced sensing performance were discussed from the complicated defect surface structure, the large specific surface area, and the excellent catalytic properties of Eu dopant.

  5. Nitrogen-Doped Carbon-Encapsulated SnO2@Sn Nanoparticles Uniformly Grafted on Three-Dimensional Graphene-like Networks as Anode for High-Performance Lithium-Ion Batteries.

    Science.gov (United States)

    Li, Yunyong; Zhang, Haiyan; Chen, Yiming; Shi, Zhicong; Cao, Xiaoguo; Guo, Zaiping; Shen, Pei Kang

    2016-01-13

    A peculiar nanostructure consisting of nitrogen-doped, carbon-encapsulated (N-C) SnO2@Sn nanoparticles grafted on three-dimensional (3D) graphene-like networks (designated as N-C@SnO2@Sn/3D-GNs) has been fabricated via a low-cost and scalable method, namely an in situ hydrolysis of Sn salts and immobilization of SnO2 nanoparticles on the surface of 3D-GNs, followed by an in situ polymerization of dopamine on the surface of the SnO2/3D-GNs, and finally a carbonization. In the composites, three-layer core-shell N-C@SnO2@Sn nanoparticles were uniformly grafted onto the surfaces of 3D-GNs, which promotes highly efficient insertion/extraction of Li(+). In addition, the outermost N-C layer with graphene-like structure of the N-C@SnO2@Sn nanoparticles can effectively buffer the large volume changes, enhance electronic conductivity, and prevent SnO2/Sn aggregation and pulverization during discharge/charge. The middle SnO2 layer can be changed into active Sn and nano-Li2O during discharge, as described by SnO2 + Li(+) → Sn + Li2O, whereas the thus-formed nano-Li2O can provide a facile environment for the alloying process and facilitate good cycling behavior, so as to further improve the cycling performance of the composite. The inner Sn layer with large theoretical capacity can guarantee high lithium storage in the composite. The 3D-GNs, with high electrical conductivity (1.50 × 10(3) S m(-1)), large surface area (1143 m(2) g(-1)), and high mechanical flexibility, tightly pin the core-shell structure of the N-C@SnO2@Sn nanoparticles and thus lead to remarkably enhanced electrical conductivity and structural integrity of the overall electrode. Consequently, this novel hybrid anode exhibits highly stable capacity of up to 901 mAh g(-1), with ∼89.3% capacity retention after 200 cycles at 0.1 A g(-1) and superior high rate performance, as well as a long lifetime of 500 cycles with 84.0% retention at 1.0 A g(-1). Importantly, this unique hybrid design is expected to be

  6. THE HIGHLY ENERGETIC EXPANSION OF SN 2010bh ASSOCIATED WITH GRB 100316D

    Energy Technology Data Exchange (ETDEWEB)

    Bufano, Filomena [INAF-Osservatorio Astronomico di Catania, Via Santa Sofia, I-95123, Catania (Italy); Pian, Elena; Turatto, Massimo [INAF-Osservatorio Astronomico di Trieste, Via G.B. Tiepolo 11, I-34143 Trieste (Italy); Sollerman, Jesper [Oskar Klein Centre, Department of Astronomy, AlbaNova, SE-106 91 Stockholm (Sweden); Benetti, Stefano; Valenti, Stefano; Cappellaro, Enrico; Mazzali, Paolo A. [INAF-Osservatorio Astronomico di Padova, Vicolo dell' Osservatorio 5, I-35122 Padova (Italy); Pignata, Giuliano [Departamento de Ciencias Fisicas, Universidad Andres Bello, Av. Republica 252, Santiago (Chile); Covino, Stefano; D' Avanzo, Paolo; Vergani, Susanna D. [INAF-Osservatorio Astronomico di Brera, Via Emilio Bianchi 46, Merate I-23807 (Italy); Malesani, Daniele; Fynbo, Johan; Hjorth, Jens [Dark Cosmology Centre, Niels Bohr Institute, University of Copenhagen, Juliane Maries Vej 30, DK-2100 Copenhagen (Denmark); Della Valle, Massimo [INAF-Osservatorio Astronomico di Capodimonte, Salita Moiariello, 16, I-8013 Napoli (Italy); Reichart, Daniel E. [Department of Physics and Astronomy, University of North Carolina at Chapel Hill, Campus Box 3255, Chapel Hill, NC 27599-3255 (United States); Starling, Rhaana L. C.; Wiersema, Klass [Department of Physics and Astronomy, University of Leicester, University Road, Leicester LE1 7RH (United Kingdom); Amati, Lorenzo [INAF-Istituto di Astrofisica Spaziale e Fisica cosmica, Via Gobetti 101, I-40129 Bologna (Italy); and others

    2012-07-01

    We present the spectroscopic and photometric evolution of the nearby (z = 0.059) spectroscopically confirmed Type Ic supernova, SN 2010bh, associated with the soft, long-duration gamma-ray burst (X-ray flash) GRB 100316D. Intensive follow-up observations of SN 2010bh were performed at the ESO Very Large Telescope (VLT) using the X-shooter and FORS2 instruments. Thanks to the detailed temporal coverage and the extended wavelength range (3000-24800 A), we obtained an unprecedentedly rich spectral sequence among the hypernovae, making SN 2010bh one of the best studied representatives of this SN class. We find that SN 2010bh has a more rapid rise to maximum brightness (8.0 {+-} 1.0 rest-frame days) and a fainter absolute peak luminosity (L{sub bol} Almost-Equal-To 3 Multiplication-Sign 10{sup 42} erg s{sup -1}) than previously observed SN events associated with GRBs. Our estimate of the ejected {sup 56}Ni mass is 0.12 {+-} 0.02 M{sub Sun }. From the broad spectral features, we measure expansion velocities up to 47,000 km s{sup -1}, higher than those of SNe 1998bw (GRB 980425) and 2006aj (GRB 060218). Helium absorption lines He I {lambda}5876 and He I 1.083 {mu}m, blueshifted by {approx}20,000-30,000 km s{sup -1} and {approx}28,000-38,000 km s{sup -1}, respectively, may be present in the optical spectra. However, the lack of coverage of the He I 2.058 {mu}m line prevents us from confirming such identifications. The nebular spectrum, taken at {approx}186 days after the explosion, shows a broad but faint [O I] emission at 6340 A. The light curve shape and photospheric expansion velocities of SN 2010bh suggest that we witnessed a highly energetic explosion with a small ejected mass (E{sub k} Almost-Equal-To 10{sup 52} erg and M{sub ej} Almost-Equal-To 3 M{sub Sun }). The observed properties of SN 2010bh further extend the heterogeneity of the class of GRB SNe.

  7. High mobility La-doped BaSnO3 on non-perovskite MgO substrate

    Science.gov (United States)

    Kim, Youjung; Shin, Juyeon; Kim, Young Mo; Char, Kookrin

    (Ba,La)SnO3 is a transparent perovskite oxide with high electron mobility and excellent oxygen stability. Field effect device with (Ba,La)SnO3 channel was reported to show good output characteristics on STO substrate. Here, we fabricated (Ba,La)SnO3\\ films and field effect devices with (Ba,La)SnO3 channel on non-perovskite MgO substrates, which are available in large size wafers. X-ray diffraction and transmission electron microscope (TEM) images of (Ba,La)SnO3\\ films on MgO substrates show that the films are epitaxial with many threading dislocations. (Ba,La)SnO3 exhibits the high mobility with 97.2 cm2/Vs at 2 % La doping on top of 150 nm thick BaSnO3 buffer layer. Excellent carrier modulation was observed in field effect devices. FET performances on MgO substrates are slightly better than those on SrTiO3 substrates in spite of the higher dislocation density on MgO than on SrTiO3 substrates. These high mobility BaSnO3 thin films and transistors on MgO substrates will accelerate development for applications in high temperature and high power electronics. Samsung Science and Technology Foundation.

  8. Microstructure and Sn crystal orientation evolution in Sn-3.5Ag lead-free solders in high temperature packaging applications

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Bite [ORNL; Muralidharan, Govindarajan [ORNL; Kurumaddali, Nalini Kanth [ORNL; Parish, Chad M [ORNL; Leslie, Dr Scott [Powerex Inc; Bieler, T. R. [Michigan State University, East Lansing

    2014-01-01

    Understanding the reliability of eutectic Sn-3.5Ag lead-free solders in high temperature packaging applications is of significant interest in power electronics for the next generation electric grid. Large area (2.5mm 2.5mm) Sn-3.5Ag solder joints between silicon dies and direct bonded copper substrates were thermally cycled between 5 C and 200 C. Sn crystal orientation and microstructure evolution during thermal cycling were characterized by electron backscatter diffraction (EBSD) in scanning electron microscope (SEM). Comparisons are made between observed initial texture and microstructure and its evolution during thermal cycling. Gradual lattice rotation and grain boundary misorientation evolution suggested the continuous recrystallization mechanism. Recrystallization behavior was correlated with dislocation slip activities.

  9. SnO2 nanocrystals anchored on N-doped graphene for high-performance lithium storage.

    Science.gov (United States)

    Zhou, Wei; Wang, Jinxian; Zhang, Feifei; Liu, Shumin; Wang, Jianwei; Yin, Dongming; Wang, Limin

    2015-02-28

    A SnO2-N-doped graphene (SnO2-NG) composite is synthesized by a rapid, facile, one-step microwave-assisted solvothermal method. The composite exhibits excellent lithium storage capability and high durability, and is a promising anode material for lithium ion batteries.

  10. GeSn growth kinetics in reduced pressure chemical vapor deposition from Ge2H6 and SnCl4

    Science.gov (United States)

    Aubin, J.; Hartmann, J. M.

    2018-01-01

    We have investigated the low temperature epitaxy of high Sn content GeSn alloys in a 200 mm industrial Reduced Pressure - Chemical Vapor Deposition tool from Applied Materials. Gaseous digermane (Ge2H6) and liquid tin tetrachloride (SnCl4) were used as the Ge and Sn precursors, respectively. The impact of temperature (in the 300-350 °C range), Ge2H6 and SnCl4 mass-flows on the GeSn growth kinetics at 100 Torr has been thoroughly explored. Be it at 300 °C or 325 °C, a linear GeSn growth rate increase together with a sub-linear Sn concentration increase occurred as the SnCl4 mass-flow increased, irrespective of the Ge2H6 mass flow (fixed or varying). The Sn atoms seemed to catalyze H desorption from the surface, resulting in higher GeSn growth rates for high SnCl4 mass-flows (in the 4-21 nm min-1 range). The evolution of the Sn content x with the F (SnCl4) 2 ·/F (Ge2H6) mass-flow ratio was fitted by x2/(1 - x) = n ·F (SnCl4) 2 ·/F (Ge2H6), with n = 0.25 (325 °C) and 0.60 (300 °C). We have otherwise studied the impact of temperature, in the 300-350 °C range, on the GeSn growth kinetics. The GeSn growth rate exponentially increased with the temperature, from 15 up to 32 nm min-1. The associated activation energy was low, i.e. Ea = 10 kcal mol-1. Meanwhile, the Sn content decreased linearly as the growth temperature increased, from 15% at 300 °C down to 6% at 350 °C.

  11. Effects of the copper content on the structural and electrical properties of Cu{sub 2}ZnSnSe{sub 4} bulks

    Energy Technology Data Exchange (ETDEWEB)

    Tsega, Moges, E-mail: mogestsega@yahoo.com [Department of Physics, University of the Free State (Qwaqwa Campus), Private Bag X13, Phuthaditjhaba 9866 (South Africa); Department of Physics, Bahir Dar University (Ethiopia); Dejene, F.B.; Koao, L.F. [Department of Physics, University of the Free State (Qwaqwa Campus), Private Bag X13, Phuthaditjhaba 9866 (South Africa)

    2016-01-01

    We have investigated the concept of defect in Cu{sub x}ZnSnSe{sub 4} (x=1.6–2.0) and Cu{sub y}(Zn{sub 0.9}Sn{sub 1.1})Se{sub 4} (y= 1.6–2.0) bulks prepared by liquid-phase sintering at 600 °C for 2 h with soluble sintering aids of Sb{sub 2}S{sub 3} and Te. All samples were found to exhibit p-type semiconductor for Cu{sub x}ZnSnSe{sub 4}, while n-type of behavior obtained at y= 1.8–2.0 for Cu{sub y}(Zn{sub 0.9}Sn{sub 1.1})Se{sub 4} pellets. The Cu vacancy acts as an acceptor point defect to form the p-type semiconductor, and Sn{sup 4+} acts as a donor to form the n-type behavior for the Sn-rich CZTSe. SEM images of pellets show dense surface morphology, and increase in grain size upon Cu inclusion. The largely increased Hall mobility and the slightly changed carrier concentration for Cu{sub y}(Zn{sub 0.9}Sn{sub 1.1})Se{sub 4} with increasing the Cu content is related to the types of its defects. At y=2.0 with carrier concentration of 4.88×10{sup 17} cm{sup −3} showed the highest mobility of around 58 cm{sup 2}/V s. Based upon the proposed point defects, the CZTSe property can be consistently explained.

  12. Impact of an Elevated Temperature Environment on Sn-Ag-Cu Interconnect Board Level High-G Mechanical Shock Performance

    Science.gov (United States)

    Lee, Tae-Kyu; Chen, Zhiqiang; Baty, Greg; Bieler, Thomas R.; Kim, Choong-Un

    2016-12-01

    The mechanical stability of Sn-Ag-Cu interconnects with low and high silver content against mechanical shock at room and elevated temperatures was investigated. With a heating element-embedded printed circuit board design, a test temperature from room temperature to 80°C was established. High impact shock tests were applied to isothermally pre-conditioned ball-grid array interconnects. Under cyclic shock testing, degradation and improved shock performances were identified associated with test temperature variation and non-solder mask defined and solder-mask defined pad design configuration differences. Different crack propagation paths were observed, induced by the effect of the elevated temperature test conditions and isothermal aging pre-conditions.

  13. Development of a Cu-Sn based brazing system with a low brazing and a high remelting temperature

    Science.gov (United States)

    Schmieding, M.; Holländer, U.; Möhwald, K.

    2017-03-01

    Objective of the project presented is the development of a joining process for hot working steel components at low brazing temperatures leading to a bond with a much higher remelting temperature. This basically is achieved by the use of a Cu-Sn melt spinning foil combined with a pure Cu foil. During brazing, the Sn content of the foil is decreased by diffusion of Sn into the additional Cu resulting in a homogenious joint with a increased remelting temperature of the filler metal. Within this project specimens were brazed and diffusion annealed in a vacuum furnace at 850 °C varying the processing times (0 - 10 h). The samples prepared were studied metallographically and diffusion profiles of Sn were recorded using EDX line scans. The results are discussed in view of further investigations and envisaged applications.

  14. Few-layer SnSe{sub 2} transistors with high on/off ratios

    Energy Technology Data Exchange (ETDEWEB)

    Pei, Tengfei; Bao, Lihong, E-mail: lhbao@iphy.ac.cn; Wang, Guocai; Ma, Ruisong; Yang, Haifang; Li, Junjie; Gu, Changzhi; Du, Shixuan; Gao, Hong-jun [Institute of Physics, Chinese Academy of Sciences, P. O. Box 603, Beijing 100190 (China); Pantelides, Sokrates [Department of Physics and Astronomy, Vanderbilt University, Nashville, Tennessee 37235 (United States); Material Science and Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37381 (United States)

    2016-02-01

    We report few-layer SnSe{sub 2} field effect transistors (FETs) with high current on/off ratios. By trying different gate configurations, 300 nm SiO{sub 2} and 70 nm HfO{sub 2} as back gate only and 70 nm HfO{sub 2} as back gate combined with a top capping layer of polymer electrolyte, few-layer SnSe{sub 2} FET with a current on/off ratio of 10{sup 4} can be obtained. This provides a reliable solution for electrically modulating quasi-two-dimensional materials with high electron density (over 10{sup 13} cm{sup −2}) for field-effect transistor applications.

  15. Enhanced Conductivity and High Thermal Stability of W-Doped SnO2 Based on First-Principle Calculations

    Science.gov (United States)

    Chen, C. Z.; Wen, N. Y.; Chen, H. J.; Li, Y.; Cai, C. B.

    2017-02-01

    Tungsten (W)-doped SnO2 is investigated by first-principle calculations, with a view to understand the effect of doping on the lattice structure, thermal stability, conductivity, and optical transparency. Due to the slight difference in ionic radius as well as high thermal and chemical compatibility between the native element and the heterogeneous dopant, the doped system changes a little with different deviations in the lattice constant from Vegard's law, and good thermal stability is observed as the doping level reaches x = 0.125 in Sn1- x W x O2 compounds. Nevertheless, the large disparities in electron configuration and electronegativity between W and Sn atoms will dramatically modify the electronic structure and charge distribution of W-doped SnO2, leading to a remarkable enhancement of conductivity, electron excitation in the low energy region, and the consequent optical properties, while the visible transparency of Sn1 -x W x O2 is still preserved. Particularly, it is found that the optimal photoelectric properties of W-doped SnO2 may be achieved at x = 0.03. These observations are consistent with the experimental results available on the structural, thermal, electronic, and optical properties of Sn1- x W x O2, thus presenting a practical way of tailoring the physical behaviors of SnO2 through the doping technique.

  16. Superior cycle performance and high reversible capacity of SnO2/graphene composite as an anode material for lithium-ion batteries

    National Research Council Canada - National Science Library

    Liu, Lilai; An, Maozhong; Yang, Peixia; Zhang, Jinqiu

    2015-01-01

    .... The size of SnO2 grains deposited on graphene sheets is less than 3.5 nm. The SnO2/graphene composite exhibits high capacity and excellent electrochemical performance in lithium-ion batteries...

  17. Enhanced Reaction Kinetics and Structure Integrity of Ni/SnO2 Nanocluster toward High-Performance Lithium Storage.

    Science.gov (United States)

    Jiang, Yinzhu; Li, Yong; Zhou, Peng; Yu, Shenglan; Sun, Wenping; Dou, Shixue

    2015-12-09

    SnO2 is regarded as one of the most promising anodes via conversion-alloying mechanism for advanced lithium ion batteries. However, the sluggish conversion reaction severely degrades the reversible capacity, Coulombic efficiency and rate capability. In this paper, through constructing porous Ni/SnO2 composite electrode composed of homogeneously distributed SnO2 and Ni nanoparticles, the reaction kinetics of SnO2 is greatly enhanced, leading to full conversion reaction, superior cycling stability and improved rate capability. The uniformly distributed Ni nanoparticles provide a fast charge transport pathway for electrochemical reactions, and restrict the direct contact and aggregation of SnO2 nanoparticles during cycling. In the meantime, the void space among the nanoclusters increases the contact area between the electrolyte and active materials, and accommodates the huge volume change during cycling as well. The Ni/SnO2 composite electrode possesses a high reversible capacity of 820.5 mAh g(-1) at 1 A g(-1) up to 100 cycles. More impressively, large capacity of 841.9, 806.6, and 770.7 mAh g(-1) can still be maintained at high current densities of 2, 5, and 10 A g(-1) respectively. The results demonstrate that Ni/SnO2 is a high-performance anode for advanced lithium-ion batteries with high specific capacity, excellent rate capability, and cycling stability.

  18. Reliability of Sn-3.5Ag Solder Joints in High Temperature Packaging Applications

    Energy Technology Data Exchange (ETDEWEB)

    Muralidharan, Govindarajan [ORNL; Kurumaddali, Nalini Kanth [ORNL; Kercher, Andrew K [ORNL; Leslie, Dr Scott [Powerex Inc

    2010-01-01

    There is a significant need for next generation, high performance power electronic packages and systems with wide band gap devices to operate at high temperatures in automotive and electricity transmission applications. Sn-3.5Ag solder is a candidate for use in such packages with potential operating temperatures up to 200oC. However, there is a need to understand thermal cycling reliability of Sn-3.5Ag solders subject to such operating conditions. The results of a study on the damage evolution occurring in large area Sn-3.5Ag solders joints between silicon dies and DBC substrates subject to thermal cycling between 200oC and 5oC is presented in this paper. Damage accumulation was followed using high resolution X-ray radiography techniques while nonlinear finite element models were developed based on the mechanical property data available in literature to understand the relationship between the stress state within the solder joint and the damage evolution occurring under thermal cycling conditions. It was observed that regions of damage observed in the experiments do not correspond to the finite element predictions of the location of regions of maximum plastic work.

  19. Highly Active, Carbon-supported, PdSn Nano-core, Partially ...

    African Journals Online (AJOL)

    Carbon-supported, Pt partially covered, PdSn alloy nanoparticles (Pt-PdSn/C) were synthesized via a metathetical reaction of PdSn alloy nanoparticles, and a platinum precursor. The electrochemical activity was evaluated by methanol oxidation. The Pt-PdSn/C catalysts were characterized by transmission electron ...

  20. Highly Sensitive Flexible Human Motion Sensor Based on ZnSnO3/PVDF Composite

    Science.gov (United States)

    Yang, Young Jin; Aziz, Shahid; Mehdi, Syed Murtuza; Sajid, Memoon; Jagadeesan, Srikanth; Choi, Kyung Hyun

    2017-07-01

    A highly sensitive body motion sensor has been fabricated based on a composite active layer of zinc stannate (ZnSnO3) nano-cubes and poly(vinylidene fluoride) (PVDF) polymer. The thin film-based active layer was deposited on polyethylene terephthalate flexible substrate through D-bar coating technique. Electrical and morphological characterizations of the films and sensors were carried out to discover the physical characteristics and the output response of the devices. The synergistic effect between piezoelectric ZnSnO3 nanocubes and β phase PVDF provides the composite with a desirable electrical conductivity, remarkable bend sensitivity, and excellent stability, ideal for the fabrication of a motion sensor. The recorded resistance of the sensor towards the bending angles of -150° to 0° to 150° changed from 20 MΩ to 55 MΩ to 100 MΩ, respectively, showing the composite to be a very good candidate for motion sensing applications.

  1. Solvothermal-induced 3D macroscopic SnO2/nitrogen-doped graphene aerogels for high capacity and long-life lithium storage.

    Science.gov (United States)

    Wang, Ronghua; Xu, Chaohe; Sun, Jing; Gao, Lian; Yao, Heliang

    2014-03-12

    3D macroscopic tin oxide/nitrogen-doped graphene frameworks (SnO2/GN) were constructed by a novel solvothermal-induced self-assembly process, using SnO2 colloid as precursor (crystal size of 3-7 nm). Solvothermal treatment played a key role as N,N-dimethylmethanamide (DMF) acted both as reducing reagent and nitrogen source, requiring no additional nitrogen-containing precursors or post-treatment. The SnO2/GN exhibited a 3D hierarchical porous architecture with a large surface area (336 m(2)g(-1)), which not only effectively prevented the agglomeration of SnO2 but also facilitated fast ion and electron transport through 3D pathways. As a result, the optimized electrode with GN content of 44.23% exhibited superior rate capability (1126, 855, and 614 mAh g(-1) at 1000, 3000, and 6000 mA g(-1), respectively) and extraordinary prolonged cycling stability at high current densities (905 mAh g(-1) after 1000 cycles at 2000 mA g(-1)). Electrochemical impedance spectroscopy (EIS) and morphological study demonstrated the enhanced electrochemical reactivity and good structural stability of the electrode.

  2. Hierarchical three-dimensional porous SnS{sub 2}/carbon cloth anode for high-performance lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Chao, Junfeng, E-mail: chchjjff@163.com [College of Electronic Information and Electric Engineering, Anyang Institute of Technology, Anyang 455000 (China); Zhang, Xiutai [College of Electronic Information and Electric Engineering, Anyang Institute of Technology, Anyang 455000 (China); Xing, Shumin [College of Mathematics and Physics, Anyang Institute of Technology, Anyang 455000 (China); Fan, Qiufeng; Yang, Junping; Zhao, Luhua; Li, Xiang [College of Electronic Information and Electric Engineering, Anyang Institute of Technology, Anyang 455000 (China)

    2016-08-15

    Graphical abstract: Hierarchical 3D porous SnS{sub 2}/carbon cloth, good electrochemical performance. - Highlights: • Hierarchical 3D porous SnS{sub 2}/carbon cloth has been firstly synthesized. • The SnS{sub 2}/carbon clothes were good candidates for excellent lithium ion batteries. • The SnS{sub 2}/carbon cloth exhibits improved capacity compared to pure SnS{sub 2}. - Abstract: Hierarchical three-dimension (3D) porous SnS{sub 2}/carbon clothes were synthesized via a facile polyol refluxing process. The as-synthesized samples were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmet–Teller (BET) and UV–vis diffuse reflectance spectrometer (UV–vis DRS). The 3D porous SnS{sub 2}/carbon clothes-based lithium ion batteries exhibited high reversible capacity and good rate capability as anode materials. The good electrochemical performance for lithium ion storage could be attributed to the special nanostructure, leading to high-rate transportation of electrolyte ion and electrons throughout the electrode matrix.

  3. Contents

    Directory of Open Access Journals (Sweden)

    Editor IJRED

    2012-11-01

    Full Text Available International Journal of Renewable Energy Development www.ijred.com Volume 1             Number 3            October 2012                ISSN 2252- 4940   CONTENTS OF ARTICLES page Design and Economic Analysis of a Photovoltaic System: A Case Study 65-73 C.O.C. Oko , E.O. Diemuodeke, N.F. Omunakwe, and E. Nnamdi     Development of Formaldehyde Adsorption using Modified Activated Carbon – A Review 75-80 W.D.P Rengga , M. Sudibandriyo and M. Nasikin     Process Optimization for Ethyl Ester Production in Fixed Bed Reactor Using Calcium Oxide Impregnated Palm Shell Activated Carbon (CaO/PSAC 81-86 A. Buasri , B. Ksapabutr, M. Panapoy and N. Chaiyut     Wind Resource Assessment in Abadan Airport in Iran 87-97 Mojtaba Nedaei       The Energy Processing by Power Electronics and its Impact on Power Quality 99-105 J. E. Rocha and B. W. D. C. Sanchez       First Aspect of Conventional Power System Assessment for High Wind Power Plants Penetration 107-113 A. Merzic , M. Music, and M. Rascic   Experimental Study on the Production of Karanja Oil Methyl Ester and Its Effect on Diesel Engine 115-122 N. Shrivastava,  , S.N. Varma and M. Pandey  

  4. Development of (Nb,Ta3Sn multifilamentary superconductor wire for high current applications

    Directory of Open Access Journals (Sweden)

    Durval Rodrigues Jr.

    2000-10-01

    Full Text Available The optimization of the energy generated by a MagnetoHydroDynamic (MHD channel using a superconducting magnet demands the optimization of the magnetic field of the system and of the critical points on the magnet winding. This work must include the development of a high performance superconductor wire suitable for this system. Aiming to the construction of improved performance MHD channel, it was developed a low cost superconductor wire, with the required characteristics. The wire was made using a technology compatible with the assembling steps and heat treatment conditions of the MHD superconducting magnets fabrication. It was used the internal Sn method in Nb-7.5wt%Ta tube to fabricate a 271-filament wire with a diameter of 0.81 mm and a Cu/nonCu ratio of 2.3. The wire was heat treated at 200 °C to diffuse the Sn into the Cu shell, producing bronze, followed by the final reaction at temperatures ranging from 670 °C to 730 °C during 25 to 150 h, to produce (Nb,Ta3Sn. The superconducting wire characterization was made measuring the critical current Ic versus the applied magnetic field in the range of 5 to 20 T, the critical temperature Tc and the residual resistivity ratio (RRR. The wire transported critical currents above those available in commercial superconducting wires. These values of Ic are higher than the expected values for the optimization of the MHD channel.

  5. High-sensitivity humidity sensor based on SnO{sub 2} nanoparticles synthesized by microwave irradiation method

    Energy Technology Data Exchange (ETDEWEB)

    Parthibavarman, M.; Hariharan, V. [Centre for Nanoscience and Technology, Department of Physics, Periyar University, Salem - 636 011, T.N. (India); Sekar, C., E-mail: Sekar2025@gmail.com [Centre for Nanoscience and Technology, Department of Physics, Periyar University, Salem - 636 011, T.N. (India); Department of Bioelectronics and Biosensors, Alagappa University, Karaikudi - 630 003 (India)

    2011-07-20

    Tin oxide hexagonal-shaped nanodiscs (SnO) and spherical nanoparticles (SnO{sub 2}) have been prepared by using a simple household microwave irradiation method with an operating frequency of 2.45 GHz. This technique permits us to produce gram quantity of homogeneous nanoparticles in just 10 min. The crystallite size was evaluated from powder X-ray diffraction (XRD) studies and was in the 20 to 25 nm range. Transmission electron microscopy (TEM) analysis showed that the as prepared SnO form as hexagonal-shaped nanodiscs and upon subsequent annealing at 500 deg. C for 5 h in air, the SnO gets converted to spherical-shaped nanoparticles of SnO{sub 2}. The SnO{sub 2} sample shows good sensitivity towards the relative humidity. The calculated response and recovery time were found to be 32 s and 25 s respectively. These results indicate promising applications of SnO{sub 2} nanoparticles in a highly sensitive environmental monitoring and humidity controlled electronic devices. The samples were further subjected to thermal analyses (TG-DTA) and UV-VIS diffusion reflectance spectroscopy (DRS) studies.

  6. Modification of SnO2 Anodes by Atomic Layer Deposition for High Performance Lithium Ion Batteries

    KAUST Repository

    Yesibolati, Nulati

    2013-05-01

    Tin dioxide (SnO2) is considered one of the most promising anode materials for Lithium ion batteries (LIBs), due to its large theoretical capacity and natural abundance. However, its low electronic/ionic conductivities, large volume change during lithiation/delithiation and agglomeration prevent it from further commercial applications. In this thesis, we investigate modified SnO2 as a high energy density anode material for LIBs. Specifically two approaches are presented to improve battery performances. Firstly, SnO2 electrochemical performances were improved by surface modification using Atomic Layer Deposition (ALD). Ultrathin Al2O3 or HfO2 were coated on SnO2 electrodes. It was found that electrochemical performances had been enhanced after ALD deposition. In a second approach, we implemented a layer-by-layer (LBL) assembled graphene/carbon-coated hollow SnO2 spheres as anode material for LIBs. Our results indicated that the LBL assembled electrodes had high reversible lithium storage capacities even at high current densities. These superior electrochemical performances are attributed to the enhanced electronic conductivity and effective lithium diffusion, because of the interconnected graphene/carbon networks among nanoparticles of the hollow SnO2 spheres.

  7. Highly efficient electrochemical degradation of perfluorooctanoic acid (PFOA) by F-doped Ti/SnO{sub 2} electrode

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Bo, E-mail: boyang@szu.edu.cn [Department of Environmental Engineering, College of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen 518060 (China); School of Environment, POPs Research Center, Tsinghua University, Beijing 100084 (China); Jiang, Chaojin [Department of Environmental Engineering, College of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen 518060 (China); Yu, Gang, E-mail: yg-den@tsinghua.edu.cn [School of Environment, POPs Research Center, Tsinghua University, Beijing 100084 (China); Zhuo, Qiongfang [South China Institute of Environmental Sciences, The Ministry of Environment Protection, Guangzhou 510655 (China); Deng, Shubo [School of Environment, POPs Research Center, Tsinghua University, Beijing 100084 (China); Wu, Jinhua [School of Environment and Energy, South China University of Technology, Guangzhou 510006 (China); Zhang, Hong [Department of Environmental Engineering, College of Chemistry and Chemical Engineering, Shenzhen University, Shenzhen 518060 (China)

    2015-12-15

    Highlights: • A novel SnO{sub 2} electrode is prepared by F doping instead of the traditional Sb doping. • SnF{sub 4} as single-source precursor is used to fabricate the long-life Ti/SnO{sub 2}–F anode. • F-doped Ti/SnO{sub 2} anode possesses high OEP and decomposition ability for PFOA. • Further mechanistic detail of PFOA degradation on Ti/SnO{sub 2}–F electrode is proposed. - Abstract: The novel F-doped Ti/SnO{sub 2} electrode prepared by SnF{sub 4} as the single-source precursor was used for electrochemical degradation of aqueous perfluorooctanoic acid (PFOA). Higher oxidation reactivity and significantly longer service life were achieved for Ti/SnO{sub 2}–F electrode than Ti/SnO{sub 2}–X (X = Cl, Br, I, or Sb) electrode, which could decomposed over 99% of PFOA (50 mL of 100 mg L{sup −1}) within 30-min electrolysis. The property of Ti/SnO{sub 2}–F electrode and its electrooxidation mechanism were investigated by XRD, SEM–EDX, EIS, LSV, and interfacial resistance measurements. We propose that the similar ionic radii of F and O as well as strong electronegativity of F caused its electrochemical stability with high oxygen evolution potential (OEP) and smooth surface to generate weakly adsorbed ·OH. The preparation conditions of electrode were also optimized including F doping amount, calcination temperature, and dip coating times, which revealed the formation process of electrode. Additionally, the major mineralization product, F{sup −}, and low concentration of shorter chain perfluorocarboxylic acids (PFCAs) were detected in solution. So the reaction pathway of PFOA electrooxidation was proposed by intermediate analysis. These results demonstrate that Ti/SnO{sub 2}–F electrode is promising for highly efficient treatment of PFOA in wastewater.

  8. Expression of Castor LPAT2 Enhances Ricinoleic Acid Content at the sn-2 Position of Triacylglycerols in Lesquerella Seed

    Directory of Open Access Journals (Sweden)

    Grace Q. Chen

    2016-04-01

    Full Text Available Lesquerella is a potential industrial oilseed crop that makes hydroxy fatty acid (HFA. Unlike castor its seeds are not poisonous but accumulate lesquerolic acid mostly at the sn-1 and sn-3 positions of triacylglycerol (TAG, whereas castor contains ricinoleic acid (18:1OH at all three positions. To investigate whether lesquerella can be engineered to accumulate HFAs in the sn-2 position, multiple transgenic lines were made that express castor lysophosphatidic acid acyltransferase 2 (RcLPAT2 in the seed. RcLPAT2 increased 18:1OH at the sn-2 position of TAGs from 2% to 14%–17%, which resulted in an increase of tri-HFA-TAGs from 5% to 13%–14%. Our result is the first example of using a LPAT to increase ricinoleic acid at the sn-2 position of seed TAG. This work provides insights to the mechanism of HFA-containing TAG assembly in lesquerella and directs future research to optimize this plant for HFA production.

  9. Metallic Sn-Based Anode Materials: Application in High-Performance Lithium-Ion and Sodium-Ion Batteries.

    Science.gov (United States)

    Ying, Hangjun; Han, Wei-Qiang

    2017-11-01

    With the fast-growing demand for green and safe energy sources, rechargeable ion batteries have gradually occupied the major current market of energy storage devices due to their advantages of high capacities, long cycling life, superior rate ability, and so on. Metallic Sn-based anodes are perceived as one of the most promising alternatives to the conventional graphite anode and have attracted great attention due to the high theoretical capacities of Sn in both lithium-ion batteries (LIBs) (994 mA h g-1) and sodium-ion batteries (847 mA h g-1). Though Sony has used Sn-Co-C nanocomposites as its commercial LIB anodes, to develop even better batteries using metallic Sn-based anodes there are still two main obstacles that must be overcome: poor cycling stability and low coulombic efficiency. In this review, the latest and most outstanding developments in metallic Sn-based anodes for LIBs and SIBs are summarized. And it covers the modification strategies including size control, alloying, and structure design to effectually improve the electrochemical properties. The superiorities and limitations are analyzed and discussed, aiming to provide an in-depth understanding of the theoretical works and practical developments of metallic Sn-based anode materials.

  10. Cu-SnO2 nanostructures obtained via galvanic replacement control as high performance anodes for lithium-ion storage

    Science.gov (United States)

    Nguyen, Tuan Loi; Park, Duckshin; Hur, Jaehyun; Son, Hyung Bin; Park, Min Sang; Lee, Seung Geol; Kim, Ji Hyeon; Kim, Il Tae

    2018-01-01

    SnO2 has been considered as a promising anode material for lithium ion batteries (LIBs) because of its high theoretical capacity (782 mAh g-1). However, the reaction between lithium ions and Sn causes a large volume change, resulting in the pulverization of the anode, a loss of contact with the current collector, and a deterioration in electrochemical performance. Several strategies have been proposed to mitigate the drastic volume changes to extend the cyclic life of SnO2 materials. Herein, novel composites consisting of Cu and SnO2 were developed via the galvanic replacement reaction. The reaction was carried out at 180 °C for different durations and triethylene glycol was used as the medium solvent. The structure, morphology, and composition of the composites were analyzed by X-ray diffraction, transmission electron microscopy, and energy dispersive X-ray spectroscopy. The reaction time affected the particle size, which in turn affected the reaction kinetics. Furthermore, the novel nanostructures contained an inactive metal phase (Cu), which acted both as the buffer space against the volume change of Sn during the alloying reaction and as the electron conductor, resulting in a lower impedance of the composites. When evaluated as potential anodes for LIBs, the composite electrodes displayed extraordinary electrochemical performance with a high capacity and Coulombic efficiency, an excellent cycling stability, and a superior rate capability compared to a Sn electrode.

  11. Confined Porous Graphene/SnOx Frameworks within Polyaniline-Derived Carbon as Highly Stable Lithium-Ion Battery Anodes.

    Science.gov (United States)

    Zhou, Dan; Song, Wei-Li; Li, Xiaogang; Fan, Li-Zhen

    2016-06-01

    Tin oxides are promising anode materials for their high theoretical capacities in rechargeable lithium-ion batteries (LIBs). However, poor stability usually limits the practical application owing to the large volume variation during the cycling process. Herein, a novel carbon confined porous graphene/SnOx framework was designed using a silica template assisted nanocasting method followed by a polyaniline-derived carbon coating process. In this process, silica served as a template to anchor SnOx nanoparticles on porous framework and polyaniline was used as the carbon source for coating on the porous graphene/SnOx framework. The synthesized carbon confined porous graphene/SnOx frameworks demonstrate substantially improved rate capacities and enhanced cycling stability as the anode materials in LIBs, showing a high reversible capacity of 907 mAh g(-1) after 100 cycles at 100 mA g(-1) and 555 mAh g(-1) after 400 cycles at 1000 mA g(-1). The remarkably improved electrochemical performance could be assigned to the unique porous architecture, which effectively solves the drawbacks of SnOx including poor electrical conductivity and undesirable volume expansion during cycling process. Consequently, such design concept for promoting SnOx performance could provide a novel stage for improving anode stability in LIBs.

  12. Ohmic contact mechanism for RF superimposed DC sputtered-ITO transparent p-electrodes with a variety of Sn2O3 content for GaN-based light-emitting diodes

    Science.gov (United States)

    Kim, Tae Kyoung; Yoon, Yeo Jin; Oh, Seung Kyu; Lee, Yu Lim; Cha, Yu-Jung; Kwak, Joon Seop

    2018-02-01

    The dependence of the electrical and optical properties of radio frequency (RF) superimposed direct current (DC) sputtered-indium tin oxide (ITO) on the tin oxide (Sn2O3) content of the ITO is investigated, in order to elucidate an ohmic contact mechanism for the sputtered-ITO transparent electrodes on p-type gallium nitride (p-GaN). Contact resistivity of the RF superimposed DC sputtered-ITO on p-GaN in LEDs decreased when Sn2O3 content was increased from 3 wt% to 7 wt% because of the reduced sheet resistance of the sputtered-ITO with the increasing Sn2O3 content. Further increases in Sn2O3 content from 7 wt% to 15 wt% resulted in deterioration of the contact resistivity, which can be attributed to reduction of the work function of the ITO with increasing Sn2O3 content, followed by increasing Schottky barrier height at the sputtered ITO/p-GaN interface. Temperature-dependent contact resistivity of the sputtered-ITO on p-GaN also revealed that the ITO contacts with 7 wt% Sn2O3 yielded the lowest effective barrier height of 0.039 eV. Based on these results, we devised sputtered-ITO transparent p-electrodes having dual compositions of Sn2O3 content (7/10 wt%). The radiant intensity of LEDs having sputtered-ITO transparent p-electrodes with the dual compositions (7/10 wt%) was enhanced by 13% compared to LEDs having ITO with Sn2O3 content of 7 wt% only.

  13. Construction of High-Quality SnO2@MoS2 Nanohybrids for Promising Photoelectrocatalytic Applications.

    Science.gov (United States)

    Zhang, Xinyu; Yang, Yawei; Ding, Shujiang; Que, Wenxiu; Zheng, Zhiping; Du, Yaping

    2017-03-20

    High-quality three-dimensional (3D) hierarchical SnO2@MoS2 nanohybrids were successfully obtained via a facile but effective wet chemistry synthesis method. Meanwhile, the SnO2@MoS2 hybrid film was fabricated through an electrophoretic deposition method to promote photoelectrocatalytic (PEC) efficiency and solve the recovery problem. Compared with the pure SnO2 and MoS2 films, the SnO2@MoS2 heterostructures could decrease the rate of the photoelectron-hole pair's recombination, which resulted in the superior PEC pollutant degradation and water splitting activities. Meanwhile, the SnO2@MoS2 hybrid films with well-defined 3D hierarchical configurations have large surface areas, abundant active edge sites, and defects on the basal surfaces, which were also advantageous for the PEC activities (for pollutant degradation, apparent rate constant k = 5.91 h(-1); for water splitting, onset potential = -0.05 V and current density = 10 mA/cm(2)). Therefore, the SnO2@MoS2 hybrid film proved to be a superior structure for PEC applications.

  14. Rapid solidification mechanism of highly undercooled ternary Cu40Sn45Sb15 alloy

    Science.gov (United States)

    Zhai, W.; Wang, B. J.; Lu, X. Y.; Wei, B.

    2015-10-01

    The rapid solidification of ternary Cu40Sn45Sb15 peri-eutectic type alloy was realized by glass fluxing and drop tube methods, and the corresponding maximum undercoolings are 185 K (0.22 T L) and 321 K (0.39 T L), respectively. The phase constitution of Cu40Sn45Sb15 alloy in these two rapid solidification experiments deviates from the two equilibrium phases (Sn + Cu6Sn5). In glass fluxing method, the structural morphology of Cu40Sn45Sb15 alloy is mainly characterized by a three-layer lamellar structure, which is comprised by an inner layer of long strips of primary ɛ(Cu3Sn) phase, an intermediate layer of η(Cu6Sn5) phase and an outer layer of β(SnSb) phase. As undercooling rises, this lamellar structure is remarkably refined. When small alloy droplets are containerlessly solidified during free fall in drop tube, the primary ɛ(Cu3Sn) phase grows by non-faceted mode into dendrites as droplet diameter decreases. Especially, solidification path alters in the smallest droplet with 50 μm diameter, in which η(Cu6Sn5) and Sn3Sb2 phases form directly from the metastable liquid phase by suppressing the primary ɛ phase formation and the following peri-eutectic transformation.

  15. SnO{sub 2} thin films grown by atomic layer deposition using a novel Sn precursor

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Min-Jung [Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul, 136-791 (Korea, Republic of); Department of Materials Science and Engineering, Yonsei University, Seoul, 120-749 (Korea, Republic of); Cho, Cheol Jin [Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul, 136-791 (Korea, Republic of); Department of Materials Science and Engineering, Seoul National University, Seoul, 151-744 (Korea, Republic of); Kim, Kwang-Chon; Pyeon, Jung Joon [Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul, 136-791 (Korea, Republic of); Park, Hyung-Ho [Department of Materials Science and Engineering, Yonsei University, Seoul, 120-749 (Korea, Republic of); Kim, Hyo-Suk; Han, Jeong Hwan; Kim, Chang Gyoun; Chung, Taek-Mo [Division of Advanced Materials, Korea Research Institute of Chemical Technology (KRICT), Daejeon, 305-600 (Korea, Republic of); Park, Tae Joo [Department of Materials Science and Engineering, Hanyang University, Ansan, 426-791 (Korea, Republic of); Kwon, Beomjin [Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul, 136-791 (Korea, Republic of); Jeong, Doo Seok; Baek, Seung-Hyub [Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul, 136-791 (Korea, Republic of); Department of Nanomaterials, Korea University of Science and Technology, Daejeon, 305-333 (Korea, Republic of); Kang, Chong-Yun; Kim, Jin-Sang [Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul, 136-791 (Korea, Republic of); Kim, Seong Keun, E-mail: s.k.kim@kist.re.kr [Electronic Materials Research Center, Korea Institute of Science and Technology, Seoul, 136-791 (Korea, Republic of); Department of Nanomaterials, Korea University of Science and Technology, Daejeon, 305-333 (Korea, Republic of)

    2014-11-30

    Highlights: • We developed a new ALD process for SnO{sub 2} films using dimethylamino-2-methyl-2-propoxy-tin(II) as a novel Sn precursor. • The SnO{sub 2} films grown from Sn(dmamp){sub 2} has negligible impurity contents. • Sn ions in the films had a single binding state corresponding to Sn{sup 4+} in SnO{sub 2}. - Abstract: SnO{sub 2} thin films were grown by atomic layer deposition (ALD) with dimethylamino-2-methyl-2-propoxy-tin(II) (Sn(dmamp){sub 2}) and O{sub 3} in a temperature range of 100–230 °C. The ALD window was found to be in the range of 100–200 °C. The growth per cycle of the films in the ALD window increased with temperature in the range from 0.018 to 0.042 nm/cycle. Above 230 °C, the self-limiting behavior which is a unique characteristic of ALD, was not observed in the growth because of the thermal decomposition of the Sn(dmamp){sub 2} precursor. The SnO{sub 2} films were amorphous in the ALD window and exhibited quite a smooth surface. Sn ions in all films had a single binding state corresponding to Sn{sup 4+} in SnO{sub 2}. The concentration of carbon and nitrogen in the all SnO{sub 2} films was below the detection limit of the auger electron spectroscopy technique and a very small amount of carbon, nitrogen, and hydrogen was detected by secondary ions mass spectroscopy only. The impurity contents decreased with increasing the growth temperature. This is consistent with the increase in the density of the SnO{sub 2} films with respect to the growth temperature. The ALD process with Sn(dmamp){sub 2} and O{sub 3} shows excellent conformality on a hole structure with an aspect ratio of ∼9. This demonstrates that the ALD process with Sn(dmamp){sub 2} and O{sub 3} is promising for growth of robust and highly pure SnO{sub 2} films.

  16. Critical current measurements of High-Jc Nb3Sn Rutherford cables under Transverse Compression

    CERN Document Server

    Bordini, B; Ballarino, A; Bottura, L; Oberli, L

    2013-01-01

    For the LHC upgrade, CERN has launched a large program to develop next generation accelerator magnets based on high-Jc Nb3Sn Rutherford cables. These magnets are characterized by a magnetic field and/or an aperture significantly larger than that of current Nb-Ti LHC magnets. The increased field/aperture will require coil pre-stresses much larger than 100 MPa. Since Nb3Sn cables are extremely sensitive to strain, critical current measurements under traverse compression are essential to estimate the transport current properties of the conductor within the magnet. To this purpose CERN has developed a sample holder (to be used in the FRESCA test station) that allows testing Rutherford cables under a transverse force of up to 2 MN/m. The new holder can house cable samples up to 1.8 m long and 20 mm wide. The large transverse force is only applied over the sample high field region, which is 70 cm long and over which the FRESCA dipole magnet generates a homogeneous fields of up to 10 T. Recently the critical current...

  17. Facile Synthesis of Different Morphologies of Cu2SnS3 for High-Performance Supercapacitors.

    Science.gov (United States)

    Wang, Chao; Tian, Hanqing; Jiang, Jing; Zhou, Ting; Zeng, Qing; He, XinRui; Huang, Pei; Yao, Yan

    2017-08-09

    Cu2SnS3 is considered as an emerging potential candidate for electrode materials due to considerable interlayer spaces and tunnels in its crystal structures and excellent conducting ability. Ternary Cu2SnS3 as anode in lithium ion batteries has already been reported, but it is rarely mentioned to be applied in supercapacitors which is considered to be a complementary energy storage device for lithium ion batteries. It is an effective method to improve the electrochemical performance of materials by adjusting the morphology and microstructure of materials. In present study, ternary nanosheet-assembled Cu2SnS3 microspheres (M-CTS) and nanoparticles-like Cu2SnS3 (N-CTS) are synthesized via a facile solvothermal route. The results suggest that Cu2SnS3 microspheres (M-CTS) exhibit better capacitive performance compared with Cu2SnS3 (N-CTS) nanoparticles, which means that morphology does have a significant effect on the electrochemical reaction. M-CTS presents excellent supercapacitor performances with the high specific capacity of about 406 C g-1 at a current density of 1 A g-1 and achieves a high energy density of 85.6 W h kg-1 and power density of 720 W kg-1. The remarkable electrochemical performance of Cu2SnS3 can be attributed to the large specific surface area, smaller average pore size, and improved electrical conductivity. Our research indicates that it is very suitable for large-scale production and has enormous potential in the practical application of high-performance supercapacitors.

  18. Effect of copper content and sulfurization process on optical, structural and electrical properties of ultrasonic spray pyrolysed Cu{sub 2}ZnSnS{sub 4} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Kermadi, S., E-mail: kermadisalim@yahoo.fr [CRTSE- Division DDCS 02, Bd Dr Frantz Fanon BP: 140, Les 07 Merveilles, 16038, Algiers (Algeria); Sali, S.; Ait Ameur, F.; Zougar, L.; Boumaour, M. [CRTSE- Division DDCS 02, Bd Dr Frantz Fanon BP: 140, Les 07 Merveilles, 16038, Algiers (Algeria); Toumiat, A. [Ceramics Laboratory, Physics Department, Constantine University 1, 25017, Constantine (Algeria); Melnik, N.N. [Lebedev Physical Institute, Russian Academy of Sciences, Leninskii pr. 53, Moscow, 119991 (Russian Federation); Hewak, D.W. [Optoelectronics Research Centre, University of Southampton, Southampton, SO17 1BJ (United Kingdom); Duta, Anca [Transilvania University of Brasov, Department of Renewable Energy Systems and Recycling, Eroilor 29, 500036, Brasov (Romania)

    2016-02-01

    This paper reports the effect of copper content and of the sulfurization process (using elemental sulfur vapor) on the growth, structure, elemental composition, and on the optical and electrical properties of Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films deposited on glass substrates using ultrasonic Spray Pyrolysis. For this purpose, a series of aqueous solutions consisting of copper (II) and tin (IV) chlorides, zinc (II) acetate and thiourea with different copper concentrations (x = Cu/(Zn + Sn) = 0.8, 1, 1.2 and 1.4 while Zn/Sn = 1) were prepared. X-ray diffraction, raman spectroscopy, scanning electronic microscopy, atomic force microscopy, energy dispersive X-ray spectroscopy, ultraviolet–visible–near infrared absorbance spectroscopy and sheet resistance analyses were used to follow the evolution of the investigated properties. The results outlined a Kesterite type CZTS phase and a secondary copper sulfide (Cu{sub 2-x}S) phase, and their ratio strongly depends on the copper salt concentration and heat-treatment atmosphere. No traces of secondary phases of zinc or tin sulfides are found while high purity CZTS was obtained with the post-sulfurized film at x = 1.2. It was found that the application of additional sulfurization enhances the grain growth to reach 300 nm in size and induces significant improvement of both CZTS crystallinity and electrical conductivity. The optical band gap ranges between 1.44 and 1.57 eV depending on the composition and the sulfur deficiency is strongly reduced leading to Cu-poorer and Zn-richer compounds, as compared to those annealed in nitrogen atmosphere. This study shows promising results, as a first step in developing photovoltaic applications, using sprayed CZTS as absorber. - Highlights: • Cu{sub 2}ZnSnS{sub 4} (CZTS) thin films were obtained by ultrasonic Spray Pyrolysis. • The copper content and sulfurization process affect the Cu{sub 2}S/CZTS ratio. • Cu/(Zn + Sn) = 1.2 found to be optimum composition

  19. Nanowires of Lead-Free Solder Alloy SnCuAg

    Directory of Open Access Journals (Sweden)

    F. E. Atalay

    2011-01-01

    Full Text Available Ternary Sn88Ag5Cu7, Sn93Ag4Cu3, Sn58Ag18Cu24, Sn78Ag16Cu6, Sn90Ag4Cu6, Sn87Ag4Cu9 alloy nanowires were produced at various values of deposition potential by dc electrodeposition on highly ordered porous anodic alumina oxide (AAO templates. During the deposition process some parameters, such as ion content, deposition time, pH, and temperature of the solution, were kept constant. The diameter and length of regular Sn93Ag4Cu3 nanowires electrodeposited at −1 V were determined by scanning electron microscopy (SEM to be approximately 200–250 nm and 7-8 μm, respectively. Differential scanning calorimetry (DSC results indicate that the melting onset temperature of Sn93Ag4Cu3 nanowires is about 204°C.

  20. S-N Curves of high resistance steels in the gigacyclic regime; Curvas S-N de aceros de alta resistencia dentro del regimen gigaciclico

    Energy Technology Data Exchange (ETDEWEB)

    Marinez G, I [Conservatoire National des Arts et Metiers-Institut des Technologies et des Materiaux Avances (CNAM-ITMA), Paris (France); Dominguez A, G [Instituto Tecnologico de Celaya, Guanajuato (Mexico); Bathias, C [Conservatoire National des Arts et Metiers-Institut des Technologies et des Materiaux Avances (CNAM-ITMA), Paris (France)

    2004-04-15

    In this paper, the fatigue behavior of high strength steel used for mechanical parts has been investigated in the gigacycle fatigue regime. An experimental study has been carried out with both: R = 0.1 (perlitic-ferritic steel) and R = -1 (perlitic-ferritic steel, bainitic steel, martensitic steels) loads, at a high frequency of 20 khz up to 1010 cycles, to determine the S-N curves when fatigue life is more than 107 cycles. Comparison of experimental results at frequencies of 20 khz and 30 Hz with R = -1, shows that the S-N curve has a good agreement between 105 and 107 cycles for the high strength steels, Furthermore, fracture surface observations are made by SEM; the transition of crack initiation site is described. The generalization of gigacycle fatigue behavior is analyzed. More often initiation of fatigue crack at 109 cycles is a bulk phenomenon with an important effect of stress concentration due to mineral inclusions or perlitic platelets. Thus, the Murakami model is efficient when we can measure the defects associated with fracture, but it can not take into account the microstructure effect related to platelets phenomenon. [Spanish] En este trabajo se investigo el comportamiento en fatiga gigaciclica de varios aceros de alta resistencia utilizados en la industria automotriz. El estudio experimental se llevo a cabo utilizando dos diferentes valores de carga: R = 0.1 (acero perlitoferritico) y R = -1 (acero perlito-ferritico, acero bainitico, aceros martensiticos), a una frecuencia de ensayo de 20 kHz y hasta 1010 ciclos, para determinar las curvas S-N arriba de 107 ciclos. La comparacion de resultados experimentales obtenidos utilizando frecuencias de ensayo de 20 kHz y 30 Hz con la relacion de carga R = - 1, muestran la continuidad de las curvas S-N entre 105 y 107 ciclos para estos aceros de alta resistencia. Por otro lado, observaciones de la superficie de fractura se efectuaron utilizando el microscopio electronico de barrido; se describe la transicion

  1. Investigation of preparation and characteristics of Sn-Bi eutectic powders derived from a high shear mechanical approach

    Energy Technology Data Exchange (ETDEWEB)

    Liang Kun; Tang Xianzhong [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China); Yu Lijing [Kunming Institute of Physics, Kunming 650223 (China); Wang Ni [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China); Hu Wencheng, E-mail: huwc@uestc.edu.cn [State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054 (China)

    2011-10-13

    Graphical abstract: Highlights: > Sn-Bi eutectic powders were prepared by a high shear mechanical approach. This approach is a green one because no chemical reaction occurs in the process and the high boiling point solvent can be used repeatedly. > The melting point of the as-prepared powders is about 140 deg. C, which is in agreement with the low melting point solder for industrial applications. > The size of Sn-Bi eutectic powders can be controlled by addition of Poly(N-vinylpyrrolidone) (PVP) due to the adsorption. - Abstract: Fusible Sn-Bi eutectic alloy particles were synthesized from bulk Sn-Bi alloy via a high-shear mechanical approach. The morphology, composition, and structure of the as-prepared Sn-Bi alloy particles were characterized by XRD, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, differential scanning calorimetry, thermogravimetry, and Fourier-transform infrared spectroscopy. The particles were found to be spherical and consist of the tetragonal phase of tin as well as the rhombohedral phase of bismuth. In addition, there were large amounts of poly(N-vinylpyrrolidone) coated on the particles.

  2. Vanadium Nitride Nanowire Supported SnS2 Nanosheets with High Reversible Capacity as Anode Material for Lithium Ion Batteries.

    Science.gov (United States)

    Balogun, Muhammad-Sadeeq; Qiu, Weitao; Jian, Junhua; Huang, Yongchao; Luo, Yang; Yang, Hao; Liang, Chaolun; Lu, Xihong; Tong, Yexiang

    2015-10-21

    The vulnerable restacking problem of tin disulfide (SnS2) usually leads to poor initial reversible capacity and poor cyclic stability, which hinders its practical application as lithium ion battery anode (LIB). In this work, we demonstrated an effective strategy to improve the first reversible capacity and lithium storage properties of SnS2 by growing SnS2 nanosheets on porous flexible vanadium nitride (VN) substrates. When evaluating lithium-storage properties, the three-dimensional (3D) porous VN coated SnS2 nanosheets (denoted as CC-VN@SnS2) yield a high reversible capacity of 75% with high specific capacity of about 819 mAh g(-1) at a current density of 0.65 A g(-1). Remarkable cyclic stability capacity of 791 mAh g(-1) after 100 cycles with excellent capacity retention of 97% was also achieved. Furthermore, discharge capacity as high as 349 mAh g(-1) is still retained after 70 cycles even at a elevated current density of 13 A g(-1). The excellent performance was due to the conductive flexible VN substrate support, which provides short Li-ion and electron pathways, accommodates large volume variation, contributes to the capacity, and provides mechanical stability, which allows the electrode to maintain its structural stability.

  3. Data on metal contents (As, Ag, Sr, Sn, Sb, and Mo in sediments and shells of Trachycardium lacunosum in the northern part of the Persian Gulf

    Directory of Open Access Journals (Sweden)

    Vahid Noroozi Karbasdehi

    2016-09-01

    Full Text Available In this data article, by using inductively coupled plasma optical spectrometry (ICP-OES1 Inductively Coupled Plasma Optical Spectrometry., we aimed to (1 determine the concentration levels of As, Ag, Sr, Sn, Sb, and Mo in the sediments and the shells of Trachycardium lacunosum simultaneously in two separated areas (unpolluted and polluted areas (2 comparison between the metal contents of sediments in the unpolluted and polluted areas as well as shells. Analysis of data showed that sediment as well as shell samples in polluted area contained significantly higher concentration levels of all measured metals compared with unpolluted area.

  4. The developments of SnO2/graphene nanocomposites as anode materials for high performance lithium ion batteries: A review

    Science.gov (United States)

    Deng, Yuanfu; Fang, Chengcheng; Chen, Guohua

    2016-02-01

    With the increasing energy demands for electronic devices and electrical vehicles, anode materials for lithium ion batteries (LIBs) with high specific capacity, good cyclic and rate performances become one of the focal areas of research. Among the various anode materials, SnO2/graphene nanocomposites have drawn extensive attentions due to their high theoretical specific capacities, low charge potential vs. Li/Li+ and environmental benignity. In this review, the advances, including the synthetic methods and structural optimizations, of the SnO2/graphene nanocomposites as anode materials for LIBs have been reviewed in detail. By providing an in-depth discussion of SnO2/graphene nanocomposites, we aim to demonstrate that the electrochemical performances of SnO2/graphene nanocomposites could be significantly enhanced by rational modifications of morphology and crystal structures, chemical compositions and surface features. Though only focusing on SnO2/graphene-based composites, the concepts and strategies should be referential to other metal oxide/graphene composites.

  5. Ultrasmall SnO2 Nanocrystals: Hot-bubbling Synthesis, Encapsulation in Carbon Layers and Applications in High Capacity Li-Ion Storage

    Science.gov (United States)

    Ding, Liping; He, Shulian; Miao, Shiding; Jorgensen, Matthew R.; Leubner, Susanne; Yan, Chenglin; Hickey, Stephen G.; Eychmüller, Alexander; Xu, Jinzhang; Schmidt, Oliver G.

    2014-01-01

    Ultrasmall SnO2 nanocrystals as anode materials for lithium-ion batteries (LIBs) have been synthesized by bubbling an oxidizing gas into hot surfactant solutions containing Sn-oleate complexes. Annealing of the particles in N2 carbonifies the densely packed surface capping ligands resulting in carbon encapsulated SnO2 nanoparticles (SnO2/C). Carbon encapsulation can effectively buffer the volume changes during the lithiation/delithiation process. The assembled SnO2/C thus deliver extraordinarily high reversible capacity of 908 mA·h·g−1 at 0.5 C as well as excellent cycling performance in the LIBs. This method demonstrates the great potential of SnO2/C nanoparticles for the design of high power LIBs. PMID:24732294

  6. High quality NMP exfoliated graphene nanosheet-SnO2 composite anode material for lithium ion battery.

    Science.gov (United States)

    Ravikumar, Raman; Gopukumar, Sukumaran

    2013-03-21

    A graphene nanosheet-SnO(2) (GNS-SnO(2)) composite is prepared using N-methylpyrrolidone as a solvent to exfoliate graphene from graphite bar with the aid of CTAB by single phase co-precipitation method. The synthesized composites has been characterised physically by powder XRD which confirms the formation of the composite tetragonal SnO(2) crystal system with the low intense broad 002 plane for GNS. The sandwiched morphology of GNS-SnO(2) and the formation of nanosized particles (around 20 nm) have been confirmed by SEM and TEM images. The presence of sp(2) carbon in the GNS is clear by the highly intense G than D band in laser Raman spectroscopy analysis; furthermore, a single chemical shift has been observed at 132.14 ppm from solid-state (13)C NMR analysis. The synthesized composite has been electrochemically characterized using charge-discharge and EIS analysis. The capacity retentions at the end of the first 10 cycles is 57% (100 mA g(-1) rate), the second 10 cycles is 77.83% (200 mA g(-1)), and the final 10 cycles (300 mA g(-1)) is 81.5%. Moreover the impedance analysis clearly explains the low resistance pathway for Li(+) insertion after 30 cycles when compared with the initial cycle. This superior characteristic of GNS-SnO(2) composite suggests that it is a promising candidate for lithium ion battery anode.

  7. A review and prospects for Nb3Sn superconductor development

    Science.gov (United States)

    Xu, Xingchen

    2017-09-01

    Nb3Sn superconductors have significant applications in constructing high-field (>10 T) magnets. This article briefly reviews development of Nb3Sn superconductor and proposes prospects for further improvement. It is shown that significant improvement of critical current density (J c) is needed for future accelerator magnets. After a brief review of the development of Nb3Sn superconductors, the factors controlling J c are summarized and correlated with their microstructure and chemistry. The non-matrix J c of Nb3Sn conductors is mainly determined by three factors: the fraction of current-carrying Nb3Sn phase in the non-matrix area, the upper critical field B c2, and the flux line pinning capacity. Then prospects to improve the three factors are discussed respectively. An analytic model was developed to show how the ratios of precursors determine the phase fractions after heat treatment, based on which it is predicted that the limit of current-carrying Nb3Sn fraction in subelements is ∼65%. Then, since B c2 is largely determined by the Nb3Sn stoichiometry, a thermodynamic/kinetic theory is presented to show what essentially determines the Sn content of Nb3Sn conductors. This theory explains the influences of Sn sources and Ti addition on stoichiometry and growth rate of Nb3Sn layers. Next, to improve flux pinning, previous efforts in this community to introduce additional pinning centers to Nb3Sn wires are reviewed, and an internal oxidation technique is described. Finally, prospects for further improvement of non-matrix J c of Nb3Sn conductors are discussed, and it is seen that the only opportunity for further significantly improving J c lies in improving flux pinning.

  8. High photoactive TiO2/SnO2 nanocomposites prepared by laser pyrolysis

    Science.gov (United States)

    Scarisoreanu, Monica; Fleaca, Claudiu; Morjan, Ion; Niculescu, Ana-Maria; Luculescu, Catalin; Dutu, Elena; Ilie, Alina; Morjan, Iuliana; Florescu, Lavinia Gavrila; Vasile, Eugeniu; Fort, Carmen Ioana

    2017-10-01

    TiO2/SnO2 nanocomposites have been prepared by laser pyrolysis of volatile TiCl4 and SnCl4 precursors introduced together or separately in the reaction zone in the presence of air as oxidant and ethylene as sensitizer. Prior to the obtaining of TiO2/SnO2 nanocomposites with the different Sn concentrations (1.1-4.8 at.%), the best experimental conditions were identified for preparing pure anatase phase TiO2 samples considered as photoactive reference sample. The TiO2/SnO2 composites were characterized using X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), and UV-vis diffuse reflectance spectroscopy (DRS) techniques. The structural results show the presence of both TiO2 main phases: anatase (65-82% - the majority one) and rutile, as well as of small amounts of SnO2 tetragonal phase, all those with mean crystallite dimensions in the 8-22 nm range. Laser synthesized TiO2/SnO2 samples have a lower band gap energy and some of them (containing 1.8 or 4.8 at.% Sn) show higher photoactivity in the process of Methyl Orange solutions UV discoloration when compared with the P25 Degussa commercial sample.

  9. SnO2/graphene composite with high lithium storage capability for lithium rechargeable batteries

    National Research Council Canada - National Science Library

    Kim, Haegyeom; Kim, Sung-Wook; Park, Young-Uk; Gwon, Hyeokjo; Seo, Dong-Hwa; Kim, Yuhee; Kang, Kisuk

    2010-01-01

    SnO2/graphene nanocomposites have been fabricated by a simple chemical method. In the fabrication process, the control of surface charge causes echinoid-like SnO2 nanoparticles to be formed and uniformly decorated on the graphene...

  10. Realization of ppm-level CO detection with exceptionally high sensitivity using reduced graphene oxide-loaded SnO2 nanofibers with simultaneous Au functionalization.

    Science.gov (United States)

    Kim, Jae-Hun; Katoch, Akash; Kim, Hyoun Woo; Kim, Sang Sub

    2016-03-07

    We have realized the highly sensitive, selective ppm-level carbon monoxide (CO) detection based on graphene oxide (RGO) nanosheets-loaded SnO2 nanofibers with simultaneous Au functionalization. The interplay between RGO/Au and SnO2 in terms of transfer of charge carriers and modulation of potential barriers is responsible for the exceptionally high CO detectability.

