Academic literature on the topic 'A-SiOx'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'A-SiOx.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "A-SiOx"
Li, Feitao, Siyao Wan, Dong Wang, and Peter Schaaf. "Formation of nanoflowers: Au and Ni silicide cores surrounded by SiOx branches." Beilstein Journal of Nanotechnology 14 (January 20, 2023): 133–40. http://dx.doi.org/10.3762/bjnano.14.14.
Full textТурищев, С. Ю., В. А. Терехов, Д. А. Коюда, А. В. Ершов, А. И. Машин, Е. В. Паринова, Д. Н. Нестеров, Д. А. Грачев, И. А. Карабанова, and Э. П. Домашевская. "Формирование нанокристаллов кремния в многослойных нанопериодических структурах a-SiO-=SUB=-x-=/SUB=-/диэлектрик по результатам синхротронных исследований." Физика и техника полупроводников 51, no. 3 (2017): 363. http://dx.doi.org/10.21883/ftp.2017.03.44208.8374.
Full textRamesh, P. D., and K. J. Rao. "Carbothermal reduction and nitridation reaction of SiOx and preoxidized SiOx: Formation of α-Si3N4 fibers." Journal of Materials Research 9, no. 9 (September 1994): 2330–40. http://dx.doi.org/10.1557/jmr.1994.2330.
Full textDelimitis, A., S. D. Pappas, S. Grammatikopoulos, Panagiotis Poulopoulos, Vassilios Kapaklis, D. Trachylis, and C. Politis. "Microstructural Investigation of SiOx Thin Films Grown by Reactive Sputtering on (001) Si Substrates." Journal of Nano Research 17 (February 2012): 147–56. http://dx.doi.org/10.4028/www.scientific.net/jnanor.17.147.
Full textПеревалов, Т. В., В. А. Володин, Ю. Н. Новиков, Г. Н. Камаев, В. А. Гриценко, and И. П. Просвирин. "Наноразмерные флуктуации потенциала в SiO-=SUB=-x-=/SUB=-, синтезированном плазмохимическим осаждением." Физика твердого тела 61, no. 12 (2019): 2528. http://dx.doi.org/10.21883/ftt.2019.12.48589.552.
Full textCZARNACKA, Karolina. "Zmiennoprądowe właściwości dielektryczne materiałów nanowarstwowych a-SiOx/SiO2." PRZEGLĄD ELEKTROTECHNICZNY 1, no. 8 (August 5, 2018): 61–64. http://dx.doi.org/10.15199/48.2018.08.16.
Full textParka, Chan Hwi, Kyung Sub Leeb, and Dong Wook Shina. "Fabrication of Silicon Oxide Base Powders for Anode of Lithium Ion Battery by Hydrolysis Flame Synthesis." Advanced Materials Research 811 (September 2013): 98–103. http://dx.doi.org/10.4028/www.scientific.net/amr.811.98.
Full textShin, Young Chul, Eun Hong Kim, and Tae Geun Kim. "EUROPIUM SILICATE THIN FILMS FABRICATED BY RF MAGNETRON SPUTTERING AND THERMAL TREATMENT." ASEAN Journal on Science and Technology for Development 24, no. 1&2 (November 15, 2017): 147–52. http://dx.doi.org/10.29037/ajstd.195.
Full textIskhakzay, R. M. Kh, V. N. Kruchinin, V. Sh Aliev, V. A. Gritsenko, E. V. Dementieva, and M. V. Zamoryanskaya. "Charge Transport in Nonstoichiometric SiOx Obtained by Treatment of Thermal SiO2 in Hydrogen Plasma of Electronic-Cyclotron Resonance." Russian Microelectronics 51, no. 1 (February 2022): 24–35. http://dx.doi.org/10.1134/s1063739721060081.
Full textKawasaki, Masahiro, Masateru Nose, Ichiro Onishi, and Makoto Shiojiri. "Structural Investigation of AlN/SiOx Nanocomposite Hard Coatings Fabricated by Differential Pumping Cosputtering." Microscopy and Microanalysis 22, no. 3 (April 12, 2016): 673–78. http://dx.doi.org/10.1017/s1431927616000611.
Full textDissertations / Theses on the topic "A-SiOx"
Ribeiro, Rafael Parra. "Efeito do tratamento de oxidação a plasma na produção de uma bicamada SiOx/SiOxCyHz." Universidade Estadual Paulista (UNESP), 2017. http://hdl.handle.net/11449/152465.
