DESENVOLVIMENTO DE NANOEMULSÕES E NANOCÁPSULAS POLIMÉRICAS CONTENDO TIOCONAZOL E INCORPORAÇÃO EM HIDROGÉIS

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Andréia Pisching Garcia Härter

2013-01-01

Este trabalho objetivou o desenvolvimento de nanoemulsões e nanocápsulas poliméricas contendo tioconazol para o tratamento tópico de micoses superficiais. Inicialmente, foi validado um método por cromatografia líquida com detecção UV para quantificação do tioconazol nas formulações nanoestruturadas. O método apresentou-se específico, linear, preciso, exato e robusto. As nanoemulsões e nanocápsulas de PCL contendo o tioconazol (1,0 mg/mL) foram preparadas pelos métodos de emulsificação espontâ...

Processamento de grãos de milho para ruminantes: Digestibilidade aparente e "in situ"

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Carlos de Sousa Lucci

2008-02-01

Full Text Available Seis carneiros machos Suffolk, com pesos de 35 a 40 kg e idades de 2 anos, dotados de cânulas de rúmen, foram utilizados para comparar dietas contendo milho em grãos processados para diferentes tamanhos de partículas: A grosseiramente quebrado B grosseiramente moído (quirera grossa C finamente moído (fubá. O delineamento empregado foi o "change-over", com dois grupos de três animais em período experimental de 84 dias. A ração era composta de farelo de soja (14 %, milho em grãos (26 % e feno (60 %, medindo-se digestibilidade total e "in situ" do milho e do feno parâmetros ruminais: pH, N-NH3 e cinética de líquidos. Os resultados mostraram menores taxas de degradabilidade da matéria seca e proteína bruta do milho quando fornecido grosseiramente quebrado. Não ocorreram influências dos tratamentos sobre a fibra do feno ou sobre parâmetros ruminais. Concluiu-se que, no interior do rúmen, grãos de milho finamente moídos tiveram maior digestibilidade sem provocar alterações na digestão da fibra.

¿Cómo enviar mensajes a extraterrestres?

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Comité Seti

2015-01-01

Full Text Available Durante más de treinta años, los humanos han utilizado la tecnología de radio para buscar evidencia de inteligencia extraterrestre -ETI-. Colectivamente, estos esfuerzos se conocen como SETI. Si SETI detecta exitosamente una civilización extraterrestre, surgirá la pregunta de si la humanidad debe intentar establecer comunicación con otra civilización y cómo, ¿Cuál debe ser el procedimiento para tomar la decisión? ¿Cuál debe ser el contenido del mensaje? ¿Quién debe decidir? Las mismas preguntas se pueden aplicar a las propuestas con respecto al envío de señales en ausencia de su detección.

Dietas para frangos de corte contendo quirera de arroz Performance of broiler feed with broken rice in diets

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Berilo de Souza Brum Júnior

2007-10-01

Full Text Available O experimento foi realizado para avaliar o uso da quirera de arroz na dieta de frangos de corte. Foram utilizados 240 pintos machos, alojados em galpão, contendo 12 boxes de 2m² de área. Cada box continha comedouro tubular, bebedouro pendular e campânula nos 21 dias iniciais. As aves foram distribuídas em um delineamento inteiramente casualizado, com três tratamentos e quatro repetições, as quais receberam dietas contendo 0, 20 e 40% de inclusão de quirera de arroz. Os dados foram submetidos à análise de regressão e à análise de variância e, quando houve diferença, aplicou-se o teste de Tukey. O ganho de peso, o consumo de ração e a conversão alimentar de 1-21, 1-35 e 1-42 dias (P>0,05 não foram afetados pela substituição do milho por quirera de arroz. A umidade de cama, o índice de eficiência produtivo, o rendimento de carcaça quente, de fígado, coração, coxa, sobre-coxa e peito não apresentaram diferença (P>0,05. No entanto, os rendimentos de moela, bem como a pigmentação da canela e do bico, diminuíram linearmente com o aumento do nível de quirera de arroz na dieta. Conclui-se que a quirera de arroz pode ser incluída nas dieta, substituindo o milho, para frangos de corte.An experiment was carried to evaluate the performance of broilers fed with diferent levels of broken rice. The experiment was conducted with 240 males broilers chicks, Cobb 500, were distributed in floor pens of 2m² each, with one tubular feeder, one pendular drinker, an electrical brooder and on the top of rice hulls. An entirely randomized experimental design was used, with 3 treatments and 4 replicates with 20 birds each, which received, diets containing 0, 20 and 40% of broken rice. Data were submitted to Analisis of regression. Weight gain, feed intake, feed conversion to the1- 21, 1- 35 and 1-42 days of age, litter humidity, carcass, liver, breast, thigh and drumstick yield did not present significant difference. The gizzard and the

Consumo e digestibilidade aparente em bezerros da raça holandesa alimentados com dietas contendo diferentes níveis de volumoso

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Ricardo Dias Signoretti

1999-02-01

Full Text Available O objetivo deste trabalho foi avaliar o efeito de diferentes níveis de volumoso nas dietas sobre os consumos e as digestibilidades aparentes de matéria seca (MS, matéria orgânica (MO, proteína bruta (PB, extrato etéreo (EE, fibra em detergente neutro (FDN, carboidratos totais (CHOT e energia bruta (EB e sobre os consumos de nutrientes digestíveis totais (NDT. Trinta e cinco bezerros da raça Holandesa puros por cruzamento, não-castrados, com idade média de 60 dias e peso vivo inicial de 78 kg, foram distribuídos em delineamento inteiramente casualizado, com nove repetições por dieta, exceto para a dieta com 10% de volumoso, com oito repetições. Os animais foram alimentados à vontade com dietas contendo níveis de 10, 25, 40 e 55% de volumoso, na base da MS, usando-se feno de capim coast-cross (Cynodon dactylon, fubá de milho e farelo de soja, os quais constituíram dietas com aproximadamente 16% de PB. O óxido crômico foi usado para obtenção das estimativas dos fluxos de MS fecal. Os carboidratos totais foram obtidos por 100 - (%PB + %EE + %Cinzas. O consumo de NDT foi obtido por (cPB - PBf + 2,25 (cEE - EEf + (cCHOT - CHOTf, em que c significa consumo e f, excreção fecal. Não houve efeito dos níveis de volumoso nas dietas sobre os consumos de MS e MO (kg/dia, % PV e g/kg0,75 e de PB e CHOT (kg/dia e % PV. O consumo de FDN (kg/dia, %PV e g/kg0,75 aumentou, enquanto o consumo de EE e NDT (em kg/dia e %PV reduziu linearmente em função dos níveis de volumoso na dieta. Houve efeito linear decrescente sobre as digestibilidades aparentes de MS, MO, PB, EE, CHOT e EB, em função do aumento dos níveis de volumoso nas dietas, enquanto a digestibilidade aparente da FDN não foi influenciada. Os consumos de EE, FDN e NDT e as digestibilidades aparentes de MS, MO, EE, PB, CHOT e EB foram influenciados pelos níveis de volumoso nas dietas.

Nutritional evaluation of elephant-grass silages with byproduct of annato Avaliação nutricional de silagens de capim-elefante contendo subproduto do urucum

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Margareth Maria Teles Rêgo

2010-10-01

Full Text Available The objective of the present study was to evaluate the nutritional value of elephant-grass silages containing annato byproduct. Twenty intact rams were distributed in a complete randomized block design with five diets (0; 4; 8; 12 and 16% annato byproduct in the silage and four replications and used to estimate the intake, apparent nutrient digestibility, content of total digestible nutrients and nitrogen balance. The addition of annato byproduct raised the intakes of dry matter (DM, organic matter (OM, crude protein (CP, neutral detergent fiber (NDF, acid detergent fiber (ADF, ether extract (EE, total carbohydrates (TC, non-fibrous carbohydrates (NFC and total digestible nutrients (TDN, in body weight (%BW and in metabolic weight (g kg-1BW0.75. The digestibilities of DM (55.95%, OM (58.19%, CP (45.34%, NDF (52.79%, ADF (45.79%, EE (34.96% and NFC (99.86% were not influenced by the addition of annato byproduct. The inclusion of annato byproduct in elephant-grass silage increased digestibility of total carbohydrates, the TDN content and the nitrogen balance. The aditions of annato byproduct at levels up to 16% of the elephant grass silage natural matter improves nutrient intake and nitrogen balance.Objetivou-se avaliar o valor nutritivo de silagens de capim-elefante contendo subproduto do processamento do urucum. Vinte ovinos machos, não-castrados, foram distribuídos em delineamento inteiramente casualizado com cinco dietas (0; 4; 8; 12 e 16% de subproduto de urucum na silagem e quatro repetições, e utilizados para estimar o consumo, a digestibilidade aparente de nutrientes, o teor de nutrientes digestíveis totais e o balanço de nitrogênio. A adição de subproduto de urucum elevou os consumos de matéria seca (MS, matéria orgânica (MO, proteína bruta (PB, fibra em detergente neutro (FDN, fibra em detergente ácido (FDA, extrato etéreo (EE, carboidratos não-fibrosos (CNF, carboidratos totais e nutrientes digestíveis totais (NDT

Evaluation of '9{sup 9}Mo presence in eluates of {sup 99}mTc used in nuclear medicine; Avaliacao da presenca de {sup 99}Mo em eluatos de {sup 99m}Tc utilizados em medicina nuclear

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Ribeiro, Bianca da Silva

2010-07-01

Tc-99m is used for diagnostic imaging in nuclear medicine through SPECT technique. It is obtained by the elution of {sup 99}Mo/{sup 99m}Tc generators. During the elution process {sup 99}Mo can be extracted becoming a radionuclidic impurity. One of the quality parameters of the eluate is the radionuclidic purity, MBT (molybdenum break through), defined as the ratio between {sup 99}Mo and {sup 99m}Tc activities in the eluate. The North-American and European pharmacopoeias restrict the {sup 99}Mo content, respectively, in 0.015 e 0.1% and, according to the International Atomic Energy Agency (IAEA), the activity ratio at the moment of administration of the radiopharmaceutical to the patient, should not exceed 0.015%. In Brazil, the control of such parameter is not obliged in official regulations. Thus, the objective of this work is to evaluate the occurrence of {sup 99}Mo in {sup 99m}Tc eluates. It was initially optimized a methodology to determine the activity of {sup 99}Mo in eluate samples. Efficiency curves were obtained for a NaI (Tl) 8'' x 4'' scintillation detector installed at the In Vivo Monitoring Laboratory (LABMIV-IRD). The methodology has been validated through the measurement of a {sup 99}Mo standard liquid source calibrated at the National Metrology Laboratory for Ionizing Radiation (LNMRI-IRD). The samples analyzed in this work were gently supplied by 5 Nuclear Medicine Clinics located in the city of Rio de Janeiro. The activities of {sup 99}mTc and {sup 99}Mo in those samples have been measured respectively at the clinics and at the LABMIV. By applying a standardized methodology, the ration between the activities were calculated. The results show that 147 out of 174 samples presented {sup 99}Mo activities above the minimum detectable activity of the technique. On the other hand, only 2 out of 147 samples surpassed the MBT limit suggested by the IAEA and have been detected in samples eluted from generators of 750 mCi. In one of the

Valor nutritivo de dietas contendo torta de mamona submetida a métodos alternativos de destoxificação para ovinos

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R.N. Furtado

2012-02-01

Full Text Available Avaliaram-se o consumo e a digestibilidade de nutrientes por ovinos alimentados com rações contendo torta de mamona sem tratamento (NT, tratadas com calcário calcítico (CC, ureia (UR, fosfato monobicálcico (FOS e por autoclave (ACL. Foram utilizados 20 ovinos em delineamento em blocos ao acaso, sendo 10 machos inteiros e 10 fêmeas, mestiços de raça Morada Nova. As dietas foram isoproteicas e isoenergéticas. A ricina foi parcialmente desnaturada pelos tratamentos de destoxificação da torta de mamona. Não houve efeito dos tratamentos de destoxificação da torta de mamona sobre o consumo de nutrientes. A digestibilidade da fibra em detergente neutro no tratamento NT foi de 57,5%, maior que no tratamento CC, de 52,4%. A digestibilidade do extrato etéreo foi mais alta no tratamento CC, média de 71,3%, em relação ao tratamento FOS, de 68,2%. Houve maior consumo de fibra em detergente neutro e fibra em detergente ácido dos machos em relação às fêmeas quando o consumo foi expresso em g/dia. A torta de mamona NT pode ser utilizada em dietas de ovinos como alimento proteico alternativo, participando em até 8% da dieta total, sem ocasionar redução expressiva no consumo e na digestibilidade.

Porta-enxertos utilizados na citricultura

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Schäfer Gilmar

2001-01-01

Full Text Available A muda cítrica é o insumo mais importante na formação de um pomar. As características mais importantes da muda cítrica são a origem do enxerto e do porta-enxerto, a qualidade do sistema radicular e a sua sanidade. Os porta-enxertos são capazes de influenciar várias características horticulturais e sanitárias nas árvores e nos frutos cítricos, como: sólidos solúveis totais, tamanho da copa e do fruto, resistência a moléstias e ao frio, distribuição da raízes, etc. O principal porta-enxerto utilizado no Brasil (cerca de 80% é o limoeiro ?Cravo? (Citrus limonia Osbeck cv. Cravo. No Rio Grande do Sul, mais especificamente, destaca-se o Poncirus trifoliata (L. Raf em mais de 90% dos pomares. Isso torna a citricultura vulnerável ao surgimento de moléstias que afetem estes porta-enxertos, como ocorreu na década de 40 em todo o Brasil com a 'Tristeza' dos citros em plantas enxertadas sobre laranjeira azeda, e, mais recentemente, com o 'declínio'. Assim, o conhecimento das características dos diversos porta-enxertos e de algumas particularidades do uso destes é de grande importância para a diversificação e escolha do porta-enxerto a ser utilizado pelo citricultor.

Determination of 99Mo contamination in a nuclear medicine patient submitted to a diagnostic procedure with 99mTc

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Bernardo Maranhão Dantas

2005-10-01

Full Text Available 99mTc is a radionuclide widely used for imaging diagnosis in nuclear medicine. In Brazil it is obtained by elution from 99Mo-99mTc generators supplied by the Nuclear Energy Research Institute (IPEN. The elution is carried out in radiopharmacy laboratories located in hospitals and clinics. Depending of the quality of the generator and conditions of use during the elution process, 99Mo can be extracted from the column of the generator, becoming a radionuclidic impurity of the eluate used for the obtention of the radiopharmaceutical to be administered to the patient. 99Mo emits high-energy photons and beta particles and its presence degrades the quality of the image and unnecessarily increases the radiation dose delivered to the patient. An in-vivo measurement technique was developed to verify the occurrence of internal contamination by 99Mo in nuclear medicine patients. Direct measurements were made in a volunteer who underwent myocardial scintigraphy with 99mTc-sestamibi. The results indicated the presence of internal contamination of the patien by 99Mot. The activity was tracked for several days, and an assessment of the radiation dose from the contaminant 99Mo was made.O 99mTc é um radionuclídeo largamente utilizado em diagnósticos por imagem em medicina nuclear. No Brasil, ele é obtido por eluição de um gerador de 99Mo-99mTc fornecido pelo IPEN. A eluição do gerador é feita nas clínicas onde se realizam os exames. Durante a eluição o 99Mo pode ser carreado da coluna, tornando-se uma impureza radionuclídica do eluato a ser utilizado para a obtenção do radiofármaco administrado ao paciente. O 99Mo emite fótons de alta energia e partículas beta, e sua presença, além de provocar degradação na qualidade da imagem do exame, aumenta desnecessariamente a dose de radiação no paciente. Assim, com o objetivo de verificar a possível ocorrência de contaminação interna por 99Mo em pacientes de medicina nuclear, foi desenvolvida

Avaliação da estabilidade e atividade antioxidante de uma emulsão base não-iônica contendo resveratrol

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Marcela Kist Lange

2009-03-01

Full Text Available Vários são os fatores que podem ocasionar a instabilidade de uma emulsão, destacando-se a oxidação, reação prevenida pelo emprego de antioxidantes. O butil-hidróxi-tolueno (BHT tem sido um dos antioxidantes sintéticos mais utilizados em formulações cosméticas, porém, a busca da indústria farmacêutica e cosmética pelo emprego de produtos de origem natural tem sido cada vez maior. Visto isso, o objetivo do presente trabalho foi a incorporação do resveratrol, um composto fenólico encontrado principalmente em uvas bem como em vinhos tintos, em uma emulsão base não-iônica para avaliação do perfil de estabilidade e atividade antioxidante em comparação a uma emulsão base não-iônica contendo o BHT. O perfil de estabilidade foi analisado pela observação das características organolépticas, determinação do pH e espalhabilidade, e atividade antioxidante através do teste com o radical livre 2,2-difenil-1-picrilhidrazila (DPPH. Em relação à estabilidade, a altas temperaturas, a emulsão contendo BHT mostrou-se superior à emulsão contendo resveratrol. Pela análise da atividade antioxidante, o resveratrol tanto na sua forma de extrato seco, como quando incorporado na emulsão, demonstrou significativa superioridade em relação ao BHT, podendo ser sua utilização uma alternativa viável em preparações cosméticas, devido ao seu grande potencial antioxidante.There are several factors that can lead to the instability of an emulsion, highlighting the oxidation, a reaction prevented by the use of antioxidants. The butylated hydroxytoluene (BHT has been one of the most used synthetic antioxidants in cosmetic formulations; however, pharmaceutical and cosmetic industries have shown considerable interest regarding the search for the use of natural products. Based on this, the objective of this work was the incorporation of resveratrol, a natural phenolic compound found mainly in grapes as well as in red wines, into a non

Verificação da atividade antibacteriana de sabonete líquido contendo extrato glicólico de Dimorphandra mollis Benth.

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KETYLIN FERNANDA MIGLIATO

2009-12-01

Full Text Available Dimorphandra mollis Benth., Compositae, falsobarbatimão, é utilizada topicamente como cicatrizante, adstringente e antimicrobiano. No presente estudo, verificou-se a atividade antibacteriana de sabonete líquido contendo extrato glicólico de D. mollis (EGD em diferentes concentrações (8, 15 e 20% e em diferentes pHs (6 e 8. Foram preparadas cinco formulações (F de sabonete: F1 - triclosan (0,1%, F2 - EGD (8%, F3 - EGD (15%, F4 - EGD (20% e F5 - sem conservante. Cascas de D. mollis foram secas em estufa de ar circulante e pulverizadas. Os extratos brutos foram preparados por turbo-extração utilizando-se etanol. Após filtração, os extratos foram concentrados em evaporador rotatório, liofilizados e ressuspendidos em propilenoglicol para a obtenção do extrato glicólico. A atividade antibacteriana foi verificada pelo método de difusão em ágar, empregando cilindros em placa. Placas contendo Staphylococcus aureus, Pseudomonas aeruginosa e Escherichia coli foram incubadas a 37ºC durante 24 horas. Após incubação, as leituras foram realizadas com paquímetro, observando-se o diâmetro do halo de inibição de crescimento bacteriano. Verificouse que o sabonete líquido contendo triclosan provocou inibição do crescimento bacteriano em ambos os pHs; já os sabonetes sem conservante e contendo EGD, independente da concentração e do pH empregados, não apresentaram atividade antibacteriana. Palavras-chave: Atividade antibacteriana. Sabonete líquido. Dimorphandra mollis Benth.

Synthesis and irradiation of titanium molybdates used as matrices of the {sup 99} Mo/ {sup 99m} Tc generators; Sintesis e irradiacion de molibdatos de titanio utilizados como matrices de los generadores de {sup 99} Mo/ {sup 99m} Tc

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Diaz V, H. [Facultad de Quimica, UAEM 50000 Toluca, Estado de Mexico (Mexico); Monroy G, F. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico)

2005-07-01

The {sup 99m} Tc is the radioisotope but used in nuclear medicine. Commercially it takes place starting from generators of {sup 99} Mo/{sup 99m} Tc, composed by a chromatography column padded of aluminium oxide of aluminum, where it is deposited the {sup 99} Mo, product of the fission of the {sup 235} U adsorbed and eluted, by means of a saline solution, in form of {sup 99m} TcO{sub 4}{sup -}. The production of {sup 99} Mo as a result of the fission, imposes radiochemical separations that generate significant quantities of radioactive waste of medium activity, and inflict elaborated radiochemical manipulation. Due to this, its have been carried out intense investigations to substitute the {sup 99} Mo fission product, by chemical compounds that produce {sup 99} Mo via the reaction {sup 98} Mo(n, {gamma}){sup 99} Mo. Presently work intends the use of gels of titanium molybdates like matrices of these generators. Titanium molybdates were synthesized starting from solutions TiCl{sub 3} and ammonium molybdates and it was studied the effect of the final pH of the gels, the concentration of the Ti{sup +3} and the influence of the laundry of these on the acting of generators. The best efficiencies and chemical purity, radiochemical and radionuclides of the gels like matrices of generators {sup 99} Mo/{sup 99m} Tc were gotten with the washed gel, elaborated with the solution of TiCI{sub 3} 0.35M, and to a final pH of 5.9 (Author)

Diffusion barrier performances of thin Mo, Mo-N and Mo/Mo-N films between Cu and Si

International Nuclear Information System (INIS)

Song Shuangxi; Liu Yuzhang; Mao Dali; Ling Huiqin; Li Ming

2005-01-01

In this work, we have studied the diffusion barrier performances of Mo, Mo-N and Mo/Mo-N metallization layers deposited by sputtering Mo in Ar/N 2 atmospheres, respectively. Samples were subsequently annealed at different temperatures ranging from 400 to 800 deg C in vacuum condition. The film properties and their suitability as diffusion barriers and protective coatings in silicon devices were characterized using four-point probe measurement, X-ray diffractometry, scanning electron microscopy, Auger electron spectroscopy and transmission electron microscopy analyses. Experimental results revealed that the Mo (20 nm)/Mo-N (30 nm) layer was able to prevent the diffusion reaction between Cu and Si substrate after being annealed at 600 deg C for 30 min. The adhesion between layers and the content of N atoms are the key parameters to improve the properties of Mo-based barrier materials. The Mo layer interposed between Cu and Mo-N diluted the high nitrogen concentration of the barrier and so enhanced the barrier performances

Dinâmica das exportações e avaliação da competitividade do setor de base florestal de Moçambique

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Mahanzule, Rosalina Zefanais

2013-01-01

Resumo: Este estudo teve como objetivo geral analisar a competitividade das exportações moçambicanas de produtos de madeira no período de 1994 a 2010. Os dados utilizados foram séries históricas das exportações moçambicanas e mundiais de produtos de madeira coletados no site da base de dados das Nações Unidas- UN- Comtrade. As metodologias utilizadas para alcançar os objetivos específicos traçados foram: estatística descritiva, princípio de Pareto, taxas de crescimento, razão de concentração ...

Microstructure and properties of MoSi2-MoB and MoSi2-Mo5Si3 molybdenum silicides

International Nuclear Information System (INIS)

Schneibel, J.H.; Sekhar, J.A.

2003-01-01

MoSi 2 -based intermetallics containing different volume fractions of MoB or Mo 5 Si 3 were fabricated by hot-pressing MoSi 2 , MoB, and Mo 5 Si 3 powders in vacuum. Both classes of alloys contained approximately 5 vol.% of dispersed silica phase. Additions of MoB or Mo 5 Si 3 caused the average grain size to decrease. The decrease in the grain size was typically accompanied by an increase in flexure strength, a decrease in the room temperature fracture toughness, and a decrease in the hot strength (compressive creep strength) measured around 1200 deg. C, except when the Mo 5 Si 3 effectively became the major phase. Oxidation measurements on the two classes of alloys were carried out in air. Both classes of alloys were protected from oxidation by an in-situ adherent scale that formed on exposure to high temperature. The scale, although not analyzed in detail, is commonly recognized in MoSi 2 containing materials as consisting mostly of SiO 2 . The MoB containing materials showed an increase in the scale thickness and the cyclic oxidation rate at 1400 deg. C when compared with pure MoSi 2 . However, in contrast with the pure MoSi 2 material, oxidation at 1400 deg. C began with a weight loss followed by a weight gain and the formation of the protective silica layer. The Mo 5 Si 3 containing materials experienced substantial initial weight losses followed by regions of small weight changes. Overall, the MoB and Mo 5 Si 3 additions to MoSi 2 tended to be detrimental for the mechanical and oxidative properties

DESCOLORIMENTO DE EFLUENTE ASSOCIADO AO TINGIMENTO DE ÁGATAS CONTENDO RODAMINA B COM DIFERENTES COMBINAÇÕES FOTOCATALÍTICAS VIA PROCESSOS OXIDATIVOS AVANÇADOS (POA´s

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Tiago Bender Wermuth

2013-12-01

Full Text Available O tingimento é um dos processos de acabamento das pedras semi-preciosas até a sua comercialização. Este é muito usado na indústria da ágata utilizando elevada demanda de água o que gera uma grande quantidade de águas residuárias, contendo moléculas corantes complexas, como a Rodamina B, que apresenta características de poluente orgânico com ecotoxicidade e genotoxicidade elevadas. Neste trabalho objetivou-se buscar o desenvolvimento de POA’s capazes de degradar os efluentes sintéticos provenientes do tingimento de pedras semi-preciosas contendo o corante Rodamina B (C.I 45170. Para uma melhor eficiência de remoção da Rodamina B, utilizou-se dois métodos distintos de fixação do catalisador utilizado. Primeiramente se trabalho com sílica-gel branca (1-3 mm, Tyvek e posteriormente com o Polietileno de baixa densidade (PEBD. Realizada a preparação dos materiais, investigou-se algumas combinações de métodos como UV/TiO2/SiO2/O3, UV/TiO2/PEBD/O3 bem como, o monitoramento de alguns parâmetros, como pH e a absorbância de amostras sintéticas. Os testes foram realizados em um reator em acrílico composto de lâmpada germicida (SCT – G13/T8/15W, onde se trabalhou com um volume útil de 1 L.Compondo ainda o reator, utilizou-se uma proveta de 1 litro e uma bomba peristáltica. A concentração de Rodamina B utilizada foi de 20 mg L-1. A partir dos resultados obtidos foi possível verificar que a combinação do UV/TiO2/PEBD/O3 mostrou-se ser mais eficiente. Essa combinação proporcionou um valor de constante cinética na ordem de 28,6 x 10-3 min-1. Se comparado aos demais processos investigados, pode-se observar que se teve um aumento do valor de k.

99Mo production by 100Mo(n,2n)99Mo using accelerator neutrons

International Nuclear Information System (INIS)

Sato, Nozomi; Kawabata, Masako; Nagai, Yasuki; Hashimoto, Kazuyuki; Hatsukawa, Yuichi; Saeki, Hideya; Motoishi, Shoji; Kin, Tadahiro; Konno, Chikara; Ochiai, Kentaro; Takakura, Kosuke; Minato, Futoshi; Iwamoto, Osamu; Iwamoto, Nobuyuki; Hashimoto, Shintaro

2013-01-01

We proposed a new route to produce a medical radioisotope 99 Mo by the 100 Mo(n,2n) 99 Mo reaction using accelerator neutrons. A high-quality 99 Mo with a minimum level of radioactive waste can be obtained by the proposed reaction. The decay product of 99 Mo, 99m Tc, is separated from 99 Mo by the sublimation method. The proposed route could bring a major breakthrough in the solution of ensuring a constant and reliable supply of 99 Mo. (author)

Management of radioactive waste from 99Mo production by nuclear fission

OpenAIRE

REGO, MARIA E. de M.

2014-01-01

O Brasil planeja construir uma planta de produção do 99Mo por fissão do 235U, devido à crescente utilização deste radioisótopo no setor de medicina nuclear. Neste trabalho buscou-se estimar as características físico-químicas e radiológicas dos rejeitos radioativos que serão gerados em tal instalação, além de fornecer subsídios teóricos a serem utilizados na definição do gerenciamento desses rejeitos. Estabelecidos dois cenários de produção para este projeto e utilizando-se o código Scale®, fo...

Preparation of MoB and MoB-MoSi2 composites by combustion synthesis in SHS mode

International Nuclear Information System (INIS)

Yeh, C.L.; Hsu, W.S.

2007-01-01

Combustion synthesis in the mode of self-propagating high-temperature synthesis (SHS) was carried out in the Mo-B and Mo-B-Si systems for the preparation of molybdenum boride MoB and the composite of MoB-MoSi 2 from elemental powder compacts. Under a preheating temperature above 150 deg. C , the reaction of Mo with boron in the sample compact of Mo:B = 1:1 is characterized by a planar combustion front propagating in a self-sustaining and steady manner. As the preheating temperature or sample compaction density increased, combustion temperature was found to increase and the propagation rate of the combustion front was correspondingly enhanced. Moreover, the XRD analysis provides evidence of yielding nearly single-phase α-MoB from the Mo-B sample at equiatomic stoichiometry. In the synthesis of MoB-MoSi 2 composites, the starting stoichiometry of the Mo-B-Si powder compact was varied so as to produce the final composites containing 20-80 mol% MoB. It was also found the increase of flame-front velocity and combustion temperature with increasing MoB content formed in the composite. The composition analysis by XRD shows excellent conversion from the Mo-B-Si powder compact to the MoB-MoSi 2 composite through the SHS reaction; that is, in addition to a small amount of Mo 5 Si 3 , the as-synthesized composite is composed entirely of MoB and MoSi 2

PRODUÇÃO DE QUEIJO TIPO QUARK FUNCIONAL CONTENDO EXOPOLISSACARÍDEOS

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Tatia Tie Yuhara

2015-01-01

Full Text Available Alimentos com bactérias probióticas ou prebióticos estão incluídos na categoria de alimentos contendo compostos bioativos que tem despertado interesse devido ao efeito benéfico sobre a saúde. O objetivo do trabalho foi a formulação de produto simbiótico e funcional com bactérias láticas probióticas produtoras de exopolissacarídeos (EPS. Para isto, promoveu-se a fermentação por 24 h a 37 ºC de soro de leite em pó e leite desnatado em duas formulações: “F1” contendo o prebiótico goma acácia e inoculada de bactéria probiótica Lactobacillus casei LC1, e “F2” formulada com inulina como prebiótico e fermentação por L. acidophilus LA5. Nos produtos fermentados foi determinada a quantidade de EPS produzida pelos diferentes probióticos e os valores encontrados foram de 103,5 mg/100g (F1 e 109,2 mg/100g (F2. Verificou-se que os produtos apresentaram estabilidade microbiológica e físico-química com contagens de probióticos ao final de 21 dias de armazenamento refrigerado de 2,5x109 UFC/g, pH 3,98 e 32% de extrato seco total (EST para F1 e 6,0x108 UFC/g, pH 4,16 e 31,5% EST para F2, ausência S. aureus e de coliformes. Conclui-se que o queijo Quark funcional apresentou altas contagens de bactérias láticas probióticas e presença de EPS, níveis estes importantes para a ação como alimentos funcionais e sobrevivência no trato gastrointestinal.

Measurement of target and double-spin asymmetries for the mo>→>p<mo>→→eπ+(n)> reaction in the nucleon resonance region at low $Q^2$

Energy Technology Data Exchange (ETDEWEB)

Zheng, X.; Adhikari, K. P.; Bosted, P.; Deur, A.; Drozdov, V.; El Fassi, L.; Kang, Hyekoo; Kovacs, K.; Kuhn, S.; Long, E.; Phillips, S. K.; Ripani, M.; Slifer, K.; Smith, L. C.; Adikaram, D.; Akbar, Z.; Amaryan, M. J.; Anefalos Pereira, S.; Asryan, G.; Avakian, H.; Badui, R. A.; Ball, J.; Baltzell, N. A.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Biselli, A. S.; Briscoe, W. J.; Bültmann, S.; Burkert, V. D.; Carman, D. S.; Celentano, A.; Chandavar, S.; Charles, G.; Chen, J. -P.; Chetry, T.; Choi, Seonho; Ciullo, G.; Clark, L.; Colaneri, L.; Cole, P. L.; Compton, N.; Contalbrigo, M.; Crede, V.; D' Angelo, A.; Dashyan, N.; De Vita, R.; De Sanctis, E.; Djalali, C.; Dodge, G. E.; Dupre, R.; Egiyan, H.; El Alaoui, A.; Elouadrhiri, L.; Eugenio, P.; Fanchini, E.; Fedotov, G.; Fersch, R.; Filippi, A.; Fleming, J. A.; Gevorgyan, N.; Ghandilyan, Y.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Gleason, C.; Golovach, E.; Gothe, R. W.; Griffioen, K. A.; Guidal, M.; Guler, N.; Guo, L.; Hanretty, C.; Harrison, N.; Hattawy, M.; Hicks, K.; Holtrop, M.; Hughes, S. M.; Ilieva, Y.; Ireland, D. G.; Ishkhanov, B. S.; Isupov, E. L.; Jenkins, D.; Jiang, H.; Jo, H. S.; Joosten, S.; Keller, D.; Khachatryan, G.; Khandaker, M.; Kim, A.; Kim, W.; Klein, F. J.; Kubarovsky, V.; Lanza, L.; Lenisa, P.; Livingston, K.; MacGregor, I. J. D.; Markov, N.; McKinnon, B.; Mirazita, M.; Mokeev, V.; Movsisyan, A.; Munevar, E.; Munoz Camacho, C.; Murdoch, G.; Nadel-Turonski, P.; Net, L. A.; Ni, A.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Paolone, M.; Paremuzyan, R.; Park, K.; Pasyuk, E.; Peng, P.; Pisano, S.; Pogorelko, O.; Price, J. W.; Puckett, A. J. R.; Raue, B. A.; Rizzo, A.; Rosner, G.; Rossi, P.; Roy, P.; Sabatié, F.; Salgado, C.; Schumacher, R. A.; Sharabian, Y. G.; Skorodumina, Iu.; Smith, G. D.; Sokhan, D.; Sparveris, N.; Stankovic, I.; Strakovsky, I. I.; Strauch, S.; Taiuti, M.; Tian, Ye; Ungaro, M.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Watts, D. P.; Wei, X.; Weinstein, L. B.; Wood, M. H.; Zachariou, N.; Zhang, J.; Zonta, I.

2016-10-01

We report measurements of target- and double-spin asymmetries for the exclusive channel mo>→>p<mo>→→eπ+(n)> in the nucleon resonance region at Jefferson Lab using the CEBAF Large Acceptance Spectrometer (CLAS). These asymmetries were extracted from data obtained using a longitudinally polarized NH3 target and a longitudinally polarized electron beam with energies 1.1, 1.3, 2.0, 2.3, and 3.0 GeV. The new results are consistent with previous CLAS publications but are extended to a low Q² range from 0.0065 to 0.35 (GeV/c)². The Q² access was made possible by a custom-built Cherenkov detector that allowed the detection of electrons for scattering angles as low as 6 degrees. These results are compared with the unitary isobar models JANR and MAID, the partial-wave analysis prediction from SAID, and the dynamic model DMT. In many kinematic regions our results, in particular results on the target asymmetry, help to constrain the polarization-dependent components of these models.

Valor nutricional e energia metabolizável de subprodutos do trigo utilizados para alimentação de suínos em crescimento

Directory of Open Access Journals (Sweden)

William Rui Wesendonck

2013-02-01

Full Text Available O objetivo deste trabalho foi avaliar o valor nutricional e energético de subprodutos do trigo, em dietas para suínos em crescimento, e obter equações de predição da energia metabolizável. Foram utilizados 36 suínos machos, castrados, alojados em gaiolas metabólicas individuais. Realizou-se a coleta total de fezes e urina em dois períodos de dez dias: cinco para adaptação e cinco para coleta. Utilizou-se o delineamento de blocos ao acaso, tendo-se considerado o período de coleta como bloco, com seis tratamentos e seis repetições. A dieta referência foi substituída em 30% por um dos subprodutos testados: farinheta, farelo fino, farelo de trigo, farelo grosso e farelo grosso moído; este último usado para avaliar a influência da granulometria na digestibilidade. A fibra bruta foi a variável que proporcionou a melhor estimativa da energia metabolizável. O farelo fino foi superior em energia digestível e metabolizável, em comparação ao farelo grosso moído. O farelo grosso moído apresentou os menores coeficientes de digestibilidade, e a diminuição de seu diâmetro geométrico médio não aumentou a digestibilidade dos nutrientes e da energia. Entre os subprodutos avaliados, a farinheta apresenta maior energia digestível, energia metabolizável e proteína digestível, o que mostra elevado potencial para utilização em dietas para suínos em crescimento.

Electronic structures of B1 MoN, fcc Mo2N, and hexagonal MoN

International Nuclear Information System (INIS)

Ihara, H.; Kimura, Y.; Senzaki, K.; Kezuka, H.; Hirabayashi, M.

1985-01-01

The electronic structures of B1 MoN, fcc Mo 2 N, and hexagonal MoN were observed by photoelectron spectroscopic measurement. The B1-MoN phase has been predicted to be a high-T/sub c/ superconductor because of a large density of states at Fermi level. The observed electronic structure of the stoichiometric B1-MoN phase is different from that of the real B1-MoN type. The nitrogen excess B1-MoN/sub x/ (x> or =1.3) phase, however, shows the B1-type electronic structure. This is explained by the occurrence of a nitrogen vacancy in the apparent stoichiometric B1 phase and the occupation of the nitrogen vacancy in the nitrogen-excess B1 phase. This property is related to the previously reported low T/sub c/ of the B1-MoN crystals

Estudo de propriedades físico-químicas envolvidas no processo de compactação de uma formulação experimental contendo zidovudina

Directory of Open Access Journals (Sweden)

Tatiana Angiolucci

2012-04-01

Full Text Available Estudo das propriedades físico-químicas envolvidos no processo de compactação de uma formulação experimental contendo como fármaco modelo a zidovudina. O objetivo foi caracterizar o comportamento físico-químico de comprimidos produzidos por compressão direta usando-se diferentes pressões de compactação. Nas análises foram empregadas metodologias convencionais e não convencionais. A metodologia não convencional foi o uso da técnica da atenuação de raios-gama na determinação da porosidade. As metodologias convencionais utilizadas foram os testes de friabilidade, dureza e dissolução. Os modelos teóricos utilizados para explicar o comportamento físico-químico da formulação sob compressão são os proposto por Heckel e Walker. Os estudos mostraram que o processo de densificação é governado principalmente por deformações do tipo plásticas e pressões em torno de 246MPa são suficientes para induzir deformação plástica e consolidação do sistema compactado. Os resultados da análise de Walker indicam que a formulação tem propriedades de compressão que podem ser melhoradas.

en ocho cuentos utilizados en el tercer ciclo de la educación general básica del sistema educativo costarricense en el año 2005

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Rodolfo Fernández Carballo

2006-01-01

Full Text Available En este artículo se realiza una enumeración de los diversos preceptos que la ideología patriarcal asigna a los géneros femenino y masculino, y se pretende demostrar, a partir de las concepciones teóricas de Bajtín sobre las relaciones texto-sociedad, el enunciado y las valoraciones sociales, cómo dichos preceptos se refractan en ocho cuentos de lectura obligatoria utilizados por los estudiantes del Tercer Ciclo de la Educación General Básica del Sistema Educativo Costarricense en el año 2005. Finalmente, se establecen, en la conclusión, algunas recomendaciones en torno al tema tratado por su incidencia en la formación de los estudiantes.

Measurement and Estimation of the 99Mo Production Yield by 100Mo(n,2n)99Mo

Science.gov (United States)

Minato, Futoshi; Tsukada, Kazuaki; Sato, Nozomi; Watanabe, Satoshi; Saeki, Hideya; Kawabata, Masako; Hashimoto, Shintaro; Nagai, Yasuki

2017-11-01

We, for the first time, measured the yield of 99Mo, the mother nuclide of 99mTc used in nuclear medicine diagnostic procedures, produced by the 100Mo(n,2n)99Mo reaction with accelerator neutrons. The neutrons with a continuous energy spectrum from the thermal energy up to about 40 MeV were provided by the C(d,n) reaction with 40 MeV deuteron beams. It was proved that the 99Mo yield agrees with that estimated by using the latest data on neutrons from the C(d,n) reaction and the evaluated cross section of the 100Mo(n,2n)99Mo reaction given in the Japanese Evaluated Nuclear Data Library. On the basis of the agreement, a systematic calculation was carried out to search for an optimum condition that enables us to produce as much 99Mo as possible with a good 99Mo/100Mo value from an economical point of view. The calculated 99Mo yield from a 150 g 100MoO3 sample indicated that about 30% of the demand for 99Mo in Japan can be met with a single accelerator capable of 40 MeV, 2 mA deuteron beams. Here, by referring to an existing 18F-fluorodeoxyglucose (FDG) distribution system we assumed that 99mTc radiopharmaceuticals formed after separating 99mTc from 99Mo can be delivered to hospitals from a radiopharmaceutical company within 6 h. The elution of 99mTc from 99Mo twice a day would meet about 50% of the demand for 99Mo.

Mass spectrometric determination of stability of gaseous BaMoO2, Ba2MoO4, Ba2MoO5, Ba2Mo2O8 molecules

International Nuclear Information System (INIS)

Kudin, L.S.; Balduchchi, Dzh.; Dzhil'i, G.; Gvido, M.

1982-01-01

During the mass spectrometric investigation of BaCrO 4 evaporation Cr + , Ba + , BaO + main ions are recorded as well as BaMoO 4 + , BaMoO 3 + , BaMoO 2 + , BaMoO + , BaMoO 4 + , Ba 2 MoO 5 + , BaMo 2 O 8 + ions - the products of ionization of three-component (Ba, Mo, M) molecules, forming as a result of substance chemical interaction with the material of an effusion cell (Mo). Heats of formation of BaMoO 2 , Ba 2 MoO 4 , Ba 2 MoO 5 and Ba 2 Mo 2 O 8 molecules which constituted - 577+-70, -1343+-115, -1464+-70, -2393+-90 k J/mol respectively are determined on the base of the analysis of curves of ionisation efficiency and of reaction heats Ba 2 MoO 5 =BaO+BaMoO 4 , ΔH 0 0 =322+-60 kJ/mol Ba 2 Mo 2 O 8 =2BaMoO 4 , ΔH 0 0 =351+-80 kJ/mol calculated with the use of third low of thermodynamics [ru

99Mo Yield Using Large Sample Mass of MoO3 for Sustainable Production of 99Mo

Science.gov (United States)

Tsukada, Kazuaki; Nagai, Yasuki; Hashimoto, Kazuyuki; Kawabata, Masako; Minato, Futoshi; Saeki, Hideya; Motoishi, Shoji; Itoh, Masatoshi

2018-04-01

A neutron source from the C(d,n) reaction has the unique capability of producing medical radioisotopes such as 99Mo with a minimum level of radioactive waste. Precise data on the neutron flux are crucial to determine the best conditions for obtaining the maximum yield of 99Mo. The measured yield of 99Mo produced by the 100Mo(n,2n)99Mo reaction from a large sample mass of MoO3 agrees well with the numerical result estimated with the latest neutron data, which are a factor of two larger than the other existing data. This result establishes an important finding for the domestic production of 99Mo: approximately 50% of the demand for 99Mo in Japan could be met using a 100 g 100MoO3 sample mass with a single accelerator of 40 MeV, 2 mA deuteron beams.

Avaliação toxicológica e reprodutiva de camundongos machos adultos tratados com femproporex - DOI: 10.4025/actascihealthsci.1089 Fenproporex treatment in male mice: behavior and toxicology reproductive analysis - DOI: 10.4025/actascihealthsci.1089

OpenAIRE

Estefânia Gastaldello Moreira; Camila Queiroz Moreira; José Eduardo Baroneza; Maria José Sparça Salles de Faria

2008-01-01

O femproporex é utilizado no mundo todo como potente anorexígeno. Este estudo visa esclarecer se o uso diário de femproporex provoca toxicidade comportamental e/ou reprodutiva em camundongos machos adultos. Para tanto, foram utilizados 40 camundongos, divididos em quatro grupos experimentais, cada um contendo dez animais. Um dos grupos recebeu, via gavage, apenas água, e os outros foram tratados diariamente com femproporex, nas doses de 7,5, 15 e 30 mg kg-1, por um período de 40 dias. Como re...

Produção de leite, consumo e digestibilidade aparente dos nutrientes, pH e concentração de amônia ruminal em vacas lactantes recebendo rações contendo silagem de milho e fenos de alfafa e de capim-coastcross

Directory of Open Access Journals (Sweden)

Moreira Andréia Luciane

2001-01-01

Full Text Available Utilizaram-se 10 vacas lactantes HPC e mestiças H*Z, com 55 dias de parição, peso médio de 540 kg, distribuídas em um delineamento em switch-back com o objetivo de avaliar a produção e a composição do leite, o consumo e a digestibilidade aparente de matéria seca (MS, matéria orgânica (MO, fibra em detergente neutro (FDN, proteína bruta (PB, carboidratos totais (CT e extrato etéreo (EE, e o pH e a concentração de amônia ruminal. Os animais foram alimentados ad libitum com cinco dietas contendo silagem de milho (SM, feno de alfafa (FA, feno de capim-coastcross (FCC, ½ FA+½ SM, ½ FCC+1/2 SM, na proporção de 60%, da ração total (base de matéria seca. Os consumos dos nutrientes não foram influenciados pelas dietas. As digestibilidades aparentes de MS, PB e FDN foram maiores para as dietas contendo silagem de milho. O pH e a concentração de amônia do líquido ruminal não foram influenciados pelas dietas, porém observou-se resposta quadrática para o tempo de coletas. Registrou-se maior produção de leite para os animais que receberam silagem de milho. Os teores de proteína bruta e gordura do leite não foram influenciados pelas dietas.

Dipole strength distribution below the giant dipole resonance in {sup 92}Mo, {sup 98}Mo and {sup 100}Mo

Energy Technology Data Exchange (ETDEWEB)

Rusev, G.Y.

2006-07-01

Investigations of the dipole-strength distributions in {sup 92}Mo, {sup 98}Mo and {sup 100}Mo were carried out by means of the method of nuclear resonance fluorescence. The low-lying excitations in the nuclides {sup 92}Mo, {sup 98}Mo and {sup 100}Mo have been studied in photon-scattering experiments at an electron energy of 6 MeV at the ELBE accelerator and at electron energies from 3.2 to 3.8 MeV at the Dynamitron accelerator. Five levels were observed in {sup 92}Mo. Five levels in {sup 98}Mo and 14 in {sup 100}Mo were identified for the first time in the energy range from 2 to 4 MeV. Dipole-strength distributions up to the neutron-separation energies in the nuclides {sup 92}Mo, {sup 98}Mo and {sup 100}Mo have been investigated at the ELBE accelerator. Because of the possible observation of transitions in the neighboring nuclei produced via ({gamma},n) reaction, additional measurements at electron energies of 8.4 and 7.8 MeV, below the neutron-separation energy, were performed on {sup 98}Mo and {sup 100}Mo, respectively. The number of transitions assigned to {sup 92}Mo, {sup 98}Mo and {sup 100}Mo is 340, 485 and 499, respectively, the main part of them being dipole transitions. Statistical properties of the observed transitions are obtained. The continuum contains the ground-state transitions as well as the branching transitions to the low-lying levels and the subsequent deexcitations of these levels. (orig.)

Impact of Reduced Graphene Oxide on MoS2 Grown by Sulfurization of Sputtered MoO3 and Mo Precursor Films (Postprint)

Science.gov (United States)

2016-05-26

1,2 intercalation assisted exfoliation,8–11 physical vapor deposition (PVD),12,13 and a wet chemistry approach involving thermal decomposition of a... annealed MoO3, MoS2 films S1 (MoS2 using Mo precursor), S2 (MoS2 using MoO3 precursor), S1r (MoS2 using Mo pre- cursor and rGO), and S2r (MoS2 using...MoO3 precursor and rGO). The annealed MoO3 (a) shows Mo(IV) peaks which are indicative of MoO2, and Mo(VI) peaks that occur when MoO3 is present. Both

Phase formation in Na2MoO4 - MgMoO4 - Cr2(MoO4)3 system

International Nuclear Information System (INIS)

Kotova, I.Yu.; Kozhevnikova, N.M.

1998-01-01

Interaction within Na 2 MoO 4 - MgMoO 4 - Cr 2 (MoO 4 ) 3 ternary system is studied by X ray phase and DTA methods. State diagram of NaCr(MoO 4 ) 2 - MgMoO 4 section is plotted. Production of ternary molybdates of Na 1-x Mg 1-x Cr 1+x (MoO 4 ) 3 , where 0 ≤ x ≤ 0.3, and NaMg 3 Cr(MoO 4 ) 5 composition is ascertained [ru

Desempenho de um filme livre de cromo na proteção contra a corrosão de ligas de alumínio 2024.

OpenAIRE

Mayra Rúbia Silva Castro

2001-01-01

Este trabalho propõe o uso de um filme preparado a partir de solução aquosa alcalina contendo íons de lítio, borato e alumínio, no sentido de inibir a corrosão de ligas de alumínio de uso aeronáutico, buscando sempre comparações com filmes de sais de cromo, atualmente utilizados. Os filmes foram obtidos por dip coating (5 minutos) e por polarização anódica (5 e 45 minutos) de ligas de alumínio 2024-T3 na solução aquosa alcalina contendo íons de lítio, borato e alumínio. Foram feitas micrograf...

Impact of reduced graphene oxide on MoS{sub 2} grown by sulfurization of sputtered MoO{sub 3} and Mo precursor films

Energy Technology Data Exchange (ETDEWEB)

Pacley, Shanee, E-mail: shanee.pacley@us.af.mil; Brausch, Jacob; Beck-Millerton, Emory [U.S. Air Force Research Laboratory (AFRL)/Wright Patterson Air Force Base, Wright Patterson, Ohio 45433-7707 (United States); Hu, Jianjun; Jespersen, Michael [University of Dayton Research Institute, 300 College Park, Dayton, Ohio 45469 (United States); Hilton, Al [Wyle Laboratories, 4200 Colonel Glenn Hwy, Beavercreek, Ohio 45431 (United States); Waite, Adam [University Technology Corporation, 1270 N Fairfield Rd., Beavercreek, Ohio 45432 (United States); Voevodin, Andrey A. [Department of Materials Science and Engineering, University of North Texas, 1155 Union Circle, Denton, Texas 76203 (United States)

2016-07-15

Monolayer molybdenum disulfide (MoS{sub 2}), a two dimensional semiconducting dichalcogenide material with a bandgap of 1.8–1.9 eV, has demonstrated promise for future use in field effect transistors and optoelectronics. Various approaches have been used for MoS{sub 2} processing, the most common being chemical vapor deposition. During chemical vapor deposition, precursors such as Mo, MoO{sub 3}, and MoCl{sub 5} have been used to form a vapor reaction with sulfur, resulting in thin films of MoS{sub 2}. Currently, MoO{sub 3} ribbons and powder, and MoCl{sub 5} powder have been used. However, the use of ribbons and powder makes it difficult to grow large area-continuous films. Sputtering of Mo is an approach that has demonstrated continuous MoS{sub 2} film growth. In this paper, the authors compare the structural properties of MoS{sub 2} grown by sulfurization of pulse vapor deposited MoO{sub 3} and Mo precursor films. In addition, they have studied the effects that reduced graphene oxide (rGO) has on MoS{sub 2} structure. Reports show that rGO increases MoS{sub 2} grain growth during powder vaporization. Herein, the authors report a grain size increase for MoS{sub 2} when rGO was used during sulfurization of both sputtered Mo and MoO{sub 3} precursors. In addition, our transmission electron microscopy results show a more uniform and continuous film growth for the MoS{sub 2} films produced from Mo when compared to the films produced from MoO{sub 3}. Atomic force microscopy images further confirm this uniform and continuous film growth when Mo precursor was used. Finally, x-ray photoelectron spectroscopy results show that the MoS{sub 2} films produced using both precursors were stoichiometric and had about 7–8 layers in thickness, and that there was a slight improvement in stoichiometry when rGO was used.

Nanoparticles of superconducting γ-Mo2N and δ-MoN

International Nuclear Information System (INIS)

Gomathi, A.; Sundaresan, A.; Rao, C.N.R.

2007-01-01

We have been able to prepare nanoparticles (∼4 nm diameter) of cubic γ-Mo 2 N by a simple procedure involving the reaction of MoCl 5 with urea at 873 K. The nanoparticles show a superconducting transition around 6.5 K. The γ-Mo 2 N nanoparticles are readily transformed to nanoparticles of δ-MoN with a slightly larger diameter on heating in a NH 3 atmosphere at 573 K. Phase-pure δ-MoN obtained by this means shows a superconducting transition around 5 K. - Graphical abstract: TEM image of the γ-Mo 2 N particles with the inset showing the resistivity of the sample as a function of temperature

Microwave effects on NiMoS and CoMoS single-sheet catalysts.

Science.gov (United States)

Borges, I; Silva, Alexander M; Modesto-Costa, Lucas

2018-05-04

Single-sheet nanoclusters of MoS 2 , NiMoS or CoMoS are widely used in hydrodesulfurization (HDS) catalysis in the petroleum industry. In HDS reactions under microwave irradiation, experiments indirectly pointed out that for pristine MoS 2 reaction rates are accelerated because hot spots are generated on the catalyst bed. In this work, we investigated NiMoS and CoMoS isolated single-sheet substituted catalysts before and after thiophene adsorption focusing on quantifying the effect of microwave irradiation. For that purpose, density functional theory (DFT) molecular charge densities of each system were decomposed according to the distributed multipole analysis (DMA) of Stone. Site dipole values of each system were directly associated with a larger or smaller interaction with the microwave field according to a proposed general approach. We showed that microwave enhancement of HDS reaction rates can occur more efficiently in the CoMoS and NiMoS promoted clusters compared to pristine MoS 2 in the following order: CoMoS > NiMoS > MoS 2 . The atomic origin of the catalyst hot spots induced by microwaves was clearly established in the promoted clusters.

Electronic structure of structural open derivatives of the [Mo6X14]2- cluster: [Mo5Cl13]2- and [Mo4I11]2-

International Nuclear Information System (INIS)

Miessner, H.; Korol'kov, D.V.

1983-01-01

The electronic structure of structural open derivatives of the [Mo 6 X 14 ] 2 - -cluster [Mo 5 Cl 13 ] 2 - and [Mo 4 I 11 ] 2 - has been studied by the EHMO method. In [Mo 5 Cl 13 ] 2 - 9 occupied MO's with dominant Mo4d character are responsible for the formation of the 8 metal-metal bonds. In [Mo 4 I 11 ] 2 - the stronger covalent character of the Mo-I bonds affects the localization and the energy of molecular orbitals and also the charge distribution. The metal-metal bonds are formed by 8 MO's containing considerable participation of halogen AO's contrary to the chloride cluster. There is no bonding between the Mo atoms at the wing tips of the Mo 4 butterfly and the reason for decreasing the dihedral angle between the Mo 3 planes in [Mo 4 I 11 ] 2 - compared with the octahedral angle is apparently the stabilization of the whole system (Mo-Mo and Mo-I bonds). The unpaired electron occupies in both clusters a slightly antibonding (with regard to the Mo-Mo bonds) orbital. (author)

Phase relations in the M2MoO4 - Ag2MoO4 - Hf(MoO4)2 (M=Li, Na) systems

International Nuclear Information System (INIS)

Bazarova, Zh.G.; Bazarov, B.G.; Balsanova, L.V.

2002-01-01

The M 2 MoO 4 - Ag 2 MoO 4 - Hf(MoO 4 ) 2 (M=Li, Na) systems were studied by X-ray diffraction and differential thermal analyses in the subsolidus area (450 - 500 Deg C) for the first time. The formation of the binary compound with the variable composition Li 4-x Hf 1+0.2x (MoO 4 ) 4 (0 ≤ x ≤ 0.6) in the Li 2 MoO 4 - Hf(MoO 4 ) 2 system and the ternary molybdates Li 4 Ag 2 Hf(MoO 4 ) 5 (S 1 ) and Na 2 Ag 2 Hf(MoO 4 ) 4 (S 2 ) was established and the thermal characteristics of the prepared compounds were examined. The new binary molybdate Ag 2 Hf(MoO 4 ) 3 was prepared by the reaction between Ag 2 MoO 4 and Hf(MoO 4 ) 2 [ru

Phase formation in the Li2MoO4–K2MoO4–In2(MoO4)3 system and crystal structures of new compounds K3InMo4O15 and LiK2In(MoO4)3

International Nuclear Information System (INIS)

Khal’baeva, Klara M.; Solodovnikov, Sergey F.; Khaikina, Elena G.; Kadyrova, Yuliya M.; Solodovnikova, Zoya A.; Basovich, Olga M.

2012-01-01

XRD study of solid-phase interaction in the Li 2 MoO 4 –K 2 MoO 4 –In 2 (MoO 4 ) 3 system was performed. The boundary K 2 MoO 4 –In 2 (MoO 4 ) 3 system is an non-quasibinary join of the K 2 O–In 2 O 3 –MoO 3 system where a new polymolybdate K 3 InMo 4 O 15 isotypic to K 3 FeMo 4 O 15 was found. In the structure (a=33.2905(8), b=5.8610(1), c=15.8967(4) Å, β=90.725(1)°, sp. gr. C2/c, Z=8, R(F)=0.0407), InO 6 octahedra, Mo 2 O 7 diortho groups and MoO 4 tetrahedra form infinite ribbons {[In(MoO 4 ) 2 (Mo 2 O 7 )] 3− } ∞ along the b-axis. Between the chains, 8- to 10-coordinate potassium cations are located. A subsolidus phase diagram of the Li 2 MoO 4 –K 2 MoO 4 –In 2 (MoO 4 ) 3 system was constructed and a novel triple molybdate LiK 2 In(MoO 4 ) 3 was revealed. Its crystal structure (a=7.0087(2), b=9.2269(3), c=10.1289(3) Å, β=107.401(1)°, sp. gr. P2 1 , Z=2, R(F)=0.0280) contains an open framework of vertex-shared MoO 4 tetrahedra, InO 6 octahedra and LiO 5 tetragonal pyramids with nine- and seven-coordinate potassium ions in the framework channels. - Graphical abstract: Exploring the Li 2 MoO 4 –K 2 MoO 4 –In 2 (MoO 4 ) 3 system showed its partial non-quasibinarity and revealed new compounds K 3 InMo 4 O 15 (isotypic to K 3 FeMo 4 O 15 ) and LiK 2 In(MoO 4 ) 3 which were structurally studied. An open framework of the latter is formed by vertex-shared MoO 4 tetrahedra, InO 6 octahedra and LiO 5 tetragonal pyramids. Highlights: ► Subsolidus phase relations in the Li 2 MoO 4 –K 2 MoO 4 –In 2 (MoO 4 ) 3 system were explored. ► The K 2 MoO 4 –In 2 (MoO 4 ) 3 system is a non-quasibinary join of the K 2 O–In 2 O 3 –MoO 3 system. ► New compounds K 3 InMo 4 O 15 and LiK 2 In(MoO 4 ) 3 were obtained and structurally studied. ► K 3 InMo 4 O 15 is isotypic to K 3 FeMo 4 O 15 and carries bands of InO 6 , MoO 4 and Mo 2 O 7 units. ► An open framework of LiK 2 In(MoO 4 ) 3 is formed by polyhedra MoO 4 , InO 6 and LiO 5 .

Avaliação nutricional e desempenho da silagem de raiz de mandioca contendo ou não soja integral em dietas para suínos = Nutritional evaluation and performance of cassava root silage with or without whole soybean in swine diets

Directory of Open Access Journals (Sweden)

Marcos Augusto Alves da Silva

2010-04-01

Full Text Available Dois experimentos foram conduzidos para determinar o valor nutritivo e o desempenho de suínos nas fases de crescimento e período total, alimentados com dietas formuladas com silagem de raiz de mandioca contendo ou não soja integral. No primeiro, foram utilizados 15 suínos, distribuídos em delineamento inteiramente casualizado em parcelas (animais subdivididas no tempo (subparcelas, totalizando cinco tratamentos e seis repetições. Os alimentos avaliados foram silagem de raiz de mandioca (MA, silagem de raiz de mandioca com inoculante (MI, silagem de raiz de mandioca + soja integral (MS e silagem de raiz de mandioca + soja integral com inoculante (MSI. As silagens apresentaram bons valores nutritivos e o uso de inoculante não foi efetivo para melhorar a digestibilidade dos nutrientes. No segundo, foram utilizados 36 suínos mestiços, distribuídos em um delineamento inteiramente casualizado, com restrição na casualização para duas classes de peso inicial, com três tratamentos, seisrepetições e dois animais por unidade experimental. Os tratamentos consistiram em raçãotestemunha à base de milho e farelo de soja (RT e outras duas com substituição total do milho por MA e MS. Para fase de crescimento, a conversão alimentar melhorou com o uso das silagens.Conclui-se que as silagens de mandioca, contendo ou não soja integral, apresentam bons valores nutritivos e podem substituir totalmente o milho na ração de suínos nas fases de crescimento eperíodo total.Two experiments were carried out to determine the nutritional value and performance of growing and total-period swine fed cassava root silage with or without whole soybean. In the first group, 15 crossbred swine were used, in a completely randomized design with parcels (animals subdivided in time (subparcels with five treatmentsand six replications. The study evaluated cassava root silage (CA, cassava root silage with inoculant (CI, cassava root silage + whole soybean (CS and

ITO-free flexible organic photovoltaics with multilayer MoO3/LiF/MoO3/Ag/MoO3 as the transparent electrode

International Nuclear Information System (INIS)

Chen, Shilin; Dai, Yunjie; Zhang, Hongmei; Zhao, Dewei

2016-01-01

We present efficient flexible organic photovoltaics (OPVs) with multiple layers of molybdenum oxide (MoO 3 )/LiF/MoO 3 /Ag/MoO 3 as the transparent electrode, where the thin Ag layer yields high conductivity and the dielectric layer MoO 3 /LiF/MoO 3 has high transparency due to optical interference, leading to improved power conversion efficiency compared with indium tin oxide (ITO) based devices. The MoO 3 contacting organic active layer is used as a buffer layer for good hole extraction. Thus, the multilayer MoO 3 /LiF/MoO 3 /Ag/MoO 3 can improve light transmittance and also facilitate charge carrier extraction. Such an electrode shows excellent mechanical bendability with a 9% reduction of efficiency after 1000 cycles of bending due to the ductile nature of the thin metal layer and dielectric layer used. Our results suggest that the MoO 3 /LiF/MoO 3 /Ag/MoO 3 multilayer electrode is a promising alternative to ITO as an electrode in OPVs. (paper)

Thermal expansion studies on Th(MoO4)2, Na2Th(MoO4)3 and Na4Th(MoO4)4

International Nuclear Information System (INIS)

Keskar, Meera; Krishnan, K.; Dahale, N.D.

2008-01-01

Thermal expansion behavior of Th(MoO 4 ) 2 , Na 2 Th(MoO 4 ) 3 and Na 4 Th(MoO 4 ) 4 was studied under vacuum in the temperature range of 298-1123 K by high temperature X-ray diffractometer. Th(MoO 4 ) 2 was synthesized by reacting ThO 2 with 2 mol of MoO 3 , at 1073 K in air and Na 2 Th(MoO 4 ) 3 and Na 4 Th(MoO 4 ) 4 were prepared by reacting Th(MoO 4 ) 2 with 1 and 2 mol of Na 2 MoO 4 , respectively at 873 K in air. The XRD data of Th(MoO 4 ) 2 was indexed on orthorhombic system where as XRD data of Na 2 Th(MoO 4 ) 3 and Na 4 Th(MoO 4 ) 4 were indexed on tetragonal system. The lattice parameters and cell volume of all the three compounds, fit into polynomial expression with respect to temperature, showed positive thermal expansion (PTE) up to 1123 K. The average value of thermal expansion coefficients for Th(MoO 4 ) 2 , Na 2 Th(MoO 4 ) 3 and Na 4 Th(MoO 4 ) 4 were determined from the high temperature data

Ternary system of Na2MoO4-Cs2MoO4-MoO3

International Nuclear Information System (INIS)

Zueva, V.P.; Shabanova, A.N.; Drobasheva, T.I.