  11. High content analysis in amyotrophic lateral sclerosis.

    Science.gov (United States)

    Rinaldi, Federica; Motti, Dario; Ferraiuolo, Laura; Kaspar, Brian K

    2017-04-01

    Amyotrophic lateral sclerosis (ALS) is a devastating disease characterized by the progressive loss of motor neurons. Neurons, astrocytes, oligodendrocytes and microglial cells all undergo pathological modifications in the onset and progression of ALS. A number of genes involved in the etiopathology of the disease have been identified, but a complete understanding of the molecular mechanisms of ALS has yet to be determined. Currently, people affected by ALS have a life expectancy of only two to five years from diagnosis. The search for a treatment has been slow and mostly unsuccessful, leaving patients in desperate need of better therapies. Until recently, most pre-clinical studies utilized the available ALS animal models. In the past years, the development of new protocols for isolation of patient cells and differentiation into relevant cell types has provided new tools to model ALS, potentially more relevant to the disease itself as they directly come from patients. The use of stem cells is showing promise to facilitate ALS research by expanding our understanding of the disease and help to identify potential new therapeutic targets and therapies to help patients. Advancements in high content analysis (HCA) have the power to contribute to move ALS research forward by combining automated image acquisition along with digital image analysis. With modern HCA machines it is possible, in a period of just a few hours, to observe changes in morphology and survival of cells, under the stimulation of hundreds, if not thousands of drugs and compounds. In this article, we will summarize the major molecular and cellular hallmarks of ALS, describe the advancements provided by the in vitro models developed in the last few years, and review the studies that have applied HCA to the ALS field to date. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Control of Ge1-x-y Si x Sn y layer lattice constant for energy band alignment in Ge1-x Sn x /Ge1-x-y Si x Sn y heterostructures

    Science.gov (United States)

    Fukuda, Masahiro; Watanabe, Kazuhiro; Sakashita, Mitsuo; Kurosawa, Masashi; Nakatsuka, Osamu; Zaima, Shigeaki

    2017-10-01

    The energy band alignment of Ge1-x Sn x /Ge1-x-y Si x Sn y heterostructures was investigated, and control of the valence band offset at the Ge1-x Sn x /Ge1-x-y Si x Sn y heterointerface was achieved by controlling the Si and Sn contents in the Ge1-x-y Si x Sn y layer. The valence band offset in the Ge0.902Sn0.098/Ge0.41Si0.50Sn0.09 heterostructure was evaluated to be as high as 330 meV, and its conduction band offset was estimated to be 150 meV by considering the energy bandgap calculated from the theoretical prediction. In addition, the formation of the strain-relaxed Ge1-x-y Si x Sn y layer was examined and the crystalline structure was characterized. The epitaxial growth of a strain-relaxed Ge0.64Si0.21Sn0.15 layer with the degree of strain relaxation of 55% was examined using a virtual Ge substrate. Moreover, enhancement of the strain relaxation was demonstrated by post-deposition annealing, where a degree of strain relaxation of 70% was achieved after annealing at 400 °C. These results indicate the possibility for enhancing the indirect-direct crossover with a strained and high-Sn-content Ge1-x Sn x layer on a strain-relaxed Ge1-x-y Si x Sn y layer, realizing preferable carrier confinement by type-I energy band alignment with high conduction and valence band offsets.

  13. Ultrathin Layered SnSe Nanoplates for Low Voltage, High-Rate, and Long-Life Alkali-Ion Batteries.

    Science.gov (United States)

    Wang, Wei; Li, Peihao; Zheng, Henry; Liu, Qiao; Lv, Fan; Wu, Jiandong; Wang, Hao; Guo, Shaojun

    2017-12-01

    2D electrode materials with layered structures have shown huge potential in the fields of lithium- and sodium-ion batteries. However, their poor conductivity limits the rate performance and cycle stability of batteries. Herein a new colloid chemistry strategy is reported for making 2D ultrathin layered SnSe nanoplates (SnSe NPs) for achieving more efficient alkali-ion batteries. Due to the effect of weak Van der Waals forces, each semiconductive SnSe nanoplate stacks on top of each other, which can facilitate the ion transfer and accommodate volume expansion during the charge and discharge process. This unique structure as well as the narrow-bandgap semiconductor property of SnSe simultaneously meets the requirements of achieving fast ionic and electronic conductivities for alkali-ion batteries. They exhibit high capacity of 463.6 mAh g-1 at 0.05 A g-1 for Na-ion batteries and 787.9 mAh g-1 at 0.2 A g-1 for Li-ion batteries over 300 cycles, and also high stability for alkali-ion batteries. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Development of Au-Ge based candidate alloys as an alternative to high-lead content solders

    DEFF Research Database (Denmark)

    Chidambaram, Vivek; Hald, John; Hattel, Jesper Henri

    2010-01-01

    Au-Ge based candidate alloys have been proposed as an alternative to high-lead content solders that are currently being used for high-temperature applications. The changes in microstructure and microhardness associated with the addition of low melting point metals namely In, Sb and Sn to the Au......-Ge eutectic were investigated in this work. Furthermore, the effects of thermal aging on the microstructure and its corresponding microhardness of these promising candidate alloys have been extensively reported. To investigate the effects of aging temperature, candidate alloys were aged at a lower temperature......, 150°C for up to 3 weeks and compared with aging at 200°C. After being subjected to high-temperature aging, the microstructure varied a lot in morphology in the case of both Au-Ge-Sb and Au-Ge-Sn candidate alloys while the microstructure remained relatively stable even after long-term thermal aging...

  15. Study on a novel Sn-electroplated silver brazing filler metal

    Science.gov (United States)

    Wang, Xingxing; Peng, Jin; Cui, Datian

    2017-08-01

    Novel Sn-electroplated Ag brazing filler metal with a high tin content was prepared by combining the plating and thermal diffusion method. The BAg45CuZn alloy was used as a base filler metal, and a Sn layer was electroplated on it. Then the H62 brass was brazed with the Sn-plated brazing filler metal containing 6.2 wt% of Sn. The results showed that the microstructure of the brazed joints with the Sn-plated filler mainly consisted of the Ag phase, Cu phase, CuZn phase and Cu5Zn8 phase. The tensile strength of the joints brazed with the Sn-plated filler metal was 326 MPa, which was higher than that of the joints with the base filler metal. Fracture analysis showed that the fractures of the joints brazed by the Sn-plated filler metal was mainly ductile fracture mixed with a small quantity of brittle fracture.

  16. Amorphous Ultrathin SnO2 Films by Atomic Layer Deposition on Graphene Network as Highly Stable Anodes for Lithium-Ion Batteries.

    Science.gov (United States)

    Xie, Ming; Sun, Xiang; George, Steven M; Zhou, Changgong; Lian, Jie; Zhou, Yun

    2015-12-23

    Amorphous SnO2 (a-SnO2) thin films were conformally coated onto the surface of reduced graphene oxide (G) using atomic layer deposition (ALD). The electrochemical characteristics of the a-SnO2/G nanocomposites were then determined using cyclic voltammetry and galvanostatic charge/discharge curves. Because the SnO2 ALD films were ultrathin and amorphous, the impact of the large volume expansion of SnO2 upon cycling was greatly reduced. With as few as five formation cycles best reported in the literature, a-SnO2/G nanocomposites reached stable capacities of 800 mAh g(-1) at 100 mA g(-1) and 450 mAh g(-1) at 1000 mA g(-1). The capacity from a-SnO2 is higher than the bulk theoretical values. The extra capacity is attributed to additional interfacial charge storage resulting from the high surface area of the a-SnO2/G nanocomposites. These results demonstrate that metal oxide ALD on high surface area conducting carbon substrates can be used to fabricate high power and high capacity electrode materials for lithium-ion batteries.

  17. High similarity of U2 snDNA sequence between A and B chromosomes in the grasshopper Abracris flavolineata.

    Science.gov (United States)

    Menezes-de-Carvalho, Nahanna Zimmermann; Palacios-Gimenez, Octavio Manuel; Milani, Diogo; Cabral-de-Mello, Diogo Cavalcanti

    2015-10-01

    B chromosomes are frequently enriched for a wide variety of repetitive DNAs. Among grasshoppers in the species Abracris flavolineata (Ommatolampidinae) the B chromosomes are submetacentric, C-negative and harbor repetitive DNAs such as, U2 snDNA, C 0 t-1 DNA, two Mariner-like elements and some microsatellites. Here, we provide evidence showing the intragenome similarity between the B chromosome and the A complement in A. flavolineata, combining analysis of microdissection and chromosome painting and B chromosome-specific amplification through polymerase chain reaction (PCR) of U2 snDNA. Chromosome painting revealed signals spread through the C-negative regions, including the A and B chromosomes. Moreover, significant clustered signals forming bands were observed in some A chromosomes, and for the B chromosome, significant signals were located on both arms, which could be caused by accumulation of repetitive DNA sequences. The C-positive regions did not reveal any signals. Sequence comparison of U2 snDNA between that obtained from a genome without the B chromosome and that from µB-DNA revealed high similarity with the occurrence of four shared haplotypes, one of them (i.e., Hap1) being highly prevalent and putatively ancestral. The highest divergence from Hap1 was observed for Hap3, which was caused by only six mutational steps. These data support an intraspecific origin of the B chromosome in A. flavolineata that is highly similar with the A complement, and the low U2 snDNA sequence diversity observed in the B chromosome could be related to its recent origin, besides intrachromosomal concerted evolution for U2 snDNA repeats in the B chromosome.

  18. High performance p-type NiOx thin-film transistor by Sn doping

    Science.gov (United States)

    Lin, Tengda; Li, Xiuling; Jang, Jin

    2016-06-01

    Major obstacles towards power efficient complementary electronics employing oxide thin-film transistors (TFTs) lie in the lack of equivalent well performing p-channel devices. Here, we report a significant performance enhancement of solution-processed p-type nickel oxide (NiOx) TFTs by introducing Sn dopant. The Sn-doped NiOx (Sn-NiOx) TFTs annealed at 280 °C demonstrate substantially improved electrical performances with the increase in the on/off current ratio (Ion/Ioff) by ˜100 times, field-effect mobility (μlin) by ˜3 times, and the decrease in subthreshold swing by half, comparing with those of pristine NiOx TFTs. X-ray photoelectron spectroscopy and X-ray diffraction results confirm that Sn atoms tend to substitute Ni sites and induce more amorphous phase. A decrease in density of states in the gap of NiOx by Sn doping and the shift of Fermi level (EF) into the midgap lead to the improvements of TFT performances. As a result, Sn-NiOx can be a promising material for the next-generation, oxide-based electronics.

  19. Substrate effects in high gain, low operating voltage SnSe2 photoconductor

    Science.gov (United States)

    Krishna, Murali; Kallatt, Sangeeth; Majumdar, Kausik

    2018-01-01

    High gain photoconductive devices find wide spread applications in low intensity light detection. Ultra-thin layered materials have recently drawn a lot of attention from researchers in this regard. However, in general, a large operating voltage is required to obtain large responsivity in these devices. In addition, the characteristics are often confounded by substrate induced trap effects. Here we report multi-layer SnSe2 based photoconductive devices using two different structures: (1) SiO2 substrate supported inter-digitated electrode (IDE), and (2) suspended channel. The IDE device exhibits a responsivity of ≈ {10}3 A W‑1 and ≈ 8.66× {10}4 A W‑1 at operating voltages of 1 mV and 100 mV, respectively—a superior low voltage performance over existing literature on planar 2D structures. However, the responsivity reduces by more than two orders of magnitude, while the transient response improves for the suspended device—providing insights into the critical role played by the channel-substrate interface in the gain mechanism. The results, on one hand, are promising for highly sensitive photoconductive applications consuming ultra-low power, and on the other hand, show a generic methodology that could be applied to other layered material based photoconductive devices as well for extracting the intrinsic behavior.

  20. Thermal Design of an Nb3Sn High Field Accelerator Magnet

    CERN Document Server

    Pietrowicz, S

    2011-01-01

    Within the framework of the European project EuCARD, a Nb3Sn high field accelerator magnet is under design to serve as a test bed for future high field magnets and to upgrade the vertical CERN cable test facility, Fresca. The Fresca 2 block coil type magnet will be operated at 1.9 K or 4.2 K and is designed to produce about 13 T. A 2D numerical thermal model was developed to determinate the temperature margin of the coil in working conditions and the appropriate cool-down scenario. The temperature margin, which is DTmarge=5.8 K at 1.9 K and DTmarge=3.5 K at 4.2 K, was investigated in steady state condition with the AC losses due to field ramp rate as input heat generation. Several cool-down scenarios were examined in order to minimize the temperature difference and therefore reducing the mechanical constraints within the structure. The paper presents the numerical model, the assumptions taken for the calculations and several results of the simulation for the cool-down and temperature distributions due to seve...

  1. Comparison of mechanical concepts for $Nb_3Sn$ high field accelerator magnets

    CERN Document Server

    Loffler, Christian Hannes; Peter, Schmolz

    Several magnets using Nb3Sn as conductor are currently developed at CERN; these magnets are either slated for future updates of the LHC or for research purposes relating to future accelerators. The mechanical structure is one of the challenging aspects of superconducting high-field magnets. The main purpose of the mechanical structure is to keep the coils in compression till the emergence of the highest electromagnetic forces that are developed in the ultimate field of the magnet. Any loss of pre-compression during the magnet’s excitation would cause too large deformation of the coil and possibly a quench in the conductor owing to relative movements of strands in contact associated with excessive local heat release. However, too high pre-compression would overstrain the conductor and thereby limit the performance of the magnet. This thesis focuses on the mechanical behaviour of three of these magnets. All of them are based on different mechanical designs, “bladder and key” and “collar-based”, for t...

  2. Quench Protection System Optimization for the High Luminosity LHC Nb $_3$Sn Quadrupoles

    CERN Document Server

    Ravaioli, E; Auchmann, B; Ferracin, P; Maciejewski, M; Rodriguez-Mateos, F; Sabbi, GL; Todesco, E; Verweij, A P

    2017-01-01

    The upgrade of the large hadron collider to achieve higher luminosity requires the installation of twenty-four 150 mm aperture, 12 T, $Nb_3Sn$ quadrupole magnets close to the two interaction regions at ATLAS and CMS. The protection of these high-field magnets after a quench is particularly challenging due to the high stored energy density, which calls for a fast, effective, and reliable protection system. Three design options for the quench protection system of the inner triplet circuit are analyzed, including quench heaters attached to the coil's outer and inner layer, Coupling-Loss Induced Quench (CLIQ), and combinations of those. The discharge of the magnet circuit and the electromagnetic and thermal transients occurring in the coils are simulated by means of the TALES and LEDET programs. The sensitivity to strand parameters and the effects of several failure cases on the coil's hot-spot temperature and peak voltages to ground are assessed. A protection system based only on quench heaters attached to the o...

  3. Enhanced B doping in CVD-grown GeSn:B using B δ-doping layers

    Science.gov (United States)

    Kohen, David; Vohra, Anurag; Loo, Roger; Vandervorst, Wilfried; Bhargava, Nupur; Margetis, Joe; Tolle, John

    2018-02-01

    Highly doped GeSn material is interesting for both electronic and optical applications. GeSn:B is a candidate for source-drain material in future Ge pMOS device because Sn adds compressive strain with respect to pure Ge, and therefore can boost the Ge channel performances. A high B concentration is required to obtain low contact resistivity between the source-drain material and the metal contact. To achieve high performance, it is therefore highly desirable to maximize both the Sn content and the B concentration. However, it has been shown than CVD-grown GeSn:B shows a trade-off between the Sn incorporation and the B concentration (increasing B doping reduces Sn incorporation). Furthermore, the highest B concentration of CVD-grown GeSn:B process reported in the literature has been limited to below 1 × 1020 cm-3. Here, we demonstrate a CVD process where B δ-doping layers are inserted in the GeSn layer. We studied the influence of the thickness between each δ-doping layers and the δ-doping layers process conditions on the crystalline quality and the doping density of the GeSn:B layers. For the same Sn content, the δ-doping process results in a 4-times higher B doping than the co-flow process. In addition, a B doping concentration of 2 × 1021 cm-3 with an active concentration of 5 × 1020 cm-3 is achieved.

  4. Effects of minor Sn addition on the glass formation and properties of Fe-metalloid metallic glasses with high magnetization and high glass forming ability

    Science.gov (United States)

    Shi, Minjie; Liu, Zengqian; Zhang, Tao

    2015-03-01

    Effects of minor Sn addition on the glass-forming ability (GFA) as well as thermal, magnetic, and mechanical properties of Fe-P-C-B-Si bulk metallic glasses (BMGs) with compositions of Fe80-xSnxP9C8B2Si1 (x=0, 1, 2 and 3 at%) were investigated. The minor Sn substitution for Fe effectively enhances the GFA. The fully glassy rods can be produced up to 3 and 3.5 mm in diameter for the alloys with 1 and 2 at% Sn addition, respectively. Moreover, these Sn-containing BMGs exhibit good soft magnetic properties including high saturation magnetization (Ms) of 1.46-1.51 T, low coercivity (Hc) of 3.8-5.0 A/m and good mechanical properties, i.e., high fracture strength (σf) above 3.2 GPa and limited plastic strain (εp) above 0.4%. The combination of large GFA, good soft magnetic and mechanical properties as well as low cost makes the Fe-Sn-P-C-B-Si BMGs promising as soft magnetic materials for industrial applications.

  5. A novel route to graphite-like carbon supporting SnO{sub 2} with high electron transfer and photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xianjie; Liu, Fenglin; Liu, Bing [Hubei Collaborative Innovation Center for Advanced Organochemical Materials, Hubei University, Wuhan 430062 (China); Ministry of Education Key Laboratory for the Synthesis and Applications of Organic Functional Molecules, Hubei University, Wuhan 430062 (China); Tian, Lihong, E-mail: tian7978@hubu.edu.cn [Hubei Collaborative Innovation Center for Advanced Organochemical Materials, Hubei University, Wuhan 430062 (China); Ministry of Education Key Laboratory for the Synthesis and Applications of Organic Functional Molecules, Hubei University, Wuhan 430062 (China); Hu, Wei; Xia, Qinghua [Hubei Collaborative Innovation Center for Advanced Organochemical Materials, Hubei University, Wuhan 430062 (China); Ministry of Education Key Laboratory for the Synthesis and Applications of Organic Functional Molecules, Hubei University, Wuhan 430062 (China)

    2015-04-28

    Highlights: • Mesoporous nanocomposites that graphite-like carbon supporting SnO{sub 2} are prepared by solvothermal method combined with a post- calcination. • The polyvinylpyrrolidone not only promotes the nucleation and crystallization but also provides the carbon source in the process. • The graphite-like carbon hinders the recombination of photogenerated electron and holes efficiently. • The mesoporous carbon–SnO{sub 2} nanocomposite shows high photocatalytic activity on the degradation of Rhodamine B and glyphosate under simulated sunlight. - Abstract: Mesoporous graphite-like carbon supporting SnO{sub 2} (carbon–SnO{sub 2}) nanocomposites were prepared by a modified solvothermal method combined with a post-calcination at 500 °C under a nitrogen atmosphere. The polyvinylpyrrolidone not only promotes the nucleation and crystallization, but also provides the carbon source in the process. The results of scanning electron microscopy and transmission electron microscopy show a uniform distribution of SnO{sub 2} nanoparticles on the graphite- like carbon surface. Raman and X-ray photoelectron spectra indicate the presence of strong C–Sn interaction between SnO{sub 2} and graphite-like carbon. Photoelectrochemical measurements confirm that the effective separation of electron–hole pairs on the carbon–SnO{sub 2} nanocomposite leads to a high photocatalytic activity on the degradation of Rhodamine B and glyphosate under simulated sunlight irradiation. The nanocomposite materials show a potential application in dealing with the environmental and industrial contaminants under sunlight irradiation.

  6. Design Studies and Optimization of High-Field Nb$_3$Sn Dipole Magnets for a Future Very High Energy PP Collider

    Energy Technology Data Exchange (ETDEWEB)

    Kashikhin, V. V. [Fermilab; Novitski, I. [Fermilab; Zlobin, A. V. [Fermilab

    2017-05-01

    High filed accelerator magnets with operating fields of 15-16 T based on the $Nb_3Sn$ superconductor are being considered for the LHC energy upgrade or a future Very High Energy pp Collider. Magnet design studies are being conducted in the U.S., Europe and Asia to explore the limits of the $Nb_3Sn$ accelerator magnet technology while optimizing the magnet design and performance parame-ters, and reducing magnet cost. The first results of these studies performed at Fermilab in the framework of the US-MDP are reported in this paper.

  7. Are high-water-content contact lenses safe?

    Science.gov (United States)

    Bhatia, R P; Panday, Kshama; Srivastava, Rashmi; Indolia, Hitendra Singh

    2006-01-01

    We examined the role of tear secretion on contact lens water content during selection. Tear secretion was estimated using Schirmer's tests. High-water-content contact lenses compromised the tear film more than low-water-content contact lenses, hence they should not be advised in low or marginal Schirmer's test cases.

  8. A Compact Circumstellar Shell as the Source of High-velocity Features in SN 2011fe

    Science.gov (United States)

    Mulligan, Brian W.; Wheeler, J. Craig

    2018-01-01

    High-velocity features (HVF), especially of Ca II, are frequently seen in Type Ia supernova observed prior to B-band maximum (Bmax). These HVF evolve in velocity from more than 25, 000 km sec-1, in the days after first light, to about 18, 000 km sec-1 near Bmax. To recreate the evolution of the Ca II near-infrared triplet (CaNIR) HVF in SN 2011fe, we consider the interaction between a model Type Ia supernova and compact circumstellar shells with masses between 0.003 M⊙ and 0.012 M⊙. We fit the observed CaNIR feature using synthetic spectra generated from the models using SYN++. The CaNIR feature is better explained by the supernova model interacting with a shell than the model without a shell, with a shell of mass 0.005 M⊙ tending to be better fitting than the other shells. The evolution of the optical depth of CaNIR suggests that the ionization state of calcium within the ejecta and shell is not constant. We discuss the method used to measure the observed velocity of CaNIR and other features and conclude that HVF or other components can be falsely identified. We briefly discuss the possible origin of the shells and the implications for the progenitor system of the supernova.

  9. Influence of the Cu Content in Cu2ZnSn(S,Se)4 solar cell absorbers on order-disorder related band gap changes

    Science.gov (United States)

    Lang, Mario; Renz, Tobias; Mathes, Niklas; Neuwirth, Markus; Schnabel, Thomas; Kalt, Heinz; Hetterich, Michael

    2016-10-01

    We investigate the electronic structure and the radiative recombination in wet-chemically fabricated Cu2ZnSn(S,Se)4 solar cell absorbers utilizing photoluminescence (PL) and photoluminescence excitation (PLE) spectroscopy, focusing especially on the effects of varying Cu content. This includes the impact of the latter on the band gap energy and the change in band gap energy related to the order-disorder transition. Characteristic PL and PLE parameters like the energetic position of the PL maximum and the PL yield as a function of the excitation power as well as the PLE tailing parameter do not depend on composition indicating that the nature of the radiative transition is not altered by the Cu content. However, the band gap energy Eg significantly increases as a function of decreasing Cu content. This increase is more pronounced in the disordered than in the ordered atomic arrangement of Cu and Zn atoms in the Cu-Zn planes of the kesterite crystal structure.

  10. SnO2@PANI Core-Shell Nanorod Arrays on 3D Graphite Foam: A High-Performance Integrated Electrode for Lithium-Ion Batteries.

    Science.gov (United States)

    Zhang, Feng; Yang, Chengkai; Gao, Xin; Chen, Shuai; Hu, Yiran; Guan, Huanqin; Ma, Yurong; Zhang, Jin; Zhou, Henghui; Qi, Limin

    2017-03-22

    The rational design and controllable fabrication of electrode materials with tailored structures and superior performance is highly desirable for the next-generation lithium ion batteries (LIBs). In this work, a novel three-dimensional (3D) graphite foam (GF)@SnO2 nanorod arrays (NRAs)@polyaniline (PANI) hybrid architecture was constructed via solvothermal growth followed by electrochemical deposition. Aligned SnO2 NRAs were uniformly grown on the surface of GF, and a PANI shell with a thickness of ∼40 nm was coated on individual SnO2 nanorods, forming a SnO2@PANI core-shell structure. Benefiting from the synergetic effect of 3D GF with large surface area and high conductivity, SnO2 NRAs offering direct pathways for electrons and lithium ions, and the conductive PANI shell that accommodates the large volume variation of SnO2, the binder-free, integrated GF@SnO2 NRAs@PANI electrode for LIBs exhibited high capacity, excellent rate capability, and good electrochemical stability. A high discharge capacity of 540 mAh g-1 (calculated by the total mass of the electrode) was achieved after 50 cycles at a current density of 500 mA g-1. Moreover, the electrode demonstrated superior rate performance with a discharge capacity of 414 mAh g-1 at a high rate of 3 A g-1.

  11. Facile synthesis of hollow Sn-Co@PMMA nanospheres as high performance anodes for lithium-ion batteries via galvanic replacement reaction and in situ polymerization

    Science.gov (United States)

    Yu, Xiaohui; Jiang, Anni; Yang, Hongyan; Meng, Haowen; Dou, Peng; Ma, Daqian; Xu, Xinhua

    2015-08-01

    Polymethyl methacrylate (PMMA)-coated hollow Sn-Co nanospheres (Sn-Co@PMMA) with superior electrochemical performance had been synthesized via a facile galvanic replacement method followed by an in situ emulsion polymerization route. The properties were investigated in detail and results show that the hollow Sn-Co nanospheres were evenly coated with PMMA. Benefiting from the protection of the PMMA layers, the hollow Sn-Co@PMMA nanocomposite is capable of retaining a high capacity of 590 mAh g-1 after 100 cycles with a coulomb efficiency above 98%, revealing better electrochemical properties compared with hollow Sn-Co anodes. The PMMA coating could help accommodate the mechanical strain caused by volume expansion and stabilize the solid electrolyte interphase (SEI) film formed on the electrode. Such a facile process could be further extended to other anode materials for lithium-ion batteries.

  12. Highly Conductive In-SnO2/RGO Nano-Heterostructures with Improved Lithium-Ion Battery Performance.

    Science.gov (United States)

    Liu, Ying; Palmieri, Alessandro; He, Junkai; Meng, Yongtao; Beauregard, Nicole; Suib, Steven L; Mustain, William E

    2016-05-11

    The increasing demand of emerging technologies for high energy density electrochemical storage has led many researchers to look for alternative anode materials to graphite. The most promising conversion and alloying materials do not yet possess acceptable cycle life or rate capability. In this work, we use tin oxide, SnO2, as a representative anode material to explore the influence of graphene incorporation and In-doping to increase the electronic conductivity and concomitantly improve capacity retention and cycle life. It was found that the incorporation of In into SnO2 reduces the charge transfer resistance during cycling, prolonging life. It is also hypothesized that the increased conductivity allows the tin oxide conversion and alloying reactions to both be reversible, leading to very high capacity near 1200 mAh/g. Finally, the electrodes show excellent rate capability with a capacity of over 200 mAh/g at 10C.

  13. Analysis of Uncertainties in Protection Heater Delay Time Measurements and Simulations in Nb$_{3}$Sn High-Field Accelerator Magnets

    CERN Document Server

    Salmi, Tiina; Marchevsky, Maxim; Bajas, Hugo; Felice, Helene; Stenvall, Antti

    2015-01-01

    The quench protection of superconducting high-field accelerator magnets is presently based on protection heaters, which are activated upon quench detection to accelerate the quench propagation within the winding. Estimations of the heater delay to initiate a normal zone in the coil are essential for the protection design. During the development of Nb3Sn magnets for the LHC luminosity upgrade, protection heater delays have been measured in several experiments, and a new computational tool CoHDA (Code for Heater Delay Analysis) has been developed for heater design. Several computational quench analyses suggest that the efficiency of the present heater technology is on the borderline of protecting the magnets. Quantifying the inevitable uncertainties related to the measured and simulated delays is therefore of pivotal importance. In this paper, we analyze the uncertainties in the heater delay measurements and simulations using data from five impregnated high-field Nb3Sn magnets with different heater geometries. ...

  14. Topological Crystalline Insulator SnTe/Si Vertical Heterostructure Photodetectors for High-Performance Near-Infrared Detection.

    Science.gov (United States)

    Zhang, Hongbin; Man, Baoyuan; Zhang, Qi

    2017-04-26

    Due to the gapless surface state and narrow bulk band gap, the light absorption of topological crystalline insulators covers a broad spectrum ranging from terahertz to infrared, revealing promising applications in new generation optoelectronic devices. To date, the photodetectors based on topological insulators generally suffer from a large dark current and a weaker photocurrent especially under the near-infrared lights, which severely limits the practical application of devices. Owing to the lower excitation energy of infrared lights, the photodetection application of topological crystalline insulators in the near-infrared region relies critically on understanding the preparation and properties of their heterostructures. Herein, we fabricate the high-quality topological crystalline insulator SnTe film/Si vertical heterostructure by a simple physical vapor deposition process. The resultant heterostructure exhibits an excellent diode characteristic, enabling the construction of high-performance near-infrared photodetectors. The built-in electric field at SnTe/Si interface enhances the absorption efficiency of near-infrared lights and greatly facilitates the separation of photogenerated carriers, making the device capable of operating as a self-driven photodetector. The as-grown SnTe film acts as the hole transport layer in heterostructure photodetectors, promoting the transport of holes to electrode and reducing electron-hole recombination effectively. These merits enable the SnTe/Si heterostructure photodetector to have a high responsivity of 2.36 AW-1, a high detectivity of 1.54 × 1014 Jones, and a large bandwidth of 104 Hz in the near-infrared wavelength, which makes the detector have a promising market in novel device applications.

  15. CsSnI3: Semiconductor or metal? High electrical conductivity and strong near-infrared photoluminescence from a single material. High hole mobility and phase-transitions.

    Science.gov (United States)

    Chung, In; Song, Jung-Hwan; Im, Jino; Androulakis, John; Malliakas, Christos D; Li, Hao; Freeman, Arthur J; Kenney, John T; Kanatzidis, Mercouri G

    2012-05-23

    intrinsically. Thus, although stoichiometric CsSnI(3) is a semiconductor, the material is prone to intrinsic defects associated with Sn vacancies. This creates highly mobile holes which cause the materials to appear metallic.

  16. Synthesis and enhanced acetone gas-sensing performance of ZnSnO3/SnO2 hollow urchin nanostructures

    Science.gov (United States)

    Lian, Dandan; Shi, Bing; Dai, Rongrong; Jia, Xiaohua; Wu, Xiangyang

    2017-12-01

    A kind of novel ZnSnO3/SnO2 hollow urchin nanostructure was synthesized by a facile, eco-friendly two-step liquid-phase process. The structure, morphology, and composition of samples were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and nitrogen adsorption-desorption techniques. The results revealed that many tiny needle-like SnO2 nanowires with the average diameter of 5 nm uniformly grew on the surface of the ZnSnO3 hollow microspheres and the ZnSnO3/SnO2 hollow urchin nanostructures with different SnO2 content also were successfully prepared. In order to comprehend the evolution process of the ZnSnO3/SnO2 hollow urchin nanostructures, the possible growth mechanism of samples was illustrated via several experiments in different reaction conditions. Moreover, the gas-sensing performance of as-prepared samples was investigated. The results showed that ZnSnO3/SnO2 hollow urchin nanostructures with high response to various concentration levels of acetone enhanced selectivity, satisfying repeatability, and good long-term stability for acetone detection. Specially, the 10 wt% ZnSnO3/SnO2 hollow urchin nanostructure exhibited the best gas sensitivity (17.03 for 50 ppm acetone) may be a reliable biomarker for the diabetes patients, which could be ascribed to its large specific surface area, complete pore permeability, and increase of chemisorbed oxygen due to the doping of SnO2.

  17. Gene Controlling High Milk Lactoferrin Content in Holstein Friesian Cows

    OpenAIRE

    Cece Sumantri

    2006-01-01

    Lactoferrin is considered as an antimicrobial and antiviral protein, therefore milk that contains high lactoferrin is potential for health-enhancing nutraceuticals for food and pharmaceutical applications . The main objective of this paper is to discuss in more detail about lactoferrin function and how gene could control high lactoferrin content in milk . Milk lactoferrin content is still various among individual . Therefore, selection should be carried out to increase lactoferrin content in ...

  18. Does the SN rate explain the very high energy cosmic rays in the central 200 pc of our Galaxy?

    Science.gov (United States)

    Jouvin, L.; Lemière, A.; Terrier, R.

    2017-06-01

    The High Energy Stereoscopic System (H.E.S.S.) collaboration revealed the presence of a very high energy (VHE) diffuse emission in the inner 100 pc of the Galaxy in close correlation with the central molecular zone (CMZ). Recently, they deduced from this emission a cosmic ray (CR) overdensity in the region with a local peak towards the Galactic Centre (GC) and proposed a diffusive scenario with a stationary source at the GC to explain it. However, the high supernovae (SN) rate in the GC must also create a sustained CR injection in the region via the shocks produced at the time of their explosion. Considering a typical diffusion coefficient close to the interstellar medium (ISM) value yields a diffuse escape time much lower than the recurrence time between each SN explosion, showing that a steady-state model will fail to reproduce the data. This work aims to study the impact of the spatial and temporal distribution of SNs in the CMZ on the VHE emission morphology and spectrum: we build a 3D model of VHE CR injection and diffusive propagation with a realistic gas distribution. We show that a peaked γ-ray profile towards the GC can be obtained using realistic SN spatial distribution taking into account the central massive star cluster. We conclude that the contribution of SNs cannot be neglected, in particular at large longitudes; however, an additional CR injection at the GC is required to reproduce the very central excess.

  19. Preparation of High Quality Ti-6.5Al-1.4Si-2Zr-0.5Mo-2Sn Alloy Powder by Plasma Rotating Electrode Process

    Directory of Open Access Journals (Sweden)

    KUANG Quan-bo

    2017-10-01

    Full Text Available This research aims to prepare high quality powder of Ti-6.5Al-1.4Si-2Zr-0.5Mo-2Sn,which lays foundation for the following preparation of powder high temperature titanium alloy component.Ti-6.5Al-1.4Si-2Zr-0.5Mo-2Sn alloy ingots were prepared by vacuum arc remelting (VAR. The chemical compositions of ingots were examined. The loss of alloy elements, uniformity of composition, phase composition and microstructure of titanium alloy ingots were analyzed. Then powders were prepared by plasma rotating electrode process (PREP with different rotating speeds. Alloy powders were sieved into different particle sizes. The relationship between rotating speed and physical and chemical properties of powder was studied. X-ray diffraction(XRD, scanning electron microscope(SEM and metallurgical microscope(OM were used to investigate the phase composition, morphology and microstructure of the powder. The results show that the composition distribution of titanium alloy ingot prepared by VAR is uniform and the content of alloy elements meets the requirements of national standard, through a unique pressing electrode. Microstructure of the ingot is lamellar structure with small amounts of silicide particles disperse in the matrix. The size distribution of the powders made by PREP method exhibits the normal distribution. The sphericity of the powder is excellent,and no hollow ball and satellite ball exists. With the increase of rotating speed, the proportion of small particles increases dramatically,the proportion of large particles decreases greatly. The phase composition of powder is mainly α' phase,and it is mainly composed of peritectic and small amount of dendrite structures. Compared with the alloy ingot, the elements of the powders have a slight loss, the content of O is less than 0.1%,which is beneficial to obtain high-performance powder titanium alloy.

  20. Using High-Content Imaging to Analyze Toxicological Tipping ...

    Science.gov (United States)

    Presentation at International Conference on Toxicological Alternatives & Translational Toxicology (ICTATT) held in China and Discussing the possibility of using High Content Imaging to Analyze Toxicological Tipping Points Slide Presentation at International Conference on Toxicological Alternatives & Translational Toxicology (ICTATT) held in China and Discussing the possibility of using High Content Imaging to Analyze Toxicological Tipping Points

  1. Highly sensitive photodetectors based on hybrid 2D-0D SnS{sub 2}-copper indium sulfide quantum dots

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Yun; Zhan, Xueying; Xu, Kai; Yin, Lei; Cheng, Zhongzhou; Jiang, Chao; Wang, Zhenxing, E-mail: wangzx@nanoctr.cn, E-mail: hej@nanoctr.cn; He, Jun, E-mail: wangzx@nanoctr.cn, E-mail: hej@nanoctr.cn [CAS Key Laboratory of Nanosystem and Hierarchical Fabrication, National Center for Nanoscience and Technology, Beijing 100190 (China)

    2016-01-04

    Both high speed and efficiency of photoelectric conversion are essential for photodetectors. As an emerging layered metal dichalcogenide (LMD), tin disulfide owns intrinsic faster photodetection ability than most other LMDs but poor light absorption and low photoelectric conversion efficiency. We develop an efficient method to enhance its performance by constructing a SnS{sub 2}-copper indium sulfide hybrid structure. As a result, the responsivity reaches 630 A/W, six times stronger than pristine SnS{sub 2} and much higher than most other LMDs photodetectors. Additionally, the photocurrents are enhanced by more than 1 order of magnitude. Our work may open up a pathway to improve the performance of photodetectors based on LMDs.

  2. Constraints on high-energy neutrino emission from SN 2008D

    NARCIS (Netherlands)

    Abbasi, R.; Abdou, Y.; Abu-Zayyad, T.; Adams, J.; Aguilar, J.A.; Ahlers, M.; Andeen, K.; Auffenberg, J.; Bai, X.; Baker, M.; Barwick, S.W.; Bay, R.; Alba, J.L.B.; Beattie, K.; Beatty, J.J.; Bechet, S.; Becker, J.K.; Becker, K.H.; Benabderrahmane, M.L.; BenZvi, S.; Berdermann, J.; Berghaus, P.; Berley, D.; Bernardini, E.; Bertrand, D.; Besson, D.Z.; Bissok, M.; Blaufuss, E.; Blumenthal, J.; Boersma, D.J.; Bohm, C.; Bose, D.; Boser, S.; Botner, O.; Braun, J.; Buitink, S.; Carson, M.; Chirkin, D.; Christy, B.; Clem, J.; Clevermann, F.; Cohen, S.; Colnard, C.; Cowen, D.F.; D'Agostino, M.V.; Danninger, M.; Davis, J.C.; Clercq, C. De; Demirors, L.; Depaepe, O.; Descamps, F.; Desiati, P.; Vries-Uiterweerd, G. de; DeYoung, T.; Diaz-Velez, J.C.; Dierckxsens, M.; Dreyer, J.; Dumm, J.P.; Duvoort, M.R.; Ehrlich, R.; Eisch, J.; Ellsworth, R.W.; Engdegard, O.; Euler, S.; Evenson, P.A.; Fadiran, O.; Fazely, A.R.; Fedynitch, A.; Feusels, T.; Filimonov, K.; Finley, C.; Foerster, M.M.; Fox, B.D.; Franckowiak, A.; Franke, R.; Gaisser, T.K.; Gallagher, J.; Geisler, M.; Gerhardt, L.; Gladstone, L.; Glusenkamp, T.; Goldschmidt, A.; Goodman, J.A.; Grant, D.; Griesel, T.; Gross, A.; Grullon, S.; Gurtner, M.; Ha, C.; Hallgren, A.; Halzen, F.; Han, K.; Hanson, K.; Helbing, K.; Herquet, P.; Hickford, S.; Hill, G.C.; Hoffman, K.D.; Homeier, A.; Hoshina, K.; Lafebre, S.J.

    2011-01-01

    SN 2008D, a core collapse supernova at a distance of 27 Mpc, was serendipitously discovered by the Swift satellite through an associated X-ray flash. Core collapse supernovae have been observed in association with long gamma-ray bursts and X-ray flashes and a physical connection is widely assumed.

  3. Normal Zone Propagation in High-Current Density Nb3Sn Conductors for Accelerator Magnets

    NARCIS (Netherlands)

    den Ouden, A.; van Weeren, H.; Wessel, Wilhelm A.J.; ten Kate, Herman H.J.; Kirby, G.A.; Siegel, N.; Taylor, T.

    2004-01-01

    Self-absorbing quench protection schemes for accelerator magnets mainly rely on longitudinal and turn-to-turn normal zone propagation (NZP) immediately after the occurrence of a quench and subsequently on the effectiveness of protection heaters. Especially for impregnated Nb/sub 3/Sn coils the

  4. Rapid Ag/Sn/Ag transient liquid phase bonding for high-temperature power devices packaging by the assistance of ultrasound.

    Science.gov (United States)

    Shao, Huakai; Wu, Aiping; Bao, Yudian; Zhao, Yue; Liu, Lei; Zou, Guisheng

    2017-07-01

    Rapid transient liquid phase (TLP) bonding process on Ag/Sn/Ag system is achieved in air by the assistance of ultrasonic, which has great potential to be applied to high-temperature power devices packaging. In this study, the influence of ultrasonic effect on the morphology and growth kinetics of Ag3Sn grains, and the joint microstructure, mechanical property and thermal reliability were systematically investigated. Experimental results indicated that the rapid consumption of the "dynamic" transient liquid phase was attributed to the accelerated dissolution of Ag substrate and the extrusion of liquid Sn, which were entirely induced by the complex sonochemical effects on the liquid/solid intermetallic compounds (IMCs) interface. An elongated scallop-like morphology of Ag3Sn grains was developed during Ag/Sn interfacial reaction with ultrasonic, accompanied by widening of grooves between neighbored grains. This phenomenon is called as a strengthening thermal grooving, in which the grooves at grain boundaries provide stable molten channels for Ag atoms diffusion from the substrate. Consequently, the improved elemental diffusion was evaluated through the growth kinetics of Ag3Sn IMCs, with conservative estimation of 6-16.5 times faster than the traditional TLP process. In addition, both excellent mechanical property and thermal reliability of the Ag-Sn intermetallic joint were experimentally verified by shear test and high-temperature storage test, respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Correlation of gas sensitivite properties with microstructure of Fe2O3-SnO2 ceramics prepared by high energy ball milling

    DEFF Research Database (Denmark)

    Jiang, Jianzhong; Lu, S.W.; Zhou, Y.X.

    1997-01-01

    A remarkable gas sensitivity to ethnaol gas has been observed in nanostructured Fe2O3-SnO2 materials with a composition of 6.4 mol% SnO2 prepared by high energy ball milling. The microstructure of the materials has been examined by x-ray diffraction (XRD) and Mossbauer spectroscopy. It was found ...... that tin in the hematite phase plays an important role in high gas sensitivity....

  6. Superior cycle performance and high reversible capacity of SnO2/graphene composite as an anode material for lithium-ion batteries

    OpenAIRE

    Lilai Liu; Maozhong An; Peixia Yang; Jinqiu Zhang

    2015-01-01

    SnO2/graphene composite with superior cycle performance and high reversible capacity was prepared by a one-step microwave-hydrothermal method using a microwave reaction system. The SnO2/graphene composite was characterized by X-ray diffraction, thermogravimetric analysis, Fourier-transform infrared spectroscopy, Raman spectroscopy, scanning electron microscope, X-ray photoelectron spectroscopy, transmission electron microscopy and high resolution transmission electron microscopy. The size of ...

  7. Effect of the bismuth content on the interface reactions between copper substrate and Sn-Zn-Al-Bi lead-free solder

    Directory of Open Access Journals (Sweden)

    Soares, D.

    2005-12-01

    Full Text Available Because of environmental and health concerns, some alternative solder alloys, named lead-free ones, are being developed. Among them, the Sn-Zn-Al system has been studied and reveals promising properties. In this work the presence of bismuth, in the range of 0-8 wt%, was evaluated in what concerns to the chemical interactions between solder/substrate and the equilibrium phases present at the interface. The phases formed at the interface between the copper substrate and a molten lead-free solder were studied with different time of stage and alloy compositions. The effect of bismuth content on transformation temperatures of a Sn-9Zn-1Al base alloy was studied by Differential Scanning Calorimetry (DSC. For each alloy the solidification range was determined, which is an important characteristic regarding the application of these materials in the electronic industry. Identification of equilibrium phases and their chemical composition evaluation was performed by scanning electron microscopy (SEM/EDS. The interface thickness and chemical composition profiles were also evaluated.

    Debido a las preocupaciones ambientales y sanitarias, se están desarrollando aleaciones alternativas para soldadura sin plomo. Entre ellas se ha estudiado el sistema Sn-Zn-Al, que revela propiedades prometedoras. En este trabajo se evalúa la presencia de bismuto, en el rango de 0 a 8 % en peso, en relación con las interacciones químicas entre soldadura y substrato y con las fases de equilibrio presentes en la superficie de contacto. Se han estudiado las fases formadas en la superficie de contacto entre el substrato de cobre y una soldadura fundida sin plomo en función del tiempo de mantenimiento y de la composición de la aleación. Se ha evaluado el efecto del contenido en bismuto sobre las temperaturas de transformación de una aleación de base Sn-9Zn-1Al mediante Calorimetría de Barrido Diferencial (DSC. Se ha determinado el rango de solidificación para cada

  8. Development of the Nb3Sn Rutherford Cable for the EuCARD High Field Dipole Magnet FRESCA2

    CERN Document Server

    Oberli, l

    2013-01-01

    This paper reports on the development of the Nb3Sn Rutherford cable for the EuCARD high field dipole magnet FRESCA2 designed to achieve a central field of 13 T at 4.2 K in a 100 mm bore. The FRESCA2 cable is rectangular and made of 40 strands of 1.0 mm diameter. The cable shall be able to carry a current of 15.7 kA at 4.2 K in a field of 15 T. In the first stage of cable development, focus was put on the cable parameters (cable width, cable mid-thickness and pitch length) to provide a cable made with Nb3Sn PIT strands achieving both a minimal critical current reduction of the strand during cabling and a good mechanical stability of the cable for coil winding. In the second stage of cable development, the cable was produced with Nb3Sn RRP strands. The cables, which were produced following an iterative process, were characterized and the results of the critical current measurements of extracted strands are discussed together with the cabling parameters and the type of strand.

  9. Microstructural Evolution and Migration Mechanism Study in a Eutectic Sn-37Pb Lap Joint Under High Current Density

    Science.gov (United States)

    Zhang, Zhihao; Cao, Huijun; Yang, Haifeng; Xiao, Yong; Li, Mingyu; Yu, Yuxi; Yao, Shun

    2017-08-01

    The microstructural evolution in eutectic Sn-37Pb solder under high current density seriously threatens the reliability of solder interconnections, but atomic electromigration has often been confused with thermomigration. In this paper, after decoupling the effect of the non-uniform temperature distribution in a Cu/Sn-37Pb/Cu lap joint from the current stress, the microstructural evolution was investigated under an average current density of 1.84 × 104 A cm-2 for 0-24 h. The decomposition and recombination of the Pb-rich phase occurred at the cathode and the anode, respectively. The corresponding migration mechanism was proposed from the viewpoint of energy and was explained by the interactions among the potential energies of ripening, electron wind force, and back stress. Our study may be helpful for understanding the migration mechanism and reliability of eutectic two-phase solder joints and provides supporting data for interpreting the acceleration tests of Sn-37Pb solder joints under electromigration.

  10. Carbon-Confined SnO2-Electrodeposited Porous Carbon Nanofiber Composite as High-Capacity Sodium-Ion Battery Anode Material.

    Science.gov (United States)

    Dirican, Mahmut; Lu, Yao; Ge, Yeqian; Yildiz, Ozkan; Zhang, Xiangwu

    2015-08-26

    Sodium resources are inexpensive and abundant, and hence, sodium-ion batteries are promising alternative to lithium-ion batteries. However, lower energy density and poor cycling stability of current sodium-ion batteries prevent their practical implementation for future smart power grid and stationary storage applications. Tin oxides (SnO2) can be potentially used as a high-capacity anode material for future sodium-ion batteries, and they have the advantages of high sodium storage capacity, high abundance, and low toxicity. However, SnO2-based anodes still cannot be used in practical sodium-ion batteries because they experience large volume changes during repetitive charge and discharge cycles. Such large volume changes lead to severe pulverization of the active material and loss of electrical contact between the SnO2 and carbon conductor, which in turn result in rapid capacity loss during cycling. Here, we introduce a new amorphous carbon-coated SnO2-electrodeposited porous carbon nanofiber (PCNF@SnO2@C) composite that not only has high sodium storage capability, but also maintains its structural integrity while ongoing repetitive cycles. Electrochemical results revealed that this SnO2-containing nanofiber composite anode had excellent electrochemical performance including high-capacity (374 mAh g(-1)), good capacity retention (82.7%), and large Coulombic efficiency (98.9% after 100th cycle).

  11. 2D/3D quench simulation using ANSYS for epoxy impregnated Nb3Sn high field magnets

    Energy Technology Data Exchange (ETDEWEB)

    Ryuji Yamada et al.

    2002-09-19

    A quench program using ANSYS is developed for the high field collider magnet for three-dimensional analysis. Its computational procedure is explained. The quench program is applied to a one meter Nb{sub 3}Sn high field model magnet, which is epoxy impregnated. The quench simulation program is used to estimate the temperature and mechanical stress inside the coil as well as over the whole magnet. It is concluded that for the one meter magnet with the presented cross section and configuration, the thermal effects due to the quench is tolerable. But we need much more quench study and improvements in the design for longer magnets.

  12. 2-D/3-D quench simulation using ANSYS for epoxy impregnated $Nb_{3}$ Sn high field magnets

    CERN Document Server

    Yamada, R; Marscin, E; Rey, J M; Wake, M

    2003-01-01

    A quench program using ANSYS is developed for the high field collider magnet for 3-D analysis. Its computational procedure is explained. The quench program is applied to a one meter Nb/sub 3/Sn high field model magnet, which is epoxy impregnated. The quench simulation program is used to estimate the temperature and mechanical stress inside the coil as well as over the whole magnet. It is concluded that for the one meter magnet with the presented cross section and configuration, the thermal effects due to the quench is tolerable. But we need much more quench study and improvements in the design for longer magnets. (6 refs).

  13. Magnetic Measurements of the First Nb$_3$Sn Model Quadrupole (MQXFS) for the High-Luminosity LHC

    CERN Document Server

    DiMarco, J; Chlachidze, G; Ferracin, P; Holik, E; Sabbi, G; Stoynev, S; Strauss, T; Sylvester, C; Tartaglia, M; Todesco, E; Velev, G; Wang, X

    2016-01-01

    The US LHC Accelerator Research Program (LARP) and CERN are developing high-gradient Nb3Sn magnets for the High Luminosity LHC interaction regions. Magnetic measurements of the first 1.5 m long, 150 mm aperture model quadrupole, MQXFS1, were performed during magnet assembly at LBNL, as well as during cryogenic testing at Fermilab’s Vertical Magnet Test Facility. This paper reports on the results of these magnetic characterization measurements, as well as on the performance of new probes developed for the tests.

  14. Systems and methods for the synthesis of high thermoelectric performance doped-SnTe materials

    Energy Technology Data Exchange (ETDEWEB)

    Ren, Zhifeng; Zhang, Qian; Chen, Gang

    2018-02-27

    A thermoelectric composition comprising tin (Sn), tellurium (Te) and at least one dopant that comprises a peak dimensionless figure of merit (ZT) of 1.1 and a Seebeck coefficient of at least 50 .mu.V/K and a method of manufacturing the thermoelectric composition. A plurality of components are disposed in a ball-milling vessel, wherein the plurality of components comprise tin (Sn), tellurium (Te), and at least one dopant such as indium (In). The components are subsequently mechanically and thermally processed, for example, by hot-pressing. In response to the mechanical-thermally processing, a thermoelectric composition is formed, wherein the thermoelectric composition comprises a dimensionless figure of merit (ZT) of the thermoelectric composition is at least 0.8, and wherein a Seebeck coefficient of the thermoelectric composition is at least 50 .mu.V/K at any temperature.

  15. High-Field Nb3Sn Cos-theta Dipole with Stress Management

    Energy Technology Data Exchange (ETDEWEB)

    Novitski, Igor [Fermilab; Carmichael, Justin [Fermilab; Kashikhin, Vadim V. [Fermilab; Zlobin, Alexander V. [Fermilab

    2017-01-01

    Cost-effective superconducting dipole magnets with operating fields up to 16 T are being considered for the LHC en-ergy upgrade (HE-LHC) and a Future Circular Collider (FCC). To demonstrate feasibility of 15 T accelerator quality dipole mag-nets, FNAL as a part of the US-MDP is developing a single-aper-ture Nb3Sn dipole demonstrator based on a 4-layer graded cos-theta coil with 60 mm aperture and cold iron yoke. In parallel, to explore the limit of the Nb3Sn accelerator magnet technology, op-timize magnet design and performance parameters, and reduce magnet cost, magnet design studies are also being performed to push the nominal bore field to 16 T in a 60-mm aperture cos-theta dipole. Results of these studies are reported and discussed in this paper.

  16. High Efficient Dye-Sensitized Solar Cells Based on Synthesized SnO2 Nanoparticles

    Directory of Open Access Journals (Sweden)

    W. M. N. M. B. Wanninayake

    2016-01-01

    Full Text Available In this study, SnO2 semiconductor nanoparticles were synthesized for DSC applications via acid route using tin(ii chloride as a starting material and hydrothermal method through the use of tin(iv chloride. Powder X-ray diffraction studies confirmed the formation of the rutile phase of SnO2 with nanoranged particle sizes. A quasi-solid-state electrolyte was employed instead of a conventional liquid electrolyte in order to overcome the practical limitations such as electrolyte leakage, solvent evaporation, and sealing imperfections associated with liquid electrolytes. The gel electrolytes were prepared incorporating lithium iodide (LiI and tetrapropylammonium iodide (Pr4N+I− salts, separately, into the mixture which contains polyacrylonitrile as a polymer, propylene carbonate and ethylene carbonate as plasticizers, iodide/triiodide as the redox couple, acetonitrile as the solvent, and 4-tertiary butylpyridine as an electrolyte additive. In order to overcome the recombination problem associated with the SnO2 due to its higher electron mobility, ultrathin layer of CaCO3 coating was used to cover the surface recombination sites of SnO2 nanoparticles. Maximum energy conversion efficiency of 5.04% is obtained for the device containing gel electrolyte incorporating LiI as the salt. For the same gel electrolyte, the ionic conductivity and the diffusion coefficient of the triiodide ions are 4.70 × 10−3 S cm−1 and 4.31 × 10−7 cm2 s−1, respectively.

  17. Ultraviolet photodetectors with high photosensitivity based on type-II ZnS/SnO2 core/shell heterostructured ribbons.

    Science.gov (United States)

    Huang, Xing; Yu, Yong-Qiang; Xia, Jing; Fan, Hua; Wang, Lei; Willinger, Marc-Georg; Yang, Xiao-Ping; Jiang, Yang; Zhang, Tie-Rui; Meng, Xiang-Min

    2015-03-12

    Semiconducting heterostructures with type-II band structure have attracted much attention due to their novel physical properties and wide applications in optoelectronics. Herein, we report, for the first time, a controlled synthesis of type-II ZnS/SnO2 heterostructured ribbon composed of SnO2 nanoparticles that uniformly cover the surface of ZnS ribbon via a simple and versatile thermal evaporation approach. Structural analysis indicated that the majority of SnO2 nanoparticles have an equivalent zone axis, i.e., of rutile SnO2, which is perpendicular to ±(2-1-10) facets (top/down surfaces) of ZnS ribbon. For those SnO2 nanoparticles decorated on ±(01-10) facets (side surfaces) of ZnS ribbon, an epitaxial relationship of (01-10)ZnO//(020)SnO2 and [2-1-10]ZnO//[001]SnO2 was identified. To explore their electronic and optoelectronic properties, we constructed field-effect transistors from as-prepared new heterostructures, which exhibited an n-type characteristic with an on/off ratio of ∼10(3) and a fast carrier mobility of ∼33.2 cm2 V(-1) s(-1). Owing to the spatial separation of photogenerated electron-hole pairs from type-II band alignment together with the good contacts between electrodes and ribbon, the resultant photodetector showed excellent photoresponse properties, including large photocurrent, high sensitivity (external quantum efficiency as high as ∼2.4×10(7)%), good stability and reproducibility, and relatively fast response speed. Our results suggest great potential of ZnS/SnO2 heterostructures for efficient UV light sensing, and, more importantly, signify the advantages of type-II semiconducting heterostructures for construction of high-performance nano-photodetectors.

  18. High crystalline Cu2ZnSnS4 semiconductor prepared from low toxicity ethanol-based precursors

    Science.gov (United States)

    Munir, Badrul; Prastyo, Bayu Eko; Nurjaya, Dwi Marta; Muslih, Ersan Yudhapratama; Alfauzan, Sahri Karim

    2017-01-01

    At this moment, we present a new, cost-effective, and environmentally friendly method of preparing a high crystalline Cu2ZnSnS4 (CZTS) absorber layer for thin film solar cells using ethanol-based solutions. Ethanolamine (ETA) and 2-mercaptopropionic acid (MPA) were studied as a stabilizer and to improve wetting ability of the precursors during the deposition process. Cu2ZnSnS4 precursors are deposited onto soda lime glass using spin coater in different molar of cations in the precursor. The effects of a precursor system, ethanol-ETA-MPA, and ethanol-MPA, on the structure, morphology, composition and optical properties of CZTS thin films have been investigated in details. X-ray diffraction and energy-dispersive X-ray spectroscopy analyses confirmed the successful fabrication of high crystalline Cu2ZnSnS4 kesterite phase. The crystallinity of CZTS is continue increasing before reaching 2.2 molar cations of the ethanol-MPA precursors. The crystallinity of ethanol-ETA-MPA precursors remains similar in the experiment using 1.2 molar and 1.6 molars. The highest crystallinity was achieved using 2 molar cations of the ethanol-MPA precursor. Its band gap energy is found to be around 1.4 eV. The SEM micrographs of CZTS film shows the average grain size around 1.5 µm and some porosity which indicated the room of improvement. The high-crystallinity CZTS achieved in the present study brings a low-cost absorber semiconductor one step closer to practical use.

  19. Mesoporous SnO2 Nanotubes via Electrospinning-Etching Route: Highly Sensitive and Selective Detection of H2S Molecule.

    Science.gov (United States)

    Bulemo, Peresi Majura; Cho, Hee-Jin; Kim, Nam-Hoon; Kim, Il-Doo

    2017-08-09

    We report the facile synthesis of thin-walled SnO2 nanotubes (NTs) with numerous clustered pores (pore radius 6.56 nm) and high surface area (125.63 m(2)/g) via selective etching of core (SiO2) region in SiO2-SnO2 composite nanofibers (NFs), in which SnO2 phase preferentially occupies the shell while SiO2 is concentrated in the center of the composite NFs. The SiO2-etched SnO2 NTs are composed of ultrasmall crystallites (∼6 nm in size) originating from crystal growth inhibition by small SiO2 domains, which are partially segregated in the polycrystalline SnO2 shell during calcination. These features account for efficacious diffusion and innumerable active sites, which maximize interaction between background gas (air) and analyte gas (H2S). Evaluation of gas-sensing performance of the porous SnO2 NTs before and after decorating the exterior and interior walls with Pt nanoparticles (NPs) reveals exceptional selectivity and superior response (Ra/Rg) of 154.8 and 89.3 to 5 and 1 ppm of H2S, respectively. Excellent gas-sensing characteristics are attributed to the porous topography, nanosized crystallites, high surface area, and the catalytic activity of Pt/PtOx NPs.

  20. SPECTROSCOPIC OBSERVATIONS OF SN 2012fr: A LUMINOUS, NORMAL TYPE Ia SUPERNOVA WITH EARLY HIGH-VELOCITY FEATURES AND A LATE VELOCITY PLATEAU

    Energy Technology Data Exchange (ETDEWEB)

    Childress, M. J.; Scalzo, R. A.; Sim, S. A.; Tucker, B. E.; Yuan, F.; Schmidt, B. P. [Research School of Astronomy and Astrophysics, Australian National University, Canberra, ACT 2611 (Australia); Cenko, S. B.; Filippenko, A. V. [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Silverman, J. M. [Department of Astronomy, University of Texas, Austin, TX 78712-0259 (United States); Contreras, C.; Hsiao, E. Y.; Phillips, M.; Morrell, N. [Las Campanas Observatory, Carnegie Observatories, Casilla 601, La Serena (Chile); Jha, S. W.; McCully, C. [Department of Physics and Astronomy, Rutgers, State University of New Jersey, 136 Frelinghuysen Road, Piscataway, NJ 08854 (United States); Anderson, J. P.; De Jaeger, T.; Forster, F. [Departamento de Astronomia, Universidad de Chile, Casilla 36-D, Santiago (Chile); Benetti, S. [INAF Osservatorio Astronomico di Padova, Vicolo dell' Osservatorio 5, I-35122 Padova (Italy); Bufano, F., E-mail: mjc@mso.anu.edu.au [Departamento de Ciencias Fisicas, Universidad Andres Bello, Avda. Republica 252, Santiago (Chile); and others

    2013-06-10

    We present 65 optical spectra of the Type Ia SN 2012fr, 33 of which were obtained before maximum light. At early times, SN 2012fr shows clear evidence of a high-velocity feature (HVF) in the Si II {lambda}6355 line that can be cleanly decoupled from the lower velocity ''photospheric'' component. This Si II {lambda}6355 HVF fades by phase -5; subsequently, the photospheric component exhibits a very narrow velocity width and remains at a nearly constant velocity of {approx}12,000 km s{sup -1} until at least five weeks after maximum brightness. The Ca II infrared triplet exhibits similar evidence for both a photospheric component at v Almost-Equal-To 12,000 km s{sup -1} with narrow line width and long velocity plateau, as well as an HVF beginning at v Almost-Equal-To 31,000 km s{sup -1} two weeks before maximum. SN 2012fr resides on the border between the ''shallow silicon'' and ''core-normal'' subclasses in the Branch et al. classification scheme, and on the border between normal and high-velocity Type Ia supernovae (SNe Ia) in the Wang et al. system. Though it is a clear member of the ''low velocity gradient'' group of SNe Ia and exhibits a very slow light-curve decline, it shows key dissimilarities with the overluminous SN 1991T or SN 1999aa subclasses of SNe Ia. SN 2012fr represents a well-observed SN Ia at the luminous end of the normal SN Ia distribution and a key transitional event between nominal spectroscopic subclasses of SNe Ia.

  1. High-Loading Nano-SnO2 Encapsulated in situ in Three-Dimensional Rigid Porous Carbon for Superior Lithium-Ion Batteries.

    Science.gov (United States)

    Xue, Hairong; Zhao, Jianqing; Tang, Jing; Gong, Hao; He, Ping; Zhou, Haoshen; Yamauchi, Yusuke; He, Jianping

    2016-03-24

    Tin oxide nanoparticles (SnO2 NPs) have been encapsulated in situ in a three-dimensional ordered space structure. Within this composite, ordered mesoporous carbon (OMC) acts as a carbon framework showing a desirable ordered mesoporous structure with an average pore size (≈6 nm) and a high surface area (470.3 m(2) g(-1)), and the SnO2 NPs (≈10 nm) are highly loaded (up to 80 wt %) and homogeneously distributed within the OMC matrix. As an anode material for lithium-ion batteries, a SnO2 @OMC composite material can deliver an initial charge capacity of 943 mAh g(-1) and retain 68.9 % of the initial capacity after 50 cycles at a current density of 50 mA g(-1), even exhibit a capacity of 503 mA h g(-1) after 100 cycles at 160 mA g(-1). In situ encapsulation of the SnO2 NPs within an OMC framework contributes to a higher capacity and a better cycling stability and rate capability in comparison with bare OMC and OMC ex situ loaded with SnO2 particles (SnO2/OMC). The significantly improved electrochemical performance of the SnO2@OMC composite can be attributed to the multifunctional OMC matrix, which can facilitate electrolyte infiltration, accelerate charge transfer, and lithium-ion diffusion, and act as a favorable buffer to release reaction strains for lithiation/delithiation of the SnO2 NPs. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. High performance asymmetric V2O5-SnO2 nanopore battery by atomic layer deposition.

    Science.gov (United States)

    Liu, Chanyuan; Kim, Nam; Rubloff, Gary W; Lee, Sang Bok

    2017-08-17

    Here we report the high performance and cyclability of an asymmetric full cell nanopore battery, comprised of V2O5 as the cathode and prelithiated SnO2 as the anode, with integrated nanotubular Pt current collectors underneath each nanotubular storage electrode, confined within an anodized aluminium oxide (AAO) nanopore. Enabled by atomic layer deposition (ALD), this coaxial nanotube full cell is fully confined within a high aspect ratio nanopore (150 nm in diameter, 50 μm in length), with an ultra-small volume of about 1 fL. By controlling the amount of lithium ion prelithiated into the SnO2 anode, we can tune the full cell output voltage in the range of 0.3 V to 3 V. When tested as a massively parallel device (∼2 billion cm(-2)), this asymmetric nanopore battery array displays exceptional rate performance and cyclability: when cycled between 1 V and 3 V, capacity retention at the 200C rate is ∼73% of that at 1C, and at 25C rate only 2% capacity loss occurs after more than 500 charge/discharge cycles. With the increased full cell output potential, the asymmetric V2O5-SnO2 nanopore battery shows significantly improved energy and power density over the previously reported symmetric cell, 4.6 times higher volumetric energy and 5.2 times higher power density - an even more promising indication that controlled nanostructure designs employing nanoconfined environments with large electrode surface areas present promising directions for future battery technology.

  3. Honeycomb-inspired design of ultrafine SnO2@C nanospheres embedded in carbon film as anode materials for high performance lithium- and sodium-ion battery

    Science.gov (United States)

    Ao, Xiang; Jiang, Jianjun; Ruan, Yunjun; Li, Zhishan; Zhang, Yi; Sun, Jianwu; Wang, Chundong

    2017-08-01

    Tin oxide (SnO2) has been considered as one of the most promising anodes for advanced rechargeable batteries due to its advantages such as high energy density, earth abundance and environmental friendly. However, its large volume change during the Li-Sn/Na-Sn alloying and de-alloying processes will result in a fast capacity degradation over a long term cycling. To solve this issue, in this work we design and synthesize a novel honeycomb-like composite composing of carbon encapsulated SnO2 nanospheres embedded in carbon film by using dual templates of SiO2 and NaCl. Using these composites as anodes both in lithium ion batteries and sodium-ion batteries, no discernable capacity degradation is observed over hundreds of long term cycles at both low current density (100 mA g-1) and high current density (500 mA g-1). Such a good cyclic stability and high delivered capacity have been attributed to the high conductivity of the supported carbon film and hollow encapsulated carbon shells, which not only provide enough space to accommodate the volume expansion but also prevent further aggregation of SnO2 nanoparticles upon cycling. By engineering electrodes of accommodating high volume expansion, we demonstrate a prototype to achieve high performance batteries, especially high-power batteries.

  4. Localized Liquid-Phase Synthesis of Porous SnO2 Nanotubes on MEMS Platform for Low-Power, High Performance Gas Sensors.

    Science.gov (United States)

    Cho, Incheol; Kang, Kyungnam; Yang, Daejong; Yun, Jeonghoon; Park, Inkyu

    2017-08-16

    We have developed highly sensitive, low-power gas sensors through the novel integration method of porous SnO2 nanotubes (NTs) on a micro-electro-mechanical-systems (MEMS) platform. As a template material, ZnO nanowires (NWs) were directly synthesized on beam-shaped, suspended microheaters through an in situ localized hydrothermal reaction induced by local thermal energy around the Joule-heated area. Also, the liquid-phase deposition process enabled the formation of a porous SnO2 thin film on the surface of ZnO NWs and simultaneous etching of the ZnO core, eventually to generate porous SnO2 NTs. Because of the localized synthesis of SnO2 NTs on the suspended microheater, very low power for the gas sensor operation (<6 mW) has been realized. Moreover, the sensing performance (e.g., sensitivity and response time) of synthesized SnO2 NTs was dramatically enhanced compared to that of ZnO NWs. In addition, the sensing performance was further improved by forming SnO2-ZnO hybrid nanostructures due to the heterojunction effect.