Full textApproved for entry into archive by Maria Marlene Zaniboni null (zaniboni@bauru.unesp.br) on 2018-01-11T13:13:15Z (GMT) No. of bitstreams: 1 ribeiro_rp_me_bauru.pdf: 3444946 bytes, checksum: 0a56c18e1734b605a90aea40283cc295 (MD5)
Made available in DSpace on 2018-01-11T13:13:15Z (GMT). No. of bitstreams: 1 ribeiro_rp_me_bauru.pdf: 3444946 bytes, checksum: 0a56c18e1734b605a90aea40283cc295 (MD5) Previous issue date: 2017-08-16
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Devido às suas propriedades mecânicas, soldabilidade e baixo custo, o aço carbono é um material amplamente utilizado nos mais diversos setores. Entretanto, o aço carbono é facilmente oxidado quando exposto ao ambiente. Para evitar esse problema, alguns trabalhos sugerem o desenvolvimento de revestimentos protetivos utilizando técnicas de deposição a plasma baseadas no composto hexametildisiloxano, HMDSO. A partir deste composto podese obter desde estruturas organosilicones até as inorgânicas pela alteração dos parâmetros de deposição. Revestimentos tipo óxido de silício são mais resistentes à corrosão que os organosilicones, porém sua estabilidade física é menor. Com o objetivo de associar as propriedades favoráveis de ambos os tipos de revestimentos, investigou-se, no presente trabalho, a possibilidade de revestir o aço carbono com sistemas bicamadas SiOx/SiOxCyHz através da combinação de metodologia de deposição e oxidação em plasmas de baixa pressão. Para tanto, filmes do tipo SiOxCyHz foram depositados a plasma de mistura de HMDSO (70%), O2 (20%) e Ar (10%) excitado por radiofrequência (150 W). A pressão total da atmosfera de deposição foi de 20 Pa. Os filmes foram depositados por 30 min e, posteriormente, expostos a plasmas de O2 (3,3 Pa, 10-300 W, 60 min) com o objetivo de criar uma camada superficial inorgânica. Foram investigados os efeitos da potência de excitação do plasma de O2 na espessura de camada, estrutura química e composição elementar das amostras. Avaliou-se também o efeito da potência do plasma de oxidação nas propriedades de barreira do revestimento depositado sobre aço carbono. Filmes como-depositados foram caracterizados como organosilicones. A exposição ao plasma de oxigênio foi observada remover hidrogênio, carbono e grupos metil da estrutura transformando-a em óxido de silício, sendo, todavia, o grau de conversão e a espessura da camada convertida fortemente dependentes da potência do plasma de oxidação. A resistência do sistema preparado sobre o aço carbono à corrosão foi observada depender da espessura final da camada e também da conectividade da estrutura convertida em sílica mais que do grau de conversão. A condição de tratamento eleita como ótima neste trabalho foi a conduzida com 50 W de potência por criar uma camada superficial inorgânica fina, compacta, com uma estrutura superficial similar a da sílica além de preservar a espessura do filme e aumentar as propriedades de barreira do sistema.
Due to its mechanical properties, welding and low cost, carbon steel is a material widely used in several sectors. However, carbon steel is easily oxidized when exposed to the environment. To avoid this problem, some work suggests the development of protective coating using plasma deposition techniques based on the compound hexamethyldisiloxane, HMDSO. From this compound it is possible to obtain from organosilicones structures to inorganic by changing the parameters of deposition. Silicon oxide type coatings are more resistant to corrosion than organosilicones, but their physical stability is lower. With the objective of associating the favorable properties of both types of coatings, the present work investigated the possibility of coating the carbon steel with SiOx/SiOxCyHz bilayer systems through the combination of deposition and oxidation methodology in low pressure plasmas. For that, SiOxCyHz films were deposited in a mixture plasma of HMDSO (70%), O2 (20%) and Ar (10%) excited by radiofrequency (150 W). The total pressure of the atmosphere of deposition was 20 Pa. The films were deposited for 30 min and subsequently exposed to O2 plasmas (3.3 Pa, 10-300 W, 60 min) to create an inorganic surface layer. The effects of the excitation power of the O2 plasma on the layer thickness, chemical structure and elemental composition of the samples were investigated. The effect of the oxidation plasma power was also evaluated in the barrier properties of the coating deposited on carbon steel. As-deposited films were characterized as organosilicones. Exposure to oxygen plasma was observed to remove hydrogen, carbon and methyl groups from the structure transforming it into a silicon oxide, however, the degree of conversion and the thickness of the converted layer is strongly dependent on the power of the oxidation plasma. The corrosion resistance of the system prepared on carbon steel was observed to depend on the final thickness of the layer and also on the connectivity of the structure converted to silica rather than the degree of conversion. The treatment condition chosen as optimal in this work was the one conducted with 50 W of power by creating a thin, compact, inorganic surface layer with a silica-like surface structure in addition to preserving the film thickness and increasing the barrier properties of the system.
1560670
1545023
Queiroz, José Renato Cavalcanti de [UNESP]. "Filmes de SiOx crescidos em substrato de zircônia tetragonal policristalina estabilizada por ítria: influência na durabilidade da adesão a cimentos resinosos." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/105537.