1982-01-01

Using the methods of thermal analysis interaction of components in ternary system Na 2 MoO 4 -Cs 2 MoO 4 -MoO 3 has been studied. Crystallization surface consists of nine fields belonging to initial components and compounds of lateral sides. Triangulation of the system is carried out and the character of nonvariant points is clarified, the temperature of 360 deg C corresponds to low-melting eutectics

Microstructure and tribological properties of NiMo/Mo2Ni3Si intermetallic 'in-situ' composites

International Nuclear Information System (INIS)

Gui Yongliang; Song Chunyan; Yang Li; Qin Xiaoling

2011-01-01

Research highlights: → Wear resistant NiMo/Mo 2 Ni 3 Si intermetallic 'in-situ' composites was fabricated successfully with Mo-Ni-Si powder blends as the starting materials. Microstructure of the NiMo/Mo 2 Ni 3 Si composites consists of Mo 2 Ni 3 Si primary dendrites, binary intermetallic phase NiMo and small amount of Ni/NiMo eutectics structure. The NiMo/Mo 2 Ni 3 Si composites exhibited high hardness and outstanding tribological properties under room-temperature dry-sliding wear test conditions which were attributed to the covalent-dominant strong atomic bonds and excellent combination of strength and ductility and toughness. - Abstract: Wear resistant NiMo/Mo 2 Ni 3 Si intermetallic 'in-situ' composites with a microstructure of ternary metal silicide Mo 2 Ni 3 Si primary dendritic, the long strip-like NiMo intermetallic phase, and a small amount of Ni/NiMo eutectics structure were designed and fabricated using molybdenum, nickel and silicon elemental powders. Friction and wear properties of NiMo/Mo 2 Ni 3 Si composites were evaluated under different contact load at room-temperature dry-sliding wear test conditions. Microstructure, worn surface morphologies and subsurface microstructure were characterized by OM, XRD, SEM and EDS. Results indicate that NiMo/Mo 2 Ni 3 Si composites have low fiction coefficient, excellent wear resistance and sluggish wear-load dependence. The dominant wear mechanisms of NiMo/Mo 2 Ni 3 Si composites are soft abrasion and slightly superficial oxidative wear.

Análise exploratória aplicada no estudo de medicamentos contendo piroxicam Exploratory analysis applied in study of pharmaceutical formulations with piroxicam

Directory of Open Access Journals (Sweden)

Graciele Parisotto

2005-12-01

Full Text Available A identificação de diferentes formulações de medicamentos manipulados contendo piroxicam foi estudada, empregando espectros de reflexão difusa no infravermelho médio com transformada de Fourier (DRIFTS, em associação com a técnica de análise por agrupamentos hierárquicos (AAH. Os espectros de amostras, de 5 diferentes farmácias de manipulação, contendo piroxicam (10 mg e 20 mg e seus respectivos excipientes, foram adquiridos em um espectrofotômetro NICOLET Magna 550, obtendo-se duas réplicas de cada amostra. Para a análise multivariada, as informações espectrais foram tratadas no programa Pirouette® 2.7 da Infometrix, utilizando-se as regiões espectrais 1340 a 1470 cm-1, 1535 a 1680 cm-1, 2800 a 3004 cm-1 e 3290 a 3400 cm-1. Os dendogramas foram construídos com os dados auto-escalados, e correção do espalhamento da luz (MSC, utilizando três tipos de construção: simples, flexível e incremental. Com a aplicação da análise hierárquica de agrupamentos constatou-se a formação de dois grupos distintos, um contendo os princípios ativos, e outro contendo os excipientes. Os resultados demonstram que a técnica DRIFTS em conjunto com análise por agrupamentos hierárquicos constitui uma alternativa para o controle de qualidade dos processos de produção de medicamentos.The identification of different pharmaceutical formulations with piroxicam was studied, using spectra of diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS, in association with hierarchical cluster analysis (HCA technique. The spectra of samples of the 5 different compounding pharmacies, containing 10 or 20 mg of piroxicam and its respective inactive ingredients, had been collected in Nicolet Magna 550 spectrophotometer. For the multivariate analysis, the spectral information had been processed in software package Pirouette® 2.7 of the Infometrix. The dendograms had been constructed with the autoscaled data, and multiplicative scatter

In-situ fabrication of MoSi2/SiC–Mo2C gradient anti-oxidation coating on Mo substrate and the crucial effect of Mo2C barrier layer at high temperature

International Nuclear Information System (INIS)

Liu, Jun; Gong, Qianming; Shao, Yang; Zhuang, Daming; Liang, Ji

2014-01-01

MoSi 2 /SiC–Mo 2 C gradient coating on molybdenum was in situ prepared with pack cementation process by two steps: (1) carburizing with graphite powder to obtain a Mo 2 C layer on Mo substrate, and (2) siliconizing with Si powder to get a composite MoSi 2 /SiC layer on the upper part of Mo 2 C layer. The microstructure and elemental distribution in the coating were investigated with scanning electron microscopy (SEM), backscattered electron (BSE), energy dispersive spectroscopy (EDS), electron probe microanalysis (EPMA) and X-ray diffraction (XRD). Cyclic oxidation tests (at 500 °C, 1200 °C, 1400 °C and 1600 °C) demonstrated excellent oxidation resistance for the gradient composite coating and the mass loss was only 0.23% in 60 min at 1600 °C. XRD, EPMA, thermal dynamic and phase diagram analyses indicated that the Mo 2 C barrier layer played the key role in slowing down the diffusion of C and Si toward inner Mo substrate at high temperature and principally this contributed to the excellent anti-oxidation for Mo besides the outer MoSi 2 /SiC composite layer.

MoEDAL expands

CERN Multimedia

Anaïs Schaeffer

2011-01-01

The MoEDAL collaboration deployed a test array of 18 plastic Nuclear Track Etch Detector (NTD) stacks – covering an area of 1 m2 – in the MoEDAL/VELO cavern at Point 8 of the LHC ring in November 2009. This small array was supplemented by a further 110 stacks this past January. The MoEDAL test array, which now covers an area of 8 m2, will reveal its secrets early in 2013. The full MoEDAL detector will be installed in the next long shutdown of the LHC in 2013.   View of the MoEDAL detectors installed at Point 8 of the LHC ring in January 2011. MoEDAL (Monopole and Exotics Detector At the LHC), the seventh LHC experiment, was approved by the CERN Research Board at the end of 2009. Its goal is to search for very specific exotics such as highly ionising massive stable (or pseudo-stable) particles with conventional electrical charge and magnetic monopoles. “The main LHC experiments are designed to detect conventionally charged particles, with conventional ionisation patte...

Solution chemistry of Mo(III) and Mo(IV): Thermodynamic foundation for modeling localized corrosion

International Nuclear Information System (INIS)

Wang Peiming; Wilson, Leslie L.; Wesolowski, David J.; Rosenqvist, Joergen; Anderko, Andrzej

2010-01-01

To investigate the behavior of molybdenum dissolution products in systems that approximate localized corrosion environments, solubility of Mo(III) in equilibrium with solid MoO 2 has been determined at 80 deg. C as a function of solution acidity, chloride concentration and partial pressure of hydrogen. The measurements indicate a strong increase in solubility with acidity and chloride concentration and a weak effect of hydrogen partial pressure. The obtained results have been combined with literature data for systems containing Mo(III), Mo(IV), and Mo(VI) in solutions to develop a comprehensive thermodynamic model of aqueous molybdenum chemistry. The model is based on a previously developed framework for simulating the properties of electrolyte systems ranging from infinite dilution to solid saturation or fused salt limit. To reproduce the measurements, the model assumes the presence of a chloride complex of Mo(III) (i.e., MoCl 2+ ) and hydrolyzed species (MoOH 2+ , Mo(OH) 2 + , and Mo(OH) 3 0 ) in addition to the Mo 3+ ion. The model generally reproduces the experimental data within experimental scattering and provides a tool for predicting the phase behavior and speciation in complex, concentrated aqueous solutions. Thus, it provides a foundation for simulating the behavior of molybdenum species in localized corrosion environments.

Spectrophotometric and potentiometric studies of oxidation of Mo(III) by Mo(VI) in phosphoric acid medium

Energy Technology Data Exchange (ETDEWEB)

Kumar, A; Verma, G S.P. [Ranchi Coll. (India). Dept. of Chemistry

1975-12-01

Oxidation of Mo(III) (green) by Mo(VI) in an inert atmosphere and in orthophosphoric acid medium at various acid concentrations is reported. Potentiometric and spectrophotometric data suggest that oxidation of Mo(III) proceeds to Mo(V) through a binuclear species Mo(III) Mo(IV) absorbing at 400 nm. The formation of this species is facilitated at high acid concentrations. It is further found that quantitative conversion of Mo(III) into Mo(V) takes place at fairly high acid concentrations. In high phosphoric acid concentrations, solution of Mo(III) has been found to be oxidized to Mo(VI) by air and hence this can be used as a good oxygen absorber.

Transfer matrix approach to electron transport in monolayer MoS2/MoO x heterostructures

Science.gov (United States)

Li, Gen

2018-05-01

Oxygen plasma treatment can introduce oxidation into monolayer MoS2 to transfer MoS2 into MoO x , causing the formation of MoS2/MoO x heterostructures. We find the MoS2/MoO x heterostructures have the similar geometry compared with GaAs/Ga1‑x Al x As semiconductor superlattice. Thus, We employ the established transfer matrix method to analyse the electron transport in the MoS2/MoO x heterostructures with double-well and step-well geometries. We also considere the coupling between transverse and longitudinal kinetic energy because the electron effective mass changes spatially in the MoS2/MoO x heterostructures. We find the resonant peaks show red shift with the increasing of transverse momentum, which is similar to the previous work studying the transverse-momentum-dependent transmission in GaAs/Ga1‑x Al x As double-barrier structure. We find electric field can enhance the magnitude of peaks and intensify the coupling between longitudinal and transverse momentums. Moreover, higher bias is applied to optimize resonant tunnelling condition to show negative differential effect can be observed in the MoS2/MoO x system.

Phase formation in the Li2MoO4-Rb2MoO4-Ln2(MoO4)3 systems and the properties of LiRbLn2(MoO4)4

International Nuclear Information System (INIS)

Basovich, O.M.; Khajkina, E.G.; Vasil'ev, E.V.; Frolov, A.M.

1995-01-01

Phase equilibria within subsolidus range of ternary salt systems Li 2 MoO 4 -Rb 2 MoO 4 -Ln 2 (MoO 4 ) 4 (Ln - Nd, Er) are analyzed. Formation of ternary molybdate LiRbNd 2 (MoO 4 ) 4 is proved along LiNd(MoO 4 ) 2 -RbNd(MoO 4 )-2 cross-section. Phase diagram of this cross-section is plotted. Similar compounds are synthesized for Ln = La-Eu. The parameters of their monoclinic elementary cells are determined. Luminescent properties of LiRbLa 2 (MoO 4 ) 4 -Nd 3+ are studied. 17 refs., 4 figs., 2 tabs

Stacking change in MoS2 bilayers induced by interstitial Mo impurities.

Science.gov (United States)

Cortés, Natalia; Rosales, Luis; Orellana, Pedro A; Ayuela, Andrés; González, Jhon W

2018-02-01

We use a theoretical approach to reveal the electronic and structural properties of molybdenum impurities between MoS 2 bilayers. We find that interstitial Mo impurities are able to reverse the well-known stability order of the pristine bilayer, because the most stable form of stacking changes from AA' (undoped) into AB' (doped). The occurrence of Mo impurities in different positions shows their split electronic levels in the energy gap, following octahedral and tetrahedral crystal fields. The energy stability is related to the accommodation of Mo impurities compacted in hollow sites between layers. Other less stable configurations for Mo dopants have larger interlayer distances and band gaps than those for the most stable stacking. Our findings suggest possible applications such as exciton trapping in layers around impurities, and the control of bilayer stacking by Mo impurities in the growth process.

Crescimento e produtividade do almeirão em concentrações de N total contendo NH4+ na solução nutritiva Growth and yield of chicory plants under total N concentrations containing NH4+ in the nutrient solution

Directory of Open Access Journals (Sweden)

Rodrigo dos Santos Godoi

2007-08-01

Full Text Available O crescimento e a produtividade do almeirão foram determinados em cultivo hidropônico fechado com cinco concentrações de N contendo NH4+ na solução nutritiva. As cultivares "Amarelo" e "Pão de Açúcar" foram semeadas diretamente em fileiras distanciadas de 0,05m, em uma camada de areia de 0,15m, distribuída sobre telhas de fibrocimento. Após a emergência, foi efetuado o desbaste, mantendo-se uma densidade de 1.600plantas m-2. Foi empregada uma solução nutritiva padrão com a composição de, em mmol L-1, 11,0 de NO3-; 1,5 de H2PO4-; 6,5 de SO4-2; 7,5 de Ca+2; 10,0 de K+ e 1,5 de Mg+2 e, em mg L-1, 0,42 de Mn; 0,26 de Zn; 0,05 de Cu; 0,50 de B; 0,04 de Mo, e 4,82 de Fe quelatizado. Os tratamentos foram constituídos por concentrações totais de N de 11,0 (T1; 16,0 (T2; 21,0 (T3; 26,0 (T4 e 31,0 (T5mmol L-1, contendo concentrações de NH4+ de, zero; 2,5; 5,0; 7,5 e 10,0mmol L-1, respectivamente. O delineamento experimental inteiramente casualizado foi empregado, com quatro repetições e parcelas subdivididas. Foram efetuadas colheitas aos 35, 59, 76 e 97 dias após a semeadura, mediante corte da parte aérea das plantas a 0,02m acima da superfície da areia, para determinar a matéria seca e fresca. A maior produtividade foi obtida com a solução nutritiva contendo 16mmol L-1 de N total e 2,5mmol L-1 de NH4+.Chicory plants, cv. Amarela and Pão de Açúcar, were hidroponically grown to determine growth and yield under five ammonium and nitrate N concentrations in the nutrient solution. Sowing was made in rows placed 0.05m apart, over a 0.15m deep sand growing bed supported by fibber cement tiles. After emergency, plants were thinned to a plant density of 1,600plants m-2. A standard nutrient solution was used, with the composition of, in mmol L-1, 11.0 de NO3-; 1.5 H2PO4-; 6.5 SO4-2; 7.5 Ca+2; 10.0 K+ and 1.5 Mg+2, and, in mg L-1, 0.42 Mn; 0.26 Zn; 0.05 Cu; 0.50 B; 0.04 Mo, and 4.82 chelated Fe. Treatments were total N

High performance Mo adsorbent PZC

Energy Technology Data Exchange (ETDEWEB)

Anon,

1998-10-01

We have developed Mo adsorbents for natural Mo(n, {gamma}){sup 99}Mo-{sup 99m}Tc generator. Among them, we called the highest performance adsorbent PZC that could adsorb about 250 mg-Mo/g. In this report, we will show the structure, adsorption mechanism of Mo, and the other useful properties of PZC when you carry out the examination of Mo adsorption and elution of {sup 99m}Tc. (author)

Spectrophotometric and potentiometric studies of oxidation of Mo(III) by Mo(VI) in phosphoric acid medium

International Nuclear Information System (INIS)

Kumar, Arvind; Verma, G.S.P.

1975-01-01

Oxidation of Mo(III) (green) by Mo(VI) in an inert atmosphere and in orthophosphoric acid medium at various acid concentrations is reported. Potentiometric and spectrophotometric data suggest that oxidation of Mo(III) proceeds to Mo(V) through a binuclear species Mo(III) Mo(IV) absorbing at 400 nm. The formation of this species is facilitated at high acid concentrations. It is further found that quantitative conversion of Mo(III) into Mo(V) takes place at fairly high acid concentrations. In high phosphoric acid concentrations, solution of Mo(III) has been found to be oxidized to Mo(VI) by air and hence this can be used as a good oxygen absorber. (author)

Alimentação de Codornas com Milho Moído e Ração de Postura no Período Pós-jejum Durante a Muda Forçada e Seus Efeitos Sobre o Desempenho

OpenAIRE

Garcia,EA; Mendes,AA; Pizzolante,CC; Veiga,N; Mattos,TK

2002-01-01

O experimento foi realizado com o objetivo de avaliar o desempenho de codornas poedeiras alimentadas por diferentes períodos com milho moído ou ração de postura durante sete dias após três dias de jejum, método de muda utilizado. Após esse período, as aves foram alimentadas com ração de postura durante as 20 semanas do período experimental. Utilizou-se um delineamento inteiramente ao acaso com três tratamentos (ração de postura por sete dias, ração de postura por três dias e milho moído por q...

Spent 99Mo/99mTc generator as an economical source of 99Mo

International Nuclear Information System (INIS)

El-Kolaly, M.T.

1990-01-01

An improved method for utilization and purification of 99 Mo from spent 90 Mo/ 99m Tc generators has been described. After washing the generator with saline to remove the generated 99m Tc, followed by 2 mL 5 M NaOH containing a few drops of H 2 O 2 , the 99 Mo was quantitatively eluted from the generator with 5 mL 5 M NaOH. The alkaline eluate containing 99 Mo was contaminated with partially dissolved alumina. In the present method, an anion-exchange resin Dowex 1 x 8 column was used for purification of 99 Mo from the contaminating alumina. The resultant 99 Mo was of high purity and contained 3+ /mL 99 Mo solution, as estimated by atomic absorption. (author)

Avaliação de plantas transgênicas de Petunia x hybrida contendo o gene Psag12 - ipt cultivadas sob deficiência nutricional.

Directory of Open Access Journals (Sweden)

Francine Lorena Cuquel

2001-05-01

Full Text Available Deficiência nutricional em plantas pode causar clorose, necrose, desfolha, redução do crescimento e da produtividade e senescência prematura. Aplicações xógenas de citocinina podem aliviar tais sintomas. Este estudo foi efetuado para avaliar os efeitos da produção auto-regulada de citocinina na tolerância de plantas de petúnia (Petunia x hybrida à deficiência nutricional. Um gene quimérico contendo o promotor SAG12 unido ao gene ipt, o qual codifica a produção de isopentenyl transferase, uma enzima da rota metabólica da biossíntese de citocinina, foi introduzido em petúnia através de transformação mediada por Agrobacterium. Duas plantas contendo o gene ipt foram selecionadas e autopolinizadas para obtenção das linhas a serem submetidas à deficiência nutricional. Ambas as linhas PSAG12–ipt avaliadas foram mais tolerantes à deficiência nutricional que as plantas do tipo selvagem. Os resultados indicam que a produção endógena de citocinina pode aumentar a tolerância das plantas à deficiência nutricional.

Study of the activation of targets containing Mo for the production of 99Mo by the 98Mo(n,γ)99Mo nuclear reaction and the behaviour of the radionuclidic impurities of the process

International Nuclear Information System (INIS)

Nieto, Renata Correa

1998-01-01

The most used radioisotope in Nuclear Medicine is 99m Tc, in the 99 Mo- 99m Tc generator form. 99 Mo can be produced by several nuclear reactions in reactors and cyclotrons. The cyclotron production is not technically and economically viable. The production in the reactor can be done in two different ways: by the fission of 235 U and by 98 Mo(n,γ) 99 Mo reaction. A project for the production of 99 Mo by the activation of Mo and the preparation of gel type generators is under development at the 'Instituto de Pesquisas Energeticas e Nucleares'. In the present work, the radionuclidic impurities produced in the activation of MOO 3 and MoZr gel were evaluated, and these represent the two possible ways of preparing the gel of MoZr. A target of metallic Mo was also studied. The radionuclidic purity of 99m Tc eluted from generators prepared in these ways was also measured and compared with the generators prepared with fission 99 Mo. The results showed that, by all the parameters analysed, the best way of preparing the generator of 99 Mo - 99m Tc is the irradiation of MOO 3 and further preparation of the gel and the generators. (author)

Reflexões sobre os juramentos utilizados nas faculdades médicas do Brasil

Directory of Open Access Journals (Sweden)

Almir Galvão Vieira Bitencourt

Full Text Available OBJETIVO: Avaliar os juramentos médicos (JM utilizados nas faculdades de Medicina do Brasil. MÉTODOS: Estudo descritivo, incluindo as escolas médicas brasileiras com turmas formadas até 2004. Foi enviado um questionário aos responsáveis por cada faculdade, em três diferentes tentativas de contato, por correio convencional, telefone, fax e correio eletrônico. RESULTADOS: De um total de 96 faculdades, 48 (51,1% responderam ao questionário, sendo 25 destas (52,1% públicas. Todas as escolas utilizavam algum tipo de juramento durante o curso. Quanto ao texto utilizado: 44 faculdades (91,7% utilizavam o Juramento de Hipócrates (JH, trechos ou modificações deste. Trinta e oito respostas (79,2% continham o juramento na íntegra, que foram analisados quanto ao conteúdo. Os temas mais citados foram os princípios da beneficência e não-maleficência (94,7% e o segredo médico (97,4%. Somente um juramento citava autonomia dos pacientes, e nenhum o princípio da justiça. CONCLUSÕES: A utilização de JM é amplamente difundida nas escolas médicas brasileiras, mas, ao contrário do que é visto em outros países, os textos utilizados ainda são baseados, em sua grande maioria, no JH e não abordam temas atuais importantes para a ética médica e bioética.

Development Period of Forensic Importance Calliphoridae (Diptera: Brachycera in Urban Area Under Natural Conditions in Manaus, Amazonas, Brazil

Directory of Open Access Journals (Sweden)

Alex Barros-Souza

2012-06-01

Resumo. Para descrever o tempo de desenvolvimento dos imaturos de Calliphoridae sob condições naturais, dois experimentos foram realizados no Campus II do Instituto Nacional de Pesquisas da Amazônia (INPA, Manaus, Amazonas, um na estação chuvosa e o outro na estação menos chuvosa. Cadáveres de porcos domésticos (25kg cada foram utilizados como substrato atrativo para a ovipostura dos califorídeos. Fêmeas grávidas de Calliphoridae foram coletadas e os ovos foram transferidos para potes plásticos contendo placas de Petri com carne bovina moída. As espécies criadas, com respectivo tempo de desenvolvimento de ovo a adulto (em dias, na estação mais chuvosa e menos chuvosa, foram: Chrysomya albiceps (Wiedemann, 14,5 e 9,4 dias, Chrysomya megacephala (Fabricius, 10,7 e 9,4, Hemilucilia segmentaria (Fabricius, 11,5 e 10,7 Lucilia eximia (Wiedemann 19,4 e 14,3 e Paralucilia paraensis (Mello, 11,8 dias, essa criada somente na estação menos chuvosa. Este é o primeiro registro do tempo de desenvolvimento de P. paraensis.

Interstitial Mo-Assisted Photovoltaic Effect in Multilayer MoSe2 Phototransistors.

Science.gov (United States)

Kim, Sunkook; Maassen, Jesse; Lee, Jiyoul; Kim, Seung Min; Han, Gyuchull; Kwon, Junyeon; Hong, Seongin; Park, Jozeph; Liu, Na; Park, Yun Chang; Omkaram, Inturu; Rhyee, Jong-Soo; Hong, Young Ki; Yoon, Youngki

2018-03-01

Thin-film transistors (TFTs) based on multilayer molybdenum diselenide (MoSe 2 ) synthesized by modified atmospheric pressure chemical vapor deposition (APCVD) exhibit outstanding photoresponsivity (103.1 A W -1 ), while it is generally believed that optical response of multilayer transition metal dichalcogenides (TMDs) is significantly limited due to their indirect bandgap and inefficient photoexcitation process. Here, the fundamental origin of such a high photoresponsivity in the synthesized multilayer MoSe 2 TFTs is sought. A unique structural characteristic of the APCVD-grown MoSe 2 is observed, in which interstitial Mo atoms exist between basal planes, unlike usual 2H phase TMDs. Density functional theory calculations and photoinduced transfer characteristics reveal that such interstitial Mo atoms form photoreactive electronic states in the bandgap. Models indicate that huge photoamplification is attributed to trapped holes in subgap states, resulting in a significant photovoltaic effect. In this study, the fundamental origin of high responsivity with synthetic MoSe 2 phototransistors is identified, suggesting a novel route to high-performance, multifunctional 2D material devices for future wearable sensor applications. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preparation of a gel of zirconium molybdate for use in the generators of 99 Mo - 99m Tc prepared with 99 Mo produced by the 98 Mo(n,γ)99 Mo reaction

International Nuclear Information System (INIS)

Osso Junior, Joao A.; Lima, Ana Lucia V.P.; Silva, Nestor C. da; Nieto, Renata C.; Velosa, Adriana C. de

1998-01-01

IPEN develops a project concerning the preparation of a gel of Zirconium Molybdate for use in the generators of 99 Mo- 99m Tc . 99m Tc is the most used radioisotope in nuclear medicine diagnosis procedures and nowadays the generators are being prepared with imported 99 Mo, produced by 235 U fission. The production of 99 Mo by the 98 Mo(n, γ) 99 Mo reaction is now possible because of the power upgrade of IPEN's IEA-R1 reactor, from 2 to 5 MW. This work describes the preparation method of Zirconium Molybdate gel that will be used in the 99 Mo- 99m Tc generators. The gel is prepared by the chemical reaction between Mo, in Mo O 3 form, and Zr, in Zr O Cl 2 .8H 2 O form. After the reaction, the gel is filtered, dried and cracked with saline solution. The product is then loaded into glass columns for use as 99m Tc generator. The results showed the good quality of the gel prepared at laboratory level and of the generators evaluated. (author)

Edge termination of MoS2 and CoMoS catalyst particles

DEFF Research Database (Denmark)

Byskov, Line Sjolte; Nørskov, Jens Kehlet; Clausen, B. S.

2000-01-01

The edge termination of MoS2 and CoMoS catalyst particles is studied by density functional calculations. We show that for structures without vacancies Mo-terminated edges have the lowest edge energies. Creation of vacancies, which are believed to be active sites in these catalyst systems, leads...

Desempenho bioeconÃmico de ovinos alimentados com raÃÃes contendo farelo de mamona destoxificado

OpenAIRE

Marieta Maria Martins Vieira

2009-01-01

Objetivou-se avaliar o efeito da substituiÃÃo do farelo de soja pelo farelo de mamona destoxificado sobre o consumo e o desempenho de ovinos. Foram utilizados 20 borregos, mestiÃos, machos, inteiros, com peso vivo mÃdio de 19,3 Â 1,35 kg e idade mÃdia de 7 meses, e distribuÃdos aleatoriamente em quatro tratamentos de 0, 50, 75 ou 100% de substituiÃÃo, com base na matÃria seca. O volumoso utilizado foi o feno de capim-elefante. As raÃÃes foram fornecidas diariamente em duas refeiÃÃes, coletand...

Deoxygenation of glycolaldehyde and furfural on Mo2C/Mo(100)

Science.gov (United States)

McManus, Jesse R.; Vohs, John M.

2014-12-01

The desire to produce fuels and chemicals in an energy conscious, environmentally sympathetic approach has motivated considerable research on the use of cellulosic biomass feedstocks. One of the major challenges facing the utilization of biomass is finding effective catalysts for the efficient and selective removal of oxygen from the highly-oxygenated, biomass-derived platform molecules. Herein, a study of the reaction pathways for the biomass-derived platform molecule furfural and biomass-derived sugar model compound glycolaldehyde provides insight into the mechanisms of hydrodeoxygenation (HDO) on a model molybdenum carbide catalyst, Mo2C/Mo(100). Using temperature programmed desorption (TPD) and high resolution electron energy loss spectroscopy (HREELS), it was found that the Mo2C/Mo(100) catalyst was active for selective deoxygenation of the aldehyde carbonyl by facilitating adsorption of the aldehyde in an η2(C,O) bonding configuration. Furthermore, the catalyst showed no appreciable activity for furanic ring hydrogenation, highlighting the promise of relatively inexpensive Mo2C catalysts for selective HDO chemistry.

Efeito da adição de fitase associada a diferentes níveis de proteína bruta e fósforo disponível sobre o desempenho e excreção de proteína bruta de frangos de corte

OpenAIRE

Andréia Cristina Nakashima Vaz; Ricardo de Albuquerque; Marcelo Landim Brisola; Daniella Carolina Zanardo Donato; Paula Duarte Silva Rangel Garcia

2009-01-01

Foram utilizados 504 pintos de linhagem comercial para frangos de corte (Ag Ross 308) de 1 dia de idade, distribuídos em 12 tratamentos com seis repetições. O delineamento experimental utilizado foi de blocos casualizados em esquema factorial de 2x2x3, com dois níveis de fósforo disponível (0,45 e 0,34%), dois níveis de fitase (0 e 1200 FTU/kg) e três níveis de proteína bruta (22,5; 20,5 e 18,5%). Houve um aumento do peso das aves que receberam dietas contendo a enzima fitase embora não tenha...

Effect of Mo/B atomic ratio on the properties of Mo2NiB2-based cermets

International Nuclear Information System (INIS)

Xie, Lang; Li, XiaoBo; Zhang, Dan; Yi, Li; Gao, XiaoQing; Xiangtan Univ.

2015-01-01

Using three elementary substances, Mo, Ni, and amorphous B as raw materials, four series of Mo 2 NiB 2 -based cermets with the Mo/B atomic ratio ranging from 0.9 to 1.2 were successfully prepared via reaction sintering. The effect of Mo/B atomic ratio on the microstructure and properties was studied for the cermets. The results indicate that there is a strong correlation between the Mo/B atomic ratio and properties. The transverse rupture strength of the cermets increases with an increase in Mo/B ratio and shows a maximum value of 1 872 MPa at an Mo/B atomic ratio of 1.1 and then decreases with increasing Mo/B atomic ratio. The hardness and the corrosion resistance of the cermets increase monotonically with an increase in Mo/B atomic ratio. In Mo-rich cermets with an atomic ratio of Mo/B above 1.1, a small amount Ni-Mo intermetallic compound is found precipitated at the interface of Mo 2 NiB 2 grains.

In-situ fabrication of MoSi{sub 2}/SiC–Mo{sub 2}C gradient anti-oxidation coating on Mo substrate and the crucial effect of Mo{sub 2}C barrier layer at high temperature

Energy Technology Data Exchange (ETDEWEB)

Liu, Jun [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Beijing 100084 (China); State Key Laboratory of New Ceramics and Fine Processing, Beijing 100084 (China); Gong, Qianming, E-mail: gongqianming@mail.tsinghua.edu.cn [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Beijing 100084 (China); State Key Laboratory of New Ceramics and Fine Processing, Beijing 100084 (China); Shao, Yang; Zhuang, Daming [School of Materials Science and Engineering, Tsinghua University, Beijing 100084 (China); Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Beijing 100084 (China); State Key Laboratory of New Ceramics and Fine Processing, Beijing 100084 (China); Liang, Ji [Key Laboratory for Advanced Materials Processing Technology, Ministry of Education, Beijing 100084 (China); Department of Mechanical Engineering, Tsinghua University, Beijing 100084 (China)

2014-07-01

MoSi{sub 2}/SiC–Mo{sub 2}C gradient coating on molybdenum was in situ prepared with pack cementation process by two steps: (1) carburizing with graphite powder to obtain a Mo{sub 2}C layer on Mo substrate, and (2) siliconizing with Si powder to get a composite MoSi{sub 2}/SiC layer on the upper part of Mo{sub 2}C layer. The microstructure and elemental distribution in the coating were investigated with scanning electron microscopy (SEM), backscattered electron (BSE), energy dispersive spectroscopy (EDS), electron probe microanalysis (EPMA) and X-ray diffraction (XRD). Cyclic oxidation tests (at 500 °C, 1200 °C, 1400 °C and 1600 °C) demonstrated excellent oxidation resistance for the gradient composite coating and the mass loss was only 0.23% in 60 min at 1600 °C. XRD, EPMA, thermal dynamic and phase diagram analyses indicated that the Mo{sub 2}C barrier layer played the key role in slowing down the diffusion of C and Si toward inner Mo substrate at high temperature and principally this contributed to the excellent anti-oxidation for Mo besides the outer MoSi{sub 2}/SiC composite layer.

Facile synthesis of stable structured MoS{sub 2}-Mo-CNFs heteroarchitecture with enhanced hydrogen evolution

Energy Technology Data Exchange (ETDEWEB)

Mo, Qionghua [Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Chongqing 402160 (China); Faculty of Material and Energy, South West University, Chongqing 400700 (China); Yao, Yucen [Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Chongqing 402160 (China); Liu, Bitao, E-mail: liubitao007@163.com [Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Chongqing 402160 (China); Peng, Lingling; Yan, Hengqing; Hou, Zhupei; Wang, Jun [Research Institute for New Materials Technology, Chongqing University of Arts and Sciences, Chongqing 402160 (China); Lin, Yue, E-mail: linyue@ustc.edu.cn [Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Anhui 230026 (China)

2017-06-01

3D structured MoS{sub 2} are grown in-situ on Mo particles embedded carbon nanofibers (CNFs) via a hydrothermal method. Due to this special structure, the bonding and effective electron delivery between CNFs and MoS{sub 2} are both enhanced, and which will exhibits a better hydrogen evolution activity. The onset potential of this MoS{sub 2}-Mo-CNFs catalyst will decreased to 60 mV compared to the 90 mV for the MoS{sub 2}-CNFs. And its current density nearly no change with 5000 cycles which is better than the 32.3% decrease of MoS{sub 2}-CNFs at η = 300 mV (V vs RHE). - Highlights: • Newly structured MoS{sub 2}-Mo-CNFs with effectively connection between MoS{sub 2} and CNFs successfully synthesized. • This structure can enhance the charge transfer and significantly increase electrocatalytic efficiency. • Nearly no HER activity loss after 5000 CV cycles.

Interdiffusion between U(Mo,Pt) or U(Mo,Zr) and Al or Al A356 alloy

International Nuclear Information System (INIS)

Komar Varela, C.; Mirandou, M.; Arico, S.; Balart, S.; Gribaudo, L.

2009-01-01

Solid state reactions in chemical diffusion couples U-7 wt.%Mo-0.9 wt.%Pt/Al at 580 deg. C and U-7 wt.%Mo-0.9 wt.%Pt/Al A356 alloy, U-7 wt.%Mo-1 wt.%Zr/Al and U-7 wt.%Mo-1 wt.%Zr/Al A356 alloy at 550 deg. C were characterized. Results were obtained from optical and scanning electron microscopy, electron probe microanalysis and X-ray diffraction. The UAl 3, UAl 4 and Al 20 Mo 2 U phases were identified in the interaction layers of γU(Mo,Pt)/Al and γU(Mo,Zr)/Al diffusion couples. Al 43 Mo 4 U 6 ternary compound was also identified in γU(Mo,Zr)/Al due to the decomposition of γU(Mo,Zr) phase. The U(Al,Si) 3 and U 3 Si 5 phases were identified in the interaction layers of γU(Mo,Pt)/Al A356 and γU(Mo,Zr)/Al A356 diffusion couples. These phases are formed due to the migration of Si to the interaction layer. In the diffusion couple U(Mo,Zr)/Al A356, Zr 5 Al 3 phase was also identified in the interaction layer. The use of synchrotron radiation at Brazilian Synchrotron Light Laboratory (LNLS, CNPq, Campinas, Brazil) was necessary to achieve a complete crystallographic characterization.

On the reduction of orthorhombic MoO3 to MoO2

International Nuclear Information System (INIS)

Delannay, F.

1982-01-01

Electron diffraction shows evidence of topotactic orientation relationships between the original MoO 3 crystal and MoO 2 crystals formed under mild reduction conditions. These relationships differ from previously published literature data. A possible mechanism of formation of the [100] strings of edge sharing octahedra in the MoO 2 structure is tentatively proposed. (author)

Cu4Pr6(MoO4)11-Pr2(MoO4)3 system

International Nuclear Information System (INIS)

Arzumanyan, G.A.

1982-01-01

Existence boundaries and Dalton compositions (CuPr(MoO 4 ) 2 , CuPr 3 (MoO 4 ) 5 ) of solid solutions that in the mojority are of shcheelite dsitored structure have been determined in the Cu 4 Pr 6 (MoO 4 ) 11 -Pr 2 (MoO 4 ) 3 system. It has been revealed that regions of homogeneity near the CuPr(MoO 4 ) 2 composition have a horseshoeshaped profile

Sal de iodônio aumenta a resistência coesiva de uma resina adesiva experimental na presença de solvente

Directory of Open Access Journals (Sweden)

Fernanda B. Leal

2013-01-01

Full Text Available Este estudo avaliou o efeito da concentração de solvente na resistência coesiva de um adesivo experimental contendo um derivado do difeniliodônio. Uma blenda monomérica baseada em Bis-GMA, TEGDMA e HEMA foi utilizada como resina adesiva modelo. Foram avaliados dois sistemas de fotoiniciação: um sistema bináriocanforquinona (CQ e etil 4-dimetilamino benzoato (EDAB] e um sistema ternário [CQ, EDAB e hexafluorfosfato de difeniliodônio (DPI]. Nestas resinas foram adicionadas diferentes concentrações de etanol, 0, 5, 10, 20, 30, 40% e teste de resistência coesiva foi utilizado para investigar o efeito deste solvente sobre as propriedades do material. A presença de solvente reduziu a resistência coesiva do polímero, independentemente do sistema de fotoiniciação utilizado. Além disso, o uso do sal de iodônio no sistema de fotoiniciação aumentou a resistência coesiva quando comparado com o sistema binário, e independentemente da concentração de solvente, a resistência coesiva dos polímeros contendo difeniliodônio foi superior à do sistema binário de fotoiniciação.

The modulation of Schottky barriers of metal-MoS2 contacts via BN-MoS2 heterostructures.

Science.gov (United States)

Su, Jie; Feng, Liping; Zhang, Yan; Liu, Zhengtang

2016-06-22

Using first-principles calculations within density functional theory, we systematically studied the effect of BN-MoS2 heterostructure on the Schottky barriers of metal-MoS2 contacts. Two types of FETs are designed according to the area of the BN-MoS2 heterostructure. Results show that the vertical and lateral Schottky barriers in all the studied contacts, irrespective of the work function of the metal, are significantly reduced or even vanish when the BN-MoS2 heterostructure substitutes the monolayer MoS2. Only the n-type lateral Schottky barrier of Au/BN-MoS2 contact relates to the area of the BN-MoS2 heterostructure. Notably, the Pt-MoS2 contact with n-type character is transformed into a p-type contact upon substituting the monolayer MoS2 by a BN-MoS2 heterostructure. These changes of the contact natures are ascribed to the variation of Fermi level pinning, work function and charge distribution. Analysis demonstrates that the Fermi level pinning effects are significantly weakened for metal/BN-MoS2 contacts because no gap states dominated by MoS2 are formed, in contrast to those of metal-MoS2 contacts. Although additional BN layers reduce the interlayer interaction and the work function of the metal, the Schottky barriers of metal/BN-MoS2 contacts still do not obey the Schottky-Mott rule. Moreover, different from metal-MoS2 contacts, the charges transfer from electrodes to the monolayer MoS2, resulting in an increment of the work function of these metals in metal/BN-MoS2 contacts. These findings may prove to be instrumental in the future design of new MoS2-based FETs with ohmic contact or p-type character.

Phase formation in the Li2MoO4–Rb2MoO4–Fe2(MoO4)3 system and crystal structure of a novel triple molybdate LiRb2Fe(MoO4)3

International Nuclear Information System (INIS)

Khal'baeva, Klara M.; Solodovnikov, Sergey F.; Khaikina, Elena G.; Kadyrova, Yuliya M.; Solodovnikova, Zoya A.; Basovich, Olga M.

2013-01-01

X-ray investigation of solid state interaction of the components in the Li 2 MoO 4 –Rb 2 MoO 4 –Fe 2 (MoO 4 ) 3 system was carried out, and a subsolidus phase diagram of the said system was constructed. The subsystem Rb 2 MoO 4 –LiRbMoO 4 –RbFe(MoO 4 ) 2 was shown to be non-quasiternary. Formation of a novel triple molybdate LiRb 2 Fe(MoO 4 ) 3 was established, conditions of solid state synthesis and crystallization of the compound were found. Its crystal structure (orthorhombic, space group Pnma, Z=4, a=24.3956(6), b=5.8306(1), c=8.4368(2) Å) represents a new structure type and includes infinite two-row ribbons ([Fe(MoO 4 ) 3 ] 3− ) ∞ parallel to the b axis and composed of FeO 6 octahedra, terminal Mo(3)O 4 tetrahedra, and bridge Mo(1)O 4 and Mo(2)O 4 tetrahedra connecting two or three FeO 6 octahedra. The ribbons are connected to form 3D framework via corner-sharing LiO 4 tetrahedra. Rubidium cations are 11- and 13-coordinated and located in cavities of this heterogeneous polyhedral framework. - Graphical abstract: Exploring the Li 2 MoO 4 –Rb 2 MoO 4 –Fe 2 (MoO 4 ) 3 system showed its partial non-quasiternarity and revealed a new compound LiRb 2 Fe(MoO 4 ) 3 which was structurally studied. - Highlights: • The Li 2 MoO 4 –Rb 2 MoO 4 –Fe 2 (MoO 4 ) 3 system study revealed a new compound LiRb 2 Fe(MoO 4 ) 3 . • Its structure of a new type includes ribbons of FeO 6 octahedra and MoO 4 tetrahedra. • The ribbons are connected into a 3D framework via corner-sharing LiO 4 tetrahedra

Successful labeling of 99mTc-MDP using 99mTc separated from 99Mo produced by 100Mo(n,2n)99Mo

International Nuclear Information System (INIS)

Nagai, Yasuki; Hatsukawa, Yuichi; Kin, Tadahiro; Hashimoto, Kazuyuki; Motoishi, Shoji; Konno, Chikara; Ochiai, Kentaro; Takakura, Kosuke; Sato, Yuichi; Sato, Norihito; Ohta, Akio; Yamabayashi, Hisamichi; Tanase, Masakazu; Fujisaki, Saburo; Kawauchi, Yukimasa; Teranaka, Tomoyuki; Takeuchi, Nobuhiro; Igarashi, Takashi

2011-01-01

We have for the first time succeeded in separating 99m Tc from a MoO 3 sample irradiated with accelerator neutrons free from any radioactive impurities and in formulating 99m Tc-methylene diphosphonate ( 99 mTc-MDP). 99 Mo, the mother nuclide of 99m Tc, was produced by the 100 Mo(n,2n) 99 Mo reaction using about 14 MeV neutrons provided by the 3 H(d,n) 4 He reaction at the Fusion Neutronics Source of Japan Atomic Energy Agency. The 99m Tc was separated from 99 Mo by sublimation and its radionuclide purity was confirmed to be higher than 99.99% by γ-spectroscopy. The labeling efficiency of 99m Tc-MDP was shown to be higher than 99% by thin-layer chromatography. These values exceed the United States Pharmacopeia requirements for a fission product, 99 Mo. Consequently, a 99m Tc radiopharmaceutical preparation formed by using the mentioned 99 Mo can be a promising substitute for the fission product 99 Mo, which is currently produced using a highly enriched uranium target in aging research reactors. A longstanding problem to ensure a reliable and constant supply of 99 Mo in Japan can be partially mitigated. (author)

Lattice structures and electronic properties of MO/MoSe2 interface from first-principles calculations

Science.gov (United States)

Zhang, Yu; Tang, Fu-Ling; Xue, Hong-Tao; Lu, Wen-Jiang; Liu, Jiang-Fei; Huang, Min

2015-02-01

Using first-principles plane-wave calculations within density functional theory, we theoretically studied the atomic structure, bonding energy and electronic properties of the perfect Mo (110)/MoSe2 (100) interface with a lattice mismatch less than 4.2%. Compared with the perfect structure, the interface is somewhat relaxed, and its atomic positions and bond lengths change slightly. The calculated interface bonding energy is about -1.2 J/m2, indicating that this interface is very stable. The MoSe2 layer on the interface has some interface states near the Fermi level, the interface states are mainly caused by Mo 4d orbitals, while the Se atom almost have no contribution. On the interface, Mo-5s and Se-4p orbitals hybridize at about -6.5 to -5.0 eV, and Mo-4d and Se-4p orbitals hybridize at about -5.0 to -1.0 eV. These hybridizations greatly improve the bonding ability of Mo and Se atom in the interface. By Bader charge analysis, we find electron redistribution near the interface which promotes the bonding of the Mo and MoSe2 layer.

Effects of Mo Content on Microstructure and Mechanical Property of PH13-8Mo Martensitic Precipitation-Hardened Stainless Steel

Science.gov (United States)

Yubing, Pei; Tianjian, Wang; Zhenhuan, Gao; Hua, Fan; Gongxian, Yang

This paper introduces the effects of Mo content on microstructure and mechanical property of PH13-8Mo martensitic precipitation-hardened stainless steel which is used for LP last stage blade in steam turbine. Thermodynamic software Thermo-Calc has been used to calculate precipitation temperature and the mass fraction of precipitated phases in PH13-8Mo steel with different Mo content. The result shows that when the mass of Mo is below 0.6wt.%, chi-phase mu-phase and sigma-phase could disappear. The microstructure and mechanical property of high Mo PH13-8Mo (Mo=0.57wt.%) and low Mo PH13-8Mo (Mo=2.15wt.%)have been investigated in different heat treatments. The investigations reveal that austenitizing temperature decrease with the reduce of Mo content, so the optimum solution temperature for low Mo PH13-8Mo is lower than that for high Mo PH13-8Mo.The influence of solution temperature on grain size is weakened with the increase of Mo content, Mo rich carbides could retard coarsening of grain. An enormous amount of nano-size uniformly distributed β-NiAl particles are found in both kinds of steels using transmission electron microscopy, they are the most important strengthening phase in PH13-8Mo.

Perpendicular magnetic anisotropy in Mo/Co2FeAl0.5Si0.5/MgO/Mo multilayers with optimal Mo buffer layer thickness

Science.gov (United States)

Saravanan, L.; Raja, M. Manivel; Prabhu, D.; Pandiyarasan, V.; Ikeda, H.; Therese, H. A.

2018-05-01

Perpendicular Magnetic Anisotropy (PMA) was realized in as-deposited Mo(10)/Co2FeAl0.5Si0.5(CFAS)(3)/MgO(0.5)/Mo multilayer stacks with large perpendicular magnetic anisotropy energy (Keff). PMA of this multilayer is found to be strongly dependent on the thickness of the individual CFAS (tCFAS), Mo (tMo) and MgO (tMgO) layers and annealing temperatures. The interactions at the Mo/CFAS/MgO interfaces are critical to induce PMA and are tuned by the interfacial oxidation. The major contribution to PMA is due to iron oxide at the CFAS/MgO interface. X-ray diffraction (XRD) and infrared spectroscopic (FT-IR) studies further ascertain this. However, an adequate oxidation of MgO and the formation of (0 2 4) and (0 1 8) planes of α-Fe2O3 at the optimal Mo buffer layer thickness is mainly inducing PMA in Mo/CFAS/MgO/Mo stack. Microstructural changes in the films are observed by atomic force microscopy (AFM). X-ray photoelectron spectroscopy (XPS) demonstrates the oxidation of CFAS/MgO interface and the formation of Fe-O bonds confirming that the real origin of PMA in Mo/CFAS/MgO is due to hybridization of Fe (3dz2) and O (2pz) orbitals and the resulted spin-orbit interaction at their interface. The half-metallic nature CFAS with Mo layer exhibiting PMA can be a potential candidate as p-MTJs electrodes for the new generation spintronic devices.

Comparative study of NiW, NiMo and MoW prepared by mechanical alloying

International Nuclear Information System (INIS)

Gonzalez, G.; Sagarzazu, A.; Villalba, R.; Ochoa, J.

2007-01-01

The present work concern the amorphisation process induced by mechanical alloying in the NiW, NiMo and MoW systems. The alloys chosen combine a group of transition elements varying from very similar atomic radius and electronic valences (MoW) to different ones (NiW and NiMo). The three systems achieved an amorphous state after 50 h of milling. The mechanism of amorphisation proposed for NiW and NiMo was the combined effect of an excess concentration of the solute atoms entering into the structure of one of the elements and a critical concentration of defects. Continuous formation of an amorphous phase at the interface of the crystalline phase was observed during the process. MoW seems to amorphize by continuous reduction of grain size down to a critical value where the amorphisation takes place

Consumo, digestibilidade e parâmetros ruminais em bovinos de corte alimentados com dietas contendo silagem de sorgo e pré-secado de capim-tifton 85 Intake, digestibility and ruminal parameters in beef cattle fed diets with sorghum silage and tifton 85 haylage

Directory of Open Access Journals (Sweden)

Odilon Gomes Pereira

2007-12-01

Full Text Available Avaliaram-se o consumo e as digestibilidades total e parcial dos nutrientes, a eficiência microbiana, o balanço de nitrogênio, a taxa de passagem da digesta ruminal, o pH e a concentração de amônia ruminal em bovinos de corte alimentados com dietas contendo como fonte de volumoso pré-secado de capim-tifton 85 e silagem de sorgo nas seguintes proporções: 100:0; 68:32; 34:66 e 0:100, respectivamente, com base na MS. Foram utilizados quatro animais mestiços Holandês × Zebu (H × Z, fistulados no rúmen e abomaso, com peso médio de 364 kg, distribuídos em um quadrado latino 4 × 4. A relação volumoso:concentrado foi de 60:40, na base da MS. Os consumos de MS, MO, PB, carboidratos totais (CT, assim como as digestibilidades totais da PB, EE, CNF e FDN não foram influenciados pelas dietas, registrando-se valores médios de 6,01; 5,69; 0,76 e 4,64 kg/dia e 67,94; 82,42; 84,43 e 53,57%, respectivamente. Os consumos de EE, CNF, FDN e NDT e as digestibilidades aparentes totais da MS, MO e CT aumentaram linearmente com o incremento da proporção de silagem de sorgo no volumoso. As digestibilidades ruminais e intestinais de MS, CT, CNF e FDN não foram influenciadas pelas dietas. O pH não foi alterado pelos tempos de coleta nem pelas dietas. A concentração de amônia foi influenciada pelos tempos de coleta, estimando-se valor máximo de 13,14 mg/100 mL, às 2,90 horas após a alimentação. Para as dietas contendo 0; 32; 66 e 100% de silagem de sorgo no volumoso estimaram-se taxas de passagem da digesta ruminal da ordem de 4,10: 4,22; 4,27 e 5,30%/hora, respectivamente. A eficiência microbiana não foi afetada pelo nível de silagem de sorgo na dieta. O uso de silagem pré-secada de capim tifton 85 associada à silagem de sorgo mostrou-se uma boa alternativa de volumoso para bovinos de corte.The intake and the total and partial digestibility of nutrients, the microbial efficiency, the nitrogen balance, the passage rates of ruminal

Phase relations in the systems M2MoO4-Cr2(MoO4)3-Zr(MoO4)2 (M=Li, Na, or Rb)

International Nuclear Information System (INIS)

Bazarov, B.G.; Chimitova, O.D.; Bazarova, Ts.T.; Arkhincheeva, S.I.; Bazarova, Zh.G.

2008-01-01

Phase equilibria in the systems M 2 MoO 4 -Cr 2 (MoO 4 ) 3 -Zr(MoO 4 ) 2 (M=Li, Na, or Rb) were investigated by X-ray powder diffraction analysis, DTA, and IR spectroscopy. The subsolidus structure of the phase diagrams of the systems under study was established. Two phases are formed in the Rb 2 MoO 4 -Cr 2 (MoO 4 ) 3 -Zr(MoO 4 ) 2 system with the molar ratios of the starting components equal to 5:1:1 (S 2 ) and 1:1:1 (S 1 ). Proceeding from isostructural character of Rb 5 FeHf(MoO 4 ) 6 and S 2 , the unit cell parameters are determined for S 2 [ru

Controllable synthesis of carbon nanotubes by changing the Mo content in bimetallic Fe-Mo/MgO catalyst

International Nuclear Information System (INIS)

Xu Xiangju; Huang Shaoming; Yang Zhi; Zou Chao; Jiang Junfan; Shang Zhijie

2011-01-01

Research highlights: → Increasing the Mo content in the Fe-Mo/MgO catalysts resulted in an increase in wall number, diameter and growth yield of carbon nanotubes. → The Fe interacts with MgO to form complex (MgO) x (FeO) 1-x (0 4 and relative large metal Mo particles can be generated after reduction. → The avalanche-like reduction of MgMoO 4 makes the catalyst particles to be small thus enhances the utilize efficiency of Fe nanoparticles. - Abstract: A series of Fe-Mo/MgO catalysts with different Mo content were prepared by combustion method and used as catalysts for carbon nanotube (CNT) growth. Transmission electron microscopy studies of the nanotubes show that the number of the CNT walls and the CNT diameters increase with the increasing of Mo content in the bimetallic catalyst. The growth yield determined by thermogravimetric analysis also follows the trend: the higher the Mo content, the higher the yield of the CNTs. However, the increase of Mo content leads to the lower degree of graphitization of CNTs. A comparative study on the morphology and catalytic functions of Fe/MgO, Mo/MgO and Fe-Mo/MgO catalysts was carried out by scanning electron microscopy and X-ray diffraction. It is found that the Fe interacts with MgO to form complexes and is then dispersed into the MgO support uniformly, resulting in very small Fe nanoparticles after reduction. The Mo interacts with MgO to form stoichiometry compound MgMoO 4 and relative large metal Mo particles can be generated after reduction. High yield CNTs with small diameter can be generated from Fe-Mo/MgO because the avalanche-like reduction of MgMoO 4 makes the catalyst particles to be small thus enhances the utilize efficiency of Fe nanoparticles.

Desenvolvimento de formulações de biscoitos tipo cookie contendo café Development of cookie formulations containing coffee

Directory of Open Access Journals (Sweden)

Melissa de Abreu Andrade Rodrigues

2007-03-01

Full Text Available Este trabalho teve como objetivo desenvolver formulações de biscoitos tipo cookie contendo café. Desenvolveram-se três formulações com inserção de café como: bebida tipo expresso, café solúvel e café torrado e moído, utilizando como base uma formulação americana adaptada aos ingredientes brasileiros e à inserção de café. A composição centésimal média (base seca foi: 7% umidade, 70% carboidratos, 8% proteínas, 21% gorduras e 1% minerais, com valor calórico médio de 499 kcal.100 g -1. A composição centesimal e o valor calórico observados foram similares a valores reportados para biscoitos cookie comercialmente disponíveis. A forma de inserção de café afetou as características sensoriais dos produtos, avaliados por metodologia descritiva de perfil de sabor e de textura. A Formulação 1 (bebida tipo expresso apresentou valores inferiores para a intensidade dos atributos referentes à presença de rachaduras, fragmentação, presença de pontos escuros, aroma de café e queimado. A Formulação 2 (café solúvel apresentou notas superiores de intensidade dos atributos de cor marrom, brilho, sabor amargo e de queimado, sabor residual de açúcar mascavo e crocância da borda e inferiores para concavidade. A Formulação 3 (café torrado e moído apresentou valores superiores para a presença de pontos escuros. As três formulações apresentaram notas satisfatórias e equivalentes de aceitação por crianças.The aim of the present study is to develop cookie formulations containing coffee. Three formulations were developed, each with a distinct way of adding coffee: espresso beverage, instant coffee and roasted coffee powder. The average proximate composition (dry basis of the formulations was 7% moisture, 70% carbohydrates, 8% protein, 21% fat and 1% minerals, resulting in an average caloric value of 499 kcal per 100 g product. Both the proximate composition and average caloric value were similar to values reported

Adaptación cultural de instrumentos utilizados en salud ocupacional

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Alexandre Neusa Maria Costa

2002-01-01

Full Text Available Se han creado numerosos instrumentos estandarizados para evaluar el estado de salud y la eficacia de los tratamientos. Sin embargo, la mayoría de ellos han sido desarrollados y validados en la lengua inglesa. En la literatura se recomienda la utilización de escalas y cuestionarios estandarizados cuyos resultados puedan ser comparados internacionalmente. Las diferencias culturales no permiten hacer una simple traducción de estos instrumentos. En este artículo se resumen normas sistematizadas para la adaptación cultural de instrumentos utilizados en salud ocupacional, derivadas de investigaciones especializadas.

Effect of unlabelled monoclonal antibody (MoAb) on biodistribution of /sup 111/Indium labelled (MoAb)

Energy Technology Data Exchange (ETDEWEB)

Lamki, L M; Murray, J L; Rosenblum, M G; Patt, Y Z; Babaian, Richard; Unger, M W

1988-08-01

We have evaluated immunoscintigraphy in cancer patients using four /sup 111/In-labelled murine monoclonal antibodies (MoAb): 96.5 (anti-P97 of melanoma), ZME-018 (anti-high molecular weight antibody of melanoma), ZCE-025 (anti-CEA for colon cancer) and PAY-276 (anti-prostatic acid phosphatase for prostatic cancer). The effect of increasing the doses of unlabelled MoAb (co-infused with 1 mg labelled MoAb) on the relative body distribution of each labelled MoAb was assessed. Localization in the liver decreased significantly in all cases, with increasing MoAb dose, except for ZME-018. Localization in other organs increased significantly as the liver activity decreased. The spleen activity, however, fell in the case of MoAb ZME-018. Blood-pool activity increased with MoAb dose in all four MoAbs. These findings correlated with the rise in the detection rate of metastases, the plasma half-life, and other pharmacokinetic parameters. However, the dose level at which this correlation occurred varied with each antibody. These data demonstrate the co-infusion of unlabelled MoAb with /sup 111/In-labelled MoAb could alter the organ distribution, pharmacokinetics and tumour uptake in a favourable manner, though the degree to which this occurs depends on the antibody in question.

Photo-transmutation of {sup 100}Mo to {sup 99}Mo with Laser-Compton Scattering Gamma-ray

Energy Technology Data Exchange (ETDEWEB)

Lee, Jiyoung; Rehman, Haseeb ur; Kim, Yonghee [KAIST, Daejeon (Korea, Republic of)

2016-10-15

This paper presents a photonuclear transmutation method using laser Compton scattering (LCS) gamma-ray beam. Potential production rate (reaction rate) of 99Mo using the photonuclear (γ,n) reaction is evaluated. Rigorous optimization of the LCS spectrum has also been performed to maximize production of the 99Mo. Cyclotron proton accelerators are used worldwide to produce many short-living medical isotopes. However, few are capable of producing Mo-99 and none are suitable for producing more than a small fraction of the required amounts. More than 90% of the world's demand of 99Mo is sourced from five nuclear reactors. Two of these reactors have already been decommissioned and the rest are more than 45 years old. Relatively short half-life of the parent 99Mo requires continuous re-supply to meet the requirements of medical industry. Therefore, there is an urgent need to produce the 99Mo and 99mTc isotopes by alternative ways. One such alternative is giant dipole resonance (GDR) based photonuclear transmutation of 100Mo to 99Mo. For 99Mo production with the LCS photons using GDR-based (γ,n) reaction, the gamma-ray energy should be around 15 MeV. This study indicates that optimization of LCS spectrum by varying the electron and laser energies within practical limits can enhance the transmutation of Mo-100 to M-99 quite significantly. It has been found that irradiation time should be rather short, e.g., less than 6 hours, to maximize the weekly production of Mo-99 in the GDR-based Mo-99 production facility using the LCS photons. The analysis shows that production of 99Mo using a high-performance LCS facility offers a potentially-promising alternative for the production of 99mTc.

Holey Reduced Graphene Oxide Coupled with an Mo2 N-Mo2 C Heterojunction for Efficient Hydrogen Evolution.

Science.gov (United States)

Yan, Haijing; Xie, Ying; Jiao, Yanqing; Wu, Aiping; Tian, Chungui; Zhang, Xiaomeng; Wang, Lei; Fu, Honggang

2018-01-01

An in situ catalytic etching strategy is developed to fabricate holey reduced graphene oxide along with simultaneous coupling with a small-sized Mo 2 N-Mo 2 C heterojunction (Mo 2 N-Mo 2 C/HGr). The method includes the first immobilization of H 3 PMo 12 O 40 (PMo 12 ) clusters on graphite oxide (GO), followed by calcination in air and NH 3 to form Mo 2 N-Mo 2 C/HGr. PMo 12 not only acts as the Mo heterojunction source, but also provides the Mo species that can in situ catalyze the decomposition of adjacent reduced GO to form HGr, while the released gas (CO) and introduced NH 3 simultaneously react with the Mo species to form an Mo 2 N-Mo 2 C heterojunction on HGr. The hybrid exhibits superior activity towards the hydrogen evolution reaction with low onset potentials of 11 mV (0.5 m H 2 SO 4 ) and 18 mV (1 m KOH) as well as remarkable stability. The activity in alkaline media is also superior to Pt/C at large current densities (>88 mA cm -2 ). The good activity of Mo 2 N-Mo 2 C/HGr is ascribed to its small size, the heterojunction of Mo 2 N-Mo 2 C, and the good charge/mass-transfer ability of HGr, as supported by a series of experiments and theoretical calculations. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthesis, structure and optical properties of two isotypic crystals, Na3MO4Cl (M=W, Mo)

International Nuclear Information System (INIS)

Han, Shujuan; Bai, Chunyan; Zhang, Bingbing; Yang, Zhihua; Pan, Shilie

2016-01-01

Two isotypic compounds, Na 3 MO 4 Cl (M = W, Mo) have been obtained from the high temperature solution, and their structures were determined by single-crystal X-ray diffraction. Both of them crystallize in the space group P4/nmm of tetragonal system with the unit cells: a=7.5181(15), c=5.360(2) for Na 3 WO 4 Cl and a=7.4942(12), c=5.3409(18) for Na 3 MoO 4 Cl. The structure exhibits a 3D network built up by the ClNa 6 groups, and the MO 4 groups reside in the tunnels of the 3D network. The structural similarities and differences between Na 3 MO 4 Cl (M=W, Mo) and Sr 3 MO 4 F (M=Al, Ga) have been discussed. Meanwhile, detailed structure comparison analyses between Na 3 MO 4 Cl (M=W, Mo) and Na 3 MO 4 F (M=W, Mo) indicate that the different connection modes of ClNa 6 and FNa 6 make Na 3 MO 4 Cl and Na 3 MO 4 F crystallize in different structures. The IR spectra were used to verify the validity of the structure. The diffuse reflectance spectra show that the UV absorption edges are about 249 nm (4.99 eV) and 265 nm (4.69 eV) for Na 3 WO 4 Cl and Na 3 MoO 4 Cl, respectively. In addition, the first-principles theoretical studies are also carried out to aid the understanding of electronic structures and linear optical properties. - Graphical abstract: Two isotypic compounds, Na 3 MO 4 Cl (M=W, Mo) have been obtained from the high temperature solution. Both of them crystallize in the space group P4/nmm of tetragonal system. The structure exhibits a 3D network built up by the ClNa 6 groups, and the MO 4 groups reside in the tunnels of the 3D network. - Highlights: • Structure and properties of Na 3 MO 4 Cl (M=W, Mo) are reported for the first time. • They show a 3D network built by ClNa 6 , and WO 4 lies in the tunnels of the network. • IR spectra were used to verify the validity of the structure. • Band structures and density of states have been calculated.