  5. Superior cycle performance and high reversible capacity of SnO2/graphene composite as an anode material for lithium-ion batteries

    Science.gov (United States)

    Liu, Lilai; An, Maozhong; Yang, Peixia; Zhang, Jinqiu

    2015-01-01

    SnO2/graphene composite with superior cycle performance and high reversible capacity was prepared by a one-step microwave-hydrothermal method using a microwave reaction system. The SnO2/graphene composite was characterized by X-ray diffraction, thermogravimetric analysis, Fourier-transform infrared spectroscopy, Raman spectroscopy, scanning electron microscope, X-ray photoelectron spectroscopy, transmission electron microscopy and high resolution transmission electron microscopy. The size of SnO2 grains deposited on graphene sheets is less than 3.5 nm. The SnO2/graphene composite exhibits high capacity and excellent electrochemical performance in lithium-ion batteries. The first discharge and charge capacities at a current density of 100 mA g−1 are 2213 and 1402 mA h g−1 with coulomb efficiencies of 63.35%. The discharge specific capacities remains 1359, 1228, 1090 and 1005 mA h g−1 after 100 cycles at current densities of 100, 300, 500 and 700 mA g−1, respectively. Even at a high current density of 1000 mA g−1, the first discharge and charge capacities are 1502 and 876 mA h g−1, and the discharge specific capacities remains 1057 and 677 mA h g−1 after 420 and 1000 cycles, respectively. The SnO2/graphene composite demonstrates a stable cycle performance and high reversible capacity for lithium storage. PMID:25761938

  6. Superior cycle performance and high reversible capacity of SnO2/graphene composite as an anode material for lithium-ion batteries.

    Science.gov (United States)

    Liu, Lilai; An, Maozhong; Yang, Peixia; Zhang, Jinqiu

    2015-03-12

    SnO2/graphene composite with superior cycle performance and high reversible capacity was prepared by a one-step microwave-hydrothermal method using a microwave reaction system. The SnO2/graphene composite was characterized by X-ray diffraction, thermogravimetric analysis, Fourier-transform infrared spectroscopy, Raman spectroscopy, scanning electron microscope, X-ray photoelectron spectroscopy, transmission electron microscopy and high resolution transmission electron microscopy. The size of SnO2 grains deposited on graphene sheets is less than 3.5 nm. The SnO2/graphene composite exhibits high capacity and excellent electrochemical performance in lithium-ion batteries. The first discharge and charge capacities at a current density of 100 mA g(-1) are 2213 and 1402 mA h g(-1) with coulomb efficiencies of 63.35%. The discharge specific capacities remains 1359, 1228, 1090 and 1005 mA h g(-1) after 100 cycles at current densities of 100, 300, 500 and 700 mA g(-1), respectively. Even at a high current density of 1000 mA g(-1), the first discharge and charge capacities are 1502 and 876 mA h g(-1), and the discharge specific capacities remains 1057 and 677 mA h g(-1) after 420 and 1000 cycles, respectively. The SnO2/graphene composite demonstrates a stable cycle performance and high reversible capacity for lithium storage.

  7. The Cu{sub 2}ZnSnS{sub 4} solar cell with high open circuit voltage

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Min; Ma, Xun; Jiang, Zhi; Li, Zhishan; Liu, Sijia; Lu, Yilei; Wang, Shurong, E-mail: shrw88@aliyun.com

    2017-03-15

    In this paper, the effects of two different sulfurization processes on the CZTS films were investigated, and the results indicated that a rapid high-temperature crystallization process after sulfurization was beneficial for CZTS thin films to obtain a compact and flat surface with large grains. However, a common sulfurization without rapid high-temperature crystallization process would easily lead to undesirable properties of films, such as rough surface with pin holes, which degenerate the performance of devices. Cu{sub 2}ZnSnS{sub 4} (CZTS) solar cell based on a rapid high-temperature process after sulfurization achieved a high open circuit voltage of 722 mV and the best efficiency 3.32% was obtained.

  8. Cost of high-field Nb/sub 3/Sn and NbTi accelerator dipole magnets

    Energy Technology Data Exchange (ETDEWEB)

    Hassenzahl, W.V.

    1982-11-01

    Future high-energy proton accelerators will likely require very high magnetic fields if the size of the accelerator and associated experimental areas are to be limited to dimensions that can be accomodated by the terrain at convenient sites. Two commercially available superconductors can be used to produce magnetic fields of 10T or more. The first is Nb/sub 3/Sn, which can operate in pool boiling helium at 4.4 K. The second is NbTi, which must be cooled to about 1.9 K in superfluid helium. In this paper the costs of 5-cm-bore, 6-m-long magnets made of these materials and operating at fields from 5 to 11 T are compared. At 10 T the capital cost of a NbTi coil operating in superfluid helium is 35% less than the cost of a Nb/sub 3/Sn coil. The cost of the NbTi coil is still 10% less after the differential operating costs that will be incurred over the life of the accelerator are included. The results presented here are a summary of a detailed analysis of these costs given in a separate report.

  9. Synthesis and optical properties of Sn-rich Ge{sub 1–x–y}Si{sub x}Sn{sub y} materials and devices

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Chi [Department of Physics, Arizona State University, Tempe, AZ 85287-1504 (United States); Beeler, Richard T. [Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287-1604 (United States); Jiang, Liying; Gallagher, James D.; Favaro, Ruben [Department of Physics, Arizona State University, Tempe, AZ 85287-1504 (United States); Menéndez, José, E-mail: jose.menendez@asu.edu [Department of Physics, Arizona State University, Tempe, AZ 85287-1504 (United States); Kouvetakis, John [Department of Chemistry and Biochemistry, Arizona State University, Tempe, AZ 85287-1604 (United States)

    2014-04-30

    Sn-rich Ge{sub 1−x−y}Si{sub x}Sn{sub y} alloys (y > x) have been deposited on Si(100) using recently developed growth processes aimed at achieving the material quality and compositions required to investigate their optical emission properties. The samples are produced using two different methods, each providing optimal quality material within distinct composition ranges of low (2–4% Sn and 1–2% Si) and high (5–10% Sn and 3–4% Si) Sn and Si contents, allowing a comprehensive investigation of their optical response over the targeted 2–10% Sn range. The growth processes are based on ultra-low temperature (310–260 °C) Ultra-High Vacuum Chemical Vapor Deposition and Gas-Source Molecular Beam Epitaxy techniques using stoichiometric reactions of highly reactive hydride sources, including Ge{sub 4}H{sub 10}, Ge{sub 3}H{sub 8}, Si{sub 4}H{sub 10} and SnD{sub 4}. Under these conditions the depositions produce monocrystalline layers exhibiting high quality microstructure, flat surfaces, and large thicknesses of 450–600 nm. The latter provide a significantly high volume-fraction of GeSiSn active component away from the inherently defective GeSiSn/Si(100) interface, leading to dramatically improved optical quality materials which are found to exhibit a tunable direct-gap photoluminescence below 1550 nm. Photocurrent measurements of prototype photodiodes were also used to corroborate and further explore the dependence of the direct gap on the Si/Sn concentration. Collectively the results indicate that thermally superior Ge{sub 1−x−y}Si{sub x}Sn{sub y} alloys may offer an alternative technology to Ge{sub 1−y}Sn{sub y} analogs for long-wavelength applications beyond the absorption edge of elemental Ge. - Highlights: • Ge{sub 1−x−y}Si{sub x}Sn{sub y} alloys with y > x have been synthesized. • Photoluminescence shows that the alloys have direct band gaps below that of Ge. • GeSiSn may represent an alternative to GeSn for long

  10. Magnetic Analysis of the Nb$_3$Sn low-beta Quadrupole for the High Luminosity LHC

    CERN Document Server

    Izquierdo Bermudez, S; Chlachidze, G; Ferracin, P; Holik, E; Di Marco, J; Todesco, E; Sabbi, G L; Vallone, G; Wang, X

    2017-01-01

    As part of the Large Hadron Collider Luminosity upgrade (HiLumi-LHC) program, the US LARP collaboration and CERN are working together to design and build 150 mm aperture $Nb_3Sn$ quadrupoles for the LHC interaction regions. A first series of 1.5 m long coils were fabricated, assembled and tested in the first short model. This paper presents the magnetic analysis, comparing magnetic field measurements with the expectations and the field quality requirements. The analysis is focused on the geometrical harmonics, iron saturation effect and cold-warm correlation. Three dimensional effects such as the variability of the field harmonics along the magnet axis and the contribution of the coil ends are also discussed. Moreover, we present the influence of the conductor magnetization and the dynamic effects.

  11. A graphene–SnO{sub 2}–TiO{sub 2} ternary nanocomposite electrode as a high stability lithium-ion anode material

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Jicai [Key Laboratory of Automobile Materials, Ministry of Education, and College of Materials Science and Engineering, Jilin University, Changchun, 130025 (China); Roll Forging Research Institute, Jilin University, Changchun, 130025, Jilin (China); Wang, Juan; Zhou, Meixin; Li, Yi [Key Laboratory of Automobile Materials, Ministry of Education, and College of Materials Science and Engineering, Jilin University, Changchun, 130025 (China); Wang, Xiaofeng [State Key Laboratory of Inorganic Synthesis and Preparative Chemistry, College of Chemistry, Jilin University, Changchun, 130012 (China); Yu, Kaifeng, E-mail: yukf@jlu.edu.cn [Key Laboratory of Automobile Materials, Ministry of Education, and College of Materials Science and Engineering, Jilin University, Changchun, 130025 (China)

    2016-07-15

    In this work, a solvothermal method combined with a hydrothermal two-step method is developed to synthesize graphene–SnO{sub 2}–TiO{sub 2} ternary nanocomposite, in which the nanometer-sized TiO{sub 2} and SnO{sub 2} nanoparticles form in situ uniformly anchored on the surface of graphene sheets, as high stability and capacity lithium-ion anode materials. Compared to graphene–TiO{sub 2}, bulk TiO{sub 2} and grapheme–SnO{sub 2} composites, the as-prepared nanocomposite delivers a superior rate performance of 499.3 mAhg{sup −1} at 0.2 C and an outstanding stability cycling capability (1073.4 mAhg{sup −1} at 0.2 C after 50 cycles), due to the synergistic effects contributed from individual components, for example, high specific capacity of SnO{sub 2}, excellent conductivity of 3D graphene networks. - Graphical abstract: Graphene–SnO{sub 2}–TiO{sub 2} nanocomposite is synthesized by a hydrothermal two-step method. The composite exhibits higher reversible capacity and better cycle/rate performance due to the unique structure. - Highlights: • We have synthesized a graphene–SnO{sub 2}–TiO{sub 2} nanocomposite by a two-step method to improve the cycling performance. • Graphene–SnO{sub 2}–TiO{sub 2} nanocomposite is synthesized by a hydrothermal two-step method. • The composite exhibits higher reversible capacity and better cycle/rate performance due to the unique structure.

  12. Well-crystalline porous ZnO-SnO2 nanosheets: an effective visible-light driven photocatalyst and highly sensitive smart sensor material.

    Science.gov (United States)

    Lamba, Randeep; Umar, Ahmad; Mehta, S K; Kansal, Sushil Kumar

    2015-01-01

    This work demonstrates the synthesis and characterization of porous ZnO-SnO2 nanosheets prepared by the simple and facile hydrothermal method at low-temperature. The prepared nanosheets were characterized by several techniques which revealed the well-crystallinity, porous and well-defined nanosheet morphology for the prepared material. The synthesized porous ZnO-SnO2 nanosheets were used as an efficient photocatalyst for the photocatalytic degradation of highly hazardous dye, i.e., direct blue 15 (DB 15), under visible-light irradiation. The excellent photocatalytic degradation of prepared material towards DB 15 dye could be ascribed to the formation of ZnO-SnO2 heterojunction which effectively separates the photogenerated electron-hole pairs and possess high surface area. Further, the prepared porous ZnO-SnO2 nanosheets were utilized to fabricate a robust chemical sensor to detect 4-nitrophenol in aqueous medium. The fabricated sensor exhibited extremely high sensitivity of ~ 1285.76 µA/mmol L(-1)cm(-2) and an experimental detection limit of 0.078 mmol L(-1) with a linear dynamic range of 0.078-1.25 mmol L(-1). The obtained results confirmed that the prepared porous ZnO-SnO2 nanosheets are potential material for the removal of organic pollutants under visible light irradiation and efficient chemical sensing applications. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. A yield-optimized access to double-helical SnIP via a Sn/SnI2 approach

    Science.gov (United States)

    Utrap, André; Xiang, Ng Yan; Nilges, Tom

    2017-10-01

    Herein we report on the optimized synthesis process of SnIP, the first inorganic double helix compound which shows high mechanical flexibility, a strong tendency for cleavage or delamination and intriguing electronic properties. In this work we analyzed the influence of SnI2 as a reaction promotor or mineralizer compound for the synthesis of SnIP. In previous studies Sn/SnI4 was used as a precursor and chemical transport agent for the SnIP synthesis but significant amounts of non-reacted tin halide (SnI2 and SnI4) remained after the formation of the target compound reducing its quality and yield. Significantly less tin halide residue can be observed which suggests a reduction of side-reactions. While the Sn/SnI4 couple works perfectly for the synthesis of the two-dimensional material phosphorene precursor black phosphorus the Sn/SnI2 couple is beneficial for the one-dimensional ternary polyphosphide SnIP. These results strongly encourage the theory of SnI2 as the important reaction intermediate in the synthesis of covalently-bonded polyphosphide substructures and element allotropes at elevated temperatures.

  14. Highly sensitive and thermal stable CO gas sensor based on SnO2 modified by SiO2.

    Science.gov (United States)

    Zhan, Zili; Chen, Juling; Guan, Shaokang; Si, Lifen; Zhang, Pengshuai

    2013-02-01

    Effects of surface chemical modification with SiO2 on the thermal stability and CO gas-sensing properties of SnO2 were investigated. The SiO2 on the SnO2 surface effectively inhibits the nanocrystal growth of SnO2. The average size of modified SnO2 sintered at 600 degrees C is 5.8 nm. The gas sensitivity to CO was found to be markedly enhanced by the surface chemical modification. The CO gas as low as 5 ppm can be effectively detected by the modified SnO2-based sensors. At the same time, the modified SnO2-based sensor has excellent selectivity to CO, fast response and recovery properties.

  15. The impact of dietary sn-2 palmitic triacylglycerols in combination with docosahexaenoic acid or arachidonic acid on lipid metabolism and host faecal microbiota composition in Sprague Dawley rats.

    Science.gov (United States)

    Wan, Jianchun; Hu, Songyou; Jacoby, Jörg J; Liu, Jie; Zhang, Yaqiong; Yu, Liangli Lucy

    2017-05-24

    Sn-2 palmitic acid triacylglycerols (sn2PA fat) and polyunsaturated fatty acids are thought to influence the metabolic status and intestinal bacterial population of the host. In this study, the impact of sn2PA fat in combination with DHA or ARA in the diet on lipid metabolism in the liver and faecal microbiota composition were investigated in rats fed diets containing sn2PA fat, 90% sn2PA fat + 10% DHA oil (wt%), or 90% sn2PA fat + 10% ARA oil (wt%). Tissue fatty acid composition was measured using gas chromatography (GC), whereas the faecal microbial composition was assessed using 16S rRNA high-throughput sequencing technology. In addition, faecal short-chain fatty acids (SCFA) were analyzed using ion chromatography. The results showed that sn2PA fat in combination with DHA or ARA significantly reduced liver triacylglyceride (TG) content compared with the sn2PA fat only group. Moreover, the supplementation with sn2PA fat in combination with DHA or ARA significantly promoted the growth of Lactobacillus in the feces at the genus level. On the other hand, the growth of the opportunistic pathogen Desulfovibrio was significantly inhibited by sn2PA fat in combination with ARA compared with the sn2PA fat group. In addition, sn2PA fat in combination with DHA or ARA significantly increased total SCFA concentration in the faeces, suggesting a beneficial effect on host intestinal health.

  16. Preparation of transparent and conductive multicomponent Zn-In-Sn oxide thin films by vacuum arc plasma evaporation

    Science.gov (United States)

    Minami, Tadatsugu; Tsukada, Satoshi; Minamino, Youhei; Miyata, Toshihiro

    2005-07-01

    This article describes the preparation of transparent conducting oxide (TCO) thin films by a vacuum arc plasma evaporation (VAPE) method using multicomponent oxide materials composed of any combination of two of the following binary compounds: ZnO, In2O3, and SnO2. The resulting TCO thin films were prepared with high deposition rates with the desired chemical composition in the ZnO-In2O3, In2O3-SnO2, and SnO2-ZnO systems by altering the composition of the sintered oxide fragments used as the source materials. Minimum resistivities were obtained in amorphous In2O3-ZnO, SnO2-In2O3, and ZnO-SnO2 thin films that were prepared with a Zn content of about 8.5 at. %, an In content of about 46 at. %, and a Sn content of about 78 at. %, respectively. It was found that the electrical, optical and chemical properties in ZnO-SnO2 thin films prepared using the VAPE method could be controlled by altering the Sn content.

  17. Preparation of highly dispersed Pt-SnO{sub x} nanoparticles supported on multi-walled carbon nanotubes for methanol oxidation

    Energy Technology Data Exchange (ETDEWEB)

    Hu Chuangang [College of Chemistry and Environmental Science, Henan Normal University, Engineering Technology Research Center of Motive Power and Key Materials of Henan Province, Xinxiang 453007 (China); Cao Yanxia [College of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001 (China); Yang Lin, E-mail: yanglin1819@163.com [College of Chemistry and Environmental Science, Henan Normal University, Engineering Technology Research Center of Motive Power and Key Materials of Henan Province, Xinxiang 453007 (China); Bai Zhengyu; Guo Yuming; Wang Kui; Xu Pengle; Zhou Jianguo [College of Chemistry and Environmental Science, Henan Normal University, Engineering Technology Research Center of Motive Power and Key Materials of Henan Province, Xinxiang 453007 (China)

    2011-07-01

    To maximize the utilization of catalysts and thereby reduce the high price, a new strategy was developed to prepare highly dispersed Pt-SnO{sub x} nanoparticles supported on 8-Hydroxyquinoline (HQ) functionalized multi-walled carbon nanotubes (MWCNTs). HQ functionalized MWCNTs (HQ-MWCNTs) provide an ideal support for improving the utilization of platinum-based catalysts, and the introduction of SnO{sub x} to the catalyst prevents the CO poisoning effectively. The as-prepared catalysts are characterized by Transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy. It is found that the HQ functionalization process preserves the integrity and electronic structure of MWCNTs, and the resulting Pt-SnO{sub x} particles are well dispersed on the HQ-MWCNTs with an average diameter of ca. 2.2 nm. Based on the electrochemical properties characterized by cyclic voltammetry and chronoamperometry, the Pt-SnO{sub x}/HQ-MWCNTs catalyst displays better electrocatalytic activity and stability for the methanol oxidation. It is worth mentioning that the forward peak current density of Pt-SnO{sub x}/HQ-MWCNTs catalyst is ca. 1.9 times of that of JM commercial 20% Pt/C catalyst, which makes it the preferable catalyst for direct methanol fuel cells.

  18. SnS2 nanosheets arrays sandwiched by N-doped carbon and TiO2 for high-performance Na-ion storage

    Directory of Open Access Journals (Sweden)

    Weina Ren

    2018-01-01

    Full Text Available In this paper, SnS2 nanosheets arrays sandwiched by porous N-doped carbon and TiO2 (TiO2@SnS2@N-C on flexible carbon cloth are prepared and tested as a free-standing anode for high-performance sodium ion batteries. The as-obtained TiO2@SnS2@N-C composite delivers a remarkable capacity performance (840 mA h g−1 at a current density of 200 mA g−1, excellent rate capability and long-cycling life stability (293 mA h g−1 at 1 A g−1 after 600 cycles. The excellent electrochemical performance can be attributed to the synergistic effect of each component of the unique hybrid structure, in which the SnS2 nanosheets with open framworks offer high capacity, while the porous N-doped carbon nanoplates arrays on flexible carbon cloth are able to improve the conductivity and the TiO2 passivation layer can keep the structure integrity of SnS2 nanosheets.

  19. Graphene/Fe2O3/SnO2 ternary nanocomposites as a high-performance anode for lithium ion batteries.

    Science.gov (United States)

    Xia, Guofeng; Li, Ning; Li, Deyu; Liu, Ruiqing; Wang, Chen; Li, Qing; Lü, Xujie; Spendelow, Jacob S; Zhang, Junliang; Wu, Gang

    2013-09-11

    We report an rGO/Fe2O3/SnO2 ternary nanocomposite synthesized via homogeneous precipitation of Fe2O3 nanoparticles onto graphene oxide (GO) followed by reduction of GO with SnCl2. The reduction mechanism of GO with SnCl2 and the effects of reduction temperature and time were examined. Accompanying the reduction of GO, particles of SnO2 were deposited on the GO surface. In the graphene nanocomposite, Fe2O3 nanoparticles with a size of ∼20 nm were uniformly dispersed surrounded by SnO2 nanoparticles, as demonstrated by transmission electron microscopy analysis. Due to the different lithium insertion/extraction potentials, the major role of SnO2 nanoparticles is to prevent aggregation of Fe2O3 during the cycling. Graphene can serve as a matrix for Li+ and electron transport and is capable of relieving the stress that would otherwise accumulate in the Fe2O3 nanoparticles during Li uptake/release. In turn, the dispersion of nanoparticles on graphene can mitigate the restacking of graphene sheets. As a result, the electrochemical performance of rGO/Fe2O3/SnO2 ternary nanocomposite as an anode in Li ion batteries is significantly improved, showing high initial discharge and charge capacities of 1179 and 746 mAhg(-1), respectively. Importantly, nearly 100% discharge-charge efficiency is maintained during the subsequent 100 cycles with a specific capacity above 700 mAhg(-1).

  20. Contents of training process of highly qualified weightlifters.

    Directory of Open Access Journals (Sweden)

    Oleshko Valentin Grigor'evich

    2011-10-01

    Full Text Available The content of the training of highly skilled weightlifters in the annual macrocycle. The study involved 38 highly skilled lifters aged 19 to 29 years old. Considered periods of preparation for various weight categories of athletes. Shows the model parameters volume of training work weightlifting exercises in groups. The variants in the training load and intensity control areas (71.0 - 100% depending on the training period. Recommended options for building training sessions of various kinds.

  1. GeSn/Ge quantum well photodetectors for short-wave infrared photodetection: experiments and modeling

    Science.gov (United States)

    Tsai, Chia-Ho; Chang, Guo-En

    2017-05-01

    Group-IV GeSn material systems have recently considered as a new material for sensitive photodetection in the short-wave infrared (SWIR) region. The introduction of Sn into Ge can effectively narrow the bandgap energies, thereby extending the absorption edges toward the longer wavelengths and enabling effective photodetection in SWIR region. Here we present an experimental and modeling study of GeSn/Ge quantum well (QW) photodetectors on silicon substrates for effective SRIW photodetection. Epitaxial growth of pseudomorphic GeSn/Ge QW structures was realized on Ge-buffered silicon substrates using low-temperature molecular beam epitaxy. Normal incident GeSn/Ge QW photodetectors were then fabricated and characterized. The optical responsivity experiments demonstrate that the photodetection cutoff wavelengths is extended to beyond 1800 nm, enabling effective photodetection in SWIR spectral region. We then develop theoretical models to calculate the composition-dependent strained electron band structures, oscillation strengths, and optical absorption spectra for the pseudomorphic GeSn/Ge QW structures. The results show that Ge1-xSnx well sandwiched by Ge barriers can achieve a critical type-I alignment at Γ point to provide necessary quantum confinement of carriers. With an increase in the Sn content, the band offsets between the GeSn well and Ge barreirs increases, thus enhancing the oscillation strengths of direct interband transitions. In addition, despite stronger quantum confinement with increasing Sn content, the absorption edge can be effectively shifted to longer wavelengths due to the direct bandgap reduction caused by Sn-alloying. These results suggest that GeSn/Ge QW photodetectors are promising for low-cost, high-performance SWIR photodetection applications.

  2. Shedding Light on Filovirus Infection with High-Content Imaging

    Directory of Open Access Journals (Sweden)

    Rekha G. Panchal

    2012-08-01

    Full Text Available Microscopy has been instrumental in the discovery and characterization of microorganisms. Major advances in high-throughput fluorescence microscopy and automated, high-content image analysis tools are paving the way to the systematic and quantitative study of the molecular properties of cellular systems, both at the population and at the single-cell level. High-Content Imaging (HCI has been used to characterize host-virus interactions in genome-wide reverse genetic screens and to identify novel cellular factors implicated in the binding, entry, replication and egress of several pathogenic viruses. Here we present an overview of the most significant applications of HCI in the context of the cell biology of filovirus infection. HCI assays have been recently implemented to quantitatively study filoviruses in cell culture, employing either infectious viruses in a BSL-4 environment or surrogate genetic systems in a BSL-2 environment. These assays are becoming instrumental for small molecule and siRNA screens aimed at the discovery of both cellular therapeutic targets and of compounds with anti-viral properties. We discuss the current practical constraints limiting the implementation of high-throughput biology in a BSL-4 environment, and propose possible solutions to safely perform high-content, high-throughput filovirus infection assays. Finally, we discuss possible novel applications of HCI in the context of filovirus research with particular emphasis on the identification of possible cellular biomarkers of virus infection.

  3. Enhanced temperature stability and quality factor with Hf substitution for Sn and MnO2 doping of (Ba0.97Ca0.03(Ti0.96Sn0.04O3 lead-free piezoelectric ceramics with high Curie temperature

    Directory of Open Access Journals (Sweden)

    Cheng-Che Tsai

    2016-12-01

    Full Text Available In this work, the process of two-stage modifications for (Ba0.97Ca0.03(Ti0.96Sn0.04-xHfxO3 (BCTS4-100xH100x ceramics was studied. The trade-off composition was obtained by Hf substitution for Sn and MnO2 doping (two-stage modification which improves the temperature stability and piezoelectric properties. The phase structure ratio, microstructure, and dielectric, piezoelectric, ferroelectric, and temperature stability properties were systematically investigated. Results showed that BCTS4-100xH100x piezoelectric ceramics with x=0.035 had a relatively high Curie temperature (TC of about 112 °C, a piezoelectric charge constant (d33 of 313 pC/N, an electromechanical coupling factor (kp of 0.49, a mechanical quality factor (Qm of 122, and a remnant polarization (Pr of 19μC/cm2. In addition, the temperature stability of the resonant frequency (fr, kp, and aging d33 could be tuned via Hf content. Good piezoelectric temperature stability (up to 110 °C was found with x =0.035. BCTS0.5H3.5 + a mol% Mn (BCTSH + a Mn piezoelectric ceramics with a = 2 had a high TC of about 123 °C, kp ∼ 0.39, d33 ∼ 230 pC/N, Qm ∼ 341, and high temperature stability due to the produced oxygen vacancies. This mechanism can be depicted using the complex impedance analysis associated with a valence compensation model on electric properties. Two-stage modification for lead-free (Ba0.97Ca0.03(Ti0.96Sn0.04O3 ceramics suitably adjusts the compositions for applications in piezoelectric motors and actuators.

  4. Building high dimensional imaging database for content based image search

    Science.gov (United States)

    Sun, Qinpei; Sun, Jianyong; Ling, Tonghui; Wang, Mingqing; Yang, Yuanyuan; Zhang, Jianguo

    2016-03-01

    In medical imaging informatics, content-based image retrieval (CBIR) techniques are employed to aid radiologists in the retrieval of images with similar image contents. CBIR uses visual contents, normally called as image features, to search images from large scale image databases according to users' requests in the form of a query image. However, most of current CBIR systems require a distance computation of image character feature vectors to perform query, and the distance computations can be time consuming when the number of image character features grows large, and thus this limits the usability of the systems. In this presentation, we propose a novel framework which uses a high dimensional database to index the image character features to improve the accuracy and retrieval speed of a CBIR in integrated RIS/PACS.

  5. Flake structured SnSbCo/MCMB/C composite as high performance anodes for lithium ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xiaoqiu [School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China); Engineering Research Center of Materials and Technology for Electrochemical Energy Storage (Ministry of Education), Guangzhou 510006 (China); Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China); Guangdong Engineering Technology Research Center of Low Carbon and Advanced Energy Materials, Guangzhou 510631 (China); Ru, Qiang, E-mail: rq7702@yeah.net [School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China); Engineering Research Center of Materials and Technology for Electrochemical Energy Storage (Ministry of Education), Guangzhou 510006 (China); Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China); Guangdong Engineering Technology Research Center of Low Carbon and Advanced Energy Materials, Guangzhou 510631 (China); Zhao, Doudou; Mo, Yudi; Hu, Shejun [School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China); Engineering Research Center of Materials and Technology for Electrochemical Energy Storage (Ministry of Education), Guangzhou 510006 (China); Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, School of Physics and Telecommunication Engineering, South China Normal University, Guangzhou 510006 (China); Guangdong Engineering Technology Research Center of Low Carbon and Advanced Energy Materials, Guangzhou 510631 (China)

    2015-10-15

    SnSbCo/MCMB/C composite with flake structure were prepared by stepwise synthesis method. Firstly, SnSbCo nanoparticles were fabricated by co-precipitation, and then nanosized SnSbCo alloy were embedded in mesocarbon microbeads (MCMB) by ball-milling to synthesize primitive SnSbCo/MCMB hybrids, followed by carbonization of phenolic resin to produce an outer layer of carbon coating. The crystal structure, morphology and electrochemical properties of the SnSbCo/MCMB/C composite were evaluated by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and galvanostatical cycling tests. Compared with bare SnSbCo alloy and SnSbCo/MCMB hybrids, the efficiently enhanced electrochemical performance of SnSbCo/MCMB/C composite were mainly ascribed to the improved electron conductivity and volume buffering effect provided by the amorphous carbon coating. The resultant SnSbCo/MCMB/C composite delivered an initial discharge capacity of 848 mAh g{sup −1} under 100 mA g{sup −1}, with a good capacity retention of 85.6% after 70 cycles. The composite also exhibited excellent rate capability of 603 mAh g{sup −1} and 405 mAh g{sup −1} at the current density of 200 mA g{sup −1} and 1000 mA g{sup −1}, respectively. - Highlights: • Flake structured SnSbCo/MCMB/C composite have been prepared by stepwise synthesis method. • SnSbCo/MCMB/C composite show good cycle performance and rate capability. • Using both MCMB and phenolic resin as dual carbon sources.

  6. Confined SnO2 quantum-dot clusters in graphene sheets as high-performance anodes for lithium-ion batteries

    Science.gov (United States)

    Zhu, Chengling; Zhu, Shenmin; Zhang, Kai; Hui, Zeyu; Pan, Hui; Chen, Zhixin; Li, Yao; Zhang, Di; Wang, Da-Wei

    2016-01-01

    Construction of metal oxide nanoparticles as anodes is of special interest for next-generation lithium-ion batteries. The main challenge lies in their rapid capacity fading caused by the structural degradation and instability of solid-electrolyte interphase (SEI) layer during charge/discharge process. Herein, we address these problems by constructing a novel-structured SnO2-based anode. The novel structure consists of mesoporous clusters of SnO2 quantum dots (SnO2 QDs), which are wrapped with reduced graphene oxide (RGO) sheets. The mesopores inside the clusters provide enough room for the expansion and contraction of SnO2 QDs during charge/discharge process while the integral structure of the clusters can be maintained. The wrapping RGO sheets act as electrolyte barrier and conductive reinforcement. When used as an anode, the resultant composite (MQDC-SnO2/RGO) shows an extremely high reversible capacity of 924 mAh g−1 after 200 cycles at 100 mA g−1, superior capacity retention (96%), and outstanding rate performance (505 mAh g−1 after 1000 cycles at 1000 mA g−1). Importantly, the materials can be easily scaled up under mild conditions. Our findings pave a new way for the development of metal oxide towards enhanced lithium storage performance. PMID:27181691

  7. In Situ Synthesis of Tungsten-Doped SnO2 and Graphene Nanocomposites for High-Performance Anode Materials of Lithium-Ion Batteries.

    Science.gov (United States)

    Wang, Shuai; Shi, Liyi; Chen, Guorong; Ba, Chaoqun; Wang, Zhuyi; Zhu, Jiefang; Zhao, Yin; Zhang, Meihong; Yuan, Shuai

    2017-05-24

    The composite of tungsten-doped SnO2 and reduced graphene oxide was synthesized through a simple one-pot hydrothermal method. According to the structural characterization of the composite, tungsten ions were doped in the unit cells of tin dioxide rather than simply attaching to the surface. Tungsten-doped SnO2 was in situ grown on the surface of graphene sheet to form a three-dimensional conductive network that enhanced the electron transportation and lithium-ion diffusion effectively. The issues of SnO2 agglomeration and volume expansion could be also avoided because the tungsten-doped SnO2 nanoparticles were homogeneously distributed on a graphene sheet. As a result, the nanocomposite electrodes of tungsten-doped SnO2 and reduced graphene oxide exhibited an excellent long-term cycling performance. The residual capacity was still as high as 1100 mA h g(-1) at 0.1 A g(-1) after 100 cycles. It still remained at 776 mA h g(-1) after 2000 cycles at the current density of 1A g(-1).

  8. Confined SnO2 quantum-dot clusters in graphene sheets as high-performance anodes for lithium-ion batteries.

    Science.gov (United States)

    Zhu, Chengling; Zhu, Shenmin; Zhang, Kai; Hui, Zeyu; Pan, Hui; Chen, Zhixin; Li, Yao; Zhang, Di; Wang, Da-Wei

    2016-05-16

    Construction of metal oxide nanoparticles as anodes is of special interest for next-generation lithium-ion batteries. The main challenge lies in their rapid capacity fading caused by the structural degradation and instability of solid-electrolyte interphase (SEI) layer during charge/discharge process. Herein, we address these problems by constructing a novel-structured SnO2-based anode. The novel structure consists of mesoporous clusters of SnO2 quantum dots (SnO2 QDs), which are wrapped with reduced graphene oxide (RGO) sheets. The mesopores inside the clusters provide enough room for the expansion and contraction of SnO2 QDs during charge/discharge process while the integral structure of the clusters can be maintained. The wrapping RGO sheets act as electrolyte barrier and conductive reinforcement. When used as an anode, the resultant composite (MQDC-SnO2/RGO) shows an extremely high reversible capacity of 924 mAh g(-1) after 200 cycles at 100 mA g(-1), superior capacity retention (96%), and outstanding rate performance (505 mAh g(-1) after 1000 cycles at 1000 mA g(-1)). Importantly, the materials can be easily scaled up under mild conditions. Our findings pave a new way for the development of metal oxide towards enhanced lithium storage performance.

  9. Self-annealing in a two-phase Pb-Sn alloy after processing by high-pressure torsion

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Nian Xian [Materials Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ (United Kingdom); Chinh, Nguyen Q. [Department of Materials Physics, Eötvös Loránd University, 1117 Budapest, Pázmány Péter s. 1/A. (Hungary); Kawasaki, Megumi [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Departments of Aerospace & Mechanical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089-1453 (United States); Huang, Yi, E-mail: Y.Huang@soton.ac.uk [Materials Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ (United Kingdom); Langdon, Terence G. [Materials Research Group, Faculty of Engineering and the Environment, University of Southampton, Southampton SO17 1BJ (United Kingdom); Departments of Aerospace & Mechanical Engineering and Materials Science, University of Southern California, Los Angeles, CA 90089-1453 (United States)

    2016-06-01

    A Pb-62% Sn two-phase eutectic alloy was processed by high-pressure torsion (HPT) and stored at room temperature (RT) to investigate the occurrence of self-annealing. The microstructural characteristics and mechanical properties were recorded during self-annealing using scanning electron microscopy, tensile testing and nanoindentation. Processing by HPT produces a weakening effect but storage at RT leads to a gradual increase in the hardness together with significant grain growth. Nanoindentation tests were performed by applying both the indentation depth-time (h-t) relationship at the holding stage and the hardness, H, at various loading rates in order to explore the evolution of the strain rate sensitivity (SRS), m. The results obtained by tensile testing and nanoindentation are consistent despite the large difference in the volumes of the examined regions, thereby confirming the validity of using nanoindentation to measure the strain rate sensitivity.

  10. Test results of HD2, a high field Nb$_{3}$Sn dipole with a 36 mm bore

    CERN Document Server

    Ferracin, P

    2009-01-01

    The Superconducting Magnet Program at Lawrence Berkeley National Laboratory (LBNL) has developed the 1 m long Nb3Sn dipole magnet HD2. With tilted (flared) ends to avoid obstructing a 36 mm clear bore, HD2 represents a step towards the use of block-type coils in high-field accelerator magnets. The coil design has been optimized to minimize geometric harmonics and reduce the conductor peak field in the end region, resulting in an expected short sample dipole field of 15 T. The support structure is composed by an external aluminum shell pretensioned with pressurized bladders and interference keys, and by two stainless steel end plates compressing the coil ends through four aluminum axial rods. We report on magnet design, assembly, and test results, including training performance, quench locations, and strain gauge measurements

  11. Quench Analysis of High Current Density Nb3Sn Conductors in Racetrack Coil Configuration

    CERN Document Server

    Bajas, H; Bordini, B; Bottura, L; Izquierdo Bermudez, S; Feuvrier, J; Chiuchiolo, A; Perez, J C; Willering, G

    2015-01-01

    The luminosity upgrade of the Large Hadron Collider (HL-LHC) requires the development of new type of superconducting cables based on advanced Nb3Sn strands. In the framework of the FP7 European project EUCARD the cables foreseen for the HL-LHC project have been tested recently in a simplified racetrack coil configuration, the so-called Short Model Coil (SMC). In 2013 to 2014, two SMCs wound with 40-strand (RRP 108/127) cables, with different heat treatment processes, reached during training at 1.9 K a current and peak magnetic field of 15.9 kA, 13.9T,and 14.3 kA, 12.7 Trespectively. Using the measured signals from the voltage taps, the behavior of the quenches is analyzed in terms of transverse and longitudinal propagation velocity and hot spot temperature. These measurements are compared with both analytical and numerical calculations from adiabatic models.The coherence of the results from the presented independent methods helps in estimating the relevance of the material properties and the adiabatic assump...

  12. Information management for high content live cell imaging

    Directory of Open Access Journals (Sweden)

    White Michael RH

    2009-07-01

    Full Text Available Abstract Background High content live cell imaging experiments are able to track the cellular localisation of labelled proteins in multiple live cells over a time course. Experiments using high content live cell imaging will generate multiple large datasets that are often stored in an ad-hoc manner. This hinders identification of previously gathered data that may be relevant to current analyses. Whilst solutions exist for managing image data, they are primarily concerned with storage and retrieval of the images themselves and not the data derived from the images. There is therefore a requirement for an information management solution that facilitates the indexing of experimental metadata and results of high content live cell imaging experiments. Results We have designed and implemented a data model and information management solution for the data gathered through high content live cell imaging experiments. Many of the experiments to be stored measure the translocation of fluorescently labelled proteins from cytoplasm to nucleus in individual cells. The functionality of this database has been enhanced by the addition of an algorithm that automatically annotates results of these experiments with the timings of translocations and periods of any oscillatory translocations as they are uploaded to the repository. Testing has shown the algorithm to perform well with a variety of previously unseen data. Conclusion Our repository is a fully functional example of how high throughput imaging data may be effectively indexed and managed to address the requirements of end users. By implementing the automated analysis of experimental results, we have provided a clear impetus for individuals to ensure that their data forms part of that which is stored in the repository. Although focused on imaging, the solution provided is sufficiently generic to be applied to other functional proteomics and genomics experiments. The software is available from: fhttp://code.google.com/p/livecellim/

  13. Information management for high content live cell imaging

    Science.gov (United States)

    Jameson, Daniel; Turner, David A; Ankers, John; Kennedy, Stephnie; Ryan, Sheila; Swainston, Neil; Griffiths, Tony; Spiller, David G; Oliver, Stephen G; White, Michael RH; Kell, Douglas B; Paton, Norman W

    2009-01-01

    Background High content live cell imaging experiments are able to track the cellular localisation of labelled proteins in multiple live cells over a time course. Experiments using high content live cell imaging will generate multiple large datasets that are often stored in an ad-hoc manner. This hinders identification of previously gathered data that may be relevant to current analyses. Whilst solutions exist for managing image data, they are primarily concerned with storage and retrieval of the images themselves and not the data derived from the images. There is therefore a requirement for an information management solution that facilitates the indexing of experimental metadata and results of high content live cell imaging experiments. Results We have designed and implemented a data model and information management solution for the data gathered through high content live cell imaging experiments. Many of the experiments to be stored measure the translocation of fluorescently labelled proteins from cytoplasm to nucleus in individual cells. The functionality of this database has been enhanced by the addition of an algorithm that automatically annotates results of these experiments with the timings of translocations and periods of any oscillatory translocations as they are uploaded to the repository. Testing has shown the algorithm to perform well with a variety of previously unseen data. Conclusion Our repository is a fully functional example of how high throughput imaging data may be effectively indexed and managed to address the requirements of end users. By implementing the automated analysis of experimental results, we have provided a clear impetus for individuals to ensure that their data forms part of that which is stored in the repository. Although focused on imaging, the solution provided is sufficiently generic to be applied to other functional proteomics and genomics experiments. The software is available from: PMID:19622144

  14. Performance of the first short model 150 mm aperture Nb$_3$Sn Quadrupole MQXFS for the High-Luminosity LHC upgrade

    CERN Document Server

    Chlachidze, G; Anerella, M; Bossert, R; Cavanna, E; Cheng, D; Dietderich, D; DiMarco, J; Felice, H; Ferracin, P; Ghosh, A; Grosclaude, P; Guinchard, M; Hafalia, A R; Holik, E; Izquierdo Bermudez, S; Krave, S; Marchevsky, M; Nobrega, F; Orris, D; Pan, H; Perez, J C; Prestemon, S; Ravaioli, E; Sabbi, G L; Salmi, T; Schmalzle, J; Stoynev, S; Strauss, T; Sylvester, C; Tartaglia, M; Todesco, E; Vallone, G; Velev, G; Wanderer, P; Wang, X; Yu, M

    2016-01-01

    The US LHC Accelerator Research Program (LARP) and CERN combined their efforts in developing Nb3Sn magnets for the High-Luminosity LHC upgrade. The ultimate goal of this collaboration is to fabricate large aperture Nb3Sn quadrupoles for the LHC interaction regions (IR). These magnets will replace the present 70 mm aperture NbTi quadrupole triplets for expected increase of the LHC peak luminosity by a factor of 5. Over the past decade LARP successfully fabricated and tested short and long models of 90 mm and 120 mm aperture Nb3Sn quadrupoles. Recently the first short model of 150 mm diameter quadrupole MQXFS was built with coils fabricated both by the LARP and CERN. The magnet performance was tested at Fermilab’s vertical magnet test facility. This paper reports the test results, including the quench training at 1.9 K, ramp rate and temperature dependence studies.

  15. Design of lead-free candidate alloys for high-temperature soldering based on the Au–Sn system

    DEFF Research Database (Denmark)

    Chidambaram, Vivek; Hattel, Jesper Henri; Hald, John

    2010-01-01

    of the Au–Sn binary system were explored in this work. Furthermore, the effects of thermal aging on the microstructure and microhardness of these promising Au–Sn based ternary alloys were investigated. For this purpose, the candidate alloys were aged at a lower temperature, 150°C for up to 1week...

  16. SnO2 Quantum Dots@Graphene Oxide as a High-Rate and Long-Life Anode Material for Lithium-Ion Batteries.

    Science.gov (United States)

    Zhao, Kangning; Zhang, Lei; Xia, Rui; Dong, Yifan; Xu, Wangwang; Niu, Chaojiang; He, Liang; Yan, Mengyu; Qu, Longbin; Mai, Liqiang

    2016-02-03

    Tin-based electrode s offer high theoretical capacities in lithium ion batteries, but further commercialization is strongly hindered by the poor cycling stability. An in situ reduction method is developed to synthesize SnO2 quantum dots@graphene oxide. This approach is achieved by the oxidation of Sn(2+) and the reduction of the graphene oxide. At 2 A g(-1), a capacity retention of 86% is obtained even after 2000 cycles. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Fluorine-doped SnO2 nanoparticles anchored on reduced graphene oxide as a high-performance lithium ion battery anode

    Science.gov (United States)

    Cui, Dongming; Zheng, Zhong; Peng, Xue; Li, Teng; Sun, Tingting; Yuan, Liangjie

    2017-09-01

    The composite of fluorine-doped SnO2 anchored on reduced graphene oxide (F-SnO2/rGO) has been synthesized through a hydrothermal method. F-SnO2 particles with average size of 8 nm were uniformly anchored on the surfaces of rGO sheets and the resulting composite had a high loading of F-SnO2 (ca. 90%). Benefiting from the remarkably improved electrical conductivity and Li-ion diffusion in the electrode by F doping and rGO incorporation, the composite material exhibited high reversible capacity, excellent long-term cycling stability and superior rate capability. The electrode delivered a large reversible capacity of 1037 mAh g-1 after 150 cycles at 100 mA g-1 and high rate capacities of 860 and 770 mAh g-1 at 1 and 2 A g-1, respectively. Moreover, the electrode could maintain a high reversible capacities of 733 mAh g-1 even after 250 cycles at 500 mA g-1. The outstanding electrochemical performance of the as-synthesized composite make it a promising anode material for high-energy lithium ion batteries.

  18. Method for creating high carbon content products from biomass oil

    Science.gov (United States)

    Parker, Reginald; Seames, Wayne

    2012-12-18

    In a method for producing high carbon content products from biomass, a biomass oil is added to a cracking reactor vessel. The biomass oil is heated to a temperature ranging from about 100.degree. C. to about 800.degree. C. at a pressure ranging from about vacuum conditions to about 20,700 kPa for a time sufficient to crack the biomass oil. Tar is separated from the cracked biomass oil. The tar is heated to a temperature ranging from about 200.degree. C. to about 1500.degree. C. at a pressure ranging from about vacuum conditions to about 20,700 kPa for a time sufficient to reduce the tar to a high carbon content product containing at least about 50% carbon by weight.

  19. Anchoring function for polysulfide ions of ultrasmall SnS{sub 2} in hollow carbon nanospheres for high performance lithium–sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xueliang, E-mail: xueliangli2015@163.com [School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009 (China); Anhui Key Laboratory of Controllable Chemical Reaction and Material Chemical Engineering, Hefei 230009 (China); Chu, Linbo; Wang, Yiyi; Pan, Lisheng [School of Chemistry and Chemical Engineering, Hefei University of Technology, Hefei 230009 (China); Anhui Key Laboratory of Controllable Chemical Reaction and Material Chemical Engineering, Hefei 230009 (China)

    2016-03-15

    Graphical abstract: - Highlights: • S/AHCNS-SnS{sub 2} were synthesized by APCVD and wet-impregnation method. • Ultrasmall SnS{sub 2} particles are homogeneous particles with a diameter of about 6 nm. • The cell retains a high capacity of 924 mAh g{sup −1} after 200 cycles at 0.2 C. • The improved cycling performance is ascribed to the anchoring function of SnS{sub 2}. - Abstract: Tin sulfide-anchored sulfur-hollow carbon nanospheres (S/AHCNS-SnS{sub 2}) composites are synthesized by uniformly dispersing conductive SnS{sub 2} particles into hollow carbon nanospheres activated with potassium hydroxide, followed by impregnating sulfur. Surface morphology and structure of this composite are characterized using a field emission scanning electron microscopy (FESEM), field emission transmission electron microscopy (FETEM), Brunauer–Emmett–Teller (BET) method, X-ray power diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The first discharge capacity of the sample containing 10 wt.% SnS{sub 2} exhibits a high special capacity value of about 1237.5 mAh g{sup −1} at 0.2 C, and after 200 cycles retains 924 mAh g{sup −1}. Tin sulfide particles play a favorable role on adsorption towards polysulfides which would influence electrochemical process. This strategy of immobilization of sulfur with small amount of metal sulfide particles anchored in AHCNS provides a considerable approach to elevate the sulfur loading, coulombic efficiency, and cycling stability for Li–S batteries.

  20. Solvent-Free Synthesis of Uniform MOF Shell-Derived Carbon Confined SnO2/Co Nanocubes for Highly Reversible Lithium Storage.

    Science.gov (United States)

    He, Qiu; Liu, Jinshuai; Li, Zhaohuai; Li, Qi; Xu, Lin; Zhang, Baoxuan; Meng, Jiashen; Wu, Yuzhu; Mai, Liqiang

    2017-10-01

    Tin dioxide (SnO 2 ) has attracted much attention in lithium-ion batteries (LIBs) due to its abundant source, low cost, and high theoretical capacity. However, the large volume variation, irreversible conversion reaction limit its further practical application in next-generation LIBs. Here, a novel solvent-free approach to construct uniform metal-organic framework (MOF) shell-derived carbon confined SnO 2 /Co (SnO 2 /Co@C) nanocubes via a two-step heat treatment is developed. In particular, MOF-coated CoSnO 3 hollow nanocubes are for the first time synthesized as the intermediate product by an extremely simple thermal solid-phase reaction, which is further developed as a general strategy to successfully obtain other uniform MOF-coated metal oxides. The as-synthesized SnO 2 /Co@C nanocubes, when tested as LIB anodes, exhibit a highly reversible discharge capacity of 800 mAh g -1 after 100 cycles at 200 mA g -1 and excellent cycling stability with a retained capacity of 400 mAh g -1 after 1800 cycles at 5 A g -1 . The experimental analyses demonstrate that these excellent performances are mainly ascribed to the delicate structure and a synergistic effect between Co and SnO 2 . This facile synthetic approach will greatly contribute to the development of functional metal oxide-based and MOF-assisted nanostructures in many frontier applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. The aluminium content of infant formulas remains too high.

    Science.gov (United States)

    Chuchu, Nancy; Patel, Bhavini; Sebastian, Blaise; Exley, Christopher

    2013-10-08

    Recent research published in this journal highlighted the issue of the high content of aluminium in infant formulas. The expectation was that the findings would serve as a catalyst for manufacturers to address a significant problem of these, often necessary, components of infant nutrition. It is critically important that parents and other users have confidence in the safety of infant formulas and that they have reliable information to use in choosing a product with a lower content of aluminium. Herein, we have significantly extended the scope of the previous research and the aluminium content of 30 of the most widely available and often used infant formulas has been measured. Both ready-to-drink milks and milk powders were subjected to microwave digestion in the presence of 15.8 M HNO3 and 30% w/v H2O2 and the aluminium content of the digests was measured by TH GFAAS. Both ready-to-drink milks and milk powders were contaminated with aluminium. The concentration of aluminium across all milk products ranged from ca 100 to 430 μg/L. The concentration of aluminium in two soya-based milk products was 656 and 756 μg/L. The intake of aluminium from non-soya-based infant formulas varied from ca 100 to 300 μg per day. For soya-based milks it could be as high as 700 μg per day. All 30 infant formulas were contaminated with aluminium. There was no clear evidence that subsequent to the problem of aluminium being highlighted in a previous publication in this journal that contamination had been addressed and reduced. It is the opinion of the authors that regulatory and other non-voluntary methods are now required to reduce the aluminium content of infant formulas and thereby protect infants from chronic exposure to dietary aluminium.

  2. Ideal Menu and Boil Conditions for High Content Amilose Rice

    OpenAIRE

    坂井,堅太郎; 山内,真知子; 水羽,陽子; 清水池,綾子; 鉄穴森,陽子; 谷廣,佳奈子; 高松,寛子; 井原,久美; 井上, 明美; 中西,弘子; 谷田,真奈美; 出戸,綾子; 普家,由香理; 高橋,恵里; 渡邉,奈奈

    2007-01-01

    Dietetic therapy is a primary base for diabetes mellitus, therefore food items should be selected for the patients with this disease to control blood glucose level, which lightens the burden of the other medical treatment they need. High amilose content rice is an ideal food to supply carbohydrate as nutrient for the patients with diabetes mellitus, based on our recent research showing moderate increase of blood glucose level after eating cooked rice with this race in human and ra...

  3. Catalytic growth of vertically aligned SnS/SnS2 p-n heterojunctions

    Science.gov (United States)

    Degrauw, Aaron; Armstrong, Rebekka; Rahman, Ajara A.; Ogle, Jonathan; Whittaker-Brooks, Luisa

    2017-09-01

    Nanowire arrays of SnS/SnS2 p-n heterojunctions are grown on transparent indium tin oxide (ITO) coated-glass and Si/SiO2 substrates via chemical vapor transport (CVT). The nanowire arrays are comprised of individual SnS/SnS2 heterostructures that are highly oriented with their lengths and morphologies controlled by the CVT conditions (i.e. reaction temperature, flow rate, and reaction time). The growth and optoelectronic characterization of these well-defined SnS/SnS2 p-n heterostructures pave the way for the fabrication of highly efficient solar cell devices.

  4. Engineering properties for high kitchen waste content municipal solid waste

    Directory of Open Access Journals (Sweden)

    Wu Gao

    2015-12-01

    Full Text Available Engineering properties of municipal solid waste (MSW depend largely on the waste's initial composition and degree of degradation. MSWs in developing countries usually have a high kitchen waste content (called HKWC MSW. After comparing and analyzing the laboratory and field test results of physical composition, hydraulic properties, gas generation and gas permeability, and mechanical properties for HKWC MSW and low kitchen waste content MSW (called LKWC MSW, the following findings were obtained: (1 HKWC MSW has a higher initial water content (IWC than LKWC MSW, but the field capacities of decomposed HKWC and LKWC MSWs are similar; (2 the hydraulic conductivity and gas permeability for HKWC MSW are both an order of magnitude smaller than those for LKWC MSW; (3 compared with LKWC MSW, HKWC MSW has a higher landfill gas (LFG generation rate but a shorter duration and a lower potential capacity; (4 the primary compression feature for decomposed HKWC MSW is similar to that of decomposed LKWC MSW, but the compression induced by degradation of HKWC MSW is greater than that of LKWC MSW; and (5 the shear strength of HKWC MSW changes significantly with time and strain. Based on the differences of engineering properties between these two kinds of MSWs, the geo-environmental issues in HKWC MSW landfills were analyzed, including high leachate production, high leachate mounds, low LFG collection efficiency, large settlement and slope stability problem, and corresponding advice for the management and design of HKWC MSW landfills was recommended.

  5. Sn-MoS2 -C@C Microspheres as a Sodium-Ion Battery Anode Material with High Capacity and Long Cycle Life.

    Science.gov (United States)

    Zheng, Fenghua; Pan, Qichang; Yang, Chenghao; Xiong, Xunhui; Ou, Xing; Hu, Renzong; Chen, Yu; Liu, Meilin

    2017-04-11

    Sodium ion batteries (SIBs) have been regarded as a prime candidate for large-scale energy storage, and developing high performance anode materials is one of the main challenges for advanced SIBs. Novel structured Sn-MoS2 -C@C microspheres, in which Sn nanoparticles are evenly embedded in MoS2 nanosheets and a thin carbon film is homogenously engineered over the microspheres, have been fabricated by the hydrothermal method. The Sn-MoS2 -C@C microspheres demonstrate an excellent Na-storage performance as an anode of SIBs and deliver a high reversible charge capacity (580.3 mAh g(-1) at 0.05 Ag(-1) ) and rate capacity (580.3, 373, 326, 285.2, and 181.9 mAh g(-1) at 0.05, 0.5, 1, 2, and 5 Ag(-1) , respectively). A high charge specific capacity of 245 mAh g(-1) can still be achieved after 2750 cycles at 2 Ag(-1) , indicating an outstanding cycling performance. The high capacity and long-term stability make Sn-MoS2 -C@C composite a very promising anode material for SIBs. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Content

    DEFF Research Database (Denmark)

    Keiding, Tina Bering

    Aim, content and methods are fundamental categories of both theoretical and practical general didactics. A quick glance in recent pedagogical literature on higher education, however, reveals a strong preoccupation with methods, i.e. how teaching should be organized socially (Biggs & Tang, 2007...... a theoretical approach, which takes complexity as fundamental premise for modern society (Luhmann, 1985, 2002). In educational situations conditionally valuable content generally will exceed what can actually be taught within the frames of an education. In pedagogy this situation is often referred...... to as ‘abundance of material’, and in many cases it is not obvious, how the line between actually chosen and conditionally relevant content can be draw. Difficulties in drawing the line between actual educational content and conditionally relevant content can be handled in different way. One way, quite efficient...

  7. Normal-pressure microwave rapid synthesis of hierarchical SnO₂@rGO nanostructures with superhigh surface areas as high-quality gas-sensing and electrochemical active materials.

    Science.gov (United States)

    Yin, Li; Chen, Deliang; Cui, Xue; Ge, Lianfang; Yang, Jing; Yu, Lanlan; Zhang, Bing; Zhang, Rui; Shao, Guosheng

    2014-11-21

    Hierarchical SnO2@rGO nanostructures with superhigh surface areas are synthesized via a simple redox reaction between Sn(2+) ions and graphene oxide (GO) nanosheets under microwave irradiation. XRD, SEM, TEM, XPS, TG-DTA and N2 adsorption-desorption are used to characterize the compositions and microstructures of the SnO2@rGO samples obtained. The SnO2@rGO nanostructures are used as gas-sensing and electroactive materials to evaluate their property-microstructure relationship. The results show that SnO2 nanoparticles (NPs) with particle sizes of 3-5 nm are uniformly anchored on the surfaces of reduced graphene oxide (rGO) nanosheets through a heteronucleation and growth process. The as-obtained SnO2@rGO sample with a hierarchically sesame cake-like microstructure and a superhigh specific surface area of 2110.9 m(2) g(-1) consists of 92 mass% SnO2 NPs and ∼8 mass% rGO nanosheets. The sensitivity of the SnO2@rGO sensor upon exposure to 10 ppm H2S is up to 78 at the optimal operating temperature of 100 °C, and its response time is as short as 7 s. Compared with SnO2 nanocrystals (5-10 nm), the hierarchical SnO2@rGO nanostructures have enhanced gas-sensing behaviors (i.e., high sensitivity, rapid response and good selectivity). The SnO2@rGO nanostructures also show excellent electroactivity in detecting sunset yellow (SY) in 0.1 M phosphate buffer solution (pH = 2.0). The enhancement in gas-sensing and electroactive performance is mainly attributed to the unique hierarchical microstructure, high surface areas and the synergistic effect of SnO2 NPs and rGO nanosheets.

  8. Normal-pressure microwave rapid synthesis of hierarchical SnO2@rGO nanostructures with superhigh surface areas as high-quality gas-sensing and electrochemical active materials

    Science.gov (United States)

    Yin, Li; Chen, Deliang; Cui, Xue; Ge, Lianfang; Yang, Jing; Yu, Lanlan; Zhang, Bing; Zhang, Rui; Shao, Guosheng

    2014-10-01

    Hierarchical SnO2@rGO nanostructures with superhigh surface areas are synthesized via a simple redox reaction between Sn2+ ions and graphene oxide (GO) nanosheets under microwave irradiation. XRD, SEM, TEM, XPS, TG-DTA and N2 adsorption-desorption are used to characterize the compositions and microstructures of the SnO2@rGO samples obtained. The SnO2@rGO nanostructures are used as gas-sensing and electroactive materials to evaluate their property-microstructure relationship. The results show that SnO2 nanoparticles (NPs) with particle sizes of 3-5 nm are uniformly anchored on the surfaces of reduced graphene oxide (rGO) nanosheets through a heteronucleation and growth process. The as-obtained SnO2@rGO sample with a hierarchically sesame cake-like microstructure and a superhigh specific surface area of 2110.9 m2 g-1 consists of 92 mass% SnO2 NPs and ~8 mass% rGO nanosheets. The sensitivity of the SnO2@rGO sensor upon exposure to 10 ppm H2S is up to 78 at the optimal operating temperature of 100 °C, and its response time is as short as 7 s. Compared with SnO2 nanocrystals (5-10 nm), the hierarchical SnO2@rGO nanostructures have enhanced gas-sensing behaviors (i.e., high sensitivity, rapid response and good selectivity). The SnO2@rGO nanostructures also show excellent electroactivity in detecting sunset yellow (SY) in 0.1 M phosphate buffer solution (pH = 2.0). The enhancement in gas-sensing and electroactive performance is mainly attributed to the unique hierarchical microstructure, high surface areas and the synergistic effect of SnO2 NPs and rGO nanosheets.

  9. MgO Nanoparticle Modified Anode for Highly Efficient SnO2-Based Planar Perovskite Solar Cells.

    Science.gov (United States)

    Ma, Junjie; Yang, Guang; Qin, Minchao; Zheng, Xiaolu; Lei, Hongwei; Chen, Cong; Chen, Zhiliang; Guo, Yaxiong; Han, Hongwei; Zhao, Xingzhong; Fang, Guojia

    2017-09-01

    Reducing the energy loss and retarding the carrier recombination at the interface are crucial to improve the performance of the perovskite solar cell (PSCs). However, little is known about the recombination mechanism at the interface of anode and SnO 2 electron transfer layer (ETL). In this work, an ultrathin wide bandgap dielectric MgO nanolayer is incorporated between SnO 2 :F (FTO) electrode and SnO 2 ETL of planar PSCs, realizing enhanced electron transporting and hole blocking properties. With the use of this electrode modifier, a power conversion efficiency of 18.23% is demonstrated, an 11% increment compared with that without MgO modifier. These improvements are attributed to the better properties of MgO-modified FTO/SnO 2 as compared to FTO/SnO 2 , such as smoother surface, less FTO surface defects due to MgO passivation, and suppressed electron-hole recombinations. Also, MgO nanolayer with lower valance band minimum level played a better role in hole blocking. When FTO is replaced with Sn-doped In 2 O 3 (ITO), a higher power conversion efficiency of 18.82% is demonstrated. As a result, the device with the MgO hole-blocking layer exhibits a remarkable improvement of all J-V parameters. This work presents a new direction to improve the performance of the PSCs based on SnO 2 ETL by transparent conductive electrode surface modification.

  10. SN Refsdal

    DEFF Research Database (Denmark)

    Kelly, P. L.; Brammer, G.; Selsing, J.

    2016-01-01

    (SNe), and we find strong evidence for a broad H-alpha P-Cygni profile in the HST grism spectrum at the redshift (z = 1.49) of the spiral host galaxy. SNe IIn, powered by circumstellar interaction, could provide a good match to the light curve of SN Refsdal, but the spectrum of a SN IIn would not show...... 1987A, we estimate it would have an ejecta mass of 20+-5 solar masses. The evolution of the light curve at late times will provide additional evidence about the potential existence of any substantial circumstellar material (CSM). Using MOSFIRE and X-shooter spectra, we estimate a subsolar host-galaxy...

  11. Nb 3Sn material development in Russia

    Science.gov (United States)

    Pantsyrny, V.; Shikov, A.; Vorobieva, A.

    2008-07-01

    In the USSR and later in Russia, the main activities in technical superconductivity were concentrated in the institutes that belonged to the Ministry of Atomic Energy (Minatom). The development of new technologies shortly transferred to the large-scale industrial production of NbTi and Nb 3Sn superconductors in early 1970s. Two main technologies for multifilamentary Nb 3Sn strands were under investigation during that time - bronze-process and internal tin method. More than 25 ton of Nb 3Sn bronze-processed strands were produced for the fabrication of 90 ton of conductors for application in the magnet system of first in the world fusion facility (tokamak T-15) with magnet system based on the intermetallic compound. The characteristics of these strands and conductors have been briefly described. The requirements for the Nb 3Sn strands constantly increased and the main R&D on the enhancement of critical current density have been reviewed. For bronze-processed strands the increase of the tin content in large ingots was the crucial factor. The artificial doping of niobium filaments by niobium-titanium alloy was invented, which enabled to improve the workability of Nb 3Sn strands, with enhanced critical current density in high fields. For internal tin Nb 3Sn strands the main R&D were concentrated on the optimization of the layouts of the strand and on the multistage heat treatment because of the inevitable liquid phase formation which could result in severe distortion of the geometrical arrangement of the filaments and even in destruction of the whole strand. The main results of these investigations have been presented. The corresponding impact of these R&D on the design of bronze-processed and internal tin strands has been analyzed. The quantitative estimations of the grain size were made for bronze-processed and internal tin strands. It was shown that in bronze-processed and internal tin strands subjected to the standard ITER heat treatment characterized by two stages

  12. The infrared-dark dust content of high redshift galaxies

    Science.gov (United States)

    Ferrara, A.; Hirashita, H.; Ouchi, M.; Fujimoto, S.

    2017-11-01

    We present a theoretical model aimed at explaining the IRX-β relation for high redshift (z ≳ 5) galaxies. Recent observations have shown that early Lyman-Break Galaxies, although characterized by a large ultraviolet (UV) attenuation (e.g. flat UV β slopes), show a striking far-infrared (FIR) deficit, i.e. they are `infrared-dark'. This marked deviation from the local IRX-β relation can be explained by the larger molecular gas content of these systems. While dust in the diffuse interstellar medium attains relatively high temperatures (Td ≃ 45 K for typical size a = 0.1 μm; smaller grains can reach Td ≳ 60 K), a sizable fraction of the dust mass is embedded in dense gas, and therefore remains cold. If confirmed, the FIR deficit might represent a novel, powerful indicator of the molecular content of high-z galaxies which can be used to pre-select candidates for follow-up deep CO observations. Thus, high-z CO line searches with ALMA might be much more promising than currently thought.

  13. 3D macroporous electrode and high-performance in lithium-ion batteries using SnO2 coated on Cu foam

    Science.gov (United States)

    Um, Ji Hyun; Choi, Myounggeun; Park, Hyeji; Cho, Yong-Hun; Dunand, David C.; Choe, Heeman; Sung, Yung-Eun

    2016-01-01

    A three-dimensional porous architecture makes an attractive electrode structure, as it has an intrinsic structural integrity and an ability to buffer stress in lithium-ion batteries caused by the large volume changes in high-capacity anode materials during cycling. Here we report the first demonstration of a SnO2-coated macroporous Cu foam anode by employing a facile and scalable combination of directional freeze-casting and sol-gel coating processes. The three-dimensional interconnected anode is composed of aligned microscale channels separated by SnO2-coated Cu walls and much finer micrometer pores, adding to surface area and providing space for volume expansion of SnO2 coating layer. With this anode, we achieve a high reversible capacity of 750 mAh g−1 at current rate of 0.5 C after 50 cycles and an excellent rate capability of 590 mAh g−1 at 2 C, which is close to the best performance of Sn-based nanoscale material so far. PMID:26725652

  14. Fabrication of porous carbon sphere@SnO2@carbon layer coating composite as high performance anode for sodium-ion batteries

    Science.gov (United States)

    Li, Xin; Sun, Xiaohong; Gao, Zhiwen; Hu, Xudong; Guo, Jingdong; Cai, Shu; Guo, Ruisong; Ji, Huiming; Zheng, Chunming; Hu, Wenbin

    2018-03-01

    SnO2 has triggered lots of research efforts as anode for sodium-ion batteries. However, the volume expansion and poor conductivity lead to an unsatisfactory electrochemical performance for the practical application of SnO2. In this work, a novel carbon-coated SnO2 supported by porous carbon sphere composite is synthesized by hydrothermal process combining with annealing method. The porous carbon sphere@SnO2@carbon layer coating composite anode delivers a reversible capacity of 326 mAh g-1 over 80 cycles at a current density of 50 mA g-1. Even at 1600 mA g-1, a capacity of 82 mAh g-1 is still maintained after 550 cycles. Such excellent performance can be ascribed to the unique structure, which efficiently accommodates volume expansion, enhances conductivity and offers shortened sodium-ion transport pathway. The charge-storage mechanisms can be comprised of diffusion-controlled reaction and pseudocapacitance effect. At high scan rate of 1.0 mV s-1, the capacity contribution of pseudocapacitance effect could reach as high as 78%.