Full textCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
Este estudo comparou o efeito de filmes à base de Si depositados pela técnica reactive magnetron sputtering com o uso do jateamento de partículas de alumina e a aplicação de primer na adesão de cimentos resinoso a superfície de zircônia. Blocos de zirconia (N=300) (4,5×4,5)mm foram sinterizados e regularizados com lixas de SiC (1200), sonicamente limpos com água destilada por 10 min e randomicamente divididos em 30 grupos (n=10) de acordo com 3 parâmetros: 1- cimento resinoso (Panavia/Kuraray; Multilink/Ivoclar; RelyX U100/3M); 2- tratamento de superfície (sem tratamentocontrole, Metal/Zirconia Primer, jateamento com partículas + Metal/Zirconia Primer, Filme A + Monobond S; Filme B + Monobond S); 3- termociclagem (TC). Parâmetros de rugosidade da superfície (Ra, Rz, Sdr) foram avaliados por Microscopia de Interferência e Microscopia Eletrônica de Varredura (MEV). Cilindros de cimento resinoso foram construídos (Ø: 2,4 mm; altura: 2 mm) sobre a superfície de zirconia. O ensaio de resistência adesiva ao cisalhamento foi realizado no momento inicial (24 h) e após a termociclagem (5o- 55oC, 6.000 ciclos) utilizando máquina de ensaio universal (1 mm/min). As superfícies fraturadas foram analisadas por microscopia ótica (30×) e MEV (100× e 2000×) para categorizar o modo de falha. Adicionais blocos de zirconia (15×15)mm confeccionados para análises por Espectroscopia por Retroespalhamento de Rutheford (RBS), e Trabalho de Adesão (WA) após os tratamentos de superfície. Os dados foram estatisticamente analisados por Anova 3-fatores e 11 teste Tukey (5%). Fotomicrografias revelaram microdefeitos nos filmes. Os resultados de Wa mostraram que os filmes melhoraram a molhabilidade da superfície. As análises por RBS mostraram que a concentração elementar dos filmes...
This study compared the effect of si-based nanofilm deposition using reactive magnetron sputtering to application of air-abrasion (alumina particles) and zirconia primers on the adhesion of resin cements to zirconia. Zirconia (Nblocks=300) (4.5 mm × 3.5 mm × 4.5 mm) were sintered, ground finished to 1200 SiC paper and cleaned ultrasonically in distilled water for 10 min. The blocks were randomly divided into 30 groups (n=10) according to 3 testing parameters: 1- Resin Cements (Panavia/Kuraray; Multilink/Ivoclar; RelyX U100/3M); 2- Surface conditioning (no conditioning-control, Metal/Zirconia Primer, air-abrasion + Metal/Zirconia Primer, Sibased film A + Monobond S; Si-based film B + Monobond S); 3- Aging (with and without). Surface roughness parameters (Ra, Rz, Sdr) before and after surface conditioning were evaluated using interference microscopy (IM). Rutheford Backscattering Spectroscopy (RBS), Scanning Electron Microscopy (SEM), and Work of Adhesion (WA) analyses were performed after surface treatments. Resin cements were incrementally built up (Ø: 2.4 mm; height: 4 mm) on the zirconia surfaces. Bonded specimens were then thermocycled (5o-55oC, 6,000 cycles). Shear bond strength (SBS) was performed using the Universal Testing Machine (1 mm/min). After fracture, the surfaces were analyzed using an optical microscopy (30 ×), SEM (100 × and 2000 ×) to categorize the failure modes. The data were statistically evaluated using 3-way ANOVA and Tukey's test (5%). Scanning Electron Microscopy showed micro defects on Si-based nanofilms surface. The result to Wa showed that surface coated with Si-based nanofilms improved wetability when compared to the other surface treatments. RBS analysis showed that was produced films with different chemical elemental concentration. While air-abraded... (Complete abstract click electronic access below)
Queiroz, José Renato Cavalcanti de. "Filmes de SiOx crescidos em substrato de zircônia tetragonal policristalina estabilizada por ítria : influência na durabilidade da adesão a cimentos resinosos /." São José dos Campos : [s.n.], 2011. http://hdl.handle.net/11449/105537.
