Science.gov

Sample records for pacientes na fase

  1. The Moon Phases in a Paper Box. (Spanish Title: Las Fases de la Luna en Una Caja de Cartón.) As Fases da Lua Numa Caixa de Papelão

    NASA Astrophysics Data System (ADS)

    de Fátima O. Saraiva, Maria; Amador, Cláudio B.; Kemper, Érico; Goulart, Paulo; Muller, Angela

    2007-12-01

    We present a very simple concrete model to demonstrate the concept of phases of an illuminated body. The main objective of our model is to help the understanding of the Moon phases as viewed from the perspective of an observer on Earth. The material allows the visualization of two important effects: (1st) even though all the time half Moon is illuminated by the Sun, we see different fractions of the illuminated Moon surface, depending on our angle of sight; (2nd) the orientation of the convex part of the Moon in the crescent and waning phases on the sky also depends on our perspective from Earth. The use of a closed box allows one to see the contrast among the different phases with no need of a dark room. We also present a text on the Moon phases, emphasizing the dependence of the aspect of the bright part on the angle of sight. En este trabajo proponemos la construcción de material didáctico de bajo costo para demostración del concepto de fases de un cuerpo iluminado. El principal objetivo de nuestro material es facilitar la comprensión de las fases de la Luna desde la perspectiva de un observador en la Tierra. El material ayuda la visualización de dos efectos importantes: (1º) a pesar de tener siempre la mitad de la Luna (representada por una bolita de espuma plástica o de ping-pong), iluminada por el Sol ( representado por una fuente de luz natural o artificial), vemos diferentes fracciones de su superficie iluminada, dependiendo del ángulo por el cual la vemos; (2º) la orientación del borde convexo de la Luna en las fases Creciente y Menguante también depende de la perspectiva por la cual la miramos desde la Tierra. El uso de una caja cerrada permite observar el contraste entre las diferentes fases sin necesidad de estar en un recinto oscuro. Presentamos también un texto explicativo sobre las fases de la Luna, enfatizando la dependencia de la apariencia de la parte iluminada con el ángulo de visión. Neste trabalho propomos a construção de material didático de baixo custo para demonstração do conceito de fases de um corpo iluminado. O principal objetivo de nosso material é facilitar a compreensão das fases da Lua da perspectiva de um observador na Terra. O material ajuda na visualização de dois efeitos importantes: (1º) mesmo tendo sempre a metade da "Lua" (representada por uma bolinha de isopor ou de ping-pong) iluminada pelo "Sol" (representado por uma fonte de luz natural ou artificial), nós vemos diferentes frações de sua superfície iluminada, dependendo do ângulo pelo qual a olhamos; (2º) a orientação da borda convexa da Lua nas fases Crescente e Minguante também depende da perspectiva pela qual a olhamos da Terra. O uso de uma caixa fechada permite observar o contraste entre as diferentes fases sem necessidade de estar em uma sala escurecida. Apresentamos também um texto explicativo sobre fases da Lua, enfatizando a dependência da aparência da parte iluminada com o ângulo de visada.

  2. Transies de fases qunticas Mucio A. Continentino

    E-print Network

    Liu, I-Shih

    mínimo da energia livre F #12;Transições de fase quânticas Ocorrem a temperatura nula ( T = 0 ), não há) Neste caso a entropia é nula e não ha competição com a energia AFP SC N #12;Modelo de Ising em campo Expansão da energia livre próxima do ponto critico #12;= 0 = 1/2 = 1 = 3 = 1/2 2 = d Expoentes de campo

  3. Lunar Phases and Earthly Events: Beliefs from Different Education Levels. (Spanish Title: Fases de la Luna y Acontecimientos Terrestres: Creencia de Distintos Niveles de Instrucción.) As Fases da Lua e os Acontecimentos Terrestres: a Crença de Diferentes Níveis de Instrução

    NASA Astrophysics Data System (ADS)

    Darroz, Luiz Marcelo; da Rosa, Cleci Teresinha Werner; Alves Vizzotto, Patrick; Becker da Rosa, Álvaro

    2013-12-01

    This article presents the result of a research carried out in the first semester of 2013 with a group of 80 subjects from different education levels. In this research, we sought to investigate the earthly events that this group of people attributes to the phenomenon of lunar phases. For data collection we used semi-structured interviews guided by questions that aimed to keep the focus on subjects of the investigation. Interviews were recorded and transcribed, and the results were compared to scientific studies in the area after being quantitatively and qualitatively analyzed. Research data showed that the Moon and the phenomenon of lunar phases still fascinate and raise the interest of people. However, the lack of knowledge to find correct explanations to the phenomena involving the moon ends up originating a series of beliefs about its influence on earthly events. En este artículo se presenta el resultado de una investigación realizada en el primer semestre de 2013 con a un grupo de 80 individuos de distintos niveles de instrucción. En esta investigación, tratamos de averiguar cuáles son los acontecimientos terrestres que este grupo de personas atribuye al fenómeno las fases lunares. Como instrumento de colecta de datos, se emplearon entrevistas semiestructuradas guiadas por preguntas que trataban de mantener la atención de los entrevistados en el objeto investigado. Las entrevistas fueron grabadas y transcriptas, y los resultados, después de ser analizados cuantitatativa y cualitativamente, fueron confrontados con estudios científicos del área. Los datos de la investigación demuestran que la Luna y de sus fases continúan fascinando y despertando el interés de la población. Sin embargo, la falta de conocimientos para encontrar explicaciones correctas relacionadas a los fenómenos que ocurren con el astro acaba originando una serie de creencias en la población sobre su influencia en los sucesos terrestres. Apresenta-se neste artigo o resultado de uma pesquisa realizada no primeiro semestre de 2013 junto a um grupo de 80 sujeitos de diferentes níveis de instrução. Nesta pesquisa, buscou-se averiguar os acontecimentos terrestres que esse grupo de pessoas atribui ao fenômeno das fases lunares. Como instrumento de coleta de dados, foram empregadas entrevistas semiestruturadas guiadas por questões que buscavam manter a atenção dos entrevistados no objeto de investigação. As entrevistas foram gravadas e transcritas, e os resultados, após serem analisados quanti e qualitativamente, foram confrontados com estudos científicos da área. Os dados da pesquisa demonstram que a Lua e suas fases continuam fascinando e despertando o interesse da população. No entanto, a falta de conhecimentos para proferir explicações corretas relativas aos fenômenos que ocorrem com o astro acaba originando uma série de crenças na população sobre sua influência nos acontecimentos terrestres.

  4. A Proposed Activity for a Meaningful Learning about the Moon Phases. (Breton Title: Uma Proposta de Atividade Para a Aprendizagem Significativa sobre as Fases da Lua.) Una Actividad Propuesta Para EL Aprendizaje Significativo Acerca de Las Fases de la Luna

    NASA Astrophysics Data System (ADS)

    Martins, Bruno Andrade; Langhi, Rodolfo

    2012-12-01

    This paper presents one of the concepts of Astronomy and its consequent failure in teaching this topic in high school, even when the official documents point out the necessity of Astronomy teaching at this school level. Among the spontaneous conceptions in Astronomy that high school students carry with them, even after the end of the school, we emphasized in this research the Moon phases. The development of different strategies in relation to traditional methods, aimed to teaching-learning process on this topic was considered in this study. These strategies were devised based on the reference frame of the Meaningful Learning, as elaborated by Ausubel. The proposals presented here include the active participation of students in experimental activities and other didactic activities, for their continuous evaluation during the process. These activities finished with a Comics elaboration about the Moon phases. Therefore, the objective of this paper is to present a proposal for differentiated teaching activity about Moon phases supported by the theoretical principles of Meaningful Learning at Physics classes. Este texto foca um dos conteúdos de Astronomia e a consequente falha no ensino deste tema no ensino médio, apesar de os documentos oficiais apresentarem a necessidade de se trabalhar a Astronomia neste nível de ensino. Dentre as concepções alternativas em Astronomia que os alunos do ensino médio carregam consigo, mesmo após o término dos estudos, destacamos, nesta pesquisa, o fenômeno das fases da Lua. O desenvolvimento de estratégias diferenciadas em relação ao ensino tradicional, visando o processo de ensino-aprendizagem sobre este tema, foi contemplado neste trabalho como um dos resultados obtidos sob a luz dos referenciais da aprendizagem significativa, fundamentados em Ausubel. Segundo a proposta aqui apresentada, a participação ativa dos alunos na execução de uma atividade experimental e outras atividades didáticas, que visam sua contínua avaliação durante o processo, culmina com a elaboração de uma história em quadrinhos envolvendo as fases da Lua. Portanto, o objetivo deste trabalho é apresentar uma proposta de atividade didática diferenciada sustentada pelos princípios teóricos da aprendizagem significativa aplicada ao ensino das fases da Lua durante as aulas de Física no ensino médio. En este trabajo se presenta uno de los contenidos de la Astronomía y el evidente fracaso en la enseñanza del tema en la escuela secundaria, a pesar del hecho que los documentos oficiales apuntan para la necesidad de trabajar contenidos de Astronomía en este nivel. Entre los conceptos alternativos en Astronomía que los alumnos secundarios llevan consigo, aún después de terminados los estudios, destacamos aquí el fenómeno de las fases de la Luna. El desarrollo de diferentes estrategias en relación con los métodos tradicionales, dirigidas al proceso de enseñanza-aprendizaje en este tema fue considerado en este trabajo como uno de los resultados obtenidos a la luz de los referenciales del aprendizaje significativo, tal como fueron fundamentados por Ausubel. Según la propuesta que aquí se presenta, la participación activa de los estudiantes en la ejecución de una actividad experimental y otras actividades educativas destinadas a la evaluación continua durante el proceso culminó en la elaboración de una historieta respecto de las fases de la Luna. Por lo tanto, el objetivo de este trabajo es presentar una propuesta de actividad de enseñanza diferenciada con el apoyo de los principios teóricos del aprendizaje significativo aplicado a la enseñanza de las fases de la luna durante las clases de física del ciclo secundario.

  5. The FASES instrument development and experiment preparation for the ISS

    NASA Astrophysics Data System (ADS)

    Picker, Gerold; Gollinger, Klaus; Greger, Ralf; Dettmann, Jan; Winter, Josef; Dewandre, Thierry; Castiglione, Luigi; Vincent-Bonnieu, Sebastien; Liggieri, Libero; Clausse, Daniele; Antoni, Mickael

    The FASES experiments target the investigation of the stability of emulsions. The main objec-tives are the study of the surfactant adsorption at the liquid / liquid interfaces, the interaction of the droplets as well as the behaviour of the liquid film between nearby drops. Particular focus is given to the dynamic droplet evolution during emulsion destabilisation. The results of the experiments shall support development of methods for the modelling of droplet size distri-butions, which are important to many industries using stable emulsions like food production, cosmetics and pharmaceutics or unstable emulsions as required for applications in waste water treatment or crude oil recovery. The development of the experimental instrumentation was initiated in 2002. The flight instru-ment hardware development was started in 2004 and finally the flight unit was completed in 2009. Currently the final flight preparation is proceeding targeting a launch to the International Space Station (ISS) with Progress 39P in September 2010. The experiment setup of the instrument is accommodated in a box type insert called Experiment Container (EC), which will be installed in the Fluid Science Laboratory part of the European Columbus module of the ISS. The EC is composed of two diagnostics instruments for the investigation of transparent and opaque liquid emulsion. The transparent emulsions will be subject to the experiment called "Investigations on drop/drop interactions in Transparent Emulsions" (ITEM). The opaque emulsion samples will be studied in the experiment called "Investigations on concentrated or opaque Emulsions and on Phase Inversions" (EMPI). The thermal conditioning unit (TCU) allows performing homogeneous thermalization, tem-perature sweeps, emulsion preparation by stirrer, and optical diagnostics with a scanning mi-croscope. The objective of the instrument is the 3D reconstruction of the emulsion droplet distribution in the liquid matrix in terms of the droplet sizes, location and their time depen-dent evolution. The TCU will be used for the stability experiment ITEM-S and the droplet freezing experiment ITEM-F. The Differential Scanning Calorimeter (DSC) will give an information about the evolution of the emulsion through the droplet size distribution and the dispersion state of the droplets within the emulsion during a controlled temperature sweep by measuring the latent heat of droplet freezing and melting during the EMPI experiments. For this purpose the calorimeter is equipped with a reference sample filled with a pure liquid matrix and a similar measurement sample filled with the specific emulsion under investigation. The differential heat flux between measurement sample and reference sample is measured with a sensitive heat flux sensor. Each instrument is serviced by a robotic sample stowage system, which accommodates in total 44 different ITEM and EMPI emulsion samples each filled with a specific composition of the emulsion. Currently the flight preparation is ongoing with particular focus on the preparation of the emulsion flight sample set and the instrument's operating parameters. The FASES flight instrument was developed by ASTRIUM Space Transportation Germany with support of RUAG Aerospace Wallisellen under ESA / ESTEC contract. The science team of FASES is supported by ESA/ESTEC (Microgravity Application Programme, AO99-052).

  6. University Students' Conceptions about the Moon Phases. (Spanish Title: Concepciones de Estudiantes Universitários sobre Las Fases de la Luna.) Concepções de Estudantes Universitários sobre as Fases da Lua

    NASA Astrophysics Data System (ADS)

    de Fátima Oliveira Saraiva, Maria; da Silveira, Fernando Lang; Steffani, Maria Helena

    2011-07-01

    In this article we describe the development of a multiple choice test about lunar phases and analyze the results of its application to ten groups of Physics students at the UFRGS. During the improvement of the test, we noticed that the percentage of right answers about some concepts increased significantly when associated with the reformulation of the question, emphasizing the importance of being careful to avoid incorrect answers generated by unclear questions, and not by ignorance on the matter. We confirm the results of other studies that show that students have great difficulty to relate the Moon's phase with its position in the sky at given time. On the other hand, our results suggest that, in general, students of Physics understand the phenomenon of lunar phases better than the average of university students. En estese artículo se describe la elaboración de una prueba de opción múltiple sobre las fases de la Luna y se analizan los resultados de su aplicación en diez grupos de estudiantes de Física de UFRGS. Durante el mejoramiento de la prueba observamos que el porcentaje de aciertos creció considerablemente cuando considerada una nueva redacción de la pregunta, destacando el cuidado que se debe tomar a fin de evitar respuestas incorrectas generadas por preguntas poco claras y no a causa de la ignorancia de los estudiantes sobre el tema. Confirmamos los resultados de otros estudios que las mayores dificultades de los alumnos sobre el tema fases de la Luna están en relacionar la fase de la Luna con su posición en el cielo en determinado momento. Por otra parte, nuestros resultados sugieren que, en general, los estudiantes de la Física comprenden mejor el fenómeno de las fases lunares que el promedio de los estudiantes universitarios. Neste artigo descrevemos a elaboração de um teste de múltipla escolha sobre as fases da Lua e analisamos os resultados de sua aplicação em dez grupos de estudantes de Física da UFRGS. Durante o aprimoramento do teste notamos que a porcentagem de acertos a respeito de alguns conceitos teve um aumento significativo associado à reformulação da pergunta, ressaltando a importância de tomar cuidado para evitar respostas erradas geradas por perguntas pouco claras e não por ignorância do respondente sobre o assunto. Confirmamos os resultados de outros estudos de que as maiores dificuldades dos alunos sobre o tema Fases da Lua dizem respeito a relacionar a fase que a Lua apresenta com a sua posição no céu em determinada hora. Por outro lado, nossos resultados sugerem que, em geral, os estudantes de Física entendem melhor o fenômeno das fases lunares do que a média dos estudantes universitários.

