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Sample records for cao trong sn

  1. CAOS

    DEFF Research Database (Denmark)

    Erdman Thomsen, Hanne; Madsen, Bodil Nistrup

    2011-01-01

    This paper presents some principles of terminological ontologies implemented in the prototype that has been developed in the research project CAOS - Computer-Aided Ontology Structuring. Furthermore, some issues that have to be faced to further develop facilities for automatic consistency checking...... and automatic changes to ontologies, are discussed. The presentation will illustrate central facilities of the current version of the CAOS prototype, which is interactive and presupposes an end-user with a background in terminology rather than in formal ontology....

  2. Use of heterogeneous CaO and SnO{sub 2} catalysts supported on rice husk ash to produce biodiesel; Emprego de catalisadores heterogeneos de CaO e SnO{sub 2} suportados em cinza de casca de arroz na obtencao de biodiesel

    Energy Technology Data Exchange (ETDEWEB)

    Soares, Ana Brigida [Instituto Federal do Espirito Santo, Vitoria, ES (Brazil); Silva, Paulo Roberto Nagipe da; Stumbo, Alexandre Moura, E-mail: nagipe@uenf.br [Laboratorio de Ciencias Quimicas, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ (Brazil); Freitas, Jair C.C. [Departamento de Fisica, Centro de Ciencias Exatas, Universidade Federal do Espirito Santo, Vitoria, ES (Brazil)

    2012-07-01

    Silica obtained from rice husk after acid leaching and calcination was compared to commercial silica as a catalyst support. CaO and SnO{sub 2} catalysts were prepared by impregnation and tested in the transesterification of soybean oil and the esterification of oleic acid. CaO catalysts showed basic character and were the most active for transesterification, whereas SnO{sub 2} catalysts were acid and the most effective for esterification. In both cases the performances of the catalysts prepared with rice husk ash and commercial silica were similar. These results demonstrate that rice husk is a cost-effective and environmentally-friendly source of silica that can be used as a catalyst support. (author)

  3. Revisiting Cao Xueqin Museum

    Institute of Scientific and Technical Information of China (English)

    1997-01-01

    A Dream of Red Mansions is known by all Chinese. Its author Cao Xueqin spent his later years writing the novel at the foot of Fragrant Hills, in a western suburb of Beijing. In 1984, Cao Xueqin Museum was built there, at the site of the Man nationality residential area during the Qing Dynasty (1644-1911 ), adding a cultural scenic spot. I first visited the Cao Xueqin Museum in the spring soon after it opened. At that time, few people knew

  4. Le leggi del caos

    CERN Document Server

    Prigogine, Ilya

    1993-01-01

    Contro la concezione deterministica delle leggi di natura, teocratica e indifferente alla dimensione temporale, Prigogine riconosce nuova dignita al 'caos', la cui instabilità è fonte di disordine ma anche di ordine.

  5. CAOS-CMOS camera.

    Science.gov (United States)

    Riza, Nabeel A; La Torre, Juan Pablo; Amin, M Junaid

    2016-06-13

    Proposed and experimentally demonstrated is the CAOS-CMOS camera design that combines the coded access optical sensor (CAOS) imager platform with the CMOS multi-pixel optical sensor. The unique CAOS-CMOS camera engages the classic CMOS sensor light staring mode with the time-frequency-space agile pixel CAOS imager mode within one programmable optical unit to realize a high dynamic range imager for extreme light contrast conditions. The experimentally demonstrated CAOS-CMOS camera is built using a digital micromirror device, a silicon point-photo-detector with a variable gain amplifier, and a silicon CMOS sensor with a maximum rated 51.3 dB dynamic range. White light imaging of three different brightness simultaneously viewed targets, that is not possible by the CMOS sensor, is achieved by the CAOS-CMOS camera demonstrating an 82.06 dB dynamic range. Applications for the camera include industrial machine vision, welding, laser analysis, automotive, night vision, surveillance and multispectral military systems.

  6. Caso e caos

    CERN Document Server

    Ruelle, David

    1992-01-01

    Caso e caos – Il caso ha la sua ragione. Ma quale? E cos’è in realtà il caso? Da dove viene e come può fare irruzione nella nostra descrizione dell’universo? A tutte queste domande, in una chiara e lucida esposizione, cerca di dare risposta David Ruelle. Curiosando tra i risultati scientifici del XX secolo e soffermandosi anche su fenomeni e problemi estranei alla scienza tradizionale – le lotterie, gli oroscopi, la teoria dei giochi, la genesi della turbolenza – Ruelle ci guida a conoscere il caso avendo la matematica, la fisica e tutte le scienze naturali come compagne. Ancora oggi il modo in cui il caso irrompe nelle nostre vite e nel mondo può essere un mistero, ma grazie ai progressi della scienza, qui raccontati, riusciamo a saperne un poco di più.

  7. The Structural Optimization System CAOS

    DEFF Research Database (Denmark)

    Rasmussen, John

    1990-01-01

    CAOS is a system for structural shape optimization. It is closely integrated in a Computer Aided Design environment and controlled entirely from the CAD-system AutoCAD. The mathematical foundation of the system is briefly presented and a description of the CAD-integration strategy is given together...

  8. The Structural Optimization System CAOS

    DEFF Research Database (Denmark)

    Rasmussen, John

    1990-01-01

    CAOS is a system for structural shape optimization. It is closely integrated in a Computer Aided Design environment and controlled entirely from the CAD-system AutoCAD. The mathematical foundation of the system is briefly presented and a description of the CAD-integration strategy is given together...

  9. Caos, complejidad y cardiología

    OpenAIRE

    Martínez-Lavín,Manuel

    2012-01-01

    La ciencia es una disciplina en constante evolución. La medicina moderna está basada en la ciencia. El paradigma médico vigente es lineal y reduccionista. Existe una nueva teoría general avalada por cálculos computacionales avanzados, la teoría del caos y la complejidad. Esta nueva visión probablemente modificará la práctica de la medicina. La cardiología fue una puerta de entrada de la complejidad, al campo de la medicina. El caos y los fractales son fenómenos frecuentes en la fisiología car...

  10. Internet desde la perspectiva del caos

    OpenAIRE

    FANNY DE HIMMELSTERN

    2000-01-01

    En este artículo, la autora utiliza algunas cateogorías de la Teoria del Caos para comprender el fenómeno de internte. Según la autora, la relación entre cultura, tecnolgoía y ciencia, y el uso del internet han modificado nuestras percepciones sociales.

  11. SN Refsdal

    DEFF Research Database (Denmark)

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

    2015-01-01

    in the rest frame, provide additional evidence that supports the SN 1987A-like classification. In comparison with other examples of SN 1987A-like SNe, SN Refsdal has a blue B-V color and a high luminosity for the assumed range of potential magnifications. If SN Refsdal can be modeled as a scaled version of SN...

  12. APLICABILIDADE DA TEORIA DO CAOS A ORGANIZAÇÕES

    OpenAIRE

    Ernesto José Vieira; Henrique Cordeiro Martins; Carlos Alberto Gonçalves

    2015-01-01

    Objetivou-se compreender os fundamentos da Teoria do Caos na gestão das empresas e a existência de elementos típicos dessa teoria nos processos de planejamento, e variáveis controláveis que previnam o caos de ruptura. Além disso, foi também investigado se visão, missão e objetivos corporativos consistem em atratores que evitem a instalação do caos de ruptura; e variáveis e faixas de controle utilizadas pelos dirigentes para evitar o caos de ruptura. A metodologia qualitativa empregou estudo e...

  13. CAOS spectroscopy of Am stars Kepler targets

    CERN Document Server

    Catanzaro, G; Biazzo, K; Busa', I; Frasca, A; Leone, F; Giarrusso, M; Munari, M; Scuderi, S

    2015-01-01

    The {\\it Kepler} space mission and its {\\it K2} extension provide photometric time series data with unprecedented accuracy. These data challenge our current understanding of the metallic-lined A stars (Am stars) for what concerns the onset of pulsations in their atmospheres. It turns out that the predictions of current diffusion models do not agree with observations. To understand this discrepancy, it is of crucial importance to obtain ground-based spectroscopic observations of Am stars in the {\\it Kepler} and {\\it K2} fields in order to determine the best estimates of the stellar parameters. In this paper, we present a detailed analysis of high-resolution spectroscopic data for seven stars previously classified as Am stars. We determine the effective temperatures, surface gravities, projected rotational velocities, microturbulent velocities and chemical abundances of these stars using spectral synthesis. These spectra were obtained with {\\it CAOS}, a new instrument recently installed at the observing station...

  14. CAOS/COMPLEJIDAD, FRACTALES E IDENTIDADES SOCIALES

    OpenAIRE

    Gustavo Alvarez Vázquez

    2012-01-01

    En el presente artículo se presenta una propuesta para articular elementos básicos de la Teoría del Caos/Complejidad y la geometría fractal con el estudio de las identidades sociales, partiendo de la tesis que dicha teoría presenta una revolución paradigmática desde cuestiones epistemológicas, la cual es consecuencia no de la transformación de la realidad, sino de la modificación del esquema de percepción que de ella se ha dado en las ciencias en el último siglo, cuestión que también es posib...

  15. Paradoxo da razão no caos. Teoria do caos aplicada na das probabilidades

    Directory of Open Access Journals (Sweden)

    David Magalhães Filho Magalhães Filho

    2016-02-01

    Full Text Available São estabelecidas as bases de um ensaio sobre a aplicabilidade da Ciência da Computação, sustentadas pela Teoria do Caos, para resolução de certas questões tipicamente probabilísticas onde, através de experimentos computacionais conclusivos, as evidências apontam para o fato de que há fortes indícios a favor deste estudo. O estudo consiste em mostrar um paradoxo que é criado em situações específicas na Teoria das Probabilidades porque elas de fato estão intrinsecamente relacionadas a questões sistemáticas que têm tendência ao comportamento caótico e, portanto, próprias para as soluções que emergem da Teoria do Caos.

  16. Behavior of CaO and Calcium in pure Magnesium

    Institute of Scientific and Technical Information of China (English)

    HA Seong-Ho; LEE Jin-Kyu; JO Hyung-Ho; JUNG Seung-Boo; KIM Shae K.

    2006-01-01

    Mg alloys exhibit a number of good properties such as low density, good castability and high specific strength.However, molten Mg and Mg alloys are ignited without the melt protective gases during melting and casting process due to their high reactivity.The purpose of this study is to investigate effects of Ca and CaO on pure Mg through microstructure observation, ignition test and phase analysis.With increasing Ca and CaO contents, the ignition resistance of Ca or CaO added pure Mg is increased and the grains are refined.As results of XRD and EDS, CaO is reduced to Ca in CaO added pure Mg.Mg2Ca phase is formed even in 0.1 wt.%CaO added pure Mg by reduction mechanism, while Mg2Ca phase is formed over 1.35 wt.% Ca added pure Mg.

  17. In memory of Professor Tianqin Cao(Tien-chin Tsao)

    Institute of Scientific and Technical Information of China (English)

    Youshang Zhang

    2010-01-01

    @@ In December this year,the 4th Tianqin Cao Memorial Symposium on Protein Research will be held in Xiamen(Amoy).On this occasion,it is my pleasure to write a recollection in memory of Professor Tianqin Cao.It was rather late when Ⅰ was able to study in Prof.Cao's laboratory as a graduate student in the Institute of Biochemistry.After graduating from the Department of Chemical Engineering of Zhejiang University in 1948,Ⅰ could not find a job in a chemical engineering factory; therefore,Ⅰ changed my profession to biochemistry and worked as an assistant in the Department of Biochemistry of Hunan Yale Medical College.

  18. Structural, electronics and optical properties of CaO

    Energy Technology Data Exchange (ETDEWEB)

    Albuquerque, E L [Departamento de Fisica, Universidade Federal do Rio Grande do Norte 59072-970 Natal-RN (Brazil); Vasconcelos, M S [Departamento de Ciencias Exatas, Centro Federal de Educacao Tecnologica do Maranhao 65025-001 Sao Luis-MA (Brazil)], E-mail: eudenilson@dfte.ufrn.br

    2008-03-15

    The carrier effective masses of CaO in the cubic phase are estimated by ab initio calculations, which are used for the simulation of Si/CaO metal-oxide-semiconductor (MOS) devices by solving Schroedinger and Poisson equations self consistently. It is shown that higher switching speed, longer lifetimes, and higher endurance can be obtained replacing SiO{sub 2} by CaO as gate dielectric, suggesting promising biomedical applications for Si/CaO-based MOS devices due to the CaO bio-compatibility.

  19. Paradoxo da razão no caos. Teoria do caos aplicada na das probabilidades

    OpenAIRE

    David Magalhães Filho Magalhães Filho; Klaus Ribeiro Cavalcante

    2016-01-01

    São estabelecidas as bases de um ensaio sobre a aplicabilidade da Ciência da Computação, sustentadas pela Teoria do Caos, para resolução de certas questões tipicamente probabilísticas onde, através de experimentos computacionais conclusivos, as evidências apontam para o fato de que há fortes indícios a favor deste estudo. O estudo consiste em mostrar um paradoxo que é criado em situações específicas na Teoria das Probabilidades porque elas de fato estão...

  20. Magnetic properties and microstructures of SnO2 doped Mn-Zn ferrites

    Institute of Scientific and Technical Information of China (English)

    FAN Jiwei; NG Foong-Kee; SALE Frank R.3

    2006-01-01

    The effects of additive SnO2 (0.4wt.%), with and without SiO2 (0.02wt.%) and/or CaO(0.04wt.%), on the microstructure and magnetic properties of Mn-Zn ferrites were reported. The results reveal that SnO2 on its own increases the initial permeability ( μi) slightly, but SnO2 with SiO2 and/or CaO decreases the values of μi. However, ferrites with SnO2 additions have reduced power losses. The separate contributions of hysteresis loss and eddy current loss to the total power loss show that SnO2 (with or without SiO2 and/or CaO) doping increases the hysteresis loss slightly, but SnO2 doping alone reduces the eddy current loss significantly (~14%). The additions of SiO2 or CaO further decrease the eddy current loss, and by interaction of SnO2-CaO-SiO2, the eddy current loss is reduced by more thaN20%. These magnetic and microstructural effects were discussed in terms of the additive-impurity interaction, the existence of grain boundary phases, and the effective bulk and grain boundary resistivities of the ferrites.

  1. SN Refsdal

    DEFF Research Database (Denmark)

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

    2016-01-01

    We have acquired Hubble Space Telescope (HST) and Very Large Telescope near-infrared spectra and images of supernova (SN) Refsdal after its discovery as an Einstein cross in Fall 2014. The HST light curve of SN Refsdal matches the distinctive, slowly rising light curves of SN 1987A-like supernovae...

  2. A Psychobiographical Study of Cao Cao's Personality%曹操人格的心理传记学分析

    Institute of Scientific and Technical Information of China (English)

    谢章明; 解登峰; 刘征宇

    2014-01-01

    通过心理传记学研究探讨曹操的主要人格特点。采用人格形容词评定法和心理传记分析法,结果表明曹操具有“机智勇敢”、“乐观开朗”、“赏罚分明”、“目光远大”、“奸诈狡猾”、“残忍狠毒”六大人格特征。通过对该评定结果与收集到的历史资料进行相互印证,分析曹操人格特征形成的影响因素。%The research explores Cao Cao's personality character-istics and its formation process through psychobiographical study. The result shows that Cao Cao's personality structures consisted of the following factors: "tactful and brave", "optimistic and cheerful","harsh reward and punishment","foresight","treacher-ous and cunning" and "cruel and vicious" six major personality traits. Cao Cao's personality characteristics resulted from the in-teraction of inherited trait and social environment.

  3. APLICABILIDADE DA TEORIA DO CAOS A ORGANIZAÇÕES

    Directory of Open Access Journals (Sweden)

    Ernesto José Vieira

    2015-01-01

    Full Text Available Objetivou-se compreender os fundamentos da Teoria do Caos na gestão das empresas e a existência de elementos típicos dessa teoria nos processos de planejamento, e variáveis controláveis que previnam o caos de ruptura. Além disso, foi também investigado se visão, missão e objetivos corporativos consistem em atratores que evitem a instalação do caos de ruptura; e variáveis e faixas de controle utilizadas pelos dirigentes para evitar o caos de ruptura. A metodologia qualitativa empregou estudo exploratório, para identificar as variáveis e faixas de controle empregadas. Estudaram-se dez empresas da Grande Belo Horizonte. Os resultados validaram as proposições teóricas iniciais, indicando a possibilidade da utilização dos conceitos da Teoria do Caos em mercados altamente competitivos.

  4. Graffiti mochicas en la huaca Cao Viejo, Complejo El Brujo

    Directory of Open Access Journals (Sweden)

    2001-01-01

    Full Text Available GRAFFITI MOCHICA DE LA HUACA CAO VIEJO, COMPLEXE ARCHÉOLOGIQUE DU BRUJO. Sur des murs et colonnes de quatre des sept édifices superposés (E, D, B, A qui forment la huaca Cao Viejo, nous avons identifié des graffitis qui représentent une grande variété de dessins. Nous analysons actuellement leur élaboration, les techniques employées, leur mise en relation, leur chronologie relative, et leur présence dans d’autres sites monumentaux de la côte péruvienne. En las superficies de muros y columnas de cuatro de los siete edificios superpuestos (E, D, B, A que forman la Huaca Cao Viejo, se han identificado graffiti en una amplia variedad de diseños. Se discute el propósito de su elaboración, la técnica, asociaciones, cronología relativa, y su recurrencia en otros sitios monumentales de la costa peruana. MOCHICA GRAFFITI IN HUACA CAO VIEJO, EL BRUJO COMPLEX. On the surfaces and columns of four among seven superimposed phases (E,D,B,A that form the Huaca Cao Viejo, graffiti representing a great variety of designs were discovered. We discuss their relevance, their significance, the techniques used in creating them, their relative chronology, and their use in other monumental buildings on the northern Peruvian coast.

  5. Thermoelasticity of CaO from first principles

    Institute of Scientific and Technical Information of China (English)

    Liu Zi-Jiang; Qi Jian-Hong; Guo Yuan; Chen Qi-Feng; Cai Ling-Cang; Yang Xiang-Dong

    2007-01-01

    The thermoelastic properties of CaO over a wide range of pressure and temperature are studied using density functional theory in the generalized gradient approximation. The transition pressure taken from the enthalpy calculations is 66.7 GPa for CaO, which accords with the experimental result very well. The athermal elastic moduli of the two phases of CaO are calculated as a function of pressure up to 200 GPa. The calculated results are in excellent agreement with existing experimental data at ambient pressure and compared favourably with other pseudopotential predictions over the pressure regime studied. It is also found that the degree of the anisotropy rapidly decreases with pressure increasing in the B1 phase, whereas it strongly increases as the pressure increases in the B2 phase. The thermodynamic properties of the B1 phase of CaO are predicted using the quasi-harmonic Debye model; the heat capacity and entropy are consistent with other previous results at zero pressure.

  6. Coded access optical sensor (CAOS) imager and applications

    Science.gov (United States)

    Riza, Nabeel A.

    2016-04-01

    Starting in 2001, we proposed and extensively demonstrated (using a DMD: Digital Micromirror Device) an agile pixel Spatial Light Modulator (SLM)-based optical imager based on single pixel photo-detection (also called a single pixel camera) that is suited for operations with both coherent and incoherent light across broad spectral bands. This imager design operates with the agile pixels programmed in a limited SNR operations starring time-multiplexed mode where acquisition of image irradiance (i.e., intensity) data is done one agile pixel at a time across the SLM plane where the incident image radiation is present. Motivated by modern day advances in RF wireless, optical wired communications and electronic signal processing technologies and using our prior-art SLM-based optical imager design, described using a surprisingly simple approach is a new imager design called Coded Access Optical Sensor (CAOS) that has the ability to alleviate some of the key prior imager fundamental limitations. The agile pixel in the CAOS imager can operate in different time-frequency coding modes like Frequency Division Multiple Access (FDMA), Code-Division Multiple Access (CDMA), and Time Division Multiple Access (TDMA). Data from a first CAOS camera demonstration is described along with novel designs of CAOS-based optical instruments for various applications.

  7. 20世纪曹操形象诠释综述%A Review of Image Interpretations of Cao Cao in the 20th Century

    Institute of Scientific and Technical Information of China (English)

    郭素媛

    2012-01-01

      With historical changes of the 20th century, interpreters, starting from their respective historical stances, have made distinc-tive interpretations about the image of Cao Cao. Therefore, the image of Cao Cao develops with those rich and colorful interpretations. The interpretative history of the image of Cao Cao in the 20th century is also a historical reality.%  20世纪,随着历史的风云变幻,诠释者从各自的历史性出发对曹操形象做出了带有鲜明时代印记的诠释.曹操形象也在这些丰富多彩的诠释中得到了丰富、发展.20世纪曹操形象的诠释史就是它的存在史.

  8. Introduction à la CAO CADENCE - French version only

    CERN Multimedia

    Davide Vitè

    2002-01-01

    CERN Technical Training Programme: Learning for the LHC ! Dans le cadre du suivi du programme ELEC-2002 : Electronics in HEP, une nouvelle session du cours Introduction à la CAO CADENCE : de la saisie de schéma Concept-HDL au PCB est programmée pour les 10 et 11 décembre prochains. Le cours, en français, est gratuit et sera animé par Serge Brobecker de la division IT/PS/EAS. L'objectif de cette formation est de donner une vue générale du système CAO CADENCE utilisé au CERN, et d'en connaître l'environnement et les possibilités, en acquérant des notions suffisantes pour utiliser la saisie de schéma. Le cours est ciblé pour une audience d'ingénieurs et techniciens désirant utiliser les outils CAO disponibles au CERN, afin de concevoir des circuits logiques et des circuits programmables digitaux. Si vous désirez partic...

  9. The Oxygenase CAO-1 of Neurospora crassa Is a Resveratrol Cleavage Enzyme

    KAUST Repository

    Diaz-Sanchez, V.

    2013-07-26

    The genome of the ascomycete Neurospora crassa encodes CAO-1 and CAO-2, two members of the carotenoid cleavage oxygenase family that target double bonds in different substrates. Previous studies demonstrated the role of CAO-2 in cleaving the C40 carotene torulene, a key step in the synthesis of the C35 apocarotenoid pigment neurosporaxanthin. In this work, we investigated the activity of CAO-1, assuming that it may provide retinal, the chromophore of the NOP-1 rhodopsin, by cleaving β-carotene. For this purpose, we tested CAO-1 activity with carotenoid substrates that were, however, not converted. In contrast and consistent with its sequence similarity to family members that act on stilbenes, CAO-1 cleaved the interphenyl Cα-Cβ double bond of resveratrol and its derivative piceatannol. CAO-1 did not convert five other similar stilbenes, indicating a requirement for a minimal number of unmodified hydroxyl groups in the stilbene background. Confirming its biological function in converting stilbenes, adding resveratrol led to a pronounced increase in cao-1 mRNA levels, while light, a key regulator of carotenoid metabolism, did not alter them. Targeted Δcao-1 mutants were not impaired by the presence of resveratrol, a phytoalexin active against different fungi, which did not significantly affect the growth and development of wild-type Neurospora. However, under partial sorbose toxicity, the Δcao-1 colonies exhibited faster radial growth than control strains in the presence of resveratrol, suggesting a moderate toxic effect of resveratrol cleavage products.

  10. Caos en sistemas clásico-cuánticos

    Science.gov (United States)

    Dirani, L. D.; Núñez, J. A.

    Una de las formas de estudiar la existencia de caos en el comportamiento de un sistema clásico-cuántico, es truncando el espacio de Hilbert del sistema cuántico. El objetivo de este trabajo es analizar como afecta dicho truncamiento en la dinámica del sistema. Para tal fin se propone un Hamiltoniano integrable, cuyos valores de expectación asociados a coordenadas y momentos cuánticos responden, por el teorema de Ehrenfest, a un sistema de dos osciladores clásicos con acoplamiento lineal.

  11. Conference “Computational Analysis and Optimization” (CAO 2011)

    CERN Document Server

    Tiihonen, Timo; Tuovinen, Tero; Numerical Methods for Differential Equations, Optimization, and Technological Problems : Dedicated to Professor P. Neittaanmäki on His 60th Birthday

    2013-01-01

    This book contains the results in numerical analysis and optimization presented at the ECCOMAS thematic conference “Computational Analysis and Optimization” (CAO 2011) held in Jyväskylä, Finland, June 9–11, 2011. Both the conference and this volume are dedicated to Professor Pekka Neittaanmäki on the occasion of his sixtieth birthday. It consists of five parts that are closely related to his scientific activities and interests: Numerical Methods for Nonlinear Problems; Reliable Methods for Computer Simulation; Analysis of Noised and Uncertain Data; Optimization Methods; Mathematical Models Generated by Modern Technological Problems. The book also includes a short biography of Professor Neittaanmäki.

  12. Two Expanding Integrable Models of the Geng-Cao Hierarchy

    Directory of Open Access Journals (Sweden)

    Xiurong Guo

    2014-01-01

    interesting results. In the paper, we will deduce two kinds of expanding integrable models of the Geng-Cao (GC hierarchy by constructing different 6-dimensional Lie algebras. One expanding integrable model (actually, it is a nonlinear integrable coupling reduces to a generalized Burgers equation and further reduces to the heat equation whose expanding nonlinear integrable model is generated. Another one is an expanding integrable model which is different from the first one. Finally, the Hamiltonian structures of the two expanding integrable models are obtained by employing the variational identity and the trace identity, respectively.

  13. Effect of CaO composition on oxidation and burning behaviors of AM50 Mg alloy

    Institute of Scientific and Technical Information of China (English)

    Jin-Kyu LEE; Shae K. KIM

    2011-01-01

    Oxidation and burning behaviors were studied for CaO added AM50 Mg composites which were manufactured by conventional melting and casting processes without SF6 protective gas. CaO added AM50 Mg composites show the stable oxidation resistance. while AM50 Mg alloys show the poor oxidation resistance. The effects of CaO addition on the burning resistance under ambient, nitrogen and dry air atmospheres were examined for CaO added AM50 Mg composites. With increasing CaO addition, the burning temperature increases under ambient, nitrogen and dry air atmospheres. The burning temperatures of small test specimen under all conditions greatly increase even by 0.3% CaO (mass fraction) addition into AM50 Mg alloys.

  14. Complejidad, Caos y Sistemas Biológicos.

    Directory of Open Access Journals (Sweden)

    Jorge Farbiarz F.

    2000-04-01

    Full Text Available

    La física y las matemáticas han sido utilizadas por el hombre para explicar los fenómenos naturales que observa. La teoría del caos y los fractales son términos cada vez mas encontrados en diversos ámbitos sin que la medicina sea una excepción. Con esta revisión, se pretende dar a conocer de manera sencilla y breve, los principales conceptos de la teoría de caos y los fractales y la manera como pueden ser utilizadas como herramientas de estudio de los sistemas biológicos

    Abstract


    Physics and mathematics have been used to explain natural phenomena. Chaos theory and fractals are found frequently in different fields including medicine. With this review, we pretend to explain in a simple way the main concepts of chaos theory and fractals and how they can be used to study biological systems.

  15. Bartleby o la política del caos

    Directory of Open Access Journals (Sweden)

    Andrés Camilo Torres Estrada

    2013-01-01

    Full Text Available El artículo presenta un análisis del cuento de Herman Melville: “Bartleby, el escribiente”. Este análisis parte de un acercamiento a la literatura desde una noción de política inspirada en autores como Jacques Derrida y Jacques Rancière, pero que se aparta de esta filosofía cuando, por encima del propio texto y sus posibilidades, se pretende encontrar en él heterotopías, esperanzas y comunidades por venir. Esta noción de política acerca a la literatura al mundo efectivo, transfigurando los modos de ser y no ser. Así, el personaje de Bartleby se presenta en medio del mundo de la representación como un agente del caos. En esto consiste la política del escribiente: su incursión devela las farsas del mundo construido y soñado por los hombres; pero esta destrucción que causa es inútil: el mundo de la representación ha sentido su absurdo, no sabe qué hacer con dicho agente del caos, pero no es suficiente para arruinarlo. Bartleby, quien se ha indeterminado y ha abandonado las dualidades de ser y no ser, tampoco puede seguir viviendo: ya no hay espacio para la vida sin referencias en un mundo humano y ficticio.

  16. Development of electrically insulating CaO coatings

    Energy Technology Data Exchange (ETDEWEB)

    Natesan, K.; Reed, C.B.; Uz, M.; Rink, D.L. [Argonne National Lab., IL (United States)

    1998-09-01

    A systematic study has been initiated to develop electrically insulating CaO coatings by vapor phase transport and by in-situ formation in a liquid Li environment. Several experiments were conducted in vapor transport studies with variations in process temperature, time, specimen location, specimen surface preparation, and pretreatment. Several of the coatings obtained by the method exhibited Ca concentration in the range of 60--95 wt.% on the surface. However, coating thickness has not been very uniform among several samples exposed in the same run or even within the same sample. The coatings developed in these early tests degraded after 24 h exposure to Li at 500 C. Additional experiments are underway to develop better-adhering and more dense coatings by this method. A program to develop in-situ CaO coatings in Li has been initiated, and the first set of capsule tests at 800 C in three different Li-Ca mixtures will be completed in early July. Specimens included in the run are bare V-4Cr-4Ti alloy, specimens with a grit-blasted surface and O-precharged in 99.999% Ar, polished specimens precharged in a 99.999% Ar and 5000 ppm O{sub 2}-N{sub 2} mixture, and prealuminized V-5Cr-5Ti alloy preoxidized in a 5000 ppm O{sub 2}-N{sub 2} mixture. Additional experiments at lower temperatures are planned.

  17. Effect of CaO on Fluorine in the Decomposition of REFCO3

    Institute of Scientific and Technical Information of China (English)

    Sun Shuchen; Wu Zhiying; Gao Bo; Bian Xue; Wu Wenyuan; Tu Ganfeng

    2007-01-01

    Influence of CaO on thermal decomposition of REFCO3 was studied. The results showed that CaO did not affect significantly the decomposition ratio of REFCO3. The XRD experiment showed that there was a great deal of CaF2 in the roasting production, the gas chromatographic analysis on the gas of REFCO3 decomposed, and the 70% content of fluorine in the gas of REFCO3 added 15% CaO was reduced. CaO could absorb the fluorine from the decomposition of REFCO3, and the environmental pollution of the fluorine was greatly alleviated.

  18. Optical Properties and Electronic Structure of CaO

    Science.gov (United States)

    Sobolev, V. V.; Merzlyakov, D. A.; Sobolev, V. Val.

    2016-09-01

    Spectra of 11 optical functions of CaO in the ranges 6.5-7.2 eV at 2 K and 0-60 eV at 77 K were determined. A total of 14 maxima and shoulders of excitons and interband transitions were found including two distinct exciton structures at 6.9 and 11.4 eV and volume and surface plasmon maxima at ~38.3 and 33.2 eV, respectively. Their principal features and general trends were established. Variable formation efficiencies of spectra of the dielectric permittivity and characteristic electron-energy losses in different spectral ranges were analyzed. The calculations used known experimental reflectance spectra and computer programs based on the Kramers-Kronig correlations and analytical formulae for the relationship between optical functions.

  19. APLICABILIDADE DA TEORIA DO CAOS A ORGANIZAÇÕES

    Directory of Open Access Journals (Sweden)

    VIEIRA, Ernesto Jose

    2014-10-01

    Full Text Available This study seeks to verify if there are typical elements in Chaos Theory in organizations as well as to verify if vision, mission, and objectives consist of attractors which prevent the installation of bifurcation or chaos rupture. In order to respond to these questions, it was necessary to include in this study general in addition to specific objectives. As a support a theoretical reference on Chaos Theory was developed. This theory presents a system with order within an apparently random system with patterns - behaviors which occur more than once, through time. The qualitative methodology utilized exploratory study. Ten companies within Metropolitan Belo Horizonte were studied. The results validated the initial theoretical propositions. En este trabajo se trata de determinar si existen elementos típicos de la teoría del caos en las organizaciones, así como la visión, misión y objetivos consisten en atractores que impiden bifurcación o punto de ruptura instalar. Para responder a estas preguntas, se hizo necesario incluir en este estudio un objetivo general más allá específico.Como apoyo desarrollado un marco teórico sobre la Teoría del Caos.Esta teoría se presenta un sistema con un orden aparentemente aleatoria con las normas - comportamentos que ocurre más de una vez en el tiempo. Entonces-se dirigió a la metodología que se clasifica como cualitativa, a través de un estudio exploratorio para evaluar diez empresas de Gran Belo Horizonte. Se analizaron los datos obtenidos de entrevistas cuando se llegó a la conclusión de que los resultados observados validan las declaraciones iniciales. Este trabalho procura verificar se existem elementos típicos da Teoria do Caos em organizações, assim como se a visão, missão e objetivos consistem em atratores que evitam que a bifurcação ou ponto de ruptura se instale. Para responder à estas perguntas, tornou-se necessário incluir nesta pesquisa um objetivo geral além dos espec

  20. SSC Model Fits to Simultaneous Fermi and CAO observations of Bl Lac's

    Science.gov (United States)

    Gordon, Tyler; Macomb, Daryl J.; Hand, Jared; Norris, Jay P.; Long, Min

    2016-01-01

    The Challis Astronomical Observatory (CAO) has been surveying a sample of blazar-type AGN since 2010. The CAO blazar sample includes4 3 sources - comprising 30 FSRQs, 15 BL Lacs, one radio galaxy and four unclassified sources - covering a redshift range 0.02 Potter and Cotter (MNRAS, 2012, 423, 756-765).

  1. [TG-FTIR study on pyrolysis of wheat-straw with abundant CaO additives].

    Science.gov (United States)

    Han, Long; Wang, Qin-Hui; Yang, Yu-Kun; Yu, Chun-Jiang; Fang, Meng-Xiang; Luo, Zhong-Yang

    2011-04-01

    Biomass pyrolysis in presence of abundant CaO additives is a fundamental process prior to CaO sorption enhanced gasification in biomass-based zero emission system. In the present study, thermogravimetric Fourier transform infrared (TG-FTIR) analysis was adopted to examine the effects of CaO additives on the mass loss process and volatiles evolution of wheat-straw pyrolysis. Observations from TG and FTIR analyses simultaneously demonstrated a two-stage process for CaO catalyzed wheat-straw pyrolysis, different from the single stage process for pure wheat-straw pyrolysis. CaO additives could not only absorb the released CO2 but also reduce the yields of tar species such as toluene, phenol, and formic acid in the first stage, resulting in decreased mass loss and maximum mass loss rate in this stage with an increase in CaO addition. The second stage was attributed to the CaCO3 decomposition and the mass loss and maximum mass loss rate increased with increasing amount of CaO additives. The results of the present study demonstrated the great potential of CaO additives to capture CO2 and reduce tars yields in biomass-based zero emission system. The gasification temperature in the system should be lowered down to avoid CaCO3 decomposition.

  2. Electrodeposition of Ca Metal in CaCl2-CaO Molten Salt

    Institute of Scientific and Technical Information of China (English)

    GUO; Jun-kang; WANG; Chang-shui; CAO; Long-hao; OUYANG; Ying-gen

    2013-01-01

    To realize the continuouscalciothermic reduction in molten salts,the electrodeposition behavior of Ca metal in CaCl2-CaO molten salt was investigated by cylic voltammetry.The cyclic voltammograms at the scan rate of 100 mV/s are shown in Fig.1.As is shown,the electrodeposition potential of Ca deviated from-1.66 V to-0.97 V after CaO was added to molten CaCl2 and the decomposition of CaO

  3. Ordem e caos: um conceito alternativo de mercado

    Directory of Open Access Journals (Sweden)

    Édivo de Almeira Oliveira

    2016-01-01

    Full Text Available Mesmo constituindo-se um dos pilares de funcionamento do sistema capitalista, é bem verdade que o conceito de mercado não é consensual entre as distintas abordagens do pensamento econômico, dado as diferentes premissas e axiomas que fundamentam suas análises. Isto posto, o presente trabalho objetiva fornecer uma concepção holística e mais pragmática do mercado a partir dos conceitos de ordem espontânea, taxas naturais e expectativas racionais articulados com a Teoria do Caos. Com base nesses fundamentos teóricos conclui-se que o mercado é uma ordem espontânea evolutiva, repleta de relações não-lineares e formada por agentes autointeressados que, mediante processo de aprendizagem social, complexificam e aprimoram os padrões institucionais, culturais e técnicos que configuram o próprio mercado no transcorrer de um tempo dinâmico.

  4. [Academic heritage of Jiu huang ben cao (Materia Medica for Relief of Famines) in Japan].

    Science.gov (United States)

    He, Huiling; Xiao, Yongzhi

    2014-11-01

    Jiu huang ben cao (Materia Medica for Relief of Famines) was the first monograph on famines herbal in the history of China, which creates a new research field of edible plants. Around the middle and late 17th century, Jiu huang ben cao was spread to Japan and aroused great attention of famous Japanese herbalists. Thus, all versions of different edition systems were circulated in Japan. Later, some famous Japanese scholar ssuccessively quoted texts of Jiu huang ben cao from the Nong zheng quan shu (Whole book on Agricultural Administration) spread in Japan, and block-printed it as an independent work. As a result, Jiu huang ben cao virtually circulated widely in Japan.

  5. Infrared absorption spectroscopy of hydrogen and deuterium in CaO and SrO crystals

    Energy Technology Data Exchange (ETDEWEB)

    Park, J.L.; Gonzalez, R.

    1989-01-01

    Infrared absorption spectra have been used to characterize OH- and OD- ions at the surface and the bulk of undoped CaO, lithium doped Cao, and SrO crystals. Diffusion of deuterons from D/sub 2/O vapor into these crystals was performed at elevated temperatures. Diffusion coefficients were obtained to be D (CaO) = 3 x 10/sup -6/ cm/sup 2//sec at 1773 K and D(SrO) = 4 x 10/sup -7/ cm/sup 2//sec at 1523 K. For the doped CaO crystal with lithium concentration of 310 ppm, the diffusion coefficient was measured to be D(CaO:Li) = 4 x 10/sup -7/ cm/sup 2//sec at 1473 K and the activation energy in the Arrhenius equation was estimated to be 1.7 eV.

  6. Theoretical Study of Mercury Species Adsorption on CaO(100) Surface

    Science.gov (United States)

    Zhang, Chong; Liu, Yu; Zhao, Li; Cui, Min-Shu; Lu, Qiang

    2017-05-01

    As an important air pollutant, mercury produced by power generation can be captured by CaO incoal-firedfly ash. In order to understand the interaction mechanism of CaO with mercury in HCl atmosphere, the density functional theory method is utilizedto investigate the adsorption of mercury species on the fly ash components. The CaO(100) surface is built to study the stable adsorption configurations of Hg0, HCl, HgCl and HgCl2 on all possible adsorption sites. The results show that CaO(100) surface cannot absorb Hg0 directly, but the intermediate HgCl can be adsorbed on the surface stably, and then continue to combine with a Cl radical to produce HgCl2, which is easy to be removed.

  7. Influence of NaCl-CaCl2 on Decomposing REPO4 with CaO

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The influence of NaCl-CaCl2 on thermal decomposition of REPO4 (RE: Ce, La, Nd, Th) with CaO was studied.The heat decomposing process of REPO4 was tested with TG-DTA experiments.The results showed that the decomposition temperature of REPO4 with CaO was reduced because of adding NaCl-CaCl2 mixture (NaCl:CaCl2=1:1).The influence of the addition of NaCl-CaCl2, roasting temperature and roasting time on decomposition ratio of REPO4 with CaO was studied.The results showed that the decomposition ratio of REPO4with CaO was 79% when the addition percentage of NaCl-CaCl2 was 10%, the roasting temperature was 750℃, and the roasting time was 1 h.

  8. 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.

  9. Correlation effects in MgO and CaO Cohesive energies and lattice constants

    CERN Document Server

    Doll, K; Stoll, H; Doll, Klaus; Dolg, Michael; Stoll, Hermann

    1996-01-01

    A recently proposed computational scheme based on local increments has been applied to the calculation of correlation contributions to the cohesive energy of the CaO crystal. Using ab-initio quantum chemical methods for evaluating individual increments, we obtain 80% of the difference between the experimental and Hartree-Fock cohesive energies. Lattice constants corrected for correlation effects deviate by less than 1% from experimental values, in the case of MgO and CaO.

  10. Phase Composition and Thermal Expansion of CaO Stabilised ZrO2 Refactories

    Institute of Scientific and Technical Information of China (English)

    ZHAOShike; WUJingyuan; 等

    2000-01-01

    In this,phase compsition and thermal expansion behaviour of CaO Stabilised refractories were studied,Special attention was paid to the expasion behaviour of three materials with different phase composition,The research results indicated that the expansion behaviour could be improved by modifying the stabilization of ZrO2,which thus leads to the increase in the thermal shock resistance and possibly eroion resistace of as-obtained CaO stabilised ZrO material.

  11. Experimental Study on Pore Distribution Characters and Convert Rate of CaO

    Institute of Scientific and Technical Information of China (English)

    Li JIA; Yanyan ZENG; Tao ZHANG

    2005-01-01

    During the reaction between calcium sorbents and SO2, calcium sorbents are first calcined and converted into CaO. CaO can be obtained by calcining Ca(OH)2 or CaCO3. The porosity of the sorbent is increased because of calcination and is decreased because of sulfurization. In the calcination process H2O or CO2 is escaped from the particles and pores are formed in particles. The reaction or convert rate of CaO is influenced strongly by the pore structure characters. From Ca(OH)2 to CaO the escape velocity of H2O or its mass transfer is one of the key factors influencing the pore forming. During calcination process different heating velocity, different heating time and temperature were suggested. The temperature rising rate and calcining temperature play important role to the pore structure. The convert rates of CaO obtained through different calcining conditions were investigated experimentally. Some interesting results were showed that the calcium utilization of CaO particles is determined not only by the special surface area and total pore volume, but also by pore-size distribution. The main factor influencing the sulfation is the pore diameter distribution at lower sulfation temperature. For higher reaction temperature specific volume is the important reason. But pore-size distribution is strongly influenced by heat flux and temperature in the calcining process.

  12. Inspiration that Cao Cao Humanism Management Thoughts to Modern Enterprise%曹操人本管理思想对现代企业的启示

    Institute of Scientific and Technical Information of China (English)

    黄巍

    2012-01-01

    Three kingdoms period, Cao Cao is leaders that cherish talents. His thinking of human capital control that only is uses and reward and punishment has a great effect on the later world. Cao Cao humanism management thoughts have enlightenment to improve the modern enterprise management ability. It requires enterprise managers to set up Bole consciousness and promote ability of commander, set up tolerant consciousness and overcome demand perfection on employment, set up respect consciousness and establish reward and punishment incentive mechanism talent.%曹操是三国时期著名的爱才惜才的领导人,他“唯才是举、因材授任、赏罚分明”的人力资本管控思想对后世影响深远。曹操人本管理思想对提升现代企业管理能力有诸多启示,它要求我们时下的企业管理者要树立“伯乐”意识,提升“将才”之能;要树立“包容”意识,克服“求全责备”的用人观;要树立“尊重”意识,建立“赏罚分明”的人才激励机制。

  13. CAOS: the nested catchment soil-vegetation-atmosphere observation platform

    Science.gov (United States)

    Weiler, Markus; Blume, Theresa

    2016-04-01

    Most catchment based observations linking hydrometeorology, ecohydrology, soil hydrology and hydrogeology are typically not integrated with each other and lack a consistent and appropriate spatial-temporal resolution. Within the research network CAOS (Catchments As Organized Systems), we have initiated and developed a novel and integrated observation platform in several catchments in Luxembourg. In 20 nested catchments covering three distinct geologies the subscale processes at the bedrock-soil-vegetation-atmosphere interface are being monitored at 46 sensor cluster locations. Each sensor cluster is designed to observe a variety of different fluxes and state variables above and below ground, in the saturated and unsaturated zone. The numbers of sensors are chosen to capture the spatial variability as well the average dynamics. At each of these sensor clusters three soil moisture profiles with sensors at different depths, four soil temperature profiles as well as matric potential, air temperature, relative humidity, global radiation, rainfall/throughfall, sapflow and shallow groundwater and stream water levels are measured continuously. In addition, most sensors also measure temperature (water, soil, atmosphere) and electrical conductivity. This setup allows us to determine the local water and energy balance at each of these sites. The discharge gauging sites in the nested catchments are also equipped with automatic water samplers to monitor water quality and water stable isotopes continuously. Furthermore, water temperature and electrical conductivity observations are extended to over 120 locations distributed across the entire stream network to capture the energy exchange between the groundwater, stream water and atmosphere. The measurements at the sensor clusters are complemented by hydrometeorological observations (rain radar, network of distrometers and dense network of precipitation gauges) and linked with high resolution meteorological models. In this

  14. Combined effects of Fenton peroxidation and CaO conditioning on sewage sludge thermal drying.

    Science.gov (United States)

    Liu, Huan; Liu, Peng; Hu, Hongyun; Zhang, Qiang; Wu, Zhenyu; Yang, Jiakuan; Yao, Hong

    2014-12-01

    Joint application of Fenton's reagent and CaO can dramatically enhance sludge dewaterability, thus are also likely to affect subsequent thermal drying process. This study investigated the synergistic effects of the two conditioners on the thermal drying behavior of sewage sludge and the emission characteristics of main sulfur-/nitrogen-containing gases. According to the results, Fenton peroxidation combined with CaO conditioning efficiently promoted sludge heat transfer, reduced the amounts of both free and bound water, and created porous structure in solids to provide evaporation channels, thus producing significant positive effects on sludge drying performance. In this case, the required time for drying was shortened to one-third. Additionally, joint usage of Fenton's reagent and CaO did not increase the losses of organic matter during sludge drying process. Meanwhile, they facilitated the formation of sulfate and sulfonic acid/sulfone, leading to sulfur retention in dried sludge. Both of Fenton peroxidation and CaO conditioning promoted the oxidation, decomposition, and/or dissolution of protein and inorganic nitrogen in sludge pre-treatment. As a consequence, the emissions of sulfurous and nitrogenous gases from dewatered sludge drying were greatly suppressed. These indicate that combining Fenton peroxidation with CaO conditioning is a promising strategy to improve drying efficiency of sewage sludge and to control sulfur and nitrogen contaminants during sludge thermal drying process.

  15. Study on rapid bio-drying technology of cow dung with CaO2

    Science.gov (United States)

    Chen, Xiaotian; Qu, Guangfei; Liu, Shugen; Xie, Ruosong; He, Yanhua

    2017-05-01

    Effect of CaO2 on cow dung rapid bio-drying technology was researched. A static aerobic composting system was applied to this experiment which combining natural ventilation with Turing in the process of composting. The physical characteristics of cow dung was observed and the compost temperature, moisture content, organic matter, total nitrogen, total phosphorus, potassium content was determined which in order to study the effect of CaO2 on rapid drying of cattle in the compost. In the initial stage of compost, adding CaO2 groups compared with the control group, the temperature rise faster, 4-6 days in advance to the thermophilic phase; at the end of composting, the CaO2 composition and moisture content decreased significantly to below 30%. The addition of CaO2 in fertilizer was shorten the composting time, extend the thermophilic phase, to provide sufficient oxygen meeting the growth needs of aerobic microorganisms. It convinced that the rapid bio-drying of dairy manure has a good effect and provided a new idea for the effective treatment of cow dung.

  16. New pyrometallurgical process of EAF dust treatment with CaO addition

    Institute of Scientific and Technical Information of China (English)

    Romchat Chairaksa-Fujimoto; Yosuke Inoue; Naoyoshi Umeda; Satoshi Itoh; Tetsuya Nagasaka

    2015-01-01

    The non-carbothermic zinc pyrometallurgical processing of electric arc furnace (EAF) dust was investigated on a laboratory scale. The main objective of this process was to convert highly stable zinc ferrite (ZnFe2O4), which accounts for more than half of total zinc in the EAF dust, into ZnO and Ca2Fe2O5 by CaO addition. The EAF dust was mixed with CaO powder in various ratios, pressed into pellets, and heated in a muffle furnace in air at temperatures ranging from 700 to 1100°C for a predetermined holding time. All ZnFe2O4 was transformed into ZnO and Ca2Fe2O5 at a minimum temperature of 900°C within 1 h when sufficient CaO to achieve a Ca/Fe molar ratio of 1.1 was added. However, at higher temperatures, excess CaO beyond the stoichiometric ratio was required because it was consumed by reactions leading to the formation of compounds other than ZnFe2O4. The evaporation of halides and heavy metals in the EAF dust was also studied. These components could be pref-erentially volatilized into the gas phase at 1100°C when CaO was added.

  17. Simultaneous carbonation and sulfation of CaO in Oxy-Fuel CFB combustion

    Energy Technology Data Exchange (ETDEWEB)

    Wang, C. [School of Energy and Power Engineering, North China Electric Power University, Baoding City, Hebei Province (China); Jia, L.; Tan, Y. [CanmetENERGY, 1 Haanel Drive, Ottawa, Ontario, K1A 1M1 (Canada)

    2011-10-15

    For anthracites and petroleum cokes, the typical combustion temperature in a circulating fluidized bed (CFB) is > 900 C. At CO{sub 2} concentrations of 80-85 % (typical of oxy-fuel CFBC conditions), limestone still calcines. When the ash which includes unreacted CaO cools to the calcination temperature, carbonation of fly ash deposited on cool surfaces may occur. At the same time, indirect and direct sulfation of limestone also will occur, possibly leading to more deposition. In this study, CaO was carbonated and sulfated simultaneously in a thermogravimetric analyzer (TGA) under conditions expected in an oxy-fuel CFBC. It was found that temperature, and concentrations of CO{sub 2}, SO{sub 2}, and especially H{sub 2}O are important factors in determining the carbonation/sulfation reactions of CaO. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  18. PROPERTIES OF CaO SINTERED WITH ADDITION OF ACTIVE ALUMINA

    Directory of Open Access Journals (Sweden)

    A. Miskufova

    2015-06-01

    Full Text Available This work provides research and evaluation of the influence of active gama alumina addition on green and sintered CaO material properties, microstructures and mineralogical phase formation. Experimental results have shown the possibility to prepare more stable CaO with excellent properties by energy saving one-stage burning process of natural ground limestone with small addition of γ-Al2O3 (1 wt. % at up to 1550oC for two hours. The additive caused increasing of the sintered density but especially significant decreasing of apparent porosity of CaO. X-ray diffraction and energy dispersive X-ray fluorescence analysis confirmed mainly the presence of 3CaO∙ Al2O3 on the grain boundaries. Formation of other phases during sintering, more specifically 12CaO∙7 Al2O3 and CaO∙6 Al2O3 with lower tendency to hydration was also proved.

  19. Highly active CaO for the transesterification to biodiesel production from rapeseed oil

    Directory of Open Access Journals (Sweden)

    Ying Tang

    2011-04-01

    Full Text Available The catalytic performance of commercial CaO modified by trimethylchlorosilane (TMCS for transesterification of rapeseed oil and methanol to biodiesel production was studied. It was found that the fatty acid methyl esters (FAME yield of the modified CaO was greatly enhanced from 85.4% to 94.6% under 65 oC with 15:1 molar ratios of methanol/oil by using 5 wt.% catalyst (weight to oil. The possible reason lies on promoting the absorption of grease to modified CaO surface. Both the characterization of the catalyst and the effects of various factors such as mass ratio of catalyst to oil, reaction temperature and molar ratio of methanol to oil were investigated.

  20. Zerovalent Selenium Adsorption Mechanisms on CaO Surface: DFT Calculation and Experimental Study.

    Science.gov (United States)

    Fan, Yaming; Zhuo, Yuqun; Zhu, Zhenwu; Du, Wen; Li, Liangliang

    2017-10-05

    Zerovalent Se (Se atom and small Se2 molecule) adsorption mechanisms on a CaO surface were studied by both density functional theory (DFT) calculations and adsorption experiments. Nonvalent Se adsorption on the CaO(001) surface was simulated using a slab model. The adsorption energy, adsorption structure, electron density clouds, and electron properties were calculated. Different Se surface coverages were investigated to elucidate the adsorption process. In the experiments, the Se adsorption products were prepared in a U-shaped quartz reactor at 300 °C. The properties were investigated by X-ray photoelectron spectroscopy (XPS), inductively coupled plasma atomic emission spectroscopy (ICP-AES), field emission scanning electron microscopy/energy dispersive X-ray spectroscopy (FE-SEM/EDS), and X-ray diffraction (XRD), respectively. The experimental results match up with the DFT results, which reveal fundamental monochemisorption mechanisms of zerovalent Se on the CaO surface.

  1. Effect of CaO content on residual stress of CAS glass-ceramic

    Institute of Scientific and Technical Information of China (English)

    XIE Jun; CHENG Jin-shu; LONG Xin-jiang; YANG Shu-zhen

    2006-01-01

    The mismatch in thermal expansion coefficient between crystalline phase and glass phase can result in large thermal stresses during thermal processing,as well as the low thermal conductivity,which is the most troublesome in the production of the CaO-Al2O3-SiO2 glass-ceramic. CaO content may influence the residual stress in the system. Therefore X-ray diffraction (XRD) 'sin2ψ' method was used to calculate the residual stress in samples containing various contents of CaO. The relationship between CaO content and residual stress in CAS system was investigated. Finally reasons causing such residual stress were analyzed.

  2. Formation of Water Chains on CaO(001): What Drives the 1D Growth?

    Science.gov (United States)

    Zhao, Xunhua; Shao, Xiang; Fujimori, Yuichi; Bhattacharya, Saswata; Ghiringhelli, Luca M; Freund, Hans-Joachim; Sterrer, Martin; Nilius, Niklas; Levchenko, Sergey V

    2015-04-02

    Formation of partly dissociated water chains is observed on CaO(001) films upon water exposure at 300 K. While morphology and orientation of the 1D assemblies are revealed from scanning tunneling microscopy, their atomic structure is identified with infrared absorption spectroscopy combined with density functional theory calculations. The latter exploit an ab initio genetic algorithm linked to atomistic thermodynamics to determine low-energy H2O configurations on the oxide surface. The development of 1D structures on the C4v symmetric CaO(001) is triggered by symmetry-broken water tetramers and a favorable balance between adsorbate-adsorbate versus adsorbate-surface interactions at the constraint of the CaO lattice parameter.

  3. [Quantitative estimation of CaO content in surface rocks using hyperspectral thermal infrared emissivity].

    Science.gov (United States)

    Zhang, Li-Fu; Zhang, Xue-Wen; Huang, Zhao-Qiang; Yang, Hang; Zhang, Fei-Zhou

    2011-11-01

    The objective of the present paper is to study the quantitative relationship between the CaO content and the thermal infrared emissivity spectra. The surface spectral emissivity of 23 solid rocks samples were measured in the field and the first derivative of the spectral emissivity was also calculated. Multiple linear regression (MLR), principal component analysis (PCR) and partial least squares regression (PLSR) were modeled and the regression results were compared. The results show that there is a good relationship between CaO content and thermal emissivity spectra features; emissivities become lower when CaO content increases in the 10.3-13 mm region; the first derivative spectra have a better predictive ability compared to the original emissivity spectra.

  4. Desulphurization during VIM Refining Ni-base Superalloy using CaO Crucible

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The variation of S content during VIM refining Ni-base superalloy using CaO crucible was stud[ed. It was foundthat the desulphurization process could not be carried out by only using CaO crucible. The role of Al additionto desulphurization was also studied. Combining with the results of XRD and composition analysis of the CaOcrucible, the mechanism of desulphurization was proposed. Thermodynamical calculation about the reaction betweenthe interface of CaO crucible and liquid metal has been discussed. This work indicated that under proper refiningtechnology the S content in the liquid Ni-base alloy could be reduced from 3×10-5 to 2×10-6~4×10-6.

  5. An Exploration into the Cao Cao's Poem English Translation of Turtles Live long%四言古诗《龟虽寿》的英译初探

    Institute of Scientific and Technical Information of China (English)

    万兵

    2012-01-01

    There are varied versions of the English translation of the Chinese classical poem Turtles Live long,composed by Cao Cao, a famous poet and King of Wei in the Three Kingdoms era. Professor Zhao Yanchun's version, actually a trinity of imitation, consistency and variability, has a theoretical awareness con-cerning the translation of Chinese poetry into English.%三国诗人曹操《龟虽寿》的英译,已经有多个版本面世。赵彦春教授的译本独树一帜,其译品实为模仿性、一致性、变异性的三位一体,具有译诗理论上的自觉。

  6. Application of Chinese Jun-Cao technique for the production of Brazilian Ganoderma lucidum strains

    Directory of Open Access Journals (Sweden)

    Leonardo do Nascimento Rolim

    2014-06-01

    Full Text Available Ganoderma lucidum is a medicinal mushroom traditionally used in China against a wide range of diseases such as cancer and also for its prevention. In this work, commercial Chinese strains G. lucidum were compared to wild Brazilian strains aiming to determine the cultivation potential through the use of Jun-Cao. Six formulations were tested and the strains presented good response to the applied method. In general, the mixture between the grass and wood was well suited for the basidiomycetes, contributing to the preparation of substrates that generated better results in Jun Cao.

  7. Los azules tigres del caos. Un vistazo al pensamiento de la complejidad en la obra de Jorge Luis Borges

    OpenAIRE

    Mata, Esteban

    2010-01-01

    El siguiente ensayo discute algunos temas relacionados con la ciencia dentro de la narrativa de Jorge Luis Borges; en especial aquellos concernientes a la teoría del caos y la dificultad -para el entendimiento humano- de discernir un orden en medio del caos, situación propia de todos los sistemas complejos.

  8. Active Heterogeneous CaO Catalyst Synthesis from Anadara granosa (Kerang Seashells for Jatropha Biodiesel Production

    Directory of Open Access Journals (Sweden)

    Reddy ANR

    2017-01-01

    Full Text Available Heterogeneous catalysts are often used at large to produce biodiesel from non-edible vegetable crude oils such as Jatropha curcas oil (JCO. In this study, an active heterogeneous CaO catalyst was synthesized from a tropical biodiversity seashells Anadara granosa (A.granosa. The catalytic efficiency of A.granosa CaO was investigated in transesterification of JCO as biodiesel. The A.granosa CaO catalyst was synthesized using ‘Calcination – hydration – dehydration’ protocol. The spectral characterization of the catalyst were investigated by employing FT-IR, SEM, BET and BJH spectrographic techniques. The experimental design was executed with four reaction parameters that include catalyst concentration (CC, methanol ratio (MR, transesterification time (TT and reaction temperature (RT. The JCO transesterification reactions as well as impact of reaction parameters on the Jatropha biodiesel yield (JBY were analyzed. The sufficiency of the experimental results conformed through sequential validation tests, as a result, an average of 96.2% JMY was noted at optimal parametric conditions, CC of 3wt. %, TT of 120 min, MR of 5 mol. and RT of 60ºC at a constant agitation speed of 300rpm. An average JMY of 87.6% was resulted from the A.granosa CaO catalyst during their recycling and reuse studies up to third reuse cycle.

  9. Evaluation of antibacterial activity of plant mediated CaO nanoparticles using Cissus quadrangularis extract.

    Science.gov (United States)

    Marquis, Gowdhami; Ramasamy, Balagurunathan; Banwarilal, Sarkar; Munusamy, Ayyasamy Pudukadu

    2016-02-01

    An assessment of antibacterial activity of greenly synthesized nanoparticles using aqueous stem extract of Cissus quadrangularis was carried out. The synthesized nanoparticles were characterized by UV-Vis spectroscopy, SEM, XRD, FTIR and further subjected for antibacterial activity against the pathogens Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, Shigella dysenteriae and Vibrio cholerae. The SEM photograph represents cubic and hexagonal shape of NPs about 58nm respectively whereas the XRD indicated the pure phase of the product and no impurity in peaks of well crystallized products. The FTIR spectrum of nanoparticles showed intensive peaks with blue shift indicating the crystalline and shorten the distance of crystal lattice. The plant mediated CaO nanoparticles showed maximum inhibition on E. coli followed by other strains. In MIC, the plant mediated CaO NPs possess high activity against all the test organisms whereas the CaCl2 and CaO compounds were moderately active. The approach to the synthesis of plant mediated CaO NPs has many advantages as scaled up, economic viability, etc. Application of such ecofriendly nanoparticles in bactericidal, wound healing and other medical applications makes this method potential existing for the large scale synthesis of the inorganic materials.

  10. Highly basic CaO nanoparticles in mesoporous carbon materials and their excellent catalytic activity.

    Science.gov (United States)

    Raja, Pradeep Kumar; Chokkalingam, Anand; Priya, Subramaniam V; Balasubramanian, Veerappan V; Benziger, Mercy R; Aldeyab, Salem S; Jayavell, Ramasamy; Ariga, Katsukiho; Vinu, Ajayan

    2012-06-01

    Highly basic CaO nanoparticles immobilized mesoporous carbon materials (CaO-CMK-3) with different pore diameters have been successfully prepared by using wet-impregnation method. The prepared materials were subjected to extensive characterization studies using sophisticated techniques such as XRD, nitrogen adsorption, HRSEM-EDX, HRTEM and temperature programmed desorption of CO2 (TPD of CO2). The physico-chemical characterization results revealed that these materials possess highly dispersed CaO nanoparticles, excellent nanopores with well-ordered structure, high specific surface area, large specific pore volume, pore diameter and very high basicity. We have also demonstrated that the basicity of the CaO-CMK-3 samples can be controlled by simply varying the amount of CaO loading and pore diameter of the carbon support. The basic catalytic performance of the samples was investigated in the base-catalyzed transesterification of ethylacetoacetate by aryl, aliphatic and cyclic primary alcohols. CMK-3 catalyst with higher CaO loading and larger pore diameter was found to be highly active with higher conversion within a very short reaction time. The activity of 30% CaO-CMK3-150 catalyst for transesterification of ethylacetoacetate using different alcohols increases in the following order: octanol > butanol > cyclohexanol > benzyl alcohol > furfuryl alcohol.

  11. Finding fatigue resistant and lightweight designs using the optimization methods CAO and SKO

    Science.gov (United States)

    Mattheck, C.; Walther, Frank; Baumgartner, A.

    1992-07-01

    Computer Aided Optimization (CAO), a new method of shape optimization based on the computer simulation of biological growth and Soft Kill Option (SKO), and a strategy to find new design solutions with reduced weight are presented. CAO is used to improve the design of technical components by gaining a homogenized stress distribution on the surface of two and three dimensional finite element models. SKO helps to define new topologies starting from a general oversized 'design area'. With CAO it is also possible to simulate the 'adaptive growth' of biological load carriers, while SKO simulates the mineralization process of bones adapted to their loading. The main ideas of the methods are outlined and several examples of optimizations are shown. If completely new solutions for technical problems are desired, SKO is used first and the design proposal being found is then optimized by CAO in order to achieve a lightweight and fatigue resistant design. The efficiency of the combination of the two methods as a complete layout procedure is shown.

  12. Food selection in relation to nutritional chemistry of Cao Vit gibbons in Jingxi, China.

    Science.gov (United States)

    Ma, Changyong; Liao, Jiancun; Fan, Pengfei

    2017-01-01

    The Cao Vit gibbon (Nomascus nasutus) has only one population with about 110 individuals living in a degraded karst forest along the China-Vietnam border. Investigation of food choice in relation to chemical nutrition will offer important insights into its conservation. We studied the food choice of two groups of Cao Vit gibbons using instantaneous scan sampling in Bangliang National Nature Reserve, Guangxi, China, over 4 years, and analyzed the chemical components (total nitrogen, TN; water-soluble sugar, WSS; crude fat, CF; neutral detergent fiber, NDF; acid detergent fiber, ADF; acid detergent lignin, ADL; condensed tannin, CT; and ash) of 48 food plant parts and 22 non-food plant parts. Fruits and figs that are rich in sugar are important food resources for gibbons. For other food types, flowers are a good source of total nitrogen and carbohydrates, and leaves and buds provide sources of protein and minerals. Cao Vit gibbons selected fruits that contain less total nitrogen, less acid detergent fiber and more water-soluble sugar than non-food fruits. Several food species that were heavily consumed by Cao Vit gibbons are suggested as potential tree species for ongoing habitat restoration.

  13. CaO as Drop-In Colloidal Catalysts for the Synthesis of Higher Polyglycerols

    NARCIS (Netherlands)

    Kirby, Fiona; Nieuwelink, Anne Eva; Kuipers, Bonny W M; Kaiser, Anton; Bruijnincx, Pieter C A; Weckhuysen, Bert M.

    2015-01-01

    Glycerol is an attractive renewable building block for the synthesis of polyglycerols, which find application in the cosmetic and pharmaceutical industries. The selective etherification of glycerol to higher oligomers was studied in the presence of CaO colloids and the data are compared with those o

  14. Effect of CaO doping on mechanical properties and thermal shock resistance of 10NiO-NiFe2O4 composite ceramics

    Institute of Scientific and Technical Information of China (English)

    LAI Yan-qing; ZHANG Yong; ZHANG Gang; TIAN Zhong-liang; LI Jie

    2008-01-01

    The CaO doped 10NiO-NiFe2O4 composite ceramics were prepared by the cold isostatic pressing-sintering process, and the effects of CaO content on the phase composition, mechanical property and thermal shock resistance of 10NiO-NiFe2O4 composite ceramics were studied. The results show that the samples mainly consist of NiO and NiFe2O4 when content of CaO is less than4%(mass fraction), bending strength increases obviously by CaO doping. Bending strength of the samples doped with 2% CaO is above 185 Mpa, but that of the samples without CaO is only 60 Mpa. Fracture toughness is improved obviously by CaO doping, the undoped ceramics. CaO doping is bad to thermal shock resistance of 10NiO-NiFe2O4 composite ceramics.

  15. Caos sensible : orden y caos en la construcción de los proyectos de creación en las artes plásticas

    OpenAIRE

    Rabazas Romero, Antonio

    2012-01-01

    Este estudio trata de establecer relaciones entre algunas conceptos que consideramos relevantes alrededor de las nociones de orden y caos. La elección viene justificada por su amplitud conceptual y su máxima transversalidad, pues se originan en la misma raíz del conocimiento. Dado que el Arte maneja realidades complejas y objetos confusos o mal definidos, consideramos importante el conocimiento y uso de estas nociones en un entorno de aprendizaje, a través de una óptica proyectual. Se plantea...

  16. Non-isothermal Crystallization Kinetics of Spinels in Vanadium Slag with High CaO Content

    Science.gov (United States)

    Zhou, Wang; Xie, Bing; Tan, Wen-Feng; Diao, Jiang; Zhang, Xie; Li, Hong-Yi

    2016-09-01

    This paper investigated the non-isothermal crystallization kinetics of the spinel crystals in vanadium slags containing high CaO content. Experiments were performed in combination with theoretical calculation to address this issue, and statistical analyses based on the Crystal Size Distribution theory. The results indicate that low cooling rate and high CaO content benefit the growth of spinel crystals. The growth mechanism is revealed to be controlled by interface reactions and diffusion at the cooling rates of 5 K/min and 15 K/min, respectively. However, at higher temperatures (>1673 K), the growth of spinel crystals is controlled by nucleation. While the temperature is decreased to 1523 K at the cooling rate of 5 K/min, the mean diameter of spinel crystals could reach 36.44 μm. Experimental results combining with theoretical reveal that low cooling rate benefits spinels growth, especially for the interval of 1523 K-1200 K.

  17. LA TEORÍA DEL CAOS... ESA NUBE TURBULENTA QUE DA QUÉ PENSAR

    Directory of Open Access Journals (Sweden)

    Rubén Antonio Sánchez Godoy

    1999-01-01

    Full Text Available Este texto plantea algunos de los problemas suscitados por la teoria del caos. Es decir, pretende mostrar algunas de las cuestiones que han surgido apartir de la formulación de un modo de obtención de conocimiento que parece tener ventajas sobre otros y según algunos de sus difusores, constituye una revolución en la práctica y el saber cientificos. En consecuencia, presentaremos a continuación un panorama de estos ploblemas 01 tanto que, por una parte, nos muesmi las posibilidades y los límites de dicha teona y , por otra, nos indican en qué sentido la teoría del caos puede dar qué pensar.

  18. Kinetic study of CO2 reaction with CaO by a modified random pore model

    Directory of Open Access Journals (Sweden)

    Nouri S.M.M.

    2016-03-01

    Full Text Available In this work, a modified random pore model was developed to study the kinetics of the carbonation reaction of CaO. Pore size distributions of the CaO pellets were measured by nitrogen adsorption and mercury porosimetry methods. The experiments were carried out in a thermogravimeter at different isothermal temperatures and CO2 partial pressures. A fractional concentration dependency function showed the best accuracy for predicting the intrinsic rate of reaction. The activation energy was determined as 11 kcal/mole between 550–700°C. The effect of product layer formation was also taken into account by using the variable product layer diffusivity. Also, the model was successfully predicted the natural lime carbonation reaction data extracted from the literature.