  15. Characterization of crystallinity of Ge{sub 1−x}Sn{sub x} epitaxial layers grown using metal-organic chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Inuzuka, Yuki [Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Ike, Shinichi; Asano, Takanori [Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Japan Society for the Promotion of Science, Chiyoda-ku, Tokyo 102-8472 (Japan); Takeuchi, Wakana [Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Nakatsuka, Osamu, E-mail: nakatuka@alice.xtal.nagoya-u.ac.jp [Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Zaima, Shigeaki [Department of Crystalline Materials Science, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); EcoTopia Science Institute, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan)

    2016-03-01

    The epitaxial growth of a Ge{sub 1−x}Sn{sub x} layer was examined using metal-organic chemical vapor deposition (MOCVD) with two types of Ge precursors; tetra-ethyl-germane (TEGe) and tertiary-butyl-germane (TBGe); and the Sn precursor tri-butyl-vinyl-tin (TBVSn). Though the growth of a Ge{sub 1−x}Sn{sub x} layer on a Ge(001) substrate by MOCVD has been reported, a high-Sn-content Ge{sub 1−x}Sn{sub x} layer and the exploration of MO material combinations for Ge{sub 1−x}Sn{sub x} growth have not been reported. Therefore, the epitaxial growth of a Ge{sub 1−x}Sn{sub x} layer on Ge(001) and Si(001) substrates was examined using these precursors. The Ge{sub 1−x}Sn{sub x} layers were pseudomorphically grown on a Ge(001) substrate, while the Ge{sub 1−x}Sn{sub x} layer with a high degree of strain relaxation was obtained on a Si(001) substrate. Additionally, it was found that the two Ge precursors have different growth temperature ranges, where the TBGe could realize a higher growth rate at a lower growth temperature than the TEGe. The Ge{sub 1−x}Sn{sub x} layers grown using a combination of TBGe and TBVSn exhibited a higher crystalline quality and a smoother surface compared with the Ge{sub 1−x}Sn{sub x} layer prepared by low-temperature molecular beam epitaxy. In this study, a Ge{sub 1−x}Sn{sub x} epitaxial layer with a Sn content as high as 5.1% on a Ge(001) substrate was achieved by MOCVD at 300 °C. - Highlights: • Tertiary-butyl-germane and tri-butyl-vinyl-tin are suitable for Ge{sub 1−x}Sn{sub x} MOCVD growth. • We achieved a Sn content of 5.1% in Ge{sub 1−x}Sn{sub x} epitaxial layer on Ge(001). • The Ge{sub 1−x}Sn{sub x} layers grown on Ge and Si by MOCVD have high crystalline quality.

  16. High Efficiency Dye-sensitized Solar Cells Constructed with Composites of TiO2 and the Hot-bubbling Synthesized Ultra-Small SnO2 Nanocrystals.

    Science.gov (United States)

    Mao, Xiaoli; Zhou, Ru; Zhang, Shouwei; Ding, Liping; Wan, Lei; Qin, Shengxian; Chen, Zhesheng; Xu, Jinzhang; Miao, Shiding

    2016-01-13

    An efficient photo-anode for the dye-sensitized solar cells (DSSCs) should have features of high loading of dye molecules, favorable band alignments and good efficiency in electron transport. Herein, the 3.4 nm-sized SnO2 nanocrystals (NCs) of high crystallinity, synthesized via the hot-bubbling method, were incorporated with the commercial TiO2 (P25) particles to fabricate the photo-anodes. The optimal percentage of the doped SnO2 NCs was found at ~7.5% (SnO2/TiO2, w/w), and the fabricated DSSC delivers a power conversion efficiency up to 6.7%, which is 1.52 times of the P25 based DSSCs. The ultra-small SnO2 NCs offer three benefits, (1) the incorporation of SnO2 NCs enlarges surface areas of the photo-anode films, and higher dye-loading amounts were achieved; (2) the high charge mobility provided by SnO2 was confirmed to accelerate the electron transport, and the photo-electron recombination was suppressed by the highly-crystallized NCs; (3) the conduction band minimum (CBM) of the SnO2 NCs was uplifted due to the quantum size effects, and this was found to alleviate the decrement in the open-circuit voltage. This work highlights great contributions of the SnO2 NCs to the improvement of the photovoltaic performances in the DSSCs.

  17. Guidelines for Microplate Selection in High Content Imaging.

    Science.gov (United States)

    Trask, Oscar J

    2018-01-01

    Since the inception of commercialized automated high content screening (HCS) imaging devices in the mid to late 1990s, the adoption of media vessels typically used to house and contain biological specimens for interrogation has transitioned from microscope slides and petri dishes into multi-well microtiter plates called microplates. The early 96- and 384-well microplates commonly used in other high-throughput screening (HTS) technology applications were often not designed for optical imaging. Since then, modifications and the use of next-generation materials with improved optical clarity have enhanced the quality of captured images, reduced autofocusing failures, and empowered the use of higher power magnification objectives to resolve fine detailed measurements at the subcellular pixel level. The plethora of microplates and their applications requires practitioners of high content imaging (HCI) to be especially diligent in the selection and adoption of the best plates for running longitudinal studies or larger screening campaigns. While the highest priority in experimental design is the selection of the biological model, the choice of microplate can alter the biological response and ultimately may change the experimental outcome. This chapter will provide readers with background, troubleshooting guidelines, and considerations for choosing an appropriate microplate.

  18. Tools to Measure Autophagy Using High Content Imaging and Analysis.

    Science.gov (United States)

    Dolman, Nick J; Samson, Brent A; Chambers, Kevin M; Janes, Michael S; Mandavilli, Bhaskar S

    2018-01-01

    Macroautophagy, hereafter referred to as autophagy, is a predominately pro-survival catabolic process responsible for the degradation of long-lived or aggregated proteins, invading microorganisms and damaged or redundant intracellular organelles. Removal of these entities is achieved through encompassment of the target by the autophagosome and subsequent delivery to the lysosome. The use of fluorescence microscopy is a common method to investigate autophagy through monitoring the spatial and temporal recruitment both of autophagosomal markers and cargo to the autophagosome. In this section, we will discuss the use of high content imaging (HCI) and analysis in the study of autophagy with reference to commonly used markers of autophagosomal formation.

  19. The microstructure and properties of as-cast Sn-Zn-Bi solder alloys

    Directory of Open Access Journals (Sweden)

    Mladenović Srba A.

    2012-01-01

    Full Text Available Research on the lead-free solders has attracted wide attention, mostly as the result of the implementation of the Directive on the Restriction of the Use of Hazardous Substances in Electrical and Electronic Equipment. The Sn-Zn solder alloys have been considered to be one of the most attractive lead-free solders due to its ability to easily replace Sn-Pb eutectic alloy without increasing the soldering temperature. Furthermore, the mechanical properties are comparable or even superior to those of Sn-Pb solder. However, other problems still persist. The solution to overcoming these drawbacks is to add a small amount of alloying elements (Bi, Ag, Cr, Cu, and Sb to the Sn-Zn alloys. Microstructure, tensile strength, and hardness of the selected Sn-Zn-Bi ternary alloys have been investigated in this study. The SEM-EDS was used for the identification of co-existing phases in the samples. The specimens’ microstructures are composed of three phases: Sn-rich solid solution as the matrix, Bi-phase and Zn-rich phase. The Bi precipitates are formed around the Sn-dendrit grains as well as around the Zn-rich phase. The amount of Bi segregation increases with the increase of Bi content. The Sn-Zn-Bi alloys exhibit the high tensile strength and hardness, but the values of these mechanical properties decrease with the increase of Bi content, as well as the reduction of Zn content. The results presented in this paper may offer further knowledge of the effects various parameters have on the properties of lead-free Sn-Zn-Bi solders.

  20. Highly effective Ir(x)Sn(1-x)O2 electrocatalysts for oxygen evolution reaction in the solid polymer electrolyte water electrolyser.

    Science.gov (United States)

    Li, Guangfu; Yu, Hongmei; Wang, Xunying; Sun, Shucheng; Li, Yongkun; Shao, Zhigang; Yi, Baolian

    2013-02-28

    We developed an advanced surfactant-assistant method for the Ir(x)Sn(1-x)O(2) (0 < x ≤ 1) nanoparticle (NP) preparation, and examined the OER performances by a series of half-cell and full-cell tests. In contrast to the commercial Ir black, the collective data confirmed the outstanding activity and stability of the fabricated Ir(x)Sn(1-x)O(2) (x = 1, 0.67 and 0.52) NPs, which could be ascribed to the amorphous structure, good dispersion, high pore volume, solid-solution state and Ir-rich surface for bi-metal oxides, and relatively large size (10-11 nm), while Ir(0.31)Sn(0.69) exhibited poor electro-catalytic activity because of the separated two phases, a SnO(2)-rich phase and an IrO(2)-rich phase. Furthermore, compared with highly active IrO(2), the improved durability, precious-metal Ir utilization efficiency and correspondingly reduced Ir loading were realized by the addition of Sn component. When the Ir(0.52)Sn(0.48)O(2) cell operated at 80 °C using Nafion® 115 membrane and less than 0.8 mg cm(-2) of the noble-metal Ir loading, the cell voltages we achieved were 1.631 V at 1000 mA cm(-2), and 1.821 V at 2000 mA cm(-2). The IR-free voltage at the studied current density was very close to the onset voltage of oxygen evolution. The only 50 μV h(-1) of voltage increased for the 500 h durability test at 500 mA cm(-2). In fact, these results are exceptional compared to the performances for OER in SPEWE cells known so far. This work highlights the potential of using highly active and stable IrO(2)-SnO(2) amorphous NPs to enhance the electrolysis efficiency, reduce the noble-metal Ir loading and thus the cost of hydrogen production from the solid polymer electrolyte water electrolysis.

  1. MgO Nanoparticle Modified Anode for Highly Efficient SnO2‐Based Planar Perovskite Solar Cells

    Science.gov (United States)

    Ma, Junjie; Yang, Guang; Qin, Minchao; Zheng, Xiaolu; Lei, Hongwei; Chen, Cong; Chen, Zhiliang; Guo, Yaxiong; Han, Hongwei; Zhao, Xingzhong

    2017-01-01

    Reducing the energy loss and retarding the carrier recombination at the interface are crucial to improve the performance of the perovskite solar cell (PSCs). However, little is known about the recombination mechanism at the interface of anode and SnO2 electron transfer layer (ETL). In this work, an ultrathin wide bandgap dielectric MgO nanolayer is incorporated between SnO2:F (FTO) electrode and SnO2 ETL of planar PSCs, realizing enhanced electron transporting and hole blocking properties. With the use of this electrode modifier, a power conversion efficiency of 18.23% is demonstrated, an 11% increment compared with that without MgO modifier. These improvements are attributed to the better properties of MgO‐modified FTO/SnO2 as compared to FTO/SnO2, such as smoother surface, less FTO surface defects due to MgO passivation, and suppressed electron–hole recombinations. Also, MgO nanolayer with lower valance band minimum level played a better role in hole blocking. When FTO is replaced with Sn‐doped In2O3 (ITO), a higher power conversion efficiency of 18.82% is demonstrated. As a result, the device with the MgO hole‐blocking layer exhibits a remarkable improvement of all J–V parameters. This work presents a new direction to improve the performance of the PSCs based on SnO2 ETL by transparent conductive electrode surface modification. PMID:28932663

  2. Electrospinning Hetero-Nanofibers In2O3/SnO2 of Homotype Heterojunction with High Gas Sensing Activity

    Science.gov (United States)

    Du, Haiying; Yao, PengJun; Sun, Yanhui; Wang, Jing; Wang, Huisheng; Yu, Naisen

    2017-01-01

    In2O3/SnO2 composite hetero-nanofibers were synthesized by an electrospinning technique for detecting indoor volatile organic gases. The physical and chemical properties of In2O3/SnO2 hetero-nanofibers were characterized and analyzed by X-ray diffraction (XRD), field emission scanning electron microscope (FE-SEM), Energy Dispersive X-Ray Spectroscopy (EDX), specific surface Brunauer–Emmett–Teller (BET) and X-ray photoelectron spectroscopy (XPS). Gas sensing properties of In2O3/SnO2 composite hetero-nanofibers were measured with six kinds of indoor volatile organic gases in concentration range of 0.5~50 ppm at the operating temperature of 275 °C. The In2O3/SnO2 composite hetero-nanofibers sensor exhibited good formaldehyde sensing properties, which would be attributed to the formation of n-n homotype heterojunction in the In2O3/SnO2 composite hetero-nanofibers. Finally, the sensing mechanism of the In2O3/SnO2 composite hetero-nanofibers was analyzed based on the energy-band principle. PMID:28792433

  3. High thermal behavior of a new glass ceramic developed from silica xerogel/SnO{sub 2} composite

    Energy Technology Data Exchange (ETDEWEB)

    Aripin, H., E-mail: aripin@unsil.ac.id [Faculty of Learning Teacher and Education Science, Siliwangi University, Jl. Siliwangi 24 Tasikmalaya 46115, West Java (Indonesia); Mitsudo, Seitaro, E-mail: mitsudo@fir.u-fukui.ac.jp [Research Center for Development of Far Infrared Region (FIR Center), University of Fukui, Bunkyo 3-9-1 Fukui 910-8507 (Japan); Sudiana, I. Nyoman, E-mail: sudiana75@yahoo.com [Departement Physics, Faculty of Mathematics and Natural Science, Haluoleo University, Kampus Bumi Tridharma Anduonohu, Kendari 93232 (Indonesia); Priatna, Edvin, E-mail: ujack05@yahoo.com [Department of Electrical Engineering, Faculty of Engineering, Siliwangi University, Tasikmalaya (Indonesia); Sabchevski, Svilen, E-mail: sabch@ie.bas.bg [Lab. Plasma Physics and Engineering, Institute of Electronics of the Bulgarian Academy of Sciences, 72 Tzarigradsko Shose Blvd., Sofia 1784 (Bulgaria)

    2016-02-08

    In this investigation, a new glass ceramics have been produced by mixing SnO{sub 2} and amorphous silica xerogel (ASX) extracted from sago waste ash. The composition has been prepared by adding 10 mol% of SnO{sub 2} into SX. The samples have been dry pressed and sintered in the temperature range between 800 °C and 1500 °C. The effects of temperature on the crystallization of silica xerogel after adding SnO{sub 2} and their relationship to bulk density have been studied. The crystallization process of the silica xerogel/SnO{sub 2} composite has been examined by an X-ray diffraction (XRD) and the bulk density has been characterized on the basis of the experimental data obtained using Archimedes′ principle. It has been found that an addition of SnO{sub 2} confers an appreciable effect on the grain and from the interpretation of XRD patterns allow one to explain the increase in the density by an increased crystallite size of SnO{sub 2} in the composite.

  4. High thermal behavior of a new glass ceramic developed from silica xerogel/SnO2 composite

    Science.gov (United States)

    Aripin, H.; Mitsudo, Seitaro; Sudiana, I. Nyoman; Priatna, Edvin; Sabchevski, Svilen

    2016-02-01

    In this investigation, a new glass ceramics have been produced by mixing SnO2 and amorphous silica xerogel (ASX) extracted from sago waste ash. The composition has been prepared by adding 10 mol% of SnO2 into SX. The samples have been dry pressed and sintered in the temperature range between 800 °C and 1500 °C. The effects of temperature on the crystallization of silica xerogel after adding SnO2 and their relationship to bulk density have been studied. The crystallization process of the silica xerogel/SnO2 composite has been examined by an X-ray diffraction (XRD) and the bulk density has been characterized on the basis of the experimental data obtained using Archimedes' principle. It has been found that an addition of SnO2 confers an appreciable effect on the grain and from the interpretation of XRD patterns allow one to explain the increase in the density by an increased crystallite size of SnO2 in the composite.

  5. High resolution DNA content measurements of mammalian sperm

    Energy Technology Data Exchange (ETDEWEB)

    Pinkel, D.; Lake, S.; Gledhill, B.L.; Van Dilla, M.A.; Stephenson, D.; Watchmaker, G.

    1982-01-01

    The high condensation and flat shape of the mammalian sperm nucleus present unique difficulties to flow cytometric measurement of DNA content. Chromatin compactness makes quantitative fluorescent staining for DNA difficult and causes a high index of refraction. The refractive index makes optical measurements sensitive to sperm head orientation. We demonstrate that the optical problems can be overcome using the commercial ICP22 epiillumination flow cytometer (Ortho Instruments, Westwood, MA) or a specially built cell orientating flow cytometer (OFCM). The design and operation of the OFCM are described. Measurements of the angular dependence of fluorescence from acriflavine stained rabbit sperm show that it is capable of orienting flat sperm with a tolerance of +-7/sup 0/. Differences in the angular dependence for the similarly shaped bull and rabbit sperm allow discrimination of these cells. We show that DNA staining with 4-6 diamidino-2-phenylindole (DAPI) or an ethidium bromide mithramycin combination allows resolution of the X and Y populations in mouse sperm. They have also been successful with sperm from the bull, ram, rabbit, and boar. Reliable results with human sperm are not obtained. The accuracy of the staining and measurement techniques are verified by the correct determination of the relative content of these two populations in sperm from normal mice and those with the Cattanach (7 to X) translocation. Among the potential uses of these techniques are measurement of DNA content errors induced in sperm due to mutagen exposure, and assessment of the fractions of X and Y sperm in semen that may have one population artifically enriched.

  6. Sensors based on mesoporous SnO{sub 2}-CuWO{sub 4} with high selective sensitivity to H{sub 2}S at low operating temperature

    Energy Technology Data Exchange (ETDEWEB)

    Stanoiu, Adelina; Simion, Cristian E. [National Institute of Materials Physics, Atomistilor 405A, P.O. Box MG-7, 077125 Bucharest, Măgurele (Romania); Calderon-Moreno, Jose Maria; Osiceanu, Petre [“Ilie Murgulescu” Institute of Physical Chemistry, Romanian Academy, Surface Chemistry and Catalysis Laboratory, Spl. Independentei 202, 060021, Bucharest (Romania); Florea, Mihaela [University of Bucharest, Faculty of Chemistry, Department of Organic Chemistry, Biochemistry and Catalysis, B-dul Regina Elisabeta 4-12, Bucharest (Romania); National Institute of Materials Physics, Atomistilor 405A, P.O. Box MG-7, 077125 Bucharest, Măgurele (Romania); Teodorescu, Valentin S. [National Institute of Materials Physics, Atomistilor 405A, P.O. Box MG-7, 077125 Bucharest, Măgurele (Romania); Somacescu, Simona, E-mail: somacescu.simona@gmail.com [“Ilie Murgulescu” Institute of Physical Chemistry, Romanian Academy, Surface Chemistry and Catalysis Laboratory, Spl. Independentei 202, 060021, Bucharest (Romania)

    2017-06-05

    Highlights: • Mesoporous SnO{sub 2}-CuWO{sub 4} obtained by an inexpensive synthesis route. • Powders characterization performed by a variety of complementary techniques. • SnO{sub 2}-CuWO{sub 4} layers with high selective sensitivity to H{sub 2}S. • Low operating temperature and relative humidity influences. - Abstract: Development of new sensitive materials by different synthesis routes in order to emphasize the sensing properties for hazardous H{sub 2}S detection is one of a nowadays challenge in the field of gas sensors. In this study we obtained mesoporous SnO{sub 2}-CuWO{sub 4} with selective sensitivity to H{sub 2}S by an inexpensive synthesis route with low environmental pollution level, using tripropylamine (TPA) as template and polyvinylpyrrolidone (PVP) as dispersant/stabilizer. In order to bring insights about the intrinsic properties, the powders were characterized by means of a variety of complementary techniques such as: X-Ray Diffraction, XRD; Transmission Electron Microscopy, TEM; High Resolution TEM, HRTEM; Raman Spectroscopy, RS; Porosity Analysis by N{sub 2} adsorption/desorption, BET; Scanning Electron Microscopy, SEM and X-ray Photoelectron Spectroscopy, XPS. The sensors were fabricated by powders deposition via screen-printing technique onto planar commercial Al{sub 2}O{sub 3} substrates. The sensor signals towards H{sub 2}S exposure at low operating temperature (100 °C) reaches values from 10{sup 5} (for SnWCu600) to 10{sup 6} (for SnWCu800) over the full range of concentrations (5–30 ppm). The recovery processes were induced by a short temperature trigger of 500 °C. The selective sensitivity was underlined with respect to the H{sub 2}S, relative to other potential pollutants and relative humidity (10–70% RH).

  7. Live-Cell High Content Screening in Drug Development.

    Science.gov (United States)

    Esner, Milan; Meyenhofer, Felix; Bickle, Marc

    2018-01-01

    In the past decade, automated microscopy has become an important tool for the drug discovery and development process. The establishment of imaging modalities as screening tools depended on technological breakthroughs in the domain of automated microscopy and automated image analysis. These types of assays are often referred to as high content screening or high content analysis (HCS/HCA). The driving force to adopt imaging for drug development is the quantity and quality of cellular information that can be collected and the enhanced physiological relevance of cellular screening compared to biochemical screening. Most imaging in drug development is performed on fixed cells as this allows uncoupling the preparation of the cells from the acquisition of the images. Live-cell imaging is technically challenging, but is very useful for many aspects of the drug development pipeline such as kinetic studies of compound mode of action or to analyze the motion of cellular components. Most vendors of HCS microscopy systems offer the option of environmental chambers and onboard pipetting on their platforms. This reflects the wish and desire of many customers to have the ability to perform live-cell assays on their HCS automated microscopes. This book chapter summarizes the challenges and advantages of live-cell imaging in drug discovery. Examples of applications are presented and the motivation to perform these assays in kinetic mode is discussed.

  8. SCC with high volume of fly ash content

    Directory of Open Access Journals (Sweden)

    Bakhrakh Anton

    2017-01-01

    Full Text Available Self-compacting concrete is a very perspective building material. It provides great benefits during the construction of heavily reinforced buildings. SCC has outstanding properties such as high flowability, dense structure and high strength due to specific quality of aggregates, fillers, their proportion in mix, use of polycarboxylate-based superplasticizers. Main disadvantages of SCC are high price and the difficulty of obtaining a proper mix. Use of fillers, such as fly ash type F, is a way to make SCC cheaper by replacing part of cement. Fly ash also provides some technological and operating advantages. In this paper the influence of high volume (60% from cement fly ash type F on the properties of concrete mixture and hardened concrete is investigated. The result of the work shows the possibility of reduction the cost of SCC using ordinary fillers and high amount of fly ash. The investigated SCC has low speed of hardening (7-day compressive strength at the range of 41.8 MPa and high volume of entrained air content (3.5%.

  9. A SnOx-brookite TiO2 bilayer electron collector for hysteresis-less high efficiency plastic perovskite solar cells fabricated at low process temperature.

    Science.gov (United States)

    Kogo, Atsushi; Ikegami, Masashi; Miyasaka, Tsutomu

    2016-06-21

    Thin plastic film-based CH3NH3PbI3-xClx perovskite solar cells were fabricated at low process temperature using a bilayer comprising an amorphous SnOx and mesoporous brookite TiO2 as electron collectors. Void-less high quality heterojunction structures achieve hysteresis-less photovoltaic performance with a power conversion efficiency as high as 13.4% and mechanical stability against cyclic bending.

  10. Synthetic studies on taxol: highly stereoselective construction of the taxol C-ring via SN2' reduction of an allylic phosphonium salt.

    Science.gov (United States)

    Utsugi, Masayuki; Miyano, Masayuki; Nakada, Masahisa

    2006-07-06

    [reaction: see text] The highly stereoselective construction of the C3 stereogenic center of the taxol C-ring is described. The trans isomer at the C3-C8 position of the taxol C-ring, which is required for the total synthesis, as well as its diastereomeric cis isomer were successfully synthesized with highly diastereoselective S(N)2' reduction of the allylic phosphonium salts.

  11. SnO2-doped α-Fe2O3 patulous microtubes for high performance formaldehyde sensing

    Science.gov (United States)

    Ying, He; Deyin, Wang; Fan, Ge; Li, Liu

    2015-08-01

    SnO2-doped α-Fe2O3 patulous microtubes (SFPNs) are synthesized by an electrospinning method. The as-synthesized materials are characterized by scanning electron microscope, X-ray powder diffraction and energy dispersive spectroscopy. The gas sensing results show SFPNs possess an excellent sensing property to formaldehyde. The response value of SFPNs gas sensor to 50 ppm formaldehyde is 25.4 at 220 °C. The lowest detecting limit of 1 ppm formaldehyde is 3.2. Response and recovery characteristic curves of SFPNs gas sensors to 1, 2, 3, 5, 5, 3, 2 and 1 ppm formaldehyde are also tested. The results show a good reversibility and repeatability of SFPNs gas sensors. The sensor exhibits a high selectivity in the presence of acetone, ethanol, toluene, ammonia, hydrogen, carbon monoxide and butane. Moreover, the sensor has a good long-time stability. Project supported by the Jilin Provincial Science and Technology Department (No. 20140204027GX) and the Competition Funded Projects of “Challenge Cup” College Students' Extracurricular Academic Science and Technology Works (No. 2014LG064).

  12. A content analysis of tweets about high-potency marijuana.

    Science.gov (United States)

    Cavazos-Rehg, Patricia A; Sowles, Shaina J; Krauss, Melissa J; Agbonavbare, Vivian; Grucza, Richard; Bierut, Laura

    2016-09-01

    "Dabbing" involves heating extremely concentrated forms of marijuana to high temperatures and inhaling the resulting vapor. We studied themes describing the consequences of using highly concentrated marijuana by examining the dabbing-related content on Twitter. Tweets containing dabbing-related keywords were collected from 1/1-1/31/2015 (n=206,854). A random sample of 5000 tweets was coded for content according to pre-determined categories about dabbing-related behaviors and effects experienced using a crowdsourcing service. An examination of tweets from the full sample about respiratory effects and passing out was then conducted by selecting tweets with relevant keywords. Among the 5000 randomly sampled tweets, 3540 (71%) were related to dabbing marijuana concentrates. The most common themes included mentioning current use of concentrates (n=849; 24%), the intense high and/or extreme effects from dabbing (n=763; 22%) and excessive/heavy dabbing (n=517; 15%). Extreme effects included both physiological (n=124/333; 37%) and psychological effects (n=55/333; 17%). The most common physiologic effects, passing out (n=46/333; 14%) and respiratory effects (n=30/333; 9%), were then further studied in the full sample of tweets. Coughing was the most common respiratory effect mentioned (n=807/1179; 68%), and tweeters commonly expressed dabbing with intentions to pass out (416/915; 45%). This study adds to the limited understanding of marijuana concentrates and highlights self-reported physical and psychological effects from this type of marijuana use. Future research should further examine these effects and the potential severity of health consequences associated with concentrates. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  13. Effect of the undoped BaSnO3 space layer on the high mobility LaInO3/Ba1-xLaxSnO3 polar interface

    Science.gov (United States)

    Shin, Juyeon; Park, Chulkwon; Kim, Young Mo; Kim, Youjung; Char, Kookrin

    We have recently reported on the sheet conductance enhancement at the interface between two band insulators: LaInO3 (LIO) and BaSnO3 (BSO). The advantages of the two-dimensional electron gas-like (2DEG) state at the LIO/Ba1-xLaxSnO3 (BLSO) polar interface are its stability, the controllability of the local carrier concentration, and the high electron mobility of BLSO. The origin of enhanced conductance at the interface is still under investigation, but the doping level of BSO is a critical parameter for the polar charge contribution. We have investigated a new structure using an undoped BSO space layer at the LIO/BLSO interface. On one hand, this new structure will improve the mobility of the LIO/BLSO structure by reducing La impurity scattering. On the other hand, through this new structure we can answer the issues related with La diffusion at the LIO/BLSO polar interface and trace the origin of the 2DEG-like charge. This new modified structure of the LIO/BSO polar interface looks promising for higher electron mobility devices.

  14. Production of JET fuel containing molecules of high hydrogen content

    Directory of Open Access Journals (Sweden)

    Tomasek Sz.

    2017-12-01

    Full Text Available The harmful effects of aviation can only be reduced by using alternative fuels with excellent burning properties and a high hydrogen content in the constituent molecules. Due to increasing plastic consumption the amount of the plastic waste is also higher. Despite the fact that landfill plastic waste has been steadily reduced, the present scenario is not satisfactory. Therefore, the aim of this study is to produce JET fuel containing an alternative component made from straight-run kerosene and the waste polyethylene cracking fraction. We carried out our experiments on a commercial NiMo/Al2O3/P catalyst at the following process parameters: T=200-300°C, P=40 bar, LHSV=1.0-3.0 h-1, hydrogen/hydrocarbon ratio= 400 Nm3/m3. We investigated the effects of the feedstocks and the process parameters on the product yields, the hydrodesulfurization and hydrodearomatization efficiencies, and the main product properties. The liquid product yields varied between 99.7-99.8%. As a result of the hydrogenation the sulfur (1-1780 mg/kg and the aromatic contents (9.0-20.5% of the obtained products and the values of their smoke points (26.0-34.7 mm fulfilled the requirements of JET fuel standard. Additionally, the concentration of paraffins increased in the products and the burning properties were also improved. The freezing points of the products were higher than -47°C, therefore product blending is needed.

  15. High GC content causes orphan proteins to be intrinsically disordered.

    Directory of Open Access Journals (Sweden)

    Walter Basile

    2017-03-01

    Full Text Available De novo creation of protein coding genes involves the formation of short ORFs from noncoding regions; some of these ORFs might then become fixed in the population. These orphan proteins need to, at the bare minimum, not cause serious harm to the organism, meaning that they should for instance not aggregate. Therefore, although the creation of short ORFs could be truly random, the fixation should be subjected to some selective pressure. The selective forces acting on orphan proteins have been elusive, and contradictory results have been reported. In Drosophila young proteins are more disordered than ancient ones, while the opposite trend is present in yeast. To the best of our knowledge no valid explanation for this difference has been proposed. To solve this riddle we studied structural properties and age of proteins in 187 eukaryotic organisms. We find that, with the exception of length, there are only small differences in the properties between proteins of different ages. However, when we take the GC content into account we noted that it could explain the opposite trends observed for orphans in yeast (low GC and Drosophila (high GC. GC content is correlated with codons coding for disorder promoting amino acids. This leads us to propose that intrinsic disorder is not a strong determining factor for fixation of orphan proteins. Instead these proteins largely resemble random proteins given a particular GC level. During evolution the properties of a protein change faster than the GC level causing the relationship between disorder and GC to gradually weaken.

  16. Nanocrystalline BaSnO3 as an Alternative Gas Sensor Material: Surface Reactivity and High Sensitivity to SO2

    Directory of Open Access Journals (Sweden)

    Artem Marikutsa

    2015-09-01

    Full Text Available Nanocrystalline perovskite-type BaSnO3 was obtained via microwave-assisted hydrothermal route followed by annealing at variable temperature. The samples composition and microstructure were characterized. Particle size of 18–23 nm was unaffected by heat treatment at 275–700 °C. Materials DC-conduction was measured at variable temperature and oxygen concentration. Barium stannate exhibited n-type semiconductor behavior at 150–450 °C with activation energy being dependent on the materials annealing temperature. Predominant ionosorbed oxygen species types were estimated. They were shown to change from molecular to atomic species on increasing temperature. Comparative test of sensor response to various inorganic target gases was performed using nanocrystalline SnO2-based sensors as reference ones. Despite one order of magnitude smaller surface area, BaSnO3 displayed higher sensitivity to SO2 in comparison with SnO2. DRIFT spectroscopy revealed distinct interaction routes of the oxides surfaces with SO2. Barium-promoted sulfate formation favoring target molecules oxidation was found responsible for the increased BaSnO3 sensitivity to ppm-range concentrations of SO2 in air.

  17. In-situ sulfuration synthesis of sandwiched spherical tin sulfide/sulfur-doped graphene composite with ultra-low sulfur content

    Science.gov (United States)

    Zhao, Bing; Yang, Yaqing; Wang, Zhixuan; Huang, Shoushuang; Wang, Yanyan; Wang, Shanshan; Chen, Zhiwen; Jiang, Yong

    2018-02-01

    SnS is widely studied as anode materials since of its superior structural stability and physicochemical property comparing with other Sn-based composites. Nevertheless, the inconvenience of phase morphology control and excessive consumption of sulfur sources during synthesis hinder the scalable application of SnS nanocomposites. Herein, we report a facile in-situ sulfuration strategy to synthesize sandwiched spherical SnS/sulfur-doped graphene (SnS/S-SG) composite. An ultra-low sulfur content with approximately stoichiometric ratio of Sn:S can effectively promote the sulfuration reaction of SnO2 to SnS and simultaneous sulfur-doping of graphene. The as-prepared SnS/S-SG composite shows a three-dimensional interconnected spherical structure as a whole, in which SnS nanoparticles are sandwiched between the multilayers of graphene sheets forming a hollow sphere. The sandwiched sphere structure and high S doping amount can improve the binding force between SnS and graphene, as well as the structural stability and electrical conductivity of the composite. Thus, a high reversibility of conversion reaction, promising specific capacity (772 mAh g-1 after 100 cycles at 0.1 C) and excellent rate performance (705 and 411 mAh g-1 at 1 C and 10 C, respectively) are exhibited in the SnS/S-SG electrode, which are much higher than that of the SnS/spherical graphene synthesized by traditional post-sulfuration method.

  18. Oxy-combustion of high water content fuels

    Science.gov (United States)

    Yi, Fei

    As the issues of global warming and the energy crisis arouse extensive concern, more and more research is focused on maximizing energy efficiency and capturing CO2 in power generation. To achieve this, in this research, we propose an unconventional concept of combustion - direct combustion of high water content fuels. Due to the high water content in the fuels, they may not burn under air-fired conditions. Therefore, oxy-combustion is applied. Three applications of this concept in power generation are proposed - direct steam generation for the turbine cycle, staged oxy-combustion with zero flue gas recycle, and oxy-combustion in a low speed diesel-type engine. The proposed processes could provide alternative approaches to directly utilize fuels which intrinsically have high water content. A large amount of energy to remove the water, when the fuels are utilized in a conventional approach, is saved. The properties and difficulty in dewatering high water content fuels (e.g. bioethanol, microalgae and fine coal) are summarized. These fuels include both renewable and fossil fuels. In addition, the technique can also allow for low-cost carbon capture due to oxy-combustion. When renewable fuel is utilized, the whole process can be carbon negative. To validate and evaluate this concept, the research focused on the investigation of the flame stability and characteristics for high water content fuels. My study has demonstrated the feasibility of burning fuels that have been heavily diluted with water in a swirl-stabilized burner. Ethanol and 1-propanol were first tested as the fuels and the flame stability maps were obtained. Flame stability, as characterized by the blow-off limit -- the lowest O2 concentration when a flame could exist under a given oxidizer flow rate, was determined as a function of total oxidizer flow rate, fuel concentration and nozzle type. Furthermore, both the gas temperature contour and the overall ethanol concentration in the droplets along the

  19. Photogenerated carriers transfer in dye-graphene-SnO2 composites for highly efficient visible-light photocatalysis.

    Science.gov (United States)

    Zhuang, Shendong; Xu, Xiaoyong; Feng, Bing; Hu, Jingguo; Pang, Yaru; Zhou, Gang; Tong, Ling; Zhou, Yuxue

    2014-01-08

    The visible-light-driven photocatalytic activities of graphene-semiconductor catalysts have recently been demonstrated, however, the transfer pathway of photogenerated carriers especially where the role of graphene still remains controversial. Here we report graphene-SnO2 aerosol nanocomposites that exhibit more superior dye adsorption capacity and photocatalytic efficiency compared with pure SnO2 quantum dots, P25 TiO2, and pure graphene aerosol under the visible light. This study examines the origin of the visible-light-driven photocatalysis, which for the first time links to the synergistic effect of the cophotosensitization of the dye and graphene to SnO2. We hope this concept and corresponding mechanism of cophotosensitization could provide an original understanding for the photocatalytic reaction process at the level of carrier transfer pathway as well as a brand new approach to design novel and versatile graphene-based composites for solar energy conversion.

  20. Effects of High-Temperature Treatment on the Reaction Between Sn-3%Ag-0.5%Cu Solder and Sputtered Ni-V Film on Ferrite Substrate

    Science.gov (United States)

    Shen, Xiaohu; Jin, Hao; Dong, Shurong; Wong, Hei; Zhou, Jian; Guo, Zhaodi; Wang, Demiao

    2012-11-01

    We have demonstrated a novel sputtering method for lead-free thin metal films on ferrite substrates for surface-mount inductor applications. In a surface-mounting process, the cladding of enameled wire needs to be burnt off at high temperature, which requires the devices to withstand a high-temperature reliability test at 420°C for 10 s. There are no reports that a sputtered film of thickness less than 6 μm can withstand this test. In this work, we used Ag/Ni-7 wt.%V double metal layers for the metallization. The dissolution of Ni-7 wt.%V in Sn-3%Ag-0.5%Cu lead-free solder at various temperatures was studied in detail. Scanning electron microscopy with energy-dispersive x-ray spectroscopy was used to investigate the interfacial reaction between the sputtered films and the solder. The intermetallic compounds are mainly (Cu,Ni)6Sn5 at 250°C; however, (Ni,Cu)3Sn4 becomes the predominant composition at 420°C. In addition, although outdiffusion of V atoms from the Ni-V layer was observed, its effect on the intermetallic compound (IMC) was insignificant. We further confirmed that the proposed metallization is able to pass the aforementioned high-temperature reliability test.

  1. One-step electrochemical growth of a three-dimensional Sn-Ni@PEO nanotube array as a high performance lithium-ion battery anode.

    Science.gov (United States)

    Fan, Xin; Dou, Peng; Jiang, Anni; Ma, Daqian; Xu, Xinhua

    2014-12-24

    Various well-designed nanostructures have been proposed to optimize the electrode systems of lithium-ion batteries for problems like Li(+) diffusion, electron transport, and large volume changes so as to fulfill effective capacity utilization and increase electrode stability. Here, a novel three-dimensional (3D) hybrid Sn-Ni@PEO nanotube array is synthesized as a high performance anode for a lithium-ion battery through a simple one-step electrodeposition for the first time. Superior to the traditional stepwise synthesis processes of heterostructured nanomaterials, this one-step method is more suitable for practical applications. The electrode morphology is well preserved after repeated Li(+) insertion and extraction, indicating that the positive synergistic effect of the alloy nanotube array and 3D ultrathin PEO coating could authentically optimize the current volume-expansion electrode system. The electrochemistry results further confirm that the superiority of the Sn-Ni@PEO nanotube array electrode could largely boost durable high reversible capacities and superior rate performances compared to a Sn-Ni nanowire array. This proposed ternary hybrid structure is proven to be an ideal candidate for the development of high performance anodes for lithium-ion batteries.

  2. High performance, self-powered UV-photodetector based on ultrathin, transparent, SnO{sub 2}–TiO{sub 2} core–shell electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Caitian, E-mail: caitiangao10@163.com [School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, Gansu (China); Li, Xiaodong [New Materials R and D Center, Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, Sichuan (China); Zhu, Xupeng [Key Laboratory for Micro–Nano Optoelectronic Devices of Ministry of Education, State Key Laboratory for Chemo/Biosensing and Chemometrics, Hunan University, Changsha 410000, Hunan (China); Chen, Lulu; Wang, Youqing; Teng, Feng; Zhang, Zhenxing [School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, Gansu (China); Duan, Huigao [New Materials R and D Center, Institute of Chemical Materials, China Academy of Engineering Physics, Mianyang 621900, Sichuan (China); Xie, Erqing, E-mail: xieeq@lzu.edu.cn [School of Physical Science and Technology, Lanzhou University, Lanzhou 730000, Gansu (China)

    2014-12-15

    Graphical abstract: - Highlight: • An ultrathin, transparent SnO{sub 2}–TiO{sub 2} core–shell structure was developed. • This structure was used in self-powered UVPDs. • UVPDs deliver large responsivity (0.6 A/W) and high on/off ratio (440,563%). - Abstract: We have fabricated SnO{sub 2} nanosheet film directly on conductive glass and further designed branched TiO{sub 2} nanoneedles on SnO{sub 2} nanosheets, forming a heterojunction core–shell structure. The resultant ultrathin and high transparency film can serve as the fast electron transport network for a new developed photoelectrochemical cell based UV photodetector. The UV photodetector shows great responsivity (0.6 A/W); high on/off ratio of the J{sub sc} signal (440,563%); very fast response (0.02 s for rise time and 0.004 s for decay time) under 40 mW cm{sup −2} UV irradiation. Compared with the previous reported devices, our detector emerges comparable and even better self-powered UV light detecting properties just using less material.

  3. The Complete Automation of Cell Culture: Improvements for High-Throughput and High-Content Screening

    NARCIS (Netherlands)

    Jain, S.; Sondervan, D.; Rizzu, P.; Bochdanovits, Z.; Caminada, D.; Heutink, P.

    2011-01-01

    Genomic approaches provide enormous amounts of raw data with regard to genetic variation, the diversity of RNA species, and protein complement. high-throughput (HT) and high-content (HC) cellular screens are ideally suited to contextualize the information gathered from other "omic" approaches into

  4. Rapid formation of Ni3Sn4 joints for die attachment of SiC-based high temperature power devices using ultrasound-induced transient liquid phase bonding process.

    Science.gov (United States)

    Li, Z L; Dong, H J; Song, X G; Zhao, H Y; Feng, J C; Liu, J H; Tian, H; Wang, S J

    2017-05-01

    High melting point Ni3Sn4 joints for the die attachment of SiC-based high temperature power devices was successfully achieved using an ultrasound-induced transient liquid phase (TLP) bonding process within a remarkably short bonding time of 8s. The formed intermetallic joints, which are completely composed of the refined equiaxial Ni3Sn4 grains with the average diameter of 2μm, perform the average shear strength of 26.7MPa. The sonochemical effects of ultrasonic waves dominate the mechanism and kinetics of the rapid formation of Ni3Sn4 joints. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Fully Biodegradable Biocomposites with High Chicken Feather Content

    Directory of Open Access Journals (Sweden)

    Ibon Aranberri

    2017-11-01

    Full Text Available The aim of this work was to develop new biodegradable polymeric materials with high loadings of chicken feather (CF. In this study, the effect of CF concentration and the type of biodegradable matrix on the physical, mechanical and thermal properties of the biocomposites was investigated. The selected biopolymers were polylactic acid (PLA, polybutyrate adipate terephthalate (PBAT and a PLA/thermoplastic copolyester blend. The studied biocomposites were manufactured with a torque rheometer having a CF content of 50 and 60 wt %. Due to the low tensile strength of CFs, the resulting materials were penalized in terms of mechanical properties. However, high-loading CF biocomposites resulted in lightweight and thermal-insulating materials when compared with neat bioplastics. Additionally, the adhesion between CFs and the PLA matrix was also investigated and a significant improvement of the wettability of the feathers was obtained with the alkali treatment of the CFs and the addition of a plasticizer like polyethylene glycol (PEG. Considering all the properties, these 100% fully biodegradable biocomposites could be adequate for panel components, flooring or building materials as an alternative to wood–plastic composites, contributing to the valorisation of chicken feather waste as a renewable material.

  6. Breeding elite japonica-type soft rice with high protein content ...

    African Journals Online (AJOL)

    rice grains. In an attempt to analyze whether the anti-Waxy gene could increase protein content while reducing amylose content in the rice grains, and develop good soft rice varieties with high protein content, an anti-Waxy gene was introduced into the high-yield japonica rice strain, Shangshida No. 2. The amylose contents ...

  7. High-Pressure Synthesis and Local Structure of Corundum-Type In[subscript 2−2x]Zn[subscript x]Sn[subscript x]O[subscript 3] (x ≤ 0.7)

    Energy Technology Data Exchange (ETDEWEB)

    Hoel, Cathleen A.; Amores, Jos Manuel Gallardo; Morn, Emilio; Alario-Franco, Miguel Angel; Gaillard, Jean-Franois; Poeppelmeier, Kenneth R. (UCDM); (NWU)

    2010-12-06

    The corundum-type In{sub 2-2x}Zn{sub x}Sn{sub x}O{sub 3} solid solution (cor-ZITO, x {le} 0.7) was synthesized at 1000 C under a high pressure of 70 kbar. cor-ZITO is a high-pressure polymorph of the transparent conducting oxide bixbyite-In{sub 2-2x}Zn{sub x}Sn{sub x}O{sub 3} (x {le} 0.4). Analysis of the extended X-ray absorption fine structure suggests that significant face-sharing of Zn and Sn octahedra occurs, as expected for the corundum structure type. In contrast to the ideal corundum structure, however, Zn and Sn are displaced and form oxygen bonds with lengths that are similar to those observed in high-pressure ZnSnO{sub 3}. Powder X-ray diffraction patterns of cor-ZITO showed the expected unit cell contraction with increased cosubstitution, but no evidence for ilmenite-type ordering of the substituted Zn and Sn. A qualitative second harmonic generation measurement, for the solid solution x = 0.6 and using 1064 nm radiation, showed that Zn and Sn adopt a polar LiNbO{sub 3}-type arrangement.

  8. High-Pressure Synthesis and Local Structure of Corundum-Type In[subscript 2;#8722;2x]Zn[subscript x]Sn[subscript x]O[subscript 3] (x ;#8804; 0.7)

    Energy Technology Data Exchange (ETDEWEB)

    Hoel, Cathleen A.; Amores, Jose Manuel Gallardo; Moran, Emilio; Alario-Franco, Miguel Angel; Gaillard, Jean-Francois; Poeppelmeier, Kenneth R. (UCDM); (NWU)

    2011-08-09

    The corundum-type In{sub 2-2x}Zn{sub x}Sn{sub x}O{sub 3} solid solution (cor-ZITO, x {<=} 0.7) was synthesized at 1000 C under a high pressure of 70 kbar. cor-ZITO is a high-pressure polymorph of the transparent conducting oxide bixbyite-In{sub 2-2x}Zn{sub x}Sn{sub x}O{sub 3} (x {<=} 0.4). Analysis of the extended X-ray absorption fine structure suggests that significant face-sharing of Zn and Sn octahedra occurs, as expected for the corundum structure type. In contrast to the ideal corundum structure, however, Zn and Sn are displaced and form oxygen bonds with lengths that are similar to those observed in high-pressure ZnSnO{sub 3}. Powder X-ray diffraction patterns of cor-ZITO showed the expected unit cell contraction with increased cosubstitution, but no evidence for ilmenite-type ordering of the substituted Zn and Sn. A qualitative second harmonic generation measurement, for the solid solution x = 0.6 and using 1064 nm radiation, showed that Zn and Sn adopt a polar LiNbO{sub 3}-type arrangement.

  9. Reduction of secondary phases in Cu{sub 2}SnSe{sub 3} absorbers for solar cell application

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Zeguo, E-mail: tangzg@fc.ritsumei.ac.jp [Ritsumeikan Global Innovation Research Organization, Ritsumeikan University, Shiga (Japan); Nukui, Yuki; Kosaka, Kiichi; Ashida, Naoki; Uegaki, Hikaru; Minemoto, Takashi [College of Science and Engineering, Ritsumeikan University, Shiga (Japan)

    2014-09-01

    Highlights: • Cu{sub 2}SnSe{sub 3} thin films for absorber of solar cell are fabricated by selenization of Cu–Sn precursors. • Secondary phase of Cu{sub 2–x}Se can be suppressed via using Se and SnSe mixture powders as Se source. • Selective etching of secondary phase of Cu{sub 2–x}Se is realized by potassium cyanide solution. • Cu{sub 2–x}Se rather than SnSe makes major contribution to the high carrier concentration of CTSe films. - Abstract: The creation of secondary phases, such as Cu{sub 2−x}Se and SnSe, and their influence on electrical properties of Cu{sub 2}SnSe{sub 3} (CTSe) thin films fabricated by selenization of Cu–Sn metal precursors are investigated. The Cu{sub 2−x}Se content in CTSe films is estimated via deconvolution of grazing incidence X-ray diffraction (GIXRD) patterns, and the results suggest that the Cu{sub 2−x}Se content increases with the increasing Cu/Sn ratio in metal precursors. We also found that using Se and SnSe mixture powders as Se source is an effective approach to suppress the creation of Cu{sub 2−x}Se secondary phase. Meanwhile, selective etching of Cu{sub 2−x}Se is realized by potassium cyanide (KCN) solution. Hall measurement results reveal that the secondary phase of Cu{sub 2−x}Se rather than SnSe makes major contribution to the high carrier concentration (larger than 10{sup 18} cm{sup −3}) of CTSe films. The approach to further decrease the carrier concentration in CTSe films is discussed.

  10. Measuring quality of omnidirectional high dynamic range content

    Science.gov (United States)

    Perrin, Anne-Flore; Bist, Cambodge; Cozot, Rémi; Ebrahimi, Touradj

    2017-09-01

    Although HDR content processing, coding and quality assessment have been largely addressed in the last few years, little to no work has been concentrating on how to assess quality in HDR for 360° or omnidirectional content. This paper is an attempt to answer to various questions in this direction. As a minimum, a new data set for 360° HDR content is proposed and a new methodology is designed to assess subjective quality of HDR 360° content when it is displayed on SDR HMD after applying various tone mapping operators. The results are then analyzed and conclusions are drawn.

  11. A dislocation density based micromechanical constitutive model for Sn-Ag-Cu solder alloys

    Science.gov (United States)

    Liu, Lu; Yao, Yao; Zeng, Tao; Keer, Leon M.

    2017-10-01

    Based on the dislocation density hardening law, a micromechanical model considering the effects of precipitates is developed for Sn-Ag-Cu solder alloys. According to the microstructure of the Sn-3.0Ag-0.5Cu thin films, intermetallic compounds (IMCs) are assumed as sphere particles embedded in the polycrystalline β-Sn matrix. The mechanical behavior of polycrystalline β-Sn matrix is determined by the elastic-plastic self-consistent method. The existence of IMCs not only impedes the motion of dislocations but also increases the overall stiffness. Thus, a dislocation density based hardening law considering non-shearable precipitates is adopted locally for single β-Sn crystal, and the Mori-Tanaka scheme is applied to describe the overall viscoplastic behavior of solder alloys. The proposed model is incorporated into finite element analysis and the corresponding numerical implementation method is presented. The model can describe the mechanical behavior of Sn-3.0Ag-0.5Cu and Sn-1.0Ag-0.5Cu alloys under high strain rates at a wide range of temperatures. Furthermore, the overall Young’s modulus changes due to different contents of IMCs is predicted and compared with experimental data. Results show that the proposed model can describe both elastic and inelastic behavior of solder alloys with reasonable accuracy.

  12. Enhanced Thermoelectric Properties of Graphene/Cu2SnSe3 Composites

    Directory of Open Access Journals (Sweden)

    Degang Zhao

    2017-02-01

    Full Text Available Cu2SnSe3 material is regarded as a potential thermoelectric material due to its relatively high carrier mobility and low thermal conductivity. In this study, graphene was introduced into the Cu2SnSe3 powder by ball milling, and the bulk graphene/Cu2SnSe3 thermoelectric composites were prepared by spark plasma sintering. The graphene nanosheets distributed uniformly in the Cu2SnSe3 matrix. Meanwhile, some graphene nanosheets tended to form thick aggregations, and the average length of these aggregations was about 3 μm. With the fraction of graphene increasing, the electrical conductivity of graphene/Cu2SnSe3 samples increased greatly while the Seebeck coefficient was decreased. The introduction of graphene nanosheets can reduce the thermal conductivity effectively resulting from the phonon scattering by the graphene interface. When the content of graphene exceeds a certain value, the thermal conductivity of graphene/Cu2SnSe3 composites starts to increase. The achieved highest figure of merit (ZT for 0.25 vol % graphene/Cu2SnSe3 composite was 0.44 at 700 K.

  13. Detection and quantitative determination by PIXE of the mutagen Sn{sup 2+} in yeast cells

    Energy Technology Data Exchange (ETDEWEB)

    Viau, C.M. [Departamento de Biofisica/Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, UFRGS (Brazil); Yoneama, M.-L. [Instituto de Fisica, UFRGS, Av. Bento Goncalves 9500, CEP 91501-970, CP 15051, Porto Alegre, RS (Brazil)]. E-mail: jfdias@if.ufrgs.br; Dias, J.F. [Instituto de Fisica, UFRGS, Av. Bento Goncalves 9500, CEP 91501-970, CP 15051, Porto Alegre, RS (Brazil); Pungartnik, C. [Departamento de Ciencias Biologicas, Universidade Estadual de Santa Cruz, UESC, Ilheus, BA (Brazil); Brendel, M. [Departamento de Biofisica/Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, UFRGS (Brazil); Departamento de Ciencias Biologicas, Universidade Estadual de Santa Cruz, UESC, Ilheus, BA (Brazil); Henriques, J.A.P. [Departamento de Biofisica/Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, UFRGS (Brazil); Faculdade de Farmacia, Universidade Luterana do Brasil, ULBRA, Porto Alegre, RS (Brazil)

    2006-08-15

    The main goal of this work was to determine the concentration of Sn{sup 2+} ions in cells of the yeast Saccharomyces cerevisiae and to correlate their quantity with the genotoxicity of intracellularly accumulated metal ions. The intracellular metal content of yeast cells was determined by PIXE (particle-induced X-ray emission) after cell exposure to SnCl{sub 2}. To that end, a thick target protocol was developed for PIXE analysis. The samples were irradiated with a 2 MeV proton beam, while the induced X-rays were detected with a high-purity germanium detector. The results of the toxicity of SnCl{sub 2} and the PIXE analysis performed with two different yeast strains (haploid and diploid) suggest that the exposure of haploid and diploid yeast to Sn{sup 2+} induces DNA lesions and that the absorption depends on the genetic background of each strain.

  14. High-content neurite development study using optically patterned substrates.

    Directory of Open Access Journals (Sweden)

    Jonathan M Bélisle

    Full Text Available The study of neurite guidance in vitro relies on the ability to reproduce the distribution of attractive and repulsive guidance molecules normally expressed in vivo. The identification of subtle variations in the neurite response to changes in the spatial distribution of extracellular molecules can be achieved by monitoring the behavior of cells on protein gradients. To do this, automated high-content screening assays are needed to quantify the morphological changes resulting from growth on gradients of guidance molecules. Here, we present the use of laser-assisted protein adsorption by photobleaching (LAPAP to allow the fabrication of large-scale substrate-bound laminin-1 gradients to study neurite extension. We produced thousands of gradients of different slopes and analyzed the variations in neurite attraction of neuron-like cells (RGC-5. An image analysis algorithm processed bright field microscopy images, detecting each cell and quantifying the soma centroid and the initiation, terminal and turning angles of the longest neurite.

  15. Metadata management for high content screening in OMERO.

    Science.gov (United States)

    Li, Simon; Besson, Sébastien; Blackburn, Colin; Carroll, Mark; Ferguson, Richard K; Flynn, Helen; Gillen, Kenneth; Leigh, Roger; Lindner, Dominik; Linkert, Melissa; Moore, William J; Ramalingam, Balaji; Rozbicki, Emil; Rustici, Gabriella; Tarkowska, Aleksandra; Walczysko, Petr; Williams, Eleanor; Allan, Chris; Burel, Jean-Marie; Moore, Josh; Swedlow, Jason R

    2016-03-01

    High content screening (HCS) experiments create a classic data management challenge-multiple, large sets of heterogeneous structured and unstructured data, that must be integrated and linked to produce a set of "final" results. These different data include images, reagents, protocols, analytic output, and phenotypes, all of which must be stored, linked and made accessible for users, scientists, collaborators and where appropriate the wider community. The OME Consortium has built several open source tools for managing, linking and sharing these different types of data. The OME Data Model is a metadata specification that supports the image data and metadata recorded in HCS experiments. Bio-Formats is a Java library that reads recorded image data and metadata and includes support for several HCS screening systems. OMERO is an enterprise data management application that integrates image data, experimental and analytic metadata and makes them accessible for visualization, mining, sharing and downstream analysis. We discuss how Bio-Formats and OMERO handle these different data types, and how they can be used to integrate, link and share HCS experiments in facilities and public data repositories. OME specifications and software are open source and are available at https://www.openmicroscopy.org. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  16. Volcanic-plutonic connections and metal fertility of highly evolved magma systems: A case study from the Herberton Sn-W-Mo Mineral Field, Queensland, Australia

    Science.gov (United States)

    Cheng, Yanbo; Spandler, Carl; Chang, Zhaoshan; Clarke, Gavin

    2018-03-01

    Understanding the connection between the highly evolved intrusive and extrusive systems is essential to explore the evolution of high silicic magma systems, which plays an important role in discussions of planetary differentiation, the growth of continents, crustal evolution, and the formation of highly evolved magma associated Sn-W-Mo mineral systems. To discern differences between "fertile" and "non-fertile" igneous rocks associated with Sn-W-Mo mineralization and reveal the genetic links between coeval intrusive and extrusive rocks, we integrate whole rock geochemistry, geochronology and Hf isotope signatures of igneous zircons from contemporaneous plutonic and volcanic rocks from the world-class Herberton Mineral Field of Queensland, Australia. The 310-300 Ma intrusive rocks and associated intra-plutonic W-Mo mineralization formed from relatively oxidized magmas after moderate degrees of crystal fractionation. The geochemical and isotopic features of the coeval volcanic succession are best reconciled utilizing the widely-accepted volcanic-plutonic connection model, whereby the volcanic rocks represent fractionated derivatives of the intrusive rocks. Older intrusions emplaced at 335-315 Ma formed from relatively low fO2 magmas that fractionated extensively to produce highly evolved granites that host Sn mineralization. Coeval volcanic rocks of this suite are compositionally less evolved than the intrusive rocks, thereby requiring a different model to link these plutonic-volcanic sequences. In this case, we propose that the most fractionated magmas were not lost to volcanism, but instead were effectively retained at the plutonic level, which allowed further localized build-up of volatiles and lithophile metals in the plutonic environment. This disconnection to the volcanism and degassing may be a crucial step for forming granite-hosted Sn mineralization. The transition between these two igneous regimes in Herberton region over a ∼30 m.y. period is attributed to

  17. Nutritional and Phytochemical Content of High-Protein Crops.

    Science.gov (United States)

    Multari, Salvatore; Neacsu, Madalina; Scobbie, Lorraine; Cantlay, Louise; Duncan, Gary; Vaughan, Nicholas; Stewart, Derek; Russell, Wendy R

    2016-10-11

    Sustainable sources of high-protein plants could help meet future protein requirements. Buckwheat, green pea, fava bean, hemp, and lupin were analyzed by proximate analysis and inductively coupled plasma mass spectrometry to determine their macro- and micronutrient contents, and liquid chromatography-mass spectrometry was used to elucidate the phytochemical profiles. The protein contents ranged from 20 to 43% (w/w), and all samples were found to be rich in insoluble fiber: 9-25% (w/w). The selected crops had a favorable micronutrient profile, with phosphorus levels ranging from 2.22 ± 0.05 to 9.72 ± 0.41 g kg-1, while iron levels ranged from 20.23 ± 0.86 to 69.57 ± 7.43 mg kg-1. The crops contained substantial amounts of phytophenolic compounds. In particular, buckwheat was a rich source of pelargonidin (748.17 ± 75.55 mg kg-1), epicatechin (184.1 ± 33.2 mg kg-1), quercetin (35.66 ± 2.22 mg kg-1), caffeic acid (41.74 ± 22.54 mg kg-1), and 3-hydroxyphenylacetic acid (63.64 ± 36.16 mg kg-1); hemp contained p-coumaric acid (84.02 ± 8.10 mg kg-1), cyanidin (58.43 ± 21.01 mg kg-1), protocatechualdehyde (34.77 ± 5.15 mg kg-1), and gentisic acid (31.20 ± 1.67 mg kg-1); and fava bean was the richest source of ferulic acid (229.51 ± 36.58 mg kg-1) and its 5-5' (39.99 ± 1.10 mg kg-1) and 8-5 dimers (58.17 ± 6.68 mg kg-1). Demonstrating that these crops are rich sources of protein, fiber, and phytochemicals could encourage higher consumption and utilization of them as healthy and sustainable ingredients in the food and drink industry.

  18. Hierarchical SnO2 /Carbon Nanofibrous Composite Derived from Cellulose Substance as Anode Material for Lithium-Ion Batteries.

    Science.gov (United States)

    Wang, Mengya; Li, Shun; Zhang, Yiming; Huang, Jianguo

    2015-11-02

    A hierarchical fibrous SnO2 /carbon nanocomposite composed of fine SnO2 nanocrystallites immobilized as a thin layer on a carbon nanofiber surface was synthesized employing natural cellulose substance as both scaffold and carbon source. It was achieved by calcination/carbonization of the as-deposited SnO2 -gel/cellulose hybrid in an argon atmosphere. As being employed as an anode material for lithium-ion batteries, the porous structures, small SnO2 crystallite sizes, and the carbon buffering matrix possessed by the nanocomposite facilitate the electrode-electrolyte contact, promote the electron transfer and Li(+) diffusion, and relieve the severe volume change and aggregation of the active particles during the charge/discharge cycles. Hence, the nanocomposite showed high reversible capacity, significant cycling stability, and rate capability that are superior to the nanotubular SnO2 and SnO2 sol-gel powder counter materials. For such a composite with 27.8 wt % SnO2 content and 346.4 m(2)  g(-1) specific surface area, a capacity of 623 mAh g(-1) was delivered after 120 cycles at 0.2 C. Further coating of the SnO2 /carbon nanofibers with an additional carbon layer resulted in an improved cycling stability and rate performance. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Investigation of methanol oxidation on a highly active and stable Pt–Sn electrocatalyst supported on carbon–polyaniline composite for application in a passive direct methanol fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Amani, Mitra [Department of Chemical Engineering, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Kazemeini, Mohammad [Department of Chemical and Petroleum Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of); Hamedanian, Mahboobeh [Department of Chemistry, Faculty of Science, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Pahlavanzadeh, Hassan [Department of Chemical Engineering, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Gharibi, Hussein, E-mail: h.gharibi@utah.edu [Department of Chemistry, Faculty of Science, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Department of Material Science & Engineering, 122 S Campus Drive, University of Utah, Salt Lake City, UT 84112 (United States)

    2015-08-15

    Highlights: • PtSn/C-PANI performed superior in the MOR compared with a commercial PtRu/C. • Catalytic activity of PtRu/C was highly reduced during the accelerated durability test. • Anode of the PtSn/C-PANI in a passive DMFC lowered methanol crossover by 30%. - Abstract: Polyaniline fiber (PANI) was synthesized and utilized to fabricate a vulcan–polyaniline (C-PANI) composite. Pt/C-PANI and PtSn/C-PANI electro-catalysts with different Pt:Sn atomic ratios were prepared by the impregnation method. These electro-catalysts, along with commercial PtRu/C (Electrochem), were characterized with respect to their structural and electrochemical properties in methanol oxidation reaction (MOR). PtSn(70:30)/C-PANI showed excellent performance in MOR, the obtained maximum current density being about 40% and 50% higher than that for PtRu/C and Pt/C-PANI, respectively. It was also found that the CO tolerance and stability of PtSn(70:30)/C-PANI was considerably higher than that of PtRu/C. Finally, the performance of these two materials was compared in a passive direct methanol fuel cell (DMFC). The DMFC test results demonstrated that the membrane electrode assembly (MEA) prepared using PtSn(70:30)/C-PANI anode catalyst performed more satisfactorily in terms of maximum power density and lower methanol crossover.

  20. High-content analysis in preclinical drug discovery.

    Science.gov (United States)

    Denner, Philip; Schmalowsky, Janine; Prechtl, Stefan

    2008-03-01

    High-Content Analysis (HCA) has developed into an established tool and is used in a wide range of academic laboratories and pharmaceutical research groups. HCA is now routinely proving to be effective in providing functionally relevant results. It is essential to select the appropriate HCA application with regard to the targeted compound's cellular function. The cellular impact and compound specificity as revealed by HCA analysis facilitates reaching definitive conclusions at an early stage in the drug discovery process. This technology therefore has the potential to substantially improve the efficiency of pharmaceutical research. Recent advances in fluorescent probes have significantly boosted the success of HCA. Auto-fluorescent proteins which minimally hinder the functioning of the living cell have been playing a decisive role in cell biology research. For companies the severely restricted license conditions regarding auto-fluorescent proteins hamper their general use in pharmaceutical research. This has opened the field for other solutions such as self-labeling protein technology, which could potentially replace the well established methods that utilize auto-fluorescent proteins. In addition, direct labeling techniques have improved considerably and may supersede many of the approaches based on fusion proteins. Following sample preparation, treated cells are imaged and the resulting multiple fluorescent signals are subjected to contextual and statistical analysis. The extraordinary advantage of HCA is that it enables the large-scale and simultaneous quantification and correlation of multiple phenotypic responses and physiological reactions using sophisticated software solutions that permit assay-specific image analysis. Hence, HCA once more has demonstrated its outstanding potential to significantly support establishing effective pharmaceutical research processes in order to both advance research projects and cut costs.

  1. Breeding elite japonica-type soft rice with high protein content ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-01-19

    Jan 19, 2009 ... The T5 transgenic rice seeds were developed, in which amylose content and protein content ... amylose content and high protein content was obtained through the introduction of an anti-Waxy gene. ... fragment of Waxy gene from rice cv.232; LB, RB: left and right boarder of T-DNA, respectively; Nos-ter:.