Radiochemical purity of Mo and Tc solution obtained after irradiation and dissolution of Mo-100-enriched and ultra-high-purity natural Mo disks

Energy Technology Data Exchange (ETDEWEB)

Tkac, Peter [Argonne National Lab. (ANL), Argonne, IL (United States); Gromov, Roman [Argonne National Lab. (ANL), Argonne, IL (United States); Chemerisov, Sergey D. [Argonne National Lab. (ANL), Argonne, IL (United States); Rotsch, David A. [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States)

2016-09-01

Four irradiations of ultra-high-purity natural Mo targets and one irradiation using 97.4% Mo-100-enriched material were performed. The purpose of these irradiations was to determine whether the presence of Sn stabilizer in the H₂O₂ used for the dissolution of sintered Mo disks can affect the radiochemical purity of the final K₂MoO₄ in 5M KOH solution. Results from radiochemical purity tests performed using thin-layer paper chromatography show that even 2– 3× excess of Sn-stabilized H₂O₂ typically used for dissolution of sintered Mo disks did not affect the radiochemical purity of the final product.

Microestrutura, fases cristalinas e propriedades elétricas de porcelanas aluminosas contendo diferentes concentrações de Fe2O3sinterizadas em atmosfera redutora e oxidante

Directory of Open Access Journals (Sweden)

D. H. Piva

2015-09-01

Full Text Available ResumoPorcelanas aluminosas contendo diferentes concentrações de Fe2O3 foram sinterizadas em atmosfera oxidante e redutora. A microestrutura e fases formadas foram investigadas com o auxílio de difração de raios X e microscopia eletrônica de varredura. Espectroscopia de impedância foi utilizada para estudar as propriedades elétricas. Os resultados indicaram que todas as amostras apresentaram mulita e coríndon como fases majoritárias e pequenas frações de quartzo. A adição de Fe2O3 provocou o surgimento de hematita nas amostras sinterizadas em atmosfera oxidante e, ferro metálico nas amostras contendo > 3%p sinterizadas em atmosfera redutora. Os espectros de impedância indicam que as características da fase vítrea e interface entre fase vítrea /fases cristalinas regem o comportamento elétrico global das amostras. Não obstante, diferentes atmosferas de queima provocam efeitos opostos na resistividade elétrica das porcelanas contendo Fe2O3. A presença de hematita foi considerada a responsável pela diminuição da resistividade elétrica nas amostras sinterizadas em atmosfera oxidante, enquanto que o aumento na resistividade elétrica das amostras sinterizadas em atmosfera redutora foi atribuído à elevada quantidade de fase vítrea e porosidade. Estes resultados indicam que atmosfera redutora durante a queima pode favorecer o uso de matérias-primas com maiores concentrações de Fe2O3, desde que todo óxido de ferro tenha se dissolvido na fase liquida durante a queima.

Development on UO3-K2O and MoO3-K2O binary systems and study of UO2MoO4-MoO3 domain within UO3-MoO3-K2O ternary system

International Nuclear Information System (INIS)

Dion, C.; Noel, A.

1983-01-01

This paper confirms the previous study on the MoO 3 -K 2 O system, and constitutes a clarity of the UO 3 -K 2 O system. Four distinct uranates VI with alkaline metal/uranium ratio's 2, 1, 0,5 and 0,285 exist. Preparation conditions and powder diffraction spectra of these compounds are given. Additional informations relative to K 2 MoO 4 allotropic transformations are provided. Study of UO 2 MoO 4 -K 2 MoO 4 diagram has brought three new phases into prominence: (B) K 6 UMo 4 O 18 incongruently melting point, (E) K 2 UMo 2 O 10 congruently melting and (F) K 2 U 3 Mo 4 O 22 incongruently melting point. Within MoO 3 -K 2 MoO 4 -UO 2 MoO 4 ternary system, no new phase is found. The general appearance of ternary liquidus and crystallization fields of several compounds are given. These three new compounds become identified with these of UO 2 MoO 4 -Na 2 MoO 4 binary system [fr

Investigation of BaMoO4-Ln2(MoO4)3 systems (Ln = Nd, Sm, Yb)

International Nuclear Information System (INIS)

Vakulyuk, V.V.; Evdokimov, A.A.; Khomchenko, G.P.

1982-01-01

Using the methods of X-ray phase and differential-thermal analyses phase ratios in the systems BaMoO 4 -Ln 2 (MoO 4 ) 3 (Ln=Nd, Sm, Yb); BaNd 2 (MoO 4 ) 4 -MaGd 2 (MoO 4 ) are studied. Unit cell parameters and the character of melting of the compounds BaLn 2 (MoO 4 ) 4 are specified. Effect of growth conditions on laminated nature of BaGd 2 (MoO 4 ) 4 monocrystals is studied

Respostas da Tilápia do Nilo (Oreochromis niloticus à atratividade e palatabilidade de ingredientes utilizados na alimentação de peixes

Directory of Open Access Journals (Sweden)

Pereira-da- Silva Elyara Maria

2000-01-01

Full Text Available Avaliaram-se as respostas da tilápia do Nilo à atratividade e palatabilidade de 14 ingredientes. O método utilizado foi de dupla escolha, comparando-se cada ingrediente peletizado à uma ração controle. Foram empregados quatro aquários (750 litros contendo, cada um, três alevinos e dois comedouros instalados nos cantos direito e esquerdo, sendo registrados tempo decorrido entre colocação do ingrediente e chegada dos animais aos comedouros, freqüência de visitas aos comedouros, número de grânulos ingeridos e freqüência de ejeções. Os tratamentos foram comparados pela prova não-paramétrica de Kruskal-Wallis e a comparação dos ingredientes para o conjunto de variáveis, por intermédio da "Análise de Agrupamento" e "Análise de Componentes Principais". Os ingredientes foram assim classificados: a baixa atrato-palatabilidade = farelos de trigo, soja e algodão, farinha e raspa de mandioca, farinha de girassol e fubá de milho, b média atrato-palatabilidade = levedura de cana-de-açúcar e glúten de milho e c alta atrato-palatabilidade = ovo integral liofilizado, farinhas de crisálidas, peixes, carne e camarão. Ingestão de grânulos (manhã e tarde e freqüência de visitas aos comedouros (tarde foram consideradas as variáveis mais discriminatórias e freqüência de ejeção de grânulos e tempo gasto para aproximação dos comedouros (manhã e tarde, as menos discriminatórias. As respostas comportamentais dos peixes variaram de acordo com o ingrediente apresentado. A avaliação do grau de atrato-palatabilidade deve ser realizada considerando-se uma combinação de parâmetros.

Systems Tl2MoO4-E(MoO4)2, where E=Zr or Hf, and the crystal structure of Tl8Hf(MoO4)6

International Nuclear Information System (INIS)

Bazarov, B.G.; Bazarova, Ts.T.; Fedorov, K.N.; Bazarova, Zh.G.; Chimitova, O.D.; Klevtsova, R.F.; Glinskaya, L.A.

2006-01-01

Systems Tl 2 MoO 4 -E(MoO 4 ) 2 (E=Zr, Hf) were studied by X-ray diffraction, differential thermal analysis and IR spectroscopy. Formation of Tl 8 E(MoO 4 ) 6 and Tl 2 E(MoO 4 ) 2 compounds was established. Phase T-x diagrams of the Tl 2 MoO 4 -Zr(MoO 4 ) 2 system were constructed. Monocrystals were grown, and structure of Tl 8 Hf(MoO 4 ) 6 was studied. The compound is crystallized in monoclinic syngony with elementary cell parameters a=9.9688(6), b=18.830(1), c=7.8488(5) A, β=108.538(1) Deg, Z=2, sp. gr. C2/m. The isolated group [HfMo 6 O 24 ] 8- is responsible for fundamental fragment of the structure. Three varieties of crystallographically independent Tl-polyhedra fill space evenly between fragments [HfMo 6 O 24 ] 8- forming three-dimensional form [ru

Produção de mudas de tomateiro em substratos contendo fibra de coco e pó de rocha Tomato seedlings production using substrates with coconut fiber and rock waste

Directory of Open Access Journals (Sweden)

Regynaldo A Sampaio

2008-12-01

Full Text Available Com o objetivo de avaliar proporções dos resíduos fibra de coco (FC e pó de rocha de granito (RG como substratos na produção de mudas de tomateiro, cultivar Kada Gigante, realizou-se um experimento em casa de vegetação na UFMG-ICA. Foi utilizado o delineamento experimental em blocos ao acaso, com quatro repetições. Os tratamentos foram constituídos por uma testemunha e seis proporções de fibra de coco (FC e pó de rocha de granito (RG: T1 - Substrato comercial Hortimix®; T2 - 0% FC + 100% RG; T3 - 20% FC + 80% RG; T4 - 40% FC + 60% RG; T5 - 60% FC + 40% RG; T6 - 80% FC + 20% RG; T7 - 100% FC + 0% RG. O cultivo foi feito em bandeja de poliestireno expandido com células de 3,5 x 3,5 x 5,0 cm. Foram avaliados o diâmetro do coleto, a altura da planta, o índice de velocidade de emergência, a percentagem de emergência e a massa fresca e seca da parte aérea e da raiz. Em praticamente todas as características avaliadas o substrato comercial foi superior aos substratos contendo fibra de coco e pó de rocha. Considerando-se apenas os substratos contendo fibra de coco e pó de rocha, as mudas com melhores características foram obtidas com a mistura de aproximadamente 70% em volume de fibra de coco.A greenhouse experiment was carried out to evaluate the ratio of coconut fiber and rock waste, in the tomato seedling production (cultivar Kada Gigante, in Montes Claros, Brazil. The experimental design was of randomized complete blocks with four replicates. The treatments were composed of a control and six ratios of coconut fiber (FC and rock waste (RG: T1 - Commercial Substrate Hortimix®; T2 - 0% FC + 100% RG; T3 - 20% FC + 80% RG; T4 - 40% FC + 60% RG; T5 - 60% FC + 40% RG; T6 - 80% FC + 20% RG; T7 - 100% FC + 0% RG. The cultivation was done in polystyrene trays with cells of 3.5 x 3.5 x 5,0 cm. Stem diameter, seedling height, emergency speed index, emergency percentage, root and aerial part of fresh and dry matter were evaluated. In

Phase equilibria in the Tl2MoO4–R2(MoO43–Zr(MoO42 (R = Al, Cr systems: synthesis, structure and properties of new triple molybdates Tl5RZr(MoO46 and TlRZr0.5(MoO43

Directory of Open Access Journals (Sweden)

V. G. Grossman

2017-12-01

Full Text Available The Tl2MoO4–R2(MoO43–Zr(MoO42 (R = Al, Cr systems were studied in the subsolidus region using X-ray powder diffraction and differential scanning calorimetric (DSC analysis. Quasi-binary joins were revealed, and triangulation was carried out. New ternary molybdates: Tl5RZr(MoO46 (5:1:2 and TlRZr0.5(MoO43 (1:1:1 (R = Al, Cr were prepared. The unit cell parameters for the new compounds were calculated.

Hydrothermal Synthesis of MoO2 and Supported MoO2 Cata-lysts for Oxidative Desulfurization of Dibenzothiophene

Institute of Scientific and Technical Information of China (English)

Wang Danhong; Zhang Jianyong; Liu Ni; Zhao Xin; Zhang Minghui

2014-01-01

A novel method for obtaining spherical MoO2 nanoparticles and SiO2-Al2O3 supported MoO2 by hydrothermal reduction of Mo (VI) species was studied. The obtained MoO2 catalysts show very high catalytic activity in the oxidative desulfurization (ODS) process. The effect of hydrothermal temperature and crystallization temperature on ODS activity was investigated. The ODS activity of supported MoO2 catalysts with various MoO2 contents were also investigated. The mecha-nism for formation of MoO2 involving oxalic acid was proposed.

Phase equilibria in the CdMoO4-Gd2(MoO4)3 system

International Nuclear Information System (INIS)

Tunik, T.A.; Fedorov, N.F.; Razumovskij, S.N.

1980-01-01

The constitutional diagram of the CdMoO 4 -Cd 2 (MoO 4 ) 3 system has been plotted using statistical and dynamic methods as well as a complex of instrumental analysis procedures. Three major phases have been found to occur in the systems, viz.: CdMoO 4 based solid solutions that crystallize in the range from 0 to 25 mol.percent of Cd 2 (MoO 4 ) 3 and pass in transit the two-phase narrow region becoming then solid solutions having a distorted scheelite structure and existing in concentrations from 40 to 65 mol.% of Cd 2 (MoO 4 ) 3 . The entire range, in which the Cd 2 (MoO 4 ) 3 solid solutions can exist, amounts to less than 5 mol.%. Certain crystallochemical constants of the phases that occur in the system have been determined [ru

Measurement of formation cross-section of 99Mo from the 98Mo(n,γ) and 100Mo(n,2n) reactions.

Science.gov (United States)

Badwar, Sylvia; Ghosh, Reetuparna; Lawriniang, Bioletty M; Vansola, Vibha; Sheela, Y S; Naik, Haladhara; Naik, Yeshwant; Suryanarayana, Saraswatula V; Jyrwa, Betylda; Ganesan, Srinivasan

2017-11-01

The formation cross-section of medical isotope 99 Mo from the 98 Mo(n,γ) reaction at the neutron energy of 0.025eV and from the 100 Mo(n,2n) reaction at the neutron energies of 11.9 and 15.75MeV have been determined by using activation and off-line γ-ray spectrometric technique. The thermal neutron energy of 0.025eV was used from the reactor critical facility at BARC, Mumbai, whereas the average neutron energies of 11.9 and 15.75MeV were generated using 7 Li(p,n) reaction in the Pelletron facility at TIFR, Mumbai. The experimentally determined cross-sections were compared with the evaluated nuclear data libraries of ENDF/B-VII.1, CENDL-3.1, JENDL-4.0 and JEFF-3.2 and are found to be in close agreement. The 100 Mo(n,2n) 99 Mo reaction cross-sections were also calculated theoretically by using TALYS-1.8 and EMPIRE-3.2 computer codes and compared with the experimental data. Copyright © 2017 Elsevier Ltd. All rights reserved.

Artigo revisão: estabilização de suspensões aquosas contendo grafite Review article: stabilization of graphite-containing aqueous suspensions

Directory of Open Access Journals (Sweden)

I. R. de Oliveira

2000-12-01

Full Text Available A aplicação de materiais refratários contendo grafite tem aumentado muito nos últimos 10 anos, especialmente no caso de concretos refratários. Tais refratários são considerados compósitos singulares em que o grafite contribui para a redução da expansão térmica, aumento da resistência ao choque térmico, da energia de fratura e da resistência ao ataque por escória. Entretanto, sua baixa molhabilidade por água e líquidos orgânicos dificulta o seu processamento por meio de suspensões. Em virtude disso, um tratamento da superfície das partículas de grafite deve ser realizado visando melhorar sua molhabilidade e dispersão em suspensão aquosa. As principais características estruturais e superficiais responsáveis pela sua baixa molhabilidade e os métodos de tratamento superficial mais utilizados são abordados nesta revisão. Tais métodos de tratamento superficial envolvem, principalmente, a adsorção de agentes ativos na superfície, como é o caso dos surfactantes e polieletrólitos, e a cobertura da superfície por uma espécie hidrofílica.The application of graphite-containing refractories has increased enormously over the latest ten years, especially in the case of refractory castables. Graphite in such refractories contributes to the reduction of the material thermal expansion and improvement on its thermal shock resistance, fracture energy and slag resistance. However, the low wettability of graphite in water and organic liquids represents a barrier to its processing. Therefore, a surface treatment of graphite particles is required to improve its wettability and enable its dispersion in aqueous suspensions. The main structural and surface characteristics responsible for the low wettability of graphite, as well as the most common surface treatment methods applied are discussed in the present review article. Such surface treatment methods include the surface covering of graphite by hydrophilic species and the

Comparitive study of fluorescence lifetime quenching of rhodamine 6G by MoS2 and Au-MoS2

Science.gov (United States)

Shakya, Jyoti; Kasana, Parath; Mohanty, T.

2018-04-01

Time resolved fluorescence study of Rhodamine 6G (R6G) in the presence of Molybdenum disulfide (MoS2) nanosheets and gold doped MoS2 (Au-MoS2) have been carried out and discussed. We have analyzed the fluorescence decay curves of R6G and it is observed that Au-MoS2 is a better fluorescence lifetime quencher as compare to MoS2 nanosheets. Also, the energy transfer efficiency and energy transfer rate from R6G to MoS2 and Au-MoS2 has been calculated and found higher for Au-MoS2.

Demonstration of resonant photopumping of Mo VII by Mo XII for a VUV laser near 600 Angstrom

International Nuclear Information System (INIS)

Ilcisin, K.J.; Aumayr, F.; Schwob, J.L.; Suckewer, S.

1993-09-01

We present data of experiments on the resonant photopumping of Mo VII by Mo XII as a method of generating a coherent VUV source near 600 angstrom. The experiment is based on a scheme proposed by Feldman and Reader in which the 4p 6 -- 4p 5 6s transition in Mo VII in resonantly photopumped by the 5s 2 S 1/2 -- 4p 2 P 1/2 transition in Mo XII. Results of the laser produced plasma experiments show the successful enhancement of the population of the Mo VII 4p 5 6s upper lasing level when pumped by an adjacent Mo VII plasma. No enhancement was seen in a control experiment where the Mo VII plasma was pumped by a Zr X plasma. Improvements of the intensity of the Mo XII pump source, achieved using an additional pump laser, lead to the generation of a population inversion for the VUV transition

Ternary CoS{sub 2}/MoS{sub 2}/RGO electrocatalyst with CoMoS phase for efficient hydrogen evolution

Energy Technology Data Exchange (ETDEWEB)

Liu, Yan-Ru; Shang, Xiao [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); Gao, Wen-Kun [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); College of Science, China University of Petroleum (East China), Qingdao 266580 (China); Dong, Bin, E-mail: dongbin@upc.edu.cn [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); College of Science, China University of Petroleum (East China), Qingdao 266580 (China); Chi, Jing-Qi; Li, Xiao; Yan, Kai-Li; Chai, Yong-Ming [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); Liu, Yun-Qi, E-mail: liuyq@upc.edu.cn [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China); Liu, Chen-Guang [State Key Laboratory of Heavy Oil Processing, China University of Petroleum (East China), Qingdao 266580 (China)

2017-08-01

Highlights: • Ternary CoS{sub 2}/MoS{sub 2}/RGO with CoMoS phase as electrocatalyst for HER was prepared. • CoMoS phase have the metallic nature and highly intrinsic activity for HER. • RGO support ensures good distribution of CoMoS phase and enhances the conductivity. • The introduction of CoMoS and RGO may be a novel strategy for efficient HER of MoS{sub 2}. - Abstract: CoMoS phase with metallic character plays crucial role on enhancing the activity of MoS{sub 2} electrocatalysts for hydrogen evolution reaction (HER). However, only Co atoms located in the edges of MoS{sub 2} can create CoMoS phase, so it is a challenge to obtain CoMoS phase with homogeneous distribution limited by the layered MoS{sub 2} and doping method of Co. Herein, we reported a simple one-pot hydrothermal method to prepare novel ternary CoS{sub 2}/MoS{sub 2}/RGO with CoMoS phase for HER using reduced graphene oxide (RGO) as support. XPS proves the formation of CoMoS phase, implying the enhanced activity for HER. RGO support ensures the well distribution of CoMoS phase and enhances the conductivity of CoS{sub 2}/MoS{sub 2}/RGO. Compared to CoS{sub 2}/RGO, MoS{sub 2}/RGO and CoS{sub 2}/MoS{sub 2}, the obtained CoS{sub 2}/MoS{sub 2}/RGO shows superior activity for HER with an onset overpotential of −80 mV (vs. RHE), small Tafel slope of 56 mV dec{sup −1}, high exchange current density of 11.4 μA cm{sup −2} and rigid electrochemical durability. The enhanced performances for HER may be ascribed to the formation of CoMoS phase with high activity and the existence of RGO support with good electrical conductivitys in ternary CoS{sub 2}/MoS{sub 2}/RGO. Therefore, the introduction of CoMoS phase and RGO into MoS{sub 2} could effectively enhance electrocatalytic properties for HER.

On-stack two-dimensional conversion of MoS2 into MoO3

Science.gov (United States)

Yeoung Ko, Taeg; Jeong, Areum; Kim, Wontaek; Lee, Jinhwan; Kim, Youngchan; Lee, Jung Eun; Ryu, Gyeong Hee; Park, Kwanghee; Kim, Dogyeong; Lee, Zonghoon; Lee, Min Hyung; Lee, Changgu; Ryu, Sunmin

2017-03-01

Chemical transformation of existing two-dimensional (2D) materials can be crucial in further expanding the 2D crystal palette required to realize various functional heterostructures. In this work, we demonstrate a 2D ‘on-stack’ chemical conversion of single-layer crystalline MoS2 into MoO3 with a precise layer control that enables truly 2D MoO3 and MoO3/MoS2 heterostructures. To minimize perturbation of the 2D morphology, a nonthermal oxidation using O2 plasma was employed. The early stage of the reaction was characterized by a defect-induced Raman peak, drastic quenching of photoluminescence (PL) signals and sub-nm protrusions in atomic force microscopy images. As the reaction proceeded from the uppermost layer to the buried layers, PL and optical second harmonic generation signals showed characteristic modulations revealing a layer-by-layer conversion. The plasma-generated 2D oxides, confirmed as MoO3 by x-ray photoelectron spectroscopy, were found to be amorphous but extremely flat with a surface roughness of 0.18 nm, comparable to that of 1L MoS2. The rate of oxidation quantified by Raman spectroscopy decreased very rapidly for buried sulfide layers due to protection by the surface 2D oxides, exhibiting a pseudo-self-limiting behavior. As exemplified in this work, various on-stack chemical transformations can be applied to other 2D materials in forming otherwise unobtainable materials and complex heterostructures, thus expanding the palette of 2D material building blocks.

Geochronology of the Thompson Creek Mo Deposit: Evidence for the Formation of Arc-related Mo Deposits

Science.gov (United States)

Lawrence, C. D.; Coleman, D. S.; Stein, H. J.

2016-12-01

The Thompson Creek Mo deposit in central ID, has been categorized as an arc-related Mo deposit due to the location, grade of Mo, and relative lack of enrichments in F, Rb, and Nb, compared to the Climax-type Mo deposits. Geochronology from this arc-related deposit provides an opportunity to compare and contrast magmatism, and mineralization to that in Climax-type deposits. Distinct pulses of magmatism were required to form the Thompson Creek Mo deposit, which is consistent with recent geochronology from Climax-type deposits. Molybdenite Re-Os geochronology from five veins requires at least three pulses of magmatism and mineralization between 89.39 +/- 0.37 and 88.47 +/- 0.16 Ma. Zircon U-Pb ages from these mineralized samples overlap with molybdenite mineralization, but show a much wider range (91.01 +/- 0.37 to 87.27 +/- 0.69). Previous work from Climax-type Mo deposits suggest a correlation between a super eruption, and the subsequent rapid (<1 Ma) onset, and completion of Mo mineralizing intrusions. The longer life (3-4 Ma) for the Thompson Creek Mo deposit suggests that the mineralizing intrusions for arc-related Mo deposits may not need to have as high [Mo] as the Climax-type deposits. This study also finds a shift in the source of magmatism from the pre- to syn-mineralizing intrusions. Zircons from pre-mineralizing intrusions have much higher (15-60 pg) concentrations of radiogenic Pb than zircons from mineralized intrusions, which all have less than 15 pg, though whole rock [U] are similar.

Phase equilibria in the MgMoO4-Ln2(MoO4)3 (Ln=La,Gd) systems

International Nuclear Information System (INIS)

Fedorov, N.F.; Ipatov, V.V.; Kvyatkovskij, O.V.

1980-01-01

Phase equilibria in the MgMoO 4 -Ln 2 (MoO 4 ) 3 systems (Ln=La, Gd) have been studied by static and dynamic methods of the physico-chemical analysis, using differential thermal, visual-polythermal, crystal-optical, X-ray phase, and infrared spectroscopic methods, and their phase diagrams have been constructed. Phase equilibria in the systems studied are characterized by limited solubility of components in the liquid state, formation of solid solutions on the base of α- and β-forms of Gd 2 (MoO 4 ) 3 . Eutectics in the MgMoO 4 -Ln 2 (MoO 4 ) 3 (Ln=La, Gd) systems corresponds to the composition of 71 mode % La 2 (MoO 4 ) 3 -29 mole % MgMoO 4 , tsub(melt)--935+-5 deg C and 57 mole % Gd 2 (MoO 4 ) 3 -43 mole % MgMoO 4 , tsub(melt)=1020+-5 deg C. The region of glass formation has been established [ru

Magnetoresistance in Co/2D MoS2/Co and Ni/2D MoS2/Ni junctions.

Science.gov (United States)

Zhang, Han; Ye, Meng; Wang, Yangyang; Quhe, Ruge; Pan, Yuanyuan; Guo, Ying; Song, Zhigang; Yang, Jinbo; Guo, Wanlin; Lu, Jing

2016-06-28

Semiconducting single-layer (SL) and few-layer MoS2 have a flat surface, free of dangling bonds. Using density functional theory coupled with non-equilibrium Green's function method, we investigate the spin-polarized transport properties of Co/2D MoS2/Co and Ni/2D MoS2/Ni junctions with MoS2 layer numbers of N = 1, 3, and 5. Well-defined interfaces are formed between MoS2 and metal electrodes. The junctions with a SL MoS2 spacer are almost metallic owing to the strong coupling between MoS2 and the ferromagnets, while those are tunneling with a few layer MoS2 spacer. Both large magnetoresistance and tunneling magnetoresistance are found when fcc or hcp Co is used as an electrode. Therefore, flat single- and few-layer MoS2 can serve as an effective nonmagnetic spacer in a magnetoresistance or tunneling magnetoresistance device with a well-defined interface.

Determination of Mo- and Ca-isotope ratios in Ca100MoO4 crystal for AMoRE-I experiment

Science.gov (United States)

Karki, S.; Aryal, P.; Kim, H. J.; Kim, Y. D.; Park, H. K.

2018-01-01

The first phase of the AMoRE (Advanced Mo-based Rare process Experiment) is to search for neutrinoless double-beta decay of 100Mo with calcium molybdate (Ca100MoO4) crystals enriched in 100Mo and depleted in 48Ca using a cryogenic technique at Yangyang underground laboratory in Korea. It is important to know 100Mo- and 48Ca-isotope ratios in Ca100MoO4 crystal to estimate half-life of 100Mo decays and to 2 νββ background from 48Ca. We employed the ICP-MS (Inductive Coupled Plasma Mass Spectrometer) to measure 100Mo- and 48Ca-isotope ratios in Ca100MoO4 crystal. The measured results for 100Mo- and 48Ca-isotope ratios in the crystal are (94 . 6 ± 2 . 8) % and (0 . 00211 ± 0 . 00006) %, respectively, where errors are included both statistical and systematic uncertainties.

Postirradiation tensile properties of Mo and Mo alloys irradiated with 600 MeV protons

International Nuclear Information System (INIS)

Mueller, G.V.; Gavillet, D.; Victoria, M.; Martin, J.L.

1994-01-01

Tensile specimens of pure Mo and Mo-5 Re, Mo-41 Re and TZM alloys have been irradiated with 600 MeV protons in the PIREX facility at 300 and 660 K to 0.5 dpa. Results of the postirradiation tensile testing show a strong radiation hardening and a severe loss of ductility for all the materials tested at room temperature. ((orig.))

MoMoSat -- Mobile Service for Monitoring with GeoNotes via Satellite

Energy Technology Data Exchange (ETDEWEB)

Niemeyer, Irmgard [Forschungszentrum Juelich (Germany). Programme Group Systems Analysis and Technology Evaluation (STE); Jonas, Karl [Univ. of Applied Science Bonn-Rhein-Sieg, Sankt Augustin (Germany). FhG FOKUS CC SATCom; Horz, Alexander [horz informatik, Sankt Augustin (Germany); Wettschereck, Dietrich; Schmidt, Dirk [DIALOGIS GmbH, Bonn (Germany)

2003-05-01

The MoMoSat service will enable mobile end-users to view, manage, annotate, and communicate mapbased information in the field. The handled information exists of a huge volume of raster (satellite or aerial images) and vector data (i.e. street networks, cadastral maps or points of interest), as well as text-specific geo-referenced textual notes (the so-called 'GeoNotes') and real-time voice. A secure real-time communication between mobile units and the primary data store is an essential task of the MoMoSat service. The basic information is stored in the primary database that is accessible through a virtual private network (VPN) and cached at a server at a base station in order to ensure data availability. The base station may be installed in a car or another mobile vehicle. The two servers will periodically communicate with each other via secure satellite communication in order to check for updates. The base station supplies the relevant GIS data for the mobile units (people or even robots in the field at remote solutions). The communication between the mobile units is based on a peer-to-peer wireless local area network (WLAN) architecture. The mobile units are equipped with mobile computers (i.e. laptop, tablet PC or PDA) combined with a satellite-based positioning system (GPS) that enables them to request the proper geographic data sets from yhe base station's map server. An interactive mapping software shows the actual location on the map and allows the user to navigate (zoom, pan) through the high-resolution map display. The user can switch 'on' or 'off' several thematic layers (i.e. street network or points of interest) on the map. The software also supports collaborative aspects of MoMoSat by offering tools for the management of the GeoNotes that can be visualized by categories. The user can extend the existing GeoNotes with his personnel comments or create new GeoNotes by defining categories, recipients and the level of

The fracture toughness and DBTT of MoB particle-reinforced MoSi2 composites

International Nuclear Information System (INIS)

Xiong Zhi; Wang Gang; Jiang Wan

2005-01-01

The room temperature fracture toughness and the high temperature DBTT of MoB particle-reinforced MoSi 2 composites were investigated using Vickers indentation technique and MSP testing method, respectively. Modified small punch (MSP) test is a method for evaluation of mechanical properties using very small specimens, and it's appropriate for the determination of strength and DBTT. It was found that the approximate fracture toughness of the composite is 1.3 times that of monolithic MoSi 2 , and its DBTT is 100 C higher than that of monolithic MoSi 2 materials. Cracks deflection is a probable mechanism responsible for this behavior. (orig.)

Nota científica: perfil bioquímico de ratos alimentados com iogurte contendo extrato de erva-mate (Ilex paraguariensis St. Hil)

OpenAIRE

Ril,Franciele Taís; Loch,Camila Ronsoni; Valduga,Alice Teresa; Macedo,Sandra Manoela Dias; Cichoski,Alexandre José

2011-01-01

Este estudo teve como objetivo avaliar o efeito do iogurte contendo extrato de erva-mate (Ilex paraguariensis) e com/sem culturas probióticas sobre o perfil lipídico, glicêmico, hepático e renal de ratos alimentados com esses tipos de iogurtes. Ratos da linhagem Wistar (42) foram divididos em três grupos (n=14), e receberam iogurte sem extrato de erva-mate, iogurte com extrato de erva-mate 0,1% e iogurte com extrato de erva-mate 0,1% e culturas probióticas, durante 30 dias. Não foi observado ...

Theoretical prediction of high electron mobility in multilayer MoS2 heterostructured with MoSe2

Science.gov (United States)

Ji, Liping; Shi, Juan; Zhang, Z. Y.; Wang, Jun; Zhang, Jiachi; Tao, Chunlan; Cao, Haining

2018-01-01

Two-dimensional (2D) MoS2 has been considered to be one of the most promising semiconducting materials with the potential to be used in novel nanoelectronic devices. High carrier mobility in the semiconductor is necessary to guarantee a low power dissipation and a high switch speed of the corresponding electronic device. Strain engineering in 2D materials acts as an important approach to tailor and design their electronic and carrier transport properties. In this work, strain is introduced to MoS2 through perpendicularly building van der Waals heterostructures MoSe2-MoS2. Our first-principles calculations demonstrate that acoustic-phonon-limited electron mobility can be significantly enhanced in the heterostructures compared with that in pure multilayer MoS2. It is found that the effective electron mass and the deformation potential constant are relatively smaller in the heterostructures, which is responsible for the enhancement in the electron mobility. Overall, the electron mobility in the heterostructures is about 1.5 times or more of that in pure multilayer MoS2 with the same number of layers for the studied structures. These results indicate that MoSe2 is an excellent material to be heterostructured with multilayer MoS2 to improve the charge transport property.

MoDnm1 Dynamin Mediating Peroxisomal and Mitochondrial Fission in Complex with MoFis1 and MoMdv1 Is Important for Development of Functional Appressorium in Magnaporthe oryzae.

Directory of Open Access Journals (Sweden)

Kaili Zhong

2016-08-01

Full Text Available Dynamins are large superfamily GTPase proteins that are involved in various cellular processes including budding of transport vesicles, division of organelles, cytokinesis, and pathogen resistance. Here, we characterized several dynamin-related proteins from the rice blast fungus Magnaporthe oryzae and found that MoDnm1 is required for normal functions, including vegetative growth, conidiogenesis, and full pathogenicity. In addition, we found that MoDnm1 co-localizes with peroxisomes and mitochondria, which is consistent with the conserved role of dynamin proteins. Importantly, MoDnm1-dependent peroxisomal and mitochondrial fission involves functions of mitochondrial fission protein MoFis1 and WD-40 repeat protein MoMdv1. These two proteins display similar cellular functions and subcellular localizations as MoDnm1, and are also required for full pathogenicity. Further studies showed that MoDnm1, MoFis1 and MoMdv1 are in complex to regulate not only peroxisomal and mitochondrial fission, pexophagy and mitophagy progression, but also appressorium function and host penetration. In summary, our studies provide new insights into how MoDnm1 interacts with its partner proteins to mediate peroxisomal and mitochondrial functions and how such regulatory events may link to differentiation and pathogenicity in the rice blast fungus.

Studies of the effect of irradiation in a nuclear reactor, of targets containing Mo used for the preparation of 99Mo gel, material that constitutes the 99Mo - 99mTc generators

International Nuclear Information System (INIS)

Nieto, Renata Correa

2004-01-01

The most used radioisotope in Nuclear Medicine is 99m Tc, obtained in the 99 Mo - 99m Tc generator form. 99 Mo can be produced by several nuclear reactions in Cyclotron and Reactor. The production in Cyclotron is not technically and commercially feasible. The production in Nuclear Reactor can be made in two ways: 235 U fission and 99 Mo (n,γ) 99 Mo reaction. A project aiming the production of 99 Mo by activation of Mo is under way at IPEN, producing a gel type MoZr generator. There are two ways of preparing the gel and the generators: by irradiating MoO 3 and preparing the gel or by the preparation of the gel and further irradiation. This work consists in the study of the irradiation effects in several targets containing Mo for the production of 99 Mo by the 98 Mo (n,γ) 99 Mo reaction and further preparation of the gel for use as a gel type 99 Mo - 99m Tc generator. Three rinds of gel were studied: zirconium, titanium and cerium molybdate, and their morphology, infrared structure and elution yield of 99m Tc were analysed. The best results were achieved with the generators prepared with MoZr post formed gel, with amorphous structure and better elution yields. The pre formed gel induced crystallinity and worst performance of the generators. (author)

Ternary alloying study of MoSi2

International Nuclear Information System (INIS)

Yi, D.; Li, C.; Akselsen, O.M.; Ulvensoen, J.H.

1998-01-01

Ternary alloying of MoSi 2 with adding a series of transition elements was investigated by X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscopy (TEM), and energy dispersive spectroscopy (EDS). Iron, Co, Ni, Cr, V, Ti, and Nb were chosen as alloying elements according to the AB 2 structure map or the atomic size factor. The studied MoSi 2 base alloys were prepared by the arc melting process from high-purity metals. The EDS analysis showed that Fe, Co, and Ni have no solid solubility in as-cast MoSi 2 , while Cr, V, Ti, and Nb exhibit limited solid solubilities, which were determined to be 1.4 ± 0.7, 1.4 ± 0.4, 0.4 ± 0.1, and 0.8 ± 0.1. Microstructural characterization indicated that Mo-Si-M VIII (M VIII = Fe, Co, Ni) and Mo-Si-Cr alloys have a two-phase as-cast microstructure, i.e., MoSi 2 matrix and the second-phase FeSi 2 , CoSi, NiSi 2 , and CrSi 2 , respectively. In as-cast Mo-Si-V, Mo-Si-Ti, and Mo-Si-Nb alloys, besides MoSi 2 and C40 phases, the third phases were observed, which have been identified to be (Mo, V) 5 Si 3 , TiSi 2 , and (Mo, Nb) 5 Si 3

Physicochemical investigation of Bi2MoO6 solid-phase interaction with Sm2MoO6

International Nuclear Information System (INIS)

Khajkina, E.G.; Kovba, L.M.; Bazarova, Zh.G.; Khal'baeva, K.M.; Khakhinov, V.V.; Mokhosoev, M.V.

1986-01-01

Bi 2 MoO 6 -Sm 2 MoO 6 interaction in the temperature range of 700-1000 deg C is studied using X-ray phase analysis and vibrational spectroscopy. Formation of monoclinic solid solutions based on γ'-Bi 2 MoO 6 and B 2-x Sm x MoO 6 varied composition phase with α-Ln 2 MoO 6 structure which homogeneity region extent at 1000 deg C constitutes ∼ 50 mol % (0.7≤x≤1.7) is stated. Crystallographic characteristics of the synthesized phases are determined

O Talco deve ser utilizado para Pleurodese

Directory of Open Access Journals (Sweden)

Steven A. Sahn

2001-03-01

Full Text Available RESUMO: A pleurodese està recomendada nos den·ames pleurais malignos quando o tumor não é sensível à quimioterapia. Aprcsenta taxas de sucesso vari:lveis em parte justificadas pelos diferentes agentes e doses utilizadas, a selecção de doentes eo tipo de técnica aplicada. O talco parece ser o agente mais efi caz de pleurodese.Steven Sahn defende que o talco deve ser utilizado para pleurodese, apoiando a sua opini ao em diferentes factores:Mecanisme da pleurodese para talcagcm - o talco após contacto com as células mesoteliais promove um influxo de neutrófil os IL8 mediadus e posterior acumulação de macrófagos, diminuiçãa actividade fibrinolftica e aumento do factor de crescimento dos fi broblastos. Quando o tumor reveste uma grande area de mesotclio, a pleurodese não é tao eficaz.Eficácia - uma revisão da li teratura inglesa de I966 a 1994 constatou que u talco foi o agente mais eficaz de pleurodese, cum uma taxa de sucesso de 93%, comparada cum a da tetraciclina de 67 %, doxicicli na de 72% e bleomicina de 54%. Outras séries reve1aram uma taxa de sucesso do talco sempre superior a 91 %.Custo - o talco é pouco dispendioso e se apl icado em suspensao (“slutTy” por tubo de toracostomia ainda reduz mais os custos inerentes a uma toracoscopia 4uando se utiliza o talco em pó, aprescntando cstas duas tecnicas, taxas ue eticacia scmelhantes. Reacçãoes Adversas Minor e Major Agudas- a toracalgia e a febre são OS efcitos adversos mains frequcntes, frequcntes de todos os agentes de pleurudese. A toracalgia surge em 7% dos doentcs submetiuos a plcurodesc com talco, em 28% com a bleomicina c 40% com a dox iciclina. A tetraciclina provoca geralmente wracalgia grave. A febre surge entre I6 a 69% após talcagem não ultrapassando as 72 horas.As reacçãoes adversas graves sao raras e incluern o cmpiema. arritmia cardfaca e insufcicncia rcspiratória. Se o talco

AMORE Mo-99 Spike Test Results

Energy Technology Data Exchange (ETDEWEB)

Youker, Amanda J. [Argonne National Lab. (ANL), Argonne, IL (United States); Krebs, John F. [Argonne National Lab. (ANL), Argonne, IL (United States); Quigley, Kevin J. [Argonne National Lab. (ANL), Argonne, IL (United States); Byrnes, James P. [Argonne National Lab. (ANL), Argonne, IL (United States); Rotsch, David A [Argonne National Lab. (ANL), Argonne, IL (United States); Brossard, Thomas [Argonne National Lab. (ANL), Argonne, IL (United States); Wesolowski, Kenneth [Argonne National Lab. (ANL), Argonne, IL (United States); Alford, Kurt [Argonne National Lab. (ANL), Argonne, IL (United States); Chemerisov, Sergey [Argonne National Lab. (ANL), Argonne, IL (United States); Vandegrift, George F. [Argonne National Lab. (ANL), Argonne, IL (United States)

2017-09-27

With funding from the National Nuclear Security Administrations Material Management and Minimization Office, Argonne National Laboratory (Argonne) is providing technical assistance to help accelerate the U.S. production of Mo-99 using a non-highly enriched uranium (non-HEU) source. A potential Mo-99 production pathway is by accelerator-initiated fissioning in a subcritical uranyl sulfate solution containing low enriched uranium (LEU). As part of the Argonne development effort, we are undertaking the AMORE (Argonne Molybdenum Research Experiment) project, which is essentially a pilot facility for all phases of Mo-99 production, recovery, and purification. Production of Mo-99 and other fission products in the subcritical target solution is initiated by putting an electron beam on a depleted uranium (DU) target; the fast neutrons produced in the DU target are thermalized and lead to fissioning of U-235. At the end of irradiation, Mo is recovered from the target solution and separated from uranium and most of the fission products by using a titania column. The Mo is stripped from the column with an alkaline solution. After acidification of the Mo product solution from the recovery column, the Mo is concentrated (and further purified) in a second titania column. The strip solution from the concentration column is then purified with the LEU Modified Cintichem process. A full description of the process can be found elsewhere [1–3]. The initial commissioning steps for the AMORE project include performing a Mo-99 spike test with pH 1 sulfuric acid in the target vessel without a beam on the target to demonstrate the initial Mo separation-and-recovery process, followed by the concentration column process. All glovebox operations were tested with cold solutions prior to performing the Mo-99 spike tests. Two Mo-99 spike tests with pH 1 sulfuric acid have been performed to date. Figure 1 shows the flow diagram for the remotely operated Mo-recovery system for the AMORE project

Decay of 99Mo

International Nuclear Information System (INIS)

Dickens, J.K.; Love, T.A.

1976-01-01

Relative intensities for K x-rays and gamma rays emanating from 99 Mo in equilibrium with its 99 Tc* daughter have been measured using several Ge photon detectors. Combining these intensities with an evaluated set of electron-conversion coefficients has provided a set of absolute intensities for the observed gamma rays. The absolute intensity for the dominant 140.5-keV gamma ray in 99 Tc was determined to be 90.7 +- 0.6/100 99 Mo disintegrations for 99 Mo decay in equilibrium with decay of the 99 Tc* daughter

High pressure effect on MoS2 and MoSe2 single crystals grown by ...

Indian Academy of Sciences (India)

Unknown

tetrahedral anvil apparatus up to 5 GPa. In this paper we report room temperature resistance mea- surements as a function of pressure on MoS2 and MoSe2 single crystals. In each case the resistance decreases un- der pressure due to an increase in the carrier concentration. 2. Experimental. Single crystals of MoS2 and ...

Measurement of Mo-99 column activity in the evaluation of Mo-99/Tc-99m generator

International Nuclear Information System (INIS)

Kuster, Z.

1994-01-01

In order to calculate the real elution efficiency of Mo-99/Tc-99m generator the Mo-99 content on the column has to be previously determined. As found in this work, the external measurement of Mo-99-column activity by means of Geiger-Mueller counter is a simple, fast and reliable method. Generally, Mo-99-column is placed slightly out of the center of the generator; therefore the externally measured flux of photons (φ) is an angular-dependent function. If the thickness of the lead container is radially uniform, the flux measured at some distance from the generator (which is rotated in 2π/3 steps) is given by the equation φ = A (1 + Bcos (α-2π(i - 2)/3)) -1 , i=1,2 or 3 (Eq.1) where A is a numerical constant depending on the Mo-99-column activity, B is a numerical constant depending on the Mo-99- column position within the lead container, the angle α depends on the initial orientation of the generator. A total of 20 generator were studied. The measured Mo-99-column activities (Capintec dose calibrator) were in the range 13.1- 35.11 GBq. Contrary to the findings of Vinberg and Kristensen (Eur J Nucl Med 1/1976(219), values of A (Eq. 1) are in good correlation (r 2 =0.9794) with the measured Mo-99-column activities. (author)

Highly flexible, conductive and transparent MoO3/Ag/MoO3 multilayer electrode for organic photovoltaic cells

International Nuclear Information System (INIS)

Abachi, T.; Cattin, L.; Louarn, G.; Lare, Y.; Bou, A.; Makha, M.; Torchio, P.

2013-01-01

MoO 3 /Ag/MoO 3 (MAM) multilayer structures were deposited by vacuum evaporation on polyethylene terephthalate (PET) substrate. We demonstrate that, as in the case of glass substrate, the sheet resistance of such structures depends significantly on the Ag film deposition rate. When it is deposited between 0.2 and 0.4 nm/s, an Ag thickness of 11 nm allows achieving sheet resistance of 13 Ω/sq and an averaged transmission of 74%. A study of the influence of the PET substrate on the optimum MoO 3 thicknesses was done. A good qualitative agreement between the theoretical calculations of the variation of the optical transmittance of the MoO 3 /Ag/MoO 3 structures is obtained. The optimum MAM structures MoO 3 (17.5 nm)/Ag (11 nm)/MoO 3 (35 nm) has a factor of merit F M = 4.21 10 −3 (Ω/sq) −1 . Proven by the scotch test the MAM structures exhibit a good adhesion to the PET substrates. The MAM structures were also submitted to bending tests. For outer bending, the samples exhibit no variation of their resistance value, while for inner bending there is a small increase of the resistance of the MAM structures. However this increasing is smaller than that exhibited by Indium Tin Oxide. When the PET/MAM structures are used as anode in organic photovoltaic cells, it is shown that the need to use thicker Ag films inside the multilayer and to cover the MAM with Au to obtain promising Current density vs Voltage characteristics is due to the heating of the PET substrate during the deposition process. - Highlights: • MoO 3 /Ag/MoO 3 structures deposited on polyethylene terephthalate substrate. • MoO 3 /Ag/MoO 3 structures deposited by vacuum evaporation. • The Ag deposition rate influences the properties of the structures. • The MoO 3 /Ag/MoO 3 optimum structure has a factor of merit F M = 4.21 10 −3 (Ω/sq) −1 . • The MoO 3 /Ag/MoO 3 structures exhibit a high flexibility

EXAFS study of Mo2N and Mo nitrides supported on zeolites

International Nuclear Information System (INIS)

Liu Zhenlin; Meng Ming; Fu Yilu; Jiang Ming; Hu Tiandou; Xie Yaning; Liu Tao

2002-01-01

In the present study, the reaction is applied to prepare molybdenum nitrides with high surface area, and zeolites are used as supports. The EXAFS of the Mo K-absorption edge is measured and the change of coordination environment of Mo atoms before and after the nitridation is revealed

Study of methodologies for quality control of 99Mo used in 99Mo/99mTc generators

International Nuclear Information System (INIS)

Said, Daphne de Souza

2016-01-01

99m Tc is the most used radionuclide in nuclear medicine. In Brazil, the 99 Mo/ 99m Tc generators are exclusively produced by Radiopharmacy Center at IPEN-CNEN/ SP, by importing 99 Mo from different suppliers. 99 Mo (t 1/2 = 66 h) is a fission product of 235 U and it can have radionuclidic impurities that are prejudicial for human health. For safe use of generators, it is necessary to perform the evaluation of 99 Mo by quality control tests in order to assess if 99 Mo complies with the specifications. The European Pharmacopoeia (EP) presents a monograph for evaluation of the quality of the [ 99 Mo] solution as sodium molybdate,that is used as raw material for 99 Mo/ 99m Tc generators production, including specification parameters (identification, radiochemical purity and radionuclidic purity), analysis methods and limits. However, it has been observed difficulties on the execution and implementation of these methods by the generators producers, with a few literature about this subject, probably due to complexity of the proposed methods. In this work, many quality control parameters of 99 Mo described in the EP monograph were evaluated. Separation methods for 99M o from its radionuclidic impurities by solid phase extraction (SPE) and TLC were studied. After SPE separation, the quantification of metals by ICP-OES to evaluate the percentage of retention of Mo and the percentage of recovery of Ru, Te and Sr using different types of cartridges were proposed, replacing radiotracers use. It was observed that the specific type of SPE cartridge recommended by the EP for separation of 99 Mo presented low recoveries for Ru, compared to other available anion exchange SPE cartridges. 99 Mo samples from different worldwide suppliers were analyzed. It was observed that quantification of 103 Ru in 99 Mo samples with decay time higher than 4 weeks is possible. An alternative method for separation of 131 I from 99 Mo showed promising results by TLC. The quantification of beta and

Measurement of the molar heat capacities of MoO2 and MoO3 from 350 to 950 K

International Nuclear Information System (INIS)

Inaba, H.; Miyahara, K.; Naito, K.

1984-01-01

Molar heat capacities of MoO 2 and MoO 3 were measured in the range between 350 and 950 K by means of adiabatic scanning calorimetry. For MoO 2 , a sharp heat-capacity anomaly with a molar enthalpy change of (178 +- 24) J.mol -1 and a molar entropy change of (0.207 +- 0.028) J.K -1 .mol -1 was observed at 865 K, which had not been detected by drop calorimetry. For MoO 3 , two heat-capacity anomalies with molar enthalpy changes of (88 +- 21) and (60 +- 36) J.mol -1 were found at 808 K and 857 K, respectively; neither anomaly had been detected by the drop method. The lattice molar heat capacities of MoO 2 and MoO 3 are estimated as Csub(l,m)(MoO 2 ) = D(469 K/T) + E(578 K/T) + E(876 K/T) and Csub(l,m)(MoO 3 ) = D(208 K/T) + 2E(488 K/T) + E(1170 K/T), where D(x) and E(x) are the Debye and Einstein functions, respectively. The temperature coefficient of the electronic molar heat capacity of MoO 2 is estimated as (6.0 +- 0.5) mJ.K -2 .mol -1 . The excess heat capacity in MoO 3 found at higher temperatures is interpreted as being due to vacancy formation with a molar activation energy of (98 +-5) kJ.mol -1 . The origin of the heat-capacity anomalies is inferred as arising from the slight movement of distorted MoO 6 octahedra in the MoO 2 and MoO 3 structures. (author)

Carbon and Mo transformations during the synthesis of mesoporous Mo2C/carbon catalysts by carbothermal hydrogen reduction

Science.gov (United States)

Wang, Haiyan; Liu, Shida; Liu, Bing; Montes, Vicente; Hill, Josephine M.; Smith, Kevin J.

2018-02-01

The synthesis of mesoporous Mo2C/carbon catalysts by carbothermal hydrogen reduction is reported. Petroleum coke (petcoke) was activated with KOH at 800 °C to obtain high surface area microporous activated petcoke (APC; 2000 m2/g). The APC was wet impregnated with ammonium heptamolybdate (AHM: 10 wt% Mo), dried and reduced in H2 at temperatures from 400 to 800 °C, to yield Mo2C/APC catalysts. Increased reduction temperature increased the Mo2C yield and the mesoporous volume of the Mo2C/APC. At a reduction temperature of 750 °C the mesopore volume of the catalyst doubled compared to the APC support and accounted for 37% of the total pore volume. Maintaining the final CHR temperature for 90 min further increased the Mo2C yield and mesoporosity of the catalyst. The role of Mo2C in the catalytic hydrogenation of the APC and mesopore generation is demonstrated. The activity of the Mo2C/carbon catalysts in the hydrodeoxygenation of 4-methyl phenol increased with increased CHR temperature and catalyst mesoporosity.

Vertical MoSe2-MoO x p-n heterojunction and its application in optoelectronics

Science.gov (United States)

Chen, Xiaoshuang; Liu, Guangbo; Hu, Yunxia; Cao, Wenwu; Hu, PingAn; Hu, Wenping

2018-01-01

The hybrid n-type 2D transition-metal dichalcogenide (TMD)/p-type oxide van der Waals (vdW) heterojunction nanosheets consist of 2D layered MoSe2 (the n-type 2D material) and MoO x (the p-type oxide) which are grown on SiO2/Si substrates for the first time via chemical vapor deposition technique, displaying the regular hexagon structures with the average length dimension of sides of ˜8 μm. Vertical MoSe2-MoO x p-n heterojunctions demonstrate obviously current-rectifying characteristic, and it can be tuned via gate voltage. What is more, the photodetector based on vertical MoSe2-MoO x heterojunctions displays optimal photoresponse behavior, generating the responsivity, detectivity, and external quantum efficiency to 3.4 A W-1, 0.85 × 108 Jones, and 1665.6%, respectively, at V ds = 5 V with the light wavelength of 254 nm under 0.29 mW cm-2. These results furnish a building block on investigating the flexible and transparent properties of vdW and further optimizing the structure of the devices for better optoelectronic and electronic performance.

99Mo production using MoO3 pellets obtained by mechanical compression and heat treatment

International Nuclear Information System (INIS)

Rojas, Jorge; Mendoza, Pablo; Lopez, Alcides

2014-01-01

This paper shows the results of the MoO 3 pellets fabrication by mechanical compression and the heat treatment method (MCHT) in order to optimize the production of 99 Mo in the RACSO Nuclear Center. The effects of polyvinyl alcohol (PVA) as binder are assessed by heat treatment of pellets in air atmosphere, evaluating the elimination process with increasing temperature and solubility in 5N NaOH. The results show that the pellets fabrication technique is suitable because fulfills the required technical specifications, allows to irradiate 50 % more of 98 Mo mass and facilitate a safer radiological handling of the irradiated MoO 3 . (authors).

Achieving tunable doping of MoSe2 based devices using GO@MoSe2 heterostructure

Science.gov (United States)

Maji, Tuhin Kumar; Tiwary, Krishna Kanhaiya; Karmakar, Debjani

2017-05-01

Doping nature of MoSe2, one of the promising Graphene analogous device material, can be tuned by controlling the concentration of functional groups in Graphene oxide (GO)@MoSe2 heterostructure. In this study, by first-principles simulation, we have observed that GO can be used as a carrier injection layer for MoSe2, where n or p type carriers are introduced within MoSe2 layer depending on the type and concentration of functional moieties in it. Both n and p-type Schottky barrier height modulations are investigated for different modeled configurations of the heterostructure. This combinatorial heterostructure can be a promising material for future electronic device application.

Microstructural defects modeling in the Al-Mo system

International Nuclear Information System (INIS)

Pascuet, Maria I.; Fernandez, Julian R.; Monti, Ana M.

2006-01-01

In this work we have utilized computer simulation techniques to study microstructural defects, such as point defects and interfaces, in the Al-Mo alloy. Such alloy is taken as a model to study the Al(fcc)/U-Mo(bcc) interface. The EAM interatomic potential used has been fitted to the formation energy and lattice constant of the AlMo 3 intermetallic. Formation of vacancies for both components Al and Mo and anti-sites, Al Mo and Mo Al , as well as vacancy migration was studied in this structure. We found that the lowest energy defect complex that preserves stoichiometry is the antisite pair Al Mo +Mo Al , in correspondence with other intermetallics of the same structure. Our results also suggest that the structure of the Al(fcc)/Mo(bcc) interface is unstable, while that of the Al(fcc)/Al 5 Mo interface is stable, as observed experimentally. (author) [es

Development of improved HP/IP rotor material 2% CrMoNiWV (23 CrMoNiWV 88)

International Nuclear Information System (INIS)

Wiemann, W.

1989-01-01

The new 2% CrMoNiWV steel has a sufficient strength level, a very good creep (rupture) behaviour and an excellent toughness behaviour for a creep resistant steel. Even after long time high temperature exposure the toughness degradation is so small that it is still better than this of best 1% CrMo(Ni)V steels. The fatigue behaviour is well comparable to this of 1% CrMo(Ni)V. The 2% CrMoNiWV steel has the capability to substitute the traditional 1% CrMo(Ni)V. (orig.) With 26 annexes

Electrical characteristics of multilayer MoS2 FET's with MoS2/graphene heterojunction contacts.

Science.gov (United States)

Kwak, Joon Young; Hwang, Jeonghyun; Calderon, Brian; Alsalman, Hussain; Munoz, Nini; Schutter, Brian; Spencer, Michael G

2014-08-13

The electrical properties of multilayer MoS2/graphene heterojunction transistors are investigated. Temperature-dependent I-V measurements indicate the concentration of unintentional donors in exfoliated MoS2 to be 3.57 × 10(11) cm(-2), while the ionized donor concentration is determined as 3.61 × 10(10) cm(-2). The temperature-dependent measurements also reveal two dominant donor levels, one at 0.27 eV below the conduction band and another located at 0.05 eV below the conduction band. The I-V characteristics are asymmetric with drain bias voltage and dependent on the junction used for the source or drain contact. I-V characteristics of the device are consistent with a long channel one-dimensional field-effect transistor model with Schottky contact. Utilizing devices, which have both graphene/MoS2 and Ti/MoS2 contacts, the Schottky barrier heights of both interfaces are measured. The charge transport mechanism in both junctions was determined to be either thermionic-field emission or field emission depending on bias voltage and temperature. On the basis of a thermionic field emission model, the barrier height at the graphene/MoS2 interface was determined to be 0.23 eV, while the barrier height at the Ti/MoS2 interface was 0.40 eV. The value of Ti/MoS2 barrier is higher than previously reported values, which did not include the effects of thermionic field emission.

Development of Mo recycle technique from generator materials

Energy Technology Data Exchange (ETDEWEB)

Tanimoto, Masataka; Kurosawa, Makoto; Kimura, Akihiro; Nishikata, Kaori; Tsuchiya, Kunihiko [Japan Atomic Energy Agency, Oarai Research and Development Center, Oarai, Ibaraki (Japan); Kakei, Sadanori; Yoshinaga, Hideo [Taiyo Koko Corp., Ako Laboratory, Ako, Hyogo (Japan)

2012-03-15

The domestic {sup 99}Mo production by the (n,{gamma}) method is proposed in JMTR because of low amount of radioactive wastes and easy {sup 99}Mo/{sup 99m}Tc production process. For the development of domestic production, it is necessary to use the enriched {sup 98}MoO{sub 3}, which is very expensive, for high specific activity of {sup 99}Mo. A large amount of used PZC/PTC embraced {sup 98}Mo is also generated after the decay of {sup 99}Mo. JAEA and Taiyo Koko is proposed to recover molybdenum from the used PZC/PTC for an effective use of resources and reduction of radioactive wastes. Preliminary experiments of Mo recycling with un-irradiated MoO{sub 3} were carried out by the elution and sublimation methods. From the results, Mo recovery rate from the PZC/PTC was more than 95% by two kinds of methods. The prospects are bright for Mo recycle and reduction of radioactive wastes using these methods. (author)

Investigation of the fabrication process of hot-worked stainless-steel and Mo sheathed PbMo6 S8 wires

International Nuclear Information System (INIS)

Yamasaki, H.; Kimura, Y.

1988-01-01

Stainless-steel and Mo sheathed PbMo 6 S 8 wires have been fabricated by hot working from modified PbS, Mo, and MoS 2 mixed powders which were prepared by reacting Pb, Mo, and S at 530 0 C. Critical current densities were investigated for different preparation conditions, and it is revealed that obtaining continuous current path between PbMo 6 S 8 grains is the most important factor to achieve high critical current density. The J/sub c/ value of 2.8 x 10 4 Acm 2 (8 T), 7.8 x 10 3 Acm 2 (15 T), and 1.3 x 10 3 Acm 2 (23 T) was observed for the PbMo 6 S/sub 7.0/ wire heat treated at 700 0 C.copic

Effect of Mo addition on the electrocatalytic activity of Pt-Sn-Mo/C for direct ethanol fuel cells

International Nuclear Information System (INIS)

Lee, Eungje; Murthy, Arun; Manthiram, Arumugam

2011-01-01

Carbon-supported Pt-Sn-Mo electrocatalysts have been synthesized by a polyol reduction method and characterized for ethanol electro-oxidation reaction (EOR). While the percent loading of the synthesized nanoparticles on the carbon support is higher than 35%, energy dispersive spectroscopy (EDS) reveals that the Mo contents in the nanoparticle catalysts are lower than the nominal value, indicating incomplete reduction of the Mo precursor. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analyses reveal that the Sn and Mo exist as oxide phases at the surface layers of the nanoparticles and the degree of alloying is very low. The electrochemical properties of the electrocatalysts have been evaluated by cyclic voltammetry (CV) and chronoamperometry. The catalytic activity for EOR decreases in the order PtSnMo 0.6 /C > PtSnMo 0.4 /C > PtSn/C. Single cell direct ethanol fuel cell (DEFC) tests also confirm that the PtSnMo 0.6 /C anode catalyst exhibit better performance than the PtSn/C anode catalyst. An analysis of the electrochemical data suggests that the incorporation of Mo to Pt-Sn enhances further the catalytic activity for EOR.

Phase formation in the Rb2MoO4-Li2MoO4-Hf(MoO4)2 system and the crystal structure of Rb5(Li1/3Hf5/3)(MoO4)6

International Nuclear Information System (INIS)

Solodovnikov, S.F.; Zolotova, E.S.; Balsanova, L.V.; Bazarov, B.G.; Bazarova, Zh.G.

2003-01-01

Phase formation in the Rb 2 MoO 4 -Li 2 MoO 4 -Hf(MoO 4 ) 2 system is studied in subsolidus region in air by the method of crossing sections. Three ternary molybdates are detected in the system. Compositions of two of them are corroborated by selection of isostructural analogues [ru

Thermal and x-ray studies on Tl2U(MoO4)3 and Tl4U(MoO4)4

International Nuclear Information System (INIS)

Dahale, N.D.; Keskar, Meera; Kulkarni, N.K.; Singh Mudher, K.D.

2006-01-01

In the quaternary Tl-U(IV)-Mo-O system, two new compounds namely Tl 2 U(MoO 4 ) 3 and Tl 4 U(MoO 4 ) 4 were prepared and characterized by powder X-ray diffraction and thermal methods. These compounds were prepared by solid state reactions of Tl 2 MoO 4 , UMoO 5 and MoO 3 in the required stoichiometric ratio at 500 deg C in evacuated sealed quartz ampoule. The XRD data of Tl 2 U(MoO 4 ) 3 and Tl 4 U(MoO 4 ) 4 were indexed on orthorhombic cell. TG curves of Tl 2 U(MoO 4 ) 3 and Tl 4 U(MoO 4 ) 4 did not show any weight change up to 700 deg C in an inert atmosphere. During heating in an inert atmosphere, Tl 2 U(MoO 4 ) 3 and Tl 4 U(MoO 4 ) 4 showed endothermic Dta peaks due to melting of the compounds at 519 and 565 deg C, respectively. (author)

Synthesis of MoS2 and MoO2 for their applications in H2 generation and lithium ion batteries: a review

International Nuclear Information System (INIS)

Zhao Yufei; Zhang Yuxia; Yang Zhiyu; Yan Yiming; Sun Kening

2013-01-01

Scientists increasingly witness the applications of MoS 2 and MoO 2 in the field of energy conversion and energy storage. On the one hand, MoS 2 and MoO 2 have been widely utilized as promising catalysts for electrocatalytic or photocatalytic hydrogen evolution in aqueous solution. On the other hand, MoS 2 and MoO 2 have also been verified as efficient electrode material for lithium ion batteries. In this review, the synthesis, structure and properties of MoS 2 and MoO 2 are briefly summarized according to their applications for H 2 generation and lithium ion batteries. Firstly, we overview the recent advancements in the morphology control of MoS 2 and MoO 2 and their applications as electrocatalysts for hydrogen evolution reactions. Secondly, we focus on the photo-induced water splitting for H 2 generation, in which MoS 2 acts as an important co-catalyst when combined with other semiconductor catalysts. The newly reported research results of the significant functions of MoS 2 nanocomposites in photo-induced water splitting are presented. Thirdly, we introduce the advantages of MoS 2 and MoO 2 for their enhanced cyclic performance and high capacity as electrode materials of lithium ion batteries. Recent key achievements in MoS 2 - and MoO 2 -based lithium ion batteries are highlighted. Finally, we discuss the future scope and the important challenges emerging from these fascinating materials. (review)

Diodes based on semi-insulating CdTe crystals with Mo/MoO{sub x} contacts for X- and γ-ray detectors

Energy Technology Data Exchange (ETDEWEB)

Maslyanchuk, O.; Kulchynsky, V.; Solovan, M. [Chernivtsi National University, Chernivtsi (Ukraine); Gnatyuk, V. [Institute of Semiconductor Physics, NAS of Ukraine, Kyiv (Ukraine); Potiriadis, C. [Greek Atomic Energy Commission, Attiki (Greece); Kaissas, I. [Greek Atomic Energy Commission, Attiki (Greece); Department of Electrical and Computer Engineering, Aristotle University of Thessaloniki (Greece); Brus, V. [Helmholtz-Zentrum Berlin fuer Materialien und Energie GmbH, Berlin (Germany)

2017-03-15

This paper reports on the possible applications of molybdenum oxide (Mo/MoO{sub x}) contacts in combination with semi-insulating CdTe crystals. The electrical contacts to p-type Cl-doped CdTe crystals were formed by the deposition of molybdenum oxide and pure molybdenum thin films by the DC reactive magnetron sputtering. Electrical properties of the prepared Mo-MoO{sub x}/p-CdTe/MoO{sub x}-Mo surface-barrier structures were investigated at different temperatures. It is shown that the rapid growth of the reverse current with increasing bias voltage higher than 10 V is caused by the space-charge limited currents. Spectrometric properties of the Mo-MoO{sub x}/p-CdTe/MoO{sub x}-Mo structures have been also analyzed. It is revealed that the developed heterojunction has shown promising characteristics for its practical application in X- and γ-ray radiation detector fabrication. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Phase formation in the K2MoO4-Lu2(MoO4)3-Hf(MoO4)2 system and the structural study of triple molybdate K5LuHf(MoO4)6

International Nuclear Information System (INIS)

Romanova, E.Yu.; Bazarov, B.G.; Tushinova, Yu.L.; Fedorov, K.N.; Bazarova, Zh.G.; Klevtsova, R.F.; Glinskaya, L.A.