  19. El caos en los barrios de la frontera en la obra narrativa de L. H. Crosthwaite

    Directory of Open Access Journals (Sweden)

    Mara Donat

    2013-07-01

    Full Text Available If apocalypse is a metaphor of the end and the beginning of an age, collapse of cultural, political and social concepcions, construction of new identities and social realities, literature of “frontera norte de México” is good to realize an investigation of the biblical and mythical theme in postmodern sence. Colapsing any idea of legal and civil life in a national State, urban culture of “la Frontera” presents the social caos of ilegal and criminal conducts, as much es gendre violence and the political idea of national identity in crisis. México protagonize a contradiction between nacionalist pride, frontier defence and emigration to the Unites States, with apocalyptical implication these days. The narrative of Luis Humberto Crosthwaite permit to analyze the different representations of broken identity in the social caos of the frontier. The apocalypsis as inminent catastrophe, social insicurity and uncertain identity leads the individual to new urban and social representations.

  20. Biodiesel Production by Using CaO Catalyst and Ultrasonic Assisted

    Science.gov (United States)

    Widayat, W.; Darmawan, T.; Rosyid, R. Ar; Hadiyanto, H.

    2017-07-01

    Biodiesel is an alternative energy and sustainable products. Biodiesel can be produced from vegetable oil by using homogenous and heterogenous catalyst. In this research, biodiesel was produced by using CaO catalyst from limestone and assisted by ultrasonic wave. CaO catalyst was used 1- 4.4% of oil weight. Ultrasonic wave was generated by using ultrasonic cleaner at 28 and 42 kHz of frequency. Cooking oil was preparated by esterification process by using sulphuric acid as catalyst until amount of free fatty acid (FFA) is under 0.5%. The results shown yield of methyl ester obtained highest 89.98% on the reaction carried on mole ratio methanol to oil, 9: 1 and frequency of 40 kHz. Increasing frequency of ultrasonic wave cause increasing of yield of biodiesel.

  1. Tricalcium phosphate based resorbable ceramics: Influence of NaF and CaO addition

    Energy Technology Data Exchange (ETDEWEB)

    Seeley, Zachary; Bandyopadhyay, Amit [W. M. Keck Biomedical Materials Research Lab, School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164 (United States); Bose, Susmita [W. M. Keck Biomedical Materials Research Lab, School of Mechanical and Materials Engineering, Washington State University, Pullman, WA 99164 (United States)], E-mail: sbose@wsu.edu

    2008-01-10

    Resorbable bioceramics have gained much attention due to their time-varying mechanical properties in-vivo. Implanted ceramics degrade allowing bone in-growth and eventual replacement of the artificial material with natural tissue. Calcium phosphate based materials have caught the most significant attention because of their excellent biocompatibility and compositional similarities to natural bone. Doping these ceramics with various metal ions has significantly influenced their properties. In this study, tricalcium phosphate (TCP) compacts were fabricated via uniaxial compression with five compositions: (i) pure TCP, (ii) TCP with 2.0 wt.% NaF, (iii) TCP with 3.0 wt.% CaO, (iv) TCP with a binary of 2.0 wt.% NaF and 0.5 wt.% Ag{sub 2}O, and (v) TCP with a quaternary of 1.0 wt.% TiO{sub 2}, 0.5 wt.% Ag{sub 2}O, 2.0 wt.% NaF, and 3.0 wt.% CaO. These compacts were sintered at 1250 deg. C for 4 h to obtain dense ceramic structures. Phase analyses were carried out using X-ray diffraction. The presence of NaF in TCP improved densification and increased compression strength from 70 ({+-} 25) to 130 ({+-} 40) MPa. Addition of CaO had no influence on density or strength. Human osteoblast cell growth behavior was studied using an osteoprecursor cell line (OPC 1) to assure that the biocompatibility of these ceramics was not altered due to the dopants. For long-term biodegradation studies, density, weight change, surface microstructure, and uniaxial compression strength were measured as a function of time in a simulated body fluid (SBF). Weight gain in SBF correlated strongly with precipitation viewed in the inter-connected pores of the samples. After 3 months in SBF, all samples displayed a reduction in strength. NaF, CaO and the quaternary compositions maintained the most steady strength loss under SBF.

  2. Initial stages of CO2 adsorption on CaO: a combined experimental and computational study.

    Science.gov (United States)

    Solis, Brian H; Cui, Yi; Weng, Xuefei; Seifert, Jan; Schauermann, Swetlana; Sauer, Joachim; Shaikhutdinov, Shamil; Freund, Hans-Joachim

    2017-02-08

    Room temperature adsorption of carbon dioxide (CO2) on monocrystalline CaO(001) thin films grown on a Mo(001) substrate was studied by infrared reflection-absorption spectroscopy (IRAS) and quantum chemical calculations. For comparison, CO2 adsorption was examined on poorly ordered, nanoparticulate CaO films prepared on Ru(0001). For both systems, CO2 readily adsorbs on the clean CaO surface. However, additional bands were observable on the CaO/Ru(0001) films compared with CaO/Mo(001), because the stricter IRAS surface selection rules do not apply to adsorption on the disordered thin films grown on Ru(0001). Spectral evolution with increasing exposure of the IRA bands suggested the presence of several adsorption sites which are consecutively populated by CO2. Density functional calculations showed that CO2 adsorption occurs as monodentate surface carbonate (CO3(2-)) species at monatomic step sites and other low-coordinated sites, followed by formation of carbonates on terraces, which dominate at increasing CO2 exposure. To explain the coverage-dependent IRAS results, we propose CO2 surface islanding from the onset, most likely in the form of pairs and other chain-like species, which were calculated as thermodynamically favorable. The calculated adsorption energy for isolated CO2 on the terrace sites (184 ± 10 kJ mol(-1)) is larger than the adsorption energy obtained by temperature programmed desorption (∼120-140 kJ mol(-1)) and heat of adsorption taken from microcalorimetry measurements at low coverage (∼125 kJ mol(-1)). However, the calculated adsorption energies become less favorable when carbonate chains intersect on CaO terraces, forming kinks. Furthermore, our assignments of the initial stages of CO2 adsorption are consistent with the observed coverage effect on the CO2 adsorption energy measured by microcalorimetry and the IRAS results.

  3. Porous carbon material containing CaO for acidic gas capture: preparation and properties.

    Science.gov (United States)

    Przepiórski, Jacek; Czyżewski, Adam; Pietrzak, Robert; Toyoda, Masahiro; Morawski, Antoni W

    2013-12-15

    A one-step process for the preparation of CaO-containing porous carbons is described. Mixtures of poly(ethylene terephthalate) with natural limestone were pyrolyzed and thus hybrid sorbents could be easily obtained. The polymeric material and the mineral served as a carbon precursor and CaO delivering agent, respectively. We discuss effects of the preparation conditions and the relative amounts of the raw materials used for the preparations on the porosity of the hybrid products. The micropore areas and volumes of the obtained products tended to decrease with increasing CaO contents. Increase in the preparation temperature entailed a decrease in the micropore volume, whereas the mesopore volume increased. The pore creation mechanism is proposed on the basis of thermogravimetric and temperature-programmed desorption measurements. The prepared CaO-containing porous carbons efficiently captured SO2 and CO2 from air. Washing out of CaO from the hybrid materials was confirmed as a suitable method to obtain highly porous carbon materials.

  4. 论曹文轩的文学观%On Cao Wenxuan's View of Literature

    Institute of Scientific and Technical Information of China (English)

    倪厚玉; 周宁

    2015-01-01

    Cao Wenxuan is one of the most powerful and influential writers in contemporary Chinese literary a-rena, for a series of expositions on literature made by him have been favorably conducive to enriching contemporary Chinese literary criticism theories.This paper aims to systematize and study the origin, formation and change of Cao Wenxuan's literature view and attempts to elucidate the connotation of his literature view with"beauty" and"aes-thetic perception" as its core so as to reveal Cao's idea and individuality in literary creation.%曹文轩是中国当代文坛最具实力与影响的作家之一.特别是他发表的一系列有关文学的论述对丰富当代文学批评理论具有良好的补给作用.论文将着重对曹文轩文学观的渊源、形成及流变进行系统梳理与研究,试图阐释以"美"和"美感"为核心的文学观内涵,从而揭示其独特的创作理念和创作个性.

  5. 曹乃谦小说中的女性%The Female in Cao Naiqian's Novel

    Institute of Scientific and Technical Information of China (English)

    赵海涛

    2015-01-01

    The woman palys an outstanding role in the stories of Cao Naiqian,the ebullient one,the merciful one,the kind one and the lonely one ,however,they are all the beautiful representatives.Cao always insisted on praising the wonderful woman in his stories,but these women's destiny are always tragedic, leaving people melancholy and regreful.And therefore,under such obivious contrast between the beauty and sadness,Cao's stories are beautiful with unique desolation.%女性在曹乃谦小说中的位置十分突出,她们有的多情大方,有的善良可爱,有的慈悲无私,有的孤苦伶仃,但不论怎样,她们都是一种美好的存在。曹乃谦在小说中一直坚持赞美女性,歌颂女性,把女性作为最美的诗与歌进行咏唱,但是这些女性的命运与结局却又总是以悲剧的形式出现,令人唏嘘惆怅。女性的美与悲之间的强烈反差,使曹乃谦的小说独具一种凄婉伤感之美。

  6. Intense ${^31-35}$Ar beams produced with a nanostructured CaO target at ISOLDE

    CERN Document Server

    Ramos, J P; Mendonça, T M; Seiffert, C; Senos, A M R; Fynbo, H O U; Tengblad, O; Briz, J A; Lund, M V; Koldste, G T; Carmona-Gallardo, M; Pesudo, V; Stora, T

    2014-01-01

    At the ISOLDE facility at CERN, thick targets are bombarded with highly energetic pulsed protons to produce radioactive ion beams (RIBs). The isotopes produced in the bulk of the material have to diffuse out of the grain and effuse throughout the porosity of the material to a transfer line which is connected to an ionizer, from which the charged isotopes are extracted and delivered for physics experiments. Calcium oxide (CaO) powder targets have been used to produce mainly neutron deficient argon and carbon RIBs over the past decades. Such targets presented unstable yields, either decaying over time or low from the beginning of operation. These problems were suspected to come from the degradation of the target microstructure (sintering due to high temperature and/or high proton intensity). In this work, a CaO microstructural study in terms of sintering was conducted on a nanostructured CaO powder synthesized from the respective carbonate. Taking the results of this study, several changes were made at ISOLDE i...

  7. CERN Technical Training 2002: Learning for the LHC! Introduction à la CAO CADENCE - French version only

    CERN Multimedia

    Davide Vitè

    2002-01-01

    Dans le cadre du suivi du programme ELEC-2002 : Electronics in HEP, une nouvelle session du cours Introduction à la CAO CADENCE. De la saisie de schéma Concept-HDL au PCB est programmée pour le 4 et 5 juin prochains. Le cours, en français, est gratuit et sera animé par Serge Brobecker de la division IT/PS/EAS. Objectif de cette formation est de donner une vue générale du système CAO CADENCE utilisé au CERN, et d'en connaître l'environnement et les possibilités, en acquérant des notions suffisantes pour utiliser la saisie de schéma. Le cours est ciblé pour une audience d'ingénieurs et techniciens désirant utiliser les outils CAO disponibles au CERN, afin de concevoir des circuits logiques et des circuits programmables digitaux. Plus d'information, et possibilité d'inscription par EDH sont accessibles depuis les pages «...

  8. [Textual research on Costus root (Aucklandia lappa Decne) in the Sheng nong ben cao jing (Shennong's Classic of Materia Medica)].

    Science.gov (United States)

    Li, Guangyan; Wang, Dequn; Fang, Shiying; Xu, Maohong

    2014-05-01

    Aucklandia lappa Decne was first recorded in the Sheng nong ben cao jing (Shennong's Classic of Materia Medica). Through the textual research of herbal literature, it was found that the costus root in the Sheng nong ben cao jing perhaps was not the plant of Aucklandia lappa Decne of Compositae, but the eaglewood or Lignum Aquilasria Resinatum based on the comprehensive judgment of shape, taste, nature, and function etc. In the Sheng nong ben cao jing, it only includes costus root without the title of eaglewood, and Tao Hongjing recorded both herbs together in his Ming yi bie lu (Supplementary Records of Celebrated Physicians), which became a foreshadow of misunderstanding of the later generations. Beginning from the Tang ben cao (Materia Medica of the Tang Dynasty), the costus root was considered as the plant of Auckiandia lappa Decne from the Compostae with its profound influence until now.

  9. Decomposition Reaction of Mixed Rare Earth Concentrate and Roasted with CaO and NaCl

    Institute of Scientific and Technical Information of China (English)

    Wu Wenyuan; Hu Guangyong; Sun Shuchen; Chen Xudong; Tu Ganfeng

    2004-01-01

    The reaction of the mixed rare earth concentrate including monazite ( REPO4 ) and bastnaesite ( REFCO3 )decomposed by CaO and NaCl additives at the temperature range from 100 to 1000 ℃ was studied by means of XRD and TG-DTA.The results show that when CaO and NaCl are not added, only REFCO3 can be decomposed at the temperature of 377 ~ 450 ℃.The decomposition products include REOF, RE2O3 and CeO2.However, REFCO3 can not be decomposed.When CaO is added, the decomposition reactions occur at the temperature range from 660 to 750 ℃.CaO has three decomposition functions: ( 1 ) REPO4 can be decomposed by CaO and the decomposition products include RE2O3 and Ca3 (PO4)2; (2) CaO can decompose REOF, and the decomposition products are RE2O3 and CaF2; (3)CaO can decompose REPO4 with CaF2, and the decomposition products are RE2 O3, Ca5 F( PO4 )3.The decomposition ratio of the mixed rare earth concentrate increased obviously, when CaO and NaC1 were added.NaC1 can supply the liquid for the reaction, improve the mass transfer process and accelerate the reaction.At the same time, NaC1 participated in the reaction that REPO4 was decomposed by CaO.

  10. CaO nanocrystals grown over SiO2 microtubes for efficient CO2 capture: organogel sets the platform.

    Science.gov (United States)

    Prathap, Annamalai; Shaijumon, M M; Sureshan, Kana M

    2016-01-25

    Materials that can capture and store CO2 are important. Though CaO is a cheap sorbent, it is inefficient for practical purposes due to sintering and poor diffusion of CO2 through the surface-CaCO3 layer. We have developed a high performance, sintering-resistant CaO-based sorbent by uniformly nanofabricating the CaO nanocrystals on SiO2 microtubes made by organogel templated polymerization.

  11. Homegardens of the Cao Lan, a Tai-Speaking Ethnic Minority in Vietnam’s Northern Mountains

    OpenAIRE

    2015-01-01

    The Cao Lan are a Tai-speaking ethnic group living in the Midlands of Northern Vietnam. Homegardens are an important component of their agroecosystem. The ecological structures of each homegarden of 17 households of the Cao Ngoi village in Tuyen Quang province were described and modal patterns identified. Most homegardens have organically shaped planting areas with indeterminate boundaries, polycentric planting patterns, and contain multiple species within the same bed or planting area. All o...

  12. Reduction-melting behaviors of boron-bearing iron concentrate/carbon composite pellets with addition of CaO

    Institute of Scientific and Technical Information of China (English)

    Jing-song Wang

    2015-01-01

    Although the total amount of boron resources in China is high, the grades of these resources are low. The authors have already proposed a new comprehensive utilization process of boron-bearing iron concentrate based on the iron nugget process. The present work de-scribes a further optimization of the conditions used in the previous study. The effects of CaO on the reduction–melting behavior and proper-ties of the boron-rich slag are presented. CaO improved the reduction of boron-bearing iron concentrate/carbon composite pellets when its content was less than 1wt%. Melting separation of the composite pellets became difficult with the CaO content increased. The sulfur content of the iron nugget gradually decreased from 0.16wt%to 0.046wt%as the CaO content of the pellets increased from 1wt%to 5wt%. CaO negatively affected the iron yield and boron extraction efficiency of the boron-rich slag. The mineral phase evolution of the boron-rich slag during the reduction–melting separation of the composite pellets with added CaO was also deduced.

  13. Ultrathin oxide films and heterojunctions: CaO layers on BaO and SrO.

    Science.gov (United States)

    Mohn, Chris E; Allan, Neil L; Harding, John H

    2009-05-07

    We examine the form of the islands formed by CaO on BaO and SrO substrates using both periodic density functional theory and atomistic simulation techniques. (100) edges dominate the island morphology and we examine how the CaO adjusts to the substrate in small and medium sized islands and at much larger coverages. There is no direct overlay of CaO ion pairs over OBa or OSr pairs in the top substrate layer. Rather, island bond lengths are all much shorter than those even in bulk CaO, even in the interior of the islands, and more similar to those in CaO clusters and isolated thin films. Corner atoms are associated with particularly short Ca-O bond lengths and the low coordination numbers at such positions. The islands show a marked deviation from planarity which can be broadly rationalized in terms of different preferential bond lengths for Ca and O with substrate O and Ba (Sr), respectively. The marked preferences for particular bond lengths lead to the formation of loops or gaps in non-square islands, areas where islands interact and along the mid-edges of large islands. Exchange with the much larger cations in the substrate is surprisingly facile. Our results indicate the difficulties of preparing sharp, ordered thin oxide films even at low temperatures.

  14. Viability of Clostridium sporogenes spores after CaO hygienization of meat waste.

    Science.gov (United States)

    Bauza-Kaszewska, Justyna; Paluszak, Zbigniew; Skowron, Krzysztof

    2014-01-01

    The occurrence of the pathogenic species C. perfringens and C. botulinum spores in animal by-products poses a potential epidemiological hazard. Strong entero- and neurotoxins produced by these bacteria adversely affect human health. To inactivate pathogens present in animal by-products, waste must be subjected to various methods of sanitization. The aim of the presented study was to estimate the effect of different doses of CaO on the viability of spores Clostridium sporogenes in meat wastes category 3. During the research, two doses of burnt lime were added to the poultry mince meat and meat mixed with swine blood contaminated with Clostridium sporogenes spore suspension. Half of the samples collected for microbiological analyses were buffered to achieve the pH level ~7, the other were examined without pH neutralization. To estimate the spore number, 10-fold dilution series in peptone water was prepared and heat-treated at 80 °C for 10 min. After cooling-down, one milliliter of each dilution was pour-plated onto DRCM medium solidified with agar. Statistical analysis were performed using the Statistica software. Application of 70% CaO caused complete inactivation of Clostridium spores in meat wastes after 48 hours. The highest temperature achieved during the experiment was 67 °C. Rapid alkalization of the biomass resulted in increasing pH to values exceeding 12. The effect of liming was not dependent on the meat wastes composition nor CaO dose. The experiment proved the efficiency of liming as a method of animal by-products sanitization. Application of the obtained results may help reduce the epidemiological risk and ensure safety to people handling meat wastes at each stage of their processing and utilization.

  15. Viability of Clostridium sporogenes spores after CaO hygienization of meat waste

    Directory of Open Access Journals (Sweden)

    Justyna Bauza-Kaszewska

    2014-09-01

    Full Text Available The occurrence of the pathogenic species [i]C. perfringens[/i] and [i]C. botulinum spores[/i] in animal by-products poses a potential epidemiological hazard. Strong entero- and neurotoxins produced by these bacteria adversely affect human health. To inactivate pathogens present in animal by-products, waste must be subjected to various methods of sanitization. The aim of the presented study was to estimate the effect of different doses of CaO on the viability of spores [i] Clostridium sporogenes[/i] in meat wastes category 3. During the research, two doses of burnt lime were added to the poultry mince meat and meat mixed with swine blood contaminated with [i]Clostridium sporogenes[/i] spore suspension. Half of the samples collected for microbiological analyses were buffered to achieve the pH level ~7, the other were examined without pH neutralization. To estimate the spore number, 10-fold dilution series in peptone water was prepared and heat-treated at 80 °C for 10 min. After cooling-down, one milliliter of each dilution was pour-plated onto DRCM medium solidified with agar. Statistical analysis were performed using the Statistica software. Application of 70% CaO caused complete inactivation of [i]Clostridium spores[/i] in meat wastes after 48 hours. The highest temperature achieved during the experiment was 67 °C. Rapid alkalization of the biomass resulted in increasing pH to values exceeding 12. The effect of liming was not dependent on the meat wastes composition nor CaO dose. The experiment proved the efficiency of liming as a method of animal by-products sanitization. Application of the obtained results may help reduce the epidemiological risk and ensure safety to people handling meat wastes at each stage of their processing and utilization.

  16. Characteristics of Sn segregation in Ge/GeSn heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Li, H.; Chang, C.; Chen, T. P.; Cheng, H. H., E-mail: hhcheng@ntu.edu.tw [Center for Condensed Matter Sciences and Graduate Institute of Electronics Engineering, National Taiwan University, Taipei 10617, Taiwan (China); Shi, Z. W.; Chen, H. [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-10-13

    We report an investigation of Sn segregation in Ge/GeSn heterostructures occurred during the growth by molecular beam epitaxy. The measured Sn profile in the Ge layer shows that: (a) the Sn concentration decreases rapidly near the Ge/GeSn interface, and (b) when moving away from the interface, the Sn concentration reduced with a much slower rate. The 1/e decay lengths of the present system are much longer than those of the conventional group IV system of Ge segregation in the Si overlayer because of the smaller kinetic potential as modeled by a self-limited two-state exchange scheme. The demonstration of the Sn segregation shows the material characteristics of the heterostructure, which are needed for the investigation of its optical properties.

  17. Chaumont 2004: disordine apparente, ordine reale: la teoria del caos e l’arte dei giardini

    Directory of Open Access Journals (Sweden)

    Claudia Maria Bucelli

    2015-11-01

    Full Text Available Nella sua tredicesima edizione il Festival Internazionale di Chaumont-sur-Loire propone uno dei temi di riflessione più avanzati della speculazione scientifica contemporanea, la Teoria del Caos. Chiamati a confrontarsi con un argomento già ampiamente oggetto di dibattiti scientifici e riflessioni filosofiche e artistiche, i 23 vincitori di quest’anno hanno allestito giardini sui quali si indaga sotto il profilo sia speculativo che intuitivamente creativo, ricercando una lettura trasversale, supportata dalle dirette testimonianze dei Concepteurs, delle complesse dinamiche teoriche e culturali alla base della contemporanea speculazione attorno al giardino. 

  18. Utilización de los conceptos de caos y complejidad en empresas del sector financiero

    OpenAIRE

    Monroy Heredia, Valeria; Camacho Arteaga, Catalina

    2014-01-01

    Este proyecto busca determinar que utilización se hace de los conceptos de caos y complejidad en las empresas del sector financiero colombiano, para así encontrar la relación entre estos conceptos y la ocurrencia de eventos en la economía actual. Se adoptó un método descriptivo, donde se tomará como unidad de análisis una empresa representativa del sector financiero de Colombia. La compañía escogida para el análisis fue Bancolombia, la cual debido a su larga trayectoria dentro de la econo...

  19. "CAOS, COMPLEJIDAD, CREATIVIDAD: DISEÑANDO FRACTALES EN 'GERONIMO. AN AMERICAN LEGEND' DE WALTER HILL"

    OpenAIRE

    Rose Lema

    2010-01-01

    El objeto central del estudio consiste en analizar secuencias en el filme Geronimo. An American Legend del cineasta Walter Hill (1993), aplicando conceptos y procesos provenientes de las teorías del Caos, la Complejidad y la Creatividad. En la primera parte, se desarrollan y se caracterizan conceptos y términos caóticos, indicando cómo se van extrapolando hacia el campo cinematográfico: 1) el principio de la teoría de los tres cuerpos -proveniente principalmente de la astronomía-; 2) los fenó...

  20. Effect of sulfation on the surface activity of CaO for N{sub 2}O decomposition

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Lingnan, E-mail: wulingnan@126.com [School of Energy, Power and Mechanical Engineering, North China Electric Power University, 102206 Beijing (China); National Engineering Laboratory for Biomass Power Generation Equipment, North China Electric Power University, 102206 Beijing (China); Hu, Xiaoying, E-mail: huxy@ncepu.edu.cn [National Engineering Laboratory for Biomass Power Generation Equipment, North China Electric Power University, 102206 Beijing (China); Qin, Wu, E-mail: qinwugx@126.com [National Engineering Laboratory for Biomass Power Generation Equipment, North China Electric Power University, 102206 Beijing (China); Dong, Changqing, E-mail: cqdong1@163.com [National Engineering Laboratory for Biomass Power Generation Equipment, North China Electric Power University, 102206 Beijing (China); Yang, Yongping, E-mail: yypncepu@163.com [School of Energy, Power and Mechanical Engineering, North China Electric Power University, 102206 Beijing (China)

    2015-12-01

    Graphical abstract: - Highlights: • Sulfation of CaO (1 0 0) surface greatly deactivates its surface activity for N{sub 2}O decomposition. • An increase of sulfation degree leads to a decrease of CaO surface activity for N{sub 2}O decomposition. • Sulfation from CaSO{sub 3} into CaSO{sub 4} is the crucial step for deactivating the surface activity for N{sub 2}O decomposition. • The electronic interaction CaO (1 0 0)/CaSO{sub 4} (0 0 1) interface is limited to the bottom layer of CaSO{sub 4} (0 0 1) and the top layer of CaO (1 0 0). • CaSO{sub 4} (0 0 1) and (0 1 0) surfaces show negligible catalytic ability for N{sub 2}O decomposition. - Abstract: Limestone addition to circulating fluidized bed boilers for sulfur removal affects nitrous oxide (N{sub 2}O) emission at the same time, but mechanism of how sulfation process influences the surface activity of CaO for N{sub 2}O decomposition remains unclear. In this paper, we investigated the effect of sulfation on the surface properties and catalytic activity of CaO for N{sub 2}O decomposition using density functional theory calculations. Sulfation of CaO (1 0 0) surface by the adsorption of a single gaseous SO{sub 2} or SO{sub 3} molecule forms stable local CaSO{sub 3} or CaSO{sub 4} on the CaO (1 0 0) surface with strong hybridization between the S atom of SO{sub x} and the surface O anion. The formed local CaSO{sub 3} increases the barrier energy of N{sub 2}O decomposition from 0.989 eV (on the CaO (1 0 0) surface) to 1.340 eV, and further sulfation into local CaSO{sub 4} remarkably increases the barrier energy to 2.967 eV. Sulfation from CaSO{sub 3} into CaSO{sub 4} is therefore the crucial step for deactivating the surface activity for N{sub 2}O decomposition. Completely sulfated CaSO{sub 4} (0 0 1) and (0 1 0) surfaces further validate the negligible catalytic ability of CaSO{sub 4} for N{sub 2}O decomposition.

  1. Initial reaction between CaO and SO2 under carbonating and non-carbonating conditions

    DEFF Research Database (Denmark)

    Rasmussen, Martin Hagsted; Wedel, Stig; Pedersen, Kim H.;

    2015-01-01

    The initial kinetics of the CaO/SO2 reaction have been investigated for reaction times shorter than 1s and in the temperature interval between 450 and 600°C under both carbonating and non-carbonating conditions (0-20 vol% CO2) to clarify how recirculating CaO influences the emission of SO2 from...... showed that the CaO conversion with respect to SO2 declined when the CO2 concentration was increased. Under all conditions, larger specific surface areas of CaO gave higher reaction rates with SO2. Higher temperatures had a positive effect on the reaction between SO2 and CaO under non...... a modern dry kiln preheater system for cement production. Calcined Faxe Bryozo limestone with a particle size smaller than 400μm was utilized as CaO source. It was shown, both theoretically and experimentally, that the observed reaction rates were influenced by mass transport limitations. The results...

  2. Relationship between alkaloid contents and growth environment of Yimu Cao (Herba Leonuri)

    Institute of Scientific and Technical Information of China (English)

    CHAO Zhi; YAN Gang

    2001-01-01

    To study the relationship between alkaloids contents in Chinese traditional drug Yimu Cao (the dried aerial parts ofLeonurus artemisia) and its growing environment. Methods: Samples of the drug and the soil at the growing site collected from 5 selected regions. Reference materials were checked and on-the-spot observations were carried out to investigate the growth environment. RP-HPLC was performed to determine the alkaloid contents in the drug. Results: Different regions had different environmental conditions, including climate, soil, vegetation, and so on.No matter barren or fertile the soil at the growing site was, the herb ofL. Artemisia could grow well, but the contents of alkaloid in the drug varied greatly. The drugs produced in 2 northern regions, where the soil is alkaline, had higher content of alkaloid (about 0.4%) than that produced in southern regions (0.1%-0.2%), where the soil is acid. Conclusion:The contents of organic matters, effective phosphorus, quick-acting potassium, and the pH value of the growing site soil were the factors correlating with alkaloid contents in the drug, among which the pH value of soil was an important positively correlating factor. The alkaline soils in North benefit the accumulation of alkaloids more than the acid soils in South. The other probable elements affecting the alkaloid contents in Yimu Cao were climate and genetic factors.

  3. The Experiences of e-Learning Implementation in CAO - Results of the Pilot Project

    Directory of Open Access Journals (Sweden)

    Zsuzsanna Vörös

    2010-12-01

    Full Text Available The various tasks of Central Agricultural Office are carried out by its central and regional directorates. For performing a high standard labour, well- and continuously educated team in needed, so the more thousands of colleagues working at central and regional levels have to be trained. Beside the traditional training forms – and built to them - there was a need for implementing a new distant teaching system, which provides a comprehensive distance education, resting on multimedia foundations, for the all colleagues of Central Agricultural Office working in different parts of the country and in different professional areas. The aim of our publication is to show how we introduced the e-Learning education within the distance education framework system of CAO, and to share our experiences obtained during the pilot training. The five courses of pilot training turned out a success: the results of examinations (the mean values: 84-91% and evaluations of questionnaires filled out by more than 200 colleagues taking part in training proved the entitlement of e-Learning education in CAO. However this method needs additional refinements in order to adapt to the specific requirements of andrology.

  4. Influence of hot isostatic pressing on ZrO2-CaO dental ceramics properties.

    Science.gov (United States)

    Gionea, Alin; Andronescu, Ecaterina; Voicu, Georgeta; Bleotu, Coralia; Surdu, Vasile-Adrian

    2016-08-30

    Different hot isostatic pressing conditions were used to obtain zirconia ceramics, in order to assess the influence of HIP on phase transformation, compressive strength, Young's modulus and density. First, CaO stabilized zirconia powder was synthesized through sol-gel method, using zirconium propoxide, calcium isopropoxide and 2-metoxiethanol as precursors, then HIP treatment was applied to obtain final dense ceramics. Ceramics were morphologically and structurally characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Density measurements, compressive strength and Young's modulus tests were also performed in order to evaluate the effect of HIP treatment. The zirconia powders heat treated at 500°C for 2h showed a pure cubic phase with average particle dimension about 70nm. The samples that were hot isostatic pressed presented a mixture of monoclinic-tetragonal or monoclinic-cubic phases, while for pre-sintered samples, cubic zirconia was the single crystalline form. Final dense ceramics were obtained after HIP treatment, with relative density values higher than 94%. ZrO2-CaO ceramics presented high compressive strength, with values in the range of 500-708.9MPa and elastic behavior with Young's modulus between 1739MPa and 4372MPa. Finally zirconia ceramics were tested for biocompatibility allowing the normal development of MG63 cells in vitro.

  5. The Sentimental Feelings in Cao Pi's Fu%论曹丕赋中的感伤情怀

    Institute of Scientific and Technical Information of China (English)

    张靖

    2012-01-01

    曹丕的赋具有很强的抒情性,由于特殊的政治地位和人生遭遇,使得曹丕在其赋中流露出凄凉哀婉的心境,以及孤立无援的精神状态,展现了曹丕精神世界中敏感脆弱的一面。%Cao Pi' s Fu has strong lyricism due to the special political status and life experience. Cao Pi in his ode re- veals the desolate pathos mood, as well as the isolated and helpless mental state, which shows Cao Pi' s spiritual world of fragile and sensitive side.

  6. Preparation of TiFe based alloys melted by CaO crucible and its hydrogen storage properties

    Energy Technology Data Exchange (ETDEWEB)

    Li, Chong-he, E-mail: chli@staff.shu.edu.cn [Shanghai Key Laboratory of Modern Metallurgy and Materials Processing, Shanghai University, Shanghai 200072 (China); Shanghai Special Casting Engineering Technology Research Center, Shanghai 201605 (China); He, Jin; Zhang, Zhao; Yang, Bo; Leng, Hai-yan [Shanghai Key Laboratory of Modern Metallurgy and Materials Processing, Shanghai University, Shanghai 200072 (China); Lu, Xiong-gang, E-mail: luxg@staff.shu.edu.cn [Shanghai Key Laboratory of Modern Metallurgy and Materials Processing, Shanghai University, Shanghai 200072 (China); Shanghai Special Casting Engineering Technology Research Center, Shanghai 201605 (China); Li, Zhi-lin; Wu, Zhu [Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Wang, Hong-bin [Shanghai Key Laboratory of Modern Metallurgy and Materials Processing, Shanghai University, Shanghai 200072 (China); Shanghai Special Casting Engineering Technology Research Center, Shanghai 201605 (China)

    2015-01-05

    Highlights: • The home-made CaO crucible was used to prepare the TiFe based alloys. • The compositions as well as the content of oxygen can be effectively controlled. • The microstructure of the alloy melted by CaO crucible is dendrite. • The samples performed a good hydrogen storage performance. • The CaO crucible may be the promising candidate for melting the TiFe based alloys. - Abstract: The carbon contamination of alloys prepared by the electro graphite crucible is impossible to avoid due to the inherit reaction between the melt and the crucible. In this study, the TiFe-based alloy is prepared by VIM process using CaO crucible as well as the electro graphite crucible. The samples are examined by means of Optical Microscopy (OM), Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Energy Dispersive Spectrometer (EDS), and the PCT curves are also measured. It is resulted that, the oxygen content of alloys melted by CaO crucible is almost equal to the one melted by graphite crucible and without the carbon contamination, meanwhile the carbon content of alloys obtained by the electro graphite crucible is 1860 ppm, which exceeds the tolerance of the commercial alloy (1000 ppm). The microstructure of the alloy melted by CaO crucible is dendrite, while it is composed of the equiaxed crystal with the lamellar structure and the spherical TiC particles distributed along grain boundaries or within the grain when melted by the graphite crucible; the interfacial reaction of the electro graphite crucible with TiFe alloy melt is serious and the interaction layer is formed up to 200 μm in thickness, the carbon in TiFe-based alloys forms TiC. The hydrogen desorption plateau pressure of alloys melted by CaO crucible is (0.11–0.4) × 10{sup 5} Pa, and that by the graphite crucible is (0.6–1) × 10{sup 5} Pa. This may imply that the CaO crucible may be the promising candidate for melting the high performance TiFe based hydrogen storage alloys.

  7. Ab initio study of the low-lying electronic states of the CaO molecule

    Energy Technology Data Exchange (ETDEWEB)

    Khalil, Hossain; Brites, Vincent; Quere, Frederic Le [Universite Paris-Est, Laboratoire de Modelisation et Simulation Multi Echelle, UMR 8208 CNRS, Batiment Lavoisier, 5 boulevard Descartes, Champs sur Marne, 77454 Marne-la-Vallee, Cedex 2 (France); Leonard, Celine, E-mail: celine.leonard@univ-paris-est.fr [Universite Paris-Est, Laboratoire de Modelisation et Simulation Multi Echelle, UMR 8208 CNRS, Batiment Lavoisier, 5 boulevard Descartes, Champs sur Marne, 77454 Marne-la-Vallee, Cedex 2 (France)

    2011-07-28

    Graphical abstract: Highly correlated ab initio calculations have been performed for an accurate determination of the electronic structure of the low-lying electronic states of the CaO molecule. The computations are done using the aug-cc-pV5Z basis set for O and the cc-pCV5Z for Ca. The potential energy curves for the molecular states correlating to the lowest three asymptotes are calculated at the CASSCF level. The potential curves of the lowest five molecular states, X{sup 1}{Sigma}{sup +}, a{sup 3}{Pi}, A'{sup 1{Pi}}, b{sup 3}{Sigma}{sup +} and A{sup 1}{Sigma}{sup +}, and the corresponding dipole moment functions have been determined using internally contracted multi-reference configuration interaction approaches. The spectroscopic constants associated with these electronic states are compared to experimental values. The corresponding electronic wavefunctions have also been analyzed using the dipole moment functions. Display Omitted Highlights: {yields} The five lowest electronic states of Cao have been determined ab initio at a high level of accuracy. {yields} Large active space, core-valence correlation and configuration interaction are required. {yields} The multi-configurational nature of the electronic ground state is confirmed as well as its monovalent and divalent ionic nature using dipole moment analysis. {yields} These interacting potentials will serve for future obtention of spin-rovibronic levels. - Abstract: Highly correlated ab initio calculations have been performed for an accurate determination of the electronic structure of the low-lying electronic states of the CaO molecule. The computations are done using the aug-cc-pV5Z basis set for O and the cc-pCV5Z for Ca. The potential energy curves for the molecular states correlating to the lowest three asymptotes are calculated at the CASSCF level. The potential curves of the lowest five molecular states, X{sup 1}{Sigma}{sup +}, a{sup 3}{Pi}, A'{sup 1}{Pi}, b{sup 3}{Sigma}{sup +} and A{sup 1

  8. Electron Beam Etching of CaO Crystals Observed Atom by Atom.

    Science.gov (United States)

    Shen, Yuting; Xu, Tao; Tan, Xiaodong; Sun, Jun; He, Longbing; Yin, Kuibo; Zhou, Yilong; Banhart, Florian; Sun, Litao

    2017-08-09

    With the rapid development of nanoscale structuring technology, the precision in the etching reaches the sub-10 nm scale today. However, with the ongoing development of nanofabrication the etching mechanisms with atomic precision still have to be understood in detail and improved. Here we observe, atom by atom, how preferential facets form in CaO crystals that are etched by an electron beam in an in situ high-resolution transmission electron microscope (HRTEM). An etching mechanism under electron beam irradiation is observed that is surprisingly similar to chemical etching and results in the formation of nanofacets. The observations also explain the dynamics of surface roughening. Our findings show how electron beam etching technology can be developed to ultimately realize tailoring of the facets of various crystalline materials with atomic precision.

  9. Caos, complexidade e Lingüística Aplicada: diálogos transdisciplinares

    Directory of Open Access Journals (Sweden)

    Antônio Carlos Soares Martins

    2007-01-01

    Full Text Available Neste texto, apresentamos um panorama de estudos na área da Lingüística Aplicada que discutem questões relativas ao processo de desenvolvimento de segunda língua, bem como aspectos relacionados aos ambientes interacionais de aprendizagem na perspectiva das teorias do Caos e Complexidade. Para isso, discutimos as principais noções da perspectiva da complexidade, retomando alguns aspectos da física clássica e contemporânea.In this paper, we present a panorama of studies in the area of Applied Linguistics that discuss questions regarding second language development as well as aspects related to interactional learning environments in the light of Chaos and Complexity theories. To accomplish this, we discuss the main notions of complexity through the rethinking of some aspects of classic and contemporary physics.

  10. Study on the Surface Free Energy of Ground CaO by IGC

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    CaO formed by decomposing CaCO3 at 1450℃ was ground in a vibrational mill,then the long-time ground sample was reheated at different temperatures.Inverse Gas Chromatography (IGC) was used to measure the variation of the sample′s surface free energy under grinding and reheating.It is concluded that the total surface free energy and the London dispersive component of the surface free energy increases with grinding,while the polar component first increases with grinding,and then decreases,and finally disappears.When the long-time ground sample was reheated,its total surface free energy decreases,among which the London component decreases,but the polar component appears again.

  11. Teoría del caos, cognitivismo y semántica

    Directory of Open Access Journals (Sweden)

    Lic. Raymond Colle

    1998-01-01

    Full Text Available El origen del pensamiento no tiene nada de secuencial: el cerebro es un "mecanismo" que opera con una altísima tasa de paralelismo. Es también un sistema altamente complejo y comparte algunas características de funcionamiento de todos los sistemas altamente complejos. En este artículo se citan a diversos investigadores que han puesto en evidencia los fenómenos de aparición del orden en medio del "caos" en sistemas complejos; se explica cómo el pensamiento se ordena en torno a "atractores", formando "mapas" de relaciones y se ilustra con un caso practico cómo este mapa aparece en nuestros discursos.

  12. Thermoluminescence properties of gamma irradiated CaO: Sm{sup 3+} phosphor

    Energy Technology Data Exchange (ETDEWEB)

    Prakash, D. [Physics R& D Center, PES Institute of Technology, 100 ft. Ring Road, BSK 3rd Stage, Bangalore 560085 (India); Department of Physics, Government Science College, Bangalore 560001 (India); Nagabhushana, K.R., E-mail: bhushankr@gmail.com [Physics R& D Center, PES Institute of Technology, 100 ft. Ring Road, BSK 3rd Stage, Bangalore 560085 (India); Department of Physics - S& H, PES University, Bangalore 560085 (India)

    2016-07-15

    Pure and samarium doped calcium oxide (CaO) is synthesized by solution combustion technique. The samples are annealed at 600 °C for two hours. X-ray diffraction (XRD) pattern of the annealed sample show cubic phase with space group Fm3m. The average crystallite size is found to be ∼54 nm. Fourier transform infra red (FTIR) spectrum exhibits bands at 424, 544 cm{sup −1} (Ca–O bond), 875 cm{sup −1} (C–O bond), 1460 cm{sup −1} (C–O stretch) and 3640 cm{sup −1} (O–H stretch). The samples are irradiated with gamma rays in a dose range 100–4000 Gy. Thermoluminescence (TL) glow curves are recorded at a linear heating rate (β) of 5 Ks{sup −1}. A prominent TL glow with a peak at 636 K is observed in undoped sample. A new TL glow with peak at ∼458 K is observed in addition to 636 K in samarium doped (1 mol%) CaO. TL glow peak intensity (I{sub max}) at 636 K increases with γ – dose in the study range. TL emissions at 560, 600 and 640 nm are observed in doped samples corresponding to Sm{sup 3+} transitions along with pristine emissions. TL glow curves are deconvoluted to obtain kinetic parameters. The mean value of activation energy and the frequency factor of the prominent deconvoluted TL glow peak (626 K) are found to be 1.26 eV and 4.49 × 10{sup 9} s{sup −1} respectively.

  13. DUSTER: collection of meteoric CaO and carbon smoke particles in the upper stratosphere .

    Science.gov (United States)

    Della Corte, V.; Rietmeijer, F. J. M.; Rotundi, A.; Ferrari, M.; Palumbo, P.

    Nanometer- to micrometer-size particles present in the upper stratosphere are a mixture of terrestrial and extra-terrestrial origins. They can be extraterrestrial particles condensed after meteor ablation. Meteoric dust in bolides is occasionally deposited into the lower stratosphere around 20 km altitude. Nanometer CaO and pure carbon smoke particles were collected at 38 km altitude in the upper stratosphere in the Arctic during June 2008 using DUSTER (Dust in the Upper Stratosphere Tracking Experiment and Retrieval), a balloon-borne instrument for the non-destructive collection of solid particles between 200 nm to 40 microns. We report the collection of micron sized CaCO_3 (calcite) grains. Their morphologies show evidence of melting and condensation after vaporization suggest at temperatures of approximately 3500 K. The formation environment of the collected grains was probably a dense dust cloud formed by the disintegration of a carbonaceous meteoroid during deceleration in the Earth� atmosphere. For the first time, DUSTER collected meteor ablation products that were presumably associated with the disintegration of a bolide crossing the Earth's atmosphere. The collected mostly CaO and pure carbon nanoparticles from the debris cloud of a fireball, included: 1) intact fragments; 2) quenched melted grains; and 3) vapor phase condensation products. The DUSTER project was funded by the Italian Space Agency (ASI), PRIN2008/MIUR (Ministero dell'Istruzione dell'Universitá e della Ricerca), PNRA 2013(Piano Nazionale Ricerca Antartide). CNES graciously provided this flight opportunity. We thank E. Zona and S. Inarta at the Laboratorio di Fisica Cosmica INAF, Osservatorio Astronomico di Capodimonte-Universitá di Napoli Parthenope. F.J.M.R. was supported by grant NNX07AI39G from the NASA Cosmochemistry Program. We thank three anonymous reviewers who assisted us in introducing our new instrument.

  14. CaO insulator coatings on a vanadium-base alloy in liquid 2 at.% calcium-lithium

    Energy Technology Data Exchange (ETDEWEB)

    Park, J.H.; Kassner, T.F. [Argonne National Laboratory, IL (United States)

    1996-10-01

    The electrical resistance of CaO coatings produced on V-4%Cr-4%Ti and V-15%Cr-5%Ti by exposure of the alloy (round bottom samples 6-in. long by 0.25-in. dia.) to liquid lithium that contained 2 at.% dissolved calcium was measured as a function of time at temperatures between 300-464{degrees}C. The solute element, calcium in liquid lithium, reacted with the alloy substrate at these temperatures for 17 h to produce a calcium coating {approx}7-8 {mu}m thick. The calcium-coated vanadium alloy was oxidized to form a CaO coating. Resistance of the coating layer on V-15Cr-5Ti, measured in-situ in liquid lithium that contained 2 at.% calcium, was 1.0 x 10{sup 10} {Omega}-cm{sup 2} at 300{degrees}C and 400 h, and 0.9 x 10{sup 10} {Omega}-cm{sup 2} at 464{degrees}C and 300 h. Thermal cycling between 300 and 464{degrees}C changed the resistance of the coating layer, which followed insulator behavior. Examination of the specimen after cooling to room temperature revealed no cracks in the CaO coating. The coatings were evaluated by optical microscopy, scanning electron microscopy (SEM), electron dispersive spectroscopy (EDS), and X-ray analysis. Adhesion between CaO and vanadium alloys was enhanced as exposure time increased.

  15. La anticipación de las crisis (una aplicación del enfoque del caos

    Directory of Open Access Journals (Sweden)

    Manuel Guzmán Hennessey

    2007-01-01

    Full Text Available Este ensayo explora la posibilidad de aplicar la teoría del caos en el contexto de las dinámicas de crisis. Se examinan las bases filosóficas del pensamiento cognitivo borroso y se explora un modelo de aproximación a la realidad, a partir del reconocimiento de sus ciclos evolutivos caos orden. El problema de ver es la línea de investigación del Centro de Aplicaciones de la Teoría del Caos (Bogotá, Buenos Aires. Este trabajo es un avance de la investigación “Mil Matices: materiales para una teoría de las crisis”, cuyo propósito, entre otros, plantea: ¿Cuál es, en realidad, la esencia y el origen del Caos, y cómo pueden aplicarse sus enfoques en una sociedad que necesita superar sus crisis y aprender a moverse en contextos turbulentos?

  16. Evaporation Mechanism of Sn and SnS from Liquid Fe: Part II: Residual Site and Evaporation Kinetics via Sn(g) and SnS(g)

    Science.gov (United States)

    Jung, Sung-Hoon; Kang, Youn-Bae; Seo, Jeong-Do; Park, Joong-Kil; Choi, Joo

    2015-02-01

    Evaporation of Sn from molten steel was experimentally investigated for Fe-Sn-S alloy with low initial S (0.0007 chemical reaction controlled the evaporation of Sn. The model equation is able to represent the evaporation of Sn in the forms of Sn(g) and SnS(g) simultaneously, from very low S melt (when there is no S) to very high S melt investigated in the present study up to ~0.9 mass pct. Gradual transition of major evaporation species from SnS(g) to Sn(g) was well accounted for by the developed model.

  17. Homegardens of the Cao Lan, a Tai-Speaking Ethnic Minority in Vietnam’s Northern Mountains

    Directory of Open Access Journals (Sweden)

    Pijika Timsuksai

    2015-08-01

    Full Text Available The Cao Lan are a Tai-speaking ethnic group living in the Midlands of Northern Vietnam. Homegardens are an important component of their agroecosystem. The ecological structures of each homegarden of 17 households of the Cao Ngoi village in Tuyen Quang province were described and modal patterns identified. Most homegardens have organically shaped planting areas with indeterminate boundaries, polycentric planting patterns, and contain multiple species within the same bed or planting area. All of the gardens have multiple vegetation levels, with the largest share having 5 levels and a majority having more than 50% of their planting area covered by overlapping vegetation layers. Biodiversity is high with a total of 113 species recorded. Most plant species are used for food, but smaller numbers have ornamental, medicinal, and construction uses or are used for animal fodder, as stimulants, or for other purposes. Comparison of the modal structure of the Cao Lan homegardens with several Tai minority groups in Northeast Thailand, shows that, although the Cao Lan have been geographically isolated from other Tai groups for many centuries, their homegardens share a similar structural pattern, one commonly referred to as the tropical forest type. This structure is very different from the temperate type gardens of the Kinh in Vietnam with whom the Cao Lan share a common environment and are in frequent contact. The persistence of a common structural pattern among these related Tai ethnic groups, despite their inhabiting different environments, and having had no direct contact with each other for a very long time, suggests that culture exerts a strong influence over agroecosystem structure.

  18. Spatial and temporal variations of water quality in Cao-E River of eastern China

    Institute of Scientific and Technical Information of China (English)

    CHEN Ding-jiang; LU Jun; YUAN Shao-feng; JIN Shu-quan; SHEN Ye-na

    2006-01-01

    Evaluation and analysis of water quality variations were performed with integrated consideration of water quality parameters, hydrological-meteorologic and anthropogenic factors in Cao-E River, Zhejiang Province of China. Cao-E River system has been polluted and the water quality of some reaches are inferior to Grade V according to National Surface Water Quality Standard of China (GB2002). However, mainly polluted indices of each tributary and mainstream are different. Total nitrogen (TN) and total phosphorus (TP) in the water are the main polluted indices for mainstream that varies from 1.52 to 45.85 mg/L and 0.02 to 4.02 mg/L,respectively. TN is the main polluted indices for Sub-watershed Ⅰ, Ⅱ, Ⅳ and Ⅴ (0.76 to 18.27 mg/L). BOD5 (0.36 to 289.5 mg/L),CODMn (0.47 to 78.86 mg/L), TN (0.74 to 31.09 mg/L) and TP (0 to 3.75 mg/L) are the main polluted indices for Sub-watershed Ⅲ.There are tow pollution types along the river including nonpoint source pollution and point source pollution types. Remarkably temporal variations with a few spatial variations occur in nonpoint pollution type reaches (including mainstream, Sub-watershed Ⅰ and Ⅱ) that mainly drained by arable field and/or dispersive rural dwelling district, and the maximum pollutant concentration appears in flooding seasons. It implied that the runoff increases the pollutant concentration of the water in the nonpoint pollution type reaches. On the other hand, remarkably spatial variations occur in the point pollution type reaches (include Sub-watershed Ⅲ, Ⅳ and Ⅴ) and the maximum pollutant concentration appears in urban reaches. The runoff always decreases the pollutant concentration of the river water in the seriously polluted reaches that drained by industrial point sewage. But for the point pollution reaches resulted from centralized town domestic sewage pipeline and from frequent shipping and digging sands, rainfall always increased the concentration of pollutant (TN) in the river water

  19. Cathodic behavior of molten CaCl2-CaO and CaCl2-NaCl-CaO

    Science.gov (United States)

    Wang, Shu-Lan; Wang, Wei; Li, Shi-Chao; Cao, Shan-Hui

    2010-12-01

    The cathodic behavior of molten CaCl2, CaCl2-CaO and equimolar CaCl2-NaCl-CaO was studied by cyclic voltammograms and constant potential polarization at temperatures of 1123 to 1173 K on molybdenum and titanium electrodes. The diffusion coefficient of Ca2+ (CaO) in molten CaCl2-CaO was calculated from the linear relationship between the square root of scan rate and the peak current density. The deposition potentials and the potential temperature coefficient of CaO in molten CaCl2-0.5mol%CaO and CaCl2-NaCl-0.5mol%CaO were also obtained from their cyclic voltammograms. The result shows that CaO is more easily reduced than CaCl2. The addition of NaCl in molten CaCl2-CaO induces the underpotential electrodeposition of CaO.

  20. Study of solid state interactions in the systems ZnFe2O4 - CaO, ZnFe2O4 - MgO and zinc cake with CaO and MgO

    Directory of Open Access Journals (Sweden)

    Peltekov A.B.

    2013-01-01

    Full Text Available The solid state interactions of CaO and MgO with synthetic and industrial ZnFe2O4 (in zinc cake have been studied using chemical, XRD analysis and Mössbauer spectroscopy. The exchange reactions in the systems ZnFe2O4 - CaO and ZnFe2O4 - MgO have been investigated in the range of 850-1200ºC and duration up to 180 min. It has been established that Ca2+ and Mg2+ ions exchange Zn2+ in ferrite partially and the solubility of zinc in a 7% sulfuric acid solution increases. The possibilities for utilization of the obtained results in zinc hydrometallurgy have been discussed.

  1. 从接受美学的维度看影视剧中曹操形象的塑造%A Survey on the Screen Image of Cao Cao from the Perspective of ReceptionAesthetics

    Institute of Scientific and Technical Information of China (English)

    齐学东

    2014-01-01

    T he flourished Chinese historical literature has helped to bring historical personages in-to literature and traditional opera .However ,being influenced by different historical background ,aes-thetic ideologies ,moral judgment and creative personalities ,the artistic image of historical images al-ways differ from its original image and it is difficult to achieve the unification of historical reality and artistic reality ,w hich puzzles the adaption of film and television programs .Cao Cao is a typical exam-ple .As there are many debates about his historical image and artistic image ,it has become a tough task to reallocate the image of Cao Cao in films and television plays .Up to now ,in China ,there are no less than one hundred Three-kingdoms-themed plays ,which have directly or indirectly related to the image of Cao Cao .Therefore ,his screen image has become rich ,marvelous and contradictory . From the perspective of reception aesthetics ,the shaping of Cao Cao’s image is the editors’ ,direc-tors’ and actors’ reception of Cao Cao’s historical image and artistic image .%中国史传文学发达,历史人物常常成为文学、戏曲等艺术描绘的对象。由于受不同时代的历史氛围、审美思想、道德评判、个性创作等因素的影响,历史人物的艺术形象很难做到历史真实与艺术真实的完美统一,往往存在或多或少的差异,这给当代影视改编带来很大困惑。尤其像曹操这样的历史人物,其历史形象和艺术形象呈现不同向度的矛盾,历来存在争议,在影视创作时,影视作者对其影视形象的定位就非常困难。《三国》题材的影视作品多达百部,大多直接或间接描写曹操这一人物,其影视形象也呈现出丰富、复杂、矛盾的面貌。从接受美学的维度看,曹操影视形象的塑造,正是影视编剧、导演、演员对其历史形象和艺术形象的接受。

  2. A Comparative Study of Female-Themed Literary Creations by Cao Pi and Cao Zhi%曹丕、曹植女性题材创作比较论

    Institute of Scientific and Technical Information of China (English)

    张竞怿

    2012-01-01

    As prominent representatives of Jian'an Literature,and influenced by the circumstances of that era,Cao Pi and Cao Zhi both have produced a series of outstanding literary works themed on females.However,owing to differences in personal experiences,character,and temperament,they have developed diverse artistic styles in their respective poetry creation.The exquisitely subtle mood,the masterly skills of expressing emotions,and the delicate and gentle nature of literati are the main characteristics of Cao Pi's poems.By contrast,the poems written by Cao Zhi feature gorgeous and refined diction,deep personal sentiments,and various remarkable descriptions of feelings,affections and attitudes.Their literatures can not only exhibit the spirit of the times,but also add creative and unique radiance to the literature world.%曹丕与曹植是建安文学的杰出代表,受时代风气的影响,都写出了一系列优秀的女性题材作品。但由于二人的经历、性格、气质有所不同,因此在这类诗歌创作中又形成了不同的艺术风格:曹丕的代言体诗委婉细腻,工于言情,多文士之气。曹植诗则多生情态,辞采华茂,经常寄予个人深沉的情感。他们的作品既有浓郁的时代气息,又放射出独特的个性光辉。

  3. Ab initio structure dertermination and property characterization of high-pressure Ca-O compounds and Li2(OH)Br crystals

    Science.gov (United States)

    Higgins, Christopher A.

    Theoretical modeling and computational simulations play an important role in materials research. In this thesis, we report on the study of two material systems using various computational methods. The first material system studied here are Cax-Oy compounds under high pressure. Calcium and oxygen are amongst the most abundant elements on Earth, and they form the compound calcium oxide (CaO) that is widely used and very stable at ambient pressures. Although the crystal structure and chemical composition of CaO seems to be simple and well understood, metastable or stable Ca-O compounds with unconventional stoichiometry may exist at high pressures. In this work, first-principles density functional theory calculations and ab initio evolutionary simulations have been used to predict high pressure Ca-O structures. We show that under increasing pressure, the stability of the Ca-O system changes and new materials emerge with different stable or metastable structures. In addition to CaO, we systematically examined structures for Ca, Ca2O, Ca2O3, Ca3O, Ca 3O2, Ca7O, CaO2, CaO3, CaO 7, and O at high pressures. The high-pressure phase diagram for these compounds is determined along with the electronic density of states and stoichiometry plots. Our energetic analysis identified three new stable Ca-O compounds, namely Ca2O3 and CaO2 that are thermodynamically stable above 40 GPa, and CaO3 becomes thermodynamically stable at 150 GPa. The second material system studied in this work is the compound Li 2(OH)Br. This compound has been shown by experiment to be a promising solid electrolyte for advanced solid state ionic battery applications. However, the crystal structure of this compound is highly complex and has not been determined accurately. This has impeded its further investigation and potential applications. We modeled the structure effectively using the density functional theory via VASP software. Having successfully determined the correct structure within our model and

  4. Determinación experimental de la sección isotermal de 1300º C del Sistema CaO – Al2O3 – CoO

    Directory of Open Access Journals (Sweden)

    Vásquez Méndez, B. A.

    2011-04-01

    Full Text Available The subsolidus of the system CaO-Al2O3-CoO has been studied. Was established the existence of nine compatibility triangles. It had been found a phase Ca3Al4CoO10, isoestructural to Ca3MgAl4O10. Solid solutions of CaO, CoO and CoAl2O4 were determinated. Color variation on diferent samples was observed as function of the phase diagram region. When Co was substituted for other bivalents cations (Sr, a, n, Ni, Cu, Cd, Sn and Pb, were not found new phases. This study depicts the most outstanding results concerning the alternate materials research line. The importance focused on the stability of the new compound into the matrix of other materials from some technological processes such as the cement one, into which industrial wastes can be incorporated as alternate raw materials and fuels.Se ha estudiado el subsolidus del sistema CaO-Al2O3-CoO estableciendo la existencia de nueve triángulos de compatibilidad en estado sólido. Se ha encontrado una fase de fórmula Ca3CoAl4O10 isoestructural a Ca3MgAl4O10. Se ha establecido la existencia de soluciones sólidas de Co en CaO, de Ca en CoO y en CoAl2O4. Se ha observado la formación de fases con diversos colores en función de la zona del diagrama. Al sustituir Co por otros cationes bivalentes (Sr, Ba, Mn, Ni, Cu, Cd, Sn y Pb no se encontraron nuevas fases. Este estudio presenta los resultados más relevantes en relación con la línea de investigación del uso de materiales alternos. La relevancia se enfoca en mantener la estabilidad de un nuevo compuesto en la matriz de algún proceso tecnológico, como por ejemplo el proceso del cemento, en el cual pueden ser incorporados desechos industriales como materias primas y combustibles alternos.

  5. Preparation and characterizaton of CaO nanoparticle for biodiesel production

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Jharna, E-mail: onlinejharna@gmail.com; Agarwal, Madhu, E-mail: madhunaresh@gmail.com [Department of Chemical Engineering, MNIT, Jaipur, 302017 (India)

    2016-04-13

    Nanoparticle of CaO from calcium Nitrate (CaO/CaN) and Snail shell (CaO/SS) are successfully synthesized by method as described in the literature and used as an active and stable catalyst for the biodiesel production. These catalysts are characterized by Fourier-transform infrared spectra (FT-IR), X-ray diffraction (XRD), and thermal gravimetric analysis (TGA). The average crystalline size in nanometer was also calculated by Debye–Scherrer equation. The performance of the CaO/CaN and CaO/SS were tested for their catalytic activity via transesterification process and it was found that biodiesel yield has been increased from 93 to 96%. The optimum conditions for the highest yield were 8wt% catalyst loading, 65°C temperature, 12:1 methanol/oil molar ratio, and 6 h for reaction time. The nano catalyst from snail shell exhibits excellent catalytic activity and stability for the transesterification reaction, which suggested that this catalyst would be potentially used as a solid base nano catalyst for biodiesel production. In order to examine the reusability of catalyst developed from snail shell, five transesterification reaction cycles were also performed.

  6. Preparation and characterizaton of CaO nanoparticle for biodiesel production

    Science.gov (United States)

    Gupta, Jharna; Agarwal, Madhu

    2016-04-01

    Nanoparticle of CaO from calcium Nitrate (CaO/CaN) and Snail shell (CaO/SS) are successfully synthesized by method as described in the literature and used as an active and stable catalyst for the biodiesel production. These catalysts are characterized by Fourier-transform infrared spectra (FT-IR), X-ray diffraction (XRD), and thermal gravimetric analysis (TGA). The average crystalline size in nanometer was also calculated by Debye-Scherrer equation. The performance of the CaO/CaN and CaO/SS were tested for their catalytic activity via transesterification process and it was found that biodiesel yield has been increased from 93 to 96%. The optimum conditions for the highest yield were 8wt% catalyst loading, 65°C temperature, 12:1 methanol/oil molar ratio, and 6 h for reaction time. The nano catalyst from snail shell exhibits excellent catalytic activity and stability for the transesterification reaction, which suggested that this catalyst would be potentially used as a solid base nano catalyst for biodiesel production. In order to examine the reusability of catalyst developed from snail shell, five transesterification reaction cycles were also performed.

  7. Thermoluminescence properties of CaO powder obtained from chicken eggshells

    Science.gov (United States)

    Nagabhushana, K. R.; Lokesha, H. S.; Satyanarayana Reddy, S.; Prakash, D.; Veerabhadraswamy, M.; Bhagyalakshmi, H.; Jayaramaiah, J. R.

    2017-09-01

    Eggshell wastage has created serious problem in disposal of the food processing industry which has been triggered the thoughts of researchers to use wasted eggshells as good source of calcium. In the present work, calcium oxide (CaO) has been synthesized by combustion process in furnace (F-CaO) and microwave oven (M-CaO) using the source of chicken eggshells. The obtained F-CaO and M-CaO are characterized by XRD, SEM with EDX and thermoluminescence (TL) technique. XRD pattern of both the samples show cubic phase with crystallite size 45-52 nm. TL glow curves are recorded for various gamma radiation dose (300-4000 Gy). Two TL glows, a small peak at 424 K and stronger peak at 597 K are observed. TL response of M-CaO is 2.67 times higher than F-CaO sample. TL kinetic parameters are calculated by computerized curve deconvolution analysis (CCDA) and discussed.

  8. Response of Stream Pollution Characteristics to Catchment Land Cover in Cao-E River Basin, China

    Institute of Scientific and Technical Information of China (English)

    SHEN Ye-Na; L(U) Jun; CHEN Ding-Jiang; SHI Yi-Ming

    2011-01-01

    This study addressed the relationship of river water pollution characteristics to land covers and human activities in the catchments in a complete river system named Cao-E River in eastcrn China. Based on the hydrogsochemical data collected monthly over a period of 3 years, cluster analysis (CA) and principal component analysis (PCA) were adopted to categorize the river reaches and reveal their pollution characteristics. According to the differences of water quality in the river reaches and land use patterns and average population densities in their catchments, the whole river system could be categorized into three groups of river reaches, i.e., non-point sources pollution reaches (NPSPR), urban reaches (UR) and mixed sources pollution reaches (MSPR). In UR and MSPR, the water quality was mainly impacted by nutrient and organic pollution, while in NPSPR nutrient pollution was the main cause. The nitrate was the main nitrogen form in NPSPR and particulate phosphorus was the main phosphorus form in MSPR. There were no apparent trends for the variations of pollutant concentrations with increasing river flows in NPSPR and MSPR, while in UR the pollutant concentrations decreased with increasing river flows. Thus dry season was the critical period for water pollution control in UR. Therefore, catchment land covers and human activities had significant impact on river reach water pollution type, nutrient forms and water quality responses to hydrological conditions, which might be crucial for developing strategies to combat water pollution in watershed scale.

  9. Inhibitory Effects of Daiokanzoto (Da-Huang-Gan-Cao-Tang on P-Glycoprotein

    Directory of Open Access Journals (Sweden)

    Yuka Watanabe

    2012-01-01

    Full Text Available We have studied the effects of various Kampo medicines on P-glycoprotein (P-gp, a drug transporter, in vitro. The present study focused on Daiokanzoto (Da-Huang-Gan-Cao-Tang, which shows the most potent inhibitory effects on P-gp among the 50 Kampo medicines studied, and investigated the P-gp inhibitory effects of Daiokanzoto herbal ingredients (rhubarb and licorice root and their components by an ATPase assay using human P-gp membrane. Both rhubarb and licorice root significantly inhibited ATPase activity, and the effects of rhubarb were more potent than those of licorice root. The content of rhubarb in Daiokanzoto is double that in licorice root, and the inhibition patterns of Daiokanzoto and rhubarb involve both competitive and noncompetitive inhibition, suggesting that the inhibitory effects of Daiokanzoto are mainly due to rhubarb. Concerning the components of rhubarb, concentration-dependent inhibitory effects were observed for (−-catechin gallate, (−-epicatechin gallate, and (−-epigallocatechin gallate. In conclusion, rhubarb may cause changes in the drug dispositions of P-gp substrates through the inhibition of P-gp. It appears that attention should be given to the interactions between these drugs and Kampo medicines containing rhubarb as an herbal ingredient.

  10. Fabrication and performance testing of CaO insulator coatings on V-5%Cr-5%Ti in liquid lithium

    Energy Technology Data Exchange (ETDEWEB)

    Park, J.H.; Dragel, G. [Argonne National Lab., Chicago, IL (United States)

    1995-04-01

    Corrosion resistance of structural materials, and the magnetohydrodynamic (MHD) force and its influence on thermal hydraulics and corrosion, are major concerns in the design of liquid-metal blankets for magnetic fusion reactors (MFRs). The objective of this study is to develop in-situ stable coatings at the liquid-metal/structural-material interface, with emphasis on coatings that can be converted to an electrically insulating film to prevent adverse currents that are generated by the MHD force from passing through the structural walls. The electrical resistance of CaO coatings produced on V-5Cr-5Ti by exposure of the alloy to liquid Li that contained 0.5 - 8.5 wt.% dissolved Ca was measured as a function of time at temperatures between 250 and 600{degree}C. The solute element, Ca in liquid Li, reacted with the alloy substrate at 400-420{degree}C to produce a CaO coating.

  11. Uma introdução ao controle do caos em sistemas hamiltonianos quase integráveis

    OpenAIRE

    Silva Junior,Vilarbo da; Carvalho, Alexsandro M.

    2014-01-01

    Sistemas Hamiltonianos quase integráveis são de grande interesse em diversos campos de pesquisa da física e da matemática. Nesses sistemas, o espaço de fase apresenta trajetórias regulares e caóticas. Essas trajetórias dependem, em parte, da amplitude da perturbação que quebra a integrabilidade do sistema. O valor da perturbação crítica responsável por esta transição é um elemento chave no controle do caos. No presente trabalho, exploramos um procedimento para o controle do caos em sistema ha...

  12. Pengaruh Katalis Koh Dan Cao Pada Pembuatan Biodiesel Minyak Kemiri Dengan Reaksi Transesterifikasi Menggunakan Eter Sebagai Kosolvent

    OpenAIRE

    Limbong, Juniar

    2010-01-01

    Fuel reserves are limited it is necessary to utilize alternative technologies to exploit the vegetable oil as an energy-friendly alternatives that can be processed with transesterification reaction to obtain an alternative fuel by using an alkaline catalyst such as KOH and CaO. Base catalyzed transesterification is a slow reaction and the production of esters is not the optimum metal can be used to overcome such kosolvent ether Transesterification reaction has been carried out in the media...

  13. Fabrication of 45 degrees template grain boundary junctions using a CaO lift-off technique

    NARCIS (Netherlands)

    IJsselsteijn, R.P.J.; Terpstra, D.; Flokstra, J.; Rogalla, H.