Full textCoorientador: Marcos Massi
Banca: Luiz Felipe Valandro
Banca: Argemiro Soares da Silva Sobrinho
Banca: Rodrigo Othavio de Assunção e Souza
Banca: Marco Cícero Bottino
Resumo: Este estudo comparou o efeito de filmes à base de Si depositados pela técnica reactive magnetron sputtering com o uso do jateamento de partículas de alumina e a aplicação de primer na adesão de cimentos resinoso a superfície de zircônia. Blocos de zirconia (N=300) (4,5×4,5)mm foram sinterizados e regularizados com lixas de SiC (1200), sonicamente limpos com água destilada por 10 min e randomicamente divididos em 30 grupos (n=10) de acordo com 3 parâmetros: 1- cimento resinoso (Panavia/Kuraray; Multilink/Ivoclar; RelyX U100/3M); 2- tratamento de superfície (sem tratamentocontrole, Metal/Zirconia Primer, jateamento com partículas + Metal/Zirconia Primer, Filme A + Monobond S; Filme B + Monobond S); 3- termociclagem (TC). Parâmetros de rugosidade da superfície (Ra, Rz, Sdr) foram avaliados por Microscopia de Interferência e Microscopia Eletrônica de Varredura (MEV). Cilindros de cimento resinoso foram construídos (Ø: 2,4 mm; altura: 2 mm) sobre a superfície de zirconia. O ensaio de resistência adesiva ao cisalhamento foi realizado no momento inicial (24 h) e após a termociclagem (5o- 55oC, 6.000 ciclos) utilizando máquina de ensaio universal (1 mm/min). As superfícies fraturadas foram analisadas por microscopia ótica (30×) e MEV (100× e 2000×) para categorizar o modo de falha. Adicionais blocos de zirconia (15×15)mm confeccionados para análises por Espectroscopia por Retroespalhamento de Rutheford (RBS), e Trabalho de Adesão (WA) após os tratamentos de superfície. Os dados foram estatisticamente analisados por Anova 3-fatores e 11 teste Tukey (5%). Fotomicrografias revelaram microdefeitos nos filmes. Os resultados de Wa mostraram que os filmes melhoraram a molhabilidade da superfície. As análises por RBS mostraram que a concentração elementar dos filmes... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: This study compared the effect of si-based nanofilm deposition using reactive magnetron sputtering to application of air-abrasion (alumina particles) and zirconia primers on the adhesion of resin cements to zirconia. Zirconia (Nblocks=300) (4.5 mm × 3.5 mm × 4.5 mm) were sintered, ground finished to 1200 SiC paper and cleaned ultrasonically in distilled water for 10 min. The blocks were randomly divided into 30 groups (n=10) according to 3 testing parameters: 1- Resin Cements (Panavia/Kuraray; Multilink/Ivoclar; RelyX U100/3M); 2- Surface conditioning (no conditioning-control, Metal/Zirconia Primer, air-abrasion + Metal/Zirconia Primer, Sibased film A + Monobond S; Si-based film B + Monobond S); 3- Aging (with and without). Surface roughness parameters (Ra, Rz, Sdr) before and after surface conditioning were evaluated using interference microscopy (IM). Rutheford Backscattering Spectroscopy (RBS), Scanning Electron Microscopy (SEM), and Work of Adhesion (WA) analyses were performed after surface treatments. Resin cements were incrementally built up (Ø: 2.4 mm; height: 4 mm) on the zirconia surfaces. Bonded specimens were then thermocycled (5o-55oC, 6,000 cycles). Shear bond strength (SBS) was performed using the Universal Testing Machine (1 mm/min). After fracture, the surfaces were analyzed using an optical microscopy (30 ×), SEM (100 × and 2000 ×) to categorize the failure modes. The data were statistically evaluated using 3-way ANOVA and Tukey's test (5%). Scanning Electron Microscopy showed micro defects on Si-based nanofilms surface. The result to Wa showed that surface coated with Si-based nanofilms improved wetability when compared to the other surface treatments. RBS analysis showed that was produced films with different chemical elemental concentration. While air-abraded... (Complete abstract click electronic access below)
Doutor
Dresch, Mauro André. "Aplicação de catalisadores PtSn/C e membranas Nafion-SiO2 em células a combustível de etanol direto em elevadas temperaturas." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-06102014-102906/.
Full textThis work has as objective to evaluate anodes and electrolytes in direct ethanol fuel cells (DEFC) operating at high temperature (130 ºC). As anode materials, electrocatalysts based on PtSn/C were prepared by Modified Polyol Method with various Pt:Sn atomic ratios. Such methodology promotes selforganized electrocatalysts production with narrow particle size distribution and high alloying degree. The eletrocatalysts were characterized by XRD, and CO stripping. The results showed that these materials presented high alloying degree and Eonset CO oxidation at lower potential as commercial materials. As electrolyte, Nafion-SiO2 hybrids were synthesized by sol-gel reaction, by the incorporation of oxide directly into the ionic aggregates of various kinds of Nafion membranes. The synthesis parameter, such sol-gel solvent, membrane thickness and silicon precursor concentration were studied in terms of silica incorporation degree and hybrid mechanical stability. Finally, the optimized anodes and electrolytes were evaluated in DEFC operating at 80 130 ºC temperature range. The results showed a significant improvement of the DEFC performance (122 mW cm-2), resulted from the acceleration of ethanol oxidation reaction rate due to anode material optimization and high temperature operation once the use of hybrids possibilities the increase of temperature without a significant conductivity loses. In this sense, the combination of optimized electrodes and electrolytes are a promising alternative for the development of these devices.
Dresch, Mauro André. "Síntese e caracterizção eletroquímica de membranas híbridas Nafion-SIO2 para a aplicação como eletrólito polimérico em células a combustível tipo PEM." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/85/85134/tde-26092011-141218/.