2007-01-01

Interactions in the ternary system K 2 MoO 4 -Lu 2 (MoO 4 ) 3 -Hf(MoO 4 ) 2 have been studied by X-ray powder diffraction and differential thermal analysis. A new triple (potassium lutetium hafnium) molybdate with the 5 : 1 : 2 stoichiometry has been found. Monocrystals of this molybdate have been grown. Its X-ray diffraction structure has been refined (an X8 APEX automated diffractometer, MoK α radiation, 1960 F(hkl), R = 0.0166). The trigonal unit cell has the following parameters: a = 10.6536(1) A, c = 37.8434(8) A, V=3719.75(9) A, Z = 6, space group R3-bar c. The mixed 3D framework of the structure is built of Mo tetrahedra sharing corners with two independent (Lu,Hf)O 6 octahedra. Two sorts of potassium atoms occupy large framework voids [ru

Three-Dimensional Heterostructures of MoS 2 Nanosheets on Conducting MoO 2 as an Efficient Electrocatalyst To Enhance Hydrogen Evolution Reaction

KAUST Repository

Nikam, Revannath Dnyandeo

2015-10-05

Molybdenum disulfide (MoS) is a promising catalyst for hydrogen evolution reaction (HER) because of its unique nature to supply active sites in the reaction. However, the low density of active sites and their poor electrical conductivity have limited the performance of MoS in HER. In this work, we synthesized MoS nanosheets on three-dimensional (3D) conductive MoO via a two-step chemical vapor deposition (CVD) reaction. The 3D MoO structure can create structural disorders in MoS nanosheets (referred to as 3D MoS/MoO), which are responsible for providing the superior HER activity by exposing tremendous active sites of terminal disulfur of S2 (in MoS) as well as the backbone conductive oxide layer (of MoO) to facilitate an interfacial charge transport for the proton reduction. In addition, the MoS nanosheets could protect the inner MoO core from the acidic electrolyte in the HER. The high activity of the as-synthesized 3D MoS/MoO hybrid material in HER is attributed to the small onset overpotential of 142 mV, a largest cathodic current density of 85 mA cm, a low Tafel slope of 35.6 mV dec, and robust electrochemical durability.

Three-Dimensional Heterostructures of MoS 2 Nanosheets on Conducting MoO 2 as an Efficient Electrocatalyst To Enhance Hydrogen Evolution Reaction

KAUST Repository

Nikam, Revannath Dnyandeo; Lu, Ang-Yu; Sonawane, Poonam Ashok; Kumar, U. Rajesh; Yadav, Kanchan; Li, Lain-Jong; Chen, Yit Tsong

2015-01-01

Molybdenum disulfide (MoS) is a promising catalyst for hydrogen evolution reaction (HER) because of its unique nature to supply active sites in the reaction. However, the low density of active sites and their poor electrical conductivity have limited the performance of MoS in HER. In this work, we synthesized MoS nanosheets on three-dimensional (3D) conductive MoO via a two-step chemical vapor deposition (CVD) reaction. The 3D MoO structure can create structural disorders in MoS nanosheets (referred to as 3D MoS/MoO), which are responsible for providing the superior HER activity by exposing tremendous active sites of terminal disulfur of S2 (in MoS) as well as the backbone conductive oxide layer (of MoO) to facilitate an interfacial charge transport for the proton reduction. In addition, the MoS nanosheets could protect the inner MoO core from the acidic electrolyte in the HER. The high activity of the as-synthesized 3D MoS/MoO hybrid material in HER is attributed to the small onset overpotential of 142 mV, a largest cathodic current density of 85 mA cm, a low Tafel slope of 35.6 mV dec, and robust electrochemical durability.

Controllable Growth of Monolayer MoS2 and MoSe2 Crystals Using Three-temperature-zone Furnace

Science.gov (United States)

Zheng, Binjie; Chen, Yuanfu

2017-12-01

Monolayer molybdenum disulfide (MoS2) and molybdenum diselenide (MoSe2) have attracted a great attention for their exceptional electronic and optoelectronic properties among the two dimensional family. However, controllable synthesis of monolayer crystals with high quality needs to be improved urgently. Here we demonstrate a chemical vapor deposition (CVD) growth of monolayer MoS2 and MoSe2 crystals using three-temperature-zone furnace. Systematical study of the effects of growth pressure, temperature and time on the thickness, morphology and grain size of crystals shows the good controllability. The photoluminescence (PL) characterizations indicate that the as-grown monolayer MoS2 and MoSe2 crystals possess excellent optical qualities with very small full-width-half-maximum (FWHM) of 96 me V and 57 me V, respectively. It is comparable to that of exfoliated monolayers and reveals their high crystal quality. It is promising that our strategy should be applicable for the growth of other transition metal dichalcogenides (TMDs) monolayer crystals.

Phase transitions in alloys of the Ni-Mo system

International Nuclear Information System (INIS)

Ustinovshikov, Y.; Shabanova, I.

2011-01-01

Graphical abstract: The structure of Ni-20 at.% Mo and Ni-25 at.% Mo alloys was studied by methods of TEM and XPS. It is shown that at high temperatures the tendency toward phase separation takes place in the alloys and crystalline bcc Mo particles precipitate in the liquid solution. At 900 deg. C and below, the tendency toward ordering leads to the dissolution of Mo particles and precipitation of the particles of Ni 3 Mo, Ni 2 Mo or Ni 4 Mo chemical compounds. Highlights: → 'Chemical' phase transition 'ordering-phase separation' is first discovered in alloys of the Ni-Mo system. → It is first shown that the phase separation in the alloys studied begins at temperatures above the liquidus one. → The formation of Ni 3 Mo from A1 has gone through the intervening stage of the Ni 4 Mo and Ni 2 Mo coexistence. - Abstract: The structure of Ni-20 at.% Mo and Ni-25 at.% Mo alloys heat treated at different temperatures was studied by the method of transmission electron microscopy. X-ray photoelectron spectroscopy was used to detect the sign of the chemical interaction between Ni and Mo atoms at different temperatures. It is shown that at high temperatures the tendency toward phase separation takes place. The system of additional reflections at positions {1 1/2 0} on the electron diffraction patterns testifies that the precipitation of crystalline bcc Mo particles begins in the liquid solution. At 900 deg. C and below, the tendency toward ordering leads to the precipitation of the particles of the chemical compounds. A body-centered tetragonal phase Ni 4 Mo (D1 a ) is formed in the Ni-20 at.% Mo alloy. In the Ni-25 at.% Mo alloy, the formation of the Ni 3 Mo (D0 22 ) chemical compound from the A1 solid solution has gone through the intervening stage of the Ni 4 Mo (D1 a ) and Ni 2 Mo (Pt 2 Mo) formation.

Anatomical characterization of the leaf, stem and rhizome of Digitaria insularis

OpenAIRE

Machado, A.F.L.; Meira, R.M.S.; Ferreira, L.R.; Ferreira, F.A.; Tuffi Santos, L.D.; Fialho, C.M.T.; Machado, M.S.

2008-01-01

A anatomia da folha, de colmo e do rizoma de Digitaria insularis foi investigada, visando identificar características que possam estar relacionadas à sua tolerância ao glyphosate. Sementes e rizomas de plantas adultas foram coletadas em campo, em área de plantio direto, onde o herbicida glyphosate vem sendo utilizado repetidamente há vários anos. As plantas provenientes dessas sementes e desses rizomas foram cultivadas em vasos com capacidade de 3 L, contendo solo de textura média, em casa de...

Materiais a base de colágeno com capacidade de autorreparo

OpenAIRE

Camila Silva Brey Gil

2013-01-01

Foram sintetizadas, por polimerização interfacial, microcápsulas de poliuretano contendo diisocianato em seu interior. As microcápsulas foram preparadas variando-se a velocidade de agitação (1500, 1000 e 700rpm) e o tipo de isocianato utilizado (4,4-difenilmetano diisocianato (MDI) ou isoforona diisocianato (IPDI)).Foram gerados um total de 6 tipos diferentes de microcápsulas. A caracterização dessas microcápsulas permitiu verificar, por Microscopia Eletrônica de Varredura (MEV) e Microscopia...

X-ray and electron microscopy investigation of the topotactic transformation of MoO3 into MoO2

International Nuclear Information System (INIS)

Bertrand, O.; Dufour, L.C.

1980-01-01

The reduction of MoO 3 is investigated by X-ray analysis and electron microscopy from MoO 3 (010) platelets between 1000 A and 5 mm long. In all cases, the following orientation relationship between both lattices is found: [100] 2 parallel [010] 3 , [122] 2 parallel [100] 3 . [-12-2] 2 parallel [001] 3 . MoO 3 crystallites twinning and misorientation are discussed in relation with the particular importance of [101] 3 directions in MoO 3 preserved in the transformation and becoming [010] 2 of MoO 2 . A model for this topotactic reduction is proposed where the reaction develops layer (010) 3 by layer (010) 3 to form [20-1] 2 type planes in MoO 2 structure. Data on the kinetics of the boundary moving in [010] 3 direction are also presented. (author)

PENGARUH SERBUK U-Mo HASIL PROSES MEKANIK DAN HYDRIDE – DEHYDRIDE – GRINDING MILL TERHADAP KUALITAS PELAT ELEMEN BAKAR U-Mo/Al

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Supardjo Supardjo

2015-07-01

Full Text Available PENGARUH SERBUK U-Mo HASIL PROSES MEKANIK DAN HYDRIDE – DEHYDRIDE – GRINDING MILL TERHADAP KUALITAS PELAT ELEMEN BAKAR U-Mo/Al. Penelitian bahan bakar U-7Mo/Al tipe pelat dilakukan dalam rangka pengembangan bahan bakar U3Si2/Al untuk mendapatkan bahan bakar baru yang memiliki densitas uranium lebih tinggi, stabil selama digunakan sebagai bahan bakar di dalam reaktor dan mudah dilakukan proses olah ulangnya. Lingkup penelitian meliputi pembuatan: paduan U-7Mo dengan teknik peleburan, pembuatan serbuk U-7Mo dengan dikikir dan hydride - dehydride - grinding mill, IEB U-7Mo/Al dengan teknik kompaksi pada tekanan 20 bar, dan PEB U-7Mo/Al dengan teknik pengerolan panas pada temperatur 425oC. Paduan U-7Mo hasil proses peleburan cukup homogen, berat jenis 16,34 g/cm3 dan bersifat ulet, kemudian dibuat menjadi serbuk dengan cara dikikir dan hydride - dehydride - grinding mill. Serbuk U-7Mo hasil proses kikir berbentuk pipih, kontaminan Fe cukup tinggi, sedangkan serbuk hasil proses hydride - dehydride - grinding mill, cenderung equiaxial dengan kontaminan yang rendah. Kedua jenis serbuk U-7Mo tersebut digunakan sebagai bahan baku pembuatan IEB U-7Mo/Al dan PEB U-7Mo/Al dengan densitas uranium 7 gU/cm3 dan diperoleh produk dengan kualitas yang hampir sama. Hasil uji IEB U-7Mo/Al berukuran 25 x 15 x 3,15±0,05 mm, tidak terdapat cacat/retak, distribusi U-7Mo di dalam matriks cukup homogen dan tidak terdapat pengelompokan/aglomerasi U-7Mo yang berdimensi >1 mm. PEB U-7Mo/Al hasil pengerolan dengan tebal akhir 1,45 mm, memiliki ketebalan meat rerata 0,60 mm dan tebal kelongsong 0,4 mm dan terdapat 1 titik pengukuran kelongsong dengan ketebalan 0,15 mm. Dengan membandingkan penggunaan kedua jenis serbuk U-7Mo tersebut, IEB U-7Mo/Al dan PEB U-7Mo/Al yang dihasilkan memiliki kualitas hampir sama. Namun demikian penggunaan serbuk U- 7Mo hasil proses hydride - dehydride - grinding mill lebih baik karena proses pengerjaannya lebih cepat dan impuritas dalam

Microstructure investigation of NiAl-Cr(Mo) interface in a directionally solidified NiAl-Cr(Mo) eutectic alloyed with refractory metal

International Nuclear Information System (INIS)

Chen, Y.X.; Cui, C.Y.; Guo, J.T.; Li, D.X.

2004-01-01

The microstructure of a directionally solidified NiAl-Cr(Mo) eutectic alloyed with refractory metal in as-processed and heat-treated states has been studied by means of scanning electron microscopy and high resolution electron microscopy (HREM). The microstructure of the NiAl-Cr(Mo) eutectic was characterized by lamellar Cr(Mo) phases embedded within NiAl matrix with common growth direction of . The interface between NiAl and lamellar Cr(Mo) did not have any transition layers. Misfit dislocations were observed at the NiAl-Cr(Mo) interface. In addition to lamellar Cr(Mo) phases, coherent Cr(Mo, Ni, Al) precipitates and NiAl precipitates were also observed in the NiAl matrix and lamellar Cr(Mo) phases, respectively. After hot isostatic pressing and heat treatment, the NiAl-Cr(Mo) interfaces became smooth and straight. Square array of misfit dislocations was directly observed at the (0 0 1) interface between NiAl and Cr(Mo, Ni, Al) precipitate. The configuration of misfit dislocation network showed a generally good agreement with prediction based on the geometric O-lattice model

Intermediate report of MoReMo. Modelling resilience for maintenance and outage

Energy Technology Data Exchange (ETDEWEB)

Oedewald, P.; Macchi, L. (VTT Technical Research Centre of Finland (Finland)); Axelsson, C. (Ringhals AB, Vattenfall AB (Sweden)); Eitrheim, M.H.R. (Institute for Energy Technology (Norway))

2012-02-15

Resilience Engineering (RE) is a new approach to safety that helps organisations and individuals adapt to unforeseen events and long-term changes. Such an approach is needed by nuclear power plants (NPPs) as they face demanding modification projects, high staff turnover and increased pressures to maintain and improve safety. The goal of the Modelling Resilience for Maintenance and Outage (MoReMO) project is to develop and test models and methods to identify and analyse resilience in safety-critical activities in natural everyday settings. In 2011, we have applied four approaches in different case studies: Organisational Core Task modelling (OCT), Functional Resonance Analysis Method (FRAM), Efficiency Thoroughness Trade-Off (ETTO) analysis, and Work Practice and Culture Characterisation. The project has collected data through observations, interviews and document reviews at two NPPs. Together, the four approaches have provided valuable insights for understanding the rationale behind work practices, their effects on safety, and the support of flexibility and adaptability. In 2012, the MoReMO project will complete the data collection and integrate results on how resilience can be operationalized in practical safety management tools for the companies. (Author)

Intermediate report of MoReMo. Modelling resilience for maintenance and outage

International Nuclear Information System (INIS)

Oedewald, P.; Macchi, L.; Axelsson, C.; Eitrheim, M.H.R.

2012-02-01

Resilience Engineering (RE) is a new approach to safety that helps organisations and individuals adapt to unforeseen events and long-term changes. Such an approach is needed by nuclear power plants (NPPs) as they face demanding modification projects, high staff turnover and increased pressures to maintain and improve safety. The goal of the Modelling Resilience for Maintenance and Outage (MoReMO) project is to develop and test models and methods to identify and analyse resilience in safety-critical activities in natural everyday settings. In 2011, we have applied four approaches in different case studies: Organisational Core Task modelling (OCT), Functional Resonance Analysis Method (FRAM), Efficiency Thoroughness Trade-Off (ETTO) analysis, and Work Practice and Culture Characterisation. The project has collected data through observations, interviews and document reviews at two NPPs. Together, the four approaches have provided valuable insights for understanding the rationale behind work practices, their effects on safety, and the support of flexibility and adaptability. In 2012, the MoReMO project will complete the data collection and integrate results on how resilience can be operationalized in practical safety management tools for the companies. (Author)

First-principles study of van der Waals interactions in MoS2 and MoO3

International Nuclear Information System (INIS)

Peelaers, H; Van de Walle, C G

2014-01-01

Van der Waals interactions play an important role in layered materials such as MoS 2 and MoO 3 . Within density functional theory, several methods have been developed to explicitly include van der Waals interactions. We compare the performance of several of these functionals in describing the structural and electronic properties of MoS 2 and MoO 3 . We include functionals based on the local density or generalized gradient approximations, but also based on hybrid functionals. The coupling of the semiempirical Grimme D2 method with the hybrid functional HSE06 is shown to lead to a very good description of both structural and electronic properties. (paper)

Controlled synthesis of MoO3 microcrystals by subsequent calcination of hydrothermally grown pyrazine–MoO3 nanorod hybrids and their photodecomposition properties

International Nuclear Information System (INIS)

Rajagopal, S.; Nataraj, D.; Khyzhun, O.Y.; Djaoued, Yahia; Robichaud, Jacques; Kim, Chang-Koo

2013-01-01

We present our results on successful synthesis of pyrazine–MoO 3 nanorod hybrids by using pyrazine and MoO 3 nanorods. On the first stage, MoO 3 nanorods were grown hydrothermally and, on the second stage, their mixture with pyrazine was again involved in a hydrothermal reaction to produce organic–inorganic hybrids. To understand the growth mechanism of the hybrids we varied time and temperature of the hydrothermal process. Intercalation of pyrazine was confirmed through X-ray diffraction analysis, X-ray photoelectron spectroscopy, X-ray emission spectroscopy, scanning electron microscopy methods. Upon calcinations, pyrazine was deintercalated, i.e. removed from the MoO 3 hybrid system, and the MoO 3 nanorods were found to bind together resulting in formation of MoO 3 microslabs with increased surface area. Photodecomposition performance of the MoO 3 nanorods, pyrazine–MoO 3 hybrids and MoO 3 microcrystals was studied against Procion Red MX-5B textile dye. A high photodecomposition performance was found to decrease when going from MoO 3 nanorods to MoO 3 microcrystal and, further, to pyrazine–MoO 3 hybrids. - Graphical abstract: Display Omitted - Highlights: • High aspect ratio MoO 3 nanorods were prepared through a new hydrothermal method. • Hybrids of pyrazine–MoO 3 were formed by intercalating pyrazine into MoO 3 nanorods. • Intercalation of pyrazine was confirmed in X-ray spectroscopic analysis. • After calcinations, MoO 3 crystal was retained by binding MoO 3 nanorods together. • High photodegradation performance was noticed from MoO 3 nanorods

Biodistribution of 99Mo in rats

International Nuclear Information System (INIS)

Souza, Raphael Sancho Sisley de; Ribeiro, Bianca da Silva; Dantas, Ana Leticia Almeida; Dantas, Bernardo Maranhao; Bernardo Filho, Mario

2009-01-01

The modification of 99 Mo standard metabolism in the presence of MDP would alter the dosimetry of this radionuclide in nuclear medicine patients. Therefore, the objective of this work is to evaluate the influence of MDP in the biodistribution of 99 Mo. Wistar rats were divided in two groups of six animals, being inoculated respectively 99 Molibdate and 99 Mo+MDP via plex ocular. The biodistribution study was carried out after 10 and 120 minutes respectively. The organs were counted with a NaI(Tl) detector. The uptake values did not present significant differences among the groups. An in vitro study through planar chromatography was carried out to determine the affinity between molybdenum and MDP. The results show that 99 Mo has low affinity both to propanone and NaCl-0.9% solution. However, 99 Mo in the presence of MDP presented affinity to NaCl-0.9% solution and low affinity to propanone suggesting that 99 Mo was bound to MDP under the conditions of the experiment. (author)

Intake and apparent digestibility of rations containing different proportions of Coastcross (Cynodon dactylon (L. Pers. hay plus ground soybean grain and sheep eating behaviour/ Consumo e digestibilidade aparente de rações com diferentes proporções de feno de capim Coastcross (Cynodon dactylon (L. Pers. e soja crua moída e comportamento alimentar de ovinos

Directory of Open Access Journals (Sweden)

Tiago Rodrigues Casimiro

2006-07-01

Full Text Available The aims of this experiment were to determine the average daily intake (ADI and the apparent digestibility coefficient (ADC of rations containing two levels of coastcross hay and ground soybean grain, as well as, to study the behavior of sheep fed on these rations. Ten wethers averaging 40.0 kg of live weight were allocated in feeding trial cages for this experiment. A completely randomized design with two treatments (T1= 80% coastcross hay + 20% soybean grain and T2= 60% coast cross hay + 40% soybean grain and five replicates, were used. The treatments were evaluated under two feeding systems (voluntary and restrict. There were two experimental periods of seven days with fifteen days of previous adaptation each. The animals were fed twice a day with rations containing half of the estimated daily intake. The behaviours studied were times spent eating, ruminating and resting in a five minutes interval observation during twelve hours. There were no significant differences (P>0.05 between treatments for nutrientsADI but for crude protein and ether extract (EE. The ADC for dry matter (DM, fiber (F and total carbohydrates (TC were significantly greater (PO objetivo deste trabalho foi determinar o consumo médio e a digestibilidade aparente dos nutrientes de rações contendo dois níveis de feno de capim coast-cross e soja crua moída, bem como estudar o comportamento de ovinos alimentados com essas rações. Foram utilizados dez ovinos machos, castrados, com peso vivo médio de 40,0 kg, em delineamento experimental inteiramente casualizado com dois tratamentos (T (T1= 80% de feno de coastcross picado + 20% de soja crua moída e T2= 60% de feno de coastcross picado + 40% de soja crua moída e cinco repetições. Os tratamentos foram avaliados em regimes de consumo voluntário e consumo restrito. O ensaio compreendeu um período de adaptação de 15 dias, seguido de dois períodos de coleta de sete dias cada. A ração foi fornecida em duas refei

Synthesis of Fine Mo2C Powder from Prereduced Mo in Undiluted CH4 Flow

Science.gov (United States)

Cetinkaya, S.; Eroglu, S.

2017-10-01

The carburization behavior of prereduced Mo was investigated in undiluted CH4 flow at 900-1000 K. Prior to the experiments, equilibrium thermodynamic analysis was carried out in the Mo-C-H system. The products were characterized by mass measurement, x-ray diffraction and scanning electron microscopy techniques. A single Mo2C phase was obtained within 45 min, 5 min, and 2.5 min at 900 K, 950 K, and 1000 K, respectively, at CH4 contents higher than the predicted ones. The reasons for this behavior were discussed in terms of CH4 stability, open tube flow, and self-created atmosphere in the powder bed. The fractional conversion-time curves indicated that the carburization kinetics followed a linear rate law. The Mo2C crystallite size (26-37 nm) and platelet thickness (50-100 nm) were found to be smaller than those of the parent Mo phase. These findings were attributable to the defects formed as a result of stresses associated with the reduction and the carburization.

Benchmark experiment for the cross section of the 100Mo(p,2n)99mTc and 100Mo(p,pn)99Mo reactions

Science.gov (United States)

Takács, S.; Ditrói, F.; Aikawa, M.; Haba, H.; Otuka, N.

2016-05-01

As nuclear medicine community has shown an increasing interest in accelerator produced 99mTc radionuclide, the possible alternative direct production routes for producing 99mTc were investigated intensively. One of these accelerator production routes is based on the 100Mo(p,2n)99mTc reaction. The cross section of this nuclear reaction was studied by several laboratories earlier but the available data-sets are not in good agreement. For large scale accelerator production of 99mTc based on the 100Mo(p,2n)99mTc reaction, a well-defined excitation function is required to optimise the production process effectively. One of our recent publications pointed out that most of the available experimental excitation functions for the 100Mo(p,2n)99mTc reaction have the same general shape while their amplitudes are different. To confirm the proper amplitude of the excitation function, results of three independent experiments were presented (Takács et al., 2015). In this work we present results of a thick target count rate measurement of the Eγ = 140.5 keV gamma-line from molybdenum irradiated by Ep = 17.9 MeV proton beam, as an integral benchmark experiment, to prove the cross section data reported for the 100Mo(p,2n)99mTc and 100Mo(p,pn)99Mo reactions in Takács et al. (2015).

Solid state reactions of MoO3 and Na2MoO4 with (U.85,Ce.15)O2x

International Nuclear Information System (INIS)

Dahale, N.D.; Keskar, Meera; Singh Mudher, K.D.; Chawla, K.L.

1999-01-01

(U .85 ,Ce .15 )MoO 6-x was prepared by the solid state reactions of (U .85 ,Ce .15 )O 2±x with MoO 3 in air at 600 deg C. Solid state reactions of Na 2 MoO 4 with (U .85 ,Ce .15 )MoO 6.x up to 550 deg C in air led to the formation of Na 2 (U .85 ,Ce .15 )Mo 2 O 10-x and Na 2 (U .85 , Ce .15 ) 2 Mo 3 O 16-x . These compounds were characterised by x-ray and thermal methods. The x-ray powder data of (U .85 , Ce .15 ) MoO 6-x were indexed on monoclinic system whereas, data of Na 2 (U .85 ,Ce .15 ) Mo 2 O 10-x and Na 2 (U .85 ,Ce .15 ) 2 Mo 3 O 16-x were indexed on orthorhombic and monoclinic system respectively. (author)

Emprego do ultra-som modo B e com efeito Doppler, termômetro infravermelho e medidas antropométricas na avaliação de uma formulação cosmética anticelulítica contendo extrato hidroglicólico de Trichilia catigua e Ptychopetalum olacoides Bentham

OpenAIRE

Idalina Maria Nunes Salgado Reis dos Santos

2005-01-01

Hidrolipodistrofia ginóide (H.L.D.G.), a celulite, é comumente tratada com cosméticos contendo extratos vegetais. O estudo realizado foi: ultra-sonografia na avaliação da espessura da hipoderme e a microcirculação cutânea; uso de termômetro infravermelho na medida da temperatura e análise das medidas antropométricas da uma formulação cosmética anticelulítica contendo extrato hidroglicólico de Trichilia catigua e Ptychopetalum olacoides Bentham (catuaba e marapuama). Foram realizadas medidas i...

Study of gels of molybdenum with cerium in the preparation of generators of 99Mo - 99mTc

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Vanessa Moraes

2005-10-01

Full Text Available 99mTc has ideal nuclear properties for organ imaging in nuclear medicine, and it is obtained from the 99Mo-99mTc generator. Four different types of generators are available: chromatographic that uses 99Mo from fission of uranium; MEK solvent extraction; Tc2O7 sublimation; gel chromatographic. This work presents the preparation of gel generators of molybdenum with cerium and characterization of the gels: mass ratio between molybdenum and cerium, structure, size of particles and elution percentage of 99mTc after irradiating the gels. Eight gels were prepared at the same temperature of 50 ºC with concentrations of NaOH of 2 and 4 mol/L, mass ratio of 0.31 and 0.38 and final pH of 3.5 and 4.5. The analysis of the results proved that these gels are not adequate for preparation of the generators of 99Mo-99mTc, since the elution percentages are low, when compared with the gel of molybdenum with zirconium.O 99mTc é o radiofármaco mais utilizado em Medicina Nuclear. Ele é obtido do gerador de 99Mo-99mTc e existem quatro tipos diferentes de geradores: cromatográfico que utiliza 99Mo de fissão; extração por solvente com MKT; sublimação do heptaóxido de tecnécio; cromatográfico tipo gel. Este trabalho apresenta a preparação de geradores tipo gel de molibdênio com cério, a caracterização desses géis com relação à quantidade de molibdênio e de cério, sua estrutura, tamanho das partículas e porcentagem de eluição do 99mTc após o gel ser irradiado. Foram preparados oito géis na temperatura de 50ºC com concentração de NaOH de 2 e 4 mol/L, relação de massa de 0,31 e 0,38 e pH final de 3,5 e 4,5. A análise dos resultados comprovou que esses géis não são adequados para preparação dos geradores de 99Mo-99mTc, já que as porcentagens de eluição são baixas, quando comparadas com o gel de molibdênio com zircônio.

Normal and grazing incidence pulsed laser deposition of nanostructured MoSx hydrogen evolution catalysts from a MoS2 target

Science.gov (United States)

Fominski, V. Yu.; Romanov, R. I.; Fominski, D. V.; Dzhumaev, P. S.; Troyan, I. A.

2018-06-01

Pulsed laser ablation of a MoS2 target causes enhanced splashing of the material. So, for MoSx films obtained by pulsed laser deposition (PLD) in the conventional normal incidence (NI) configuration, their typical morphology is characterized by an underlying granular structure with an overlayer of widely dispersed spherical Mo and MoSx particles possessing micro-, sub-micro- and nanometer sizes. We investigated the possibility of using high surface roughness, which occurs due to particle deposition, as a support with a large exposed surface area for thin MoSx catalytic layers for the hydrogen evolution reaction (HER). For comparison, the HER performance of MoSx layers formed by grazing incidence (GI) PLD was studied. During GI-PLD, a substrate was placed along the direction of laser plume transport and few large particles loaded the substrate. The local structure and composition of thin MoSx layers formed by the deposition of the vapor component of the laser plume were varied by changing the pressure of the buffer gas (argon, Ar). In the case of NI-PLD, an increase in Ar pressure caused the formation of quasi-amorphous MoSx (x ≥ 2) films that possessed highly active catalytic sites on the edges of the layered MoS2 nanophase. At the same time, a decrease in the deposition rate of the MoSx film appeared due to the scattering of the vapor flux by Ar molecules during flux transport from the target to the substrate. This effect prevented uniform deposition of the MoSx catalytic film on the surface of most particles, whose deposition rate was independent of Ar pressure. The scattered vapor flux containing Mo and S atoms was a dominant source for MoSx film growth during GI-PLD. The thickness and composition distribution of the MoSx film on the substrate depended on both the pressure of the buffer gas and the distance from the target. For 1.0-2.5 cm from the target, the deposition rate was quite sufficient to form S-enriched quasi-amorphous MoSx (2.5 < x < 6) catalytic

Study on Mo(V) species, location and adsorbates interactions in MoH-SAPO-34 by employing ESR and electron spin-echo modulation spectroscopies

International Nuclear Information System (INIS)

Back, Gern Ho; Jang, Chang Ki; Ru, Chang Kuk; Cho, Young Hwan; So, Hyun Soo; Larry, Keven

2002-01-01

A solid-state reaction of MoO 3 with as-synthesized H-SAPO-34 generated paramagnetic Mo(V) species. The dehydration resulted in weak Mo(V) species, and subsequent activation resulted in the formation of Mo(V) species such as Mo(V) 5c and Mo(V) 6c that are characterized by ESR. The data of ESR and ESEM show the oxomolybdenum species, to be (MoO 2 ) + or (MoO) 3+ . The (MoO 2 ) + species seems to be more probable. Since H-SAPO-34 has a low framework negative charge, (MoO) 3+ with a high positive charge can not be easily stabilized. A solution reaction between the solution of silico-molybdic acid and calcined H-SAPO-34 resulted in only MoO + 2 species. A rhombic ESR signal is observed on adsorption of D 2 O, CD 3 OH, CH 3 CH 2 OD and ND 3 . The Location and coordination structure of Mo(V) species has been determined by three-pulse electron spin-echo modulation data and their simulations. After the adsorption of methanol, ethylene, ammonia, and water for MoH-SAPO-34, three molecules, one and one molecule, respectively, are directly coordinated to (MoO 2 ) +

Cinética da degradação ruminal de dietas contendo farelo de casca de pequi Ruminal degradation kinetics of diets with pequi hulls bran

Directory of Open Access Journals (Sweden)

Luciana Castro Geraseev

2011-09-01

Full Text Available A casca de pequi é um resíduo do processamento do fruto, encontrado em grande volume nas regiões do cerrado brasileiro, que pode constituir uma alternativa para a alimentação de ruminantes. Avaliou-se a cinética da degradação ruminal da matéria seca (MS, proteína bruta (PB e fibra em detergente neutro (FDN do farelo da casca de pequi (FCP e de dietas contendo diferentes níveis do resíduo em substituição ao capim-elefante (CE. Foram utilizados quatro caprinos, machos, portando cânulas ruminais, dispostos em um delineamento experimental de blocos ao acaso com parcela subdividida. Avaliaram-se os parâmetros de degradabilidade do FCP, capim-elefante e de dietas contendo 0, 10, 20 e 30% de FCP em substituição ao CE. Os alimentos foram incubados no rúmen nos tempos de 4, 8, 12, 24, 48, 72 e 96 horas. Os resultados indicaram degradação potencial da MS, PB e FDN do resíduo superiores a 90, 80 e 80%, respectivamente. A adição do FCP em substituição ao CE resultou em maior degradabilidade da matéria seca e fibra em detergente neutro, reflexo da maior fração solúvel e potencialmente degradável da MS do FCP. Para a fração protéica, a adição de FCP correlacionou-se negativamente com a fração solúvel, degradação potencial e efetiva, e positivamente com a fração insolúvel potencialmente degradável. A substituição do capim-elefante por FCP permite melhor aproveitamento da dieta, elevando o aporte de nutrientes ao animal.The pequi hulls is a waste of pequi processing, found in large volume in the Brazilian Cerrado, which may provide an alternative to ruminants' diet. This experiment was developed to evaluate the ruminal degradation kinects of dry matter (DM, crude protein (CP and neutral detergent fiber (NDF of pequi hulls bran (PHB and experimental diets, with different substitution levels of elephant grass (EG by pequi hulls bran. Four goats castrated with ruminal cannulas were used in a randomized complete block

Computational identification of MoRFs in protein sequences.

Science.gov (United States)

Malhis, Nawar; Gsponer, Jörg

2015-06-01

Intrinsically disordered regions of proteins play an essential role in the regulation of various biological processes. Key to their regulatory function is the binding of molecular recognition features (MoRFs) to globular protein domains in a process known as a disorder-to-order transition. Predicting the location of MoRFs in protein sequences with high accuracy remains an important computational challenge. In this study, we introduce MoRFCHiBi, a new computational approach for fast and accurate prediction of MoRFs in protein sequences. MoRFCHiBi combines the outcomes of two support vector machine (SVM) models that take advantage of two different kernels with high noise tolerance. The first, SVMS, is designed to extract maximal information from the general contrast in amino acid compositions between MoRFs, their surrounding regions (Flanks), and the remainders of the sequences. The second, SVMT, is used to identify similarities between regions in a query sequence and MoRFs of the training set. We evaluated the performance of our predictor by comparing its results with those of two currently available MoRF predictors, MoRFpred and ANCHOR. Using three test sets that have previously been collected and used to evaluate MoRFpred and ANCHOR, we demonstrate that MoRFCHiBi outperforms the other predictors with respect to different evaluation metrics. In addition, MoRFCHiBi is downloadable and fast, which makes it useful as a component in other computational prediction tools. http://www.chibi.ubc.ca/morf/. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Ordering in rapidly solidified Ni/sub 2/Mo

International Nuclear Information System (INIS)

Kulkarni, U.D.; Dey, G.K.; Banerjee, S.

1988-01-01

Ordering processes in the Ni-Mo system have been a subject of several investigations. Although the ordering behaviour of the Ni/sub 4/Mo and the Ni/sub 3/Mo has been examined in detail, no such study has been reported in the case of the Ni/sub 2/Mo alloy. The lack of experimental work on ordering transformations in Ni/sub 2/Mo is presumably due to the difficulty in obtaining a single phase fcc alloy of this composition. Enhanced solid solubility of Mo in Ni, which accompanies rapid solidification processing (RSP) makes the formation of such a phase possible. The ordering processes in Ni-Mo based alloys show several remarkable features. Firstly, the alloy (15 - 28 at % Mo) quenched from the α -phase filed exhibit a short range order (SRO) characterized by the presence of intensity maxima at /1 1/2 0/ fcc positions of the reciprocal space. This state of SRO has been attributed to the occurrence of 1 1/2 O spinodal ordering in the system. Secondly, the transformation from the state of SRO to the equilibrium/metastable coherent long range ordered (LRO) structures appears to take place in a continuous manner at relatively low temperatures of aging. Three different coherent LRO structures, namely: the equilibrium Ni/sub 4/Mo (prototype structure D1/sub a/) and the metastable Ni/sub 3/Mo (DO/sub 22/) and Ni/sub 2/Mo (Pt/sub 2/Mo) structures have reported to evolve from the SRO alloy, depending upon the aging treatment and the composition of the alloy

Fission 99Mo production technology

International Nuclear Information System (INIS)

Miao Zengxing; Luo Zhifu; Ma Huimin; Liang Yufu; Yu Ningwen

2003-01-01

This paper describes a production technology of fission 99 Mo in the Department Isotope, CIAE. The irradiation target is tubular U-Al alloy containing highly enriched uranium. The target is irradiated in the swimming pool reactor core. The neutron flux is about 4x10 13 /cm 2 .sec. The production scale is 3.7-7.4 TBq (100-200Ci) of fission 99 Mo per batch. Total recovery of 99 Mo is more than 70%. The production practice proves that the process and equipment are safe and reliable. (author)

A cytochemical study of acid carbohydrates on the surface of Candida lipolytica grown in tween 80-containing medium Estudo citoquímico dos carboidratos ácidos na superfície de Candida lipolytica crescida em meio contendo tween 80

Directory of Open Access Journals (Sweden)

Aline E. Nascimento

2000-03-01

Full Text Available Carbohydrate-containing molecules were located on the surface of Candida lipolytica by using ruthenium red in a cytochemical study. The yeast was grown in media containing Tween 80. The surfactant, at 1.0% and 0.5%, was added to the culture medium in different intervals of time, correspondent to the beginning of exponential growth phase, mid of logarithimic phase and beginning of stationary growth phase. Control cultures were grown in a medium containing glucose. The growth of the yeast in media containing glucose and Tween 80 induced changes in the pattern of distribution and location of acid polyssacharides in the cell wall of the microorganism. In adition, the pattern also changed according to Tween 80 concentration. The influence of Tween 80 on cellular carbohydrate expression is discussed.Moléculas contendo resíduos de açúcares foram localizadas sobre a superfície de Candida lipolytica utilizando-se o vermelho de rutênio como marcador citoquímico. A levedura foi semeada em meio contendo Tween 80. O surfactante, nas concentrações de 1,0% e 0,5%, foi adicionado ao meio de cultivo em diferentes intervalos de tempo, correspondentes ao início da fase exponencial de crescimento, meio da fase logarítmica e final da fase exponencial de crescimento, Culturas-controles foram cultivadas em meio contendo glicose como fonte de carbono. O crescimento da levedura em meios contendo glicose ou Tween 80 induziu o surgimento de alterações na distribuição e na localização de polissacarídeos ácidos na parede celular do organismo. Células crescidas em glicose ou Tween 80 exibiram variações citoquímicas em função de sua fase de crescimento. Adicionalmente, o padrão de marcação citoquímica também sofreu variações de acordo com a concentração do surfactante. A influência do surfactante na expressão de carboidratos é discutida.

Resonant photoelectron spectroscopy at the Mo 4p→4d absorption edge in MoS2

International Nuclear Information System (INIS)

Lince, J.R.; Didziulis, S.V.; Yarmoff, J.A.

1991-01-01

A systematic study has been conducted of the resonant behavior of the valence-band photoelectron spectrum of MoS 2 for hν=26--70 eV, spanning the Mo 4p→4d transition region. A broad Fano-like resonance appears at ∼42 eV in the constant-initial-state (CIS) intensity plot of the d z 2 peak near the valence-band maximum [∼2 eV binding energy (BE)], confirming its predominantly Mo 4d character. A second shoulder on the higher-hν side of the maximum in the d z 2 CIS intensity plot is suggested to result from transitions to unoccupied states in the 5sp band ∼10 eV above E F , by comparison with a partial-yield spectrum and previous inverse-photoemission data. The region of the valence band in the range 3--4.5-eV BE also exhibits resonant behavior, indicating Mo 4d character, although somewhat less than for the d z 2 peak. The 5--7-eV BE range does not exhibit resonance behavior at the Mo 4p edge and, therefore, contains negligible Mo 4d character. A feature at ∼30 eV in the CIS intensity plot for the 5--7-eV BE range could not be definitively assigned in this study, but may be due to a resonance between direct photoemission and a process involving absorption and autoionization of electronic states that contain Mo 5s and 5p character

Creep and shrinkage of Mo(Ni)

International Nuclear Information System (INIS)

Kaysser, W.A.; Hofmann-Amtenbrink, M.; Petzow, G.

1984-01-01

To avoid some of the errors inherent in a quantitative interpretation of shrinkage of powder compacts as Mo-Ni, other experiments were looked for, where the influence of Ni on the material transport properties of Mo could be measured semi-quantitatively during heating up to temperature and subsequent isothermal annealing. The bending of thin Mo foils under small loads was found to be an experimental arrangement, where variations in stress, in Ni-concentration and in intrinsic material properties could be realized. The results of these creep experiments will be compared in a qualitative sense with sintering experiments in Mo-Ni done under similar conditions as the creep experiments

Study of the water-gas shift reaction on Mo2C/Mo catalytic coatings for application in microstructured fuel processors

NARCIS (Netherlands)

Rebrov, E.V.; Kuznetsov, S.A.; Croon, de M.H.J.M.; Schouten, J.C.

2007-01-01

The activity and stability of two types of molybdenum carbide coatings deposited on molybdenum substrates (Mo2C/Mo) were compared in the water-gas shift reaction at 513–631 K. The activity of the Mo2C/Mo coatings obtained by carburization of preoxidized molybdenum substrates in a CH4/H2 mixture at

IEA Mobility Model (MoMo) and its use in the ETP 2008

International Nuclear Information System (INIS)

Fulton, Lew; Cazzola, Pierpaolo; Cuenot, Francois

2009-01-01

The IEA published 'Energy Technology Perspectives' (ETP) in June 2008. That document reports on IEA scenarios for baseline and low-CO 2 alternative scenarios to 2050, across the energy economy. The study included creating scenarios for transport, using the IEA Mobility Model (MoMo). This paper reports on the transport-related ETP scenarios and describes the model used in the analysis. According to the ETP Baseline scenario, world transport energy use and CO 2 emissions will more than double by 2050. In the most challenging scenario, called 'BLUE', transport emissions are reduced by 70% in 2050 compared to their baseline level in that year (and about 25% below their 2005 levels). There are several versions of the BLUE scenario, but all involve: a 50% or greater improvement in LDV efficiency, 30-50% improvement in efficiency of other modes (e.g. trucks, ships and aircraft), 25% substitution of liquid fossil fuels by biofuels, and considerable penetration of electric and/or fuel-cell vehicles. In the second half of this paper, an overview of the MoMo model is provided. Details on the complete analysis are contained in the ETP 2008 document, available at (www.iea.org). Details of the LDV fuel economy analysis are contained in a separate paper in this collection.

Síntese e caracterização de compósito magnético nanoestruturado contendo óxido de manganês para remoção de íons Cd(II do meio aquoso

Directory of Open Access Journals (Sweden)

A. P. Heitmann

2014-09-01

Full Text Available O tratamento de efluentes contendo cádmio é de grande interesse devido à persistência desse contaminante no meio ambiente e às graves doenças que pode causar ao homem. No presente trabalho, foi utilizado o compósito magnético Mn3O4/Fe3O4 como adsorvente do íon cádmio (II em meio aquoso. O material adsorvente foi sintetizado e caracterizado segundo as técnicas de difração de raios X (DRX, espectroscopia Raman, microscopia eletrônica de transmissão e sorção de N2 (BET. Ênfase foi dada à quantificação das fases do compósito pela análise de DRX combinada ao método Rietveld. O estudo de adsorção foi realizado variando o pH do meio e a concentração do íon cádmio em solução. A análise dos resultados possibilitou verificar que a remoção de Cd(II utilizando compósito magnético Mn3O4/Fe3O4 em meio aquoso é dependente do pH duplicando a medida que o pH varia de 3 para 7. O estudo de imobilização do íon contaminante em solução apresentou valores significativos de capacidade máxima de adsorção, de 12,3 mgCd/g no pH 6 e 13,6 mgCd/g no pH 7, indicando uma remoção de até 98% para concentrações baixas do íon, sugerindo que o adsorvente apresenta elevado potencial para remoção de Cd(II em meio aquoso.

Single Phase Melt Processed Powellite (Ba,Ca) MoO{sub 4} For The Immobilization Of Mo-Rich Nuclear Waste

Energy Technology Data Exchange (ETDEWEB)

Brinkman, Kyle [Savannah River Site (SRS), Aiken, SC (United States); Marra, James [Savannah River Site (SRS), Aiken, SC (United States); Fox, Kevin [Savannah River Site (SRS), Aiken, SC (United States); Reppert, Jason [Savannah River Site (SRS), Aiken, SC (United States); Crum, Jarrod [Paci fic Northwest National Laboratory , Richland, WA (United States); Tang, Ming [Los Alamos National Laboratory , Los Alamos, NM (United States)

2012-09-17

Crystalline and glass composite materials are currently being investigated for the immobilization of combined High Level Waste (HLW) streams resulting from potential commercial fuel reprocessing scenarios. Several of these potential waste streams contain elevated levels of transition metal elements such as molybdenum (Mo). Molybdenum has limited solubility in typical silicate glasses used for nuclear waste immobilization. Under certain chemical and controlled cooling conditions, a powellite (Ba,Ca)MoO{sub 4} crystalline structure can be formed by reaction with alkaline earth elements. In this study, single phase BaMoO{sub 4} and CaMoO{sub 4} were formed from carbonate and oxide precursors demonstrating the viability of Mo incorporation into glass, crystalline or glass composite materials by a melt and crystallization process. X-ray diffraction, photoluminescence, and Raman spectroscopy indicated a long range ordered crystalline structure. In-situ electron irradiation studies indicated that both CaMoO{sub 4} and BaMoO{sub 4} powellite phases exhibit radiation stability up to 1000 years at anticipated doses with a crystalline to amorphous transition observed after 1 X 10{sup 13} Gy. Aqueous durability determined from product consistency tests (PCT) showed low normalized release rates for Ba, Ca, and Mo (<0.05 g/m{sup 2}).

U-Mo fuel qualification program in HANARO

International Nuclear Information System (INIS)

Lee, K.H.; Lee, C.S.; Kim, H.R.; Kuk, I.H.; Kim, C.K.

2000-01-01

Atomized U-Mo fuel has shown good performance from the results of previous out-of-pile tests and post-irradiation examinations. A qualification program of rod type U-Mo fuel is in progress and the fuel will be irradiated in HANARO. 6 gU/cm 3 U-7Mo, U-8Mo and U-9Mo are considered in this program. The laboratory test results of porosity, mechanical property, thermal conductivity, and thermal compatibility test are discussed in this paper. In parallel with this qualification program, the feasibility study on the core conversion from the present U 3 Si fuel to U-Mo in HANARO will be initiated to provide technical bases for the policy making. Several options of core conversion for HANARO are proposed and each option will be addressed briefly in terms of the operation policy, fuel management, and licensing of HANARO. (author)

On the coexistence of copper-molybdenum bronzes: CuxMoO3 (0.2 yMoO3-z (0.1 2-O quasi-ternary system

International Nuclear Information System (INIS)

Warner, T.E.; Skou, E.M.

2010-01-01

Two copper-molybdenum bronzes: Cu y MoO 3-z (0.1 x MoO 3 (0.2 3 at 600 o C under argon in Pt crucibles. Powder XRD showed that the material with global composition '0.1Cu.MoO 3 ' comprises ∼Cu 0.15 MoO 3 and MoO 3 ; whilst '0.2Cu.MoO 3 ' comprises ∼Cu 0.15 MoO 3 and ∼Cu 0.23 MoO 3 . DTA performed on '0.2Cu.MoO 3 ' reveals a reversible solid state phase transition ∼520 o C under argon. Reacting equimolar amounts of Cu 2 O and MoO 2 at 600 o C in a Cu crucible under argon yields: Cu 6 Mo 5 O 18 , Cu and MoO 2 . A tentative subsolidus Cu-MoO 2 -O isothermal (∼25 o C) phase diagram under argon is drawn from these data. Oxidation states of Cu and Mo within this system are discussed.

DFT study of the reactions of Mo and Mo with CO2 in gas phase

Indian Academy of Sciences (India)

understanding the mechanism of second-row metal reacting with CO2. The minimum energy ... et al.18 performed an IR study on the reaction of laser- ablated Mo atom .... indicate that the weak electrostatic interaction between. Mo. + and CO2 ...

A facile route to large-scale synthesis MoO2 and MoO3 as electrode materials for high-performance supercapacitors

International Nuclear Information System (INIS)

Xuan, H.C.; Du, Y.W.; Zhang, Y.Q.; Xu, Y.K.; Li, H.; Han, P.D.; Wang, D.H.

2016-01-01

MoO 3 and MoO 2 materials have been successfully synthesized by thermal decomposition of ammonium paramolybdate in air and a sealed quartz tube, respectively. The microstructure of as-synthesized MoO 3 is composed of irregular lamellar plates with a plate thickness around 100 nm and MoO 2 has the larger grain size with lamellar plates connected with each other. A maximum specific capacitance of 318 F/g at 0.5 A/g is obtained for MoO 2 prepared in a closed environment. On the other hand, the sample MoO 3 exhibits excellent rate capacity with specific capacitances of 218, 209, 196, 188, 176, and 160 F/g at current densities of 0.5, 1, 2, 3, 4, and 5 A/g, respectively. These results pave the way to consider MoO 3 and MoO 2 as prospective materials for energy-storage applications. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Estudo da degradação de polimeros sinteticos de importancia industrial por linhagens fungicas

OpenAIRE

Karla Cristina Freitas Costa

2001-01-01

Resumo: Este trabalho descreve a ação de fungos basidiomicetos na degradabilidade dos quatro principais polímeros sintéticos utilizados em embalagens de alimentos: polietileno tereftalato (PET), polipropileno (PP), poliestireno (PS), policloreto de vinila (PVC), e um outro polímero sintético, a espuma poliuretana (PU). Os microrganismos foram crescidos em meio líquido de sais, pH 6,8, contendo 0,1 % de tiamina, com 0,5 % do polímero sintético como única fonte de carbono durante 20, 30 e 40 di...

Atualização da proteína ideal para frangos de corte

OpenAIRE

Jéssica de Souza Vilela

2015-01-01

O objetivo deste estudo foi avaliar o desempenho produtivo, o rendimento de carcaça e de cortes comerciais de frango alimentados com rações peletizadas contendo diferentes relações de valina/isoleucina durante as fases de crescimento e final (22 a 42 dias) desses animais. Foram utilizados 630 pintos machos de um dia de idade, da linhagem cobb 500. De 1 a 22 dias de idade, todas as aves receberam uma ração basal comum e aos 22 dias foram pesadas e distribuídas em um delineamento inteiramente c...

Development of fission Mo-99 production technology

Energy Technology Data Exchange (ETDEWEB)

Park, Jin Ho; Choung, W. M.; Lee, K. I. and others

2001-05-01

This R and D project is planed to supply domestic demands of Mo-99 through fission route, and consequently this project will be expected to rise up utilization of HANARO and KAERI's capability for marketing extension into domestic and oversea radiopharmaceutical market. HEU and LEU target types are decided and designed for fission Mo-99 production in domestic. Experimental study of target fabrication technology was performed and developed processing equipments. And conceptual design of target loading/unloading in/from HANARO device are performed. Tracer test of Mo-99 separation and purification process was performed, test results reach to Mo-99 recovery yield above 80% and decontamination factor above 1600. Combined Mo-99 separation and purification process was decided for hot test scheduled from next year, and performance test was performed. Conceptual design for modification of existing hot cell for fission Mo-99 production facility was performed and will be used for detail design. Assumption for the comparison of LEU and HEU target in fission Mo-99 production process were suggested and compared of merits and demerits in view of fabrication technology and economy feasibility.

Development of fission Mo-99 production technology

International Nuclear Information System (INIS)

Park, Jin Ho; Choung, W. M.; Lee, K. I. and others

2001-05-01

This R and D project is planed to supply domestic demands of Mo-99 through fission route, and consequently this project will be expected to rise up utilization of HANARO and KAERI's capability for marketing extension into domestic and oversea radiopharmaceutical market. HEU and LEU target types are decided and designed for fission Mo-99 production in domestic. Experimental study of target fabrication technology was performed and developed processing equipments. And conceptual design of target loading/unloading in/from HANARO device are performed. Tracer test of Mo-99 separation and purification process was performed, test results reach to Mo-99 recovery yield above 80% and decontamination factor above 1600. Combined Mo-99 separation and purification process was decided for hot test scheduled from next year, and performance test was performed. Conceptual design for modification of existing hot cell for fission Mo-99 production facility was performed and will be used for detail design. Assumption for the comparison of LEU and HEU target in fission Mo-99 production process were suggested and compared of merits and demerits in view of fabrication technology and economy feasibility

Measurements of emissivities on JT-60 first wall materials (inconel 625, Mo, TiC-coated Mo)

International Nuclear Information System (INIS)

Nakamura, Hiroo; Shimizu, Masatsugu; Makino, Toshiro; Kunitomo, Takeshi.

1985-02-01

To evaluate heat removal performance of JT-60 first wall, emissivities and reflectivities on Inconel 625, Mo, TiC coated Mo with optically smooth surface and actual surface are measured at temperature from a room temperature to 1300 K. Spectra are measured in the rnage of wave lengthes from 0.34 μm to 20 μm. Actual surfaces are machined/pickled surfaces for Inconel 625, electro-polished surfaces for molybdenum, and as-coated surfaces for TiC-coated molybdenum. Results of Inconel 625 and molybdenum with oplically smooth surfaces are examined by a two-electrons-type dispersion model of optical constants. Electronic constants of the equation are given and formulated in order to correlates the macroscopic properties of the radiative heat transfer. Total emissivities, obtained from the spectral emissivities of optically smooth surface, are 0.13(RT) -- 0.21(1300 K) for Inconel 625, 0.035(RT) -- 0.18(1300 K) for Mo, and 0.053(RT) for TiC-coated Mo. Moreover, total emissivities of the actual surface at a room temperature are 0.35(Inconel 625), 0.124(Mo), and 0.073(TiC-coated Mo). Large dependence of the emissivities on temperature and wave length shows that the model including these dependences is necessary for an accurate evaluation of the radiative heat transfer. (author)

Study of the dynamics of the MoO2-Mo2C system for catalytic partial oxidation reactions

Science.gov (United States)

Cuba Torres, Christian Martin

On a global scale, the energy demand is largely supplied by the combustion of non-renewable fossil fuels. However, their rapid depletion coupled with environmental and sustainability concerns are the main drivers to seek for alternative energetic strategies. To this end, the sustainable generation of hydrogen from renewable resources such as biodiesel would represent an attractive alternative solution to fossil fuels. Furthermore, hydrogen's lower environmental impact and greater independence from foreign control make it a strong contender for solving this global problem. Among a wide variety of methods for hydrogen production, the catalytic partial oxidation offers numerous advantages for compact and mobile fuel processing systems. For this reaction, the present work explores the versatility of the Mo--O--C catalytic system under different synthesis methods and reforming conditions using methyl oleate as a surrogate biodiesel. MoO2 exhibits good catalytic activity and exhibits high coke-resistance even under reforming conditions where long-chain oxygenated compounds are prone to form coke. Moreover, the lattice oxygen present in MoO2 promotes the Mars-Van Krevelen mechanism. Also, it is introduced a novel beta-Mo2C synthesis by the in-situ formation method that does not utilize external H2 inputs. Herein, the MoO 2/Mo2C system maintains high catalytic activity for partial oxidation while the lattice oxygen serves as a carbon buffer for preventing coke formation. This unique feature allows for longer operation reforming times despite slightly lower catalytic activity compared to the catalysts prepared by the traditional temperature-programmed reaction method. Moreover, it is demonstrated by a pulse reaction technique that during the phase transformation of MoO2 to beta-Mo2C, the formation of Mo metal as an intermediate is not responsible for the sintering of the material wrongly assumed by the temperature-programmed method.

Controlled formation of MoSe{sub 2} by MoN{sub x} thin film as a diffusion barrier against Se during selenization annealing for CIGS solar cell

Energy Technology Data Exchange (ETDEWEB)

Jeon, Chan-Wook [School of Chemical Engineering, Yeungnam University, Gyeongsangbuk-do 712-749 (Korea, Republic of); Cheon, Taehoon [School of Materials Science and Engineering, Yeungnam University, Gyeongsangbuk-do 712-749 (Korea, Republic of); Center for Core Research Facilities, DaeguGyeongbuk Institute of Science & Technology, Daegu (Korea, Republic of); Kim, Hangil [School of Materials Science and Engineering, Yeungnam University, Gyeongsangbuk-do 712-749 (Korea, Republic of); Kwon, Min-Su [School of Chemical Engineering, Yeungnam University, Gyeongsangbuk-do 712-749 (Korea, Republic of); Kim, Soo-Hyun [School of Materials Science and Engineering, Yeungnam University, Gyeongsangbuk-do 712-749 (Korea, Republic of)

2015-09-25

Highlights: • Mo/MoN{sub x}/Mo multilayer was investigated as a back contact for CIGS solar cell. • The MoN{sub x} protected the underlying Mo layer during high temperature selenization. • The formation of MoSe{sub 2} layer was precisely controlled. • The diffusion barrier performance of MoN{sub x} against Se was evaluated using TEM analysis. - Abstract: This study investigated the interfacial reactions and electrical properties of a Mo single layer and Mo/MoN{sub x}/Mo multilayer during high temperature selenization annealing. The Mo single layer was converted easily to MoSe{sub 2}, which was 7 times thicker than the Mo layer consumed ∼900 nm, by selenization at 460 °C for 10 min and the sheet resistance increased 8 fold compared to that of the as-deposited Mo film. On the other hand, in the Mo/MoN{sub x}/Mo structure, transmission electron microscopy (TEM) showed that the MoSe{sub 2} transformation was localized only in the top Mo layer and the bottom Mo layer was completely unaffected, even after selenization at 560 °C. The sheet resistance of the multilayer was relatively unchanged by selenization. This suggests that the MoN{sub x} layer performed well as a diffusion barrier against Se and the thickness of MoSe{sub 2} can be controlled precisely by adjusting the top Mo layer thickness. Furthermore, TEM and energy dispersive spectroscopy analysis showed that the selenized multilayer consisted of MoSe{sub 2}/Mo/MoN{sub x}/Mo, in which the top Mo layer of 60 nm was not fully converted to MoSe{sub 2} and 20 nm was left unreacted. The residual Mo interlayer located at the interface of MoSe{sub 2} and MoN{sub x} is believed to be beneficial for the ohmic contact of the selenized multilayer.

An experimental study: Role of different ambient on sulfurization of MoO{sub 3} into MoS{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Kumar, Prabhat, E-mail: prabhat89k@gmail.com; Singh, Megha; Sharma, Rabindar K.; Reddy, G.B.

2016-06-25

Molybdenum disulfide (MoS{sub 2}) nanostructured thin films (NTFs) were synthesised by sulfurizing MoO{sub 3} NTFs using three different non-conventional methods (named methods 1–3). Method 1 uses sulfur vapors, second employs H{sub 2}S/Ar gas and third adopts plasma of H{sub 2}S/Ar gas. HRTEM revealed formation of core–shell nanostructures with maximum shell thickness obtained in method 3. The samples showed uniform nanoflakes (NFs) throughout substrate, revealed by SEM, same as their precursor MoO{sub 3.} XRD and Raman analysis disclosed crystalline MoS{sub 2} and degree of crystallinity was greatest in case of sulfurization in plasma ambient. Quantitative analysis of sulfurized films carried out by XPS shows presence of MoS{sub 2} in all three methods with percentage found to be 18%, 87% and ∼100% respectively. The effect of sulfurizing ambient on its efficiency to convert MoO{sub 3} into MoS{sub 2} has been studied and it was found out that plasma ambient has resulted in high quality of MoS{sub 2} NTFs based on parameters as crystallinity, purity, uniformity and stoichiometry control. - Highlights: • Comparison of three non-conventional methods of sulfurization. • Parameters used for comparison are crystallinity, purity, sulfurized thickness, uniformity and stoichiometry. • H{sub 2}S/Ar plasma based method came out to be best among other techniques. • A soft template reactions for sulfurization of MoO{sub 3} nanoflake is proposed.

MoEDAL: Passive but no less active

CERN Multimedia

MoEDAL Collaboration

2015-01-01

Relying almost completely on passive detectors, MoEDAL is a pioneering experiment designed to search for highly ionising avatars of new physics, such as magnetic monopoles or massive (pseudo-)stable charged particles. The first test detectors were deployed at LHC Point 8 in 2012 and analysed in 2013, and the full MoEDAL detector was installed in the winter of 2014 to start data-taking during Run 2 this year.   The image shows the MoEDAL detector systems installed at Point 8 of the LHC. MoEDAL’s groundbreaking physics programme defines over 30 scenarios that yield potentially revolutionary insights into such fundamental questions as: are there extra dimensions or new symmetries? Does magnetic charge exist? What is the nature of dark matter? And how did the big bang develop? MoEDAL's purpose is to meet such far-reaching challenges at the frontier of the field. Having reached its final configuration in winter 2014, MoEDAL now consists of ten layers of plastic attached to the ...

Desenvolvimento e atividade do fitocosmético contendo licopeno para o combate à aceleração do envelhecimento cutâneo

OpenAIRE

Cefali, Letícia Caramori [UNESP

2009-01-01

O licopeno é um carotenóide com poderosa ação antioxidante, encontrado em maior quantidade no tomate, utilizado no combate a inúmeras doenças como vários tipos de câncer, dentre eles o de próstata, e doenças cardiovasculares. Sua ação tópica é pouco explorada e, por isso, a proposta de ser utilizado no combate à aceleração do envelhecimento cutâneo, incorporado em uma emulsão. Um estudo preliminar foi realizado para a escolha do tipo de tomate que apresenta maior concentração de licopeno e/ou...