    1994-01-01

    45 degrees grain boundary junctions have been made using (100) MgO substrates, a CeO2 template layer and an YBa2Cu3O7 top layer. To minimize the damage to the MgO surface, which will occur if the CeO2 is structured using ion milling, the CeO2 layer has been structured using the CaO lift-off techniqu

  14. The decrease of carbonation efficiency of CaO along calcination-carbonation cycles: Experiments and modelling

    Energy Technology Data Exchange (ETDEWEB)

    Bouquet, E.; Leyssens, G.; Schonnenbeck, C.; Gilot, P. [Laboratoire de Gestion des Risques et Environnement, Mulhouse (France)

    2009-05-15

    Successive calcination-carbonation cycles, using CaO as sorbent, have been performed either in a classical fixed bed reactor or using a thermogravimetric analyser. Significant differences in carbonation efficiencies were obtained, possibly due to different conditions prevailing for CaO sintering during the calcination stage. The effect of the presence of CO{sub 2} on sintering was confirmed. A simple model of the decay of the carbonation capacity along cycles based on the specific surface area of non-sintered micrograins of CaO is able to predict the decrease of the extent of conversion obtained after 40 carbonations along calcination-carbonation cycles. The asymptotic extent of conversion is obtained when all the micrograins present within a grain are sintered. A detailed model of the carbonation shows that the voids present between the micrograins are filled up by carbonate when a critical thickness of the carbonate layer around each micrograin reaches 43 nm. Then, carbonation becomes controlled by diffusion at the scale of the whole grain, with the CO{sub 2} diffusion coefficient decreasing (at 650 {sup o}C) from 2 x 10{sup -12} to 6.5 x 10{sup -14} m{sup 2}/s as carbonation proceeds from 50% conversion to 76% (first cycle). This scale change for diffusion is responsible for the drastic decrease of the carbonation rate after the voids between micrograins are filled up.

  15. Effect of FeO and CaO on the Sulfide Capacity of the Ferronickel Smelting Slag

    Science.gov (United States)

    Kim, Ki Deok; Huh, Wan Wook; Min, Dong Joon

    2014-06-01

    The effect of FeO and CaO on the sulfide capacity in MgO-SiO2-FeO based slags equilibrating with Fe-Ni alloys at 1773 K and 1873 K (1500 °C and 1600 °C) was investigated. The sulfide capacity in the MgO-SiO2-FeO and MgO-SiO2-CaO-FeO slags increased with higher FeO content and higher temperatures due to an increase in the activity of O2- and a decrease in the activity coefficient of sulfide ion in slag. The sulfide capacity of the MgO-SiO2-CaO-FeO slag also increased with an increase in the CaO content due largely to the increase in the activity of O2-. Furthermore, CaO and FeO seem to be more effective than MgO in increasing the sulfide capacity in the MgO-SiO2-CaO-FeO slag system. In addition, the comparison of the experimental results with the theoretical estimate using the modified empirical optical basicity showed relatively good linear agreement.

  16. Promotion Effect of CaO Modification on Mesoporous Al2O3-Supported Ni Catalysts for CO2 Methanation

    Directory of Open Access Journals (Sweden)

    Wen Yang

    2016-01-01

    Full Text Available The catalysts Ni/Al2O3 and CaO modified Ni/Al2O3 were prepared by impregnation method and applied for methanation of CO2. The catalysts were characterized by N2 adsorption/desorption, temperature-programmed reduction of H2 (H2-TPR, X-ray diffraction (XRD, and temperature-programmed desorption of CO2 and H2 (CO2-TPD and H2-TPD techniques, respectively. TPR and XRD results indicated that CaO can effectively restrain the growth of NiO nanoparticles, improve the dispersion of NiO, and weaken the interaction between NiO and Al2O3. CO2-TPD and H2-TPD results suggested that CaO can change the environment surrounding of CO2 and H2 adsorption and thus the reactants on the Ni atoms can be activated more easily. The modified Ni/Al2O3 showed better catalytic activity than pure Ni/Al2O3. Ni/CaO-Al2O3 showed high CO2 conversion especially at low temperatures compared to Ni/Al2O3, and the selectivity to CH4 was very close to 1. The high CO2 conversion over Ni/CaO-Al2O3 was mainly caused by the surface coverage by CO2-derived species on CaO-Al2O3 surface.

  17. The Software Package PAOLAC: an embedment of the analytical code PAOLA within the CAOS problem-solving environment

    Science.gov (United States)

    Carbillet, Marcel; Jolissaint, Laurent; Maire, Anne-Lise

    We present the Software Package PAOLAC (“PAOLA within Caos”) in its first distributed version. This new numerical simulation tool is an embedment of the analytical adaptive optics simulation code PAOLA (“Performance of Adaptive Optics for Large (or Little) Apertures”) within the CAOS problem-solving environment. The main goal of this new tool is to allow an easier and direct comparison between studies performed with the analytical open-loop code PAOLA and studies performed with the end-to-end closed-loop Software Package CAOS (“Code for Adaptive Optics Systems”), with the final scope of better understanding how to take advantage from the two approaches: one analytical allowing extremely quick results on a wide range of cases and the other extremely detailed but with a computational and memory costs which can be impressive. The practical implementation of this embedment is briefly described, showing how this absolutely does not affect any aspect of the original code which is simply directly called from the CAOS global graphical interface through ad hoc modules. A comparison between end-to-end modelling and analytical modelling is hence also initiated, within the specific framework of wide-field adaptive optics at Dome C, Antarctica.

  18. Influence of SrO substitution for CaO on the properties of bioactive glass S53P4.

    Science.gov (United States)

    Massera, Jonathan; Hupa, Leena

    2014-03-01

    Commercial melt-quenched bioactive glasses consist of the oxides of silicon, phosphorus, calcium and sodium. Doping of the glasses with oxides of some other elements is known to affect their capability to support hydroxyapatite formation and thus bone tissue healing but also to modify their high temperature processing parameters. In the present study, the influence of gradual substitution of SrO for CaO on the properties of the bioactive glass S53P4 was studied. Thermal analysis and hot stage microscopy were utilized to measure the thermal properties of the glasses. The in vitro bioactivity and solubility was measured by immersing the glasses in simulated body fluid for 6 h to 1 week. The formation of silica rich and hydroxyapatite layers was assessed from FTIR spectra analysis and SEM images of the glass surface. Increasing substitution of SrO for CaO decreased all characteristic temperatures and led to a slightly stronger glass network. The initial glass dissolution rate increased with SrO content. Hydroxyapatite layer was formed on all glasses but on the SrO containing glasses the layer was thinner and contained also strontium. The results suggest that substituting SrO for CaO in S53P4 glass retards the bioactivity. However, substitution greater than 10 mol% allow for precipitation of a strontium substituted hydroxyapatite layer.

  19. Melting of CaO and CaSiO3 at Deep Mantle Condition Using First Principles Simulations

    Science.gov (United States)

    Bajgain, S. K.; Ghosh, D. B.; Karki, B. B.

    2015-12-01

    Accurate prediction of melting temperatures of major mantle minerals at high pressures is important to understand the Hadean Earth as well as to explain the observed seismic anomalies at ultra-low velocity zone (ULVZ). To further investigate the geophysical implications of our recent first principles study of molten CaO and CaSiO­3, we calculated the melting temperatures of the corresponding solid phases by integrating the Clausius-Clapeyron equation. The melting behavior of their high-pressure phases can constrain the lower mantle solidus. Our calculations show melting temperature of 5700 ± 500 kelvins for CaSiO3 and 7800 ± 600 kelvins for CaO at the base of the lower mantle (136 GPa). The bulk sound velocities of CaO and CaSiO3 liquids at the core-mantle boundary are found to be 40 % lower than P-wave seismic velocity and 22 % lower than that of MgSiO3 liquid. With substantial decrease of melting temperature by freezing point depression and iron partitioning, the partial melting of multi-component silicate and its gravitational buoyancy at ULVZ cannot be ruled out.

  20. First-principles simulations of CaO and CaSiO3 liquids: structure, thermodynamics and diffusion

    Science.gov (United States)

    Bajgain, Suraj K.; Ghosh, Dipta B.; Karki, Bijaya B.

    2015-05-01

    We have performed first-principles molecular dynamics simulations of CaO and CaSiO3 liquids over broad ranges of pressure (0-150 GPa) and temperature (2,500-8,000 K) within density-functional theory. The simulated liquid structure changes considerably on compression with the mean cation-anion coordination numbers increasing nearly linearly with volume. The Ca-O coordination number increases from 5 (7) near the ambient pressure to 8 (10) at high pressure for CaO (CaSiO3) liquid. The Si-O coordination number increases from 4 to 6 over the same pressure regime. Our results show that both liquids are much more compressible than their solid counterparts implying the possibility of liquid-solid density crossovers at high pressure. The Grüneisen parameter of both the liquids increases with pressure, which is opposite in case of crystalline phases. The calculated self-diffusion coefficients strongly depend on temperature and pressure, thereby requiring non-Arrhenian representation with variable activation volume. The diffusivity differences between the two liquids tend to be large at low-temperature and low-pressure regime. Also, comparisons with MgSiO3 liquid suggest that network modifier cations Ca and Mg behave similarly though Ca is more coordinated and more mobile as compared to Mg.

  1. Galaxy Formation and SN Feedback

    CERN Document Server

    Tissera, P B; White, S D M; Springel, V

    2006-01-01

    We present a Supernova (SN) feedback model that succeeds at describing the chemical and energetic effects of SN explosions in galaxy formation simulations. This new SN model has been coupled to GADGET-2 and works within a new multiphase scheme which allows the description of a co-spatial mixture of cold and hot interstellar medium phases. No ad hoc scale-dependent parameters are associated to these SN and multiphase models making them particularly suited to studies of galaxy formation in a cosmological framework. Our SN model succeeds not only in setting a self-regulated star formation activity in galaxies but in triggering collimated chemical-enriched galactic winds. The effects of winds vary with the virial mass of the systems so that the smaller the galaxy, the larger the fraction of swept away gas and the stronger the decrease in its star formation activity. The fact that the fraction of ejected metals exceeds 60 per cent regardless of mass, suggests that SN feedback can be the responsible mechanism of th...

  2. Study on the influence of CaO on NH{sub 3}+NO+O{sub 2} reaction system in pre-calciner

    Energy Technology Data Exchange (ETDEWEB)

    Tang, J.S.; Song, Q.; Fu, S.L.; Wu, X.Y.; Yao, Q. [Tsinghua Univ., Beijing (China). Inst. of Thermal Engineering

    2013-07-01

    This paper studied the influence of CaO on NH{sub 3}+NO+O{sub 2} reaction system in pre-calciner. Experiments were carried out in a fixed bed reactor. Influence of CaO on NH{sub 3}+NO+O{sub 2} reaction, NH{sub 3} oxidation, NH{sub 3} decomposition and NO reduction by NH{sub 3} at O{sub 2} free condition were studied. NH{sub 3} conversion rates and product selectivities were obtained for each reaction condition. It was proved that the influence of CaO on SNCR performance changed with temperature. CaO promoted SNCR performance at 650 C and changed to inhibit SNCR performance when temperature increased above 700 C. CaO influenced the reaction of NH{sub 3}+NO+O{sub 2} mainly by catalyzing NH{sub 3} oxidation. NH{sub 3} conversion rate and NO selectivity decreased when NH{sub 3} concentration increased. Addition of NO into NH{sub 3} heterogeneous oxidation had little effect on NH{sub 3} conversion rate but decreased NO selectivity. A reaction mechanism for NH{sub 3}NO+O{sub 2} reaction on CaO surface was proposed. Heterogeneous reaction model of NH{sub 3}+NO+O{sub 2} on CaO surface was established based on the proposed reaction mechanism. Numerical results showed that the reaction model in this paper could predict NH3 oxidation and NH{sub 3}+NO+O{sub 2} reaction on CaO surface very well.

  3. 用"需求层次理论"解读曹植悲情人生%Interpretation of Cao Zhi's Tragic Life with Maslow's Hierarchy of Needs

    Institute of Scientific and Technical Information of China (English)

    赵光存

    2015-01-01

    Maslow's hierarchy of needs can be divided into five levels in the shape of pyramids. From the low to the high, they are respectively physiological needs, safety needs, love and belonging needs, esteem needs and self-actualization needs. Cao Zhi's life can be divided into two parts, i.e. the period of time before Cao Pi becomes the emperor of Wei and the period of time after that. The former part of Cao Zhi's life is full of independence and freedom, and his needs are greatly satisfied. Cao Zhi lives a happy and full life. Howev-er, in the latter part of his life, things have changed dramatically. Under the great pressure of being suspected and persecuted by Cao Pi and his son Cao Rui, Cao Zhi's needs cannot be met, which directly leads to Cao Zhi's tragic life.%马斯洛需求层次理论用金字塔的形式把人的需求分为五个层次,从低到高依次为生理需求、安全需求、爱和归属需求、尊重需求和自我实现需求.纵观曹植的一生,以建安二十五年(220年)曹丕继曹操为魏王为界,曹丕称帝前,曹植的需求能得到极大满足和实现,曹植的人生是幸福的,充实的;而曹丕称帝后,由于受到曹丕父子的猜忌和迫害,曹植的人生发生了急剧变化,需求无法得到满足和实现,这直接导致了曹植的悲情人生.

  4. Relationship between catchment characteristics and forms of nitrogen in Cao-E River Basin, Eastern China

    Institute of Scientific and Technical Information of China (English)

    JIN Shuquan; LU Jun; CHEN Dingjiang; SHEN Yena; SHI Yiming

    2009-01-01

    The distribution of different nitrogen forms and their spatial and temporal variations in different pollution types of tributaries or reaches were investigated. Based on the catchments characteristics the tributaries or reaches can be classified into 4 types including headwater in mountainous areas (type I), agricultural non-point source (NPS) pollution in rural areas (type II), municipal and industrial pollution in urban areas (type III), and combined pollution in the main stream (type IV). Water samples were collected monthly from July 2003 to June 2006 in the Cao-E River basin in Zhejiang, Eastern China. The concentrations of NO3-N, NH4+-N, and total nitrogen (TN) were measured. The mean concentrations of NO3-N were in the order type IV > type II> type III > type I, whereas, NH4+-N, total organic nitrogen (TON), and TN were in the order type III > type IV > type II> type I. In headwater and rural reaches, CNO3-N was much higher than CNH4+-N. In urban reaches, TON and NH4+-N were the main forms, accounting for 54.7% and 32.1% of TN, respectively. In the whole river system, CNH4+-N decrease with increasing distance from cities, and CNO3-N increased with the increasing area of farmland in the catchments. With increased river flow, the CNO3-N increased and the CNH4+-N decreased in all types of reaches, while the variations of CTON and CTN were different. For TN, the concentration may be decreased with the increase of river flow, but the export load always increased.

  5. Theoretical study on influence of CaO and MgO on the reduction of FeO by CO

    Science.gov (United States)

    Zhong, Hong; Er, Dequan; Wen, Liangying

    2017-03-01

    Coating of CaO or MgO on the particle surface can prevent the sticking among iron ore particles effectively during fluidization process. However, CaO and MgO promote the formation of iron whiskers at high temperature, leading to the catastrophic defluidization. The density functional theory (DFT) calculations were implemented to investigate the influence of CaO and MgO on reduction of FeO/Fe2O2 by CO. Our results show that the CO molecule tends to bind to FeO/Fe2O2 on CaO(100) and MgO(100) surfaces through newly formed C-Fe and Csbnd O bonds. The CaO(100) surface will accelerate the reduction reactions which occur on it, in particular, in the initial stage of reactions, however, will slow down the reactions in the posterior stage. For the MgO(100) surface, the reduction reactions which occur on it will be promoted. The positive roles displayed by CaO and MgO in promoting the reduction of FeO by CO accelerate the precipitation of fresh iron and therefore, leading to the formation of iron whiskers.

  6. 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

  7. Laser processing issues of nanosized intermetallic Fe-Sn and metallic Sn particles

    Energy Technology Data Exchange (ETDEWEB)

    Alexandrescu, R., E-mail: ralexandrescu2001@yahoo.co.uk [National Institute for Lasers, Plasma and Radiation Physics Bucharest, POB MG-36, 077125 (Romania); Morjan, I.; Dumitrache, F.; Birjega, R.; Fleaca, C.; Morjan, Iuliana; Scarisoreanu, M.; Luculescu, C.R.; Dutu, E. [National Institute for Lasers, Plasma and Radiation Physics Bucharest, POB MG-36, 077125 (Romania); Kuncser, V.; Filoti, G. [National Institute of Materials Physics, POB MG-7, 077125 Bucharest-Magurele (Romania); Vasile, E. [Metav R and D, Rosetti 31, Bucharest (Romania); Ciupina, V. [Ovidius University of Constanta, Bd. Mamaia 124, Constanta (Romania)

    2012-09-15

    Highlights: Black-Right-Pointing-Pointer Intermetallic Fe-Sn and metallic Sn nanoparticles synthesized by laser pyrolysis. Black-Right-Pointing-Pointer Fe(CO){sub 5} and Sn(CH{sub 3}){sub 4} were used as precursors. Black-Right-Pointing-Pointer FeSn{sub 2}, Sn and Fe{sub 3}SnC phases were identified by XRD. Black-Right-Pointing-Pointer Complex core-shell structural characteristics were found by HRTEM analysis. Black-Right-Pointing-Pointer Higher magnetization was found in samples with increased Fe/Sn atomic ratio. - Abstract: Intermetallic Fe-Sn and nanocrystalline metallic Sn nanoparticles have been successfully synthesized from organic precursors using the laser pyrolysis technique with ethylene as sensitizer. Nano-structured Sn (single phase) was prepared by the pyrolysis of Sn(CH{sub 3}){sub 4} (TMT) vapors. Controlled Fe/Sn atomic ratios, ranging from 0.69 to 1.64 were obtained for the prepared Fe-Sn nanopowders by the control of Fe(CO){sub 5} and TMT flows, respectively. XRD studies evidence three main phases: the tetragonal metallic Sn phase and the intermetallic FeSn{sub 2} phase and, to a much lesser extent, the cubic ternary carbide Fe{sub 3}SnC. Complex core-shell structural characteristics were found by HRTEM analysis. More complete information about the Fe phase distributions in the new intermetallic Fe-Sn nanomaterial is provided by temperature dependent {sup 57}Fe Moessbauer spectroscopy.

  8. Directed and Elliptic Flows in 112Sn+112Sn Collisions

    Institute of Scientific and Technical Information of China (English)

    张虎勇; 马余刚; 余礼平; 沈文庆; 蔡翔舟; 方德清; 钟晨; 韩定定

    2001-01-01

    The directed and elliptic flows in collisions of 112Sn+112Sn at energies from 35 to 90 MeV/nucleon are studied inan isospin-dependent quantum molecule dynamics model. With increasing incident energy, the directed flow risesfrom negative to positive. Its magnitude depends on the nuclear equation of state (EOS). However, the ellipticflow decreases with increasing incident energy and its magnitude is not very sensitive to EOS. Systematic studiesof the impact parameter dependence and the cluster mass dependence are also performed. The study of directedflow at intermediate energies thus provides a means of extracting the information on the nuclear equation of state.

  9. Intermitência alfvênica gerada por caos na atmosfera solar e no vento solar

    Science.gov (United States)

    Rempel, E. L.; Chian, A. C.-L.; Macau, E. E. N.; Rosa, R. R.

    2003-08-01

    Dados medidos no vento solar rápido proveniente dos buracos coronais revelam que os plasmas no meio interplanetário são dominados por flutuações Alfvênicas, caracterizadas por uma alta correlação entre as variações do campo magnético e da velocidade do plasma. As flutuações exibem muitas características esperadas em turbulência magneto-hidrodinâmica totalmente desenvolvida, tais como intermitência e espectros contínuos. Contudo, os mecanismos responsáveis pela evolução de turbulência Alfvênica intermitente não são completamente compreendidos. Neste trabalho a teoria de caos é usada para explicar como sistemas Alfvênicos, modelados pela equação Schrödinger não-linear derivativa e pela equação Kuramoto-Sivashinsky, podem se tornar fortemente caóticos à medida em que parâmetros do plasma são variados. Pequenas perturbações no parâmetro de dissipação podem fazer com que o sistema mude bruscamente de um regime periódico, ou fracamente caótico, para um regime fortemente caótico. As séries temporais das flutuações do campo magnético nos regimes fortemente caóticos exibem comportamento intermitente, em que fases laminares ou fracamente caóticas são interrompidas por fortes estouros caóticos. É mostrado que o regime fortemente caótico é atingido quando as soluções periódicas ou fracamente caóticas globalmente estáveis interagem com soluções do sistema que são fortemente caóticas, mas globalmente instáveis. Estas soluções globalmente instáveis são conjuntos caóticos não-atrativos conhecidos como selas caóticas, e são responsáveis pelos fortes estouros nos regimes intermitentes. Selas caóticas têm sido detectadas experimentalmente em uma grande variedade de sistemas, sendo provável que elas desempenhem um papel importante na turbulência intermitente observada em plasmas espaciais.

  10. Thermodynamic description of Sn-Y and Mg-Sn-Y systems

    Institute of Scientific and Technical Information of China (English)

    吕东显; 郭翠萍; 李长荣; 杜振民

    2014-01-01

    The thermodynamic optimization of the Sn-Y and Mg-Sn-Y systems was critically carried out by means of the CALPHAD (CALculation of PHAse Diagram) technique. In the Sn-Y system, the solution phases (liquid, bcc, bct and hcp) were described by the substitutional solution model. The compound Sn3Y5, which has a homogeneity range, was treated as the formula (Sn, Y)3(Sn, Y)2Y3 by a three-sublattice model in accordance with the site occupancies. In the Mg-Sn-Y system, the liquid phase was treated as the for-mula (Mg, Sn, Y, Mg2Sn) using an associated solution model, and bcc, bct and hcp were treated as the formula (Mg, Sn, Y). The compound Sn3Y5 was treated as the formula (Sn, Y, Mg)3(Sn, Y, Mg)2Y3. The ternary compound MgSnY was treated as stoichiomet-ric compound. A set of self-consistent thermodynamic parameters of the Mg-Sn-Y system was obtained. The projection of the liq-uidus surfaces and the reaction scheme of the Mg-Sn-Y system were predicted.

  11. La5Zn2Sn

    Directory of Open Access Journals (Sweden)

    Igor Oshchapovsky

    2011-11-01

    Full Text Available A single crystal of pentalanthanum dizinc stannide, La5Zn2Sn, was obtained from the elements in a resistance furnace. It belongs to the Mo5SiB2 structure type, which is a ternary ordered variant of the Cr5B3 structure type. The space is filled by bicapped tetragonal antiprisms from lanthanum atoms around tin atoms sharing their vertices. Zinc atoms fill voids between these bicapped tetragonal antiprisms. All four atoms in the asymmetric unit reside on special positions with the following site symmetries: La1 (..m; La2 (4/m..; Zn (m.2m; Sn (422.

  12. Structural Characteristics of Liquid Sn

    Institute of Scientific and Technical Information of China (English)

    WU Ai-Qing; GUO Li-Jun; LIU Chang-Song; ZHU Zhen-Gang

    2005-01-01

    @@ We investigate the structural properties of liquid Sn. With the help of the internal friction (tan φ) method, it is found that a peak appears in the tan φ - T curve, suggesting that an anomalous discontinuous temperature induced structure change may take place in liquid Sn. From the experimental data of pair distribution functions, we calculate the viscosity η and the excess entropy S and it is found that there are a peak of viscosity in the η - T curve and a bend of excess entropy in the S - T curve, which give a positive support to the appearance of the internal-friction peak in the tan φ - T curve.

  13. MODIFIKASI KATALIS CaO DENGAN SrO PADA REAKSI TRANSESTERIFIKASI MINYAK JELANTAH MENJADI BIODIESEL MENGGUNAKAN

    Directory of Open Access Journals (Sweden)

    N Widiarti

    2016-03-01

    Full Text Available Minyak jelantah merupakan salah satu jenis minyak nabati yang dapat digunakan sebagai sumber produksi biodiesel yang murah. Biodiesel dapat diperoleh melalui proses esterifikasi dengan katalis asam maupun transesterifikasi dengan menggunakan katalis homogen basa kuat. Pengolahan minyak jelantah menjadi biodiesel merupakan langkah yang tepat dan efektif untuk menurunkan harga biodiesel karena bahan baku yang murah dan memanfaatkan limbah minyak goreng yang dapat mengatasi masalah pembuangan minyak dan kesehatan masyarakat. Pada penelitian ini dilakukan reaksi transesterifikasi dari minyak jelantah menjadi biodiesel menggunakan katalis CaO dan SrO. Tujuan penelitian ini adalah untuk mengetahui karakteristik katalis dan aktivitas katalitiknya pada reaksi transesterifikasi minyak jelantah. Modifikasi katalis dilakukan dengan metode impregnasi SrNO3 pada katalis CaO. Katalis digunakan pada reaksi transesterifikasi minyak jelantah dengan variasi energi  (input daya 80 dan 100 watt, variasi waktu (30, 60, 90, 120 dan 150 detik dan variasi jumlah SrO/CaO (1%, 2%, 4%, 8% dan 16% b/b sebagai katalis. Karakterisasi katalis dilakukan dengan XRD dan FTIR. Hasil analisis XRD menunjukkan bahwa katalis SrO/CaO bersifat kristalin dan mempunyai karakteristik pola difraksi gabungan CaO dan SrO. Reaksi transesterifikasi optimal terjadi dengan aktivitas katalis terbaik pada energi  100 watt, waktu reaksi 120 detik dan jumlah katalis SrO/CaO sebesar 4% b/b dengan produk reaksi metil ester sebesar 92,86%. Wasted cooking oil is one type of vegetable oil that can be used as an inexpensive source of biodiesel production. Biodiesel can be obtained through esterification process with acid catalyst or transesterification using homogeneous catalyst of strong bases. Processing of wasted cooking oil into biodiesel is an appropriate and effective measures to reduce the high price of biodiesel because of cheap raw materials and it can overcome the problem of oil disposal and

  14. SN 2009E: a faint clone of SN 1987A

    DEFF Research Database (Denmark)

    Pastorello, A.; Pumo, M. L.; Navasardyan, H.

    2012-01-01

    Context.1987A-like events form a rare sub-group of hydrogen-rich core-collapse supernovae that are thought to originate from the explosion of blue supergiant stars. Although SN 1987A is the best known supernova, very few objects of this group have been discovered and, hence, studied. Aims. In thi...

  15. Enhanced Ce{sup 3+} photoluminescence by Li{sup +} co-doping in CaO phosphor and its use in blue-pumped white LEDs

    Energy Technology Data Exchange (ETDEWEB)

    Hao, Zhendong, E-mail: haozd@ciomp.ac.cn; Zhang, Xia; Luo, Yongshi; Zhang, Ligong; Zhao, Haifeng; Zhang, Jiahua, E-mail: zhangjh@ciomp.ac.cn

    2013-08-15

    In this paper, we demonstrate a method to improve the photoluminescence of CaO: Ce{sup 3+} phosphor and delineate its first use in blue-pumped white LEDs. The results show that the yellow emission of Ce{sup 3+} is enhanced by a factor of 1.88 by adding Li{sup +} into CaO host at 474 nm blue light excitation. On analyzing the diffuse reflection spectra and fluorescence decay curves, we reveal that the photoluminescence enhancement is originated from the rise of absorbance to the excitation photons but not from the improvement of the luminescent efficiency. Li{sup +}-improved CaO: Ce{sup 3+} exhibits more red component when it is compared with the commercial Y{sub 3}Al{sub 5}O{sub 12}: Ce{sup 3+} (YAG: Ce{sup 3+}) phosphor, indicating its potential application for high color rendering white LEDs. Thus, a white LED is fabricated by combining blue InGaN LED chip with CaO: Ce{sup 3+}, Li{sup +} phosphor and a warm white light with high color rendering index (R{sub a}) of 80, low correlated color temperature (T{sub c}) of 4524 K, and sufficient luminous efficiency of 50 lm W{sup −1} is obtained. -- Highlights: • The photoluminescence of Ce{sup 3+} in CaO host was enhanced by Li{sup +} co-doping. • A CaO: Ce{sup 3+}, Li{sup +} based white LED was fabricated for the first time. • An efficient warm white light was obtained. • CaO: Ce{sup 3+}, Li{sup +} is expected to be used as a yellow phosphor for blue-pumped white LEDs.

  16. Epitaxial growth of strained and unstrained GeSn alloys up to 25% Sn

    Energy Technology Data Exchange (ETDEWEB)

    Oehme, Michael, E-mail: oehme@iht.uni-stuttgart.de; Kostecki, Konrad; Schmid, Marc; Oliveira, Filipe; Kasper, Erich; Schulze, Jörg

    2014-04-30

    Strained and unstrained GeSn layers on Si substrates were grown with Sn contents up to 20% and 25%, respectively. All metastable layer structures were fabricated by means of an ultra-low temperature molecular beam epitaxy process. The useful thickness of the metastable layers for a range of Sn contents, growth temperatures and two different strain values (unstrained, compressive strained) is explored. The epitaxial breakdown thickness which limits the useful thickness range decreases exponentially with increasing growth temperature and Sn concentration. - Highlights: • GeSn epitaxy • GeSn layers with Sn contents up to 25% • Limited layer thickness.

  17. On the use of ocean-atmosphere-wave models during an extreme CAO event: the importance of being coupled

    Science.gov (United States)

    Carniel, Sandro; Barbariol, Francesco; Benetazzo, Alvise; Bonaldo, Davide; Falcieri, Francesco M.; Miglietta, Mario M.; Ricchi, Antonio; Sclavo, Mauro

    2015-04-01

    During winter 2012 an extreme meteorological event stroke the whole Europe and particularly its central-southern sector. A strong and persistent spit of cold air coming from Siberian region (a Cold Air Outbreak, CAO) insisted on northern Italy and the Adriatic sea basin, leading to decreases in the sea temperatures up to 6 °C in less than two weeks, ice formation on the Venice lagoon and an exceptional snow fall in the Apennine region. In the sea the CAO was associated to a significant episode of dense water formation (DWF), a crucial phenomenon that heavily impacts the whole Adriatic Sea (from the sinking of water masses and associated ventilation of the northernmost shelf, to the flow along the western coast, until the flushing of southern Adriatic open slope and submarine canyons, with associated sediment transport and bottom reshaping). The extent of the DWF event in the Northern Adriatic sub-basin was estimated by means of coastal observatories, ad hoc measurements and, until now, results from existing one-way coupled atmosphere-ocean models. These are characterized by no SST feedback from the ocean to the atmosphere, and therefore by turbulent heat fluxes that may heavily reflect a non-consistent ocean state. The study proposes an investigation of the 2012 CAO using a fully coupled, three components, ocean-atmosphere-wave system (COAWST). Results highlight that, although the energy interplays between air and sea do not seem to significantly impact the wind forecasts, when providing heat fluxes that are consistent with the ocean temperature we find modified heat fluxes and air sea temperatures figures. Moreover, the consistent description of thermal exchanges adopted in the fully coupled model can affect the basin circulation, the quantification of dense water produced mass, and the description of its migration pathways and rates of off-shelf descent.

  18. Laser processing issues of nanosized intermetallic Fe-Sn and metallic Sn particles

    Science.gov (United States)

    Alexandrescu, R.; Morjan, I.; Dumitrache, F.; Birjega, R.; Fleaca, C.; Morjan, Iuliana; Scarisoreanu, M.; Luculescu, C. R.; Dutu, E.; Kuncser, V.; Filoti, G.; Vasile, E.; Ciupina, V.

    2012-09-01

    Intermetallic Fe-Sn and nanocrystalline metallic Sn nanoparticles have been successfully synthesized from organic precursors using the laser pyrolysis technique with ethylene as sensitizer. Nano-structured Sn (single phase) was prepared by the pyrolysis of Sn(CH3)4 (TMT) vapors. Controlled Fe/Sn atomic ratios, ranging from 0.69 to 1.64 were obtained for the prepared Fe-Sn nanopowders by the control of Fe(CO)5 and TMT flows, respectively. XRD studies evidence three main phases: the tetragonal metallic Sn phase and the intermetallic FeSn2 phase and, to a much lesser extent, the cubic ternary carbide Fe3SnC. Complex core-shell structural characteristics were found by HRTEM analysis. More complete information about the Fe phase distributions in the new intermetallic Fe-Sn nanomaterial is provided by temperature dependent 57Fe Mössbauer spectroscopy.

  19. Design of a Novel Fluidized Bed Reactor To Enhance Sorbent Performance in CO2 Capture Systems Using CaO

    OpenAIRE

    Diego de Paz, María Elena; Arias Rozada, Borja; Grasa, Gemma; Abanades García, Juan Carlos

    2014-01-01

    This work deals with the modeling and design of a novel bubbling fluidized bed reactor that aims to improve the CO2 carrying capacity of CaO particles in CO2 capture systems by calcium looping (CaL). Inside the new reactor (the recarbonator) the particles that arrive from the carbonator of the CaL system react with a concentrated stream of CO2, thereby increasing their carbonate content up to a certain value, which can be predicted by means of the model proposed. The recarbonator model presen...

  20. O estatuto político da amizade: A Alma do Osso, de Cao Guimarães

    Directory of Open Access Journals (Sweden)

    Rafael de Almeida

    2013-06-01

    Full Text Available A partir do conceito de amizade proposto por Giorgio Agamben, este ensaio reflete, em uma interface entre estética e política, acerca das relações de poder presentes em A Alma do Osso (Cao Guimarães, 2004. O maior relevo é dado ao modo que o cineasta partilha, por meio do filme, sua existência com o ermitão Dominguinhos da Pedra, bem como as reverberações que isso garante à forma do documentário.

  1. Excellent Li-ion storage performances of hierarchical SnO-SnO2 composite powders and SnO nanoplates prepared by one-pot spray pyrolysis

    Science.gov (United States)

    Kim, Jung Hyun; Jeon, Kyung Min; Park, Jin-Sung; Kang, Yun Chan

    2017-08-01

    Hierarchical-structured SnO-SnO2 composite powders and SnO nanoplates with some SnO2 nanorods are prepared by one-pot spray pyrolysis. Dicyandiamide dissolved in the spray solution plays a key role in the preparation of the hierarchical-structured SnO-SnO2 composite powder and SnO nanoplates. The hierarchical-structured SnO-SnO2 composite powders, in which the SnO nanoplates are trapped in the porous SnO2 nanosphere, are prepared by spray pyrolysis at 800 °C. Sufficient conversion of the porous SnO2 nanospheres to SnO at 900 °C results in aggregation-free SnO2 nanoplates. SnO2 nanorods with a spherical nanodroplet at the tip are formed by Ostwald ripening. The hierarchical-structured SnO-SnO2 composite powder having high structural stability during repeated lithium alloying and dealloying reactions, shows superior discharge capacities and rate performances for lithium-ion storage compared to those of the dense-structured SnO2 powders. The discharge capacities of the hierarchical-structured SnO-SnO2 composite powders, SnO nanoplates with SnO2 nanorods, and dense-structured SnO2 powders at a current density of 1 A g-1 for the 300th cycle are 561, 504, and 416 mA h g-1, respectively. The SnO nanoplates with SnO2 nanorods and hierarchical-structured SnO-SnO2 powders deliver high reversible discharge capacities of 433 and 379 mA h g-1 at an extremely high current density of 10 A g-1, respectively.

  2. Structure and vibrational dynamics of interfacial Sn layers in Sn/Si multilayers

    Science.gov (United States)

    Cuenya, B. Roldan; Keune, W.; Sturhahn, W.; Toellner, T. S.; Hu, M. Y.

    2001-12-01

    The structure and vibrational dynamics of room-temperature-grown nanoscale Sn/amorphous (a-)Si multilayers have been studied by x-ray diffraction, Raman scattering, 119Sn Mössbauer spectroscopy, and 119Sn nuclear-resonant inelastic x-ray scattering (NRIXS) of synchrotron radiation. With increasing Sn-layer thickness, the formation of β-Sn was observed, except at the Sn/Si interfaces, where a 10-Å-thick metastable pure amorphous-α-Sn-like layer remains stabilized. By means of NRIXS we have measured the Sn-projected vibrational density of states (VDOS) in these multilayers (in particular, at the interfaces), and in 500-Å-thick epitaxial α-Sn films on InSb(001) as a reference. Further, the Sn-specific Lamb-Mössbauer factor (f factor), mean kinetic energy per atom, mean atomic force constant, and vibrational entropy per atom were obtained. The VDOS of the amorphous-α-Sn-like interface layer is observed to be distinctly different from that of (bulk) α-Sn and β-Sn, and its prominent vibrational energies are found to scale with those of amorphous Ge and Si. The observed small difference in vibrational entropy (ΔS/kB=+0.17+/-0.05 per atom) between α-Sn and interfacial amorphous-α-like Sn does not account for the stability of the latter phase.

  3. Solar light-facilitated oxytetracycline removal from the aqueous phase utilizing a H2O2/ZnWO4/CaO catalytic system

    Directory of Open Access Journals (Sweden)

    Pankaj Raizada

    2017-09-01

    Full Text Available A CaO-supported ZnWO4 nanocomposite (ZnWO4/CaO was successfully synthesized using a novel hydrothermal method and was characterized by scanning electron microscopy (SEM, tunnelling electron microscopy (TEM, X-ray diffraction (XRD, electron diffraction X-ray (EDX, Fourier transform infrared spectroscopy (FTIR and UV–visible (UV–vis spectral analysis. The ZnWO4/CaO composites exhibited rod-like morphologies with variable lengths from 45 nm to 147 nm and diameters from 26 nm to 36 nm. The catalytic efficiency of the synthesized ZnWO4/CaO composites was displayed for the photodegradation of oxytetracycline (OTC antibiotic from the aqueous phase. The synergistic degradation of OTC was investigated in the presence of H2O2 and ZnWO4/CaO. The rate of photodegradation followed pseudo-first-order kinetics. The antibiotic removal was strongly influenced by the catalyst loading, H2O2 concentration, pH and OTC concentration. Using a solar/H2O2/ZnWO4/CaO catalytic system, 85% COD removal was attained for OTC degradation in 210 min. The oxidative degradation occurred through hydroxyl radicals. The prepared nanocomposites possessed high recyclability and were easily separated from the aqueous solution by a simple sedimentation process.

  4. La teoría d el caos... Esa nube turbulenta que da qué pensar

    Directory of Open Access Journals (Sweden)

    Ruben Antonio Sánchez G.

    1999-10-01

    Full Text Available "Ver las cosas hasta el fondo...¿Y si las cosas no tuvieran fondo?iAh, que bella la superficie!Quizá la superficie sea la esenciaY lo que excede la superficie sea lo que excede a todoY lo que excede a todo no es nada./Oh rostro del mundo, sólo tu, de todos los rostros,Eres la propia alma que reflejas/”PESSOA, Fernando, Poemas inconjuntos 65.(En: Poesías completas de Alberto Caeiro. Valencia: Pre-textos, 1997, p.3 19.Este texto plantea algunos de los problemas suscitados por la teoría del caos.Es decir, pretende mostrar algunas de las cuestiones que han surgido a partir de la formulación de un modo de obtención de conocimiento que parece tener ventajas sobre otros y según algunos de sus difusores, constituye una revolución en la práctica y el saber científicos. En consecuencia, presentaremos a continuación un panorama de estos problemas 01 tanto que, por una parte, nos muestran las posibilidades y los límites de dicha teoría y , por otra, nos indican en qué sentido la teoría del caos puede dar qué pensar.

  5. Relevance of the Physicochemical Properties of Calcined Quail Eggshell (CaO as a Catalyst for Biodiesel Production

    Directory of Open Access Journals (Sweden)

    Leandro Marques Correia

    2017-01-01

    Full Text Available The CaO solid derived from natural quail eggshell was calcined and employed as catalyst to produce biodiesel via transesterification of sunflower oil. The natural quail eggshell was calcined at 900°C for 3 h, in order to modify the calcium carbonate present in its structure in CaO, the activity phase of the catalyst. Both precursor and catalyst were characterized using Hammett indicators method, X-ray fluorescence (XRF, X-ray diffraction (XRD, thermogravimetric analysis (TG/DTG, CO2 temperature-programmed desorption (CO2-TPD, X-ray photoelectronic spectroscopy (XPS, Fourier infrared spectroscopy (FTIR, scanning electron microscopy (SEM, N2 adsorption-desorption at −196°C, and distribution particle size. The maximum biodiesel production was of 99.00 ± 0.02 wt.% obtained in the following transesterification reaction conditions: XMR (sunflower oil/methanol molar ratio of 1 : 10.5 mol : mol, XCAT (catalyst loading of 2 wt.%, XTIME (reaction time of 2 h, stirring rate of 1000 rpm, and temperature of 60°C.

  6. Generation of hydrogen from polyvinyl chloride by milling and heating with CaO and Ni(OH)2.

    Science.gov (United States)

    Tongamp, William; Zhang, Qiwu; Shoko, Miyagi; Saito, Fumio

    2009-08-15

    This work discusses an alternative process option for the treatment of polyvinyl chloride (PVC) by producing hydrogen (H(2)) gas, at the same time fixing chlorine for proper environmental control. In the first-stage, a milling operation is performed in a planetary ball mill to obtain a mixture of PVC sample with CaO and Ni(OH)(2) to be used as feed in the second-step, involving heating of the milled product. Analyses by thermogravimetry-mass spectroscopy (TG-MS) and gas chromatography (GC) showed H(2), CH(4), CO and CO(2) as main constituents. The results clearly show that addition of Ni(OH)(2) to provide nickel as catalyst and CaO as adsorbent to fix CO(2) and HCl gases generated during heating, assisted in clean H(2) generation with concentration near 90% at temperatures between 450 and 550 degrees C. Analyses of solids after heating by X-ray diffraction and TG-DTA techniques showed both CaOHCl and CaCO(3) as main phases in the product. This process could be developed to treat PVC wastes together with other polymers and/or plastic wastes for production of H(2) gas.

  7. CaO insulator and Be intermetallic coatings on V-base alloys for liquid-lithium fusion blanket applications

    Energy Technology Data Exchange (ETDEWEB)

    Park, J.H.; Kassner, T.F. [Argonne National Laboratory, Chicago, IL (United States)

    1996-04-01

    The objective of this study is to develop (a) stable CaO insulator coatings at the Liquid-Li/structural-material interface, with emphasis on electrically insulating coating that prevent adverse MHD-generated currents from passing through the V-alloy wall, and (b) stable Be-V intermetallic coating for first-wall components that face the plasma. Electrically insulating and corrosion-resistant coatings are required at the liquid-Li/structural interface in fusion first-wall/blanket application. The electrical resistance of CaO coatings produced on oxygen-enriched surface layers of V-5%Cr-5%Ti by exposing the alloy to liquid Li that contained 0.5-85 wt% dissolved Ca was measured as a function of time at temperatures between 250 and 600{degrees}C. Crack-free Be{sub 2}V intermetallic coatings were also produced by exposing V-alloys to liquid Li that contained Be as a solute. These techniques can be applied to various shapes (e.g., inside/outside of tubes, complex geometrical shapes) because the coatings are formed by liquid-phase reactions.

  8. Fabrication, property characterization and toushening mechanism of HA-ZrO2(CaO)/316L fibre composite biomaterials

    Institute of Scientific and Technical Information of China (English)

    ZOU JianPeng; HE ZeQiang; ZHOU ZhongCheng; HUANG BaiYun; CHEN QiYuan; RUAN JianMing

    2008-01-01

    HA-ZrO2(CaO)/316L fibre composites were successfully fabricated with vacuum sintering method and their properties and toughening mechanism were studied.The results showed that HA-ZrO2(CaO)/316L fibre biocomposite having 20 vol% fibres had optimal comprehensive properties with bending strength,Young's modulus,fracture toughness and relative density equal to 140.1 MPa,117.8 GPa,5.81 MPa.m1/2and 87.1%,respectively.The research also addressed that different volume ratios of the composites led to different metallographic microstructures,and that metallographic morphologies change regularly with volume ratios of the composites.316L fibres were distributed randomly and evenly in the composites and the integration circumstance of the two phases was very well since there were no obvious flaws or pores in the composites.Two toughening mechanisms in-cluding ZrO2 phase transformation toughening mechanism and fibre pulling-out toughening mechanism existed in the compsites with the latter being the main toughening mechanism.

  9. A study of the dissociative recombination of CaO+ with electrons: Implications for Ca chemistry in the upper atmosphere

    Science.gov (United States)

    Bones, D. L.; Gerding, M.; Höffner, J.; Martín, Juan Carlos Gómez; Plane, J. M. C.

    2016-12-01

    The dissociative recombination of CaO+ ions with electrons has been studied in a flowing afterglow reactor. CaO+ was generated by the pulsed laser ablation of a Ca target, followed by entrainment in an Ar+ ion/electron plasma. A kinetic model describing the gas-phase chemistry and diffusion to the reactor walls was fitted to the experimental data, yielding a rate coefficient of (3.0 ± 1.0) × 10-7 cm3 molecule-1 s-1 at 295 K. This result has two atmospheric implications. First, the surprising observation that the Ca+/Fe+ ratio is 8 times larger than Ca/Fe between 90 and 100 km in the atmosphere can now be explained quantitatively by the known ion-molecule chemistry of these two metals. Second, the rate of neutralization of Ca+ ions in a descending sporadic E layer is fast enough to explain the often explosive growth of sporadic neutral Ca layers.

  10. Utilization of desulfurization gypsum to producing SO{sub 2} and CaO in multi-stage fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Miao, Zhu; Wang, Tao; Yang, Hairui; Zhang, Hai; Zhang, Zuyi [Tsinghua Univ., Beijing (China). Dept. of Thermal Engineering; Ministry of Education, Beijing (China). Key Lab. for Thermal Science and Power Engineering

    2013-07-01

    With emission control becomes more and more stringent, flue gas desulphurization (FGD) is commonly employed for desulfurization. However, the product of FGD, gypsum, causes the unexpected environmental problems. How to utilize the byproduct of FGD effectively and economically is a challenging task. This paper proposed the new technical process to produce SO{sub 2} and CaO by reducing the gypsum in multi-stage fluidized bed reactor with different atmosphere. In addition, some preliminary experiments were carried out in PTGA. The results show that CO concentration has little effect on the initial decomposing temperature, but affect the decomposing rate of phosphogypsum obviously. The decomposing product composed of CaS and CaO simultaneously. The ratio of the two products was determined by CO concentration. Lower CO content benefits to produce more CO product and more SO{sub 2}. The decomposition reaction of phosphogypsum in reducing atmosphere is parallel competition reaction. Therefore, it is necessary to eliminate the effect of CaS and other byproduct efficiently by the new technology, which utilize multi-atmosphere in multistage fluidized bed reactors.

  11. Influence of the Sn oxidation state in ferromagnetic Sn-doped In2O3 nanowires

    Science.gov (United States)

    Maloney, Francis Scott; Wang, Wenyong

    2016-12-01

    Sn-doped indium oxide nanowires were grown using a vapor-liquid-solid technique (VLS). The Sn content of the nanowires was tunable based on the source powder ratios used in the VLS process. The oxidation state of the Sn ions was examined using x-ray photoelectron spectroscopy. It was found that Sn2+ was the dominant ionic species in samples over 6% (atomic percentage) Sn. The nanowires were found to be ferromagnetic at room temperature, and their saturation magnetization increased with increasing Sn concentration, which could be associated with the spin-splitting of a defect band that was encouraged by the imbalance of Sn2+ to Sn4+ species at high Sn concentrations.

  12. Solid state interactions in the systems CaO(CaCO3-Fe2O3 and CuFe2O4-CaO

    Directory of Open Access Journals (Sweden)

    Boyanov B.S.

    2005-01-01

    Full Text Available The solid state interactions in the systems CaO(CaCO3-Fe2O3 and CuFe2O4-CaO have been studied using X-ray diffraction analysis. The influence of the temperature on the ferrite formation process has been investigated in the range of 900-1200 oC and duration up to 360 min. It has been shown that a mixture of ferrites forms at 1000 oC and interaction of 240 min. The exchange reactions in the systems CuFe2O4-CaO and Cu0.5Zn0.5Fe2O4-CaO have been studied, too. It has been established that Ca2+ ions exchange Cu2+ and Zn2 partially and the solubility of copper and zinc in a 7 % sulfuric acid solution increases 10-15 times.

  13. 面子观与曹植的郁郁而终%Integration of Face View and Cao Zhi’s Bleak Destination

    Institute of Scientific and Technical Information of China (English)

    赵光存

    2014-01-01

    曹植在曹丕称帝前,个人的积极面子和消极面子都能得到极大的维护和保证;而曹丕称帝后及曹叡执政期间,曹植个人的积极面子得到的是虚伪的维护和认可,而个人的消极面子则受到极大的冒犯和侵害。智慧无法施展、政治抱负无法实现、对于真爱的追求被极端地压抑、知己被铲除,如此等等,使曹植备受煎熬,产生极大的性格分裂,找不到身份的认同感和归属感,最终导致郁郁而终。%Before Cao Pi became emperor of Kingdom Wei, Cao Zhi’s positive face and negative face could be maintained and guaranteed. However, after Cao Pi’s getting on the throne and during the reign of Cao Rui, Cao Zhi’s positive face was maintained and recognized hypocritically, and his negative face was offend-ed and violated terribly. His wisdom could not be utilized and his political pursuit failed to be realized, mean-while his right of pursuing genuine love was extremely suppressed and his close friends were killed or ex-pelled, all of which made Cao Zhi tortured. His personality was split and he had no sense of identity and be-longing, which led to his bleak destination.

  14. The study of CaO and MgO heterogenic nano-catalyst coupling on transesterification reaction efficacy in the production of biodiesel from recycled cooking oil.

    Science.gov (United States)

    Tahvildari, Kambiz; Anaraki, Yasaman Naghavi; Fazaeli, Reza; Mirpanji, Sogol; Delrish, Elham

    2015-01-01

    Fossil fuels' pollution and their non-renewability have motivated the search for alternative fuels. Some common example of seed oils are sunflower oil, date seed oil, soy bean oil. For instance, soy methyl and soy-based biodiesel are the main biodiesel. Biodiesel is a clean diesel fuel that can be produced through transesterification reaction. Recycled cooking oil, on the other hand, is one of the inexpensive, easily available sources for producing biodiesel. This article is aimed at production of biodiesel via trans-esterification method, Nano CaO synthesis using sol-gel method, and Nano MgO synthesis using sol-gel self-combustion. Two catalysts' combination affecting the reaction's efficacy was also discussed. Optimum conditions for the reaction in the presence of Nano CaO are 1.5 % weight fracture, 1:7 alcohol to oil proportion and 6 h in which biodiesel and glycerin (the byproduct) are produced. Moreover, the optimum conditions for this reaction in the presence of Nano CaO and Nano MgO mixture are 3 % weight fracture (0.7 g of Nano CaO and 0.5 g of Nano MgO), 1:7 alcohols to oil proportion and 6 h. Nano MgO is not capable of catalyzing the transesterification by itself, because it has a much weaker basic affinity but when used with Nano CaO due to its surface structure, the basic properties increase and it becomes a proper base for the catalyst so that CaO contact surface increases and transesterification reaction yield significantly increases as well. This study investigates the repeatability of transesterification reaction in the presence of these Nano catalysts as well.

  15. Development of mechanical properties in a CaO added AZ31 magnesium alloy processed by equal-channel angular pressing

    Energy Technology Data Exchange (ETDEWEB)

    Bae, Seong-Hwan [Division of Materials Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Metal Forming Technology R& D Group, Korea Institute of Industrial Technology, Incheon 406-840 (Korea, Republic of); Jung, Ki Ho; Shin, Young-Chul; Yoon, Duk Jae [Metal Forming Technology R& D Group, Korea Institute of Industrial Technology, Incheon 406-840 (Korea, Republic of); Kawasaki, Megumi, E-mail: megumi@hanyang.ac.kr [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)

    2016-02-15

    Processing through the application of equal-channel angular pressing (ECAP) is recognized as one of the attractive severe plastic deformation techniques where the processed bulk metals generally achieve ultrafine-grained microstructure leading to improved physical characteristics and mechanical properties. Magnesium has received much attention to date for its lightweight, high strength and excellent elasticity. Mg alloys with addition of CaO is reported to provide the successful casting procedure without usage of greenhouse gas, SF{sub 6}, whereas it is generally used for preventing the oxidation of Mg during casting. In the present investigation, a CaO added AZ31 (AZ31-CaO) magnesium alloy was processed by ECAP at elevated temepratures with a few steps of reduction which result in significant grain refinement to ~ 1.5 μm after 6 passes. Compression testing at room temperature demonstrated the AZ31-CaO alloy after ECAP showed enhanced yield strength more than the as-processed commercial AZ31 alloy while both alloys maintained ductility in spite of significant reduction in grain size. The improved strength in the AZ31-CaO alloy was attributed to the formation of fine Al{sub 2}Ca precipitates which experience breaking-up through ECAP and accelerate the microstructural refinement. Moreover, the preservation of ductility was attributed to the enhancement of strain hardening capability in the AZ31 alloy at room temperature. This study discusses the feasibility of using ECAP to improve both strength and ductility on magnesium alloys by applying the diagram describing the paradox of strength and ductility. - Highlights: • AZ31 and AZ31-CaO magnesium alloys were processed by ECAP up to 6 passes. • AZ31-CaO alloy after ECAP showed improved yield strength without losing ductility. • CaO in AZ31 forms fine Al{sub 2}Ca accelerating microstructural refinement during ECAP. • Feasibility of using ECAP was shown to improve both strength and ductility in Mg.

  16. Um estudo sobre aplicações da teoria do caos e complexidade à gestão das cadeias de suprimentos

    OpenAIRE

    Rodolfo Leandro de Faria Olivo

    2010-01-01

    Este estudo aborda a aplicação da teoria do caos e complexidade à gestão das cadeias de suprimentos. Seu objetivo consiste em responder a questão orientadora da pesquisa, se a teoria do caos e complexidade pode enriquecer o entendimento e compreensão da gestão das cadeias de suprimentos. A fim de contextualizar essa discussão, este trabalho procurou resgatar alguns dos principais autores e conceitos do processo de mudança da visão do determinismo clássico científico do século XIX para as nova...

  17. La5Zn2Sn

    Science.gov (United States)

    Oshchapovsky, Igor; Pavlyuk, Volodymyr; Dmytriv, Grygoriy; Chumak, Igor; Ehrenberg, Helmut

    2011-01-01

    A single crystal of penta­lanthanum dizinc stannide, La5Zn2Sn, was obtained from the elements in a resistance furnace. It belongs to the Mo5SiB2 structure type, which is a ternary ordered variant of the Cr5B3 structure type. The space is filled by bicapped tetra­gonal anti­prisms from lanthanum atoms around tin atoms sharing their vertices. Zinc atoms fill voids between these bicapped tetra­gonal anti­prisms. All four atoms in the asymmetric unit reside on special positions with the following site symmetries: La1 (..m); La2 (4/m..); Zn (m.2m); Sn (422). PMID:22219730

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

    Science.gov (United States)

    Kang, Yujin; Park, Juyun; Kim, Dong-Woo; Kim, Hakjun; Kang, Yong-Cheol

    2016-12-01

    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.

  19. Investigation of the Phase Equilibria of Sn-Cu-Au Ternary and Ag-Sn-Cu-Au Quaternary Systems and Interfacial Reactions in Sn-Cu/Au Couples

    Science.gov (United States)

    Yen, Yee-Wen; Jao, Chien-Chung; Hsiao, Hsien-Ming; Lin, Chung-Yung; Lee, Chiapyng

    2007-02-01

    The phase equilibria of the Sn-Cu-Au ternary, Ag-Sn-Cu-Au quaternary systems and interfacial reactions between Sn-Cu alloys and Au were experimentally investigated at specific temperatures in this study. The experimental results indicated that there existed three ternary intermetallic compounds (IMCs) and a complete solid solubility between AuSn and Cu6Sn5 phases in the Sn-Cu-Au ternary system at 200°C. No quaternary IMC was found in the isoplethal section of the Ag-Sn-Cu-Au quaternary system. Three IMCs, AuSn, AuSn2, and AuSn4, were found in all couples. The same three IMCs and (Au,Cu)Sn/(Cu,Au)6Sn5 phases were found in all Sn-Cu/Au couples. The thickness of these reaction layers increased with increasing temperature and time. The mechanism of IMC growth can be described by using the parabolic law. In addition, when the reaction time was extended and the Cu content of the alloy was increased, the AuSn4 phase disappeared gradually. The (Au, Cu)Sn and (Cu,Au)6Sn5 layers played roles as diffusion barriers against Sn in Sn-Cu/Au reaction couple systems.

  20. Investigations of the efficiency of CaO and MgO swelling cements for deep wells. Untersuchungen zur Wirksamkeit von CaO- und MgO-Quellzementen fuer Tiefbohrungen; Abschlussbericht zur Vorphase des DGMK-Projektes 444

    Energy Technology Data Exchange (ETDEWEB)

    Ghofrani, R.; Plack, H.

    1993-02-01

    The problem of gas tightness in annular cementing of deep wells has not been comprehensively solved in conformance with present demands. It is known from practical experience, for example, that leakage may occur in cementation over short distances. Besides possible cementing failures, the problems of gas migration are also aggravated by the setting and hardening behavior of hydraulic cements and the resulting hydration volume reduction. Swelling cements, which show a real expansion of their outer dimensions, can help to solve the present problems by filling up existing void spaces in the annulus and improving the bonding at the formation/cement and cement/pipe interfaces. This applies especially to the cementing of horizontal wells, where cavities form preferentially at the top because of gravity and thus also can result in the creation of long leak channels. The object of the present work was the ascertainment of the efficiency in principle for swelling cements based on CaO and MgO additives under simulated borehole conditions. Besides the usual characteristics of cement slurries (rheological parameters, thickening time, filtrate loss) and cement stones (compressive strength, shear bond strength, permeability), special emphasis has been placed on the swelling behavior (matrix expansion, beginning and duration of the swelling phase) of such formulations. Specialized equipment has been developed and constructed for continuous measurements of the swelling behavior. With CaO cements, real expansion by up to 10 percent has been demonstrated under hydrostatic pressures up to 120 MPa. The swelling behavior depends on the timing between hydration rate of the swelling additive and the degree of hydration of the structure-forming cement. Hydration of the swelling additive generally results in increased porosity of the cement stone. However, restrained expansion led to a reduction in pore size.

  1. Effect of the substitution of Y2O3 for CaO on the bioactivity of 2.5CaO.2SiO2 glass.

    Science.gov (United States)

    Costantini, A; Fresa, R; Buri, A; Branda, F

    1997-03-01

    Glasses were prepared whose composition is defined by the following general formula: (2.5-x)CaO.x/3Y2O3.2SiO2 (0 < or = x < or = 1). Their behaviour when they were soaked in a simulated body fluid (SBF) and their thermal properties (glass transformation and softening temperatures, Tg and Ts respectively) were studied Tg and Ts increase with the Y2O3 content. The trend can be explained on the basis of the increased structural rigidity when Ca2+ ions are substituted by Y2+ ions, because of the formation of stronger bonds to the oxygen. The bioactivity was studied by means of electron microscopy equipped with an energy dispersive system for elemental analysis and IR spectroscopy. All the glasses studied except the one with the greatest amount of Y2O3. x = 1.0, reacted with SBF by forming a calcium phosphate layer. The experimental results suggest that the bioactivity is negatively influenced by the Y2O3 content: the tendency to form a calcium phosphate layer is reduced the greater the amount of CaO substituted. A comparison with literature data indicates that the amount of Y2O3 that can be substituted depends on the CaO content of the base CaO-SiO2 glass. The experimental results are in good agreement with the mechanism reported in the literature. After 7 days soaking, crystalline hydroxyapatite is formed in the Y2O3-free glass and in the glasses of low Y2O3 content (x-0.2).

  2. Updated Physical Parameters of SN 2012cg

    Science.gov (United States)

    Marion, G. H.; Challis, P.; Hicken, M.; Mandel, K.; Meyer, S.; Kirshner, R. P.; Foley, R. J.; Friedman, A.; Irwin, J.; Wood-Vasey, W. M.; Wheeler, J. C.; Vinko, J.; Rines, K.; Wilhelmy, S.; Macri, L.

    2012-06-01

    The Harvard-Smithsonian Center for Astrophysics Supernova Group reports photometric and spectroscopic observations of SN 2012cg (ATEL #4115, #4159). We find that SN 2012cg has a slow decline rate and low expansion velocities. BayeSN fits to the data show that SN 2012cg has significant dust extinction (A_v ~ 0.67 mag). We find R_v = 2.7 +/- 0.5, which is consistent with the Milky Way value of 3.1 and mildly inconsistent with the extremely low values reported for some highly reddened SN (e.g., R_v = 1.59 +/- 0.07 for SN 2002cv; Elias-Rosa et al.

  3. 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.

  4. Hydrogen-rich gas production via CaO sorption-enhanced steam gasification of rice husk: a modelling study.

    Science.gov (United States)

    Beheshti, Sayyed Mohsen; Ghassemi, Hojat; Shahsavan-Markadeh, Rasoul; Fremaux, Sylvain

    2015-01-01

    Gasification is a thermochemical process in which solid or liquid fuels are transformed into synthesis gas through partial oxidation. In this paper, a kinetic model of rice husk gasification has been developed, which is interesting for the applications of the syngas produced. It is a zero-dimensional, steady-state model based on global reaction kinetic, empirical correlation of pyrolysis and is capable of predicting hydrogen yield in the presence of sorbent CaO. The model can also be used as a useful tool to investigate the influence of process parameters including steam/biomass ratio, CaO/fuel ratio (CaO/Fuel), and gasification temperature on hydrogen efficiency, CO2 capture ratio (CCR), and average carbonation conversion (Save). Similar to hydrogen formation, CCR also increases with increasing CaO/Fuel, but an opposite trend is exhibited in Save. Model predictions were compared with available data from the literature, which showed fairly good agreement.

  5. Thermal and catalytic cracking of ethylene in presence of CaO, MgO, zeolite and calcined dolomite

    Energy Technology Data Exchange (ETDEWEB)

    Taralas, G.; Sjoestroem, K.; Jaeraas, S.; Bjoernbom, E. [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Chemical Technology

    1993-12-31

    The subject of the present work is to study the effect of catalysts such as calcined dolomite (CaO.MgO), CaO (quicklime), MgO and Zeolite (EKZ-4) on the cracking of ethylene in the presence and absence of steam. N-heptane, toluene, naphthalene, thiophene have been some suitable model compounds for studies of the thermal and catalytic decomposition of tar. Previous results showed that the reaction scheme of the thermal decomposition of n-heptane was consistent with the high yield of ethylene observed in thermal decomposition of n-heptane. The effect of the reactor wall and the ferric impurities in the dolomite are also subjects of the research in this study. The results may also throw some additional light on the nature of the gas-phase thermal and catalytic reactions occurring in the use of dolomite as tar cracking catalysts. 28 refs

  6. Strain induced phenomena in Ca(OH)/sub 2/ made by reaction of CaO with water vapor

    Energy Technology Data Exchange (ETDEWEB)

    Beruto, D.; Searcy, A.W.; Barco, L.; Belleri, G.

    1980-01-01

    Three physically distinguishable, poorly crystalline forms of Ca(OH)/sub 2/ which are made by reactions of water vapor at 25/sup 0/C with CaO powders evolve heat and develop sharper x-ray diffraction patterns when heated to 300/sup 0/C. Measurements of x-ray diffraction peak line breadths, surface areas, porosities, and pore size distributions were made before and after heat treatment. The exothermic process of the one of these forms of Ca(OH)/sub 2/ which is nonporous is recrystallization of the highly strained solid to essentially unstrained crystals. The exothermic process in two porous forms of Ca(OH)/sub 2/, not only reduces their internal strains, but also reduces their surface areas and porosities.

  7. 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

  8. Transesterification of linoleic and oleic sunflower oils to biodiesel using CaO as a solid base catalyst

    Directory of Open Access Journals (Sweden)

    Predojević Zlatica

    2012-01-01

    Full Text Available The purpose of this work is to characterize biodiesel (i.e. methyl esters, MEs produced from linoleic and oleic sunflower oils (LSO and OSO, respectively by alkali transesterification with methanol and CaO as a heterogeneous catalyst under different reaction parameters. The parameters investigated were the methanol/oil molar ratio (4.5:1, 6:1, 7.5:1, 9:1 and 12:1 and the mass ratio of CaO to oil (2% and 3%. The physical and chemical properties of the feedstocks and MEs, like density at 15oC, kinematic viscosity at 40oC, acid value, iodine value, saponification value, cetane index, fatty acid (methyl ester composition, were determined in order to investigate the effects of LSO and OSO properties and reaction parameters on the product characteristics, yields and purity. The properties of feedstock had decisive effect on the physical and chemical properties of MEs as majority of them did not differ significantly under studied reaction conditions. The MEs produced generally met the criteria required for commercial biodiesel; in fact, the only exception was in the case of iodine value of ME produced from LSO. The product yields only slightly changed with the applied conditions; the highest yield (99.22% was obtained for ME-LSO produced at 6 mol% methanol to oil ratio, while the lowest one (93.20% was for ME-OSO produced under the lowest methanol/oil molar ratio (4.5:1. The applied catalyst amounts had similar influence on the oil conversion to biodiesel. The yields of ME-LSOs were in general somewhat higher than those obtained for ME-OSOs under the same conditions, which was attributed to the influence of the respective feedstocks' acid value and viscosity.

  9. Pseudomorphic GeSn/Ge (001) heterostructures

    Energy Technology Data Exchange (ETDEWEB)

    Tonkikh, A. A., E-mail: tonkikh@mpi-halle.de [Max Planck Institute of Microstructure Physics (Germany); Talalaev, V. G. [Martin Luther University Halle-Wittenberg, ZIK SiLi-nano (Germany); Werner, P. [Max Planck Institute of Microstructure Physics (Germany)

    2013-11-15

    The synthesis of pseudomorphic GeSn heterostructures on a Ge (001) substrate by molecular-beam epitaxy is described. Investigations by transmission electron microscopy show that the GeSn layers are defect free and possess cubic diamondlike structure. Photoluminescence spectroscopy reveals interband radiative recombination in the GeSn quantum wells, which is identified as indirect transitions between the subbands of heavy electrons and heavy holes. On the basis of experimental data and modeling of the band structure of pseudomorphic GeSn compounds, the lower boundary of the bowing parameter for the indirect band gap is estimated as b{sub L} {>=} 1.47 eV.

  10. 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

  11. Mechanisms of Vanadium Recovery from Stone Coal by Novel BaCO3/CaO Composite Additive Roasting and Acid Leaching Technology

    Directory of Open Access Journals (Sweden)

    Zhenlei Cai

    2016-03-01

    Full Text Available In this report, the vanadium recovery mechanisms by novel BaCO3/CaO composite additive roasting and acid leaching technology, including the phase transformations and the vanadium leaching kinetics, were studied. The purpose of this manuscript is to realize and improve the vanadium recovery from stone coal using BaCO3/CaO as the composite additive. The results indicated that during the composite additive BaCO3/CaO roasting process, the monoclinic crystalline structure of muscovite (K(Al,V2[Si3AlO10](OH2 was converted into the hexagonal crystalline structure of BaSi4O9 and the tetragonal crystalline structure of Gehlenite (Ca2Al2SiO7, which could, therefore, facilitate the release and extraction of vanadium. Vanadium in leaching residue was probably in the form of vanadate or pyrovanadate of barium and calcium, which were hardly extracted during the sulfuric acid leaching process. The vanadium leaching kinetic analysis indicated that the leaching process was controlled by the diffusion through a product layer. The apparent activation energy could be achieved as 46.51 kJ/mol. The reaction order with respect to the sulfuric acid concentration was 1.1059. The kinetic model of vanadium recovery from stone coal using novel composite additive BaCO3/CaO could be finally established.

  12. SeO2 adsorption on CaO surface: DFT study on the adsorption of a single SeO2 molecule

    Science.gov (United States)

    Fan, Yaming; Zhuo, Yuqun; Lou, Yu; Zhu, Zhenwu; Li, Liangliang

    2017-08-01

    Selenium is a hazardous element in coal. During coal combustion, most of the selenium will convert to SeO2 in the flue gas. Ca-based adsorbents, especially CaO, have been considered as a potential sorbent to adsorb SeO2 due to its low cost. In this paper, the adsorption mechanisms of single SeO2 on CaO surface were investigated by density functional theory (DFT) calculation. Both the physisorption and chemisorption structures were determined. It has been identified that the adsorption of SeO2 on CaO surface is primarily chemisorption, while physisorption takes effects at the initial stage of the process. Under O2 atmosphere, selenate is hard to form. Most of the adsorption products are selenite. Additionally, the electron density maps were obtained to reveal the surface active sites. The partial density of states (PDOS) was calculated for analyzing the electronic structural change of SeO2 and CaO surface during adsorption. The results provide fundamental information of the adsorption process, which could be meaningful for the development of new absorbents.