  7. Centro Clnico del NIH Manual del Paciente

    E-print Network

    Shen, Jun

    39 Programa de los amigos de la Familia 39 s e C C i ó n 5 SERVICIOS DE APOYO PARA LOS PACIENTES Y LAS FAMILIAS servicios de trabajo social 42 Servicios de peluquería y cosmetología Programa de los Amigos de la Familia (Family Friend Program) Programa para el familiar/encargado del paciente

  8. Los Derechos de los Pacientes del Centro Clnico

    E-print Network

    Los Derechos de los Pacientes del Centro Clínico Los Derechos de los Pacientes del Centro Clínico medir las respuestas de los pacientes al tratamiento. Existen procesos que protegen los derechos de paciente que se observen los derechos fundamentales de la dignidad humana. Esta Declaración de Derechos

  9. Lista de problemas da rea I 1. Superfcie e volume no espao de fase: Com as definies usuais de su-

    E-print Network

    Stariolo, Daniel Adrián

    a energia livre, a energia interna, a entropia e a magnetização por sítio m = i i /N, em função de T e H su- perfície no espaço de fase (E, V, N) e volume (E, V, N), se é uma pequena faixa de energias tal quânticos de frequência . Os 3N osciladores são independentes e a energia total da rede é H = ¯h 3N i=1 ni

  10. Familiares a cargo de pacientes de cáncer (PDQ)—Versión para pacientes

    Cancer.gov

    Sumario informativo revisado por expertos acerca de los desafíos que enfrentan los familiares a cargo de los pacientes con cáncer. Este resumen se centra en las funciones típicas y las inquietudes de las personas a cargo del paciente y en las intervenciones útiles para esas personas.

  11. RELACIÓN MÉDICO PACIENTE: DERECHOS DEL ADULTO MAYOR

    PubMed Central

    Barrantes-Monge, Melba; Rodríguez, Eduardo; Lama, Alexis

    2009-01-01

    Existen prejuicios en relación con la vejez, incluso entre los profesionales que se dedican a la gerontología. Uno común y peligroso es considerar que los viejos son todos enfermos o discapacitados. La relación médico-paciente es la piedra angular de la práctica y ética médicas. Para alcanzar el respeto por los adultos mayores es necesaria una medicina prudente, basada en una práctica en la cual la reflexión ética y clínica pueda contribuir. Esto último es posible si se hacen valer los derechos del adulto mayor, en particular como paciente para la toma de decisiones. PMID:20379380

  12. NaF Documentation

    Cancer.gov

    The NaF documentation files are presented in Adobe Acrobat or Word files. PDF Generic Documentation for NaF PDF file Word Generic Documentation for NaF Word file Contact G. Craig Hill, Ph.D. for information. Email: hillgc@mail.nih.gov, Phone: 240-276-5913 Print

  13. II CURSO DE FLORES EN LA GASTRONOMA: DE LA BOTNICA A LA COCINA. 21-22 noviembre de 2015 Facultad de Ciencias Fase IV

    E-print Network

    Escolano, Francisco

    II CURSO DE FLORES EN LA GASTRONOMÍA: DE LA BOTÁNICA A LA COCINA. 21-22 noviembre de 2015 Facultad de Ciencias Fase IV SÁBADO 9:00-9:30 ­ Presentación del curso. 9:30-12:00 ­ Teoría 1. - Las plantas. 14:30-15:00 ­ Evaluación y clausura del curso. *El programa puede estar sujeto a cambios de última

  14. Etapa final de la vida (PDQ)—Versión para pacientes

    Cancer.gov

    Sumario informativo revisado por expertos sobre el tratamiento y la atención del paciente de cáncer desde los últimos días hasta las últimas horas de vida; esto incluye los síntomas comunes, los dilemas éticos que pueden surgir y la función que desempeña el oncólogo en proveer cuidados al paciente y su familia durante este período.

  15. Providing Meaningful Learning for Students of the Sixth Grade of Middle School: a Study on the Moon Phases. (Breton Title: Propiciando Aprendizagem Significativa Para Alunos do Sexto Ano do Ensino Fundamental: um Estudo sobre as Fases da Lua.) Propiciando el Aprendizaje Significativo Para Alumnos del Sexto Nivel de la Educación General Básica: un Estudio sobre Las Fases de la Luna

    NASA Astrophysics Data System (ADS)

    Darroz, Luiz Marcelo; Samudio Pérez, Carlos Ariel; da Rosa, Cleci Werner; Heineck, Renato

    2012-07-01

    We relate in this article a didactic experience studying the moon phases with a group of middle school students of a private school of the municipality of Passo Fundo, RS. Based on David Ausubel's Meaningful Learning Theory, we have sought to develop a proposal following a didactic model which simulates the phases of the Moon, as based on the previous conceptions of the students. The signs of learning were evidenced by means of memory registries of the activity. From the obtained results we believe that the proposal achieved its goals, since the students were able to identify, differentiate and transfer the phenomenon of the moon phases to new contexts. Thus, it is concluded that a methodology focused on a meaningful content for the students is fundamental to the construction and genuine grasping of what is being learned. Neste artigo, relata-se uma experiência didática de estudo das fases da Lua com uma turma do 6° ano do Ensino Fundamental, de uma escola privada do município de Passo Fundo, RS. Tendo como fundamentação teórica a Teoria da Aprendizagem Significativa de David Ausubel, buscou-se desenvolver a proposta a partir de um modelo didático que simula as fases da Lua e com base nas concepções prévias dos estudantes. Os indícios da aprendizagem foram constatados através de registros de memórias da atividade. Pelos resultados apresentados, acredita-se que a proposta alcançou seus objetivos, uma vez que os estudantes conseguiram identificar, diferenciar e transferir o fenômeno das fases da Lua para novos contextos. Assim, conclui-se que uma metodologia com enfoque em um conteúdo significativo ao estudante é fundamental para a construção e compreensão genuína do que está sendo aprendido. En este artículo se relata una experiencia didáctica de estudio de las fases de la Luna con una clase de 6º año de la educación general básica de una escuela privada del municipio de Passo Fundo, RS. Teniendo como fundamentación teórica la Teoría del Aprendizaje Significativo de David Ausubel, se buscó desenvolver la propuesta a partir de un modelo didáctico que simula las Fases de la Luna, usando como base las concepciones previas de los estudiantes. Los indicios del aprendizaje fueron verificados a través de registros de memorias de la actividad. Por los resultados obtenidos creemos que la propuesta alcanzó sus objetivos, una vez que los estudiantes consiguieron identificar y transferir el fenómeno de las fases de la Luna para nuevos contextos. Así, se concluye que una metodología con enfoque en un contenido significativo para el estudiante es fundamental para la construcción y comprensión genuina de lo que está siendo aprendido.

  16. Directrices instan al ejercicio a pacientes con cáncer y supervivientes

    Cancer.gov

    Los beneficios del ejercicio están bien documentados en relación con varios tipos de cáncer. Una panel de expertos en cáncer, acondicionamiento físico, obesidad y entrenamiento físico, convocados por el Colegio Americano de Medicina Deportiva, está pasando la voz sobre uno de los más importantes mensajes para los pacientes con cáncer y los supervivientes: hay que evitar la inactividad física.

  17. Na Cauda do Cometa

    NASA Astrophysics Data System (ADS)

    Voelzke, M. R.

    2009-01-01

    Quando viam um cometa, os antigos gregos imaginavam uma estrela com uma vasta cabeleira. Não à toa, a palavra deriva do termo koma, que significa cabelo. Constituídos por fragmentos de gelo e gases, os cometas possuem um núcleo sólido, que pode ter vários quilômetros de diâmetro, e uma cauda que sempre aponta na direção contrária ao Sol, devido aos ventos solares. Graças à aparência de pontos luminosos em movimento (ao contrário de outros astros, que parecem estáticos), esses corpos celestes foram interpretados por diferentes povos com muito misticismo, inspirando mitos tanto de boas-novas como de maus presságios. Conheça algumas dessas histórias:

  18. Na+?sensing quantum dots for cell-based screening of intracellular Na+ concentrations ([Na+]i).

    PubMed

    Wang, Yuchi; Mao, Hua; Wong, Lid B

    2011-07-15

    We have developed a Na-quantum dot (QD) nanosensor for [Na(+)]i measurements. Using this Na-QD, we determined the dynamic physiological responses of [Na(+)]i in nonexcitable human HEK-293F cells and excitable primary rat cardiac myocytes by pharmacologically manipulating the membrane permeability to Na(+), the Na-K-2Cl cotransporter, and the Na(+)/H(+) antiporter. These data suggest that the mechanisms of [Na(+)]i homeostasis can now be elucidated with this novel Na-QD nanosensor. This could have a broad impact on Na(+) channel drug discovery. PMID:21645760

  19. Kaon experiments at CERN: NA48 and NA62

    E-print Network

    Evgueni Goudzovski

    2011-12-22

    Searches for violation of lepton flavour universality and lepton number conservation in kaon decays by the NA62 and NA48/2 experiments at CERN, status and future plans of the CERN kaon programme are presented. A precision measurement of the helicity-suppressed ratio $R_K$ of the $K^\\pm\\to e^\\pm\

  20. Recent results from NA61/SHINE and NA49

    NASA Astrophysics Data System (ADS)

    Rustamov, Anar; Na61/Shine; Na49 Collaborations

    2013-03-01

    Preliminary results on particle spectra and fluctuations in inelastic p+p interactions measured by NA61/SHINE at the CERN SPS are presented and its future ion program is discussed. We also show results on the excitation functions of event-by-event particle ratio fluctuations in central Pb+Pb collisions from NA49 using a novel approach. We found a dependence of the results on phase space coverage which appears to explain the reported difference between measurements of NA49 and those of STAR in central Au+Au collisions.

  1. Results from the NA61/SHINE and NA49 experiments

    NASA Astrophysics Data System (ADS)

    Rustamov, Anar

    2013-05-01

    Preliminary results on particle spectra and fluctuations in inelastic p + p interactions measured by NA61/SHINE at the CERN SPS are presented and its future ion program is discussed. We also show results on the excitation functions of event-by-event particle ratio fluctuations in central Pb + Pb collisions from NA49 using a novel approach. We found a dependence of the results on phase space coverage of the apparatus which appears to explain the reported difference between measurements of NA49 and those of STAR in central Au + Au collisions.

  2. Drugs preventing Na+ and Ca2+ overload.

    PubMed

    Ravens, U; Himmel, H M

    1999-03-01

    Cardiac intracellular Na+and Ca2+homeostasis is regulated by the concerted action of ion channels, pumps and exchangers. The Na+, K+-ATPase produces the electrochemical concentration gradient for Na+, which is the driving force for Ca2+removal from the cytosol via the Na+/Ca2+exchange. Reduction of this gradient by increased intracellular Na+concentration leads to cellular Ca2+overload resulting in arrhythmias and contractile dysfunction. Na+and Ca2+overload-associated arrhythmias can be produced experimentally by inhibition of Na+efflux (digitalis-induced intoxication) and by abnormal Na+influx via modulated Na+channels (veratridine, DPI 201-106; hypoxia) or via the Na+, H+exchanger. Theoretically, blockers of Na+and Ca2+channels, inhibitors of abnormal oscillatory release of Ca2+from internal stores or modulators of the Na+, Ca2+and Na+, H+exchanger activities could protect against cellular Na+and Ca2+overload. Three exemplary drugs that prevent Na+and Ca2+overload, i.e. the benzothiazolamine R56865, the methylenephenoxydioxy-derivative CP-060S, and the benzoyl-guanidine Hoe 642, a Na+, H+exchange blocker, are briefly reviewed with respect to their efficacy on digitalis-, veratridine- and ischaemia/reperfusion-induced arrhythmias. PMID:10094840

  3. Comunicación en la atención del cáncer (PDQ)—Versión para pacientes

    Cancer.gov

    Resumen de la información revisada por expertos acerca de la comunicación con el paciente de cáncer y sus familiares, que incluye los aspectos distintivos de la comunicación con pacientes de cáncer, los factores que afectan la comunicación y la capacitación en aptitudes para la comunicación.

  4. Tratamiento Quirúrgico de los Meningiomas del Foramen Óptico, Técnicay Resultados de una Serie de 18 Pacientes

    PubMed Central

    Goldschmidt, Ezequiel; Ajler, Pablo; Campero, Álvaro; Landriel, Federico; Sposito, Maximiliano; Carrizo, Antonio

    2014-01-01

    Introducción: los meningiomas del foramen óptico producen un rápido deterioro de la función visual aún cuando su tamaño es pequeño, por eso su diagnóstico y manejo difiere del resto de los meningiomas clinoideos. El propósito de este estudio es presentar la técnica y los resultados de nuestro manejo quirúrgico de meningiomas foraminales (MF). Pacientes y Métodos: se llevó a cabo una revisión de las historias clínicas de 47 pacientes con meningiomas primarios intraorbitarios. Se realizaron 52 cirugías en los pacientes con MF. Se empleó una craneotomía fronto-orbitaria, seguida de una descompresión extradural del canal óptico, resección del componente intraorbitario y exploración intradural del nervio óptico. Resultados: de los 12 pacientes con MF que presentaban la visión conservada, la agudeza visual fue preservada en 7 casos, mejoró en 2, y empeoró en 3. En 18 pacientes, el principal síntoma fue exoftalmos y en 35 pacientes ceguera unilateral. Ocurrieron 6 recurrencias, 2 a 10 años después de la resección quirúrgica. Cinco de ellos fueron reoperados. Se indicó radioterapia después de la recurrencia en 3 pacientes. Conclusión: el manejo de los MF continúa siendo controvertido y frecuentemente se propone un tratamiento conservador. Basados en nuestros hallazgos de frecuente extensión intracraneal, proponemos realizar una resección total o subtotal del tumor, preservando el nervio óptico en pacientes con visión prequirúrgica conservada. PMID:25165616

  5. Sodium iron hexacyanoferrate with high Na content as a Na-rich cathode material for Na-ion batteries

    DOE PAGESBeta

    You, Ya; Yu, Xi -Qian; Yin, Ya -Xia; Nam, Kyung -Wan; Guo, Yu -Guo

    2014-10-27

    Owing to the worldwide abundance and low-cost of Na, room-temperature Na-ion batteries are emerging as attractive energy storage systems for large-scale grids. Increasing the Na content in cathode material is one of the effective ways to achieve high energy density. Prussian blue and its analogues (PBAs) are promising Na-rich cathode materials since they can theoretically store two Na ions per formula. However, increasing the Na content in PBAs cathode materials is a big challenge in the current. Here we show that sodium iron hexacyanoferrate with high Na content could be obtained by simply controlling the reducing agent and reaction atmospheremore »during synthesis. The Na content can reach as high as 1.63 per formula, which is the highest value for sodium iron hexacyanoferrate. This Na-rich sodium iron hexacyanoferrate demonstrates a high specific capacity of 150 mA h g-1 and remarkable cycling performance with 90% capacity retention after 200 cycles. Furthermore, the Na intercalation/de-intercalation mechanism is systematically studied by in situ Raman, X-ray diffraction and X-ray absorption spectroscopy analysis for the first time. As a result, the Na-rich sodium iron hexacyanoferrate could function as a plenteous Na reservoir and has great potential as a cathode material toward practical Na-ion batteries.« less

  6. Sodium iron hexacyanoferrate with high Na content as a Na-rich cathode material for Na-ion batteries

    SciTech Connect

    You, Ya; Yu, Xi -Qian; Yin, Ya -Xia; Nam, Kyung -Wan; Guo, Yu -Guo

    2014-10-27

    Owing to the worldwide abundance and low-cost of Na, room-temperature Na-ion batteries are emerging as attractive energy storage systems for large-scale grids. Increasing the Na content in cathode material is one of the effective ways to achieve high energy density. Prussian blue and its analogues (PBAs) are promising Na-rich cathode materials since they can theoretically store two Na ions per formula. However, increasing the Na content in PBAs cathode materials is a big challenge in the current. Here we show that sodium iron hexacyanoferrate with high Na content could be obtained by simply controlling the reducing agent and reaction atmosphere during synthesis. The Na content can reach as high as 1.63 per formula, which is the highest value for sodium iron hexacyanoferrate. This Na-rich sodium iron hexacyanoferrate demonstrates a high specific capacity of 150 mA h g-1 and remarkable cycling performance with 90% capacity retention after 200 cycles. Furthermore, the Na intercalation/de-intercalation mechanism is systematically studied by in situ Raman, X-ray diffraction and X-ray absorption spectroscopy analysis for the first time. As a result, the Na-rich sodium iron hexacyanoferrate could function as a plenteous Na reservoir and has great potential as a cathode material toward practical Na-ion batteries.