  2. High sensitivity ethanol gas sensor based on Sn - doped ZnO under visible light irradiation at low temperature

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Peishuo; Pan, Guofeng; Zhang, Bingqiang; Zhen, Jiali; Sun, Yicai, E-mail: pgf@hebut.edu.cn [Institute of Microelectronic, Hebei University of Technology, Tianjin (China)

    2014-07-15

    Pure ZnO and 5at%, 7at%, 9at% Sn - doped ZnO materials are prepared by the chemical co - precipitation method. They were annealed by furnace at temperature range of 300 - 700ºC in air for 1h. The ZnO materials are characterized by X - ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that the Sn - doped ZnO materials appear rough porous structures. The maximum sensitivity can be achieved by doping the amount of 7 at%. It has much better sensing performance towards ethanol vapor under visible light irradiation. The response and recovery time are ~1s and ~5s, respectively. The mechanism for the improvement in the sensing properties can be explained with the surface adsorption theory and the photoactivation theory. (author)

  3. Embedded fiber Bragg grating sensors for true temperature monitoring in Nb$_3$Sn superconducting magnets for high energy physics

    CERN Document Server

    Chiuchiolo, A; Bajko, M; Consales, M; Giordano, M; Perez, J C; Cusano, A

    2016-01-01

    The luminosity upgrade of the Large Hadron Collider (HL-LHC) planned at the European Organization for Nuclear Research (CERN) requires the development of a new generation of superconducting magnets based on Nb3Sn technology. The instrumentation required for the racetrack coils needs the development of reliable sensing systems able to monitor the magnet thermo-mechanical behavior during its service life, from the coil fabrication to the magnet operation. With this purpose, Fiber Bragg Grating (FBG) sensors have been embedded in the coils of the Short Model Coil (SMC) magnet fabricated at CERN. The FBG sensitivity to both temperature and strain required the development of a solution able to separate mechanical and temperature effects. This work presents for the first time a feasibility study devoted to the implementation of an embedded FBG sensor for the measurement of the "true" temperature in the impregnated Nb3Sn coil during the fabrication process. © (2016) COPYRIGHT Society of Photo-Optical Instrumentatio...

  4. High Performance Complementary Circuits Based on p-SnO and n-IGZO Thin-Film Transistors

    Directory of Open Access Journals (Sweden)

    Jiawei Zhang

    2017-03-01

    Full Text Available Oxide semiconductors are regarded as promising materials for large-area and/or flexible electronics. In this work, a ring oscillator based on n-type indium-gallium-zinc-oxide (IGZO and p-type tin monoxide (SnO is presented. The IGZO thin-film transistor (TFT shows a linear mobility of 11.9 cm2/(V∙s and a threshold voltage of 12.2 V. The SnO TFT exhibits a mobility of 0.51 cm2/(V∙s and a threshold voltage of 20.1 V which is suitable for use with IGZO TFTs to form complementary circuits. At a supply voltage of 40 V, the complementary inverter shows a full output voltage swing and a gain of 24 with both TFTs having the same channel length/channel width ratio. The three-stage ring oscillator based on IGZO and SnO is able to operate at 2.63 kHz and the peak-to-peak oscillation amplitude reaches 36.1 V at a supply voltage of 40 V. The oxide-based complementary circuits, after further optimization of the operation voltage, may have wide applications in practical large-area flexible electronics.

  5. A genetic strategy generating wheat with very high amylose content.

    Science.gov (United States)

    Regina, Ahmed; Berbezy, Pierre; Kosar-Hashemi, Behjat; Li, Suzhi; Cmiel, Mark; Larroque, Oscar; Bird, Anthony R; Swain, Steve M; Cavanagh, Colin; Jobling, Stephen A; Li, Zhongyi; Morell, Matthew

    2015-12-01

    Resistant starch (RS), a type of dietary fibre, plays an important role in human health; however, the content of RS in most modern processed starchy foods is low. Cereal starch, when structurally manipulated through a modified starch biosynthetic pathway to greatly increase the amylose content, could be an important food source of RS. Transgenic studies have previously revealed the requirement of simultaneous down-regulation of two starch branching enzyme (SBE) II isoforms both located on the long arm of chromosome 2, namely SBEIIa and SBEIIb, to elevate the amylose content in wheat from ~25% to ~75%. The current study revealed close proximity of genes encoding SBEIIa and SBEIIb isoforms in wheat with a genetic distance of 0.5 cM on chromosome 2B. A series of deletion and single nucleotide polymorphism (SNP) loss of function alleles in SBEIIa, SBEIIb or both was isolated from two different wheat populations. A breeding strategy to combine deletions and SNPs generated wheat genotypes with altered expression levels of SBEIIa and SBEIIb, elevating the amylose content to an unprecedented ~85%, with a marked concomitant increase in RS content. Biochemical assays were used to confirm the complete absence in the grain of expression of SBEIIa from all three genomes in combination with the absence of SBEIIb from one of the genomes. © 2015 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  6. Impact of sodium on the secondary phases and current pathway in Cu{sub 2}(Zn,Sn)Se{sub 4} thin film solar cell

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Yi-Cheng, E-mail: ielinyc@cc.ncue.edu.tw [Department of Mechatronics Engineering, National Changhua University of Education, Changhua, Taiwan (China); Lai, Chien-Mu [Department of Mechatronics Engineering, National Changhua University of Education, Changhua, Taiwan (China); Hsu, Hung-Ru [Green Energy & Environment Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan (China)

    2017-05-01

    In this study, we investigated the influence of Na content on secondary phases and current pathway in Cu{sub 2}(Zn,Sn)Se{sub 4} (CZTSe) thin film solar cells with the following structure: Ti/Mo:Na/Mo/CZTSe/CdS/i-ZnO/ZnO:Al/Al. The application of Na-doped Mo target as a source of sodium. Experimental results demonstrate that increasing the Na content leads to an increase in the quantity of secondary phase SnSe{sub 2} on the surface of the absorber layer; however, it did not appear to affect the secondary phases of Cu{sub 2}SnSe{sub 3} (CTSe) or ZnSe. Excessive quantities of Na were shown to have an adverse effect on device efficiency. Our results using conductive atomic force microscopy (C-AFM) revealed that an increase in the quantity of secondary phase SnSe{sub 2} can shift the current pathway on the surface of CZTSe from CZTSe grain boundaries (GBs) to the SnSe{sub 2} grains. The role of secondary phase SnSe{sub 2} of the CZTSe acted as a channel for the current flow, which results in high leakage current and low device efficiency. - Highlights: • Increasing the Na content leads to an increase in the quantity of secondary phase SnSe{sub 2}. • An increase of secondary phase SnSe{sub 2} can shift the current pathway from CZTSe grain boundaries to the SnSe{sub 2} grains. • The secondary phase SnSe{sub 2} acted as a channel for the current flow, which results in high leakage current.

  7. Topological crystalline insulator SnTe nanoribbons

    Science.gov (United States)

    Dahal, Bishnu R.; Dulal, Rajendra P.; Pegg, Ian L.; Philip, John

    2017-03-01

    Topological crystalline insulators are systems in which a band inversion that is protected by crystalline mirror symmetry gives rise to nontrivial topological surface states. SnTe is a topological crystalline insulator. It exhibits p-type conductivity due to Sn vacancies and Te antisites, which leads to high carrier density in the bulk. Thus growth of high quality SnTe is a prerequisite for understanding the topological crystalline insulating behavior. We have grown SnTe nanoribbons using a solution method. The width of the SnTe ribbons varies from 500 nm to 2 μm. They exhibit rock salt crystal structure with a lattice parameter of 6.32 Å. The solution method that we have adapted uses low temperature, so the Sn vacancies can be controlled. The solution grown SnTe nanoribbons exhibit strong semiconducting behavior with an activation energy of 240 meV. This activation energy matches with the calculated band gap for SnTe with a lattice parameter of 6.32 Å, which is higher than that reported for bulk SnTe. The higher activation energy makes the thermal excitation of bulk charges very difficult on the surface. As a result, the topological surfaces will be free from the disturbance caused by the thermal excitations

  8. Sn - Induced decomposition of SiGeSn alloys grown on Si by molecular-beam epitaxy

    Science.gov (United States)

    Talochkin, A. B.; Timofeev, V. A.; Gutakovskii, A. K.; Mashanov, V. I.

    2017-11-01

    Structural features of Si1-x-yGexSny alloy layers grown on Si by molecular-beam epitaxy are studied. These layers with the thickness of 2.0 nm, the nominal Ge composition of x0 ≈ 0.3, and the Sn-content of y ≈ 2-6 at.% have been grown at low temperatures (100-150 °C). We have used high-resolution transmission electron microscopy to analyze atomic structure of grown layers and Raman spectroscopy to evaluate the real Ge-content x from the observed optical phonon frequencies. It is found that the x value coincides with the nominal one at low Sn-content (2-3 at.%), and when it is increased (y ≥ 5 at.%), the decomposition of alloys into two fractions occurs. One of them is enriched by Ge with x up to 0.6 and the other fraction is Si-enriched. It is shown that the observed decomposition is Sn-induced and related to increase in Ge adatoms mobility in the growth process. This mechanism is similar to that theoretically predicted by Venezuela and Tersoff (Phys. Rev. 58, 10871 (1998)) for the case of high growth temperature.

  9. High efficiency indirect shoot regeneration and hypericin content in ...

    African Journals Online (AJOL)

    ... were analyzed for their hypericin content. And they were found to produce hypericin as 48 ìg/g DM. Regenerated plantlets were rooted in MS containing 1 mg/L IAA. The highest percentages (94%) of survival of transferred plantlets to freeliving circumstances were limited when they were acclimatized in sand : peat : perlite ...

  10. High efficiency indirect shoot regeneration and hypericin content in ...

    African Journals Online (AJOL)

    USER

    2010-04-12

    Apr 12, 2010 ... secondary metabolite content in medicinal plants. Many secondary ... Plant materials. H. triquetrifolium Turra seeds collected from Kaz Mountains in. Turkey, seasonally. They were surface sterilized by immersing in a. 70% (v/v) .... for the biosynthesis of such compounds (Verpoorte et al.,. 1993; Hsu and ...

  11. Microstructure, corrosion behavior and cytotoxicity of biodegradable Mg–Sn implant alloys prepared by sub-rapid solidification

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Chaoyong [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 (China); Pan, Fusheng, E-mail: fspan@cqu.edu.cn [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 (China); National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044 (China); Chongqing Academy of Science and Technology, Chongqing 401123 (China); Zhao, Shuang; Pan, Hucheng; Song, Kai [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 (China); Tang, Aitao [College of Materials Science and Engineering, Chongqing University, Chongqing 400044 (China); National Engineering Research Center for Magnesium Alloys, Chongqing University, Chongqing 400044 (China)

    2015-09-01

    In this study, biodegradable Mg–Sn alloys were fabricated by sub-rapid solidification, and their microstructure, corrosion behavior and cytotoxicity were investigated by using optical microscopy, scanning electron microscopy equipped with an energy dispersive X-ray spectroscopy, X-ray diffraction, immersion test, potentiodynamic polarization test and cytotoxicity test. The results showed that the microstructure of Mg–1Sn alloy was almost equiaxed grain, while the Mg–Sn alloys with higher Sn content (Sn ≥ 3 wt.%) displayed α-Mg dendrites, and the secondary dendrite arm spacing of the primary α-Mg decreased significantly with increasing Sn content. The Mg–Sn alloys consisted of primary α-Mg matrix, Sn-rich segregation and Mg{sub 2}Sn phase, and the amount of Mg{sub 2}Sn phases increased with increasing Sn content. Potentiodynamic polarization and immersion tests revealed that the corrosion rates of Mg–Sn alloys increased with increasing Sn content. Cytotoxicity test showed that Mg–1Sn and Mg–3Sn alloys were harmless to MG63 cells. These results of the present study indicated that Mg–1Sn and Mg–3Sn alloys were promising to be used as biodegradable implants. - Highlights: • Biodegradable Mg–Sn implant alloys were prepared by sub-rapid solidification. • Secondary dendrite arm spacing of alloys decreased with increasing Sn content. • Corrosion rates of alloys increased significantly with increasing Sn content. • Mg–1Sn and Mg–3Sn alloys were harmless to MG63 cells.

  12. A global view of the phase transitions of SnO2 in rechargeable batteries based on results of high throughput calculations

    KAUST Repository

    Cheng, Yingchun

    2015-08-28

    Lithium, sodium and magnesium have attracted wide attention as potential ions for rechargeable batteries. The Materials Project database of high throughput first principles calculations is used to investigate the phase transitions of SnO2 during ion intercalation and extraction. Various intermediate phases are predicted to be formed during the first intercalation, whereas in later cycles other intermediate phases are encountered. The volume expansions after intercalation and extraction are analyzed. We show that different lithium and sodium oxide products found in recent experiments are due to different oxygen chemical potentials.

  13. PROTEUS-SN User Manual

    Energy Technology Data Exchange (ETDEWEB)

    Shemon, Emily R. [Argonne National Lab. (ANL), Argonne, IL (United States); Smith, Micheal A. [Argonne National Lab. (ANL), Argonne, IL (United States); Lee, Changho [Argonne National Lab. (ANL), Argonne, IL (United States)

    2016-02-16

    PROTEUS-SN is a three-dimensional, highly scalable, high-fidelity neutron transport code developed at Argonne National Laboratory. The code is applicable to all spectrum reactor transport calculations, particularly those in which a high degree of fidelity is needed either to represent spatial detail or to resolve solution gradients. PROTEUS-SN solves the second order formulation of the transport equation using the continuous Galerkin finite element method in space, the discrete ordinates approximation in angle, and the multigroup approximation in energy. PROTEUS-SN’s parallel methodology permits the efficient decomposition of the problem by both space and angle, permitting large problems to run efficiently on hundreds of thousands of cores. PROTEUS-SN can also be used in serial or on smaller compute clusters (10’s to 100’s of cores) for smaller homogenized problems, although it is generally more computationally expensive than traditional homogenized methodology codes. PROTEUS-SN has been used to model partially homogenized systems, where regions of interest are represented explicitly and other regions are homogenized to reduce the problem size and required computational resources. PROTEUS-SN solves forward and adjoint eigenvalue problems and permits both neutron upscattering and downscattering. An adiabatic kinetics option has recently been included for performing simple time-dependent calculations in addition to standard steady state calculations. PROTEUS-SN handles void and reflective boundary conditions. Multigroup cross sections can be generated externally using the MC2-3 fast reactor multigroup cross section generation code or internally using the cross section application programming interface (API) which can treat the subgroup or resonance table libraries. PROTEUS-SN is written in Fortran 90 and also includes C preprocessor definitions. The code links against the PETSc, METIS, HDF5, and MPICH libraries. It optionally links against the MOAB library and

  14. STRESS a SN survey at ESO

    Science.gov (United States)

    Botticella, M. T.

    We performed the Southern inTermediate Redshift ESO Supernova Search (STRESS), a survey specifically designed to measure the rate of both SNe Ia and CC SNe, in order to obtain a direct comparison of the high redshift and local rates and to investigate the dependence of the rates on specific galaxy properties, most notably their colour. We found that the type Ia SN rate, at mean redshift z = 0.3, is 0.22+0.10+0.16-0.08-0.14 h270 SNu, while the CC SN rate, at z = 0.21, is 0.82+0.31+0.300.24-0.26 h270 SNu. The quoted errors are the statistical and systematic uncertainties. With respect to the local value, the CC SN rate at z = 0.2 is higher by a factor of ˜ 2, whereas the type Ia SN rate remains almost constant. We also measured the SN rates in the red and blue galaxies and found that the SN Ia rate seems to be constant in galaxies of different colour, whereas the CC SN rate seems to peak in blue galaxies, as in the local Universe. Finally we exploited the link between SFH and SN rates to predict the evolutionary behaviour of the SN rates and compare it with the path indicated by observations.

  15. HIGH-DENSITY CIRCUMSTELLAR INTERACTION IN THE LUMINOUS TYPE IIn SN 2010jl: THE FIRST 1100 DAYS

    Energy Technology Data Exchange (ETDEWEB)

    Fransson, Claes; Ergon, Mattias; Sollerman, Jesper [Oskar Klein Centre, Department of Astronomy, Stockholm University, AlbaNova, SE-106 91 Stockholm (Sweden); Challis, Peter J.; Kirshner, Robert P.; Marion, G. H.; Milisavljevic, Dan; Friedman, Andrew S.; Chornock, Ryan; Czekala, Ian; Soderberg, Alicia [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Chevalier, Roger A. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904 (United States); France, Kevin [CASA, University of Colorado, 593UCB Boulder, CO 80309-0593 (United States); Smith, Nathan [Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Bufano, Filomena [Departamento de Ciencias Fisicas, Universidad Andres Bello, Avda. Republica 252, Santiago (Chile); Kangas, Tuomas [Tuorla Observatory, University of Turku, Väisäläntie 20 FI-21500 Piikkiö (Finland); Larsson, Josefin [KTH, Department of Physics, and the Oskar Klein Centre, AlbaNova, SE-106 91 Stockholm (Sweden); Mattila, Seppo [Finnish Centre for Astronomy with ESO (FINCA), University of Turku, Väisäläntie 20 FI-21500 Piikkiö (Finland); Benetti, Stefano [INAF-Osservatorio Astronomico di Padova, Vicolo dellOsservatorio 5, I-35122 Padova (Italy)

    2014-12-20

    Hubble Space Telescope and ground-based observations of the Type IIn supernova (SN) 2010jl are analyzed, including photometry and spectroscopy in the ultraviolet, optical, and near-IR bands, 26-1128 days after first detection. At maximum, the bolometric luminosity was ∼3 × 10{sup 43} erg s{sup –1} and even at 850 days exceeds 10{sup 42} erg s{sup –1}. A near-IR excess, dominating after 400 days, probably originates in dust in the circumstellar medium (CSM). The total radiated energy is ≳ 6.5 × 10{sup 50} erg, excluding the dust component. The spectral lines can be separated into one broad component that is due to electron scattering and one narrow with expansion velocity ∼100 km s{sup –1} from the CSM. The broad component is initially symmetric around zero velocity but becomes blueshifted after ∼50 days, while remaining symmetric about a shifted centroid velocity. Dust absorption in the ejecta is unlikely to explain the line shifts, and we attribute the shift instead to acceleration by the SN radiation. From the optical lines and the X-ray and dust properties, there is strong evidence for large-scale asymmetries in the CSM. The ultraviolet lines indicate CNO processing in the progenitor, while the optical shows a number of narrow coronal lines excited by the X-rays. The bolometric light curve is consistent with a radiative shock in an r {sup –2} CSM with a mass-loss rate of M-dot ∼0.1  M{sub ⊙} yr{sup −1}. The total mass lost is ≳ 3 M {sub ☉}. These properties are consistent with the SN expanding into a CSM characteristic of a luminous blue variable progenitor with a bipolar geometry. The apparent absence of nuclear processing is attributed to a CSM that is still opaque to electron scattering.

  16. Design of Reduction Process of SnO2 by CH4 for Efficient Sn Recovery.

    Science.gov (United States)

    Ha, Hyunwoo; Yoo, Mi; An, Hyesung; Shin, Kihyun; Han, Taeyang; Sohn, Youhan; Kim, Sangyeol; Lee, Sang-Ro; Han, Jun Hyun; Kim, Hyun You

    2017-10-31

    We design a novel method for the CH4 reduction of SnO2 for the efficient recovery of Sn from SnO2 through a study combining theory and experiment. The atomic-level process of CH4-SnO2 interaction and temperature-dependent reduction behavior of SnO2 were studied with a combination of a multi-scale computational method of thermodynamic simulations and density functional theory (DFT) calculations. We found that CH4 was a highly efficient and a versatile reducing agent, as the total reducing power of CH4 originates from the carbon and hydrogen of CH4, which sequentially reduce SnO2. Moreover, as a result of the CH4 reduction of SnO2, a mixture of CO and H2 was produced as a gas-phase product (syngas). The relative molar ratio of the produced gas-phase product was controllable by the reduction temperature and the amount of supplied CH4. The laboratory-scale experimental study confirmed that CH4 actively reduces SnO2, producing 99.34% high-purity Sn and H2 and CO. Our results present a novel method for an efficient, green, and economical recycling strategy for Sn with economic value added that is held by the co-produced clean energy source (syngas).

  17. Decomposition kinetics of expanded austenite with high nitrogen contents

    DEFF Research Database (Denmark)

    Christiansen, Thomas; Somers, Marcel A. J.

    2006-01-01

    This paper addresses the decomposition kinetics of synthesized homogeneous expanded austenite formed by gaseous nitriding of stainless steel AISI 304L and AISI 316L with nitrogen contents up to 38 at.% nitrogen. Isochronal annealing experiments were carried out in both inert (N2) and reducing (H2......) atmospheres. Differential thermal analysis (DTA) and thermogravimetry were applied for identification of the decomposition reactions and X-ray diffraction analysis was applied for phase analysis. CrN precipitated upon annealing; the activation energies are 187 kJ/mol and 128 kJ/mol for AISI 316L and AISI 304L...

  18. High nitrogen availability reduces polyphenol content in Sphagnum peat.

    Science.gov (United States)

    Bragazza, Luca; Freeman, Chris

    2007-05-15

    Peat mosses of the genus Sphagnum constitute the bulk of living and dead biomass in bogs. These plants contain peculiar polyphenols which hamper litter peat decomposition through their inhibitory activity on microbial breakdown. In the light of the increasing availability of biologically active nitrogen in natural ecosystems, litter derived from Sphagnum mosses is an ideal substrate to test the potential effects of increased atmospheric nitrogen deposition on polyphenol content in litter peat. To this aim, we measured total nitrogen and soluble polyphenol concentration in Sphagnum litter peat collected in 11 European bogs under a chronic gradient of atmospheric nitrogen deposition. Our results demonstrate that increasing nitrogen concentration in Sphagnum litter, as a consequence of increased exogenous nitrogen availability, is accompanied by a decreasing concentration of polyphenols. This inverse relationship is consistent with reports that in Sphagnum mosses, polyphenol and protein biosynthesis compete for the same precursor. Our observation of modified Sphagnum litter chemistry under chronic nitrogen eutrophication has implications in the context of the global carbon balance, because a lower content of decay-inhibiting polyphenols would accelerate litter peat decomposition.

  19. 119Sn Mössbauer studies on ferromagnetic and photocatalytic Sn-TiO2 nanocrystals

    Science.gov (United States)

    Ganeshraja, Ayyakannu Sundaram; Nomura, Kiyoshi; Wang, Junhu

    2016-12-01

    Diluted Sn doped TiO2 nanocrystals (Sn/Ti ratio: x ≤ 1.37 %) were synthesized by a simple hydrothermal method using pure reagents without any surfactant and dispersant material. The XRD of these samples showed an anatase phase, anatase and rutile mixed phases, and a rutile phase of TiO2 and SnO2 with the increase of Sn dopant concentrations. 119Sn Mössbauer spectra gave the broad peaks, which were decomposed into doublets and sextets because almost all these samples showed magnetic hysteresis even at room temperature. The titanium oxides doped with x ≤ 0.12 % showed the relatively large magnetic hysteresis and high photocatalytic activity. Mössbauer spectra of samples doped with x > 0.3 % were analyzed by one doublet and two sextets although the samples showed weak ferromagnetism. Three kinds of Sn species may be distinguished as Sn 4+ substituted TiO2 and two different magnetic arrangements of Sn doped TiO2: one with more oxygen defects and other at the interface of TiO2 and precipitated SnO2 containing Ti atoms. The correlation between various amounts of Sn sites and photocatalytic activity and/ or magnetic property was discussed.

  20. Tin (Sn) for enhancing performance in silicon CMOS

    KAUST Repository

    Hussain, Aftab M.

    2013-10-01

    We study a group IV element: tin (Sn) by integrating it into silicon lattice, to enhance the performance of silicon CMOS. We have evaluated the electrical properties of the SiSn lattice by performing simulations using First-principle studies, followed by experimental device fabrication and characterization. We fabricated high-κ/metal gate based Metal-Oxide-Semiconductor capacitors (MOSCAPs) using SiSn as channel material to study the impact of Sn integration into silicon. © 2013 IEEE.

  1. High content screening as high quality assay for biological evaluation of photosensitizers in vitro.

    Directory of Open Access Journals (Sweden)

    Gisela M F Vaz

    Full Text Available A novel single step assay approach to screen a library of photdynamic therapy (PDT compounds was developed. Utilizing high content analysis (HCA technologies several robust cellular parameters were identified, which can be used to determine the phototoxic effects of porphyrin compounds which have been developed as potential anticancer agents directed against esophageal carcinoma. To demonstrate the proof of principle of this approach a small detailed study on five porphyrin based compounds was performed utilizing two relevant esophageal cancer cell lines (OE21 and SKGT-4. The measurable outputs from these early studies were then evaluated by performing a pilot screen using a set of 22 compounds. These data were evaluated and validated by performing comparative studies using a traditional colorimetric assay (MTT. The studies demonstrated that the HCS assay offers significant advantages over and above the currently used methods (directly related to the intracellular presence of the compounds by analysis of their integrated intensity and area within the cells. A high correlation was found between the high content screening (HCS and MTT data. However, the HCS approach provides additional information that allows a better understanding of the behavior of these compounds when interacting at the cellular level. This is the first step towards an automated high-throughput screening of photosensitizer drug candidates and the beginnings of an integrated and comprehensive quantitative structure action relationship (QSAR study for photosensitizer libraries.

  2. Effect of Cr Addition on Wetting Behavior Between Cu and High-Temperature Zn-25Sn-0.15Al-0.1Ga- xCr Pb-Free Solder

    Science.gov (United States)

    Liu, Chin-Wei; Lin, Kwang-Lung

    2014-12-01

    In this study the effect of Cr content (0.02 wt.% to 0.2 wt.%) on the wetting interaction between high-temperature Zn-25Sn-0.15Al-0.1Ga- xCr Pb-free solders and Cu has been investigated using the wetting balance method. Differential scanning calorimetry (DSC) investigation showed that Cr addition reduces the liquidus temperature slightly while raising the solidus temperature. Flux-assisted wetting experiments were carried out at an immersion rate of 15 mm/s at 435°C. The results show that the shortest wetting time of around 0.7 s was achieved when 0.1 wt.% Cr was added, but the wetting force tends to decrease with the Cr content. Cr addition enhances the formation of interfacial Cu5Zn8 intermetallic compound (IMC) during air cooling, but the opposite effect was observed for water cooling. The results suggest that Cr addition depresses the formation of the Cu5Zn8 layer in liquid/solid reaction, but enhances the formation of the Cu5Zn8 layer in solid/solid reaction.

  3. Analysis of the flux and polarization spectra of the type Ia supernova SN 2001el: Exploring the geometry of the high-velocity Ejecta

    Energy Technology Data Exchange (ETDEWEB)

    Kasen, Daniel; Nugent, Peter; Wang, Lifan; Howell, D.A.; Wheeler, J. Craig; Hoeflich, Peter; Baade, Dietrich; Baron, E.; Hauschildt, P.H.

    2003-01-15

    SN 2001el is the first normal Type Ia supernova to show a strong, intrinsic polarization signal. In addition, during the epochs prior to maximum light, the CaII IR triplet absorption is seen distinctly and separately at both normal photospheric velocities and at very high velocities. The unusual, high-velocity triplet absorption is highly polarized, with a different polarization angle than the rest of the spectrum. The unique observation allows us to construct a relatively detailed picture of the layered geometrical structure of the supernova ejecta: in our interpretation, the ejecta layers near the photosphere (v approximately 10,000 km/s) obey a near axial symmetry, while a detached, high-velocity structure (v approximately 18,000-25,000 $ km/s) of CaII line opacity deviates from the photospheric axisymmetry. By partially obscuring the underlying photosphere, the high-velocity structure causes a more incomplete cancellation of the polarization of the photospheric light, and so gives rise to the polarization peak of the high-velocity IR triplet feature. In an effort to constrain the ejecta geometry, we develop a technique for calculating 3-D synthetic polarization spectra and use it to generate polarization profiles for several parameterized configurations. In particular, we examine the case where the inner ejecta layers are ellipsoidal and the outer, high-velocity structure is one of four possibilities: a spherical shell, an ellipsoidal shell, a clumped shell, or a toroid. The synthetic spectra rule out the clearly discriminated if observations are obtained from several different lines of sight. Thus, assuming the high velocity structure observed for SN 2001el is a consistent feature of at least known subset of type Ia supernovae, future observations and analyses such as these may allow one to put strong constraints on the ejecta geometry and hence on supernova progenitors and explosion mechanisms.

  4. Pedagogical content knowledge and preparation of high school physics teachers

    Directory of Open Access Journals (Sweden)

    Eugenia Etkina

    2010-08-01

    Full Text Available This paper contains a scholarly description of pedagogical practices of the Rutgers Physics/Physical Science Teacher Preparation program. The program focuses on three aspects of teacher preparation: knowledge of physics, knowledge of pedagogy, and knowledge of how to teach physics (pedagogical content knowledge—PCK. The program has been in place for 7 years and has a steady production rate of an average of six teachers per year who remain in the profession. The main purpose of the paper is to provide information about a possible structure, organization, and individual elements of a program that prepares physics teachers. The philosophy of the program and the coursework can be implemented either in a physics department or in a school of education. The paper provides details about the program course work and teaching experiences and suggests ways to adapt it to other local conditions.

  5. Electric-arc synthesis of soot with high content of higher fullerenes in parallel arc

    Science.gov (United States)

    Dutlov, A. E.; Nekrasov, V. M.; Sergeev, A. G.; Bubnov, V. P.; Kareev, I. E.

    2016-12-01

    Soot with a relatively high content of higher fullerenes (C76, C78, C80, C82, C84, C86, etc.) is synthesized in a parallel arc upon evaporation of pure carbon electrodes. The content of higher fullerenes in soot extract amounts to 13.8 wt % when two electrodes are simultaneously burnt in electric-arc reactor. Such a content is comparable with the content obtained upon evaporation of composite graphite electrodes with potassium carbonate impurity.

  6. Using High-Content Imaging to Analyze Toxicological Tipping Points (ICTATT meeting China)

    Science.gov (United States)

    Presentation at International Conference on Toxicological Alternatives & Translational Toxicology (ICTATT) held in China and Discussing the possibility of using High Content Imaging to Analyze Toxicological Tipping Points

  7. Self-assembly of novel hierarchical flowers-like Sn{sub 3}O{sub 4} decorated on 2D graphene nanosheets hybrid as high-performance anode materials for LIBs

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Xuefang, E-mail: 1021633952@qq.com [Department of Applied Chemistry and The Key Laboratory of Space Applied Physics and Chemistry, Ministry of Education, School of Science, Northwestern Polytechnical University, Xi’an 710072 (China); Huang, Ying, E-mail: yingh@nwpu.edu.cn [Department of Applied Chemistry and The Key Laboratory of Space Applied Physics and Chemistry, Ministry of Education, School of Science, Northwestern Polytechnical University, Xi’an 710072 (China); Li, Tianpeng [Shijiazhuang Mechanical Engineering College, Shi Jia Zhuang 050003 (China); Wei, Chao; Yan, Jing; Feng, Xuansheng [Department of Applied Chemistry and The Key Laboratory of Space Applied Physics and Chemistry, Ministry of Education, School of Science, Northwestern Polytechnical University, Xi’an 710072 (China)

    2017-05-31

    Highlights: • Novel hierarchical Sn{sub 3}O{sub 4} decorated on graphene nanosheets has been synthesized. • As the anode materials, the composite has not been investigated. • An insight into the common discharging behavior of the composite. • The composite displayed high capacity and good cycling stability. - Abstract: Novel hierarchical flower-like Sn{sub 3}O{sub 4} assembled by thin Sn{sub 3}O{sub 4} nanosheets{sub ,} as a kind of mixed-valence tin oxide, decorated on two-dimensional graphene nanosheets has been synthesized via a hydrothermal route and a step solution deoxidization technique. More importantly, as the anode materials for lithium ion batteries, the flower-like Sn{sub 3}O{sub 4}/graphene composite has not been investigated in detail. Noticeably, the nanosheets stemming from flower-like Sn{sub 3}O{sub 4} and graphene have been linked together to form a specials three dimensional structure, possessing high active surface area and large enough inner spaces, which is benefit to the diffusion of liquid electrolyte into the electrode materials. In addition, the special structure could provide sufficient free volume to buffer the volume expansion appeared in the process of discharging and charging. The as-prepared flowers-like Sn{sub 3}O{sub 4}/graphene displayed excellent electrochemical performance with high capacity and good cycling stability as anode materials for lithium ion batteries. The discharge capacity is 1727 mAh/g in the first cycle at the current density of 60 mA/g. The obtained reversible capacity is 631mAh/g with a coulomb efficiency of 97.04% after 50 cycles. With its better electrochemical properties, the as-prepared flowers-like Sn{sub 3}O{sub 4}/graphene has the potential to be the next generation materials as an environmentally benign, abundant, cheap anode materials for lithium ion batteries.

  8. High-performance flexible perovskite solar cells exploiting Zn2SnO4 prepared in solution below 100 °C.

    Science.gov (United States)

    Shin, Seong Sik; Yang, Woon Seok; Noh, Jun Hong; Suk, Jae Ho; Jeon, Nam Joong; Park, Jong Hoon; Kim, Ju Seong; Seong, Won Mo; Seok, Sang Il

    2015-06-22

    Fabricating inorganic-organic hybrid perovskite solar cells (PSCs) on plastic substrates broadens their scope for implementation in real systems by imparting portability, conformability and allowing high-throughput production, which is necessary for lowering costs. Here we report a new route to prepare highly dispersed Zn2SnO4 (ZSO) nanoparticles at low-temperature (introduction of the ZSO film significantly improves transmittance of flexible polyethylene naphthalate/indium-doped tin oxide (PEN/ITO)-coated substrate from ∼75 to ∼90% over the entire range of wavelengths. The best performing flexible PSC, based on the ZSO and CH3NH3PbI3 layer, exhibits steady-state power conversion efficiency (PCE) of 14.85% under AM 1.5G 100 mW·cm(-2) illumination. This renders ZSO a promising candidate as electron-conducting electrode for the highly efficient flexible PSC applications.

  9. The complete automation of cell culture: improvements for high-throughput and high-content screening.

    Science.gov (United States)

    Jain, Shushant; Sondervan, David; Rizzu, Patrizia; Bochdanovits, Zoltan; Caminada, Daniel; Heutink, Peter

    2011-09-01

    Genomic approaches provide enormous amounts of raw data with regard to genetic variation, the diversity of RNA species, and protein complement. High-throughput (HT) and high-content (HC) cellular screens are ideally suited to contextualize the information gathered from other "omic" approaches into networks and can be used for the identification of therapeutic targets. Current methods used for HT-HC screens are laborious, time-consuming, and prone to human error. The authors thus developed an automated high-throughput system with an integrated fluorescent imager for HC screens called the AI.CELLHOST. The implementation of user-defined culturing and assay plate setup parameters allows parallel operation of multiple screens in diverse mammalian cell types. The authors demonstrate that such a system is able to successfully maintain different cell lines in culture for extended periods of time as well as significantly increasing throughput, accuracy, and reproducibility of HT and HC screens.

  10. Study of a SiGeSn/GeSn/SiGeSn structure toward direct bandgap type-I quantum well for all group-IV optoelectronics.

    Science.gov (United States)

    Ghetmiri, Seyed Amir; Zhou, Yiyin; Margetis, Joe; Al-Kabi, Sattar; Dou, Wei; Mosleh, Aboozar; Du, Wei; Kuchuk, Andrian; Liu, Jifeng; Sun, Greg; Soref, Richard A; Tolle, John; Naseem, Hameed A; Li, Baohua; Mortazavi, Mansour; Yu, Shui-Qing

    2017-02-01

    A SiGeSn/GeSn/SiGeSn single quantum well structure was grown using an industry standard chemical vapor deposition reactor with low-cost commercially available precursors. The material characterization revealed the precisely controlled material growth process. Temperature-dependent photoluminescence spectra were correlated with band structure calculation for a structure accurately determined by high-resolution x-ray diffraction and transmission electron microscopy. Based on the result, a systematic study of SiGeSn and GeSn bandgap energy separation and barrier heights versus material compositions and strain was conducted, leading to a practical design of a type-I direct bandgap quantum well.

  11. Summary of Test Results of MQXFS1—The First Short Model 150 mm Aperture Nb$_3$Sn Quadrupole for the High-Luminosity LHC Upgrade

    CERN Document Server

    Stoynev, S; Anerella, M; Bossert, R; Cavanna, E; Cheng, D; Dietderich, D; DiMarco, J; Felice, H; Ferracin, P; Chlachidze, G; Ghosh, A; Grosclaude, P; Guinchard, M; Hafalia, A R; Holik, E; Izquierdo Bermudez, S; Krave, S; Marchevsky, M; Nobrega, F; Orris, D; Pan, H; Perez, J C; Prestemon, S; Ravaioli, E; Sabbi, G; Salmi, T; Schmalzle, J; Strauss, T; Sylvester, C; Tartaglia, M; Todesco, E; Vallone, G; Velev, G; Wanderer, P; Wang, X; Yu, M

    2017-01-01

    The development of $Nb_3Sn$ quadrupole magnets for the High-Luminosity LHC upgrade is a joint venture between the US LHC Accelerator Research Program (LARP)* and CERN with the goal of fabricating large aperture quadrupoles for the LHC in-teraction regions (IR). The inner triplet (low-β) NbTi quadrupoles in the IR will be replaced by the stronger Nb3Sn magnets boosting the LHC program of having 10-fold increase in integrated luminos-ity after the foreseen upgrades. Previously LARP conducted suc-cessful tests of short and long models with up to 120 mm aperture. The first short 150 mm aperture quadrupole model MQXFS1 was assembled with coils fabricated by both CERN and LARP. The magnet demonstrated strong performance at the Fermilab’s verti-cal magnet test facility reaching the LHC operating limits. This paper reports the latest results from MQXFS1 tests with changed pre-stress levels. The overall magnet performance, including quench training and memory, ramp rate and temperature depend-ence, is also summariz...

  12. Summary of Test Results of MQXFS1 - The First Short Model 150 mm Aperture $Nb_3Sn$ Quadrupole for the High-Luminosity

    Energy Technology Data Exchange (ETDEWEB)

    Stoynev, S.; et al.

    2017-01-01

    The development of $Nb_3Sn$ quadrupole magnets for the High-Luminosity LHC upgrade is a joint venture between the US LHC Accelerator Research Program (LARP)* and CERN with the goal of fabricating large aperture quadrupoles for the LHC in-teraction regions (IR). The inner triplet (low-β) NbTi quadrupoles in the IR will be replaced by the stronger Nb3Sn magnets boosting the LHC program of having 10-fold increase in integrated luminos-ity after the foreseen upgrades. Previously LARP conducted suc-cessful tests of short and long models with up to 120 mm aperture. The first short 150 mm aperture quadrupole model MQXFS1 was assembled with coils fabricated by both CERN and LARP. The magnet demonstrated strong performance at the Fermilab’s verti-cal magnet test facility reaching the LHC operating limits. This paper reports the latest results from MQXFS1 tests with changed pre-stress levels. The overall magnet performance, including quench training and memory, ramp rate and temperature depend-ence, is also summarized.

  13. Second Generation Coil Design of the Nb3Sn low-beta Quadrupole for the High Luminosity LHC

    CERN Document Server

    Izquierdo Bermudez, S; Ballarino, A; Cavanna, E; Bossert, R; Cheng, D; Dietderich, D; Ferracin, P; Ghosh, A; Hagen,P; Holik, E; Perez, J C; Rochepault, E; Schmalzle, J; Todesco, E; Yu, M

    2016-01-01

    As part of the Large Hadron Collider Luminosity upgrade (HiLumi-LHC) program, the US LARP collaboration and CERN are working together to design and build a 150 mm aperture Nb3Sn quadrupole for the LHC interaction regions. A first series of 1.5 m long coils were fabricated and assembled in a first short model. A detailed visual inspection of the coils was carried out to investigate cable dimensional changes during heat treatment and the position of the windings in the coil straight section and in the end region. The analyses allow identifying a set of design changes which, combined with a fine tune of the cable geometry and a field quality optimization, were implemented in a new, second-generation, coil design. In this paper we review the main characteristics of the first generation coils, describe the modification in coil lay-out, and discuss their impact on parts design and magnet analysis.

  14. High-speed photorefraction at telecommunication wavelength 1.55 microm in Sn2P2S6:Te.

    Science.gov (United States)

    Mosimann, Roger; Marty, Patrick; Bach, Tobias; Juvalta, Flurin; Jazbinsek, Mojca; Günter, Peter; Grabar, Alexander A

    2007-11-15

    We demonstrated for what is the first time to our knowledge photorefractive two-wave mixing in a bulk ferroelectric crystal using cw light at the telecommunication wavelength 1.55 microm. In the Te-doped ferroelectric semiconductor Sn2P2S6 with absorption constant <0.1 cm(-1) at 1.55 microm, grating recording times of 10 ms and a two-beam coupling gain of 2.8 cm(-1) have been measured at 350 mW power (intensity 440 W/cm(2)) without a necessity to apply an external electric field. With a moving grating technique, a maximal gain of 6.0 cm(-1) has been obtained.

  15. Thermal Analysis of ZPPR High Pu Content Stored Fuel

    Directory of Open Access Journals (Sweden)

    Charles W. Solbrig

    2014-01-01

    Full Text Available The Zero Power Physics Reactor (ZPPR operated from April 18, 1969, until 1990. ZPPR operated at low power for testing nuclear reactor designs. This paper examines the temperature of Pu content ZPPR fuel while it is in storage. Heat is generated in the fuel due to Pu and Am decay and is a concern for possible cladding damage. Damage to the cladding could lead to fuel hydriding and oxidizing. A series of computer simulations were made to determine the range of temperatures potentially occuring in the ZPPR fuel. The maximum calculated fuel temperature is 292°C (558°F. Conservative assumptions in the model intentionally overestimate temperatures. The stored fuel temperatures are dependent on the distribution of fuel in the surrounding storage compartments, the heat generation rate of the fuel, and the orientation of fuel. Direct fuel temperatures could not be measured but storage bin doors, storage sleeve doors, and storage canister temperatures were measured. Comparison of these three temperatures to the calculations indicates that the temperatures calculated with conservative assumptions are, as expected, higher than the actual temperatures. The maximum calculated fuel temperature with the most conservative assumptions is significantly below the fuel failure criterion of 600°C (1,112°F.

  16. Rational design of Sn/SnO{sub 2}/porous carbon nanocomposites as anode materials for sodium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiaojia [Tianjin International Joint Research Centre of Surface Technology for Energy Storage Materials, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Li, Xifei, E-mail: xfli2011@hotmail.com [Tianjin International Joint Research Centre of Surface Technology for Energy Storage Materials, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Center for Advanced Energy Materials and Devices, Xi’an University of Technology, Xi’an 710048 (China); Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education), Collaborative Innovation Center of Chemical Science and Engineering, College of Chemistry, Nankai University, Tianjin 300071 (China); Fan, Linlin; Yu, Zhuxin; Yan, Bo; Xiong, Dongbin; Song, Xiaosheng; Li, Shiyu [Tianjin International Joint Research Centre of Surface Technology for Energy Storage Materials, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Adair, Keegan R. [Nanomaterials and Energy Lab., Department of Mechanical and Materials Engineering, Western University, London, Ontario N6A 5B9 (Canada); Li, Dejun, E-mail: dejunli@mail.tjnu.edu.cn [Tianjin International Joint Research Centre of Surface Technology for Energy Storage Materials, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China); Sun, Xueliang, E-mail: xsun9@uwo.ca [Nanomaterials and Energy Lab., Department of Mechanical and Materials Engineering, Western University, London, Ontario N6A 5B9 (Canada); Tianjin International Joint Research Centre of Surface Technology for Energy Storage Materials, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387 (China)

    2017-08-01

    Highlights: • Sn/SnO{sub 2}/porous carbon nanocomposites are rationally designed via a facile strategy. • The porous carbon mitigates the volume change and poor conductivity of Sn/SnO{sub 2}. • The nanocomposites exhibit the enhanced sodium storage performance. - Abstract: Sodium-ion batteries (SIBs) have successfully attracted considerable attention for application in energy storage, and have been proposed as an alternative to lithium ion batteries (LIBs) due to the abundance of sodium resources and low price. Sn has been deemed as a promising anode material in SIBs which holds high theoretical specific capacity of 845 mAh g{sup −1}. In this work we design nanocomposite materials consisting of porous carbon (PC) with SnO{sub 2} and Sn (Sn/SnO{sub 2}/PC) via a facile reflux method. Served as an anode material for SIBs, the Sn/SnO{sub 2}/PC nanocomposite delivers the primary discharge and charge capacities of 1148.1 and 303.0 mAh g{sup −1}, respectively. Meanwhile, it can preserve the discharge capacity approximately of 265.4 mAh g{sup −1} after 50 cycles, which is much higher than those of SnO{sub 2}/PC (138.5 mAh g{sup −1}) and PC (92.2 mAh g{sup −1}). Furthermore, the Sn/SnO{sub 2}/PC nanocomposite possesses better cycling stability with 77.8% capacity retention compared to that of SnO{sub 2}/PC (61.88%) over 50 cycles. Obviously, the Sn/SnO{sub 2}/PC composite with excellent electrochemical performance shows the great possibility of application in SIBs.

  17. Aconitum alkaloid content and the high toxicity of aconite tincture.

    Science.gov (United States)

    Chan, Thomas Y K

    2012-10-10

    Although proprietary medicines and decoction of processed aconite roots are the most widely used, tincture accounts for the great majority of aconite poisoning cases in China, indicating that it is much more toxic than other formulations. Aconite tincture is often self-prepared at home and raw aconite plants or roots are often used. Even if processed aconite roots were used to make the tincture, the amount of Aconitum alkaloids is highly variable, depending on the adequacy of processing and quality control. Aconitum alkaloids dissolve efficiently in alcohol. For these reasons, tincture contains very high concentrations of Aconitum alkaloids. Despite its high intrinsic toxicity, overdose of aconite tincture by the users has been common. Severe aconite poisoning can be complicated by fatal ventricular tachyarrhythmias and asystole. The public should be repeatedly warned of the danger of taking aconite tincture by mouth. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  18. An Efficient Pd-Sn Catalyst Supported on MWNTs for Hydrogenation of High Concentrated Acetylene Feedstocks: The Potential Role of Isolated Adsorption Site

    Directory of Open Access Journals (Sweden)

    E. Esmaeili

    2014-04-01

    Full Text Available In the present study, tin-promoted Pd/MWNTs nanocatalystwas synthesized via polyol technique for application in hydrogenation of high-concentrated acetylene feedstocks. TEM images showed a restricted distribution of nanoparticles in the range of 3-5 nm. The results indicated that nanoparticles sizes were resistant to further catalyst deactivation. XRD patterns signified alloying between Pd and Sn which contained a high percentage of ordered intermetallic structures (70.8%, as confirmed by XPS. According to the results, pore blocking and/or fouling was known as the main reasons of the catalyst deactivation. Here, we supposed a novel deactivation mechanism based on which dehydrogenation susceptibility of carbonaceous species (green oil played a significant role in the formation of the isolated adsorption sites and then, catalyst deactivation.

  19. INSIDIA: A FIJI Macro Delivering High-Throughput and High-Content Spheroid Invasion Analysis.

    Science.gov (United States)

    Moriconi, Chiara; Palmieri, Valentina; Di Santo, Riccardo; Tornillo, Giusy; Papi, Massimiliano; Pilkington, Geoff; De Spirito, Marco; Gumbleton, Mark

    2017-10-01

    Time-series image capture of in vitro 3D spheroidal cancer models embedded within an extracellular matrix affords examination of spheroid growth and cancer cell invasion. However, a customizable, comprehensive and open source solution for the quantitative analysis of such spheroid images is lacking. Here, the authors describe INSIDIA (INvasion SpheroID ImageJ Analysis), an open-source macro implemented as a customizable software algorithm running on the FIJI platform, that enables high-throughput high-content quantitative analysis of spheroid images (both bright-field gray and fluorescent images) with the output of a range of parameters defining the spheroid "tumor" core and its invasive characteristics. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. An Introduction to Computing: Content for a High School Course.

    Science.gov (United States)

    Rogers, Jean B.

    A general outline of the topics that might be covered in a computers and computing course for high school students is provided. Topics are listed in the order in which they should be taught, and the relative amount of time to be spent on each topic is suggested. Seven units are included in the course outline: (1) general introduction, (2) using…

  1. Chemistry, growth kinetics, and epitaxial stabilization of Sn2+ in Sn-doped SrTiO3 using (CH36Sn2 tin precursor

    Directory of Open Access Journals (Sweden)

    Tianqi Wang

    2016-12-01

    Full Text Available PbTiO3-based ferroelectrics have impressive electroactive properties, originating from the Pb2+ 6s2 electron lone-pair, which cause large elastic distortion and electric polarization due to cooperative pseudo Jahn-Teller effect. Recently, tin-based perovskite oxide (SnTiO3 containing Sn2+ and a chemistry similar to that of the 6s2 lone-pair has been identified as a thermally stable, environmentally friendly substitute for PbTiO3-based ferroelectrics. However experimental attempts to stabilize Sn2+ on the A-site of perovskite ATiO3 have so far failed. In this work, we report on the growth of atomically smooth, epitaxial, and coherent Sn-alloyed SrTiO3 films on SrTiO3 (001 substrates using a hybrid molecular beam epitaxy approach. With increasing Sn concentration, the out-of-plane lattice parameter first increases in accordance with the Vegard’s law and then decreases for Sn(Sr+Ti+Sn at. % ratio > 0.1 due to the incorporation of Sn2+ at the A-site. Using a combination of high-resolution X-ray photoelectron spectroscopy and density functional calculations, we show that while majority of Sn is on the B-site, there is a quantitatively unknown fraction of Sn being consistent with the A-site occupancy making SrTiO3 polar. A relaxor-like ferroelectric local distortion with monoclinic symmetry, induced by A-site Sn2+, was observed in Sn-doped SrTiO3 with Sn(Sr+Ti+Sn at. % ratio = 0.1 using optical second harmonic generation measurements. The role of growth kinetics on the stability of Sn2+ in SrTiO3 is discussed.

  2. Ultrafine Sn nanoparticles embedded in shell of N-doped hollow carbon spheres as high rate anode for lithium-ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Dou, Peng; Cao, Zhenzhen; Wang, Chao; Zheng, Jiao [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Xu, Xinhua, E-mail: xhxutju@gmail.com [School of Materials Science and Engineering, Tianjin University, Tianjin 300072 (China); Tianjin Key Laboratory of Composite and Functional Materials, Tianjin 300072 (China)

    2017-05-15

    Highlights: • Dynamic covalent bond in polymeric nanoparticles is used to induce hollow Sn{sup 4+}-MOPs. • Ultrafine Sn nanoparticles uniformly embedded in shell of N-doped hollow carbon spheres is successfully synthesized by pyrolysis of the Sn{sup 4+}-MOPs precursor. • The composite exhibits superior cycle stability and rate capacity. - Abstract: A novel reversible interaction in polymeric nanoparticles is used to induce hollow Sn{sup 4+}-MOPs. Then ultrafine Sn nanoparticles uniformly embedded in shell of N-doped hollow carbon spheres is successfully synthesized by pyrolysis of the Sn{sup 4+}-MOPs precursor. In this architecture, the N-doped carbon shells can effectively avoid the direct exposure of embedded Sn nanoparticles to the electrolyte and efficiently accommodate the volume change of Sn nanoparticles. Furthermore, the hollow structure of carbon sphere can prevent Sn nanoparticles aggregation over repeated cycling and shorten the diffusion path of both electrons and ions. As a consequence, this N-doped hollow Sn/C anode delivers a reversible capacity of 606 mA h g{sup −1} at a current density of 0.2 A g{sup −1} after 250 cycles and a reversible capacity of 221 mA h g{sup −1} even at a much higher current density of 10 A g{sup −1}, which are much better than those of pure Sn nanoparticles. The desirable cyclic stability and rate capability were attributed to the unique architecture that provided fast pathway for electron transport and simultaneously solved the major issues of Sn-based anodes, such as pulverization, aggregation and loss of electrical contact.

  3. High Light Absorption and Charge Separation Efficiency at Low Applied Voltage from Sb-Doped SnO2/BiVO4 Core/Shell Nanorod-Array Photoanodes.

    Science.gov (United States)

    Zhou, Lite; Zhao, Chenqi; Giri, Binod; Allen, Patrick; Xu, Xiaowei; Joshi, Hrushikesh; Fan, Yangyang; Titova, Lyubov V; Rao, Pratap M

    2016-06-08

    BiVO4 has become the top-performing semiconductor among photoanodes for photoelectrochemical water oxidation. However, BiVO4 photoanodes are still limited to a fraction of the theoretically possible photocurrent at low applied voltages because of modest charge transport properties and a trade-off between light absorption and charge separation efficiencies. Here, we investigate photoanodes composed of thin layers of BiVO4 coated onto Sb-doped SnO2 (Sb:SnO2) nanorod-arrays (Sb:SnO2/BiVO4 NRAs) and demonstrate a high value for the product of light absorption and charge separation efficiencies (ηabs × ηsep) of ∼51% at an applied voltage of 0.6 V versus the reversible hydrogen electrode, as determined by integration of the quantum efficiency over the standard AM 1.5G spectrum. To the best of our knowledge, this is one of the highest ηabs × ηsep efficiencies achieved to date at this voltage for nanowire-core/BiVO4-shell photoanodes. Moreover, although WO3 has recently been extensively studied as a core nanowire material for core/shell BiVO4 photoanodes, the Sb:SnO2/BiVO4 NRAs generate larger photocurrents, especially at low applied voltages. In addition, we present control experiments on planar Sb:SnO2/BiVO4 and WO3/BiVO4 heterojunctions, which indicate that Sb:SnO2 is more favorable as a core material. These results indicate that integration of Sb:SnO2 nanorod cores with other successful strategies such as doping and coating with oxygen evolution catalysts can move the performance of BiVO4 and related semiconductors closer to their theoretical potential.

  4. Obtaining of High Cr Content Cast Iron Materials

    Science.gov (United States)

    Florea, C.; Bejinariu, C.; Carcea, I.; Cimpoesu, N.; Chicet, D. L.; Savin, C.

    2017-06-01

    We have obtained, through the classic casting process, 3 highly chromium-based experimental alloys proposed for replacing the FC 250 classical cast iron in braking applications. Casting was carried out in an induction furnace and cast into moulds made of KALHARTZ 8500 resin casting mixture and HARTER hardener at SC RanCon SRL Iasi. It is known that the microstructure of the cast iron is a combination of martensite with a small amount of residual austenite after the heat treatment of the ingot. In the case of high-alloy chromium alloys, the performance of the material is due to the presence of M7C3 carbides distributed in the iron matrix Resistance to machining and deformation is based on alloy composition and microstructure, while abrasion resistance will depend on properties and wear conditions.

  5. An objective method for High Dynamic Range source content selection

    DEFF Research Database (Denmark)

    Narwaria, Manish; Mantel, Claire; Da Silva, Matthieu Perreira

    2014-01-01

    With the aim of improving the immersive experience of the end user, High Dynamic Range (HDR) imaging has been gaining popularity. Therefore, proper validation and performance benchmarking of HDR processing algorithms is a key step towards standardization and commercial deployment. A crucial compo...... visible errors on contrast reduction. This information is subsequently analyzed via fuzzy clustering to enable a probabilistic interpretation. To evaluate the proposed approach, we performed an experimental study on a large set of publicly available HDR images....

  6. Ultrafine Sn nanoparticles embedded in shell of N-doped hollow carbon spheres as high rate anode for lithium-ion batteries

    Science.gov (United States)

    Dou, Peng; Cao, Zhenzhen; Wang, Chao; Zheng, Jiao; Xu, Xinhua

    2017-05-01

    A novel reversible interaction in polymeric nanoparticles is used to induce hollow Sn4+-MOPs. Then ultrafine Sn nanoparticles uniformly embedded in shell of N-doped hollow carbon spheres is successfully synthesized by pyrolysis of the Sn4+-MOPs precursor. In this architecture, the N-doped carbon shells can effectively avoid the direct exposure of embedded Sn nanoparticles to the electrolyte and efficiently accommodate the volume change of Sn nanoparticles. Furthermore, the hollow structure of carbon sphere can prevent Sn nanoparticles aggregation over repeated cycling and shorten the diffusion path of both electrons and ions. As a consequence, this N-doped hollow Sn/C anode delivers a reversible capacity of 606 mA h g-1 at a current density of 0.2 A g-1 after 250 cycles and a reversible capacity of 221 mA h g-1 even at a much higher current density of 10 A g-1, which are much better than those of pure Sn nanoparticles. The desirable cyclic stability and rate capability were attributed to the unique architecture that provided fast pathway for electron transport and simultaneously solved the major issues of Sn-based anodes, such as pulverization, aggregation and loss of electrical contact.

  7. High-content screening of yeast mutant libraries by shotgun lipidomics

    DEFF Research Database (Denmark)

    Tarasov, Kirill; Stefanko, Adam; Casanovas, Albert

    2014-01-01

    To identify proteins with a functional role in lipid metabolism and homeostasis we designed a high-throughput platform for high-content lipidomic screening of yeast mutant libraries. To this end, we combined culturing and lipid extraction in 96-well format, automated direct infusion...... factor KAR4 precipitated distinct lipid metabolic phenotypes. These results demonstrate that the high-throughput shotgun lipidomics platform is a valid and complementary proxy for high-content screening of yeast mutant libraries....

  8. SiO{sub 2}@SnO{sub 2}/graphene composite with a coating and hierarchical structure as high performance anode material for lithium ion battery

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Xingfa; Zhang, Haiyan, E-mail: hyzhang@gdut.edu.cn; Chen, Yiming; Li, Na; Li, Yunyong; Liu, Liying

    2016-08-25

    In order to ease the agglomeration and huge volume change of SnO{sub 2} particles, SnO{sub 2} nanoparticles were usually anchored on reduced graphene oxide (rGO) and used as anode materials for lithium ion batteries. Unfortunately, graphene sheets tended to overlap with adjacent ones and SnO{sub 2} nanoparticles still suffered from agglomeration and huge volume changes to some extent. In this paper, a composite SiO{sub 2}@SnO{sub 2}/rGO with coating and hierarchical structure was synthesized by a facile hydrothermal method. SnO{sub 2} nanoparticles mono-dispersed on the surface of rGO sheets and SiO{sub 2} spheres, while the SiO{sub 2}@SnO{sub 2} spheres were imbedded in the layers of rGO, which was in favor of alleviating the overlapping of graphene sheets and could make large spacious room to accommodate the huge volume changes of SnO{sub 2} nanoparticles. SiO{sub 2}@SnO{sub 2}/rGO composite also displayed good electrochemical performance. In the first charge/discharge cycle, the SiO{sub 2}@SnO{sub 2}/rGO electrode exhibited a large discharge capacity of 1548 mA h g{sup −1} at a current density of 100 mA g{sup −1} and it still retained a discharge capacity of about 600 mA h g{sup −1} after 100 cycles. - Highlights: • Anodes fabricated by using activated carbon have the highest fracture strength. • SnO{sub 2} nanoparticles are mono-dispersed on the surface of rGO sheets and SiO{sub 2} spheres. • The hierarchical structure SiO{sub 2}@SnO{sub 2}/rGO shows a good electrochemical performance.

  9. Investigation on the variation of channel resistance and contact resistance of SiZnSnO semiconductor depending on Si contents using transmission line method

    Science.gov (United States)

    Lee, Byeong Hyeon; Han, Sangmin; Lee, Sang Yeol

    2018-01-01

    Amorphous silicon-zinc-tin-oxide (a-SZTO) thin film transistors (TFTs) have been fabricated depending on the silicon ratio in channel layers. The a-SZTO TFT exhibited high electrical properties, such as high mobility of 23 cm2 V-1 s-1, subthreshold swing of 0.74 V/decade and ION/OFF of 2.8 × 108, despite of the addition of Si suppressor. The physical mechanism on the change of the sheet resistance and the contact resistance in a-SZTO TFT has been investigated and proposed closely related with the Si ratio. Both resistances were increased as increasing Si ratio, which clearly indicated that the role of Si is a carrier suppressor directly leading to the increase of channel and contact resistances. To explain the role of Si as a carrier suppressor, the conduction band offset mechanism has been also proposed depending on the change of carrier concentration in channel layer and at the interface between electrode and channel layer. 2007.01-2011.12 Senior Researcher at korea institute of science and technology (KOREA). 2008.01-2011.12 Professor at University of Science and Technology (KOREA). 1995.01-2007.12 Professor at Yonsei University (KOREA). 2002.01-2003.12 Inviting Researcher at Los Alamos National Lab (USA). 1993.01-1995.12 Senior Researcher at Electronics and Telecommunications Research Institute (KOREA). 1992.01-1993.01 Research Associate at State University of New York at Buffalo (USA).

  10. Facile synthesis of Cu2ZnSnS4 absorber layer for thin film solar cells using a highly stable precursor solution

    Science.gov (United States)

    Dhanasekar, M.; Bhat, S. Venkataprasad

    2017-10-01

    In search of simpler, environment friendly, scalable method to make device quality Cu2ZnSnS4 semiconductor thinfilms for solar cell applications, we have developed a solution based technique based on a highly stable precursor solution. A clear transparent precursor solution, stable for more than a year was prepared using a novel combination of the sulfur source and the solvent. The absorber film on Mo coated glass substrate was formed by dip-coating and drying in open air, followed by annealing in inert atmosphere. Further, we have fabricated and demonstrated a simple solar cell, combining this method with vacuum-free laminated conductive tape as the top electrode, having the device structure of glass/Mo/CZTS/CdS/Al.

  11. Photoelectrochemical, impedance and optical data for self Sn-diffusion doped Fe2O3 photoanodes fabricated at high temperature by one and two-step annealing methods

    Directory of Open Access Journals (Sweden)

    Pravin S. Shinde

    2015-12-01

    Full Text Available The optical, morphological and photoelectrochemical (PEC properties of transition metal oxide semiconductors are important to understand their influence on water oxidation performance. Herein, we provide experimental evidences for a better understanding of the factors that dictate the interactions of Sn-diffusion doping on the PEC properties of Fe2O3 photoanodes fabricated at high temperature by one- and two-step annealing methods. The synthesis, characterization methods and other experimental details are provided. Limited previous information on the PEC and electrochemical impedance spectroscopic studies has been published. This data article contains Supplementary data, figures and methods related to the research article by Shinde et al. (2015 [1]. Here, we provide a further set of the obtained experimental data results.

  12. Highly sensitive room temperature carbon monoxide detection using SnO2 nanoparticle-decorated semiconducting single-walled carbon nanotubes

    Science.gov (United States)

    Zhang, Yang; Cui, Shumao; Chang, Jingbo; Ocola, Leonidas E.; Chen, Junhong

    2013-01-01

    We demonstrate a practical sensing platform, consisting of SnO2 nanoparticle-decorated semiconducting single-walled carbon nanotubes assembled on gold electrodes via a dielectrophoretic process, for highly sensitive CO detection with fast response at room temperature. The highest sensitivity obtained was 0.27 and the response time was ˜2 s for 100 ppm CO detection. The lower detection limit was ˜1 ppm. These results indicate that the sensing performance of our device is among the best of CO sensors implemented with SWNTs. Further, we observed a significant increase in sensitivity to 0.67 after subjecting the device to an electrical breakdown at 8 V. We also proposed a theoretical model to reveal the relationship between the sensitivity and the gas concentration. The new model not only resulted in a nice fit to our data, but also allowed us to estimate the contact resistance between an individual SWNT and the gold electrodes.

  13. Highly luminescent S,N co-doped carbon quantum dots-sensitized chemiluminescence on luminol-H2 O2 system for the determination of ranitidine.

    Science.gov (United States)

    Chen, Jianqiu; Shu, Juan; Chen, Jiao; Cao, Zhiran; Xiao, An; Yan, Zhengyu

    2017-05-01

    S,N co-doped carbon quantum dots (N,S-CQDs) with super high quantum yield (79%) were prepared by the hydrothermal method and characterized by transmission electron microscopy, photoluminescence, UV-Vis spectroscopy and Fourier transformed infrared spectroscopy. N,S-CQDs can enhance the chemiluminescence intensity of a luminol-H2 O2 system. The possible mechanism of the luminol-H2 O2 -(N,S-CQDs) was illustrated by using chemiluminescence, photoluminescence and ultraviolet analysis. Ranitidine can quench the chemiluminescence intensity of a luminol-H2 O2 -N,S-CQDs system. So, a novel flow-injection chemiluminescence method was designed to determine ranitidine within a linear range of 0.5-50 μg ml(-1) and a detection limit of 0.12 μg ml(-1) . The method shows promising application prospects. Copyright © 2016 John Wiley & Sons, Ltd.

  14. [Microstructure and spectral property of Er3+ doped transparent oxyfluoride glass ceramics with high fluorine contents].

    Science.gov (United States)

    Lin, Le-Jing; Ren, Guo-Zhong; Chen, Min-Peng; Liu, Yang

    2009-12-01

    The microstructure and spectral properties of Er3+ doped transparent oxyfluoride glass ceramics with high fluorine content were reported. Two samples with the same initial contents (50SiO2-45PbF2-5PbO-1ErF3) were prepared under the different preparation parameters. The final fluorine contents were detected by a fluoride ion selective electrode. The results shows that the final fluorine contents increase by covering crucibles with corundum lid during melt. The samples were characterized by X-ray diffraction, transmission electron microscopy (TEM), absorption spectra and upconversion luminescence spectra. The results show that PbF2 crystals were precipitated in the sample with high fluorine content before heat treatment. And the PbF2 crystals precipitated inside the glass matrix are spherical with diameters of approximately 10-15 nm in size from the high resolution TEM micrograph. The absorption spectra, J-O parameters and the upconversion spectra show that the Er3+ ions were located in crystalline and vitreous mixed states. It is different from the sample with low fluorine content which is completely amorphous. After heat treatment, Er3+ ions that remain in the glassy phase entered into fluoride nanocrystals in the sample with high fluorine content. The fluorine environment decreases non-radiative transfer which eases the upconversion processes. Hence, the upconversion luminescence intensity of Er3+ ions in the high fluorine content sample after heat treatment is much stronger than that in the precursor sample.

  15. Trend in Plutonium Content of MOX in Thermal Reactor Use and Irradiation Behavior of MOX with High Plutonium Content

    Energy Technology Data Exchange (ETDEWEB)

    Nakae, N.; Baba, T.; Kamimura, K. [Japan Nuclear Energy Safety Organization - JNES, TOKYU REIT Toranomon Bldg., 3-17-1, Toranomon, Minato-ku, Tokyo, 105-0001 (Japan); Verwerft, M.; Jutier, F. [SCK-CEN (Belgium)

    2009-06-15

    The uranium enrichment of UO{sub 2} fuel for the current power reactors, both PWR and BWR, tends to increase because of increasing burn-up target. The plutonium content of MOX fuel used in thermal reactors shall be determined in order to have reactivity worth equivalent to enriched UO{sub 2} fuel based on physical accounting method for adjusting fissile enrichment, thus the plutonium content tends to increase according to the increment of the uranium enrichment of UO{sub 2} fuel and this trend shall further be accentuated due to the fact that Pu recovered from reprocessing of the spent high burnup UO{sub 2} fuel contains less fissile isotopes. The plutonium content is calculated by use of the physical accounting method with the plutonium having several kinds of isotope ratios and the calculation results indicate that the plutonium content in MOX will evolve to ratios in excess of 10%. It shall be, therefore, important to know the irradiation behavior of MOX with high plutonium content of more than 10 wt%. MOX fuel rods having a plutonium content of about 14 wt% and fabricated by use of MIMAS process have been irradiated under PWR conditions in the Belgian test reactors BR-3 and BR-2. The peak fuel rod burn-up of the fuel rods studied in this paper ranges from 31 to 37 GWd/t-HM, and their average burnup is about 22-26 GWd/t-HM with the rod averaged linear heat generation rate of about 15-21 kW/m. The MOX rods are investigated by destructive and non-destructive post irradiation examinations and some of them are now continued to be irradiated in BR-2. Mixed Oxide (U,Pu)O{sub 2} fuel produced by the MIMAS process results in a fine dispersion of Pu enriched particles in a UO{sub 2} matrix and effectively gives three enrichment classes: low, medium and high enriched. The high enriched particles (often called 'Pu spots'), have an enrichment of around 25 wt% Pu, the low enriched phase is the UO{sub 2} matrix and contains only trace amounts of Pu. An

  16. Development of a high-performance nanostructured V(sub2)O(sub5)/SnO(sub2)catalyst for efficient benzene hydroxylation

    CSIR Research Space (South Africa)

    Makgwane, PR

    2015-02-01

    Full Text Available Nanostructured vanadium-tin oxide (V(sub2)O(sub5)/SnO(sub2)) catalysts with V(sub2)O(sub5) loading in a range of 5–20 wt% have been synthesized. The V(sub2)O(sub5)/SnO(sub2) nanostructures exhibited effective catalytic performance...