  13. Multishelled CaO Microspheres Stabilized by Atomic Layer Deposition of Al2 O3 for Enhanced CO2 Capture Performance.

    Science.gov (United States)

    Armutlulu, Andac; Naeem, Muhammad Awais; Liu, Hsueh-Ju; Kim, Sung Min; Kierzkowska, Agnieszka; Fedorov, Alexey; Müller, Christoph R

    2017-08-22

    CO2 capture and storage is a promising concept to reduce anthropogenic CO2 emissions. The most established technology for capturing CO2 relies on amine scrubbing that is, however, associated with high costs. Technoeconomic studies show that using CaO as a high-temperature CO2 sorbent can significantly reduce the costs of CO2 capture. A serious disadvantage of CaO derived from earth-abundant precursors, e.g., limestone, is the rapid, sintering-induced decay of its cyclic CO2 uptake. Here, a template-assisted hydrothermal approach to develop CaO-based sorbents exhibiting a very high and cyclically stable CO2 uptake is exploited. The morphological characteristics of these sorbents, i.e., a porous shell comprised of CaO nanoparticles coated by a thin layer of Al2 O3 (CO2 capture and release, and (iii) a minimal quantity of Al2 O3 for structural stabilization, thus maximizing the fraction of CO2 -capture-active CaO. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. First measurement of the dissociative recombination of CaO+ with electrons brings closure to Ca ion recycling chemistry in the lower thermosphere

    Science.gov (United States)

    Bones, David; Plane, John

    2016-04-01

    Modelling the temporal and spatial extent of the metal layers in the mesosphere/lower thermosphere requires knowledge of the rate coefficients of dissociative recombination of metal oxide ions with electrons. Previously, these coefficients have been assumed to be 3 × 10-7 cm3 s-1 at 200 K. In this study the coefficient has been measured directly for the dissociative recombination of CaO+. Measurements are made in a flowing afterglow system with a Langmuir probe. Calcium oxide ions are introduced into an argon ion/electron plasma by pulsed laser ablation of a solid target. The relative concentration of CaO+ is measured by a quadrupole mass spectrometer as a function of flow rate (3 - 5 slm), which is inversely proportional to the reaction time of the CaO+ ions with the electrons in the plasma (2.1 to 3.5 ms). Charge transfer reactions between argon ions and neutral molecules complicate the analysis. A kinetic model describing gas-phase chemistry and diffusion to the reactor walls was fitted to the experimental data to extract the DR rate coefficient for CaO+. Unlike other metals present in the atmosphere, Ca+ ions are far more abundant than neutral Ca. The new DR rate coefficient is used to explore possible reasons for this anomaly in a model of meteor-ablated calcium in the mesosphere and lower thermosphere.

  15. The melting diagram of the Ti-Dy-Sn system below 40 at.% Sn

    Energy Technology Data Exchange (ETDEWEB)

    Fartushna, Y.; Meleshevich, K.; Samelyuk, A.; Bulanova, M. [Frantsevich Inst. for Problems of Materials Science of NASU, Kiev (Ukraine)

    2010-10-15

    Phase equilibria in the Ti-Dy-Sn system below 40 at.% Sn were studied using differential thermal analysis, X-ray diffraction, metallography and electron microprobe. The partial liquidus and solidus projections and the melting diagram (liquidus + solidus) were constructed. A new ternary compound {tau} with composition Ti{sub 4.2-4.3}Dy{sub 0.8-0.7}Sn{sub {approx_lt}3}, found by us previously, melts congruently above 1543 C and coexists with all the phases based on the binary compounds of the boundary binaries in the concentration interval studied. The liquidus surface is characterized by primary crystallization regions of ({beta}Ti), ({beta}Dy), ({alpha}Dy), (Ti{sub 3}Sn), (Ti{sub 2}Sn), (Ti{sub 5}Sn{sub 3}), (Dy{sub 5}Sn{sub 3}) and {tau}. Five three-phase fields in the solidus surface result from three eutectic and two transition type invariant four-phase equilibria: L{sub E{sub 1}} {r_reversible} ({beta}Ti) + (Ti{sub 3}Sn) + (Dy{sub 5}Sn{sub 3}), L{sub E{sub 2}} {r_reversible} (Ti{sub 3}Sn) + {tau} + (Dy{sub 5}Sn{sub 3}), L{sub E{sub 3}} {r_reversible} ({beta}Ti) + ({alpha}Dy) + (Dy{sub 5}Sn{sub 3}), L{sub U{sub 1}} + (Ti{sub 2}Sn) {r_reversible} (Ti{sub 3}Sn) + {tau} and L{sub U{sub 2}} + (Ti{sub 2}Sn) {r_reversible} (Ti{sub 5}Sn{sub 3}) + {tau} at 1524, 1500, 1150, 1543 and 1498 C, respectively. In the two-phase areas ({beta}Ti) + (Dy{sub 5}Sn{sub 3}),(Ti{sub 3}Sn) + (Dy{sub 5}Sn{sub 3}), (Ti{sub 2}Sn) + {tau} and {tau} + (Dy{sub 5}Sn{sub 3}) the solidus surface has the temperature maxima at 1620, 1540, > 1543 and > 1500 C, respectively. (orig.)

  16. A Luminous Peculiar Type Ia Supernova SN 2011hr: More Like SN 1991T or SN 2007if?

    CERN Document Server

    Zhang, Jujia; Sasdelli, Michele; Zhang, Tianmeng; Liu, Zhengweei; Mazzali, Paolo A; Meng, Xiangcun; Maeda, Keiichi; Chen, Juncheng; Huang, Fang; Zhao, Xulin; Zhang, Kaicheng; Zhai, Qian; Pian, Elena; Wang, Bo; Chang, Liang; Yi, Weimin; Wang, Chuan-Jun; Wang, Xueli; Xin, Yuxin; Wang, Jianguo; Lun, Baoli; Zheng, Xiangming; Zhang, Xiliang; Fan, Yufeng; Bai, Jinming

    2015-01-01

    Photometric and spectroscopic observations of a slowly declining, luminous type Ia supernova (SN Ia) 2011hr in the star-burst galaxy NGC 2691 are presented. SN~2011hr is found to peak at $M_{B}=-19.84 \\pm 0.40\\,\\rm{mag}$, with a post-maximum decline rate $\\Delta$m$_{15}$(B) = 0.92 $\\pm$ 0.03\\,$\\rm{mag}$. From the maximum-light bolometric luminosity, $L=(2.30 \\pm 0.90) \\times 10^{43}\\,\\rm{erg\\,s^{-1}}$, we estimate the mass of synthesized \\Nifs\\ in SN~2011hr to be $M(\\rm{^{56}Ni})=1.11 \\pm 0.43\\,M_{\\sun}$. SN 2011hr appears more luminous than SN 1991T at around maximum light, and the absorption features from its intermediate-mass elements (IMEs) are noticeably weaker than the latter at similar phases. Spectral modelling suggests that SN 2011hr has the IMEs of $\\sim$\\,0.07 M$_{\\sun}$ in the outer ejecta, which is much lower than the typical value of normal SNe Ia (i.e., 0.3 -- 0.4 M$_{\\sun}$) and is also lower than the value of SN 1991T (i.e., $\\sim$\\,0.18 M$_{\\sun}$). These results indicate that SN~2011hr may ...

  17. Influence of alkali metal doping on surface properties and catalytic activity/selectivity of CaO catalysts in oxidative coupling of methane

    Institute of Scientific and Technical Information of China (English)

    V.H.Rane; S.T.Chaudhari; V.R.Choudhary

    2008-01-01

    Surface properties (viz. surface area, basicity/base strength distribution, and crystal phases) of alkali metal doped CaO (alkali metal/Ca = 0.1 and 0.4) catalysts and their catalytic activity/selectivity in oxidative coupling of methane (OCM) to higher hydrocarbons at different reaction conditions (viz. temperature, 700 and 750 ℃; CH4/O2 ratio, 4.0 and 8.0 and space velocity, 5140-20550 cm3·g-1·h-1) have been investigated. The influence of catalyst calcination temperature on the activity/selectivity has also been investigated. The surface properties (viz. surface area, basicity/base strength distribution) and catalytic activity/selectivity of the alkali metal doped CaO catalysts are strongly influenced by the alkali metal promoter and its concentration in the alkali metal doped CaO catalysts. An addition of alkali metal promoter to CaO results in a large decrease in the surface area but a large increase in the surface basicity (strong basic sites) and the C2+ selectivity and yield of the catalysts in the OCM process. The activity and selectivity are strongly influenced by the catalyst calcination temperature. No direct relationship between surface basicity and catalytic activity/selectivity has been observed. Among the alkali metal doped CaO catalysts, Na-CaO (Na/Ca = 0.1, before calcination) catalyst (calcined at 750 ℃), showed best performance (C2+selectivity of 68.8% with 24.7% methane conversion), whereas the poorest performance was shown by the Rb-CaO catalyst in the OCM process.

  18. Significance of the structural properties of CaO catalyst in the production of biodiesel: An effect on the reduction of greenhouse gases emission

    Directory of Open Access Journals (Sweden)

    Ljupković Radomir B.

    2014-01-01

    Full Text Available The influence of the physicochemical properties of a series of CaO catalysts activated at different temperatures on the biodiesel production was investigated. These catalysts show dissimilar yields in the transesterification of triglycerides with methanol. We have found significant relationships between structural properties (the type of the pore system, the typical CaO crystal phase and the sizes of crystallites (up to 25 nm, the minimal weight percentage of CaO phase, the total surface basicity and potential existence of two types of basic active sites of CaO prepared and activated by means of thermal treatment at highest temperature and catalytic efficiency. Benefits of this catalyst are short contact time, standard operating temperature and atmospheric conditions, relatively low molar ratios and small catalyst loading. These all together resulted in a very high biodiesel yield of high purity. The properties of different biodiesel (obtained with the use of the prepared CaO catalyst blends with different diesel and biodiesel ratios indicate that the higher the fraction of biodiesel fuel the better the achieved fuel properties according to the EU standards. A significant reduction of CO2 and CO emissions and only a negligible NOx increase occurred when blends with an increased biodiesel portion was used. The use of biodiesel derived blends, and the eventual complete replacement of fossil fuels with biodiesel as a renewable, alternative fuel for diesel engines, would greatly contribute to the reduction of greenhouse gases emissions. [Projekat Ministarstva nauke Republike Srbije, br. ON 172061 i TR 34008

  19. Process Modules for GeSn Nanoelectronics with high Sn-contents

    OpenAIRE

    Schulte-Braucks, C; Glass, S; Hofmann, E; Stange, D; Von Den Driesch, N; Hartmann, JM; Ikonic, Z; Zhao, GT; Buca, D.; Mantl, S

    2017-01-01

    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 at.% to 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 t...

  20. Effect of Sn Content in a CuSnZn Metal Precursor on Formation of MoSe2 Film during Selenization in Se+SnSe Vapor

    OpenAIRE

    Liyong Yao; Jianping Ao; Ming-Jer Jeng; Jinlian Bi; Shoushuai Gao; Guozhong Sun; Qing He; Zhiqiang Zhou; Yun Sun; Liann-Be Chang

    2016-01-01

    The preparation of Cu2ZnSnSe4 (CZTSe) thin films by the selenization of an electrodeposited copper–tin–zinc (CuSnZn) precursor with various Sn contents in low-pressure Se+SnSex vapor was studied. Scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) measurements revealed that the Sn content of the precursor that is used in selenization in a low-pressure Se+SnSex vapor atmosphere only slightly affects the elemental composition of the formed CZTSe films. However, the Sn co...

  1. GeSn/SiGeSn photonic devices for mid-infrared applications: experiments and calculations

    Science.gov (United States)

    Han, Genquan; Zhang, Qingfang; Liu, Yan; Zhang, Chunfu; Hao, Yue

    2016-11-01

    In this work, a fully strained GeSn photodetector with Sn atom percent of 8% is fabricated on Ge buffer on Si(001) substrate. The wavelength λ of light signals with obvious optical response for Ge0.92Sn0.08 photodetector is extended to 2 μm. The impacts of compressive strain introduced during the epitaxial growth of GeSn on Ge/Si are studied by simulation. Besides, the tensile strain engineering of GeSn photonic devices is also investigated. Lattice-matched GeSn/SiGeSn double heterostructure light emitting diodes (LEDs) with Si3N4 tensile liner stressor are designed to promote the further mid-infrared applications of GeSn photonic devices. With the releasing of the residual stress in Si3N4 liner, a large biaxial tensile strain is induced in GeSn active layer. Under biaxial tensile strain, the spontaneous emission rate rsp and internal quantum efficiency ηIQE for GeSn/SiGeSn LED are significantly improved.

  2. Studying superconducting Nb3Sn wire

    CERN Multimedia

    AUTHOR|(CDS)2099575

    2015-01-01

    Studying superconducting Nb3Sn wire. From the current experience from LHC and HL-LHC we know that the performance requirements for Nb3Sn conductor for future circular collider are challenging and should exceed that of present state-of-the-art materials.

  3. Correlation Between Sn Grain Orientation and Corrosion in Sn-Ag-Cu Solder Interconnects

    Science.gov (United States)

    Lee, Tae-Kyu; Liu, Bo; Zhou, Bite; Bieler, Thomas; Liu, Kuo-Chuan

    2011-09-01

    The impact of a marine environment on Sn-Ag-Cu interconnect reliability is examined using salt spray exposure followed by thermal cycling. Sn-Ag-Cu solder alloy wafer-level packages, with and without pretreatment with 5% NaCl salt spray, were thermally cycled to failure. The prior salt spray reduced the characteristic lifetime of the Sn-Ag-Cu solder joints by over 43%. Although Sn-based materials show strong resistance to corrosion, the nature of localized corroded areas at critical locations in the solder joint caused significant degradation in the Sn-Ag-Cu solder joints. An important link between the corrosion path and Sn grain orientation was observed using orientation imaging microscopy (OIM). A strong correlation between the corrosion path and grain orientation was identified, indicating that the corrosion attack preferentially followed the basal plane of the Sn lattice.

  4. Effect of graphite content on electrochemical performance of Sn-SnSb/graphite composite powders

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Sn-SnSb alloy was synthesized by reducing a aqueous solution containing Sn( Ⅱ ) and Sb(Ⅲ) salts with NaBH4 in the presence of sodium citrate. The product was characterized by X-ray diffractometry(XRD) and scanning electron microscopy(SEM).Sn-SnSb/graphite composite powders were prepared by mechanical milling and the mass fraction of graphite was increased from20% to 50%. The effect of graphite content on the electrochemical performance of Sn-SnSb/graphite composite electrode was investigated. The results show the increase of graphite content is in favor of enhancing the first charge-discharge efficiency and improving the cycle performance, but the capacity of the composite electrode decreases with increasing content of graphite.

  5. Laser spectroscopy of neutron deficient Sn isotopes

    CERN Multimedia

    We propose to study the ground state properties of neutron-deficient Sn isotopes towards the doubly-magic nucleus $^{100}$Sn. Nuclear spins, changes in the rms charge radii and electromagnetic moments of $^{101-121}$Sn will be measured by laser spectroscopy using the CRIS experimental beam line. These ground-state properties will help to clarify the evolution of nuclear structure properties approaching the $\\textit{N = Z =}$ 50 shell closures. The Sn isotopic chain is currently the frontier for the application of state-of-the-art ab-initio calculations. Our knowledge of the nuclear structure of the Sn isotopes will set a benchmark for the advances of many-body methods, and will provide an important test for modern descriptions of the nuclear force.

  6. Electrodeposition of nanostructured Sn-Zn coatings

    Science.gov (United States)

    Salhi, Y.; Cherrouf, S.; Cherkaoui, M.; Abdelouahdi, K.

    2016-03-01

    The electrodeposition of Sn-Zn coating at ambient temperature was investigated. The bath consists of metal salts SnCl2·2H2O and ZnSO4·7H2O and sodium citrate (NaC6H5Na3O7·2H2O) as complexing agent. To prevent precipitation, the pH is fixed at 5. Reducing tin and zinc through Sncit2- and ZnHcit- complex respectively is confirmed by the presence of two cathodic peaks on the voltammogram. The kinetic of tin (II) reduction process is limited by the SnCit2- dissociation. The SEM and TEM observations have showed that the coating consists of a uniform Sn-Zn layer composed of fine grains on which tin aggregates grow up. XRD revealed peaks corresponding to the hexagonal Zn phase and the tetragonal β-Sn phase.

  7. Application of 119Sn CPMG MAS NMR for Fast Characterization of Sn Sites in Zeolites with Natural 119Sn Isotope Abundance

    DEFF Research Database (Denmark)

    G. Kolyagin, Yury; V. Yakimo, Alexander; Tolborg, Søren

    2016-01-01

    119Sn CPMG MAS NMR is demonstrated to be a fast and efficient method for characterization of Sn-sites in Sn-containing zeolites. Tuning of the CPMG echo-train sequence decreases the experimental time by a factor of 5–40 in the case of as-synthesized and hydrated Sn-BEA samples and by 3 orders......-BEA zeolites with natural 119Sn isotope abundance using conventional MAS NMR equipment....

  8. Synthesis of Epitaxial Films Based on Ge-Si-Sn Materials with Ge/GeSn, Ge/GeSiSn, and GeSn/GeSiSn Heterojunctions

    Science.gov (United States)

    Timofeev, V. A.; Kokhanenko, A. P.; Nikiforov, A. I.; Mashanov, V. I.; Tuktamyshev, A. R.; Loshkarev, I. D.

    2015-11-01

    Results of investigations into the synthesis of heterostructures based on Ge-Si-Sn materials by the method of low-temperature molecular beam epitaxy are presented. The formation of epitaxial films during structure growth has been controlled by the reflection high-energy electron diffraction method. Films with Ge/GeSn, Ge/GeSiSn, and GeSn/GeSiSn heterojunctions are grown with Sn content changing from 2 to 10 % at temperatures in the interval 150-350°C. The stressed state, the composition, and the lattice parameter are studied by the x-ray diffraction method using Omega-scan curves and reciprocal space maps. A tensile strain in the Ge film during Ge/Ge0.9Sn0.1/Si structure growth has reached 0.86%.

  9. Direct observation of Sn crystal growth during the lithiation and delithiation processes of SnO(2) nanowires.

    Science.gov (United States)

    Zhang, Li Qiang; Liu, Xiao Hua; Perng, Ya-Chuan; Cho, Jea; Chang, Jane P; Mao, Scott X; Ye, Zhi Zhen; Huang, Jian Yu

    2012-11-01

    Tin (Sn) crystal growth on Sn-based anodes in lithium ion batteries is hazardous for reasons such as possible short-circuit failure by Sn whiskers and Sn-catalyzed electrolyte decomposition, but the growth mechanism of Sn crystals during battery cycling is not clear. Here we report different growth mechanisms of Sn crystal during the lithiation and delithiation processes of SnO(2) nanowires revealed by in situ transmission electron microscopy (TEM). Large spherical Sn nanoparticles with sizes of 20-200nm grew instantaneously upon lithiation of a single-crystalline SnO(2) nanowire at large current density (j>20A/cm(2)), which suppressed formation of the Li(x)Sn alloy but promoted agglomeration of Sn atoms. Control experiments of Joule-heating (j≈2400A/cm(2)) the pristine SnO(2) nanowires resulted in melting of the SnO(2) nanowires but not Sn particle growth, indicating that the abnormal Sn particle growth was induced by both chemical reduction (i.e., breaking the SnO(2) lattice to produce Sn atoms) and agglomeration of the Sn atoms assisted by Joule heating. Intriguingly, Sn crystals grew out of the nanowire surface via a different "squeeze-out" mechanism during delithiation of the lithiated SnO(2) nanowires coated with an ultra-thin solid electrolyte LiAlSiO(x) layer. It is attributed to the negative stress gradient generated by the fast Li extraction in the surface region through the Li(+)-conducting LiAlSiO(x) layer. Our previous studies showed that Sn precipitation does not occur in the carbon-coated SnO(2) nanowires, highlighting the effect of nanoengineering on tailoring the electrochemical reaction kinetics to suppress the hazardous Sn whiskers or nanoparticles formation in a lithium ion battery.

  10. Desulfurization and oxidation behavior of ultra-fine CaO particles prepared from brown coal; Kattan wo mochiite choseishita CaO chobiryushi no datsuryu tokusei to sanka tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Benjamin, G.; Roman, M.; Yamazaki, Y.; Abe, H.; Harano, Y.; Takarada, Y. [Gunma University, Gunma (Japan). Faculty of Engineering

    1996-10-28

    The effect of reaction temperature and oxygen concentration on the desulfurization and oxidation behavior of ion-exchanged brown coal by Ca as new desulfurizing agent was studied. In experiment, Yallourn coal was used for ion- exchange, and limestone produced in Tochigi prefecture was also used for comparative study. Ca-exchanged brown coal was prepared by agitating coal in Ca(OH)2 slurry for 24 hours. The desulfurization behavior of a desulfurizing agent was obtained by measuring H2S and sulfur compounds in outlet gas of a reactor, and the oxidation behavior by measuring SO2 emission in outlet gas after oxidation reaction. As the experimental result, CaO produced from Ca-exchanged brown coal offered the extremely high activity to desulfurization reaction in a temperature range of 850-950{degree}C as compared with limestone. Although the oxidation behavior was dependent on oxidation temperature and oxygen concentration, CaS obtained from Ca-exchanged brown coal was more rapidly converted to CaSO4 than limestone. 3 refs., 8 figs., 2 tabs.

  11. Dynamic viscosities of pure tin and Sn-Ag, Sn-Cu, and Sn-Ag-Cu eutectic melts

    Science.gov (United States)

    Rozhitsina, E. V.; Gruner, S.; Kaban, I.; Hoyer, W.; Sidorov, V. E.; Popel', P. S.

    2011-02-01

    The dynamic viscosities of the melts of pure tin and eutectic Sn-Ag, Sn-Cu, and Sn-Ag-Cu alloys are studied in heating followed by cooling, and the maximum heating temperature was 1200°C. An irreversible decrease in the viscosity is found in the temperature range 800-1000°C in the polytherms of all melts. This finding is related to the loss of a local order in a melt and can be used to develop temperature regimes for the production of lead-free solders.

  12. 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.

  13. Growth of highly textured SnS on mica using an SnSe buffer layer

    Energy Technology Data Exchange (ETDEWEB)

    Wang, S.F.; Fong, W.K.; Wang, W.; Surya, C., E-mail: charles.surya@polyu.edu.hk

    2014-08-01

    We report the growth of SnS thin films on mica substrates by molecular beam epitaxy. Excellent 2D layered structure and strong (001) texture were observed with a record low rocking curve full width at half maximum of ∼ 0.101° for the SnS(004) diffraction. An interface model is used to investigate the nucleation of SnS on mica which indicates the co-existence of six pairs of lateral growth orientations and is in excellent agreement with the experimental Φ-scan measurements indicating 12 peaks separated by 30° from each other. To control the lateral growth of the SnS epilayers we investigate the utilization of a thin SnSe buffer layer deposited on the mica substrate prior to the growth of the SnS thin film. The excellent lattice match between SnSe and mica enhances the alignment of the nucleation of SnS and suppresses the minor lateral orientations along the mica[110] direction and its orthogonal axis. Detailed low-frequency noise measurement was performed to characterize the trap density in the films and our results clearly demonstrate substantial reduction in the density of the localized states in the SnS epilayer with the use of an SnSe buffer layer. - Highlights: • A record low rocking curve FWHM for deposited SnS on mica • Investigation of the nucleation of SnS on mica using the interface model • Investigation of nucleation mechanism by phi-scan measurement • Grain boundary formation from crystallites of various nucleation orientations • Suppression of nucleation orientations using an SnSe buffer layer.

  14. Beta decay of {sup 101}Sn

    Energy Technology Data Exchange (ETDEWEB)

    Kavatsyuk, O.; Kavatsyuk, M. [Gesellschaft fuer Schwerionenforschung, Damrstadt (Germany); National Taras Shevchenko Univ. of Kyiv (Ukraine); Mazzocchi, C. [Gesellschaft fuer Schwerionenforschung, Damrstadt (Germany); Univ. of Tennessee, Knoxville (United States); Janas, Z.; Karny, M.; Miernik, K.; Plochocki, A.; Zylicz, J. [University of Warsaw (Poland); Banu, A.; Becker, F.; Bruechle, W.; Doering, J.; Gorska, M.; Grawe, H.; Klepper, O.; Kirchner, R.; Plettner, C.; Roeckl, E.; Schaedel, M. [Gesellschaft fuer Schwerionenforschung, Darmstadt, Darmstadt (Germany); Batist, L. [St. Petersburg Nuclear Physics Institute (Russian Federation); Blazhev, A. [Gesellschaft fuer Schwerionenforschung, Damrstadt (Germany); Univ. of Sofia (Bulgaria); Faestermann, T. [Technische Universitaet Muenchen (Germany); Jungclaus, A. [Instituto Estructura de la Materia, CSIC (Spain); Departamento de Fisica Teorica, UAM, Madrid (Spain); La Commara, M.; Romoli, M. [Universita ' ' Federico II' ' , Napoli (Italy); INFN, Napoli (Italy); Mukha, I. [Gesellschaft fuer Schwerionenforschung, Damrstadt (Germany); Kurchatov Inst., Moscow (Russian Federation); Rykaczewski, K. [Oak Ridge National Laboratory, Oak Ridge (United States); Schmidt, K. [Continental Teves AG and Co., Frankfurt am Main (Germany); Schwengner, R. [Institut fuer Kern- und Hadronenphysik, Forschungszentrum Rossendorf, Dresden (Germany)

    2007-03-15

    The {beta} decay of the very neutron-deficient isotope {sup 101}Sn was studied at the GSI on-line mass separator using silicon detectors for recording charged particles and germanium detectors for {gamma}-ray spectroscopy. Based on the {beta}-delayed proton data the production cross-section of {sup 101}Sn in the {sup 50}Cr+{sup 58}Ni fusion-evaporation reaction was determined to be about 60nb. The half-life of {sup 101}Sn was measured to be 1.9(3)s. For the first time {beta}-delayed {gamma}-rays of {sup 101}Sn were tentatively identified, yielding weak evidence for a cascade of 352 and 1065keV transitions in {sup 101}In. The results for the {sup 101}Sn decay as well as those from previous work on the {sup 103}Sn decay are discussed by comparing them to predictions obtained from shell model calculations employing a new interaction in the {sup 88}Sr to {sup 132}Sn model space. (orig.)

  15. Axions and SN1987A

    Science.gov (United States)

    Burrows, Adam; Turner, Michael S.; Brinkmann, R. P.

    1988-01-01

    The effect of free-streaming axion emission on numerical models for the cooling of the newly born neutron star associated with SN1987A is considered. It is found that for an axion mass of greater than approximately 10 to the -3 eV, axion emission shortens the duration of the expected neutrino burst so significantly that it would be inconsistent with the neutrino observations made by the Kamiokande II and Irvine-Michigan-Brookhaven detectors. However, the possibility has not been investigated that axion trapping (which should occur for masses greater than or equal to 0.02 eV) sufficiently reduces axion emission so that axion masses greater than approximately 2 eV would be consistent with the neutrino observations.

  16. Comparison of Catabolic Rates of sn-1, sn-2, and sn-3 Fatty Acids in Triacylglycerols Using (13)CO2 Breath Test in Mice.

    Science.gov (United States)

    Beppu, Fumiaki; Kawamatsu, Takashi; Yamatani, Yoshio; Nagai, Toshiharu; Yoshinaga, Kazuaki; Mizobe, Hoyo; Yoshida, Akihiko; Kubo, Atsushi; Kanda, Jota; Gotoh, Naohiro

    2017-01-01

    Fatty acids in triacylglycerols (TAGs) are catabolized after digestion. However, the catabolic rates of the fatty acids at the sn-1, sn-2, and sn-3 positions of TAGs have not been compared. To elucidate the differences, we studied the catabolic rates of (13)C-labeled palmitic acid, oleic acid, and capric acid at the sn-1, sn-2, or sn-3 position of TAGs using isotope-ratio mass spectrometry. Specifically, we measured the (13)C-to-(12)C ratio in CO2 (Δ(13)C (‰)) exhaled by mice. For all analyzed fatty acids, we observed significant differences between sn-2 and other binding positions. In contrast, no significant difference was detected between the sn-1 and sn-3 positions. These results indicated that the catabolic rates of fatty acids are strongly influenced by their positions in TAGs.

  17. 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).

  18. Progenitors of supernova Ibc: a single Wolf-Rayet star as the possible progenitor of the SN Ib iPTF13bvn

    CERN Document Server

    Groh, Jose H; Ekstrom, Sylvia

    2013-01-01

    Core-collapse supernova (SN) explosions mark the end of the tumultuous life of massive stars. Determining the nature of their progenitors is a crucial step towards understanding the properties of SNe. Until recently, no progenitor has been directly detected for SN of type Ibc, which are believed to come from massive stars that lose their Hydrogen envelope through stellar winds and from binary systems where the companion has stripped the H envelope from the primary. Here we analyze recently-reported observations of iPTF13bvn, which could possibly be the first detection of a SN Ib progenitor based on pre-explosion images. Very interestingly, the recently published Geneva models of single stars can reproduce the observed photometry of the progenitor candidate and its mass-loss rate, confirming the scenario from Cao et al 2013. We find that a single WR star with initial mass in the range 31-35 Msun fits the observed photometry of the progenitor of iPTF13bvn. The progenitor likely has a luminosity of log (L/Lsun)~...

  19. ¿Caos en el electrocardiograma de estudiantes con miedo a volar? Un análisis de no linealidad

    Directory of Open Access Journals (Sweden)

    Jordi Llabrés

    2005-01-01

    Full Text Available La Teoría del Caos proporciona una nueva forma de analizar las respuestas psicofisiológicas asociadas a los trastornos de ansiedad. Pero para poder aplicar los métodos de análisis no lineal de esta relativamente reciente teoría, primero es necesario comprobar la existencia de algún tipo de no linealidad que justifique su uso. En este estudio experimental se analiza, mediante el procedimiento de los datos vicarios, la no linealidad de las señales generadas por el sistema cardiovascular (ECG de estudiantes con y sin miedo a volar, en diferentes condiciones de estimulación. Los errores de predicción de las series vicarias fueron siempre mayores que los de las correspondientes series empíricas (p < 0,05, demostrándose así que las señales ECG, en todos los sujetos y en todas las condiciones, presentan propiedades no lineales y que por tanto resulta adecuado analizarlas desde planteamientos no lineales para obtener conocimiento acerca de su complejidad, entropía, regularidad, etc.

  20. CONTROLE DE COHERENCE ET DE FAISABILITE DE PROJETS DANS UN SYSTEME DE C.A.O. BATIMENT

    Directory of Open Access Journals (Sweden)

    M BELACHIA

    2001-06-01

    Full Text Available Le contrôle de la cohérence et de la faisabilité est devenu une préoccupation essentielle pour les développeurs de systèmes de C.A.O, car les concepteurs et les utilisateurs ont besoin d’outils pour vérifier la validité de leur conception. Nous supposons qu’une large partie de ce contrôle est intégrée dans les modules techniques. Cependant, plus particulièrement lors de l’étude des phases précoces de conception, il s’avère indispensable d’identifier les causes des dysfonctionnements. Après une analyse des différents types d’anomalies que nous pouvons rencontrer durant le processus de conception pouvant conduire à des incohérences ou des «non faisabilité» d’un projet, nous avons déduit les méthodes appropriées pour informer les utilisateurs à bon escient. Elles sont généralement basées sur des vérifications automatiques et transparentes avec des possibilités de reports de déclenchement des contrôles.

  1. Monolayer alkali and transition-metal monoxides: MgO, CaO, MnO, and NiO

    Science.gov (United States)

    Shayeganfar, F.; Vasu, K. S.; Nair, R. R.; Peeters, F. M.; Neek-Amal, M.

    2017-04-01

    Two-dimensional crystals with strong interactions between layers has attracted increasing attention in recent years in a variety of fields. In particular, the growth of a single layer of oxide materials (e.g., MgO, CaO, NiO, and MnO) over metallic substrates were found to display different physical properties than their bulk. In this study, we report on the physical properties of a single layer of metallic oxide materials and compare their properties with their bulk and other two-dimensional (2D) crystals. We found that the planar structure of metallic monoxides are unstable whereas the buckled structures are thermodynamically stable. Also, the 2D-MnO and NiO exhibit different magnetic (ferromagnetic) and optical properties than their bulk, whereas band-gap energy and linear stiffness are found to be decreasing from NiO to MgO. Our findings provide insight into oxide thin-film technology applications.

  2. Meteoric CaO and carbon smoke particles collected in the upper stratosphere from an unanticipated source

    Directory of Open Access Journals (Sweden)

    Marco Ferrari

    2013-07-01

    Full Text Available Nanometre CaO and pure carbon smoke particles were collected at 38-km altitude in the upper stratosphere in the Arctic during June 2008 using DUSTER (Dust in the Upper Stratosphere Tracking Experiment and Retrieval. This balloon-borne instrument was designed for non-destructive collection of solid particles between 200 nm to 40 µm. We report here on micrometre CaCO3 (calcite grains with evidence of thermal erosion and smoke particles that formed after melting and vaporisation and complete dissociation of some of the CaCO3 grains at temperatures of approximately 3500 K. These conditions and processes suggest that the environment of this dust was a dense dust cloud that had formed after disintegration of a carbonaceous meteoroid during deceleration in the atmosphere. The balloon-borne collector must have coincidentally travelled through the dust cloud of a recent bolide event that had penetrated between 38.5 and 37 km altitude. This work identified a previously unknown meteoric smoke forming process in addition to meteoric smoke particles due to photolysis-driven oxidation of mesospheric metals from meteor ablation that had settled into the upper stratosphere.

  3. Biodiesel Production From the Microalgae Nannochloropsis by Microwave Using CaO and MgO Catalysts

    Directory of Open Access Journals (Sweden)

    Herman Hindarso

    2015-02-01

    Full Text Available The needs of world petroleum are increased; in contrast, the fuel productions are getting decreased. Therefore, it has lead to the search for bio-fuel as an alternative energy. There are several different types of biofuel, such as biodiesel, ethanol, bioalcohol, and biogas. Biodiesel is typically made by chemically reacting lipids from a vegetable oil or animal fat with an alcohol producing fatty acid esters, such as methyl or ethyl ester. The present study aimed to study the effect of temperature (50, 60 and 65°C, reaction time (1 to 5 minutes dan types of catalyst (CaO dan MgO of 1 and 3 % in the production of biodiesel from microalgae by the transesterification process using microwave methods. It also studied the characteristics of biodiesel which had the greatest yield in the present study, i.e. flash point, cetane number, density, viscosity, and FAME. The greatest yield was 99.35% and obtained with combination of 3% MgO catalyst quantity at temperature of 60°C, in 3 minutes reaction time. At this process conditions, the biodiesel has a flash point of 122°C, cetane number of 55, density of  0.89, viscosity of 5 cP and FAME of 75.12 %.

  4. Effect of Sn Content in a CuSnZn Metal Precursor on Formation of MoSe2 Film during Selenization in Se+SnSe Vapor

    Directory of Open Access Journals (Sweden)

    Liyong Yao

    2016-03-01

    Full Text Available The preparation of Cu2ZnSnSe4 (CZTSe thin films by the selenization of an electrodeposited copper–tin–zinc (CuSnZn precursor with various Sn contents in low-pressure Se+SnSex vapor was studied. Scanning electron microscope (SEM and energy dispersive spectroscopy (EDS measurements revealed that the Sn content of the precursor that is used in selenization in a low-pressure Se+SnSex vapor atmosphere only slightly affects the elemental composition of the formed CZTSe films. However, the Sn content of the precursor significantly affects the grain size and surface morphology of CZTSe films. A metal precursor with a very Sn-poor composition produces CZTSe films with large grains and a rough surface, while a metal precursor with a very Sn-rich composition procures CZTSe films with small grains and a compact surface. X-ray diffraction (XRD and SEM revealed that the metal precursor with a Sn-rich composition can grow a thicker MoSe2 thin film at CZTSe/Mo interface than one with a Sn-poor composition, possibly because excess Sn in the precursor may catalyze the formation of MoSe2 thin film. A CZTSe solar cell with an efficiency of 7.94%was realized by using an electrodeposited metal precursor with a Sn/Cu ratio of 0.5 in selenization in a low-pressure Se+SnSex vapor.

  5. Single-Particle States in $^{133}$Sn

    CERN Multimedia

    Huck, A

    2002-01-01

    % IS338 \\\\ \\\\ It is suggested to investigate the $\\beta^- $-decay of $^{133}$In and $^{134}$In in order to determine the single-particle states in $^{133}$Sn, which are so far unknown and needed for the shell-model description of the region close to $^{132}$Sn. Large hyper-pure Ge-detectors will be used for the $\\gamma$-ray spectroscopy. In the experiments with $^{134}$In, delayed neutrons in coincidence with $\\gamma$-rays from excited states in $^{133}$Sn provide the opportunity for a very selective detection of the states in question.

  6. Abnormal growth of Ag3Sn intermetallic compounds in Sn-Ag lead-free solder

    Institute of Scientific and Technical Information of China (English)

    SHEN Jun; LIU Yongchang; GAO Houxiu

    2006-01-01

    The abnormal growth of Ag3Sn intermetallic compounds in eutectic Sn-3.5% Ag solder was investigated through high-temperature aging treatment. Microstructural evolutions of this solder before and after the aging treatment were observed by optical microscopy and scanning electron microscopy. Precise differential thermal analysis was made to study the changes in enthalpies of the solder under different conditions. The results reveal that the water-cooled solder is in metastable thermodynamic state due to the high free energy of Ag3Sn nanoparticles, which sporadically distribute in the matrix as second-phase. The second-phase Ag3Sn nanoparticles aggregate rapidly and grow to form bulk intermetallic compounds due to the migration of grain boundary between primary Sn-rich phase and the Ag3Sn nanoparticles during high temperature aging treatment.

  7. Influence of Solid Fraction on Gravity Segregation of Sn in Al-20Sn Alloy Casting

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The influence of solid fraction of Al-20Sn alloy mushy on gravity segregation of Sn in casting was studied and, the relationship between solid fraction and the temperature of alloy mushy and that between solid fraction of alloy mushy and size of Sn particle in ingot were determined. The results show that the relationship between solid fraction and the temperature of alloy mushy was fs=1683-4.86t+0.0035t2. The extent of gravity segregation of Sn in casting reduced gradually with the increasing of solid fraction of alloy mushy. When solid fraction of alloy mushy was arger than 40%, the gravity segregation of Sn in casting could be removed basically, and the relationship between solid fraction of alloy mushy and size of Sn particle in ingot was s=-0.64fs+70.8.

  8. Thermodynamic and surface properties of Sb-Sn and In-Sn liquid alloys

    Indian Academy of Sciences (India)

    B C Anusionwu

    2006-08-01

    The thermodynamic properties of Sb-Sn and In-Sn liquid alloys have been studied using the quasi-chemical model for compound forming binary alloys and that for simple regular alloys. The concentration fluctuation cc(0) and the Warren-Cowley short-range order parameter (1) were determined for the whole concentration range at a temperature of 770 K. The surface tensions of these liquid alloys were determined for the whole concentration range by using energetics determined from thermodynamic calculations. In all calculations, In{Sn manifested properties very close to alloys of ideal mixing, while Sb-Sn showed properties that are asymmetric about equiatomic composition. Our results suggest that a weak complex of the form SbSn2 could be present in the Sb-Sn alloy at a temperature of about 770 K.

  9. OPTIMASI SUHU REAKSI TRANSESTERIFIKASI PADA MINYAK JERAMI PADI (ORYZA SATIVA L. MENJADI BIODIESEL DENGAN MENGGUNAKAN KATALIS CAO DARI KULIT TELUR AYAM

    Directory of Open Access Journals (Sweden)

    Tasik Sinta

    2016-11-01

    Full Text Available The research on optimization of transesterification temperature for production of biodiesel from rice straw oil (Oryza sativa L. using CaO catalyst derived from the chicken egg skin has been conducted. Production of biodiesel was conducted at varied temperatures, namely 30oC, 40oC, 50oC, 60oC and 70oC. The fatty acid compositions of the transesterification products were determined by using GC-MS and the physical and chemical characteristics were determined using SNI Methods 04-7182-2006. The AAS result suggested that the chicken egg skin contained 91.41% CaO. The optimum transesterification temperature was 60oC producing 90,8405% methyl ester. The results of GC-MS showed that the highest percentage of fatty acid was methyl oleic (44.56%.

  10. Synthesis and photoluminescence properties of Eu2+ activated CaO ceramic powders for near-ultraviolet chip based white light emitting diodes

    Science.gov (United States)

    Hao, Zhendong; Wang, Ying; Zhang, Liangliang; Pan, Guohui; Zhang, Xia; Wu, Huajun; Luo, Yongshi; Zhang, Jiahua

    2017-09-01

    In this paper, we synthesized series of Eu2+ activated CaO ceramic powders by conventional solid state reaction. Using NH4Cl as a reducing additives, the Eu3+ has been successfully reduced to Eu2+. An intense blue emission peaked at 460 nm from Eu2+ was observed. The luminescent intensity of the doping-optimized CaO:Eu2+ sample can be as high as 106% of commercial BAM blue phosphor under 400 nm near-ultraviolet (NUV) excitation. The effect of Eu2+ and NH4Cl contents on photoluminescence properties and crystal phase formation have been investigated, respectively. The thermal stable property which is an important performance for LED application has also been measured. The emission intensity at 120 °C can maintain 94% of that at room temperature. Our results suggest that CaO: Eu2+ ceramic powder could be used as a promising blue emitting phosphor for NUV chip based white LEDs.

  11. Reactions in Electrodeposited Cu/Sn and Cu/Ni/Sn Nanoscale Multilayers for Interconnects

    Directory of Open Access Journals (Sweden)

    Pay Ying Chia

    2016-05-01

    Full Text Available Miniaturization of electronic devices has led to the development of 3D IC packages which require ultra-small-scale interconnections. Such small interconnects can be completely converted into Cu-Sn based intermetallic compounds (IMCs after reflow. In an effort to improve IMC based interconnects, an attempt is made to add Ni to Cu-Sn-based IMCs. Multilayer interconnects consisting of stacks of Cu/Sn/Cu/Sn/Cu or Cu/Ni/Sn/Ni/Sn/Cu/Ni/Sn/Ni/Cu with Ni = 35 nm, 70 nm, and 150 nm were electrodeposited sequentially using copper pyrophosphate, tin methanesulfonic, and nickel Watts baths, respectively. These multilayer interconnects were investigated under room temperature aging conditions and for solid-liquid reactions, where the samples were subjected to 250 °C reflow for 60 s and also 300 °C for 3600 s. The progress of the reaction in the multilayers was monitored by using X-ray Diffraction, Scanning Electron Microscope, and Energy dispersive X-ray Spectroscopy. FIB-milled samples were also prepared for investigation under room temperature aging conditions. Results show that by inserting a 70 nanometres thick Ni layer between copper and tin, premature reaction between Cu and Sn at room temperature can be avoided. During short reflow, the addition of Ni suppresses formation of Cu3Sn IMC. With increasing Ni thickness, Cu consumption is decreased and Ni starts acting as a barrier layer. On the other hand, during long reflow, two types of IMC were found in the Cu/Ni/Sn samples which are the (Cu,Ni6Sn5 and (Cu,Ni3Sn, respectively. Details of the reaction sequence and mechanisms are discussed.

  12. Preserved Collateral Blood Flow in the Endovascular M2CAO Model Allows for Clinically Relevant Profiling of Injury Progression in Acute Ischemic Stroke

    Science.gov (United States)

    Little, Philip; Kvist, Ola; Grankvist, Rikard; Jonsson, Stefan; Damberg, Peter; Söderman, Michael; Arnberg, Fabian; Holmin, Staffan

    2017-01-01

    Interventional treatment regimens have increased the demand for accurate understanding of the progression of injury in acute ischemic stroke. However, conventional animal models severely inhibit collateral blood flow and mimic the malignant infarction profile not suitable for treatment. The aim of this study was to provide a clinically relevant profile of the emergence and course of ischemic injury in cases suitable for acute intervention, and was achieved by employing a M2 occlusion model (M2CAO) that more accurately simulates middle cerebral artery (MCA) occlusion in humans. Twenty-five Sprague-Dawley rats were subjected to Short (90 min), Intermediate (180 min) or Extended (600 min) transient M2CAO and examined longitudinally with interleaved diffusion-, T2- and arterial spin labeling perfusion-weighted magnetic resonance imaging before and after reperfusion. We identified a rapid emergence of cytotoxic edema within tissue regions undergoing infarction, progressing in several distinct phases in the form of subsequent moderation and then reversal at 230 min (p < 0.0001). We identified also the early emergence of vasogenic edema, which increased consistently before and after reperfusion (p < 0.0001). The perfusion of the penumbra correlated more strongly to the perfusion of adjacent tissue regions than did the perfusion of regions undergoing infarction (p = 0.0088). This was interpreted as an effect of preserved collateral blood flow during M2CAO. Accordingly, we observed only limited recruitment of penumbra regions to the infarction core. However, a gradual increase in infarction size was still occurring as late as 10 hours after M2CAO. Our results indicate that patients suffering MCA branch occlusion stand to benefit from interventional therapy for an extended time period after the emergence of ischemic injury. PMID:28068417

  13. 《救荒本草》在日本的传承%Academic heritage of Jiu huang ben cao (Materia Medica for Relief of Famines) in Japan

    Institute of Scientific and Technical Information of China (English)

    何慧玲; 肖永芝

    2014-01-01

    《救荒本草》是中国历史上第1部救荒类本草专著,开创了可食用植物研究的新领域.该书大约在17世纪中后叶传入日本,受到日本著名本草学家的重视,不同传本系统的版本都在日本流传.其后,一些日本名家先后从传到日本的《农政全书》中析出《救荒本草》的内容单独校刻刊行,使《救荒本草》在日本得以更广泛地流传.%Jiu huang ben cao (Materia Medica for Relief of Famines) was the first monograph on famines herbal in the history of China,which creates a new research field of edible plants.Around the middle and late 17th century,Jiu huang ben cao was spread to Japan and aroused great attention of famous Japanese herbalists.Thus,all versions of different edition systems were circulated in Japan.Later,some famous Japanese scholar ssuccessively quoted texts of Jiu huang ben cao from the Nong zheng quan shu (Whole book on Agricultural Administration) spread in Japan,and block-printed it as an independent work.As a result,Jiu huang ben cao virtually circulated widcly in Japan.

  14. Dissolution and Interfacial Reactions of (Cu,Ni)6Sn5 Intermetallic Compound in Molten Sn-Cu-Ni Solders

    Science.gov (United States)

    Wang, Chao-hong; Lai, Wei-han; Chen, Sinn-wen

    2014-01-01

    (Cu,Ni)6Sn5 is an important intermetallic compound (IMC) in lead-free Sn-Ag-Cu solder joints on Ni substrate. The formation, growth, and microstructural evolution of (Cu,Ni)6Sn5 are closely correlated with the concentrations of Cu and Ni in the solder. This study reports the interfacial behaviors of (Cu,Ni)6Sn5 IMC (Sn-31 at.%Cu-24 at.%Ni) with various Sn-Cu, Sn-Ni, and Sn-Cu-Ni solders at 250°C. The (Cu,Ni)6Sn5 substrate remained intact for Sn-0.7 wt.%Cu solder. When the Cu concentration was decreased to 0.3 wt.%, (Cu,Ni)6Sn5 significantly dissolved into the molten solder. Moreover, (Cu,Ni)6Sn5 dissolution and (Ni,Cu)3Sn4 formation occurred simultaneously for the Sn-0.1 wt.%Ni solder. In Sn-0.5 wt.%Cu-0.2 wt.%Ni solder, many tiny (Cu,Ni)6Sn5 particulates were formed and dispersed in the solder matrix, while in Sn-0.3 wt.%Cu-0.2 wt.%Ni a lot of (Ni,Cu)3Sn4 grains were produced. Based on the local equilibrium hypothesis, these results are further discussed based on the liquid-(Cu, Ni)6Sn5-(Ni,Cu)3Sn4 tie-triangle, and the liquid apex is suggested to be very close to Sn-0.4 wt.%Cu-0.2 wt.%Ni.

  15. In situ{sup 119}Sn Moessbauer spectroscopy study of Sn-based electrode materials

    Energy Technology Data Exchange (ETDEWEB)

    Aboulaich, Abdelmaula, E-mail: abdelmaula.aboulaich@univ-mont2.fr; Robert, Florent; Lippens, Pierre Emmanuel; Aldon, Laurent; Olivier-Fourcade, Josette [Universite Montpellier II, Laboratoire des Agregats Moleculaires et Materiaux Inorganiques (UMR 5072-CNRS) (France); Willmann, Patrick [Centre National d' Etudes Spatiales (France); Jumas, Jean-Claude [Universite Montpellier II, Laboratoire des Agregats Moleculaires et Materiaux Inorganiques (UMR 5072-CNRS) (France)

    2006-01-15

    Sn-based composite materials were synthetized by a conventional melt-quenching method, and studied by X-ray diffraction, electrochemistry and in situ{sup 119}Sn Moesssbauer spectroscopy. Tin was dispersed ex situ into a matrix formed from B{sub 2}O{sub 3}:P{sub 2}O{sub 5}. XRD and {sup 119}Sn Moessbauer spectroscopy show the formation of an interface between the active species (Sn{sup 0}) and the matrix. This amorphous interface acts as a 'buffer-zone' which compensates volume changes during the tin-lithium alloy formation and avoids aggregation of tin particles.

  16. Electrochemical properties of Ti-Ni-Sn materials predicted by 119Sn Mössbauer spectroscopy

    Science.gov (United States)

    Ladam, A.; Aldon, L.; Lippens, P.-E.; Olivier-Fourcade, J.; Jumas, J.-C.; Cenac-Morthe, C.

    2016-12-01

    The electrochemical activity of TiNiSn, TiNi 2Sn and Ti 6Sn 5 compounds considered as negative electrode materials for Li-ion batteries has been predicted from the isomer shift- Hume-Rothery electronic density correlation diagram. The ternary compounds were obtained from solid-state reactions and Ti 6Sn 5 by ball milling. The 119Sn Mössbauer parameters were experimentally determined and used to evaluate the Hume-Rothery electronic density [e av]. The values of [e av] are in the region of Li-rich Li-Sn alloys for Ti 6Sn 5 and outside this region for the ternary compounds, suggesting that the former compound is electrochemically active but not the two latter ones. Electrochemical tests were performed for these different materials confirming this prediction. The close values of [e av] for Ti 6Sn 5 and Li-rich Li-Sn alloys indicate that the observed good capacity retention could be related to small changes in the global structures during cycling.

  17. Aperiodic SiSn/Si multilayers for thermoelectric applications

    Science.gov (United States)

    Tonkikh, A. A.; Zakharov, N. D.; Eisenschmidt, C.; Leipner, H. S.; Werner, P.

    2014-04-01

    We report on novel defect-free SiSn/Si heterostructures grown pseudomorphically on Si(001) substrates using temperature-modulated molecular beam epitaxy. This approach results in a sustainable epitaxial growth for SiSn/Si multilayers. Transmission electron microscopy and electron diffraction manifest that SiSn layers possess a diamond lattice structure. X-ray diffraction reveals up to 9.5 at% Sn in the crystal lattice of SiSn layers.

  18. Anomalous creep in Sn-rich solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ho Geon; Morris Jr., John W.; Hua, Fay

    2002-03-15

    This paper discusses the creep behavior of example Sn-rich solders that have become candidates for use in Pb-free solder joints. The specific solders discussed are Sn-3.5Ag, Sn-3Ag-0.5Cu, Sn-0.7Cu and Sn-10In-3.1Ag, used in thin joints between Cu and Ni-Au metallized pads.

  19. SeO2 adsorption on CaO surface: DFT and experimental study on the adsorption of multiple SeO2 molecules

    Science.gov (United States)

    Fan, Yaming; Zhuo, Yuqun; Li, Liangliang

    2017-10-01

    SeO2 adsorption mechanisms on CaO surface were firstly investigated by both density functional theory (DFT) calculations and adsorption experiments. Adsorption of multiple SeO2 on the CaO (001) surface was investigated using slab model. Based on the results of adsorption energy and surface property, a double-layer adsorption mechanisms were proposed. In experiments, the SeO2 adsorption products were prepared in a U-shaped quartz reactor at 200 °C. The surface morphology was investigated by field emission scanning electron microscopy (FE-SEM). The superficial and total SeO2 mass fractions were measured by X-ray photoelectron spectroscopy (XPS) and inductively coupled plasma atomic emission spectroscopy (ICP-AES), respectively. The surface valence state and bulk structure are determined by XPS and X-Ray Diffraction (XRD). The experimental results are in good agreement with the DFT results. In conclusion, the fundamental SeO2 chemisorption mechanisms on CaO surface were suggested.

  20. A density functional theory study of the adsorption of Hg and HgCl2 on a CaO(001) surface

    Institute of Scientific and Technical Information of China (English)

    GUO Xin; ZHENG Chuguang; LU Nanxia

    2007-01-01

    The adsorption of mercury and mercury chloride on a CaO(001) surface was investigated by the density functional theory (DFT) by using Ca9O9 cluster embedded in an electrostatic field represented by 178 point charges at the crystal CaO lattice positions.For the mercury molecular axis normal to the surface,the mercury can only coordinate to the O2- anion and has a very weak binding energy of 19.649 kJ/mol.When the mercury chloride molecular axis is vertical to the surface,the Cl atom coordinates to the Ca2+ cation and has a binding energy of 23.699 kJ/mol.When the mercury chloride molecular axis is parallel to the surface,the Hg atom coordinates to the O2- anion and has a binding energy of 87.829 kJ/mol,which means that the parallel geometry is more stable than the vertical one.The present calculations show that CaO injection could substantially reduce gaseous mercury chloride,but have no apparent effect on the mercury,which is compatible with the available experimental results.This research will provide valuable information for optimizing and selecting a sorbent for the trace element in flue gas.

  1. Ceramsite obtained from water and wastewater sludge and its characteristics affected by Fe2O3, CaO, and MgO.

    Science.gov (United States)

    Zou, J L; Xu, G R; Li, G B

    2009-06-15

    To solve the disposal problems of residual sludges, wastewater treatment sludge (WWTS) and drinking-water treatment sludge (DWTS) were tested as components for producing ceramsite. Fe(2)O(3), CaO, and MgO were the major basic oxides in WWTS and DWTS, so their effect on characteristics of ceramsite was also investigated to optimize the process. Results show that WWTS and DWTS can be utilized for producing ceramsite with optimal contents of Fe(2)O(3), CaO, and MgO ranging 5-8%, 2.75-7%, and 1.6-4%, respectively. Ceramsite within the optimal Fe(2)O(3), CaO, and MgO contents ranges was characterized using thermal analysis, X-ray diffraction (XRD), morphological structures analyses, and compressive strength measurements. Higher strength ceramsite with more complex crystalline phases and fewer pores can be obtained at 6%needed ions for producing electrical neutrality of silicate networks. Ceramsite characteristics are not dramatically influenced by MgO because Mg(2+) cannot destroy the unity of crystalline structures. This revolutionary technology of utilization of WWTS and DWTS can produce high performance ceramsite thus reducing costs of sludge disposal, in accordance with the concept of sustainable development.

  2. First-principles study of the thermodynamical, structural, transport properties of liquid CaO and CaSiO3 at high pressure

    Science.gov (United States)

    Bajgain, S. K.; Karki, B. B.; Ghosh, D. B.

    2014-12-01

    We have performed first principles molecular dynamics simulations of CaO and CaSiO3 liquids overbroad ranges of pressure (0 to 150 GPa) and temperature (2500 to 8000 K) within density functionaltheory. They show that both liquids are much more compressible than their solid counterpartsimplying possible liquid-solid density crossover. The liquid Grüneisen parameter increases onpressure, which is opposite of crystalline phases. Our analysis shows that the liquid structurechanges considerably on compression, with the mean cation-anion coordination numbers increasingnearly linearly with volume. The Ca-O coordination number increases from 7 (5) near the ambientpressure to 9 (7) at high pressure for CaSiO3 (CaO) liquid. The Si-O coordination number increasesfrom 4 to 6 over the same pressure regime. The calculated self-diffusion coefficients are stronglydependent on temperature and pressure and require non-Arrhenian representation with variableactivation volume. The diffusivity differences between the two liquids are considerable in low-temperature and low-pressure regime. Also, comparisons with MgSiO3 liquid suggest that networkmodifier cations Ca and Mg behave similarly though Ca is more coordinated and more mobile ascompared with Mg.

  3. Sn-inserted Al-induced layer exchange for large-grained GeSn thin films on insulator

    OpenAIRE

    Toko, Kaoru; Oya, Naoki; Nakata, Mitsuki; Suemasu, Takashi

    2016-01-01

    Large-grained polycrystalline GeSn layers on glass are achieved through the layer exchange between a-Ge and Sn-doped Al layers. The thicker Sn layers, inserted below Al layers, provided the faster growth velocity, resulting in the smaller grain size of the GeSn layer. Controlling the Sn thickness (10 nm) and the growth temperature (300 °C) allowed for approximately 80% (111)-oriented GeSn layer with grains having an average size of 40 μm. The lower growth temperature led to the higher Sn cont...

  4. Ag3Sn plate formation in the solidification of near-ternary eutectic Sn-Ag-Cu

    Science.gov (United States)

    Kang, Sung K.; Shih, Da-Yuan; Donald, Ny.; Henderson, W.; Gosselin, Timothy; Sarkhel, Amit; Charles Goldsmith, Ny.; Puttlitz, Karl J.; Choi, Won Kyoung

    2003-06-01

    Near-ternary eutectic Sn-Ag-Cu alloys are leading lead-free candidate solders for various applications. These alloys yield three phases upon solidification: β-Sn,Ag3Sn, and Cu6Sn5. Large, plate-like, pro-eutectic Ag3Sn structures can grow rapidly within the liquid phase, potentially adversely affecting the mechanical behavior and reducing the fatigue life of solder joints. This article reports on the formation of such plates in Sn-Ag-Cu solder balls and joints and demonstrates how large Ag3Sn plate formation can be minimized.

  5. On Mossbauer dynamics in Nb3Sn

    Indian Academy of Sciences (India)

    Ashok Razdan

    2000-06-01

    We compare the anharmonic Lamb Mossbauer factor and the -Lamb Mossbauer factor by studying the anharmonicity observed in the -factor data of Nb3Sn. We also show that this anharmonicity does not arise due to the presence of potential.

  6. The system SnSe-Bi

    Energy Technology Data Exchange (ETDEWEB)

    Alidzhanov, M.A.; Alizade, M.Z.; Aslanov, G.A.; Gurshumov, A.P.; Persakhova, A.Y.

    1986-10-01

    The authors study the system SnSe-Bi on annealed samples by methods of physicochemical analysis; x-ray phase, differential-thermal analysis, microstructural analysis, and measurements of the microhardness. It was established that the eutectic contains five mole % SnSe and melts at 260 C. A bounded region of the SnSe-based solid solutions exist, and the solubility of SnSe in bismuth was not observed. Anomalies in the temperature dependences of the thermo-emf and electrical conductivity of the solid solutions were determined by the phase transformations of tin monoselenide. The nature of the changes in the thermo-emf and the electrical conductivity as a function of the temperature is associated with the changes in the density and effective mass of the charge carriers.

  7. Theoretical study of projectile fragmentation in the reactions $^{112}$Sn + $^{112}$Sn and $^{124}$Sn + $^{124}$Sn at 1 GeV/nucleon

    CERN Document Server

    Imal, H; Buyukcizmeci, N; Ogul, R; Botvina, A S; Trautmann, W

    2014-01-01

    We analyze the production cross sections and isotopic distributions of projectile-like residues in the reactions $^{112}$Sn + $^{112}$Sn and $^{124}$Sn + $^{124}$Sn at an incident beam energy of 1 GeV/nucleon measured with the FRS fragment separator at the GSI laboratory. Calculations within the statistical multifragmentation model (SMM) for an ensemble of excited sources were performed with ensemble parameters determined previously for similar reactions at 600 MeV/nucleon. The obtained good agreement with the experiment establishes the universal properties of the excited spectator systems produced during the dynamical stage of the reaction. It is furthermore confirmed that a significant reduction of the symmetry-energy term at the freeze-out stage of reduced density and high temperature is necessary to reproduce the experimental isotope distributions. A trend of decreasing symmetry energy for large neutron-rich fragments of low excitation energy is interpreted as a nuclear-structure effect.

  8. MCNP6 Study of Fragmentation Products from 112Sn + 112Sn and 124Sn + 124Sn at 1 GeV/nucleon

    CERN Document Server

    Mashnik, Stepan G

    2013-01-01

    Isotope production cross sections from 112Sn + 112Sn and 124Sn + 124Sn reactions at 1 GeV/nucleon, which were measured recently at GSI using the heavy-ion accelerator SIS18 and the Fragment Separator (FRS), have been analyzed with the latest Los Alamos Monte-Carlo transport code MCNP6 using the LAQGSM03.03 event generator. MCNP6 reproduces reasonably well all the measured cross sections. Comparison of the MCNP6 results with the measured data and with calculations by a modification of the Los Alamos version of the Quark-Gluon String Model allowing for multifragmentation processes in the framework of the Statistical Multifragmentation Model (SMM) by Botvina and coauthors, as realized in the code LAQGSM03.S1, does not suggest unambiguous evidence of a multifragmentation signature.

  9. SN 1054: A pulsar-powered supernova?

    Science.gov (United States)

    Li, Shao-Ze; Yu, Yun-Wei; Huang, Yan

    2015-11-01

    The famous ancient supernova SN 1054 could have been too bright to be explained in the “standard” radioactive-powered supernova scenario. As an alternative attempt, we demonstrate that the spin-down of the newly born Crab pulsar could provide a sufficient energy supply to make SN 1054 visible at daytime for 23 days and at night for 653 days, where a one-zone semi-analytical model is employed. Our results indicate that SN 1054 could be a “normal” cousin of magnetar-powered superluminous supernovae. Therefore, SN 1054-like supernovae could be a probe to uncover the properties of newly born neutron stars, which provide initial conditions for studies on neutron star evolutions.

  10. Optical Characterization of Si-Based Ge1- x Sn x Alloys with Sn Compositions up to 12%

    Science.gov (United States)

    Al-Kabi, Sattar; Ghetmiri, Seyed Amir; Margetis, Joe; Du, Wei; Mosleh, Aboozar; Alher, Murtadha; Dou, Wei; Grant, Joshua M.; Sun, Greg; Soref, Richard A.; Tolle, John; Li, Baohua; Mortazavi, Mansour; Naseem, Hameed A.; Yu, Shui-Qing

    2016-04-01

    Optical properties of germanium tin (Ge1- x Sn x ) alloys have been comprehensively studied with Sn compositions from 0 (Ge) to 12%. Raman spectra of the GeSn samples with various Sn compositions were measured. The room temperature photoluminescence (PL) spectra show a gradual shift of emission peaks towards longer wavelength as Sn composition increases. Temperature dependent PL shows the PL intensity variation along with the temperature change, which reveals the indirectness or directness of the bandgap of the material. As temperature decreases, the PL intensity decreases with Sn composition less than 8%, indicating the indirect bandgap Ge1- x Sn x ; while the PL intensity increases with Sn composition higher than 10%, implying the direct bandgap Ge1- x Sn x . Moreover, the PL study of n-doped samples shows bandgap narrowing compared to the unintentionally (Boron) doped thin film with similar Sn compositions due to the doping.

  11. Advances in $Nb_{3}Sn$ performance

    CERN Document Server

    Godeke, A

    2009-01-01

    Nb3Sn wires with non-Cu critical current densities (Jc) that surpass 3 kAmm−2 at 12 T and 4.2 K are commercially available in piece lengths longer than 10 km. Acceleratortype magnets that utilize these conductors have achieved record magnetic fields. This article summarizes key developments in the last decade that have led to these significant improvements in the performance of Nb3Sn wires.

  12. Advances in Nb3Sn Performance

    Energy Technology Data Exchange (ETDEWEB)

    Godeke, Arno

    2008-05-19

    Nb{sub 3}Sn wires with non-Cu critical current densities (J{sub c}) that surpass 3 kAmm{sup -2} at 12 T and 4.2 K are commercially available in piece lengths longer than 10 km. Accelerator-type magnets that utilize these conductors have achieved record magnetic fields. This article summarizes key developments in the last decade that have led to these significant improvements in the performance of Nb{sub 3}Sn wires.

  13. Explosion Calculations of SN1087

    Science.gov (United States)

    Wooden, Diane H.; Morrison, David (Technical Monitor)

    1994-01-01

    Explosion calculations of SNT1987A generate pictures of Rayleigh-Taylor fingers of radioactive Ni-56 which are boosted to velocities of several thousand km/s. From the KAO observations of the mid-IR iron lines, a picture of the iron in the ejecta emerges which is consistent with the "frothy iron fingers" having expanded to fill about 50% of the metal-rich volume of the ejecta. The ratio of the nickel line intensities yields a high ionization fraction of greater than or equal to 0.9 in the volume associated with the iron-group elements at day 415, before dust condenses in the ejecta. From the KAO observations of the dust's thermal emission, it is deduced that when the grains condense their infrared radiation is trapped, their apparent opacity is gray, and they have a surface area filling factor of about 50%. The dust emission from SN1987A is featureless: no 9.7 micrometer silicate feature, nor PAH features, nor dust emission features of any kind are seen at any time. The total dust opacity increases with time even though the surface area filling factor and the dust/gas ratio remain constant. This suggests that the dust forms along coherent structures which can maintain their radial line-of-sight opacities, i.e., along fat fingers. The coincidence of the filling factor of the dust and the filling factor of the iron strongly suggests that the dust condenses within the iron, and therefore the dust is iron-rich. It only takes approximately 4 x 10(exp -4) solar mass of dust for the ejecta to be optically thick out to approximately 100 micrometers; a lower limit of 4 x 10(exp -4) solar mass of condensed grains exists in the metal-rich volume, but much more dust could be present. The episode of dust formation started at about 530 days and proceeded rapidly, so that by 600 days 45% of the bolometric luminosity was being emitted in the IR; by 775 days, 86% of the bolometric luminosity was being reradiated by the dust. Measurements of the bolometric luminosity of SN1987A from

  14. The Nature of SN 1961V

    CERN Document Server

    Chu, Y H; Stockdale, C J; Rupen, M P; Cowan, J J; Teare, S W; Chu, You-Hua; Gruendl, Robert A.; Stockdale, Christopher J.; Rupen, Michael P.; Cowan, John J.; Teare, Scott W.

    2004-01-01

    The nature of SN 1961V has been uncertain. Its peculiar optical light curve and slow expansion velocity are similar to those of super-outbursts of luminous blue variables (LBVs), but its nonthermal radio spectral index and declining radio luminosity are consistent with decades-old supernovae (SNe). We have obtained Hubble Space Telescope STIS images and spectra of the stars in the vicinity of SN 1961V, and find Object 7 identified by Filippenko et al. to be the closest to the optical and radio positions of SN 1961V. Object 7 is the only point source detected in our STIS spectra and only its H-alpha emission is detected; it cannot be the SN or its remnant because of the absence of forbidden lines. While the H-alpha line profile of Object 7 is remarkably similar to that of eta Car, the blue color (similar to an A2Ib supergiant) and lack of appreciable variability are unlike known post-outburst LBVs. We have also obtained Very Long Baseline Array (VLBA) observations of SN 1961V at 18 cm. The non-detection of SN ...

  15. Mapping the geographic distribution of canopy species communities in lowland Amazon rainforest with CAO-AToMS (Invited)

    Science.gov (United States)

    Feret, J.; Asner, G. P.

    2013-12-01

    Mapping regional canopy diversity will greatly advance our understanding as well as the conservation of tropical rainforests. Changes in species composition across space and time are particularly important to understand the influence of climate, human activity and environmental factors on these ecosystems, but to date such monitoring is extremely challenging and is facing a scale gap between small-scale, highly detailed field studies and large-scale, low-resolution satellite observations. Advances were recently made in the field of spectroscopic imagery for the estimation of canopy alpha-diversity, and an original approach based on the segmentation of the spectral space proved its ability to estimate Shannon diversity index with unprecedented accuracy. We adapted this method in order to estimate spectral dissimilarity across landscape as a proxy for changes in species composition. We applied this approach and mapped species composition over four sites located in lowland rainforest of Peruvian Amazon. This study was based on spectroscopic imagery acquired using the Carnegie Airborne Observatory (CAO) Airborne Taxonomic Mapping System (AToMS), operating a unique sensor combining the fine spectral and spatial resolution required for such task. We obtained accurate estimation of Bray-Curtis distance between pairs of plots, which is the most commonly used metric to estimate dissimilarity in species composition (n=497 pairs, r=0.63). The maps of species composition were then compared to topo-hydrographic properties. Our results indicated a strong shift in species composition and community diversity between floodplain and terra firme terrain conditions as well as a significantly higher diversity of species communities within Amazonian floodplains. These results pave the way for global mapping of tropical canopy diversity at fine geographic resolution.