  7. Melting of the Na Layers in Solid Na0.8CoO2

    NASA Astrophysics Data System (ADS)

    Weller, M.; Sacchetti, A.; Ott, H. R.; Mattenberger, K.; Batlogg, B.

    2009-02-01

    Data of Na23 NMR spectra and relaxation measurements are interpreted as suggesting that, upon increasing temperature, the Na layers in Na0.8CoO2 adopt a 2D liquid state at T=291K. The corresponding first order phase transition is preceded by a rapidly increasing mobility and diffusion of Na ions above 200 K. Above 291 K, the Na23 NMR response is similar to that previously observed in superionic conductors with planar Na layers.

  8. Ionic regulation of Na absorption in proximal colon: cation inhibition of electroneutral Na absorption

    SciTech Connect

    Sellin, J.H.; De Soignie, R.

    1987-01-01

    Active Na absorption (J/sub net//sup NA/) in rabbit proximal colon in vitro is paradoxically stimulated as (Na) in the bathing media is lowered with constant osmolarity. J/sub m..-->..s//sup Na/ increases almost linearly from 0 to 50 mM (Na)/sub 0/ but then plateaus and actually decreases from 50 to 140 mM (Na)/sub 0/, consistent with inhibition of an active transport process. Both lithium and Na are equally effective inhibitors of J/sub net//sup Na/, whereas choline and mannitol do not block the high rate of J/sub net//sup Na/ observed in decreased (Na)/sub 0/. Either gluconate or proprionate replacement of Cl inhibits J/sub net//sup Na/. J/sub net//sup Na/ at lowered (Na)/sub 0/ is electrically silent and is accompanied by increased Cl absorption; it is inhibited by 10/sup -3/ M amiloride and 10/sup -3/ theophylline but not by 10/sup -4/ M bumetanide. Epinephrine is equally effective at stimulating Na absorption at 50 and 140 mM (Na). Na gradient experiments are consistent with a predominantly serosal effect of the decreased (Na)/sub 0/. These results suggest that 1) Na absorption in rabbit proximal colon in vitro is stimulated by decreased (Na); 2) the effect is cation specific, both Na and Li blocking the stimulatory effect; 3) the transport is mediated by Na-H exchange and is Cl dependent but 4) is under different regulatory mechanisms than the epinephrine-sensitive Na-Cl cotransport previously described in proximal colon. Under the appropriate conditions, proximal colon absorbs Na extremely efficiently. Na-H exchange in this epithelium is cation inhibitable, either directly or by a secondary regulatory process.

  9. Europlanet NA2 Science Networking

    NASA Astrophysics Data System (ADS)

    Harri, Ari-Matti; Szego, Karoly; Genzer, Maria; Schmidt, Walter; Krupp, Norbert; Lammer, Helmut; Kallio, Esa; Haukka, Harri

    2013-04-01

    Europlanet RI / NA2 Science Networking [1] focused on determining the major goals of current and future European planetary science, relating them to the Research Infrastructure that the Europlanet RI project [2] developed, and placing them in a more global context. NA2 also enhanced the ability of European planetary scientists to participate on the global scene with their own agenda-setting projects and ideas. The Networking Activity NA2 included five working groups, aimed at identifying key science issues and producing reference books on major science themes that will bridge the gap between the results of present and past missions and the scientific preparation of the future ones. Within the Europlanet RI project (2009-2012) the NA2 and NA2-WGs organized thematic workshops, an expert exchange program and training groups to improve the scientific impact of this Infrastructure. The principal tasks addressed by NA2 were: • Science activities in support to the optimal use of data from past and present space missions, involving the broad planetary science community beyond the "space club" • Science activities in support to the preparation of future planetary missions: Earth-based preparatory observations, laboratory studies, R&D on advanced instrumentation and exploration technologies for the future, theory and modeling etc. • Develop scientific activities, joint publications, dedicated meetings, tools and services, education activities, engaging the public and industries • Update science themes and addressing the two main scientific objectives • Prepare and support workshops of the International Space Science Institute (ISSI) in Bern and • Support Trans National Activities (TNAs), Joined Research Activities (JRAs) and the Integrated and Distributed Information Service (IDIS) of the Europlanet project These tasks were achieved by WG workshops organized by the NA2 working groups, by ISSI workshops and by an Expert Exchange Program. There were 17 official WG workshops and in addition there were numerous smaller NA2 WG meetings during the conferences (EPSC, EGU, etc.) and other events. The total number of NA2 meetings and workshops was 37. There were three NA2 supported ISSI workshops within the Europlanet project. The first ISSI workshop "Comparison of the plasma-spheres of Mars, Venus, and Titan" organized by K. Szego was held in December 2009. The second workshop "Quantifying the Martian Geochemical Reservoirs" by M. Toplis was held in April 2011. The third one, themed "Giant Planet Magnetodiscs and Aurorae" by N. Krupp, N. Achilleos and C. Arridge, was in November 2012. All three ISSI workshops were selected by the ISSI scientific committee to be organized within the frame of ISSI/Europlanet agreement and held in Bern. The main objective of the Expert Exchange Program was to support the activities of Europlanet RI with experts whenever needed. The programme provided funding for short visits (up to one week) of expert with the goal of improving infrastructure facilities and services offered to the scientific community by the Europlanet RI participant (contractor) laboratories or institutes. Between July 2009 and September 2012 26 applications were selected. Acknowledgement: Europlanet RI was funded by the European Commission under the 7th Framework Program, grant 228319 "Capacities Specific Programme" - Research Infrastructures Action. References: [1] http://www.europlanet-ri.eu/ [2] https://europlanet-scinet.fi/

  10. The NA62 RICH Detector

    NASA Astrophysics Data System (ADS)

    Pepe, Monica

    The CERN NA62 experiment aims to measure the ultra-rare charged kaon decay K+ ? ?+?? (branching fraction O(10-10)) with a 10% accuracy. The detector must be able to reject background events from decay channels of which the branching fractions are up to 10 orders of magnitude larger than the signal and with similar experimental signature. To totally suppress the main background from K+??+? decay (BR ? 63%), NA62 will need a further ? rejection factor better than 5x10-3. This will be provided by a gas RICH detector for ?/? separation in a momentum range between 15 and 35 GeV/c. The details of the RICH project will be described and the results of two beam tests performed at CERN with prototypes will be presented.

  11. Przestrzenie CAT(0) Referat na 30. kwietnia

    E-print Network

    Weber, Andrzej

    Przestrzenie CAT(0) Referat na 30. kwietnia Oparty na ,,Lectures on proper CAT(0) spaces (jednoznacznie) geode- zyjna (na przyklad graf metryczny) · Wprowadzenie: trójkt porównania, nierówno CAT(0), przestrze CAT(0) · Przyklady: ­ Kada przestrze prehilbertowska jest CAT(0) ­ Graf metryczny jest CAT(0

  12. FDA aprueba fármaco en combinación para pacientes con cáncer colorrectal avanzado

    Cancer.gov

    aprobó una tableta que combina los fármacos trifluridina y clorhidrato de tipiracilo (Lonsurf®) para tratar a pacientes con cáncer colorrectal metastático cuya enfermedad haya avanzado después de tratamientos convencionales.

  13. Capacitación del personal y de los pacientes en torno a los cuidados terminales

    Cancer.gov

    Artículo sobre programas innovadores de base científica para ayudar a médicos y pacientes a hablar sobre la transición de un tratamiento activo para el cáncer a los cuidados en la etapa final de la vida.

  14. Personal de enfermería asume diversas funciones con expansión de programas de gestión para pacientes

    Cancer.gov

    Artículo sobre los profesionales de enfermería oncológica que ayudan a los pacientes durante todas las etapas de la atención oncológica, desde los exámenes de detección y el diagnóstico, hasta el tratamiento y la supervivencia.

  15. Adaptación al cáncer: ansiedad y sufrimiento (PDQ)—Versión para pacientes

    Cancer.gov

    Resumen de información revisada por expertos acerca de las difíciles respuestas emocionales que se presentan en muchos de los pacientes con cáncer. Este sumario se enfoca en asuntos de la adaptación normal, alteración psicosocial y trastornos de adaptación.

  16. Tensión postraumática relacionada con el cáncer (PDQ)—Versión para pacientes

    Cancer.gov

    Resumen de información revisada por expertos acerca de la tensión postraumática y los síntomas relacionados en los pacientes con cáncer, sobrevivientes del cáncer y miembros de la familia. Se discuten la evaluación y el tratamiento de estos síntomas.

  17. Complicaciones orales de la quimioterapia y la radioterapia (PDQ)—Versión para pacientes

    Cancer.gov

    Resumen de información revisada por expertos acerca de las complicaciones orales, como la mucositis y la disfunción de la glándula salival, que se presentan en pacientes de cáncer tratados con quimioterapia y radioterapia dirigida a la cabeza y el cuello.

  18. A long-life Na-air battery based on a soluble NaI catalyst.

    PubMed

    Yin, Wen-Wen; Shadike, Zulipiya; Yang, Yin; Ding, Fei; Sang, Lin; Li, Hong; Fu, Zheng-Wen

    2015-02-11

    A Na-air battery with NaI dissolved in a typical organic electrolyte could run up to 150 cycles with a capacity limit of 1000 mA h g(-1). The low charge voltage plateau of 3.2 V vs. Na(+)/Na in a Na-air battery should mainly be attributed to the oxidation reaction of active iodine anions. PMID:25562720

  19. Kinetic Analysis of H(+)-Na(+) Selectivity in a Light-Driven Na(+)-Pumping Rhodopsin.

    PubMed

    Kato, Yoshitaka; Inoue, Keiichi; Kandori, Hideki

    2015-12-17

    Krokinobacter eikastus rhodopsin 2 (KR2) is a recently identified light-driven Na(+) pump from a marine bacterium. KR2 pumps Na(+) in NaCl solution but pumps H(+) in the absence of Na(+) and Li(+). The Na(+) transport mechanism in KR2 has been extensively studied, whereas understanding of the H(+) transport mechanism is very limited. Here we studied ion uptake mechanisms and H(+)-Na(+) selectivity using flash photolysis. The results show that decay of the blue-shifted M intermediate is dependent on both [Na(+)] and [H(+)], indicating that KR2 competitively uptakes Na(+) or H(+) upon M decay. Comprehensive concentration dependence of Na(+) and H(+) revealed that the rate constant of H(+) uptake (kH) was much larger than that of Na(+) uptake (kNa) with a ratio (kH/kNa) of >10(3). Therefore, KR2 pumps only H(+) when Na(+) and H(+) concentrations are similar. On the contrary, KR2 pumps Na(+) exclusively under physiological conditions in which [Na(+)] is much greater than [H(+)]. PMID:26673197

  20. Redetermination of NaGdS2, NaLuS2 and NaYS2.

    PubMed

    Fábry, Jan; Havlák, Lubomír; Ku?eráková, Monika; Dušek, Michal

    2014-06-01

    The title structures NaGdS2 (sodium gadolinium sulfide), NaLuS2 (sodium lutetium sulfide) and NaYS2 (sodium yttrium sulfide) were redetermined in order to improve the structural information available for the family of group 1 and thallium rare earth sulfides, which are isostructural with the rhombohedral ?-NaFeO2 structure type. In particular, the present investigation has been directed at the rhombohedral sodium rare earth sulfides. The observed dependence of the fractional coordinate z(S(2-)) on the identity of the rare earth element in the newly determined structures is in agreement with the known structures of the potassium and rubidium analogues. Crystals of NaGdS2 and NaLuS2 display obverse-reverse twinning. PMID:24898952

  1. The effect of Na vapor on the Na content of chondrules

    NASA Technical Reports Server (NTRS)

    Lewis, R. Dean; Lofgren, Gary E.; Franzen, Hugo F.; Windom, Kenneth E.

    1993-01-01

    Chondrules contain higher concentrations of volatiles (Na) than expected for melt droplets in the solar nebula. Recent studies have proposed that chondrules may have formed under non-canonical nebular conditions such as in particle/gas-rich clumps. Such chondrule formation areas may have contained significant Na vapor. To test the hypothesis of whether a Na-rich vapor would minimize Na volatilization reaction rates in a chondrule analog and maintain the Na value of the melt, experiments were designed where a Na-rich vapor could be maintained around the sample. A starting material with a melting point lower that typical chondrules was required to keep the logistics of working with Na volatilization from NaCl within the realm of feasibility. The Knippa basalt, a MgO-rich alkali olivine basalt with a melting temperature of 1325 +/- 5 C and a Na2O content of 3.05 wt%, was used as the chondrule analog. Experiments were conducted in a 1 atm, gas-mixing furnace with the fO2 controlled by a CO/CO2 gas mixture and fixed at the I-W buffer curve. To determine the extent of Na loss from the sample, initial experiments were conducted at high temperatures (1300 C - 1350 C) for duration of up to 72 h without a Na-rich vapor present. Almost all (up to 98%) Na was volatilized in runs of 72 h. Subsequent trials were conducted at 1330 C for 16 h in the presence of a Na-rich vapor, supplied by a NaCl-filled crucible placed in the bottom of the furnace. Succeeding Knudsen cell weight-loss mass-spectrometry analysis of NaCl determined the P(sub Na) for these experimental conditions to be in the 10(exp -6) atm range. This value is considered high for nebula conditions but is still plausible for non-canonical environments. In these trials the Na2O content of the glass was maintained or in some cases increased; Na2O values ranged from 2.62% wt to 4.37% wt. The Na content of chondrules may be controlled by the Na vapor pressure in the chondrule formation region. Most heating events capable of producing chondrules are sufficient to volatile Na. Sodium volatilization reaction rates will be reduced to varying degrees from melt droplets, depending on the magnitude of the P(sub Na) generated. A combination of Na vapor during, and Na diffusion back into chondrules after, formation could maintain and/or enrich Na concentrations in chondrules.

  2. Maintaining the Na atmosphere of Mercury

    NASA Technical Reports Server (NTRS)

    Killen, Rosemary M.; Morgan, Thomas H.

    1993-01-01

    The possible sources of the Na atmosphere of Mercury are calculatively studied. The likely structure, composition, and temperature of the planet's upper crust is examined along with the probable flux of Na from depth by grain boundary diffusion and by Knudsen flow. The creation of fresh regolith is considered along with mechanisms for supplying Na from the surface to the exosphere. The implications of the calculations for the probable abundances in the regolith are discussed.