Phase equilibria of the Mo-Al-Ho ternary system

Energy Technology Data Exchange (ETDEWEB)

Li, Yitai; Chen, Xiaoxian; Liu, Hao [Guangxi Univ., Nanning (China). College of Materials Science and Engineering; Guangxi Univ., Nanning (China). Guangxi Key Laboratory of Processing for Non-ferrous Metal and Featured Materials; Zhan, Yongzhong [Guangxi Univ., Nanning (China). College of Materials Science and Engineering; Guangxi Univ., Nanning (China). Guangxi Key Laboratory of Processing for Non-ferrous Metal and Featured Materials; Guangxi Univ., Nanning (China). Center of Ecological Collaborative Innovation for Aluminum Industry

2017-08-15

Investigation into the reactions and phase equilibria of transition metal elements (i.e. Mo, Zr, Cr, V and Ti), Al and rare earths is academically and industrially important for the development of both refractory alloys and lightweight high-temperature materials. In this work, the equilibria of the Mo-Al-Ho ternary system at 773 K have been determined by using X-ray powder diffraction and scanning electron microscopy equipped with energy dispersive X-ray analysis. A new ternary phase Al{sub 4}Mo{sub 2}Ho has been found and the other ternary phase Al{sub 43}Mo{sub 4}Ho{sub 6} is observed. Ten binary phases in the Al-Mo and Al-Ho systems, including Al{sub 17}Mo{sub 4} rather than Al{sub 4}Mo, have been determined to exist at 773 K. The homogeneity ranges of AlMo{sub 3} and Al{sub 8}Mo{sub 3} phase are 7.5 at.% and 1 at.%, respectively. According to the phase-disappearing method, the maximum solubility of Al in Mo is about 16 at.%.

Faceted MoS2 nanotubes and nanoflowers

International Nuclear Information System (INIS)

Deepak, Francis Leonard; Mayoral, Alvaro; Yacaman, Miguel Jose

2009-01-01

A simple synthesis of novel faceted MoS 2 nanotubes (NTs) and nanoflowers (NFs) starting from molybdenum oxide and thiourea as the sulphur source is reported. The MoS 2 nanotubes with the faceted morphology have not been observed before. Further the as-synthesized MoS 2 nanotubes have high internal surface area. The nanostructures have been characterized by a variety of electron microscopy techniques. It is expected that these MoS 2 nanostrutures will find important applications in energy storage, catalysis and field emission.

Effect of Mo2C/(Mo2C + WC) weight ratio on the microstructure and mechanical properties of Ti(C,N)-based cermet tool materials

International Nuclear Information System (INIS)

Xu, Qingzhong; Zhao, Jun; Ai, Xing; Qin, Wenzhen; Wang, Dawei; Huang, Weimin

2015-01-01

To optimize the Mo 2 C content in Ti(C,N)-based cermet tool materials used for cutting the high-strength steel of 42CrMo (AISI 4140/4142 steel), the cermets with different Mo 2 C/(Mo 2 C + WC) weight ratios were prepared. And the microstructure and mechanical properties of cermets were investigated by scanning electron microscope (SEM), X-ray diffraction (XRD) and measurements of transverse rupture strength (TRS), Vickers hardness (HV) and fracture toughness (K IC ). The results indicate that the Mo 2 C/(Mo 2 C + WC) ratios have great influences on the microstructure features and mechanical properties of Ti(C,N)-based cermets. When the Mo 2 C/(Mo 2 C + WC) ratio increases, the Ti(C,N) grains become finer with smaller black cores surrounded by thinner rims, and the structure of cermets tends to be more compact with smaller binder mean free path. Owing to the medium grains and moderate rims, the cermets with a Mo 2 C/(Mo 2 C + WC) ratio of 0.4 exhibit better mechanical properties, and can be chosen as the tool material for machining 42CrMo steel due to the lower Mo content. - Highlights: • Mo 2 C/(Mo 2 C + WC) ratios affect microstructure and mechanical properties of cermets. • Grains become fine and structure of cermets tends to be compact with raised Mo 2 C. • The cermets with a Mo 2 C/(Mo 2 C + WC) ratio of 0.4 can be used to machine 42CrMo steel

Single-layer MoS2 electronics.

Science.gov (United States)

Lembke, Dominik; Bertolazzi, Simone; Kis, Andras

2015-01-20

CONSPECTUS: Atomic crystals of two-dimensional materials consisting of single sheets extracted from layered materials are gaining increasing attention. The most well-known material from this group is graphene, a single layer of graphite that can be extracted from the bulk material or grown on a suitable substrate. Its discovery has given rise to intense research effort culminating in the 2010 Nobel Prize in physics awarded to Andre Geim and Konstantin Novoselov. Graphene however represents only the proverbial tip of the iceberg, and increasing attention of researchers is now turning towards the veritable zoo of so-called "other 2D materials". They have properties complementary to graphene, which in its pristine form lacks a bandgap: MoS2, for example, is a semiconductor, while NbSe2 is a superconductor. They could hold the key to important practical applications and new scientific discoveries in the two-dimensional limit. This family of materials has been studied since the 1960s, but most of the research focused on their tribological applications: MoS2 is best known today as a high-performance dry lubricant for ultrahigh-vacuum applications and in car engines. The realization that single layers of MoS2 and related materials could also be used in functional electronic devices where they could offer advantages compared with silicon or graphene created a renewed interest in these materials. MoS2 is currently gaining the most attention because the material is easily available in the form of a mineral, molybdenite, but other 2D transition metal dichalcogenide (TMD) semiconductors are expected to have qualitatively similar properties. In this Account, we describe recent progress in the area of single-layer MoS2-based devices for electronic circuits. We will start with MoS2 transistors, which showed for the first time that devices based on MoS2 and related TMDs could have electrical properties on the same level as other, more established semiconducting materials. This

Interface morphology of Mo/Si multilayer systems with varying Mo layer thickness studied by EUV diffuse scattering.

Science.gov (United States)

Haase, Anton; Soltwisch, Victor; Braun, Stefan; Laubis, Christian; Scholze, Frank

2017-06-26

We investigate the influence of the Mo-layer thickness on the EUV reflectance of Mo/Si mirrors with a set of unpolished and interface-polished Mo/Si/C multilayer mirrors. The Mo-layer thickness is varied in the range from 1.7 nm to 3.05 nm. We use a novel combination of specular and diffuse intensity measurements to determine the interface roughness throughout the multilayer stack and do not rely on scanning probe measurements at the surface only. The combination of EUV and X-ray reflectivity measurements and near-normal incidence EUV diffuse scattering allows to reconstruct the Mo layer thicknesses and to determine the interface roughness power spectral density. The data analysis is conducted by applying a matrix method for the specular reflection and the distorted-wave Born approximation for diffuse scattering. We introduce the Markov-chain Monte Carlo method into the field in order to determine the respective confidence intervals for all reconstructed parameters. We unambiguously detect a threshold thickness for Mo in both sample sets where the specular reflectance goes through a local minimum correlated with a distinct increase in diffuse scatter. We attribute that to the known appearance of an amorphous-to-crystallization transition at a certain thickness threshold which is altered in our sample system by the polishing.

Synthesis and electrochemical properties of tin-doped MoS{sub 2} (Sn/MoS{sub 2}) composites for lithium ion battery applications

Energy Technology Data Exchange (ETDEWEB)

Lu, Lin; Min, Feixia; Luo, Zhaohui; Wang, Shiquan, E-mail: wsqhao@126.com [Hubei University, Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for Synthesis and Applications of Organic Functional Molecules (China); Teng, Fei [Nanjing University of Information Science and Technology, Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control (AEMPC), School of Environmental Sciences and Engineering (China); Li, Guohua [Zhejiang University of Technology, School of Chemical Engineering and Materials Science (China); Feng, Chuanqi [Hubei University, Hubei Collaborative Innovation Center for Advanced Organic Chemical Materials, Ministry-of-Education Key Laboratory for Synthesis and Applications of Organic Functional Molecules (China)

2016-12-15

SnO{sub 2}-MoO{sub 3} composites were synthesized by using (NH{sub 4}){sub 6}Mo{sub 7}O{sub 24}·4H{sub 2}O and SnCl{sub 2}·2H{sub 2}O as raw materials through a simple solvothermal method followed by pyrolysis. Tin-doped MoS{sub 2} (Sn/MoS{sub 2}) flowers have been synthesized by a solvothermal method followed with annealing in Ar(H{sub 2}) atmosphere, with SnO{sub 2}-MoO{sub 3}, thioacetamide (TAA), and urea as starting materials. The doping and the content of Sn-doping play crucial roles in the morphology and electrochemical performance of the MoS{sub 2}. As anode materials for lithium ion battery (LIB), all Sn/MoS{sub 2} composites exhibit both higher reversible capacity and better cycling performance at current density of 200 mA g{sup −1}, compared with MoS{sub 2} without Sn doping. The achieved discharge capacity for Sn/MoS{sub 2} composites is above 1000 mAh g{sup −1} after 100 cycles with nearly 100% coulombic efficiency. The doping of metal Sn in MoS{sub 2} can improve the conductivity of MoS{sub 2} and significantly enhance its electrochemical properties. The good electrochemical performance suggests that the Sn/MoS{sub 2} composite could be a promising candidate as a novel anode material for LIB application. Our present work provides a new approach to the fabrication of anode materials for LIB applications.

K(MoO24O3(AsO4

Directory of Open Access Journals (Sweden)

Raja Jouini

2013-06-01

Full Text Available A new compound with a non-centrosymmetric structure, potassium tetrakis[dioxomolybdenum(IV] arsenate trioxide, K(MoO24O3(AsO4, has been synthesized by a solid-state reaction. The [(MoO24O3(AsO4]+ three-dimensional framework consists of single arsenate AsO4 tetrahedra, MoO6 octahedra, MoO5 bipyramids and bioctahedral units of edge-sharing Mo2O10 octahedra. The [Mo2O8]∞ octahedral chains running along the a-axis direction are connected through their corners to the AsO4 tetrahedra, MoO6 octahedra and MoO5 bipyramids, so as to form large tunnels propagating along the a axis in which the K+ cations are located. This structure is compared with compounds containing M2O10 (M = Mo, V, Fe dimers and with those containing M2O8 (M = V chains.

Structural, morphological, and optical characterizations of Mo, CrN and Mo:CrN sputtered coatings for potential solar selective applications

Science.gov (United States)

Ibrahim, Khalil; Mahbubur Rahman, M.; Taha, Hatem; Mohammadpour, Ehsan; Zhou, Zhifeng; Yin, Chun-Yang; Nikoloski, Aleksandar; Jiang, Zhong-Tao

2018-05-01

Mo, CrN, and Mo:CrN sputtered coatings synthesized onto silicon Si(100) substrates were investigated as solar selective surfaces and their potential applications in optical devices. These coatings were characterized using XRD, SEM, UV-vis, and FTIR techniques. XRD investigation, showed a change in CrN thin film crystallite characteristic due to Mo doping. Compared to the CrN coating, the Mo:CrN film has a higher lattice parameter and lower grain size of 4.19 nm and 106.18 nm, respectively. FESEM morphology confirmed the decrement in Mo:CrN crystal size due to Mo doping. Optical analysis showed that in the visible range of the solar spectrum, the CrN coatings exhibit the highest solar absorptance of 66% while the lowest thermal emittance value of 5.67 was recorded for the CrN coating doped with Mo. Consequently, the highest solar selectivity of 9.6, and the energy band-gap of 2.88 eV were achieved with the Mo-doped CrN coatings. Various optical coefficients such as optical absorption coefficient, refractive index, extinction coefficient, real and imaginary parts of dielectric constants, and energy loss functions of these coatings were also estimated from the optical reflectance data recorded in the wavelength range of 190-2300 nm.

Cyclic tensile response of Mo-27 at% Re and Mo-0.3 at% Si solid solution alloys

Energy Technology Data Exchange (ETDEWEB)

Yu, X.J.; Kumar, K.S., E-mail: Sharvan_Kumar@brown.edu

2016-10-31

Stress-controlled uniaxial cyclic tensile tests were conducted on binary Mo-27 at% Re and Mo-0.3 at% Si solid solutions as a function of temperature and compared against the previously reported cyclic response of pure Mo. The Mo-27 at% Re alloy with a recrystallized grain size of ~30 µm was evaluated in the temperature range 25 °C–800 °C at R=0.1 and stress range that was 80% of the ultimate tensile strength (UTS); a peak in fatigue life was observed between 300 °C and 500 °C. The decrease in fatigue life at the higher temperatures of 700 °C and 800 °C is attributed to dynamic strain aging. Transmission electron microscopy of the cyclically-deformed alloy revealed parallel bands of dislocation at room temperature that transitioned to a uniform cell structure at 500 °C and back to orthogonal planar arrays at 800 °C. The as-extruded Mo-0.3 at% Si alloy was evaluated from 25 °C to 1200 °C and showed superior fatigue life and ratcheting strain resistance as compared to pure Mo and the Mo-27 at% Re alloy (within the temperature range where data were available for comparison). The superior resistance is attributed to the high density of dislocations within the material in this mostly unrecrystallized state rather than Si in solid solution. Above 800 °C, the ratcheting strain increases and fatigue life decreases rapidly with increasing temperature and is associated with dynamic recovery.

Plasma-assisted synthesis of MoS2

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Campbell, Philip M.; Perini, Christopher J.; Chiu, Johannes; Gupta, Atul; Ray, Hunter S.; Chen, Hang; Wenzel, Kevin; Snyder, Eric; Wagner, Brent K.; Ready, Jud; Vogel, Eric M.

2018-03-01

There has been significant interest in transition metal dichalcogenides (TMDs), including MoS2, in recent years due to their potential application in novel electronic and optical devices. While synthesis methods have been developed for large-area films of MoS2, many of these techniques require synthesis temperatures of 800 °C or higher. As a result of the thermal budget, direct synthesis requiring high temperatures is incompatible with many integrated circuit processes as well as flexible substrates. This work explores several methods of plasma-assisted synthesis of MoS2 as a way to lower the synthesis temperature. The first approach used is conversion of a naturally oxidized molybdenum thin film to MoS2 using H2S plasma. Conversion is demonstrated at temperatures as low as 400 °C, and the conversion is enabled by hydrogen radicals which reduce the oxidized molybdenum films. The second method is a vapor phase reaction incorporating thermally evaporated MoO3 exposed to a direct H2S plasma, similar to chemical vapor deposition (CVD) synthesis of MoS2. Synthesis at 400 °C results in formation of super-stoichiometric MoS2 in a beam-interrupted growth process. A final growth method relies on a cyclical process in which a small amount of Mo is sputtered onto the substrate and is subsequently sulfurized in a H2S plasma. Similar results could be realized using an atomic layer deposition (ALD) process to deposit the Mo film. Compared to high temperature synthesis methods, the lower temperature samples are lower quality, potentially due to poor crystallinity or higher defect density in the films. Temperature-dependent conductivity measurements are consistent with hopping conduction in the plasma-assisted synthetic MoS2, suggesting a high degree of disorder in the low-temperature films. Optimization of the plasma-assisted synthesis process for slower growth rate and better stoichiometry is expected to lead to high quality films at low growth temperature.

On the Mo-Papas equation

Science.gov (United States)

Aguirregabiria, J. M.; Chamorro, A.; Valle, M. A.

1982-05-01

A new heuristic derivation of the Mo-Papas equation for charged particles is given. It is shown that this equation cannot be derived for a point particle by closely following Dirac's classical treatment of the problem. The Mo-Papas theory and the Bonnor-Rowe-Marx variable mass dynamics are not compatible.

XPS study of organic/MoO3 hybrid thin films for aldehyde gas sensors. Correlation between average Mo valance and sensitivity

International Nuclear Information System (INIS)

Itoh, Toshio; Matsubara, Ichiro; Shin, Woosuck; Izu, Noriya; Nishibori, Maiko

2010-01-01

We investigate the formaldehyde gas sensing properties of poly(5,6,7,8-tetrahydro-1-naphthylamine)-intercalated MoO 3 thin films ((PTHNA) x MoO 3 ). The resistance responses of (PTHNA) x MoO 3 to formaldehyde increase with increasing intercalation temperature. X-ray photoelectron spectroscopy reveals that the molar ratio of Mo 5+ decreases with increasing intercalation temperature. (author)

Physical properties of monolithic U8 wt.%-Mo

Science.gov (United States)

Hengstler, R. M.; Beck, L.; Breitkreutz, H.; Jarousse, C.; Jungwirth, R.; Petry, W.; Schmid, W.; Schneider, J.; Wieschalla, N.

2010-07-01

As a possible high density fuel for research reactors, monolithic U8 wt.%-Mo ("U8Mo") was examined with regard to its structural, thermal and electric properties. X-ray diffraction by the Bragg-Brentano method was used to reveal the tetragonal lattice structure of rolled U8Mo. The specific heat capacity of cast U8Mo was determined by differential scanning calorimetry, its thermal diffusivity was measured by the laser flash method and its mass density by Archimedes' principle. From these results, the thermal conductivity of U8Mo in the temperature range from 40 °C to 250 °C was calculated; in the measured temperature range, it is in good accordance with literature data for UMo with 8 and 9 wt.% Mo, is higher than for 10 wt.% Mo and lower than for 5 wt.% Mo. The electric conductivity of rolled and cast U8Mo was measured by a four-wire method and the electron based part of the thermal conductivity calculated by the Wiedemann-Frantz law. Rolled and cast U8Mo was irradiated at about 150 °C with 80 MeV 127I ions to receive the same iodine ion density in the damage peak region as the fission product density in the fuel of a typical high flux reactor after the targeted nuclear burn-up. XRD analysis of irradiated U8Mo showed a change of the lattice parameters as well as the creation of UO 2 in the superficial sample regions; however, a phase change by irradiation was not observed. The determination of the electron based part of the thermal conductivity of the irradiated samples failed due to high measurement errors which are caused by the low thickness of the damage region in the ion irradiated samples.

An alternative route for the preparation of the medical isotope 99Mo from the 238U(γ, f) and 100Mo(γ, n) reactions

International Nuclear Information System (INIS)

Naik, H.; Goswami, A.; Suryanarayana, S.V.; Jagadeesan, K.C.; Thakare, S.V.; Joshi, P.V.; Nimje, V.T.; Mittal, K.C.; Venugopal, V.; Kailas, S.

2013-01-01

The radionuclide 99 Mo, which has a half-life of 65.94 h was produced from 238 U(γ, f) and 100 Mo(γ, n) reactions using a 10 MeV electron linac at EBC, Kharghar Navi-Mumbai, India. This has been investigated since the daughter product 99m Tc is very important from a medical point of view and can be produced in a generator from the parent 99 Mo. The activity of 99 Mo was analyzed by a γ-ray spectrometric technique using a HPGe detector. From the detected γ-rays activity of 140.5 and 739.8 keV, the amount of 99 Mo produced was determined. For comparison, the amount of 99 Mo from 238 U(γ, f) and 100 Mo(γ, n) reactions was also estimated using the experimental photon flux from 197 Au(γ, n) 196 Au reaction. The amount of 99 Mo from the detected γ-lines is in agreement with the estimated value for 238 U(γ, f) and 100 Mo(γ, n) reactions. The production of 99 Mo activity from 238 U(γ, f) and 100 Mo(γ, n) reactions is a relevant and novel approach, which provides alternative routes to 235,238 U(n, f) and 98 Mo(n, γ) reactions, circumventing the need for a reactor. The viability and practicality of the 99 Mo production from the 238 U(γ, f) and 100 Mo(γ, n) reactions alternative to 235,238 U(n, f) and 98 Mo(n, γ) reactions has been emphasize. An estimate has been also arrived based on the experimental data of present work to fulfill the requirement of DOE. (author)

Structural transformation of MoO3 nanobelts into MoS2 nanotubes

International Nuclear Information System (INIS)

Deepak, Francis Leonard; Mayoral, Alvaro; Yacaman, Miguel Jose

2009-01-01

The structural transformation of MoO 3 nanobelts into MoS 2 nanotubes using a simple sulfur source has been reported. This transformation has been extensively investigated using electron microscopic and spectroscopic techniques including scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), electron diffraction (ED), and energy-dispersive X-ray analysis (SEM-EDAX and TEM-EDX). The method described in this report will serve as a generic route for the transformation of other oxide nanostructures into the chalcogenide nanostructures. (orig.)

A first principle Comparative study of electronic and optical properties of 1H –MoS2 and 2H –MoS2

International Nuclear Information System (INIS)

Kumar, Ashok; Ahluwalia, P.K.

2012-01-01

First principle calculations of electronic and optical properties of monolayer MoS 2 , so called 1H –MoS 2 , is performed which has emerged as a new direct band gap semiconductor. Before calculations of the properties of 1H –MoS 2 , we have calculated structural parameters, electronic properties (electronic band structure and electronic density of states) and frequency dependent optical response (real and imaginary part of dielectric function, energy loss function, absorption and reflectance spectra) of 2H –MoS 2 and compared with existing experimental results and found that our calculated results are in very good agreements with experimental results. To compare the dielectric functions of bulk (2H –MoS 2 ) and monolayer (1H –MoS 2 ) phases we have further extended these calculations to the single layer MoS 2 (1H –MoS 2 ) which is analogous to graphene. Structural parameters of 1H –MoS 2 are found very close to its bulk 2H –MoS 2 . We find direct electronic band gap at ‘K’ high symmetry point as compared to indirect band gap in its bulk 2H – MoS2. Our calculated dielectric function for 1H – MoS2 shows structure at nearly same energy positions as compared to 2H – MoS2 with additional structure at 3.8 eV. Also additional well defined energy loss peaks revealing the plasmonic resonances at 15.7 eV and 16.0 eV for E vector perpendicular and parallel to c axis respectively for 1H – MoS2 have been found, which are the signatures of surface plasmons at these energies. -- Highlights: ► Structural parameters of 2H-MoS2 and 1H-MoS2 are nearly identical. ► States around the Fermi energy are mainly due to the metal d states. ► Strong hybridization between Mo-d and S-p states below the Fermi energy has been found. ► Optical spectra of 2H-MoS2 finds very good agreements with experimental optical spectra. ► The band gap is found to be direct for 1H-MoS2 as compared to indirect for 2H-MoS2.

Phase transformations in Mo-doped FINEMETs

Energy Technology Data Exchange (ETDEWEB)

Silveyra, Josefina M., E-mail: jsilveyra@fi.uba.a [Lab. de Solidos Amorfos, INTECIN, FIUBA-CONICET, Paseo Colon 850, (C1063ACV) Buenos Aires (Argentina); Illekova, Emilia; Svec, Peter; Janickovic, Dusan [Institute of Physics SAS, Dubravska cesta 9, 845 11 Bratislava (Slovakia); Rosales-Rivera, Andres [Laboratorio de Magnetismo y Materiales Avanzados, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Manizales (Colombia); Cremaschi, Victoria J. [Lab. de Solidos Amorfos, INTECIN, FIUBA-CONICET, Paseo Colon 850, (C1063ACV) Buenos Aires (Argentina)

2010-06-15

In this paper, the phase transformations occurring during the crystallization process of FINEMETs in which Nb has been gradually replaced by Mo have been studied by a variety of techniques including DSC, DTA, TGA, XRD and TEM. The thermal stability of the alloy was deteriorated as a consequence of Mo's smaller atomic size. The gradual replacement of Nb by Mo reduced the onset temperature of Fe-Si and of the borides. The Curie temperature of the amorphous phase slightly decreased from 594 K for x=0 to 587 K for x=3. The borides compounds Fe{sub 2}B and Fe{sub 23}B{sub 6} as well as the (Nb,Mo){sub 5}Si{sub 3} phase were found to precipitate in the second and third crystallization.

Ligand bridging-angle-driven assembly of molecular architectures based on quadruply bonded Mo-Mo dimers.

Science.gov (United States)

Li, Jian-Rong; Yakovenko, Andrey A; Lu, Weigang; Timmons, Daren J; Zhuang, Wenjuan; Yuan, Daqiang; Zhou, Hong-Cai

2010-12-15

A systematic exploration of the assembly of Mo2(O2C-)4-based metal-organic molecular architectures structurally controlled by the bridging angles of rigid organic linkers has been performed. Twelve bridging dicarboxylate ligands were designed to be of different sizes with bridging angles of 0, 60, 90, and 120° while incorporating a variety of nonbridging functional groups, and these ligands were used as linkers. These dicarboxylate linkers assemble with quadruply bonded Mo-Mo clusters acting as nodes to give 13 molecular architectures, termed metal-organic polygons/polyhedra with metal cluster node arrangements of a linear shape, triangle, octahedron, and cuboctahedron/anti-cuboctahedron. The syntheses of these complexes have been optimized and their structures determined by single-crystal X-ray diffraction. The results have shown that the shape and size of the resulting molecular architecture can be controlled by tuning the bridging angle and size of the linker, respectively. Functionalization of the linker can adjust the solubility of the ensuing molecular assembly but has little or no effect on the geometry of the product. Preliminary gas adsorption, spectroscopic, and electrochemical properties of selected members were also studied. The present work is trying to enrich metal-containing supramolecular chemistry through the inclusion of well-characterized quadruply bonded Mo-Mo units into the structures, which can widen the prospect of additional electronic functionality, thereby leading to novel properties.

Tetracarbonylbis(η5-cyclopentadienylbis(diphenylphosphinedimolybdenum(Mo—Mo hexane solvate

Directory of Open Access Journals (Sweden)

David R. Tyler

2008-07-01

Full Text Available The title compound, [Mo2(C5H52(C12H11P2(CO4]·C6H14, is a centrosymmetric Mo complex in which two Mo atoms are connected by an Mo—Mo bond [3.2072 (12 Å]. Each Mo atom is coordinated by an η5-cyclopentadienyl ligand, two carbonyl ligands and a diphenylphosphine ligand in a piano-stool fashion.

Room-temperature superparamagnetism due to giant magnetic anisotropy in Mo S defected single-layer MoS2

Science.gov (United States)

Khan, M. A.; Leuenberger, Michael N.

2018-04-01

Room-temperature superparamagnetism due to a large magnetic anisotropy energy (MAE) of a single atom magnet has always been a prerequisite for nanoscale magnetic devices. Realization of two dimensional (2D) materials such as single-layer (SL) MoS2, has provided new platforms for exploring magnetic effects, which is important for both fundamental research and for industrial applications. Here, we use density functional theory (DFT) to show that the antisite defect (Mo S ) in SL MoS2 is magnetic in nature with a magnetic moment μ of  ∼2 μB and, remarkably, exhibits an exceptionally large atomic scale MAE =\\varepsilon\\parallel-\\varepsilon\\perp of  ∼500 meV. Our calculations reveal that this giant anisotropy is the joint effect of strong crystal field and significant spin–orbit coupling (SOC). In addition, the magnetic moment μ can be tuned between 1 μB and 3 μB by varying the Fermi energy \\varepsilonF , which can be achieved either by changing the gate voltage or by chemical doping. We also show that MAE can be raised to  ∼1 eV with n-type doping of the MoS2:Mo S sample. Our systematic investigations deepen our understanding of spin-related phenomena in SL MoS2 and could provide a route to nanoscale spintronic devices.

Diversification of 99Mo/99mTc separation: non–fission reactor production of 99Mo as a strategy for enhancing 99mTc availability.

Science.gov (United States)

Pillai, Maroor R A; Dash, Ashutosh; Knapp, Furn F Russ

2015-01-01

This paper discusses the benefits of obtaining (99m)Tc from non-fission reactor-produced low-specific-activity (99)Mo. This scenario is based on establishing a diversified chain of facilities for the distribution of (99m)Tc separated from reactor-produced (99)Mo by (n,γ) activation of natural or enriched Mo. Such facilities have expected lower investments than required for the proposed chain of cyclotrons for the production of (99m)Tc. Facilities can receive and process reactor-irradiated Mo targets then used for extraction of (99m)Tc over a period of 2 wk, with 3 extractions on the same day. Estimates suggest that a center receiving 1.85 TBq (50 Ci) of (99)Mo once every 4 d can provide 1.48-3.33 TBq (40-90 Ci) of (99m)Tc daily. This model can use research reactors operating in the United States to supply current (99)Mo needs by applying natural (nat)Mo targets. (99)Mo production capacity can be enhanced by using (98)Mo-enriched targets. The proposed model reduces the loss of (99)Mo by decay and avoids proliferation as well as waste management issues associated with fission-produced (99)Mo.

PREPARATION AND CATALYTIC ACTIVITY FOR ISOPROPYL BENZENE CRACKING OF Co, Mo AND Co/Mo-Al2O3-PILLARED MONTMORILLONITE CATALYSTS

Directory of Open Access Journals (Sweden)

Hasanudin Hasanudin

2010-06-01

Full Text Available It has been prepared Co, Mo and Co/Mo-Al2O3-pillared montmorillonite catalysts using montmorillonite clay  as raw material. The structure and porosity of the catalysts were determined using N2 adsorption-desorption and FT-IR spectroscopy analysis methods. Isopropyl benzene cracking using these catalysts were used to test the catalytic activity and performance of Co, Mo and Co/Mo-Al2O3-pillared montmorillonites.  Characterization results showed that pillarization resulted in the increase of the total pore volume and specific surface area of the clay. Meanwhile, transition metals (Co, Mo and Co/Mo loaded on Al2O3-pillared monmorillonites could increase the catalytic activity of the catalysts for isopropyl benzene cracking significantly.   Keywords: pillared monmorillonite, isopropyl benzene  and cracking catalyst

Double molybdates in Li2MoO4 - Na2MoO4 - H2O system at 25 grad C

International Nuclear Information System (INIS)

Karov, Z.G.; Mirzoev, R.S.; Makitova, D.D.; Zhilova, S.B.; Podnek, A.G.; Urusova, R.Kh.

1989-01-01

Solubility in Li 2 MoO 4 - Na 2 MoO 4 - H 2 O system at 25 deg C is first stuied. Formation of two Li 2 MoO 4 · Na 2 MoO 4 · 4H 2 O and Li 2 MoO 4 · 3Na 2 MoO 4 · 12H 2 O compounds in a system is ascertained. Density, refractive index, viscosity, surface tension, electric conductivity and pH of saturated solutions are determined. Isothermes of mole volume, equivalent and reduced electric conductivity and seeming mole volume of salts sum in solutions are calculated. All these properties adequtely confirm the character of components interaction in a system determined by solubility method. Crystallhydrates of binary molybdates are separated, indentified and studied

Effects of Mo on microstructure of as-cast 28 wt.% Cr–2.6 wt.% C–(0–10) wt.% Mo irons

Energy Technology Data Exchange (ETDEWEB)

Imurai, S. [Department of Physics and Materials Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Thanachayanont, C.; Pearce, J.T.H. [National Metal and Materials Technology Center, Pathumthani 12120 (Thailand); Tsuda, K. [Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai 980-8577 (Japan); Chairuangsri, T., E-mail: tchairuangsri@gmail.com [Department of Industrial Chemistry, Chiang Mai University, Chiang Mai 50200 (Thailand)

2014-04-01

Microstructures of as-cast 28 wt.% Cr–2.6 wt.% C irons containing (0–10) wt.% Mo with the Cr/C ratio of about 10 were studied and related to hardness. The experimental irons were cast into dry sand molds. Microstructural investigation was performed by light microscopy, X-ray diffractometry, scanning electron microscopy, transmission electron microscopy and energy-dispersive X-ray spectrometry. It was found that the iron with about 10 wt.% Mo was eutectic/peritectic, whereas the others with less Mo content were hypoeutectic. The matrix in all irons was austenite, partly transformed to martensite during cooling. Mo addition promoted the formation of M{sub 23}C{sub 6} and M{sub 6}C. At 1 wt.% Mo, multiple eutectic carbides including M{sub 7}C{sub 3}, M{sub 23}C{sub 6} and M{sub 6}C were observed. M{sub 23}C{sub 6} existed as a transition zone between eutectic M{sub 7}C{sub 3} and M{sub 6}C, indicating a carbide transition as M{sub 7}C{sub 3}(M{sub 2.3}C) → M{sub 23}C{sub 6}(M{sub 3.8}C) → M{sub 6}C. At 6 wt.% Mo, multiple eutectic carbides including M{sub 7}C{sub 3} and M{sub 23}C{sub 6} were observed together with fine cellular/lamellar M{sub 6}C aggregates. In the iron with 10 wt.% Mo, only eutectic/peritectic M{sub 23}C{sub 6} and M{sub 6}C were found without M{sub 7}C{sub 3}. Mo distribution to all carbides has been determined to be increased from ca. 0.4 to 0.7 in mass fraction as the Mo content in the irons was increased. On the other hand, Cr distribution to all carbides is quite constant as ca. 0.6 in mass fraction. Mo addition increased Vickers macro-hardness of the irons from 495 up to 674 HV{sub 30}. High Mo content as solid-solution in the matrix and the formation of M{sub 6}C or M{sub 23}C{sub 6} aggregates were the main reasons for hardness increase, indicating potentially improved wear performance of the irons with Mo addition. - Highlights: • Mo promoted the formation of M{sub 23}C{sub 6} and M{sub 6}C in the irons with Cr/C ratio of about 10

Irradiation performance of U-Mo-Ti and U-Mo-Zr dispersion fuels in Al-Si matrixes

Energy Technology Data Exchange (ETDEWEB)

Kim, Yeon Soo, E-mail: yskim@anl.gov [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Hofman, G.L. [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Robinson, A.B.; Wachs, D.M. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States); Ryu, H.J.; Park, J.M.; Yang, J.H. [Korea Atomic Energy Research Institute, 150 Deokjin-dong, Yuseong-gu, Daejeon 305-353 (Korea, Republic of)

2012-08-15

Performance of U-7 wt.%Mo with 1 wt.%Ti, 1 wt.%Zr or 2 wt.%Zr, dispersed in an Al-5 wt.%Si alloy matrix, was investigated through irradiation tests in the ATR at INL and HANARO at KAERI. Post-irradiation metallographic features show that the addition of Ti or Zr suppresses interaction layer growth between the U-Mo and the Al-5 wt.%Si matrix. However, higher fission gas swelling was observed in the fuel with Zr addition, while no discernable effect was found in the fuel with Ti addition as compared to U-Mo without the addition. Known to have a destabilizing effect on the {gamma}-phase U-Mo, Zr, either as alloy addition or fission product, is ascribed for the disadvantageous result. Considering its benign effect on fuel swelling, with slight disadvantage from neutron economy point of view, Ti may be a better choice for this purpose.

Influence of Mo/MoSe{sub 2} microstructure on the damp heat stability of the Cu(In,Ga)Se{sub 2} back contact molybdenum

Energy Technology Data Exchange (ETDEWEB)

Theelen, Mirjam, E-mail: mirjam.theelen@tno.nl [TNO Solliance, Thin Film Technology, High Tech Campus 21, 5656 AE Eindhoven (Netherlands); Delft University of Technology, Photovoltaic Materials and Devices, Mekelweg 4, 2628 CD Delft (Netherlands); Harel, Sylvie [Institut des Matériaux Jean Rouxel (IMN)-UMR 6502, Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France); Verschuren, Melvin [TNO Solliance, Thin Film Technology, High Tech Campus 21, 5656 AE Eindhoven (Netherlands); Tomassini, Mathieu [Institut des Matériaux Jean Rouxel (IMN)-UMR 6502, Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France); Hovestad, Arjan [TNO Solliance, Thin Film Technology, High Tech Campus 21, 5656 AE Eindhoven (Netherlands); Barreau, Nicolas [Institut des Matériaux Jean Rouxel (IMN)-UMR 6502, Université de Nantes, CNRS, 2 rue de la Houssinière, BP 32229, 44322 Nantes Cedex 3 (France); Berkum, Jurgen van [Philips Innovation Services, High Tech Campus 11, 5656 AE Eindhoven (Netherlands); Vroon, Zeger [TNO Solliance, Thin Film Technology, High Tech Campus 21, 5656 AE Eindhoven (Netherlands); Zeman, Miro [Delft University of Technology, Photovoltaic Materials and Devices, Mekelweg 4, 2628 CD Delft (Netherlands)

2016-08-01

The degradation behavior of Mo/MoSe{sub 2} layers have been investigated using damp heat exposure. The two studied molybdenum based films with different densities and microstructures were obtained by lifting off Cu(In,Ga)Se{sub 2} layers from a bilayer molybdenum stack on soda lime glass. Hereby, a glass/Mo/MoSe{sub 2} was obtained, which resembles the back contact as present in Cu(In,Ga)Se{sub 2} solar cells. The samples were degraded for 150 h under standard damp heat conditions and analyzed before, during and after degradation. It was observed that the degradation resulted in the formation of needles and molybdenum oxide layers near the glass/Mo and the Mo/Cu(In,Ga)Se{sub 2} interfaces. X-ray Photoelectron Spectroscopy measurements have shown that the sodium was also present at the surface of the degraded material and it is proposed that the degraded material consists mostly of MoO{sub 3} with intercalated Na{sup +}. This element has likely migrated from the soda lime glass. This intercalation process could have led to the formation of Na{sub x}MoO{sub 3} ‘molybdenum bronze’ following this redox reaction: xNa{sup +} + MoO{sub 3} + xe{sup −} ↔ Na{sub x}MoO{sub 3} It is proposed that the formed oxide layer contains Na{sub x}MoO{sub 3} with different Na{sup +} contents and different grades of conductivity. This intercalation process can also explain the high mobility of Na{sup +} via the grain boundaries in molybdenum. It was also observed that the molybdenum film with a top layer deposited at a high pressure is more susceptible for damp heat degradation. - Highlights: • SLG/high pressure Mo/low pressure Mo/MoSe{sub 2} stacks were exposed to damp heat. • Molybdenum deposited at low pressure retained the best reflectivity and conductivity. • Damp heat exposure leads to a Na{sub x}MoO{sub 3}/Mo multilayer structure. • The Na{sub x}MoO{sub 3} probably consists of Na{sup +} intercalated in a (reduced) MoO{sub 3} matrix. • Intercalation can explain the

Photochemical studies of alkylammonium molybdates. Part 12. O→Mo charge-transfer triplet-states-initiated self-assembly to {Mo154} ring- and tube-molybdenum-blues

Science.gov (United States)

Yamase, T.; Prokop, P.; Arai, Y.

2003-08-01

The chemically induced dynamic electron-spin-polarization technique is employed in order to investigate the primary steps of the photoredox reaction between polyoxomolybdates and alkylammonium cations as both proton and electron-donors in solutions. An observation of emissive electron-spin-polarization signals of alkylamino radical cations for the photoredox reaction between polyoxomolybdates and alkylammonium cations in solutions reveals that the O→Mo ligand-to-metal charge-transfer triplet states are involved in the transfers of both proton and electron from alkylammonium cation to polyoxomolybdate anions. Prolonged photolysis of aqueous solutions containing [Mo36O112(H2O)16]8-, [iPrNH3]+, and LaCl3 at pH 1.0 leads to formation of two kinds of {Mo154} molybdenum-blues, [Mo28VMo126VIO462H28(H2O)70]·156.5H2O (1) and [iPrNH3]8 [Mo28VMo126VIO458H12(H2O)66]·127H2O (2), which were X-ray crystallographically characterized. The former exhibits the intact car-tire-shaped {Mo154} ring structure (with thickness of about 1.1 nm and with outer- and inner-rings of approximately 3.5- and 2.3-nm diameters, respectively) derived formally from the dehydrated cyclic heptamerization of four-electron reduced building blocks of {Mo22} (≡[Mo4VMo18VIO70H12(H2O)10]) with overall symmetry of D7d. The anion for the latter, [Mo28VMo126VIO458H12(H2O)66]8- (2a), exhibits a nanotube structure of {Mo154} rings, each inner ring of which contains a bis(μ-oxo)-linkaged [MoO2(μ-O)(μ-H2O)MoO2]2+ unit replacing one of seven [Mo(H2O)O2(μ-O)Mo(H2O)O2]2+linker units. The neighboring {Mo154} rings are connected by six Mo-O-Mo bridge between inner-rings consisting of 7 head- and 14 linkers-MoO6 octahedra for each.

Avaliação nutricional e desempenho da silagem de raiz de mandioca contendo ou não soja integral em dietas para suínos - doi: 10.4025/actascianimsci.v32i2.8055 Nutritional evaluation and performance of cassava root silage with or without whole soybean in swine diets - doi: 10.4025/actascianimsci.v32i2.8055

Directory of Open Access Journals (Sweden)

Paulo Levi Oliveira Carvalho

2010-07-01

Full Text Available Dois experimentos foram conduzidos para determinar o valor nutritivo e o desempenho de suínos nas fases de crescimento e período total, alimentados com dietas formuladas com silagem de raiz de mandioca contendo ou não soja integral. No primeiro, foram utilizados 15 suínos, distribuídos em delineamento inteiramente casualizado em parcelas (animais subdivididas no tempo (subparcelas, totalizando cinco tratamentos e seis repetições. Os alimentos avaliados foram silagem de raiz de mandioca (MA, silagem de raiz de mandioca com inoculante (MI, silagem de raiz de mandioca + soja integral (MS e silagem de raiz de mandioca + soja integral com inoculante (MSI. As silagens apresentaram bons valores nutritivos e o uso de inoculante não foi efetivo para melhorar a digestibilidade dos nutrientes. No segundo, foram utilizados 36 suínos mestiços, distribuídos em um delineamento inteiramente casualizado, com restrição na casualização para duas classes de peso inicial, com três tratamentos, seis repetições e dois animais por unidade experimental. Os tratamentos consistiram em ração-testemunha à base de milho e farelo de soja (RT e outras duas com substituição total do milho por MA e MS. Para fase de crescimento, a conversão alimentar melhorou com o uso das silagens. Conclui-se que as silagens de mandioca, contendo ou não soja integral, apresentam bons valores nutritivos e podem substituir totalmente o milho na ração de suínos nas fases de crescimento e período total. alimentos alternativos; amido; desempenho; digestibilidade; valores energéticosTwo experiments were carried out to determine the nutritional value and performance of growing and total-period swine fed cassava root silage with or without whole soybean. In the first group, 15 crossbred swine were used, in a completely randomized design with parcels (animals subdivided in time (subparcels with five treatments and six replications. The study evaluated cassava root silage (CA

Mo isotope fractionation during hydrothermal evolution of porphyry Cu systems

Science.gov (United States)

Shafiei, Behnam; Shamanian, GholamHossein; Mathur, Ryan; Mirnejad, Hassan

2015-03-01

We present Mo isotope compositions of molybdenite types from three successive stages of ore deposition in several porphyry copper deposits of the Kerman region, Iran. The data provide new insights into controlling processes on Mo isotope fractionation during the hydrothermal evolution of porphyry systems. The Mo isotope compositions of 27 molybdenite samples show wide variations in δ97Mo ranging from -0.37 to +0.92 ‰. The data reveal that molybdenites in the early and transitional stages of mineralization (preferentially 2H polytypes; δ97Mo mean = 0.35 ‰) have higher δ97Mo values than late stage (mainly 3R polytypes; δ97Mo mean = 0.02 ‰) molybdenites. This trend suggests that fractionation of Mo isotopes occurred in high-temperature stages of mineralization and that hydrothermal systems generally evolve towards precipitation of molybdenite with lower δ97Mo values. Taking into account the genetic models proposed for porphyry Cu deposits along with the temperature-dependent fractionation of Mo isotope ratios, it is proposed that large variations of Mo isotopes in the early and the transitional stages of ore deposition could be controlled by the separation of the immiscible ore-forming fluid phases with different density, pH, and ƒO2 properties (i.e., brine and vapor). The fractionation of Mo isotopes during fluid boiling and Rayleigh distillation processes likely dominates the Mo isotope budget of the remaining ore-forming fluids for the late stage of mineralization. The lower δ97Mo values in the late stage of mineralization can be explained by depletion of the late ore-forming hydrothermal solutions in 97Mo, as these fluids have moved to considerable distance from the source. Finally, the relationship observed between MoS2 polytypes (2H and 3R) and their Mo isotopic compositions can be explained by the molecular vibration theory, in which heavier isotopes are preferentially partitioned into denser primary 2H MoS2 crystals.

Coke formation during the hydrotreatment of bio-oil using NiMo and CoMo catalysts

NARCIS (Netherlands)

Kadarwati, Sri; Hu, Xun; Gunawan, Richard; Westerhof, Roel; Gholizadeh, Mortaza; Hasan, M. D.Mahmudul; Li, Chun-Zhu

2017-01-01

This study aims to investigate the coke formation during the hydrotreatment of bio-oil at low temperature. The catalytic hydrotreatment of bio-oil produced from the pyrolysis of mallee wood was carried out using pre-sulphided NiMo and CoMo catalysts at a temperature range of 150–300 °C. Our results

Comparative study of 99Mo/99mTc generators at base of synthesized gels starting from activation and fission 99Mo

International Nuclear Information System (INIS)

Lopez M, I.Z.; Monroy G, F.; Rivero G, T.; Rojas N, P.

2007-01-01

The 99m Tc is used for diagnostic and therapy. It is produced starting from 99 Mo, absorbed in chromatographic columns, loaded with alumina that absorb only 0.2% of 99 Mo with high specific activities of 99 Mo, obtained from the 235 U fission. Given these conditions and limitations, new preparation procedures of 99 Mo/ 99m Tc generators, its have been developed, using zirconium molybdates gels that incorporates until 30% of 99 Mo, conserve similar characteristics of quality and purity that the traditional generator. The radiochemical characteristics of the 99m Tc elution, depend strongly on the gel preparation conditions. In particular, the present work has by object to determine the influence of the 99 Mo used type, fission or activation product, during the gels synthesis, as well as the used air flow for the agitation in the gels preparation and its influence in the 99 Mo/ 99m Tc generators quality. When diminishing the flow of agitation air the efficiency it increases and in the radionuclide purity of the eluates and when using 99 Mo from fission for the gels production it increases in an important way the elutriation efficiency, the radiochemical and radionuclide purity of the 99m Tc eluates. (Author)

Quality control studies of 99Mo used in 99Mo/99mTc generators produced at IPEN/CNEN-SP, Brazil

International Nuclear Information System (INIS)

Said, Daphne S.; Brambilla, Tania P.; Matsuda, Margareth M.N.; Osso Junior, Joao A.

2015-01-01

99m Tc is the most used radionuclide in nuclear medicine. In Brazil, the 99 Mo/ 99m Tc generators are produced exclusively by the Center of Radiopharmacy at IPEN-CNEN/SP, by importing 99 Mo from different suppliers. 99 Mo (t 1/2 = 66 h) is a fission product of 235 U, therefore, it can be accompanied by several radioisotopes that are highly prejudicial for human health, demanding a strict quality control of this product for generators safe use. The European Pharmacopoeia established some parameters and limits that evaluate the quality of the solution of sodium [ 99 Mo]molybdate, that is used as raw material for generator's production. The European Pharmacopoeia also recommends some analytical methods to perform these evaluations, however, it has been observed difficulties on the implementation of these methods by the generator's producers. These difficulties are probably related to the lack of practicability of the proposed methods and the extensive list of utilized reagents. In this work some procedures of the European Pharmacopoeia's quality control method for 99 Mo were evaluated. Different types of solid phase exchanger cartridges were tested for retention of 99 Mo in 3 different conditions. Cartridges that presented percentages of retention higher than 90% were also tested for separation of 99 Mo from possible contaminants (Ru e Te). The results shown that solid phase exchanger cartridges that presented percentages of retention of Mo higher than 90% also presented significant percentages of retention of Ru and Te. An alternative method for separation of 99 Mo from 131 I (other contaminant) are also proposed. (author)

Development of fission Mo-99 production technology

International Nuclear Information System (INIS)

Park, Jin Ho; Choung, W. M.; Lee, K. I. and others

2000-05-01

Fission Mo-99 is the only parent nuclide of Tc-99m, an extremely useful tool for mdeical diagnosis, with an estimated usage of greater than 80% of nuclear medicine applicatons. HEU and LEU targets to optimize in HANARO irradiation condition suggested and designed for domestic production of fission Mo-99. The optimum process conditions are established in each unit process to meet quality requirements of fission Mo-99 products, and the results of performance test in combined process show Mo separation and purification yield of the above 97%. The concept of Tc generator production process is established, and the result of performance test show Tc production yield of 98.4% in Tc generator procuction process. The drafts is prepared for cooperation of technical cooperation and business investment with foreign country. Evaluation on economic feasibility is accompanied for fission Mo-99 and Tc-99m generator production

Development of fission Mo-99 production technology

Energy Technology Data Exchange (ETDEWEB)

Park, Jin Ho; Choung, W. M.; Lee, K. I. and others

2000-05-01

Fission Mo-99 is the only parent nuclide of Tc-99m, an extremely useful tool for mdeical diagnosis, with an estimated usage of greater than 80% of nuclear medicine applicatons. HEU and LEU targets to optimize in HANARO irradiation condition suggested and designed for domestic production of fission Mo-99. The optimum process conditions are established in each unit process to meet quality requirements of fission Mo-99 products, and the results of performance test in combined process show Mo separation and purification yield of the above 97%. The concept of Tc generator production process is established, and the result of performance test show Tc production yield of 98.4% in Tc generator procuction process. The drafts is prepared for cooperation of technical cooperation and business investment with foreign country. Evaluation on economic feasibility is accompanied for fission Mo-99 and Tc-99m generator production.

Monolayer MoS2 heterojunction solar cells

KAUST Repository

Tsai, Menglin

2014-08-26

We realized photovoltaic operation in large-scale MoS2 monolayers by the formation of a type-II heterojunction with p-Si. The MoS 2 monolayer introduces a built-in electric field near the interface between MoS2 and p-Si to help photogenerated carrier separation. Such a heterojunction photovoltaic device achieves a power conversion efficiency of 5.23%, which is the highest efficiency among all monolayer transition-metal dichalcogenide-based solar cells. The demonstrated results of monolayer MoS 2/Si-based solar cells hold the promise for integration of 2D materials with commercially available Si-based electronics in highly efficient devices. © 2014 American Chemical Society.

Grotrian diagrams for highly ionized molybdenum Mo VI through Mo XLII

International Nuclear Information System (INIS)

Shirai, Toshizo; Sugar, J.; Wiese, W.L.

1997-07-01

Grotrian diagrams are presented to provide graphical overviews for 1,930 spectral lines of highly ionized molybdenum, Mo VI through Mo XLII. In the usual diagram display such as that by Bashkin and Stoner (North-Holland, Amsterdam, 1975), the density of transitions is often too high to allow each transition to be drawn separately. Here in our modified diagrams, the transitions are also represented by lines connecting the upper and lower energy levels, but the lower energy levels are extended and repeated for successive configurations as needed. As a sequence, dense packing is avoided and all lines in a multiplet can be accommodated. (author)

Nanostructured Mo-based electrode materials for electrochemical energy storage.

Science.gov (United States)

Hu, Xianluo; Zhang, Wei; Liu, Xiaoxiao; Mei, Yueni; Huang, Yunhui

2015-04-21

The development of advanced energy storage devices is at the forefront of research geared towards a sustainable future. Nanostructured materials are advantageous in offering huge surface to volume ratios, favorable transport features, and attractive physicochemical properties. They have been extensively explored in various fields of energy storage and conversion. This review is focused largely on the recent progress in nanostructured Mo-based electrode materials including molybdenum oxides (MoO(x), 2 ≤ x ≤ 3), dichalconides (MoX2, X = S, Se), and oxysalts for rechargeable lithium/sodium-ion batteries, Mg batteries, and supercapacitors. Mo-based compounds including MoO2, MoO3, MoO(3-y) (0 energy storage systems because of their unique physicochemical properties, such as conductivity, mechanical and thermal stability, and cyclability. In this review, we aim to provide a systematic summary of the synthesis, modification, and electrochemical performance of nanostructured Mo-based compounds, as well as their energy storage applications in lithium/sodium-ion batteries, Mg batteries, and pseudocapacitors. The relationship between nanoarchitectures and electrochemical performances as well as the related charge-storage mechanism is discussed. Moreover, remarks on the challenges and perspectives of Mo-containing compounds for further development in electrochemical energy storage applications are proposed. This review sheds light on the sustainable development of advanced rechargeable batteries and supercapacitors with nanostructured Mo-based electrode materials.

Intercalation of Si between MoS2 layers

Directory of Open Access Journals (Sweden)

Rik van Bremen

2017-09-01

Full Text Available We report a combined experimental and theoretical study of the growth of sub-monolayer amounts of silicon (Si on molybdenum disulfide (MoS2. At room temperature and low deposition rates we have found compelling evidence that the deposited Si atoms intercalate between the MoS2 layers. Our evidence relies on several experimental observations: (1 Upon the deposition of Si on pristine MoS2 the morphology of the surface transforms from a smooth surface to a hill-and-valley surface. The lattice constant of the hill-and-valley structure amounts to 3.16 Å, which is exactly the lattice constant of pristine MoS2. (2 The transitions from hills to valleys are not abrupt, as one would expect for epitaxial islands growing on-top of a substrate, but very gradual. (3 I(V scanning tunneling spectroscopy spectra recorded at the hills and valleys reveal no noteworthy differences. (4 Spatial maps of dI/dz reveal that the surface exhibits a uniform work function and a lattice constant of 3.16 Å. (5 X-ray photo-electron spectroscopy measurements reveal that sputtering of the MoS2/Si substrate does not lead to a decrease, but an increase of the relative Si signal. Based on these experimental observations we have to conclude that deposited Si atoms do not reside on the MoS2 surface, but rather intercalate between the MoS2 layers. Our conclusion that Si intercalates upon the deposition on MoS2 is at variance with the interpretation by Chiappe et al. (Adv. Mater. 2014, 26, 2096–2101 that silicon forms a highly strained epitaxial layer on MoS2. Finally, density functional theory calculations indicate that silicene clusters encapsulated by MoS2 are stable.

Excitation functions of the 98Mo+d reactions

International Nuclear Information System (INIS)

Zarubin, P.P.; Padalko, V.Yu.; Khrisanfov, Yu.V.; Lebedev, P.P.; Podkopaev, Yu.N.

The excitation functions of the 98 Mo+d reactions were studied. The energy dependence of (d,p),(d,n) and (d,α) reactions was investigated by the activation analysis. The energies of deuterons in the range (6-12) MeV were determined by means of the aluminium filters. 98 Mo foils with surface densities of 1.02, 0.23 and 0.14 mgxcm -2 with 98 Mo enrichment of 94.1% were used as targets. The gamma spectra were measured by a Ge(Li) detector. The 98 Mo(d,p) 99 Mo reaction excitation function was determined via detection of 739 and 181 keV γ-radiation of 99 Mo (Tsub(1/2)=66.47h); 140 keV γ-radiation of 99 Tc (Tsub(1/2)=6h) was detected for the 98 Mo(d,n) 99 Tc reaction excitation function determination and 460, 568, 1091, 1200 and 1492 keV γ-quanta of 96 Nb (Tsub(1/2)=23.35h) - for the 98 Mo(d,α) 96 Nb reaction. In the excitation function the wide extremum was observed at Esub(d) approximately 10 MeV. The ratio of cross sections σsup(m)(d,n)/σ(d,p) on the 98 Mo target was determined. The ratio σsup(m)(d,n)/σ(d,p) was found to be decreasing function of the deuteron energy. The relative cross sections were determined with an accuracy of +-5%, while for the absolute values of cross sections the accuracy was +-15%

OPAL: prediction of MoRF regions in intrinsically disordered protein sequences.

Science.gov (United States)

Sharma, Ronesh; Raicar, Gaurav; Tsunoda, Tatsuhiko; Patil, Ashwini; Sharma, Alok

2018-06-01

Intrinsically disordered proteins lack stable 3-dimensional structure and play a crucial role in performing various biological functions. Key to their biological function are the molecular recognition features (MoRFs) located within long disordered regions. Computationally identifying these MoRFs from disordered protein sequences is a challenging task. In this study, we present a new MoRF predictor, OPAL, to identify MoRFs in disordered protein sequences. OPAL utilizes two independent sources of information computed using different component predictors. The scores are processed and combined using common averaging method. The first score is computed using a component MoRF predictor which utilizes composition and sequence similarity of MoRF and non-MoRF regions to detect MoRFs. The second score is calculated using half-sphere exposure (HSE), solvent accessible surface area (ASA) and backbone angle information of the disordered protein sequence, using information from the amino acid properties of flanks surrounding the MoRFs to distinguish MoRF and non-MoRF residues. OPAL is evaluated using test sets that were previously used to evaluate MoRF predictors, MoRFpred, MoRFchibi and MoRFchibi-web. The results demonstrate that OPAL outperforms all the available MoRF predictors and is the most accurate predictor available for MoRF prediction. It is available at http://www.alok-ai-lab.com/tools/opal/. ashwini@hgc.jp or alok.sharma@griffith.edu.au. Supplementary data are available at Bioinformatics online.

Coordination of {Mo142} Ring to La3+ Provides Elliptical {Mo134La10} Ring with a Variety of Coordination Modes

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Eri Ishikawa

2009-12-01

Full Text Available A28-electron reduced C2h-Mo-blue 34Ǻ outer ring diameter circular ring, [Mo142O429H10(H2O49(CH3CO25(C2H5CO2]30- (≡{Mo142(CH3CO25(C2H5CO2} comprising eight carboxylate-coordinated (with disorder {Mo2} linkers and six defect pockets in two inner rings (four and three for each, respectively, reacts with La3+ in aqueous solutions at pH 3.5 to yield a 28-electron reduced elliptical Ci-Mo-blue ring of formula [Mo134O416H20(H2O46{La(H2O5}4{La(H2O7}4{LaCl2(H2O5}2]10- (≡{Mo134La10}, isolated as the Na10[Mo134O416H20(H2O46{La(H2O5}4{La(H2O7}4{LaCl2(H2O5}2]·144 H2O Na+ salt. The elliptical structure of {Mo134La10} showing 36 and 31 Å long and short axes for the outer ring diameters is attributed to four (A-D modes of LaO9/LaO7Cl2 tricapped-trigonal-prismatic coordination (TTP geometries. Two different LaO2(H2O7 and one LaO2(H2O2Cl2 TTP geometries (as A-C modes for each of two inner rings result from the coordination of all three defect pockets of the inner ring for {Mo142(CH3CO25(C2H5CO2}, and two LaO4(H2O5 TTP geometries (as D mode result from the displacement of two (acetate/propionate-coordinated binuclear {Mo2} linkers with La3+ in each inner ring. The isothermal titration calorimetry (ITC of the ring modification from circle to ellipsoid, showing the endothermic reaction of [La3+]/[{Mo142(CH3CO25(C2H5CO2}] = 6/1 with DH = 22 kJ×mol-1, DS = 172 J×K-1×mol-1, DG = −28 kJ×mol-1, and K = 9.9 ´ 104 M-1 at 293 K, leads to the conclusion that the coordination of the defect pockets to La3+ precedes the replacement of the {Mo2} linkers with La3+. 139La- NMR spectrometry of the coordination of {Mo142(CH3CO25(C2H5CO2} ring to La3+ is also discussed.

A modified {sup 99} Mo- {sup 99} Tc generator on Zirconium molybdo- phosphate-{sup 99} Mo gel. Vol. 3

Energy Technology Data Exchange (ETDEWEB)

El-Kolaly, M T; Talaat, H [Labelled Compounds Department, Cairo (Egypt); Botros, N [Radioistspe and Generator Department, Radioisotope Production and Sealed Source Division, Hot Laboratories Center, Atomic Energy Authority, Cairo (Egypt)

1996-03-01

A modified {sup 99} Mo - {sup 99} Tc gel generator is described. The new generator is based on the use of zirconium molybdophosphate - {sup 99} Mo gel in which {sup 99} Mo chemically combined in the gel structure, where {sup 99m}Tc can be easily eluted with distilled water or saline. The gel was prepared via chemical reaction between zirconyl chloride and molybdophosphate - {sup 99} Mo solution. The PH of the reaction mixture was adjusted with NaOH. Different gels have been prepared by varying the molar ratio of Mo:Zr:p. The PH and time of digeston on complete gel formation was also investigated in order to optimize the condition of gel preparation. Molybdophosphate {sup 32} P solution was used to determine the phosphorous content in the gel and in the {sup 99m}Tc eluate. The temperature and time of drying of the gel and their effect on {sup 99m}Tc elution efficiency were also studied. From the data obtained, the optimum conditions for routine production of {sup 99} Mo - {sup 99m}Tc generator are presented and discussed. 2 figs., 6 tabs.

Theoretical calculations of valence states in Fe-Mo compounds

International Nuclear Information System (INIS)

Estrada, F; Navarro, O; Noverola, H; Suárez, J R; Avignon, M

2014-01-01

The half-metallic ferromagnetic double perovskite compound Sr 2 FeMoO 6 is considered as an important material for spintronic applications. It appears to be fundamental to understand the role of electronic parameters controlling the half-metallic ground state. Fe-Mo double perovskites usually present some degree of Fe/Mo disorder which generally increases with doping. In this work, we study the valence states of Fe-Mo cations in the off-stoichiometric system Sr 2 Fe 1+x Mo 1−x O 6 (−1 ≤ x ≤ 1/3) with disorder. Our results for Fe and Mo valence states are obtained using the Green functions and the renormalization perturbation expansion method. The model is based on a correlated electron picture with localized Fe-spins and conduction Mo-electrons interacting with the local spins via a double-exchange-type mechanism

Efeito de soluções fluoretadas contendo xilitol e sorbitol no número de estreptococos do grupo mutans na saliva de seres humanos

Directory of Open Access Journals (Sweden)

Gonçalves Nilza Cristina Lopes Afonso de Valor

2001-01-01

Full Text Available O objetivo do estudo foi avaliar o efeito de soluções de fluoreto de sódio a 0,05% contendo 2,5% ou 12,5% de xilitol no número de estreptococos do grupo mutans presentes na saliva. Participaram do estudo duplo cego, do tipo cruzado, 50 meninos entre 8 e 16 anos, distribuídos aleatoriamente em quatro grupos. Destes, 33 finalizaram o estudo. As soluções utilizadas foram: solução placebo; solução de fluoreto de sódio a 0,05%; solução de fluoreto de sódio a 0,05% + 2,5% xilitol + 2% sorbitol; solução de fluoreto de sódio a 0,05% + 12,5% xilitol + 2% sorbitol. Os indivíduos utilizaram 20 mL de uma das soluções, duas vezes ao dia. Cada solução foi utilizada por um período experimental de 28 dias. Os períodos experimentais foram intercalados por períodos de descanso de 10 dias. As soluções contendo xilitol a 2,5% e 12,5% não apresentaram diferença significativa (P = 0,32 em termos do logaritmo do número de estreptococos do grupo mutans. No entanto, a diferença foi significativa quando essas soluções foram comparadas às soluções de fluoreto de sódio e placebo (P < 0,001. Os resultados sugerem que a solução de fluoreto de sódio a 0,05% com adição de xilitol a 2,5% ou 12,5% reduziu significativamente o número de estreptococos do grupo mutans.