  16. Um plano sobre o caos (reflexão acerca do evento A plan on chaos (a reflection on event

    Directory of Open Access Journals (Sweden)

    Ana Lúcia M. de Oliveira

    1995-02-01

    Full Text Available Inspirado no método das investigações wittgensteinianas, este ensaio parte de um breve estudo sobre a forma do fragmento para chegar a seu foco central: um questionamento da categoria de evento. Em síntese, intenta-se uma abordagem estética de um problema situado em um ponto de cruzamento entre a teoria da literatura, a história, a filosofia e até mesmo a ciência. A liga possível é sugerida por Deleuze e Guattari, em sua análise das três grandes formas de pensamento - a arte, a ciência e a filosofia - como diferentes maneiras de enfrentar o caos, traçando um plano secante que o atravessa. Como se trata de uma pesquisa ainda em curso, o que se pretende é o levantamento de questões básicas, apontando para os possíveis desdobramentos por vir.Inspired by Wittgensteinian philosophical investigation, this essay begins with an analysis of fragmentary form in order to reach the central point: a discussion on event as a category. Briefly, it seeks an aesthetic approach to a problem situated at the crossroads of literary theory, history, philosophy, and even science. A possible link is suggested by Deleuze and Guattari in their discussion of the three major trends of thought - art, science, and philosophy- as different ways of dealing with chaos, tracing a plan which traverses it. As a study still in progress, the essay is intended to raise basic questions to be developed further through future investigation.

  17. Caos determinístico em um modelo simplificado de cadeia produtiva Deterministic chaos in simplified supply chain model

    Directory of Open Access Journals (Sweden)

    Júlio César Bastos de Figueiredo

    2013-06-01

    Full Text Available Este trabalho tem por objetivo apresentar um modelo teórico simplificado de cadeia produtiva onde as relações entre o número de competidores, os tempos de resposta para ajustes da produção e a intensidade da resposta das empresas levam intrinsecamente ao surgimento de oscilações caóticas na oferta e na demanda. No modelo proposto, desenvolvido com o uso da metodologia de dinâmica de sistemas, as flutuações irregulares na demanda e nos preços estão intimamente relacionadas com a própria estrutura da cadeia, ou seja, com suas regras, políticas e capacidades produtivas. São feitas considerações sobre a importância do estudo de caos aplicado à economia e são discutidas técnicas para caracterização de comportamento caótico em séries econômicas.The purpose of this study was to present a simplified supply chain model where the relations between the number of competitors, the delay in production adjustments, and the intensity response of each company lead, intrinsically, to the emergence of chaotic oscillations in supply and demand. In the considered model, developed with the use of the System Dynamics methodology, the irregular fluctuations in demand and prices are closely related to the supply chain structure, that is, its rules, policies and capabilities. Discussions about the importance of the study of chaos applied to the economy are developed and specific techniques for characterization of chaotic behavior in economic time series are presented.

  18. Synthesis of Ni supported by CaO from Ni(0)L complexes (L=dihydrazine, bisethylenediamine)

    Science.gov (United States)

    Perangin-angin, Sabarmin; Bangun, Nimpan; Ginting, Adil; Putri, Nabila Karina

    2017-01-01

    Ni/CaO have been synthesis by using thermal reaction between Ni(0)L complexes (L=dihydrazine, bisethylenediamine) and CaO from Ca-stearate or CaCO3. Ni(0)L complexes (L=dihydrazine, bisethylenediamine) prepared by ligand substitution between Cl and hydrazine to perform dichlorohydrazine-Nickel (II) and this reaction monitored by IR spectroscopy and then mention as A. Two ways reaction have been used due to obtain dihydrazine-Nickel (0) from dichlorohydrazine-Nickel (II). The resulted dihydrazine-Nickel (0), B and E, then analyzed by FT-IR. To compare the result, dichloroethylenediamine-Nickel (II), as C, also has been prepared by ligand substitution between Cl and ethylenediamine. The obtain dichloroethylenediaminedichloro-Nickel (II) was then further reduction by using Zinc dust then analyzed by IR spectroscopy and result bisethylenediamine-Nickel (0), as D. The N-H functional groups have been indicated at 3500 - 3000 cm -1 for all A-E. Ni(0)L that obtain then characterized by SEM-EDX to confirm the morphology and molecules that contain in Ni(0)L that form. The reaction between Ca-stearate and dihydrazine-Nickel (0) then resulted black that mention as F. While the reaction between CaCO3 and Ni(0)L respectively resulted Ni/CaO, G, H and I. Ni/CaO surface then characterized by XRD, SEM-EDX and surface area analysis. The EDX analysis confirm the forming compounds of Ni/CaO. All of G, H and I are mesoporous materials.

  19. Heat recovery from a thermal energy storage based on the Ca(OH){sub 2}/CaO cycle

    Energy Technology Data Exchange (ETDEWEB)

    Azpiazu, M.N. [E.T.S. Ingenieros, Bilbao (Spain). Dpto. de Ingenieria Quimica y del Medio Ambiente; Morquillas, J.M. [E.T.S. Ingenieros, Bilbao (Spain). Dpto. de Maquinas y Motores Termicos; Vazquez, A. [E.S. da Marina Civil, La Coruna (Spain). Dpto. de Energia y Propulsion Maritima

    2003-04-01

    Thermal energy storage is very important in many applications related to the use of waste heat from industrial processes, renewable energies or from other sources. Thermochemical storage is very interesting for long-term storage as it can be carried out at room temperature with no energy losses. Dehydration/hydration cycle of Ca(OH){sub 2}/CaO has been applied for thermal energy storage in two types of reactors. One of them was a prototype designed by the authors, and in the other type conventional laboratory glassware was used. Parameters such as specific heats, reaction rate and enthalpy, mass losses and heat release were monitored during cycles. Although in the hydration step water is normally added in vapour phase, liquid water, at 0{sup o}C has been used in these experiences. Results indicated that the energy storage system performance showed no significant differences, when we compared several hydration/dehydration cycles. The selected chemical reaction did not exhibit a complete reversibility because complete Ca(OH){sub 2} dehydration, was not achieved. However the system could be used satisfactorily along 20 cycles at least. Heat recovery experiments showed general system behaviour during the hydration step in both types of reactors. The designed prototype was more efficient in this step. Main conclusions suggested carrying out one complete cycle at a higher dehydration temperature to recover total system reversibility. A modification of the prototype design trying to enhance heat transfer from the Ca(OH){sub 2} bed could also be proposed. (author)

  20. The influence of SrO and CaO in silicate and phosphate bioactive glasses on human gingival fibroblasts.

    Science.gov (United States)

    Massera, J; Kokkari, A; Närhi, T; Hupa, L

    2015-06-01

    In this paper, we investigate the effect of substituting SrO for CaO in silicate and phosphate bioactive glasses on the human gingival fibroblast activity. In both materials the presence of SrO led to the formation of a CaP layer with partial Sr substitution for Ca. The layer at the surface of the silicate glass consisted of HAP whereas at the phosphate glasses it was close to the DCPD composition. In silicate glasses, SrO gave a faster initial dissolution and a thinner reaction layer probably allowing for a continuous ion release into the solution. In phosphate glasses, SrO decreased the dissolution process and gave a more strongly bonded reaction layer. Overall, the SrO-containing silicate glass led to a slight enhancement in the activity of the gingival fibroblasts cells when compared to the SrO-free reference glass, S53P4. The cell activity decreased up to 3 days of culturing for all phosphate glasses containing SrO. Whereas culturing together with the SrO-free phosphate glass led to complete cell death at 7 days. The glasses containing SrO showed rapid cell proliferation and growth between 7 and 14 days, reaching similar activity than glass S53P4. The addition of SrO in both silicate and phosphate glasses was assumed beneficial for proliferation and growth of human gingival fibroblasts due to Sr incorporation in the reaction layer at the glass surface and released in the cell culture medium.

  1. SN 2009kn - The Twin of the Type IIn SN 1994W

    CERN Document Server

    Kankare, E; Bufano, F; Spyromilio, J; Mattila, S; Chugai, N N; Lundqvist, P; Pastorello, A; Kotak, R; Benetti, S; Botticella, M-T; Cumming, R J; Fransson, C; Fraser, M; Leloudas, G; Miluzio, M; Sollerman, J; Stritzinger, M; Turatto, M; Valenti, S

    2012-01-01

    We present an optical and near-infrared photometric and spectroscopic study of supernova (SN) 2009kn spanning ~1.5 yr from the discovery. The optical spectra are dominated by the narrow (FWHM ~1000 km s^-1) Balmer lines distinctive of a Type IIn SN with P-Cygni profiles. Contrarily the photometric evolution resembles more that of a Type IIP SN with a large drop in luminosity at the end of the plateau phase. These characteristics are similar to those of SN 1994W, whose nature has been explained with two different models with different approaches. The well-sampled dataset on SN 2009kn offers the possibility to test these models, both in the case of SN 2009kn and SN 1994W. We associate the narrow P-Cygni lines with a swept-up shell composed of circumstellar matter and SN ejecta. The broad emission line wings, seen during the plateau phase arise from internal electron scattering in this shell. The slope of the light curve after the post-plateau drop is fairly consistent with that expected from the radioactive dec...

  2. Effect of Sn:Zn Ratio on Corrosion Behavior of Mg-aSn-bZn Extrusions

    Science.gov (United States)

    Yim, Chang Dong; Woo, Sang Kyu; You, Bong Sun

    The effect of Sn:Zn ratio on corrosion behavior of magnesium alloys containing Sn and Zn was evaluated systematically by potentiodynamic polarization and immersion tests. The hydrogen evolution rate during cathodic polarization and the average corrosion rate measured by immersion test increased with increasing Sn content and Sn:Zn ratio. The changes of fraction of second phase with more positive corrosion potential and solute contents in the matrix phase were responsible for the change of corrosion behavior according to Sn content and Sn:Zn ratio. Mg2Sn particle accelerated the corrosion by formation of micro-galvanic cell, which resulted in faster corrosion rates of Mg-5Sn-xZn alloys than those of Mg-2Sn-xZn alloys. The increase of Zn in the matrix was harmful to the corrosion resistance because Zn accelerated the hydrogen evolution although ZnO was beneficial to the passivity of surface film.

  3. Turismo y Caos

    Directory of Open Access Journals (Sweden)

    María Camila Troncoso Diazgranados

    2008-11-01

    Full Text Available “Turismo y caos” es una producción literaria que brinda una reflexión acerca del pensamiento turístico posmoderno, enfocándose principalmente en las teorías de Alberto Sessa, Claude Kaspar, José Miguel Fernán dez Güell y finalmente, la Organización Mundial del Turismo, OMT. Es así como este texto pretende integrar, a través de una visión sistémica, los diferentes elementos que conforman y definen el turismo, dando lugar a un nuevo concepto que fusiona las teorías propuestas a través del tiempo y además la opinión personal de los autores de esta obra.

  4. Turismo y Caos

    OpenAIRE

    María Camila Troncoso Diazgranados; Carolina Gómez Gómez

    2008-01-01

    “Turismo y caos” es una producción literaria que brinda una reflexión acerca del pensamiento turístico posmoderno, enfocándose principalmente en las teorías de Alberto Sessa, Claude Kaspar, José Miguel Fernán dez Güell y finalmente, la Organización Mundial del Turismo, OMT. Es así como este texto pretende integrar, a través de una visión sistémica, los diferentes elementos que conforman y definen el turismo, dando lugar a un nuevo concepto que fusiona las teorías propuestas a través del tiemp...

  5. Dal caos... alla coscienza

    CERN Document Server

    Prattico, Franco

    1989-01-01

    Attraverso i domini della fisica, della genetica e della biologia, fino alle neuroscienze, alla ricerca dei percorsi che hanno portato alla nascita del cervello umano : frutto di una singolare serie casuale o di una necessità inscritta nelle leggi del Cosmo?

  6. Turismo y Caos

    Directory of Open Access Journals (Sweden)

    Carolina Gómez Gómez

    2008-11-01

    Full Text Available “Turismo y caos” es una producción literaria que brinda una reflexión acerca del pensamiento turístico posmoderno, enfocándose principalmente en las teorías de Alberto Sessa, Claude Kaspar, José Miguel Fernán dez Güell y finalmente, la Organización Mundial del Turismo, OMT. Es así como este texto pretende integrar, a través de una visión sistémica, los diferentes elementos que conforman y definen el turismo, dando lugar a un nuevo concepto que fusiona las teorías propuestas a través del tiempo y además la opinión personal de los autores de esta obra.

  7. Caos, fluidos y flujos

    Directory of Open Access Journals (Sweden)

    Luis Fernando Herrera Díaz

    2011-02-01

    Full Text Available During the last 30 years, the world of science has been revolutionized with the birth of a new paradigm: this form of seeing the world is known as The Chaos Theory. "In their short life it has already touched all the branches of knowledge, including Engineering" says Mora (1998.1t is so that many of the will known engineers like Aris in the ñeld of the chemical reactors, Froment in heterogeneous catalysis, Coppens who investigates the phenomena's of diffusionreaction in Zeolites, Julio Ottino in the mixing offluids, have begun to improve old outlines through thís theory. The present article seeks for to show the main concepts, in which the theory of chaos is based, through simple examples, showing mainly its relationships with chemical engineering, such as flow and mixing offluids.

  8. Creep performance of Zr-1Nb-0.75Sn-0.1Fe cladding tubes with optimized Sn content

    Science.gov (United States)

    Kim, Won Nyeon; Choi, Yong; Hong, Sun Ig

    2014-12-01

    Creep properties of stress-relieved Zr-1Nb-0.75Sn-0.1Fe alloy with a lower Sn content were studied. Zr-1Nb-0.75Sn-0.1Fe alloy was found to have stress exponents of 6-7, independent of stress level, unlike Zr-1Nb-1Sn-0.1Fe alloy, in which the transition of stress exponent with increase of stress was observed. The constancy of stress exponent, without the transition observed in Zr-1Nb-0.75Sn-0.1Fe alloy with lower Sn content, is associated with the decrease of Sn atoms. The activation energies for creep deformation were calculated to be between 210 and 260 kJ/mol for the Zr-1Nb-0.75Sn-0.1Fe alloy with a lower Sn content. The slightly smaller creep activation energy in Zr-1Nb-0.75Sn-0.1Fe, compared with that of Zr-1Nb-1Sn-0.1Fe alloy, is thought to be attributed to the lower Sn content. The creep data obtained at different temperatures and stress fell close to a single line, suggesting the creep life of Zr-1Nb-0.75Sn-0.1Fe alloy with a lower Sn content is well expressed by the Larson-Miller Parameter.

  9. 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.

  10. Chemistry, growth kinetics, and epitaxial stabilization of Sn2+ in Sn-doped SrTiO3 using (CH3)6Sn2 tin precursor

    Science.gov (United States)

    Wang, Tianqi; Pitike, Krishna Chaitanya; Yuan, Yakun; Nakhmanson, Serge M.; Gopalan, Venkatraman; Jalan, Bharat

    2016-12-01

    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.

  11. GRB 080319b and SN1054 .

    Science.gov (United States)

    Martocchia, A.; Polcaro, V. F.

    A typical SN Type IIp model can fit the SN1054 explosion light curve when data coming from European sources are also considered. Though a detailed study of these texts reveals a number of problems in their precise datation, it is likely that they actually describe the observation of an unusual celestial event which occurred in a day near to the one of Pope Leo IX's death (19 April, 1054). In particular, they seem to show that a very bright transient celestial phenomenon, lasting about 30 min, was observed. We already suggested that this Medieval testimonies were due to a very short and bright light flash in the first phase of the SN precursor collapse. The discovery of a similar flash in GRB 080319b brought us to consider this hypothesis more deeply. We thus scaled the intensity of the GRB 080319b to a distance of 1.83 kpc, in order to evaluate the intensity of a similar flash in the SN1054. We then took this value as input of the atmospheric optical effects simulation code \\textit{HaloSim3}, using the point-like source option for the dates and sites reported in European texts connected with the SN1054 event, and in various atmospheric conditions. The results are remarkably similar to the effects reported in Medieval chronicles.

  12. 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.

  13. Experimental Investigation of the Ti-Nb-Sn Isothermal Section at 1173 K

    Directory of Open Access Journals (Sweden)

    Jianli Wang

    2016-03-01

    Full Text Available Isothermal section of Ti-Nb-Sn at 1173 K was experimentally studied by back-scattered electron, electron probe microanalysis and X-ray diffraction analysis. Solid solution phase β(Ti, Nb, liquid Sn and eight intermetallic compounds Ti3Sn, Ti2Sn, Ti5Sn3, Ti6Sn5, Nb6Sn5, Nb3Sn, Ti3Nb2Sn2 and Ti3NbSn coexisted. Four ternary phase regions Ti3Sn + Ti3NbSn + β(Ti, Nb, Ti3NbSn + Ti3Nb3Sn2 + Ti3Sn, Ti2Sn + Ti3Sn + Ti3Nb3Sn2 and Ti6Sn5 + Ti3Nb3Sn2 + Nb3Sn were experimented. In addition, the proper composition range of the single phase was suggested. All the detected Ti-Sn and Nb-Sn compounds have a remarkable solubility along the isoconcentration of Sn. β(Ti, Nb has a relatively large solution while liquid Sn has a little in the isothermal section.

  14. Raman spectral shift versus strain and composition in GeSn layers with: 6 to 15% Sn contents

    OpenAIRE

    Gassenq, A.; Milord, L.; Aubin, J.; Pauc, N.; Guilloy, K.; Rothman, J.; Rouchon, D.; Chelnokov, A.; Hartmann, J.M.; Reboud, V.; Calvo, V.

    2017-01-01

    GeSn alloys are the subject of intense research activities as these group IV semiconductors present direct bandgap behaviors for high Sn contents. Today, the control of strain becomes an important challenge to improve GeSn devices. Strain micro-measurements are usually performed by Raman spectroscopy. However, different relationships linking the Raman spectral shifts to the built-in strain can be found in the literature. They were deduced from studies on low Sn content GeSn layers (i.e. xSn

  15. The theme of Jiang Cao terror works%姜草恐怖作品的主题研究

    Institute of Scientific and Technical Information of China (English)

    刘红芹

    2014-01-01

    韩国艺术家姜草的恐怖作品非常有特色,他一改以往恐怖作品的风格与特点,在作品中表现出高度的人文关怀。他的几部恐怖作品,主题表现出了某种程度的一致性,笔者就异化主题,时间主题与拯救主题进行细致的探究,试图挖掘姜草作品背后思路与主题的连贯与相关性,从而更好地理解姜草及作品。主题研究这个思路起源于德国民俗学,通常的主题研究,是指由纵向的角度对艺术家的作品进行探索,整体性地关注作品及作者的精神世界,从而丰富对作品及作者的阅读。%Korean artist ,Jiang Cao's terror works are very distinctive .He changed the terror work style and charac-teristic,showing high degree of human concern in the works .Several of his horror works ,subjects showed some de-gree of consistency ,the theme of alienation ,time subject and theme of salvation and meticulous research ,trying to dig out the ginger grass works behind the ideas and themes of coherence and relevance , and thus a better under-standing of ginger grass and works .The theme of this idea originated from German folklore ,the subject study usual-ly,refers to the exploration of the vertical angle of the artist's work,the whole attention to works and the author's spiritual world ,thus enriching the works and the author's reading .

  16. Ultraviolet emission from low resistance Cu2SnS3/SnO2 and CuInS2/Sn:In2O3 nanowires

    Directory of Open Access Journals (Sweden)

    E. Karageorgou

    2014-11-01

    Full Text Available SnO2 and Sn:In2O3 nanowires were grown on Si(001, and p-n junctions were fabricated in contact with p-type Cu2S which exhibited rectifying current–voltage characteristics. Core-shell Cu2SnS3/SnO2 and CuInS2/Sn:In2O3 nanowires were obtained by depositing copper and post-growth processing under H2S between 100 and 500 °C. These consist mainly of tetragonal rutile SnO2 and cubic bixbyite In2O3. We observe photoluminescence at 3.65 eV corresponding to band edge emission from SnO2 quantum dots in the Cu2SnS3/SnO2 nanowires due to electrostatic confinement. The Cu2SnS3/SnO2 nanowires assemblies had resistances of 100 Ω similar to CuInS2/In2O3 nanowires which exhibited photoluminescence at 3.0 eV.

  17. Interplay between relaxation and Sn segregation during thermal annealing of GeSn strained layers

    Science.gov (United States)

    Comrie, C. M.; Mtshali, C. B.; Sechogela, P. T.; Santos, N. M.; van Stiphout, K.; Loo, R.; Vandervorst, W.; Vantomme, A.

    2016-10-01

    The effect of thermal annealing on epitaxial GeSn (6.5% Sn) strained layers grown on Ge-buffered Si(100) wafers has been investigated using Rutherford backscattering spectrometry and X-ray diffraction to unambiguously determine the Sn substitutional content as well as the elastic strain in the layers. Vacuum annealing at temperatures below 400 °C for 20 min has no noticeable effect on the strain in the epitaxial layers. Once the temperature was raised above 400 °C, however, relaxation of the layer sets in and the GeSn layer has essentially completely relaxed following a 20 min anneal at 650 °C. Using Rutherford backscattering and channelling spectrometry to provide compositional information as a function of depth enables one to monitor the effect of the thermal anneal on the Sn distribution throughout the layer, and also to directly extract their substitutional fraction (i.e., their solubility in the lattice). The results obtained show that when the relaxation initially sets in both the Ge and the Sn remain firmly bound in substitutional lattice sites and it is only around 600 °C, and after substantial relaxation has taken place, that Sn is finally expelled from lattice sites and diffuses to the surface of the sample.

  18. Primary solidification phases of the Sn-rich Sn-Ag-Cu-Ni quaternary system

    Science.gov (United States)

    Chang, Cheng-An; Chen, Sinn-Wen; Chiu, Chen-Nan; Huang, Yu-Chih

    2005-08-01

    The eutectic and near-eutectic Sn-Ag-Cu solders are the most promising lead-free solders, and nickel is frequently used as the barrier layer material. Nickel dissolves into the molten Sn-Ag-Ni alloy during the soldering process, and the ternary solder becomes a Sn-Ag-Cu-Ni quaternary melt near the nickel substrate. Liquidus projection is the projection of the liquidus trough and it delineates the boundaries of various primary solidification phases. Information of liquidus projection is helpful for understanding the alloys’ solidification behavior. This study prepared the Sn-Ag-Cu-Ni alloys of various compositions at the Sn-rich corner. The alloys were melted at higher temperatures and solidified in air. The solidified alloys were metallographically examined to determine the phases formed, especially the primary solidification phases. No ternary or quaternary compounds were found. The knowledge of the primary solidification phases, phase formation sequences, and reaction temperatures determined in this study were put together with all of the available liquidus projections of the constituent ternary systems to determine the primary solidification phases of the quaternary Sn-Ag-Cu-Ni system at the Sn-rich corner.

  19. SN Refsdal: Classification as a Luminous and Blue SN 1987A-like Type II Supernova

    CERN Document Server

    Kelly, P L; Selsing, J; Foley, R J; Hjorth, J; Rodney, S A; Christensen, L; Strolger, L -G; Filippenko, A V; Treu, T; Steidel, C C; Strom, A; Riess, A G; Zitrin, A; Schmidt, K B; Bradac, M; Jha, S W; Graham, M L; McCully, C; Graur, O; Weiner, B J; Silverman, J M

    2015-01-01

    We have acquired Hubble Space Telescope (HST) and Very Large Telescope near-infrared spectra and images of supernova (SN) Refsdal after its discovery as an Einstein cross in Fall 2014. The HST light curve of SN Refsdal matches the distinctive, slowly rising light curves of SN 1987A-like supernovae (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 broad and strong H-alpha absorption. From the grism spectrum, we measure an H-alpha expansion velocity consistent with those of SN 1987A-like SNe at a similar phase. The luminosity, evolution, and Gaussian profile of the H-alpha emission of the WFC3 and X-shooter spectra, separated by ~2.5 months in the rest frame, provide additional evidence that supports the SN 1987A-like classification. In comparison with other exam...

  20. The Supernova Impostor SN 2010da

    Science.gov (United States)

    Binder, Breanna A.; Williams, Benjamin F.; Kong, Albert K. H.; Plucinsky, Paul P.; Gaetz, Terrance J.; Skillman, Evan D.; Dolphin, Andrew E.

    2016-01-01

    Supernova impostors are optical transients that, despite being assigned a supernova designation, do not signal the death of a massive star or accreting white dwarf. Instead, many impostors are thought to be major eruptions from luminous blue variables. Although the physical cause of these eruptions is still debated, tidal interactions from a binary companion has recently gained traction as a possible explanation for observations of some supernova impostors. In this talk, I will discuss the particularly interesting impostor SN 2010da, which exhibits high-luminosity, variable X-ray emission. The X-ray emission is consistent with accretion onto a neutron star, making SN 2010da a likely high mass X-ray binary in addition to a supernova impostor. SN 2010da is a unique laboratory for understanding both binary interactions as drivers of massive star eruptions and the evolutionary processes that create high mass X-ray binaries.

  1. Biological and mechanical properties of an experimental glass-ionomer cement modified by partial replacement of CaO with MgO or ZnO.

    Science.gov (United States)

    Kim, Dong-Ae; Abo-Mosallam, Hany; Lee, Hye-Young; Lee, Jung-Hwan; Kim, Hae-Won; Lee, Hae-Hyoung

    2015-01-01

    Some weaknesses of conventional glass ionomer cement (GIC) as dental materials, for instance the lack of bioactive potential and poor mechanical properties, remain unsolved.Objective The purpose of this study was to investigate the effects of the partial replacement of CaO with MgO or ZnO on the mechanical and biological properties of the experimental glass ionomer cements.Material and Methods Calcium fluoro-alumino-silicate glass was prepared for an experimental glass ionomer cement by melt quenching technique. The glass composition was modified by partial replacement (10 mol%) of CaO with MgO or ZnO. Net setting time, compressive and flexural properties, and in vitrorat dental pulp stem cells (rDPSCs) viability were examined for the prepared GICs and compared to a commercial GIC.Results The experimental GICs set more slowly than the commercial product, but their extended setting times are still within the maximum limit (8 min) specified in ISO 9917-1. Compressive strength of the experimental GIC was not increased by the partial substitution of CaO with either MgO or ZnO, but was comparable to the commercial control. For flexural properties, although there was no significance between the base and the modified glass, all prepared GICs marked a statistically higher flexural strength (p<0.05) and comparable modulus to control. The modified cements showed increased cell viability for rDPSCs.Conclusions The experimental GICs modified with MgO or ZnO can be considered bioactive dental materials.

  2. Biological and mechanical properties of an experimental glass-ionomer cement modified by partial replacement of CaO with MgO or ZnO

    Directory of Open Access Journals (Sweden)

    Dong-Ae KIM

    2015-08-01

    Full Text Available AbstractSome weaknesses of conventional glass ionomer cement (GIC as dental materials, for instance the lack of bioactive potential and poor mechanical properties, remain unsolved.Objective The purpose of this study was to investigate the effects of the partial replacement of CaO with MgO or ZnO on the mechanical and biological properties of the experimental glass ionomer cements.Material and Methods Calcium fluoro-alumino-silicate glass was prepared for an experimental glass ionomer cement by melt quenching technique. The glass composition was modified by partial replacement (10 mol% of CaO with MgO or ZnO. Net setting time, compressive and flexural properties, and in vitrorat dental pulp stem cells (rDPSCs viability were examined for the prepared GICs and compared to a commercial GIC.Results The experimental GICs set more slowly than the commercial product, but their extended setting times are still within the maximum limit (8 min specified in ISO 9917-1. Compressive strength of the experimental GIC was not increased by the partial substitution of CaO with either MgO or ZnO, but was comparable to the commercial control. For flexural properties, although there was no significance between the base and the modified glass, all prepared GICs marked a statistically higher flexural strength (p<0.05 and comparable modulus to control. The modified cements showed increased cell viability for rDPSCs.Conclusions The experimental GICs modified with MgO or ZnO can be considered bioactive dental materials.

  3. Use of CaO as an activator for producing a price-competitive non-cement structural binder using ground granulated blast furnace slag

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Min Sik; Jun, Yubin; Lee, Changha, E-mail: clee@unist.ac.kr; Oh, Jae Eun, E-mail: ohjaeeun@unist.ac.kr

    2013-12-15

    The use of calcium oxide (CaO) demonstrates a superior potential for the activation of ground granulated blast furnace slag (GGBFS), and it produces a higher mechanical strength than calcium hydroxide [Ca(OH){sub 2}]. The mechanical strength differences between CaO- and Ca(OH){sub 2}-activated GGBFS binders are explored using isothermal calorimetry, powder X-ray diffraction, thermogravimetric and differential thermal analysis (TGA and DTA) as well as compressive strength testing. Calcium silicate hydrate (C–S–H), Ca(OH){sub 2} and a hydrotalcite-like phase are found as reaction products in all samples. The TGA and DTA results indicate that the use of CaO produces more C–S–H, although this is not likely to be the primary cause of higher strength development in the CaO-activated GGBFS. Rather, other factors such as porosity may govern the strength at a higher order of magnitude. Significant reduction of Ca(OH){sub 2} occurs only with the use of Ca(OH){sub 2}, followed by the formation of carbonate (CaCO{sub 3}), indicating carbonation. -- Highlights: •CaO showed a better potential for the activation of GGBFS than Ca(OH){sub 2}. •Strength test, XRD, TGA/DTA and isothermal calorimetry are used. •C-S-H, Ca(OH){sub 2}, and a hydrotalcite-like phase are found in all samples. •The use of Ca(OH){sub 2} causes some degree of carbonation.

  4. THE INFLUENCE OF CaO AND P2O5 OF BONE ASH UPON THE REACTIVITY AND THE BURNABILITY OF CEMENT RAW MIXTURES

    Directory of Open Access Journals (Sweden)

    TOMÁŠ IFKA

    2012-03-01

    Full Text Available The influence of CaO and P2O5 upon the reactivity of cement raw meal was investigated in this paper. Ash of bone meal containing Ca3(PO42 - 3CaO·P2O5 was used as the source of P2O5. Two series of samples with different content of the ash of bone meal were prepared. In the first series, the ash of bone was added into cement raw meal. The second series of samples were prepared by considering ash as one of CaO sources. Therefore, the total content of CaO in cement raw meal was kept constant, while the amount of P2O5 increased. These different series of samples were investigated by analyzing free lime content in the clinkers. The XRD analysis and Electron Micro Probe Analyzer analysis of the clinkers were also carried out. Two parameters were used to characterize the reactivity of cement raw meal: content of free lime and Burnability Index (BI calculated from free lime content in both series of samples burnt at 1350 ºC, 1400 ºC, 1450 ºC and 1500 ºC. According to the first parameter, P2O5 content that drastically makes worse the reactivity of cement raw meal was found at 1.11 wt.% in the first series, while this limit has reached 1.52 wt.% in the second one. According to the BI, the limit of P2O5 was found at 1.42 wt. % in the first series and 1, 61 wt.% in the second one. Furthermore, EPMA has demonstrated the presence of P2O5 in both calcium silicate phases forming thus solid solutions.

  5. The Continuing Fall of SN 1987A

    Science.gov (United States)

    Dwek, Eli; Arendt, Richard; Bouchet, Patrice; Danziger, John; Frank, Kari; Gehrz, Robert; Park, Sangwook; Woodward, Charles

    2016-08-01

    We propose to use a total of 0.8 hr to obtain 3.6 and 4.5 micron photometry of SNR 1987A at four final epochs between 10900 and 11500 days after the explosion. SN 1987A has been monitored at approximately 6 month intervals throughout the Spitzer mission. The latest IRAC data clearly show that at 3.6 and 4.5 micron, the SN emission has peaked and is now in decline. Continued observation of SN 1987A will allow us to track the decline as the blast wave moves completely past the equatorial ring (ER). The rate at which new dust is swept up should be dropping to zero, and as the presently swept up dust is gradually destroyed (or cools) the emission should continue to fade. The dust traced at these wavelengths is thought to be collisionally-heated by the SN blast wave that also gives rise to the soft X-ray emission from the ER. Early in the mission, the intensity of the mid-IR emission (24 micron) was generally well correlated with that of the X-ray emission. However, the 3.6 and 4.5 micron emission are no longer tracking the brightness of the soft X-ray emission. These differences could stem from a variety of causes, including the sputtering of the dust or changes in the morphology of the ER. Ongoing X-ray observations of the remnant are taking place. Supplementing these with IR observations is essential for determining the spatial distribution, nature, and evolution of this hot dust component. Additionally, the observations may still reveal the appearance of a new emission component from the SN ejecta which is currently interacting with the reverse shock. These observations will complete the record of Spitzer's observations of SN 1987A, spanning more than 15 years from launch to end of mission.

  6. Origin of the SN2 benzylic effect.

    Science.gov (United States)

    Galabov, Boris; Nikolova, Valia; Wilke, Jeremiah J; Schaefer, Henry F; Allen, Wesley D

    2008-07-30

    The S N2 identity exchange reactions of the fluoride ion with benzyl fluoride and 10 para-substituted derivatives (RC6H 4CH 2F, R = CH3, OH, OCH 3, NH2, F, Cl, CCH, CN, COF, and NO2) have been investigated by both rigorous ab initio methods and carefully calibrated density functional theory. Groundbreaking focal-point computations were executed for the C6H5CH 2F + F (-) and C 6H 5CH2Cl + Cl (-) SN2 reactions at the highest possible levels of electronic structure theory, employing complete basis set (CBS) extrapolations of aug-cc-pV XZ (X = 2-5) Hartree-Fock and MP2 energies, and including higher-order electron correlation via CCSD/aug-cc-pVQZ and CCSD(T)/aug-cc-pVTZ coupled cluster wave functions. Strong linear dependences are found between the computed electrostatic potential at the reaction-center carbon atom and the effective SN2 activation energies within the series of para-substituted benzyl fluorides. An activation strain energy decomposition indicates that the SN2 reactivity of these benzylic compounds is governed by the intrinsic electrostatic interaction between the reacting fragments. The delocalization of nucleophilic charge into the aromatic ring in the SN2 transition states is quite limited and should not be considered the origin of benzylic acceleration of SN2 reactions. Our rigorous focal-point computations validate the benzylic effect by establishing SN2 barriers for (F (-), Cl (-)) identity exchange in (C6H5CH2F, C6H 5CH2Cl) that are lower than those of (CH3F, CH3Cl) by (3.8, 1.6) kcal mol (-1), in order.

  7. Microstructure evolution of directionally solidified Sn-16%Sb hyperperitectic alloy

    Institute of Scientific and Technical Information of China (English)

    Hu Xiaowu; Li Shuangming; Liu Lin; Fu Hengzhi

    2008-01-01

    The directionally solidified microstructure of Sn-16%Sb hyperperitectic alloy has been investigated at various solidification rates using a high-thermal gradient directional solidification apparatus. The results indicate that the solidification 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 refined with an increase in the solidification rate and dispersed more uniformly in the matrix of β-Sn phase. The volume fraction of the SnSb phase firstly decreases and then increases when the solidification rate increases in directional solidification of Sn-16%Sb hyperperitectic alloy.

  8. Electronic Structure, Oxidation State of Sn, and Chemical Stability of Photovoltaic Perovskite Variant Cs2SnI6

    CERN Document Server

    Xiao, Zewen; Zhang, Xiao; Zhou, Yuanyuan; Hosono, Hideo; Kamiya, Toshio

    2015-01-01

    Cs2SnI6, a variant of perovskite CsSnI3, is expected for a photovoltaic material. Based on a simple ionic model, it is expected that Cs2SnI6 is composed of Cs+, I-, and Sn4+ ions and that the band gap is primarily made of occupied I- 5p6 valence band maximum (VBM) and unoccupied Sn4+ 5s conduction band minimum (CBM) similar to SnO2. In this work, we performed density functional theory (DFT) calculations and revealed that the real charge state of the Sn ion in this compound is +2 similar to CsSnI3. This is due to strong covalent nature between the I ion and the Sn ion, the VBM consists of I 5p - I 5p antibonding states, and the CBM of I 5p - Sn 5s antibonding states. The +2 oxidation state of Sn is realized by the apparent charge state of I-2/3, because the I 5p - Sn 5s antibonding states form the unoccupied CBM and apparently 1/18 of the I 5p orbitals are unoccupied. These results are further supported by comparing chemical bonding analyses with those of related compounds. The chemical stability of the Cs2SnI...

  9. Ciencias de la complejidad y caos como herramientas en el análisis de la proliferación de vectores y zoonosis

    OpenAIRE

    2009-01-01

    En el presente trabajo se discuten los fundamentos de las ciencias de la complejidad y caos como herramientas en el análisis la proliferación de vectores y zoonosis. En la primera parte del artículo se describen los fundamentos y antecedentes de las ciencias de la complejidad, como una visión diferente para entender y analizar a los sistemas dinámicos, conceptos que han existido desde hace varios siglos y están relacionados con las ideas acerca del origen de la vida misma, que romperán con lo...

  10. Análisis, construcción, simulación y sincronización de circuitos electrónicos prototipos de Caos

    OpenAIRE

    Bordel Sánchez, Borja

    2014-01-01

    El proyecto tiene como objetivo el estudio de siete Sistemas Dinámicos, yendo de los que son paradigma de Caos a los más complejos, y sus posibles aplicaciones en comunicaciones privadas, bioingeniería y comunicaciones ópticas. El conjunto de sistemas seleccionados incluye algunos ejemplos paradigmáticos de Dinámicas Caóticas, así como nuevas propuestas, tanto de do sistemas básicos como de un sistema que tiene soluciones más complejas, nunca antes estudiados. Se logrará, de esta manera, rea...

  11. [Classes of crude drugs and its distribution of producing area in the attached illustrations in Ben cao tu jing (Illustrated Classic of Materia Medica)].

    Science.gov (United States)

    Xu, T; Peng, H S

    2016-03-01

    Ben cao tu jing (Illustrated Classic of Materia Medica) is the earliest extant atlas book of materia medica in China, with 933 attached drawings. Among them, the largest portion, amounting to 670, are herbaceous plants, mostly commonly used, with definite marks of the origin producing areas, distributed across 149 administrative divisions(prefectures and counties) of the Song Dynasty, most of them in Northern area which were distributed denser than those in Southern area. The densest ones were located in Southern Shanxi, Eastern Sichuan and Eastern Anhui. In the attached drawings, the frequency of highest occurrence appeared in this Classic are three prefectures, Chuzhou, Shizhou and Guangzhou.

  12. Crystallization paths in SiO2-Al2O3-CaO system as a genotype of silicate materials

    Science.gov (United States)

    Lutsyk, V. I.; Zelenaya, A. E.

    2013-12-01

    The phases trajectories in the fields of primary crystallization of cristobalite (SiO2cr), tridymite (SiO2tr), mullite (3Al2O3-2SiO2) and in a field of liquid immiscibility are analyzed on a basis of computer model for T-x-y diagram of SiO2-Al2O3-CaO system. The concentration fields with unique set of microconstituents and the fields without individual crystallization schemes and microconstituents are revealed.

  13. The Influence of Calcined Clay Pozzolan, Low-Cao Steel Slag and Granite Dust On the Alkali-Silica Reaction in Concrete

    OpenAIRE

    James Sarfo-Ansah; Eugene Atiemo

    2015-01-01

    The influence of low CaO steel slag, calcined clay and granite dust on the alkali-silica reaction was investigated over a period of 35 days under accelerated curing conditions. The mineral admixtures were used to replace varying portions of high alkali Portland limestone cement up to an admixture content of 25% in order to study their effect on the alkali-silica reaction (ASR). Portland limestone cement used for the study had a total Na2Oeq of 4.32. XRD analysis of hydrated mortar...

  14. Estudo sobre a emergência de padrões de estrutura organizacional em empresas atuantes no Brasil: uma abordagem baseada na teoria da complexidade e do caos

    OpenAIRE

    Jefferson Freitas Amancio de Oliveira

    2013-01-01

    A proposta da tese é contribuir para um melhor entendimento das organizações por meio da utilização de conceitos da teoria da Complexidade e Caos. Entendendo a organização como um sistema adaptativo complexo, busca-se, através de aspectos relacionados à conectividade, interdependência e diversidade, a identificação de padrões de estrutura organizacional em empresas brasileiras. Foi realizada uma pesquisa exploratória a partir de bases de dados de 417 empresas, 118 mil de seus funcionários, de...

  15. Evaluation of Component Activity in Molten MnO-SiO2-Al2O3-CaO System with Model SELF-SReM4

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A sub-regular solution model SE LF-SReM4 used to evaluate activity of the components in a homogeneous region of a quaternary system has been developed in Shanghai Enhanced Laboratory of Ferrometallurgy. The application of SELF-SReM4 in C-Mn-Fe-Si system without the SiC formation has been introduced in previous paper. It′s application for molten slag of MnO-SiO2-Al2O3-CaO was introduced in this paper. They provide a basis for the prediction of the metal-slag equilibrium conditions.

  16. El impacto en la ciencia económica de la teoría del caos y de los fractales: Teoría y aplicaciones

    OpenAIRE

    Andrés Fernández Díaz

    2015-01-01

    La complejidad constituye una de las características más importantes del comportamiento económico. El nuevo campo de conocimiento denominado Dinámica Caótica en Economía nació precisamente con el objetivo de comprender, estructurar y explicar de manera endógena tal complejidad. En este artículo, y tras exponer los principales conceptos y técnicas de las matemáticas del caos y de la geometría fractal, se analizan las posibilidades de aplicación de estos importantes instrumentos a las diferente...

  17. Steam-Coal Gasification Using CaO and KOH for in Situ Carbon and Sulfur Capture

    Energy Technology Data Exchange (ETDEWEB)

    Siefert, Nicholas S. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Carnegie Mellon Univ., Pittsburgh, PA (United States); Shekhawat, Dushyant [National Energy Technology Lab. (NETL), Morgantown, WV (United States); Litster, Shawn [Carnegie Mellon Univ., Pittsburgh, PA (United States); Berry, David A. [National Energy Technology Lab. (NETL), Morgantown, WV (United States)

    2013-08-15

    We present experimental results of coal gasification with and without the addition of calcium oxide and potassium hydroxide as dual-functioning catalyst-capture agents. Using two different coal types and temperatures between 700 and 900 °C, we studied the effect of these catalyst-capture agents on (1) the syngas composition, (2) CO2 and H2S capture, and (3) the steam-coal gasification kinetic rate. The syngas composition from the gasifier was roughly 20% methane, 70% hydrogen, and 10% other species when a CaO/C molar ratio of 0.5 was added. We demonstrated significantly enhanced steam–coal gasification kinetic rates when adding small amounts of potassium hydroxide to coal when operating a CaO-CaCO3 chemical looping gasification reactor. For example, the steam–coal gasification kinetic rate increased 250% when dry mixing calcium oxide at a Ca/C molar ratio of 0.5 with a sub-bituminous coal, and the kinetic rate increased 1000% when aqueously mixing calcium oxide at a Ca/C molar ratio of 0.5 along with potassium hydroxide at a K/C molar ratio of 0.06. In addition, we conducted multi-cycle studies in which CaCO3 was calcined by heating to 900 °C to regenerate the CaO, which was then reused in repeated CaO-CaCO3 cycles. The increased steam-coal gasification kinetics rates for both CaO and CaO + KOH persisted even when the material was reused in six cycles of gasification and calcination. The ability of CaO to capture carbon dioxide decreased roughly 2-4% per CaO-CaCO3 cycle. We also discuss an important application of this combined gasifier-calciner to electricity generation and selling the purge stream as a precalcined feedstock to a cement kiln. In this scenario, the amount of purge stream required is fixed not by the degradation in the capture ability but rather by the requirements at the cement kiln on the amount of CaSO4 and ash in the precalcined feedstock.

  18. 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.

  19. SN 1987A - a linear polarimetric study

    Energy Technology Data Exchange (ETDEWEB)

    Mendez, M.; Clocchiatti, A.; Benvenuto, O.G.; Feinstein, C.; Marraco, H.G.

    1988-11-01

    Multicolor linear polarimetric observations of SN 1987A have been obtained between February 28 and April 29, 1987. The intrinsic polarization was shown to decrease at a constant position angle of 27 deg during the first month after the explosion, and 30 days after the explosion the polarization began to grown in the V, R, and I filters at a different position angle. A model to interpret this behavior is proposed. Results are presented for the expansion of the outer layers of the SN and the evolution of the photospheric density. 28 references.

  20. Anomalous thermoelectric power behaviour in PrSn 3 and NdSn 3

    Science.gov (United States)

    Kletowski, Z.

    2006-03-01

    Results of the thermoelectric power (TEP) measurements done on monocrystalline samples of RESn 3 compounds (RE=La, Pr, Nd, and Gd) are presented for the temperature range of 5.5-300 K. It was found that the TEP is positive and weakly temperature dependent at temperatures T>100 K. For T<100 K pronounced anomalies have been observed for the PrSn 3 and the NdSn 3 compounds in the vicinity of 10 K.We argue that the Kondo and crystal field effects cause these anomalies. A shape of the TEP anomaly found for PrSn 3 resembles very much that observed in the electrical resistivity.

  1. Weierstrass Type Representation of Willmore Surfaces in Sn

    Institute of Scientific and Technical Information of China (English)

    Qiao Ling XIA; Yi Bing SHEN

    2004-01-01

    In this paper, we reformulate the Euler-Lagrange equations of Willmore surfaces in Sn as the flatness of a family of certain loop algebra-valued 1-forms. Therefore we can give the Weierstrass type representation of conformal Willmore surfaces. We also discuss the relations between conformal Willmore surfaces in Sn and minimal surfaces in constant curvature spaces Sn, Rn, Hn, and prove that some special Willmore surfaces can be derived from minimal surfaces in Sn, Rn, Hn.

  2. 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.

  3. Gamma bandgap determination in pseudomorphic GeSn layers grown on Ge with up to 15% Sn content

    Science.gov (United States)

    Gassenq, A.; Milord, L.; Aubin, J.; Guilloy, K.; Tardif, S.; Pauc, N.; Rothman, J.; Chelnokov, A.; Hartmann, J. M.; Reboud, V.; Calvo, V.

    2016-12-01

    Adding Tin (Sn) to Germanium (Ge) can turn it into a direct bandgap group IV semiconductor emitting in the mid-infrared wavelength range. Several approaches are currently being investigated to improve the GeSn devices. It has been theoretically predicted that the strain can improve their optical properties. However, the impact of strain on band parameters has not yet been measured for really high Sn contents (i.e., above 11%). In this work, we have used the photocurrent and photoluminescence spectroscopy to measure the gamma bandgap in compressively strained GeSn layers grown on Ge buffers. A good agreement is found with the modeling and the literature. We show here that the conventional GeSn deformation potentials used in the literature for smaller Sn contents can be applied up to 15% Sn. This gives a better understanding of strained-GeSn for future laser designs.

  4. Sputtering deposition of P-type SnO films with SnO₂ target in hydrogen-containing atmosphere.

    Science.gov (United States)

    Hsu, Po-Ching; Hsu, Chao-Jui; Chang, Ching-Hsiang; Tsai, Shiao-Po; Chen, Wei-Chung; Hsieh, Hsing-Hung; Wu, Chung-Chih

    2014-08-27

    In this work, we had investigated sputtering deposition of p-type SnO using the widely used and robust SnO2 target in a hydrogen-containing reducing atmosphere. The effects of the hydrogen-containing sputtering gas on structures, compositions, optical, and electrical properties of deposited SnOx films were studied. Results show that polycrystalline and SnO-dominant films could be readily obtained by carefully controlling the hydrogen gas ratio in the sputtering gas and the extent of reduction reaction. P-type conductivity was unambiguously observed for SnO-dominant films with traceable Sn components, exhibiting a p-type Hall mobility of up to ∼3 cm(2) V(-1) s(-1). P-type SnO thin-film transistors using such SnO-dominant films were also demonstrated.

  5. Raman spectral shift versus strain and composition in GeSn layers with 6%-15% Sn content

    Science.gov (United States)

    Gassenq, A.; Milord, L.; Aubin, J.; Pauc, N.; Guilloy, K.; Rothman, J.; Rouchon, D.; Chelnokov, A.; Hartmann, J. M.; Reboud, V.; Calvo, V.

    2017-03-01

    GeSn alloys are the subject of intense research activities as these group IV semiconductors present direct bandgap behaviors for high Sn contents. Today, the control of strain becomes an important challenge to improve GeSn devices. Strain micro-measurements are usually performed by Raman spectroscopy. However, different relationships linking the Raman spectral shifts to the built-in strain can be found in the literature. They were deduced from studies on low Sn content GeSn layers (i.e., xSn contributions of strain and chemical composition on the Ge-Ge Raman spectral shift. We have shown that the GeSn Raman-strain coefficient for high Sn contents is higher compared with that for pure Ge.

  6. Highly ionized region surrounding SN Refsdal revealed by MUSE

    NARCIS (Netherlands)

    Karman, W.; Grillo, C.; Balestra, I.; Rosati, P.; Caputi, K. I.; Di Teodoro, E.; Fraternali, F.; Gavazzi, R.; Mercurio, A.; Prochaska, J. X.; Rodney, S.; Treu, T.

    2016-01-01

    Supernova (SN) Refsdal is the first multiply imaged, highly magnified, and spatially resolved SN ever observed. The SN exploded in a highly magnified spiral galaxy at z = 1.49 behind the Frontier Fields cluster MACS1149, and provides a unique opportunity to study the environment of SNe at high z. We

  7. Metallic Sn spheres and SnO2@C core-shells by anaerobic and aerobic catalytic ethanol and CO oxidation reactions over SnO2 nanoparticles.

    Science.gov (United States)

    Kim, Won Joo; Lee, Sung Woo; Sohn, Youngku

    2015-08-24

    SnO2 has been studied intensely for applications to sensors, Li-ion batteries and solar cells. Despite this, comparatively little attention has been paid to the changes in morphology and crystal phase that occur on the metal oxide surface during chemical reactions. This paper reports anaerobic and aerobic ethanol and CO oxidation reactions over SnO2 nanoparticles (NPs), as well as the subsequent changes in the nature of the NPs. Uniform SnO2@C core-shells (10 nm) were formed by an aerobic ethanol oxidation reaction over SnO2 NPs. On the other hand, metallic Sn spheres were produced by an anaerobic ethanol oxidation reaction at 450 °C, which is significantly lower than that (1200 °C) used in industrial Sn production. Anaerobic and aerobic CO oxidation reactions were also examined. The novelty of the methods for the production of metallic Sn and SnO2@C core-shells including other anaerobic and aerobic reactions will contribute significantly to Sn and SnO2-based applications.

  8. Influences of CaO on Crystallization, Microstructures, and Properties of BaO-Al2O3-B2O3-SiO2 Glass-Ceramics

    Science.gov (United States)

    Li, Bo; Tang, Bo; Xu, Mingjiang

    2015-10-01

    We have developed BaO-CaO-Al2O3-B2O3-SiO2 glass-ceramics with high thermal coefficient of expansion (TCE) to overcome thermal mismatch at board level. The crystalline phases include quartz (major), cristobalite (minor), and bazirite BaZrSi3O9 (minor). Calculations from whole-pattern fitting show that the crystallinity varies slightly within the range of 33.48% to 34.89%, while the mass fraction of the phases changes remarkably with the CaO content. This indicates that CaO cannot promote crystallization of Ba-Al-B-Si glass, but effectively suppresses the phase transformation from quartz to cristobalite, making the thermal expansion curves linear. An empirical equation for the TCE versus the temperature and the amount of CaO is established. Furthermore, the densification mechanism of Ca modifiers is revealed. Due to its higher field strength than Ba, substitution of Ca increases the glass viscosity and inhibits ion diffusion. Excessive CaO is thus harmful to the density, bending strength, and electrical properties. The sample with 10 wt.% CaO sintered at 950°C exhibited high bending strength (154.1 MPa) and high TCE (12.38 ppm/°C) as well as good electrical properties ( ɛ = 6.2, tan δ = 5 × 10-4, ρ = 3.8 × 1012 Ω cm).

  9. Photo and electroluminescence of ZnSe: Sn and ZnSe:(Sn, Pr) phosphors

    Science.gov (United States)

    Mishra, A. K.; Mishra, S. K.; Pandey, S. P.; Lakshmi Mishra, Kshama

    2016-09-01

    We have prepared ZnSe (luminescent grade) phosphor doped with Sn and (Sn,Pr) with varying concentration in an inert atmosphere in a silica tubular furnace at temperature of (780 ± 20) °C for 1 hr to obtain ZnSe:Sn and ZnSe: (Sn,Pr) phosphors. The photo luminescence (PL) and electroluminescence (EL) spectra of these phosphors have been studied at room temperature and results were discussed in the light of existing models. Dependence of EL emission on the voltage frequency has also been carried out. It is found that the plot between the integrated light intensity versus 1/√Vrms is a straight line suggesting the existence of Mott-Schottky type barrier on the metal semiconductor interface.

  10. Spectroscopic classification of SN2017gvr as a peculiar type Ib SN

    Science.gov (United States)

    Martinez, Jorge; Galbany, L.; Gonzalez-Gaitan, S.; Forster, F.

    2017-09-01

    We report the spectroscopic classification of SN2017gvr as a peculiar type Ib supernova discovered by the OGLE-IV Real-time Transient Search (Wyrzykowski et al., 2014 arxiv:1409.1095; http://ogle.astrouw.edu.pl/).

  11. SN 2005ap: A Most Brilliant Explosion

    CERN Document Server

    Quimby, Robert M; Wheeler, J Craig; Höflich, Peter; Akerlof, Carl W; Rykoff, Eli S

    2007-01-01

    We present unfiltered photometric observations with ROTSE-III and optical spectroscopic follow-up with the HET and Keck of the most luminous supernova yet identified, SN 2005ap. The spectra taken about 3 days before and 6 days after maximum light show narrow emission lines (likely originating in the dwarf host) and absorption lines at a redshift of z=0.2832, which puts the peak unfiltered magnitude at -22.7 +/- 0.1 absolute. Broad P-Cygni features corresponding to H-alpha, CIII, NIII, and OIII, are further detected with a photospheric velocity of ~20,000 km/s. Unlike other highly luminous supernovae such as 2006gy and 2006tf that show slow photometric evolution, the light curve of SN 2005ap indicates a 1-3 week rise to peak followed by a relatively rapid decay. The spectra also lack the distinct emission peaks from moderately broadened (FWHM ~ 2,000 km/s) Balmer lines seen in SN 2006gy and SN 2006tf. We briefly discuss the origin of the extraordinary luminosity from a strong interaction as may be expected fro...

  12. Valence modulations in CeRuSn

    NARCIS (Netherlands)

    Feyerherm, R.; Dudzik, E.; Prokeš, K.; Mydosh, J.A.; Huang, Y.K.; Pöttgen, R.

    2014-01-01

    CeRuSn exhibits an extraordinary room temperature structure at 300 K with the coexistence of two types of Ce ions, namely trivalent Ce3+ and intermediate-valent Ce(4−δ)+, in a metallic environment. The ordered arrangement of these two Ce types on specific crystallographic sites results in a doubling

  13. Beta decay of {sup 103}Sn

    Energy Technology Data Exchange (ETDEWEB)

    Kavatsyuk, O.; Kavatsyuk, M. [GSI, Darmstadt (Germany); National Taras Shevcjenko Univ. of Kyiv (Australia); Batist, L. [St. Petersburg Nuclear Physics Inst. (Russian Federation); Univ. di Napoli (Italy); INFN, Napoli (Italy); Banu, A.; Becker, F.; Bruechle, W.; Doering, J.; Gorska, M.; Grawe, H.; Kirchner, R.; Mandal, S.; Mazzocchi, C.; Plettner, C.; Roeckl, E.; Schaedel, M. [GSI, Darmstadt (Germany); Blazhev, A. [GSI, Darmstadt (Germany); Univ. Sofia (Bulgaria); Faestermann, T. [Technische Universitaet Muenchen (Germany); Janas, Z.; Karny, M.; Plochocki, A.; Zylicz, J. [University of Warsaw (Poland); Jungclaus, A. [Universidad Autonoma de Madrid, Departamento de Fisica Teorica (Spain); La Commara, M.; Romoli, M. [INFN, Napoli (Italy); Mukha, I. [GSI, Darmstadt (Germany); Kurchatov Inst. Moscow (Russian Federation); Muralithar, S. [GSI, Darmstadt (Germany); Forschungszentrum Rossendorf (Germany); Schwengner, R. [Forschungszentrum Rossendorf (Germany)

    2005-08-01

    The {beta} decay of {sup 103}Sn, a three-neutron-particle nucleus with respect to the {sup 100}Sn core, was investigated at the GSI on-line mass separator using an array of 17 germanium crystals and a total absorption spectrometer. A total of 31 {beta}-delayed {gamma}-rays (29 new) of the {sup 103}Sn{yields}{sup 103}In decay were observed and, on the basis of {beta}-{gamma}-{gamma} coincidences, the {sup 103}Sn decay scheme was established for the first time. By means of total absorption spectroscopy, {beta} intensities, the Gamow-Teller strength distribution and the summed Gamow-Teller strength value of 3.5{+-}0.5 were determined for this decay. Its half-life and Q{sub EC} value were found to be 7.0{+-}0.2 s and 7.64{+-}0.7 MeV, respectively. The {beta}-delayed proton branching ratio was measured to be 1.2{+-}0.1%. The results are discussed in comparison with shell-model predictions based on realistic and empirical interactions. (orig.)

  14. Reaction mechanisms: Stripping down SN2

    Science.gov (United States)

    Orr-Ewing, Andrew J.

    2012-07-01

    The mechanism of the SN2 reaction is fundamental to understanding and controlling the stereochemistry of organic reactions, but surrounding solvent molecules may complicate the textbook picture. Micro-solvation studies have now explored the stereochemical consequences of the presence of one or two solvent molecules.

  15. Atmospheric pressure chemical vapour deposition of SnSe and SnSe{sub 2} thin films on glass

    Energy Technology Data Exchange (ETDEWEB)

    Boscher, Nicolas D.; Carmalt, Claire J.; Palgrave, Robert G. [Department of Chemistry, University College London, 20 Gordon Street, London, WC1H OAJ (United Kingdom); Parkin, Ivan P. [Department of Chemistry, University College London, 20 Gordon Street, London, WC1H OAJ (United Kingdom)], E-mail: i.p.parkin@ucl.ac.uk

    2008-06-02

    Atmospheric pressure chemical vapour deposition of tin monoselenide and tin diselenide films on glass substrate was achieved by reaction of diethyl selenide with tin tetrachloride at 350-650 {sup o}C. X-ray diffraction showed that all the films were crystalline and matched the reported pattern for SnSe and/or SnSe{sub 2}. Wavelength dispersive analysis by X-rays show a variable Sn:Se ratio from 1:1 to 1:2 depending on conditions. The deposition temperature, flow rates and position on the substrate determined whether mixed SnSe-SnSe{sub 2}, pure SnSe or pure SnSe{sub 2} thin films could be obtained. SnSe films were obtained at 650 {sup o}C with a SnCl{sub 4} to Et{sub 2}Se ratio greater than 10. The SnSe films were silver-black in appearance and adhesive. SnSe{sub 2} films were obtained at 600-650 {sup o}C they had a black appearance and were composed of 10 to 80 {mu}m sized adherent crystals. Films of SnSe only 100 nm thick showed complete absorbtion at 300-1100 nm.

  16. SN 2006oz: rise of a super-luminous supernova observed by the SDSS-II SN Survey

    DEFF Research Database (Denmark)

    Leloudas, Georgios; Chatzopoulos, E.; Dilday, B.;

    2012-01-01

    to contribute to a better understanding of these objects by studying SN 2006oz, a newly-recognized member of this class. Methods. We present multi-color light curves of SN 2006oz from the SDSS-II SN Survey that cover its rise time, as well as an optical spectrum that shows that the explosion occurred at z ~ 0...

  17. Spliceosomal small nuclear RNAs of Tetrahymena thermophila and some possible snRNA-snRNA base-pairing interactions

    DEFF Research Database (Denmark)

    Orum, H; Nielsen, Henrik; Engberg, J

    1991-01-01

    We have identified and characterized the full set of spliceosomal small nuclear RNAs (snRNAs; U1, U2, U4, U5 and U6) from the ciliated protozoan Tetrahymena thermophila. With the exception of U4 snRNA, the sizes of the T. thermophila snRNAs are closely similar to their metazoan homologues. The T...

  18. Characteristics of Reactive Ni3Sn4 Formation and Growth in Ni-Sn Interlayer Systems

    Science.gov (United States)

    Lis, Adrian; Kenel, Christoph; Leinenbach, Christian

    2016-06-01

    The near-isothermal growth and formation of Ni3Sn4 intermetallic compounds (IMC) in Ni-Sn interlayer systems was studied in the solid state at 473 K (200 °C) and under solid-liquid conditions at 523 and 573 K (250 °C and 300 °C) from an initial state of a few seconds. Scalloped solid-state IMC formation was mainly driven by grain boundary diffusion of Ni through the IMC layer combined with the grain coarsening of the IMC layer. Under solid-liquid conditions, the formation of faceted and needle-shaped Ni3Sn4 grains as well as an atypical IMC growth behavior with similar parabolic growth constants for 523 K and 573 K (250 °C and 300 °C) was observed within the first 180 seconds of the holding time, and IMC growth occurred as an isothermal solidification from the Ni-saturated Sn melt. Due to the progressive densification of the IMC layer and the diffusion-controlled growth, the kinetics slowed down by approximately one order of magnitude after 180 seconds of annealing. The final stage was characterized by the formation of IMC islands ahead of the interfacial Ni3Sn4 layer. Needle-like IMC growth was effectively suppressed under combined solid-state and solid-liquid conditions. Textured Ni3Sn4 IMC formation at the Ni-Sn interface was approved with pole figure measurements. The activation energy Q for solid-liquid IMC formation was calculated as 43.3 kJ/mol, and processing maps for IMC growth and Sn consumption were derived as functions of temperature and time, respectively.

  19. Effects of CaO, Al2O3 and MgO on liquidus temperatures of copper smelting and converting slags under controlled oxygen partial pressures

    Directory of Open Access Journals (Sweden)

    Zhao B.

    2013-01-01

    Full Text Available Phase equilibria of silicate slags relevant to the copper smelting/converting operations have been experimentally studied over a wide range of slag compositions, temperatures and atmospheric conditions. Selected systems are of industrial interest and fill the gaps in fundamental information required to systematically characterise and describe copper slag chemistry. The experimental procedures include equilibration of synthetic slag at high temperatures, rapid quenching of resulting phases, and accurate measurement of phase compositions using electron probe X-ray microanalysis (EPMA. The effects of CaO, Al2O3 and MgO on the phase equilibria of this slag system have been experimentally investigated in the temperature range 1200 to 1300 oC and oxygen partial pressures between 10-5 and 10-9 atm. It was found that spinel and silica are major primary phases in the composition range related to copper smelting/converting slags. In addition, olivine, diopside and pyroxene also appear at certain conditions. The presence of CaO, MgO and Al2O3 in the slag increases the spinel liquidus and decreases the silica liquidus. Liquidus temperatures in silica primary phase field are not sensitive to Po2; Liquidus temperatures in spinel primary phase field increase with increasing Po2. At 1300 oC and low Po2, the spinel (Fe2+,Mg2+O.(Al3+,Fe3+ primary phase field can be replaced by wustite (Fe2+,Mg2+O.

  20. The content of chromium and copper in plants and soil fertilized with sewage sludge with addition of various amounts of CaO and lignite ash

    Directory of Open Access Journals (Sweden)

    Wysokiński Andrzej

    2016-09-01

    Full Text Available The influence of fertilization with fresh sewage sludge with the addition of calcium oxide and lignite ash in the proportions dry mass 6:1, 4:1, 3:1 and 2:1 on the content of chromium and copper in plants and soil and uptake of these elements was investigated in pot experiment. Sewage sludge were taken from Siedlce (sludge after methane fermentation and Łuków (sludge stabilized in oxygenic conditions, eastern Poland. The chromium content in the biomass of the test plants (maize, sunflower and oat was higher following the application of mixtures of sewage sludge with ash than of the mixtures with CaO. The copper content in plants most often did not significantly depend on the type of additives to the sludge. Various amounts of additives to the sewage sludge did not have a significant effect on the contents of either of the studied trace elements in plants. The contents of chromium and copper in soil after 3 years of cultivation of plants were higher than before the experiment, but these amounts were not significantly differentiated depending on the type and the amount of the used additive (i.e. CaO vs. ash to sewage sludge.

  1. NMR Technique for Determining Transition Metal Cation Distribution at Low Concentrations Demonstrated Using Periclase (MgO) and CaO

    Science.gov (United States)

    McCarty, R. J.; Stebbins, J. F.

    2016-12-01

    We investigate the distribution of transition metals at or below percent-level concentrations in synthetic minerals using paramagnetic nuclear magnetic resonance (NMR). In paramagnetic systems, dilute unpaired electron spins can affect the NMR spectra of major mineral components, a phenomenon that is highly sensitive to geometric relationships and bond distance of the paramagnetic and observed atoms. In both 17O and 25Mg or 43Ca spectra of periclase (MgO) and CaO doped with transition metals, we detect paramagnetic shifts and in some cases can assign them to specific bond paths between the observed nuclide and the paramagnetic cation. A binomial distribution model is developed. Comparing computer-simulated spectra to the observed spectra indicates fully random distribution of Ni2+ and Co2+ in MgO but avoidance of neighboring transition metal cations in CaO. Paramagnetic NMR is a promising technique for investigating short range ordering in synthetic and natural minerals, which may prove useful in future minor and trace element studies.

  2. [Textual research on Guang dong xin yu (New Sayings of Guangdong) quoted in Ben cao gang mu shi yi (Supplements to Compendium of Materia Medica].

    Science.gov (United States)

    Zhang, Ruixian; Zhang, Wei; Li, Jian; Liang, Fei

    2014-05-01

    Altogether 15 terms for Guang dong xin yu (New Sayings of Guangdong) were used in Ben cao gang mu shi yi (Supplements to Compendium of Materia Medica), including Yue yu (Cantonese sayings), Chong yu (Sayings from Insect Drug), Jie yu (Sayings from Crustacean Drug), Xin yu (New Sayings), Yue hai xiang yu (Fragrant Sayings from Cantonese Region), Yue zhi mu yu (Sayings from Plants in Cantonese Annals), Guang dong suo yu (Trivial Sayings from Guangdong), Yue shan lu (Records of Cantonese Mountains), Yue lu (Cantonese Records), Jiao guang lu (Joint Guangdong Records), Yue cao zhi (Records of Cantonese Grasses), Guang guo lu (Records of Guangdong Fruits), Nan yue suo ji (Trivial Records of Southern Canton), Guang zhi (Guangdong Records), Yue zhi (Cantonese Records) etc. dealing with 57 sorts of drugs (with individual overlapping ones), the author of Xin yu was Qu Dajun, a surviving fogy of the Ming Dynasty actively involved in the activities to restore the old dynasty and resist the Qing Dynasty, and was persecuted in the literary inquisition in which his works were burnt so that Zhao Xuemin, when quoting his texts, had to go in a roundabout way.