  3. Painful Na-channelopathies: an expanding universe.

    PubMed

    Waxman, Stephen G

    2013-07-01

    The universe of painful Na-channelopathies--human disorders caused by mutations in voltage-gated sodium channels--has recently expanded in three dimensions. We now know that mutations of sodium channels cause not only rare genetic 'model disorders' such as inherited erythromelalgia and channelopathy-associated insensitivity to pain but also common painful neuropathies. We have learned that mutations of NaV1.8, as well as mutations of NaV1.7, can cause painful Na-channelopathies. Moreover, recent studies combining atomic level structural models and pharmacogenomics suggest that the goal of genomically guided pain therapy may not be unrealistic. PMID:23664154

  4. Na+-H+ exchange and Na+ entry across the apical membrane of Necturus gallbladder

    PubMed Central

    1984-01-01

    The role of Na+-H+ exchange in Na+ transport across the apical membrane was evaluated in Necturus gallbladder epithelium by means of intracellular Na+ activity (aNai) and 22Na+ uptake measurements. Under control conditions, complete replacement of Na+ in the mucosal solution with tetramethylammonium reduced aNai from 14.0 to 6.9 mM in 2 min (P less than 0.001). Mucosal addition of the Na+-H+ exchange inhibitor amiloride (10(-3) M) reduced aNai from 15.0 to 13.3 mM (P less than 0.001), whereas bumetanide (10(-5) and 10(-4) M) had no effect. Na+ influx across the apical membrane was studied by treating the tissues with ouabain, bathing them in Na-free solutions, and suddenly replacing the mucosal solution with an Na-containing solution. When the mucosal solution was replaced with Na-Ringer's, aNai increased at approximately 11 mM/min. This increase was inhibited by 54% by amiloride (10(-3) M, P less than 0.001) and was unaffected by bumetanide (10(-5) M). Amiloride- inhibitable Na+ fluxes across the apical membrane were also induced by the imposition of pH gradients. Na+ influx was also examined in tissues that had not been treated with ouabain. Under control conditions, 22Na+ influx from the mucosal solution into the epithelium was linear over the first 60 s and was inhibited by 40% by amiloride (10(-3) M, P less than 0.001) and by 19% by bumetanide (10(-5) M, P less than 0.025). We conclude that Na+-H+ exchange is a major pathway for Na+ entry in Necturus gallbladder, which accounts for at least half of apical Na+ influx both under transporting conditions and during exposure to ouabain. Bumetanide-inhibitable Na+ entry mechanisms may account for only a smaller fraction of Na+ influx under transporting conditions, and cannot explain influx in ouabain-treated tissues. These results support the hypothesis that NaCl entry results primarily from the operation of parallel Na+-H+ and Cl--HCO-3 exchangers, and not from a bumetanide-inhibitable NaCl cotransporter. PMID:6319545

  5. Regulation of Na+ fluxes in plants

    PubMed Central

    Maathuis, Frans J. M.; Ahmad, Izhar; Patishtan, Juan

    2014-01-01

    When exposed to salt, every plant takes up Na+ from the environment. Once in the symplast, Na+ is distributed within cells and between different tissues and organs. There it can help to lower the cellular water potential but also exert potentially toxic effects. Control of Na+ fluxes is therefore crucial and indeed, research shows that the divergence between salt tolerant and salt sensitive plants is not due to a variation in transporter types but rather originates in the control of uptake and internal Na+ fluxes. A number of regulatory mechanisms has been identified based on signaling of Ca2+, cyclic nucleotides, reactive oxygen species, hormones, or on transcriptional and post translational changes of gene and protein expression. This review will give an overview of intra- and intercellular movement of Na+ in plants and will summarize our current ideas of how these fluxes are controlled and regulated in the early stages of salt stress. PMID:25278946

  6. Na-doped optical Germanium bulk crystals

    NASA Astrophysics Data System (ADS)

    Pekar, G. S.; Singaevsky, A. F.

    2012-09-01

    In an effort to develop a material for infrared (IR) optics with improved parameters, bulk crystals of optical germanium doped with Na have been first grown and studied. Single-crystalline and coarse-crystalline Ge:Na boules of different shapes and dimensions, up to 10 kg by weight, have been grown. Sodium was incorporated into the Ge crystal during the crystal growing from the melt. Despite the fact that Na contamination in the source material was not strictly controlled, the density of Na in the grown crystals determined by the neutron activation analysis as well as by the glow discharge mass spectrometry did not exceed 1015 cm-3. Just this value may be supposed to be close to the solubility limit of Na incorporated in Ge in the course of bulk crystal growth. A first demonstration of donor behavior of Na in bulk Ge crystals is made by means of a thermoelectric type of testing. An interstitial location of Na impurity has been verified by experiments on donor drift in the dc electric field. The crystals are grown with free electron density in the range from 5?1013 to 4?1014 cm-3 which is optimal for using Ge crystals as an optical material for fabricating passive elements of the IR technique. A comparison between the properties of Ge:Na crystals and Ge crystals doped with Sb, a conventional impurity in optical germanium, grown under the same technological conditions and from the same intrinsic Ge as a source material, revealed a number of advantages of Ge:Na crystals; among them, the higher transparency in the IR region, smaller radiation scattering and higher regular optical transmission, lower dislocation density, more uniform distribution of electrical and optical characteristics over the crystal volume, the identity of optical parameters in the single-crystalline, and coarse-crystalline boules. No degradation of optical elements fabricated from Ge:Na crystals was detected in the course of their commercial application, starting from 1998.

  7. Extracellular Na+ levels regulate formation and activity of the NaX/alpha1-Na+/K+-ATPase complex in neuronal cells

    PubMed Central

    Berret, Emmanuelle; Smith, Pascal Y.; Henry, Mélaine; Soulet, Denis; Hébert, Sébastien S.; Toth, Katalin; Mouginot, Didier; Drolet, Guy

    2014-01-01

    MnPO neurons play a critical role in hydromineral homeostasis regulation by acting as sensors of extracellular sodium concentration ([Na+]out). The mechanism underlying Na+-sensing involves Na+-flow through the NaX channel, directly regulated by the Na+/K+-ATPase ?1-isoform which controls Na+-influx by modulating channel permeability. Together, these two partners form a complex involved in the regulation of intracellular sodium ([Na+]in). Here we aim to determine whether environmental changes in Na+ could actively modulate the NaX/Na+/K+-ATPase complex activity. We investigated the complex activity using patch-clamp recordings from rat MnPO neurons and Neuro2a cells. When the rats were fed with a high-salt-diet, or the [Na+] in the culture medium was increased, the activity of the complex was up-regulated. In contrast, drop in environmental [Na+] decreased the activity of the complex. Interestingly under hypernatremic condition, the colocalization rate and protein level of both partners were up-regulated. Under hyponatremic condition, only NaX protein expression was increased and the level of NaX/Na+/K+-ATPase remained unaltered. This unbalance between NaX and Na+/K+-ATPase pump proportion would induce a bigger portion of Na+/K+-ATPase-control-free NaX channel. Thus, we suggest that hypernatremic environment increases NaX/Na+/K+-ATPase ?1-isoform activity by increasing the number of both partners and their colocalization rate, whereas hyponatremic environment down-regulates complex activity via a decrease in the relative number of NaX channels controlled by the pump. PMID:25538563

  8. Na-site substitution effects on the thermoelectric properties of NaCo2O4

    NASA Astrophysics Data System (ADS)

    Kawata, T.; Iguchi, Y.; Itoh, T.; Takahata, K.; Terasaki, I.

    1999-10-01

    The resistivity and thermopower of Na1+xCo2O4 and Na1.1-xCaxCo2O4 are measured and analyzed. In Na1+xCo2O4, whereas the resistivity increases with x, the thermopower is nearly independent of x. This suggests that the excess Na is unlikely to supply carriers, and decreases effective conduction paths in the sample. In Na1.1-xCaxCo2O4, the resistivity and the thermopower increase with x, and the Ca2+ substitution for Na+ reduces the majority carriers in NaCo2O4. This means that they are holes, which is consistent with the positive sign of the thermopower. Strong correlation in this compound is evidenced by the peculiar temperature dependence of the resistivity.

  9. Familiares a cargo de pacientes de cáncer: funciones y desafíos (PDQ)—Versión para profesionales de salud

    Cancer.gov

    Sumario informativo revisado por expertos acerca de los desafíos que enfrentan los familiares a cargo de los pacientes con cáncer. Este resumen se centra en las funciones típicas y las inquietudes de las personas a cargo del paciente y en las intervenciones útiles para esas personas.

  10. Variational calculations of rotationally resolved infrared properties of Li 2Na +, LiNa 2+ and KLiNa +

    NASA Astrophysics Data System (ADS)

    Wang, Feng; Searles, Debra J.; von Nagy-Felsobuki, Ellak I.

    1992-10-01

    Ab initio variational rovibrational calculations have been performed for the ground electronic states of Li 2Na +, LiNa +2 and KLiNa +. Discrete potential and electric dipole moment surfaces were used to calculate rovibrational transition frequencies, absolute vibrational bands and line intensities. The variational rovibration calculations take into account a full description of the mechanical and electrical anharmonicity as well as vibration—rotation coupling effects. Absolute line intensities and square dipole matrix elements are given for some intense transitions within the P-, Q- and R-branches between the vibrational ground state and the lowest lying excited states.

  11. NMR studies on Na+ transport in Synechococcus PCC 6311

    NASA Technical Reports Server (NTRS)

    Nitschmann, W. H.; Packer, L.

    1992-01-01

    The freshwater cyanobacterium Synechococcus PCC 6311 is able to adapt to grow after sudden exposure to salt (NaCl) stress. We have investigated the mechanism of Na+ transport in these cells during adaptation to high salinity. Na+ influx under dark aerobic conditions occurred independently of delta pH or delta psi across the cytoplasmic membrane, ATPase activity, and respiratory electron transport. These findings are consistent with the existence of Na+/monovalent anion cotransport or simultaneous Na+/H+ +anion/OH- exchange. Na+ influx was dependent on Cl-, Br-, NO3-, or NO2-. No Na+ uptake occurred after addition of NaI, NaHCO3, or Na2SO4. Na+ extrusion was absolutely dependent on delta pH and on an ATPase activity and/or on respiratory electron transport. This indicates that Na+ extrusion via Na+/H+ exchange is driven by primary H+ pumps in the cytoplasmic membrane. Cells grown for 4 days in 0.5 m NaCl medium, "salt-grown cells," differ from control cells by a lower maximum velocity of Na+ influx and by lower steady-state ratios of [Na+]in/[Na+]out. These results indicate that cells grown in high-salt medium increase their capacity to extrude Na+. During salt adaptation Na+ extrusion driven by respiratory electron transport increased from about 15 to 50%.

  12. Myocardial Na,K-ATPase: Clinical aspects

    PubMed Central

    Kjeldsen, Keld

    2003-01-01

    The specific binding of digitalis glycosides to Na,K-ATPase is used as a tool for Na,K-ATPase quantification with high accuracy and precision. In myocardial biopsies from patients with heart failure, total Na,K-ATPase concentration is decreased by around 40%; a correlation exists between a decrease in heart function and a decrease in Na,K-ATPase concentration. During digitalization, around 30% of remaining pumps are occupied by digoxin. Myocardial Na,K-ATPase is also influenced by other drugs used for the treatment of heart failure. Thus, potassium loss during diuretic therapy has been found to reduce myocardial Na,K-ATPase, whereas angiotensin-converting enzyme inhibitors may stimulate Na,K pump activity. Furthermore, hyperaldosteronism induced by heart failure has been found to decrease Na,K-ATPase activity. Accordingly, treatment with the aldosterone antagonist, spironolactone, may also influence Na,K-ATPase activity. The importance of Na,K pump modulation with heart disease, inhibition in digitalization and other effects of medication should be considered in the context of sodium, potassium and calcium regulation. It is recommended that digoxin be administered to heart failure patients who, after institution of mortality-reducing therapy, still have heart failure symptoms, and that the therapy be continued if symptoms are revealed or reduced. Digitalis glycosides are the only safe inotropic drugs for oral use that improve hemodynamics in heart failure. An important aspect of myocardial Na,K pump affection in heart disease is its influence on extracellular potassium (Ke) homeostasis. Two important aspects should be considered: potassium handling among myocytes, and effects of potassium entering the extracellular space of the heart via the bloodstream. It should be noted that both of these aspects of Ke homeostasis are affected by regulatory aspects, eg, regulation of the Na,K pump by physiological and pathophysiological conditions, as well as by medical treatments. Digitalization has been shown to affect both parameters. Furthermore, in experimental animals, potassium loading and depletion are found to significantly affect Ke handling. The effects of potassium depletion are of special interest because this condition often occurs in patients treated with diuretics. In human congenital long QT syndrome caused by mutations in genes coding for potassium channels, exercise and potassium depletion are well known for their potential to elicit arrhythmias and sudden death. There is a need for further evaluation of the dynamic aspects of potassium handling in the heart, as well as in the periphery. It is recommended that resting plasma potassium be maintained at around 4 mmol/L. PMID:19641704

  13. Uso de nanopartículas dirigidas se pone a prueba en pacientes con cáncer

    Cancer.gov

    Al empacar las moléculas del fármaco quimioterapéutico docetaxel en nanopartículas, los investigadores buscan administrar una dosis más alta del medicamento directamente a los tumores y reducir la toxicidad en los pacientes. Un estudio para poner a prueba la nanopartícula dirigida en seres humanos se encuentra en marcha.

  14. Planificar la transición a la etapa final de la vida (PDQ)—Versión para pacientes

    Cancer.gov

    Resumen de información revisada por expertos sobre la preparación necesaria por parte de los proveedores de atención de la salud, los pacientes y sus familias para la transición a la atención del cáncer avanzado en la etapa final de la vida.

  15. Anamorphic high-NA EUV lithography optics

    NASA Astrophysics Data System (ADS)

    Migura, Sascha; Kneer, Bernhard; Neumann, Jens Timo; Kaiser, Winfried; van Schoot, Jan

    2015-09-01

    EUV lithography (EUVL) for a limit resolution below 8 nm requires the numerical aperture (NA) of the projection optics to be larger than 0.50. For such a high-NA optics a configuration of 4x magnification, full field size of 26 x 33 mm² and 6'' mask is not feasible anymore. The increased chief ray angle and higher NA at reticle lead to non-acceptable mask shadowing effects. These shadowing effects can only be controlled by increasing the magnification, hence reducing the system productivity or demanding larger mask sizes. We demonstrate that the best compromise in imaging, productivity and field split is a so-called anamorphic magnification and a half field of 26 x 16.5 mm² but utilizing existing 6'' mask infrastructure. We discuss the optical solutions for such anamorphic high-NA EUVL.

  16. Triplet state photoassociation of LiNa

    NASA Astrophysics Data System (ADS)

    Rvachov, Timur; Jamison, Alan; Jing, Li; Jiang, Yijun; Zwierlein, Martin; Ketterle, Wolfgang

    2015-05-01

    Ultracold molecules have promise to become a useful tool for studies in quantum simulation and ultracold chemistry. We aim to produce ultracold fermionic 6Li23Na molecules in the triplet ground state. Due to the small mass, small spin-orbit coupling, and fermionic character of LiNa, the triplet ground state is expected to be long lived. We report on photoassociation spectra of LiNa to its triplet excited states from an ultracold mixture. This is the first observation of these excited triplet potentials, which have been previously difficult to observe in heat-pipe experiments due to the small spin-orbit coupling in the system. Determining the excited state potentials is a key milestone towards forming triplet ground state LiNa via two-photon STIRAP. Work supported by the NSF, AFOSR-MURI, ARO-MURI, and NSERC.

  17. Deliquescence of NaCl-NaNO3, KNO3-NaNO3, and NaCl-KNO3 Salt Mixtures From 90 to 120?C

    SciTech Connect

    Carroll, S A; Craig, L; Wolery, T J

    2004-10-20

    We conducted reversed deliquescence experiments in saturated NaCl-NaNO{sub 3}-H{sub 2}O, KNO{sub 3}-NaNO{sub 3}-H{sub 2}O, and NaCl-KNO{sub 3}-H{sub 2}O systems from 90 to 120 C as a function of relative humidity and solution composition. NaCl, NaNO{sub 3}, and KNO{sub 3} represent members of dust salt assemblages that are likely to deliquesce and form concentrated brines on high-level radioactive waste package surfaces in a repository environment at Yucca Mountain, NV, USA. Discrepancy between model prediction and experimental code can be as high as 8% for relative humidity and 50% for dissolved ion concentration. The discrepancy is attributed primarily to the use of 25 C models for Cl-NO{sub 3} and K-NO{sub 3} ion interactions in the current Yucca Mountain Project high-temperature Pitzer model to describe the non-ideal behavior of these highly concentrated solutions.