Full textIn this work, the effect of sol-gel synthesis parameters on the preparation and polarization response of Nafion-SiO2 hybrids as electrolytes for proton exchange membrane fuel cells (PEMFC) operating at high temperatures (130 oC) was evaluated. The inorganic phase was incorporated in a Nafion matrix with the following purposes: to improve the Nafion water uptake at high temperatures (> 100 oC); to increase the mechanical strength of Nafion and; to accelerate the electrode reactions. The hybrids were prepared by an in-situ incorporation of silica into commercial Nafion membranes using an acid-catalyzed sol-gel route. The effects of synthesis parameters, such as catalyst concentration, sol-gel solvent, temperature and time of both hydrolysis and condensation reactions, and silicon precursor concentration (Tetraethylorthosilicate TEOS), were evaluated as a function on the incorporation degree and polarization response. Nafion-SiO2 hybrids were characterized by gravimetry, thermogravimetric analysis (TGA), scanning electron microscopy and X-ray dispersive energy (SEM-EDS), electrochemical impedance spectroscopy (EIS), and X-ray small angle scattering (SAXS). The hybrids were tested as electrolyte in single H2/O2 fuel cells in the temperature range of 80 130 oC and at 130 oC and reduced relative humidity (75% and 50%). Summarily, the hybrid performance showed to be strongly dependent on the synthesis parameters, mainly, the type of alcohol and the TEOS concentration.
Vecchi, Pierpaolo. "Caratterizzazione elettrica e spettroscopia superficiale di film sottili a base di silicio." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2018. http://amslaurea.unibo.it/16338/.
Full textMcConkie, Thomas O. "Curious Growth of a Buried SiO2 Layer." BYU ScholarsArchive, 2012. https://scholarsarchive.byu.edu/etd/3755.
Full textQuiroga, Jean-Manuel. "Étude des propriétés optiques de multicouches a-Si:H/a-SiO2." Grenoble 1, 1998. http://www.theses.fr/1998GRE10124.
Full textAndrade, Gessie Maria Silva de. "Oxidação parcial de metano a compostos oxigenados (HCHO e CH3OH) sobre catalizadores oxidos MoOx/MgO-SiO2 e VOx-SiO2." [s.n.], 2003. http://repositorio.unicamp.br/jspui/handle/REPOSIP/267468.
Full textTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
Made available in DSpace on 2018-08-03T15:05:56Z (GMT). No. of bitstreams: 1 Andrade_GessieMariaSilvade_D.pdf: 4290187 bytes, checksum: 47225a8be4e7efef0f24ffcc5f20c025 (MD5) Previous issue date: 2003
Resumo: A utilização cada vez maior do gás natural como combustível deve-se ao aumento da demanda de energia nos países em crescimento acompanhado da disponibilidade crescente das reservas de gás em relação às de petróleo, o que pode tomá-Io uma fonte de energia de grande importância neste século XXI. O metano é o componente presente em maior quantidade no gás natural, constituindo mais de 90% da fração dos hidrocarbonetos. Um dos processos mais utilizados para funcionalização das moléculas de hidrocarbonetos, tais como o metano, é a oxidação parcial. Desta forma, no presente estudo foi realizada a oxidação parcial do metano a compostos oxigenados (HCHO e CH30H) a pressão atmosférica utilizando catalisadores de óxidos redutíveis de MoOx/MgO-Si02 e VOx/MgO-Si02 com a finalidade de investigar a influência da introdução de MgO no suporte dos catalisadores e da concentração superficial de Mo+n e V+n na atividade e seletividade destes catalisadores, assim como o efeito da razão CH4:O2 na cinética desta reação. Os óxidos mistos de MgO- Si02 foram preparados em razões atômicas preestabelecidas (Mg:Si = 1:0, 3:1,2:1, 1:1, 1:3, 1:2 e 0:1), secos e calcinados a 400 K por 12 horas e 1050 K por 5 horas, respectivamente. O método para a introdução da fase ativa Mo ou V nos suportes foi a impregnação incipiente, obedecendo-se seis diferentes percentagens em peso de Mo+6 ou V+5 nos sólidos finais: 0,1%, 1,67%, 2,2 %, 3,25%, 4,82%, 6,4%, os quais foram caracterizados por difração de raios-X, adsorção de N2 e adsorção seletiva de O2. Os principais produtos observados para a reação em estudo foram HCHO, CO, CO2, sendo que HCHO e CH30H (produtos de oxidação parcial) foram favorecidos por altas razões molares de CH4:O2. A formação de CH3OH foi observada em teores moderados de óxidos metálicos (0:l[Mg:Si]/0,I%Mo e 0:1[Mg:Si]/3,25%Mo), os quais apresentaram consideráveis seletividades para esse produto (32% e 18%, respectivamente). Os resultados obtidos para as constantes de velocidade demonstraram que para baixas conversões, a seletividade para HCHO se aproxima de 100%, enquanto a seletividade para CO2 se manteve em valores baixos, próximos de zero, mostrando que em condições diferenciais (conversão de CH4 < 10%) a velocidade de formação de HCHO é maior que a velocidade de formação de CO2