Feasibility study on mass production of (n,γ)99Mo

International Nuclear Information System (INIS)

Jun, Byung Jin; Tanimoto, Masataka; Kimura, Akihiro; Hori, Naohiko; Izumo, Hironobu; Tsuchiya, Kunihiko

2011-01-01

The world is currently suffering from a severe shortage of 99 Mo and various efforts have been given for its availability. The (n,γ) method is one of candidates for the alternative supply of 99 Mo. The only but critical shortage of (n,γ) 99 Mo is its extremely low specific activity, which gives inconveniency in the extraction of 99m Tc and is consequently converted to additional cost. Potential technologies which make the (n,γ) 99 Mo competitive by reducing the additional cost are already available. It is expected that verification of such technologies is much easy and cost effective compared to any other options known for the alternative 99 Mo production. Because Japan and Korea import all 99 Mo from long distance, the cost benefit of local (n,γ) 99 Mo production in these countries is especially large. If five high flux reactors in China, Japan and Korea are utilized for the cross backup supply of (n,γ) 99 Mo, stable availability of 99 Mo in the region can be secured. Therefore, it is necessary to evaluate its feasibility on (n,γ) 99 Mo production in the Asia region. In this report, we studied feasibility of the mass (n,γ) 99 Mo production from viewpoints of global and regional status of 99 Mo demand and supply, competitiveness with other production methods, requirements and flow of the 99 Mo, production capability, cost, convenience in usage, and alternative technologies to overcome its shortage. (author)

A Survey On Mean Glandular Dose From Full-Field Digital Mammography Systems, Operate Using Mo/ Mo And W/Rh Target/ Filter Combinations

International Nuclear Information System (INIS)

Noriah Jamal; Siti Selina Abdul Hamid; Humairah Samad Cheung; Siti Kamariah Che Mohamed; Ellyda Muhammed Nordin; Radhiana Hassan; Rehir Dahalan

2013-01-01

We had conducted a survey on Mean Glandular Dose (MGD) from Full-Field Digital Mammography systems (FFDM) operate using Molybdenum/ Molybdenum (Mo/ Mo) and Tungsten/ Rhodium (W/ Rh) target/ filter combinations. A survey was carried out at two randomly selected mammography centres in Malaysia, namely National Cancer Society and International Islamic University of Malaysia. The first centre operates using a W/ Rh, while the second centre operates using an Mo/ Mo target/ filter combinations. On the basis of recorded information, data on mammographic views, MGD, age and Compressed Breast Thickness (CBT) were recorded for 100 patients, for each mammographic centre respectively. The MGD data were analyzed for variation with age group, with 5 years increment. The MGD data were also analyzed for variation with CBT, with 5 mm increment. We found that for both CC and MLO views, FFDM systems operated using Mo/ Mo and W/ Rh target/ filter combinations present the same trend on MGD. The average MGD decreases as age increases. While average MGD increases with the increasing of CBT. However, FFDM system operates using Mo/ Mo gives higher MGD as compared with FFDM system operates using W/ Rh. (author)

Oxygen potential of a prototypic Mo-cermet fuel containing plutonium oxide

Energy Technology Data Exchange (ETDEWEB)

Miwa, Shuhei, E-mail: miwa.shuhei@jaea.go.jp [Japan Atomic Energy Agency, 4002 Narita-cho, Oarai-machi, Higashiibaraki-gun, Ibaraki, 311-1393 (Japan); Osaka, Masahiko [Japan Atomic Energy Agency, 4002 Narita-cho, Oarai-machi, Higashiibaraki-gun, Ibaraki, 311-1393 (Japan); Nozaki, Takahiro; Arima, Tatsumi; Idemitsu, Kazuya [Kyushu University, 744 Motooka Nishi-ku, Fukuoka, 819-0395 (Japan)

2015-10-15

Oxygen potential of a prototypic Mo-cermet fuel containing 50 vol.% PuO{sub 2−x} were investigated by the thermogravimetric analysis in the temperature range from 1273 K to 1473 K. It was shown that the oxygen potential and oxidation rate of the Mo-cermet were the same as those of pure PuO{sub 2−x} below the oxygen potential of Mo/MoO{sub 2} oxidation reaction. The same features of the Mo-cermet sample containing 50 vol.% PuO{sub 2−x} with those of pure PuO{sub 2−x} were discussed in terms of the microstructure. - Highlights: • Oxygen potential of Mo-cermet fuel was investigated by thermogravimetric analysis. • It was the same as that of pure PuO{sub 2−x} below the oxygen potential for Mo/MoO{sub 2}. • Gradual oxidation of Mo matrix occurred only above the oxygen potential for Mo/MoO{sub 2}. • Mo matrix and PuO{sub 2−x} in Mo-cermet fuel can thus be thermochemically individual.

Oxygen potential of a prototypic Mo-cermet fuel containing plutonium oxide

International Nuclear Information System (INIS)

Miwa, Shuhei; Osaka, Masahiko; Nozaki, Takahiro; Arima, Tatsumi; Idemitsu, Kazuya

2015-01-01

Oxygen potential of a prototypic Mo-cermet fuel containing 50 vol.% PuO_2_−_x were investigated by the thermogravimetric analysis in the temperature range from 1273 K to 1473 K. It was shown that the oxygen potential and oxidation rate of the Mo-cermet were the same as those of pure PuO_2_−_x below the oxygen potential of Mo/MoO_2 oxidation reaction. The same features of the Mo-cermet sample containing 50 vol.% PuO_2_−_x with those of pure PuO_2_−_x were discussed in terms of the microstructure. - Highlights: • Oxygen potential of Mo-cermet fuel was investigated by thermogravimetric analysis. • It was the same as that of pure PuO_2_−_x below the oxygen potential for Mo/MoO_2. • Gradual oxidation of Mo matrix occurred only above the oxygen potential for Mo/MoO_2. • Mo matrix and PuO_2_−_x in Mo-cermet fuel can thus be thermochemically individual.

Preparation of 99Mo/99mTc generators based on 99Mo zirconium molybdates in the Gel Synthesis Device for Generators

International Nuclear Information System (INIS)

Lopez M, I. Z.; Monroy G, F.; Rivero G, T.; Rojas N, P.

2008-01-01

The 99m Tc is used for diagnosis and therapy. It is produced commercially from 99 Mo obtained from the fission of 235 U, which is retained in chromatographic columns filled with alumina whose maximum capacity is 0.2%. Given these constraints new methods of preparation 99 Mo/ 99m Tc generators have been developed using zirconium molybdates gels containing up to 30% of Mo, which is part of the generator matrix, and retaining quality and purity similar characteristics to those commercial generators. The present study aims to determine the flow of agitation, temperature and drying time optimal to prepare 99 Mo/ 99m Tc generators based on 99 Mo zirconium molybdates in the Gel Synthesis Device 99 Mo/ 99m Tc Generators designed and built by groups of the Radioactive Materials Research Laboratory and Automation and Instrumentation Department of the National Institute of Nuclear Research. (Author)

Few-layer MoS2 as nitrogen protective barrier

Science.gov (United States)

Akbali, B.; Yanilmaz, A.; Tomak, A.; Tongay, S.; Çelebi, C.; Sahin, H.

2017-10-01

We report experimental and theoretical investigations of the observed barrier behavior of few-layer MoS2 against nitrogenation. Owing to its low-strength shearing, low friction coefficient, and high lubricity, MoS2 exhibits the demeanor of a natural N-resistant coating material. Raman spectroscopy is done to determine the coating capability of MoS2 on graphene. Surface morphology of our MoS2/graphene heterostructure is characterized by using optical microscopy, scanning electron microscopy, and atomic force microscopy. In addition, density functional theory-based calculations are performed to understand the energy barrier performance of MoS2 against nitrogenation. The penetration of nitrogen atoms through a defect-free MoS2 layer is prevented by a very high vertical diffusion barrier, indicating that MoS2 can serve as a protective layer for the nitrogenation of graphene. Our experimental and theoretical results show that MoS2 material can be used both as an efficient nanocoating material and as a nanoscale mask for selective nitrogenation of graphene layer.

Adsorption of DNA/RNA nucleobases onto single-layer MoS2 and Li-Doped MoS2: A dispersion-corrected DFT study

Science.gov (United States)

Sadeghi, Meisam; Jahanshahi, Mohsen; Ghorbanzadeh, Morteza; Najafpour, Ghasem

2018-03-01

The kind of sensing platform in nano biosensor plays an important role in nucleic acid sequence detection. It has been demonstrated that graphene does not have an intrinsic band gap; therefore, transition metal dichalcogenides (TMDs) are desirable materials for electronic base detection. In the present work, a comparative study of the adsorption of the DNA/RNA nucleobases [Adenine (A), Cytosine (C) Guanine (G), Thymine (T) and Uracil (U)] onto the single-layer molybdenum disulfide (MoS2) and Li-doped MoS2 (Li-MoS2) as a sensing surfaces was investigated by using Dispersion-corrected Density Functional Theory (D-DFT) calculations and different measure of equilibrium distances, charge transfers and binding energies for the various nucleobases were calculated. The results revealed that the interactions between the nucleobases and the MoS2 can be strongly enhanced by introducing metal atom, due to significant charge transfer from the Li atom to the MoS2 when Lithium is placed on top of the MoS2. Furthermore, the binding energies of the five nucleobases were in the range of -0.734 to -0.816 eV for MoS2 and -1.47 to -1.80 eV for the Li-MoS2. Also, nucleobases were adsorbed onto MoS2 sheets via the van der Waals (vdW) force. This high affinity and the renewable properties of the biosensing platform demonstrated that Li-MoS2 nanosheet is biocompatible and suitable for nucleic acid analysis.

Converting MMSE to MoCA and MoCA 5-minute protocol in an educationally heterogeneous sample with stroke or transient ischemic attack.

Science.gov (United States)

Wong, Adrian; Black, Sandra E; Yiu, Stanley Y P; Au, Lisa W C; Lau, Alexander Y L; Soo, Yannie O Y; Chan, Anne Y Y; Leung, Thomas W H; Wong, Lawrence K S; Kwok, Timothy C Y; Cheung, Theodore C K; Leung, Kam-Tat; Lam, Bonnie Y K; Kwan, Joseph S K; Mok, Vincent C T

2018-05-01

The Montreal Cognitive Assessment (MoCA) is psychometrically superior over the Mini-mental State Examination (MMSE) for cognitive screening in stroke or transient ischemic attack (TIA). It is free for clinical and research use. The objective of this study is to convert scores from the MMSE to MoCA and MoCA-5-minute protocol (MoCA-5 min) and to examine the ability of the converted scores in detecting cognitive impairment after stroke or TIA. A total of 904 patients were randomly divided into training (n = 623) and validation (n = 281) samples matched for demography and cognition. MMSE scores were converted to MoCA and MoCA-5 min using (1) equipercentile method with log-linear smoothing and (2) Poisson regression adjusting for age and education. Receiver operating characteristics curve analysis was used to examine the ability of the converted scores in differentiating patients with cognitive impairment. The mean education was 5.8 (SD = 4.6; ranged 0-20) years. The entire spectrum of MMSE scores was converted to MoCA and MoCA-5 min using equipercentile method. Relationship between MMSE and MoCA scores was confounded by age and education, and a conversion equation with adjustment for age and education was derived. In the validation sample, the converted scores differentiated cognitively impaired patients with area under receiver operating characteristics curve 0.826 to 0.859. We provided 2 methods to convert scores from the MMSE to MoCA and MoCA-5 min based on a large sample of patients with stroke or TIA having a wide range of education and cognitive levels. The converted scores differentiated patients with cognitive impairment after stroke or TIA with high accuracy. Copyright © 2018 John Wiley & Sons, Ltd.

Thermal spreading of MoO3 in H-ZY

International Nuclear Information System (INIS)

Mosqueira, L.; Angeles-Chavez, C.; Torres-Garcia, E.

2011-01-01

Research highlights: → Molybdenum oxo-species were formed during thermally driven migration on H-ZY. → Oxo-species were identified according to the edge energy (E g ) values of bulk molybdenum oxide reference compounds. → The migration occurred via MoO 2 (OH) 2 species leading first to (MoO 4 ) 2- and (Mo 2 O 7 ) 2- formation, and finally of (Mo 7 O 24 ) 6- . - Abstract: This work provides a structural, optical and kinetics approach to the molybdenum oxo-species formed during thermally driven migration on H-ZY starting from mechanical mixtures with MoO 3 . The samples were characterized as a function of time of treatment by UV-vis diffuse reflectance, X-ray diffraction, N 2 adsorption and scanning transmission electron microscopy (STEM). Local analysis of elemental compositions obtained from linear scan of characteristic X-ray signal show a direct evidence of molybdenum presence into the zeolite crystals. Ultraviolet absorption spectra were used to determine both the kinetics of the spreading and the speciation of MoO x in the H-ZY. Besides MoO 3 , three surface molybdenum oxo-species were identified according to the edge energy (E g ) values of bulk molybdenum oxide reference compounds. This study shows that the tetrahedral species prevailed on H-ZY. This is consistent with limitations in the migration and growth of MoO x in the channel structure of the zeolite. Kinetic study suggest that migration of MoO x in the H-ZY at low temperature (ca. 723 K) occurs across the formation and diffusion of hydrated species such as MoO 2 (OH) 2 , which interact with the zeolite and form monomeric and dimeric structures (like (MoO 4 ) 2- and (Mo 2 O 7 ) 2- ). Migration of MoO x species in the H-ZY studied is significant even at 723 K and after very short periods of treatment (<5 min).

Electron microscopy studies on MoS2 nanocrystals

DEFF Research Database (Denmark)

Hansen, Lars Pilsgaard

Industrial-style MoS2-based hydrotreating catalysts are studied using electron microscopy. The MoS2 nanostructures are imaged with single-atom sensitivity to reveal the catalytically important edge structures. Furthermore, the in-situ formation of MoS2 crystals is imaged for the first time....

Measurement of the Single Top Quark Production Cross Section and mo stretchy='false'>|mo>Vtb stretchy='false'>|mo> in Events with One Charged Lepton, Large Missing Transverse Energy, and Jets at CDF

Energy Technology Data Exchange (ETDEWEB)

Aaltonen, T.; Amerio, S.; Amidei, D.; Anastassov, A.; Annovi, A.; Antos, J.; Apollinari, G.; Appel, J. A.; Arisawa, T.; Artikov, A.; Asaadi, J.; Ashmanskas, W.; Auerbach, B.; Aurisano, A.; Azfar, F.; Badgett, W.; Bae, T.; Barbaro-Galtieri, A.; Barnes, V. E.; Barnett, B. A.; Barria, P.; Bartos, P.; Bauce, M.; Bedeschi, F.; Behari, S.; Bellettini, G.; Bellinger, J.; Benjamin, D.; Beretvas, A.; Bhatti, A.; Bland, K. R.; Blumenfeld, B.; Bocci, A.; Bodek, A.; Bortoletto, D.; Boudreau, J.; Boveia, A.; Brigliadori, L.; Bromberg, C.; Brucken, E.; Budagov, J.; Budd, H. S.; Burkett, K.; Busetto, G.; Bussey, P.; Butti, P.; Buzatu, A.; Calamba, A.; Camarda, S.; Campanelli, M.; Canelli, F.; Carls, B.; Carlsmith, D.; Carosi, R.; Carrillo, S.; Casal, B.; Casarsa, M.; Castro, A.; Catastini, P.; Cauz, D.; Cavaliere, V.; Cerri, A.; Cerrito, L.; Chen, Y. C.; Chertok, M.; Chiarelli, G.; Chlachidze, G.; Cho, K.; Chokheli, D.; Clark, A.; Clarke, C.; Convery, M. E.; Conway, J.; Corbo, M.; Cordelli, M.; Cox, C. A.; Cox, D. J.; Cremonesi, M.; Cruz, D.; Cuevas, J.; Culbertson, R.; d’Ascenzo, N.; Datta, M.; de Barbaro, P.; Demortier, L.; Deninno, M.; D’Errico, M.; Devoto, F.; Di Canto, A.; Di Ruzza, B.; Dittmann, J. R.; Donati, S.; D’Onofrio, M.; Dorigo, M.; Driutti, A.; Ebina, K.; Edgar, R.; Elagin, A.; Erbacher, R.; Errede, S.; Esham, B.; Farrington, S.; Fernández Ramos, J. P.; Field, R.; Flanagan, G.; Forrest, R.; Franklin, M.; Freeman, J. C.; Frisch, H.; Funakoshi, Y.; Galloni, C.; Garfinkel, A. F.; Garosi, P.; Gerberich, H.; Gerchtein, E.; Giagu, S.; Giakoumopoulou, V.; Gibson, K.; Ginsburg, C. M.; Giokaris, N.; Giromini, P.; Glagolev, V.; Glenzinski, D.; Gold, M.; Goldin, D.; Golossanov, A.; Gomez, G.; Gomez-Ceballos, G.; Goncharov, M.; González López, O.; Gorelov, I.; Goshaw, A. T.; Goulianos, K.; Gramellini, E.; Grosso-Pilcher, C.; Group, R. C.; Guimaraes da Costa, J.; Hahn, S. R.; Han, J. Y.; Happacher, F.; Hara, K.; Hare, M.; Harr, R. F.; Harrington-Taber, T.; Hatakeyama, K.; Hays, C.; Heinrich, J.; Herndon, M.; Hirschbuehl, D.; Hocker, A.; Hong, Z.; Hopkins, W.; Hou, S.; Hughes, R. E.; Husemann, U.; Hussein, M.; Huston, J.; Introzzi, G.; Iori, M.; Ivanov, A.; James, E.; Jang, D.; Jayatilaka, B.; Jeon, E. J.; Jindariani, S.; Jones, M.; Joo, K. K.; Jun, S. Y.; Junk, T. R.; Kambeitz, M.; Kamon, T.; Karchin, P. E.; Kasmi, A.; Kato, Y.; Ketchum, W.; Keung, J.; Kilminster, B.; Kim, D. H.; Kim, H. S.; Kim, J. E.; Kim, M. J.; Kim, S. H.; Kim, S. B.; Kim, Y. J.; Kim, Y. K.; Kimura, N.; Kirby, M.; Knoepfel, K.; Kondo, K.; Kong, D. J.; Konigsberg, J.; Kotwal, A. V.; Kreps, M.; Kroll, J.; Kruse, M.; Kuhr, T.; Kurata, M.; Laasanen, A. T.; Lammel, S.; Lancaster, M.; Lannon, K.; Latino, G.; Lee, H. S.; Lee, J. S.; Leo, S.; Leone, S.; Lewis, J. D.; Limosani, A.; Lipeles, E.; Lister, A.; Liu, H.; Liu, Q.; Liu, T.; Lockwitz, S.; Loginov, A.; Lucchesi, D.; Lucà, A.; Lueck, J.; Lujan, P.; Lukens, P.; Lungu, G.; Lys, J.; Lysak, R.; Madrak, R.; Maestro, P.; Malik, S.; Manca, G.; Manousakis-Katsikakis, A.; Marchese, L.; Margaroli, F.; Marino, P.; Matera, K.; Mattson, M. E.; Mazzacane, A.; Mazzanti, P.; McNulty, R.; Mehta, A.; Mehtala, P.; Mesropian, C.; Miao, T.; Mietlicki, D.; Mitra, A.; Miyake, H.; Moed, S.; Moggi, N.; Moon, C. S.; Moore, R.; Morello, M. J.; Mukherjee, A.; Muller, Th.; Murat, P.; Mussini, M.; Nachtman, J.; Nagai, Y.; Naganoma, J.; Nakano, I.; Napier, A.; Nett, J.; Neu, C.; Nigmanov, T.; Nodulman, L.; Noh, S. Y.; Norniella, O.; Oakes, L.; Oh, S. H.; Oh, Y. D.; Oksuzian, I.; Okusawa, T.; Orava, R.; Ortolan, L.; Pagliarone, C.; Palencia, E.; Palni, P.; Papadimitriou, V.; Parker, W.; Pauletta, G.; Paulini, M.; Paus, C.; Phillips, T. J.; Pianori, E.; Pilot, J.; Pitts, K.; Plager, C.; Pondrom, L.; Poprocki, S.; Potamianos, K.; Pranko, A.; Prokoshin, F.; Ptohos, F.; Punzi, G.; Redondo Fernández, I.; Renton, P.; Rescigno, M.; Rimondi, F.; Ristori, L.; Robson, A.; Rodriguez, T.; Rolli, S.; Ronzani, M.; Roser, R.; Rosner, J. L.; Ruffini, F.; Ruiz, A.; Russ, J.; Rusu, V.; Sakumoto, W. K.; Sakurai, Y.; Santi, L.; Sato, K.; Saveliev, V.; Savoy-Navarro, A.; Schlabach, P.; Schmidt, E. E.; Schwarz, T.; Scodellaro, L.; Scuri, F.; Seidel, S.; Seiya, Y.; Semenov, A.; Sforza, F.; Shalhout, S. Z.; Shears, T.; Shepard, P. F.; Shimojima, M.; Shochet, M.; Shreyber-Tecker, I.; Simonenko, A.; Sliwa, K.; Smith, J. R.; Snider, F. D.; Song, H.; Sorin, V.; St. Denis, R.; Stancari, M.; Stentz, D.; Strologas, J.; Sudo, Y.; Sukhanov, A.; Suslov, I.; Takemasa, K.; Takeuchi, Y.; Tang, J.; Tecchio, M.; Teng, P. K.; Thom, J.; Thomson, E.; Thukral, V.; Toback, D.; Tokar, S.; Tollefson, K.; Tomura, T.; Tonelli, D.; Torre, S.; Torretta, D.; Totaro, P.; Trovato, M.; Ukegawa, F.; Uozumi, S.; Vázquez, F.; Velev, G.; Vellidis, C.; Vernieri, C.; Vidal, M.; Vilar, R.; Vizán, J.; Vogel, M.; Volpi, G.; Wagner, P.; Wallny, R.; Wang, S. M.; Waters, D.; Wester, W. C.; Whiteson, D.; Wicklund, A. B.; Wilbur, S.; Williams, H. H.; Wilson, J. S.; Wilson, P.; Winer, B. L.; Wittich, P.; Wolbers, S.; Wolfe, H.; Wright, T.; Wu, X.; Wu, Z.; Yamamoto, K.; Yamato, D.; Yang, T.; Yang, U. K.; Yang, Y. C.; Yao, W. -M.; Yeh, G. P.; Yi, K.; Yoh, J.; Yorita, K.; Yoshida, T.; Yu, G. B.; Yu, I.; Zanetti, A. M.; Zeng, Y.; Zhou, C.; Zucchelli, S.

2014-12-31

We report a measurement of single top quark production in proton-antiproton collisions at a center-of-mass energy of smo>=>1.96 TeV using a data set corresponding to 7.5 fbmo>->1 of integrated luminosity collected by the Collider Detector at Fermilab. We select events consistent with the single top quark decay process tmo stretchy="false">→mo>Wb stretchy="false">→mo>ℓ>νb by requiring the presence of an electron or muon, a large imbalance of transverse momentum indicating the presence of a neutrino, and two or three jets including at least one originating from a bottom quark. An artificial neural network is used to discriminate the signal from backgrounds. We measure a single top quark production cross section of 3.04mo>->0.53mo>+>0.57 pb and set a lower limit on the magnitude of the coupling between the top quark and bottom quark mo stretchy="false">|mo

Consumo e desempenho produtivo de ovinos alimentados com dietas que continham coprodutos do desfibramento do sisal

Directory of Open Access Journals (Sweden)

R.D. Santos

2011-12-01

Full Text Available Avaliaram-se o desempenho produtivo e o consumo de nutrientes e frações fibrosas em ovinos alimentados com dietas contendo coprodutos do desfibramento do sisal, Agave sisalana. Foram utilizados 24 ovinos, machos, alojados em baias individuais. O delineamento experimental utilizado foi o inteiramente ao acaso, com quatro tratamentos e seis repetições. Os tratamentos consistiram em quatro dietas isoproteicas, em que: i dieta padrão, contendo 38% de volumoso (silagem de milheto e 62% de concentrado (milho, farelo de soja e ureia; ii inclusão de 20% da silagem de mucilagem do sisal em substituição à silagem de milheto; iii inclusão de 20% da silagem de mucilagem associada ao pó da batedeira como aditivo em substituição à silagem de milheto; iv inclusão de 20% do feno da mucilagem em substituição à silagem de milheto. O peso corporal final, os ganhos médio diário e total e a conversão alimentar dos ovinos não foram influenciados pelas dietas avaliadas (P>0,05. Os consumos dos nutrientes, em g/dia e em %PC e g/kg0,75, não sofreram influência das dietas. Os resultados indicam que as dietas à base de coprodutos do sisal podem ser utilizadas como alternativa volumosa, além de possibilitar o aumento da rentabilidade da atividade na região semiárida brasileira.

Thermophysical properties of Na2Th (MoO4)3 (s) and Na4Th (MoO4)4 (s)

International Nuclear Information System (INIS)

Dash, Smruti; Rakshit, S.K.; Singh, Ziley; Keskar, Meera; Dahale, N.D.

2009-01-01

The heat capacity of Na 2 Th (MoO 4 ) 3 (s) and Na 4 Th (MoO 4 ) 4 (s) have been measured by differential scanning calorimeter in the temperature range 318 to 845 K. The corresponding values are: C p,m (Na 2 Th (MoO 4 ) 3 ,s,T) (JK-1 mol-1) 368.710+ 1.0 10-1 (T/K) - 4950267 (K/T)2 (318 ≤ T (K) ≤ 845). C p,m (Na 4 Th (MoO 4 ) 4 ,s,T) (JK-1 mol-1) = 638.761+ 5.12 10-3 (T/K) - 12691691 (K/T)-2 (318 ≤ T (K) ≤ 845). Experimental heat capacity values for Na 2 Th (MoO 4 ) 3 (s) match reasonably well with that of additive oxide values. But C p,m (T) values of Na 4 Th (MoO 4 ) 4 (s) deviates substantially from the additive oxide values above 700 K. The uncertainty of the measurements reported in this study is calculated to be within 1 to 3 % . (author)

Towards a uniform and large-scale deposition of MoS2 nanosheets via sulfurization of ultra-thin Mo-based solid films.

Science.gov (United States)

Vangelista, Silvia; Cinquanta, Eugenio; Martella, Christian; Alia, Mario; Longo, Massimo; Lamperti, Alessio; Mantovan, Roberto; Basset, Francesco Basso; Pezzoli, Fabio; Molle, Alessandro

2016-04-29

Large-scale integration of MoS2 in electronic devices requires the development of reliable and cost-effective deposition processes, leading to uniform MoS2 layers on a wafer scale. Here we report on the detailed study of the heterogeneous vapor-solid reaction between a pre-deposited molybdenum solid film and sulfur vapor, thus resulting in a controlled growth of MoS2 films onto SiO2/Si substrates with a tunable thickness and cm(2)-scale uniformity. Based on Raman spectroscopy and photoluminescence, we show that the degree of crystallinity in the MoS2 layers is dictated by the deposition temperature and thickness. In particular, the MoS2 structural disorder observed at low temperature (<750 °C) and low thickness (two layers) evolves to a more ordered crystalline structure at high temperature (1000 °C) and high thickness (four layers). From an atomic force microscopy investigation prior to and after sulfurization, this parametrical dependence is associated with the inherent granularity of the MoS2 nanosheet that is inherited by the pristine morphology of the pre-deposited Mo film. This work paves the way to a closer control of the synthesis of wafer-scale and atomically thin MoS2, potentially extendable to other transition metal dichalcogenides and hence targeting massive and high-volume production for electronic device manufacturing.

The Microstructure of Multi-wire U-Mo Monolithic Fuel

Energy Technology Data Exchange (ETDEWEB)

Lee, Yoon Sang; Park, Eun Kee; Cho, Woo Hyoung; Park, Jong Man [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2010-10-15

In order to use low-enriched uranium (LEU) instead of highly enriched uranium (HEU) for high performance research reactors, the reduced enrichment for research and test reactors (RERTR) program is developing high uranium density fuel such as U-Mo/Al dispersion fuel. U-Mo alloys have an excellent irradiation performance when compared to other uranium alloys or compounds. But the results from the post-irradiation examination of the U-Mo/Al dispersion fuels indicate that an interaction between the U-Mo alloy fuel and the Al matrix phases occurs readily during an irradiation and it is sensitively dependent on the temperature. In order to lessen these severe interactions, a concept of a multi-wire type fuel was proposed. The fuel configuration is that three to six U-Mo fuel wires (1.5 mm {approx} 2 mm in diameter) are symmetrically arranged at the periphery side in the Al matrix as shown. This multi-wire fuels showed very good fuel performance during the KOMO-3 irradiation test. At the KOMO-3 test, the specimen of the multi-wire fuels were U-7Mo/Al and U-7Mo-1Si/Al. In this study we investigate the microstructure change of the U-7Mo and U-7Mo-1Ti with some variation of annealing conditions. In addition to this, we want to check the effect of adding Ti element to U-7Mo on the gamma phase stability

Gold nanoparticles on MoS2 layered crystal flakes

International Nuclear Information System (INIS)

Cao, Wei; Pankratov, Vladimir; Huttula, Marko; Shi, Xinying; Saukko, Sami; Huang, Zhongjia; Zhang, Meng

2015-01-01

Inorganic layered crystal MoS 2 is considered as one of the most promising and efficient semiconductor materials for future transistors, photoelectronics, and electrocatalysis. To boost MoS 2 -based material applications, one direction is to grow physically and chemically reactive nanoparticles onto MoS 2 . Here we report on a simple route to synthesis crystalized MoS 2 –Au complexes. The gold nanoparticles were grown on MoS 2 flakes through a wet method in the oxygen free environment at room temperature. Nanoparticles with diameters varying from 9 nm to 429 nm were controlled by the molar ratios of MoS 2 and HAuCl 4 precursors. MoS 2 host flakes keep intrinsic honeycomb layered structures and the Au nanoparticles cubic-center crystal microstructures. From product chemical states analysis, the synthesis was found driven by redox reactions between the sulphide and the chloroauric acid. Photoluminescence measurement showed that introducing Au nanoparticles onto MoS 2 stacks substantially prompted excitonic transitions of stacks, as an analogy for doping Si wafers with dopants. Such composites may have potential applications in wide ranges similar as the doped Si. - Highlights: • The Au nanoparticles were decorated on MoS 2 in oxygen free ambiences via a wet method. • The Au nanoparticles are size-controllable and crystalized. • Chemical reaction scheme was clarified. • The MoS 2 –Au complexes have strong photoluminescent properties

NMR and XAS Study of Fe-Mo Double Perovskites

International Nuclear Information System (INIS)

Zajac, D.A.; Kapusta, C.; Borowiec, M.; Sikora, M.; Marquina, C.; Blasco, J.; Ibarra, M.R.

2005-01-01

The results of NMR and XAS measurements of the A 2 FeMoO 6 double perovskites (DP) (A 2 =Sr 2 , SrBa, Ba 2 , Ca 2 ) at the Fe and Mo K edges are reported and the information on the individual site electronic and magnetic properties is analysed. The compounds studied belong to the family of materials exhibiting a high field '' colossal '' magnetoresistance as well as a low field '' giant '' magnetoresistance. Magnetoresistive properties of the compounds arise from their half-metallicity, i.e. only one spin direction being populated in the conduction band, which consists of overlapping spin down 3d Fe, 2p O and 4d Mo electron bands. Within the model, a spin-down electron undergoes a fast hopping through unoccupied oxygen 2p orbitals between Fe 3+ (3d 5 - spin up) and Mo 6+ (4d 0 ) ionic cores. This mechanism implicates an anti-parallel coupling of the Fe and Mo spins and leads to non-integer magnetic moments and a metallic character below TC. The interaction, in analogy with the '' double exchange '' (DE) in manganites, is called '' double exchange-like '' interaction. The superexchange interaction (SE) is also expected to be present, resulting also in an anti-parallel coupling of 3d Fe 3+ and 4d Mo 5+ spins through occupied oxygen 2p orbitals. The insulating character of SE is connected with an increase of the tilt angle of the Fe-O-Mo bond, which is related to a change of the structural tolerance factor f and results in structural distortions. The molybdenum NMR measurements revealed the existence of a non-integer magnetic moment at Mo and Fe, which can be attributed to the DE-like interaction. However, experiments using Moessbauer spectroscopy have shown the existence of two Fe ionisation states - with integer (SE) and non integer (DE) magnetic moments. The 95 Mo and 97 Mo NMR measurements on A 2 FeMoO 6 (A 2 =Sr 2 , SrBa, Ba 2 , Ca 2 ) presented in this work show different values of the Mo hyperfine field and the corresponding magnetic moment. This is attributed

Cyanide-limited complexation of molybdenum(III): synthesis of octahedral [Mo(CN)(6)](3-) and cyano-bridged [Mo(2)(CN)(11)](5-).

Science.gov (United States)

Beauvais, Laurance G; Long, Jeffrey R

2002-03-13

Octahedral coordination of molybdenum(III) is achieved by limiting the amount of cyanide available upon complex formation. Reaction of Mo(CF(3)SO(3))(3) with LiCN in DMF affords Li(3)[Mo(CN)(6)] x 6DMF (1), featuring the previously unknown octahedral complex [Mo(CN)(6)](3-). The complex exhibits a room-temperature moment of mu(eff) = 3.80 mu(B), and assignment of its absorption bands leads to the ligand field parameters Delta(o) = 24800 cm(-1) and B = 247 cm(-1). Further restricting the available cyanide in a reaction between Mo(CF(3)SO(3))(3) and (Et(4)N)CN in DMF, followed by recrystallization from DMF/MeOH, yields (Et(4)N)(5)[Mo(2)(CN)(11)] x 2DMF x 2MeOH (2). The dinuclear [Mo(2)(CN)(11)](5-) complex featured therein contains two octahedrally coordinated Mo(III) centers spanned by a bridging cyanide ligand. A fit to the magnetic susceptibility data for 2, gives J = -113 cm(-1) and g = 2.33, representing the strongest antiferromagnetic coupling yet observed through a cyanide bridge. Efforts to incorporate these new complexes in magnetic Prussian blue-type solids are ongoing.

A facile route to large-scale synthesis MoO{sub 2} and MoO{sub 3} as electrode materials for high-performance supercapacitors

Energy Technology Data Exchange (ETDEWEB)

Xuan, H.C.; Du, Y.W. [College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan, 030024 (China); Laboratory of Solid State Microstructures, Nanjing University, Nanjing, 210093 (China); Zhang, Y.Q.; Xu, Y.K.; Li, H.; Han, P.D. [College of Materials Science and Engineering, Taiyuan University of Technology, Taiyuan, 030024 (China); Wang, D.H. [Laboratory of Solid State Microstructures, Nanjing University, Nanjing, 210093 (China)

2016-09-15

MoO{sub 3} and MoO{sub 2} materials have been successfully synthesized by thermal decomposition of ammonium paramolybdate in air and a sealed quartz tube, respectively. The microstructure of as-synthesized MoO{sub 3} is composed of irregular lamellar plates with a plate thickness around 100 nm and MoO{sub 2} has the larger grain size with lamellar plates connected with each other. A maximum specific capacitance of 318 F/g at 0.5 A/g is obtained for MoO{sub 2} prepared in a closed environment. On the other hand, the sample MoO{sub 3} exhibits excellent rate capacity with specific capacitances of 218, 209, 196, 188, 176, and 160 F/g at current densities of 0.5, 1, 2, 3, 4, and 5 A/g, respectively. These results pave the way to consider MoO{sub 3} and MoO{sub 2} as prospective materials for energy-storage applications. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Electrochemical behavior of Ni-Mo electro catalyst for water electrolysis

Energy Technology Data Exchange (ETDEWEB)

Fernandez V, S. M.; Ordonez R, E. [ININ, Departamento de Quimica, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Cabanas M, G. [IPN, Centro de Nanociencias y Micro y Nanotecnologias, A. P. 75-874, 07300 Mexico D. F. (Mexico); Solorza F, O., E-mail: suilma.fernandez@inin.gob.m [IPN, Centro de Investigacion y de Estudios Avanzados, Departamento de Quimica, A. P. 14-740, 07000 Mexico D. F. (Mexico)

2010-07-01

Nickel-molybdenum based electrocatalysts were synthesized in organic media for the hydrogen evolution reaction and oxygen evolution reaction in alkaline media. The structure, morphology and chemical composition of the catalysts were evaluated by X-ray diffraction, scanning electron microscopy and Aas. Results revealed nanocrystalline powder materials with Ni{sub 0.006}Mo, Ni{sub 0.1}Mo and Ni Mo compositions. The best performance for hydrogen evolution reaction, was obtained on Ni{sub 0.1}Mo electrode, whereas Ni Mo was for the oxygen evolution reaction. Results suggest that the material with 1:1 stoichiometric ratio could be considered as a promising electro catalyst for oxygen evolution reaction. This nanocrystalline powder is formed by Ni{sub 2}Mo{sub 3}O{sub 8} and a crystalline structure attributed to the possible formation of a Ni Mo cluster, becomes NiMoO{sub 4} after thermal treatment at 1073 K in air. The Ni Mo 1:1 cluster catalyst presented electrochemical stability during the oxygen evolution reaction. (Author)

Electrochemical behavior of Ni-Mo electro catalyst for water electrolysis

International Nuclear Information System (INIS)

Fernandez V, S. M.; Ordonez R, E.; Cabanas M, G.; Solorza F, O.

2010-01-01

Nickel-molybdenum based electrocatalysts were synthesized in organic media for the hydrogen evolution reaction and oxygen evolution reaction in alkaline media. The structure, morphology and chemical composition of the catalysts were evaluated by X-ray diffraction, scanning electron microscopy and Aas. Results revealed nanocrystalline powder materials with Ni 0.006 Mo, Ni 0.1 Mo and Ni Mo compositions. The best performance for hydrogen evolution reaction, was obtained on Ni 0.1 Mo electrode, whereas Ni Mo was for the oxygen evolution reaction. Results suggest that the material with 1:1 stoichiometric ratio could be considered as a promising electro catalyst for oxygen evolution reaction. This nanocrystalline powder is formed by Ni 2 Mo 3 O 8 and a crystalline structure attributed to the possible formation of a Ni Mo cluster, becomes NiMoO 4 after thermal treatment at 1073 K in air. The Ni Mo 1:1 cluster catalyst presented electrochemical stability during the oxygen evolution reaction. (Author)

Tunneling in BP-MoS2 heterostructure

Science.gov (United States)

Liu, Xiaochi; Qu, Deshun; Kim, Changsik; Ahmed, Faisal; Yoo, Won Jong

Tunnel field effect transistor (TFET) is considered to be a leading option for achieving SS mV/dec. In this work, black phosphorus (BP) and molybdenum disulfide (MoS2) heterojunction devices are fabricated. We find that thin BP flake and MoS2 form normal p-n junctions, tunneling phenomena can be observed when BP thickness increases to certain level. PEO:CsClO4 is applied on the surface of the device together with a side gate electrode patterned together with source and drain electrodes. The Fermi level of MoS2 on top of BP layer can be modulated by the side gating, and this enables to vary the MoS2-BP tunnel diode property from off-state to on-state. Since tunneling is the working mechanism of MoS2-BP junction, and PEO:CsClO4\\ possesses ultra high dielectric constant and small equivalent oxide thickness (EOT), a low SS of 55 mV/dec is obtained from MoS2-BP TFET. This work was supported by the Global Research Laboratory and Global Frontier R&D Programs at the Center for Hybrid Interface Materials, both funded by the Ministry of Science, ICT & Future Planning via the National Research Foundation of Korea (NRF).

Effect of Mo{sub 2}C/(Mo{sub 2}C + WC) weight ratio on the microstructure and mechanical properties of Ti(C,N)-based cermet tool materials

Energy Technology Data Exchange (ETDEWEB)

Xu, Qingzhong; Zhao, Jun, E-mail: zhaojun@sdu.edu.cn; Ai, Xing; Qin, Wenzhen; Wang, Dawei; Huang, Weimin

2015-11-15

To optimize the Mo{sub 2}C content in Ti(C,N)-based cermet tool materials used for cutting the high-strength steel of 42CrMo (AISI 4140/4142 steel), the cermets with different Mo{sub 2}C/(Mo{sub 2}C + WC) weight ratios were prepared. And the microstructure and mechanical properties of cermets were investigated by scanning electron microscope (SEM), X-ray diffraction (XRD) and measurements of transverse rupture strength (TRS), Vickers hardness (HV) and fracture toughness (K{sub IC}). The results indicate that the Mo{sub 2}C/(Mo{sub 2}C + WC) ratios have great influences on the microstructure features and mechanical properties of Ti(C,N)-based cermets. When the Mo{sub 2}C/(Mo{sub 2}C + WC) ratio increases, the Ti(C,N) grains become finer with smaller black cores surrounded by thinner rims, and the structure of cermets tends to be more compact with smaller binder mean free path. Owing to the medium grains and moderate rims, the cermets with a Mo{sub 2}C/(Mo{sub 2}C + WC) ratio of 0.4 exhibit better mechanical properties, and can be chosen as the tool material for machining 42CrMo steel due to the lower Mo content. - Highlights: • Mo{sub 2}C/(Mo{sub 2}C + WC) ratios affect microstructure and mechanical properties of cermets. • Grains become fine and structure of cermets tends to be compact with raised Mo{sub 2}C. • The cermets with a Mo{sub 2}C/(Mo{sub 2}C + WC) ratio of 0.4 can be used to machine 42CrMo steel.

PRoMoTo 2013 proceedings

OpenAIRE

Bishop, Judith; Tillmann, Nikolai; Puder, Arno; Naik, Vinayak

2013-01-01

Programming for Mobile and Touch (PRoMoTo'13) was held at the 2013 ACM SIGPLAN conference on Systems, Programming, Languages and Applications (SPLASH 2013), October 2013 in Indianapolis, USA. Submissions for this event were invited in the general area of mobile and touch-oriented programming languages and programming environments, and teaching of programming for mobile devices. These are proceedings of the PRoMoTo'13.

Synthesis and characterization of MoO3 films by acid hydrolysis of K2Mo4O13

International Nuclear Information System (INIS)

Hernan, L.; Morales, J.

1989-01-01

The behaviour of K 2 Mo 4 O 13 heated under reflux in an acid medium has been studied. A metastable polymorphic MoO 3 phase crystallizing in the hexagonal system was obtained. Lengthy treatment led to the formation of orthorhombic MoO 3 with the (010) planes perfectly oriented parallel to the substrate. SEM images do not support a topotactic mechanism for the successive transformations. The reactions involved probably take place through the polymerization of discrete units formed in the bulk solution

The Tribological Performance of CrMoN/MoS2 Solid Lubrication Coating on a Piston Ring

Directory of Open Access Journals (Sweden)

Yuelan Di

2017-05-01

Full Text Available In order to improve the tribological properties of an engine piston ring and enhance its service life, magnetron sputtering technology and low temperature ion sulphurizing treatment technology were used to prepare CrMoN/MoS2 solid lubricant coating on the surface of an engine piston ring. The morphologies and compositions of the surface and cross-section of the sulfuration layer were analyzed by field emission scanning electron microscopy (FESEM, and wear property under high load, high speed and high temperature conditions were tested by a SRV®4 friction and wear testing machine. The results show that the CrMoN/MoS2 composite coatings appear as a dense grain structure, and the coating is an ideal solid lubrication layer that possesses an excellent high temperature wear resistance, reducing the engine operating temperature abrasion effectively and prolonging the service life of the engine.

Energy dispersive X-ray fluorescence analysis with Bragg polarized Mo radiation. Energiedispersive Roentgenfluoreszenzanalyse mit Bragg-polarisierter Mo Strahlung

Energy Technology Data Exchange (ETDEWEB)

Gloeckl, H

1983-01-01

The aim of introducing energy dispersive analysis into X-ray fluorescence analysis is to suppress background from the Bremsstrahlung spectrum and the characteristic radiation without an undue reduction of the signal. The variant under consideration uses linearly polarization radiation obtained after a Bragg reflection,under delta = 90/sup 0/. In an introductory part, Bragg reflection, fluorescence and strong radiation are considered quantitatively with respect to counting statistics and detection limits. In the experimental part two combinations are describe, of a Ta crystal with a Cr tube and of a Mo crystal with a Mo tube. Details of adjustment, sample preparation and calibration and detection limits are given. The pros and cons of the Ta/Cr and the Mo/Mo are contrasted and proposals for further improvements are given.

Desempenho de novilhos Nelore alimentados com casca de soja ou farelo de gérmen de milho em substituição parcial ao milho moído Effects of partial replacement of ground corn with soybean hulls or corn germ meal on production of Nellore steers

Directory of Open Access Journals (Sweden)

Jane Maria Bertocco Ezequiel

2006-04-01

Full Text Available Objetivou-se neste trabalho estudar a substituição parcial (70% do milho moído pela casca de soja ou pelo farelo de gérmen de milho em dietas contendo farelo de girassol e uréia (fontes nitrogenadas e silagem de milho (volumoso para novilhos Nelore em confinamento. Avaliaram-se o consumo, o ganho de peso, a conversão alimentar e o rendimento de carcaça de 21 animais (25 meses de idade e peso inicial de 343 kg alimentados com as dietas-teste, fornecidas na proporção 60:40 volumoso:concentrado. O período de avaliação do consumo e do ganho de peso foi de 97 dias. Os consumos de MS (10,78; 9,73 e 10,62 kg/dia, PB (1,40; 1,22 e 1,41 kg/dia e FDN (3,41; 3,89 e 3,60 kg/dia não foram influenciados pelas dietas com milho moído, casca de soja e farelo de gérmen de milho, respectivamente. O consumo de FDA (0,56; 0,71 e 0,55% PV apresentou efeito significativo, observando-se maior valor quando a casca de soja substituiu 70% do milho moído. O ganho de peso não foi influenciado pelas dietas, registrando-se valores de 1,35; 1,29 e 1,32 kg/dia para as dietas contendo milho moído, casca de soja e farelo de gérmen de milho, respectivamente. Não houve efeito, também, sobre a conversão alimentar (7,88 kg de MS ingerida/kg ganho, a eficiência alimentar (0,12 kg ganho/kg MS ingerida e o rendimento de carcaça (54,52%. A substituição parcial do milho moído pela casca de soja e pelo farelo de gérmen de milho em dietas para novilhos em confinamento não afeta o desempenho e o rendimento de carcaça.The objective of this trial was to study the partial replacement of ground corn with soybean hulls or corn germ meal in diets containing sunflower meal and urea as nitrogen sources and corn silage as forage for confined Nellore steers. Twenty-one steers averaging 25 months of age and 343 kg of initial body weight were assigned to diets containing a forage:concentrate ratio of 60:40. The period for measurements of intake and weight gain lasted 97

Characterization of the interaction layer in diffusion couples U-Mo-Zr/Al and U-Mo-Zr/Al-A356 at 550 C degrees; Caracterizacion de la zona de interaccion en pares de difusion a 550 grados C U-Mo-Zr/Al y U-Mo-Zr/Al-A356

Energy Technology Data Exchange (ETDEWEB)

Komar Varela, Carolina; Arico, Sergio; Mirandou, Marcela; Balart, Silvia; Gribaudo, Luis [Comision Nacional de Energia Atomica, General San Martin (Argentina). Dept. de Materiales; com, carolinakomar@gmail

2007-07-01

Out-of-pile diffusion experiments were performed between U-7 wt.% Mo-1 wt.% Zr and Al or Al A356 (7,1 wt.% Si) at 550 C degrees. In this work morphological characterization and phase identification on both interaction layers are presented. They were carried out by the use of different techniques: optical and scanning electron microscopy, X-ray diffraction and WDS microanalysis. In the interaction layer U-7 wt.% Mo-1 wt.% Zr/Al, the phases UAl{sub 3}, UAl{sub 4}, Al{sub 20}Mo{sub 2}U and Al{sub 43}Mo{sub 4}U{sub 6} were identified. Similar results in the interaction layer of the U-7 % Mo/Al at 580 C degrees were previously obtained. In the interaction layer U-7 wt.% Mo-1 wt.% Zr/Al A356, the phases U(Al,Si){sub 3} with 25 at.% Si and Si{sub 5}U{sub 3} were identified. This last phase, with a higher Si concentration, was identified with X-ray diffraction synchrotron radiation performed at the National Synchrotron Light Laboratory, Campinas, Brazil. (author) [Spanish] Se realizaron experiencias fuera de reactor en pares de difusion quimica U-7 % Mo-1 % Zr/Al y U-7 % Mo-1 % Zr/Al A356. En este trabajo se presentan los resultados de la caracterizacion morfologica e identificacion de fases presentes en la zona de interaccion que se forma al ser sometidos a un tratamiento isotermico de 1,5 h a 550 grados C. Las tecnicas utilizadas fueron: microscopia optica y electronica de barrido, difraccion de rayos X y microanalisis cuantitativo por sonda electronica. En la zona de interaccion correspondiente al par U-7 % Mo-1 % Zr/Al se identificaron las fases UAl{sub 3}, UAl{sub 4}, Al{sub 20}Mo{sub 2}U y Al{sub 43}Mo{sub 4}U{sub 6}. Estas cuatro fases fueron identificadas en pares U-7 % Mo/Al a 580 grados C en trabajos anteriores. En la zona de interaccion correspondiente al par U-7 % Mo-1 % Zr/Al A356 se identificaron las fases U(Al,Si){sub 3} (con una concentracion de 25 %at.Si) y Si{sub 5}U{sub 3}. Este compuesto rico en Si solo pudo ser identificado mediante la utilizacion de

MoOx modified ZnGaO based transparent conducting oxides

Science.gov (United States)

Dutta, Titas; Gupta, P.; Bhosle, V.; Narayan, J.

2009-03-01

We report here the growth of high work function bilayered structures of thin MoOx (2.0MoOx layer, molybdenum exists in Mo4+, Mo5+, and Mo6+ oxidation states, and the ratio of (Mo4++Mo5+) to Mo6+ was determined to be ˜2:1. The bilayer films showed good optical transparency (≥80%) and low resistivity of ˜10-4 Ω cm. Different transport behavior of the MoOx/ZnGa0.05O films grown at different Ts (substrate temperature) was observed in temperature-dependent resistivity measurements. The bilayer film at higher Ts showed metallic conductivity behavior down to 113 K. Moreover, a blueshift of the absorption edge in the transmission spectrum was observed with the increase in Ts, indicating an increase in the carrier concentration. It was observed that the ZnGa0.05O films with ultrathin MoOx (˜1-2 nanometers) overlayer showed a higher work function (varying from 4.7 to 5.1 eV) as compared to the single layer ZnGa0.05O film work function (˜4.4 eV). A correlation between the surface work function and MoOx layer thickness is observed. The higher work function of the MoOx overlayer is envisaged to improve the transport of the carriers across the heterojunction in a solid state device, thus resulting an increase in device efficiency.

Using molybdenum depleted in 95Mo in UMo fuel

International Nuclear Information System (INIS)

Bakker, K.; Wijtsma, F.; Bos, A.; Mol, C.; Rakhorst, H.; Bretscher, M.; Hofman, G.; Snelgrove, J.

2002-01-01

In recent years significant interest was gained in UMo fuel to be used in Material Test Reactors. This interest was induced by the fact that UMo fuel is mechanically stable, even at high uranium concentrations and high U-burnup. These properties are required in order to use Low Enriched Uranium (LEU) and still be able to achieve high flux and burnup values and, thus, to facilitate the conversion from High Enriched Uranium (HEU) to LEU. Neutronics computations have shown that, although the Mo concentration in UMo fuel is not very high (about 5 - 10w%), the neutron absorption cross sections of natural Mo are sufficiently high to have a considerable negative impact on the reactivity of this UMo fuel. In the present research the neutron absorption cross sections of natural Mo are discussed and the option to reduce the cross section of molybdenum by depleting the Mo in 95 Mo is described. Finally the economic consequences of using Mo depleted in 95 Mo are briefly discussed

Electronic structure investigation of MoS2 and MoSe2 using angle-resolved photoemission spectroscopy and ab initio band structure studies.

Science.gov (United States)

Mahatha, S K; Patel, K D; Menon, Krishnakumar S R

2012-11-28

Angle-resolved photoemission spectroscopy (ARPES) and ab initio band structure calculations have been used to study the detailed valence band structure of molybdenite, MoS(2) and MoSe(2). The experimental band structure obtained from ARPES has been found to be in good agreement with the theoretical calculations performed using the linear augmented plane wave (LAPW) method. In going from MoS(2) to MoSe(2), the dispersion of the valence bands decreases along both k(parallel) and k(perpendicular), revealing the increased two-dimensional character which is attributed to the increasing interlayer distance or c/a ratio in these compounds. The width of the valence band and the band gap are also found to decrease, whereas the valence band maxima shift towards the higher binding energy from MoS(2) to MoSe(2).

Computation of beam quality parameters for Mo/Mo, Mo/Rh, Rh/Rh, and W/Al target/filter combinations in mammography

International Nuclear Information System (INIS)

Kharrati, Hedi; Zarrad, Boubaker

2003-01-01

A computer program was implemented to predict mammography x-ray beam parameters in the range 20-40 kV for Mo/Mo, Mo/Rh, Rh/Rh, and W/Al target/filter combinations. The computation method used to simulate mammography x-ray spectra is based on the Boone et al. model. The beam quality parameters such as the half-value layer (HVL), the homogeneity coefficient (HC), and the average photon energy were computed by simulating the interaction of the spectrum photons with matter. The checking of this computation was done using a comparison of the results with published data and measured values obtained at the Netherlands Metrology Institute Van Swinden Laboratorium, National Institute of Standards and Technology, and International Atomic Energy Agency. The predicted values with a mean deviation of 3.3% of HVL, 3.7% of HC, and 1.5% of average photon energy show acceptable agreement with published data and measurements for all target/filter combinations in the 23-40 kV range. The accuracy of this computation can be considered clinically acceptable and can allow an appreciable estimation for the beam quality parameters

Digestibilidade e tempo de trânsito gastrintestinal de dietas contendo níveis crescentes de fibra bruta para pacu - doi: 10.4025/actascianimsci.v32i2.8625 Digestibility and gastrointestinal transit time of diets with increasing dietary fiber levels to pacu - doi: 10.4025/actascianimsci.v32i2.8625

Directory of Open Access Journals (Sweden)

Thiago Matias Torres Nascimento

2010-07-01

Full Text Available O objetivo deste trabalho foi avaliar a digestibilidade e o tempo de trânsito gastrintestinal (TTGI de dietas contendo níveis crescentes de fibra bruta (FB para pacus. Para avaliar a digestibilidade foram utilizados 288 pacus, em delineamento inteiramente casualizado, alimentados em aquários e transferidos para coletores do tipo Guelf Modificado, utilizando-se o método de coleta parcial de fezes. As rações foram marcadas com 1% de óxido de crômio para a determinação da digestibilidade das dietas. No ensaio de TTGI, 288 pacus foram distribuídos em 24 aquários em delineamento inteiramente casualizado e alimentados com rações contendo 1% óxido de titânio ou crômio, que apresentam cores diferentes, verde ou branca, respectivamente. Por meio de massagem abdominal foi averiguada periodicamente a cor das fezes, e o TTGI foi estabelecido quando as fezes de todos os peixes apresentaram cor verde. Os coeficientes de digestibilidade aparente das dietas e o TTGI foram reduzidos com aumento do nível de FB nas dietas. Conclui-se que em dietas para pacus pode-se empregar até 9% de FB sem efeito negativo na digestibilidade da energia, proteína, matéria seca e estrato etéreo e sem alterar o TTGI.This work aimed to evaluate the effect of increasing dietary fiber levels on the digestibility and gastrointestinal transit time (GTT for pacu. The digestibility trial used 288 pacu in a completely randomized design, fed in aquaria and transferred to a modified Guelf-type feces collector, using the partial sampling method. The inert marker on the diets was chromic oxide (1% to establish the diet digestibility. In the GTT assay, 288 pacu were distributed in 24 aquaria in a completely randomized design. Fish were fed with two colored diets – green and white – and feces color was determined after abdominal pressure. The white and green diets used 1% of titanium and chromic oxides, respectively. Total GTT was determined when all fish showed green

Soymilk yogurt supplemented with fructooligosaccharides: probiotic properties and acceptance

OpenAIRE

Hauly, Maria Célia de Oliveira; Fuchs, Renata Hernandez Barros; Prudencio-Ferreira, Sandra Helena

2005-01-01

OBJETIVO: Foram avaliadas as características probióticas dos microorganismos utilizados no preparo de iogurte de soja suplementado com os prebióticos oligofrutose e inulina (frutooligossacarídeos), suas características físico-químicas, microbiológicas e índice de aceitação. MÉTODOS: A formulação contendo extrato de soja em pó, oligofrutose e inulina, obtida por fermentação durante seis horas, em estufa mantida à temperatura de 42ºC, foi caracterizada e comparada a uma formulação de iogurte de...

Uso da alga Lithothamnium calcareum como fonte alternativa de cálcio nas rações de frangos de corte

OpenAIRE

Carlos,André Carreira; Sakomura,Nilva Kazue; Pinheiro,Sandra Regina Freitas; Toledano,Fernando Marcelo Micai; Giacometti,Renato; Silva Júnior,José Walter da

2011-01-01

Objetivou-se, com este trabalho, avaliar o uso da alga Lithothamnium calcareum (Pallas) Areschoug nas rações para frangos de corte de 1 a 21 e 21 a 42 dias de idade, em substituição à fonte de cálcio tradicional (calcário calcítico). Para isso, foram utilizados 300 pintos machos, da linhagem Cobb®, que receberam rações contendo o calcário calcítico e a alga Lithothamnium calcareum (colhida de inteira e na forma de areia biodentrítica) como fontes de cálcio. O delineamento experimental utiliza...

Uso da alga Lithothamnium calcareum como fonte alternativa de cálcio nas rações de frangos de corte Use of algae Lithothamnium calcareum as alternative source of calcium in diets for broiler chickens

OpenAIRE

André Carreira Carlos; Nilva Kazue Sakomura; Sandra Regina Freitas Pinheiro; Fernando Marcelo Micai Toledano; Renato Giacometti; José Walter da Silva Júnior

2011-01-01

Objetivou-se, com este trabalho, avaliar o uso da alga Lithothamnium calcareum (Pallas) Areschoug nas rações para frangos de corte de 1 a 21 e 21 a 42 dias de idade, em substituição à fonte de cálcio tradicional (calcário calcítico). Para isso, foram utilizados 300 pintos machos, da linhagem Cobb®, que receberam rações contendo o calcário calcítico e a alga Lithothamnium calcareum (colhida de inteira e na forma de areia biodentrítica) como fontes de cálcio. O delineamento experimental utiliza...

Sedentarismo e hábitos de sono entre adolescentes de 10 a 19 anos estudantes de escolas estaduais do município de Ribeirão Preto

OpenAIRE

Adriana Lucas Louro

2015-01-01

O presente estudo objetivou estudar as características relacionadas ao nível de atividade física e hábitos de sono entre adolescentes de 10 a 19 anos de idade. Trata-se de um estudo transversal, observacional e descritivo que foi realizado por meio de entrevistas, o qual foram utilizados dois questionários, um contendo questões acerca dos hábitos de sono, e o IPAQ para estudar o nível de atividade física. Foram estudados 535 adolescentes de ambos os sexos, estudantes de escolas públicas estad...

Creep Rupture Analysis and Life Estimation of 1.25Cr-0.5Mo, 2.25Cr-1Mo and Modified 9Cr-1Mo Steel: A Comparative Study

Science.gov (United States)

Roy, Prabir Kumar

2018-04-01

This paper highlights a comparative assessment of creep life of 1.25Cr-0.5Mo, 2.25Cr-1Mo and modified 9Cr-1Mo steels based on accelerated creep rupture tests. Creep rupture test data have been analysed and creep life of the above mentioned materials have been assessed using Larson Miller parameter at the stress levels of 60 and 42 MPa for different temperatures. Limiting steam temperatures for minimum design life of 105 h at 42 and 60 MPa for the above mentioned steels have also been calculated. Microstructural studies for the three above mentioned steels are also done.

Stable MoS2 Field-Effect Transistors Using TiO2 Interfacial Layer at Metal/MoS2 Contact

KAUST Repository

Park, Woojin

2017-09-07

Molybdenum disulphide (MoS2) is an emerging 2-dimensional (2D) semiconductor for electronic devices. However, unstable and low performance of MoS2 FETs is an important concern. In this study, inserting an atomic layer deposition (ALD) titanium dioxide (TiO2) interfacial layer between contact metal and MoS2 channel is suggested to achieve more stable performances. The reduced threshold voltage (VTH) shift and reduced series resistance (RSD) were simultaneously achieved.

Atomic structure calculations of Mo XV-XL

International Nuclear Information System (INIS)

Kubo, Hirotaka; Sugie, Tatsuo; Shiho, Makoto; Suzuki, Yasuo; Ishii, Keishi; Maeda, Hikosuke.

1986-06-01

Energy levels and oscillator strengths were calculated for Mo XV - Mo XL. The computer program for atomic structure calculation, developed by Dr. Robert D. Cowan, Los Alamos National Laboratory, was used in the present work. The scaled energy parameters were empirically determined from the observed spectral data. We present wavelengths and transition probabilities of Mo XV-XL. Energy levels and spectral patterns are presented in figures that are useful for the identification of spectral lines. (author)

Phase diagrams for the M2MoO4–Ln2(MoO43–Hf(MoO42 systems, where M = Li–Cs, Tl and Ln = La–Lu

Directory of Open Access Journals (Sweden)

Zh. G. Bazarova

2017-12-01

Full Text Available In this paper, the results of systematic studies of complex molybdate systems M2MoO4–Ln2(MoO43–Hf(MoO42 (M = Li–Cs, Tl; Ln = La–Lu are presented. Subsolidus phase diagrams of ternary systems were constructed and new triple molybdates were obtained. The optimum synthesis conditions for poly- and monocrystalline form were determined. According to single-crystal data, the structure of one of the representatives of triple molybdates was determined.

Effect of monoclonal antibodies (MoAb) to class I and class II HLA antigens on lectin- and MoAb OKT3-induced lymphocyte proliferation.

Science.gov (United States)

Akiyama, Y; Zicht, R; Ferrone, S; Bonnard, G D; Herberman, R B

1985-04-01

We have examined the effect of several monoclonal antibodies (MoAb) to monomorphic determinants of class II HLA antigens, and MoAb to monomorphic determinants of class I HLA antigens and to beta-2-microglobulin (beta 2-mu) on lectin- and MoAb OKT3-induced proliferation of human peripheral blood mononuclear cells (PBMNC) and cultured T cells (CTC). Some, but not all, anti-class II HLA MoAb inhibited the proliferative response of PBMNC to MoAb OKT3 and pokeweed mitogen (PWM). The degree of inhibitory effect varied considerably. This effect was not limited to anti-class II HLA MoAb since anti-class I HLA MoAb and anti-beta 2-mu MoAb also inhibited MoAb OKT3- or PWM-induced proliferative responses. In contrast, the response of PBMNC to phytohemagglutinin (PHA) and concanavalin A (Con A) was not blocked by any anti-class II HLA MoAb. However, some anti-class II HLA MoAb also inhibited the proliferative response of CTC plus allogeneic peripheral blood adherent accessory cells (AC) to PHA or Con A as well as to MoAb OKT3 or PWM. This may be attributable to the substantially greater class II HLA antigen expression by CTC than by fresh lymphocytes. Pretreatment of either CTC or AC with anti-class II HLA MoAb inhibited OKT3-induced proliferation. In contrast, pretreatment of CTC, but not AC, with anti-class I HLA MoAb inhibited the proliferative response of CTC to OKT3. Pretreatment of CTC with anti-class I HLA MoAb inhibited PHA-, Con A and PWM-induced proliferation, to a greater degree than the anti-class II HLA MoAb. It appears as if lymphocyte activation by different mitogens exhibits variable requirements for the presence of cells expressing major histocompatibility determinants. Binding of Ab to membrane markers may interfere with lymphocyte-AC cooperation, perhaps by inhibiting binding of mitogens to their receptors or by interfering with lymphocyte and AC function. We also have examined the role of class II HLA antigens on CTC by depleting class II HLA-positive cells

Characterization of interaction between U-Mo alloy and Al diffusion-couple

International Nuclear Information System (INIS)

Liu Yunming; Yin Changgeng; Sun Changlong; Chen Jiangang; Sun Xudong

2011-01-01

In this paper, the interaction behavior of U-Mo/Al was studied with the diffusion-couple method, and the couple was continuously jointed by hot-pressing with special device. Annealing experiments were accomplished in a vacuum hot-pressing furnace, and at 550∼570℃ for 5∼21 hours. The results show that the morphology and composition of interaction Layer depend on the interaction layer thickness. The content of U (Mo) and Al is mutational at the interface of U-Mo/interaction layer/Al. The layer close to U-Mo side is mainly composed of product (U, Mo)Al 3 , while the Al side is composed of (U, Mo)Al 4 and UMO 2 Al 20 . Diffusion process of U-Mo/Al is Al immigrating over the Al/U-Mo original interface into U-Mo side and reacting with U-Mo, subsequently the interaction layer is growing into Al. (authors)

Mo-Mo Quintuple Bond is Highly Reactive in H-H, C-H, and O-H σ-Bond Cleavages Because of the Polarized Electronic Structure in Transition State.