  3. Effect of carbonation temperature on CO{sub 2} adsorption capacity of CaO derived from micro/nanostructured aragonite CaCO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Hlaing, Nwe Ni, E-mail: nwenihlaing76@gmail.com [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Department of International Development Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo (Japan); Department of Physics, University of Yangon, 11041 Kamayut, Yangon (Myanmar); Sreekantan, Srimala, E-mail: srimala@usm.my [School of Materials and Mineral Resources Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Hinode, Hirofumi, E-mail: hinode@ide.titech.ac.jp; Kurniawan, Winarto, E-mail: Kurniawan.w.ab@m.titech.ac.jp [Department of International Development Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo (Japan); Thant, Aye Aye, E-mail: a2thant@gmail.com [Department of Physics, University of Yangon, 11041 Kamayut, Yangon (Myanmar); Othman, Radzali, E-mail: radzali@utem.edu.my [Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, Hang Tuah Jaya, 76100 Durian Tunggal, Malacca (Malaysia); Mohamed, Abdul Rahman, E-mail: chrahman@eng.usm.my [Low Carbon Economy (LCE) Research Group, School of Chemical Engineering, Engineering Campus, Universiti Sains Malaysia, 14300 Nibong Tebal, Penang (Malaysia); Salime, Chris, E-mail: chris.salim@surya.ac.id [Environmental Engineering, Surya University, Tangerang, 15810 Banten (Indonesia)

    2016-07-06

    Recent years, CaO-based synthetic materials have been attracted attention as potential adsorbents for CO{sub 2} capture mainly due to their high CO{sub 2} adsorption capacity. In this study, micro/nanostructured aragonite CaCO{sub 3} was synthesized by a simple hydrothermal method with using polyacrylamide (PAM). The structural, morphological and thermal properties of the synthesized sample were investigated by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) and thermogravimetry analysis (TG-DTA). The XRD and FESEM results showed that the obtained sample was aragonite CaCO{sub 3} with aggregated nanorods and microspheres composed of nanorods. A TG-DTA apparatus with Thermoplus 2 software was used to investigate the effect of carbonation temperature on the CO{sub 2} adsorption capacity of CaO derived from aragonite CaCO{sub 3} sample. At 300 °C, the sample reached the CO{sub 2} adsorption capacity of 0.098 g-CO{sub 2}/g-adsorbent, whereas the sample achieved the highest capacity of 0.682 g-CO{sub 2}/g-adsorbent at 700 °C. The results showed that the carbonation temperature significantly influenced on the CO{sub 2} adsorption capacity of the CaO derived from aragonite CaCO{sub 3}.

  4. Removal of Pb from Molten Copper by FetO-SiO2 (-CaO, Al2O3) Slag Treatment in Mitsubishi Process

    Science.gov (United States)

    Park, Soo Sang; Park, Joo Hyun

    The distribution behavior of Pb between molten copper and FetO-SiO2 (-CaO, Al2O3) slags was investigated at 1473 K (1200 °C) and p(O2)=10-10 atm in view of the reaction mechanism of Pb dissolution into the slag. The distribution ratio of Pb (L Pb) decreases with increasing CaO content ( 6 mass pct) irrespective of Fe/SiO2 ratio (1.4 1.7). However, the addition of alumina into a slag with Fe/SiO2=1.5 linearly decreases the L Pb, whereas a minimum value is observed at about 4 mass pct Al2O3 at Fe/SiO2=1.3. The log L Pb continuously decreases with increasing Fe/SiO2 ratio, and the addition of Al2O3 (5 to 15 mass pct) into the silica-saturated iron silicate slag (Fe/SiO2 > 1.0) yields the highest Pb distribution ratio. The log LPb linearly decreases by increasing the log (Fe3+/Fe2+) value. The Pb distribution ratio increases and the excess free energy of PbO decreases with increasing Cu2O content in the slag. However, from the viewpoint of copper loss into the slag, the silica-saturated system containing small amounts of alumina is strongly recommended to stabilize PbO in the slag phase at a low Cu2O content.

  5. Performance and economic assessments of a solid oxide fuel cell system with a two-step ethanol-steam-reforming process using CaO sorbent

    Science.gov (United States)

    Tippawan, Phanicha; Arpornwichanop, Amornchai

    2016-02-01

    The hydrogen production process is known to be important to a fuel cell system. In this study, a carbon-free hydrogen production process is proposed by using a two-step ethanol-steam-reforming procedure, which consists of ethanol dehydrogenation and steam reforming, as a fuel processor in the solid oxide fuel cell (SOFC) system. An addition of CaO in the reformer for CO2 capture is also considered to enhance the hydrogen production. The performance of the SOFC system is analyzed under thermally self-sufficient conditions in terms of the technical and economic aspects. The simulation results show that the two-step reforming process can be run in the operating window without carbon formation. The addition of CaO in the steam reformer, which runs at a steam-to-ethanol ratio of 5, temperature of 900 K and atmospheric pressure, minimizes the presence of CO2; 93% CO2 is removed from the steam-reforming environment. This factor causes an increase in the SOFC power density of 6.62%. Although the economic analysis shows that the proposed fuel processor provides a higher capital cost, it offers a reducing active area of the SOFC stack and the most favorable process economics in term of net cost saving.

  6. The melting diagram of the Ti-Zr-Sn system below 40 at.% Sn

    Energy Technology Data Exchange (ETDEWEB)

    Saltykov, V.A.; Meleshevich, K.A.; Samelyuk, A.V. [I.N. Frantsevich Institute for Problems of Materials Science, Street Krzhyzhanovsky, 3, Kiev 03142 (Ukraine); Bulanova, M.V. [I.N. Frantsevich Institute for Problems of Materials Science, Street Krzhyzhanovsky, 3, Kiev 03142 (Ukraine)], E-mail: bulanova@lycos.com; Tedenac, J.C. [Institut de Chimie moleculaire et des materiaux-I.C.G., UMR-CNRS 5253-Universite Montpellier II, case 1504, Pl. Eugene Bataillon, 34095 Montpellier Cedex 5 (France)

    2009-04-03

    By the methods of DTA, X-ray diffraction, metallography and EPMA, phase equilibria in the Ti-Zr-Sn system at <40 at.% Sn were studied. The partial liquidus and solidus projections, and the melting diagram (solidus + liquidus) were constructed. The liquidus surface is characterized by the presence of primary crystallization regions of ({beta}Ti) ({beta}), (Ti{sub 3}Sn) ({alpha}{sub 2}) and (Ti,Zr){sub 5}Sn{sub 3} (5/3) phases. The solidus surface is characterized by the presence of two three-phase fields, {beta} + {alpha}{sub 2} + 5/3 and {alpha}{sub 2} + (Ti{sub 2}Sn)(2/1) + 5/3. The first one results from an invariant four-phase equilibrium L{sub U} + {alpha}{sub 2} {r_reversible} {beta} + 5/3 taking place at 1510 {+-} 10 deg. C. The invariant point U is located at the composition {approx}53Ti-30Zr-17Sn. The second three-phase region results from an equilibrium at 1515 deg. C with participation of L + {alpha}{sub 2} + 5/3 + 2/1 phases. The character of the equilibrium is not determined. Two invariant three-phase equilibria were found, L{sub e{sub 1}}{r_reversible}{alpha}{sub 2}+5/3 at 1600-1650 deg. C and L{sub e{sub 4}}{r_reversible}{beta}+5/3 at 1423 deg. C.

  7. On integrable deformations of superstring sigma models related to AdSn×Sn supercosets

    Directory of Open Access Journals (Sweden)

    B. Hoare

    2015-08-01

    Full Text Available We consider two integrable deformations of 2d sigma models on supercosets associated with AdSn×Sn. The first, the “η-deformation” (based on the Yang–Baxter sigma model, is a one-parameter generalization of the standard superstring action on AdSn×Sn, while the second, the “λ-deformation” (based on the deformed gauged WZW model, is a generalization of the non-abelian T-dual of the AdSn×Sn superstring. We show that the η-deformed model may be obtained from the λ-deformed one by a special scaling limit and analytic continuation in coordinates combined with a particular identification of the parameters of the two models. The relation between the couplings and deformation parameters is consistent with the interpretation of the first model as a real quantum deformation and the second as a root of unity quantum deformation. For the AdS2×S2 case we then explore the effect of this limit on the supergravity background associated with the λ-deformed model. We also suggest that the two models may form a dual Poisson–Lie pair and provide direct evidence for this in the case of the integrable deformations of the coset associated with S2.

  8. 70 °C synthesis of high-Sn content (25%) GeSn on insulator by Sn-induced crystallization of amorphous Ge

    Energy Technology Data Exchange (ETDEWEB)

    Toko, K., E-mail: toko@bk.tsukuba.ac.jp; Oya, N.; Suemasu, T. [Institute of Applied Physics, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8573 (Japan); Saitoh, N.; Yoshizawa, N. [Electron Microscope Facility, TIA, AIST, 16-1 Onogawa, Tsukuba 305-8569 (Japan)

    2015-02-23

    Polycrystalline GeSn thin films are fabricated on insulating substrates at low temperatures by using Sn-induced crystallization of amorphous Ge (a-Ge). The Sn layer stacked on the a-Ge layer (100-nm thickness each) had two roles: lowering the crystallization temperature of a-Ge and composing GeSn. Slow annealing at an extremely low temperature of 70 °C allowed for a large-grained (350 nm) GeSn layer with a lattice constant of 0.590 nm, corresponding to a Sn composition exceeding 25%. The present investigation paves the way for advanced electronic optical devices integrated on a flexible plastic substrate as well as on a Si platform.

  9. Low Temperature Deposition of High-k/Metal Gate Stacks on High-Sn Content (Si)GeSn-Alloys.

    Science.gov (United States)

    Schulte-Braucks, C; von den Driesch, N; Glass, S; Tiedemann, A T; Breuer, U; Besmehn, A; Hartmann, J-M; Ikonic, Z; Zhao, Q T; Mantl, S; Buca, D

    2016-05-25

    (Si)GeSn is an emerging group IV alloy system offering new exciting properties, with great potential for low power electronics due to the fundamental direct band gap and prospects as high mobility material. In this Article, we present a systematic study of HfO2/TaN high-k/metal gate stacks on (Si)GeSn ternary alloys and low temperature processes for large scale integration of Sn based alloys. Our investigations indicate that SiGeSn ternaries show enhanced thermal stability compared to GeSn binaries, allowing the use of the existing Si technology. Despite the multielemental interface and large Sn content of up to 14 atom %, the HfO2/(Si)GeSn capacitors show small frequency dispersion and stretch-out. The formed TaN/HfO2/(Si)GeSn capacitors present a low leakage current of 2 × 10(-8) A/cm(2) at -1 V and a high breakdown field of ∼8 MV/cm. For large Sn content SiGeSn/GeSn direct band gap heterostructures, process temperatures below 350 °C are required for integration. We developed an atomic vapor deposition process for TaN metal gate on HfO2 high-k dielectric and validated it by resistivity as well as temperature and frequency dependent capacitance-voltage measurements of capacitors on SiGeSn and GeSn. The densities of interface traps are deduced to be in the low 10(12) cm(-2) eV(-1) range and do not depend on the Sn-concentration. The new processes developed here are compatible with (Si)GeSn integration in large scale applications.

  10. Diffusion couple studies of the Ni-Bi-Sn system

    Directory of Open Access Journals (Sweden)

    Vassilev G.

    2012-01-01

    Full Text Available Investigations of Ni-Bi-Sn system were performed in order to inquire the phase diagram and to assess some diffusion kinetic parameters. For this purpose diffusion couples consisting of solid nickel (preliminary electroplated with tin and liquid Bi-Sn phase were annealed at 370 °C. Three compositions (0.8, 0.6 and 0.4 mole fractions Sn of the Bi-Sn melts were chosen. Annealing times from 24 to 216 h were applied. The phase and chemical compositions of the contact zone were determined by means of electron scanning microscope. It was confirmed that the diffusion layers consist mainly of Ni3Sn4 but other intermetallic phases grow as well. For the first time metastable Ni-Sn phases as NiSn and NiSn8 (NiSn9 were observed in metallurgical alloys (i.e. not in electroplated samples. The existence of a ternary compound previously reported in the literature was confirmed. More than one ternary Ni-Bi-Sn compounds might possibly be admitted. A growth coefficient of (2.29 ± 0.02 x 10-15 m2 s-1 was obtained. It was found that the apparent activation energy for diffusion layers growth (18 ± 8 kJ mol-1 is inferior to that one assessed at growth from solid state Bi-Sn mixtures (88 ± 12 kJ mol-1.

  11. (Si)GeSn nanostructures for light emitters

    Science.gov (United States)

    Rainko, D.; Stange, D.; von den Driesch, N.; Schulte-Braucks, C.; Mussler, G.; Ikonic, Z.; Hartmann, J. M.; Luysberg, M.; Mantl, S.; Grützmacher, D.; Buca, D.

    2016-05-01

    Energy-efficient integrated circuits for on-chip or chip-to-chip data transfer via photons could be tackled by monolithically grown group IV photonic devices. The major goal here is the realization of fully integrated group IV room temperature electrically driven lasers. An approach beyond the already demonstrated optically-pumped lasers would be the introduction of GeSn/(Si)Ge(Sn) heterostructures and exploitation of quantum mechanical effects by reducing the dimensionality, which affects the density of states. In this contribution we present epitaxial growth, processing and characterization of GeSn/(Si)Ge(Sn) heterostructures, ranging from GeSn/Ge multi quantum wells (MQWs) to GeSn quantum dots (QDs) embedded in a Ge matrix. Light emitting diodes (LEDs) were fabricated based on the MQW structure and structurally analyzed via TEM, XRD and RBS. Moreover, EL measurements were performed to investigate quantum confinement effects in the wells. The GeSn QDs were formed via Sn diffusion /segregation upon thermal annealing of GeSn single quantum wells (SQW) embedded in Ge layers. The evaluation of the experimental results is supported by band structure calculations of GeSn/(Si)Ge(Sn) heterostructures to investigate their applicability for photonic devices.

  12. Beta Decay of 101Sn

    Energy Technology Data Exchange (ETDEWEB)

    Kavatsyuk, O. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Mazzocchi, C. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Janas, Z. [University of Warsaw; Banu, A. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Batist, L. [St. Petersburg Nuclear Physics Institute; Becker, F. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Blazhev, A. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Bruchle, W. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Doring, J. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Faestermann, T. [Technische Universitat Munchen; Gorska, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Grawe, H. [GSI-Hemholtzzentrum fur Schwerionenforschung, Darmstadt, Germany; Jungclaus, A. [Instituto Estructura de la Materia, Madrid; Karny, M. [University of Warsaw; Kavatsyuk, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Klepper, O. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Kirchner, R. [Gesellschaft fur Schwerionenforschung (GSI), Germany; La Commara, M. [Universita Federico II and INFN Napoli; Miernik, K. [University of Warsaw; Mukha, I. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Plettner, C. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Plochocki, A. [University of Warsaw; Roeckl, E. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Romoli, M. [Universita Federico II and INFN Napoli; Rykaczewski, Krzysztof Piotr [ORNL; Schadel, M. [Gesellschaft fur Schwerionenforschung (GSI), Germany; Schmidt, K. [Continental Teves AG & Co., Frankfurt am Main, Germany; Schwengner, R. [Forschungszentrum Rossendorf, Dresden, Germany; Zylicz, J. [University of Warsaw

    2007-01-01

    The {beta} decay of the very neutron-deficient isotope 101Sn was studied at the GSI on-line mass separator using silicon detectors for recording charged particles and germanium detectors for {gamma}-ray spectroscopy. Based on the {beta}-delayed proton data the production cross-section of 101Sn in the 50Cr + 58Ni fusion-evaporation reaction was determined to be about 60nb. The half-life of 101Sn was measured to be 1.9(3)s. For the first time {beta}-delayed {gamma}-rays of 101Sn were tentatively identified, yielding weak evidence for a cascade of 352 and 1065keV transitions in 101In. The results for the 101Sn decay as well as those from previous work on the 103Sn decay are discussed by comparing them to predictions obtained from shell model calculations employing a new interaction in the 88Sr to 132Sn model space.

  13. Martensitic Transformation in Ni-Mn-Sn-Co Heusler Alloys

    Directory of Open Access Journals (Sweden)

    Alexandre Deltell

    2015-04-01

    Full Text Available Thermal and structural austenite to martensite reversible transition was studied in melt spun ribbons of Ni50Mn40Sn5Co5, Ni50Mn37.5Sn7.5Co5 and Ni50Mn35Sn10Co5 (at. % alloys. Analysis of X-ray diffraction patterns confirms that all alloys have martensitic structure at room temperature: four layered orthorhombic 4O for Ni50Mn40Sn5Co5, four layered orthorhombic 4O and seven-layered monoclinic 14M for Ni50Mn37.5Sn7.5Co5 and seven-layered monoclinic 14M for Ni50Mn35Sn5Co5. Analysis of differential scanning calorimetry scans shows that higher enthalpy and entropy changes are obtained for alloy Ni50Mn37.5Sn7.5Co5, whereas transition temperatures increases as increasing valence electron density.

  14. Chemically Resolved Structure of the Sn/Ge(111) Surface

    Science.gov (United States)

    Lee, Tien-Lin; Warren, Samantha; Cowie, Bruce C. C.; Zegenhagen, Jörg

    2006-02-01

    The structure and chemical states of the Sn/Ge(111) surface are characterized by x-ray standing waves combined with photoemission. For the room temperature 3×3 phase two chemical components, approximately 0.4 eV apart, are observed for both Sn 3d and 4d core levels. Our model-independent, x-ray standing wave analysis shows unambiguously that the two components originate from Sn adatoms located at two different heights separated vertically by 0.23 Å, in favor of a model composed of a fluctuating Sn layer. Contrary to the most accepted scenario, the stronger Sn 3d and 4d components, which appear at the lower binding-energy sides and account for 2/3 of the Sn adatoms, are identified to be associated with the higher Sn position, manifesting their filled valence state character.

  15. Structure and properties of the slags of continuous converting of copper nickel-containing mattes and concentrates: II. Effect of the SiO2/CaO ratio on the structure and liquidus temperature of the slags

    Science.gov (United States)

    Pigarev, S. P.; Tsymbulov, L. B.; Selivanov, E. N.; Chumarev, V. M.

    2012-03-01

    The structure and liquidus temperature of the SiO2-CaO-Al2O3-FeO x -Cu2O-NiO slags that form during continuous converting of copper mattes and concentrates into blister copper are analyzed. The slag melt compositions are varied over a wide SiO2/CaO range. The slags are studied by X-ray diffraction, scanning electron microscopy, and electron-probe microanalysis. The liquidus temperature of the slags is determined by differential thermal analysis. It is found that, depending on the SiO2/CaO ratio, the structure and liquidus temperature of the slags change and the forms of copper in a slag also change. The SiO2/CaO range in a slag is recommended for the process of continuous converting of a copper nickel-containing sulfide raw materials.

  16. Effect of CeO2 and CaO Promoters on Ignition Performance for Partial Oxidation of Methane over Ni/MgO-Al2O3 Catalyst

    Institute of Scientific and Technical Information of China (English)

    Yejun Qiu; Jixiang Chen; Jiyan Zhang

    2007-01-01

    The effect of CeO2 and CaO promoters on the ignition performance over Ni/MgO-Al2O3 catalyst for the partial oxidation of methane (POM) to synthesis gas was investigated. It was found that the POM reaction could not be ignited over 1wt%Ni/MgO-Al2O3 catalyst without the promoters in the temperature range from 773 K to 1073 K. CeO2 and CaO promoters enhanced the ignition performance and the POM reactivity of 1wt%Ni/MgO-Al2O3 catalyst remarkably. Moreover, the improving effect became greater with the increase of the promoter content under the investigated reactionconditions. The modification effects of CeO2 and CaO promoters were closely related to the concentration and reducibility of the surface and bulk oxygen species.

  17. The Effect of Calcination Temperatures on the Activity of CaO and CaO/SiO2 Heterogeneous Catalyst for Transesterification of Rubber Seed Oil in the Presence of Coconut Oil as A Co-Reactant

    Directory of Open Access Journals (Sweden)

    Kamisah D. Pandiangan

    2016-12-01

    Full Text Available This study was carried out to examine the potential of conversion of rubber seed oil into biodiesel. A series experiments was conducted using CaO and CaO/SiO2 as catalyst and coconut oil as co-reactant, with the main purpose to assess the effect of calcination temperatures on the performance of the catalysts. The results obtained demonstrate that the use of coconut oil as co-reactant significantly promoted conversion of fatty acids in rubber seed oil into their corresponding methylesters. It was also found that the catalytic activity of both CaO and CaO/SiO2 was significantly influenced by calcination temperatures and at the same temperature, CaO/SiO2 exhibited higher activity than unsupported CaO. The highest yield was achieved using CaO/SiO2catalyst subjected to calcination at 800 oC

  18. Low Temperature Deposition of High-k/Metal Gate Stacks on High-Sn Content (Si)GeSn-Alloys

    OpenAIRE

    Schulte-Braucks, C; Von Den Driesch, N; Glass, S; Tiedemann, AT; Breuer, U; Besmehn, A; Hartmann, JM; Ikonic, Z; Zhao, QT; Mantl, S; Buca, D.

    2016-01-01

    (Si)GeSn is an emerging group IV alloy system offering new exciting properties, with great potential for low power electronics due to the fundamental direct band gap and prospects as high mobility material. In this Article, we present a systematic study of HfO2/TaN high-k/metal gate stacks on (Si)GeSn ternary alloys and low temperature processes for large scale integration of Sn based alloys. Our investigations indicate that SiGeSn ternaries show enhanced thermal stability compared to GeSn bi...

  19. 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.

  20. Synthesis of carbon-supported PdSn-SnO2 nanoparticles with different degrees of interfacial contact and enhanced catalytic activities for formic acid oxidation.

    Science.gov (United States)

    Wang, Hui; Liu, Ziyue; Ma, Yanjiao; Julian, Key; Ji, Shan; Linkov, Vladimir; Wang, Rongfang

    2013-09-07

    The conjunction of the PdSn alloy and SnO2 is of interest for improving catalytic activity in formic acid oxidation (FAO). Here, we report the synthesis of PdSn-SnO2 nanoparticles and a study of their catalytic FAO activity. Different degrees of interfacial contact between SnO2 and PdSn were obtained using two different stabilizers (sodium citrate and EDTA) during the reduction process in catalyst preparation. Compared to the PdSn alloy, PdSn-SnO2 supported on carbon black showed enhanced FAO catalytic activity due to the presence of SnO2 species. It was also found that interfacial contact between the PdSn alloy and the SnO2 phase has an impact on the activity towards CO oxidation and FAO.

  1. Demethylation restores SN38 sensitivity in cells with acquired resistance to SN38 derived from human cervical squamous cancer cells

    Science.gov (United States)

    TANAKA, TETSUJI; BAI, TAO; TOUJIMA, SAORI; UTSUNOMIYA, TOMOKO; MATSUOKA, TOSHIHIDE; KOBAYASHI, AYA; YAMAMOTO, MADOKA; SASAKI, NORIYUKI; TANIZAKI, YUKO; UTSUNOMIYA, HIROTOSHI; TANAKA, JUNKO; YUKAWA, KAZUNORI

    2012-01-01

    Using seven monoclonal SN38-resistant subclones established from ME180 human cervical squamous cell carcinoma cells, we examined the demethylation effects of 5-aza-2′-deoxycytidine (5-aza-CdR) on the SN38-sensitivity of the cells as well as the expression of death-associated protein kinase (DAPK) in the SN38-resistant cells. The DAPK expression levels were evaluated among parent ME180 cells, SN38-resistant ME180 cells and cisplatin-resistant ME180 cells by methylation-specific DAPK-PCR, quantitative RT-PCR and western blot analysis. The SN38-resistant cells co-treated with SN38 and 5-aza-CdR strongly exhibited enhanced SN38-sensitivities resembling those found in the parent cells. In the SN38-resistant subclones, no relationships were found between the restored SN38 sensitivity and hypermethylation of the DAPK promoter, DAPK mRNA expression, DAPK protein expression and induction of DAPK protein after 5-aza-CdR treatment, unlike the strong suppression of 5-aza-CdR-induced DAPK protein expression in the cisplatin-resistant subclones. These findings indicate that reversibly methylated molecules, but not DAPK, may regulate SN38 resistance, and that demethylating agents can be strong sensitizing anticancer chemotherapeutic drugs for SN38-resistant cancers. PMID:22246465

  2. Hyperfine field distributions in disordered Mn2CoSn and Mn2NiSn Heusler alloys

    Indian Academy of Sciences (India)

    N Lakshmi; Anil Pandey; K Venugopalan

    2002-08-01

    Heusler alloys, Mn2CoSn and Mn2NiSn, were prepared and characterized by X-ray studies. Mössbauer studies using Sn-119 were carried out to investigate the hyperfine fields present at the Sn site in these alloys. The hyperfine field distribution in these alloys as well as X-ray studies point to the chemical disorder present in both alloys. Co-existence of a paramagnetic portion along with the magnetic hyperfine part was observed in Mn2CoSn even at low temperatures, while this was not found in Mn2NiSn spectra. Hyperfine fields at Sn site were calculated using Blandin and Campbell model and compared with the experimental results.

  3. Sn migration control at high temperature due to high deposition speed for forming high-quality GeSn layer

    Science.gov (United States)

    Taoka, Noriyuki; Capellini, Giovanni; von den Driesch, Nils; Buca, Dan; Zaumseil, Peter; Schubert, Markus Andreas; Klesse, Wolfgang Matthias; Montanari, Michele; Schroeder, Thomas

    2016-03-01

    A key factor for controlling Sn migration during GeSn deposition at a high temperature of 400 °C was investigated. Calculated results with a simple model for the Sn migration and experimental results clarified that low-deposition-speed (vd) deposition with vd’s of 0.68 and 2.8 nm/min induces significant Sn precipitation, whereas high-deposition-speed (vd = 13 nm/min) deposition leads to high crystallinity and good photoluminescence spectrum of the GeSn layer. These results indicate that vd is a key parameter, and that control of Sn migration at a high temperature is possible. These results are of great relevance for the application of high-quality Sn-based alloys in future optoelectronics devices.

  4. Synthesis kinetics of Mg_2Sn in Mg-Sn powder mixture using non-isothermal differential scanning calorimetry

    Institute of Scientific and Technical Information of China (English)

    WU Yu-feng; DU Wen-bo; ZUO Tie-yong

    2009-01-01

    The non-isothermal heating process of Mg-Sn powder mixture was studied by differential scanning calorimetry(DSC) technique and the synthesis kinetics of Mg_2Sn was evaluated by the model-free and model-fitting methods. The activation energy and conversion function of Mg_2Sn synthesis reaction are calculated to be 281.7 kJ/mol and g(α)=[-ln(1-α)]~(1/4), respectively. The reaction mechanism of 2Mg+Sn→Mg_2Sn under non-isothermal condition is regarded as "nucleation and growth". During the non-isothermal heating process, the phase transformation occurred in the Mg-Sn powder mixture was analyzed by XRD and the microstructure evolution of Mg_2Sn was observed by optical microscopy, which is in good agreement with the reaction mechanism of 2Mg+Sn→Mg_2Sn deduced from the kinetic evaluation.

  5. Effect of Sn content on the properties of passive film on PbSn alloy in sulfuric acid solution

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The effect of Sn content on properties of anodic film formed on PbSn alloys in sulfuric acid solution was investigated using linear sweeping voltage (LSV), cyclic voltammetry (CV), and a.c. voltammetry (ACV), based on the Mott-Schottky analysis. The results revealed that the addition of Sn into lead alloys can promote the corrosion resistance property and could decrease the impedance of anodic film; these results were more remarkable with enhancing the Sn content. The over potential of oxygen evolution on lead alloys enhanced with the increase of Sn content. The Mott-Schottky analysis indicated that the passive film appeared an n-type semiconductor, and the donor density of passive film increased with increasing Sn content. The increased vacancies in the passive film with Sn content increasing could illustrate this trend.

  6. Moessbauer Investigation of Electrodeposited Sn-Zn, Sn-Cr, Sn-Cr-Zn and Fe-Ni-Cr Coatings

    Energy Technology Data Exchange (ETDEWEB)

    Kuzmann, E.; Stichleutner, S. [Eoetvoes University, Department of Nuclear Chemistry and Research Group of Nuclear Methods in Structural Chemistry HAS (Hungary); El-Sharif, M.; Chisholm, C. U. [Glasgow Caledonian University (United Kingdom); Sziraki, L.; Homonnay, Z.; Vertes, A. [Eoetvoes University, Department of Nuclear Chemistry and Research Group of Nuclear Methods in Structural Chemistry HAS (Hungary)

    2002-06-15

    {sup 57}Fe and {sup 119}Sn CEMS, XRD and electrochemical measurements were used to investigate the effect of the preparation parameters and the components on the structure and phase composition of electrodeposited Fe-Ni-Cr alloys in connection with their corrosion behavior. XRD of the electrodeposits reflect an amorphous-like character. {sup 57}Fe CEM spectra of Fe-Ni-Cr electrodeposited samples, prepared in a continuous flow plating plastic circulation cell with variation of current density, electrolyte velocity and temperature, can be evaluated as a doublet associated with a highly disordered paramagnetic solid solution phase. This phase was identified earlier in Fe-Ni-Cr electrodeposits that were prepared by another plating method and contained both ferromagnetic and paramagnetic metastable phases. This is the first time that we have succeeded to prepare Fe-Ni-Cr alloys containing only the metastable paramagnetic phase. The effect of the plating parameters on the structure is also analysed by the quadrupole splitting distribution method. {sup 119}Sn CEM spectra of all Sn-containing plated alloys show a broad line envelop which can be decomposed at least into two components. One can be associated with {beta}-tin. The other one can be assigned to an alloy phase. The structure and distribution of microenvironments of these phases depends on the plating parameters especially on the parameters of the reverse pulse applied.

  7. 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.

  8. Phase equilibria of the Cu-Sn-Ti ternary system at 823K

    Directory of Open Access Journals (Sweden)

    Guo-jun Zhou

    2017-02-01

    Full Text Available The isothermal section in the Cu-Sn enrich part of the Cu-Sn-Ti ternary system at 823K was determined by using solid-solid-liquid diffusion triple approach. One ternary compound CuSnTi was found, and 12 three-phase fields were detected. The following 10 three-phase regions are well established: CuTi2+CuTi+Sn5Ti6, Sn5Ti6+Sn3Ti2+ CuSnTi, Liquid+Sn3Ti2+CuSnTi, Liquid+CuSnTi+Cu3Sn, CuTi+Cu4Ti3+Sn5Ti6, CuSnTi+Cu4Ti3+Sn5Ti6, CuSnTi+Cu3Sn+Cu41Sn11, CuSnTi+Cu41Sn11+Bcc_a2, CuSnTi+Cu4Ti+Cu, and CuSnTi+Bcc_a2+Cu. Phase relations in the Ti-enrich corner of this system require further investigation.

  9. Investigation of Sn surface segregation during GeSn epitaxial growth by Auger electron spectroscopy and energy dispersive x-ray spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Tsukamoto, Takahiro; Suda, Yoshiyuki [Graduate School of Engineering, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588 (Japan); Hirose, Nobumitsu; Kasamatsu, Akifumi; Mimura, Takashi; Matsui, Toshiaki [National Institute of Information and Communications Technology, 4-2-1 Nukui-Kitamachi, Koganei, Tokyo 184-8795 (Japan)

    2015-02-02

    The mechanism of Sn surface segregation during the epitaxial growth of GeSn on Si (001) substrates was investigated by Auger electron spectroscopy and energy dispersive X-ray spectroscopy. Sn surface segregation depends on the growth temperature and Sn content of GeSn layers. During Sn surface segregation, Sn-rich nanoparticles form and move on the surface during the deposition, which results in a rough surface owing to facet formation. The Sn-rich nanoparticles moving on the surface during the deposition absorb Sn from the periphery and yield a lower Sn content, not on the surface but within the layer, because the Sn surface segregation and the GeSn deposition occur simultaneously. Sn surface segregation can occur at a lower temperature during the deposition compared with that during postannealing. This suggests that the Sn surface segregation during the deposition is strongly promoted by the migration of deposited Ge and Sn adatoms on the surface originating from the thermal effect of substrate temperature, which also suggests that limiting the migration of deposited Ge and Sn adatoms can reduce the Sn surface segregation and improve the crystallinity of GeSn layers.

  10. Syntheses and structures of Sc2Nb(4–x)Sn5, YNb6Sn6, and ErNb6Sn5: exploratory studies in ternary rare-earth niobium stannides.

    Science.gov (United States)

    Yue, Cheng-Yang; Lei, Xiao-Wu

    2012-02-20

    Three new rare-earth (RE) niobium stannides, namely, Sc(2)Nb(4-x)Sn(5) (x = 0.37, 0.52), YNb(6)Sn(6), and ErNb(6)Sn(5), have been obtained by reacting the mixture of corresponding pure elements at high temperature and structurally characterized by single-crystal X-ray diffraction studies. Sc(2)Nb(4-x)Sn(5) crystallizes in the orthorhombic space group Ibam (No. 72) and belongs to the V(6)Si(5) type. Its structure features a three-dimensional (3D) network composed of two-dimensionally (2D) corrugated [Nb(2)Sn(2)] and [Nb(2)Sn(3)] layers interconnected via Nb-Sn bonds, forming one type of one-dimensional (1D) narrow tunnels along the c axis occupied by Sc atoms. YNb(6)Sn(6) crystallizes in the hexagonal space group P6/mmm (No. 191) and adopts the HfFe(6)Ge(6) type, and ErNb(6)Sn(5) crystallizes in the trigonal space group R3m (No. 166) and belongs to the LiFe(6)Ge(5) type. Their structures both feature 3D networks based on 2D [Nb(3)Sn], [Sn(2)], and [RESn(2)] layers (RE = Y, Er). In YNb(6)Sn(6), one type of [Nb(3)Sn] layer is interconnected by [Sn(2)] and [YSn(2)] layers via Nb-Sn bonds to form a 3D network. However, in ErNb(6)Sn(5), two types of [Nb(3)Sn] layers are interlinked by [Sn(2)] and [ErSn(2)] layers via Nb-Sn bonds into a 3D framework. Electronic structure calculations and magnetic property measurements for "Sc(2)Nb(4)Sn(5)" and YNb(6)Sn(6) indicate that both compounds show semimetallic and temperature-independent diamagnetic behavior.

  11. Temperature dependent electrical resistivity of liquid Sn

    Science.gov (United States)

    Prajapati, A. V.; Sonvane, Y. A.; Patel, H. P.; Thakor, P. B.

    2016-05-01

    The present paper deals with the effect of temperature variation on the electrical resistivity (ρ) of liquid Sn(Tin). We have used a new parameter free pseudopotential along with screening Taylor et al and Farid et al local field correction functions. The Percus-Yevick Hard Sphere (PYHS) reference system is used to describe structural information. Zeeman formula has been used for finding resistivity with the variation of temperature. The balanced harmonies between present data and experimental data have been achieved with a minimal deviation. So, we concluded that our newly constructed model potential is an effective one to produce the data of electrical resistivity of liquid Sn(Tin) as a function of temperature.

  12. LARP Long Nb3Sn Quadrupole Design.

    Energy Technology Data Exchange (ETDEWEB)

    Ambrosio,G.; Andreev, N.; Anerella, M.; Barzi, E.; Bossert, R.; Caspi, S.; Chlachidize, G.; Dietderich, D.; Feher, S.; Felice, H.; Ferracin, P.; Ghosh, A.; Hafalia, A.R.; Hannaford, C.R.; Kashikhin, V.V.; Kerby, J.; Lamm, M.; Lietzke, A.; McInturff, A.; Muratore, J.; Nobrega, F.; Novitsky, I.; Sabbi, G.L.; Schmalzle, J.; Tartaglia, M.; Turrioni, D.; Wanderer, P.; Whitson, G.; Zlobin, A.V.

    2007-08-27

    A major milestone for the LHC Accelerator Research Program (LARP) is the test, by the end of 2009, of two 4m-long quadrupole magnets (LQ) wound with Nb{sub 3}Sn conductor. The goal of these magnets is to be a proof of principle that Nb{sub 3}Sn is a viable technology for a possible LHC luminosity upgrade. The design of the LQ is based on the design of the LARP Technological Quadrupoles, presently under development at FNAL and LBNL, with 90-mm aperture and gradient higher than 200 T/m. The design of the first LQ model will be completed by the end of 2007 with the selection of a mechanical design. In this paper we present the coil design addressing some fabrication technology issues, the quench protection study, and three designs of the support structure.

  13. SnET2: clinical update

    Science.gov (United States)

    Razum, Nicholas J.; Snyder, Albert B.; Doiron, Daniel R.

    1996-04-01

    Tin Ethyl Etiopurpurin, SnET2, is a synthetic chlorin analog presently in Phase-II/III clinical trials for the treatment of cutaneous cancers. Trials to date include the treatment of basal cell carcinomas, squamous cell carcinomas, breast adenocarcinomas metastatic to the chest wall and cutaneous Kaposi's sarcomas in AIDS patients. Results to date have shown significant clinical responses for drug doses between 1.0 mg/kg and 1.6 mg/kg, with the threshold for Kaposi's sarcoma being slightly higher than in other indications. Light doses from 100 J/cm2 to 300 J/cm2 were delivered from 24 to 72 hours post SnET2 infusion. Induced transient skin photosensitivity at the lower therapeutic doses has been mild, lasting approximately a week. Results of the Phase I and II trials are presented.

  14. Mode-Specific SN2 Reaction Dynamics.

    Science.gov (United States)

    Wang, Yan; Song, Hongwei; Szabó, István; Czakó, Gábor; Guo, Hua; Yang, Minghui

    2016-09-01

    Despite its importance in chemistry, the microscopic dynamics of bimolecular nucleophilic substitution (SN2) reactions is still not completely elucidated. In this publication, the dynamics of a prototypical SN2 reaction (F(-) + CH3Cl → CH3F + Cl(-)) is investigated using a high-dimensional quantum mechanical model on an accurate potential energy surface (PES) and further analyzed by quasi-classical trajectories on the same PES. While the indirect mechanism dominates at low collision energies, the direct mechanism makes a significant contribution. The reactivity is found to depend on the specific reactant vibrational mode excitation. The mode specificity, which is more prevalent in the direct reaction, is rationalized by a transition-state-based model.

  15. Crystallographic Orientation Effect on Electromigration in Ni-Sn Microbump

    Science.gov (United States)

    Huang, Yi-Ting; Chen, Chih-Hao; Chakroborty, Subhendu; Wu, Albert T.

    2017-09-01

    This article addresses the reliability challenges regarding electromigration in developing three-dimensional integrated circuits (3D-ICs). The line-type sandwich structure of Ni/Sn3.5Ag(15 μm)/Ni was used to simulate microbumps to examine the reliability of electromigration in 3D-IC technology. The solder strip of Ni/Sn3.5Ag(15 μm)/Ni was stressed with a current density of 1.0 × 104 A/cm2 at 150°C. The current stressing enhanced the reaction between the solder and Ni to form Ni3Sn4, which occupied the entire joint and transformed into a Ni/Ni3Sn4/Ni structure when the solder was completely consumed. Electron backscatter diffraction was used to analyze the crystallographic characteristics of Sn and Ni3Sn4 as related to the electromigration effect. The results indicated that the crystallographic orientation of Sn plays a significant role in the Ni/Sn3.5Ag/Ni, whereas the orientation of Ni3Sn4 is the dominant factor of diffusion behavior in the Ni/Ni3Sn4/Ni.

  16. Crystallographic Orientation Effect on Electromigration in Ni-Sn Microbump

    Science.gov (United States)

    Huang, Yi-Ting; Chen, Chih-Hao; Chakroborty, Subhendu; Wu, Albert T.

    2017-07-01

    This article addresses the reliability challenges regarding electromigration in developing three-dimensional integrated circuits (3D-ICs). The line-type sandwich structure of Ni/Sn3.5Ag(15 μm)/Ni was used to simulate microbumps to examine the reliability of electromigration in 3D-IC technology. The solder strip of Ni/Sn3.5Ag(15 μm)/Ni was stressed with a current density of 1.0 × 104 A/cm2 at 150°C. The current stressing enhanced the reaction between the solder and Ni to form Ni3Sn4, which occupied the entire joint and transformed into a Ni/Ni3Sn4/Ni structure when the solder was completely consumed. Electron backscatter diffraction was used to analyze the crystallographic characteristics of Sn and Ni3Sn4 as related to the electromigration effect. The results indicated that the crystallographic orientation of Sn plays a significant role in the Ni/Sn3.5Ag/Ni, whereas the orientation of Ni3Sn4 is the dominant factor of diffusion behavior in the Ni/Ni3Sn4/Ni.

  17. 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.

  18. Cluster radioactivity leading to doubly magic 100Sn and 132Sn daughters

    Indian Academy of Sciences (India)

    K P Santhosh

    2011-03-01

    Decay of neutron-deficient 128−137Gd parents emitting 4He to 32S clusters are studied within the Coulomb and proximity potential model. The predicted half-lives are compared with other models and most of the values are well within the present experimental limit for measurements (1/2 < 1030} ). The lowest 1/2 value for 28Si emission from 128Gd indicates the role of doubly magic 100Sn daughter in cluster decay process. It is also found that neutron excess in the parent nuclei slows down the cluster decay process. Geiger–Nuttal plots for all clusters are found to be linear with different slopes and intercepts. The -decay half-lives of 148−152Gd parents are computed and are in agreement with experimental data. The role of doubly magic 132Sn daughter in cluster decay process is also examined for various neutron-rich Ba, Ce, Nd, Sm and Gd parents emitting clusters ranging from 4He to 32Si. Alpha-like structures are most probable in the decays leading to 100Sn, while non--like structures are probable in the decays leading to 132Sn. The neutron–proton asymmetry in parent and daughter nuclei is responsible for the reduced decay rate in the decay leading to 132Sn.

  19. SN 2000cx and SN 2013bh: Extremely Rare, Nearly Twin Type Ia Supernovae

    CERN Document Server

    Silverman, Jeffrey M; Kasliwal, Mansi M; Fox, Ori D; Cao, Yi; Johansson, Joel; Perley, Daniel A; Tal, David; Wheeler, J Craig; Amanullah, Rahman; Arcavi, Iair; Bloom, Joshua S; Gal-Yam, Avishay; Goobar, Ariel; Kulkarni, Shrinivas R; Laher, Russ; Lee, William H; Marion, G H; Nugent, Peter E; Shivvers, Isaac

    2013-01-01

    The Type Ia supernova (SN Ia) SN 2000cx was one of the most peculiar transients ever discovered. While its rise to maximum brightness was typical for a SN Ia, its decline was slower, causing standard light curve fitting algorithms to fail; its spectra indicated a high photospheric temperature. Thirteen years later SN 2013bh (aka iPTF13abc), the first near identical twin of SN 2000cx, was discovered. We obtained optical and near-IR photometry and low-resolution optical spectroscopy of this object from discovery until about 1 month past r-band maximum brightness. The spectra of both objects indicate the presence of iron-group elements (Co II, Ni II, Fe II, Fe III, and high-velocity features [HVFs] of Ti II), intermediate-mass elements (Si II, Si III, and S II), in addition to separate normal velocity features (~12000 km/s) and HVFs (~24000 km/s) of Ca II. Persistent absorption from Fe III and Si III, along with the colour evolution, imply relatively high blackbody temperatures for SNe 2013bh and 2000cx (~12000 ...

  20. 119Sn CEMS study of Sb doped SnO2 film

    Science.gov (United States)

    Nomura, K.; Kuzmann, E.; Garg, V. K.; de Oliveira, A. C.; Stichleutner, S.; Homonnay, Z.

    2016-12-01

    Sb doped SnO2 films prepared by DC sputtering and heating were characterized by 119Sn conversion electron Mössbauer spectrometry (CEMS). An asymmetric doublet was observed in the Mössbauer spectra of 1 %, 3 %, and 10 % Sb doped SnO2 films. The peak ratios of doublets are considered to be due to the columnar crystal growth on the substrate. With the doping level of Sb, both the isomer shift ( δ) and the quadrupole splitting (Δ) increased. After annealing, δ increased and Δ decreased for each sample. These results suggest the followings. The electron doping of the SnO2 lattice by pentavalent Sb induces the increase of the electron density at the SnIV nucleus. The annealing process leads to more complete accommodation of the Sb dopant that results in more effective electron doping and therefore increasing isomer shift for tin. Simultaneously, the distortion of the lattice caused by Sb is relaxed and the quadrupole splitting decreases.

  1. Representation of A15 composition and TC in internal-Sn Nb3Sn superconducting strands

    Institute of Scientific and Technical Information of China (English)

    Andre; SULPICE; Jean-Louis; SOUBEYROUX; Christophe; VERWAERDE; Gia; Ky; HOANG

    2010-01-01

    Four sets of mono-element (ME) and two kinds of multifilament (MF) internal-Sn Nb3Sn superconducting strands were designed and fabricated through RRP method in which different compoment ratios, various composite configurations and some third element alloying were arranged. All the strand samples underwent a 210°C/50 h + 340°C/25 h thermal duration for Cu-Sn alloying. After that A15 phase formation heat treatment (HT) was applied for which the ME samples were chosen at three reaction temperatures of 675°C, 700°C and 725°C for 100 h and 200 h while the MF samples at four temperatures of 650°C, 675°C, 700°C and 725°C for 128 h and 200 h. The heat-treated samples were examined for A15 phase composition distribution by X-ray EDS. SQUID magnetization measurement was used to determine critical temperature TC. The obtained results demonstrate that for fully-reacted internal-Sn Nb3Sn superconductors the A15 phase composition and the intrinsic property TC are determined by the diffusion and solid state reaction mechanism and are independent of the factors including HT temperature, strand composite component and configuration arrangement, and the third element addition within the experimental range.

  2. Constraining Modified Gravity with SN 1987A

    Science.gov (United States)

    Zukin, Phillip; Bertschinger, Edmund

    2009-05-01

    In the 1950's, Papapetrou found that extended bodies with spin, in general relativity, do not move along geodesics because of a spin-curvature coupling. Using an Eikonal approximation, we reproduce these results for Dirac and Majorana particles. We generalize these results to modified theories of gravity with a non-minimally coupled matter lagrangian and place constraints on the coupling field based on the arrival times of SN 1987A neutrinos.

  3. Linear polarimetric study of SN 1987A

    Science.gov (United States)

    Clocchiatti, A.; Mendez, M.; Benvenuto, O.; Feinstein, C.; Marraco, H.

    Linear polarization measurements of SN 1987A were made with 0.83-m and a 2.15-m telescopes. It is found that the polarization decreases with time (Benvenuto et al., 1987) Because the polarization produced by the interstellar matter is time independent and the wavelength dependence of the observed polarization is far from the interstellar relation (Serkowski et al., 1975) it is suggested that the time dependent characteristic is due to an intrinsic polarization vector.

  4. VERY LATE PHOTOMETRY OF SN 2011fe

    Energy Technology Data Exchange (ETDEWEB)

    Kerzendorf, W. E. [Department of Astronomy and Astrophysics, University of Toronto, 50 Saint George Street, Toronto, ON M5S 3H4 (Canada); Taubenberger, S.; Seitenzahl, I. R.; Ruiter, A. J., E-mail: wkerzendorf@gmail.com [Max-Planck-Institut für Astrophysik, Karl-Schwarzschild-Straße 1, D-85748 Garching (Germany)

    2014-12-01

    The Type Ia supernova SN 2011fe is one of the closest supernovae of the past decades. Due to its proximity and low dust extinction, this object provides a very rare opportunity to study the extremely late time evolution (>900 days) of thermonuclear supernovae. In this Letter, we present our photometric data of SN 2011fe taken at an unprecedented late epoch of ≈930 days with GMOS-N mounted on the Gemini North telescope (g = 23.43 ± 0.28, r = 24.14 ± 0.14, i = 23.91 ± 0.18, and z = 23.90 ± 0.17) to study the energy production and retention in the ejecta of SN 2011fe. Together with previous measurements by other groups, our result suggests that the optical supernova light curve can still be explained by the full thermalization of the decay positrons of {sup 56}Co. This is in spite of theoretical predicted effects (e.g., infrared catastrophe, positron escape, and dust) that advocate a substantial energy redistribution and/or loss via various processes that result in a more rapid dimming at these very late epochs.

  5. Proton-neutron correlations above 100Sn

    Science.gov (United States)

    Delion, Doru S.; Baran, Virgil V.

    2017-06-01

    Proton-neutron (pn) correlations in nuclei above the Z=50 shell closure are investigated in order to understand the peculiar behaviour of the 2+ and 4+ states in Te and Xe isotopes. It turns out that by increasing the pn pairing interaction, which becomes important for N ≈ Z nuclei, the collectivity decreases. We thus conclude that the ratio between the B(E2) value and 2+ energy is a "fingerprint" of pn collectivity. The available experimental data indeed indicate an enhanced pn pairing interaction by also approaching double magic Z=N=20 and Z=N=28 regions. It is known that the α-particle reduced width has the largest values in the region above 100Sn. In order to reproduce the reduced α-decay width we use an additional pocket-like surface potential in the single particle mean field, simulating four-body correlations. The strength of this interaction has a universal linear dependence on the experimental reduced width above the double magic nuclei 100Sn and 208Pb. Moreover, we demonstrate that pn pairing correlations have a small influence on this dependence and therefore cannot explain the larger reduced decay widths above 100Sn.

  6. Thermoelectric properties of SnSe compound

    Energy Technology Data Exchange (ETDEWEB)

    Guan, Xinhong [State Key Laboratory of Information Photonics and Optical Communications, Ministry of Education, Beijing University of Posts and Telecommunications, P.O. Box 72, Beijing 100876 (China); Lu, Pengfei, E-mail: photon@bupt.edu.cn [State Key Laboratory of Information Photonics and Optical Communications, Ministry of Education, Beijing University of Posts and Telecommunications, P.O. Box 72, Beijing 100876 (China); Wu, Liyuan; Han, Lihong [State Key Laboratory of Information Photonics and Optical Communications, Ministry of Education, Beijing University of Posts and Telecommunications, P.O. Box 72, Beijing 100876 (China); Liu, Gang [School of Electronic Engineering, Beijing University of Posts and Telecommunications, Beijing 100876 (China); Song, Yuxin [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Wang, Shumin [State Key Laboratory of Functional Materials for Informatics, Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences, Shanghai 200050 (China); Photonics Laboratory, Department of Microtechnology and Nanoscience, Chalmers University of Technology, 41296 Gothenburg (Sweden)

    2015-09-15

    Highlights: • The electronic and thermoelectric properties of SnSe bulk material are studied. • The ZT can reach as high as 1.87 along yy and 1.6 along zz direction at 800k. • SnSe is an indirect-band material, and SOC has little effect on the band structure. • The high ZT can be attributed to the intrinsically ultralow thermal conductivity. - Abstract: A first-principles study and Boltzmann transport theory have been performed to evaluate the electronic structure and thermoelectric properties of SnSe compound. The energy band structure and density of states are studied in detail. The electronic transport coefficients are then calculated as a function of chemical potential or temperature within the assumption of the constant relaxation time. The figure of merit ZT is obtained with the use of calculated thermoelectric properties and can reach as high as 1.87 along yy and 1.6 along zz direction at 800 K. Our theoretical result agrees well with previous experimental data.

  7. Very late photometry of SN 2011fe

    CERN Document Server

    Kerzendorf, W E; Seitenzahl, I R; Ruiter, A J

    2014-01-01

    The Type Ia supernova SN 2011fe is one of the closest supernovae of the past decades. Due to its proximity and low dust extinction, this object provides a very rare opportunity to study the extremely late time evolution (> 900 d) of thermonuclear supernovae. These late stages allow for a direct measurement of the decay processes of nuclei synthesized in the core of the explosion. In this paper, we present our photometric data of SN 2011fe taken at an unprecedentedly late epoch of ~ 930 d with GMOS-N mounted on the Gemini North telescope (g=23.37+/- 0.25, r=24.03 +/- 0.09, i=23.90 +/- 0.15, and z=23.74 +/- 0.16) to study the energy production and retention in the ejecta of SN 2011fe. Together with previous measurements by other groups, our result suggests that the optical supernova light curve can still be explained by the full thermalization of the decay positrons of 56Co. This is in spite of several theoretical predictions that advocate a substantial energy redistribution and/or loss via various processes wh...

  8. The Radio Evolution of SN 2001gd

    CERN Document Server

    Stockdale, Christopher J; Weiler, Kurt W; Panagia, Nino; Sramek, Richard A; Van Dyk, Schuyler D; Kelley, Matthew T

    2007-01-01

    We present the results of observations of the radio emission from Supernova 2001gd in NGC 5033 from 2002 February 8 through 2006 September 25. The data were obtained using the Very Large Array at wavelengths of 1.3 cm (22.4 GHz), 2 cm (14.9 GHz), 3.6 cm (8.4 GHz), 6 cm (4.9 GHz), and 20 cm (1.5 GHz), with one upper limit at 90 cm (0.3 GHz). In addition, one detection has been provided by the Giant Metrewave Radio Telescope at 21 cm (1.4 GHz). SN 2001gd was discovered in the optical well past maximum light, so that it was not possible to obtain many of the early radio "turn-on" measurements which are important for estimating the local circumstellar medium (CSM) properties. Only at 20 cm were turn-on data available. However, our analysis and fitting of the radio light curves, and the assumption that the Type IIb SN 2001gd resembles the much better studied Type IIb SN 1993J, enables us to describe the radio evolution as being very regular through day ~550 and consistent with a nonthermal-emitting model with a th...

  9. A facile inexpensive route for SnS thin film solar cells with SnS{sub 2} buffer

    Energy Technology Data Exchange (ETDEWEB)

    Gedi, Sreedevi [School of Chemical Engineering, Yeungnam University, 280Daehak-ro, Gyeongsan 712-749, Republic of Korea (Korea, Republic of); Solar Photovoltaic Laboratory, Department of Physics, Sri Venkateswasra University, Tirupati 517 502 (India); Minna Reddy, Vasudeva Reddy, E-mail: drmvasudr9@gmail.com [School of Chemical Engineering, Yeungnam University, 280Daehak-ro, Gyeongsan 712-749, Republic of Korea (Korea, Republic of); Solar Photovoltaic Laboratory, Department of Physics, Sri Venkateswasra University, Tirupati 517 502 (India); Pejjai, Babu [School of Chemical Engineering, Yeungnam University, 280Daehak-ro, Gyeongsan 712-749, Republic of Korea (Korea, Republic of); Solar Photovoltaic Laboratory, Department of Physics, Sri Venkateswasra University, Tirupati 517 502 (India); Jeon, Chan-Wook [School of Chemical Engineering, Yeungnam University, 280Daehak-ro, Gyeongsan 712-749, Republic of Korea (Korea, Republic of); Park, Chinho, E-mail: chpark@ynu.ac.kr [School of Chemical Engineering, Yeungnam University, 280Daehak-ro, Gyeongsan 712-749, Republic of Korea (Korea, Republic of); Ramakrishna Reddy, K.T., E-mail: ktrkreddy@gmail.com [Solar Photovoltaic Laboratory, Department of Physics, Sri Venkateswasra University, Tirupati 517 502 (India)

    2016-05-30

    Graphical abstract: PYS spectra of SnS/SnS{sub 2} interface and the related band diagram. - Highlights: • A low cost SnS solar cell is developed using chemical bath deposition. • We found E{sub I} & χ of SnS (5.3 eV & 4.0 eV) and SnS{sub 2} (6.9 eV & 4.1 eV) films from PYS. • Band offsets of 0.1 eV (E{sub c}) and 1.6 eV (E{sub v}) are estimated for SnS/SnS{sub 2} junction. • SnS based solar cell showed a conversion efficiency of 0.51%. - Abstract: Environment-friendly SnS based thin film solar cells with SnS{sub 2} as buffer layer were successfully fabricated from a facile inexpensive route, chemical bath deposition (CBD). Layer studies revealed that as-grown SnS and SnS{sub 2} films were polycrystalline; (1 1 1)/(0 0 1) peaks as the preferred orientation; 1.3 eV/2.8 eV as optical band gaps; and showed homogeneous microstructure with densely packed grains respectively. Ionization energy and electron affinity values were found by applying photoemission yield spectroscopy (PYS) to the CBD deposited SnS and SnS{sub 2} films for the first time. These values obtained as 5.3 eV and 4.0 eV for SnS films; 6.9 eV and 4.1 eV for SnS{sub 2} films. The band alignment of SnS/SnS{sub 2} junction showed TYPE-II heterostructure. The estimated conduction and valance band offsets were 0.1 eV and 1.6 eV respectively. The current density–voltage (J–V) measurements of the cell showed open circuit voltage (V{sub oc}) of 0.12 V, short circuit current density (J{sub sc}) of 10.87 mA cm{sup −2}, fill factor (FF) of 39% and conversion efficiency of 0.51%.

  10. Microwave enhanced alcoholysis of non-edible (algal, jatropha and pongamia) oils using chemically activated egg shell derived CaO as heterogeneous catalyst.

    Science.gov (United States)

    Joshi, Girdhar; Rawat, Devendra S; Sharma, Amit Kumar; Pandey, Jitendra K

    2016-11-01

    Microwave enhanced fast and efficient alcoholysis (methanolysis and ethanolysis) of non-edible oils (algal, jatropha and pongamia) is achieved using chemically activated waste egg shell derived CaO (i.e. CaO(cesp)) as heterogeneous catalyst. CaO(cesp) was extracted from waste chicken egg shell and further activated chemically by supporting transition metal oxide. The maximum conversion was achieved using 3wt% catalysts under 700W microwave irradiation and 10:1 alcohol/oil ratio in 6min. Alcoholysis using ZnO activated CaO(cesp) catalyst has shown higher reaction yields in comparison to other modified catalysts. Methanolysis has shown better biodiesel conversion in comparison to ethanolysis. The catalyst has shown longer lifetime and sustained activity after being used for four cycles. Due to more saturated fatty acid content; algal biodiesel has shown improved fuel properties in comparison to other biodiesels.

  11. Outils de CAO et conception structurée de systèmes intégrés sur siliciu

    OpenAIRE

    Rougeaux, François-René

    1987-01-01

    La représentation symbolique des masques de circuits intégrés est connue depuis environ quinze ans, mais n'est développée que depuis quelques années. Presque tous les systèmes de CAO développés récemment font usage d'une représentation symbolique des masques de circuits afin de simplifier la conception. Dans cette thèse, un système symbolique hiérarchique de dessin des masques est décrit. Un langage de description et un environnement graphique sont présentés. L'environnement graphique est uti...

  12. [Preliminary textual research on Zhijintang Sanctum re-revised version of Jinling edition of Ben cao gang mu (Compendium of Materia Medica)].

    Science.gov (United States)

    Zheng, Jinsheng

    2014-03-01

    The Zhijintang Sanctum version of the re-revised edition of Jinling edition of Ben cao gang mu (Compendium of Materia Medica)collected by Zhao Huiyuan of Baihe, Henan Province in 2008 was opted as one of the third batch of the National Directory of Rare Ancient Worksin 2010. On the second cover page (patent page), it is recorded as"Original Jiangxi version". However, it is investigated to find that most of its paper sheets were reprinted after the original Jinling version, only scores of paper sheets were supplemented block-printed, including the additional block-printed second preface and Li Jianyuan's submitted report of the Jiangxi version, the re-revised time of which should be after the Jiangxi edition, or 1603. The exact time can be determined only by checking it carefully against another Jinling re-revised version (the Sheyuantang Sanctum edition).

  13. [Experience of treatment and understanding of impediment disease in Shen nong ben cao jing (Shen-ntonz's Classic of Materia Medica)].

    Science.gov (United States)

    Ding, Hongchang; Wang, Zhenrui

    2015-01-01

    As a book with significant historical materials for the research of impediment disease not to be ignored, Shen nong ben cao jing (Shennong's Classic of Materia Medica) contains, among its 365 kinds of materia medica, 75 kinds of medicines related to impediment disease. Among the latter ones, 51 are related to "damp impediment", "cold-damp impediment", "wind-cold-damp impediment", "wind impediment", "wind-damp impediment", and "cold impediment"; 16 are related to "laryngeal impediment", "general impediment", and "blood impediment"; 8 are related to "muscular impediment", "stomach impediment", "hernia-conglomeration impediment", "internal consumptive-thirst impediment", "wilting impediment", and "hemiplegic impediment". To systematically analyze the properties, tastes, and effects of these medicines and its related knowledge, and then further explore the overall recognition and their treating experience of the physicians at that period would not only enrich the historical research on impediment disease, but also offer much help and reference to the understanding and treatment of impediment for contemporary clinicians.

  14. 曹操诗歌用典方式探微%A probe into Cao Chaoˊs allusions in his poems

    Institute of Scientific and Technical Information of China (English)

    冯颖

    2014-01-01

    用典是中国古代诗歌创作中一种常用的修辞手法。在曹操存世为数不多的二十余首诗歌中,一半以上用到了“用典”这种修辞手法,曹操诗歌用典主要采用了“明用、暗用和化用”这三种方式。%Allusion was a common rhetoric in the writing of ancient Chinese poems. Among 20 or so poems,Cao Chao used allusions in half his poems,which can be classified into three forms of explicit allusion,implicit allusion and borrowing.

  15. First Measurements of Time-Dependent Nucleation as a Function of Composition in Na2O.2CaO.3SiO2 Glasses

    Science.gov (United States)

    Kelton, K. F.; Narayan, K. Lakshmi

    1996-01-01

    The first measurements in any system of the composition dependence of the time-dependent nucleation rate are presented Nucleation rates of the stoichiometric crystalline phase, Na2O.2CaO.3SiO2, from quenched glasses made with different SiO2 concentrations were determined as a function of temperature and glass composition. A strong compositional dependence of the nucleation rates and a weak dependence for the induction times are observed. Using measured values of the liquidus temperatures and growth velocities as a function of glass composition, these data are shown to be consistent with predictions from the classical theory of nucleation, assuming a composition-dependent interfacial energy.

  16. Looking at the sky, hearing the earth: notes on body, memory and landscape in James Benning’s and Cao Guimarães’ films

    Directory of Open Access Journals (Sweden)

    Ana Costa Ribeiro

    2017-01-01

    Full Text Available Through the close analysis of  four films, the author emphasizes the importance of the poetics of the displacement in the relations between body, memory and landscape. Following the thinking of French philosophers Gilles Tiberghien and Anne Cauquelin,  landscape is understood as a physical environment that gives rise to a relation. The idea of landscape as a relation leads to a reflection on the notion of vestige. From Emmanuel Lévinas’ thoughts  on this concept, this paper discusses  two works made by American artist James Benning and two other by Brazilian artist Cao Guimarães. This research thus identifies a recurring tendency in contemporary audiovisual production from the organization of vestiges.

  17. Oxidation and reduction kinetics of eutectic SnPb, InSn, and AuSn: a knowledge base for fluxless solder bonding applications

    DEFF Research Database (Denmark)

    Kuhmann, Jochen Friedrich; Preuss, A.; Adolphi, B.;

    1998-01-01

    For microelectronics and especially for upcoming new packaging technologies in micromechanics and photonics fluxless, reliable and economic soldering technologies are needed. In this article, we consequently focus on the oxidation and reduction kinetics of three commonly used eutectic solder allo...... and reflowed AuSn(80/20) and SnPb(60/40) after the introduction of H2...

  18. Laser soldering of Sn-Ag-Cu and Sn-Zn-Bi lead-free solder pastes

    Science.gov (United States)

    Takahashi, Junichi; Nakahara, Sumio; Hisada, Shigeyoshi; Fujita, Takeyoshi

    2004-10-01

    It has reported that a waste of an electronics substrate including lead and its compound such as 63Sn-37Pb has polluted the environment with acid rain. For that environment problem the development of lead-free solder alloys has been promoted in order to find out the substitute for Sn-Pb solders in the United States, Europe, and Japan. In a present electronics industry, typical alloys have narrowed down to Sn-Ag-Cu and Sn-Zn lead-free solder. In this study, solderability of Pb-free solder that are Sn-Ag-Cu and Sn-Zn-Bi alloy was studied on soldering using YAG (yttrium aluminum garnet) laser and diode laser. Experiments were peformed in order to determine the range of soldering parameters for obtaining an appropriate wettability based on a visual inspection. Joining strength of surface mounting chip components soldered on PCB (printed circuit board) was tested on application thickness of solder paste (0.2, 0.3, and 0.4 mm). In addition, joining strength characteristics of eutectic Sn-Pb alloy and under different power density were examined. As a result, solderability of Sn-Ag-Cu (Pb-free) solder paste are equivalent to that of coventional Sn-Pb solder paste, and are superior to that of Sn-Zn-Bi solder paste in the laser soldering method.

  19. Ultrasonic spray pyrolysis deposition of SnSe and SnSe2 using a single spray solution

    Institute of Scientific and Technical Information of China (English)

    Jorge Sergio Narro-Rios; Manoj Ramachandran; Dalia Martínez-Escobar; Aarón Sánchez-Juárez

    2013-01-01

    Thin films of SnSe and SnSe2 have been deposited using the ultrasonic spray pyrolysis (USP) technique.To the best of our knowledge this is the first report of the deposition of SnSe and SnSe2 thin films using a single spray solution.The use of a single spray solution for obtaining both a p-type material,SnSe,and an n-type material,SnSe2,simplifies the deposition technique.The SnSe2 thin films have a bandgap of 1.1 eV and the SnSe thin films have a band gap of 0.9 eV.The Hall measurements were used to determine the resistivity of the thin films.The SnSe2 thin films show a resistivity of 36.73 Ω·cm and n-type conductivity while the SnSe thin films show a resistivity of 180 Ω·cm and p-type conductivity.

  20. Effect of CaF2/CaO Composite Additive on Roasting of Vanadium-Bearing Stone Coal and Acid Leaching Kinetics

    Directory of Open Access Journals (Sweden)

    Bo Wang

    2017-03-01

    Full Text Available In this paper, the composite additive of CaF2/CaO was used to extract vanadium from stone coal, and the effect of roasting and leaching kinetics were studied. The purpose of this manuscript is to realize and improve the vanadium recovery from stone coal using the composite additive. The experimental results indicated that the roasted clinker can be obtained under the conditions of CaF2/CaO at a mass ratio of 2:3 and a total additive amount of 10 wt %, a roasting temperature 850 °C, and a roasting time of 90 min. The leaching rate of vanadium can reach 86.74%, which increased by 16.4% compared with that of blank roasting under the conditions including a leaching temperature of 950 °C, a sulfuric acid concentration of 15% (v/v, a leaching time of 2 h, and a ratio of liquid to solid of 3 mL/g. The phase transformation analysis indicated that the muscovite structure was effectively destroyed during the roasting process comparing with no additives, which provided the basis for vanadium dissociation. Roasting can promote the formation of calcium vanadate, which is beneficial to the leaching of vanadium. The vanadium leaching kinetic analysis indicated that the activation energy of the acid leaching reaction decreased from 42.50 KJ/mol in the blank roasting to 22.56 KJ/mol in the calcified roasting, and the reaction order, with respect to the sulfuric acid concentration, decreased from 1.15 to 0.85. Calcified roasting has a better mineral activation than blank roasting, which can accelerate the leaching of vanadium and reduce the dependence on high-temperature and high acid levels in the leaching process.

  1. A Study on the Thermodynamic Model for CAO Waste Incineration System%CAO垃圾焚烧系统热力模型研究

    Institute of Scientific and Technical Information of China (English)

    赵绪新; 王恩堂; 马晓茜

    2001-01-01

    将CAO垃圾焚烧系统的两个燃烧室划分为:加热干燥区(A)、热解气化区(B)、残碳燃烧区(C)、可燃气燃烧区(D)。用多孔介质有效导热系数法,建立了A、B区中垃圾升温的传热模型;用不规则孔隙网络法,建立了B、C区中碳的气化和燃烧反应模型;用均相动力控制反应模型,分析了D区中多种化合物燃烬规律。最后讨论了CAO系统稳定燃烧的规律。%The two combustion chambers of CAO waste incineration system are divided into 4 zones: drying zone(A), devolatilization-gasification zone(B),residual carbon burning zone(C) and combustible gases burning zone(D).The heat transfer model of waste heating in A and B zones is established by the effective thermal conductivity method of porous media,the carbons gasifying and burning reaction model in B and C zones found by the irregular porousnet method,and the regularity for burning out compounds in D zone analyzed by the homogenous dynamically-controlled reaction model.Finally,the combustion stability for CAO is discussed.

  2. Characterization and Utilization of Calcium Oxide (CaO Thermally Decomposed from Fish Bones as a Catalyst in the Production of Biodiesel from Waste Cooking Oil

    Directory of Open Access Journals (Sweden)

    Aldes Lesbani

    2016-12-01

    Full Text Available Thermal decomposition of fish bones to obtain calcium oxide (CaO was conducted at various temperatures of 400, 500, 800, 900, 1000, and 1100 °C. The calcium oxide was then characterized using X-ray diffractometer, FTIR spectrophotometer, and SEM analysis. The calcium oxide obtained from the decomposition at 1000 °C was then used as a catalyst in the production of biodiesel from waste cooking oil. Diffraction pattern of the calcium oxide produced from decomposition at 1000 °C showed a pattern similar to that of the calcium oxide produced by the Joint Committee on Powder Diffraction Standard (JCDPS. The diffractions of 2θvalues at 1000 °C were 32.2, 37.3, 53.8, 64.1, and67.3 deg. The FTIR spectrum of calcium oxide decomposed at 1000 °C has a specific vibration at wave-length 362 cm-1, which is similar to the specific vibration of Ca-O. SEM analysis of the calcium oxide indicated that the calcium oxide’s morphology shows a smaller size and a more homogeneous structure, compared to those of fish bones. Theuse of calcium oxide as a catalyst in the production of biodiesel from waste cooking oil resulted in iod number of 15.23 g/100 g KOH, density of 0.88 g/cm3, viscosity of 6.00 cSt, and fatty acid value of 0.56 mg/KOH. These characteristic values meet the National Standard of Indonesia (SNI for biodiesel.