Abstract: Methane is the major component of natural gas, often present as more than 90% of the gas. Current1y it is primarily used as a fuel. In the chemical industry it is used in the production of synthesis gas, hydrogen, and in the manufacture of the halogen derivatives of methane, acetylene, hydrogen cyanide, technical carbon, and many other products. The direct conversion of methane to formaldehyde and methanol in a single catalytic step in sufficient1y high yield would give rise to new opportunities in the conversion of natural gas to other useful fuels and chemicals. Both the homogeneous and heterogeneous processes have been studied under various conditions although progress toward obtaining a yield that would make such a process industrially viable has been very slow. The majority of these studies have involved metal oxide catalysts. In this work, the selective oxidation of methane to oxygenated compounds (HCHO e CH3OH) at atmospheric pressure was studied on MoOxfMgO-SiO2 and VOx/MgO-SiO2. The mixed oxides of magnesia and silica were prepared in different atom ratios (Mg:Si = 1:0, 3:1,2:1, 1:1, 1:3, 1:2 or 0:1), dried at 400 K for 12 h and calcined at 1050 K for 5 h. The active phase, Mo (H24Mo7N6O24) or V (H4NO3 V), was added to the supports by the incipient wetness method. The percentages of Mo or V added to the mixed oxides were 0,1%, 1,67%,2,2%,3,25%,4,82% or 6,4%. The solids were characterized by X-ray diffraction, BET surface area and oxygen chemisorption. The objective of the present work was to study the influence of the introduction of MgO in the supports, of the amount of Mo and V on the surface of the supports and of the CH4:O2 molar ratios. Both supported Mo and V oxides were active in the conversion of methane to C1-oxygenates and Cox. The main products of the oxidation reaction were HCHO, CO and CO2. The partial oxidation products (HCHO, CH30H) were favored by high CH4:O2 molar ratios and formaldehyde was the first oxidation product, which was further oxidized to CO. The vanadium oxide catalysts were more active than the molybdenum oxide catalysts in conversion of methane. However, the higher reaction rate also resulted in a further oxidation of HCHO to CO
Doutorado
Desenvolvimento de Processos Químicos
Doutor em Engenharia Química
Soares, Liliana do Amaral. "Cu/SiO2 : catalisador reciclável para a síntese one pot de triazóis." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2013. http://hdl.handle.net/10183/97958.
Full textThe search for new technologies has inspired the science in all areas of chemistry and one of the most studied research fields lays on the search for natural product's mimetics. A good example, among different efforts for simple and efficient new methods of synthesis, is the click chemistry and its Cu catalysed 1,3-dipolar cycloaddition, once this reaction permits quick acess to 1,4-disubstituted-1,2,3-triazoles. In this work we synthesized a copper catalyst through the sol-gel methodology, so called Cu-silica and tested it in the 1,3-cycloaddition reaction, using different starting materials and energy sources. At first we applied this catalyst in a multicomponent reaction in which benzyl bromides, sodium azide and different acetylenes and the reaction was heated for 12 hours or 10 minutes under microwave irradiation (50W), providing the 1,2,3-triazoles with 95% of yield. Further we changed the benzyl halides for boronic acids; we didn’t have success using non-classical heating systems (microwave or ultrasound), however under traditional heating at 50º C for 48 hours we got the product in 91% yield. Finally we developed a new one-pot metodology to obtain 1,2,3-triazoles from alchools. This procedure consists in a two-step continuous system embracing three transformations wihtin 25 hours with an overall yield of 60%.
Books on the topic "A-SiOx"
Morris, Eleri Llewelyn. Siom a sioc. Aberystwyth: Canolfan Astudiaethau Addysg, 2000.
Find full textA Sioux chronicle. Norman: University of Oklahoma Press, 1993.
Find full textSiom, syndod a sws. Llanrwst: Carreg Gwalch, 2005.
Find full textHolley, Latza Jodi, ed. Sioux Falls: A photographic journal. Sioux Falls, SD: PeopleScapes, 2007.
Find full texttranslator, Whelan Luned, ed. Clem: A Bwgan y Sioe. Wernddu, Caerffili: Rily Publications, 2014.
Find full textDudley, Joseph Iron Eye. Choteau Creek: A Sioux reminiscence. Lincoln: University of Nebraska Press, 1992.
Find full textDudley, Joseph Iron Eye. Choteau Creek: A Sioux reminiscence. New York: Warner Books, 1994.
Find full textSaliga, Lászlóné. A Magyar Sion és az Új Magyar Sion (1863-1904) repertóriuma. Piliscsaba: PPKE BTK [u.a.], 2007.
Find full textSantella, Andrew. The Lakota Sioux: A true book. New York: Children's Press, 2001.
Find full textSaci, Maria Paola. Ludovico Lazzarelli: Da Elicona a Sion. Roma: Bulzoni, 1999.
Find full textBook chapters on the topic "A-SiOx"
Hegemann, D., U. Schütz, and C. Oehr. "RF-Plasma Deposition of SiOx and a-C:H as Barrier Coatings on Polymers." In Plasma Processes and Polymers, 23–37. Weinheim, FRG: Wiley-VCH Verlag GmbH & Co. KGaA, 2005. http://dx.doi.org/10.1002/3527605584.ch2.