Science.gov (United States)

Chen, Yue; Sakaki, Shigeyoshi

2017-04-03

The recently reported high reactivity of the Mo-Mo quintuple bond of Mo 2 (N ∧ N) 2 (1) {N ∧ N = μ-κ 2 -CH[N(2,6-iPr 2 C 6 H 3 )] 2 } in the H-H σ-bond cleavage was investigated. DFT calculations disclosed that the H-H σ-bond cleavage by 1 occurs with nearly no barrier to afford the cis-dihydride species followed by cis-trans isomerization to form the trans-dihydride product, which is consistent with the experimental result. The O-H and C-H bond cleavages by 1 were computationally predicted to occur with moderate (ΔG° ⧧ = 9.0 kcal/mol) and acceptable activation energies (ΔG° ⧧ = 22.5 kcal/mol), respectively, suggesting that the Mo-Mo quintuple bond can be applied to various σ-bond cleavages. In these σ-bond cleavage reactions, the charge-transfer (CT Mo→XH ) from the Mo-Mo quintuple bond to the X-H (X = H, C, or O) bond and that (CT XH→Mo ) from the X-H bond to the Mo-Mo bond play crucial roles. Though the HOMO (dδ-MO) of 1 is at lower energy and the LUMO + 2 (dδ*-MO) of 1 is at higher energy than those of RhCl(PMe 3 ) 2 (LUMO and LUMO + 1 of 1 are not frontier MO), the H-H σ-bond cleavage by 1 more easily occurs than that by the Rh complex. Hence, the frontier MO energies are not the reason for the high reactivity of 1. The high reactivity of 1 arises from the polarization of dδ-type MOs of the Mo-Mo quintuple bond in the transition state. Such a polarized electronic structure enhances the bonding overlap between the dδ-MO of the Mo-Mo bond and the σ*-antibonding MO of the X-H bond to facilitate the CT Mo→XH and reduce the exchange repulsion between the Mo-Mo bond and the X-H bond. This polarized electronic structure of the transition state is similar to that of a frustrated Lewis pair. The easy polarization of the dδ-type MOs is one of the advantages of the metal-metal multiple bond, because such polarization is impossible in the mononuclear metal complex.

Development of the Mo loading apparatus for adsorbing high level 99Mo to PZC and packing in 99mTc generator column

International Nuclear Information System (INIS)

Hishinuma, Yukio; Ohmori, Hiroyuki; Noguchi, Tuneyuki; Tatenuma, Katsuyoshi; Genka, Tsuguo; Machi, Sueo

2006-01-01

For developing the automatic system to produce the PZC- 99m Tc generator column based on (n, gamma) method, we developed and fabricated the proto-type apparatus for semi hot test to prepare and pack PZC adsorbed 99 Mo produced by (n, gamma) method into the generator column; PZC is Mo adsorbent with practical performance for (n, gamma) 99m Tc generator with high 99 Mo adsorption and high 99m Tc elution. For conducting the constant supply and delivery of 99m Tc generator, it is necessary to establish the technology of (n, gamma) method 99m Tc generator using PZC and to develop the fabrication system for 99 Mo loading to PZC and packing the 99m Tc generator column. By the reason, we are developing the Mo loading apparatus. In order to automatically conduct the process of 99 Mo adsorption to PZC and PZC- 99 Mo packing into the generator column, based on one channel system developed by JAERI-KAKEN at 3 years ago, an advanced automatic loading system functioned with 8 channels was developed as FNCA project proceeded by the core with Kaken Co. and JAIF for realizing a mass production of 99m Tc generators, and moreover the Japanese patent regarding the PZC- 99m Tc generator including the automatic loading system of 99 Mo to PZC and making 99m Tc generator columns has already been applied with joint applicants of BATAN and Kaken Co. Regarding the multi-type Mo loading apparatus mentioned above, we set it up in a hot of BATAN at December 2003 year. In this report, we will introduce mainly about the multi-channel automatic loading system of 99 Mo. (author)

Elevated Temperature Tensile Tests on DU–10Mo Rolled Foils

Energy Technology Data Exchange (ETDEWEB)

Schulthess, Jason [Idaho National Lab. (INL), Idaho Falls, ID (United States)

2014-09-01

Tensile mechanical properties for uranium-10 wt.% molybdenum (U–10Mo) foils are required to support modeling and qualification of new monolithic fuel plate designs. It is expected that depleted uranium-10 wt% Mo (DU–10Mo) mechanical behavior is representative of the low enriched U–10Mo to be used in the actual fuel plates, therefore DU-10Mo was studied to simplify material processing, handling, and testing requirements. In this report, tensile testing of DU-10Mo fuel foils prepared using four different thermomechanical processing treatments were conducted to assess the impact of foil fabrication history on resultant tensile properties.

Characterisation of electrodeposited and heat-treated Ni-Mo-P coatings

Energy Technology Data Exchange (ETDEWEB)

Melo, Regis L.; Casciano, Paulo N.S.; Correia, Adriana N.; Lima-Neto, Pedro de, E-mail: pln@ufc.br [Departamento de Quimica Analitica e Fisico-Quimica, Universidade Federal do Ceara, Fortaleza, CE (Brazil)

2012-07-01

The electrodeposition, hardness and corrosion resistance properties of Ni-Mo-P coatings were investigated. Characterisations of the electrodeposited coatings were carried out using scanning electron microscopy, X-ray diffraction and energy dispersive X-ray analysis techniques. Corrosion tests were performed at room temperature in 10-1 mol dm-3 NaCl solutions and by potentiodynamic linear polarisation. Amorphous Ni-Mo-P coatings were successfully obtained by electrodeposition using direct current. The coating composition showed to be dependent on the bath composition, current density and bath temperature. Both P and Mo contents contribute for the hardness properties of the Ni-Mo-P coatings and the absence of cracks is a requirement to produce electrodeposited Ni-Mo-P coatings with good hardness properties. The hardness values increase with heat-treatment temperature due to the precipitation of Ni, Ni{sub 3}P and NiMo phases during the heat treatment. The corrosion resistance of the electrodeposited Ni-Mo-P amorphous coatings increases with P content in the layer. Among the electrodeposited Ni-Mo-P amorphous coatings, Ni{sub 78}Mo{sub 10}P{sub 12} presented the best hardness and corrosion-resistance properties. The results showed that the addition of P is beneficial for the hardness and corrosion resistance properties of the Ni-Mo-based coatings. (author)

Nanostructured metal oxides: promise opportunity and challenge to develop clinically useful 99Mo/99mTc generators using (n, gamma)99Mo

International Nuclear Information System (INIS)

Dash, Ashutosh

2014-01-01

The role of 99m Tc diagnostic nuclear medicine needs hardly to be reiterated. Today, it is the most widely used radionuclide for single photon emission computed tomography (SPECT) imaging procedures. The current strategy of availing 99m Tc is ensured from column chromatographic 99 Mo/ 99m Tc generators using a bed of acidic alumina. While the column chromatographic 99 Mo/ 99m Tc generator constitute a successful exemplar of availing 99m Tc, the limited capacity of alumina (2-20 mg Mo per g of alumina) for taking up molybdate ions necessitates the use of 99 Mo of the highest specific activity available, as can be found in fission produced 99 Mo (F 99 Mo). In order to reduce dependence of F 99 Mo, the scope of using low specific activity (n,γ) 99 Mo along with high capacity adsorbent is an interesting prospect. In this context, the scope of using nanomaterials as a viable adsorbent seemed attractive by virtue of their huge surface to volume ratios, altered physical properties, tailored surface chemistry, favorable adsorption characteristics, and enhanced surface reactivity resulting from the nanoscale dimensions. This emerging class of adsorbent represents an innovative paradigm and is expected to play an important role in the development of 99 Mo/ 99m Tc generators adaptable to the existing and foreseeable demands. This talk outlines a critical assessment on the role of nanostructured metal oxides, recent developments, the contemporary status, and key challenges and apertures to the near future. (author)

Toroidal deuteron accelerator for Mo-98 neutron activation

Energy Technology Data Exchange (ETDEWEB)

Araujo, Wagner L., E-mail: wagner.leite@ifnmg.edu.br, E-mail: tprcampos@pq.cnpq.br [Instituto Federal do Norte de Minas Gerais (IFN-MG), Montes Claros, MG (Brazil); Campos, Tarcisio P.R. Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

2017-07-01

The radionuclide Tc-{sup 99m} is the most useful radioisotope in nuclear medicine. It can be produced by the Mo-99 beta minus decay. Mo-99 has often been produced in a high- flux nuclear reactor through radioactive neutron capture reactions on Mo-98. The present paper provides a preliminary design of a toroidal transmutation system (TTS) based on a toroidal compact deuteron accelerator, which can provide the Mo-98 transmutation into Mo-99. This system is essentially composed of a multi-aperture plasma electrode and a target, submitted to 180 kV, where a positive deuteron beam is accelerated toward a titanium-target loaded with deuterium in which nuclear d-d fusion reactions are induced. The Particle Studio package of the Computer Simulation Technology (CST) software was applied to design, simulate and optimize the deuteron beam on the target. MCNP code provided to neutronic analysis. Based on electromagnetic and neutronic simulations, the neutron yield and reaction rates were estimated. The simulated data allowed appraising the Mo-99 activity. A TTS, in a specific configuration, could produce a total deuterium current of 1.6 A at the target and a neutron yield of 10{sup 13} n.s{sup -1}. In a arrangement of 30 column samples, TTS provides 230 mCi s{sup -1} Mo{sup 99} in each column, which represents 80% of Tc-99m in secular equilibrium. As conclusion, the system holds potential for generating Mo-99 and Tc-99m in a suitable activity in secular equilibrium. (author)

Toroidal deuteron accelerator for Mo-98 neutron activation

International Nuclear Information System (INIS)

Araujo, Wagner L.; Campos, Tarcisio P.R. Universidade Federal de Minas Gerais

2017-01-01

The radionuclide Tc- 99m is the most useful radioisotope in nuclear medicine. It can be produced by the Mo-99 beta minus decay. Mo-99 has often been produced in a high- flux nuclear reactor through radioactive neutron capture reactions on Mo-98. The present paper provides a preliminary design of a toroidal transmutation system (TTS) based on a toroidal compact deuteron accelerator, which can provide the Mo-98 transmutation into Mo-99. This system is essentially composed of a multi-aperture plasma electrode and a target, submitted to 180 kV, where a positive deuteron beam is accelerated toward a titanium-target loaded with deuterium in which nuclear d-d fusion reactions are induced. The Particle Studio package of the Computer Simulation Technology (CST) software was applied to design, simulate and optimize the deuteron beam on the target. MCNP code provided to neutronic analysis. Based on electromagnetic and neutronic simulations, the neutron yield and reaction rates were estimated. The simulated data allowed appraising the Mo-99 activity. A TTS, in a specific configuration, could produce a total deuterium current of 1.6 A at the target and a neutron yield of 10 13 n.s -1 . In a arrangement of 30 column samples, TTS provides 230 mCi s -1 Mo 99 in each column, which represents 80% of Tc-99m in secular equilibrium. As conclusion, the system holds potential for generating Mo-99 and Tc-99m in a suitable activity in secular equilibrium. (author)

Mo-99 production by fission and future projections

International Nuclear Information System (INIS)

Carranza, E.C.; Novello, A.; Bronca, M.; Cestau, D.; Bavaro, R.; Centurion, R.; Bravo, C.; Bronca, P.; Gualda, E.; Fraguas, F.; Giomi, A.; Ivaldi, L.

2012-01-01

Description of the I-131 and Mo-99 production process: The process starts with the irradiation of uranium-aluminum mini plates in the RA-3, Argentinean Reactor No.3, Ezeiza Atomic Center. In a nuclear reactor there is a constant flow of neutrons and when a neutron with proper energy impacts on a nucleus of U-235, it is absorbed at the same time generate an unstable configuration nuclear. For this reason, the nucleus formed is fission, getting two different atoms. Approximately 6% of the fissions produce Mo-99 and 3% produce I-131; the percentage remaining corresponds to formation of atoms without interest for use in medicine. In conclusion, the objective of the process developed in the Fission Plant, is starting from uranium mini plates, separate the Mo-99 and I-131 generated, the remaining elements formed. - Evolution of Mo-99 Production in the last 10 years: The Fission Mo-99 Plant Production begins routine production of Mo-99 in 1985, using targets made of uranium enriched at 90% U-235. In the 1990s, global concern regarding the use of highly enriched uranium, due to non-proliferation issues, caused the interruption of supply of nuclear material (HEU enriched at 90% of U-235). Following this, Argentina developed target based on low-enriched uranium (less than 20% U-235), becoming in 2002 the first country in the world to produce Mo-99 with LEU targets. From 2002 to date, the activity produced of Mo-99 has been tripled annually (author)

Synthesis of nanometre-thick MoO3 sheets

Science.gov (United States)

Kalantar-Zadeh, Kourosh; Tang, Jianshi; Wang, Minsheng; Wang, Kang L.; Shailos, Alexandros; Galatsis, Kosmas; Kojima, Robert; Strong, Veronica; Lech, Andrew; Wlodarski, Wojtek; Kaner, Richard B.

2010-03-01

The formation of MoO3 sheets of nanoscale thickness is described. They are made from several fundamental sheets of orthorhombic α-MoO3, which can be processed in large quantities via a low cost synthesis route that combines thermal evaporation and mechanical exfoliation. These fundamental sheets consist of double-layers of linked distorted MoO6 octahedra. Atomic force microscopy (AFM) measurements show that the minimum resolvable thickness of these sheets is 1.4 nm which is equivalent to the thickness of two double-layers within one unit cell of the α-MoO3 crystal.

Fixation Of Mo In Uranium Leach Liquor By Activated Carbon

International Nuclear Information System (INIS)

Mainar, S.; Guswita, A.; Erni, R.A.; Susilaningtyas

1996-01-01

The use of activated carbon for Mo fixation by bulk system is reported. Several factors influencing the fixation process were examined, including contact time, carbon particle size, carbon porosity and the effect of other elements present in Mo containing solutions. Experimental data showed that an adsorption equilibrium of Mo on of activated carbon and 0,85 to 1,18 mm of carbon particle size under forced-convection mass transfer in 100 ml solution that contains + 0,56 m mol of Mo and +. 0,25 m mol Of U was reached after 6 hours period. Under those conditions, about 0,50 m mol of Mo and 0,026 m mol of U were adsorbed into carbon. High concentration of rare earth elements decreased Mo adsorption, hence, the use of activated carbon was not effective to separate Mo from the digestion liquor of Rirang are where Mo was adsorbed, into the carbon + 34,5 %

Development of Commercial-scale Fission Mo-99 Production System

Energy Technology Data Exchange (ETDEWEB)

Lee, Seung-Kon; Lee, Suseung; Hong, Soon-Bog; Jang, Kyung-Duk; Park, Ul Jael; Lee, Jun Sig [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-10-15

These days, worldwide {sup 99} Mo supply is not only insufficient but also unstable. Because, most of the main {sup 99}Mo production reactors are more than years old and suffered from frequent and unscheduled shutdown. Therefore, movement to replace old reactors to keep stable supply is now active. Under these conditions, KAERI (Korea Atomic Energy Research Institute) is developing LEU-based fission {sup 99}Mo production process which is connected to the new research reactor (Kijang New Research Reactor, KJRR), which is being constructed in Gijang, Busan, Korea. Historically, the most fission {sup 99}Mo producers have been used highly enriched uranium (HEU) targets so far. However, to reduce the use of HEU in private sector for non-proliferation, {sup 99}Mo producers are forced to convert their HEU-based process to use low enriched uranium (LEU) targets. Economic impact of a target conversion from HEU to LEU is significant. In this study, fission {sup 99}Mo process with non-irradiated LEU targets was presented except separation and purification steps. Pre- and post-irradiation tests of the fission {sup 99}Mo target will be done in 4th quarter of 2016. For the fission Mo production process development, hot experiments with irradiated LEU targets will be done in 4th quarter of 2016. Then, verification of the production process with quality control will be followed until the commercial production of fission {sup 99}Mo scheduled in 2019.

A novel three dimensional semimetallic MoS{sub 2}

Energy Technology Data Exchange (ETDEWEB)

Tang, Zhen-Kun [Beijing Computational Science Research Center, Beijing 100084 (China); Departments of Physics and Electronics, Hengyang Normal University, Hengyang 421008 (China); Zhang, Hui; Liu, Li-Min, E-mail: limin.liu@csrc.ac.cn [Beijing Computational Science Research Center, Beijing 100084 (China); Liu, Hao [Chengdu Green Energy and Green Manufacturing Technology R and D Center, Chengdu, Sichuan 610207 (China); Lau, Woon-Ming [Beijing Computational Science Research Center, Beijing 100084 (China); Chengdu Green Energy and Green Manufacturing Technology R and D Center, Chengdu, Sichuan 610207 (China)

2014-05-28

Transition metal dichalcogenides (TMDs) have many potential applications, while the performances of TMDs are generally limited by the less surface active sites and the poor electron transport efficiency. Here, a novel three-dimensional (3D) structure of molybdenum disulfide (MoS{sub 2}) with larger surface area was proposed based on first-principle calculations. 3D layered MoS{sub 2} structure contains the basal surface and joint zone between the different nanoribbons, which is thermodynamically stable at room temperature, as confirmed by first principles molecular dynamics calculations. Compared the two-dimensional layered structures, the 3D MoS{sub 2} not only owns the large surface areas but also can effectively avoid the aggregation. Interestingly, although the basal surface remains the property of the intrinsic semiconductor as the bulk MoS{sub 2}, the joint zone of 3D MoS{sub 2} exhibits semimetallic, which is derived from degenerate 3d orbitals of the Mo atoms. The high stability, large surface area, and high conductivity make 3D MoS{sub 2} have great potentials as high performance catalyst.

Homogenization of compacted blends of Ni and Mo powders

International Nuclear Information System (INIS)

Lanam, R.D.; Yeh, F.C.H.; Rovsek, J.E.; Smith, D.W.; Heckel, R.W.

1975-01-01

The homogenization behavior of compacted blends of Ni and Mo powders was studied primarily as a function of temperature, mean compact composition, and Mo powder particle size. All compact compositions were in the Ni-rich terminal solid-solution range; temperatures were between 950 and 1200 0 C (in the region of the phase diagram where only the Mo--Ni intermediate phase forms); average Mo particle sizes ranged from 8.4 mu m to 48 mu m. Homogenization was characterized in terms of the rate of decrease of the amounts of the Mo-rich terminal solid-solution phase and the Mo--Ni intermediate phase. The experimental results were compared to predictions based upon the three-phase, concentric-sphere homogenization model. In general, agreement between experimental data and model predictions was fairly good for high-temperature treatments and for compact compositions which were not close to the solubility limit of Mo in Ni. Departures from the model are discussed in terms of surface diffusion contributions to homogenization and non-uniform mixing effects. (U.S.)

Na2MoO2As2O7

Directory of Open Access Journals (Sweden)

Raja Jouini

2012-12-01

Full Text Available Disodium molybdenum dioxide diarsenate, Na2MoO2As2O7, has been synthesized by a solid-state reaction. The structure is built up from MoAs2O12 linear units sharing corners to form a three-dimensional framework containing tunnels running along the a-axis direction in which the Na+ cations are located. In this framework, the AsV atoms are tetrahedrally coordinated and form an As2O7 group. The MoVI atom is displaced from the center of an octahedron of O atoms. Two Na+ cations are disordered about inversion centres. Structural relationships between different compounds: A2MoO2As2O7 (A = K, Rb, AMOP2O7 (A = Na, K, Rb; M = Mo, Nb and MoP2O7 are discussed.

Oxidation of atomically thin MoS2 on SiO2

Science.gov (United States)

Yamamoto, Mahito; Cullen, William; Einstein, Theodore; Fuhrer, Michael

2013-03-01

Surface oxidation of MoS2 markedly affects its electronic, optical, and tribological properties. However, oxidative reactivity of atomically thin MoS2 has yet to be addressed. Here, we investigate oxidation of atomic layers of MoS2 using atomic force microscopy and Raman spectroscopy. MoS2 is mechanically exfoliated onto SiO2 and oxidized in Ar/O2 or Ar/O3 (ozone) at 100-450 °C. MoS2 is much more reactive to O2 than an analogous atomic membrane of graphene and monolayer MoS2 is completely etched very rapidly upon O2 treatment above 300 °C. Thicker MoS2 (> 15 nm) transforms into MoO3 after oxidation at 400 °C, which is confirmed by a Raman peak at 820 cm-1. However, few-layer MoS2 oxidized below 400 °C exhibits no MoO3 Raman mode but etch pits are formed, similar to graphene. We find atomic layers of MoS2 shows larger reactivity to O3 than to O2 and monolayer MoS2 transforms chemically upon O3 treatment even below 100 °C. Work supported by the U. of Maryland NSF-MRSEC under Grant No. DMR 05-20741.

Carbon potential measurement on the Mo-MoC0.47 system by methane - hydrogen equilibration

International Nuclear Information System (INIS)

Ananthasivan, K.; Kaliappan, I.; Chandramouli, V.; Anthonysamy, S.; Vasudeva Rao, P.R.; Mathews, C.K.

1993-01-01

Uranium plutonium mixed carbides are potential candidate fuel materials for liquid metal cooled fast breeder reactors. The carbon potential of the fuel is an important thermochemical property which strongly influences the carbon transport between the clad and the fuel. The carbon potential of the fuel is altered during irradiation of the fuel in the reactor. This is due to the formation of various fission products and their binary and ternary carbides. Molybdenum is a fission product with a high yield which can alter the carbon potential of the fuel. The present work forms part of our studies on the carbon potential measurements in the U - Mo - C ternary system. The carbon potential of the Mo-Mo 2 C couple measured by the methane hydrogen gas equilibration technique is presented here and the results are compared with the values cited in the literature. (author)

Influence of H2O and H2S on the Composition, Activity, and Stability of Sulfided Mo, CoMo, and NiMo Supported on MgAl2O4 for Hydrodeoxygenation of Ethylene Glycol

DEFF Research Database (Denmark)

Dabros, Trine Marie Hartmann; Gaur, Abhijeet; Pintos, Delfina Garcia

2018-01-01

In this work, density functional theory (DFT), catalytic activity tests, and in-situ X-ray absorption spectroscopy (XAS) was performed to gain detailed insights into the activity and stability of MoS2, Ni-MoS2, and Co-MoS2 catalysts used for hydrodeoxygenation (HDO) of ethylene glycol upon...

Desenvolvimento de material de referência para microbiologia de alimentos contendo Listeria monocytogenes em matriz queijo

OpenAIRE

Marcelo Luiz Lima Brandão; Juliana de Castro Beltrão da Costa; Felipe Miceli de Farias; Carla de Oliveira Rosas; Silvia Maria Lopes Bricio; Janaína dos Santos Nascimento; Paola Cardarelli Leite

2013-01-01

A NBR ISO/IEC 17025:2005, uma das normas mais utilizadas em laboratórios de ensaio, descreve como um de seus critérios para a garantia da qualidade dos resultados analíticos a participação periódica dos laboratórios em ensaios de proficiência (EP). Os analitos, utilizados nos EP são materiais de referência (MR) provenientes de um mesmo lote, e devem apresentar características de homogeneidade e estabilidade. O objetivo deste estudo foi produzir um MR qualitativo destinado ao ensaio de pesquis...

Absorption spectra of CsNd(MoO4)2 and CsGd(MoO4)2-Nd3+ crystals in strong magnetic fields

International Nuclear Information System (INIS)

Gorban', I.S.; Kozeeva, L.P.; Slobodyanyuk, A.V.; Shevchenko, V.A.

1987-01-01

The comparison of the electronic structure of Nd 3+ in CsNd(MoO 4 ) 2 and CsGd(MoO 4 ) 2 - Nd 3+ crystals is made. It is established that in these crystals the activator centers, mainly, of the certain type with the symmetry of the local environment C 2 are formed. The absorption spectra of self-activated CsNd(MoO 4 ) 2 crystal differ from spectra of CsGd(MoO 4 ) 2 - Nd 3+ by the presence of the vibrating structure. The Stark splittings of energy levels of Nd 3+ in the investigated crystalline matrices are more sensitive to the environment effect than the Zeeman ones. The ground state of Nd 3+ ion in CsNd(MoO 4 ) 2 and CsGd(MoO 4 ) 2 molybdates is characterized by the similar values of g-factors

Vedinių su priesaga *-mo- raida

Directory of Open Access Journals (Sweden)

Saulius Ambrazas

2011-12-01

Full Text Available DEVELOPMENT OF DERIVATIVES WITH THE SUFFIX *-mo-SummaryAdjectives with the suffix *-mo- have been formed from substantives (cf. Lith. tólimas / tólymas and Latv. dial. tuôl’eims ‘distant’; Pruss. *auktimas ‘high’; Skr. agrimá- ‘the first, who is at the head’ and verbs (cf. Lith. dial. ãpsukmas ‘sewn round’, pliùkšmas ‘deflated, limp’; OLith. laimas ‘happy’ and Pruss. etnīstislaims (gnadenreich III 631; Lith. liñksmas and Latv. lìksms ‘merry, gay, joyfull’, Gmc. *werma- ‘warm’, Skr. bhīmá- ‘terrible, frightfull’, Toch. A, B cämpamo- ‘well-to-do, rich’, Hitt. kišamma- ‘combed’ from the Late Proto-Indo-European. The gratest part of them became participles in the Baltic, Slavic and Albanian languages.On the other hand, the use of derivatives with the suffix *-mo- in the position of abstract nouns is also very old, cf. semanticaly concretized and derivationaly indissoluble abstract noun, in herited from Proto-Indo-European, Lith. dmas (dmai, Latv. dũmi, Pruss. dumis (rauch E 39, Slav. *dymъ, Latv. fūmus, Skr. dhūmó- ‘smoke’ and Gk. θῡ‑μός with abstract meaning ‘soal, vitality, passion,    need’ : dhe-/dh-/dhū- ‘blow; breathe; choke; smoke; rush; disperse; whirl, move, stir’.In the East Baltic languages abstract nouns with the derived suffixes, based on *-mo-, became productive, cf. nomina actionis with *-i-mo- in Lithuanian (cf. gyvẽnimas ‘life’ and corresponding derivatives with *-u-mo- in Latvian (cf. ìeradums ‘custom, habit’.

Co-Processing of Jatropha-Derived Bio-Oil with Petroleum Distillates over Mesoporous CoMo and NiMo Sulfide Catalysts

Directory of Open Access Journals (Sweden)

Shih-Yuan Chen

2018-02-01

Full Text Available The co-processing of an unconventional type of Jatropha bio-oil with petroleum distillates over mesoporous alumina-supported CoMo and NiMo sulfide catalysts (denoted CoMo/γ-Al2O3 and NiMo/γ-Al2O3 was studied. Either a stainless-steel high-pressure batch-type reactor or an up-flow fixed-bed reaction system was used under severe reaction conditions (330–350 °C and 5–7 MPa, similar to the conditions of the conventional diesel hydrodesulfurization (HDS process. To understand the catalytic performance of the mesoporous sulfide catalysts for co-processing, we prepared two series of oil feedstocks. First, model diesel oils, consisting of hydrocarbons and model molecules with various heteroatoms (sulfur, oxygen, and nitrogen were used for the study of the reaction mechanisms. Secondly, low-grade oil feedstocks, which were prepared by dissolving of an unconventional type of Jatropha bio-oil (ca. 10 wt % in the petroleum distillates, were used to study the practical application of the catalysts. Surface characterization by gas sorption, spectroscopy, and electron microscopy indicated that the CoMo/γ-Al2O3 sulfide catalyst, which has a larger number of acidic sites and coordinatively unsaturated sites (CUS on the mesoporous alumina framework, was associated with small Co-incorporated MoS2-like slabs with high stacking numbers and many active sites at the edges and corners. In contrast, the NiMo/γ-Al2O3 sulfide catalyst, which had a lower number of acidic sites and CUS on mesoporous alumina framework, was associated with large Ni-incorporated MoS2-like slabs with smaller stacking numbers, yielding more active sites at the brims and corresponding to high hydrogenation (HYD activity. Concerning the catalytic performance, the mesoporous CoMo/γ-Al2O3 sulfide catalyst with large CUS number was highly active for the conventional diesel HDS process; unfortunately, it was deactivated when oxygen- and nitrogen-containing model molecules or Jatropha bio

ITO-free organic light-emitting diodes with MoO3/Al/MoO3 as semitransparent anode fabricated using thermal deposition method

International Nuclear Information System (INIS)

Lu, Hsin-Wei; Huang, Ching-Wen; Kao, Po-Ching; Chu, Sheng-Yuan

2015-01-01

Highlights: • In this paper, the structure of the proposed devices is substrate (glass; polyethersulfone (PES))/anode (MoO 3 /Al/MoO 3 ; MoO 3 /Al)/α-naphthylphenylbiphenyl diamine (NPB) (40 nm)/tris (8-hydroxyquinoline) aluminum (Alq3) (60 nm)/LiF (1 nm)/Al (150 nm). • The optical transmittance of the metal layer was enhanced by depositing metal oxidation (MoO 3 ) and metal (Al) layers. • The optimized films show the typical sheet resistance of 7 Ω/sq and a high transmittance of 70% at 550 nm. • The indium-tin-oxide (ITO)-free OLEDs with the fabricated composite anodes on a glass substrate exhibited the high luminance and current efficiency of 21,750 cd/m 2 and 3.18 cd/A, respectively. • The bending effects on PES substrate by depositing metal oxidation (MoO 3 ) and metal (Al) layers were also investigated. • MoO 3 covering the Al layer modifies the surface of the electrode and enhances the durability. The surface roughness of the bi-layer films was higher than that of the tri-layer films. Therefore, OLEDs with OMO anode outperform those with bi-layer films anode. - Abstract: In this paper, semitransparent electrodes with the structure substrate/MoO 3 /Al/MoO 3 (OMO) were fabricated via the thermal deposition method for use as the anode in organic light-emitting diodes (OLEDs). The optical transmittance of the metal layer was enhanced by depositing metal oxidation (MoO 3 ) and metal (Al) layers. The optimal thickness of the Al thin films was determined to be 15 nm for high optical transmittance and good electrical conductivity. The optimized films show the typical sheet resistance of 7 Ω/sq and a high transmittance of 70% at 550 nm. The indium-tin-oxide (ITO)-free OLEDs with the fabricated composite anodes on a glass substrate exhibited the high luminance and current efficiency of 21,750 cd/m 2 and 3.18 cd/A, respectively. In addition, bending effects on the polyethersulfone (PES) substrate/MoO 3 /Al/MoO 3 and PES substrate/MoO 3 /Al structures were

U-Mo/Al-Si interaction: Influence of Si concentration

International Nuclear Information System (INIS)

Allenou, J.; Palancher, H.; Iltis, X.; Cornen, M.; Tougait, O.; Tucoulou, R.; Welcomme, E.; Martin, Ph.; Valot, C.; Charollais, F.; Anselmet, M.C.; Lemoine, P.

2010-01-01

Within the framework of the development of low enriched nuclear fuels for research reactors, U-Mo/Al is the most promising option that has however to be optimised. Indeed at the U-Mo/Al interfaces between U-Mo particles and the Al matrix, an interaction layer grows under irradiation inducing an unacceptable fuel swelling. Adding silicon in limited content into the Al matrix has clearly improved the in-pile fuel behaviour. This breakthrough is attributed to an U-Mo/Al-Si protective layer around U-Mo particles appeared during fuel manufacturing. In this work, the evolution of the microstructure and composition of this protective layer with increasing Si concentrations in the Al matrix has been investigated. Conclusions are based on the characterization at the micrometer scale (X-ray diffraction and energy dispersive spectroscopy) of U-Mo7/Al-Si diffusion couples obtained by thermal annealing at 450 deg. C. Two types of interaction layers have been evidenced depending on the Si content in the Al-Si alloy: the threshold value is found at about 5 wt.% but obviously evolves with temperature. It has been shown that for Si concentrations ranging from 2 to 10 wt.%, the U-Mo7/Al-Si interaction is bi-layered and the Si-rich part is located close to the Al-Si for low Si concentrations (below 5 wt.%) and close to the U-Mo for higher Si concentrations. For Si weight fraction in the Al alloy lower than 5 wt.%, the Si-rich sub-layer (close to Al-Si) consists of U(Al, Si) 3 + UMo 2 Al 20 , when the other sub-layer (close to U-Mo) is silicon free and made of UAl 3 and U 6 Mo 4 Al 43 . For Si weight concentrations above 5 wt.%, the Si-rich part becomes U 3 (Si, Al) 5 + U(Al, Si) 3 (close to U-Mo) and the other sub-layer (close to Al-Si) consists of U(Al, Si) 3 + UMo 2 Al 20 . On the basis of these results and of a literature survey, a scheme is proposed to explain the formation of different types of ILs between U-Mo and Al-Si alloys (i.e. different protective layers).

Teens join the MoEDAL collaboration

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Stephanie Hills

2013-01-01

The principal investigator for any institute joining an experimental collaboration is generally a self-assured researcher with evident leadership skills and an in-depth knowledge of their subject gained over many years. Katherine Evans fits the brief in every respect, except that she is 17 years old and her research institute is the Langton Star Centre, based at the Simon Langton Grammar School for Boys. The school has just joined the MoEDAL experiment.   Teacher Becky Parker (left) with two students from the Simon Langton Grammar School for Boys in the MoEDAL experimental area. MoEDAL, the latest LHC experiment has detectors located close to the interaction point of the LHCb experiment. This new experiment is designed to search for the highly ionizing avatars of new physics at the LHC, specifically the magnetic monopole or dyon and other highly ionizing stable massive particles from a number of beyond-the-Standard-Model scenarios. MoEDAL was approved in 2010 and is due to start taking data i...

Medios de recuperación utilizados por entrenadores en los IV Juegos Intercolegiados Centroamericanos y del Caribe

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Hilario Moreno Bolívar

2016-09-01

Full Text Available El presente estudio tuvo como objetivos identificar los medios de recuperación y ayudas ergonutricionales empleados por parte de los entrenadores participes en los IV Juegos Intercolegiados Centroamericanos y del Caribe, así como la causa o razón por la que son utilizados. Métodos. A través de una encuesta validada, se desarrolló un estudio descriptivo y corte transversal donde fueron encuestados 41 entrenadores (36 de sexo masculino y 6 de femenino de 13 modalidades deportivas y de 8 países entre los días 10 y 15 de noviembre de 2013, en la ciudad de Armenia, Colombia. Resultados. El 87 % de los entrenadores encuestados utiliza algún medio de recuperación con sus deportistas después de un entrenamiento o competición deportiva, siendo el estiramiento (91 % y el masaje (66,6 % los más utilizados; estableciendo que el principal motivo de uso de estos recursos es la facilidad de aplicación de dichas técnicas. Respecto a las ayudas ergonutricionales, el 68% de los entrenadores hace uso habitual de ellas, suministrando las vitaminas (46,4 % y las bebidas hidratantes (32,1 % en primera y segunda instancia; por su parte se determinó que la principal causa de utilización de estos suplementos alimentarios es el criterio personal del entrenador/a. Conclusiones. La mayoría de entrenadores utilizan los medios de recuperación para facilitar la recuperación física de sus deportistas, pero sus dos recursos más utilizados cuentan con poco respaldo científico. Pese a que un mayor porcentaje de entrenadores emplea ayudas ergonutricionales con los deportistas para restablecer sus fuentes energéticas y restauración de tejidos, estos requieren de un mayor acompañamiento y asesoría por parte de profesionales expertos en nutrición.

Mo-99 supply issues: Status report and lessons learned

International Nuclear Information System (INIS)

Ponsard, B.

2010-01-01

The worldwide supply of 99 Mo relies on a limited number of research reactors and processing facilities. Its production is essential for the nuclear medicine as 99m Tc, obtained from 99 Mo/ 99m Tc generators, is used in about 80% of the diagnostic nuclear imaging procedures. These applications represent yearly approximately 30 million examinations worldwide. The short half-life's of 99 Mo (66 hours) and its daughter 99m Tc (6 hours) require a regular supply of 99 Mo/ 99m Tc generators to hospitals or central radiopharmacies. Currently, there are only five nuclear reactors involved in the production of 99 Mo on industrial scale: NRU (Canada), HFR (Netherlands), BR2 (Belgium), OSIRIS (France) and SAFARI (South Africa). They irradiate highly enriched uranium targets for the production of about 95% of the available 99 Mo by four processing facilities: AECL/MDS NORDION (Canada), COVIDIEN (Netherlands), IRE (Belgium) and NTP (South Africa). However, these ageing reactors are subject to unscheduled shutdowns and longer maintenance periods making the 99 Mo supply chain vulnerable and unreliable. Several severe disruptions have been experienced since the fall 2005 due to the occurrence of problems at different stages of the supply chain: reactor outages, release of activity from processing facilities, recall of 99 Mo/ 99m Tc generators by the manufacturers, ... It is not expected that the situation will improve significantly in the near future. Therefore, several workshops have been organized in 2009 by the OECD Nuclear Energy Agency (NEA), the International Atomic Energy Agency (IAEA) and the Association of Imaging Producers and Equipment Suppliers (AIPES) to define measures that should be taken to secure the 99 Mo supply in the short, medium and long term. This paper summarizes the current status of the 99 Mo supply, discusses the ongoing plans for additional 99 Mo production capacity and outlines the issues for a reliable global supply chain. (author)

Tailored MoS2 nanorods: a simple microwave assisted synthesis

Science.gov (United States)

Reshmi, S.; Akshaya, M. V.; Satpati, Biswarup; Roy, Anupam; Basu, Palash Kumar; Bhattacharjee, K.

2017-11-01

We report here the synthesis of MoS2 nanostructures by a simple liquid phase exfoliation of MoS2 powder in organic solvents followed by microwave treatment. The probe sonication and the microwave treatment play an important role in rolling and curling of the MoS2 nanosheets to give rise to MoS2 spheres and rod/tube like-structures with diameter approximately 150-200 nm. The MoS2 nanorods formed in this fashion are hollow inside with a wall thickness of 15-20 nm and the length of the nanorods is found in the order of several micrometers. Synthesis of such tailored MoS2 nanorods by liquid phase exfoliation is not yet reported. Our observations suggest the 2H phase of bulk MoS2 remains preserved in the nanostructures with high crystalline quality.

Amorphous-crystalline transition studied in hydrated MoO3

International Nuclear Information System (INIS)

Camacho-Lopez, M.A.; Haro-Poniatowski, E.; Lartundo-Rojas, L.; Livage, J.; Julien, C.M.

2006-01-01

In this work we study the thermal behavior of hydrated MoO 3 synthesized via acidification of sodium molybdate. MoO 3 .nH 2 O (n = 1.4) amorphous compound was heated in air at increasing temperatures in order to obtain the crystalline MoO 3 phase. We have studied the structural changes as a function of annealing temperature by Raman spectroscopy. A statistical study to determine the average size of the crystallites at each annealing step has been realized by scanning electron microscopy. Results show that the hydrated MoO 3 .1.4H 2 O glass transforms in an amorphous MoO 3 .0.7H 2 O phase prior to its crystallization, while the sample heated at 500 deg. C crystallizes into the orthorhombic α-MoO 3 phase with micro-crystallites having an average size of 6.8 μm

Atomic oxygen-MoS sub 2 chemical interactions

Energy Technology Data Exchange (ETDEWEB)

Cross, J.B.; Martin, J.A. (Los Alamos National Lab., NM (USA)); Pope, L.E. (Sandia National Labs., Albuquerque, NM (USA)); Koontz, S.L. (National Aeronautics and Space Administration, Johnson Space Center, Houston, TX (USA))

1990-10-01

The present study shows that an O-atom translation energy of 1.5 eV, SO{sub 2} is generated and outgases from an anhydrous MoS{sub 2} surface with an initial reactivity nearly 50% that of kapton. The reaction of atomic oxygen with MoS{sub 2} has little or no translational energy barrier, i.e. thermally generated atomic oxygen reacts as readily as that having 1.5 eV of translational energy. For MoS{sub 2} films sputter-deposited at 50-70deg C, friction measurements showed a high initial friction coefficient (up to 0.25) for MoS{sub 2} surfaces exposed to atomic oxygen, which dropped to the normal low values after several cycles of operation in air and ultrahigh vacuum. For MoS{sub 2} films deposited at 200deg C, the friction coefficient was not affected by the O-atom exposure. (orig.).

Thermal transport properties of MoS ₂ and MoSe ₂ monolayers

Energy Technology Data Exchange (ETDEWEB)

Kandemir, Ali; Yapicioglu, Haluk; Kinaci, Alper; Çağın, Tahir; Sevik, Cem

2016-01-11

Isolation of single to few layer transition metal dichalgogenides open alternate venues in application of 2 dimensional materials to nanoelectronics. Either for general overheating issues or specific application in thermoelectric devices, the characterization of the thermal transport in these new low dimensional materials is needed for their efficient implementation. In this study, lattice thermal conductivities of single layer MoS₂ and MoSe₂ are evaluated using classical molecular dynamics method. The interactions between atoms are defined by Stillinger-Weber type empirical potentials that are developed to represent structural, mechanical, and vibrational properties of the given materials. In parameterization of the potentials, a stochastic optimization algorithm, namely particle swarm optimization is utilized. The final parameter sets produce quite consistent results with DFT in terms of lattice parameters, bond distances, elastic constants and vibrational properties of both single layer MoS₂ and MoSe₂. The predicted thermal properties of both materials are in very good agreement with earlier first principles calculations. The discrepancies between calculations and experimental measurements are most likely to be caused by pristine nature of the structures in our simulations.

Magnetism by interfacial hybridization and p-type doping of MoS(2) in Fe(4)N/MoS(2) superlattices: a first-principles study.

Science.gov (United States)

Feng, Nan; Mi, Wenbo; Cheng, Yingchun; Guo, Zaibing; Schwingenschlögl, Udo; Bai, Haili

2014-03-26

Magnetic and electronic properties of Fe4N(111)/MoS2(√3 × √3) superlattices are investigated by first-principles calculations, considering two models: (I) Fe(I)Fe(II)-S and (II) N-S interfaces, each with six stacking configurations. In model I, strong interfacial hybridization between Fe(I)/Fe(II) and S results in magnetism of monolayer MoS2, with a magnetic moment of 0.33 μB for Mo located on top of Fe(I). For model II, no magnetism is induced due to weak N-S interfacial bonding, and the semiconducting nature of monolayer MoS2 is preserved. Charge transfer between MoS2 and N results in p-type MoS2 with Schottky barrier heights of 0.5-0.6 eV. Our results demonstrate that the interfacial geometry and hybridization can be used to tune the magnetism and doping in Fe4N(111)/MoS2(√3 × √3) superlattices.

Coated U(Mo) Fuel: As-Fabricated Microstructures

Energy Technology Data Exchange (ETDEWEB)

Emmanuel Perez; Dennis D. Keiser, Jr.; Ann Leenaers; Sven Van den Berghe; Tom Wiencek

2014-04-01

As part of the development of low-enriched uranium fuels, fuel plates have recently been tested in the BR-2 reactor as part of the SELENIUM experiment. These fuel plates contained fuel particles with either Si or ZrN thin film coating (up to 1 µm thickness) around the U-7Mo fuel particles. In order to best understand irradiation performance, it is important to determine the starting microstructure that can be observed in as-fabricated fuel plates. To this end, detailed microstructural characterization was performed on ZrN and Si-coated U-7Mo powder in samples taken from AA6061-clad fuel plates fabricated at 500°C. Of interest was the condition of the thin film coatings after fabrication at a relatively high temperature. Both scanning electron microscopy and transmission electron microscopy were employed. The ZrN thin film coating was observed to consist of columns comprised of very fine ZrN grains. Relatively large amounts of porosity could be found in some areas of the thin film, along with an enrichment of oxygen around each of the the ZrN columns. In the case of the pure Si thin film coating sample, a (U,Mo,Al,Si) interaction layer was observed around the U-7Mo particles. Apparently, the Si reacted with the U-7Mo and Al matrix during fuel plate fabrication at 500°C to form this layer. The microstructure of the formed layer is very similar to those that form in U-7Mo versus Al-Si alloy diffusion couples annealed at higher temperatures and as-fabricated U-7Mo dispersion fuel plates with Al-Si alloy matrix fabricated at 500°C.

Comparative study of {sup 99}Mo/{sup 99m}Tc generators at base of synthesized gels starting from activation and fission {sup 99}Mo; Estudio comparativo de generadores {sup 99}Mo/{sup 99m}Tc a base de geles sintetizados a partir de {sup 99}Mo de activacion y de fision

Energy Technology Data Exchange (ETDEWEB)

Lopez M, I Z [UAEM, Paseo Colon esq. Paseo Tollocan, 50120 Toluca, Estado de Mexico (Mexico); Monroy G, F; Rivero G, T; Rojas N, P [ININ, Carretera Mexico -Toluca S/N, 52045 La Marquesa Ocoyoacac, Estado de Mexico (Mexico)

2007-07-01

The {sup 99m}Tc is used for diagnostic and therapy. It is produced starting from {sup 99}Mo, absorbed in chromatographic columns, loaded with alumina that absorb only 0.2% of {sup 99}Mo with high specific activities of {sup 99}Mo, obtained from the {sup 235}U fission. Given these conditions and limitations, new preparation procedures of {sup 99}Mo/{sup 99m}Tc generators, its have been developed, using zirconium molybdates gels that incorporates until 30% of {sup 99}Mo, conserve similar characteristics of quality and purity that the traditional generator. The radiochemical characteristics of the {sup 99m}Tc elution, depend strongly on the gel preparation conditions. In particular, the present work has by object to determine the influence of the {sup 99}Mo used type, fission or activation product, during the gels synthesis, as well as the used air flow for the agitation in the gels preparation and its influence in the {sup 99}Mo/{sup 99m}Tc generators quality. When diminishing the flow of agitation air the efficiency it increases and in the radionuclide purity of the eluates and when using {sup 99}Mo from fission for the gels production it increases in an important way the elutriation efficiency, the radiochemical and radionuclide purity of the {sup 99m}Tc eluates. (Author)

MoCha: Molecular Characterization of Unknown Pathways.

Science.gov (United States)

Lobo, Daniel; Hammelman, Jennifer; Levin, Michael

2016-04-01

Automated methods for the reverse-engineering of complex regulatory networks are paving the way for the inference of mechanistic comprehensive models directly from experimental data. These novel methods can infer not only the relations and parameters of the known molecules defined in their input datasets, but also unknown components and pathways identified as necessary by the automated algorithms. Identifying the molecular nature of these unknown components is a crucial step for making testable predictions and experimentally validating the models, yet no specific and efficient tools exist to aid in this process. To this end, we present here MoCha (Molecular Characterization), a tool optimized for the search of unknown proteins and their pathways from a given set of known interacting proteins. MoCha uses the comprehensive dataset of protein-protein interactions provided by the STRING database, which currently includes more than a billion interactions from over 2,000 organisms. MoCha is highly optimized, performing typical searches within seconds. We demonstrate the use of MoCha with the characterization of unknown components from reverse-engineered models from the literature. MoCha is useful for working on network models by hand or as a downstream step of a model inference engine workflow and represents a valuable and efficient tool for the characterization of unknown pathways using known data from thousands of organisms. MoCha and its source code are freely available online under the GPLv3 license.

Two-dimensional MoS2 electromechanical actuators

Science.gov (United States)

Hung, Nguyen T.; Nugraha, Ahmad R. T.; Saito, Riichiro

2018-02-01

We investigate the electromechanical properties of two-dimensional MoS2 monolayers with 1H, 1T, and 1T‧ structures as a function of charge doping by using density functional theory. We find isotropic elastic moduli in the 1H and 1T structures, while the 1T‧ structure exhibits an anisotropic elastic modulus. Moreover, the 1T structure is shown to have a negative Poisson’s ratio, while Poisson’s ratios of the 1H and 1T‧ are positive. By charge doping, the monolayer MoS2 shows a reversible strain and work density per cycle ranging from  -0.68% to 2.67% and from 4.4 to 36.9 MJ m-3, respectively, making them suitable for applications in electromechanical actuators. We also examine the stress generated in the MoS2 monolayers and we find that 1T and 1T‧ MoS2 monolayers have relatively better performance than 1H MoS2 monolayer. We argue that such excellent electromechanical performance originate from the electrical conductivity of the metallic 1T and semimetallic 1T‧ structures and also from their high Young’s modulus of about 150-200 GPa.

Thermal spreading of MoO{sub 3} in H-ZY

Energy Technology Data Exchange (ETDEWEB)

Mosqueira, L., E-mail: mmosquei@imp.mx [Instituto Mexicano del Petroleo, Eje Central Norte, Lazaro Cardenas 152, San Bartolo Atepehuacan, 07730 Mexico, D.F. (Mexico); Angeles-Chavez, C. [Instituto Mexicano del Petroleo, Eje Central Norte, Lazaro Cardenas 152, San Bartolo Atepehuacan, 07730 Mexico, D.F. (Mexico); Torres-Garcia, E., E-mail: etorresg@imp.mx [Instituto Mexicano del Petroleo, Eje Central Norte, Lazaro Cardenas 152, San Bartolo Atepehuacan, 07730 Mexico, D.F. (Mexico)

2011-04-15

Research highlights: {yields} Molybdenum oxo-species were formed during thermally driven migration on H-ZY. {yields} Oxo-species were identified according to the edge energy (E{sub g}) values of bulk molybdenum oxide reference compounds. {yields} The migration occurred via MoO{sub 2}(OH){sub 2} species leading first to (MoO{sub 4}){sup 2-} and (Mo{sub 2}O{sub 7}){sup 2-} formation, and finally of (Mo{sub 7}O{sub 24}){sup 6-}. - Abstract: This work provides a structural, optical and kinetics approach to the molybdenum oxo-species formed during thermally driven migration on H-ZY starting from mechanical mixtures with MoO{sub 3}. The samples were characterized as a function of time of treatment by UV-vis diffuse reflectance, X-ray diffraction, N{sub 2} adsorption and scanning transmission electron microscopy (STEM). Local analysis of elemental compositions obtained from linear scan of characteristic X-ray signal show a direct evidence of molybdenum presence into the zeolite crystals. Ultraviolet absorption spectra were used to determine both the kinetics of the spreading and the speciation of MoO{sub x} in the H-ZY. Besides MoO{sub 3}, three surface molybdenum oxo-species were identified according to the edge energy (E{sub g}) values of bulk molybdenum oxide reference compounds. This study shows that the tetrahedral species prevailed on H-ZY. This is consistent with limitations in the migration and growth of MoO{sub x} in the channel structure of the zeolite. Kinetic study suggest that migration of MoO{sub x} in the H-ZY at low temperature (ca. 723 K) occurs across the formation and diffusion of hydrated species such as MoO{sub 2}(OH){sub 2}, which interact with the zeolite and form monomeric and dimeric structures (like (MoO{sub 4}){sup 2-} and (Mo{sub 2}O{sub 7}){sup 2-}). Migration of MoO{sub x} species in the H-ZY studied is significant even at 723 K and after very short periods of treatment (<5 min).

Probing topological electronic effects in catalysis: thiophene adsorption on NiMoS and CoMoS clusters

Energy Technology Data Exchange (ETDEWEB)

Borges Junior, Itamar; Silva, Alexander M., E-mail: itamar@ime.eb.br [Instituto Militar de Engenharia (IME), Rio de Janeiro-RJ (Brazil). Programa de Pos-Graduacao em Engenharia de Defesa

2012-10-15

A general two-step theoretical approach to study electronic redistributions in catalytic processes is presented. In the first step, density functional theory (DFT) is used to fully optimize two geometries: the cluster representing the catalyst and the cluster plus adsorbed molecule system. In the second step, the converged electron density is divided into multipoles centered on atomic sites according to a distributed multipole analysis which provides detailed topological information on the charge redistribution of catalyst and molecule before and after adsorption. This approach is applied to thiophene adsorption on the 10{sup -}10 metal edge of Ni(Co)MoS catalysts and compared to the same reaction on bare MoS{sub 2}. Calculated adsorption energies, geometries and multipole analysis indicate weak thiophene chemisorption on both cases. A Coulombic bond model showed that surface metal-sulfur bond strengths in Ni(Co)MoS promoted catalysts are considerably smaller than in bare MoS{sub 2}, thus confirming the origin of the enhancement of hydrodesulfurization (HDS) activity in these catalysts. (author)

Comparative study of 99Mo/99mTc generators at base of synthesized gels starting from 99Mo of activation and of fission

International Nuclear Information System (INIS)

Lopez M, I.Z.; Monroy G, F.; Rivero G, T.; Rojas N, P.

2007-01-01

At the present time the more used and diffused radionuclide in nuclear medicine it is the Technetium 99 metastable ( 99 mTc) it is used for diagnostic and therapy. It is produced starting from molybdenum 99 ( 99 Mo), which is absorbed in chromatographic columns, loaded with alumina that absorb only 0.2% of 99 Mo situation that forces to use high specific activities of 99 Mo that it is obtained starting from the fission of the 235 U. Given these conditions and limitations, new preparation procedures of 99 Mo/ 99m Tc generators, of low or medium specific activity, its have been developed, using gels of zirconium molybdates that incorporates until 30% in weight of 99 Mo in the gel, and also conserve similar characteristics of quality and purity that those obtained by the traditional generator; reducing by this way the cost of production of the 99m Tc, when using 99 Mo of low specific activity, in the preparation of 99 Mo/ 99m Tc generators. The radiochemical characteristics of the elution of 99m Tc, depends strongly on the gel preparation conditions. In particular, the present work has for object to determine the influence of the used type of 99 Mo, fission or activation product, during the gels synthesis, as well as the used air flow for the agitation in the gels preparation and its influence in the quality of the 99 Mo/ 99m Tc generators. When diminishing the agitation air flow the efficiency it increases and in the radionuclide purity of the eluates and when using 99 Mo of fission for the gels production it increases in an important way the elution efficiency, the radiochemical purity and radionuclide of the eluates of 99m Tc. (Author)

Non-stoichiometry of MoS2 phase prepared by sputtering

International Nuclear Information System (INIS)

Ito, T.; Nakajima, K.

1978-01-01

The lattice parameters and S/Mo atomic ratio in sputtered MoS 2 films have been examined as a function of sputtering conditions, especially the vacuum pressure in the chamber. It was found that the deposited films had a defect MoS 2 structure ranging from 1.6 to 2 in S/Mo ratio, depending on the pressure. (author)

Synthesis of Monolayer MoS2 by Chemical Vapor Deposition

Science.gov (United States)

Withanage, Sajeevi; Lopez, Mike; Dumas, Kenneth; Jung, Yeonwoong; Khondaker, Saiful

Finite and layer-tunable band gap of transition metal dichalcogenides (TMDs) including molybdenum disulfide (MoS2) are highlighted over the zero band gap graphene in various semiconductor applications. Weak interlayer Van der Waal bonding of bulk MoS2 allows to cleave few to single layer MoS2 using top-down methods such as mechanical and chemical exfoliation, however few micron size of these flakes limit MoS2 applications to fundamental research. Bottom-up approaches including the sulfurization of molybdenum (Mo) thin films and co-evaporation of Mo and sulfur precursors received the attention due to their potential to synthesize large area. We synthesized monolayer MoS2 on Si/SiO2 substrates by atmospheric pressure Chemical Vapor Deposition (CVD) methods using sulfur and molybdenum trioxide (MoO3) as precursors. Several growth conditions were tested including precursor amounts, growth temperature, growth time and flow rate. Raman, photoluminescence (PL) and atomic force microscopy (AFM) confirmed monolayer islands merging to create large area were observed with grain sizes up to 70 μm without using any seeds or seeding promoters. These studies provide in-depth knowledge to synthesize high quality large area MoS2 for prospective electronics applications.

Performance of Tc-99m generator prepared with Mo adsorbent PZC and irradiated nature MoO3

International Nuclear Information System (INIS)

Liu Yishu

2006-01-01

This paper describes the technical process of Tc-99m generator prepared with reactor actived Mo-99 and PZC and the performance of the generator was also reported. Two generators were prepared with different batch of PZC and by different technical process. The results show that the adsorption rate was ∼65% and the adsorption efficiency of 99 Mo can be seriously affected by the adsorption process (the temperature, intensity and frequency of shaking and the PZC volume in solution etc.). The elution efficiency was 43-73%. The Mo breakthrough 1.2 - 16% without safe column and its can be decreased to be very low by connecting a hydrate zirconia (HZO) safe column. (author)

Synthesis of Epitaxial Single-Layer MoS2 on Au(111).

Science.gov (United States)

Grønborg, Signe S; Ulstrup, Søren; Bianchi, Marco; Dendzik, Maciej; Sanders, Charlotte E; Lauritsen, Jeppe V; Hofmann, Philip; Miwa, Jill A

2015-09-08

We present a method for synthesizing large area epitaxial single-layer MoS2 on the Au(111) surface in ultrahigh vacuum. Using scanning tunneling microscopy and low energy electron diffraction, the evolution of the growth is followed from nanoscale single-layer MoS2 islands to a continuous MoS2 layer. An exceptionally good control over the MoS2 coverage is maintained using an approach based on cycles of Mo evaporation and sulfurization to first nucleate the MoS2 nanoislands and then gradually increase their size. During this growth process the native herringbone reconstruction of Au(111) is lifted as shown by low energy electron diffraction measurements. Within the MoS2 islands, we identify domains rotated by 60° that lead to atomically sharp line defects at domain boundaries. As the MoS2 coverage approaches the limit of a complete single layer, the formation of bilayer MoS2 islands is initiated. Angle-resolved photoemission spectroscopy measurements of both single and bilayer MoS2 samples show a dramatic change in their band structure around the center of the Brillouin zone. Brief exposure to air after removing the MoS2 layer from vacuum is not found to affect its quality.

Alimentação de Codornas com Milho Moído e Ração de Postura no Período Pós-jejum Durante a Muda Forçada e Seus Efeitos Sobre o Desempenho

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Garcia EA

2002-01-01

Full Text Available O experimento foi realizado com o objetivo de avaliar o desempenho de codornas poedeiras alimentadas por diferentes períodos com milho moído ou ração de postura durante sete dias após três dias de jejum, método de muda utilizado. Após esse período, as aves foram alimentadas com ração de postura durante as 20 semanas do período experimental. Utilizou-se um delineamento inteiramente ao acaso com três tratamentos (ração de postura por sete dias, ração de postura por três dias e milho moído por quatro dias e milho moído por sete dias, e quatro repetições de 24 aves por parcela. Os resultados mostraram que aves alimentadas apenas com ração de postura nos sete primeiros dias após o jejum apresentaram maior produção de ovos nas seis primeiras semanas do período de produção pós-muda. Porém, não foi constatado efeito de tratamento sobre a produção de ovos, peso dos ovos, consumo de ração e conversão alimentar durante as 20 semanas do período experimental.

First-principles study of the surface properties of U-Mo system

Energy Technology Data Exchange (ETDEWEB)

Mei, Zhi-Gang; Liang, Linyun; Yacout, Abdellatif M.

2018-02-01

U-Mo alloys are promising fuels for future high-performance research reactors with low enriched uranium. Surface properties, such as surface energy, are important inputs for mesoscale simulations (e.g., phase field method) of fission gas bubble behaviors in irradiated nuclear fuels. The lack of surface energies of U-Mo alloys prevents an accurate modeling of the morphology of gas bubbles and gas bubble-induced fuel swelling. To this end, we study the surface properties of U-Mo system, including bcc Mo, alpha-U, gamma-U, and gamma U-Mo alloys. All surfaces up to a maximum Miller index of three and two are calculated for cubic Mo and gamma-U and non-cubic alpha-U, respectively. The equilibrium crystal shapes of bcc Mo, alpha-U and gamma-U are constructed using the calculated surface energies. The dominant surface orientations and the area fraction of each facet are determined from the constructed equilibrium crystal shape. The disordered gamma U-Mo alloys are simulated using the Special Quasirandom Structure method. The (1 1 0) and (1 0 0) surface energies of gamma U-7Mo and U-10Mo alloys are predicted to lie between those of gamma-U and bcc Mo, following a linear combination of the two constituents' surface energies. To better compare with future measurements of surface energies, the area fraction weighted surface energies of alpha-U, gamma-U and gamma U-7Mo and U-10Mo alloys are also predicted. (C) 2017 Published by Elsevier B.V.

Artigo revisão: atuação dos antioxidantes em refratários contendo carbono Review article: performance of the antioxidants in carbon containing refractories

Directory of Open Access Journals (Sweden)

A. P. Luz

2007-12-01

Full Text Available Os materiais refratários contendo carbono têm despertado grande atenção nos últimos anos, uma vez que são amplamente utilizados na indústria siderúrgica em virtude de suas excelentes propriedades. A presença do carbono nos refratários contribui para o aumento da resistência ao choque térmico, da energia de fratura e da resistência ao ataque por escória. Entretanto, a principal desvantagem do seu uso é a sua alta susceptibilidade a oxidação. Com o objetivo de manter o carbono presente na estrutura do material refratário o maior tempo possível, algumas medidas são requeridas para reduzir sua oxidação sob condições operacionais. Desta forma, o uso de substâncias conhecidas como antioxidantes tem sido extensivamente estudado. Os principais antioxidantes, suas características e formas de atuação são abordados nesta revisão. A formação de novos compostos devido à reação entre os antioxidantes com o carbono, nitrogênio, oxigênio e o próprio material refratário pode provocar um preenchimento parcial dos poros e redução da taxa de interdifusão dos gases, havendo assim a prevenção da oxidação do carbono presente no refratário.Carbon containing refractories have received great attention over the last years, as they are widely used in the steel making industry due to their better properties, such as: higher thermal shock resistance, fracture energy and slag resistance. However, their main disadvantage is the carbon oxidation. Aiming to keep carbon in the structure of the refractory material some actions are required in order to reduce its oxidation under operational conditions. Therefore, the use of materials known as antioxidants has been extensively studied. The main antioxidants, their characteristics and performance are discussed in the present review article. The formation of new compounds due to the reaction of the antioxidants with carbon, nitrogen, oxygen and the refractory material can induce a pore

Microstructures and Electrochemical Behavior of Ti-Mo Alloys for Biomaterials

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Back-Sub Sung

2015-01-01

Full Text Available The Ti alloy with 7 wt% Mo revealed a microstructure that contained only the orthorhombic α′′ phase of a fine acicular martensitic structure. The corrosion resistance of the Ti-Mo alloys increased as the Mo content increased. Based on the results obtained from the polarization curve and electrochemical impedance, the Ti-Mo alloys were shown to be corrosion resistant because of the passive films formed on their surfaces. No ion release was detected in SBF (simulated body fluid solution, while Ti ions were released in 0.1% lactic acid ranging from 0.05 to 0.12 μg/mL for the Ti-Mo alloys. In vitro tests showed that MC3T3-E1 cell proliferation on Ti-7 wt% Mo alloy was rather active compared to other Ti-Mo alloys and commercial-grade pure Ti.

Monolayer MoSe 2 Grown by Chemical Vapor Deposition for Fast Photodetection

KAUST Repository

Chang, Yung-Huang

2014-08-26

Monolayer molybdenum disulfide (MoS2) has become a promising building block in optoelectronics for its high photosensitivity. However, sulfur vacancies and other defects significantly affect the electrical and optoelectronic properties of monolayer MoS2 devices. Here, highly crystalline molybdenum diselenide (MoSe2) monolayers have been successfully synthesized by the chemical vapor deposition (CVD) method. Low-temperature photoluminescence comparison for MoS2 and MoSe 2 monolayers reveals that the MoSe2 monolayer shows a much weaker bound exciton peak; hence, the phototransistor based on MoSe2 presents a much faster response time (<25 ms) than the corresponding 30 s for the CVD MoS2 monolayer at room temperature in ambient conditions. The images obtained from transmission electron microscopy indicate that the MoSe exhibits fewer defects than MoS2. This work provides the fundamental understanding for the differences in optoelectronic behaviors between MoSe2 and MoS2 and is useful for guiding future designs in 2D material-based optoelectronic devices. © 2014 American Chemical Society.