  18. Vibrational signatures of sodiated oligopeptides (GG-Na+, GGG-Na+, AA-Na+ and AAA-Na+) in the gas phase

    NASA Astrophysics Data System (ADS)

    Balaj, O. P.; Kapota, C.; Lemaire, J.; Ohanessian, G.

    2008-02-01

    The structures of the sodium complexes of oligoglycines (GG-Na+, GGG-Na+) and oligoalanines (AA-Na+, AAA-Na+) have been studied by infrared spectroscopy in the gas phase. Two different experimental set-ups have been used to generate, trap and analyze the ions. In the first, the complexes were generated by MALDI and analyzed in the cell of a home built FT-ICR mass spectrometer. In the second an external electrospray source was coupled to a Paul type ion trap. Following their trapping, the ions are irradiated in both cases with intense, tunable infrared light in the 1000-2000 cm-1 range, leading to sodium ion detachment and ion fragmentation via the absorption of multiple photons. The resulting experimental spectra are compared to theoretical linear absorption spectra to assign structures. In agreement with calculations, peptide attachment to Na+ is found to have a strong structuring effect: the lowest energy structures involve binding of all carbonyl oxygens to the cation. Detailed comparison of experimental and computed spectra shows that the IRMPD spectroscopy of such gaseous ions allows the differentiation between structures which do not have the same number of carbonyl oxygens bound to Na+, and structures in which the peptide is either wrapped around the ion or capped by it.

  19. Onset of deconfinement and critical point: NA49 and NA61/SHINE at the CERN SPS

    NASA Astrophysics Data System (ADS)

    Ga?dzicki, M.

    2008-03-01

    This paper is dedicated to the memory of József Zimányi one of the founders of the experiment NA49 at the CERN SPS. Firstly, the paper summarizes the main results of NA49 concerning observation of the onset of deconfinement in central Pb+Pb collisions at the low SPS energies. Secondly, it sketches the physics program of NA61 at the CERN SPS, the successor of NA49, which in particular aims to discover the critical point of strongly interacting matter. Finaly, a brief review of the future experimental programs in the CERN SPS energy range is given.

  20. Onset of Deconfinement and Critical Point: NA49 and NA61/SHINE at the CERN SPS

    E-print Network

    Marek Gazdzicki

    2008-01-31

    This paper is dedicated to the memory of Jozsef Zimanyi one of the founders of the experiment NA49 at the CERN SPS. Firstly, the paper summarizes the main results of NA49 concerning observation of the onset of deconfinement in central Pb+Pb collisions at the low SPS energies. Secondly, it sketches the physics program of NA61 at the CERN SPS, the successor of NA49, which in particular aims to discover the critical point of strongly interacting matter. Finaly, a brief review of the future experimental programs in the CERN SPS energy range is given.

  1. Influence of sodium halides (NaF, NaCl, NaBr, NaI) on the photocatalytic performance of hydrothermally synthesized hematite photoanodes.

    PubMed

    Wang, Tsinghai; Huang, Mao-Chia; Hsieh, Yi-Kong; Chang, Wen-Sheng; Lin, Jing-Chie; Lee, Chih-Hao; Wang, Chu-Fang

    2013-08-28

    It has been suggested that a high concentration of Fe(3+) in solution, a low pH, and noncomplexing ions of high ionic strength are all essential for developing a high-quality hematite array. Our curiosity was piqued regarding the role of the electrolyte ions in the hydrothermal synthesis of hematite photoanodes. In this study, we prepared hematite photoanodes hydrothermally from precursor solutions of 0.1 M FeCl3 at pH 1.55 with a background electrolyte of 1.0 M sodium halide (NaF, NaCl, NaBr, or NaI). We compared the structures and properties of the as-obtained hematite photoanodes with those of the material prepared in 1.0 M NaNO3, the most widely adopted electrolyte in previous studies. Among our studied systems, we found that the hematite photoanode prepared in NaCl solution was the only one possessing properties similar to those of the sample obtained from the NaNO3 solution-most importantly in terms of photoelectrochemical performance (ca. 0.2 mA/cm(2) with +0.4 V vs SCE). The hematites obtained from the NaF, NaBr, and NaI solutions exhibited much lower (by approximately 2 orders of magnitude) photocurrent densities under the same conditions, possibly because of their relatively less ordered crystallinity and the absence of rodlike morphologies. Because the synthetic protocol was identical in each case, we believe that these two distinct features reflect the environments in which these hematite photoanodes were formed. Consistent with the latest studies reported in the literature of the X-ray photoelectron spectra of fast-frozen hematite colloids in aqueous solutions, it appears that the degree of surface ion loading at the electrolyte-hematite interface (Stern layer) is critical during the development of hematite photoanodes. We suspect that a lower ion surface loading benefits the hematite developing relatively higher-order and a rodlike texture, thereby improving the photoelectrochemical activity. PMID:23865744

  2. Molecular dynamics investigation of Na+ in Na2Ni2TeO6

    NASA Astrophysics Data System (ADS)

    Sau, Kartik; Kumar, P. Padma

    2014-04-01

    An inter-atomic potential for Na2Ni2TeO6 in the Parrinello- Rahman-Vashishta (PRV) model is parameterized empirically. The potential reproduces variety of structural and transport properties of that material in good agreement with recent experimental results. The study provides fresh insights on the migration channels and mechanism of Na+ in the system.

  3. Opposing effects of Na+ and K+ on the thermal stability of Na+,K(+)-ATPase.

    PubMed

    Kaufman, Sergio B; González-Flecha, F Luis; González-Lebrero, Rodolfo M

    2012-03-15

    Folding and structural stability are key factors for the proper biological function of proteins. Na(+),K(+)-ATPase is an integral membrane protein involved in the active transport of Na(+) and K(+) across the plasma membrane. In this work we characterized the effects of K(+) and Na(+) on the thermal inactivation of Na(+),K(+)-ATPase, evaluating both catalytic and transport capacities of the pump. Both activities of the enzyme decrease with the preincubation time as first-order kinetics. The thermal inactivation of Na(+),K(+)-ATPase is simultaneous with a conformational change detected by tryptophan and 1-aniline-8-naphtalenesulfonate (ANS) fluorescence. The kinetic coefficient of thermal inactivation was affected by the presence of Na(+) and K(+) (or Rb(+)) and the temperature of the preincuabtion media. Our results show that K(+) or Rb(+) stabilize the enzyme, while Na(+) decreases the stability of Na(+),K(+)-ATPase. Both effects are exerted by the specific binding of these cations to the pump. Also, we provided strong evidence that the Rb(+) (or K(+)) stabilization effect is due to the occlusion of these cations into the enzyme. Here, we proposed a minimal kinetic model that explains the behavior observed in the experimental results and allows a better understanding of the results presented by other researchers. The thermal inactivation process was also analyzed according to Kramer's theory. PMID:22283598

  4. Gas-Phase Molecular Halogen Formation from NaCl and NaBr Aerosols: When Are Interface Reactions Important?

    E-print Network

    Dabdub, Donald

    Gas-Phase Molecular Halogen Formation from NaCl and NaBr Aerosols: When Are Interface Reactions at the surface of sea-salt particles have been suggested as an important source of photolyzable gas-phase halogen the influence of interface reactions on gas-phase molecular halogen production from pure NaCl and NaBr aerosols

  5. The voltage-gated Na channel NaVBP has a role in motility, chemotaxis, and pH homeostasis

    E-print Network

    Xu, Haoxing

    The voltage-gated Na channel NaVBP has a role in motility, chemotaxis, and pH homeostasisH homeostasis at high pH. Reduced motility of bacteria lacking functional NaVBP was reversed by restoration in response to chemoeffectors. Mutants lacking functional NaVBP were also defective in pH homeostasis

  6. Na-ion dynamics in Quasi-1D compound NaV2O4

    NASA Astrophysics Data System (ADS)

    Månsson, M.; Umegaki, I.; Nozaki, H.; Higuchi, Y.; Kawasaki, I.; Watanabe, I.; Sakurai, H.; Sugiyama, J.

    2014-12-01

    We have used the pulsed muon source at ISIS to study high-temperature Na-ion dynamics in the quasi-one-dimensional (Q1D) metallic antiferromagnet NaV2O4. By performing systematic zero-field and longitudinal-field measurements as a function of temperature we clearly distinguish that the hopping rate increases exponentially above Tdiff ? 250 K. The data is well fitted to an Arrhenius type equation typical for a diffusion process, showing that the Na-ions starts to be mobile above Tdiff. Such results make this compound very interesting for the tuning of Q1D magnetism using atomic-scale ion-texturing through the periodic potential from ordered Na-vacancies. Further, it also opens the door to possible use of NaV2O4 and related compounds in energy related applications.

  7. Long-Range Effects of Na(+) Binding in Na,K-ATPase Reported by ATP.

    PubMed

    Middleton, David A; Fedosova, Natalya U; Esmann, Mikael

    2015-12-01

    This paper addresses the question of long-range interactions between the intramembranous cation binding sites and the cytoplasmic nucleotide binding site of the ubiquitous ion-transporting Na,K-ATPase using (13)C cross-polarization magic-angle spinning (CP-MAS) solid-state nuclear magnetic resonance. High-affinity ATP binding is induced by the presence of Na(+) as well as of Na-like substances such as Tris(+), and these ions are equally efficient promoters of nucleotide binding. CP-MAS analysis of bound ATP with Na,K-ATPase purified from pig kidney membranes reveals subtle differences in the nucleotide interactions within the nucleotide site depending on whether Na(+) or Tris(+) is used to induce binding. Differences in chemical shifts for ATP atoms C1' and C5' observed in the presence of Na(+) or Tris(+) suggest alterations in the residues surrounding the bound nucleotide, hydrogen bonding, and/or conformation of the ribose ring. This is taken as evidence of a long-distance communication between the Na(+)-filled ion sites in the membrane interior and the nucleotide binding site in the cytoplasmic domain and reflects the first conformational change ultimately leading to phosphorylation of the enzyme. Stopped-flow fluorescence measurements with the nucleotide analogue eosin show that the dissociation rate constant for eosin is larger in Tris(+) than in Na(+), giving kinetic evidence of the difference in structural effects of Na(+) and Tris(+). According to the recent crystal structure of the E1·AlF4(-)·ADP·3Na(+) form, the coupling between the ion binding sites and the nucleotide side is mediated by, among others, the M5 helix. PMID:26538123

  8. Recent results from NA61/SHINE

    E-print Network

    Pu?awski, Szymon

    2015-01-01

    The main physics goals of the NA61/SHINE programme on strong interactions are the study of the properties of the onset of deconfinement and the search for signatures of the critical point of strongly interacting matter. These goals are pursued by performing an energy (beam momentum 13A -158A GeV/c) and system size (p+p, p+Pb, Be+Be, Ar+Sc, Xe+La) scan. This publication reviews results and plans of NA61/SHINE. In particular, recent inclusive spectra and new results on fluctuations and correlations of identified hadrons in inelastic p+p and centrality selected Be+Be interactions at the SPS energies are presented. The energy dependence of quantities inspired by the Statistical Model of the Early Stage (kink, horn and step) show unexpected behavior in p+p collisions. The NA61/SHINE results are compared with the corresponding data of other experiments and model predictions.

  9. Z .Thin Solid Films 372 2000 212 217 Z .Na in selenized Cu In,Ga Se on Na-containing and Na-free2

    E-print Network

    Rockett, Angus

    Z .Thin Solid Films 372 2000 212 217 Z .Na in selenized Cu In,Ga Se on Na-containing and Na-free2 of the substrate glass on standard Z . Z .production Cu In Ga Se CIGS -based solar cells fabricated by selenization . The Na is found primarily in the areas of decreased grain size in the selenized CIGS where Ga is also

  10. Comparative studies of etching mechanisms of CR-39 in NaOH/H2O and NaOH/ethanol

    E-print Network

    Yu, Peter K.N.

    Comparative studies of etching mechanisms of CR-39 in NaOH/H2O and NaOH/ethanol K.C.C. Tse, DOH/ethanol was faster than those in aqueous solution of NaOH (NaOH/H2O). Furthermore, a layer of precipitate always in NaOH/H2O. In the present work, mass spectrometry results have shown that the same etched products

  11. O Grotesco na Dramaturgia de Ariano Suassuna

    E-print Network

    Telles, Narciso

    2002-04-01

    envolvimento do padre, sacristão, bispo, cangaceiro e cabra, padeiro e sua mulher (donos do cachorro) na distribuição do dinheiro deixado em testamento pelo cachorro, inventado por João Grilo para vingar-se de seu patrão, o padeiro. 2) a morte de todos, com...

  12. LA GACETA 107 RESE ~NA DE LIBROS

    E-print Network

    Rey Juan Carlos, Universidad

    LA GACETA 107 RESE ~NA DE LIBROS DYNAMICAL SYSTEMS WITH APPLICATIONS USING MAPPLE Autor: Stephen libro publicado por alg´un autor ruso, no siempre f´acil de desci- frar. En los ´ultimos a~nos, sin los muchos libros que existen en el mercado y que van apareciendo cada d´ia. Una buena elecci´on ser

  13. [Indices of intragastric pNa-graphy in dogs].

    PubMed

    Kienia, A I

    1976-01-01

    The dynamics of intragastric pNa was looked into in 6 dogs with fistulas in the gastric fundus by employing the method of its automatic registration on an empty stomach and after feeding the animals on a nutritional stimulant. The pNa parameters and the types of intragastric pNa-grams before feeding the animals, pNa changes during and after feeding them on a nutritional stimulant and with histamin stimulated secretion, as well as the time of the progressively increasing activity of the Na+ ions and the pNa curve stabilization level were determined. PMID:1030900

  14. Laser trapping of {sup 21}Na atoms

    SciTech Connect

    Lu, Zheng-Tian

    1994-09-01

    This thesis describes an experiment in which about four thousand radioactive {sup 21}Na (t{sub l/2} = 22 sec) atoms were trapped in a magneto-optical trap with laser beams. Trapped {sup 21}Na atoms can be used as a beta source in a precision measurement of the beta-asymmetry parameter of the decay of {sup 21}Na {yields} {sup 21}Ne + {Beta}{sup +} + v{sub e}, which is a promising way to search for an anomalous right-handed current coupling in charged weak interactions. Although the number o trapped atoms that we have achieved is still about two orders of magnitude lower than what is needed to conduct a measurement of the beta-asymmetry parameter at 1% of precision level, the result of this experiment proved the feasibility of trapping short-lived radioactive atoms. In this experiment, {sup 21}Na atoms were produced by bombarding {sup 24}Mg with protons of 25 MeV at the 88 in. Cyclotron of Lawrence Berkeley Laboratory. A few recently developed techniques of laser manipulation of neutral atoms were applied in this experiment. The {sup 21}Na atoms emerging from a heated oven were first transversely cooled. As a result, the on-axis atomic beam intensity was increased by a factor of 16. The atoms in the beam were then slowed down from thermal speed by applying Zeeman-tuned slowing technique, and subsequently loaded into a magneto-optical trap at the end of the slowing path. The last two chapters of this thesis present two studies on the magneto-optical trap of sodium atoms. In particular, the mechanisms of magneto-optical traps at various laser frequencies and the collisional loss mechanisms of these traps were examined.

  15. 24Mg( p, ?)21Na reaction study for spectroscopy of 21Na

    NASA Astrophysics Data System (ADS)

    Cha, S. M.; Chae, K. Y.; Kim, A.; Lee, E. J.; Ahn, S.; Bardayan, D. W.; Chipps, K. A.; Cizewski, J. A.; Howard, M. E.; Manning, B.; O'Malley, P. D.; Ratkiewicz, A.; Strauss, S.; Kozub, R. L.; Matos, M.; Pain, S. D.; Pittman, S. T.; Smith, M. S.; Peters, W. A.