  17. SnO2@a-Si core-shell nanowires on free-standing CNT paper as a thin and flexible Li-ion battery anode with high areal capacity.

    Science.gov (United States)

    Abnavi, Amin; Sadati Faramarzi, Mojtaba; Abdollahi, Ali; Ramzani, Reza; Ghasemi, Shahnaz; Sanaee, Zeinab

    2017-06-23

    Here, we report 3D hierarchical SnO2 nanowire (NW) core-amorphous silicon shell on free-standing carbon nanotube paper (SnO2@a-Si/CNT paper) as an effective anode for flexible lithium-ion battery (LIB) application. This binder-free electrode exhibits a high initial discharge capacity of 3020 mAh g(-1) with a large reversible charge capacity of 1250 mAh g(-1) at a current density of 250 mA g(-1). Compared to other SnO2 NW or its core-shell nanostructured anodes, the fabricated SnO2@a-Si/CNT structure demonstrates an outstanding performance with high mass loading (∼5.9 mg cm(-2)), high areal capacity (∼5.2 mAh cm(-2)), and large volumetric capacity (∼1750 mAh cm(-3)) after 25 cycles. Due to the incorporation of CNT paper as the current collector, the weight and thickness of the total electrode is effectively reduced with respect to the conventional LIB anodes. The fabricated electrode has a total thickness of only 30 μm and considering the total weight of the electrode (active mass + current collector), an initial discharge/charge capacity of 2460/1018 mAh g(-1) is obtained. Hence, this thin, lightweight and highly flexible structure is proposed as an excellent candidate for high-performance LIB anode materials, especially in flexible electronics.

  18. SnO2@a-Si core-shell nanowires on free-standing CNT paper as a thin and flexible Li-ion battery anode with high areal capacity

    Science.gov (United States)

    Abnavi, Amin; Sadati Faramarzi, Mojtaba; Abdollahi, Ali; Ramzani, Reza; Ghasemi, Shahnaz; Sanaee, Zeinab

    2017-06-01

    Here, we report 3D hierarchical SnO2 nanowire (NW) core-amorphous silicon shell on free-standing carbon nanotube paper (SnO2@a-Si/CNT paper) as an effective anode for flexible lithium-ion battery (LIB) application. This binder-free electrode exhibits a high initial discharge capacity of 3020 mAh g-1 with a large reversible charge capacity of 1250 mAh g-1 at a current density of 250 mA g-1. Compared to other SnO2 NW or its core-shell nanostructured anodes, the fabricated SnO2@a-Si/CNT structure demonstrates an outstanding performance with high mass loading (˜5.9 mg cm-2), high areal capacity (˜5.2 mAh cm-2), and large volumetric capacity (˜1750 mAh cm-3) after 25 cycles. Due to the incorporation of CNT paper as the current collector, the weight and thickness of the total electrode is effectively reduced with respect to the conventional LIB anodes. The fabricated electrode has a total thickness of only 30 μm and considering the total weight of the electrode (active mass + current collector), an initial discharge/charge capacity of 2460/1018 mAh g-1 is obtained. Hence, this thin, lightweight and highly flexible structure is proposed as an excellent candidate for high-performance LIB anode materials, especially in flexible electronics.

  19. Teaching Reading in High School: Improving Reading in Content Areas. Third Edition.

    Science.gov (United States)

    Karlin, Robert

    Designed for prospective and practicing secondary school teachers, this volume examines several aspects of reading in the content areas: the general reading problem in high schools, the development of programs for reading in specific subject areas, the psychology of reading instruction in the content areas, the improvement of diagnostic teaching,…

  20. Advances in Predictive Toxicology for Discovery Safety through High Content Screening.

    Science.gov (United States)

    Persson, Mikael; Hornberg, Jorrit J

    2016-12-19

    High content screening enables parallel acquisition of multiple molecular and cellular readouts. In particular the predictive toxicology field has progressed from the advances in high content screening, as more refined end points that report on cellular health can be studied in combination, at the single cell level, and in relatively high throughput. Here, we discuss how high content screening has become an essential tool for Discovery Safety, the discipline that integrates safety and toxicology in the drug discovery process to identify and mitigate safety concerns with the aim to design drug candidates with a superior safety profile. In addition to customized mechanistic assays to evaluate target safety, routine screening assays can be applied to identify risk factors for frequently occurring organ toxicities. We discuss the current state of high content screening assays for hepatotoxicity, cardiotoxicity, neurotoxicity, nephrotoxicity, and genotoxicity, including recent developments and current advances.

  1. Moessbauer spectroscopy study of the synthesis of SnFe{sub 2}O{sub 4} by high energy ball milling (HEBM) of SnO and {alpha}-Fe{sub 2}O{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Uwakweh, Oswald N C; Perez Moyet, Richard [Department of Engineering Science and Material, University of Puerto Rico-Mayagueez (Puerto Rico); Mas, Rita; Morales, Carolyn [Department of Industrial Engineering, University of Puerto Rico-Mayagueez (Puerto Rico); Vargas, Pedro; Silva, Josue; Rossa, Angel [Department of Mechanical Engineering, University of Puerto Rico-Mayagueez (Puerto Rico); Lopez, Neshma, E-mail: uwakweh@ece.uprm.ed [Department of Chemical Engineering, University of Puerto Rico-Mayagueez (Puerto Rico)

    2010-03-01

    The formation of single phase nanoparticles of spinel structured ferrite, SnFe{sub 2}O{sub 4}, by mechanochemical syntheses using HEBM of stoichiometric amounts of solid SnO and {alpha}-Fe{sub 2}O{sub 3} with acetone as surfactant was achieved progressively as function of ball milling time. Single phase SnFe{sub 2}O{sub 4} formation commenced from five hours of continuous ball milling, and reached completion after 22 hours, thereby yielding a material with a lattice parameter of 8.543 A, and particle size of 10.91 nm. The coercivity was 4.44 mT, magnetic saturation value of 17.75 Am{sup 2}/kg, and remanent magnetizations of 1.50 Am{sup 2}/kg, correspondingly. The nanosized particles exhibited superparamagnetic behavior phenomenon based on Moessbauer spectroscopy measurements. The kinetic analyses based on the modified Kissinger method yielded four characteristic stages during the thermal evolution of the 22 hours milled state with activation energies of 0.23 kJ/mol, 2.52 kJ/mol, 0.024 kJ/mol, and 1.57 kJ/mol respectively.

  2. Identifying content knowledge for teaching energy: Examples from high school physics

    Science.gov (United States)

    Robertson, Amy D.; Scherr, Rachel E.; Goodhew, Lisa M.; Daane, Abigail R.; Gray, Kara E.; Aker, Leanna B.

    2017-06-01

    "Content knowledge for teaching" is the specialized content knowledge that teachers use in practice—the content knowledge that serves them for tasks of teaching such as revoicing students' ideas, choosing an instructional activity to address a student misunderstanding, and evaluating student statements. We describe a methodology for selecting and analyzing classroom episodes showing content knowledge for teaching about energy (CKT-E), and illustrate this methodology with examples from high school physics instruction. Our work has implications for research on teacher knowledge and for professional development that enhances teacher CKT-E.

  3. [Determination of the contents of vitamin C and its derivatives in cosmetics by high performance liquid chromatography].

    Science.gov (United States)

    Chen, Peijin; Yan, Zhi; Tu, Xiaoke; Xiao, Feng; Liang, Hong

    2015-07-01

    A method has established for the detection of vitamin C (VC) and its derivatives (ascorbyl glucoside, AA-2G; magnesium ascorbyl phosphate, AA-2P; ascorbic acid ethyl ether, Only VCE) in cosmetics by high performance liquid chromatography (HPLC). Low fat cosmetic samples such as make-up water and lotion were extracted directly with 30 mL 0.02 mol/L potassium dihydrogen phosphate solution (pH 3.0). High fat cosmetic samples such as face cream and gel were well dispersed with 1.0 mL dichloromethane first, then extracted with 25 mL 0.02 mol/L potassium dihydrogen phosphate solution (pH 3.0). The sample solution was centrifuged with a speed of 12,000 r/min, then filtered through a 0.22 μm syringe filter. The filtrate was analyzed on a column of YMC-Triart C18 (250 mm x 4.6 mm, 5 μm) using 0.02 mol/L potassium dihydrogen phosphate solution (pH 3.0) and methanol as mobile phases with a flow rate of 1.0 mL/min. The temperature of the column was 25 °C and the detection wavelength was 250 nm. The standard working curves of the four analytes had good linear relationship (r2>0.9999). The detection limits of the four analytes were 0.04-0.08 g/kg (S/N=10). The recoveries were 95.6%-101.0% with the relative standard deviations of 0.62%-3.0% at the spiked levels of 0.25-5.0 g/kg. This method is a simple, rapid, exact and reliable for the determination of the contents of vitamin C and its derivatives in cosmetics.

  4. A High-Capacity and Long-Cycle-Life Lithium-Ion Battery Anode Architecture: Silver Nanoparticle-Decorated SnO2/NiO Nanotubes.

    Science.gov (United States)

    Kim, Chanhoon; Jung, Ji-Won; Yoon, Ki Ro; Youn, Doo-Young; Park, Soojin; Kim, Il-Doo

    2016-12-27

    The combination of high-capacity and long-term cyclability has always been regarded as the first priority for next generation anode materials in lithium-ion batteries (LIBs). To meet these requirements, the Ag nanoparticle decorated mesoporous SnO2/NiO nanotube (m-SNT) anodes were synthesized via an electrospinning process, followed by fast ramping rate calcination and subsequent chemical reduction in this work. The one-dimensional porous hollow structure effectively alleviates a large volume expansion during cycling as well as provides a short lithium-ion duffusion length. Furthermore, metallic nickel (Ni) nanoparticles converted from the NiO nanograins during the lithiation process reversibly decompose Li2O during delithiation process, which significantly improves the reversible capacity of the m-SNT anodes. In addition, Ag nanoparticles uniformly decorated on the m-SNT via a simple chemical reduction process significantly improve rate capability and also contribute to long-term cyclability. The m-SNT@Ag anodes exhibited excellent cycling stability without obvious capacity fading after 500 cycles with a high capacity of 826 mAh g-1 at a high current density of 1000 mA g-1. Furthermore, even at a very high current density of 5000 mA g-1, the charge-specific capacity remained as high as 721 mAh g-1, corresponding to 60% of its initial capacity at a current density of 100 mA g-1.

  5. Defect interactions in Sn1−xGex random alloys

    KAUST Repository

    Chroneos, Alexander

    2009-06-23

    Sn1−xGex alloys are candidates for buffer layers to match the lattices of III-V or II-VI compounds with Si or Ge for microelectronic or optoelectronic applications. In the present work electronic structure calculations are used to study relative energies of clusters formed between Sn atoms and lattice vacancies in Ge that relate to alloys of low Sn content. We also establish that the special quasirandom structure approach correctly describes the random alloy nature of Sn1−xGex with higher Sn content. In particular, the calculated deviations of the lattice parameters from Vegard’s Law are consistent with experimental results.

  6. Structural Stability and Performance of Noble Metal-Free SnO2-Based Gas Sensors

    Directory of Open Access Journals (Sweden)

    Antonio Tricoli

    2012-05-01

    Full Text Available The structural stability of pure SnO2 nanoparticles and highly sensitive SnO2-SiO2 nanocomposites (0–15 SiO2 wt% has been investigated for conditions relevant to their utilization as chemoresistive gas sensors. Thermal stabilization by SiO2 co-synthesis has been investigated at up to 600 °C determining regimes of crystal size stability as a function of SiO2-content. For operation up to 400 °C, thermally stable crystal sizes of ca. 24 and 11 nm were identified for SnO2 nanoparticles and 1.4 wt% SnO2-SiO2 nanocomposites, respectively. The effect of crystal growth during operation (TO = 320 °C on the sensor response to ethanol has been reported, revealing possible long-term destabilization mechanisms. In particular, crystal growth and sintering-neck formation were discussed with respect to their potential to change the sensor response and calibration. Furthermore, the effect of SiO2 cosynthesis on the cross-sensitivity to humidity of these noble metal-free SnO2-based gas sensors was assessed.

  7. Magnetic and magnetocaloric properties of Fe5-xMnxSn3

    Science.gov (United States)

    Dianoux, Alexy; Malaman, Bernard; Mazet, Thomas

    2017-07-01

    We investigate the crystal, magnetic and magnetocaloric properties of the Fe5-xMnxSn3 series (0 ≤ x ≤ 5) from X-ray diffraction and DC magnetization experiments. The alloys crystallize with the lacunar Ni2In type of structure (P 63 / mmc). The diffraction patterns of the richer Fe alloys (x ≤ 2) contain tiny superstructure lines due to ordering of T atoms and vacancies within the partially filed 2d position. The Curie temperatures decrease in a non-monotonous manner with the Mn content from 544 K in Fe5Sn3 down to 190 K in Fe1Mn4Sn5, before increasing again up to 219 K in Mn5Sn3. While most of the alloys behave as simple ferromagnets, low-field thermomagnetization data show that the Fe5-xMnxSn3 alloys with intermediate compositions (x=2.5 and 3) undergo two close ferromagnetic-like transitions. The magnetocaloric effect is of moderate magnitude ( 1 J kg-1 K-1 for μ0 ΔH = 2 T). The results are compared with previously published data and briefly discussed in view of potential high-temperature magnetocaloric applications.

  8. Structural Stability and Performance of Noble Metal-Free SnO2-Based Gas Sensors

    Science.gov (United States)

    Tricoli, Antonio

    2012-01-01

    The structural stability of pure SnO2 nanoparticles and highly sensitive SnO2-SiO2 nanocomposites (0–15 SiO2 wt%) has been investigated for conditions relevant to their utilization as chemoresistive gas sensors. Thermal stabilization by SiO2 co-synthesis has been investigated at up to 600 °C determining regimes of crystal size stability as a function of SiO2-content. For operation up to 400 °C, thermally stable crystal sizes of ca. 24 and 11 nm were identified for SnO2 nanoparticles and 1.4 wt% SnO2-SiO2 nanocomposites, respectively. The effect of crystal growth during operation (TO = 320 °C) on the sensor response to ethanol has been reported, revealing possible long-term destabilization mechanisms. In particular, crystal growth and sintering-neck formation were discussed with respect to their potential to change the sensor response and calibration. Furthermore, the effect of SiO2 cosynthesis on the cross-sensitivity to humidity of these noble metal-free SnO2-based gas sensors was assessed. PMID:25585712

  9. Rapid Solidification of Sn-Cu-Al Alloys for High-Reliability, Lead-Free Solder: Part I. Microstructural Characterization of Rapidly Solidified Solders

    Science.gov (United States)

    Reeve, Kathlene N.; Choquette, Stephanie M.; Anderson, Iver E.; Handwerker, Carol A.

    2016-12-01

    Particles of Cu x Al y in Sn-Cu-Al solders have previously been shown to nucleate the Cu6Sn5 phase during solidification. In this study, the number and size of Cu6Sn5 nucleation sites were controlled through the particle size refinement of Cu x Al y via rapid solidification processing and controlled cooling in a differential scanning calorimeter. Cooling rates spanning eight orders of magnitude were used to refine the average Cu x Al y and Cu6Sn5 particle sizes down to submicron ranges. The average particle sizes, particle size distributions, and morphologies in the microstructures were analyzed as a function of alloy composition and cooling rate. Deep etching of the samples revealed the three-dimensional microstructures and illuminated the epitaxial and morphological relationships between the Cu x Al y and Cu6Sn5 phases. Transitions in the Cu6Sn5 particle morphologies from faceted rods to nonfaceted, equiaxed particles were observed as a function of both cooling rate and composition. Initial solidification cooling rates within the range of 103 to 104 °C/s were found to be optimal for realizing particle size refinement and maintaining the Cu x Al y /Cu6Sn5 nucleant relationship. In addition, little evidence of the formation or decomposition of the ternary- β phase in the solidified alloys was noted. Solidification pathways omitting the formation of the ternary- β phase agreed well with observed room temperature microstructures.

  10. Designed synthesis CuO hollow microboxes coated with Pd nanosheets and SnO2 nanoparticles as a highly efficient Rochow reaction catalyst

    Science.gov (United States)

    Gao, Junjie; Zhang, Zailei; An, Xuebin; Zhang, Yi

    2017-12-01

    We designed and synthesized CuO/SnO2/Pd hollow microboxes, which was developed based on prepared Cu2O cubes coated Pd nanosheets, controlled oxidation of Cu2O/Pd, and etching of Cu2O/CuO/Pd by SnCl4 solution. The catalytic property of the Cu2O, Cu2O/SnO2, Cu2O/Pd/SnO2, Cu2O/Pd, Cu2O/CuO/Pd, CuO/SnO2/Pd, CuO, and commercial catalyst for dimethyldichlorosilane synthesis via the Rochow reaction was investigated. As compared to control samples and commercial catalyst, the prepared CuO/Pd/SnO2 hollow microboxes exhibited much higher silicon conversion (76.6%), which is related to the synergistic effect between CuO, Pd and SnO2, and to the distinct catalyst hollow structure which allows the efficient transportation of the reactant molecules to the active component.

  11. Three-Dimensional Graphene/Single-Walled Carbon Nanotube Aerogel Anchored with SnO2 Nanoparticles for High Performance Lithium Storage.

    Science.gov (United States)

    Wang, Jing; Fang, Fang; Yuan, Tao; Yang, Junhe; Chen, Liang; Yao, Chi; Zheng, Shiyou; Sun, Dalin

    2017-02-01

    A unique 3D graphene-single walled carbon nanotube (G-SWNT) aerogel anchored with SnO2 nanoparticles (SnO2@G-SWCNT) is fabricated by the hydrothermal self-assembly process. The influences of mass ratio of SWCNT to graphene on structure and electrochemical properties of SnO2@G-SWCNT are investigated systematically. The SnO2@G-SWCNT composites show excellent electrochemical performance in Li-ion batteries; for instance, at a current density of 100 mA g(-1), a specific capacity of 758 mAh g(-1) was obtained for the SnO2@G-SWCNT with 50% SWCNT in G-SWCNT and the Coulombic efficiency is close to 100% after 200 cycles; even at current density of 1 A g(-1), it can still maintain a stable specific capacity of 537 mAh g(-1) after 300 cycles. It is believed that the 3D G-SWNT architecture provides a flexible conductive matrix for loading the SnO2, facilitating the electronic and ionic transportation and mitigating the volume variation of the SnO2 during lithiation/delithiation. This work also provides a facile and reasonable strategy to solve the pulverization and agglomeration problem of other transition metal oxides as electrode materials.

  12. Advantages of Single-Molecule Real-Time Sequencing in High-GC Content Genomes.

    Directory of Open Access Journals (Sweden)

    Seung Chul Shin

    Full Text Available Next-generation sequencing has become the most widely used sequencing technology in genomics research, but it has inherent drawbacks when dealing with high-GC content genomes. Recently, single-molecule real-time sequencing technology (SMRT was introduced as a third-generation sequencing strategy to compensate for this drawback. Here, we report that the unbiased and longer read length of SMRT sequencing markedly improved genome assembly with high GC content via gap filling and repeat resolution.

  13. Enhanced ethanol fermentation by engineered Saccharomyces cerevisiae strains with high spermidine contents.

    Science.gov (United States)

    Kim, Sun-Ki; Jo, Jung-Hyun; Jin, Yong-Su; Seo, Jin-Ho

    2017-05-01

    Construction of robust and efficient yeast strains is a prerequisite for commercializing a biofuel production process. We have demonstrated that high intracellular spermidine (SPD) contents in Saccharomyces cerevisiae can lead to improved tolerance against various fermentation inhibitors, including furan derivatives and acetic acid. In this study, we examined the potential applicability of the S. cerevisiae strains with high SPD contents under two cases of ethanol fermentation: glucose fermentation in repeated-batch fermentations and xylose fermentation in the presence of fermentation inhibitors. During the sixteen times of repeated-batch fermentations using glucose as a sole carbon source, the S. cerevisiae strains with high SPD contents maintained higher cell viability and ethanol productivities than a control strain with lower SPD contents. Specifically, at the sixteenth fermentation, the ethanol productivity of a S. cerevisiae strain with twofold higher SPD content was 31% higher than that of the control strain. When the SPD content was elevated in an engineered S. cerevisiae capable of fermenting xylose, the resulting S. cerevisiae strain exhibited much 40-50% higher ethanol productivities than the control strain during the fermentations of synthetic hydrolysate containing high concentrations of fermentation inhibitors. These results suggest that the strain engineering strategy to increase SPD content is broadly applicable for engineering yeast strains for robust and efficient production of ethanol.

  14. Rapid Solidification of Sn-Cu-Al Alloys for High-Reliability, Lead-Free Solder: Part II. Intermetallic Coarsening Behavior of Rapidly Solidified Solders After Multiple Reflows

    Science.gov (United States)

    Reeve, Kathlene N.; Choquette, Stephanie M.; Anderson, Iver E.; Handwerker, Carol A.

    2016-12-01

    Controlling the size, dispersion, and stability of intermetallic compounds in lead-free solder alloys is vital to creating reliable solder joints regardless of how many times the solder joints are melted and resolidified (reflowed) during circuit board assembly. In this article, the coarsening behavior of Cu x Al y and Cu6Sn5 in two Sn-Cu-Al alloys, a Sn-2.59Cu-0.43Al at. pct alloy produced via drip atomization and a Sn-5.39Cu-1.69Al at. pct alloy produced via melt spinning at a 5-m/s wheel speed, was characterized after multiple (1-5) reflow cycles via differential scanning calorimetry between the temperatures of 293 K and 523 K (20 °C and 250 °C). Little-to-no coarsening of the Cu x Al y particles was observed for either composition; however, clustering of Cu x Al y particles was observed. For Cu6Sn5 particle growth, a bimodal size distribution was observed for the drip atomized alloy, with large, faceted growth of Cu6Sn5 observed, while in the melt spun alloy, Cu6Sn5 particles displayed no significant increase in the average particle size, with irregularly shaped, nonfaceted Cu6Sn5 particles observed after reflow, which is consistent with shapes observed in the as-solidified alloys. The link between original alloy composition, reflow undercooling, and subsequent intermetallic coarsening behavior was discussed by using calculated solidification paths. The reflowed microstructures suggested that the heteroepitaxial relationship previously observed between the Cu x Al y and the Cu6Sn5 was maintained for both alloys.

  15. Three-dimensional mesoporous graphene aerogel-supported SnO2 nanocrystals for high-performance NO2 gas sensing at low temperature.

    Science.gov (United States)

    Li, Lei; He, Shuijian; Liu, Minmin; Zhang, Chunmei; Chen, Wei

    2015-02-03

    A facile and cost-efficient hydrothermal and lyophilization two-step strategy has been developed to prepare three-dimensional (3D) SnO2/rGO composites as NO2 gas sensor. In the present study, two different metal salt precursors (Sn(2+) and Sn(4+)) were used to prepare the 3D porous composites. It was found that the products prepared from different tin salts exhibited different sensing performance for NO2 detection. The scanning electron microscopy and transmission electron microscopy characterizations clearly show the macroporous 3D hybrids, nanoporous structure of reduce graphene oxide (rGO), and the supported SnO2 nanocrystals with an average size of 2-7 nm. The specific surface area and porosity properties of the 3D mesoporous composites were analyzed by Braunauer-Emmett-Teller method. The results showed that the SnO2/rGO composite synthesized from Sn(4+) precursor (SnO2/rGO-4) has large surface area (441.9 m(2)/g), which is beneficial for its application as a gas sensing material. The gas sensing platform fabricated from the SnO2/rGO-4 composite exhibited a good linearity for NO2 detection, and the limit of detection was calculated to be as low as about 2 ppm at low temperature. The present work demonstrates that the 3D mesoporous SnO2/rGO composites with extremely large surface area and stable nanostructure are excellent candidate materials for gas sensing.

  16. Confined SnO2 quantum-dot clusters in graphene sheets as high-performance anodes for lithium-ion batteries

    OpenAIRE

    Chengling Zhu; Shenmin Zhu; Kai Zhang; Zeyu Hui; Hui Pan; Zhixin Chen; Yao Li; Di Zhang; Da-Wei Wang

    2016-01-01

    Construction of metal oxide nanoparticles as anodes is of special interest for next-generation lithium-ion batteries. The main challenge lies in their rapid capacity fading caused by the structural degradation and instability of solid-electrolyte interphase (SEI) layer during charge/discharge process. Herein, we address these problems by constructing a novel-structured SnO2-based anode. The novel structure consists of mesoporous clusters of SnO2 quantum dots (SnO2 QDs), which are wrapped with...

  17. Assessing New Zealand High School Science Teachers' Technological Pedagogical Content Knowledge

    Science.gov (United States)

    Owusu, Kofi Acheaw; Conner, Lindsey; Astall, Chris

    2015-01-01

    Technological pedagogical content knowledge (TPACK) is the knowledge required for effective technology integration in teaching. In this study, New Zealand high school science teachers' TPACK was assessed through an online survey. The data and its analysis revealed that New Zealand's high school science teachers in general had a high perception of…

  18. One-pot facile synthesis of Janus-structured SnO2-CuO composite nanorods and their application as anode materials in Li-ion batteries

    Science.gov (United States)

    Choi, Seung Ho; Kang, Yun Chan

    2013-05-01

    SnO2-CuO composite nanorods with a Janus structure were prepared by one-step flame spray pyrolysis. High-aspect-ratio SnO2 nanorods were positioned on one side of the spherical CuO powder. The mean length of the rod-shaped crystals decreased from 200 to 20 nm when the SnO2 content in the composite powders decreased from 70 to 10 wt%. Initially, SnO2-CuO composite nanopowders formed from the vapors in the high-temperature diffusion flame by surface growth and coagulation. Phase separation of the composite nanopowders occurred and rod-like Janus structures evolved during the growth of SnO2 and CuO crystals in the quenching process. The maximum charge capacities of pure SnO2 and the composite powders with SnO2/CuO of 90/10, 70/30, and 50/50 were 547, 499, 493, and 316 mA h g-1, respectively, at a high current density of 3000 mA g-1. The corresponding capacity retentions after 50 cycles were found to be 39, 47, 80, and 85%, respectively. The decrease in the charge capacity with increasing current density was slower in SnO2-CuO (70/30) composite powders than in pure SnO2. The Janus-structured SnO2-CuO (70/30) composite powders showed a high charge capacity and excellent cycling performance at high current densities.SnO2-CuO composite nanorods with a Janus structure were prepared by one-step flame spray pyrolysis. High-aspect-ratio SnO2 nanorods were positioned on one side of the spherical CuO powder. The mean length of the rod-shaped crystals decreased from 200 to 20 nm when the SnO2 content in the composite powders decreased from 70 to 10 wt%. Initially, SnO2-CuO composite nanopowders formed from the vapors in the high-temperature diffusion flame by surface growth and coagulation. Phase separation of the composite nanopowders occurred and rod-like Janus structures evolved during the growth of SnO2 and CuO crystals in the quenching process. The maximum charge capacities of pure SnO2 and the composite powders with SnO2/CuO of 90/10, 70/30, and 50/50 were 547, 499, 493

  19. High-performance and flexible photodetectors based on P3HT/CdS/CdS:SnS2 superlattice nanowires hybrid films

    Science.gov (United States)

    Gou, Guangyang; Dai, Guozhang; Wang, Xiaowu; Chen, Yang; Qian, Chuan; Kong, Lingan; Sun, Jia; Yang, Junliang

    2017-12-01

    Flexible photodetectors based on organic-inorganic hybrid materials have been attracted great interests because of their unique performance and potential applications. In this study, a novel hybrid photodetector has been constructed on SiO2/Si substrate using organic poly (3-hexylthiophene) (P3HT) and inorganic CdS/CdS:SnS2 superlattice nanowires (CCS SNs). Compared with pure P3HT device, the as-constructed hybrid devices exhibit a prominent photoresponse, as well as excellent photoswitch effect and repeatability due to the interactions of the photogenerated charge carriers and the interface trap sites. In addition, flexible hybrid photodetectors based on the P3HT/CCS SNs hybrid films are prepared on paper substrates, which present a high responsivity of 244 A/W, a remarkable ratio of photocurrent and dark current of 1.25 × 103, a fast response time of 12 ms, a noteworthy detectivity of 8.7 × 1012 Jones, and good reproducibility. More importantly, the photocurrent and responsivity of our paper-based hybrid device decline 9% after 200 cycles of bending, revealing high mechanical flexibility and electrical stability. Therefore, the high-performance and flexible photodetectors based on the P3HT/CCS SNs hybrid films presented in this work will have been attracted great attention as its potential application in future portable and flexible electronics.

  20. Highly efficient dye-sensitized solar cell with a novel nanohybrid film of Cu2ZnSnS4-MWCNTs as counter electrode

    Science.gov (United States)

    Chen, Hui; Wang, Jinfeng; Jia, Chenchen; Mou, Junpeng; Zhu, Lei

    2017-11-01

    For the purpose of increasing the power conversion efficiency (PCE) meanwhile decreasing the cost of dye-sensitized solar cell (DSSC), Cu2ZnSnS4- multiwall carbon nanotubes (CZTS-MWCNTs) nanohybrid Pt-free counter electrode (CE) was prepared via a facile fabricating route. In brief, CZTS nanoparticles were synthesized by a solvothermal method and the composite film was fabricated by spin coating the aqueous solution of the composite. The short-circuit current density and PCE of the DSSC with CZTS-MWCNTs CE were found to be 16.62 mA cm-2 and 9.04%, respectively. But the corresponding values were 15.42 mA cm-2 and 8.74% for a DSSC with a pure Pt-CE. This is owing to the synergistic effect of the intrinsic superior electrocatalytic activity of the CZTS nanoparticles and highly specific surface area and high electrical conductivity of the MWCNTs. The presence and distribution of CZTS-MWCNTs on the CE were characterized by X-Ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM), respectively. Cyclic voltammetry (CV) and electrochemical impedance spectra (EIS) were examined for confirming the high electrocatalytic efficiency of this nanohybrid system.

  1. An HST Survey of Cassiopeia A's Reverse Shock, High-Velocity Ejecta, and Shocked Clouds of Pre-SN Mass Loss

    Science.gov (United States)

    Fesen, Robert

    2017-08-01

    The young Galactic supernova remnant Cassiopeia A (Cas A) provides us with the clearest look at the properties and explosion dynamics of a high mass, core-collapse supernova (CCSN). With an explosion date around 1670, Cas A is the youngest Galactic core-collapse SNR known and, at an estimated distance of 3.4 kpc, it is also among the closest. Cas A's main shell ejecta knots are typically 0.1 - 0.5 arcsec in size and can show emission and morphological changes on timescales of just a few months. No other remnant, with the exception of SN 1987A, shows such rapid optical changes across large portions of its structure.Here we propose a new, complete optical survey of Cas A, the first since 2004, in order to measure the velocity and asymmetry of Cas A's reverse shock front across the whole remnant and map the distribution of its high-velocity outer ejecta, particularly in regions which align to the motion of the central compact source. Halpha images of the remnant's shocked CSM clumps will also provide strong tests of shock-cloud models across a broad range of cloud densities and sizes. These data will constitute a rich and unique archive both for Cas A and the general study of high mass CCSNe.

  2. Influence of Sn4+ on Structural and DC Electrical Resistivity of Ni-Zn Ferrite Thick Films

    Science.gov (United States)

    Dalawai, S. P.; Shinde, T. J.; Gadkari, A. B.; Tarwal, N. L.; Jang, J. H.; Vasambekar, P. N.

    2017-03-01

    Among the soft ferrites, Ni-Zn ferrite is one of the most versatile ceramic materials because of their important electrical and magnetic properties. These properties were improved by substituting Sn4+ in Ni-Zn ferrites with chemical composition of Ni x Zn1+ y- x Fe2-2 y Sn y O4 ( x = 0, 0.2, 0.4, 0.6, 0.8, 1.0; y = 0.1, 0.2). To achieve homogenous ferrite powder at lower sintering temperature and smaller duration in nano-size form, the oxalate co-precipitation method was preferred as compared to other physical and chemical methods. Using this powder, ferrite thick films (FTFs) were prepared by the screen printing technique because of its low cost and easy use. To study structural behavior, the FTFs were characterized by different techniques. The x-ray diffraction and thermo-gravimetric and differential thermal analysis studies show the formation of cubic spinel structure and ferrite phase formation, respectively. There is no remarkable trend observed in lattice constants for the Sn4+ ( y = 0.1)- and Sn4+ ( y = 0.2)-substituted Ni-Zn ferrites. The bond lengths as well as ionic radii on the A-site of Ni-Zn-Sn ferrites were found to decrease with increasing nickel content. The bond length and ionic radii on the B-sites remained almost constant for Sn4+ ( y = 0.1, 0.2)-substituted Ni-Zn ferrites. The energy dispersive x-ray analysis confirms the elemental analysis of FTFs. The Fourier transform infrared spectra show two major absorption bands near 400 cm-1 and 600 cm-1 corresponding to octahedral and tetrahedral sites, respectively, which also confirms the formation of the ferrites. The field emission scanning electron microscopy images shows that the particles are highly porous in nature and located in loosely packed agglomerates. The average particle size of the FTFs lies in the range 20-60 nm. Direct current (DC) resistivity of Ni-Zn-Sn FTFs shows the semiconductor nature. The DC resistivity of Ni-Zn-Sn0.2FTFs is lower than Ni-Zn-Sn0.1 FTFs. The DC resistivity is

  3. High variability in flavonoid contents and composition between different North-European currant (Ribes spp.) varieties.

    Science.gov (United States)

    Mattila, Pirjo H; Hellström, Jarkko; Karhu, Saila; Pihlava, Juha-Matti; Veteläinen, Merja

    2016-08-01

    This study provides information on the variation of anthocyanin and flavonol contents and composition in 32 black and 12 redcurrant varieties, as well as flavonol contents and composition in two green-fruited blackcurrant (green currant) and one white currant varieties conserved in a national ex situ germplasm field collection in Finland, North Europe. Flavonols were analysed as aglycones and anthocyanins as authentic compounds using HPLC methods. In blackcurrants, total anthocyanin content varied 1260-2878mg/100g dry weight and total flavonol content 43.6-89.9mg/100g dry weight. In redcurrants, the content of anthocyanins and flavonols varied 138-462mg/100g dry weight and from not detectable to 17.7mg/100g dry weight, respectively. The green currants contained flavonols 26.1 and 15.4mg/100g dry weight, while in the white variety no flavonols were detected. A positive correlation was found between the total content of anthocyanins and flavonols in both black and redcurrants. Berry size was negatively related to the flavonoid content in redcurrants but not in blackcurrants. The results revealed that some old varieties may be of particular interest when high contents or special composition of flavonoids are desired. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Electronic structure and crystallographic properties of skutterudite-related Ce3M4Sn13 and La3M4Sn13 (M=Co, Ru, and Rh)

    Science.gov (United States)

    Ślebarski, A.; Goraus, J.

    2013-10-01

    The structural and electronic properties of the skutterudite-related Ce3M4Sn13 and La3M4Sn13 intermetallic compounds with M=Co, Ru, and Rh have been investigated. A subtle structural transition from a simple cubic phase (Yb3Rh4Sn13-type structure) to the superlattice variant at TD˜160 K has been evidenced by x-ray diffraction, resistivity, and specific-heat data. Recently, a high charge density between metal M and Sn atoms was calculated for Ce3Rh4Sn13 and Ce3Co4Sn13. The strong charge accumulation implies a strong M-Sn2 covalent bonding interaction. In consequence, a local distortion of the trigonal Sn prisms around metal M can modify the electronic structure of the system. The main goal of this report is to study the electronic structure in the family of RE3M4Sn13, where RE=Ce or La above and below TD. We show that the Sn 4d x-ray photoelectron spectroscopy spectra have the complex structure, which can be interpreted as a result of different charge distribution around Sn atoms. The shape of the 4d Sn lines is also temperature dependent, which we attribute to the local distortion of the Sn2 cages in RE3M4Sn13.

  5. Scene content is predominantly conveyed by high spatial frequencies in scene-selective visual cortex.

    Science.gov (United States)

    Berman, Daniel; Golomb, Julie D; Walther, Dirk B

    2017-01-01

    In complex real-world scenes, image content is conveyed by a large collection of intertwined visual features. The visual system disentangles these features in order to extract information about image content. Here, we investigate the role of one integral component: the content of spatial frequencies in an image. Specifically, we measure the amount of image content carried by low versus high spatial frequencies for the representation of real-world scenes in scene-selective regions of human visual cortex. To this end, we attempted to decode scene categories from the brain activity patterns of participants viewing scene images that contained the full spatial frequency spectrum, only low spatial frequencies, or only high spatial frequencies, all carefully controlled for contrast and luminance. Contrary to the findings from numerous behavioral studies and computational models that have highlighted how low spatial frequencies preferentially encode image content, decoding of scene categories from the scene-selective brain regions, including the parahippocampal place area (PPA), was significantly more accurate for high than low spatial frequency images. In fact, decoding accuracy was just as high for high spatial frequency images as for images containing the full spatial frequency spectrum in scene-selective areas PPA, RSC, OPA and object selective area LOC. We also found an interesting dissociation between the posterior and anterior subdivisions of PPA: categories were decodable from both high and low spatial frequency scenes in posterior PPA but only from high spatial frequency scenes in anterior PPA; and spatial frequency was explicitly decodable from posterior but not anterior PPA. Our results are consistent with recent findings that line drawings, which consist almost entirely of high spatial frequencies, elicit a neural representation of scene categories that is equivalent to that of full-spectrum color photographs. Collectively, these findings demonstrate the

  6. Scene content is predominantly conveyed by high spatial frequencies in scene-selective visual cortex.

    Directory of Open Access Journals (Sweden)

    Daniel Berman

    Full Text Available In complex real-world scenes, image content is conveyed by a large collection of intertwined visual features. The visual system disentangles these features in order to extract information about image content. Here, we investigate the role of one integral component: the content of spatial frequencies in an image. Specifically, we measure the amount of image content carried by low versus high spatial frequencies for the representation of real-world scenes in scene-selective regions of human visual cortex. To this end, we attempted to decode scene categories from the brain activity patterns of participants viewing scene images that contained the full spatial frequency spectrum, only low spatial frequencies, or only high spatial frequencies, all carefully controlled for contrast and luminance. Contrary to the findings from numerous behavioral studies and computational models that have highlighted how low spatial frequencies preferentially encode image content, decoding of scene categories from the scene-selective brain regions, including the parahippocampal place area (PPA, was significantly more accurate for high than low spatial frequency images. In fact, decoding accuracy was just as high for high spatial frequency images as for images containing the full spatial frequency spectrum in scene-selective areas PPA, RSC, OPA and object selective area LOC. We also found an interesting dissociation between the posterior and anterior subdivisions of PPA: categories were decodable from both high and low spatial frequency scenes in posterior PPA but only from high spatial frequency scenes in anterior PPA; and spatial frequency was explicitly decodable from posterior but not anterior PPA. Our results are consistent with recent findings that line drawings, which consist almost entirely of high spatial frequencies, elicit a neural representation of scene categories that is equivalent to that of full-spectrum color photographs. Collectively, these findings

  7. Oxygen-Induced Ordering in Bulk Polycrystalline Cu2ZnSnS4 by Sn Removal.

    Science.gov (United States)

    Pogue, Elizabeth A; Sutrisno, Andre; Johnson, Nicole E; Shoemaker, Daniel P; Rockett, Angus A

    2017-10-16

    Solid-state nuclear magnetic resonance spectroscopy, X-ray diffraction, and Raman spectroscopy were used to show that Cu2ZnSnS4 (CZTS) bulk solids grown in the presence of oxygen had improved cation ordering compared to bulk solids grown without oxygen. Oxygen was shown to have negligible solubility in the CZTS phase. The addition of oxygen resulted in the formation of SnO2, leading to Sn-deficient CZTS. At the highest oxygen levels, other phases such as Cu9S5 and ZnS were observed. Beneficial ordering was only observed in samples produced with more than 2 at. % oxygen in the precursor materials but did not occur in samples designed with excess Sn and O. Thus, it is the removal of Sn and formation of Sn-deficient CZTS that improves ordering rather than the presence of SnO2 or O alone. These results indicate that using oxygen or air annealing to tailor the Sn content of CZTS followed by an etching step to remove SnO2 may significantly improve the properties of CZTS.

  8. Facile synthesis and characterization of a SnO2-modified LiNi0.5Mn1.5O4 high-voltage cathode material with superior electrochemical performance for lithium ion batteries.

    Science.gov (United States)

    Ma, Feng; Geng, Fushan; Yuan, Anbao; Xu, Jiaqiang

    2017-04-12

    A thin-layer-SnO2 modified LiNi0.5Mn1.5O4@SnO2 material is synthesized via a facile synthetic approach. It is physically and electrochemically characterized as a high-voltage lithium ion battery cathode and compared to the pristine LiNi0.5Mn1.5O4 material prepared under similar conditions. The two materials are proved to be crystals of a well-defined disordered spinel phase with the morphology of aggregates of micron/submicron polyhedral particles. The Mn(3+) ions and the inactive NixLiyO phase in the LiNi0.5Mn1.5O4@SnO2 is less than those in the LiNi0.5Mn1.5O4 due to incorporation of a very small amount of Sn(2+) into the spinel structure upon high-temperature calcination of the precursor. Besides, the mean particle size of the LiNi0.5Mn1.5O4@SnO2 is obviously smaller than that of the LiNi0.5Mn1.5O4. The LiNi0.5Mn1.5O4@SnO2 demonstrates much superior electrochemical performance over the LiNi0.5Mn1.5O4 in terms of specific capacity, rate capability and cyclability. For example, the discharge capacities at current rates of 0.2C, 2C and 20C are 145.4, 139.9 and 112.2 mA h g(-1), respectively. A capacity retention rate of ca. 75% is obtained after 500 cycles at 2C rate. The improved electrochemical performance is attributed to the positive effect of the surface protective SnO2 coating layer as well as the structural and morphological modifications of the spinel.

  9. Using high-content imaging data from ToxCast to analyze toxicological tipping points (TDS)

    Science.gov (United States)

    Translating results obtained from high-throughput screening to risk assessment is vital for reducing dependence on animal testing. We studied the effects of 976 chemicals (ToxCast Phase I and II) in HepG2 cells using high-content imaging (HCI) to measure dose and time-depende...

  10. Preparation of Nafion 117™-SnO2 Composite Membranes using an Ion-Exchange Method

    DEFF Research Database (Denmark)

    Nørgaard, Casper Frydendal; Nielsen, Ulla Gro; Skou, Eivind Morten

    Nafion 117™-SnO2 composite membranes were successfully prepared using an ion-exchange method. SnO2 was incorporated into Nafion 117™ membranes by ion-exchange in solutions of SnCl2 · 2 H2O in methanol, followed by oxidation to SnO2 in air. The content of SnO2 proved controllable by adjusting...... the concentration of the ion-exchange solution. The prepared nanocomposite membranes were characterized by XRD and 119Sn MAS NMR while the in-plane proton conductivity was found to decrease with SnO2 content when evaluated with EIS. However, the conductivity was comparable to Nafion™ at SnO2 contents below 8 wt%....

  11. Endohedrally filled [Ni@Sn9](4-) and [Co@Sn9](5-) clusters in the neat solids Na12Ni(1-x)Sn17 and K(13-x)Co(1-x)Sn17: crystal structure and 119Sn solid-state NMR spectroscopy.

    Science.gov (United States)

    Hlukhyy, Viktor; Stegmaier, Saskia; van Wüllen, Leo; Fässler, Thomas F

    2014-09-15

    A systematic approach to the formation of endohedrally filled atom clusters by a high-temperature route instead of the more frequent multistep syntheses in solution is presented. Zintl phases Na12Ni(1-x)Sn17 and K(13-x)Co(1-x)Sn17, containing endohedrally filled intermetalloid clusters [Ni@Sn9](4-) or [Co@Sn9](5-) beside [Sn4](4-), are obtained from high-temperature reactions. The arrangement of [Ni@Sn9](4-) or [Co@Sn9](5-) and [Sn4](4-) clusters, which are present in the ratio 1:2, can be regarded as a hierarchical replacement variant of the hexagonal Laves phase MgZn2 on the Mg and Zn positions, respectively. The alkali-metal positions are considered for the first time in the hierarchical relationship, which leads to a comprehensive topological parallel and a better understanding of the composition of these compounds. The positions of the alkali-metal atoms in the title compounds are related to the known inclusion of hydrogen atoms in the voids of Laves phases. The inclusion of Co atoms in the {Sn9} cages correlates strongly with the number of K vacancies in K(13-x)Co(1-x)Sn17 and K(5-x)Co(1-x)Sn9, and consequently, all compounds correspond to diamagnetic valence compounds. Owing to their diamagnetism, K(13-x)Co(1-x)Sn17, and K(5-x)Co(1-x)Sn9, as well as the d-block metal free binary compounds K12Sn17 and K4Sn9, were characterized for the first time by (119)Sn solid-state NMR spectroscopy. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  12. Thermally evaporated indium-free, transparent, flexible SnO2/AgPdCu/SnO2 electrodes for flexible and transparent thin film heaters.

    Science.gov (United States)

    Kim, Doo-Hee; Cho, Kyung-Su; Kim, Han-Ki

    2017-05-31

    We investigated the characteristics of themally evaporated SnO2/Ag-Pd-Cu (APC)/SnO2 multilayer films for applications as damage-free, indium-free, flexible, and transparent electrodes for high performance flexible and transparent thin film heaters (TFHs). The top and bottom SnO2 layers and APC interlayer were prepared by a multi-source evaporation process, and the effect of the thickness of each layer on the resistivity, optical transmittance, and mechanical flexibility of the SnO2/APC/SnO2 electrodes was investigated in detail. Based on a figure of merit value, we obtained a SnO2/APC/SnO2 electrode with a low sheet resistance of 9.42 Ohm/square and a high optical transmittance of 91.14%. In addition, we examined the mechanical properties of the SnO2/APC/SnO2 electrode using various bending tests such as inner bending, outer bending, dynamic fatigue, and a twisting test. By comparing the crack shape of the SnO2/APC/SnO2 electrode bent beyond the critical bending radius (2~3 mm), we suggest a possible crack formation mechanism for the SnO2/APC/SnO2 electrodes. Furthermore, we evaluated the feasibility of the SnO2/APC/SnO2 electrodes for flexible and transparent TFHs. By correlating the sheet resistance of the SnO2/APC/SnO2 electrode and the performance of TFHs, we show the importance of transparent electrodes for high performance flexible and transparent TFHs.

  13. Thermal cyclic test for Sn-4Ag-0.5Cu solders on high P Ni/Au and Ni/Pd/Au surface finishes

    Directory of Open Access Journals (Sweden)

    M.A. Azmah Hanim

    2015-12-01

    Full Text Available In electronic packaging, the reliability of the interconnection changes with the surface finish and the type of solders being used. Thermal cycling is one method of reliability assessment. In thermal cycling experiments, the strain state is simplified by soldering together regular shaped pieces of materials with different coefficients of thermal expansion and exposing the joint to repeated fluctuations of temperature within a certain range. Thus, this study focuses on the intermetallic evolution of Sn-4Ag-0.5Cu on Ni/Au and Ni/Pd/Au surface finishes with thermal cycling up to 1000 cycles with the range of temperature varying from 10 to 80 °C. Sandwich samples were prepared by placing solder balls of Sn-4Ag-0.5Cu between two substrates of two different surface finishes: Ni/Au and Ni/Pd/Au. Optical microscope and FESEM (Field emission scanning electron microscope were used to analyze the samples. From the study, it was observed that the intermetallic changes from (Cu, Ni6Sn5 to (Ni, Cu3Sn4 after 1000 thermal cycles for Ni/Au. These changes promote the formation of cracks at the solder joint because of the different mechanical properties between Ni-Sn based intermetallic and Cu-Sn intermetallics. However, for the Ni/Pd/Au surface finishes, no cracks formed after thermal cycling up to 1000 cycles. This shows that the reliability of the solder joint is higher for Ni/Pd/Au surface finishes in this experiment. Based on these results, it can be concluded that the reliability of the Ni/Pd/Au surface finishes with Sn-4Ag-0.5Cu solders is higher within the given condition of this research.

  14. Mechanical Qualification of the Support Structure for MQXF, the Nb3Sn Low-Beta; Quadrupole for the High Luminosity LHC

    CERN Document Server

    Juchno, M; Anerella, M; Bajas, H; Bajko, M; Bourcey, N; Cheng, D W; Felice, H; Ferracin, P; Grosclaude, P; Guinchard, M; Perez, J C; Prin, H; Schmalzle

    2016-01-01

    Within the scope of the High Luminosity LHC project, the collaboration between CERN and U.S. LARP is developing new low-β quadrupoles using the Nb3Sn superconducting technology for the upgrade of the LHC interaction regions. The magnet support structure of the first short model was designed and two units were fabricated and tested at CERN and at LBNL. The structure provides the preload to the collars-coils subassembly by an arrangement of outer aluminum shells pre-tensioned with water-pressurized bladders. For the mechanical qualification of the structure and the assembly procedure, superconducting coils were replaced with solid aluminum “dummy coils”, the structure was preloaded at room temperature, and then cooled-down to 77 K. Mechanical behavior of the magnet structure was monitored with the use of strain gauges installed on the aluminum shells, the dummy coils and the axial preload system. This paper reports on the outcome of the assembly and the cool-down tests with dummy coils, which were performe...

  15. Highly sensitive room temperature carbon monoxide detection using SnO2 nanoparticle-decorated semiconducting single-walled carbon nanotubes.

    Science.gov (United States)

    Zhang, Yang; Cui, Shumao; Chang, Jingbo; Ocola, Leonidas E; Chen, Junhong

    2013-01-18

    We demonstrate a practical sensing platform, consisting of SnO(2) nanoparticle-decorated semiconducting single-walled carbon nanotubes assembled on gold electrodes via a dielectrophoretic process, for highly sensitive CO detection with fast response at room temperature. The highest sensitivity obtained was 0.27 and the response time was ∼2 s for 100 ppm CO detection. The lower detection limit was ∼1 ppm. These results indicate that the sensing performance of our device is among the best of CO sensors implemented with SWNTs. Further, we observed a significant increase in sensitivity to 0.67 after subjecting the device to an electrical breakdown at 8 V. We also proposed a theoretical model to reveal the relationship between the sensitivity and the gas concentration. The new model not only resulted in a nice fit to our data, but also allowed us to estimate the contact resistance between an individual SWNT and the gold electrodes.

  16. A highly sensitive room temperature H2S gas sensor based on SnO2 multi-tube arrays bio-templated from insect bristles.

    Science.gov (United States)

    Tian, Junlong; Pan, Feng; Xue, Ruiyang; Zhang, Wang; Fang, Xiaotian; Liu, Qinglei; Wang, Yuhua; Zhang, Zhijian; Zhang, Di

    2015-05-07

    A tin oxide multi-tube array (SMTA) with a parallel effect was fabricated through a simple and promising method combining chemosynthesis and biomimetic techniques; a biomimetic template was derived from the bristles on the wings of the Alpine Black Swallowtail butterfly (Papilio maackii). SnO2 tubes are hollow and porous structures with micro-pores regularly distributed on the wall. The morphology, the delicate microstructure and the crystal structure of this SMTA were characterized by super resolution digital microscopy, scanning electron microscopy, transmission electron microscopy and X-ray diffraction. The SMTA exhibits a high sensitivity to H2S gas at room temperature. It also exhibits a short response/recovery time, with an average value of 14/30 s at 5 ppm. In particular, heating is not required for the SMTA in the gas sensitivity measurement process. On the basis of these results, SMTA is proposed as a suitable new material for the design and fabrication of room-temperature H2S gas sensors.

  17. Production of microbial oil with high oleic acid content by Trichosporon capitatum

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Hong; Zong, Minhua [State Key Laboratory of Pulp and Paper Engineering, College of Light Industry and Food Sciences, South China University of Technology, Guangzhou 510640 (China); Li, Yuanyuan; Chen, Lei [School of Biosciences and Bioengineering, South China University of Technology, Guangzhou 510640 (China)

    2011-01-15

    Microbial oils with high unsaturated fatty acids content, especially oleic acid content, are good feedstock for high quality biodiesel production. Trichosporon capitatum was found to accumulate lipid with around 80% oleic acid and 89% total unsaturated fatty acids content on nitrogen-limited medium. In order to improve its lipid yield, effects of medium components and culture conditions on cell growth and lipid accumulation were investigated. Optimization of media resulted in a 61% increase in the lipid yield of T. capitatum after cultivation at 28 C and 160 rpm for 6 days. In addition, T. capitatum could grow well on cane molasses and afford a lipid yield comparable to that on synthetic nitrogen-limited medium. The biodiesel from the microbial oil produced by T. capitatum on cane molasses displayed a low cold filter plugging point (-15 C), and so T. capitatum might be a promising strain to provide lipid suitable for high quality biodiesel production. (author)

  18. Lattice Thermal Conductivity of the Binary and Ternary Group-IV Alloys Si-Sn, Ge-Sn, and Si-Ge-Sn

    Science.gov (United States)

    Khatami, S. N.; Aksamija, Z.

    2016-07-01

    Efficient thermoelectric (TE) energy conversion requires materials with low thermal conductivity and good electronic properties. Si-Ge alloys, and their nanostructures such as thin films and nanowires, have been extensively studied for TE applications; other group-IV alloys, including those containing Sn, have not been given as much attention as TEs, despite their increasing applications in other areas including optoelectronics. We study the lattice thermal conductivity of binary (Si-Sn and Ge-Sn) and ternary (Si-Ge-Sn) alloys and their thin films in the Boltzmann transport formalisms, including a full phonon dispersion and momentum-dependent boundary-roughness scattering. We show that Si-Sn alloys have the lowest conductivity (3 W /mK ) of all the bulk alloys, more than 2 times lower than Si-Ge, attributed to the larger difference in mass between the two constituents. In addition, we demonstrate that thin films offer an additional reduction in thermal conductivity, reaching around 1 W /mK in 20-nm-thick Si-Sn, Ge-Sn, and ternary Si-Ge-Sn films, which is near the conductivity of amorphous SiO2 . We conclude that group-IV alloys containing Sn have the potential for high-efficiency TE energy conversion.

  19. Microwave-Assisted Synthesis of Graphene-SnO2 Nanocomposites and Their Applications in Gas Sensors.

    Science.gov (United States)

    Kim, Hyoun Woo; Na, Han Gil; Kwon, Yong Jung; Kang, Sung Yong; Choi, Myung Sik; Bang, Jae Hoon; Wu, Ping; Kim, Sang Sub

    2017-09-20

    We obtained extremely high and selective sensitivity to NO2 gas by fabricating graphene-SnO2 nanocomposites using a commercial microwave oven. Structural characterization revealed that the products corresponded to agglomerated structures of graphene and SnO2 particles, with small secondary SnOx (x ≤ 2) nanoparticles deposited on the surfaces. The overall oxygen atomic ratio was decreased with the appearance of an SnOx (x graphene-SnO2 nanocomposites, with the graphene promoting efficient transport of the microwave energy, evaporation and redeposition of SnOx nanoparticles were facilitated. The graphene-SnO2 nanocomposites exhibited a high sensor response of 24.7 for 1 ppm of NO2 gas, at an optimized temperature of 150 °C. The graphene-SnO2 nanocomposites were selectively sensitive to NO2 gas, in comparison with SO2, NH3, and ethanol gases. We suggest that the generation of SnOx nanoparticles and the SnOx phase in the matrix results in the formation of SnO2/SnO2 homojunctions, SnO2/SnOx (x SnO2/graphene heterojunctions, which are responsible for the excellent sensitivity of the graphene-SnO2 nanocomposites to NO2 gas. In addition, the generation of surface Sn interstitial defects is also partly responsible for the excellent NO2 sensing performance observed in this study.

  20. A deep learning and novelty detection framework for rapid phenotyping in high-content screening

    Science.gov (United States)

    Sommer, Christoph; Hoefler, Rudolf; Samwer, Matthias; Gerlich, Daniel W.

    2017-01-01

    Supervised machine learning is a powerful and widely used method for analyzing high-content screening data. Despite its accuracy, efficiency, and versatility, supervised machine learning has drawbacks, most notably its dependence on a priori knowledge of expected phenotypes and time-consuming classifier training. We provide a solution to these limitations with CellCognition Explorer, a generic novelty detection and deep learning framework. Application to several large-scale screening data sets on nuclear and mitotic cell morphologies demonstrates that CellCognition Explorer enables discovery of rare phenotypes without user training, which has broad implications for improved assay development in high-content screening. PMID:28954863

  1. Innovation management and marketing in the high-tech sector: A content analysis of advertisements

    DEFF Research Database (Denmark)

    Gerhard, D.; Brem, Alexander; Baccarella, Ch.

    2011-01-01

    Advertizing high-technology products is a tricky and critical task for every company, since it means operating in an environment with high market uncertainty. The work presents results of a content analysis of 110 adverts for consumer electronics products which examines how these products and the...... cycles. Regarding the specific content, the ‘mother brand’ is shown to play a very important role. On the other hand, the results show that incorporated technology, its superiority and functionality do not play an important role in the advertisements...

  2. Influence of roasting and different brewing processes on the ochratoxin A content in coffee determined by high-performance liquid chromatography-fluorescence detection (HPLC-FLD).

    Science.gov (United States)

    La Pera, L; Avellone, G; Lo Turco, V; Di Bella, G; Agozzino, P; Dugo, G

    2008-10-01

    A rapid and reliable procedure has been developed for the determination of ochratoxin A (OTA) in green and roasted coffee. The method consists of extraction of the sample with methanol-5% aqueous sodium hydrogen carbonate/1% PEG8000 (20:80), followed by immunoaffinity column (IAC) clean-up and, finally, high-performance liquid chromatography (HPLC) determination with fluorimetric detection. Mean recoveries for green and roasted coffee spiked at different levels ranging from 94 and 105% were obtained. The limit of determination (S/N = 3) was 0.032 ng g(-1) and the precision (within-laboratory relative standard deviation) was 6%. The method described has been used to assess the influence of roasting and different brewing processes on OTA content in commercial lots of green and roasted coffee. The results provided evidence that roasting led to a significant drop on OTA levels (65-100%). Also, the way coffee is prepared affects the OTA content: brewing using a Moka Express (Italian coffee) led to a significant reduction of OTA concentration (50-75%) since hot water stays in contact with coffee for a short time. On the contrary, Turkish coffee-making (infusion for about 10 min) cause poor reduction in OTA.

  3. Strain sensitivity of band gaps of Sn-containing semiconductors

    DEFF Research Database (Denmark)

    Li, Hong; Castelli, Ivano Eligio; Thygesen, Kristian Sommer

    2015-01-01

    Tuning of band gaps of semiconductors is a way to optimize materials for applications within photovoltaics or as photocatalysts. One way to achieve this is through applying strain to the materials. We investigate the effect of strain on a range of Sn-containing semiconductors using density...... functional theory and many-body perturbation theory calculations. We find that the band gaps of bulk Sn oxides with SnO6 octahedra are highly sensitive to volumetric strain. By applying a small isotropic strain of 2% (-2%), a decrease (increase) of band gaps as large as 0.8 to 1.0 eV are obtained. We...... attribute the ultrahigh strain sensitivity to the pure Sn s-state character of the conduction-band edges. Other Sn-containing compounds may show both increasing and decreasing gaps under tensile strain and we show that the behavior can be understood by analyzing the role of the Sn s states in both...

  4. Hierarchical Graphene-Encapsulated Hollow SnO2@SnS2 Nanostructures with Enhanced Lithium Storage Capability.

    Science.gov (United States)

    Xu, Wangwang; Xie, Zhiqiang; Cui, Xiaodan; Zhao, Kangning; Zhang, Lei; Dietrich, Grant; Dooley, Kerry M; Wang, Ying

    2015-10-14

    Complex hierarchical structures have received tremendous attention due to their superior properties over their constitute components. In this study, hierarchical graphene-encapsulated hollow SnO2@SnS2 nanostructures are successfully prepared by in situ sulfuration on the backbones of hollow SnO2 spheres via a simple hydrothermal method followed by a solvothermal surface modification. The as-prepared hierarchical SnO2@SnS2@rGO nanocomposite can be used as anode material in lithium ion batteries, exhibiting excellent cyclability with a capacity of 583 mAh/g after 100 electrochemical cycles at a specific current of 200 mA/g. This material shows a very low capacity fading of only 0.273% per cycle from the second to the 100th cycle, lower than the capacity degradation of bare SnO2 hollow spheres (0.830%) and single SnS2 nanosheets (0.393%). Even after being cycled at a range of specific currents varied from 100 mA/g to 2000 mA/g, hierarchical SnO2@SnS2@rGO nanocomposites maintain a reversible capacity of 664 mAh/g, which is much higher than single SnS2 nanosheets (374 mAh/g) and bare SnO2 hollow spheres (177 mAh/g). Such significantly improved electrochemical performance can be attributed to the unique hierarchical hollow structure, which not only effectively alleviates the stress resulting from the lithiation/delithiation process and maintaining structural stability during cycling but also reduces aggregation and facilitates ion transport. This work thus demonstrates the great potential of hierarchical SnO2@SnS2@rGO nanocomposites for applications as a high-performance anode material in next-generation lithium ion battery technology.

  5. SnO{sub 2}:F thin films deposited by RF magnetron sputtering: effect of the SnF{sub 2} amount in the target on the physical properties

    Energy Technology Data Exchange (ETDEWEB)

    De Moure F, F. [universidad Autonoma de Queretaro, Facultad de Quimica Materiales, Queretaro 76010, Queretaro (Mexico); Guillen C, A.; Nieto Z, K. E.; Quinones G, J. G.; Hernandez H, A.; Melendez L, M.; Olvera, M. de la L., E-mail: fcomoure@hotmail.com [IPN, Centro de Investigacion y de Estudios Avanzados, Departamento de Fisica, Apdo. Postal 14-740, 07360 Mexico D. F. (Mexico)

    2013-08-01

    SnO{sub 2}:F thin films were prepared by RF magnetron sputtering onto glass substrates using SnF{sub 2} as fluorine source. The films were deposited under a mixed argon/hydrogen atmosphere at a substrate temperature of 500 C. The X-ray diffraction shows that polycrystalline films were grown with a phases mixture of SnO{sub 2} and Sn O. The optical transmittance is between 80 and 90%. The physical properties of the films suggest that SnO{sub 2} thin films grown with small SnF{sub 2} content in the target can be considered as candidates for transparent electrodes. (Author)

  6. SN 185 and its Remnant RCW 86: A Type Ia Explosion within a Bubble?

    Science.gov (United States)

    Borkowski, Kazimierz; Blair, William; Ghavamian, Parviz; Long, Knox; Raymond, John; Reynolds, Stephen; Rho, Jeonghee; Williams, Brian; Winkler, P. Frank

    2008-03-01

    The bright guest star of AD185 is the earliest recorded historical supernova (SN), but its remnant has only recently been firmly identified with RCW 86 with help of X-rays and very high energy (VHE) Gamma-rays. RCW 86 is unlike any other historical SN, implicating a Type Ia explosion within a wind-blown bubble. X-ray synchrotron emission and VHE Gamma-rays are produced by relativistic particles accelerated in fast (several thousand km/s) shocks that are present in RCW 86, while slower radiative and nonradiative shocks are driven into the dusty shell swept up by the SN progenitor. We propose Spitzer observations of RCW 86, that will allow us to determine dust properties and physical conditions within both slow and fast shocks. We will determine shock densities in the whole remnant using MIPS imaging at 24 and 70 microns. This will allow us to finally determine whether VHE emission arises from relativistic electrons or from cosmic ray protons accelerated by the SN shock. We will also determine how acceleration of synchrotron-emitting electrons to TeV energies depends on the shock density. We propose IRS spectral mapping in two very different regions of the remnant to perform a more detailed and sensitive study of dust emission and dust destruction under differing plasma conditions, and of line emission produced by radiative shocks. This will also verify the results of the imaging observations, and will allow for quantitative comparison with models for dust emission and destruction in SN shocks. We request imaging with IRAC in the brightest region of the remnant to map emission from the hottest, transiently heated small grains, and to determine their destruction rates. Physical properties and dust content within the shell swept up by the RCW 86 progenitor will help us to constrain the pre-SN evolution of a Type Ia progenitor, a significant step toward understanding of progenitors of thermonuclear explosions.

  7. High Neonatal Blood Iron Content Is Associated with the Risk of Childhood Type 1 Diabetes Mellitus

    Directory of Open Access Journals (Sweden)

    Julie Nyholm Kyvsgaard

    2017-11-01

    Full Text Available (1 Background: Iron requirement increases during pregnancy and iron supplementation is therefore recommended in many countries. However, excessive iron intake may lead to destruction of pancreatic β-cells. Therefore, we aim to test if higher neonatal iron content in blood is associated with the risk of developing type 1 diabetes mellitus (T1D in childhood; (2 Methods: A case-control study was conducted, including 199 children diagnosed with T1D before the age of 16 years from 1991 to 2005 and 199 controls matched on date of birth. Information on confounders was available in 181 cases and 154 controls. Iron was measured on a neonatal single dried blood spot sample and was analyzed by laser ablation inductively coupled plasma mass spectrometry. Multivariate logistic regression was used to evaluate if iron content in whole blood was associated with the risk of T1D; (3 Results: A doubling of iron content increased the odds of developing T1D more than two-fold (odds ratio (95% CI, 2.55 (1.04; 6.24. Iron content increased with maternal age (p = 0.04 and girls had higher content than boys (p = 0.01; (4 Conclusions: Higher neonatal iron content associates to an increased risk of developing T1D before the age of 16 years. Iron supplementation during early childhood needs further investigation, including the causes of high iron in neonates.

  8. High efficiency bifacial Cu2ZnSnSe4 thin-film solar cells on transparent conducting oxide glass substrates

    Directory of Open Access Journals (Sweden)

    Jung-Sik Kim

    2016-09-01

    Full Text Available In this work, transparent conducting oxides (TCOs have been employed as a back contact instead of Mo on Cu2ZnSnSe4 (CZTSe thin-film solar cells in order to examine the feasibility of bifacial Cu2ZnSn(S,Se4 (CZTSSe solar cells based on a vacuum process. It is found that the interfacial reaction between flourine doped tin oxide (FTO or indium tin oxide (ITO and the CZTSe precursor is at odds with the conventional CZTSe/Mo reaction. While there is no interfacial reaction on CZTSe/FTO, indium in CZTSe/ITO was significantly diffused into the CZTSe layers; consequently, a SnO2 layer was formed on the ITO substrate. Under bifacial illumination, we achieved a power efficiency of 6.05% and 4.31% for CZTSe/FTO and CZTSe/ITO, respectively.