  3. The Influence of Calcined Clay Pozzolan, Low-Cao Steel Slag and Granite Dust On the Alkali-Silica Reaction in Concrete

    Directory of Open Access Journals (Sweden)

    James Sarfo-Ansah

    2015-08-01

    Full Text Available The influence of low CaO steel slag, calcined clay and granite dust on the alkali-silica reaction was investigated over a period of 35 days under accelerated curing conditions. The mineral admixtures were used to replace varying portions of high alkali Portland limestone cement up to an admixture content of 25% in order to study their effect on the alkali-silica reaction (ASR. Portland limestone cement used for the study had a total Na2Oeq of 4.32. XRD analysis of hydrated mortar bar samples confirmed the formation of an expansive sodium silica gel in the reference Portland cement mortar bar as the agent responsible for ASR. Stable calcium silicates were formed in the mortar bars containing calcined clay in increasing quantities whilst the presence of the sodium silicate gel decreased.The occurrence of these stable silicates in hydrated samples containing steel slag and granite dust was however minimal, compared to calcined clay cement mortars. The highest expansion was recorded for granite dust mortar bars, reaching a maximum of 25.98% at 35 days. Mortar-bar expansion decreased as calcined clay content in the cement increased;mortar bars with 25% calcined clay were the least expansive recording expansion less than 0.1% at all test ages. Whilst the expansion was reduced by between 42.5% and 107.8% at 14 days with increasing calcined clay content, expansion rather increased between 36.8% and 169.5% at 14 days with increasing granite dust content.Steel slag mortar bars experienced reduction in 14 days expansion between 14.3% - 46.2%.The study confirms that steel slag and calcined clay pozzolan have greater influence on ASR in mortar bars than granite dust and shows that calcined clay and low CaO steel slag could be considered as remedial admixtures for ASR at replacement levels of 25% and 15% respectively.

  4. Magnetization study of ITER-type internal-Sn Nb3Sn superconducting wire

    Institute of Scientific and Technical Information of China (English)

    Zhang Chao-Wu; Zhou Lian; Andre Sulpice; Jean-Louis Soubeyroux; Christophe Verwaerde; Gia Ky Hoang; Zhang Ping-Xiang; Lu Ya-Feng; Tang Xian-De

    2007-01-01

    Through magnetization measurement with a SQUID magnetometer the heat treatment optimization of an international thermonuclear experimental reactor (ITER)-type internal-Sn Nb3Sn superconducting wire has been investigated. The irreversibility temperature T*(H), which is mainly dependent on A15 phase composition, was obtained by a warming and cooling cycle at a fixed field. The hysteresis width △M(H) which reflects the flux pinning situation of the A15 phase is determined by the sweeping of magnetic field at a constant temperature. The results obtained from differently heat-treated samples show that the combination of T*(H) with △M(H) measurement is very effective for optimizing the heat reaction process. The heat treatment condition of the ITER-type wire is optimized at 675 ℃/128 h, which results in a composition closer to stoichiometric Nb3Sn and a state with best flux pinning.

  5. Intermediate-energy Coulomb excitation of 104Sn: Moderate E2 strength decrease approaching 100Sn

    CERN Document Server

    Doornenbal, P; Aoi, N; Matsushita, M; Obertelli, A; Steppenbeck, D; Wang, H; Audirac, L; Baba, H; Bednarczyk, P; Boissinot, S; Ciemala, M; Corsi, A; Furumoto, T; Isobe, T; Jungclaus, A; Lapoux, V; Lee, J; Matsui, K; Motobayashi, T; Nishimura, D; Ota, S; Pollacco, E C; Sakurai, H; Santamaria, C; Shiga, Y; Sohler, D; Taniuchi, R

    2013-01-01

    The reduced transition probability B(E2) of the first excited 2+ state in the nucleus 104Sn was measured via Coulomb excitation in inverse kinematics at intermediate energies. A value of 0.163(26) e^2b^2 was extracted from the absolute cross-section on a Pb target, while the method itself was verified with the stable 112Sn isotope. Our result deviates significantly from the earlier reported value of 0.10(4) e^2b^2 and corresponds to a moderate decrease of excitation strength relative to the almost constant values observed in the proton-rich, even-A 106-114Sn isotopes. Present state-of-the-art shell-model predictions, which include proton and neutron excitations across the N=Z=50 shell closures as well as standard polarization charges, underestimate the experimental findings

  6. Parametrized dielectric functions of amorphous GeSn alloys

    Science.gov (United States)

    D'Costa, Vijay Richard; Wang, Wei; Schmidt, Daniel; Yeo, Yee-Chia

    2015-09-01

    We obtained the complex dielectric function of amorphous Ge1-xSnx (0 ≤ x ≤ 0.07) alloys using spectroscopic ellipsometry from 0.4 to 4.5 eV. Amorphous GeSn films were formed by room-temperature implantation of phosphorus into crystalline GeSn alloys grown by molecular beam epitaxy. The optical response of amorphous GeSn alloys is similar to amorphous Ge and can be parametrized using a Kramers-Kronig consistent Cody-Lorentz dispersion model. The parametric model was extended to account for the dielectric functions of amorphous Ge0.75Sn0.25 and Ge0.50Sn0.50 alloys from literature. The compositional dependence of band gap energy Eg and parameters associated with the Lorentzian oscillator have been determined. The behavior of these parameters with varying x can be understood in terms of the alloying effect of Sn on Ge.

  7. Ordered CoSn-type ternary phases in Co3Sn3-xGex

    DEFF Research Database (Denmark)

    Allred, Jared M.; Jia, Shuang; Bremholm, Martin;

    2012-01-01

    CoSn is the prototype compound of the B35 structure, which has long been of interest due to its rarity and unusually low packing density. We report the synthesis and properties of the solid solution Co3Sn3-xGex for 0 ⩽ x ⩽ 2, in order to clarify the conditions necessary to stabilize such a phase...... some ambiguities about the stabilizing forces in this crystal structure. All compounds are normal metals with room temperature conductivities ranging from 5 to 50 μΩ cm and are weakly paramagnetic....

  8. Bulk and surface properties of demixing liquid Al-Sn and Sn-Tl alloys

    Science.gov (United States)

    Odusote, Y. A.; Popoola, A. I.; Oluyamo, S. S.

    2016-02-01

    The energetics of mixing in Al-Sn and Sn-Tl-segregating binary alloys has been explained through the study of surface properties (surface concentrations and surface tension) and various concentration-dependent thermodynamic (free energy of mixing, entropy of mixing and enthalpy of mixing) and transport (chemical diffusion) properties as well as the microscopic functions (concentration fluctuations in the long-wavelength limits and chemical short-range order parameter) using a statistical mechanical theory in conjunction with the self-association model (SAM). The theoretical property values obtained by the SAM were compared to the corresponding experimental values available in literature.

  9. MERLIN radio observations of two recent supernovae in Arp299: SN2010O & SN2010P

    Science.gov (United States)

    Beswick, R. J.; Perez-Torres, M. A.; Mattila, S.; Garrington, S. T.; Kankare, E.; Ryder, S.; Alberdi, A.; Romero-Canizales, C.

    2010-02-01

    We report MERLIN radio observations of the two recent supernovae in Arp299; SN2010P and SN2010O (CBET #2145 and CBET #2144, respectively). Observations of Arp299 were made between 1900UT 29th Jan 2010 and 0150UT 1st Feb 2010 at 4994MHz. The previously known compact radio structure of Arp299, including the nuclear starburst components associated with A=IC694 and B1=the southernmost nucleus of NGC3690 are detected (Neff, Ulvestad & Teng 2004, ApJ, 611, 186; Ulvestad 2009 AJ, 138, 152; Perez-Torres et al 2009, A&A 507, 17).

  10. Structural properties and hyperfine characterization of Sn-substituted goethites

    Energy Technology Data Exchange (ETDEWEB)

    Larralde, A.L. [INQUIMAE, Departamento de Quimica Inorganica, Analitica y Quimica Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (Argentina); Ramos, C.P. [Departamento de Fisica de la Materia Condensada, GIyA - CAC - CNEA, Av. Gral. Paz 1499 (1650), San Martin, Bs. As. (Argentina); Arcondo, B. [Departamento de Fisica, Facultad de Ingenieria, Universidad de Buenos Aires, Av. Paseo Colon 850 (C1063ACV), Bs. As. (Argentina); Tufo, A.E. [INQUIMAE, Departamento de Quimica Inorganica, Analitica y Quimica Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (Argentina); Saragovi, C. [Departamento de Fisica de la Materia Condensada, GIyA - CAC - CNEA, Av. Gral. Paz 1499 (1650), San Martin, Bs. As. (Argentina); Sileo, E.E., E-mail: sileo@qi.fcen.uba.ar [INQUIMAE, Departamento de Quimica Inorganica, Analitica y Quimica Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires (Argentina)

    2012-04-16

    Highlights: Black-Right-Pointing-Pointer Pure and tin-doped goethites were synthesized from Sn(II) solutions at ambient pressure and 70 Degree-Sign C. Black-Right-Pointing-Pointer The Rietveld refinement of PXRD data indicated that Sn partially substituted the Fe(III) ions. Black-Right-Pointing-Pointer The substitution provoked unit cell expansion, and a distortion of the coordination polyhedron. Black-Right-Pointing-Pointer {sup 119}Sn Moessbauer spectroscopy revealed that Sn(II) is incorporated as Sn(IV). Black-Right-Pointing-Pointer {sup 57}Fe Moessbauer spectroscopy showed a lower magnetic coupling as tin concentration increased. - Abstract: Tin-doped goethites obtained by a simple method at ambient pressure and 70 Degree-Sign C were characterized by inductively coupled plasma atomic emission spectrometry, scanning electron microscopy, Rietveld refinement of powder X-ray diffraction data, and {sup 57}Fe and {sup 119}Sn Moessbauer spectroscopy. The particles size and the length to width ratios decreased with tin-doping. Sn partially substituted the Fe(III) ions provoking unit cell expansion and increasing the crystallinity of the particles with enlarged domains that grow in the perpendicular and parallel directions to the anisotropic broadening (1 1 1) axis. Intermetallic E, E Prime and DC distances also change although the variations are not monotonous, indicating different variations in the coordination polyhedron. In general, the Sn-substituted samples present larger intermetallic distances than pure goethite, and the greatest change is shown in the E Prime distance which coincides with the c-parameter. {sup 119}Sn Moessbauer spectroscopy revealed that Sn(II) is incorporated as Sn(IV) in the samples. On the other hand, Fe(II) presence was not detected by {sup 57}Fe Moessbauer spectroscopy, suggesting the existence of vacancies in the Sn-doped samples. A lower magnetic coupling is also evidenced from the average magnetic hyperfine field values obtained as tin

  11. Factors Related to Adoption and Non-Adoption of Technical and Organizational Recommendations by Farmers Involved with Societe de Developpement du Cacao (SO.DE.CAO) in Cameroon. A Research Summary.

    Science.gov (United States)

    Kamga, Andre; Cheek, Jimmy G.

    In order to promote cocoa production and assist cocoa farmers in overcoming diseases in this crop, the government of Cameroon created an experimental corporation called Societe de Developpement du Cacao (SO.DE.CAO) in 1974. This organization functioned much like an extension service to provide information about crop production and disease control.…

  12. Factors Related to Adoption and Non-Adoption of Technical and Organizational Recommendations by Farmers Involved with Societe de Developpement du Cacao (SO.DE.CAO) in Cameroon. A Research Summary.

    Science.gov (United States)

    Kamga, Andre; Cheek, Jimmy G.

    In order to promote cocoa production and assist cocoa farmers in overcoming diseases in this crop, the government of Cameroon created an experimental corporation called Societe de Developpement du Cacao (SO.DE.CAO) in 1974. This organization functioned much like an extension service to provide information about crop production and disease control.…

  13. Real-time study of electromigration in Sn Blech structure

    Science.gov (United States)

    Ho, C. E.; Hsieh, W. Z.; Yang, C. H.; Lee, P. T.

    2016-12-01

    Electromigration has become a critical issue for reliability in Sn-based conducting materials that are used in advanced microelectronic packages with micro-joint integration. In this study, a Blech structure was used to characterize the Sn electromigration behavior of various strip lengths (L0 = 10-100 μm). We established a mathematical model based on the fundamental electromigration theory to describe the correlation between the residual strip length (L) and the current stressing time (t). A three-stage mechanism was proposed to rationalize the Sn electromigration in the Blech structure. A good agreement between the mathematical model and experimental data was obtained, advancing our understanding of Sn electromigration.

  14. GeSn/Ge multiquantum well photodetectors on Si substrates.

    Science.gov (United States)

    Oehme, M; Widmann, D; Kostecki, K; Zaumseil, P; Schwartz, B; Gollhofer, M; Koerner, R; Bechler, S; Kittler, M; Kasper, E; Schulze, J

    2014-08-15

    Vertical incidence GeSn/Ge multiquantum well (MQW) pin photodetectors on Si substrates were fabricated with a Sn concentration of 7%. The epitaxial structure was grown with a special low temperature molecular beam epitaxy process. The Ge barrier in the GeSn/Ge MQW was kept constant at 10 nm. The well width was varied between 6 and 12 nm. The GeSn/Ge MQW structures were grown pseudomorphically with the in-plane lattice constant of the Ge virtual substrate. The absorption edge shifts to longer wavelengths with thicker QWs in agreement with expectations from smaller quantization energies for the thicker QWs.

  15. The high-temperature modification of LuAgSn and high-pressure high-temperature experiments on DyAgSn, HoAgSn, and YbAgSn

    Energy Technology Data Exchange (ETDEWEB)

    Heying, B.; Rodewald, U.C.; Hermes, W.; Schappacher, F.M.; Riecken, J.F.; Poettgen, R. [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Heymann, G.; Huppertz, H. [Muenchen Univ. (Germany). Dept. fuer Chemie und Biochemie; Sebastian, C.P. [Max-Planck-Institut fuer Chemische Physik Fester Stoffe, Dresden (Germany)

    2008-02-15

    The high-temperature modification of LuAgSn was obtained by arc-melting an equiatomic mixture of the elements followed by quenching the melt on a water-cooled copper crucible. HT-LuAgSn crystallizes with the NdPtSb-type structure, space group P6{sub 3}mc: a = 463.5(1), c = 723.2(1) pm, wR2 = 0.0270, 151 F{sup 2}, and 11 variables. The silver and tin atoms build up two-dimensional, puckered [Ag{sub 3}Sn{sub 3}] networks (276 pm Ag-Sn) that are charge-balanced and separated by the lutetium atoms. The Ag-Sn distances between the [Ag{sub 3}Sn{sub 3}] layers of 294 pm are much longer. Single crystals of isotypic DyAgSn (a = 468.3(1), c = 734.4(1) pm, wR2 = 0.0343, 411 F{sup 2}, and 11 variables) and HoAgSn (a = 467.2(1), c = 731.7(2) pm, wR2 = 0.0318, 330 F{sup 2}, and 11 variables) were obtained from arc-melted samples. Under high-pressure (up to 12.2 GPa) and high-temperature (up to 1470 K) conditions, no transitions to a ZrNiAl-related phase have been observed for DyAgSn, HoAgSn, and YbAgSn. HT-TmAgSn shows Curie-Weiss paramagnetism with {mu}{sub eff} = 7.53(1) {mu}{sub B}/Tm atom and {theta}P = -15.0(5) K. No magnetic ordering was evident down to 3 K. HT-LuAgSn is a Pauli paramagnet. Room-temperature {sup 119}Sn Moessbauer spectra of HT-TmAgSn and HT-LuAgSn show singlet resonances with isomer shifts of 1.78(1) and 1.72(1) mm/s, respectively. (orig.)

  16. Cajal bodies and snRNPs - friends with benefits.

    Science.gov (United States)

    Staněk, David

    2016-09-14

    Spliceosomal snRNPs are complex particles that proceed through a fascinating maturation pathway. Several steps of this pathway are closely linked to nuclear non-membrane structures called Cajal bodies. In this review, I summarize the last 20 y of research in this field. I primarily focus on snRNP biogenesis, specifically on the steps that involve Cajal bodies. I also evaluate the contribution of the Cajal body in snRNP quality control and discuss the role of snRNPs in Cajal body formation.

  17. Elastic anisotropy in multifilament Nb$_3$Sn superconducting wires

    CERN Document Server

    Scheuerlein, C; Alknes, P; Arnau, G; Bjoerstad, R; Bordini, B

    2015-01-01

    The elastic anisotropy caused by the texture in the Nb3Sn filaments of PIT and RRP wires has been calculated by averaging the estimates of Voigt and Reuss, using published Nb3Sn single crystal elastic constants and the Nb3Sn grain orientation distribution determined in both wire types by Electron Backscatter Diffraction. At ambient temperature the calculated Nb3Sn E-moduli in axial direction in the PIT and the RRP wire are 130 GPa and 140 GPa, respectively. The calculated E-moduli are compared with tensile test results obtained for the corresponding wires and extracted filament bundles.

  18. Effect of pressure on the Curie temperature of Mn2RuSn and Mn2PdSn

    Science.gov (United States)

    Adachi, Y.; Watanabe, T.; Kanomata, T.; Hayasaka, M.; Endo, K.; Nishihara, H.; Xu, X.; Kainuma, R.

    2017-04-01

    Effect of pressure on the Curie temperature TC of the Mn-rich Heusler alloys Mn2RuSn and Mn2PdSn has been investigated by measuring the temperature dependence of initial permeability at various pressures up to 10 kbar. It was found that the Curie temperatures of Mn2RuSn and Mn2PdSn decrease with increasing pressure. The pressure derivatives of TC were estimated to be -0.59 K/kbar for Mn2RuSn and -0.80 K/kbar for Mn2PdSn. On the basis of the experimental results, the relationship between the magnetic transition temperature and the Mn-Mn distance is discussed.

  19. The attack initiation of Al-Zn-In-Sn anode by the segregation concentrating Zn,Sn and In

    Energy Technology Data Exchange (ETDEWEB)

    Qi, G.T.; Qiu, Y.B.; Cai, Q.Z. [Department of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan (China); Zhao, Y.N. [Department of Biological and Chemical Engineering, Nanyang Institute of Technology, Nanyang (China)

    2009-03-15

    The microstructure of Al-5%Zn-0.025%In-0.15%Sn anode was investigated by EPMA, and EDAX. The result showed that the microstructure at the Al-Zn-In-Sn anode can be categorized into two different types, namely the catenulate segregation enriched in Zn, Fe, Si, and the elliptical or rounded segregation where Zn, Sn, In concentrated. In order to explain the initial dissolution of the aluminum anode, the electrochemical behavior in 3% NaCl solution of the Al-Zn-In-Sn anode and its simulated segregation concentrating Zn, Sn, In were tested using potentiodynamic polarization and electrochemical impedance spectroscopy. The result showed that the simulated segregation concentrating Zn,Sn, In would preferentially be dissolved into the solution as the anode of galvanic cell. (Abstract Copyright [2009], Wiley Periodicals, Inc.)

  20. Effect of Pt:Sn atomic ratio on the preparation of PtSn/C electrocatalysts using electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Dionisio F.; Oliveira Neto, Almir; Pino, Eddy S.; Linardi, Marcelo; Spinace, Estevam V., E-mail: dfsilva@ipen.b, E-mail: espinace@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    PtSn/C electrocatalysts were prepared with Pt:Sn atomic ratios of 3:1, 1:1 and 1:3 in water/2-propanol using electron beam irradiation. The obtained materials were characterized by EDX, XRD and cyclic voltammetry. The ethanol electro-oxidation was studied by chronoamperometry. The XRD diffractograms of the PtSn/C electrocatalysts showed typical face-centered cubic (fcc) structure of platinum and the presence of a SnO{sub 2} phase (cassiterite). The mean crystallite sizes of Pt fcc phase was in the range of 3.0-3.5 nm. The PtSn/C electrocatalysts were active for ethanol electro-oxidation at room temperature and the material prepared with Pt:Sn atomic ratio of 1:1 showed the best activity. (author)

  1. Interfacial Reactions in the Ni/Sn- xZn/Cu Sandwich Couples

    Science.gov (United States)

    Yen, Yee-Wen; Lin, Chung-Yung; Lai, Mei-Ting; Chen, Wan-Ching

    2016-01-01

    The interfacial reactions in Ni/Sn- xZn/Cu sandwich couples which were reflowed at 270°C for 1 h and then aged at 160°C for 1-1000 h were investigated. When the 1000- μm-thick Sn-Zn alloy reacted with Ni and Cu in this couple, the results indicated that the (Ni, Cu)3Sn4, (Ni, Cu)5Zn21, and Ni5Zn21 phases were formed at Sn-1Zn/Ni, Sn-5Zn/Ni, and Sn-9Zn/Ni interfaces for 1 h reflowing, respectively. After 1000 h aging, each intermetallic compound (IMC) was converted to (Cu, Ni, Zn)6Sn5, (Ni, Cu, Sn)5Zn21/Ni5Zn21, and Ni5Zn21 (two layers) phases in the related couples. On the Cu side, the Cu6Sn5 phase in the Sn-1Zn/Cu interface and the Cu5Zn8 phase in the Sn-5Zn/Cu and Sn-9Zn/Cu interfaces were observed when the couple was reflowed at 270°C for 1 h. After 100 h aging, the (Cu, Ni, Zn)6Sn5, Cu5Zn8/(Cu, Zn)6Sn5, and Cu5Zn8 phases were formed at the Sn-1Zn/Cu, Sn-5Zn/Cu and Sn-9Zn/Cu interfaces. When the Sn-Zn alloy thickness was decreased to 500 μm, the (Cu, Ni, Zn)6Sn5 phase at the Sn-1Zn/Ni interface and the (Ni, Cu, Sn)5Zn21 phase at the Sn-5Zn/Ni and Sn-9Zn/Ni interfaces were observed after 1 h reflowing. When the couple was aged at 160°C for 1000 h, each IMC was converted to (Cu, Ni, Zn)6Sn5 and Cu5Zn8/(Cu, Ni, Sn)Zn/Ni5Zn21 phases at the Sn-1Zn/Ni and Sn-(5, 9)Zn/Ni interfaces. (Cu, Ni, Zn)6Sn5 and Cu5Zn8 were, respectively, formed at the Sn-1Zn/Cu and Sn-(5, 9)Zn/Cu interfaces for 1 h reflowing. After 100 h aging, the IMCs were converted to (Cu, Ni, Zn)6Sn5 and Cu5Zn8/(Cu, Zn)6Sn5 phases. This current study reveals that the IMC formation in Ni/(Sn- xZn)/Cu sandwich couples are very sensitive to the Zn concentration and thickness in Sn- xZn alloys.

  2. Influence of Sn concentration on the physical properties of CdO:Sn thin films deposited by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Vigil-Galan, O.; Ruiz, C.M. [Departamento de Fisica de Materiales, Universidad Autonoma de Madrid, 28049 Madrid (Spain); Sanchez-Gonzalez, Y. [EMPROTEL, Copextel, Carretera Prensa Latina km 111/2, Marianao, La Habana (Cuba); Arias-Carbajal, A. [Facultad de Quimica-IMRE, Universidad de La Habana, 10400 La Habana (Cuba); Contreras-Puente, G.; Tufino-Velazquez, M. [Escuela Superior de Fisica y Matematicas, Instituto Politecnico Nacional, 07738 Mexico, D.F. (Mexico)

    2006-12-15

    Sn doped cadmium oxide thin films were prepared on glass substrates by the spray pyrolysis (SP) method from a cadmium acetate aqueous solution. The Sn (IV) concentration in the solution was varied up to 2 wt%, keeping constant the other growth parameters. The structural, electrical and optical properties of the films were studied as a function of Sn concentration. The best results were obtained for CdO films doped with 1% Sn nominal concentration. The properties of these films are influenced by the air annealing performed at 450 C for 30-120 min. (copyright 2006 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  3. Simultaneous polarization monitoring of SN2007uy and the axisymmetric SN2008D/XRF080109: isolating geometry from dust

    CERN Document Server

    Gorosabel, J; Castro-Tirado, A J; Agudo, I; Jelinek, M; Leon, S; Augusteijn, T; Fynbo, J P U; Hjorth, J; Michalowski, M J; Xu, D; Ferrero, P; Kann, D A; Klose, S; Rossi, A; Madrid, J P; LLorente, A; Bremer, M; Winters, J -M

    2008-01-01

    We report the results of an optical linear polarization monitoring carried out simultaneously for SN2007uy and SN2008D. The observations span 74.9 days, starting 3.6 days after the X-ray outburst of SN2008D and are distributed in 11 visits. For both SNe the polarization is dominated by the host galaxy interstellar polarization (HGIP), especially for SN2007uy. This fact is supported by 1.2 millimeter (mm) observations of NGC2770, carried out at and around the SN2008D position. The 1.2 mm data are consistent with no intrinsic emission from SN2008D and can be entirely explained by the NGC2770 dust emission. Comparing spectroscopic extinction values reported in the literature with the extinction derived from the 1.2 mm data, we conclude that the NGC2770 extinction distribution is heterogeneous. We report also a 3.3 mm flux detection at the SN2008D position, possibly due to the intrinsic SN emission, and not due to the dust. Despite the dominant HGIP, a statistical analysis of the distribution of the SN2008D Stoke...

  4. Temperature varying photoconductivity of GeSn alloys grown by chemical vapor deposition with Sn concentrations from 4% to 11%

    Science.gov (United States)

    Hart, John; Adam, Thomas; Kim, Yihwan; Huang, Yi-Chiau; Reznicek, Alexander; Hazbun, Ramsey; Gupta, Jay; Kolodzey, James

    2016-03-01

    Pseudomorphic GeSn layers with Sn atomic percentages between 4.5% and 11.3% were grown by chemical vapor deposition using digermane and SnCl4 precursors on Ge virtual substrates grown on Si. The layers were characterized by x-ray diffraction rocking curves and reciprocal space maps. Photoconductive devices were fabricated, and the dark current was found to increase with Sn concentration. The responsivity of the photoconductors was measured at a wavelength of 1.55 μm using calibrated laser illumination at room temperature and a maximum value of 2.7 mA/W was measured for a 4.5% Sn device. Moreover, the responsivity for higher Sn concentration was found to increase with decreasing temperature. Spectral photoconductivity was measured using Fourier transform infrared spectroscopy. The photoconductive absorption edge continually increased in wavelength with increasing tin percentage, out to approximately 2.4 μm for an 11.3% Sn device. The direct band gap was extracted using Tauc plots and was fit to a bandgap model accounting for layer strain and Sn concentration. This direct bandgap was attributed to absorption from the heavy-hole band to the conduction band. Higher energy absorption was also observed, which was thought to be likely from absorption in the light-hole band. The band gaps for these alloys were plotted as a function of temperature. These experiments show the promise of GeSn alloys for CMOS compatible short wave infrared detectors.

  5. Electrochemical properties of Ti-Ni-Sn materials predicted by {sup 119}Sn Mössbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Ladam, A., E-mail: alix.ladam@univ-montp2.fr; Aldon, L.; Lippens, P.-E.; Olivier-Fourcade, J.; Jumas, J.-C. [Université de Montpellier, Institut Charles Gerhardt, UMR 5253 CNRS (France); Cenac-Morthe, C. [CNES, Service DCT/TV/El (France)

    2016-12-15

    The electrochemical activity of TiNiSn, TiNi {sub 2}Sn and Ti {sub 6}Sn {sub 5} compounds considered as negative electrode materials for Li-ion batteries has been predicted from the isomer shift- Hume-Rothery electronic density correlation diagram. The ternary compounds were obtained from solid-state reactions and Ti {sub 6}Sn {sub 5} by ball milling. The {sup 119}Sn Mössbauer parameters were experimentally determined and used to evaluate the Hume-Rothery electronic density [e {sub av}]. The values of [e {sub av}] are in the region of Li-rich Li-Sn alloys for Ti {sub 6}Sn {sub 5} and outside this region for the ternary compounds, suggesting that the former compound is electrochemically active but not the two latter ones. Electrochemical tests were performed for these different materials confirming this prediction. The close values of [e {sub av}] for Ti {sub 6}Sn {sub 5} and Li-rich Li-Sn alloys indicate that the observed good capacity retention could be related to small changes in the global structures during cycling.

  6. Creep and Mechanical Properties of Cu6Sn5 and (Cu,Ni)6Sn5 at Elevated Temperatures

    Science.gov (United States)

    Mu, Dekui; Huang, Han; McDonald, Stuart D.; Nogita, Kazuhiro

    2013-02-01

    Cu6Sn5 is the most common and important intermetallic compound (IMC) formed between Sn-based solders and Cu substrates during soldering. The Cu6Sn5 IMC exhibits significantly different thermomechanical properties from the solder alloys and the substrate. The progress of high-density three-dimensional (3D) electrical packaging technologies has led to increased operating temperatures, and interfacial Cu6Sn5 accounts for a larger volume fraction of the fine-pitch solder joints in these packages. Knowledge of creep and the mechanical behavior of Cu6Sn5 at elevated temperatures is therefore essential to understanding the deformation of a lead-free solder joint in service. In this work, the effects of temperature and Ni solubility on creep and mechanical properties of Cu6Sn5 were investigated using energy-dispersive x-ray spectroscopy and nanoindentation. The reduced modulus and hardness of Cu6Sn5 were found to decrease as temperature increased from 25°C to 150°C. The addition of Ni increased the reduced modulus and hardness of Cu6Sn5 and had different effects on the creep of Cu6Sn5 at room and elevated temperatures.

  7. Wettability of Sn-Zn, Sn-Ag-Cu and Sn-Bi-Cu Lead-free Solder Alloys with Copper Substrate%Sn-Zn,Sn-Ag-Cu和Sn-Bi-Cu无铅焊锡合金与铜的润湿性

    Institute of Scientific and Technical Information of China (English)

    张晓瑞; 汪春雷; 赵宏欣; 李建强; 袁章福

    2009-01-01

    采用静滴法对Sn-Zn,Sn-Ag-Cu Sn-Bi-Cu锡基合金在铜基板上的润湿性进行了研究.结果表明,Sn-Bi-Cu合金的润湿性良好,Sn-30Bi-0.5Cu合金在530 K时的接触角为26°,熔融的Sn-3Ag-0.5Cu共晶合金的接触角几乎不存在滞后性.锡基合金中添加Bi元素可提高合金的润湿性,添加Cu元素可有效防止溶铜发生.研究结果为无铅焊锡合金的应用提供了一定的理论依据.

  8. 'Pd20Sn13' revisited: crystal structure of Pd6.69Sn4.31.

    Science.gov (United States)

    Klein, Wilhelm; Jin, Hanpeng; Hlukhyy, Viktor; Fässler, Thomas F

    2015-07-01

    The crystal structure of the title compound was previously reported with composition 'Pd20Sn13' [Sarah et al. (1981 ▸). Z. Metallkd, 72, 517-520]. For the original structure model, as determined from powder X-ray data, atomic coordinates from the isostructural compound Ni13Ga3Ge6 were transferred. The present structure determination, resulting in a composition Pd6.69Sn4.31, is based on single crystal X-ray data and includes anisotropic displacement parameters for all atoms as well as standard uncertainties for the atomic coordinates, leading to higher precision and accuracy for the structure model. Single crystals of the title compound were obtained via a solid-state reaction route, starting from the elements. The crystal structure can be derived from the AlB2 type of structure after removing one eighth of the atoms at the boron positions and shifting adjacent atoms in the same layer in the direction of the voids. One atomic site is partially occupied by both elements with a Pd:Sn ratio of 0.38 (3):0.62 (3). One Sn and three Pd atoms are located on special positions with site symmetry 2. (Wyckoff letter 3a and 3b).

  9. `Pd20Sn13' revisited: crystal structure of Pd6.69Sn4.31

    Directory of Open Access Journals (Sweden)

    Wilhelm Klein

    2015-07-01

    Full Text Available The crystal structure of the title compound was previously reported with composition `Pd20Sn13' [Sarah et al. (1981. Z. Metallkd, 72, 517–520]. For the original structure model, as determined from powder X-ray data, atomic coordinates from the isostructural compound Ni13Ga3Ge6 were transferred. The present structure determination, resulting in a composition Pd6.69Sn4.31, is based on single crystal X-ray data and includes anisotropic displacement parameters for all atoms as well as standard uncertainties for the atomic coordinates, leading to higher precision and accuracy for the structure model. Single crystals of the title compound were obtained via a solid-state reaction route, starting from the elements. The crystal structure can be derived from the AlB2 type of structure after removing one eighth of the atoms at the boron positions and shifting adjacent atoms in the same layer in the direction of the voids. One atomic site is partially occupied by both elements with a Pd:Sn ratio of 0.38 (3:0.62 (3. One Sn and three Pd atoms are located on special positions with site symmetry 2. (Wyckoff letter 3a and 3b.

  10. Thermodynamic understanding of Sn whisker growth on the Cu surface in Cu(top)-Sn(bottom) bilayer system upon room temperature aging

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Lin; Jian, Wei; Lin, Bing; Wang, Jiangyong, E-mail: wangjy@stu.edu.cn [Department of Physics, Shantou University, 243 Daxue Road, Shantou, 515063 Guangdong (China); Wen, Yuren [School of Materials Science and Engineering, Nanchang University, Nanchang, 330031 Jiangxi (China); Institute of Physics, Chinese Academy of Sciences, 100190 Beijing (China); Gu, Lin [Institute of Physics, Chinese Academy of Sciences, 100190 Beijing (China)

    2015-06-07

    Sn whiskers are observed by scanning electron microscope on the Cu surface in Cu(top)-Sn(bottom) bilayer system upon room temperature aging. Only Cu{sub 6}Sn{sub 5} phase appears in the X-ray diffraction patterns and no Sn element is detected in the Cu sublayer by scanning transmission electron microscopy. Based on the interfacial thermodynamics, the intermetallic Cu{sub 6}Sn{sub 5} compound phase may form directly at the Sn grain boundary. Driven by the stress gradient during the formation of Cu{sub 6}Sn{sub 5} compound at Sn grain boundaries, Sn atoms segregate onto the Cu surface and accumulate to form Sn whisker.

  11. Swift Observations of SN 2007aa

    Science.gov (United States)

    Immler, S.; Brown, P. J.; Milne, P.

    2007-03-01

    Swift Ultraviolet/Optical Telescope (UVOT) and X-Ray Telescope (XRT) observed the type II SN 2007aa (CBET #850, IAUC #8814) on 2007-02-24.63 UT. The following UVOT magnitudes were measured: V = 15.8 (322 s exposure time), B = 16.4 (367 s), U = 16.9 (367 s), UVW1 [181-321nm] = 18.6 (737 s), UVM2 [166-268 nm] > 19.5 (3-sigma upper limit; 236 s), and UVW2 [112-264 nm] = 19.7 (725 s). The magnitudes have not been corrected for extinction.

  12. Spectroscopic observation of 5 SN candidates

    Science.gov (United States)

    Elias-Rosa, N.; Pursimo, T.; Korhonen, H.; Pastorello, A.; Derlopa, the NEON school PhD students S.; Marian, V.; Scognamiglio, D.; Szigeti, L.; Cabezas, M.; Fernandes, C. S.; McWhirter, P. R.; Zervas, K.

    2017-09-01

    We report the spectroscopic classification of SNe 2017gla, 2017glz, 2017gop, and 2017gqq, and the verification of SN2017gmr. The targets were supplied by the following surveys: ATLAS survey, see Tonry et al. (2011, PASP, 123, 58) and Tonry et al. (ATel #8680); Pan-STARRS Survey for Transients (Chambers et al. 2016, arXiv:1612.05560, and http://pswww.ifa.hawaii.edu ), the PMO-Tsinghua Supernova Survey (PTSS, http://www.cneost.org/ptss/ ); and the D The observations were performed with the 2.56 m Nordic Optical Telescope equipped with ALFOSC (range 350-950 nm; resolution 1.4 nm FWHM).

  13. Electronic topological transition in LaSn3 under pressure

    DEFF Research Database (Denmark)

    Ram, Swetarekha; Kanchana, V.; Vaitheeswaran, G.

    2012-01-01

    The electronic structure, Fermi surface, and elastic properties of the isostructural and isoelectronic LaSn3 and YSn3 intermetallic compounds are studied under pressure within the framework of density functional theory including spin-orbit coupling. The LaSn3 Fermi surface consists of two sheets...

  14. Microstructural evolution of eutectic Au-Sn solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ho Geon

    2002-05-31

    Current trends toward miniaturization and the use of lead(Pb)-free solder in electronic packaging present new problems in the reliability of solder joints. This study was performed in order to understand the microstructure and microstructural evolution of small volumes of nominally eutectic Au-Sn solder joints (80Au-20Sn by weight), which gives insight into properties and reliability.

  15. Microstructural evolution of eutectic Au-Sn solder joints

    Energy Technology Data Exchange (ETDEWEB)

    Song, Ho Geon [Univ. of California, Berkeley, CA (United States)

    2002-05-01

    Current trends toward miniaturization and the use of lead(Pb)-free solder in electronic packaging present new problems in the reliability of solder joints. This study was performed in order to understand the microstructure and microstructural evolution of small volumes of nominally eutectic Au-Sn solder joints (80Au-20Sn by weight), which gives insight into properties and reliability.

  16. Spectropolarimetry of the Type IIb SN 2008aq

    CERN Document Server

    Stevance, H F; Baade, D; Hoflich, P; Patat, F; Spyromilio, J; Wheeler, J C; Clocchiatti, A; Wang, L; Yang, Y; Zelaya, P

    2016-01-01

    We present optical spectroscopy and spectropolarimetry of the Type IIb SN 2008aq 16 days and 27 days post-explosion. The spectrum of SN 2008aq remained dominated by Halpha P Cygni profile at both epochs, but showed a significant increase in the strength of the helium features, which is characteristic of the transition undergone by supernovae between Type IIb and Type Ib. Comparison of the spectra of SN 2008aq to other Type IIb SNe (SN 1993J, SN 2011dh, and SN 2008ax) at similar epochs revealed that the helium lines in SN 2008aq are much weaker, suggesting that its progenitor was stripped to a lesser degree. SN 2008aq also showed significant levels of continuum polarisation at p_cont = 0.70 (+/- 0.22) % in the first epoch, increasing to p_cont = 1.21 (+/- 0.33) % by the second epoch. Moreover, the presence of loops in the q-u planes of Halpha and He I in the second epoch suggests a departure from axial symmetry.

  17. Wafer bonding using Cu-Sn intermetallic bonding layers

    NARCIS (Netherlands)

    Flötgen, C.; Pawlak, M.; Pabo, E.; Wiel, H.J. van de; Hayes, G.R.; Dragoi, V.

    2014-01-01

    Wafer-level Cu-Sn intermetallic bonding is an interesting process for advanced applications in the area of MEMS and 3D interconnects. The existence of two intermetallic phases for Cu-Sn system makes the wafer bonding process challenging. The impact of process parameters on final bonding layer

  18. Hydrogen mediated transport of Sn to Ru film surface

    NARCIS (Netherlands)

    Faradzhev, N.; Sidorkin, V.

    2009-01-01

    The authors report on the interaction of atomic hydrogen with Sn and thin Ru film at room temperature. The study is done using a combination of photoelectron and low energy ion scattering spectroscopies as well as scanning electron microscopy. The adsorption of hydrogen on a Sn surface leads to the

  19. Hydrogen mediated transport of Sn to Ru film surface

    NARCIS (Netherlands)

    Faradzhev, N.; Sidorkin, V.

    2009-01-01

    The authors report on the interaction of atomic hydrogen with Sn and thin Ru film at room temperature. The study is done using a combination of photoelectron and low energy ion scattering spectroscopies as well as scanning electron microscopy. The adsorption of hydrogen on a Sn surface leads to the

  20. Do π-conjugative effects facilitate SN2 reactions?

    Science.gov (United States)

    Wu, Chia-Hua; Galabov, Boris; Wu, Judy I-Chia; Ilieva, Sonia; Schleyer, Paul von R; Allen, Wesley D

    2014-02-26

    Rigorous quantum chemical investigations of the SN2 identity exchange reactions of methyl, ethyl, propyl, allyl, benzyl, propargyl, and acetonitrile halides (X = F(-), Cl(-)) refute the traditional view that the acceleration of SN2 reactions for substrates with a multiple bond at Cβ (carbon adjacent to the reacting Cα center) is primarily due to π-conjugation in the SN2 transition state (TS). Instead, substrate-nucleophile electrostatic interactions dictate SN2 reaction rate trends. Regardless of the presence or absence of a Cβ multiple bond in the SN2 reactant in a series of analogues, attractive Cβ(δ(+))···X(δ(-)) interactions in the SN2 TS lower net activation barriers (E(b)) and enhance reaction rates, whereas repulsive Cβ(δ(-))···X(δ(-)) interactions increase E(b) barriers and retard SN2 rates. Block-localized wave function (BLW) computations confirm that π-conjugation lowers the net activation barriers of SN2 allyl (1t, coplanar), benzyl, propargyl, and acetonitrile halide identity exchange reactions, but does so to nearly the same extent. Therefore, such orbital interactions cannot account for the large range of E(b) values in these systems.

  1. SN 2002cx The Most Peculiar Known Type Ia Supernova

    CERN Document Server

    Li, W; Chornock, R; Berger, E; Berlind, P; Calkins, M L; Challis, P M; Fassnacht, C D; Jha, S; Kirshner, R P; Matheson, T; Sargent, W L W; Simcoe, R A; Smith, G H; Squires, G; Li, Weidong; Filippenko, Alexei V.; Chornock, Ryan; Berger, Edo; Berlind, Perry; Calkins, Michael L.; Challis, Peter; Fassnacht, Chris; Jha, Saurabh; Kirshner, Robert P.; Matheson, Thomas; Sargent, Wallace L. W.; Simcoe, Robert A.; Smith, Graeme H.; Squires, Gordon

    2003-01-01

    We present photometric and spectroscopic observations of supernova (SN) 2002cx, which reveal it to be unique among all observed type Ia supernovae (SNe Ia). SN 2002cx exhibits a SN 1991T-like premaximum spectrum, a SN 1991bg-like luminosity, and expansion velocities roughly half those of normal SNe Ia. Photometrically, SN 2002cx has a broad peak in the $R$ band and a plateau phase in the $I$ band, and slow late-time decline. The $(B - V)$ color evolution is nearly normal, but the $(V - R)$ and $(V - I)$ colors are very red. Early-time spectra of SN 2002cx evolve very quickly and are dominated by lines from Fe-group elements; features from intermediate-mass elements (Ca, S, Si) are weak or absent. Mysterious emission lines are observed around 7000 \\AA\\ at about 3 weeks after maximum brightness. The nebular spectrum of SN 2002cx is also unique, consisting of narrow iron and cobalt lines. The observations of SN 2002cx are inconsistent with the observed spectral/photometric sequence, and provide a major challenge...

  2. Detection of the Sn(III) intermediate and the mechanism of the Sn(IV)/Sn(II) electroreduction reaction in bromide media by cyclic voltammetry and scanning electrochemical microscopy.

    Science.gov (United States)

    Chang, Jinho; Bard, Allen J

    2014-01-08

    Fast-scan cyclic voltammetry (CV) and scanning electrochemical microscopy (SECM) were used to investigate the reduction of Sn(IV) as the hexabromo complex ion in a 2 M HBr-4 M NaBr medium. CV at scan rates to 100 V/s and SECM indicated the reaction pathway involves ligand-coupled electron transfer via an ECEC-DISP process: (1) one-electron reduction of Sn(IV)Br6(2-) to Sn(III)Br6(3-); (2) bromide dissociation of the reduced Sn(III)Br6(3-) to Sn(III)Br5(2-); (3) disproportionation of the reduced 2Sn(III)Br5(2-) to Sn(IV)Br5(-) and Sn(II)Br5(3-); (4) one-electron reduction of Sn(III)Br5(2-) to Sn(II)Br5(3-); (5) bromide dissociation from Sn(II)Br5 to Sn(II)Br4(2-). The intermediate Sn(III) species was confirmed by SECM(3-), where the Sn(III) generated at the Au tip was collected on a Au substrate in the tip generation/substrate collection mode when the distance between the tip and substrate was a few hundred nanometers.

  3. Synthesis and lithium storage properties of Zn, Co and Mg doped SnO2 Nano materials

    CSIR Research Space (South Africa)

    Palaniyandy, Nithyadharseni

    2017-09-01

    Full Text Available In this paper, we show that magnesium and cobalt doped SnO2 (Mg-SnO2 and Co-SnO2) nanostructures have profound influence on the discharge capacity and coulombic efficiency of lithium ion batteries (LIBs) employing pure SnO2 and zinc doped SnO2 (Zn-Sn...

  4. SiSn diodes: Theoretical analysis and experimental verification

    KAUST Repository

    Hussain, Aftab M.

    2015-08-24

    We report a theoretical analysis and experimental verification of change in band gap of silicon lattice due to the incorporation of tin (Sn). We formed SiSn ultra-thin film on the top surface of a 4 in. silicon wafer using thermal diffusion of Sn. We report a reduction of 0.1 V in the average built-in potential, and a reduction of 0.2 V in the average reverse bias breakdown voltage, as measured across the substrate. These reductions indicate that the band gap of the silicon lattice has been reduced due to the incorporation of Sn, as expected from the theoretical analysis. We report the experimentally calculated band gap of SiSn to be 1.11 ± 0.09 eV. This low-cost, CMOS compatible, and scalable process offers a unique opportunity to tune the band gap of silicon for specific applications.

  5. Process of electroless plating Cu-Sn-Zn ternary alloy

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Cu-Sn-Zn ternary alloy layer with 10 μm thickness was prepared through electroless plating method. The influences of process conditions including the concentration of metallic salts, reductant and complex agent on Cu-Sn-Zn alloy were studied in details.The stability to bear color changes and corrosion resistance of Cu-Sn-Zn film layer were studied through air-exposure experiment and electrochemical analyses test respectively. The results show that the performances of Cu-Sn-Zn film layer are obviously superior to brass matrix. By use of SEM,EDS and XRD, the morphology, microstructure and chemical composition were investigated. The results show that complex agent can increase the content of Sn and Zn, improve the evenness and compactness and decrease needle holes, therefore the properties of electroless plating layer such as the stability to bear color changes and corrosion resistance are improved remarkably.The probable mechanism of complex agent was discussed.

  6. Polymer-SnO2 composite membranes

    DEFF Research Database (Denmark)

    Nørgaard, Casper Frydendal; Skou, Eivind Morten

    When designing sulfonic acid based ionomers, high ion exchange capacity (IEC) comes at the expense of the mechanical properties. With too high IEC, the membrane will excessively swell or even dissolve in water. Therefore a suitable compromise must be found between high charge carrier concentration...... and adequate mechanical properties. It has been demonstrated that this compromise can be found at higher IEC when the mechanical properties are improved by increasing crystallinity, increasing molecular weight, crosslinking or reinforcement of the membrane by dispersion of interacting particles therein....... This work utilizes the latter approach and makes use of particles of tin dioxide (SnO2). Polymer-SnO2 composite membranes were successfully prepared using an ion-exchange method. SnO2 was incorporated into membranes by ion-exchange in solutions of SnCl2 ∙ 2 H2O in methanol, followed by oxidation to SnO2...

  7. The structure of 100Sn and neighbouring nuclei

    Science.gov (United States)

    Faestermann, T.; Górska, M.; Grawe, H.

    2013-03-01

    The nuclear structure in the 100Sn region is reviewed. State-of-the-art experimental techniques involving stable and radioactive beam facilities have enabled access to exotic nuclei in its next neighbourhood. The analysis of experimental data has established the shell structure and its evolution towards N=Z=50, seniority conservation and proton-neutron interaction in the g9/2 orbit, the super-allowed Gamow-Teller decay of 100Sn, masses and half lives along the rp-path, and super-allowed α decay beyond 100Sn. The status of theoretical approaches in shell model and mean-field investigations is described and their predictive power assessed. Structure features of 100Sn and its doubly-magic neighbours 56Ni at N=Z, 132Sn and 78Ni at N≫Z are compared. An outlook is given on future developments of experimental and theoretical methods.

  8. U7 snRNAs: A Computational Survey

    Institute of Scientific and Technical Information of China (English)

    Mania; Marz; Axel; Mosig; B(a)rbel; M.R.; Stadler; Peter; F.; Stadler

    2007-01-01

    U7 small nuclear RNA (snRNA) sequences have been described only for a handful of animal species in the past. Here we describe a computational search for func- tional U7 snRNA genes throughout vertebrates including the upstream sequence elements characteristic for snRNAs transcribed by polymerase Ⅱ. Based on the results of this search, we discuss the high variability of U7 snRNAs in both se- quence and structure, and report on an attempt to find U7 snRNA sequences in basal deuterostomes and non-drosophilids insect genomes based on a combination of sequence, structure, and promoter features. Due to the extremely short se- quence and the high variability in both sequence and structure, no unambiguous candidates were found. These results cast doubt on putative U7 homologs in even more distant organisms that are reported in the most recent release of the Rfam database.

  9. Effect of Slag Composition on the Distribution Behavior of Pb between FetO-SiO2 (-CaO, Al2O3) Slag and Molten Copper

    Science.gov (United States)

    Heo, Jung Ho; Park, Soo-Sang; Park, Joo Hyun

    2012-10-01

    The distribution behavior of Pb between molten copper and FetO-SiO2 (-CaO, Al2O3) slags was investigated at 1473 K (1200 °C) and p_{{{{O}}2 }} = 10^{ - 10} {{atm}} in view of the reaction mechanism of Pb dissolution into the slag. Furthermore, the lead capacity of the slag was estimated from the experimental results. The distribution ratio of Pb ( L Pb) decreases with increasing CaO content ( 6 mass pct) irrespective of Fe/SiO2 ratio (1.4 to 1.7). However, the addition of alumina into a slag with Fe/SiO2 = 1.5 linearly decreases the L Pb, whereas a minimum value is observed at about 4 mass pct Al2O3 at Fe/SiO2 = 1.3. The log L Pb continuously decreases with increasing Fe/SiO2 ratio, and the addition of Al2O3 (5 to 15 mass pct) into the silica-saturated iron silicate slag (Fe/SiO2 < 1.0) yields the highest Pb distribution ratio. This is mainly due to a decrease in the FeO activity even at silica saturation. The log L Pb linearly decreases by increasing the log (Fe3+/Fe2+) value. The Pb distribution ratio increases and the excess free energy of PbO decreases with increasing Cu2O content in the slag. However, from the viewpoint of copper loss into the slag, the silica-saturated system containing small amounts of alumina is strongly recommended to stabilize PbO in the slag phase at a low Cu2O content. The lead capacity was defined in the current study and shows a linear correlation with the activity of FeO in a logarithmic scale, indicating that the concept of lead capacity is a good measure of absorption ability of Pb in iron silicate slags, and the activity of FeO can be a good basicity index in iron silicate slag.

  10. Intermetallic compound formation in Sn-Co-Cu, Sn-Ag-Cu and eutectic Sn-Cu solder joints on electroless Ni(P) immersion Au surface finish after reflow soldering

    Energy Technology Data Exchange (ETDEWEB)

    Sun Peng [Key State Lab for New Displays and System Integration (Chinese Ministry of Education), SMIT Center, Shanghai University, 200072 Shanghai (China) and Department of Microtechnology and Nanoscience, SMIT Center, Chalmers University of Technology, 412-96 Goeteborg (Sweden)]. E-mail: peng.sun@mc2.chalmers.se; Andersson, Cristina [Department of Microtechnology and Nanoscience, SMIT Center, Chalmers University of Technology, 412-96 Goeteborg (Sweden); Wei Xicheng [Key State Lab for New Displays and System Integration (Chinese Ministry of Education), SMIT Center, Shanghai University, 200072 Shanghai (China); Cheng Zhaonian [Department of Microtechnology and Nanoscience, SMIT Center, Chalmers University of Technology, 412-96 Goeteborg (Sweden); Shangguan Dongkai [Flextronics International, San Jose, CA (United States); Liu Johan [Key State Lab for New Displays and System Integration (Chinese Ministry of Education), SMIT Center, Shanghai University, 200072 Shanghai (China); Department of Microtechnology and Nanoscience, SMIT Center, Chalmers University of Technology, 412-96 Goeteborg (Sweden)

    2006-11-25

    The interfacial reactions between Sn-0.4Co-0.7Cu eutectic alloy and immersion Au/electroless Ni(P)/Cu substrate were investigated after reflow soldering at 260 deg. C for 2 min. Common Sn-4.0Ag-0.5Cu and eutectic Sn-0.7Cu solders were used as reference. Two types of intermetallic compounds (IMC) were found in the solder matrix of the Sn-0.4Co-0.7Cu alloy, namely coarser CoSn{sub 2} and finer Cu{sub 6}Sn{sub 5} particles, while only one ternary (Cu, Ni){sub 6}Sn{sub 5} interfacial compound was detected between the solder alloy and the electroless nickel and immersion gold (ENIG) coated substrate. The same trend was also observed for the Sn-Ag-Cu and Sn-Cu solder joints. Compared with the CoSn{sub 2} particles found in the Sn-Co-Cu solder and the Ag{sub 3}Sn particles found in the Sn-Ag-Cu solder, the Cu{sub 6}Sn{sub 5} particles found in both solder systems exhibited finer structure and more uniform distribution. It was noted that the thickness of the interfacial IMCs for the Sn-Co-Cu, Sn-Ag-Cu and Sn-Cu alloys was 3.5 {mu}m, 4.3 {mu}m and 4.1 {mu}m, respectively, as a result of longer reflow time above the alloy's melting temperature since the Sn-Ag-Cu solder alloy has the lowest melting point.

  11. Ternary Phases (Heusler) in the System Ti-Co-Sn

    Science.gov (United States)

    Kosinskiy, Andrey; Karlsen, Ole Bjørn; Sørby, Magnus H.; Prytz, Øystein

    2016-09-01

    Some of the Heusler-phases (XY 2 Z and XYZ) are known to have large homogeneity ranges which can be useful for tuning material properties. In this work, we have revised the isothermal section of the Ti-Co-Sn system at 973 K (700 °C). A total of 29 ternary compositions, mostly in the regions TiCo2-x Sn for 0 ≤ x ≤ 1 and Ti1+y Co2Sn1-y for 0 ≤ y ≤ 1, were prepared by arc-melting, then ball-milled and annealed. The resulting annealed powder samples were studied by applying the Rietveld method to X-ray and neutron powder diffraction data. Half-Heusler TiCoSn was not observed. The Heusler phase observed in TiCo2-x Sn has compositions ranging from TiCo1.52Sn to TiCo2Sn and has the half-Heusler structure where the excess of Co is located on the semi-filled tetrahedral site 4d (¾, ¾, ¾) in the space group F-43m. At 1273 K (1000 °C), this solid solubility is expanded from TiCo2Sn to TiCo with full solid solubility where Ti is gradually replacing Sn (Ti1+y Co2Sn1-y for 0 ≤ y ≤ 1), while at 973 K (700 °C) there is a small solubility gap for 0.0 ≤ y ≤ 0.2.

  12. 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.

  13. 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.

  14. 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.

  15. Carbon supported Pd-Sn and Pd-Ru-Sn nanocatalysts for ethanol electro-oxidation in alkaline medium

    CSIR Research Space (South Africa)

    Modibedi, RM

    2011-04-01

    Full Text Available the coverage of the adsorbed ethoxy (CH3COads) species on the nanocatalyst surface, thus yielding an increase in current density. Pd-Sn/C displayed better electrocatalytic activity and stability towards poisoning than Pd-Ru-Sn/C and Pt-Ru/C (E-TEK Inc...

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

    Science.gov (United States)

    Moto, Kenta; Matsumura, Ryo; Sadoh, Taizoh; Ikenoue, Hiroshi; Miyao, Masanobu

    2016-06-01

    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 Ge1-xSnx (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.

  17. Insight into the Effect of Sn on CO and Formic Acid Oxidation at PtSn Catalysts

    DEFF Research Database (Denmark)

    Stevanović, S.; Tripković, D.; Tripkovic, Vladimir

    2014-01-01

    The role of Sn on the catalytic activity for CO and formic acid oxidation is studied by comparing the activities of differently treated PtSn/C and Pt/C catalysts. The catalysts are prepared by a microwave-assisted polyol synthesis method. As revealed by scanning tunneling and transmission electron...... is present only in the subsurface layers. The subsurface Sn has a mild effect on the CO activity, and hence the onset potential is only marginally shifted to cathodic potentials by ∼50 mV compared to that on Pt/C. The formic acid oxidation is enhanced at any of the PtSn/C surfaces with Sn in the surface...... alloying degree and is mainly composed of Pt and Pt3Sn phases. The remaining Sn is present in the form of very small tin oxide particles. Different surfaces are obtained by double-layer, oxide, and CO annealing of the Pt/C and PtSn/C catalysts and by modifying the CO-annealed surfaces with irreversibly...

  18. Unexpected, spontaneous and selective formation of colloidal Pt 3Sn nanoparticles using organometallic Pt and Sn complexes

    KAUST Repository

    Boualleg, Malika

    2010-01-01

    The facile and selective synthesis of small crystalline Pt3Sn alloy nanoparticles was performed at room temperature under H2, using a colloidal approach without the use of extra-stabilizing ligands. The Pt 3Sn alloy was found to be obtained spontaneously as the unique phase regardless of the number of tin equivalents introduced. © 2010 The Royal Society of Chemistry.

  19. X-ray powder diffraction and EXAFS studies on SnAPO-5 and Cu : SnAPO-5

    DEFF Research Database (Denmark)

    Flavell, W. R.; Nicholson, D. G.; Nilsen, M. H.;

    2001-01-01

    SnAPO-5 was synthesised and calcined at 800 degreesC. Copper was introduced into the calcined material by the incipient wetness method. The as-synthesised, calcined and copper-incorporated SnAPO-5 have been studied using X-ray powder diffraction and EXAFS. Rietveld refinements show that the overa...

  20. Synthesis and characterization of highly conductive Sn-Ag bimetallic nanoparticles for printed electronics

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Yun Hwan; Jung, Inyu; Kim, Na Rae; Lee, Hyuck Mo, E-mail: hmlee@kaist.ac.kr [KAIST, Department of Materials Science and Engineering (Korea, Republic of)

    2012-03-15

    To synthesize low-cost, highly conductive metal nanoparticles for inkjet printing materials, we synthesized Sn-Ag bimetallic nanoparticles using a polyol process with poly(vinyl pyrrolidone). Because a surface oxidation layer forms on Sn nanoparticles, various compositions of Sn-xAg [x = 0, 20, 40, 60, 80, 100 (wt%)] nanoparticles were synthesized and characterized for the purpose of removing the {beta}-Sn phase. The results of XPS, TEM, and XRD analyses confirm that the formation of a bimetallic phase, such as Ag{sub 4}Sn or Ag{sub 3}Sn, hinders the {beta}-Sn phase and, consequently, leads to the removal of the surface oxidation layer. To measure the sheet resistance of various compositions of Sn-Ag nanoparticles, we made the ink that contains Sn-Ag by dispersing 10 wt% of Sn-Ag nanoparticles in methanol. The sheet resistance is decreased by the conductive Sn-Ag phases, such as the fcc, Ag{sub 4}Sn, and Ag{sub 3}Sn phases, but sharply increased by the low-conductive Sn nanoparticles and the surface oxidation layer on the Sn nanoparticles. The sheet resistance results confirm that 80Ag20Sn and 60Ag40Sn bimetallic nanoparticles are suitable candidates for inkjet printing materials.

  1. Effect of plasma etching on photoluminescence of SnO(x)/Sn nanoparticles deposited on DOPC lipid membrane.

    Science.gov (United States)

    An, Hyeun Hwan; Lee, Seung Jae; Baek, Seung Ha; Han, Won Bae; Kim, Young Ho; Yoon, Chong Seung; Suh, Sang Hee

    2012-02-15

    The photoluminescence characteristic of the SnO(x)/Sn nanoparticles deposited on a solid supported liquid-crystalline phospholipid (1,2-dioleoyl-sn-glycero-3-phosphocholine) membrane was probed after plasma etching the nanoparticle monolayer. It was shown that the plasma etching of the nanoparticle surface greatly altered the particle morphology and enhanced the PL effect, especially when the particle size was below 10 nm in spite of strong presence of surrounding carbon. The enhancement mainly stemmed from the growth of a new PL peak due to the additional defect states produced on the nanoparticle surface by the plasma etching. It was also shown that hydrating the SnO(x)/Sn nanoparticles similarly improved the PL response of the nanoparticles as the hydration produced an additional oxygen-rich oxide layer on the particle surface. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. Research on structure of Cu2ZnSn(S, Se)4 thin films with high Sn-related phases

    Science.gov (United States)

    Li, Peng-yu; Xue, Yu-ming; Liu, Hao; Xia, Dan; Song, Dian-you; Feng, Shao-jun; Sun, Hai-tao; Yu, Bing-bing; Qiao, Zai-xiang

    2016-11-01

    Cu2ZnSn(S, Se)4 (CZTSSe) thin films were deposited on flexible substrates by three evaporation processes at high temperature. The chemical compositions, microstructures and crystal phases of the CZTSSe thin films were respectively characterized by inductively coupled plasma optical emission spectrometer (ICP-OES), scanning electron microscopy (SEM), X-ray diffraction (XRD) and Raman scattering spectrum. The results show that the single-step evaporation method at high temperature yields CZTSSe thin films with nearly pure phase and high Sn-related phases. The elemental ratios of Cu/(Zn+Sn)=1.00 and Zn/Sn=1.03 are close to the characteristics of stoichiometric CZTSSe. There is the smooth and uniform crystalline at the surface and large grain size at the cross section for the films, and no other phases exist in the film by XRD and Raman shift measurement. The films are no more with the Sn-related phase deficiency.

  3. Sn powder as reducing agents and SnO2 precursors for the synthesis of SnO2-reduced graphene oxide hybrid nanoparticles.

    Science.gov (United States)

    Chen, Mingxi; Zhang, Congcong; Li, Lingzhi; Liu, Yu; Li, Xichuan; Xu, Xiaoyang; Xia, Fengling; Wang, Wei; Gao, Jianping

    2013-12-26

    A facile approach to prepare SnO2/rGO (reduced graphene oxide) hybrid nanoparticles by a direct redox reaction between graphene oxide (GO) and tin powder was developed. Since no acid was used, it is an environmentally friendly green method. The SnO2/rGO hybrid nanoparticles were characterized by ultraviolet-visible spectroscopy, Raman spectroscopy, thermogravimetric analysis, X-ray diffraction analysis, and X-ray photoelectron spectroscopy. The microstructure of the SnO2/rGO was observed with scanning electron microscopy and transmission electron microscopy. The tin powder efficiently reduced GO to rGO, and the Sn was transformed to SnO2 nanoparticles (∼45 nm) that were evenly distributed on the rGO sheets. The SnO2/rGO hybrid nanoparticles were then coated on an interdigital electrode to fabricate a humidity sensor, which have an especially good linear impedance response from 11% to 85% relative humidity.

  4. 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.

  5. Preparation of porous SnO{sub 2} helical nanotubes and SnO{sub 2} sheets

    Energy Technology Data Exchange (ETDEWEB)

    Fei, Ling; Xu, Yun [Department of Chemical Engineering, New Mexico State University, Las Cruces, NM 88003 (United States); Chen, Zheng [Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095 (United States); Yuan, Bin; Wu, Xiaofei; Hill, Joshua; Lin, Qianglu; Deng, Shuguang; Andersen, Paul [Department of Chemical Engineering, New Mexico State University, Las Cruces, NM 88003 (United States); Lu, Yunfeng [Department of Chemical and Biomolecular Engineering, University of California, Los Angeles, CA 90095 (United States); Luo, Hongmei, E-mail: hluo@nmsu.edu [Department of Chemical Engineering, New Mexico State University, Las Cruces, NM 88003 (United States)

    2013-06-15

    We report a surfactant-free chemical solution route for synthesizing one-dimensional porous SnO{sub 2} helical nanotubes templated by helical carbon nanotubes and two-dimensional SnO{sub 2} sheets templated by graphite sheets. Transmission electron microscopy, X-ray diffraction, cyclic voltammetry, and galvanostatic discharge–charge analysis are used to characterize the SnO{sub 2} samples. The unique nanostructure and morphology make them promising anode materials for lithium-ion batteries. Both the SnO{sub 2} with the tubular structure and the sheet structure shows small initial irreversible capacity loss of 3.2% and 2.2%, respectively. The SnO{sub 2} helical nanotubes show a specific discharge capacity of above 800 mAh g{sup −1} after 10 charge and discharge cycles, exceeding the theoretical capacity of 781 mAh g{sup −1} for SnO{sub 2}. The nanotubes remain a specific discharge capacity of 439 mAh g{sup −1} after 30 cycles, which is better than that of SnO{sub 2} sheets (323 mAh g{sup −1}). - Highlights: • Synthesized porous SnO{sub 2} helical nanotubes with diameters of 100–120 nm. • Synthesized porous SnO{sub 2} sheets template by graphite sheets. • The tubular and sheet SnO{sub 2} have small initial irreversible capacity loss of 3.2 and 2.2%. • The tubular structure shows better discharge capacity than the sheet structure.

  6. Influence of hydrogen surface passivation on Sn segregation, aggregation, and distribution in GeSn/Ge(001) materials

    Science.gov (United States)

    Johll, Harman; Samuel, Milla; Koo, Ruey Yi; Kang, Hway Chuan; Yeo, Yee-Chia; Tok, Eng Soon

    2015-05-01

    Plane-wave density functional theory is used to investigate the impact of hydrogen passivation of the p(2×2) reconstructed Ge1-xSnx surface on Sn segregation, aggregation, and distribution. On a clean surface, Sn preferentially segregates to the surface layer, with surface coverages of 25%, 50%, and 100% for total Sn concentrations of 2.5%, 5.0%, and 10.0%, respectively. In contrast, a hydrogen passivated surface increases interlayer migration of Sn to subsurface layers, in particular, to the third layer from the surface, and results in surface coverages of 0%, 0%, and 50% corresponding to Sn concentrations of 2.5%, 5.0%, and 10.0%, respectively. Hydrogen transfer from a Ge-capped surface to the one enriched with increasing Sn surface coverage is also an unfavorable process. The presence of hydrogen therefore reduces the surface energy by passivating the reactive dangling bonds and enhancing Sn interlayer migration to the subsurface layers. For both clean and hydrogenated surfaces, aggregation of Sn at the surface layer is also not favored. We explain these results by considering bond enthalpies and the enthalpies of hydrogenation for various surface reactions. Our results thus point to reduced Sn segregation to the surface in a Ge1-xSnx epitaxial thin film if CVD growth, using hydride precursors in the hydrogen limited growth regime, is used. This would lead to a more abrupt interface and is consistent with recent experimental observation. Hydrogenation is therefore a promising method for controlling and manipulating elemental population of Sn in a Ge1-xSnx epitaxial thin film.

  7. PDMS-SiO{sub 2}-TiO{sub 2}-CaO hybrid materials – Cytocompatibility and nanoscale surface features

    Energy Technology Data Exchange (ETDEWEB)

    Almeida, J. Carlos [CICECO - Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro (Portugal); Wacha, András [Research Centre for Natural Sciences, Hungarian Academy of Sciences, Magyar Tudósok körútja 2, Budapest 1117 (Hungary); Gomes, Pedro S.; Fernandes, M. Helena R. [Laboratory for Bone Metabolism and Regeneration, Faculdade de Medicina Dentária, Universidade do Porto (Portugal); Fernandes, M. Helena Vaz [CICECO - Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro (Portugal); Salvado, Isabel M. Miranda, E-mail: isabelmsalvado@ua.pt [CICECO - Aveiro Institute of Materials, Department of Materials and Ceramic Engineering, University of Aveiro, 3810-193 Aveiro (Portugal)

    2016-07-01

    Two PDMS-SiO{sub 2}-TiO{sub 2}-CaO porous hybrid materials were prepared using the same base composition, precursors, and solvents, but following two different sol-gel procedures, based on the authors' previous works where for the first time, in this hybrid system, calcium acetate was used as calcium source. The two different procedures resulted in monolithic materials with different structures, microstructures, and surface wettability. Even though both are highly hydrophobic (contact angles of 127.2° and 150.6°), and present different filling regimes due to different surface topographies, they have demonstrated to be cytocompatible when tested with human osteoblastic cells, against the accepted idea that high-hydrophobic surfaces are not suitable to cell adhesion and proliferation. At the nanoscale, the existence of hydrophilic silica domains containing calcium, where water molecules are physisorbed, is assumed to support this capability, as discussed. - Highlights: • Two hybrid materials were prepared following two different sol-gel procedures. • Both are highly hydrophobic but demonstrated to be cytocompatible. • Different filling regimes were observed.