    2015-10-01

    The 24Mg( p, ?)21Na reaction was measured at the Holifield Radioactive Ion Beam Facility at Oak Ridge National Laboratory in order to better constrain the spins and parities of the energy levels in 21Na for the astrophysically important 17F( ?, p)20Ne reaction rate calculation. 31-MeV proton beams from the 25-MV tandem accelerator and enriched 24Mg solid targets were used. Recoiling 4He particles from the 24Mg( p, ?)21Na reaction were detected by a highly segmented silicon detector array which measured the yields of 4He particles over a range of angles simultaneously. A new level at 6661 ± 5 keV was observed in the present work. The extracted angular distributions for the first four levels of 21Na and the results from distorted wave Born approximation (DWBA) calculations were compared to verify and extract the angular momentum transfer.

  16. Batrachotoxin-activated Na+ channels in planar lipid bilayers. Competition of tetrodotoxin block by Na+

    PubMed Central

    1984-01-01

    Single Na+ channels from rat skeletal muscle plasma membrane vesicles were inserted into planar lipid bilayers formed from neutral phospholipids and were observed in the presence of batrachotoxin. The batrachotoxin-modified channel activates in the voltage range -120 to - 80 mV and remains open almost all the time at voltages positive to -60 mV. Low levels of tetrodotoxin (TTX) induce slow fluctuations of channel current, which represent the binding and dissociation of single TTX molecules to single channels. The rates of association and dissociation of TTX are both voltage dependent, and the association rate is competitively inhibited by Na+. This inhibition is observed only when Na+ is increased on the TTX binding side of the channel. The results suggest that the TTX receptor site is located at the channel's outer mouth, and that the Na+ competition site is not located deeply within the channel's conduction pathway. PMID:6096478

  17. Chemisorbed methyl groups in NaX and NaY types of zeolitic catalysts

    NASA Astrophysics Data System (ADS)

    Vratislav, S.; Dlouhá, M.; Bosá?ek, V.

    2000-03-01

    Powder neutron diffraction and 13C MAS NMR methods were used in the structural parameters determinations of the NaX and NaY zeolites with chemisorbed methyl groups CD 3 or CH 3. Powder neutron experiments were carried out at 7 K on the KSN-2 diffractometer at the LVR-15 research reactor in ?ež near Prague. The complete structural parameters were determined by Rietveld analysis of powder neutron patterns using the GSAS package. Difference Fourier maps were determined to localize the nonframework cations and the CD 3 groups. Experimental evidence of the created chemisorbed methyl groups after reaction of methyliodide with Na+ cations of the zeolite was obtained from 13C MAS NMR spectra. The structural analysis of the NaX samples was treated in the frame of the Fd3 space group, the occupation numbers of cations and the location of CD 3 groups with center in the position 96g are given.

  18. Hydrogen sulfide inhibits Na+ uptake in larval zebrafish, Danio rerio.

    PubMed

    Kumai, Yusuke; Porteus, Cosima S; Kwong, Raymond W M; Perry, Steve F

    2015-04-01

    The present study investigated the role of hydrogen sulfide (H2S) in regulating Na(+) uptake in larval zebrafish, Danio rerio. Waterborne treatment of larvae at 4 days post-fertilization (dpf) with Na2S or GYY-4137 (chemicals known to generate H2S) significantly reduced Na(+) uptake. Exposure of larvae to water enriched with NaCl (1 mM NaCl) caused a pronounced reduction in Na(+) uptake which was prevented by pharmacological inhibition of cystathionine ?-synthase (CBS) or cystathionine ?-lyase (CSE), two key enzymes involved in the endogenous synthesis of H2S. Furthermore, translational gene knockdown of CSE and CBSb significantly increased the basal rate of Na(+) uptake. Waterborne treatment with Na2S significantly decreased whole-body acid excretion and reduced Na(+) uptake in larval zebrafish preexposed to acidic (pH 4.0) water (a condition shown to promote Na(+) uptake via Na(+)-H(+)-exchanger 3b, NHE3b). However, Na2S did not affect Na(+) uptake in larvae depleted of NHE3b-containing ionocytes (HR cells) after knockdown of transcription factor glial cell missing 2 (gcm2) in which Na(+) uptake occurs predominantly via Na(+)-Cl(-) co-transporter (NCC)-containing cells. These observations suggest that Na(+) uptake via NHE3b, but not NCC, is regulated by H2S. Whole-mount immunohistochemistry demonstrated that ionocytes expressing NHE3b also express CSE. These data suggests a physiologically relevant role of H2S as a mechanism to lower Na(+) uptake in zebrafish larvae, probably through its inhibitory action on NHE3b. PMID:24939700

  19. Computational interpretation of 23Na MQMAS NMR spectra: A comprehensive investigation of the Na environment in silicate glasses

    NASA Astrophysics Data System (ADS)

    Gambuzzi, Elisa; Charpentier, Thibault; Menziani, Maria Cristina; Pedone, Alfonso

    2014-09-01

    Molecular dynamics, density functional theory calculations and 23Na NMR experiments have been used to inspect the chemical and structural characteristics of the Na environment in soda-lime silicate (CSN) and aluminosilicate (CASN) glasses. The use of an improved 3QMAS pulse sequence has allowed a clear identification of different Na sites. Average coordination numbers have been extracted by fitting the 23Na 3QMAS spectra with the computed NMR parameters. The results show that the 23Na ?iso values correlate with the average <Na-O> distances only when the different coordination numbers are explicitly taken into account.

  20. Kaon Physics at CERN - Recent Results from the NA48/2 and NA62 Experiments

    NASA Astrophysics Data System (ADS)

    Winhart, Andreas

    2012-12-01

    This letter presents recent results from the kaon experiments NA48/2 and its successor NA62 at CERN. With samples of 2.5 × 106 Kµ3± and 4.0 × 106 Ke3± events collected by NA48/2 in 2004, precise measurements of the form factors were performed. The Chiral Perturbation Theory was tested through a new study of K± ? ?±?? decays based on data taken with minimal trigger conditions. Using the beam line and detector of NA48/2 in the years 2007-2008, NA62 performed a precison measurement of the helicitysuppressed ratio of the charged kaon leptonic decay rates K± ? e+? and K± ? ?+? Using the full data set, which is about ten times larger than the previous world data sample, the total uncertainty on this ratio is only 0.4%, representing a precision test of ? - e lepton universality. Finally, the main stage of the NA62 experiment is presented. The planned measurement of the ultra rare decay K+ ? ?+vbar v at 10% precision will provide a powerful test of the Standard Model. The experimental challenges to reach this goal require new detectors with exceptional performances.

  1. Na/beta-alumina/NaAlCl4, Cl2/C circulating cell

    NASA Technical Reports Server (NTRS)

    Cherng, Jing-Yih; Bennion, Douglas N.

    1987-01-01

    A study was made of a high specific energy battery based on a sodium negative electrode and a chlorine positive electrode with molten AlCl3-NaCl electrolyte and a solid beta alumina separator. The basic performance of a Na beta-alumina NaAlCl4, Cl2/C circulating cell at 200 C was demonstrated. This cell can be started at 150 C. The use of melting sodium chloroaluminate electrolyte overcomes some of the material problems associated with the high working temperatures of present molten salt systems, such as Na/S and LiAl/FeS, and retains the advantages of high energy density and relatively efficient electrode processes. Preliminary investigations were conducted on a sodium-chlorine static cell, material compability, electrode design, wetting, and theoretical calculations to assure a better chance of success before assembling a Na/Cl2 circulating cell. Mathematical models provide a theoretical explanation for the performance of the NaCl2 battery. The results of mathematical models match the experimental results very well. According to the result of the mathematical modeling, an output at 180 mA/sq cm and 3.2 V can be obtained with optimized cell design.

  2. Ondas gravitatorias de transiciones de fase cosmológicas

    NASA Astrophysics Data System (ADS)

    Leitao, L.

    There are several projects to build Gravitational Waves (GWs) spaceborne detectors as NGO/eLISA, which could be launched before 2022. A frequency signal in the detection range (0.1 mHz - 1 Hz) would be generated in the electroweak scale. This talk focuses on GWs generation from the electroweak phase transition. FULL TEXT IN SPANISH

  3. U. S. EPA’S NA APPROACH FOR PETROLEUM HYDROCARBONS

    EPA Science Inventory

    Most evaluations of NA of petroleum hydrocarbons use geochemical data to document the NA through biodegradation. The expected trends during biodegradation (plume interior vs. background concentrations) are Dissolved oxygen concentrations below background, Nitrate concentrations ...

  4. Formation of ultracold fermionic NaLi Feshbach molecules

    E-print Network

    Heo, Myoung-Sun

    We describe the formation of fermionic NaLi Feshbach molecules from an ultracold mixture of bosonic [superscript 23]Na and fermionic [superscript 6]Li. Precise magnetic field sweeps across a narrow Feshbach resonance at ...

  5. The putative mechanism of Na+ absorption in euryhaline

    E-print Network

    Evans, David H.

    reserved. Keywords: Osmoregulation; Na+ /H+ exchanger; Na+ /K+ ATPase; Elasmobranch; Acid­base regulation 1 and acid or base secretion that are required for systemic acid­base regulation and osmoregulation in fresh

  6. An enhancement to the NA4 gear vibration diagnostic parameter

    NASA Technical Reports Server (NTRS)

    Decker, Harry J.; Handschuh, Robert F.; Zakrajsek, James J.

    1994-01-01

    A new vibration diagnostic parameter for health monitoring of gears, NA4*, is proposed and tested. A recently developed gear vibration diagnostic parameter NA4 outperformed other fault detection methods at indicating the start and initial progression of damage. However, in some cases, as the damage progressed, the sensitivity of the NA4 and FM4 parameters tended to decrease and no longer indicated damage. A new parameter, NA4* was developed by enhancing NA4 to improve the trending of the parameter. This allows for the indication of damage both at initiation and also as the damage progresses. The NA4* parameter was verified and compared to the NA4 and FM4 parameters using experimental data from single mesh spur and spiral bevel gear fatigue rigs. The primary failure mode for the test cases was naturally occurring tooth surface pitting. The NA4* parameter is shown to be a more robust indicator of damage.

  7. Na(+) mobility in sodium strontium silicate fast ion conductors.

    PubMed

    Peet, Joseph R; Widdifield, Cory M; Apperley, David C; Hodgkinson, Paul; Johnson, Mark R; Evans, Ivana Radosavljevi?

    2015-12-14

    We present the first direct evidence of Na-ion mobility in sodium strontium silicate fast ion conductors, based on variable temperature (23)Na solid state NMR spectroscopy and spin-lattice relaxation measurements. PMID:26455837

  8. Rechargeable Na/Na0.44MnO2 cells with ionic liquid electrolytes containing various sodium solutes

    NASA Astrophysics Data System (ADS)

    Wang, Chueh-Han; Yeh, Yu-Wen; Wongittharom, Nithinai; Wang, Yi-Chen; Tseng, Chung-Jen; Lee, Sheng-Wei; Chang, Wen-Sheng; Chang, Jeng-Kuei

    2015-01-01

    Orthorhombic Na0.44MnO2 with wide structural tunnels for sodium ion transport is synthesized. Butylmethylpyrrolidinium-bis(trifluoromethanesulfonyl)imide (BMP-TFSI) ionic liquid (IL) with various Na solutes, namely NaBF4, NaClO4, NaTFSI, and NaPF6, is used as an electrolyte for rechargeable Na/Na0.44MnO2 cells. The cell with NaClO4-incorporated IL electrolyte exhibits superior charge-discharge performance due to it having the lowest solid-electrolyte-interface resistance and charge transfer resistance at both the Na and Na0.44MnO2 electrodes. The IL electrolyte shows high thermal stability and is suitable for use at an elevated temperature. At 75 °C, the measured capacity of Na0.44MnO2 in the IL electrolyte with NaClO4 is as high as 115 mAh g-1 (at 0.05 C), which is close to the theoretical value (121 mAh g-1). Moreover, 85% of this capacity can be retained when the charge-discharge rate is increased to 1 C. These properties are superior to those of a conventional organic electrolyte.

  9. Bimodal gating of the Na+ channel.

    PubMed

    Keynes, R D

    1994-02-01

    Inactivation of voltage-gated ion channels, whether they are selective for Na+, K+ or Ca2+, probably never involves their total closure, and some flow of ion current persists if large enough test pulses are applied. Incomplete inactivation was first reported for the Na+ channels of the squid giant axon, but has since been observed in other types of peripheral nerve and, more recently, in muscle fibres and the neurons of mammalian brain. The phenomenon is therefore widespread and has important implications for the functioning of voltage-gated channels in a variety of situations. It is best described in terms of a gating mechanism that switches the channel from an initial mode in which it has a high probability of opening to one in which the probability is greatly lowered, but not reduced to zero. PMID:7512769

  10. Advanced Intermediate-Temperature Na-S Battery

    SciTech Connect

    Lu, Xiaochuan; Kirby, Brent W.; Xu, Wu; Li, Guosheng; Kim, Jin Yong; Lemmon, John P.; Sprenkle, Vincent L.; Yang, Zhenguo

    2013-01-01

    In this study, we reported an intermediate-temperature (~150°C) sodium-sulfur (Na-S) battery. With a reduced operating temperature, this novel battery can potentially reduce the cost and safety issues associated with the conventional high-temperature (300~350°C) Na-S battery. A dense ?"-Al2O3 solid membrane and tetraglyme were utilized as the electrolyte separator and catholyte solvent in this battery. Solubility tests indicated that cathode mixture of Na2S4 and S exhibited extremely high solubility in tetraglyme (e.g., > 4.1 M for Na2S4 + 4 S). CV scans of Na2S4 in tetraglyme revealed two pairs of redox couples with peaks at around 2.22 and 1.75 V, corresponding to the redox reactions of polysulfide species. The discharge/charge profiles of the Na-S battery showed a slope region and a plateau, indicating multiple steps and cell reactions. In-situ Raman measurements during battery operation suggested that polysulfide species were formed in the sequence of Na2S5 + S ? Na2S5 + Na2S4? Na2S4 + Na2S2 during discharge and in a reverse order during charge. This battery showed dramatic improvement in rate capacity and cycling stability over room-temperature Na-S batteries, which makes it attractive for renewable energy integration and other grid related applications.

  11. Influence of Salt Purity on Na+ and Palmitic Acid Interactions

    E-print Network

    Influence of Salt Purity on Na+ and Palmitic Acid Interactions Zishuai Huang, Wei Hua, Dominique of salt purity on the interactions between Na+ ions and the carboxylate (COO- ) head group of palmitic frequency generation (VSFG) spectroscopy. Ultrapure (UP) and ACS grade NaCl salts are used for aqueous

  12. Homocoordination preference in NaCs and LiNa liquid alloys by first principles molecular dynamics

    NASA Astrophysics Data System (ADS)

    Costa Cabral, B. J.; Martins, J. L.

    1999-09-01

    We present structural and dynamics results based on Hellman-Feynman molecular dynamics for the liquid phase of the NaCs alloy at two Na concentrations (cNa=0.6 and 0.8) and for the Li0.61Na0.39 zero alloy at two temperatures (T=590 K and 690 K). For NaCs the calculated structure factor S(k) is in very good agreement with data from neutron scattering experiments and the partial structure factors are compared to semiexperimental, theoretical and classical molecular dynamics predictions. We predict similar values for the self-diffusion coefficients of Na and Cs atoms in the Na0.6Cs0.4 alloy. For LiNa the concentration-concentration structure factor is in good agreement with experimental data and our results for the dynamics are compared with data from classical molecular dynamics simulations.