  9. Processing of Bi-2212 and Nb$_3$Sn studied in situ by high energy synchrotron diffraction and micro-tomography

    CERN Document Server

    Kadar, Julian

    Next generation superconducting wires have been studied to obtain more information on the evolution of phase growth, crystallite size and strain state during wire processing. The high energy scattering beam line ID15 at the European Synchrotron Radiation Facility provides a very high flux of high energy photons for very fast in situ X-ray diffraction and micro-tomography studies of Bi-2212/Ag and Nb$_3$S/Cu wire samples. The typical wire processing conditions could be imitated in the X-ray transparent furnace at ID15 for diffraction and tomography studies. Efficient data analysis is mandatory in order to handle the very fast data acquisition rate. For this purpose an Excel-VBA based program was developed that allows a semi-automated fitting and tracking of peaks with pre-set constraints. With this method, more than one thousand diffraction patterns have been analysed to extract d-spacing, peak intensity and peak width values. X ray absorption micro tomograms were recorded simultaneously with the X-ray diffrac...

  10. Longitudinal and Transverse Cross-Sectional Microstructure and Critical Current Density in Nb(3)Sn Superconductors

    CERN Document Server

    Pong, I; Scheuerlein, C; Oberli, L R

    2011-01-01

    The longitudinal and transverse cross-sectional microstructures of several internal tin Nb(3)Sn strands have been systematically investigated. The critical current densities of these strands were then correlated with their design parameters. It is observed that the occurrence of certain coarse grain structures is related to the location of the filaments with respect to the subelements as well as to the strand. Experimental evidence suggests that the existence of these coarse grains is related to Sn distribution during the early stages of the heat treatment. It is also noticed that some coarse grains have high aspect ratio features, confirming the need to study the longitudinal fracture surface. We report in this paper the observation of some unusual grain sizes and morphologies. It appears that, of the high-Sn content Nb(3)Sn conductors investigated in this paper, a strand's global composition has a weaker influence on the critical current density (J(c)) than local and structural factors, such as the local Cu...

  11. Adsorption Mechanism of Cu-Doped SnO2 (110) Surface toward H2 Dissolved in Power Transformer

    OpenAIRE

    Feng Wang; Jingmin Fan; Qiuqin Sun; Qinji Jiang; She Chen; Wu Zhou

    2016-01-01

    The content of hydrogen is a key quantity in condition assessment and fault diagnosis of power transformer. Based on the density functional theory (DFT), the adsorption mechanism of Cu-doped SnO2 surface toward H2 has been systematically studied in this work. Firstly, the relaxation, the bond length, and overlap population of both the pure and Cu-doped SnO2 are computed. To determine the optimal doping position, the formation energies of four potential sites (i.e., Sn5c, Sn6c, Sn5c-s, and Sn6...

  12. Ethanol production from food waste at high solid contents with vacuum recovery technology

    Science.gov (United States)

    Ethanol production from food wastes does not only solve the environmental issues but also provide renewable biofuel to partially substitute fossil fuels. This study investigated the feasibility of utilization of food wastes for producing ethanol at high solid contents (35%, w/w). Vacuum recovery sys...

  13. 20161116 - Toxicological Tipping Points: Learning Boolean Networks from High-Content Imaging Data. (BOSC meeting)

    Science.gov (United States)

    The objective of this work is to elucidate biological networks underlying cellular tipping points using time-course data. We discretized the high-content imaging (HCI) data and inferred Boolean networks (BNs) that could accurately predict dynamic cellular trajectories. We found t...

  14. Exceptional heat stability of high protein content dispersions containing whey protein particles

    NARCIS (Netherlands)

    Saglam, D.; Venema, P.; Vries, de R.J.; Linden, van der E.

    2014-01-01

    Due to aggregation and/or gelation during thermal treatment, the amount of whey proteins that can be used in the formulation of high protein foods e.g. protein drinks, is limited. The aim of this study was to replace whey proteins with whey protein particles to increase the total protein content and

  15. A high-content subtractive screen for selecting small molecules affecting internalization of GPCRs

    CSIR Research Space (South Africa)

    Kwon, Y-J

    2012-03-01

    Full Text Available transduction to physiology. Here, the authors demonstrate a high-content screen using a panel of GPCR assays to identify receptor selective molecules acting within the kinase/phosphatase inhibitor family. A collection of 88 kinase and phosphatase inhibitors...

  16. The Cementite Spheroidization Process in High-Carbon Steels with Different Chromium Contents

    NARCIS (Netherlands)

    Luzginova, N.V.; Zhao, L.; Sietsma, J.

    2008-01-01

    The cementite spheroidization process is investigated in hypereutectoid steels with different chromium (Cr) contents. A spheroidized structure in high-carbon steel is usually obtained by a divorced eutectoid transformation (DET) reaction, which occurs during slow cooling of austenite with fine

  17. Vendors Future: Northern Light--Delivering High-Quality Content to a Large Internet Audience.

    Science.gov (United States)

    Wiggins, Richard

    1997-01-01

    Describes a Web-based information service, Northern Light, which demonstrates a new paradigm for serving large populations of users and delivering high-quality content on topics both general and narrow. Discusses performance of the search engine, search syntax, Northern Light's special collection, and pricing. (AEF)

  18. Finding Toxicological Tipping Points from High-Content Imaging Data (WC10)

    Science.gov (United States)

    A key challenge to using in vitro data in risk assessment is differentiating between chemical-induced adaptive versus adverse cellular responses. To further investigate this issue, we studied the effects of hundreds of chemicals in HepG2 cells using high-content imaging (HCI). HC...

  19. Adhesive performance of washed cottonseed meal at high solid contents and low temperatures

    Science.gov (United States)

    Water-washed cottonseed meal (WCSM) has been shown as a promising biobased wood adhesive. Recently, we prepared WSCM in a pilot scale for promoting its industrial application. In this work, we tested the adhesive strength and viscosity of the adhesive preparation with high solid contents (up to 30%...

  20. A Modified Gibson Assembly Method for Cloning Large DNA Fragments with High GC Contents.

    Science.gov (United States)

    Li, Lei; Jiang, Weihong; Lu, Yinhua

    2018-01-01

    Gibson one-step, isothermal assembly method (Gibson assembly) can be used to efficiently assemble large DNA molecules by in vitro recombination involving a 5'-exonuclease, a DNA polymerase and a DNA ligase. In the past few years, this robust DNA assembly method has been widely applied to seamlessly construct genes, genetic pathways and even entire genomes. Here, we expand this method to clone large DNA fragments with high GC contents, such as antibiotic biosynthetic gene clusters from Streptomyces . Due to the low isothermal condition (50 °C) in the Gibson reaction system, the complementary overlaps with high GC contents are proposed to easily form mismatched linker pairings, which leads to low assembly efficiencies mainly due to vector self-ligation. So, we modified this classic method by the following two steps. First, a pair of universal terminal single-stranded DNA overhangs with high AT contents are added to the ends of the BAC vector. Second, two restriction enzyme sites are introduced into the respective sides of the designed overlaps to achieve the hierarchical assembly of large DNA molecules. The optimized Gibson assembly method facilitates fast acquisition of large DNA fragments with high GC contents from Streptomyces.

  1. Platinum Activated IrO2/SnO2 Nanocatalysts and Their Electrode Structures for High Performance Proton Exchange Membrane Water Electrolysis

    DEFF Research Database (Denmark)

    Xu, Junyuan; Li, Qingfeng; Christensen, Erik

    2013-01-01

    In order to improve proton exchange membrane water electrolysis performance, anode catalyst and catalyst layer were examined in this work. SnO2 supported IrO2 nanocatalyst and its analogue with platinum enhancement were firstly synthesized for the oxygen evolution reaction. The effect of the intr...... improved due to the appropriate porosity and pore size distribution. The highest electrolyser performance of 1.63 V at 2 A cm-2 was achieved at 80 °C for optimized catalyst layers containing platinum activated IrO2/SnO2 catalyst....

  2. Observation of yielding and strain hardening in a titanium alloy having high oxygen content

    Energy Technology Data Exchange (ETDEWEB)

    Geng, F., E-mail: iamgengfang@gmail.com [Institute for Materials Research, Tohoku University, Sendai 850-8577 (Japan); Niinomi, M.; Nakai, M. [Institute for Materials Research, Tohoku University, Sendai 850-8577 (Japan)

    2011-06-25

    Highlights: {yields} TNTZ with high oxygen content indicates special mechanical properties. {yields} The phenomenon was explained by the interaction between oxygen atoms and dislocations. {yields} The deformation behavior changes with the addition of oxygen in TNTZ. {yields} There is a specific compositional area of oxygen in TNTZ exhibits good property. - Abstract: Plastic deformation behavior and its relation to tensile properties were investigated in an attractive {beta}-type titanium alloy (Ti-29Nb-13Ta-4.6Zr) with the oxygen content of 0.1-0.7 mass% subjected to hot rolling and solution treatment after hot rolling. Hereafter, Ti-29Nb-13Ta-4.6Zr is abbreviated to TNTZ. With the increase of oxygen content, the tensile strength and 0.2% proof stress of all the samples increase, however, their elongation indicates special change, which is contradictory to that reported conventionally. The elongation firstly decreases and then increases with the increase in the oxygen content. Therefore, TNTZ with high strength and high ductility due to the addition of high oxygen content (0.7 mass%) is obtained. Remarkable yielding phenomenon and strain hardening are observed in TNTZ, which can be explained by the interaction between oxygen atoms and a lot of screw and edge dislocations leading to the easy activation of the multiple slip systems. The deformation behavior changes with the addition of oxygen in TNTZ. The plastic deformation mode changes from the deformation-induced martensite transformation to slip mechanism. It is realized that there is a specific compositional area of oxygen in which the TNTZ exhibits strain hardening and high strength, and appropriate Young's modulus value.

  3. DETERMINATION OF STRONTIUM IONS IN WATERS WITH A HIGH CONTENT OF SODIUM IONS

    OpenAIRE

    Tatiana Mitina; Nadejda Bondarenco; Diana Grigoras; Elena Botizat; Tudor Lupascu

    2015-01-01

    This paper reports on the influence of sodium ions on experimental determination of strontium ions concentration in waters with a high content of sodium ions by using emission flame photometry and atomic absorption spectroscopy. For the method of emission flame photometry it was shown that at a wavelength of 460.7 nm (spectral emission line of strontium) the emission is linearly dependent on the concentration of sodium ions. The greatest impact of high concentrations of sodium ions on the res...

  4. Thermoelectric properties of chalcogenide based Cu2+xZnSn1−xSe4

    Directory of Open Access Journals (Sweden)

    Ch. Raju

    2013-03-01

    Full Text Available Quaternary chalcogenide compounds Cu2+xZnSn1−xSe4 (0 ≤ x ≤ 0.15 were prepared by solid state synthesis. Rietveld powder X-ray diffraction (XRD refinements combined with Electron Probe Micro Analyses (EPMA, WDS-Wavelength Dispersive Spectroscopy and Raman spectra of all samples confirmed the stannite structure (Cu2FeSnS4-type as the main phase. In addition to the main phase, small amounts of secondary phases like ZnSe, CuSe and SnSe were observed. Transport properties of all samples were measured as a function of temperature in the range from 300 K to 720 K. The electrical resistivity of all samples decreases with an increase in Cu content except for Cu2.1ZnSn0.9Se4, most likely due to a higher content of the ZnSe. All samples showed positive Seebeck coefficients indicating that holes are the majority charge carriers. The thermal conductivity of doped samples was high compared to Cu2ZnSnSe4 and this may be due to the larger electronic contribution and the presence of the ZnSe phase in the doped samples. The maximum zT = 0.3 at 720 K occurs for Cu2.05ZnSn0.95Se4 for which a high-pressure torsion treatment resulted in an enhancement of zT by 30% at 625 K.

  5. Deformation Experiment on Quartz Aggregates with High Porosity and High Water Contents at High Pressure and Temperature

    Science.gov (United States)

    Okazaki, K.; Hirth, G.

    2016-12-01

    Large earthquakes typically nucleate near the depth limit of seismogenic zones. In these areas, high Vp/Vs ratios are commonly observed, indicating the presence of high pore fluid pressures. Thus, it is important to understand how the water content (both water in the crystal and in the pores) and the pore structure affect the rheology of polycrystalline materials. We conducted deformation experiments on quartz aggregates using a Griggs-type deformation apparatus. Samples were hot-pressed from silica gels, which contain 9 wt% water within the amorphous structure and absorbed on the surface. Hydrostatic experiments within the α-quartz stability field at a pressure of 1.5 GPa and 900°C indicate that hot-pressed samples are composed of quartz and no relict of amorphous material is present. The average grain size and porosity of the hot-pressed aggregates is about 4 μm and 23%, respectively. The grain shape is equigranular and no crystallographic preferred orientation (CPO) is observed. Initial results from general shear experiments on the hot-pressed quartz aggregates at the equivalent strain rate of 1.5 x 10-4 1/s, a pressure of 1.5 GPa and 900°C show very low strength (equivalent stress of 140 MPa) and nominally steady state flow at shear strains up to 3.5. The samples show no CPO and evidence for strain localization along R1 riedel shears. In contrast, deformation experiments on cores of quartzite show dislocation creep at this pressure/temperature condition. The measured stress from the new experiments is significantly lower than predicted by the wet quartz flow law (e.g., Hirth et al., 2001). The low flow stress and absence of CPO suggest the operation of grain-size sensitive flow, or perhaps that the effective pressure law is still applicable and the sample deforms by a distributed semi-brittle flow process

  6. Progress on the Development of the $Nb_3Sn$ 11T Dipole for the High Luminosity Upgrade of LHC

    CERN Document Server

    Savary, Frederic; Bordini, Bernardo; Bottura, Luca; Fiscarelli, Lucio; Fleiter, Jerome; Foussat, Arnaud; Izquierdo Bermudez, Susana; Karppinen, Mikko; Lackner, Friedrich; Loffler, Christian H; Nilsson, Emelie; Perez, Juan Carlos; Prin, Herve; Principe, Rosario; Ramos, Delio; de Rijk, Gijs; Rossi, Lucio; Smekens, David; Sequeira Tavares, Sandra; Willering, Gerard; Zlobin, Alexander V

    2017-01-01

    The high-luminosity large hadron collider (LHC) project at CERN entered into the production phase in October 2015 after the completion of the design study phase. In the meantime, the development of the 11 T dipole needed for the upgrade of the collimation system of the machine made significant progress with very good performance of the first two-in-one magnet model of 2-m length made at CERN. The 11 T dipole, which is more powerful than the current main dipoles of LHC, can be made shorter with an equivalent integrated field. This will allow creating space for the installation of additional collimators in specific locations of the dispersion suppressor regions. Following tests carried out during heavy ions runs of LHC in the end of 2015, and a more recent review of the project budget, the installation plan for the 11 T dipole was revised. Consequently, one 11 T dipole full assembly containing two 11 T dipoles of 5.5-m length will be installed on either side of interaction point 7. These two units shall be inst...

  7. High School Science Teachers' Perceptions of Teaching Content-Related Reading Comprehension Instruction

    Science.gov (United States)

    Williams, Theresa

    In order to achieve academic success, students must be able to comprehend written material in content-area textbooks. However, a large number of high school students struggle to comprehend science content. Research findings have demonstrated that students make measurable gains in comprehending content-area textbooks when provided quality reading comprehension instruction. The purpose of this study was to gain an understanding of how high school science teachers perceived their responsibility to provide content-related comprehension instruction and 10 high school science teachers were interviewed for this study. Data analysis consisted of open, axial, and selective coding. The findings revealed that 8 out of the 10 participants believed that it is their responsibility to provide reading comprehension. However, the findings also revealed that the participants provided varying levels of reading comprehension instruction as an integral part of their science instruction. The potential for positive social change could be achieved by teachers and administrators. Teachers may use the findings to reflect upon their own personal feelings and beliefs about providing explicit reading comprehension. In addition to teachers' commitment to reading comprehension instruction, administrators could deliberate about professional development opportunities that might improve necessary skills, eventually leading to better comprehension skills for students and success in their education.

  8. SnAs-Based Layered Superconductor NaSn2As2

    Science.gov (United States)

    Goto, Yosuke; Yamada, Akira; Matsuda, Tatsuma D.; Aoki, Yuji; Mizuguchi, Yoshikazu

    2017-12-01

    Superconducting behavior with exotic characteristics is often observed in materials with a layered two-dimensional crystal structure. Low dimensionality affects the electronic structure of these materials, potentially leading to high transition temperatures (Tc) and/or unconventional pairing mechanisms. In this letter, we report on superconductivity in layered tin arsenide NaSn2As2. The crystal structure consists of Sn2As2 bilayers, bound by the van der Waals forces and separated by Na+ ions. Measurements of electrical resistivity and specific heat confirm the bulk nature of superconductivity of NaSn2As2, with Tc of 1.3 K. Our results suggest that layered SnAs is a basic structure, offering another universality class in the family of layered superconductors. The results provide a new platform for the studies of physics and chemistry of low-dimensional superconductors with lone pair electrons.

  9. Fast repurposing of high-resolution stereo video content for mobile use

    Science.gov (United States)

    Karaoglu, Ali; Lee, Bong Ho; Boev, Atanas; Cheong, Won-Sik; Gotchev, Atanas

    2012-06-01

    3D video content is captured and created mainly in high resolution targeting big cinema or home TV screens. For 3D mobile devices, equipped with small-size auto-stereoscopic displays, such content has to be properly repurposed, preferably in real-time. The repurposing requires not only spatial resizing but also properly maintaining the output stereo disparity, as it should deliver realistic, pleasant and harmless 3D perception. In this paper, we propose an approach to adapt the disparity range of the source video to the comfort disparity zone of the target display. To achieve this, we adapt the scale and the aspect ratio of the source video. We aim at maximizing the disparity range of the retargeted content within the comfort zone, and minimizing the letterboxing of the cropped content. The proposed algorithm consists of five stages. First, we analyse the display profile, which characterises what 3D content can be comfortably observed in the target display. Then, we perform fast disparity analysis of the input stereoscopic content. Instead of returning the dense disparity map, it returns an estimate of the disparity statistics (min, max, meanand variance) per frame. Additionally, we detect scene cuts, where sharp transitions in disparities occur. Based on the estimated input, and desired output disparity ranges, we derive the optimal cropping parameters and scale of the cropping window, which would yield the targeted disparity range and minimize the area of cropped and letterboxed content. Once the rescaling and cropping parameters are known, we perform resampling procedure using spline-based and perceptually optimized resampling (anti-aliasing) kernels, which have also a very efficient computational structure. Perceptual optimization is achieved through adjusting the cut-off frequency of the anti-aliasing filter with the throughput of the target display.

  10. Transport and NMR characteristics of the skutterudite-related compound Ca3Rh4Sn13

    Science.gov (United States)

    Tseng, C. W.; Kuo, C. N.; Li, B. S.; Wang, L. M.; Gippius, A. A.; Kuo, Y. K.; Lue, C. S.

    2018-02-01

    We report the electronic properties of the Yb3Rh4Sn13-type single crystalline Ca3Rh4Sn13 by means of the electrical resistivity, Hall coefficient, Seebeck coefficient, thermal conductivity, as well as 119Sn nuclear magnetic resonance (NMR) measurements. The negative sign of the Hall coefficient and Seebeck coefficient at low temperatures suggests that the n-type carriers dominate the electrical transport in Ca3Rh4Sn13, in contrast to the observations in Sr3Rh4Sn13 which has a p-type conduction. Such a finding indicates a significant difference in the electronic features between these two stannides. Furthermore, we analyzed the temperature-dependent 119Sn NMR spin-lattice relaxation rate for Ca3Rh4Sn13, (Sr0.7Ca0.3)3Rh4Sn13, and Sr3Rh4Sn13 to examine the change of the electronic Fermi-level density of states (DOS) in (Sr1-xCax)3Rh4Sn13. It indicates that the Sn 5s partial Fermi-level DOS enhances with increasing the Ca content, being consistent with the trend of the superconducting temperature. Since the total Fermi-level DOS usually obeys the same trend of the partial Fermi-level DOS, the NMR analysis provides microscopic evidence for the correlation between the electronic DOS and superconductivity of the (Sr1-xCax)3Rh4Sn13 system.

  11. A High Resolution Capacitive Sensing System for the Measurement of Water Content in Crude Oil

    Directory of Open Access Journals (Sweden)

    Muhammad Zubair Aslam

    2014-06-01

    Full Text Available This paper presents the design of a non-intrusive system to measure ultra-low water content in crude oil. The system is based on a capacitance to phase angle conversion method. Water content is measured with a capacitance sensor comprising two semi-cylindrical electrodes mounted on the outer side of a glass tube. The presence of water induces a capacitance change that in turn converts into a phase angle, with respect to a main oscillator. A differential sensing technique is adopted not only to ensure high immunity against temperature variation and background noise, but also to eliminate phase jitter and amplitude variation of the main oscillator that could destabilize the output. The complete capacitive sensing system was implemented in hardware and experiment results using crude oil samples demonstrated that a resolution of ±50 ppm of water content in crude oil was achieved by the proposed design.

  12. Research and Design of Soil Water Content Sensor Based on High-frequency Capacitive

    Directory of Open Access Journals (Sweden)

    Xing ZHEN

    2014-03-01

    Full Text Available Power supply and long distance cable are difficult in a field. Hence, a low power high-frequency capacitive soil water content sensor was developed. It consisted of an adjustable signal generating circuit, a signal attenuator, a true RMS detection circuit, a RC charge and discharge circuit, and two probe electrodes. The probe electrode was made up of PCB (Printed Circuit Board. In order to reduce entire energy consumption, the optimization design of sensor circuit was conducted. The results showed that the output voltage of the sensor had a positive linear correlation with soil volumetric moisture content, and the coefficient of determination R2 was 0.989. The stability and consistency of the soil moisture sensor met the needs of the long-term monitoring soil moisture content.

  13. Structure and Content Analysis for Vocational High School Website in Indonesia

    Science.gov (United States)

    Subagja, H.; Abdullah, A. G.; Trisno, B.; Nandiyanto, A. B. D.

    2017-03-01

    Statistics about the condition of the school’s website in Indonesia is still difficult. This study aims to determine website quality in terms of completeness of content’s criteria of Vocational High School (VHS) in West Java, Indonesia. The method used is the content analysis and survey. Content analysis is reviewing the documents comprising the general category, while the survey is a observation process to get the facts from 272 school websites. Aspects of the structure and content of school website are including institutional information, educators and education personnel, curriculum, student, infrastructure, school achievement, and public access. The results of this study showed the average quality of the VHS website in West Java is still low. The recommendations are needed to improve the quality of the school website.

  14. Synthesis, photocatalytic and antimicrobial properties of SnO2, SnS2 and SnO2/SnS2 nanostructure.

    Science.gov (United States)

    Fakhri, Ali; Behrouz, Sajjad; Pourmand, Melika

    2015-08-01

    Nanoscale SnO2, SnS2 and SnO2/SnS2 were synthesized by hydrothermal treatment method and characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), Barrett-Joyner-Halenda (BJH) and UV-vis spectra. The photocatalytic activity of SnO2, SnS2 and SnO2/SnS2 were tested with Enrofloxacin antibiotic. The tetragonal and hexagonal SnO2 and SnS2 phase was confirmed through XRD, respectively. The photocatalytic results indicated that the SnO2/SnS2 enhanced the photocatalytic activity and could be effectively used as photocatalyst for degradation of Enrofloxacin antibiotic pollutant. The results of antibacterial experiment under visible light irradiation demonstrate that the SnO2/SnS2 nanocomposite exhibit enhanced antibacterial efficiency compared with pure SnO2 and SnS2. The antifungal activity of the nanoscale SnO2, SnS2 and SnO2/SnS2 against Candida albicans was assessed using the disc-diffusion susceptibility tests. It was seen that the antifungal activity of SnO2/SnS2 nanocomposite is higher than the pure SnO2 and SnS2 toward pathogenic C. albicans. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. Application of PtSn/C catalysts and Nafion SiO{sub 2} membranes in direct ethanol fuel cell at high temperatures; Aplicacao de catalisadores PtSn/C e membranas Nafion SiO{sub 2} em celulas a combustivel de etanol direto em elevadas temperaturas

    Energy Technology Data Exchange (ETDEWEB)

    Dresch, Mauro Andre

    2014-07-01

    This work has as objective to evaluate anodes and electrolytes in direct ethanol fuel cells (DEFC) operating at high temperature (130 deg C). As anode materials, electrocatalysts based on Pt Sn/C were prepared by Modified Polyol Method with various Pt:Sn atomic ratios. Such methodology promotes self organized electrocatalysts production with narrow particle size distribution and high alloying degree. The electrocatalysts were characterized by XRD, and CO stripping. The results showed that these materials presented high alloying degree and Eonset CO oxidation at lower potential as commercial materials. As electrolyte, Nafion-SiO{sub 2} hybrids were synthesized by sol-gel reaction, by the incorporation of oxide directly into the ionic aggregates of various kinds of Nafion membranes. The synthesis parameter, such sol-gel solvent, membrane thickness and silicon precursor concentration were studied in terms of silica incorporation degree and hybrid mechanical stability. Finally, the optimized anodes and electrolytes were evaluated in DEFC operating at 80 - 130 deg C temperature range. The results showed a significant improvement of the DEFC performance (122 mW cm{sup -2}), resulted from the acceleration of ethanol oxidation reaction rate due to anode material optimization and high temperature operation once the use of hybrids possibilities the increase of temperature without a significant conductivity loses. In this sense, the combination of optimized electrodes and electrolytes are a promising alternative for the development of these devices. (author)

  16. Personal radiation detector at a high technology readiness level that satisfies DARPA's SN-13-47 and SIGMA program requirements

    Science.gov (United States)

    Ginzburg, D.; Knafo, Y.; Manor, A.; Seif, R.; Ghelman, M.; Ellenbogen, M.; Pushkarsky, V.; Ifergan, Y.; Semyonov, N.; Wengrowicz, U.; Mazor, T.; Kadmon, Y.; Cohen, Y.; Osovizky, A.

    2015-06-01

    There is a need to develop new personal radiation detector (PRD) technologies that can be mass produced. On August 2013, DARPA released a request for information (RFI) seeking innovative radiation detection technologies. In addition, on December 2013, a Broad Agency Announcement (BAA) for the SIGMA program was released. The RFI requirements focused on a sensor that should possess three main properties: low cost, high compactness and radioisotope identification capabilities. The identification performances should facilitate the detection of a hidden threat, ranging from special nuclear materials (SNM) to commonly used radiological sources. Subsequently, the BAA presented the specific requirements at an instrument level and provided a comparison between the current market status (state-of-the-art) and the SIGMA program objectives. This work presents an optional alternative for both the detection technology (sensor with communication output and without user interface) for DARPA's initial RFI and for the PRD required by the SIGMA program. A broad discussion is dedicated to the method proposed to fulfill the program objectives and to the selected alternative that is based on the PDS-GO design and technology. The PDS-GO is the first commercially available PRD that is based on a scintillation crystal optically coupled with a silicon photomultiplier (SiPM), a solid-state light sensor. This work presents the current performance of the instrument and possible future upgrades based on recent technological improvements in the SiPM design. The approach of utilizing the SiPM with a commonly available CsI(Tl) crystal is the key for achieving the program objectives. This approach provides the appropriate performance, low cost, mass production and small dimensions; however, it requires a creative approach to overcome the obstacles of the solid-state detector dark current (noise) and gain stabilization over a wide temperature range. Based on the presented results, we presume that

  17. Amphiphilic polymer promoted assembly of macroporous graphene/SnO2 frameworks with tunable porosity for high-performance lithium storage.

    Science.gov (United States)

    Huang, Yanshan; Wu, Dongqing; Wang, Jinzuan; Han, Sheng; Lv, Lu; Zhang, Fan; Feng, Xinliang

    2014-06-12

    3D macroporous graphene/SnO2 frameworks (MGTFs) are fabricated by amphiphilic polymer-promoted assembly method, which exhibit controllable macroporous structure and outstanding lithium storage performance. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. High renewable content sandwich structures based on flax-basalt hybrids and biobased epoxy polymers

    Science.gov (United States)

    Colomina, S.; Boronat, T.; Fenollar, O.; Sánchez-Nacher, L.; Balart, R.

    2014-05-01

    In the last years, a growing interest in the development of high environmental efficiency materials has been detected and this situation is more accentuated in the field of polymers and polymer composites. In this work, green composite sandwich structures with high renewable content have been developed with core cork materials. The base resin for composites was a biobased epoxy resin derived from epoxidized vegetable oils. Hybrid basalt-flax fabrics have been used as reinforcements for composites and the influence of the stacking sequence has been evaluated in order to optimize the appropriate laminate structure for the sandwich bases. Core cork materials with different thickness have been used to evaluate performance of sandwich structures thus leading to high renewable content composite sandwich structures. Results show that position of basalt fabrics plays a key role in flexural fracture of sandwich structures due to differences in stiffness between flax and basalt fibers.

  19. Portuguese granites associated with Sn-W and Au mineralizations

    Directory of Open Access Journals (Sweden)

    Ana M.R. Neiva

    2002-01-01

    Full Text Available In northern and central Portugal, there are different tin-bearing granites. Most of them are of S-type, others have mixed characteristics of I-type and S-type granites and a few are of I-type. Tin-tungsten deposits are commonly associated with Hercynian tin-bearing S-type granites. Some quartz veins with wolframite are associated with an I-type granite, which has a low Sn content. In suites of tin-bearing S-type granitic rocks, Sn content increases as a function of the degree of fractional crystallization. Greisenizations of two-mica S-type granites associated with tin-tungsten mineralizations are accompanied by an increase in SiO2, H2O+, Sn, W, Nb, Ta, Rb, Zn, and Pb and decrease in MgO, Na2O, V, Sc,Zr, and Sr. The granite associated with the Jales gold deposit is of S-type and strongly differentiated like the tin-bearing S-type granites, but it has a very low Sn content. During fractional crystallization, Si, Rb, Sn, Pb, Au, As, Sb, and S increase. During increasing degree of hydrothermal alteration of this granite at the gold-quartz vein walls, there are progressive increases in K2O, H2O+, Sn, Cs, Cu, Pb, Au, Sb, As, and S.

  20. Large-Scale Fabrication of Core-Shell Structured C/SnO2 Hollow Spheres as Anode Materials with Improved Lithium Storage Performance.

    Science.gov (United States)

    Cheng, Yong; Li, Qian; Wang, Chunli; Sun, Lianshan; Yi, Zheng; Wang, Limin

    2017-10-23

    Due to the high theoretical capacity as high as 1494 mAh g(-1) , SnO2 is considered as a potential anode material for high-capacity lithium-ion batteries (LIBs). Therefore, the simple but effective method focused on fabrication of SnO2 is imperative. To meet this, a facile and efficient strategy to fabricate core-shell structured C/SnO2 hollow spheres by a solvothermal method is reported. Herein, the solid and hollow structure as well as the carbon content can be controlled. Very importantly, high-yield C/SnO2 spheres can be produced by this method, which suggest potential business applications in LIBs field. Owing to the dual buffer effect of the carbon layer and hollow structures, the core-shell structured C/SnO2 hollow spheres deliver a high reversible discharge capacity of 1007 mAh g(-1) at a current density of 100 mA g(-1) after 300 cycles and a superior discharge capacity of 915 mAh g(-1) at 500 mA g(-1) after 500 cycles. Even at a high current density of 1 and 2 A g(-1) , the core-shell structured C/SnO2 hollow spheres electrode still exhibits excellent discharge capacity in the long life cycles. Consideration of the superior performance and high yield, the core-shell structured C/SnO2 hollow spheres are of great interest for the next-generation LIBs. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Dose enhancing behavior of hydrothermally grown Eu-doped SnO2 nanoparticles

    Science.gov (United States)

    Sánchez Zeferino, R.; Pal, U.; Meléndrez, R.; Durán-Muñoz, H. A.; Barboza Flores, M.

    2013-02-01

    Hydrothermally grown SnO2 and SnO2:Eu nanoparticles of 4-11 nm size range were analyzed by photoluminescence (PL) and therrmoluminescence (TL) spectroscopy to study the effect of Eu-doping on their emission behaviors. It has been observed that most of the incorporated Eu3+ ions remain at the interstitial sites of SnO2 lattice. High Eu-contents in the nanoparticles generate lattice deformation, formation of Eu3+/Eu0 clusters at interstitial sites, or segregation to their surfaces. Formation of Eu clusters at interstitial sites enhances electronic defect density in the crystal lattice, reorganizes carrier trapping centers, and modifies their activation energies. Room temperature PL emission and beta-irradiated TL dose response of SnO2 nanoparticles enhance significantly when doped with 0.5 and 1.0 mol. % nominal of Eu3+, respectively, opening up their possibilities of applications in bio-imaging and radiation therapy. Possible mechanisms of enhanced PL and TL responses of the samples have been discussed.

  2. Influence of Ta Content in High Purity Niobium on Cavity Performance Preliminary Results*

    CERN Document Server

    Kneisel, P

    2004-01-01

    In a previous paper* a program designed to study the influence of the residual tantalum content on the superconducting properties of pure niobium metal for RF cavities was outlined. The main rationale for this program was based on a potential cost reduction for high purity niobium, if a less strict limit on the chemical specification for Ta content, which is not significantly affecting the RRR–value, could be tolerated for high performance cavities. Four ingots with different Ta contents have been melted and transformed into sheets. In each manufacturing step the quality of the material has been monitored by employing chemical analysis, neutron activation analysis, thermal conductivity measurements and evaluation of the mechanical properties. The niobium sheets have been scanned for defects by an eddy current device. From three of the four ingots—Ta contents 100, 600 and 1,200 wppm—two single cell cavities each of the CEBAF variety have been fabricated and a series of tests on each ...

  3. Effect of religious context on the content of visual hallucinations in individuals high in religiosity.

    Science.gov (United States)

    Reed, Phil; Clarke, Natasha

    2014-03-30

    This study investigated the interaction between the current environment and personality factors associated with religiosity in determining the content of false perceptions (used as a model for hallucinations). A primed word-detection task was used to investigate the effect of a 'religious' context on false perceptions in individuals scoring highly on religiosity. After a subliminal prime, participants viewed letter strings, and stated any words that they saw. The prime and the actual words could have a religious connotation or not. Participants measuring high on religiosity were more likely to report false perceptions of a religious type than participants low on religiosity. It is suggested that context affects the content of false perceptions through the activation of stored beliefs and values, which vary between individuals, offering a mechanism for the effect of context on idiosyncratic content of hallucinations in schizophrenia. The effect of context and individual differences on false-perception content in the current study provides possibilities for future work regarding the underlying nature of hallucinations and their treatment. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  4. Content Analysis of the Concept of Addiction in High School Textbooks of Iran.

    Science.gov (United States)

    Mirzamohammadi, Mohammad Hasan; Mousavi, Sayedeh Zainab; Massah, Omid; Farhoudian, Ali

    2017-01-01

    This research sought to determine how well the causes of addiction, addiction harms, and prevention of addiction have been noticed in high school textbooks. We used descriptive method to select the main related components of the addiction concept and content analysis method for analyzing the content of textbooks. The study population comprised 61 secondary school curriculum textbooks and study sample consisted of 14 secondary school textbooks selected by purposeful sampling method. The tools for collecting data were "content analysis inventory" which its validity was confirmed by educational and social sciences experts and its reliability has been found to be 91%. About 67 components were prepared for content analysis and were divided to 3 categories of causes, harms, and prevention of addiction. The analysis units in this study comprised phrases, topics, examples, course topics, words, poems, images, questions, tables, and exercises. Results of the study showed that the components of the addiction concept have presented with 212 remarks in the textbooks. Also, the degree of attention given to any of the 3 main components of the addiction concept were presented as follows: causes with 52 (24.52%) remarks, harm with 89 (41.98%) remarks, and prevention with 71 (33.49%) remarks. In high school textbooks, little attention has been paid to the concept of addiction and mostly its biological dimension were addressed while social, personal, familial, and religious dimensions of addiction have been neglected.

  5. A Categorical Content Analysis of Highly Cited Literature Related to Trends and Issues in Special Education.

    Science.gov (United States)

    Arden, Sarah V; Pentimonti, Jill M; Cooray, Rochana; Jackson, Stephanie

    2017-07-01

    This investigation employs categorical content analysis processes as a mechanism to examine trends and issues in a sampling of highly cited (100+) literature in special education journals. The authors had two goals: (a) broadly identifying trends across publication type, content area, and methodology and (b) specifically identifying articles with disaggregated outcomes for students with learning disabilities (LD). Content analyses were conducted across highly cited (100+) articles published during a 20-year period (1992-2013) in a sample ( n = 3) of journals focused primarily on LD, and in one broad, cross-categorical journal recognized for its impact in the field. Results indicated trends in the article type (i.e., commentary and position papers), content (i.e., reading and behavior), and methodology (i.e., small proportions of experimental and quasi-experimental designs). Results also revealed stability in the proportion of intervention research studies when compared to previous analyses and a decline in the proportion of those that disaggregated data specifically for students with LD.

  6. SN1987A's Twentieth Anniversary

    Science.gov (United States)

    2007-02-01

    Looking back at 20 Years of Observations of this Supernova with ESO telescopes The unique supernova SN 1987A has been a bonanza for astrophysicists. It provided several observational 'firsts,' like the detection of neutrinos from an exploding star, the observation of the progenitor star on archival photographic plates, the signatures of a non-spherical explosion, the direct observation of the radioactive elements produced during the blast, observation of the formation of dust in the supernova, as well as the detection of circumstellar and interstellar material. ESO PR Photo 08a/07 ESO PR Photo 08a/07 SN1987A in the Large Magellanic Cloud Today, it is exactly twenty years since the explosion of Supernova 1987A in the Large Magellanic Cloud was first observed, at a distance of 163,000 light-years. It was the first naked-eye supernova to be seen for 383 years. Few events in modern astronomy have met with such an enthusiastic response by the scientists and now, after 20 years, it continues to be an extremely exciting object that is further studied by astronomers around the world, in particular using ESO's telescopes. When the first signs of Supernova 1987A, the first supernova of the year 1987, were noticed early on 24 February of that year, it was clear that this would be an unusual event. It was discovered by naked-eye and on a panoramic photographic plate taken with a 10-inch astrograph on Las Campanas in Chile by Oscar Duhalde and Ian Shelton, respectively. A few hours earlier, still on 23 February, two large underground detectors - in Japan and the USA - had registered the passage of high-energy neutrinos. Since SN 1987A exploded in the Large Magellanic Cloud (LMC), it was only accessible to telescopes in the Southern Hemisphere, more particularly in Australia, South Africa, and South America. In Chile, ESO's observatory at La Silla with its armada of telescopes with sizes between 0.5 and 3.6-m, played an important role. ESO PR Photo 08c/07 ESO PR Photo 08c/07 The

  7. Solid-State Method Synthesis of SnO2-Decorated g-C3N4 Nanocomposites with Enhanced Gas-Sensing Property to Ethanol

    Science.gov (United States)

    Cao, Jianliang; Qin, Cong; Wang, Yan; Zhang, Huoli; Sun, Guang; Zhang, Zhanying

    2017-01-01

    SnO2/graphitic carbon nitride (g-C3N4) composites were synthesized via a facile solid-state method by using SnCl4·5H2O and urea as the precursor. The structure and morphology of the as-synthesized composites were characterized by the techniques of X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive spectrometer (EDS), thermogravimetry-differential thermal analysis (TG-DTA), X-ray photoelectron spectroscopy (XPS), and N2 sorption. The results indicated that the composites possessed a two-dimensional (2-D) structure, and the SnO2 nanoparticles were highly dispersed on the surface of the g-C3N4 nanosheets. The gas-sensing performance of the samples to ethanol was tested, and the SnO2/g-C3N4 nanocomposite-based sensor exhibited admirable properties. The response value (Ra/Rg) of the SnO2/g-C3N4 nanocomposite with 10 wt % 2-D g-C3N4 content-based sensor to 500 ppm of ethanol was 550 at 300 °C. However, the response value of pure SnO2 was only 320. The high surface area of SnO2/g-C3N4-10 (140 m2·g−1) and the interaction between 2-D g-C3N4 and SnO2 could strongly affect the gas-sensing property. PMID:28772960

  8. Optimizing Cationic and Neutral Lipids for Efficient Gene Delivery at High Serum Content

    Science.gov (United States)

    Majzoub, Ramsey N.; Hwu, Yeu-kuang; Liang, Keng S.; Leal, Cecília; Safinya, Cyrus R.

    2014-01-01

    Background Cationic liposome (CL)-DNA complexes are promising gene delivery vectors with potential applications in gene therapy. A key challenge in creating CL-DNA complexes for applications is that their transfection efficiency (TE) is adversely affected by serum. In particular, little is known about the effects of high serum contents on TE even though this may provide design guidelines for applications in vivo. Methods We prepared CL-DNA complexes in which we varied the neutral lipid (DOPC, glycerol-monooleate (GMO), cholesterol), the headgroup charge and chemical structure of the cationic lipid, and the ratio of neutral to cationic lipid; we then measured the TE of these complexes as a function of serum content and assessed their cytotoxicity. We tested selected formulations in two human cancer cell lines (M21/melanoma and PC-3/prostate cancer). Results In the absence of serum, all CL-DNA complexes of custom-synthesized multivalent lipids show high TE. Certain combinations of multivalent lipids and neutral lipids, such as MVL5(5+)/GMO-DNA complexes or complexes based on the dendritic-headgroup lipid TMVLG3(8+) exhibited high TE both in the absence and presence of serum. Although their TE still dropped to a small extent in the presence of serum, it reached or surpassed that of benchmark commercial transfection reagents, in particular at high serum content. Conclusions Two-component vectors (one multivalent cationic lipid and one neutral lipid) can rival or surpass benchmark reagents at low and high serum contents (up to 50%, v/v). We suggest guidelines for optimizing the serum resistance of CL-DNA complexes based on a given cationic lipid. PMID:24753287

  9. Active Learning Strategies for Phenotypic Profiling of High-Content Screens.

    Science.gov (United States)

    Smith, Kevin; Horvath, Peter

    2014-06-01

    High-content screening is a powerful method to discover new drugs and carry out basic biological research. Increasingly, high-content screens have come to rely on supervised machine learning (SML) to perform automatic phenotypic classification as an essential step of the analysis. However, this comes at a cost, namely, the labeled examples required to train the predictive model. Classification performance increases with the number of labeled examples, and because labeling examples demands time from an expert, the training process represents a significant time investment. Active learning strategies attempt to overcome this bottleneck by presenting the most relevant examples to the annotator, thereby achieving high accuracy while minimizing the cost of obtaining labeled data. In this article, we investigate the impact of active learning on single-cell-based phenotype recognition, using data from three large-scale RNA interference high-content screens representing diverse phenotypic profiling problems. We consider several combinations of active learning strategies and popular SML methods. Our results show that active learning significantly reduces the time cost and can be used to reveal the same phenotypic targets identified using SML. We also identify combinations of active learning strategies and SML methods which perform better than others on the phenotypic profiling problems we studied. © 2014 Society for Laboratory Automation and Screening.

  10. Effects of calcination temperatures on photocatalytic activity of SnO2/TiO2 composite films prepared by an EPD method.

    Science.gov (United States)

    Zhou, Minghua; Yu, Jiaguo; Liu, Shengwei; Zhai, Pengcheng; Jiang, Li

    2008-06-15

    SnO2/TiO2 composite films were fabricated on transparent electro-conductive glass substrates (F-doped SnO2-coated glass:FTO glass) via an electrophoretic deposition (EPD) method using Degussa P25 as raw materials, and were further characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscope (FESEM), UV-vis diffuse reflectance spectra and Photoluminescence spectra (PL). XRD and XPS results confirmed that the films were composed of TiO2 and SnO2. FESEM images indicated that the as-prepared TiO2 films had roughness surfaces, which consisted of nano-sized particles. The effects of calcination temperatures on the surface morphology, microstructures and photocatalytic activity of SnO2/TiO2 composite films were further investigated. All the prepared SnO2/TiO2 composite films exhibited high photocatalytic activities for photocatalytic decolorization of Rhodamine-B aqueous solution. At 400 degrees C, the SnO2/TiO2 composite films showed the highest photocatalytic activity due to synergetic effects of low sodium content, good crystallization, appropriate phase composition and slower recombination rate of photogenerated charge carriers.

  11. Sulfurization Growth of SnS Thin Films and Experimental Determination of Valence Band Discontinuity for SnS-Related Solar Cells

    Science.gov (United States)

    Sugiyama, Mutsumi; Murata, Yoshitsuna; Shimizu, Tsubasa; Ramya, Kottadi; Venkataiah, Chinna; Sato, Tomoaki; Ramakrishna Reddy, K. T.

    2011-05-01

    Tin sulphide is considered to be a potential candidate for the development of low cost polycrystalline thin film solar cells. The advantages of using sulfurization process to grow SnS films were demonstrated. Polycrystalline p-type SnS films were obtained by a simple dry process at 300 °C for 90 min. The sulfurization condition depends on the deposition method of the Sn precursor. Using single-phase SnS films, band discontinuities at SnS/CdS and SnO2/SnS heterointerfaces were measured by X-ray photoelectron spectroscopy. The valence band offsets were determined to be approximately 1.5 eV for SnS/CdS and 3.5 eV for SnO2/SnS interfaces. Using these values and the energy band gaps of the corresponding layers, the energy band diagram was developed. It indicated that the SnS/CdS heterojunction is of TYPE-II form of heterostructure. This result indicated that SnS-related solar cells with CdS as window layer do not have an ideal band structure that could give high conversion efficiency.

  12. The effect of Sn addition on phase stability and phase evolution during aging heat treatment in Ti–Mo alloys employed as biomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Mello, Mariana G. de, E-mail: marianagm@fem.unicamp.br; Salvador, Camilo F., E-mail: csalvador@fem.unicamp.br; Cremasco, Alessandra, E-mail: alessandra@fem.unicamp.br; Caram, Rubens, E-mail: caram@fem.unicamp.br

    2015-12-15

    Increases in life expectancy and improvements in necessary healthcare attach great importance to the development of biomaterials. Ti alloys containing β stabilizing elements are often used as biomaterials due to their high specific strength, high corrosion resistance, unusual biocompatibility and low elastic moduli, which benefit bone tissues close to an implant. This study deals with phase stability in β Ti–Mo–Sn alloys processed under different conditions and was performed according to the following steps: a study of the effect of Sn content (a) on phase stability in Ti–Mo alloys, (b) on the suppression of α″ and ω phase precipitation; (c) on α-phase precipitation during aging heat treatments and (d) on mechanical properties, including the elastic modulus, as measured using tensile tests and acoustic techniques. The alloys were prepared by arc melting under a controlled atmosphere followed by homogenization heat treatment and hot rolling. Optical microscopy, scanning and transmission electron microscopy, X-ray diffraction and differential scanning calorimetry were employed for characterization purposes. Samples were also submitted to solution treatment above the β transus temperature and aging heat treatments under a controlled atmosphere. The results suggest that Sn suppresses the formation of the ω and α″ phases in Ti–Mo system. - Highlights: • Sn addition to Ti alloys decreases elastic modulus by suppressing ω phase precipitation. • Sn addition decreases the temperature of martensite decomposition. • Sn addition decreases the temperature of α phase precipitation and β transus. • Mechanical strength decreases with increasing Sn content.

  13. Preventing performance drops of coal mills due to high moisture content

    DEFF Research Database (Denmark)

    Odgaard, Peter Fogh; Stoustrup, Jakob; Mataji, B.

    2007-01-01

    Coal mills pulverize and dry the coal dust before it is blown into the furnace in coal-fired power plants. The coal mills can only deliver the requested coal flow if certain conditions are fulfilled. These are normally considered as constraints on individual variables. However, combinations of more...... than one variable might cause problems even though these individually variables are in an acceptable region. This paper deals with such a problem. The combination of a high load of the power plant, a large load change and high moisture content in the coal, can force the coal mill into a state where...... coal is accumulated instead of being blown into the furnace. This paper suggests a simple method for preventing the accumulation of the coal in the mill, by limiting the requested coal flow considering the coal moisture content and the temperature outside the mill.  ...

  14. Current developments in high-throughput analysis for microalgae cellular contents.

    Science.gov (United States)

    Lee, Tsung-Hua; Chang, Jo-Shu; Wang, Hsiang-Yu

    2013-11-01

    Microalgae have emerged as one of the most promising feedstocks for biofuels and bio-based chemical production. However, due to the lack of effective tools enabling rapid and high-throughput analysis of the content of microalgae biomass, the efficiency of screening and identification of microalgae with desired functional components from the natural environment is usually quite low. Moreover, the real-time monitoring of the production of target components from microalgae is also difficult. Recently, research efforts focusing on overcoming this limitation have started. In this review, the recent development of high-throughput methods for analyzing microalgae cellular contents is summarized. The future prospects and impacts of these detection methods in microalgae-related processing and industries are also addressed. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Image-Based High Content Screening: Automating the Quantification Process for DNA Damage-Induced Foci.

    Science.gov (United States)

    Lim, Yi Chieh

    2017-01-01

    Visual inspection of cellular activities based on conventional fluorescence microscope is a fundamental tool to study the role of DNA damage response (DDR). In the context of drug discovery where the capture of thousands of images is required across parallel experiments, this presents a challenge to data collection and analysis. Manual scoring is laborious and often reliant on trained personnel to intuit biological meaning through visual reasoning. On the other hand, high content screening combines the automation of microscopy image acquisition and analysis in a single platform to quantify cellular events of interests. The data generated is rapid and accurate, lessening the bias of human interpretation. Herein, this chapter will describe an image-based high content screen approach and the data analysis of Ataxia-Telangiectasia Mutated (ATM) DNA damage-induced foci.

  16. Workflow and metrics for image quality control in large-scale high-content screens.

    Science.gov (United States)

    Bray, Mark-Anthony; Fraser, Adam N; Hasaka, Thomas P; Carpenter, Anne E

    2012-02-01

    Automated microscopes have enabled the unprecedented collection of images at a rate that precludes visual inspection. Automated image analysis is required to identify interesting samples and extract quantitative information for high-content screening (HCS). However, researchers are impeded by the lack of metrics and software tools to identify image-based aberrations that pollute data, limiting experiment quality. The authors have developed and validated approaches to identify those image acquisition artifacts that prevent optimal extraction of knowledge from high-content microscopy experiments. They have implemented these as a versatile, open-source toolbox of algorithms and metrics readily usable by biologists to improve data quality in a wide variety of biological experiments.

  17. Nonisothermal Thermogravimetric Analysis of Thai Lignite with High CaO Content

    Directory of Open Access Journals (Sweden)

    Pakamon Pintana

    2013-01-01

    Full Text Available Thermal behaviors and combustion kinetics of Thai lignite with different SO3-free CaO contents were investigated. Nonisothermal thermogravimetric method was carried out under oxygen environment at heating rates of 10, 30, and 50°C min−1 from ambient up to 1300°C. Flynn-Wall-Ozawa (FWO and Kissinger-Akahira-Sunose (KAS methods were adopted to estimate the apparent activation energy (E for the thermal decomposition of these coals. Different thermal degradation behaviors were observed in lignites with low (14% and high (42% CaO content. Activation energy of the lignite combustion was found to vary with the conversion fraction. In comparison with the KAS method, higher E values were obtained by the FWO method for all conversions considered. High CaO lignite was observed to have higher activation energy than the low CaO coal.

  18. Content Validity and Authenticity of the 2012 English Test in the Senior High School National Examination

    Directory of Open Access Journals (Sweden)

    Frisca Ayu Desi Widyaningrum

    2016-12-01

    Full Text Available This paper discusses content validity and authenticity of the English test items in National Examination (UN year 2012. It is worth discussion because UN, which was administered nationally, was the most important standardized test to assess Indonesian students’ competence. The study aimed to find out how valid the content of the English test items of National Examination year 2012 for senior high schools isand how authentic the English test items of National Examination year 2012 for senior high schools is. The writers employed a qualitative research with document analysis to conduct the analysis of both content validity and authenticity of the English test items. The data were obtained from the document and analyzed by using checklists. Besides, to maintain the validitiy of the analysis, a triagulation was done by distributing aquestionnaire to four experts in language assessment. There were twofindings resulted form the analysis. First, the content of the National Examination year 2012 was 98.8% valid since almost all of the contents were relevant to the test specifications. However, there were three reading test versions which failed to represent kinds of texts, namely explanation text. Second, the National Examination year 2012 met the criteria of authenticity with percentage 79.5% since some listening and reading test items failed to conform to authenticity criteria. Natural language use, the relevance of the test topics, and real-world representativeness became problematic aspects to meet the higher standard of authenticity.   DOI: https://doi.org/10.24071/llt.2013.160103

  19. High-content analysis of Rab protein function at the ER-Golgi interface

    Science.gov (United States)

    Galea, George; Simpson, Jeremy C

    2015-01-01

    ABSTRACT The Rab family of small GTPases play fundamental roles in the regulation of trafficking pathways between intracellular membranes in eukaryotic cells. In this short commentary we highlight a recent high-content screening study that investigates the roles of Rab proteins in retrograde trafficking from the Golgi complex to the endoplasmic reticulum, and we discuss how the findings of this work and other literature might influence our thoughts on how the architecture of the Golgi complex is regulated. PMID:26693811

  20. Effect of Simulated High Hydrogen Content Combustion Environments on Abradable Properties of Ceramic Turbine Coatings

    OpenAIRE

    Basu Majumder, Madhura

    2015-01-01

    Air plasma sprayed (APS) abradable coatings are used in the turbine hot section to reduce the stator-rotor gap, minimizing gas leakage. These coatings are designed to exhibit controlled removal of material in thin layers when the turbine blades sweep through the coating, which protects the mechanical integrity of the turbine blade. In an effort to lower CO2 emissions, high H2 content fuel is being explored. This change in chemical composition of the fuel may affect the microstructure, abradab...

  1. Graphene/SnO2 nanocomposite-modified electrode for electrochemical detection of dopamine

    OpenAIRE

    R. Nurzulaikha; Lim, H. N.; Harrison, I.; Lim, S.S.; Pandikumar, A; Huang, N. M.; Lim, S. P.; G.S.H. Thien; Yusoff, N.; Ibrahim, I.

    2015-01-01

    A graphene-tin oxide (G-SnO2) nanocomposite was prepared via a facile hydrothermal route using graphene oxide and Sn precursor solution without addition of any surfactant. The hydrothermally synthesized G-SnO2 nanocomposite was characterized using a field emission scanning electron microscope (FESEM), high resolution transmission electron microscope (HRTEM), X-ray diffraction (XRD), and energy dispersive spectroscopy (EDS). A homogeneous deposition of SnO2 nanoparticles with an average partic...

  2. Viscoelastic behavior over a wide range of time and frequency in tin alloys: SnCd and SnSb

    Energy Technology Data Exchange (ETDEWEB)

    Quackenbush, J.; Brodt, M.; Lakes, R.S. [Univ. of Iowa, Iowa City, IA (United States)

    1996-08-01

    All materials exhibit some viscoelastic response, which can manifest itself as creep, relaxation, or, if the load is sinusoidal in time, a phase angle {delta} between stress and strain. Recently, a study of pure elements with low melting points, Cd, In, Pb, and Sn disclosed that cadmium exhibited a substantial loss tangent of 0.03 to 0.04 over much of the audio range of frequencies, combined with a moderate stiffness G = 20.7 GPa. Lead, by contrast, exhibited tan {delta} of 0.005 to 0.016 in the audio range. Indium exhibited a high loss tangent exceeding 0.1 at very low frequency. A eutectic alloy of indium and tin was found to exhibit substantial damping exceeding 0.1 below 0.1 Hz, and this alloy was used to make a composite exhibiting high stiffness and high damping. It is the purpose of this communication to present viscoelastic properties of two additional low melting point alloys, SnCd and SnSb. Both InSn and SnSb are used as solders. Although the melting point of Sb is 630.74 C, T{sub H} > 0.55 at ambient temperature for the alloy of SnSb (95 wt% Sn/5 wt% Sb) which melts near 240 C. Eutectic SnCd melts at 177 C so T{sub H} {approx} 0.65 at room temperature.

  3. Aluminum-stabilized NB3SN superconductor

    Science.gov (United States)

    Scanlan, Ronald M.

    1988-01-01

    An aluminum-stabilized Nb.sub.3 Sn superconductor and process for producing same, utilizing ultrapure aluminum. Ductile components are co-drawn with aluminum to produce a conductor suitable for winding magnets. After winding, the conductor is heated to convert it to the brittle Nb.sub.3 Sn superconductor phase, using a temperature high enough to perform the transformation but still below the melting point of the aluminum. This results in reaction of substantially all of the niobium, while providing stabilization and react-in-place features which are beneficial in the fabrication of magnets utilizing superconducting materials.

  4. Correlation of high-speed tensile strength with collagen content in control and lathyritic rat skin.

    Science.gov (United States)

    Dombi, G W; Haut, R C; Sullivan, W G

    1993-01-01

    Severity of lacerative skin injury depends on the applied load and the resistance of the tissue. At low (static) rates of loading there is a high degree of correlation between skin tensile strength and the degree of collagen crosslinking, with little added strength due to collagen interactions with the glycosaminoglycan matrix. We examined the effects of high (ballistic) rates of loading in order to determine the contributions to strength made by both the degree of collagen crosslinking and the collagen-matrix interaction. Tensile failure experiments were conducted using the dorsal skin of rats 1.5-6 months of age. Test specimen orientations were cut parallel and transverse to the body axis at cephalad and caudad locations on the dorsum. Tensile strength was measured at nominal strain rates of 30%/sec (low speed) and 6000%/sec (high speed) using both control and lathyrogen fed rats. Biochemical analyses were conducted to determine the amount of total and crosslinked (insoluble) collagen. In low-speed tests, there was a significant correlation (r > or = 0.900) between collagen content and skin tensile strength measured both transverse and parallel to the spine. The degree of correlation was higher with insoluble (r = 0.973) collagen content than with total (r = 0.901) collagen. The effect of a lathyrogen diet produced a significant (P collagen content (r > or = 0.858).(ABSTRACT TRUNCATED AT 250 WORDS)

  5. Integrating High-Content Analysis into a Multiplexed Screening Approach to Identify and Characterize GPCR Agonists.

    Science.gov (United States)

    Zhu, Yingjie; Watson, John; Chen, Mengjie; Shen, Ding Ren; Yarde, Melissa; Agler, Michele; Burford, Neil; Alt, Andrew; Jayachandra, Sukhanya; Cvijic, Mary Ellen; Zhang, Litao; Dyckman, Alaric; Xie, Jenny; O'Connell, Jonathan; Banks, Martyn; Weston, Andrea

    2014-08-01

    G protein-coupled receptors (GPCRs) are one of the most popular and proven target classes for therapeutic intervention. The increased appreciation for allosteric modulation, receptor oligomerization, and biased agonism has led to the development of new assay platforms that seek to capitalize on these aspects of GPCR biology. High-content screening is particularly well suited for GPCR drug discovery given the ability to image and quantify changes in multiple cellular parameters, to resolve subcellular structures, and to monitor events within a physiologically relevant environment. Focusing on the sphingosine-1-phosphate (S1P1) receptor, we evaluated the utility of high-content approaches in hit identification efforts by developing and applying assays to monitor β-arrestin translocation, GPCR internalization, and GPCR recycling kinetics. Using these approaches in combination with more traditional GPCR screening assays, we identified compounds whose unique pharmacological profiles would have gone unnoticed if using a single platform. In addition, we identified a compound that induces an atypical pattern of β-arrestin translocation and GPCR recycling kinetics. Our results highlight the value of high-content imaging in GPCR drug discovery efforts and emphasize the value of a multiassay approach to study pharmacological properties of compounds of interest. © 2014 Society for Laboratory Automation and Screening.

  6. Retrogradation of Maize Starch after High Hydrostatic Pressure Gelation: Effect of Amylose Content and Depressurization Rate

    KAUST Repository

    Yang, Zhi

    2016-05-24

    High hydrostatic pressure (HHP) has been employed to gelatinize or physically modify starch dispersions. In this study, waxy maize starch, normal maize starch, and two high amylose content starch were processed by a HHP of the order of 600 MPa, at 25°C for 15min. The effect of HHP processing on the crystallization of maize starches with various amylose content during storage at 4°C was investigated. Crystallization kinetics of HHP treated starch gels were investigated using rheology and FTIR. The effect of crystallization on the mechanical properties of starch gel network were evaluated in terms of dynamic complex modulus (G*). The crystallization induced increase of short-range helices structures were investigated using FTIR. The pressure releasing rate does not affect the starch retrogradation behaviour. The rate and extent of retrogradation depends on the amylose content of amylose starch. The least retrogradation was observed in HHP treated waxy maize starch. The rate of retrogradation is higher for HHP treated high amylose maize starch than that of normal maize starch. A linear relationship between the extent of retrogradation (phase distribution) measured by FTIR and G* is proposed.

  7. Arabidopsis Seed Content QTL Mapping Using High-Throughput Phenotyping: The Assets of Near Infrared Spectroscopy.

    Science.gov (United States)

    Jasinski, Sophie; Lécureuil, Alain; Durandet, Monique; Bernard-Moulin, Patrick; Guerche, Philippe

    2016-01-01

    Seed storage compounds are of crucial importance for human diet, feed and industrial uses. In oleo-proteaginous species like rapeseed, seed oil and protein are the qualitative determinants that conferred economic value to the harvested seed. To date, although the biosynthesis pathways of oil and storage protein are rather well-known, the factors that determine how these types of reserves are partitioned in seeds have to be identified. With the aim of implementing a quantitative genetics approach, requiring phenotyping of 100s of plants, our first objective was to establish near-infrared reflectance spectroscopic (NIRS) predictive equations in order to estimate oil, protein, carbon, and nitrogen content in Arabidopsis seed with high-throughput level. Our results demonstrated that NIRS is a powerful non-destructive, high-throughput method to assess the content of these four major components studied in Arabidopsis seed. With this tool in hand, we analyzed Arabidopsis natural variation for these four components and illustrated that they all displayed a wide range of variation. Finally, NIRS was used in order to map QTL for these four traits using seeds from the Arabidopsis thaliana Ct-1 × Col-0 recombinant inbred line population. Some QTL co-localized with QTL previously identified, but others mapped to chromosomal regions never identified so far for such traits. This paper illustrates the usefulness of NIRS predictive equations to perform accurate high-throughput phenotyping of Arabidopsis seed content, opening new perspectives in gene identification following QTL mapping and genome wide association studies.

  8. Arabidopsis seed content QTL mapping using high-throughput phenotyping: the assets of Near Infrared Spectroscopy

    Directory of Open Access Journals (Sweden)

    Sophie Jasinski

    2016-11-01

    Full Text Available Seed storage compounds are of crucial importance for human diet, feed and industrial uses. In oleo-proteaginous species like rapeseed, seed oil and protein are the qualitative determinants that conferred economic value to the harvested seed. To date, although the biosynthesis pathways of oil and storage protein are rather well known, the factors that determine how these types of reserves are partitioned in seeds have to be identified. With the aim of implementing a quantitative genetics approach, requiring phenotyping of hundreds of plants, our first objective was to establish near-infrared reflectance spectroscopic (NIRS predictive equations in order to estimate oil, protein, carbon and nitrogen content in Arabidopsis seed with high-throughput level. Our results demonstrated that NIRS is a powerful non-destructive, high-throughput method to assess the content of these four major components studied in Arabidopsis seed. With this tool in hand, we analysed Arabidopsis natural variation for these four components and illustrated that they all displayed a wide range of variation. Finally, NIRS was used in order to map QTL for these four traits using seeds from the Arabidopsis thaliana Ct-1 x Col-0 recombinant inbred line population. Some QTL co-localised with QTL previously identified, but others mapped to chromosomal regions never identified so far for such traits. This paper illustrates the usefulness of NIRS predictive equations to perform accurate high-throughput phenotyping of Arabidopsis seed content, opening new perspectives in gene identification following QTL mapping and Genome Wide Association Studies.

  9. Towards high-siderophore-content foods: optimisation of coprogen production in submerged cultures of Penicillium nalgiovense.

    Science.gov (United States)

    Emri, Tamás; Tóth, Viktória; Nagy, Csilla Terézia; Nagy, Gábor; Pócsi, Imre; Gyémánt, Gyöngyi; Antal, Károly; Balla, József; Balla, György; Román, Gyula; Kovács, István; Pócsi, István

    2013-07-01

    Fungal siderophores are likely to possess atheroprotective effects in humans, and therefore studies are needed to develop siderophore-rich food additives or functional foods to increase the siderophore uptake in people prone to cardiovascular diseases. In this study the siderophore contents of mould-ripened cheeses and meat products were analysed and the coprogen production by Penicillium nalgiovense was characterised. High concentrations of hexadentate fungal siderophores were detected in penicillia-ripened Camembert- and Roquefort-type cheeses and also in some sausages. In one sausage fermented by P. nalgiovense, the siderophore content was comparable to those found in cheeses. Penicillium nalgiovense produced high concentrations of coprogen in submerged cultures, which were affected predominantly by the available carbon and nitrogen sources under iron starvation. Considerable coprogen yields were still detectable in the presence of iron when the fermentation medium was supplemented with the iron chelator Na₂-EDTA or when P. nalgiovense was co-cultivated with Saccharomyces cerevisiae. These data may be exploitable in the future development of high-siderophore-content foods and/or food additives. Nevertheless, the use of P. nalgiovense fermentation broths for these purposes may be limited by the instability of coprogen in fermentation media and by the β-lactam production by the fungus. © 2012 Society of Chemical Industry.

  10. Retrogradation of Maize Starch after High Hydrostatic Pressure Gelation: Effect of Amylose Content and Depressurization Rate.

    Directory of Open Access Journals (Sweden)

    Zhi Yang

    Full Text Available High hydrostatic pressure (HHP has been employed to gelatinize or physically modify starch dispersions. In this study, waxy maize starch, normal maize starch, and two high amylose content starch were processed by a HHP of the order of 600 MPa, at 25°C for 15min. The effect of HHP processing on the crystallization of maize starches with various amylose content during storage at 4°C was investigated. Crystallization kinetics of HHP treated starch gels were investigated using rheology and FTIR. The effect of crystallization on the mechanical properties of starch gel network were evaluated in terms of dynamic complex modulus (G*. The crystallization induced increase of short-range helices structures were investigated using FTIR. The pressure releasing rate does not affect the starch retrogradation behaviour. The rate and extent of retrogradation depends on the amylose content of amylose starch. The least retrogradation was observed in HHP treated waxy maize starch. The rate of retrogradation is higher for HHP treated high amylose maize starch than that of normal maize starch. A linear relationship between the extent of retrogradation (phase distribution measured by FTIR and G* is proposed.