Full textBialas, Marcin, and Zenon Mróz. "An Energy Model of Segmentation Cracking of SiOx Thin Film on a Polymer Substrate." In Advanced Ceramic Coatings and Interfaces II, 231–42. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2009. http://dx.doi.org/10.1002/9780470339510.ch23.
Full textAguilera, Alvaro, Holger Mickler, Julian Kunkel, Michaela Zimmer, Marc Wiedemann, and Ralph Müller-Pfefferkorn. "A Comparison of Trace Compression Methods for Massively Parallel Applications in Context of the SIOX Project." In Tools for High Performance Computing 2013, 91–105. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-08144-1_8.
Full textRaider, S. I. "The Role of SiO in Si Oxidation at a Si-SiO2 Interface." In The Physics and Chemistry of SiO2 and the Si-SiO2 Interface, 35–42. Boston, MA: Springer US, 1988. http://dx.doi.org/10.1007/978-1-4899-0774-5_4.
Full textRavindra, N. M., D. Fathy, O. W. Holland, and J. Narayan. "Si — SiO2 Interfaces — a Hrtem Study." In The Physics and Technology of Amorphous SiO2, 279–83. Boston, MA: Springer US, 1988. http://dx.doi.org/10.1007/978-1-4613-1031-0_38.
Full textShruthi, M., D. Sendil Vadivu, and Narendran Rajagopalan. "Relationship Management in SIoT: A Survey." In Communication and Intelligent Systems, 515–26. Singapore: Springer Nature Singapore, 2023. http://dx.doi.org/10.1007/978-981-99-2100-3_40.
Full textStathis, J. H. "Identification of Native Defects in a-SiO2." In The Physics and Technology of Amorphous SiO2, 141–51. Boston, MA: Springer US, 1988. http://dx.doi.org/10.1007/978-1-4613-1031-0_17.
Full textShahab, Saima, Parul Agarwal, Tabish Mufti, and Ahmed J. Obaid. "SIoT (Social Internet of Things): A Review." In ICT Analysis and Applications, 289–97. Singapore: Springer Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-5655-2_28.
Full textMarkovits, A., and C. Minot. "A theoretical model of the Si/SiO2 interface." In Fundamental Aspects of Ultrathin Dielectrics on Si-based Devices, 131–45. Dordrecht: Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-011-5008-8_10.
Full textGriscom, David L. "Intrinsic and Extrinsic Point Defects in a-SiO2." In The Physics and Technology of Amorphous SiO2, 125–34. Boston, MA: Springer US, 1988. http://dx.doi.org/10.1007/978-1-4613-1031-0_15.
Full textConference papers on the topic "A-SiOx"
Baek, Sungkweon, Sangryol Yang, Jae-young Ahn, Bonyoung Koo, Kihyun Hwang, Siyoung Choi, Chang-Jin Kang, and Joo-Tae Moon. "Characterization of novel SiO2/a-Si/a-SiOx tunnel barrier engineered oxide." In 2010 IEEE International Memory Workshop. IEEE, 2010. http://dx.doi.org/10.1109/imw.2010.5488330.
Full textCao, Zhiqiang, Tong-Yi Zhang, and Xin Zhang. "A Nanoindentation-Based Microbridge Testing Method for Mechanical Characterization of Thin Films for MEMS Applications." In ASME 2005 International Mechanical Engineering Congress and Exposition. ASMEDC, 2005. http://dx.doi.org/10.1115/imece2005-80288.
Full textTerekhov, Vladimir, Eugene Terukov, Yurii Undalov, Konstantin Barkov, Pavel Seredin, Dmitry Goloshchapov, Igor Zanin, and Evelina Domashevskaya. "THE NANOCRYSTALS SIZE ESTIMATION USING RAMAN SPECTROSCOPY IN A-SIOX:H FILMS AFTER CRYSTALLIZATION OF SILICON NANOCLUSTERS." In International Forum “Microelectronics – 2020”. Joung Scientists Scholarship “Microelectronics – 2020”. XIII International conference «Silicon – 2020». XII young scientists scholarship for silicon nanostructures and devices physics, material science, process and analysis. LLC MAKS Press, 2020. http://dx.doi.org/10.29003/m1577.silicon-2020/126-130.
Full textPhan, Hai Trieu, Nadia Caney, Philippe Marty, Ste´phane Colasson, and Je´roˆme Gavillet. "Flow Boiling of Water on Nanocoated Surfaces in a Microchannel." In ASME 2010 8th International Conference on Nanochannels, Microchannels, and Minichannels collocated with 3rd Joint US-European Fluids Engineering Summer Meeting. ASMEDC, 2010. http://dx.doi.org/10.1115/fedsm-icnmm2010-30478.
Full textGao, Dejin, Lijie Zhang, Ru Huang, Runsheng Wang, Dongmei Wu, Yongbian Kuang, Yu Tang, Zhe Yu, Albert Z. H. Wang, and Yangyua Wang. "A novel nitrogen-doped SiOx resistive switching memory with low switching voltages." In 2010 Silicon Nanoelectronics Workshop (SNW). IEEE, 2010. http://dx.doi.org/10.1109/snw.2010.5562577.