  13. A new low-voltage plateau of Na?V?(PO?)? as an anode for Na-ion batteries

    SciTech Connect

    Jian, Zelang; Sun, Yang; Ji, Xiulei

    2015-01-01

    A low-voltage plateau at ~0.3 V is discovered during the deep sodiation of Na?V?(PO?)? by combined computational and experimental studies. This new low-voltage plateau doubles the sodiation capacity of Na?V?(PO?)?, thus turning it into a promising anode for Na-ion batteries.

  14. Formation of Na-Rich Chondrules by Melting of Na-Rich and Condensed (Ultra)-Refractory Precursors

    NASA Astrophysics Data System (ADS)

    Ebert, S.; Bischoff, A.

    2015-07-01

    We analyzed 33 Na-rich chondrules (Na2O >4.0 wt%) from 15 different chondrites. These chondrules must have formed by melting of precursors including Na-rich materials (like nepheline) as well as condensed (ultra)-refractory components.

  15. A new low-voltage plateau of Na?V?(PO?)? as an anode for Na-ion batteries

    DOE PAGESBeta

    Jian, Zelang; Sun, Yang; Ji, Xiulei

    2015-04-04

    A low-voltage plateau at ~0.3 V is discovered during the deep sodiation of Na?V?(PO?)? by combined computational and experimental studies. This new low-voltage plateau doubles the sodiation capacity of Na?V?(PO?)?, turning it into a promising anode for Na-ion batteries.

  16. pNaKtide inhibits Na/K-ATPase reactive oxygen species amplification and attenuates adipogenesis

    PubMed Central

    Sodhi, Komal; Maxwell, Kyle; Yan, Yanling; Liu, Jiang; Chaudhry, Muhammad A.; Getty, Morghan; Xie, Zijian; Abraham, Nader G.; Shapiro, Joseph I.

    2015-01-01

    Obesity has become a worldwide epidemic and is a major risk factor for metabolic syndrome. Oxidative stress is known to play a role in the generation and maintenance of an obesity phenotype in both isolated adipocytes and intact animals. Because we had identified that the Na/K-ATPase can amplify oxidant signaling, we speculated that a peptide designed to inhibit this pathway, pNaKtide, might ameliorate an obesity phenotype. To test this hypothesis, we first performed studies in isolated murine preadipocytes (3T3L1 cells) and found that pNaKtide attenuated oxidant stress and lipid accumulation in a dose-dependent manner. Complementary experiments in C57Bl6 mice fed a high-fat diet corroborated our in vitro observations. Administration of pNaKtide in these mice reduced body weight gain, restored systemic redox and inflammatory milieu, and, crucially, improved insulin sensitivity. Thus, we propose that inhibition of Na/K-ATPase amplification of oxidative stress may ultimately be a novel way to combat obesity, insulin resistance, and metabolic syndrome. PMID:26601314

  17. Na+ channel function, regulation, structure, trafficking and sequestration.

    PubMed

    Chen-Izu, Ye; Shaw, Robin M; Pitt, Geoffrey S; Yarov-Yarovoy, Vladimir; Sack, Jon T; Abriel, Hugues; Aldrich, Richard W; Belardinelli, Luiz; Cannell, Mark B; Catterall, William A; Chazin, Walter J; Chiamvimonvat, Nipavan; Deschenes, Isabelle; Grandi, Eleonora; Hund, Thomas J; Izu, Leighton T; Maier, Lars S; Maltsev, Victor A; Marionneau, Celine; Mohler, Peter J; Rajamani, Sridharan; Rasmusson, Randall L; Sobie, Eric A; Clancy, Colleen E; Bers, Donald M

    2015-03-15

    This paper is the second of a series of three reviews published in this issue resulting from the University of California Davis Cardiovascular Symposium 2014: Systems approach to understanding cardiac excitation-contraction coupling and arrhythmias: Na(+) channel and Na(+) transport. The goal of the symposium was to bring together experts in the field to discuss points of consensus and controversy on the topic of sodium in the heart. The present review focuses on Na(+) channel function and regulation, Na(+) channel structure and function, and Na(+) channel trafficking, sequestration and complexing. PMID:25772290

  18. Effect of Na+ on surface fractal dimension of compacted bentonite

    NASA Astrophysics Data System (ADS)

    Xiang, G. S.; Xu, Y. F.; Jiang, H.

    2015-05-01

    Compacted Tsukinuno bentonite was immersed into NaCl solutions of different concentrations in oedometers, and the surface fractal dimension of bentonite-saline association was measured by nitrogen adsorption isotherms. The application of the Frenkel-Halsey-Hill equation and the Neimark thermodynamic method to nitrogen adsorption isotherms indicated that the surface roughness was greater for the bentonite-saline association. The surface fractal dimension of bentonite increased in the NaCl solution with low Na+ concentration, but decreased at high Na+ concentration. This process was accompanied by the same tendency in specific surface area and microporosity with the presence of Na+ coating in the clay particles.

  19. Initial Results of Na Density and Temperature Measurements by a STAR Na Lidar at Boulder

    NASA Astrophysics Data System (ADS)

    Fong, W.; Dahlke, I.; Roberts, B.; Smith, J. A.; Yu, Z.; Huang, W.; Chu, X.

    2010-12-01

    A new Na resonance fluorescence Doppler lidar, Student Atmospheric Resonance Lidar (STAR Lidar), has been deployed at the Table Mountain Lidar Observatory in Boulder (40°N) in the summer of 2010. With the implementation of the acoustic-optic modulators in this August, the two additional shifted frequencies of the output lidar pulses enable the capability of temperature and wind measurement in the mesosphere and lower thermosphere (MLT) region. Several nights of Na density and temperature observation results will be presented and discussed, as well as sporadic Na layers at high altitude. Except to serve as a powerful tool for scientific study of temperature and wind structures, the STAR Lidar is also expected to support lidar education in Boulder providing students with hands-on experience by operating the lidar system in the future.

  20. Photoionization of the alkali dimer cations Li+2, Na+2 and LiNa+

    NASA Astrophysics Data System (ADS)

    Dumitriu, Irina; Vanne, Yulian V.; Awasthi, Manohar; Saenz, Alejandro

    2007-05-01

    Photoionization cross sections for the three alkali dimer cations (Li+2, Na+2 and LiNa+) were calculated at the equilibrium internuclear distance for parallel, perpendicular and isotropic orientations of the molecular axis with respect to the field. A model-potential method was used for the description of the cores. The influence of the model-potential parameters on the photoionization spectra was investigated. Two different methods, a time-independent and a time-dependent one, were implemented and used for computing the cross sections.

  1. Standardization method of ²²Na using two NaI(Tl) scintillation detectors.

    PubMed

    Sato, Y; Yamada, T; Hasegawa, T

    2014-05-01

    A new standardization method for a sealed (22)Na point source was developed utilizing two NaI(Tl) scintillation detectors. In the proposed method, the count rates of annihilation radiation, gamma rays, their coincidence sum, and the coincidences between the two detectors are used. The equations from which the source activity can be deduced are derived in this work. A series of EGS-5 Monte Carlo calculations were conducted to test the validity of the expressions. The calculated activity agreed within approximately 1 percent with the literature data used as input in the simulations. PMID:24411317

  2. Subnitride chemistry: A first-principles study of the NaBa 3N, Na 5Ba 3N, and Na 16Ba 6N phases

    NASA Astrophysics Data System (ADS)

    Oliva, Josep M.

    2005-04-01

    An ab initio study on the electronic structure of the subnitrides NaBa 3N, Na 5Ba 3N, and Na 16Ba 6N is performed for the first time. The NaBa 3N and Na 5Ba 3N phases consist of infinite 1?[NBa 6/2] strands composed of face-sharing NBa 6 octahedra surrounded by a "sea" of sodium atoms. The Na 16Ba 6N phase consist of discrete [NBa 6] octahedra arranged in a body-cubic fashion, surrounded by a "sea" of sodium atoms. Our calculations suggest that the title subnitrides are metals. Analysis of the electronic structure shows partial interaction of N(2s) with Ba(5 p) electrons in the lower energy region for NaBa 3N and Na 5Ba 3N. However, no dispersion is observed for the N(2s) and Ba(5 p) bands in the cubic phase Na 16Ba 6N. The metallic band below the Fermi level shows a strong mixing of N(2p), Ba(6 s), Ba(5 d), Ba(6 p), Na(3 s) and Na(3 p) orbitals. The metallic character in these nitrides stems from delocalized electrons corresponding to hybridized 5dl6sm6pn barium orbitals which interact with hybridized 3sn3pm sodium orbitals. Analysis of the electron density and electronic structure in these nitrides shows two different regions: a metallic matrix corresponding to the sodium atoms and the regions around them and heteropolar bonding between nitrogen and barium within the infinite 1?[NBa 6/2] strands of the NaBa 3N and Na 5Ba 3N phases, and within the isolated [NBa 6] octahedra of the Na 16Ba 6N phase. The nitrogen atoms inside the strands and octahedra are negatively charged, the anionic character of nitrogens being larger in the isolated octahedra of the cubic phase Na 16Ba 6N, due to the lack of electron delocalization along one direction as opposed to the other phases. The sodium and barium atoms appear to be slightly negatively and positively charged, the latter to a larger extent. From the computed Ba-N overlap populations as well as the analysis of the contour maps of differences between total density and superposition of atomic densities, we suggest partial covalent bonding between nitrogen and barium atoms along the infinite 1?[NBa 6/2] strands and within isolated [NBa 6] octahedra.

  3. Vanadate sensitivity of Na+, K+-ATPase from Schistosoma mansoni and its modulation by Na+, K+ and Mg2+.

    PubMed

    Noel, F; Pardon, R S

    1989-01-01

    Vanadate inhibitory effects on Na+, K+-ATPases from carcass of Schistosoma mansoni and from lamb kidney outer medulla were compared in the presence of various concentrations of Na+, K+ and Mg2+. Depending on the ionic conditions, the schistosomal Na+, K+-ATPase was 2.4- to 175-fold less sensitive to vanadate than the lamb kidney enzyme. In 100 mM Na+, 3 mM K+ and 3 mM Mg2+, schistosomal Na+, K+-ATPase was surprisingly resistant to vanadate (I50 = 944 microM). The difference in vanadate sensitivity between schistosomal and lamb Na+, K+-ATPases may be due to a species difference in the efficacy of Na+, K+ and Mg2+ in promoting conformational changes between E1 and E2 forms of the enzyme. PMID:2543877

  4. Minimizing Load Effects on NA4 Gear Vibration Diagnostic Parameter

    NASA Technical Reports Server (NTRS)

    Dempsey, Paula J.; Zakrajsek, James J.

    2001-01-01

    NA4 is a vibration diagnostic parameter, developed by researchers at NASA Glenn Research Center, for health monitoring of gears in helicopter transmissions. The NA4 reacts to the onset of gear pitting damage and continues to react to the damage as it spreads. This research also indicates NA4 reacts similarly to load variations. The sensitivity of NA4 to load changes will substantially affect its performance on a helicopter gearbox that experiences continuously changing load throughout its flight regimes. The parameter NA4 has been used to monitor gear fatigue tests at constant load. At constant load, NA4 effectively detects the onset of pitting damage and tracks damage severity. Previous research also shows that NA4 reacts to changes in load applied to the gears in the same way it reacts to the onset of pitting damage. The method used to calculate NA4 was modified to minimize these load effects. The modified NA4 parameter was applied to four sets of experimental data. Results indicate the modified NA4 is no longer sensitive to load changes, but remains sensitive to pitting damage.

  5. The sided action of Na+ and of K+ on reconstituted shark (Na+ + K+)-ATPase engaged in Na+-Na+ exchange accompanied by ATP hydrolysis. I. The ATP activation curve.

    PubMed

    Cornelius, F; Skou, J C

    1987-11-13

    The ATP hydrolysis dependent Na+-Na+ exchange of reconstituted shark (Na+ + K+)-ATPase is electrogenic with a transport stoichiometry as for the Na+-K+ exchange, suggesting that translocation of extracellular Na+ is taking place via the same route as extracellular K+. The preparation thus offers an opportunity to compare the sided action of Na+ and K+ on the affinity for ATP in a reaction in which the intermediary steps in the overall reaction seems to be the same without and with K+. With Na+ but no K+ on the two sides of the enzyme, the ATP-activation curve is hyperbolic and the affinity for ATP is high. Extracellular K+ in concentrations of 50 microM (the lowest tested) and up gives biphasic ATP activation curves, with both a high- and a low-affinity component for ATP. Cytoplasmic K+ also gives biphasic ATP-activation curves, however, only when the K+ concentration is 50 mM or higher (Na+ + K+ = 130 mM). The different ATP-activation curves are explained from the Albers-Post scheme, in which there is an ATP-dependent and an ATP-independent deocclusion of E2(Na2+) and E2(K2+), respectively, and in which the dephosphorylation of E2-P is rate limiting in the presence of Na+ (but no K+) extracellular, whereas in the presence of extracellular K+ it is the deocclusion of E2(K2+) which is rate limiting. PMID:2822120

  6. Apical Na+ permeability of frog skin during serosal Cl- replacement.

    PubMed

    Leibowich, S; DeLong, J; Civan, M M

    1988-05-01

    Gluconate substitution for serosal Cl- reduces the transepithelial short-circuit current (Isc) and depolarizes short-circuited frog skins. These effects could result either from inhibition of basolateral K+ conductance, or from two actions to inhibit both apical Na+ permeability (PapNa) and basolateral pump activity. We have addressed this question by studying whole-and split-thickness frog skins. Intracellular Na+ concentration (CcNa) and PapNa have been monitored by measuring the current-voltage relationship for apical Na+ entry. This analysis was conducted by applying trains of voltage pulses, with pulse durations of 16 to 32 msec. Estimates of PapNa and CcNa were not detectably dependent on pulse duration over the range 16 to 80 msec. Serosal Cl- replacement uniformly depolarized short-circuited tissues. The depolarization was associated with inhibition of Isc across each split skin, but only occasionally across the whole-thickness preparations. This difference may reflect the better ionic exchange between the bulk medium and the extracellular fluid in contact with the basolateral membranes, following removal of the underlying dermis in the split-skin preparations. PapNa was either unchanged or increased, and CcNa either unchanged or reduced after the anionic replacement. These data are incompatible with the concept that serosal Cl- replacement inhibits PapNa and Na,K-pump activity. Gluconate substitution likely reduces cell volume, triggering inhibition of the basolateral K+ channels, consistent with the data and conclusions of S.A. Lewis, A.G. Butt, M.J. Bowler, J.P. Leader and A.D.C. Macknight (J. Membrane Biol. 83:119-137, 1985) for toad bladder. The resulting depolarization reduces the electrical force favoring apical Na+ entry. The volume-conductance coupling serves to conserve volume by reducing K+ solute loss. Its molecular basis remains to be identified. PMID:2458472

  7. Anion reorientation in Na 3PO 4

    NASA Astrophysics Data System (ADS)

    Wilmer, D.; Banhatti, R. D.; Fitter, J.; Funke, K.; Jansen, M.; Korus, G.; Lechner, R. E.

    The reorientational motion of phosphate anions in the high-temperature phase of Na 3PO 4 has been investigated with a coherent quasielastic neutron-scattering experiment. Our study aimed at clarifying the relevance of the so-called “paddle-wheel” mechanism, i.e., the influence of the anion motion on the translational Na + ion conduction. In the Q range between 0.3 and 2.3 Å -1, the data could be fitted by the sum of a ? function and a single Lorentzian whose width exhibits an Arrhenius behavior with an activation energy of 0.184 eV. We have calculated Sq( Q, ?), the coherent quasielastic structure factor of the oxygen ions, based on several models. A comparison of the model predictions with our experimental data shows that only three oxygen atoms per anion are rotationally mobile. The experiment yields an additional small maximum around 1.5 Å -1, which appears more pronounced at higher temperatures. Its position on the Q scale suggests that sodium ions, further away from the center of rotation, are involved in the reorientational anion motion.