Interdiffusion studies on hot rolled U-10Mo/AA1050

Energy Technology Data Exchange (ETDEWEB)

Saliba-Silva, A.M.; Martins, I.C.; Carvalho, E.U.; Durazzo, M.; Riella, H.G. [Instituto de Pesquisas Energeticas e Nucleares (CCN/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Centro de Combustivel Nuclear], e-mail: saliba@ipen.br

2010-07-01

The U-Mo alloys are investigated with the goal of becoming nuclear material to fabricate high-density fuel elements for high performance research reactors. This enrichment level suggests that the U-Mo alloys should be between 6 to 10wt%, which can give up to 9gU/cm{sup 3} as fuel density. Nevertheless, the U-Mo alloys are very reactive with Al. Interdiffusion reaction products are formed since nuclear fission promotes chemical interaction layer during operation, leading to potential structural failure. Present studies were made with treated hot rolled diffusion couples of U-10Mo inserted in Al (AA1050). The U-10Mo/AA1050 pairs were treated in two temperature (150 degree C and 550 degree C) with three soaking times (5h, 40h and 80h). From microstructure analyses, rapid diffusion of Al happened inside U-10Mo in the first heating at 540 degree C during 15 min, reaching 8 at%Al in a range of 200 {mu}m towards U-10Mo. Longer time (5, 40, 80h) at 550 degree C maintain this level of Al-content up to 1000 {mu}m inside U-10Mo. A minor depth ({approx}1 {mu}m) near the interdiffusion contact had higher Al-content, but not sufficient to form identifiable (U,Mo)Al{sub x} structures. Probably, residual elements reduced drastically the interdiffusion phenomena between U-10Mo and AA1050, maybe due to silicon presence. (author)

Characterization of Thin Walled Mo Tubing produced by FBCVD

Energy Technology Data Exchange (ETDEWEB)

Beaux, Miles Frank [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Usov, Igor Olegovich [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-01-21

The goal of this report is to delineate the results of material characterization performed on Mo tubing produced via the fluidized bed chemical vapor deposition (FBCVD) method. Scanning electron microscopy (SEM) imaging reveals that small randomly oriented grains are achieved in the Mo deposition, but do not persist throughout the entire thickness of the material. Energy dispersive spectroscopy (EDS) reveals the Mo tubes contain residual chlorine and oxygen. EDS measurements on the tube surfaces separated from glass and quartz substrates reveal substrate material adhered to this surface. X-ray diffraction (XRD) revealed the presence of carbon contaminant in the form of Mo₂C and oxygen in the form of MoO₂. Combustion infrared detection (CID) and inert gas fusion (IGF) performed at Luvak Inc. was used to quantify weight percentages of oxygen and carbon in the tubes produced. Hardness value of the FBCVD Mo was found to be comparable to low carbon arc cast molybdenum.

High temperature interdiffusion and phase equilibria in U-Mo

International Nuclear Information System (INIS)

Lundberg, L.B.

1988-01-01

Experimental data for interdiffusion and phase equilibria in the U-Mo system have been obtained over the temperature range 1400 to 1525 K as a fallout from compatibility experiments in which UO 2 was decomposed by lithium in closed molybdenum capsules. Composition-position, x-ray diffraction and microstructural data from the interdiffusion zones indicate that the intermediate phase U 2 Mo is found in this temperature range, contrary to the currently accepted equilibrium U-Mo phase diagram. The U-Mo interdiffusion data are in good agreement with published values. Inclusion of the U 2 Mo phase in a theoretical correlation of interdiffusion and phase equilibria data using Darken's equation indicate that high temperature interdiffusion of uranium and molybdenum follows the usual thermodynamic rules. Significant changes in the value of the thermodynamic based Darken factor near the U 2 Mo phase boundary on the high uranium side are indicated from both the new and published interdiffusion data. 9 refs., 10 figs., 3 tabs

Nuclear structure of 94,95Mo at high spins

International Nuclear Information System (INIS)

Kharraja, B.; Ghugre, S.S.; Garg, U.; Janssens, R.V.; Carpenter, M.P.; Crowell, B.; Khoo, T.L.; Lauritsen, T.; Nisius, D.; Reviol, W.; Mueller, W.F.; Riedinger, L.L.; Kaczarowski, R.

1998-01-01

The high-spin level structures of 94,95 Mo (N=52,53) have been investigated via the 65 Cu( 36 S, αp2n) 94 Mo and 65 Cu( 36 S, αpn) 95 Mo reactions at 142 MeV. The level schemes have been extended up to spin J∼19ℎ and excitation energies E x ∼12 MeV. Spherical shell-model calculations have been performed and compared with the experimental energy levels. The level structure of 94 Mo exhibits a single-particle nature and the higher-angular-momentum states are dominated by the excitation of a g 9/2 neutron across the N=50 shell gap. The level sequences observed in 95 Mo have been interpreted on the basis of the spherical shell model and weak coupling of a d 5/2 or a g 7/2 neutron to the 94 Mo core. copyright 1998 The American Physical Society

Dietas contendo silagem de milho (Zea maiz L. e feno de capim-tifton 85 (Cynodon spp. em diferentes proporções para bovinos Corn silage and tifton 85 bermudagrass hay-based diets for steers

Directory of Open Access Journals (Sweden)

Ana Clara Rodrigues Cavalcante

2004-12-01

Full Text Available Avaliaram-se o consumo, a digestibilidade, o pH e concentração de amônia ruminais e a taxa de passagem em bovinos alimentados com dietas contendo feno de capim-tifton 85 (TIF e silagem de milho (SM em diferentes proporções. Utilizaram-se quatro animais castrados, com peso médio de 523kg, fistulados no rúmen, distribuídos em um quadrado latino 4 x 4, recebendo 60% de volumoso e 40% de concentrado, na base da matéria seca. O volumoso consistiu das seguintes proporções (%: 100 TIF:0 SM; 67 TIF:33 SM; 33 TIF:67 SM e 0 TIF:100 SM. Os consumos de matéria seca (MS, de matéria orgânica (MO e de matéria orgânica digestível (MOD, de proteína bruta (PB, de fibra em detergente neutro (FDN e de carboidratos totais (CHOT e digeríveis (CHOD não foram influenciados pelas diferentes proporções de feno de capim-tifton 85: silagem de milho nas dietas, registrando-se valores médios de 9,2; 8,7; 6,4; 1,1; 3,7; 7,3 e 5,4 kg/dia, respectivamente. O consumo de extrato etéreo (EE elevou linearmente com o aumento da silagem de milho nas dietas. As digestibilidades aparentes da MS, MO, PB, EE e CHO também não foram influenciadas pelas diferentes proporções de silagem de milho, obtendo-se, respectivamente, valores médios de 71,8; 73,0; 69,5; 69,2 e 73,9%. Para a digestibilidade da FDN, observou-se efeito quadrático, estimando-se valor máximo de 65,2% para dietas contendo 30,98% de silagem de milho. Estimou-se concentração máxima de amônia de 12,0 mg/100 ml e valor mínimo de pH de 5,98 às 2,44 e 6,82 horas após a alimentação, respectivamente. A taxa de passagem não foi influenciada pelas diferentes proporções de feno:silagem, no volumoso, apresentando valor médio de 4,2%/hora.The intake, digestibility, ruminal pH and ammonia concentrations and passage rate were evaluated in steers fed corn silage (CS and Tifton 85 bermudagrass hay (T85H-based diets, at different forage proportions. Four rumen fistulated steers with 523 kg of live

Phase transformation in a Ni-Mo-Cr alloy

International Nuclear Information System (INIS)

Dymek, S.; Wrobel, M.; Blicharski, M.; Dollar, M.

2001-01-01

The paper gives a characteristic of a nickel-based superalloy containing 25 wt.% Mo and 8 wt.% Cr with particular attention to the influence of a thermochemical and heat treatment on phase transformations. The applied heat treatments are comprised of soaking temperature 1100 o C followed by aging at 650 o C at three conditions: conventional aging for 72 hours, prolonged aging for 4000 hours and prolonged aging for 4000 hours followed by cold working and subsequent aging for 1000 hours. The conventional aging led to the formation of lenticular precipitates of the dispersed metastable Ni 2 (Mo,Cr) phase. The aging for 4000 hours brought about coarsening of the ordered domains without changing their crystallographic and ordering characteristics. The plastic deformation preceded the further aging for 1000 hours accelerated the decomposition of the Ni 2 (Mo,Cr) phase on the mixture of the Ni 3 Mo and Ni 4 Mo-based phases. (author)

MoO3 incorporation in magnesium aluminosilicate glasses

International Nuclear Information System (INIS)

Tan, Shengheng; Ojovan, Michael I.; Hyatt, Neil C.; Hand, Russell J.

2015-01-01

Molybdate has a very low solubility in silicate and borosilicate glass systems and its excess presence in nuclear waste glass can cause the formation of a readily soluble “yellow phase”. In this study, the incorporation of molybdenum oxide (MoO 3 ) in a magnesium aluminosilicate glass system has been investigated. The prepared glasses show a higher than 90% molybdenum retention rate and up to 5.34 mol% (12.28 wt%) MoO 3 can be incorporated into these glasses without causing visible phase separation. The incorporation of MoO 3 increases glass density, decreases glass transition and crystallisation temperatures and intensifies Raman bands assigned to vibrations of MoO 4 2− units. When excess molybdate is added liquid–liquid phase separation and crystallisation occurs. The separated phase is spherical, 200–400 nm in diameter and randomly dispersed. Based on powder X-ray diffraction, Raman spectroscopy and transmission electron microscopy, the separated phase is identified as MgMoO 4

Phase formation, structural and microstructural characterization of novel oxynitride-perovskites synthesized by thermal ammonolysis of (Ca,Ba)MoO4 and (Ca,Ba)MoO3

International Nuclear Information System (INIS)

Logvinovich, D.; Aguirre, M.H.; Hejtmanek, J.; Aguiar, R.; Ebbinghaus, S.G.; Reller, A.; Weidenkaff, A.

2008-01-01

Reactions of AMoO 4 and AMoO 3 (A=Ca 2+ , Ba 2+ ) with ammonia were investigated at 873 K 3 and to study their crystal structure. CaMo(O,N) 3 and BaMo(O,N) 3 were prepared by thermal ammonolysis of the corresponding CaMoO 3 and BaMoO 3 precursors at T=898 and 998 K, respectively. The structural parameters of the oxynitrides were obtained from Rietveld refinements of X-ray and neutron powder diffraction data. CaMo(O,N) 3 crystallizes in the GdFeO 3 distorted perovskite structure with orthorhombic space group Pbnm and a=5.5029(1) A, b=5.5546(1) A, c=7.8248(1) A as determined by X-ray powder diffraction. Its O/N content refined from the neutron diffraction data corresponds to the composition CaMoO 1.7(1) N 1.3(1) . BaMo(O,N) 3 crystallizes in the cubic perovskite structure with space group Pm3-bar m and a=4.0657(1) A as determined by X-ray powder diffraction. Transmission electron microscopy reveals a complex microstructure for both CaMoO 3 and CaMoO 1.7(1) N 1.3(1) represented by twin domains of different orientation. - Graphical abstract: Reactions of AMoO 4 and AMoO 3 (A=Ca 2+ , Ba 2+ ) oxides with ammonia have been studied at T=873-1123 K. Orthorhombic CaMoO 1.7(1) N 1.3(1) (Pbnm) and cubic BaMo(O,N) 3 (Pm3-bar m) were prepared by thermal ammonolysis of the corresponding CaMoO 3 and BaMoO 3 precursors at T=898 and 998 K, respectively. Display Omitted

Edge Epitaxy of Two-dimensional MoSe2 and MoS2 Nanosheets on One-dimensional Nanowires

KAUST Repository

Chen, Junze

2017-06-05

Rational design and synthesis of heterostructures based on transition metal dichalcogenides (TMDs) have attracted increasing interests because of their promising applications in electronics, catalysis, etc. However, the construction of epitaxial heterostructures with interface at the edges of TMD nanosheets (NSs) still remains great challenge. Here, we report a strategy for controlled synthesis of a new type of heterostructures in which TMD NSs, including MoS2 and MoSe2, vertically grow along the longitudinal direction of one-dimensional (1D) Cu2-xS nanowires (NWs) in an epitaxial manner. The obtained Cu2-xS-TMD heterostructures with tunable loading amount and lateral size of TMD NSs are achieved by the consecutive growth of TMD NSs on Cu2-xS NWs through the gradually injection of chalcogen precursors. After cation exchange of Cu in Cu2-xS-TMD heterostructures with Cd, the obtained CdS-MoS2 heterostructures remained their original architectures. Compared to the pure CdS NWs, the CdS-MoS2 heterostructures with 7.7 wt% loading of MoS2 NSs exhibit the best performance in the photocatalytic hydrogen evolution reaction with the H2 production rate up to 4,647 μmol·h-1·g-1, about 58 times that catalyzed with pure CdS NWs. Our synthetic strategy opens up a new way for the controlled synthesis of TMD-based heterostructures which could have various promising applications.

First-principle study of hydrogenation on monolayer MoS2

International Nuclear Information System (INIS)

Xu, Yong; Li, Yin; Chen, Xi; Zhang, Ru; Zhang, Chunfang; Lu, Pengfei

2016-01-01

The structural and electronic properties of hydrogenation on 1H-MoS 2 and 1T-MoS 2 have been systematically explored by using density functional theory (DFT) calculations. Our calculated results indicate an energetically favorable chemical interaction between H and MoS 2 monolayer for H adsorption when increasing concentration of H atoms. For 1H-MoS 2 , single H atom adsorption creates midgap approaching the Fermi level which increases the n-type carrier concentration effectively. As a consequence, its electrical conductivity is expected to increase significantly. For 1T-MoS 2 , H atoms adsorption can lead to the opening of a direct gap of 0.13 eV compared to the metallic pristine 1T-MoS 2 .

Atomic scale onset of Al adhesion on Mo2BC

International Nuclear Information System (INIS)

Bolvardi, Hamid; Music, Denis; Schneider, Jochen M.

2015-01-01

We have explored interfacial interactions between a Mo–C terminated Mo 2 BC(040) surface and an Al cluster using ab initio molecular dynamics. The Al cluster is disrupted and wets the Mo 2 BC(040) surface. This can be understood based on the electronic structure. Across the Al–MoC interface C s–Al s hybridized states are formed. These bonds are stronger than the Al–Al intra-cluster bonds. Hence, the onset of Al adhesion is caused by bond formation across the Al–MoC interface. - Highlights: • Interfacial interactions between Mo 2 BC and an Al cluster were explored. • Al forms bonds to C constituting the onset of Al adhesion on Mo 2 BC. • These data are relevant for other carbide coatings

Anisotropy of heat conduction in Mo/Si multilayers

International Nuclear Information System (INIS)

Medvedev, V. V.; Yakshin, A. E.; Kruijs, R. W. E. van de; Bijkerk, F.; Yang, J.; Schmidt, A. J.; Zoethout, E.

2015-01-01

This paper reports on the studies of anisotropic heat conduction phenomena in Mo/Si multilayers with individual layer thicknesses selected to be smaller than the mean free path of heat carriers. We applied the frequency-domain thermoreflectance technique to characterize the thermal conductivity tensor. While the mechanisms of the cross-plane heat conduction were studied in detail previously, here we focus on the in-plane heat conduction. To analyze the relative contribution of electron transport to the in-plane heat conduction, we applied sheet-resistance measurements. Results of Mo/Si multilayers with variable thickness of the Mo layers indicate that the net in-plane thermal conductivity depends on the microstructure of the Mo layers

Highly Enhanced Gas Adsorption Properties in Vertically Aligned MoS2 Layers.

Science.gov (United States)

Cho, Soo-Yeon; Kim, Seon Joon; Lee, Youhan; Kim, Jong-Seon; Jung, Woo-Bin; Yoo, Hae-Wook; Kim, Jihan; Jung, Hee-Tae

2015-09-22

In this work, we demonstrate that gas adsorption is significantly higher in edge sites of vertically aligned MoS2 compared to that of the conventional basal plane exposed MoS2 films. To compare the effect of the alignment of MoS2 on the gas adsorption properties, we synthesized three distinct MoS2 films with different alignment directions ((1) horizontally aligned MoS2 (basal plane exposed), (2) mixture of horizontally aligned MoS2 and vertically aligned layers (basal and edge exposed), and (3) vertically aligned MoS2 (edge exposed)) by using rapid sulfurization method of CVD process. Vertically aligned MoS2 film shows about 5-fold enhanced sensitivity to NO2 gas molecules compared to horizontally aligned MoS2 film. Vertically aligned MoS2 has superior resistance variation compared to horizontally aligned MoS2 even with same surface area exposed to identical concentration of gas molecules. We found that electrical response to target gas molecules correlates directly with the density of the exposed edge sites of MoS2 due to high adsorption of gas molecules onto edge sites of vertically aligned MoS2. Density functional theory (DFT) calculations corroborate the experimental results as stronger NO2 binding energies are computed for multiple configurations near the edge sites of MoS2, which verifies that electrical response to target gas molecules (NO2) correlates directly with the density of the exposed edge sites of MoS2 due to high adsorption of gas molecules onto edge sites of vertically aligned MoS2. We believe that this observation extends to other 2D TMD materials as well as MoS2 and can be applied to significantly enhance the gas sensor performance in these materials.

Magnetism by interfacial hybridization and p-type doping of MoS2 in Fe4N/MoS2 superlattices: A first-principles study

KAUST Repository

Feng, Nan

2014-03-26

Magnetic and electronic properties of Fe4N(111)/MoS 2(√3 × √3) superlattices are investigated by first-principles calculations, considering two models: (I) FeIFe II-S and (II) N-S interfaces, each with six stacking configurations. In model I, strong interfacial hybridization between FeI/Fe II and S results in magnetism of monolayer MoS2, with a magnetic moment of 0.33 μB for Mo located on top of Fe I. For model II, no magnetism is induced due to weak N-S interfacial bonding, and the semiconducting nature of monolayer MoS2 is preserved. Charge transfer between MoS2 and N results in p-type MoS2 with Schottky barrier heights of 0.5-0.6 eV. Our results demonstrate that the interfacial geometry and hybridization can be used to tune the magnetism and doping in Fe4N(111)/MoS2(√3 × √3) superlattices. © 2014 American Chemical Society.

Magnetism by interfacial hybridization and p-type doping of MoS2 in Fe4N/MoS2 superlattices: A first-principles study

KAUST Repository

Feng, Nan; Mi, Wenbo; Cheng, Yingchun; Guo, Zaibing; Schwingenschlö gl, Udo; Bai, Haili

2014-01-01

Magnetic and electronic properties of Fe4N(111)/MoS 2(√3 × √3) superlattices are investigated by first-principles calculations, considering two models: (I) FeIFe II-S and (II) N-S interfaces, each with six stacking configurations. In model I, strong interfacial hybridization between FeI/Fe II and S results in magnetism of monolayer MoS2, with a magnetic moment of 0.33 μB for Mo located on top of Fe I. For model II, no magnetism is induced due to weak N-S interfacial bonding, and the semiconducting nature of monolayer MoS2 is preserved. Charge transfer between MoS2 and N results in p-type MoS2 with Schottky barrier heights of 0.5-0.6 eV. Our results demonstrate that the interfacial geometry and hybridization can be used to tune the magnetism and doping in Fe4N(111)/MoS2(√3 × √3) superlattices. © 2014 American Chemical Society.

LEUbased Fission Mo-99 Process with Reduced Solid Wastes

International Nuclear Information System (INIS)

Lee, Seungkon; Lee, Suseung; Jung, Sunghee; Hong, Soonbog; Jang, Kyungduk; Choi, Sang Mu; Lee, Jun Sig; Lim, Incheol

2014-01-01

99m Tc emits 140 keV of very low gamma-ray radiation energy, as low as conventional diagnostic X-ray, and has short half-life of 6.0058 hours. Therefore, as radioactive tracer, 99m Tc provides high quality diagnostic images but keeps total patient radiation exposure low. Depending on the tagging pharmaceuticals and procedures, 99m Tc can be applied for the diagnostics of various target organs and diseases: brain, myocardium, thyroid, lungs, liver, gallbladder, kidneys, skeleton, blood and tumors. More than 95% of 99 Mo is produced through fission of 235 U worldwide because, 99m o generated from the fission (fission 99 Mo) exhibits very high specific activity (<100 Ci/g). Over 90% of fission 99 Mo producers have been used highly enriched uranium (HEU) targets so far. However, the IAEA recommends the use of low enriched uranium (LEU) to the 99 Mo producers for nonproliferation reason. These days, worldwide 99 Mo supply is not only insufficient but also unstable. Because, most of the main 99 Mo production reactors are about 50 years old and suffered from frequent and unscheduled shutdown. Planned weekly productivity of 2000 Ci fission 99 Mo, in a 6-day reference, will cover 100% domestic demand of Korea, as well as 20% of international market. It is expected to replace 4.3 million USD ($800/Ci) of 99 Mo import for domestic market while exporting 82.8 million USD for world market, annually

Epitaxial growth of AlN on single crystal Mo substrates

International Nuclear Information System (INIS)

Okamoto, Koichiro; Inoue, Shigeru; Nakano, Takayuki; Kim, Tae-Won; Oshima, Masaharu; Fujioka, Hiroshi

2008-01-01

We have grown AlN films on single-crystalline Mo(110), (100), and (111) substrates using a low temperature pulsed laser deposition (PLD) growth technique and investigated their structural properties. Although c-axis oriented AlN films grow on Mo(100), the films contain 30 o rotated domains due to the difference in the rotational symmetry between AlN(0001) and Mo(100). AlN films with only poor crystalline quality grow on Mo(111) substrates, probably due to the poor surface morphology and high reactivity of the substrates. On the other hand, single crystal AlN films grow epitaxially on Mo(110) substrates with an in-plane relationship of AlN[11-20] // Mo[001]. Reflection high-energy electron diffraction or electron backscattered diffraction analysis has revealed that neither in-plane 30 deg. rotated domains nor cubic phase domains exist in the AlN films. X-ray reflectivity measurements have revealed that the heterointerface between AlN and Mo prepared by PLD at 450 deg. C is quite abrupt. These results indicate that PLD epitaxial growth of AlN on single crystal Mo substrates is quite promising for the fabrication of future high frequency filter devices

Epitaxial growth of AlN on single crystal Mo substrates

Energy Technology Data Exchange (ETDEWEB)

Okamoto, Koichiro; Inoue, Shigeru [Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505 (Japan); Nakano, Takayuki; Kim, Tae-Won [Kanagawa Academy of Science and Technology (KAST) KSP east 301, 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa, 213-0012 (Japan); Oshima, Masaharu [Department of Applied Chemistry, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656 (Japan); Fujioka, Hiroshi [Institute of Industrial Science, University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505 (Japan); Kanagawa Academy of Science and Technology (KAST) KSP east 301, 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa, 213-0012 (Japan)], E-mail: hfujioka@iis.u-tokyo.ac.jp

2008-06-02

We have grown AlN films on single-crystalline Mo(110), (100), and (111) substrates using a low temperature pulsed laser deposition (PLD) growth technique and investigated their structural properties. Although c-axis oriented AlN films grow on Mo(100), the films contain 30{sup o} rotated domains due to the difference in the rotational symmetry between AlN(0001) and Mo(100). AlN films with only poor crystalline quality grow on Mo(111) substrates, probably due to the poor surface morphology and high reactivity of the substrates. On the other hand, single crystal AlN films grow epitaxially on Mo(110) substrates with an in-plane relationship of AlN[11-20] // Mo[001]. Reflection high-energy electron diffraction or electron backscattered diffraction analysis has revealed that neither in-plane 30 deg. rotated domains nor cubic phase domains exist in the AlN films. X-ray reflectivity measurements have revealed that the heterointerface between AlN and Mo prepared by PLD at 450 deg. C is quite abrupt. These results indicate that PLD epitaxial growth of AlN on single crystal Mo substrates is quite promising for the fabrication of future high frequency filter devices.

A review on the process technology for Mo-99 production

Energy Technology Data Exchange (ETDEWEB)

Park, Jin Hoh; Yoo, Jae Hyung; Jung, Won Myung; Lee, Kyoo Il; Woo, Moon Sik; Hwang, Doo Sung; Kim, Yun Koo [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

1994-07-01

Tc-99m is most frequently used in nuclear medical diagnostics because of its favourable nuclear properties and reasonable prices, and the demand of Tc-99m, is on the increase recently. Mo-99, the parent radionuclide of Tc-99m, is the only source of Tc-99m. This review described overall aspects of process technologies for Mo-99 production. Firstly, the chemical, physical and radioactive properties of Tc-99m, Mo-99 were examined to understand Mo-99 separation process. Also, the technology for Mo-99 production with both the neutron capture and nuclear fission method were examined. But the neutron capture method was scarcely used for large production of Mo-99 because of its low specific activity and high production cost. This review also described mainly process technologies in the nuclear fission method, fabrication and condition for irradiation of targets, transport and dissolution of targets irradiated, separation and purification of Mo-99, etc. Especially, for Mo-99 separation and purification process, the characteristics, merits and demerits of various processes, which have been developed in a few countries, were examined and analyzed. 30 figs., 16 tabs., 60 refs. (Author).

Thermal behavior analysis of U-Mo/Al dispersion fuel

Energy Technology Data Exchange (ETDEWEB)

Ryu, Ho Jin; Park, Jong Mang; Lee, Yoon Sang; Kim, Chang Kyu [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of)

2004-07-01

According to the non-proliferation policy under the reduced enrichment for research and test reactors (RERTR) program, low enriched uranium(LEU) fuel such as uranium silicide dispersion fuels are being used in research reactors. Because of a lower enrichment higher uranium density fuels are required for some high performance research reactors. Some uranium alloys with a high uranium density such as U-Mo alloys have been considered as one of the most promising candidates for a dispersion fuel due to the good irradiation performance. An international qualification program to replace the uranium silicide dispersion fuel with U-Mo dispersion fuel is being carried out under the RERTR program. Although U-Mo powders are conventionally supplied by the mechanical comminuting of as-cast U-Mo alloys, KAERI developed a centrifugal atomization method in order to simplify the preparation process and improve the properties. The centrifugally atomized powders have a rapidly solidified gamma uranium structure and a spherical shape. During the in-reactor operation of a dispersion fuel, interdiffusion or chemical reactions between the fuel particles and the matrix occurr. Intermetallic compounds in the form of UAlx are formed as a result of the diffusional reaction. Because the intermetallic compounds are less dense than the combined reactants, the volume of the fuel element increases after the reaction. In addition to the effect on the swelling performance, the reaction layers between the U-Mo and the Al matrix induces a degradation of the thermal properties of the U-Mo/Al dispersion fuels. It is important to investigate the thermal behavior of U-Mo/Al dispersion fuel according to reaction between the fuel particles and the matrix with the burnup and linear power. In this study, a finite element analysis was used for the calculation of the temperature distribution of the U-Mo/Al dispersion fuel with a burnup and linear power. Kinetics data of the reaction layers such as the growth

Thermal behavior analysis of U-Mo/Al dispersion fuel

International Nuclear Information System (INIS)

Ryu, Ho Jin; Park, Jong Mang; Lee, Yoon Sang; Kim, Chang Kyu

2004-01-01

According to the non-proliferation policy under the reduced enrichment for research and test reactors (RERTR) program, low enriched uranium(LEU) fuel such as uranium silicide dispersion fuels are being used in research reactors. Because of a lower enrichment higher uranium density fuels are required for some high performance research reactors. Some uranium alloys with a high uranium density such as U-Mo alloys have been considered as one of the most promising candidates for a dispersion fuel due to the good irradiation performance. An international qualification program to replace the uranium silicide dispersion fuel with U-Mo dispersion fuel is being carried out under the RERTR program. Although U-Mo powders are conventionally supplied by the mechanical comminuting of as-cast U-Mo alloys, KAERI developed a centrifugal atomization method in order to simplify the preparation process and improve the properties. The centrifugally atomized powders have a rapidly solidified gamma uranium structure and a spherical shape. During the in-reactor operation of a dispersion fuel, interdiffusion or chemical reactions between the fuel particles and the matrix occurr. Intermetallic compounds in the form of UAlx are formed as a result of the diffusional reaction. Because the intermetallic compounds are less dense than the combined reactants, the volume of the fuel element increases after the reaction. In addition to the effect on the swelling performance, the reaction layers between the U-Mo and the Al matrix induces a degradation of the thermal properties of the U-Mo/Al dispersion fuels. It is important to investigate the thermal behavior of U-Mo/Al dispersion fuel according to reaction between the fuel particles and the matrix with the burnup and linear power. In this study, a finite element analysis was used for the calculation of the temperature distribution of the U-Mo/Al dispersion fuel with a burnup and linear power. Kinetics data of the reaction layers such as the growth

Mechanically Activated Combustion Synthesis of MoSi₂-Based Composites

Energy Technology Data Exchange (ETDEWEB)

Shafirovich, Evgeny [Univ. of Texas, El Paso, TX (United States)

2015-09-30

The thermal efficiency of gas-turbine power plants could be dramatically increased by the development of new structural materials based on molybdenum silicides and borosilicides, which can operate at temperatures higher than 1300 °C with no need for cooling. A major challenge, however, is to simultaneously achieve high oxidation resistance and acceptable mechanical properties at high temperatures. One approach is based on the fabrication of MoSi2-Mo5Si3 composites that combine high oxidation resistance of MoSi2 and good mechanical properties of Mo5Si3. Another approach involves the addition of boron to Mo-rich silicides for improving their oxidation resistance through the formation of a borosilicate surface layer. In particular, materials based on Mo5SiB2 phase are promising materials that offer favorable combinations of high temperature mechanical properties and oxidation resistance. However, the synthesis of Mo-Si-B multi-phase alloys is difficult because of their extremely high melting temperatures. Mechanical alloying has been considered as a promising method, but it requires long milling times, leading to large energy consumption and contamination of the product by grinding media. In the reported work, MoSi2-Mo5Si3 composites and several materials based on Mo5SiB2 phase have been obtained by mechanically activated self-propagating high-temperature synthesis (MASHS). Short-term milling of Mo/Si mixture in a planetary mill has enabled a self-sustained propagation of the combustion front over the mixture pellet, leading to the formation of MoSi2-T1 composites. Combustion of Mo/Si/B mixtures for the formation of T2 phase becomes possible if the composition is designed for the addition of more exothermic reactions leading to the formation of MoB, TiC, or TiB2. Upon ignition, Mo/Si/B and Mo/Si/B/Ti mixtures exhibited spin combustion, but the products were porous, contained undesired secondary phases, and had low oxidation resistance. It has been shown that use of

Oxidation Behavior of Mo-Si-B Alloys in Wet Air; TOPICAL

International Nuclear Information System (INIS)

M. Kramer; A. Thom; O. Degirmen; V. Behrani; M. Akinc

2002-01-01

Multiphase composite alloys based on the Mo-Si-B system are candidate materials for ultra-high temperature applications. In non load-bearing uses such as thermal barrier coatings or heat exchangers in fossil fuel burners, these materials may be ideally suited. The present work investigated the effect of water vapor on the oxidation behavior of Mo-Si-B phase assemblages. Three alloys were studied: Alloy 1= Mo(sub 5)Si(sub 3)B(sub x) (T1)- MoSi(sub 2)- MoB, Alloy 2= T1- Mo(sub 5)SiB(sub 2) (T2)- Mo(sub 3)Si, and Alloy 3= Mo- T2- Mo(sub 3)Si. Tests were conducted at 1000 and 1100C in controlled atmospheres of dry air and wet air nominally containing 18, 55, and 150 Torr H(sub 2)O. The initial mass loss of each alloy was approximately independent of the test temperature and moisture content of the atmosphere. The magnitude of these initial losses varied according to the Mo content of the alloys. All alloys formed a continuous, external silica scale that protected against further mass change after volatilization of the initially formed MoO(sub 3). All alloys experienced a small steady state mass change, but the calculated rates cannot be quantitatively compared due to statistical uncertainty in the individual mass measurements. Of particular interest is that Alloy 3, which contains a significant volume fraction of Mo metal, formed a protective scale. All alloys formed varying amounts of subscale Mo and MoO(sub 2). This implies that oxygen transport through the external silica scale has been significantly reduced. For all alloys, water vapor accelerated the growth of a multiphase interlayer at the silica scale/unoxidized alloy interface. This interlayer is likely composed of fine Mo and MoO(sub 2) that is dispersed within a thin silica matrix. Alloy 3 was particularly sensitive to water accelerated growth of this interlayer. At 1100 C, the scale thickness after 300 hours increased from about 20 mm in dry air to nearly 100 mm in wet air

Revaluation of 99Mo production by (n,γ) method at HANARO

International Nuclear Information System (INIS)

Jun, Byung Jin; Kimura, Akihiro; Hori, Naohiko; Izumo, Hironobu; Tsuchiya, Kunihiko; Lee, Byung Cheol

2010-07-01

After the feasibility study on 99 Mo production by (n,γ) method at HANARO was published by a KAERI report, worldwide supply of 99 Mo became worse and a need for early available alternative 99 Mo became stronger. Previous study indicated that the (n,γ) 99 Mo has a potential to be an alternative mass 99 Mo available earlier than those by any other methods. It can be realized when radioisotope industry of each country accepts the use of (n,γ) 99 Mo for a meaningful portion of national demand. A good backup supply system among high flux reactors in the region is a prerequisite to guarantee a stable and sufficient availability of the (n,γ) 99 Mo for the region, for which active collaboration among reactors is essential. As the initial stage of collaboration between HANARO and JMTR for the (n,γ) 99 Mo supply, the specific experience and 99 Mo production capability in HANARO have been discussed and revisited on the base of the previous report. (author)

Conceptual study of 99Mo production in JRR-3

International Nuclear Information System (INIS)

Hirose, Akira; Komeda, Masao; Kinase, Masami; Sorita, Takami; Wada, Shigeru

2010-06-01

We investigated the production process of 99 Mo, which is parent nuclide of 99m Tc, in JRR-3. 99m Tc is most commonly used as a radiopharmaceutical in the field of nuclear medicine. Currently the supplying of 99 Mo is only dependent on imports from foreign countries, so JAEA is aiming at domestic production of a part of 99 Mo in cooperation with the industrial arena. This report presents the technical study for the production process of 99 Mo by using the neutron radiation method of (n, γ) reaction in JRR-3. (author)

Reaction of LaB6 with MoSi2

International Nuclear Information System (INIS)

Ordan'yan, S.S.; Gardagina, E.N.; Barabanova, S.N.

1989-01-01

Investigation results of interaction in LaB 6 -MoSi 2 system within wide concentration and temperature ranges are presented. LaB 6 and MoSi 2 powders were preliminary squeezed out in vacuum at 1470 K. Presence of LaB 6 and MoSi 2 initial phases only is determined using X-ray pahse analysis of sintered and melted specimens of all compositions. Traces of MoB (probably, due to quick crystallization after melting and partial evaporation of silicon from the melt) are detected in some alloys exposed to melting

Thermodynamic evidence for phase transition in MoO2-δ

International Nuclear Information System (INIS)

Jacob, K.T.; Saji, V.S.; Gopalakrishnan, J.; Waseda, Y.

2007-01-01

The standard Gibbs free energy of formation of MoO 2-δ , Δ f G 0 (MoO 2-δ ), has been measured over a wide temperature range (925 to 1925) K using an advanced version of bi-electrolyte solid-state electrochemical cell incorporating a buffer electrode: Pt vertical bar Mo + MoO 2-δ -parallel (Y 2 O 3 )ThO 2 -parallel (CaO)ZrO 2 -parallel O 2 (0.1 MPa) vertical bar Pt The Gibbs free energy of formation of MoO 2-δ , which is directly related to the measured cell e.m.f., can be represented by two linear segments: Δ f G 0 (MoO 2-δ )±570/(J.mol -1 )=-579,821+170.003(T/K), in the temperature range (925 to 1533) K, and Δ f G 0 (MoO 2-δ )±510/(J.mol -1 )=-564,634+160.096(T/K), in the temperature range (1533 to 1925) K. The change in slope at T = 1533 K is probably related to the phase transition of MoO 2 from monoclinic structure with space group P2 1 /c to tetragonal structure characteristic of rutile with space group P4 2 /mnm. The enthalpy and entropy change for the phase transition are: ΔH tr = (15.19 ± 2.1) kJ . mol -1 ; ΔS tr (9.91 ± 1.27) J . mol -1 . K -1 . The standard enthalpy of formation of MoO 2-δ at T = 298.15 K assessed by the third-law method is: Δ f H 0 (MoO 2-δ ) = (-592.28 ± 0.33) kJ . mol -1 . The new measurements refine thermodynamic data for MoO 2

Determination of 99Mo contamination in 99mTc elute obtained from 99Mo/99mTc- generator

International Nuclear Information System (INIS)

Momennezhad, M.; Zakavi, S. R.; Sadeghi, R.

2010-01-01

99m Tc is a widely used radioisotope in nuclear medicine centers which is obtained by elution from Mo-99/Tc-99m generators. Usually the generators are either supplied by the Iran Atomic Energy Agency or by private companies from foreign countries. In this study we have measured 99 Mo contamination in 99m Tc elute from different generators in a period of one year. Materials and Methods: The radionuclide impurity of the 99m Tc elute were studied in two types of radionuclide generators (A: produced in Iran and B: Imported from other country). In-vitro measurements were performed using dose calibrator. Direct measurements were made, using a standard canister at the time of milking of the generators and also in Subsequent hours after milking. Results: The results showed a mean of 99 Mo impurity in generators A and B to be 0.00932±0.0043 and 0.0170±0.0127 respectively. Although the results showed that the 99 Mo contamination in 99 mTc elute was lesser than the maximum accepted activity limit of 0.015%, the difference in these two types may reflect different methods of productions of generator, as well as the quality control procedures. Conclusion: The mean of 99 Mo contamination in generators produced in Iran Atomic Energy Organization was lesser than generators imported from foreign origin.

Detecting the Extent of Eutectoid Transformation in U-10Mo

International Nuclear Information System (INIS)

Devaraj, Arun; Jana, Saumyadeep; McInnis, Colleen A.; Lombardo, Nicholas J.; Joshi, Vineet V.; Sweet, Lucas E.; Manandhar, Sandeep; Lavender, Curt A.

2016-01-01

During eutectoid transformation of U-10Mo alloy, uniform metastable ? UMo phase is expected to transform to a mixture of ?-U and ?'-U_2Mo phase. The presence of transformation products in final U-10Mo fuel, especially the ? phase is considered detrimental for fuel irradiation performance, so it is critical to accurately evaluate the extent of transformation in the final U-10Mo alloy. This phase transformation can cause a volume change that induces a density change in final alloy. To understand this density and volume change, we developed a theoretical model to calculate the volume expansion and resultant density change of U-10Mo alloy as a function of the extent of eutectoid transformation. Based on the theoretically calculated density change for 0 to 100% transformation, we conclude that an experimental density measurement system will be challenging to employ to reliably detect and quantify the extent of transformation. Subsequently, to assess the ability of various methods to detect the transformation in U-10Mo, we annealed U-10Mo alloy samples at 500°C for various times to achieve in low, medium, and high extent of transformation. After the heat treatment at 500°C, the samples were metallographically polished and subjected to optical microscopy and x-ray diffraction (XRD) methods. Based on our assessment, optical microscopy and image processing can be used to determine the transformed area fraction, which can then be correlated with the ? phase volume fraction measured by XRD analysis. XRD analysis of U-10Mo aged at 500°C detected only ? phase and no ?' was detected. To further validate the XRD results, atom probe tomography (APT) was used to understand the composition of transformed regions in U-10Mo alloys aged at 500°C for 10 hours. Based on the APT results, the lamellar transformation product was found to comprise ? phase with close to 0 at% Mo and ? phase with 28-32 at% Mo, and the Mo concentration was highest at the ?/? interface.

Crystal structure and thermal stability of AgIn(MoO4)2

International Nuclear Information System (INIS)

Klevtsov, P.V.; Solodovnikov, S.F.; Perepelitsa, A.P.; Klevtsova, R.F.

1984-01-01

Tetragonal crystals of double molybdate AgIn(MoO 4 ) 2 are prepared bi crystallization from solution in Ag 2 Mo 2 O 7 melt (a=4.998, c=36.725 A, space group I4 1 , Z=6). Its crystal structure is determined (autodaffractometer ''Syntex P2 1 '', MoKsub(α)-radiation, 876 reflections, R=0.054) in which along with Mo-tetrahedrons Mo-octahedrons are present. By mutual edges latter are united into bands forming fragments of wolframite structure alonside with (In, Ag) octahedrons. In the direction of c axis wolframite fragments alternate with scheelite fragments consisting of Mo-tetrahedrons and Ag-octavertices. The crystallochemical formula of the compound is Ag(Insub(0.75)Agsub(0.25))sub(2)Mosub(2)Osub(8) [MoO 4 ]. At a temperature of about 600 deq C AgIn-molybdate transforms into modification with NaIn(MoO 4 ) 2 structure NaIn(MoO 4 ) 2 and melts at 650 deg C decomposing into In 2 (MoO 4 ) 3 solid phase and Ag 2 MoO 4 melt

FeS2-doped MoS2 nanoflower with the dominant 1T-MoS2 phase as an excellent electrocatalyst for high-performance hydrogen evolution

International Nuclear Information System (INIS)

Zhao, Xue; Ma, Xiao; Lu, Qingqing; Li, Qun; Han, Ce; Xing, Zhicai; Yang, Xiurong

2017-01-01

Well-established methods to improve the hydrogen evolution reaction (HER) performances include, but are not limited to, tailoring the morphology and electronic structure of transition metal dichalcogenides (TMDs), and doping of earth abundant chemicals such as iron pyrite FeS 2 into existing TMDs. In this work, MoS 2 nanoflowers with the majority being octahedral MoS 2 (1T-MoS 2 ) and doped with FeS 2 were prepared and applied to HER. The as-prepared catalysts were characterized by X-ray absorption fine structure at the K-edge of Mo, S, and Fe to probe the local electronic structures. The resulting nanomaterial was identified to be FeS 2 doped MoS 2 nanoflower (denoted as Fe-MoS 2 NF) with 66% 1T-MoS 2 which was the metallic phase and could drastically boost the HER properties. The Fe-MoS 2 NF exhibited high HER performance with a Tafel slope of 82 mV dec −1 and it needs 136 mV to achieve a current density of 10 mA cm −2 . The synthesis of Fe-MoS 2 NF with refined morphology and active electronic structure is expected to open a new era for improving the catalytic activity and stability of MoS 2 .

Reaction layer in U-7WT%MO/Al diffusion couples

International Nuclear Information System (INIS)

Mirandou, M.I.; Balart, S.N.; Ortiz, M.; Granovsky, M.S.

2003-01-01

New results of the reaction layer characterization between γ (U-7wt%Mo) alloy and Al, in chemical diffusion couples, are presented. The analysis was performed using optical and scanning electron microscopy with EDAX and X-ray diffraction techniques. Besides the main components (U, Mo)Al 3 and (U, Mo)Al 4 , already reported, two ternary compounds of high Al content have been identified in the reaction layer when it grew in retained or decomposed γ (U, Mo) phase, respectively. The drastic consequence on the interdiffusion behavior due to the thermal instability of the retained γ (U, Mo) phase is discussed. (author)

The lanthanum(III molybdate(VI La4Mo7O27

Directory of Open Access Journals (Sweden)

Petra Becker

2009-08-01

Full Text Available Crystals of the orthorhombic phase La4Mo7O27 (lanthanum molybdenum oxide were obtained from a non-stoichiometric melt in the pseudo-ternary system La2O3–MoO3–B2O3. In the crystal structure, distorted square-antiprismatic [LaO8] and monocapped square-antiprismatic [LaO9] polyhedra are connected via common edges and faces into chains along [010]. These chains are arranged in layers that alternate with layers of [MoO4] and [MoO5] polyhedra parallel to (001. In the molybdate layers, a distorted [MoO5] trigonal bipyramid is axially connected to two [MoO4] tetrahedra, forming a [Mo3O11] unit.

Fission induced swelling of U–Mo/Al dispersion fuel

Energy Technology Data Exchange (ETDEWEB)

Kim, Yeon Soo, E-mail: yskim@anl.gov [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Jeong, G.Y. [Ulsan National Institute of Science and Technology, 50 UNIST-gil, Eonyang-eup, Uljoo-gun, Ulsan 689-798 (Korea, Republic of); Park, J.M. [Korea Atomic Energy Research Institute, 989-111 Daedeok-daero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Robinson, A.B. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-6188 (United States)

2015-10-15

Fission-induced swelling of U–Mo/Al dispersion fuel meat was measured using microscopy images obtained from post-irradiation examination. The data of reduced-size plate-type test samples and rod-type test samples were employed for this work. A model to predict the meat swelling of U–Mo/Al dispersion fuel was developed. This model is composed of several submodels including a model for interaction layer (IL) growth between U–Mo and Al matrix, a model for IL thickness to IL volume conversion, a correlation for the fission-induced swelling of U–Mo alloy particles, a correlation for the fission-induced swelling of IL, and models of U–Mo and Al consumption by IL growth. The model was validated using full-size plate data that were not included in the model development.

Plasmons on the edge of MoS2 nanostructures

DEFF Research Database (Denmark)

Andersen, Kirsten; Jacobsen, Karsten Wedel; Thygesen, Kristian Sommer

2014-01-01

Using ab initio calculations we predict the existence of one-dimensional (1D), atomically confined plasmons at the edges of a zigzag MoS2 nanoribbon. The strongest plasmon originates from a metallic edge state localized on the sulfur dimers decorating the Mo edge of the ribbon. A detailed analysis...... of the dielectric function reveals that the observed deviations from the ideal 1D plasmon behavior result from single-particle transitions between the metallic edge state and the valence and conduction bands of the MoS2 sheet. The Mo and S edges of the ribbon are clearly distinguishable in calculated spatially...... resolved electron energy loss spectrum owing to the different plasmonic properties of the two edges. The edge plasmons could potentially be utilized for tuning the photocatalytic activity of MoS2 nanoparticles....

Thermal expansion studies on UMoO5, UMoO6, Na2U(MoO4)3 and Na4U(MoO4)4

International Nuclear Information System (INIS)

Keskar, Meera; Dahale, N.D.; Krishnan, K.

2009-01-01

In the present work, thermal expansion behavior of lower valent sodium uranium molybdates, i.e., Na 2 U(MoO 4 ) 3 and Na 4 U(MoO 4 ) 4 were studied under vacuum in the temperature range of 298-873 K using high temperature X-ray diffractometry (HTXRD). Expansion behaviors of UMoO 5 and UMoO 6 were also studied in vacuum from 298 to 873 K and 773 K, respectively. UMoO 5 was synthesized by reacting UO 2 with MoO 3 in equi-molar proportion in evacuated sealed quartz ampoule at 1173 K for 14 h. Na 2 U(MoO 4 ) 3 and Na 4 U(MoO 4 ) 4 were prepared by reacting UMoO 5 and MoO 3 with 1 and 2 moles of Na 2 MoO 4 , respectively, at 873 K in evacuated sealed quartz ampoule. XRD data of UMoO 5 and UMoO 6 were indexed on orthorhombic and monoclinic systems, respectively, whereas, the data of Na 2 U(MoO 4 ) 3 and Na 4 U(MoO 4 ) 4 were indexed on tetragonal system. The lattice parameters and cell volume of all the four compounds, fit into polynomial expression with respect to temperature, showed positive thermal expansion (PTE) up to 873 K.

Hydrothermal synthesis and polymorphism of RbPr(MoO4)2

International Nuclear Information System (INIS)

Protasova, V.I.; Kharchenko, L.Yu.; Klevtsov, P.V.

1977-01-01

Hydrothermal method has been successfully used to obtain crystals of rubidium-rare-earth molibdates of RbLn(MoO 4 ) 2 composition (Ln is a rare earth element). In Rb 2 MoO 4 solutions at 575-600degC the RbPr(MoO 4 ) 2 crystals were obtained in a modification new for Rb-Ln-molibdates, i.e. isostructural to triclinic α-KEu(MoO 4 ) 2 , and in a structural modification of laminated rhombic KY(MoO 4 ) 2 type. Polymorphism of RbPr(MoO 4 ) 2 has been studied, four crystalline modifications found and their complex interchanges investigated

Redox and oxo-abstraction reactions of silylamine with MoOCl4

International Nuclear Information System (INIS)

Vasisht, S.K.; Singh, G.

1985-01-01

Trimethylsilyldiethylamine Me 3 SiNEt 2 and MoOCl 4 (1:1) undergo a free radical redox reaction in CH 2 Cl 2 or Et 2 O to form MoCl 3 O(HNEt 2 ). Reduction occurs even in aprotic media like CCl 4 and CS 2 to give Mo(V) complexes Mo 2 Cl 6 O 2 (N 2 Et 4 ) and Mo 2 Cl 6 O 2 [(SCNEt 2 ) 2 S 2 ], respectively. A 2:1 reaction in nonionizing protic solvents undergoes redox cum cleavage to provide MoCl 2 O(NEt 2 )(HNEt 2 ) but a reaction at reflux temperature in 1,2-dichloroethane leads to diethylammonium salt, [Et 2 NH 2 ][MoCl 4 O(HNEt 2 )]. Higher molar reactions (3:1, 4:1) in CH 2 Cl 2 or Et 2 O are associated with redox reaction as well as oxygen atom abstraction to form de-oxo Mo(IV) complex MoCl 3 (NEt 2 )(HNEt 2 ) 2 , whereas, a 3:1 reaction in CS 2 forms Mo 2 Cl 4 O(S 2 CNEt 2 ) 4 . Compounds have been characterized by elemental analyses, redox titration, magnetic moment, conductance, infrared, electronic absorption and 1 H-NMR measurements. (author)

99mTc gel generators based on zirconium molybdate-99Mo: III: Influence of preparatory conditions of zirconium molybdate-99Mo gel on generator performance

International Nuclear Information System (INIS)

Saraswathy, P.; Sarkar, S.K.; Arjun, G.; Ramamoorthy, N.; Nandy, S.K.

2004-01-01

The effect of subtle variations on zirconium molybdate- 99 Mo gel preparatory conditions, such as stoichiometry of reactants, pH of gel formation, conditioning of gel granules etc., prior to elution were investigated primarily to arrive at the conditions resulting in high 99m Tc release and minimal 99 Mo breakthrough upon elution with normal saline. Zirconium molybdate- 99 Mo gels were prepared by reacting solutions of Zr and Mo in mole ratios of 0.75-1.5. Both water and normal saline were used for gel disintegration, and the release of 99m Tc and 99 Mo from gel columns into eluates was compared. Sharper elution profile of 99m Tc, but with significantly higher 99 Mo breakthrough (5-8 times), was obtained when water alone was used for disintegration and elution, in comparison to when saline was used. Gels exhibiting optimum characteristics were found to be formed at a pH of 4-5 by reacting [Zr]: [Mo] in the mole ratio of 1.25: 1 and after drying, the product was dispersed into granules by disintegration with normal saline. 99m Tc elution efficiency was found to be ∝ 75% and 99 Mo breakthrough ∝ 0.05%. The elution profile was sharp when a 6 g gel column coupled to a 2 g acidic alumina column (to trap 99 Mo) was eluted with 6-9 ml normal saline. Generators containing upto 23 GBq 99 Mo were prepared, eluted extensively without changing the alumina column and found to provide pertechnetate of good quality, commensurate with hospital radiopharmacy requirements. (orig.)

Observation of Vacancies, Faults, and Superstructures in Ln5Mo2O12 (Ln = La, Y, and Lu) Compounds with Direct Mo-Mo Bonding.

Science.gov (United States)

Colabello, Diane M; Sobalvarro, Elizabeth M; Sheckelton, John P; Neuefeind, Joerg C; McQueen, Tyrel M; Khalifah, Peter G

2017-11-06

Among oxide compounds with direct metal-metal bonding, the Y 5 Mo 2 O 12 (A 5 B 2 O 12 ) structural family of compounds has a particularly intriguing low-dimensional structure due to the presence of bioctahedral B 2 O 10 dimers arranged in one-dimensional edge-sharing chains along the direction of the metal-metal bonds. Furthermore, these compounds can have a local magnetic moment due to the noninteger oxidation state (+4.5) of the transition metal, in contrast to the conspicuous lack of a local moment that is commonly observed when oxide compounds with direct metal-metal bonding have integer oxidation states resulting from the lifting of orbital degeneracy typically induced by the metal-metal bonding. Although a monoclinic C2/m structure has been previously proposed for Ln 5 Mo 2 O 12 (Ln = La-Lu and Y) members of this family based on prior single crystal diffraction data, it is found that this structural model misses many important structural features. On the basis of synchrotron powder diffraction data, it is shown that the C2/m monoclinic unit cell represents a superstructure relative to a previously unrecognized orthorhombic Immm subcell and that the superstructure derives from the ordering of interchangeable Mo 2 O 10 and LaO 6 building blocks. The superstructure for this reason is typically highly faulted, as evidenced by the increased breadth of superstructure diffraction peaks associated with a coherence length of 1-2 nm in the c* direction. Finally, it is shown that oxygen vacancies can occur when Ln = La, producing an oxygen deficient stoichiometry of La 5 Mo 2 O 11.55 and an approximately 10-fold reduction in the number of unpaired electrons due to the reduction of the average Mo valence from +4.5 to +4.05, a result confirmed by magnetic susceptibility measurements. This represents the first observation of oxygen vacancies in this family of compounds and provides an important means of continuously tuning the magnetic interactions within the one

Scalable Patterning of MoS2 Nanoribbons by Micromolding in Capillaries.

Science.gov (United States)

Hung, Yu-Han; Lu, Ang-Yu; Chang, Yung-Huang; Huang, Jing-Kai; Chang, Jeng-Kuei; Li, Lain-Jong; Su, Ching-Yuan

2016-08-17

In this study, we report a facile approach to prepare dense arrays of MoS2 nanoribbons by combining procedures of micromolding in capillaries (MIMIC) and thermolysis of thiosalts ((NH4)2MoS4) as the printing ink. The obtained MoS2 nanoribbons had a thickness reaching as low as 3.9 nm, a width ranging from 157 to 465 nm, and a length up to 2 cm. MoS2 nanoribbons with an extremely high aspect ratio (length/width) of ∼7.4 × 10(8) were achieved. The MoS2 pattern can be printed on versatile substrates, such as SiO2/Si, sapphire, Au film, FTO/glass, and graphene-coated glass. The degree of crystallinity of the as-prepared MoS2 was discovered to be adjustable by varying the temperature through postannealing. The high-temperature thermolysis (1000 °C) results in high-quality conductive samples, and field-effect transistors based on the patterned MoS2 nanoribbons were demonstrated and characterized, where the carrier mobility was comparable to that of thin-film MoS2. In contrast, the low-temperature-treated samples (170 °C) result in a unique nanocrystalline MoSx structure (x ≈ 2.5), where the abundant and exposed edge sites were obtained from highly dense arrays of nanoribbon structures by this MIMIC patterning method. The patterned MoSx was revealed to have superior electrocatalytic efficiency (an overpotential of ∼211 mV at 10 mA/cm(2) and a Tafel slope of 43 mV/dec) in the hydrogen evolution reaction (HER) when compared to the thin-film MoS2. The report introduces a new concept for rapidly fabricating cost-effective and high-density MoS2/MoSx nanostructures on versatile substrates, which may pave the way for potential applications in nanoelectronics/optoelectronics and frontier energy materials.

Microstructures and room temperature fracture toughness of Nb/Nb5Si3 composites alloyed with W, Mo and W–Mo fabricated by spark plasma sintering

International Nuclear Information System (INIS)

Xiong, Bowen; Cai, Changchun; Wang, Zhenjun

2014-01-01

Highlights: • Microstructure of Nb/Nb 5 Si 3 composite alloyed with W and Mo is change obviously. • W and Mo elements can solid solution in Nb and Nb 5 Si 3 phase respectively. • Alloyed with W and Mo together, the solid solubility of Nb 5 Si 3 phases is undetected. • The Nb/Nb 5 Si 3 composite alloyed with W and Mo together has high fracture toughness. - Abstract: Microstructures and room temperature fracture toughness of Nb/Nb 5 Si 3 composites alloyed with W, Mo and W–Mo fabricated by spark plasma sintering were investigated. The microstructures were examined using scanning electron microscope (SEM). X-ray diffraction (XRD) was performed on the bulk specimens for identification of phases. The chemical species were analyzed using electron-probe micro-analysis (EPMA). Results indicated that the microstructures of Nb/Nb 5 Si 3 composites alloyed with W or Mo is unaltered, including primary Nb and eutectic mixtures of Nb and Nb 5 Si 3 , and the coarse and fine eutectic mixtures. The W and Mo elements solid solution in Nb and Nb 5 Si 3 phase are detected. But that alloyed with W and Mo together, The microstructures are change obviously, including Nb phase, the solid solubility phases of W and Mo atoms in Nb, and the solid solubility phases of Nb atoms in W are also found, but the solid solubility phenomenon of Nb 5 Si 3 phases is not detected. The microhardness of Nb and Nb 5 Si 3 phases increases obviously because of solid solution strengthening. The Nb/Nb 5 Si 3 composite alloyed with W and Mo together hashing high fracture toughness is attributable to the big eutectic Nb and interface of eutectic phases, which can bear large deformation to absorb the crack energy and form the decohesion between eutectic phases

Radionuclidic contamination of 99Mo, 131I and 103Ru in the eluate of 99Mo-99mTc chromatographic generator: comparision on fission produced 99Mo from RPC, Nordio and ARI

International Nuclear Information System (INIS)

Soenarjo, Sunarhadijoso; Gunawan, Adang Hardi

1996-01-01

The 99 Mo- 99m Tc Chromatographic generators is the most popular system to provide 99m Tc medical radioisotope. Radioisotope Production Centre (RPC)- BATAN has routinely produced the generator loaded with 99 Mo prepared by 235 U fission. By using fission produced 99 Mo, the resulting 99m Tc is potentially contaminated by other fission products which are difficult to eliminate completely. In order to study the characteristic of the generator and radionuclidic impurity pattern of the 99m Tc eluates, an evaluation of gamma spectrometric determination has been carried out. The bulk solutions of 99 Mo produced by RPC BATAN (Indonesia), Nordion (Canada) and ARI (Australia) were loaded to generators manufactured between July 1993 to May 1994. The saline-eluate 99m Tc, in a total volume of 10 ml each, was subjected to gamma spectrometric determination. The radiation of 99m Tc was eliminated by lead shield of 0.6913 cm thickness. The 99m Tc yield fluctuation from 28 generators indicated that the characteristics of the generator columns were very good. The 99m Tc eluates were consistently contaminated by 99 Mo, 131 I and 103 Ru, although the contamination level in all cases did not exceed the maximum permissible levels. The fluctuation of radionuclidic impurities were probably caused by variation in the irradiation parameter or by variation in the 99 Mo separation methods. (author), 23 refs, 1 tab, 3 figs

Effect of Silicon in U-10Mo Alloy

Energy Technology Data Exchange (ETDEWEB)

Kautz, Elizabeth J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Devaraj, Arun [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Kovarik, Libor [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Joshi, Vineet V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2017-08-31

This document details a method for evaluating the effect of silicon impurity content on U-10Mo alloys. Silicon concentration in U-10Mo alloys has been shown to impact the following: volume fraction of precipitate phases, effective density of the final alloy, and 235-U enrichment in the gamma-UMo matrix. This report presents a model for calculating these quantities as a function of Silicon concentration, which along with fuel foil characterization data, will serve as a reference for quality control of the U-10Mo final alloy Si content. Additionally, detailed characterization using scanning electron microscope imaging, transmission electron microscope diffraction, and atom probe tomography showed that Silicon impurities present in U-10Mo alloys form a Si-rich precipitate phase.

Enhancing photoresponsivity using MoTe2-graphene vertical heterostructures

Science.gov (United States)

Kuiri, Manabendra; Chakraborty, Biswanath; Paul, Arup; Das, Subhadip; Sood, A. K.; Das, Anindya

2016-02-01

MoTe2 with a narrow band-gap of ˜1.1 eV is a promising candidate for optoelectronic applications, especially for the near-infrared photo detection. However, the photo responsivity of few layers MoTe2 is very small (graphene vertical heterostructures have a much larger photo responsivity of ˜20 mA W-1. The trans-conductance measurements with back gate voltage show on-off ratio of the vertical transistor to be ˜(0.5-1) × 105. The rectification nature of the source-drain current with the back gate voltage reveals the presence of a stronger Schottky barrier at the MoTe2-metal contact as compared to the MoTe2-graphene interface. In order to quantify the barrier height, it is essential to measure the work function of a few layers MoTe2, not known so far. We demonstrate a method to determine the work function by measuring the photo-response of the vertical transistor as a function of the Schottky barrier height at the MoTe2-graphene interface tuned by electrolytic top gating.

The molecular mechanism of Mo isotope fractionation during adsorption to birnessite

Science.gov (United States)

Wasylenki, L.E.; Weeks, C.L.; Bargar, J.R.; Spiro, T.G.; Hein, J.R.; Anbar, A.D.

2011-01-01

Fractionation of Mo isotopes during adsorption to manganese oxides is a primary control on the global ocean Mo isotope budget. Previous attempts to explain what drives the surprisingly large isotope effect ??97/95Modissolved-??97/95Moadsorbed=1.8??? have not successfully resolved the fractionation mechanism. New evidence from extended X-ray absorption fine structure analysis and density functional theory suggests that Mo forms a polymolybdate complex on the surfaces of experimental and natural samples. Mo in this polynuclear structure is in distorted octahedral coordination, while Mo remaining in solution is predominantly in tetrahedral coordination as MoO42- Our results indicate that the difference in coordination environment between dissolved Mo and adsorbed Mo is the cause of isotope fractionation. The molecular mechanism of metal isotope fractionation in this system should enable us to explain and possibly predict metal isotope effects in other systems where transition metals adsorb to mineral surfaces. ?? 2011 Elsevier Ltd.

Glicerina bruta na dieta de bovinos de corte confinados: efeito sobre o hemograma

Directory of Open Access Journals (Sweden)

David Attuy Vey da Silva

2012-06-01

Full Text Available Objetivou-se com este estudo avaliar o hemograma de bovinos alimentados com glicerina bruta. Trinta novilhos da raça Nelore foram utilizados para as colheitas de sangue, as quais foram realizadas a cada 28 dias. Os animais foram mantidos confinados durante 103 dias e foram alimentados com cinco dietas contendo 0, 7,5, 15, 22,5 e 30% de glicerina bruta com base na matéria seca, formuladas na proporção volumoso:concentrado de 30:70 sendo a silagem de milho o volumoso e o concentrado composto por milho em grão, casca de soja, farelo de girassol, glicerina, calcário calcítico, fostatobicálcico e sal comum. O delineamento utilizado foi em blocos casualisados com cinco tratamentos. Contrastes ortogonais foram usados para determinar os efeitos linear, quadrático, cúbico e tratamento com glicerina × controle. Não houve efeito dos tratamentos (P>0,05 sobre as concentrações sanguíneas de hemácias, hematócrito, basófilos, eosinófilos, neutrófilos bastonetes e linfócitos, porém houve efeito linear sobre as concentrações de plaquetas, hemoglobina e monócitos (P=0,009, P=0,001 e P=0,043, respectivamente, e efeito cúbico sobre as concentrações de leucócitos totais e neutrófilos segmentados (P=0,008 e P=0,004, respectivamente. Dietas para bovinos de corte, contendo relação volumoso:concentrado 30:70 aditivadas com glicerina bruta, promovem alterações no eritrograma e no leucograma destes animais.