Full textMorales-Vilches, Anna Belen, Yevgeniya Larionova, Tobias Wietler, Alexandros Cruz, Lars Korte, Robby Peibst, Rolf Brendel, Rutger Schlatmann, and Bernd Stannowski. "ZnO:Al/a-SiOx front contact for polycrystalline-silicon-on-oxide (POLO) solar cells." In SILICONPV 2018, THE 8TH INTERNATIONAL CONFERENCE ON CRYSTALLINE SILICON PHOTOVOLTAICS. Author(s), 2018. http://dx.doi.org/10.1063/1.5049279.
Full textSalles, Caroline Lima, William Nemeth, Harvey Guthrey, Sumit Agarwal, and Paul Stradins. "Controlling pinhole radius and areal density in a-Si/SiOx using metal-assisted chemical etching." In SiliconPV 2021, The 11th International Conference on Crystalline Silicon Photovoltaics. AIP Publishing, 2022. http://dx.doi.org/10.1063/5.0089213.
Full textFeldman, Albert, E. N. Farabaugh, and Y. N. Sun. "Stoichiometry of Reactively Evaporated Films." In Optical Interference Coatings. Washington, D.C.: Optica Publishing Group, 1988. http://dx.doi.org/10.1364/oic.1988.tua4.
Full textDesrues, Thibaut, Adeline Lanterne, Charles Seron, Sylvain Rousseau, Etienne Pihan, Sebastien Dubois, Gael Borvon, Frank Torregrosa, and Laurent Roux. "Poly-Si/SiOx Passivating Contacts on Both Sides: A Versatile Technology For High Efficiency Solar Cells." In 2021 IEEE 48th Photovoltaic Specialists Conference (PVSC). IEEE, 2021. http://dx.doi.org/10.1109/pvsc43889.2021.9518773.
Full textKim, Namsu, Seunghyup Yoo, William Potscavage, Benoit Domercq, Bernard Kippelen, and Samuel Graham. "Fabrication and Characterization of SiOx/Parylene and SiNx/Parylene Thin Film Encapsulation Layers." In ASME 2007 InterPACK Conference collocated with the ASME/JSME 2007 Thermal Engineering Heat Transfer Summer Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/ipack2007-33332.
Full textReports on the topic "A-SiOx"
Hudspeth, Matthew, Joe Olles, James Williams, Anirban Mandal, Seth Root, and Seth Vogler. Strength of porous alpha-SiO2 in a shock loaded environment. Office of Scientific and Technical Information (OSTI), August 2019. http://dx.doi.org/10.2172/1762993.
Full textMaerzke, Katie A., and J. Tinka Gammel. A New Multiphase Equation of State for SiO2. Office of Scientific and Technical Information (OSTI), October 2017. http://dx.doi.org/10.2172/1398902.
Full textДядына, Г. А., В. Г. Карпов, and Володимир Миколайович Соловйов. Низкоэнергетические возбуждения в α-SiO2. ФТИ им. А.Ф.Иоффе, 1990. http://dx.doi.org/10.31812/0564/1015.
Full textFritz, S. Structural Characterization of a pentacene monolayer on an amorphous SiO2 substrate with grazing incidence x-ray diffraction. Office of Scientific and Technical Information (OSTI), February 2004. http://dx.doi.org/10.2172/826751.
Full textДядына, Г. А., В. Г. Карпов, Володимир Миколайович Соловйов, and Виктор Александрович Хрисанов. Флуктуации локальных атомных потенциалов в аморфных веществах. ФТИ им. А.Ф.Иоффе, 1989. http://dx.doi.org/10.31812/0564/1010.
Full textUner, Denis Ozbay. Interactions of hydrogen with alkali promoted Ru/SiO2 catalysts: A proton NMR study. Office of Scientific and Technical Information (OSTI), May 1994. http://dx.doi.org/10.2172/10161807.
Full textWilliams, R., J. E. Rubensson, and S. Eisebitt. Ion-implanted Si-nanostructures buried in a SiO{sub 2} substrate studied with soft-x-ray spectroscopy. Office of Scientific and Technical Information (OSTI), April 1997. http://dx.doi.org/10.2172/603520.
Full textHansen, Paul L., and George R. Hoffman. The vegetation of the Grand River/Cedar River, Sioux, and Ashland Districts of the Custer National Forest: a habitat type classification. Ft. Collins, CO: U.S. Department of Agriculture, Forest Service, Rocky Mountain Forest and Range Experiment Station, 1988. http://dx.doi.org/10.2737/rm-gtr-157.
Full textCollis, W. J. Deposition of a-SiC:H, a-SiO{sub 2} and tetrahedral-C with programmable in-situ etching. Final performance report, March 1, 1988--November 30, 1991. Office of Scientific and Technical Information (OSTI), June 1995. http://dx.doi.org/10.2172/79027.
Full textCowell and Roesch. PR-283-14204-R01 SoLoNOx Low Load Controls to Reduce Emissions for Less Restrictive Load Following. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), July 2016. http://dx.doi.org/10.55274/r0011016.
Full text