  8. The Produce of Methyl Ester from Crude Palm Oil (CPO) Using Heterogene Catalyst Ash of Chicken Bone (CaO) using Ethanol as Solvent

    Science.gov (United States)

    Sinaga, M. S.; Fauzi, R.; Turnip, J. R.

    2017-03-01

    Methyl Ester (methyl ester) is generally made by trans esterification using heterogeneous base catalyst. To simplify the separation, the heterogeneous catalyst is used, such as CaO, which in this case was isolated from chicken bones made by softening chicken bones and do calcination process. Some other important variables other than the selection of the catalyst is the catalyst dosage, molar ratio of ethanol to the CPO and the reaction temperature. The best result from this observe is at the molar ratio of ethanol to the CPO is 17: 1, the reaction temperature is 70 ° C and 7% catalyst (w.t) with reaction time for 7 hours at 500 rpm as a constant variable, got 90,052 % purity, so that this result does not get the standard requirements of biodiesel, because of the purity of the biodiesel standard temporary must be achieve > 96.5 %. This study aims to produce methyl ester yield with the influence of the reaction temperature, percent of catalyst and molar ratio of ethanol and CPO. The most influential variable is the temperature of the reaction that gives a significant yield difference of methyl ester produced. It’s been proven by the increasing temperature used will also significantly increase the yield of methyl ester.

  9. A network pharmacology approach to discover active compounds and action mechanisms of San-Cao Granule for treatment of liver fibrosis

    Science.gov (United States)

    Wei, Shizhang; Niu, Ming; Wang, Jian; Wang, Jiabo; Su, Haibin; Luo, Shengqiang; Zhang, Xiaomei; Guo, Yanlei; Liu, Liping; Liu, Fengqun; Zhao, Qingguo; Chen, Hongge; Xiao, Xiaohe; Zhao, Pan; Zhao, Yanling

    2016-01-01

    Ethnopharmacological relevance San-Cao Granule (SCG) has been used in patients with liver fibrosis for many years and has shown good effect. However, its mechanism of therapeutic action is not clear because of its complex chemical system. The purpose of our study is to establish a comprehensive and systemic method that can predict the mechanism of action of SCG in antihepatic fibrosis. Materials and methods In this study, a “compound–target–disease” network was constructed by combining the SCG-specific and liver fibrosis–specific target proteins with protein–protein interactions, and network pharmacology was used to screen out the underlying targets and mechanisms of SCG for treatment of liver fibrosis. Then, some key molecules of the enriched pathway were chosen to verify the effects of SCG on liver fibrosis induced by thioacetamide (TAA). Results This systematic approach had successfully revealed that 16 targets related to 11 SCG compounds were closely associated with liver fibrosis therapy. The pathway-enrichment analysis of them showed that the TGF-β1/Smad signaling pathway is relatively important. Animal experiments also proved that SCG could significantly ameliorate liver fibrosis by inhibiting the TGF-β1/Smad pathway. Conclusion SCG could alleviate liver fibrosis through the molecular mechanisms predicted by network pharmacology. Furthermore, network pharmacology could provide deep insight into the pharmacological mechanisms of Chinese herbal formulas. PMID:26929602

  10. The adsorption of mercury-species on relaxed and rumpled CaO (0 0 1) surfaces investigated by density functional theory.

    Science.gov (United States)

    Blowers, Paul; Kim, Bo Gyeong

    2011-03-01

    This research examines the importance of several computational choices in modeling mercury species adsorption on calcium oxide surfaces and is the second in a series of papers. The importance of surface relaxation was tested and it was found that adsorption energies changed for HgCl(2), moving adsorption from being at the borderline of physisorption and chemisorption to being strongly chemisorbed. Results for Hg and HgCl were unaffected. A second computational choice, that of the cluster or periodic model size was tested in both the plane of the model (4 × 4 or 5 × 5 model sizes) and for the depth (two or three layers). It was found that the minimum cluster size for handling mercury adsorption was 5 × 5 and that only two layers of depth were needed. The energetic results show that rumpled CaO surfaces will only weakly physisorb elemental mercury, but could be used to capture HgCl(2) from coal combustion flue gases, which is in agreement with limited experimental data.

  11. 租界文化影响下的曹禺及其剧作%Cao Yu and his Plays Influenced by the Culture of Leased Territory

    Institute of Scientific and Technical Information of China (English)

    王侠

    2015-01-01

    Living in a time of leased territory and settled in one literarily in Tianjin, playwright Cao Yu could not be free from influence of the culture of the leased territory, neither his character or his plays. Some of his best plays -The Tempest, The Sunrise, and The Beijing Natives -are set in the leased terri-tory and provide pictures of the leased territory not unintentionally.The author of this paper attempts to read his plays and the playwright himself from the perspective of the culture of leased territory.%身处租界时代又长在天津租界区的曹禺,不可能不受到租界空气的影响,从而形成他的独特个性气质及创作心理。在这一创作心理的潜性诱导下,他创作了一系列优秀的剧作,以《雷雨》、《日出》、《北京人》为代表,并在其中绘制了一幅幅鲜明的租界图景。笔者试图从租界文化的角度来解读曹禺及其剧作,以期为理解曹禺寻求另一种解读路径。

  12. STUDI PENGARUH VARIASI SUHU KALSINASI TERHADAP KEKERASAN BENTUK MORFOLOGI, DAN ANALISIS POROSITAS NANOKOMPOSIT CAO/SiO2 UNTUK APLIKASI BAHAN BIOMATERIAL

    Directory of Open Access Journals (Sweden)

    Akhmad Kurniawan

    2015-01-01

    Full Text Available Bahan biomaterial saat ini dibutuhkan bagi masyarakat, namun saat ini penyediaannya sangat terbatas dan harganya yang mahal. Hal ini mendorong terciptanya inovasi bahan biomaterial yang efisien dan berasal dari alam Untuk itu dilakukan penelitian yang bertujuan untuk membuat bahan biomaterial dari limbah cangkang kerang dan lumpur Sidoarjo. Metode yang digunakan adalah melakukan sintesis nanokomposit CaO dan SiO2, dan mencampur dengan rasio 2:1, kemudian dikalsinasi pada suhu 700oC, 800oC, 900oC setelah itu mengkaraterisasinya menggunakan uji mekanik harness vickers dan SEM, BET. Hasil karakterisasi menunjukkan pada suhu 900oC nilai kekerasan tertinggi dicapai pada suhu pemanasan 900oC yaitu sebesar 109,1 ± 5,22 VHN. Kemudian bentuk mikrostruktur dimana pada suhu ini terbentuk butiran yang menggumpal dan membesar dengan ukuran pori mengecil. Sedangkan untuk analisa porositasnya pada suhu ini nilai surface area sebesar 23.843 m2/g dan volume pori sebesar 0.007 cc/g. Dari analisis diatas dapat disimpulkan bahwa meningkatnya suhu pemanasan menyebabkan sifat kekerasannya semakin meningkat dan mempengaruhi bentuk mikrostruktur serta surface area pada permukaan sampel.Kata kunci : Biomaterial, nanokomposit CaO/SiO2, Hardness Vickers, SEM, BET

  13. 论曹禺早期剧作中的空白人物%Discussion on Blank Characters in CAO Yu's Early Drama

    Institute of Scientific and Technical Information of China (English)

    李朔梅

    2012-01-01

    CAO Yu creates many vivid drama characters. They include not only visible figures with distinct personality and color- ful feature, but also blank characters that have never showed up on the stage. Though these blank characters do not appear on the stage, they closely interact with visible figures, participating in the story, deepening the figures, and demonstrating the u- niquely aesthetic implication of the writers. Starting with Thunderstorm, Sunrise, Champaign and Pekingese, the blank characters are explored.%曹禺塑造了许多栩栩如生的戏剧人物,既有个性鲜明、有声有色的有形人物,也不乏不曾现身舞台的空白人物。这些空白人物在舞台上虽然是无形的,但他们与有形人物遥相呼应,一起参与剧情,深化人物,展示着作家独特的审美意趣。从曾禺早期的几部戏剧作品《雷雨》、《日出》、《原野》和《北京人》入手分析其中的空白人物。

  14. Ab initio study of the positronation of the CaO and SrO molecules including calculation of annihilation rates.

    Science.gov (United States)

    Buenker, Robert J; Liebermann, Heinz-Peter

    2012-07-15

    Ab initio multireference single- and double-excitation configuration interaction calculations have been performed to compute potential curves for ground and excited states of the CaO and SrO molecules and their positronic complexes, e(+)CaO, and e(+)SrO. The adiabatic dissociation limit for the (2)Σ(+) lowest states of the latter systems consists of the positive metal ion ground state (M(+)) and the OPs complex (e(+)O(-)), although the lowest energy limit is thought to be e(+)M + O. Good agreement is found between the calculated and experimental spectroscopic constants for the neutral diatomics wherever available. The positron affinity of the closed-shell X (1)Σ(+) ground states of both systems is found to lie in the 0.16-0.19 eV range, less than half the corresponding values for the lighter members of the alkaline earth monoxide series, BeO and MgO. Annihilation rates (ARs) have been calculated for all four positronated systems for the first time. The variation with bond distance is generally similar to what has been found earlier for the alkali monoxide series of positronic complexes, falling off gradually from the OPs AR value at their respective dissociation limits. The e(+)SrO system shows some exceptional behavior, however, with its AR value reaching a minimum at a relatively large bond distance and then rising to more than twice the OPs value close to its equilibrium distance. Copyright © 2012 Wiley Periodicals, Inc.

  15. Quantum mechanics/molecular mechanics simulation of the ligand vibrations of the water-oxidizing Mn4CaO5 cluster in photosystem II.

    Science.gov (United States)

    Nakamura, Shin; Noguchi, Takumi

    2016-10-11

    During photosynthesis, the light-driven oxidation of water performed by photosystem II (PSII) provides electrons necessary to fix CO2, in turn supporting life on Earth by liberating molecular oxygen. Recent high-resolution X-ray images of PSII show that the water-oxidizing center (WOC) is composed of an Mn4CaO5 cluster with six carboxylate, one imidazole, and four water ligands. FTIR difference spectroscopy has shown significant structural changes of the WOC during the S-state cycle of water oxidation, especially within carboxylate groups. However, the roles that these carboxylate groups play in water oxidation as well as how they should be properly assigned in spectra are unresolved. In this study, we performed a normal mode analysis of the WOC using the quantum mechanics/molecular mechanics (QM/MM) method to simulate FTIR difference spectra on the S1 to S2 transition in the carboxylate stretching region. By evaluating WOC models with different oxidation and protonation states, we determined that models of high-oxidation states, Mn(III)2Mn(IV)2, satisfactorily reproduced experimental spectra from intact and Ca-depleted PSII compared with low-oxidation models. It is further suggested that the carboxylate groups bridging Ca and Mn ions within this center tune the reactivity of water ligands bound to Ca by shifting charge via their π conjugation.

  16. Host Galaxy Spectra and Consequences for SN Typing from the SDSS SN Survey

    Energy Technology Data Exchange (ETDEWEB)

    Olmstead, Matthew D.; Brown, Peter J.; Sako, Masao; Bassett, Bruce; Bizyaev, Dmitry; Brinkmann, J.; Brownstein, Joel R.; Brewington, Howard; Campbell, Heather; D’Andrea, Chris B.; Dawson, Kyle S.; Ebelke, Garrett L.; Frieman, Joshua A.; Galbany, Lluís; Garnavich, Peter; Gupta, Ravi R.; Hlozek, Renee; Jha, Saurabh W.; Kunz, Martin; Lampeitl, Hubert; Malanushenko, Elena; Malanushenko, Viktor; Marriner, John; Miquel, Ramon; Montero-Dorta, Antonio D.; Nichol, Robert C.; Oravetz, Daniel J.; Pan, Kaike; Schneider, Donald P.; Simmons, Audrey E.; Smith, Mathew; Snedden, Stephanie A.

    2014-03-06

    We present the spectroscopy from 5254 galaxies that hosted supernovae (SNe) or other transient events in the Sloan Digital Sky Survey II (SDSS-II). Obtained during SDSS-I, SDSS-II, and the Baryon Oscillation Spectroscopic Survey (BOSS), this sample represents the largest systematic, unbiased, magnitude limited spectroscopic survey of supernova (SN) host galaxies. Using the host galaxy redshifts, we test the impact of photometric SN classification based on SDSS imaging data with and without using spectroscopic redshifts of the host galaxies. Following our suggested scheme, there are a total of 1166 photometrically classified SNe Ia when using a flat redshift prior and 1126 SNe Ia when the host spectroscopic redshift is assumed. For 1024 (87.8%) candidates classified as likely SNe Ia without redshift information, we find that the classification is unchanged when adding the host galaxy redshift. Using photometry from SDSS imaging data and the host galaxy spectra, we also report host galaxy properties for use in future nalysis of SN astrophysics. Finally, we investigate the differences in the interpretation of the light curve properties with and without knowledge of the redshift. When using the SALT2 light curve fitter, we find a 21% increase in the number of fits that converge when using the spectroscopic redshift. Without host galaxy redshifts, we find that SALT2 light curve fits are systematically biased towards lower photometric redshift estimates and redder colors in the limit of low signal-to-noise data. The general improvements in performance of the light curve fitter and the increased diversity of the host galaxy sample highlights the importance of host galaxy spectroscopy for current photometric SN surveys such as the Dark Energy Survey and future surveys such as the Large Synoptic Survey Telescope.

  17. SnSAG5 is an alternative surface antigen of Sarcocystis neurona strains that is mutually exclusive to SnSAG1.

    Science.gov (United States)

    Crowdus, Carolyn A; Marsh, Antoinette E; Saville, Willliam J; Lindsay, David S; Dubey, J P; Granstrom, David E; Howe, Daniel K

    2008-11-25

    Sarcocystis neurona is an obligate intracellular parasite that causes equine protozoal myeloencephalitis (EPM). Previous work has identified a gene family of paralogous surface antigens in S. neurona called SnSAGs. These surface proteins are immunogenic in their host animals, and are therefore candidate molecules for development of diagnostics and vaccines. However, SnSAG diversity exists in strains of S. neurona, including the absence of the major surface antigen gene SnSAG1. Instead, sequence for an alternative SnSAG has been revealed in two of the SnSAG1-deficient strains. Herein, we present data characterizing this new surface protein, which we have designated SnSAG5. The results indicated that the protein encoded by the SnSAG5 sequence is indeed a surface-associated molecule that has characteristics consistent with the other SAGs identified in S. neurona and related parasites. Importantly, Western blot analyses of a collection of S. neurona strains demonstrated that 6 of 13 parasite isolates express SnSAG5 as a dominant surface protein instead of SnSAG1. Conversely, SnSAG5 was not detected in SnSAG1-positive strains. One strain, which was isolated from the brain of a sea otter, did not express either SnSAG1 or SnSAG5. Genetic analysis with SnSAG5-specific primers confirmed the presence of the SnSAG5 gene in Western blot-positive strains, while also suggesting the presence of a novel SnSAG sequence in the SnSAG1-deficient, SnSAG5-deficient otter isolate. The findings provide further indication of S. neurona strain diversity, which has implications for diagnostic testing and development of vaccines against EPM as well as the population biology of Sarcocystis cycling in the opossum definitive host.

  18. $Nb_{3}Sn macrostructure, microstructure, and property comparisons for bronze and internal Sn process strands

    CERN Document Server

    Lee, P J; Larbalestier, D C

    2000-01-01

    The variation in irreversibility field, B*(T), with temperature has been measured for Nb/sub 3/Sn superconducting strands manufactured for ITER using vibrating sample and SQUID magnetometers. The high performance strands were developed for both high transport critical current density, J/sub c/, and low hysteresis loss. Despite a wide variety of designs and components, the strands could be split into two distinctive groups, based on the extrapolated irreversibility fields, which lie about 10% lower than the upper critical field. "Bronze-process" strands exhibited consistently higher B*(T) (28 T to 31 T) compared with "internal Sn" process (24 T to 26 T) conductors. The intrinsic critical current density of the superconductor, J/sub c (sc)/, and the specific pinning force of the grain boundaries, Q/sub gb/, were evaluated using the measured J/sub c/, and image analysis of the macro- and micro-structures. A bronze-processed Nb(-Ta)/sub 3 /Sn was found to have a higher J/sub c(sc)/ but lower Q/sub gb/ than Nb/sub...

  19. SnS Thin Film Solar Cells: Perspectives and Limitations

    Directory of Open Access Journals (Sweden)

    Simone Di Mare

    2017-02-01

    Full Text Available Thin film solar cells have reached commercial maturity and extraordinarily high efficiency that make them competitive even with the cheaper Chinese crystalline silicon modules. However, some issues (connected with presence of toxic and/or rare elements are still limiting their market diffusion. For this reason new thin film materials, such as Cu2ZnSnS4 or SnS, have been introduced so that expensive In and Te, and toxic elements Se and Cd, are substituted, respectively, in CuInGaSe2 and CdTe. To overcome the abundance limitation of Te and In, in recent times new thin film materials, such as Cu2ZnSnS4 or SnS, have been investigated. In this paper we analyze the limitations of SnS deposition in terms of reproducibility and reliability. SnS deposited by thermal evaporation is analyzed by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and atomic force microscopy. The raw material is also analyzed and a different composition is observed according to the different number of evaporation (runs. The sulfur loss represents one of the major challenges of SnS solar cell technology.

  20. Parametrized dielectric functions of amorphous GeSn alloys

    Energy Technology Data Exchange (ETDEWEB)

    D' Costa, Vijay Richard, E-mail: elevrd@nus.edu.sg; Wang, Wei; Yeo, Yee-Chia, E-mail: eleyeoyc@nus.edu.sg [Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583 (Singapore); Schmidt, Daniel [Singapore Synchrotron Light Source, National University of Singapore, Singapore 117603 (Singapore)

    2015-09-28

    We obtained the complex dielectric function of amorphous Ge{sub 1−x}Sn{sub x} (0 ≤ x ≤ 0.07) alloys using spectroscopic ellipsometry from 0.4 to 4.5 eV. Amorphous GeSn films were formed by room-temperature implantation of phosphorus into crystalline GeSn alloys grown by molecular beam epitaxy. The optical response of amorphous GeSn alloys is similar to amorphous Ge and can be parametrized using a Kramers-Kronig consistent Cody-Lorentz dispersion model. The parametric model was extended to account for the dielectric functions of amorphous Ge{sub 0.75}Sn{sub 0.25} and Ge{sub 0.50}Sn{sub 0.50} alloys from literature. The compositional dependence of band gap energy E{sub g} and parameters associated with the Lorentzian oscillator have been determined. The behavior of these parameters with varying x can be understood in terms of the alloying effect of Sn on Ge.

  1. Facile route to SnS nanocrystals and their characterization

    Energy Technology Data Exchange (ETDEWEB)

    Koktysh, Dmitry S., E-mail: dmitry.koktysh@vanderbilt.edu [Department of Chemistry, Vanderbilt University, Station B 351822, Nashville, TN 37235 (United States); Vanderbilt Institute of Nanoscale Science and Engineering, Vanderbilt University, Station B 350106, Nashville, TN 37235 (United States); McBride, James R. [Department of Chemistry, Vanderbilt University, Station B 351822, Nashville, TN 37235 (United States); Vanderbilt Institute of Nanoscale Science and Engineering, Vanderbilt University, Station B 350106, Nashville, TN 37235 (United States); Geil, Robert D. [Vanderbilt Institute of Nanoscale Science and Engineering, Vanderbilt University, Station B 350106, Nashville, TN 37235 (United States); Department of Chemical and Biomolecular Engineering, Vanderbilt University, VU Station B 351604, Nashville, TN 37235 (United States); Schmidt, Benjamin W. [Department of Chemical and Biomolecular Engineering, Vanderbilt University, VU Station B 351604, Nashville, TN 37235 (United States); Rogers, Bridget R. [Vanderbilt Institute of Nanoscale Science and Engineering, Vanderbilt University, Station B 350106, Nashville, TN 37235 (United States); Department of Chemical and Biomolecular Engineering, Vanderbilt University, VU Station B 351604, Nashville, TN 37235 (United States); Rosenthal, Sandra J. [Department of Chemistry, Vanderbilt University, Station B 351822, Nashville, TN 37235 (United States); Vanderbilt Institute of Nanoscale Science and Engineering, Vanderbilt University, Station B 350106, Nashville, TN 37235 (United States); Department of Chemical and Biomolecular Engineering, Vanderbilt University, VU Station B 351604, Nashville, TN 37235 (United States); Department of Physics and Astronomy, Vanderbilt University, 1807 Station B, Nashville, TN 37235 (United States); Department of Pharmacology, Vanderbilt University, 1211 Medical Center Drive, Nashville, TN 37232 (United States)

    2010-06-15

    SnS nanocrystals (NCs) were synthesized in oleylamine using the hot-injection technique from tin(II) chloride and diethylammonium diethyldithiocarbamate in the presence of dodecanethiol. X-ray diffraction (XRD) and high resolution transmission electron microscopy (HRTEM) analysis revealed the formation of single crystalline SnS NCs with sizes finely controlled by synthetic conditions. Rutherford backscattering spectrometry (RBS) and X-ray photoelectron spectroscopy (XPS) investigation confirmed the formation of SnS in a nearly stoichiometric ratio with additional evidence of the SnS NCs surface oxidation when NCs were stored in the air. Optical absorption measurements showed a shift in band gap energy of SnS NCs towards larger values with decreasing particle sizes. SnS NCs were successfully transferred into water using cetyltrimethylammonium bromide and Vitamin E as surfactants. These VIS/NIR absorbing SnS NCs should have widespread applications in the construction of efficient photoelectronic devices and probes in bioimaging due to their unique optoelectronic properties and low toxicity.

  2. Mechanothermal synthesis of SrSnO{sub 3}

    Energy Technology Data Exchange (ETDEWEB)

    Berbenni, Vittorio; Milanese, Chiara; Bruni, Giovanna; Girella, Alessandro; Marini, Amedeo [Pavia Univ. (Italy). Sezione di Chimica Fisica

    2014-03-15

    The synthesis of strontium metastannate (SrSnO{sub 3}) has been performed by coupling mechanical activation with thermal activation of SnC{sub 2}O{sub 4}-SrCO{sub 3} mixtures. The solid-state reaction has been studied by TG-DSC analysis and powder X-ray diffraction. By annealing experiments performed on physical mixtures (no mechanical activation) it has been assessed that the formation of SrSnO{sub 3} occurs through the intermediate Sr{sub 2}SnO{sub 4} and is complete only after annealing at 1400 C. By performing the annealing experiments on activated mixtures it has been established that the formation of SrSnO{sub 3} takes place directly at temperatures between 800 and 1000 C. The SrSnO{sub 3} samples obtained at 800 and 900 C show, by TG analysis, mass loss processes that suggest that SrSnO{sub 3} obtained at these temperatures absorbs H{sub 2}O and CO{sub 2} from the air so that its use as gas sensor can be envisaged. This is no longer true for the sample obtained at 1000 C or above.

  3. 136Sn and three-body forces

    Indian Academy of Sciences (India)

    M Saha Sarkar; S Sarkar

    2015-09-01

    New experimental data on 2+ energies of 136,138Sn confirm the trend of lower 2+ excitation energies of even–even tin isotopes with > 82 compared to those with N < 82. However, none of the theoretical predictions using both realistic and empirical interactions can reproduce experimental data on excitation energies as well as the transition probabilities ((2; 6+ → 4+)) of these nuclei, simultaneously, apart from the ones whose matrix elements have been changed empirically to produce mixed seniority states by weakening the pairing. We have shown that the experimental result also shows good agreement with the theory in which three-body forces have been included in a realistic interaction. The new theoretical results on transition probabilities are discussed to identify the experimental quantities which will clearly distinguish between different views.

  4. Toward models for the full oxygen-evolving complex of photosystem II by ligand coordination to lower the symmetry of the Mn3CaO4 cubane: demonstration that electronic effects facilitate binding of a fifth metal.

    Science.gov (United States)

    Kanady, Jacob S; Lin, Po-Heng; Carsch, Kurtis M; Nielsen, Robert J; Takase, Michael K; Goddard, William A; Agapie, Theodor

    2014-10-15

    Synthetic model compounds have been targeted to benchmark and better understand the electronic structure, geometry, spectroscopy, and reactivity of the oxygen-evolving complex (OEC) of photosystem II, a low-symmetry Mn4CaOn cluster. Herein, low-symmetry Mn(IV)3GdO4 and Mn(IV)3CaO4 cubanes are synthesized in a rational, stepwise fashion through desymmetrization by ligand substitution, causing significant cubane distortions. As a result of increased electron richness and desymmetrization, a specific μ3-oxo moiety of the Mn3CaO4 unit becomes more basic allowing for selective protonation. Coordination of a fifth metal ion, Ag(+), to the same site gives a Mn3CaAgO4 cluster that models the topology of the OEC by displaying both a cubane motif and a "dangler" transition metal. The present synthetic strategy provides a rational roadmap for accessing more accurate models of the biological catalyst.

  5. Study on condition of CaO2-based Fenton reaction by methylene blue spectrophotometric method%亚甲基蓝光度法研究基于CaO2的Fenton反应条件

    Institute of Scientific and Technical Information of China (English)

    刘娇; 孟范平; 王震宇; 刘启元

    2011-01-01

    The potential of calcium peroxide (CaO2) as a source of hydrogen peroxide (H2O2) in Fenton oxidation has been gradually taken note. In order to understand the characteristics of CaO2-based Fenton reactions, experiments were conducted using methylene blue spectrophotometric method to investigate effect of catalyst type, initial pH, CaO2 dose, molar ratio of catalyst to CaO2 (?Fe/?cao2 )? And phosphate buffer concentration on production of hydroxyl radicals (HO ? ). The results showed that under the experimental conditions Fez+ had better catalytic ability than Fe3+ and Cu2+. The optimal Fenton reaction conditions were; Fe2+ as catalyst, initial buffer pH = 4, CaO2 dose 1 mmol ? L"1 , wF,/?cao2 = 1/5, phosphate buffer concentration 40 mmol ? L"1. It was also indicated that the release of H2O2 and Fenton reaction were regulated by the dissolution process of CaO2 that could be a potential substitute for H2O2 in in-situ Fenton oxidations, because of decrease of H2O2 loss as well as negative impact of Fenton processes on the environment.%CaO2作为原位Fenton氧化修复中H2O2持续供源的作用逐渐受到关注.利用亚甲基蓝分光光度法评价了基于CaO2的Fenton反应中催化剂种类、初始pH值、CaO2用最、催化剂和CaO2比例、磷酸缓冲溶液浓度对羟基自由基(HO·)产率的影响.结果表明,采用Fe2作为催化剂,在pH值为4、CaO2用量为1 mmo1·L-1,催化剂CaO2摩尔比(nFe/nCaO2.)为1/5、磷酸缓冲溶液浓度为40 mmol·L-1时HO·产率较高,Fe2+催化作用最显著.CaO2溶解过程对H2O2的释放和Fenton反应起到一定调节作用,以CaO2取代H2O2可减少氧化剂的流失及其对环境产生的不利影响.

  6. Simulación del proceso de captura de CO2 mediante los ciclos de carbonatación/calcinación de CaO integrado en plantas de producción de energía

    OpenAIRE

    Martínez Berges, Isabel; Murillo Villuendas, Ramón; Abanades García, Juan Carlos; Grasa Adiego, Gemma

    2014-01-01

    La tecnología de captura de CO2 basada en los ciclos de carbonatación/calcinación de CaO cuenta con un gran potencial de aplicación como tecnología emergente de captura de CO2 tanto en configuraciones de proceso en post-combustión aplicado a un gas de combustión, como en configuraciones en pre-combustión para generación de un gas rico en hidrógeno. Esta tecnología de captura de CO2 se basa en la reacción de un sorbente basado en CaO con el CO2 presente en una corriente gaseosa, y en la reacci...

  7. [Study on carving workers of Chong xiu zheng he jing shi zheng lei bei yong ben cao (Revised Prepared Materia Medica Classified under Syndromes in Zhenghe Period) published by Huiming Xuan (Huiming Sanctum)].

    Science.gov (United States)

    Liang, Fei; Li, Jian; Zhang, Wei; Zhang, Rui-Xian

    2012-11-01

    The ancient carving workers have made a great contribution to the xylographic printing art in ancient China, so the studies on them are significant for a survey of ancient Chinese printing history, and for the identification of ancient Chinese books edition. Zheng lei ben cao published by Huiming Xuan (Huiming Sanctum) in the Jin and Yuan dynasties, which is the earliest extant edition of Zhenghe version system of Zheng lei ben cao and has important literature value. Thirty carving workers were involved in its printing process. On the whole, these workers had a relatively high technique and completed a remarkably fine work. In addition to lettering, 28 persons of them also made a total of 536 pages with 900 exquisite engraving illustrations on Chinese materia medica included in this book. Because of the high levels on carving, this precious book has been the representative of Pingshui edition, which has a great reputation but has very few works now.

  8. Axions and SN 1987A: Axion trapping

    Science.gov (United States)

    Burrows, Adam; Ressell, M. Ted; Turner, Michael S.

    1990-01-01

    If an axion of mass between about 10(exp -3) and 10 eV exists, axion emission would have significantly affected the cooling of the nascent neutron star associated with SN 1987A. For an axion of mass greater than about 10(exp -2) eV axions would, like neutrinos, have a mean-free path that is smaller than the size of a neutron star, and thus would become trapped and radiated from an axion sphere. The trapping regime is treated by using numerical models of the initial cooling of a hot neutron star that incorporate a diffusion approximation for axion-energy transport. The axion opacity due to inverse nucleon-nucleon, axion bremsstrahlung is computed; and then the numerical models are used to calculate the integrated axion luminosity, the temperature of the axion sphere, and the effect of axion emission on the neutrino bursts detected by the Kamiokande II (KII) and Irvine-Michigan-Brookhaven (IMB) water-Cherenkov detectors. The larger the axion mass, the stronger the trapping and the smaller the axion luminosity. The estimate of the axion mass is confirmed above which trapping is so strong that axion emission does not significantly affect the neutrino burst. Based upon the neutrino-burst duration - the most sensitive barometer of axion cooling - it is concluded that for an axion mass greater than about 3 eV axion emission would not have had a significant effect on the neutrino bursts detected by KII and IMB. It is strongly suggested that an axion with mass in the interval 10(exp -3) to 3 eV is excluded by the observation of neutrinos from SN 1987A.

  9. Microwave study of superconducting Sn films above and below percolation

    Science.gov (United States)

    Beutel, Manfred H.; Ebensperger, Nikolaj G.; Thiemann, Markus; Untereiner, Gabriele; Fritz, Vincent; Javaheri, Mojtaba; Nägele, Jonathan; Rösslhuber, Roland; Dressel, Martin; Scheffler, Marc

    2016-08-01

    The electronic properties of superconducting Sn films ({T}{{c}}≈ 3.8 {{K}}) change significantly when reducing the film thickness down to a few {nm}, in particular close to the percolation threshold. The low-energy electrodynamics of such Sn samples can be probed via microwave spectroscopy, e.g. with superconducting stripline resonators. Here we study Sn thin films, deposited via thermal evaporation—ranging in thickness between 38 and 842 {nm}—which encompasses the percolation transition. We use superconducting Pb stripline resonators to probe the microwave response of these Sn films in a frequency range between 4 and 20 {GHz} at temperatures from 7.2 down to 1.5 {{K}}. The measured quality factor of the resonators decreases with rising temperature due to enhanced losses. As a function of the sample thickness we observe three regimes with significantly different properties: samples below percolation, i.e. ensembles of disconnected superconducting islands, exhibit dielectric properties with negligible losses, demonstrating that macroscopic current paths are required for appreciable dynamical conductivity of Sn at GHz frequencies. Thick Sn films, as the other limit, lead to low-loss resonances both above and below T c of Sn, as expected for bulk conductors. But in an intermediate thickness regime, just above percolation and with labyrinth-like morphology of the Sn, we observe a quite different behavior: the superconducting state has a microwave response similar to the thicker, completely covering films with low microwave losses; but the metallic state of these Sn films is so lossy that resonator operation is suppressed completely.

  10. 关于柯西sn-对称空间的一个注记%A Note on Cauchy sn-Symmetric Spaces

    Institute of Scientific and Technical Information of China (English)

    陈内萍

    2013-01-01

    It is proved that a space is a Cauchy sn-symmetric space if and only if it has a sn-devel-opment consisting of cs-covers ( or sn-covers) if and only if it is a sequence-covering π-image of a metric space .%证明了一个空间是柯西sn-对称空间当且仅当它有一个由cs-复盖或sn-复盖组成sn-展开当且仅当它是度量空间的序列复盖π映射。

  11. Investigation on version and author of Zeng bu shi wu ben cao bei kao (Augmented Dietary Materia Medica for Investigation)%《增补食物本草备考》版本及作者考

    Institute of Scientific and Technical Information of China (English)

    郑洪; 廖春红

    2012-01-01

    Zeng bu shi wu ben cao bei kao,a masterpiece of Guangdong dietary materia medica works,has a variety of different versions.Based on our investigation on the existing versions,it is claimed that the statement in Zhong guo zhong yi gu ji zong mu (General Catalogues of Chinese Ancient Books),showing the first version of this book to be the version at the “renzi year of Emperor Yongzheng”,is wrong.We infer that the author of Zeng bu shi wu ben cao bei kao,HE Kejian and that of Sheng cao yao xing bei yao,HE Jian,is the same person.However,the former book is mainly a book on HE Ke-jian' s experiences sorted by HE Sheng-xuan on the basis of Shi wu ben cao hui zuan,and probably it maybe initially carved in 1738.%《增补食物本草备考》为广东食物本草类著作的代表作,现有多种版本存世,经考察,《中国中医古籍总目》著录该书最早版本为“雍正壬子”之说有误.此书署名作者何克谏与《生草药性备要》署名作者何谏为同一人.此书系何省轩整理何克谏经验,以《食物本草会纂》为蓝本辑编而成,可能初刻于1738年.

  12. Comments on “Hepatic radioembolization with yttrium-90 glass microspheres for treatment of primary liver cancer" by Cao et al, Chin Med J 1999;112:430-432

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Editors,   We would like to congratulate Cao and his colleagues on the extremely good mean survival rate of 19.5 months achieved in 17 patients with non-resectable liver cancer (16 primary and 1 metastatic).1 Because the results of their study sounds so promising, centres having access to glass yttrium-90 (90Y) microspheres may want to try their methods. It is therefore necessary to clarify some of the points mentioned in their report.

  13. Role of a Water Network around the Mn4CaO5 Cluster in Photosynthetic Water Oxidation: A Fourier Transform Infrared Spectroscopy and Quantum Mechanics/Molecular Mechanics Calculation Study.

    Science.gov (United States)

    Nakamura, Shin; Ota, Kai; Shibuya, Yuichi; Noguchi, Takumi

    2016-01-26

    Photosynthetic water oxidation takes place at the Mn4CaO5 cluster in photosystem II. Around the Mn4CaO5 cluster, a hydrogen bond network is formed by several water molecules, including four water ligands. To clarify the role of this water network in the mechanism of water oxidation, we investigated the effects of the removal of Ca(2+) and substitution with metal ions on the vibrations of water molecules coupled to the Mn4CaO5 cluster by means of Fourier transform infrared (FTIR) difference spectroscopy and quantum mechanics/molecular mechanics (QM/MM) calculations. The OH stretching vibrations of nine water molecules forming a network between D1-D61 and YZ were calculated using the QM/MM method. On the the calculated normal modes, a broad positive feature at 3200-2500 cm(-1) in an S2-minus-S1 FTIR spectrum was attributed to the vibrations of strongly hydrogen-bonded OH bonds of water involving the vibrations of water ligands to a Mn ion and the in-phase coupled vibration of a water network connected to YZ, while bands in the 3700-3500 cm(-1) region were assigned to the coupled vibrations of weakly hydrogen-bonded OH bonds of water. All the water bands were lost upon Ca(2+) depletion and Ba(2+) substitution, which inhibit the S2 → S3 transition, indicating that a solid water network was broken by these treatments. By contrast, Sr(2+) substitution slightly altered the water bands around 3600 cm(-1), reflecting minor modification in water interactions, consistent with the retention of water oxidation activity with a decreased efficiency. These results suggest that the water network around the Mn4CaO5 cluster plays an essential role in the water oxidation mechanism particularly in a concerted process of proton transfer and water insertion during the S2 → S3 transition.

  14. A Systematic Review of the Mysterious Caterpillar Fungus Ophiocordyceps sinensis in DongChongXiaCao (冬蟲夏草 Dōng Chóng Xià Cǎo and Related Bioactive Ingredients

    Directory of Open Access Journals (Sweden)

    Hui-Chen Lo

    2013-01-01

    Full Text Available The caterpillar fungus Ophiocordyceps sinensis (syn.† Cordyceps sinensis, which was originally used in traditional Tibetan and Chinese medicine, is called either “yartsa gunbu” or “DongChongXiaCao (冬蟲夏草 Dōng Chóng Xià Cǎo” (“winter worm-summer grass”, respectively. The extremely high price of DongChongXiaCao, approximately USD $20,000 to 40,000 per kg, has led to it being regarded as “soft gold” in China. The multi-fungi hypothesis has been proposed for DongChongXiaCao; however, Hirsutella sinensis is the anamorph of O. sinensis. In Chinese, the meaning of “DongChongXiaCao” is different for O. sinensis, Cordyceps spp.,‡ and Cordyceps spƒ. Over 30 bioactivities, such as immunomodulatory, antitumor, anti-inflammatory, and antioxidant activities, have been reported for wild DongChongXiaCao and for the mycelia and culture supernatants of O. sinensis. These bioactivities derive from over 20 bioactive ingredients, mainly extracellular polysaccharides, intracellular polysaccharides, cordycepin, adenosine, mannitol, and sterols. Other bioactive components have been found as well, including two peptides (cordymin and myriocin, melanin, lovastatin, γ-aminobutyric acid, and cordysinins. Recently, the bioactivities of O. sinensis were described, and they include antiarteriosclerosis, antidepression, and antiosteoporosis activities, photoprotection, prevention and treatment of bowel injury, promotion of endurance capacity, and learning-memory improvement. H. sinensis has the ability to accelerate leukocyte recovery, stimulate lymphocyte proliferation, antidiabetes, and improve kidney injury. Starting January 1st, 2013, regulation will dictate that one fungus can only have one name, which will end the system of using separate names for anamorphs. The anamorph name “H. sinensis” has changed by the International Code of Nomenclature for algae, fungi, and plants to O. sinensis.

  15. Spark plasma-sintered Sn-based intermetallic alloys and their Li-storage studies

    CSIR Research Space (South Africa)

    Nithyadharseni, P

    2016-06-01

    Full Text Available In the present study, SnSb, SnSb/Fe, SnSb/Co, and SnSb/Ni alloy powders processed by co-precipitation were subjected to spark plasma-sintering (SPS) at 400 °C for 5 min. The compacts were structurally and morphologically characterized by X...

  16. Shell Model Description of Neutron-Deficient Sn Isotopes

    Institute of Scientific and Technical Information of China (English)

    Erdal Dikmen

    2009-01-01

    The shell model calculations in the sdgh major shell for the neutron-deficient 106,107,108,109Sn isotopes have been carried out by using CD-Bonn and Nijmegenl two-body effective nucleon-nucleon interactions. The single-shell states and the corresponding matrix elements needed for describing Sn isotopes are reconstructed to calculate the coefficient of fractional parantage by reducing the calculation requirements. This reconstruction allows us to do the shell model calculations of the neutron deficient Sn isotopes in very reasonable time. The results are compared to the recent high-resolution experimental data and found to be in good agreement with experiments.

  17. Cs5Sn9(OH·4NH3

    Directory of Open Access Journals (Sweden)

    Ute Friedrich

    2014-06-01

    Full Text Available The title compound, pentacaesium nonastannide hydroxide tetraammonia, crystallized from a solution of CsSnBi in liquid ammonia. The Sn94− unit forms a monocapped quadratic antiprism. The hydroxide ion is surrounded by five caesium cations, which form a distorted quadratic pyramidal polyhedron. A three-dimensional network is formed by Cs—Sn [3.8881 (7 Å to 4.5284 (7 Å] and Cs—NH3 [3.276 (7–3.636 (7 Å] contacts.

  18. Thermodynamic Properties of Liquid Ag-Bi-Sn Alloys

    Science.gov (United States)

    Li, Zuoan; Knott, Sabine; Mikula, Adolf

    2007-01-01

    As a promising lead-free solder, the thermodynamic properties of the liquid ternary Ag-Bi-Sn system were investigated. Using an appropriate galvanic cell, the partial free energies of Sn in liquid Ag-Bi-Sn alloys were determined as a function of concentration and temperature. Thermodynamic properties were obtained for 27 alloys. Their composition was situated on three cross sections with the constant ratios of Ag:Bi = 2:1, 1:1, and 1:2. The integral Gibbs free energy and the integral enthalpy for the ternary system at 900 K were calculated by Gibbs Duhem integration.

  19. GeSn/Si Avalanche Photodetectors on Si substrates

    Science.gov (United States)

    2016-09-16

    Photodetectors on Si substrates Report Title In this project, firstly, the material growth of GeSn by chemical vapor deposition (CVD) system has been...between GeSn and other market dominating IR detectors in short-IR wavelength (First time reported the D* of a GeSn detector in the world). The D* of...Standard Form 298 (Rev 8/98) Prescribed by ANSI Std. Z39.18 Final Report W911NF-13-1-0196 64461-EL-DRP.43 479-575-7265 a. REPORT 14. ABSTRACT 16

  20. How is really decelerating the expansion of SN1993J?

    CERN Document Server

    Marcaide, J M; Pérez-Torres, M A; Guirado, J C; Lara, L; Ros, E; Diamond, P J; Mantovani, F; Shapiro, I I; Weiler, K W; Preston, R A; Schilizzi, R T; Sramek, R A; Trigilio, C; Van Dyk, S D; Whitney, A R

    2002-01-01

    SN1993J is to date the radio supernova whose evolution has been monitored in greatest detail and the one which holds best promise for a comprehensive theoretical-observational analysis. The shell-like radio structure of SN1993J has expanded in general accord with models of shock excited emission, showing almost circular symmetry for over 8 years, except for a bright feature at the south-eastern region of the shell that has been observed at every epoch. The spectrum of SN1993J has flattened from alpha =-1 to alpha =-0.67 (S_(\

  1. Simple Preparation of the Photocatalyst of Sn2+-doped Titania

    Institute of Scientific and Technical Information of China (English)

    Dao Rong LI; Ling Na SUN; Chang Wen HU

    2006-01-01

    Preparation method of photocatalyst, using TiCl4 and SnCl2 as raw material and photocatalytic activity of nano-scaled core-shell Sn2+-doped titania photocatalyst was studied in this paper. The as-prepared samples were studied by UV-Vis, XRD, XPS, TEM. The particles of Sn2+-doped TiO2 photocatalyst, calcined from 150 to 600 ℃ for 5 h, possesses narrow particle size distribution and the sample was composed of anatase phase. Its photocatalytic efficiency was investigated by UV irradiation.

  2. Aproximación al estudio del conflicto interpersonal desde las teorías del caos. Algunas reflexiones en torno a las posibilidades de gestión del conflicto

    Directory of Open Access Journals (Sweden)

    JOSÉ NAVARRO CID

    2000-01-01

    Full Text Available Considerando el conflicto como algo natural en las relaciones interpersonales, el artículo expone la aproximación a su estudio desde el entendimiento de la dinámica del conflicto como una dinámica caótica. Y ello debido, en parte, al razonamiento teórico de que no linealidad más iteración generan caos (Edward Lorenz. Hoy sabemos que el caos ha de ser entendido bajo un nuevo prisma: como potencial generador de nuevas estructuras y formas, algo similar al cambio de actitud que sucedió con respecto al conflicto al abandonar los planteamientos funcionalistas. Bajo este prisma, aún se entiende mejor el porqué el conflicto puede contribuir al cambio. En el artículo también se tratarán otras implicaciones de entender el conflicto como proceso caótico, tales como la inoperancia de estudios transversales, desde un punto de vista metodológico, la utilidad del conflicto -en tanto proceso caóticocomo generador de nuevos órdenes y la aplicación de la teoría de los atractores para su mejor comprensión. Finalmente, se abordará la problemática de la gestión de conflictos desde una perspectiva de una gestión del caos.

  3. The rotational spectra, potential function, Born-Oppenheimer breakdown, and magnetic shielding of SnSe and SnTe.

    Science.gov (United States)

    Bizzocchi, Luca; Giuliano, Barbara M; Hess, Mareike; Grabow, Jens-Uwe

    2007-03-21

    The pure rotational spectra of 27 isotopic species of SnSe and SnTe have been measured in the frequency range of 5-24 GHz using a Fabry-Perot-type resonator pulsed-jet Fourier-transform microwave spectrometer. Gaseous samples of both chalcogenides were prepared by laser ablation of suitable target rods and were stabilized in supersonic jets of Ar. Global multi-isotopolog analyses of all available high-resolution data produced spectroscopic Dunham parameters Y01, Y11, Y21, Y31, Y02, and Y12 for both species, as well as Born-Oppenheimer breakdown (BOB) coefficients delta01 for Sn, Se, and Te. A direct fit of the same data sets to an appropriate radial Hamiltonian yielded analytic potential energy functions and BOB radial functions for the X 1Sigma+ electronic state of both SnSe and SnTe. Additionally, the magnetic hyperfine interaction produced by the dipolar nuclei 119Sn, 117Sn, 77Se, and 125Te was observed, yielding first determinations of the corresponding spin-rotation coupling constants.

  4. Gap states in the electronic structure of SnO2 single crystals and amorphous SnOx thin films

    Science.gov (United States)

    Haeberle, J.; Machulik, S.; Janowitz, C.; Manzke, R.; Gaspar, D.; Barquinha, P.; Schmeißer, D.

    2016-09-01

    The electronic structure of a SnO2 single crystal is determined by employing resonant photoelectron spectroscopy. We determine the core level, valence band, and X-ray absorption (XAS) data and compare these with those of amorphous SnOx thin films. We find similar properties concerning the data of the core levels, the valence band features, and the absorption data at the O1s edge. We find strong signals arising from intrinsic in-gap states and discuss their origin in terms of polaronic and charge-transfer defects. We deduce from the XAS data recorded at the Sn3d edge that the Sn4d10 ground state has contributions of 4d9 and 4d8 states due to configuration interaction. We identify localized electronic states depending on the strength of the 4d-5s5p interaction and of the O2p-to-Sn4d charge-transfer processes, both appear separated from the extended band-like states of the conduction band. For the amorphous SnOx thin films, significant differences are found only in the absorption data at the Sn3d-edge due to a stronger localization of the in-gap states.

  5. Phase Transformations during the Reaction Heat Treatment of Internal Tin Nb$_{3}$Sn Strands with High Sn Content

    CERN Document Server

    Scheuerlein, C; Arnau-Izquierdo, G; Buta, F

    2008-01-01

    The phase transformations that occur during the reaction heat treatment of Nb3Sn superconductors depend on the overall elemental composition of the strand sub-elements. In the case of modern high Jc strands with a relatively low Cu content, liquid phases are present during large temperature intervals and phases that can be detrimental for the microstructural and microchemical homogeneity of the fully reacted strand are formed. We report synchrotron x-ray diffraction measurements during in-situ reaction heat treatment of a state-of-the-art high Jc Nb3Sn Internal Tin (IT) strand. In this strand Cu3Sn is formed upon Cu6Sn5 decomposition at 415 °C, a Sn-rich ternary Cu-Nb-Sn phase is detected in the approximate temperature interval 345-575°C and NbSn2 is present in the temperature interval 545-630°C. The formation of voids in the strand sub-elements has been monitored by synchrotron micro-tomography during in-situ reaction heat treatment.

  6. Band alignments at strained Ge1‑x Sn x /relaxed Ge1‑y Sn y heterointerfaces

    Science.gov (United States)

    Lan, H.-S.; Liu, C. W.

    2017-04-01

    Type-I, type-II, reverse type-I, and reverse type-II band alignments are found theoretically in strained Ge1‑x Sn x (0  ⩽  x  ⩽  0.3) grown on relaxed Ge1‑y Sn y substrates (0  ⩽  y  ⩽  0.3) using the model-solid theory. The prerequisite bandgaps, and energy difference between the top valence band edge and the average valence band position of GeSn are obtained by the nonlocal empirical pseudopotential method. For the indirect-gap (L valleys) Ge1‑x Sn x on relaxed Ge1‑y Sn y , the band alignments are type-I and reverse type-I under biaxial compressive strain (x  >  y) and biaxial tensile strain (x  <  y), respectively. For the direct-gap (Γ valley) Ge1‑x Sn x on relaxed Ge1‑y Sn y , the biaxial compressive strain yields type-I and type-II alignment, while the biaxial tensile strain yields reverse type-I and reverse type-II alignments.

  7. Structural Behavior of Pt-Sn Supported on MgO

    Energy Technology Data Exchange (ETDEWEB)

    Nava, N. [Instituto Mexicano del Petroleo, Simulacion Molecular (Mexico); Morales, M. A.; Vanoni, W. [Centro Brasileiro de Pesquisas Fisicas (Brazil); Toledo, J. A. [Instituto Mexicano del Petroleo, Simulacion Molecular (Mexico); Baggio-Saitovitch, E. [Centro Brasileiro de Pesquisas Fisicas (Brazil); Viveros, T. [Universidad Autonoma Metropolitana-Iztapalapa, area de Ingenieria Quimica (Mexico)

    2001-05-15

    Pt-Sn supported on magnesia and alumina were characterized, before and after treatment with hydrogen, by Moessbauer spectroscopy and X-ray diffraction. For the calcined samples on both supports tin is present as SnO{sub 2} and platinum as metal. After reduction with hydrogen, platinum and tin diffuse into the magnesia lattice to form a solid solution. On alumina Sn(IV), Sn(II), Sn(0), Pt, Pt{sub 3}Sn, PtSn and PtSn{sub 2} alloys are formed. The SnO interacts strongly with the alumina support. The catalytic activity of both Pt-Sn catalysts is strongly affected by the support. On alumina the dehydrogenation of cyclohexane is very high, whereas that on magnesia is almost non-active.

  8. Isothermal section at 1400 deg. C of the Ti-Zr-Sn system

    Energy Technology Data Exchange (ETDEWEB)

    Saltykov, V.A. [I.N. Frantsevich Institute for Problems of Materials Science, Str. Krzhyzhanovsky, 3, Kiev 03142 (Ukraine)], E-mail: ssaltykov@ipms.kiev.ua; Meleshevich, K.A.; Samelyuk, A.V.; Verbytska, O.M.; Bulanova, M.V. [I.N. Frantsevich Institute for Problems of Materials Science, Str. Krzhyzhanovsky, 3, Kiev 03142 (Ukraine)

    2008-07-14

    By the methods of X-ray diffraction, metallography and microprobe examinations the character of phase equilibria at 1400 deg. C is studied for the Ti-(Ti,Zr){sub 5}Sn{sub 3}-Zr region of the Ti-Zr-Sn system. The isothermal section at 1400 deg. C is constructed. This is similar to the solidus surface and is characterized by two 3-phase regions: <{beta}Ti,Zr> + Ti{sub 3}Sn + (Ti,Zr){sub 5}Sn{sub 3} and Ti{sub 3}Sn + Ti{sub 2}Sn + (Ti,Zr){sub 5}Sn{sub 3}. Solubility of Sn in <{beta}Ti,Zr> solid solution is between 10 and 15 at.% Sn. Solubility of zirconium in Ti{sub 3}Sn is about 12 at.%.

  9. Defect-free high Sn-content GeSn on insulator grown by rapid melting growth

    Science.gov (United States)

    Liu, Zhi; Cong, Hui; Yang, Fan; Li, Chuanbo; Zheng, Jun; Xue, Chunlai; Zuo, Yuhua; Cheng, Buwen; Wang, Qiming

    2016-12-01

    GeSn is an attractive semiconductor material for Si-based photonics. However, large lattice mismatch between GeSn and Si and the low solubility of Sn in Ge limit its development. In order to obtain high Sn-content GeSn on Si, it is normally grown at low temperature, which would lead to inevitable dislocations. Here, we reported a single-crystal defect-free graded GeSn on insulator (GSOI) stripes laterally grown by rapid melting growth (RMG). The Sn-content reaches to 14.2% at the end of the GSOI stripe. Transmission electron microscopy observation shows the GSOI stripe without stacking fault and dislocations. P-channel pseudo metal-oxide-semiconductor field effect transistors (MOSFETs) and metal-semiconductor-metal (MSM) Schottky junction photodetectors were fabricated on these GSOIs. Good transistor performance with a low field peak hole mobility of 402 cm2/Vs is obtained, which indicates a high-quality of this GSOI structure. Strong near-infrared and short-wave infrared optical absorption of the MSM photodetectors at 1550 nm and 2000 nm were observed. Owing to high Sn-content and defect-free, responsivity of 236 mA/W@-1.5 V is achieved at 1550 nm wavelength. In addition, responsivity reaches 154 mA/W@-1.5 V at 2000 nm with the optical absorption layer only 200 nm-thick, which is the highest value reported for GeSn junction photodetectors until now.

  10. Evaporation Mechanism of Sn and SnS from Liquid Fe: Part I: Experiment and Adsorption of S on Reaction Site

    Science.gov (United States)

    Jung, Sung-Hoon; Kang, Youn-Bae; Seo, Jeong-Do; Park, Joong-Kil; Choi, Joo

    2015-02-01

    In order to evaluate feasibility of Sn-containing ferrous scrap recycling by evaporation of Sn, a number of liquid-gas experiments were carried out using an electromagnetic levitation melting technique. Rate of decrease of Sn concentration in liquid steel droplets by evaporation in Ar-H2 gas mixture was determined at 1873 K (1600 °C). Evaporation rate of the Sn under various conditions (various flow rates of the gas mixture, initial S concentration, [pct Sn]0) was examined using previously reported rate equations. Increasing flow rate increased the evaporation rate of Sn initially, but the rate became constant at higher flow rate, which indicates that the rate-controlling step is the chemical reaction at the liquid/gas interface. Increasing initial S concentration significantly increased the evaporation rate of Sn, which is in good agreement with previous understanding that Sn could be evaporated as SnS(g). It was found in the present study that neither a simple first-order reaction (rate proportional to [pct Sn]) nor a second-order reaction (rate proportional to [pct Sn] × [pct S]) could account for the Sn evaporation under a chemical-reaction-controlled regime. It is proposed in the present study that surface adsorption of S should be taken into account in order to interpret the evaporation rate of Sn in such a way that S blocks available sites for SnS evaporation on the liquid steel. The ideal Langmuir isotherm was applied in order to better represent evaporation rate constant k SnS as a function of [pct S] (0.06 reaction Sn i + S i = SnSi(g), , is 2.57 × 10-8 m4 mol-1 s-1.

  11. Comparative study of SnS recrystallization in molten CdI{sub 2}, SnCl{sub 2}and KI

    Energy Technology Data Exchange (ETDEWEB)

    Timmo, Kristi; Kauk-Kuusik, Marit; Pilvet, Maris; Mikli, Valdek; Kaerber, Erki; Raadik, Taavi; Leinemann, Inga; Altosaar, Mare; Raudoja, Jaan [Department of Materials Science, Tallinn University of Technology, Tallinn (Estonia)

    2016-01-15

    In the present study, the recrystallization of polycrystalline SnS in different molten salts CdI{sub 2}, SnCl{sub 2} and KI as flux materials are presented. The recrystallization and growth of polycrystalline material in molten salts produces unique SnS monograin powders usable in monograin layer solar cells. XRD and Raman analysis revealed that single phase SnS powder can be obtained in KI at 740 C and in SnCl{sub 2} at 500 C. Long time heating of SnS in molten CdI{sub 2} was accompanied by chemical interaction between SnS and CdI{sub 2} that resulted in a mixture of CdS and Sn{sub 2}S{sub 3} crystals. SEM images showed that morphology of crystals can be controlled by the nature of the flux materials: needle-like Sn{sub 2}S{sub 3} together with round edged crystals of CdS in CdI{sub 2}, flat crystals of SnS with smooth surfaces in SnCl{sub 2} and well-formed SnS crystals with rounded edges in KI had been formed. The temperatures of phase transitions and/or the interactions of SnS and flux materials were determined by differential thermal analysis. (copyright 2015 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  12. A highly stable (SnOx-Sn)@few layered graphene composite anode of sodium-ion batteries synthesized by oxygen plasma assisted milling

    Science.gov (United States)

    Cheng, Deliang; Liu, Jiangwen; Li, Xiang; Hu, Renzong; Zeng, Meiqing; Yang, Lichun; Zhu, Min

    2017-05-01

    The (SnOx-Sn)@few layered graphene ((SnOx-Sn)@FLG) composite has been synthesized by oxygen plasma-assisted milling. Owing to the synergistic effect of rapid plasma heating and ball mill grinding, SnOx (1 ≤ x ≤ 2) nanoparticles generated from the reaction of Sn with oxygen are tightly wrapped by FLG nanosheets which are simultaneously exfoliated from expanded graphite, forming secondary micro granules. Inside the granules, the small size of the SnOx nanoparticles enables the fast kinetics for Na+ transfer. The in-situ formed FLG and residual Sn nanoparticles improve the electrical conductivity of the composite, meanwhile alleviate the aggregation of SnOx nanoparticles and relieve the volume change during the cycling, which is beneficial for the cyclic stability for the Na+ storage. As an anode material for sodium-ion batteries, the (SnOx-Sn)@FLG composite exhibits a high reversible capacity of 448 mAh g-1 at a current density of 100 mA g-1 in the first cycle, with 82.6% capacity retention after 250 cycles. Even when the current density increases to 1000 mA g-1, this composite retains 316.5 mAh g-1 after 250 cycles. With superior Na+ storage stability, the (SnOx-Sn)@FLG composite can be a promising anode material for high performance sodium-ion batteries.

  13. High-pressure / High-temperature studies on the stannides RENiSn (RE = Ce, Pr, Nd, Sm) and REPdSn (RE = La, Pr, Nd)

    Energy Technology Data Exchange (ETDEWEB)

    Riecken, J.F.; Hermes, W.; Rodewald, U.C.; Hoffmann, R.D.; Poettgen, R. [Muenster Univ. (Germany). Inst. fuer Anorganische und Analytische Chemie; Heymann, G.; Huppertz, H. [Innsbruck Univ. (Austria). Inst. fuer Allgemeine, Anorganische und Theoretische Chemie

    2008-06-15

    The normal-pressure (NP) orthorhombic TiNiSi-type (space group Pnma) stannides RENiSn (RE = Ce, Pr, Nd, Sm) and REPdSn (RE = La, Pr, Nd) were transformed into the corresponding hexagonal ZrNiAl-type (space group P anti 62m) high-pressure (HP) modifications under multianvil high-pressure (7.5 - 11.5 GPa) high-temperature (1100 - 1200 C) conditions. The structures of NP-CeNiSn, HP-PrNiSn, NP-NdNiSn, HP-LaPdSn, HP-PrPdSn, and HP-NdPdSn were refined from single crystal X-ray diffractometer data. Structural data for HP-SmNiSn were obtained from a Rietveld powder refinement. The high-pressure phase transition significantly changes the rare earth coordination, i. e. 4 RE + 6 Ni(Pd) + 6 Sn atoms for the NP-phases and 6 RE + 5 Ni(Pd) + 6 Sn atoms for the HP-phases. Susceptibility measurements of HP-PrPdSn and HP-NdPdSn reveal paramagnetic behavior with experimental magnetic moments of 3.61(1) {mu}{sub B}/Pr atom and 3.66(1) {mu}{sub B}/Nd atom, respectively. Low-temperature susceptibility and specific heat data point to inhomogeneous magnetism and spin-glass behavior, respectively. (orig.)

  14. SN 2009ip and SN 2010mc: Early and late-time behavior consistent with core-collapse Type IIn supernovae

    CERN Document Server

    Smith, Nathan; Prieto, Jose

    2013-01-01

    The recent supernova (SN) 2009ip had pre-SN eruptions followed by a final explosion in 2012. Its pre-SN observations make 2009ip the best observed SN progenitor in history, but the unprecedented data on the pre-SN activity has fueled debate about the nature of the 2012 explosion, whether it was a true SN or some extreme non-terminal event. In principle, both types of events could power shock interaction with circumstellar material (CSM), but here we argue that only a core-collapse SN provides a self-consistent explanation. Previously, we demonstrated that the light curves of SN 2009ip and another Type IIn, SN 2010mc, were nearly identical. Here we expand that comparison to their spectra as well, demonstrating that they are both consistent with known Type IIn events. The late-time spectra of SN 2009ip resemble those of the super-luminous SN 2006tf, and the underlying broad component in SN 2009ip's spectra resembles Type II-P events. The recent claim that the late-time spectrum of SN 2009ip is returning to its ...

  15. Investigation by Mössbauer spectroscopy of Sn redox transformations during H2/O2 titration on Pt/Al2O3Sn-Cl and Pt/Al2O3SnIn-Cl naphtha reforming catalysts

    Science.gov (United States)

    Jahel, Ali; Avenier, Priscilla; Lacombe, Sylvie; Olivier-Fourcade, Josette; Jumas, Jean-Claude

    2010-03-01

    Bimetallic Pt/Al2O3Sn-Cl and trimetallic Pt/Al2O3SnIn-Cl catalysts were characterized by H2/O2 double titration and 119Sn Mössbauer spectroscopy. The addition of Sn or both Sn and In to the monometallic Pt/Al2O3-Cl catalyst leads to an increase in the volume of chemisorbed O2 at each titration. For bimetallic and trimetallic catalysts the increase in the Pt dispersion, calculated from the second oxygen titre, abnormally surpasses the barrier of 100%. Characterization of samples obtained after each step of the H2/O2 titration sequence using 119Sn Mössbauer spectroscopy allowed to follow the redox transformations of Sn species suspected of contributing to O2 consumption. 119Sn Mössbauer spectra show that after reduction unalloyed metalic Sn and PtSn alloy phases are formed in bi- and trimetallic catalysts respectively. These metallic phases are oxidized upon the first oxygen titre into the so-called PtxSn(O) oxometalic phases. The index calculated from this titre thus expresses the Pt-Sn bimetallic character and is called the bimetallicity index (BMI). These latter phases further undergo reduction and regeneration (oxidation) upon the second O2 titre and thus contribute to the calculated Pt dispersion as well.

  16. Microstructural investigation and SnO nanodefects in spray-pyrolyzed SnO2 thin films

    DEFF Research Database (Denmark)

    Thanachayanont, Chanchana; Yordsri, Visittapong; Boothroyd, Chris

    2011-01-01

    Spray pyrolysis is one of the most cost-effective methods to prepare SnO2 films due to its ability to deposit large uniform area, low fabrication cost, simplicity and low deposition temperature. Conventionally, scanning electron microscopy (SEM) and X-Ray Diffraction (XRD) are routinely used...... to investigate microstructure and crystal structure of the SnO2 films. In the present study, the SnO2 films were deposited by spray pyrolysis at 300, 400 and 500°C and the microstructure of the 500°C film was further examined by using transmission electron microscopy (TEM) and convergent beam electron...

  17. Late-time spectral line formation in Type IIb supernovae, with application to SN 1993J, SN 2008ax, and SN 2011dh

    CERN Document Server

    Jerkstrand, A; Smartt, S J; Fransson, C; Sollerman, J; Taubenberger, S; Bersten, M; Spyromilio, J

    2014-01-01

    We investigate line formation processes in Type IIb supernovae (SNe) from 100 to 500 days post-explosion using spectral synthesis calculations. The modeling identifies the nuclear burning layers and physical mechanisms that produce the major emission lines, and the diagnostic potential of these. We compare the model calculations with data on the three best observed Type IIb SNe to-date - SN 1993J, SN 2008ax, and SN 2011dh. Oxygen nucleosynthesis depends sensitively on the main-sequence mass of the star and modeling of the [O I] 6300, 6364 lines constrains the progenitors of these three SNe to the M_ZAMS=12-16 M_sun range (ejected oxygen masses 0.3-0.9 M_sun), with SN 2011dh towards the lower end and SN 1993J towards the upper end of the range. The high ejecta masses from M_ZAMS >= 17 M_sun progenitors give rise to brighter nebular phase emission lines than observed. Nucleosynthesis analysis thus supports a scenario of low/moderate mass progenitors for Type IIb SNe, and by implication an origin in binary syste...

  18. Franz-Keldysh effect in GeSn pin photodetectors

    Energy Technology Data Exchange (ETDEWEB)

    Oehme, M., E-mail: oehme@iht.uni-stuttgart.de; Kostecki, K.; Schmid, M.; Kaschel, M.; Gollhofer, M.; Ye, K.; Widmann, D.; Koerner, R.; Bechler, S.; Kasper, E.; Schulze, J. [Institut für Halbleitertechnik, Universität Stuttgart, Pfaffenwaldring 47, 70569 Stuttgart (Germany)

    2014-04-21

    The optical properties and the Franz-Keldysh effect at the direct band gap of GeSn alloys with Sn concentrations up to 4.2% at room temperature were investigated. The GeSn material was embedded in the intrinsic region of a Ge heterojunction photodetector on Si substrates. The layer structure was grown by means of ultra-low temperature molecular beam epitaxy. The absorption coefficient as function of photon energy and the direct bandgap energies were determined. In all investigated samples, the Franz-Keldysh effect can be observed. A maximum absorption ratio of 1.5 was determined for 2% Sn for a voltage swing of 3 V.

  19. Beta-decay studies near {sup 100}Sn

    Energy Technology Data Exchange (ETDEWEB)

    Karny, M.; Janas, Z.; Miernik, K.; Plochocki, A.; Zylicz, J. [University of Warsaw, Institute of Experimental Physics, Warsaw (Poland); Batist, L. [St. Petersburg Nuclear Physics Institute, St. Petersburg (Russian Federation); Banu, A.; Becker, F.; Burkard, K.; Bruechle, W.; Doering, J.; Gorska, M.; Grawe, H.; Kirchner, R.; Mandal, S.; Mazzocchi, C.; Mukha, I.; Plettner, C.; Roeckl, E.; Schaedel, M. [Gesellschaft fuer Schwerionenforschung, Darmstadt (Germany); Blazhev, A. [GSI, Darmstadt (Germany); Sofia Univ. (Bulgaria); Faestermann, T. [Technische Universitaet Muenchen, Muenchen (Germany); Jungclaus, A. [Universidad Autonoma de Madrid, Departamento de Fisica Teorica, Madrid (Spain); Kavatsyuk, M.; Kavatsyuk, O. [GSI, Darmstadft (Germany); Taras Shevchenko Kiev National University, Kiev (Ukraine); La Commara, M.; Romoli, M. [Universita ' ' Federico II' ' and INFN Napoli, Dipartimento Scienze Fisiche, Napoli (Italy); Muralithar, S. [GSI, Darmstadt (Germany); Nuclear Science Center, New Delhi (India); Rykaczewski, K. [Oak Ridge National Laboratory, Oak Ridge, TN (United States); Schmidt, K. [Continental Teves AG and Co., Frankfurt am Main (Germany); Schwengner, R. [Forschungszentrum Rossendorf, Dresden (Germany)

    2005-09-01

    The {beta}-decay of {sup 102}Sn was studied by using high-resolution germanium detectors as well as a Total Absorption Spectrometer (TAS). A decay scheme has been constructed based on the {gamma}-{gamma} coincidence data. The total experimental Gamow-Teller strength B{sub GT}{sup exp} of {sup 102}Sn was deduced from the TAS data to be 4.2(9). A search for {beta}-delayed {gamma}-rays of {sup 100}Sn decay remained unsuccessful. However, a Gamow-Teller hindrance factor h = 2.2(3), and a cross-section of about 3nb for the production of {sup 100}Sn in fusion-evaporation reaction between {sup 58}Ni beam and {sup 50}Cr target have been estimated from the data on heavier tin isotopes. The estimated hindrance factor is similar to the values derived for lower shell nuclei. (orig.)

  20. The Competitive Relationships of SN2, SN1, E2, E1 Reactions in Organic Chemistry%有机化学中SN2,SN1,E2,E1反应的相互竞争关系

    Institute of Scientific and Technical Information of China (English)

    颜志明; 潘英明

    2014-01-01

    有机化学中的SN2,SN1,E2,E1反应在学习中有着重要的作用,同时也是学习中易混淆的知识点.通过总结它们的反应机理、反应影响因素和反应相互竞争关系图,并利用竞争关系图解答了一些典型考研真题,方便读者理解和掌握SN2,SN1,E2,E1反应的相互竞争关系.