  11. Thermally evaporated indium-free, transparent, flexible SnO2/AgPdCu/SnO2 electrodes for flexible and transparent thin film heaters

    OpenAIRE

    Doo-Hee Kim; Kyung-Su Cho; Han-Ki Kim

    2017-01-01

    We investigated the characteristics of themally evaporated SnO2/Ag-Pd-Cu (APC)/SnO2 multilayer films for applications as damage-free, indium-free, flexible, and transparent electrodes for high performance flexible and transparent thin film heaters (TFHs). The top and bottom SnO2 layers and APC interlayer were prepared by a multi-source evaporation process, and the effect of the thickness of each layer on the resistivity, optical transmittance, and mechanical flexibility of the SnO2/APC/SnO2 e...

  12. New formulations of sunflower based bio-lubricants with high oleic acid content – VOSOLUB project

    Directory of Open Access Journals (Sweden)

    Leao J. D.

    2016-09-01

    Full Text Available VOSOLUB project is a demonstration project supported by Executive Agency for Small and Medium-sized Enterprises (EASME that aims at testing under real operating conditions new formulations of sunflower-based biolubricants with high oleic acid content. These biolubricant formulations (including hydraulic fluids, greases, and neat oil metal-working fluids will be tested in three European demonstrating sites. Their technical performance will be evaluated and compared to corresponding mineral lubricants ones. In order to cover the demand for the sunflower base oil, a European SMEs network will be established to ensure the supply of the base at a competitive market price. Results presented concerns the base oil quality confirmed to be in accordance with the specification required, in particular on Free Fatty acid content, Phosphorus content, rancimat induction time and oleic acid content (ITERG. The oil characteristics specific for lubricant application analyzed by BfB Oil Research under normalized methods, match with lubricant specifications requirement such as viscosity, cold & hot properties, surface properties, anti-oxidant properties and thermal stability, anti-wear and EP properties, anti-corrosion properties Performance of the new biolubricant have been assessed by formulators and TEKNIKER First results on the use of new lubricant on real condition for rail Grease (produced by RS CLARE and tested with Sheffield Supertram, Hydraulic oil (produced by BRUGAROLAS and cutting oil (produced by MOTUL TECH and tested with innovative machining, turning are described.

  13. The Role of Content Knowledge in Ill-Structured Problem Solving for High School Physics Students

    Science.gov (United States)

    Milbourne, Jeff; Wiebe, Eric

    2017-03-01

    While Physics Education Research has a rich tradition of problem-solving scholarship, most of the work has focused on more traditional, well-defined problems. Less work has been done with ill-structured problems, problems that are better aligned with the engineering and design-based scenarios promoted by the Next Generation Science Standards. This study explored the relationship between physics content knowledge and ill-structured problem solving for two groups of high school students with different levels of content knowledge. Both groups of students completed an ill-structured problem set, using a talk-aloud procedure to narrate their thought process as they worked. Analysis of the data focused on identifying students' solution pathways, as well as the obstacles that prevented them from reaching "reasonable" solutions. Students with more content knowledge were more successful reaching reasonable solutions for each of the problems, experiencing fewer obstacles. These students also employed a greater variety of solution pathways than those with less content knowledge. Results suggest that a student's solution pathway choice may depend on how she perceives the problem.

  14. Analysis of the origins of content non-uniformity in high-shear wet granulation.

    Science.gov (United States)

    Oka, Sarang; Smrčka, David; Kataria, Anjali; Emady, Heather; Muzzio, Fernando; Štěpánek, František; Ramachandran, Rohit

    2017-08-07

    In this study, the origins of granule content non-uniformity in the high-shear wet granulation of a model two-component pharmaceutical blend were investigated. Using acetaminophen as the active pharmaceutical ingredient (API) and microcrystalline cellulose as the excipient, the distribution of the API across the granule size classes was measured for a range of conditions that differed in the duration of the initial dry mixing stage, the overall composition of the blend and the wet massing time. The coarse granule fractions were found to be systematically sub-potent, while the fines were enriched in the API. The extent of content non-uniformity was found to be dependent on two factors - powder segregation during dry mixing and redistribution of the API between the granule size fractions during the wet massing phase. The latter was demonstrated in an experiment where the excipient was pre-granulated, the API was added later and wet massed. The content non-uniformity in this case was comparable to that obtained when both components were present in the granulator from the beginning. With increasing wet massing time, the extent of content non-uniformity decreased, indicating that longer wet massing times might be a solution for systems with a natural tendency for component segregation. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Heterosis for oil content in maize populations andhybrids of high quality protein

    Directory of Open Access Journals (Sweden)

    Lázaro José Chaves

    2006-01-01

    Full Text Available This study aimed to evaluate QPM populations and their crosses for grain oil content to determine theheterosis and its components. Ninety-six hybrids and their 21 parents were analyzed and separated in the groups dent andflint, in the partial diallelic/diallel intergroup scheme. The oil content was extracted from dry matter by the Soxhlet method inthree replicates for each genotypic material and attained mean values of 5.04g 100g-1 and 4.78g 100g-1, respectively, in thegroups dent and flint. Among the hybrid crosses, CMS 456 x CMS 463 (6.84g 100g-1 presented the highest value. Althoughthe average heterosis (-9.83% indicates average dominance of the alleles for low oil content, combinations with positive totalheterosis were observed. In this sense, the best populations under the focus of improvement for high oil content were ZQP101and ZQP103, both of the dent group, and CMS52, BR473, CMS455c and CMS465 of the flint group. Hence, it was concludedthat there is genetic variability and significant heterosis in the genotypes under study.

  16. Four new chalcohalides, NaBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Br and CsBa{sub 2}SnS{sub 4}Cl: Syntheses, crystal structures and optical properties

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chao; Feng, Kai; Tu, Heng [Center for Crystal Research and Development, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); University of the Chinese Academy of Sciences, Beijing 100049 (China); Yao, Jiyong, E-mail: jyao@mail.ipc.ac.cn [Center for Crystal Research and Development, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Wu, Yicheng [Center for Crystal Research and Development, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Key Laboratory of Functional Crystals and Laser Technology, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China)

    2015-07-15

    Four new chalcohalides, namely NaBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Br, and CsBa{sub 2}SnS{sub 4}Cl, have been synthesized by the conventional high temperature solid-state reactions. They crystallize in three different space groups: space group I4/mcm for NaBa{sub 2}SnS{sub 4}Cl and KBa{sub 2}SnS{sub 4}Cl, Pnma for KBa{sub 2}SnS{sub 4}Br, and P2{sub 1}/c for CsBa{sub 2}SnS{sub 4}Cl. In all four compounds, the X{sup −} halide anions are only connected to six alkali metal or Ba cations, and the Sn atoms are only tetrahedrally enjoined to four S atoms. However, the M–X–Ba pseudo layers and the SnS{sub 4} tetrahedra are arranged in different ways in the three structural types, which demonstrates the interesting effect of ionic radii on the crystal structures. UV–vis–NIR spectroscopy measurements indicate that NaBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Br, and CsBa{sub 2}SnS{sub 4}Cl have band gaps of 2.28, 2.30, 1.95, and 2.06 eV, respectively. - Graphical abstract: A new series of chalcohalides, NaBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Br and CsBa{sub 2}SnS{sub 4}Cl have been obtained. They present three different space groups: NaBa{sub 2}SnS{sub 4}Cl and KBa{sub 2}SnS{sub 4}Cl in space group I4/mcm, KBa{sub 2}SnS{sub 4}Br in Pnma and CsBa{sub 2}SnS{sub 4}Cl in space group P2{sub 1}/c. UV–vis–NIR spectroscopy measurements indicate that NaBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Br and CsBa{sub 2}SnS{sub 4}Cl have band gaps of 2.28, 2.30 1.95, and 2.06 eV, respectively. - Highlights: • Four new chalcohalides, NaBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Br and CsBa{sub 2}SnS{sub 4}Cl were obtained. • They adopt three different structures owing to different ionic radii and elemental electronegativity. • NaBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Cl, KBa{sub 2}SnS{sub 4}Br and CsBa{sub 2}SnS{sub 4}Cl have band gaps

  17. Sn doped (Cu0.5Tl0.5)Ba2Ca2Cu3-ySnyO10-δ superconductors: Effect on the diamagnetism and phonon modes

    Science.gov (United States)

    Firdous, Tayyaba; Khan, Nawazish A.

    2009-10-01

    Sn doped (Cu0.5Tl0.5)Ba2Ca2Cu3-ySnyO10-δ (y =0,0.25,0.5,0.75,1.0,1.25,1.50) superconductors have been synthesized by using solid state reaction method. The crystal structure of these Sn doped samples is orthorhombic and the axis lengths are found to increase with enhanced Sn doping concentration. The critical temperature and the magnitude of the diamagnetism are suppressed with enhanced doping of Sn. The samples turn into an insulator with very high room temperature resistivity if the Sn doping concentration is increased beyond y =1.5. The carrier's concentration in the conducting CuO2/SnO2 planes has been enhanced by carrying out post-annealing experiments in the air and oxygen atmosphere. The increased concentration of holes in CuO2/SnO2 planes resulting out of oxygen diffusion in the material is evidenced by increased intensity of Oδ mode of oxygen measured by Fourier transform infrared absorption measurements and also by oxygen contents measured by iodometric titration method.

  18. Mineotaur: a tool for high-content microscopy screen sharing and visual analytics.

    Science.gov (United States)

    Antal, Bálint; Chessel, Anatole; Carazo Salas, Rafael E

    2015-12-17

    High-throughput/high-content microscopy-based screens are powerful tools for functional genomics, yielding intracellular information down to the level of single-cells for thousands of genotypic conditions. However, accessing their data requires specialized knowledge and most often that data is no longer analyzed after initial publication. We describe Mineotaur ( http://www.mineotaur.org ), a open-source, downloadable web application that allows easy online sharing and interactive visualisation of large screen datasets, facilitating their dissemination and further analysis, and enhancing their impact.

  19. Self-catalytic branch growth of SnO 2 nanowire junctions

    Science.gov (United States)

    Chen, Y. X.; Campbell, L. J.; Zhou, W. L.

    2004-10-01

    Multiple branched SnO2 nanowire junctions have been synthesized by thermal evaporation of SnO powder. Their nanostructures were studied by transmission electron microscopy and field emission scanning electron microcopy. It was observed that Sn nanoparticles generated from decomposition of the SnO powder acted as self-catalysts to control the SnO2 nanojunction growth. Orthorhombic SnO2 was found as a dominate phase in nanojunction growth instead of rutile structure. The branches and stems of nanojunctions were found to be an epitaxial growth by electron diffraction analysis and high-resolution electron microscopy observation. The growth directions of the branched SnO2 nanojunctions were along the orthorhombic [1 1 0] and [ 1 1 bar 0 ] . A self-catalytic vapor-liquid-solid growth mechanism is proposed to describe the growth process of the branched SnO2 nanowire junctions.

  20. Microstructure evolution of directionally solidifi ed Sn-16%Sb hyperperitectic alloy

    Directory of Open Access Journals (Sweden)

    Li Shuangming

    2008-11-01

    Full Text Available The directionally solidifi ed microstructure of Sn-16%Sb hyperperitectic alloy has been investigated at various solidifi cation rates using a high-thermal gradient directional solidifi cation apparatus. The results indicate that the solidifi cation microstructure consists of hard primary intermetallic SnSb phase embedded in a matrix of soft peritectic β-Sn phase. The primary SnSb phase exhibits faceted growth with tetragonal or trigonal shapes. At the same time, the primary SnSb phase is refi ned with an increase in the solidifi cation rate and dispersed more uniformly in the matrix of β-Sn phase. The volume fraction of the SnSb phase fi rstly decreases and then increases when the solidifi cation rate increases in directional solidifi cation of Sn-16%Sb hyperperitectic alloy.

  1. Evaluation of TDR sensors to estimate moisture content in a highly saline soil from northern Chile

    Science.gov (United States)

    Cristi Matte, F.; Hernandez, M. F.; Fierro, V.; Hausner, M. B.; Munoz, J.; Suarez, F. I.

    2013-12-01

    The major component of the water budget in many of the volcanic basins located in northern Chile is evaporation from zones with shallow groundwater tables. Therefore, the water fluxes in the vadose zone in those dry volcanic-origin soils are of particular interest. In these soils, it has been reported that traditional time domain reflectometry (TDR) measurement methods are ineffective. TDR is a fast and nondestructive indirect electromagnetic method that is used to estimate soil moisture from the soil's apparent dielectric permittivity. The relationship between moisture content and apparent dielectric permittivity is influenced by many factors, such as length of the sensor's rods, salinity of porous media and soil mineralogy. In volcanic soils, it has been reported that Topp's 'universal' relationship is no longer valid. In this study, we evaluated the performance of TDR probes for the estimation of soil moisture in a highly saline and volcanic-origin soil from the Salar del Huasco basin, northern Chile. TDR sensors with rods of 7.5 and 30 cm were used to test the dielectric permittivity of different potassium chloride solutions of known permittivity (with electrical conductivity ranging from 0.015 to 12.9 dS/m). The TDR probes were then used to test the permittivity of soils at known water contents and temperatures. The effects of temperature and the salinity of the solutions on the apparent permittivity were negligible, and the shorter rods proved more accurate than the longer rods. Furthermore, neither the Topp's equation nor previously proposed relationships for volcanic-origin soils developed around the world were adequate to represent the soil's moisture content used in this study. Based on the results, we propose a new relationship between moisture content and apparent dielectric permittivity for the volcanic-origin soil of the Salar del Huasco basin. Further research is ongoing to obtain analogous relationships between moisture content and apparent

  2. Recent advances in quantitative high throughput and high content data analysis.

    Science.gov (United States)

    Moutsatsos, Ioannis K; Parker, Christian N

    2016-01-01

    High throughput screening has become a basic technique with which to explore biological systems. Advances in technology, including increased screening capacity, as well as methods that generate multiparametric readouts, are driving the need for improvements in the analysis of data sets derived from such screens. This article covers the recent advances in the analysis of high throughput screening data sets from arrayed samples, as well as the recent advances in the analysis of cell-by-cell data sets derived from image or flow cytometry application. Screening multiple genomic reagents targeting any given gene creates additional challenges and so methods that prioritize individual gene targets have been developed. The article reviews many of the open source data analysis methods that are now available and which are helping to define a consensus on the best practices to use when analyzing screening data. As data sets become larger, and more complex, the need for easily accessible data analysis tools will continue to grow. The presentation of such complex data sets, to facilitate quality control monitoring and interpretation of the results will require the development of novel visualizations. In addition, advanced statistical and machine learning algorithms that can help identify patterns, correlations and the best features in massive data sets will be required. The ease of use for these tools will be important, as they will need to be used iteratively by laboratory scientists to improve the outcomes of complex analyses.

  3. High biobased content epoxy-anhydride thermosets from epoxidized sucrose esters of Fatty acids.

    Science.gov (United States)

    Pan, Xiao; Sengupta, Partha; Webster, Dean C

    2011-06-13

    Novel highly functional biobased epoxy compounds, epoxidized sucrose esters of fatty acids (ESEFAs), were cross-linked with a liquid cycloaliphatic anhydride to prepare polyester thermosets. The degree of cure or conversion was studied using differential scanning calorimetry (DSC), and the sol content of the thermosets was determined using solvent extraction. The mechanical properties were studied using tensile testing to determine Young's modulus, tensile stress, and elongation at break. Dynamic mechanical analysis (DMA) was used to determine glass-transition temperature, storage modulus, and cross-link density. The nanomechanical properties of the surfaces were studied using nanoindentation to determine reduced modulus and indentation hardness. The properties of coatings on steel substrates were studied to determine coating hardness, adhesion, solvent resistance, and mechanical durability. Compared with the control, epoxidized soybean oil, the anhydride-cured ESEFAs have high modulus and are hard and ductile, high-performance thermoset materials while maintaining a high biobased content (71-77% in theory). The exceptional performance of the ESEFAs is attributed to the unique structure of these macromolecules: well-defined compact structures with high epoxide functionality. These biobased thermosets have potential uses in applications such as composites, adhesives, and coatings.

  4. Physical and electrical characterization of high-performance Cu{sub 2}ZnSnSe{sub 4} based thin film solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Oueslati, S., E-mail: oueslatisouhaib@hotmail.fr [KACST-Intel Consortium Center of Excellence in Nano-manufacturing Applications (CENA), Riyadh (Saudi Arabia); Imec-partner in Solliance, Kapeldreef 75, 3001 Leuven (Belgium); Department of Physics, Faculty of Sciences of Tunis, Tunis El Manar University (Tunisia); Research Laboratory MMA, University of Carthage, National Institute of Applied Sciences and Technology, INSAT (Tunisia); Brammertz, G. [Imec Division IMOMEC — Partner in Solliance, Wetenschapspark 1, 3590 Diepenbeek (Belgium); Institute for Material Research (IMO), Hasselt University, Wetenschapspark 1, 3590 Diepenbeek (Belgium); Buffière, M. [Imec-partner in Solliance, Kapeldreef 75, 3001 Leuven (Belgium); Department of Electrical Engineering, KU Leuven, Kasteelpark Arenberg 10, 3001 Heverlee (Belgium); ElAnzeery, H. [KACST-Intel Consortium Center of Excellence in Nano-manufacturing Applications (CENA), Riyadh (Saudi Arabia); Imec-partner in Solliance, Kapeldreef 75, 3001 Leuven (Belgium); Microelectronics System Design Department, Nile University, Cairo (Egypt); Touayar, O. [Research Laboratory MMA, University of Carthage, National Institute of Applied Sciences and Technology, INSAT (Tunisia); Köble, C. [Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Hahn-Meitner-Platz 1, 14109 Berlin (Germany); Bekaert, J. [Condensed Matter Theory Group, Department of Physics, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerpen (Belgium); Meuris, M. [Imec Division IMOMEC — Partner in Solliance, Wetenschapspark 1, 3590 Diepenbeek (Belgium); Institute for Material Research (IMO), Hasselt University, Wetenschapspark 1, 3590 Diepenbeek (Belgium); and others

    2015-05-01

    We report on the electrical, optical and physical properties of Cu{sub 2}ZnSnSe{sub 4} solar cells using an absorber layer fabricated by selenization of sputtered Cu, Zn and Cu{sub 10}Sn{sub 90} multilayers. A maximum active-area conversion efficiency of 10.4% under AM1.5G was measured with a maximum short circuit current density of 39.7 mA/cm{sup 2}, an open circuit voltage of 394 mV and a fill factor of 66.4%. We perform electrical and optical characterization using photoluminescence spectroscopy, external quantum efficiency, current-voltage and admittance versus temperature measurements in order to derive information about possible causes for the low open circuit voltage values observed. The main defects derived from these measurements are strong potential fluctuations in the absorber layer as well as a potential barrier of the order of 133 meV at the back side contact. - Highlights: • We have fabricated 10.4% total area efficient Cu{sub 2}ZnSnSe{sub 4} solar cells. • An activation energy corresponding to a barrier at the back side was extracted. • Based on the admittance spectrum, no peaks could be observed related to deep defects.

  5. High selectivity of a CuO modified hollow SnO2 nanofiber gas sensor to H2S at low temperature

    Science.gov (United States)

    Yang, Jiejie; Gao, Chaojun; Yang, Hui; Wang, Xinchang; Jia, Jianfeng

    2017-08-01

    CuO modified hollow SnO2 nanofibers with large specific surface area were successfully synthesized via a simple two-step process, using the electrospinning method and hydrothermal technique. Gas-sensing experiments on hierarchically CuO modified SnO2 hollow nanofibers displayed higher sensitivity and selectivity to H2S gas at lower operating temperatures compared with unmodified hollow SnO2 nanofibers. At the optimal operating temperature of 125 °C, the highest response value to 10 ppm H2S gas reached 410. Response time decreased when the concentration of H2S increased. It is almost no response to other gases when the operating temperature falls below 200 °C. The specific interaction between H2S gas and the CuO nanoparticles, as well as the amplifier effect on the gas response by the p-n junctions, strongly enhances the selectivity to H2S gas at a lower operating temperature.

  6. The mechanistic exploration of porous activated graphene sheets-anchored SnO2 nanocrystals for application in high-performance Li-ion battery anodes.

    Science.gov (United States)

    Yang, Yingchang; Ji, Xiaobo; Lu, Fang; Chen, Qiyuan; Banks, Craig E

    2013-09-28

    Porous activated graphene sheets have been for the first time exploited herein as encapsulating substrates for lithium ion battery (LIB) anodes. The as-fabricated SnO2 nanocrystals-porous activated graphene sheet (AGS) composite electrode exhibits improved electrochemical performance as an anode material for LIBs, such as better cycle performance and higher rate capability in comparison with graphene sheets, activated graphene sheets, bare SnO2 and SnO2-graphene sheet composites. The superior electrochemical performances of the designed anode can be ascribed to the porous AGS substrate, which improves the electrical conductivity of the electrode, inhibits agglomeration between particles and effectively buffers the strain from the volume variation during Li(+)-intercalation-de-intercalation and provides more cross-plane diffusion channels for Li(+) ions. As a result, the designed anode exhibits an outstanding capacity of up to 610 mA h g(-1) at a current density of 100 mA g(-1) after 50 cycles and a good rate performance of 889, 747, 607, 482 and 372 mA h g(-1) at a current density of 100, 200, 500, 1000, and 2000 mA g(-1), respectively. This work is of importance for energy storage as it provides a new substrate for the design and implementation of next-generation LIBs exhibiting exceptional electrochemical performances.

  7. Utilization of potato starch processing wastes to produce animal feed with high lysine content.

    Science.gov (United States)

    Li, Ying; Liu, Bingnan; Song, Jinzhu; Jiang, Cheng; Yang, Qian

    2015-02-01

    This work aims to utilize wastes from the potato starch industry to produce single-cell protein (SCP) with high lysine content as animal feed. In this work, S-(2-aminoethyl)-L-cysteine hydrochloride-resistant Bacillus pumilus E1 was used to produce SCP with high lysine content, whereas Aspergillus niger was used to degrade cellulose biomass and Candida utilis was used to improve the smell and palatability of the feed. An orthogonal design was used to optimize the process of fermentation for maximal lysine content. The optimum fermentation conditions were as follows: temperature of 40°C, substrate concentration of 3%, and natural pH of about 7.0. For unsterilized potato starch wastes, the microbial communities in the fermentation process were determined by terminal restriction fragment length polymorphism analysis of bacterial 16S rRNA genes. Results showed that the dominant population was Bacillus sp. The protein quality as well as the amino acid profile of the final product was found to be significantly higher compared with the untreated waste product at day 0. Additionally, acute toxicity test showed that the SCP product was non-toxic, indicating that it can be used for commercial processing.

  8. Cell type discovery and representation in the era of high-content single cell phenotyping.

    Science.gov (United States)

    Bakken, Trygve; Cowell, Lindsay; Aevermann, Brian D; Novotny, Mark; Hodge, Rebecca; Miller, Jeremy A; Lee, Alexandra; Chang, Ivan; McCorrison, Jamison; Pulendran, Bali; Qian, Yu; Schork, Nicholas J; Lasken, Roger S; Lein, Ed S; Scheuermann, Richard H

    2017-12-21

    A fundamental characteristic of multicellular organisms is the specialization of functional cell types through the process of differentiation. These specialized cell types not only characterize the normal functioning of different organs and tissues, they can also be used as cellular biomarkers of a variety of different disease states and therapeutic/vaccine responses. In order to serve as a reference for cell type representation, the Cell Ontology has been developed to provide a standard nomenclature of defined cell types for comparative analysis and biomarker discovery. Historically, these cell types have been defined based on unique cellular shapes and structures, anatomic locations, and marker protein expression. However, we are now experiencing a revolution in cellular characterization resulting from the application of new high-throughput, high-content cytometry and sequencing technologies. The resulting explosion in the number of distinct cell types being identified is challenging the current paradigm for cell type definition in the Cell Ontology. In this paper, we provide examples of state-of-the-art cellular biomarker characterization using high-content cytometry and single cell RNA sequencing, and present strategies for standardized cell type representations based on the data outputs from these cutting-edge technologies, including "context annotations" in the form of standardized experiment metadata about the specimen source analyzed and marker genes that serve as the most useful features in machine learning-based cell type classification models. We also propose a statistical strategy for comparing new experiment data to these standardized cell type representations. The advent of high-throughput/high-content single cell technologies is leading to an explosion in the number of distinct cell types being identified. It will be critical for the bioinformatics community to develop and adopt data standard conventions that will be compatible with these new

  9. Airlift-reactor design and test for aerobic environmental bioprocesses with extremely high solid contents at high temperatures.

    Science.gov (United States)

    Feitkenhauer, H; Maleski, R; Märkl, H

    2003-01-01

    Bioprocesses at high temperatures gained considerably in importance within the last years and several new applications for aerobic, extreme thermophilic environmental bioprocesses are emerging. However, this development is not yet matched by adequate bioreactor designs, especially if it comes to the treatment of solids. In this communication we propose the use of airlift reactors to bridge this gap. The design of an internal draught tube bioreactor (Area(Riser)/Area(Downcomer) . 1; Height/Diameter . 8) is described in detail. The influence of the temperature on gas hold-up, liquid velocity and mixing characteristics was investigated. It was shown that this reactor could hold up to 1 t quartz sand per m3 in suspension at moderate aeration rates. Despite the decreasing oxygen solubility, the oxygen transfer rate increased with rising temperature due to the improved mass transfer parameters. With rising solid content, the oxygen transfer rate increased and reached a maximum at a solid content of about 140 kg m(-3) before it decreased again. However, it is only slightly reduced at the highest solid contents. The results demonstrate that aerobic bioprocesses at high temperatures are not only feasible, but can be very efficient if carried out in proper bioreactors.

  10. The nucleation of aerosols in flue gases with a high content of alkali - a laboratory study

    DEFF Research Database (Denmark)

    Jensen, Joakim Reimer; Schultz-Møller, Christina; Wedel, Stig

    2000-01-01

    The formation of particles during cooling of a synthetic flue gas with vapors of sodium and potassium species is studied in a laboratory tubular reactor with laminar flow. It is shown to agree well with a theoretical model for the process. The kinetics of homogeneous nucleation of the pure chloride......, in the presence of oxygen and water vapor, increases the number concentration of effluent particles significantly and affects their composition to include sulphate in addition to chloride. The sulphate content is independent of the peak temperatures of the flue gas but increases with increasing content of oxygen...... and SO2. The study proves that the alkali sulphates are formed by the sulphation of vapor phase rather than solid, alkali chloride. The sulphate vapors are formed in high supersaturation and show a pronounced tendency towards homogeneous nucleation, which is identified as the likely source...

  11. Synthesis and properties of hydroxy acrylic resin with high solid content

    Science.gov (United States)

    Yu, Zhen; Hu, Mingguang; Cui, Han; Xiao, Jijun

    2017-10-01

    Manufacturers of automotive repair finishes are tending to reduce more and more the level of volatile organic compounds in their paints in order to comply with increasingly strict environmental legislation. A high solid hydroxy acrylic resin was synthesised using CARDURA E10 and a type of hydroxyacrylic acid resin, its' acid value, hydroxylvalue, viscosity, structure, morphology was measured and film-forming properties after curing were characterised. The results show that the addition of CARDURA E10 in the copolymer composition significantly reduced the viscosity of the polymer system, improved the solid content of the resin and the physical properties of the coating. The hydroxyl acrylate resin with solid content of 90% and excellent comprehensive performance were successfully prepared by controlling the initiator dosage, polymerization temperature and monomer ratio.

  12. Iodine content of infant formulas and iodine intake of premature babies: high risk of iodine deficiency.

    Science.gov (United States)

    Ares, S; Quero, J; Durán, S; Presas, M J; Herruzo, R; Morreale de Escobar, G

    1994-11-01

    As part of a study of thyroid function in premature babies, the iodine content of their mothers' breast milk, that of 32 formulas from different brands used in Spain, and that of 127 formulas used in other countries was determined. Breast milk contained more iodine--mean (SEM) 10 (1) microgram/dl--than most of the formulas, especially those for premature babies. Iodine intakes were therefore below the recommended daily amount (RDA) for newborns: babies of 27-30 weeks' gestational age took 3.1 (1.1) micrograms/day at 5 days of age and 29.8 (2.7) micrograms by 2 months of age. This problem is not exclusive to Spanish premature babies as the iodine content of many of the formulas on sale in other countries was also inadequate. It is concluded that preterm infants who are formula fed are at high risk of iodine deficiency.

  13. Microspheres with an ultra high holmium content for brachytherapy of malignancies

    Energy Technology Data Exchange (ETDEWEB)

    Lira, Raphael A.; Myamoto, Douglas M.; Souza, Jaime R.; Nascimento, Nanci; Azevedo, Mariangela de Burgos M. de [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Biotecnologia; Osso Junior, Joao A. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Radiofarmacia; Martinelli, Jose R. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Ciencias e Tecnologia de Materiais

    2011-07-01

    The overall objective of this work is to develop biodegradable microspheres intended for internal radiation therapy which provides an improved treatment for hepatic carcinomas. The most studied brachytherapy system employing microspheres made of holmium-biopolymer system is composed by poly(L-lactic acid) (PLLA) and holmium acetylacetonate (HoAcAc). The importance of the holmium high content in the microspheres can be interpreted as follow from a therapeutic standpoint, to achieve an effective use of microspheres loaded with HoAcAc, a high content of holmium is required to yield enough radioactivity with a relatively low amount of microspheres.The usual amounts of holmium that are incorporated in the microspheres composed by poly(L-lactic acid) and HoAcAc are 17.0 {+-} 0.5% (w/w) of holmium, which corresponds to a loading of about 50% of HoAcAc. Different approaches have been investigated to increase that value. One updated approach towards this direction is the production of microspheres with ultrahigh holmium as matrix using HoAcAc crystals as the sole starting material without the use of biopolymer. Likewise, in the search of microspheres with increased holmium content , it has been demonstrated that by changing the HoAcAc crystal structure by its recrystallization from crystal phase to the amorphous there is lost of acetylacetonate and water molecules causing the increasing of the holmium content. Microspheres were prepared by solvent evaporation, using holmium acetylacetonate (HoAcAc) crystals as the sole ingredient. Microspheres were characterized by using light and scanning electron microscopy, infrared and Raman spectroscopy, differential scanning calorimetry, X-rays diffraction, and confocal laser scanning microscopy. (author)

  14. High N-content a-C:N films elaborated by femtosecond PLD with plasma assistance

    Energy Technology Data Exchange (ETDEWEB)

    Maddi, C. [Université de Lyon, F-69003, Lyon, France, Université de Saint-Étienne, Laboratoire Hubert Curien (UMR 5516 CNRS) , 42000 Saint-Étienne (France); Donnet, C., E-mail: Christophe.Donnet@univ-st-etienne.fr [Université de Lyon, F-69003, Lyon, France, Université de Saint-Étienne, Laboratoire Hubert Curien (UMR 5516 CNRS) , 42000 Saint-Étienne (France); Loir, A.-S.; Tite, T. [Université de Lyon, F-69003, Lyon, France, Université de Saint-Étienne, Laboratoire Hubert Curien (UMR 5516 CNRS) , 42000 Saint-Étienne (France); Barnier, V. [Laboratoire Georges Friedel, Ecole Nationale Supérieure des Mines, 42023 Saint-Etienne (France); Rojas, T.C.; Sanchez-Lopez, J.C. [Instituto de Ciencia de Materiales de Sevilla (CSIC-US) , Avda. Américo Vespucio 49, 41092 Sevilla (Spain); Wolski, K. [Laboratoire Georges Friedel, Ecole Nationale Supérieure des Mines, 42023 Saint-Etienne (France); Garrelie, F. [Université de Lyon, F-69003, Lyon, France, Université de Saint-Étienne, Laboratoire Hubert Curien (UMR 5516 CNRS) , 42000 Saint-Étienne (France)

    2015-03-30

    Graphical abstract: - Highlights: • Nitrogen doped amorphous carbon films were deposited by DC reactive plasma femtosecond (fs) -PLD and conventional fs-PLD. • High nitrogen content in plasma assisted films. • More ordered sp2 rich graphitic clusters both in terms of structural and topological order. • Correlation length La of the clusters increases with nitrogen incorporation. • Formation of CN bonds at the expense of CC bonds with N content. • At the highest nitrogen concentration, terminal C≡N groups are incorporated in the film. • Correlation between film composition and plasma process. - Abstract: Amorphous carbon nitride (a-C:N) thin films are a interesting class of carbon-based electrode materials. Therefore, synthesis and characterization of these materials have found lot of interest in environmental analytical microsystems. Herein, we report the nitrogen-doped amorphous carbon thin film elaboration by femtosecond pulsed laser deposition (fs-PLD) both with and without a plasma assistance. The chemical composition and atomic bonding configuration of the films were investigated by multi-wavelength (MW) Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and electron energy-loss spectroscopy (EELS). The highest nitrogen content, 28 at.%, was obtained with plasma assistance. The I(D)/I(G) ratio and the G peak position increased as a function of nitrogen concentration, whereas the dispersion and full width at half maximum (FWHM) of G peak decreased. This indicates more ordered graphitic like structures in the films both in terms of topological and structural, depending on the nitrogen content. EELS investigations were correlated with MW Raman results. The interpretation of XPS spectra of carbon nitride films remains a challenge. Plasma assisted PLD in the femtosecond regime led to a significant high nitrogen concentration, which is highlighted on the basis of collisional processes in the carbon plasma plume interacting with the nitrogen

  15. Cubic Crystal-Structured SnTe for Superior Li- and Na-Ion Battery Anodes.

    Science.gov (United States)

    Park, Ah-Ram; Park, Cheol-Min

    2017-06-27

    A cubic crystal-structured Sn-based compound, SnTe, was easily synthesized using a solid-state synthetic process to produce a better rechargeable battery, and its possible application as a Sn-based high-capacity anode material for Li-ion batteries (LIBs) and Na-ion batteries (NIBs) was investigated. The electrochemically driven phase change mechanisms of the SnTe electrodes during Li and Na insertion/extraction were thoroughly examined utilizing various ex situ analytical techniques. During Li insertion, SnTe was converted to Li4.25Sn and Li2Te; meanwhile, during Na insertion, SnTe experienced a sequential topotactic transition to NaxSnTe (x ≤ 1.5) and conversion to Na3.75Sn and Na2Te, which recombined into the original SnTe phase after full Li and Na extraction. The distinctive phase change mechanisms provided remarkable electrochemical Li- and Na-ion storage performances, such as large reversible capacities with high Coulombic efficiencies and stable cyclabilities with fast C-rate characteristics, by preparing amorphous-C-decorated nanostructured SnTe-based composites. Therefore, SnTe, with its interesting phase change mechanisms, will be a promising alternative for the oncoming generation of anode materials for LIBs and NIBs.

  16. Electrochemical studies of CNT/Si–SnSb nanoparticles for lithium ion batteries

    Energy Technology Data Exchange (ETDEWEB)

    Nithyadharseni, P. [Department of Physics, Bannari Amman Institute of Technology, Sathyamangalam 638402 (India); Department of Physics, Advanced Batteries Lab, National University of Singapore, 117542 (Singapore); Reddy, M.V., E-mail: phymvvr@nus.edu.sg [Department of Physics, Advanced Batteries Lab, National University of Singapore, 117542 (Singapore); Nalini, B., E-mail: lalin99@rediffmail.com [Department of Physics, Avinashilingam University for Women, Coimbatore 641043 (India); Ravindran, T.R. [Centre for Research in Nanotechnology, Karunya University, Coimbatore 641114 (India); Pillai, B.C.; Kalpana, M. [Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam 603102 (India); Chowdari, B.V.R. [Department of Physics, Advanced Batteries Lab, National University of Singapore, 117542 (Singapore)

    2015-10-15

    Highlights: • Si added SnSb and CNT exhibits very low particle size of below 30 nm • A strong PL quenching due to the addition of Si to SnSb. • Electrochemical studies show CNT added SnSb shows good capacity retention. - Abstract: Nano-structured SnSb, SnSb–CNT, Si–SnSb and Si–SnSb–CNT alloys were synthesized from metal chlorides of Sn, Sb and Si via reductive co-precipitation technique using NaBH{sub 4} as reducing agent. The as prepared compounds were characterized by various techniques such as X-ray diffraction (XRD), scanning electron microscope (SEM), Raman, Fourier transform infra-red (FTIR) and photoluminescence (PL) spectroscopy. The electrochemical performances of the compounds were characterized by galvanostatic cycling (GC) and cyclic voltammetry (CV). The Si–SnSb–CNT compound shows a high reversible capacity of 1200 mAh g{sup −1}. However, the rapid capacity fading was observed during cycling. In contrast, SnSb–CNT compound showed a high reversible capacity of 568 mAh g{sup −1} at 30th cycles with good cycling stability. The improved reversible capacity and cyclic performance of the SnSb–CNT compound could be attributed to the nanosacle dimension of SnSb particles and the structural advantage of CNTs.

  17. Foraminiferal indicators of high OC content in marine sediments; a question of OC source?

    Science.gov (United States)

    Lo Giudice Cappelli, Elena; Austin, William; Smith, Laura; Ward, Hannah; Clarke, Jess; Green, Jade; Smeaton, Craig

    2017-04-01

    West Shetland voes (sea inlets), on Scotland northern maritime periphery, represent a range of environmental and depositional settings in an area of coastal ocean which is characterised by a generally high organic carbon content in marine sediments. Possible sources of organic carbon are fish farms, as this region is experiencing a large expansion in marine aquaculture, and/or erosion of peatland. Twenty-one sites in six voes were sampled in August 2015 following an organic carbon gradient. The aims of this study are: 1) to establish the modern biogeography of benthic foraminifera in west Shetland voes, 2) to explore the use of these organisms as bio-indicators of high organic carbon content in marine sediments, and 3) to trace the source of organic carbon and its transportation between different habitats and pools (e.g.: terrestrial to marine; marine aquaculture to sediments). To achieve this, we paired together spatial variations in the composition of benthic foraminiferal assemblages (species abundance and diversity) with changes in the physical properties of marine sediments determined by carbon stable isotope measurements and loss on ignition analysis. Preliminary results show a positive relationship between high abundance of the agglutinated benthic foraminifera Eggerelloides scaber, high organic carbon content in the sediments and proximity to fish farms. Although aquaculture farming in these areas may be a contributing factor, radiocarbon dates demonstrate that organic enrichment in the sediments pre-dates the introduction of aquaculture, while carbon stable isotope measurements point to peat erosion as a more likely source of organic carbon in west Shetland voes. Therefore, peatland erosion is a significant source of organic carbon in marine sediments and may be an important contributor to the store of blue carbon in west Shetland voes and, more in general, in the coastal ocean.

  18. Alu elements in primates are preferentially lost from areas of high GC content

    Science.gov (United States)

    Brookfield, John FY

    2013-01-01

    The currently-accepted dogma when analysing human Alu transposable elements is that ‘young’ Alu elements are found in low GC regions and ‘old’ Alus in high GC regions. The correlation between high GC regions and high gene frequency regions make this observation particularly difficult to explain. Although a number of studies have tackled the problem, no analysis has definitively explained the reason for this trend. These observations have been made by relying on the subfamily as a proxy for age of an element. In this study, we suggest that this is a misleading assumption and instead analyse the relationship between the taxonomic distribution of an individual element and its surrounding GC environment. An analysis of 103906 Alu elements across 6 human chromosomes was carried out, using the presence of orthologous Alu elements in other primate species as a proxy for age. We show that the previously-reported effect of GC content correlating with subfamily age is not reflected by the ages of the individual elements. Instead, elements are preferentially lost from areas of high GC content over time. The correlation between GC content and subfamily may be due to a change in insertion bias in the young subfamilies. The link between Alu subfamily age and GC region was made due to an over-simplification of the data and is incorrect. We suggest that use of subfamilies as a proxy for age is inappropriate and that the analysis of ortholog presence in other primate species provides a deeper insight into the data. PMID:23717800

  19. OMASAL MORPHOLOGY OF DAIRY COWS FED WITH HIGH OR LOW GRAIN CONTENT DIET PRIOR PARTURITION

    Directory of Open Access Journals (Sweden)

    Danilo de Oliveira Rocha Bhering Santoro

    2015-12-01

    Full Text Available ABSTRACT Little is known about the morphological response of the omasum in dairy cows that consume a high-energy diet pre-partum. The aim of this study was to investigate whether a transitional diet with high grain content is able to induce changes in omasum morphology. Six weeks before the expected calving, four Holstein cows were fed a standardization diet, and four weeks before delivery, the cows were fed a diet with high grain content (HGC or low (LGC grain content. After calving, all of the cows were fed a high energy lactation diet. The cows that were fed the HGC diet pre-partum had higher dry matter and nutrient intake than the cows that were fed the LGC diet. The mitotic index of the omasum epithelium was higher than the mitotic index in the rumen, but apparently the response to the diet stimuli was slower. In the cows that were fed the HGC diet, the omasum papillae were taller one week before parturition and two weeks post-partum. Cows that were fed the HGC diet had a thinner epithelium due to thinner non-keratinized layers of the omasum epithelium. We conclude that the omasum mucosa of dairy cows responds to the stimuli of a pre-partum HGC diet, which was indicated by the greater height of the omasum papillae and by the reduced thickness of the omasum epithelium. It seems that the mitotic index responds a little more slowly, but the response to the diet stimuli is stronger in the omasum epithelium than in the rumen.

  20. High arsenic (As content in coals from Neogene deposits of the Pannonian Basin in Slovenia

    Directory of Open Access Journals (Sweden)

    Miloš Markič

    2017-12-01

    Full Text Available High contents of arsenic (As in coal samples from four localities within Neogene deposits of the Pannonian Basin in Slovenia are presented and discussed in this paper. Data from three localities represent interval samples of coal cuttings from wells TER-1 (Terbegovci, Sob-3g (Murska Sobota, and MD-1 (Mislinjska Dobrava. The fourth locality is Globoko, where the main lignite seam was analysed already in 1989. The oldest are coal samples from the MD-1 well which are supposed to be of the Lower Miocene age (except for the shallowest one, which is of the Plio-Quaternary age. Coal samples from the TER-1 and Sob-3g wells are of the Upper Miocene age (Mura Formation. The lignite sample from Globoko is of the Upper Miocene age too (Pontian; Globoko Formation. Most samples were prepared for the ICP-MS method analysis as “whole coal”, dry, pulverized lab-samples, weighting ca. 10 g. The results show for all “whole coals” samples considerably increased contents of As: 22.7, 111.4, 222.1, and 131.4 µg/g for the Lower Miocene (?, and 84.5 µg/g for the Plio-Quaternary coals from MD-1 well, 392 µg/g for coals from the Sob-3g well, and 116 µg/g for a coal from the TER-1 well (both Upper Miocene – Mura Formation. In the case of Globoko, not “whole coal” but its high temperature ash was analysed and showed As content as high as 170 µg/g applying AAS method of analysis, and even 260 µg/g applying the ICP-MS. Origin of As could be pre-Neogene rocks of the hinterland and/or Neogene calc-alkaline volcanites. Mineral-gas exhalations from the under-continental upper mantle, containing As, could also be a source of this highly volatile element.

  1. Sn surface-enriched Pt-Sn bimetallic nanoparticles as a selective and stable catalyst for propane dehydrogenation

    KAUST Repository

    Zhu, Haibo

    2014-12-01

    A new one pot, surfactant-free, synthetic route based on the surface organometallic chemistry (SOMC) concept has been developed for the synthesis of Sn surface-enriched Pt-Sn nanoparticles. Bu3SnH selectively reacts with [Pt]-H formed in situ at the surface of Pt nanoparticles, Pt NPs, obtained by reduction of K2PtCl4 by LiB(C2H5)3H. Chemical analysis, 1H MAS and 13C CP/MAS solid-state NMR as well as two-dimensional double-quantum (DQ) and triple-quantum (TQ) experiments show that organo-tin moieties Sn(n-C4H9) are chemically linked to the surface of Pt NPs to produce, in fine, after removal of most of the n-butyl fragment, bimetallic Pt-Sn nanoparticles. The Sn(n-CH2CH2CH2CH3) groups remaining at the surface are believed to stabilize the as-synthesized Pt-Sn NPs, enabling the bimetallic NPs to be well dispersed in THF. Additionally, the Pt-Sn nanoparticles can be supported on MgAl2O4 during the synthesis of the nanoparticles. Some of the Pt-Sn/MgAl2O4 catalyst thus prepared exhibits high activity in PROX of CO and an extremely high selectivity and stability in propane dehydrogenation to propylene. The enhanced activity in propane dehydrogenation is associated with the high concentration of inactive Sn at the surface of Pt nanoparticles which ”isolates” the active Pt atoms. This conclusion is confirmed by XRD, NMR, TEM, and XPS analysis.

  2. Profiling stem cell states in three-dimensional biomaterial niches using high content image informatics.

    Science.gov (United States)

    Dhaliwal, Anandika; Brenner, Matthew; Wolujewicz, Paul; Zhang, Zheng; Mao, Yong; Batish, Mona; Kohn, Joachim; Moghe, Prabhas V

    2016-11-01

    A predictive framework for the evolution of stem cell biology in 3-D is currently lacking. In this study we propose deep image informatics of the nuclear biology of stem cells to elucidate how 3-D biomaterials steer stem cell lineage phenotypes. The approach is based on high content imaging informatics to capture minute variations in the 3-D spatial organization of splicing factor SC-35 in the nucleoplasm as a marker to classify emergent cell phenotypes of human mesenchymal stem cells (hMSCs). The cells were cultured in varied 3-D culture systems including hydrogels, electrospun mats and salt leached scaffolds. The approach encompasses high resolution 3-D imaging of SC-35 domains and high content image analysis (HCIA) to compute quantitative 3-D nuclear metrics for SC-35 organization in single cells in concert with machine learning approaches to construct a predictive cell-state classification model. Our findings indicate that hMSCs cultured in collagen hydrogels and induced to differentiate into osteogenic or adipogenic lineages could be classified into the three lineages (stem, adipogenic, osteogenic) with ⩾80% precision and sensitivity, within 72h. Using this framework, the augmentation of osteogenesis by scaffold design exerted by porogen leached scaffolds was also profiled within 72h with ∼80% high sensitivity. Furthermore, by employing 3-D SC-35 organizational metrics, differential osteogenesis induced by novel electrospun fibrous polymer mats incorporating decellularized matrix could also be elucidated and predictably modeled at just 3days with high precision. We demonstrate that 3-D SC-35 organizational metrics can be applied to model the stem cell state in 3-D scaffolds. We propose that this methodology can robustly discern minute changes in stem cell states within complex 3-D architectures and map single cell biological readouts that are critical to assessing population level cell heterogeneity. The sustained development and validation of bioactive

  3. Biodiesel from the seed oil of Treculia africana with high free fatty acid content

    Energy Technology Data Exchange (ETDEWEB)

    Adewuyi, Adewale [Redeemer' s University, Department of Chemical Sciences, Faculty of Natural Sciences, Redemption City, Ogun State (Nigeria); Oderinde, Rotimi A.; Ojo, David F.K. [University of Ibadan, Industrial Unit, Department of Chemistry, Ibadan, Oyo State (Nigeria)

    2012-12-15

    Oil was extracted from the seed of Treculia africana using hexane. The oil was characterized and used in the production of biodiesel. Biodiesel was produced from the seed oil of T. africana using a two-step reaction system. The first step was a pretreatment which involved the use of 2 % sulfuric acid in methanol, and secondly, transesterification reaction using KOH as catalyst. Saponification value of the oil was 201.70 {+-} 0.20 mg KOH/g, free fatty acid was 8.20 {+-} 0.50 %, while iodine value was 118.20 {+-} 0.50 g iodine/100 g. The most dominant fatty acid was C18:2 (44 %). The result of the method applied showed a conversion which has ester content above 98 %, flash point of 131 {+-} 1.30 C, and phosphorus content below 1 ppm in the biodiesel. The biodiesel produced exhibited properties that were in agreement with the European standard (EN 14214). This study showed that the high free fatty acid content of T. africana seed oil can be reduced in a one-step pretreatment of esterification reaction using H{sub 2}SO{sub 4} as catalyst. (orig.)

  4. Effect of High Si Content on U3Si2 Fuel Microstructure

    Science.gov (United States)

    Rosales, Jhonathan; van Rooyen, Isabella J.; Meher, Subhashish; Hoggan, Rita; Parga, Clemente; Harp, Jason

    2017-11-01

    The development of U3Si2 as an accident-tolerant nuclear fuel has gained research interest because of its promising high uranium density and improved thermal properties. In the present study, three samples of U3Si2 fuel with varying silicon content have been fabricated by a conventional powder metallurgical route. Microstructural characterization via scanning and transmission electron microscopy reveals the presence of other stoichiometry of uranium silicide such as USi and UO2 in both samples. The detailed phase analysis by x-ray diffraction shows the presence of secondary phases, such as USi, U3Si, and UO2. The samples with higher concentrations of silicon content of 7.5 wt.% display additional elemental Si. These samples also possess an increased amount of the USi phase as compared to that in the conventional sample with 7.3 wt.% silicon. The optimization of U3Si2 fuel performance through the understanding of the role of Si content on its microstructure has been discussed.

  5. High-accuracy measurement of low-water-content in liquid using NIR spectral absorption method

    Science.gov (United States)

    Peng, Bao-Jin; Wan, Xu; Jin, Hong-Zhen; Zhao, Yong; Mao, He-Fa

    2005-01-01

    Water content measurement technologies are very important for quality inspection of food, medicine products, chemical products and many other industry fields. In recent years, requests for accurate low-water-content measurement in liquid are more and more exigent, and great interests have been shown from the research and experimental work. With the development and advancement of modern production and control technologies, more accurate water content technology is needed. In this paper, a novel experimental setup based on near-infrared (NIR) spectral technology and fiber-optic sensor (OFS) is presented. It has a good measurement accuracy about -/+ 0.01%, which is better, to our knowledge, than most other methods published until now. It has a high measurement resolution of 0.001% in the measurement range from zero to 0.05% for water-in-alcohol measurement, and the water-in-oil measurement is carried out as well. In addition, the advantages of this method also include pollution-free to the measured liquid, fast measurement and so on.

  6. Factor analysis in optimization of formulation of high content uniformity tablets containing low dose active substance.

    Science.gov (United States)

    Lukášová, Ivana; Muselík, Jan; Franc, Aleš; Goněc, Roman; Mika, Filip; Vetchý, David

    2017-11-15

    Warfarin is intensively discussed drug with narrow therapeutic range. There have been cases of bleeding attributed to varying content or altered quality of the active substance. Factor analysis is useful for finding suitable technological parameters leading to high content uniformity of tablets containing low amount of active substance. The composition of tabletting blend and technological procedure were set with respect to factor analysis of previously published results. The correctness of set parameters was checked by manufacturing and evaluation of tablets containing 1-10mg of warfarin sodium. The robustness of suggested technology was checked by using "worst case scenario" and statistical evaluation of European Pharmacopoeia (EP) content uniformity limits with respect to Bergum division and process capability index (Cpk). To evaluate the quality of active substance and tablets, dissolution method was developed (water; EP apparatus II; 25rpm), allowing for statistical comparison of dissolution profiles. Obtained results prove the suitability of factor analysis to optimize the composition with respect to batches manufactured previously and thus the use of metaanalysis under industrial conditions is feasible. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Mutational breeding and genetic engineering in the development of high grain protein content.

    Science.gov (United States)

    Wenefrida, Ida; Utomo, Herry S; Linscombe, Steve D

    2013-12-04

    Cereals are the most important crops in the world for both human consumption and animal feed. Improving their nutritional values, such as high protein content, will have significant implications, from establishing healthy lifestyles to helping remediate malnutrition problems worldwide. Besides providing a source of carbohydrate, grain is also a natural source of dietary fiber, vitamins, minerals, specific oils, and other disease-fighting phytocompounds. Even though cereal grains contain relatively little protein compared to legume seeds, they provide protein for the nutrition of humans and livestock that is about 3 times that of legumes. Most cereal seeds lack a few essential amino acids; therefore, they have imbalanced amino acid profiles. Lysine (Lys), threonine (Thr), methionine (Met), and tryptophan (Trp) are among the most critical and are a limiting factor in many grain crops for human nutrition. Tremendous research has been put into the efforts to improve these essential amino acids. Development of high protein content can be outlined in four different approaches through manipulating seed protein bodies, modulating certain biosynthetic pathways to overproduce essential and limiting amino acids, increasing nitrogen relocation to the grain through the introduction of transgenes, and exploiting new genetic variance. Various technologies have been employed to improve protein content including conventional and mutational breeding, genetic engineering, marker-assisted selection, and genomic analysis. Each approach involves a combination of these technologies. Advancements in nutrigenomics and nutrigenetics continue to improve public knowledge at a rapid pace on the importance of specific aspects of food nutrition for optimum fitness and health. An understanding of the molecular basis for human health and genetic predisposition to certain diseases through human genomes enables individuals to personalize their nutritional requirements. It is critically important

  8. Optimization of the Enzyme-Catalyzed Transesterification of Hungarian Sunflower Oil with High Oleic Acid Content

    Energy Technology Data Exchange (ETDEWEB)

    Kovacs, Sandor; Krar, Marton; Hancsok, Jenoe (Univ. of Pannonia, Dept. of Hydrocarbon and Coal Processing, H-8201 Veszprem (Hungary)). e-mail: kovacss@almos.uni-pannon.hu

    2008-10-15

    In our research work we defined the optimum parameters (temperature, methanol to triglyceride molar ratio, reaction time, number of methanol feeds, and the amount of Candia Antarctica lipase) of the enzyme-catalyzed transesterification of properly pre-treated high oleic acid containing sunflower oil. The oleic acid content of the previously mentioned sunflower oil was present in the structure of the triglycerides. Characteristics of the produced sunflower oil methyl esters were evaluated according to the requirements of the EN 14214 standard. Our experimental results indicated that enzyme-catalyzed transesterification could be successfully used for the conversion of high oleic sunflower oils, since we have found proper combination of process parameters resulting in high yield (>99%) of monoesters. The applied enzyme can be separated after the transesterification and used again. The glycerine - because its reaction inhibiting effect - was separated continuously by membrane separation

  9. FBC desulfurization process using coal with low sulfur content, high oxidizing conditions and metamorphic limestones

    Directory of Open Access Journals (Sweden)

    S. R. Bragança

    2009-06-01

    Full Text Available A metamorphic limestone and a dolomite were employed as SO2 sorbents in the desulfurization of gas from coal combustion. The tests were performed in a fluidized bed reactor on a bench and pilot scale. Several parameters such as bed temperature, sorbent type, and sorbent particle size at different Ca/S molar ratios were analyzed. These parameters were evaluated for the combustion of coal with low-sulfur/high-ash content, experimental conditions of high air excess and high O2 level in fluidization air. Under these conditions, typical of furnaces, few published data can be found. In this work, a medium level of desulfurization efficiency (~60% for Ca/S = 2 was obtained.

  10. Automated analysis of high-content microscopy data with deep learning.

    Science.gov (United States)

    Kraus, Oren Z; Grys, Ben T; Ba, Jimmy; Chong, Yolanda; Frey, Brendan J; Boone, Charles; Andrews, Brenda J

    2017-04-18

    Existing computational pipelines for quantitative analysis of high-content microscopy data rely on traditional machine learning approaches that fail to accurately classify more than a single dataset without substantial tuning and training, requiring extensive analysis. Here, we demonstrate that the application of deep learning to biological image data can overcome the pitfalls associated with conventional machine learning classifiers. Using a deep convolutional neural network (DeepLoc) to analyze yeast cell images, we show improved performance over traditional approaches in the automated classification of protein subcellular localization. We also demonstrate the ability of DeepLoc to classify highly divergent image sets, including images of pheromone-arrested cells with abnormal cellular morphology, as well as images generated in different genetic backgrounds and in different laboratories. We offer an open-source implementation that enables updating DeepLoc on new microscopy datasets. This study highlights deep learning as an important tool for the expedited analysis of high-content microscopy data. © 2017 The Authors. Published under the terms of the CC BY 4.0 license.

  11. Detection of abnormally high amygdalin content in food by an enzyme immunoassay.

    Science.gov (United States)

    Cho, A-Yeon; Yi, Kye Sook; Rhim, Jung-Hyo; Kim, Kyu-Il; Park, Jae-Young; Keum, Eun-Hee; Chung, Junho; Oh, Sangsuk

    2006-04-30

    Amygdalin is a cyanogenic glycoside compound which is commonly found in the pits of many fruits and raw nuts. Although amygdalin itself is not toxic, it can release cyanide (CN) after hydrolysis when the pits and nuts are crushed, moistened and incubated, possibly within the gastrointestinal tract. CN reversibly inhibits cellular oxidizing enzymes and cyanide poisoning generates a range of clinical symptoms. As some pits and nuts may contain unusually high levels of amygdalin such that there is a sufficient amount to induce critical CN poisoning in humans, the detection of abnormal content of amygdalin in those pits and nuts can be a life-saving measure. Although there are various methods to detect amygdalin in food extracts, an enzyme immunoassay has not been developed for this purpose. In this study we immunized New Zealand White rabbits with an amygdalin-KLH (keyhole limpet hemocyanin) conjugate and succeeded in raising anti-sera reactive to amygdalin, proving that amygdalin can behave as a hapten in rabbits. Using this polyclonal antibody, we developed a competition enzyme immunoassay for determination of amygdalin concentration in aqueous solutions. This technique was able to effectively detect abnormally high amygdalin content in various seeds and nuts. In conclusion, we proved that enzyme immunoassay can be used to determine the amount of amygdalin in food extracts, which will allow automated analysis with high throughput.

  12. High-content analysis screening for cell cycle regulators using arrayed synthetic crRNA libraries.

    Science.gov (United States)

    Strezoska, Žaklina; Perkett, Matthew R; Chou, Eldon T; Maksimova, Elena; Anderson, Emily M; McClelland, Shawn; Kelley, Melissa L; Vermeulen, Annaleen; Smith, Anja van Brabant

    2017-06-10

    The CRISPR-Cas9 system has been utilized for large-scale, loss-of-function screens mainly using lentiviral pooled formats and cell-survival phenotypic assays. Screening in an arrayed format expands the types of phenotypic readouts that can be used to now include high-content, morphology-based assays, and with the recent availability of synthetic crRNA libraries, new studies are emerging. Here, we use a cell cycle reporter cell line to perform an arrayed, synthetic crRNA:tracrRNA screen targeting 169 genes (>600 crRNAs) and used high content analysis (HCA) to identify genes that regulate the cell cycle. Seven parameters were used to classify cells into cell cycle categories and multiple parameters were combined using a new analysis technique to identify hits. Comprehensive hit follow-up experiments included target gene expression analysis, confirmation of DNA insertions/deletions, and validation with orthogonal reagents. Our results show that most hits had three or more independent crRNAs per gene that demonstrated a phenotype with consistent individual parameters, indicating that our screen produced high-confidence hits with low off-target effects and allowed us to identify hits with more subtle phenotypes. The results of our screen demonstrate the power of using arrayed, synthetic crRNAs for functional phenotypic screening using multiparameter HCA assays. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

  13. Non-metallic inclusions structure dimension in high quality steel with medium carbon contents

    Directory of Open Access Journals (Sweden)

    T. Lipiński

    2009-07-01

    Full Text Available The experimental material consisted of semi-finished products of high-grade, medium-carbon structural steel. The production process involved two melting technologies: steel melting in a 140-ton basic arc furnace with desulfurization and argon refining variants, and in a 100-ton oxygen converter. Billet samples were collected to analyze the content of non-metallic inclusions with the use of an optical microscope and a video inspection microscope. The results were processed and presented in graphic form.

  14. Robust, Reliable Low Emission Gas Turbine Combustion of High Hydrogen Content Fuels

    Energy Technology Data Exchange (ETDEWEB)

    Wooldridge, Margaret Stacy [Univ. of Michigan, Ann Arbor, MI (United States); Im, Hong Geum [Univ. of Michigan, Ann Arbor, MI (United States)

    2016-12-16

    The effects of high hydrogen content fuels were studied using experimental, computational and theoretical approaches to understand the effects of mixture and state conditions on the ignition behavior of the fuels. A rapid compression facility (RCF) was used to measure the ignition delay time of hydrogen and carbon monoxide mixtures. The data were combined with results of previous studies to develop ignition regime criteria. Analytical theory and direct numerical simulation were used to validate and interpret the RCF ignition data. Based on the integrated information the ignition regime criteria were extended to non-dimensional metrics which enable application of the results to practical gas turbine combustion systems.

  15. Gold-tin ordering in SrAu{sub 2}Sn{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Schwickert, Christian; Gerke, Birgit; Poettgen, Rainer [Univ. Muenster (Germany). Inst. fuer Anorganische und Analytische Chemie

    2014-07-15

    Samples of the solid solutions SrAu{sub x}Sn{sub 4-x} (1.7 ≤ x ≤ 2.2) were obtained by high-frequency melting of the elements in sealed niobium ampoules. Powder and single-crystal X-ray data confirmed the CaBe{sub 2}Ge{sub 2}-type structure, space group P4/nmm. The structures of SrAu{sub 1.76}Sn{sub 2.24}, SrAu{sub 2}Sn{sub 2}, SrAu{sub 2.16}Sn{sub 1.84} (crystal A), SrAu{sub 2.16}Sn{sub 1.84} (crystal B), and SrAu{sub 2.22}Sn{sub 1.78} were refined from single-crystal diffractometer data. Only the SrAu{sub 2}Sn{sub 2} crystal shows complete Au-Sn ordering while all other crystals show substantial mixed occupancies on the four crystallographically independent sites of the polyanionic networks in which the strontium atoms fill cages of coordination number 16. Temperature-dependent susceptibility measurements have revealed diamagnetism for SrAu{sub 2}Sn{sub 2}. {sup 119}Sn Moessbauer spectroscopic data of a bulk SrAu{sub 2}Sn{sub 2} sample have resolved the tetrahedral and square-pyramidal tin sites but point to substantial Au-Sn disorder.

  16. Structural and electronic properties of SnO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Akgul, Funda Aksoy, E-mail: fundaaksoy01@gmail.com [Physics Department, Nigde University, 51240 Nigde (Turkey); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Gumus, Cebrail, E-mail: cgumus@cu.edu.tr [Physics Department, Cukurova University, 01330 Adana (Turkey); Er, Ali O. [Department of Chemistry, University of California, Irvine, CA 92612 (United States); Farha, Ashraf H. [Electrical and Computer Engineering, Old Dominion University, Norfolk, VA 23529 (United States); Physics Department, Ain Shams University, Cairo 11566 (Egypt); Akgul, Guvenc [Bor Vocational School, Nigde University, 51700 Nigde (Turkey); Ufuktepe, Yuksel [Physics Department, Cukurova University, 01330 Adana (Turkey); Liu, Zhi [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2013-12-05

    Highlights: •Structural and electronic properties of SnO{sub 2} films were determined. •Oxidation states of the SnO{sub 2} thin films were confirmed by XPS analysis. •Chemical component is non-stoichiometric and ratio of oxygen to tin was 1.85. -- Abstract: Highly transparent polycrystalline thin film of SnO{sub 2} (tin dioxide) was deposited using a simple and low cost spray pyrolysis method. The film was prepared from an aqueous solution of tin tetrachloride (stannic chloride) onto glass substrates at 400 °C. A range of diagnostic techniques including X-ray diffraction (XRD), UV–visible absorption, atomic force microscopy (AFM), scanning electron microscopy (SEM), and synchrotron-based X-ray photoelectron spectroscopy (XPS) were used to investigate structural, optical, and electronic properties of the resulting film. Deposited film was found to be polycrystalline. A mixture of SnO and SnO{sub 2} phases was observed. The average crystallite size of ∼21.3 nm for SnO{sub 2} was calculated by Rietveld method using XRD data. The oxidation states of the SnO{sub 2} thin film were confirmed by the shape analysis of corresponding XPS O 1s, Sn 3d, and Sn 4d peaks using the decomposition procedure. The analysis of the XPS core level peaks showed that the chemical component is non-stoichiometric and the ratio of oxygen to tin (O/Sn) is 1.85 which is slightly under stoichiometry.

  17. Sn-doped hematite nanostructures for photoelectrochemical water splitting.

    Science.gov (United States)

    Ling, Yichuan; Wang, Gongming; Wheeler, Damon A; Zhang, Jin Z; Li, Yat

    2011-05-11

    We report on the synthesis and characterization of Sn-doped hematite nanowires and nanocorals as well as their implementation as photoanodes for photoelectrochemical water splitting. The hematite nanowires were prepared on a fluorine-doped tin oxide (FTO) substrate by a hydrothermal method, followed by high temperature sintering in air to incorporate Sn, diffused from the FTO substrate, as a dopant. Sn-doped hematite nanocorals were prepared by the same method, by adding tin(IV) chloride as the Sn precursor. X-ray photoelectron spectroscopy analysis confirms Sn(4+) substitution at Fe(3+) sites in hematite, and Sn-dopant levels increase with sintering temperature. Sn dopant serves as an electron donor and increases the carrier density of hematite nanostructures. The hematite nanowires sintered at 800 °C yielded a pronounced photocurrent density of 1.24 mA/cm(2) at 1.23 V vs RHE, which is the highest value observed for hematite nanowires. In comparison to nanowires, Sn-doped hematite nanocorals exhibit smaller feature sizes and increased surface areas. Significantly, they showed a remarkable photocurrent density of 1.86 mA/cm(2) at 1.23 V vs RHE, which is approximately 1.5 times higher than that of the nanowires. Ultrafast spectroscopy studies revealed that there is significant electron-hole recombination within the first few picoseconds, while Sn doping and the change of surface morphology have no major effect on the ultrafast dynamics of the charge carriers on the picosecond time scales. The enhanced photoactivity in Sn-doped hematite nanostructures should be due to the improved electrical conductivity and increased surface area.

  18. Experiences of High School Students about the Predictors of Tobacco Use: a Directed Qualitative Content Analysis

    Directory of Open Access Journals (Sweden)

    Mahmoud Ghasemi

    2015-12-01

    Full Text Available Background and Objectives: Tobacco use is one of the most important risk factors that increases the burden of diseases worldwide. Based on the increasing speed of tobacco use, the aim of the present study was to explain the experiences of high school students about the determiners of use and non-use of tobacco (cigarettes and hookah based on the theory of protection motivation. Materials and Methods: The present study is a qualitative study based on content analysis that has been carried out for five months from 22, November of 2014 to 20, April of 2015 on male high schools in Noshahr. Data were collected in the form of semi-structured interviews from 21 male high school students of whom 7 smoked cigarettes, 7 used hookah and 7 of them did not use any type of tobacco. Data analysis was carried out through the use of directed qualitative content analysis. Results: Data analysis led to the extraction of 99 primary codes that were categorized into 9 predetermined levels of protection motivation theory including perceived sensitivity, perceived intensity, fear, perceived self-efficacy, response expense, efficiency of the perceived answer, external perceived reward, internal perceived reward, protection motivation. The findings of the study showed that the most important predictors for the use of tobacco were the structures of response expense and high perceived rewards and the most important predictors for non-use of tobacco were perceived sensitivity, perceived intensity and high self-efficacy of students. Conclusions: the findings of the present study showed that the pressure from peers,