  8. Anion reorientation in Na3PO4

    NASA Astrophysics Data System (ADS)

    Wilmer, D.; Banhatti, R. D.; Fitter, J.; Funke, K.; Jansen, M.; Korus, G.; Lechner, R. E.

    1998-04-01

    The reorientational motion of phosphate anions in the high-temperature phase of Na3PO4 has been investigated with a coherent quasielastic neutron-scattering experiment. Our study aimed at clarifying the relevance of the so-called ``paddle-wheel'' mechanism, i.e., the influence of the anion motion on the translational Na+ ion conduction. In the Q range between 0.3 and 2.3 Å-1, the data could be fitted by the sum of a ? function and a single Lorentzian whose width exhibits an Arrhenius behavior with an activation energy of 0.184 eV. We have calculated Sq(Q,?), the coherent quasielastic structure factor of the oxygen ions, based on several models. A comparison of the model predictions with our experimental data shows that only three oxygen atoms per anion are rotationally mobile. The experiment yields an additional small maximum around 1.5 Å-1, which appears more pronounced at higher temperatures. Its position on the Q scale suggests that sodium ions, further away from the center of rotation, are involved in the reorientational anion motion.

  9. Na?La?(CO?)? and CsNa?Ca?(CO?)?: two new carbonates as UV nonlinear optical materials.

    PubMed

    Luo, Min; Wang, GenXiang; Lin, Chensheng; Ye, Ning; Zhou, Yuqiao; Cheng, Wendan

    2014-08-01

    Two nonlinear optical crystal carbonates (Na4La2(CO3)5 and CsNa5Ca5(CO3)8 were successfully synthesized by hydrothermal method, and both of them crystallized in the same noncentrosymmetric hexagonal space group P63mc (No. 186). The structure of Na4La2(CO3)5 consists of a three-dimensional network made up of [CO3] triangles as well as irregular [Na(0.67)La(0.33)O10] and [NaO8] polyhedra. The structure of CsNa5Ca5(CO3)8 can be described as the standing-on-edge [CO3] groups connect the adjacent infinite [CaCO3]? layers in the ab plane to construct a framework with four types of channels running parallel to [010]. The Na, Cs, and [Na(0.67)Ca(0.33)] atoms reside in these channels. The measurement of second harmonic generation (SHG) by the method adapted from Kurtz and Perry indicated that Na4La2(CO3)5 and CsNa5Ca5(CO3)8 were phase-matchable in the visible region and exhibited SHG responses of approximately 3 and 1 × KH2PO4 (KDP). Meanwhile, they exhibited wide transparent region with short UV cutoff edge at about 235 and 210 nm, respectively, suggesting that these crystals as NLO materials may have potential applications in the UV region. PMID:25027762

  10. Ionic liquid electrolytes with various sodium solutes for rechargeable Na/NaFePO4 batteries operated at elevated temperatures.

    PubMed

    Wongittharom, Nithinai; Wang, Chueh-Han; Wang, Yi-Chen; Yang, Cheng-Hsien; Chang, Jeng-Kuei

    2014-10-22

    NaFePO4 with an olivine structure is synthesized via chemical delithiation of LiFePO4 followed by electrochemical sodiation of FePO4. Butylmethylpyrrolidinium-bis(trifluoromethanesulfonyl)imide (BMP-TFSI) ionic liquid (IL) with various sodium solutes, namely NaBF4, NaClO4, NaPF6, and NaN(CN)2, is used as an electrolyte for rechargeable Na/NaFePO4 cells. The IL electrolytes show high thermal stability (>350 °C) and nonflammability, and are thus ideal for high-safety applications. The highest conductivity and the lowest viscosity of the electrolyte are obtained with NaBF4. At an elevated temperature (above 50 °C), the IL electrolyte is more suitable than a conventional organic electrolyte for the sodium cell. At 75 °C, the measured capacity of NaFePO4 in a NaBF4-incorporated IL electrolyte is as high as 152 mAh g(-1) (at 0.05 C), which is near the theoretical value (154 mAh g(-1)). Moreover, 60% of this capacity can be retained when the charge-discharge rate is increased to 1 C. PMID:25295391

  11. Regulation of persistent Na current by interactions between ? subunits of voltage-gated Na channels

    PubMed Central

    Aman, Teresa K.; Grieco-Calub, Tina M.; Chen, Chunling; Rusconi, Raffaella; Slat, Emily A.; Isom, Lori L.; Raman, Indira M.

    2009-01-01

    The ? subunits of voltage-gated Na channels (Scnxb) regulate the gating of pore-forming ? subunits, as well as their trafficking and localization. In heterologous expression systems, ?1, ?2, and ?3 subunits influence inactivation and persistent current in different ways. To test how the ?4 protein regulates Na channel gating, we transfected ?4 into HEK cells stably expressing NaV1.1. Unlike a free peptide with a sequence from the ?4 cytoplasmic domain, the full-length ?4 protein did not block open channels. Instead, ?4 expression favored open states by shifting activation curves negative, decreasing the slope of the inactivation curve, and increasing the percentage of non-inactivating current. Consequently, persistent current tripled in amplitude. Expression of ?1 or chimeric subunits including the ?1 extracellular domain, however, favored inactivation. Co-expressing NaV1.1 and ?4 with ?1 produced tiny persistent currents, indicating that ?1 overcomes the effects of ?4 in heterotrimeric channels. In contrast, ?1C121W, which contains an extracellular epilepsy-associated mutation, did not counteract the destabilization of inactivation by ?4, and also required unusually large depolarizations for channel opening. In cultured hippocampal neurons transfected with ?4, persistent current was slightly but significantly increased. Moreover, in ?4-expressing neurons from Scn1b and Scn1b/Scn2b null mice, entry into inactivated states was slowed. These data suggest that ?1 and ?4 have antagonistic roles, the former favoring inactivation and the latter favoring activation. Because increased Na channel availability may facilitate action potential firing, these results suggest a mechanism for seizure susceptibility of both mice and humans with disrupted ?1 subunits. PMID:19228957

  12. Atomic structure of Na-adsorbed Si(100) surfaces

    NASA Astrophysics Data System (ADS)

    Ko, Young-Jo; Chang, K. J.; Yi, Jae-Yel

    1995-02-01

    We examine the atomic and electronic structure of Na-adsorbed Si(100)-p(2×2) surfaces for various Na coverages (FTHETA) through first-principles pseudopotential calculations. At FTHETA=1/4, we find that the 4×1 structure with linear Na chains adsorbed on the valley bridge sites is energetically most stable, while substrate Si dimers are rearranged by buckling towards the Na chains. At FTHETA=1/2, the adsorption site of Na is the valley bridge site; however, the 2×2 structure is found to be more stable than the 2×1 structure. From the calculated formation energies, we suggest that the saturation coverage is one monolayer with the Na atoms occupying the pedestal and valley bridge sites, exhibiting a 2×1 reconstruction. The coverage dependences of surface geometry and work function are discussed.

  13. Formation of Ultracold Fermionic NaLi Feshbach Molecules

    E-print Network

    Heo, Myoung-Sun; Christensen, Caleb A; Rvachov, Timur M; Cotta, Dylan A; Choi, Jae-Hoon; Lee, Ye-Ryoung; Ketterle, Wolfgang

    2012-01-01

    We describe the formation of fermionic NaLi Feshbach molecules from an ultracold mixture of bosonic 23Na and fermionic 6Li. Precise magnetic field sweeps across a narrow Feshbach resonance at 745 G result in a molecule conversion fraction of 5% for our experimental densities and temperatures, corresponding to a molecule number of 5*10^4. The observed molecular decay ifetime is 1.3 ms after removing free Li and Na atoms from the trap.

  14. Magnesium correction to the NaKCa chemical geothermometer

    USGS Publications Warehouse

    Fournier, R.O.; Potter, R.W., II

    1979-01-01

    Equations and graphs have been devised to correct for the adverse effects of magnesium upon the Na-K-Ca chemical geothermometer. Either the equations or graphs can be used to determine appropriate temperature corrections for given waters with calculated NaKCa temperatures > 70??C and R 50 are probably derived from relatively cool aquifers with temperatures approximately equal to the measured spring temperature, irrespective of much higher calculated Na-K-Ca temperatures. ?? 1979.

  15. Glutamate transporter coupling to Na,K-ATPase.

    PubMed

    Rose, Erin M; Koo, Joseph C P; Antflick, Jordan E; Ahmed, Syed M; Angers, Stephane; Hampson, David R

    2009-06-24

    Deactivation of glutamatergic signaling in the brain is mediated by glutamate uptake into glia and neurons by glutamate transporters. Glutamate transporters are sodium-dependent proteins that putatively rely indirectly on Na,K-ATPases to generate ion gradients that drive transmitter uptake. Based on anatomical colocalization, mutual sodium dependency, and the inhibitory effects of the Na,K-ATPase inhibitor ouabain on glutamate transporter activity, we postulated that glutamate transporters are directly coupled to Na,K-ATPase and that Na,K-ATPase is an essential modulator of glutamate uptake. Na,K-ATPase was purified from rat cerebellum by tandem anion exchange and ouabain affinity chromatography, and the cohort of associated proteins was characterized by mass spectrometry. The alpha1-alpha 3 subunits of Na,K-ATPase were detected, as were the glutamate transporters GLAST and GLT-1, demonstrating that glutamate transporters copurify with Na,K-ATPases. The link between glutamate transporters and Na,K-ATPase was further established by coimmunoprecipitation and colocalization. Analysis of the regulation of glutamate transporter and Na,K-ATPase activities was assessed using [(3)H]D-aspartate, [(3)H]L-glutamate, and rubidium-86 uptake into synaptosomes and cultured astrocytes. In synaptosomes, ouabain produced a dose-dependent inhibition of glutamate transporter and Na,K-ATPase activities, whereas in astrocytes, ouabain showed a bimodal effect whereby glutamate transporter activity was stimulated at 1 microm ouabain and inhibited at higher concentrations. The effects of protein kinase inhibitors on [(3)H]D-aspartate uptake indicated the selective involvement of Src kinases, which are probably a component of the Na,K-ATPase/glutamate transporter complex. These findings demonstrate that glutamate transporters and Na,K-ATPases are part of the same macromolecular complexes and operate as a functional unit to regulate glutamatergic neurotransmission. PMID:19553454

  16. Status of the NA61 (SHINE) experiment at CERN

    E-print Network

    Magdalena Posiadala; for NA61; Collaboration

    2009-01-21

    A precise measurement of the hadron production from interactions of 30 GeV protons on carbon target is performed by NA61 (SHINE) experiment at the CERN SPS. The inclusive spectra of pions and kaons on the carbon target obtained from NA61 measurements constrain the neutrino flux in the T2K long baseline neutrino oscillation experiment at J-PARC, Japan. The article presents description of the NA61 apparatus together with the preliminary results from the pilot 2007 run.

  17. Simulation of Na D emission near Europa during eclipse

    USGS Publications Warehouse

    Cassidy, T.A.; Johnson, R.E.; Geissler, P.E.; Leblanc, F.

    2008-01-01

    The Cassini imaging science subsystem observed Europa in eclipse during Cassini's Jupiter flyby. The disk-resolved observations revealed a spatially nonuniform emission in the wavelength range of 200-1050 nm (clear filters). By building on observations and simulations of Europa's Na atmosphere and torus we find that electron-excited Na in Europa's tenuous atmosphere can account for the observed emission if the Na is ejected preferentially from Europa's dark terrain. Copyright 2008 by the American Geophysical Union.

  18. Topology of the type IIa Na+/P(i) cotransporter.

    PubMed

    Radanovic, Tamara; Gisler, Serge M; Biber, Jürg; Murer, Heini

    2006-01-01

    The type IIa Na(+)/P(i) cotransporter (NaPi-IIa) plays a key role in the reabsorption of inorganic phosphate (P(i)) in the renal proximal tubule. The rat NaPi-IIa isoform is a protein of 637 residues for which different algorithms predict 8-12 transmembrane domains (TMDs). Epitope tagging experiments demonstrated that both the N and the C termini of NaPi-IIa are located intracellularly. Site-directed mutagenesis revealed two N-glycosylation sites in a large putative extracellular loop. Results from structure-function studies suggested the assembly of two similar opposed regions that possibly constitute part of the substrate translocation pathway for one phosphate ion together with three sodium ions. Apart from these topological aspects, other structural features of NaPi-IIa are not known. In this study, we have addressed the topology of NaPi-IIa using in vitro transcription/translation of HK-M0 and HK-M1 fusion vectors designed to test membrane insertion properties of cDNA sequences encoding putative NaPi-IIa TMDs. Based on the results of in vitro transcription/translation analyses, we propose a model of NaPi-IIa comprising 12 TMDs, with both N and C termini orientated intracellularly and a large hydrophilic extracellular loop between the fifth and sixth TMDs. The proposed model is in good agreement with the prediction of the NaPi-IIa structure obtained by the hidden Markov algorithm HMMTOP. PMID:17206517

  19. Integrated control of Na transport along the nephron.

    PubMed

    Palmer, Lawrence G; Schnermann, Jürgen

    2015-04-01

    The kidney filters vast quantities of Na at the glomerulus but excretes a very small fraction of this Na in the final urine. Although almost every nephron segment participates in the reabsorption of Na in the normal kidney, the proximal segments (from the glomerulus to the macula densa) and the distal segments (past the macula densa) play different roles. The proximal tubule and the thick ascending limb of the loop of Henle interact with the filtration apparatus to deliver Na to the distal nephron at a rather constant rate. This involves regulation of both filtration and reabsorption through the processes of glomerulotubular balance and tubuloglomerular feedback. The more distal segments, including the distal convoluted tubule (DCT), connecting tubule, and collecting duct, regulate Na reabsorption to match the excretion with dietary intake. The relative amounts of Na reabsorbed in the DCT, which mainly reabsorbs NaCl, and by more downstream segments that exchange Na for K are variable, allowing the simultaneous regulation of both Na and K excretion. PMID:25098598

  20. Kaolin-based geopolymers with various NaOH concentrations

    NASA Astrophysics Data System (ADS)

    Heah, C. Y.; Kamarudin, H.; Mustafa Al Bakri, A. M.; Bnhussain, M.; Luqman, M.; Khairul Nizar, I.; Ruzaidi, C. M.; Liew, Y. M.

    2013-03-01

    Kaolin geopolymers were produced by the alkali-activation of kaolin with an activator solution (a mixture of NaOH and sodium silicate solutions). The NaOH solution was prepared at a concentration of 6-14 mol/L and was mixed with the sodium silicate solution at a Na2SiO3/NaOH mass ratio of 0.24 to prepare an activator solution. The kaolin-to-activator solution mass ratio used was 0.80. This paper aimed to analyze the effect of NaOH concentration on the compressive strength of kaolin geopolymers at 80°C for 1, 2, and 3 d. Kaolin geopolymers were stable in water, and strength results showed that the kaolin binder had adequate compressive strength with 12 mol/L of NaOH concentration. When the NaOH concentration increased, the SiO2/Na2O decreased. The increased Na2O content enhanced the dissolution of kaolin as shown in X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analyses. However, excess in this content was not beneficial for the strength development of kaolin geopolymers. In addition, there was the formation of more geopolymeric gel in 12 mol/L samples. The XRD pattern of the samples showed a higher amorphous content and a more geopolymer bonding existed as proved by FTIR analysis.

  1. Study of OSL in NaF: Ca,Cu

    NASA Astrophysics Data System (ADS)

    More, Y. K.; Wankhede, S. P.; Moharil, S. V.

    2013-06-01

    Sodium Fluoride containing Cu+ ions was prepared by R.A.P. followed by melt-quenching technique. Results on photo, thermo and optically stimulated luminescence in NaF:Ca,Cu are reported. OSL sensitivity of NaF:Ca,Cu is approximately 2 times than that of standard phosphor LMP. The rate of OSL depletion for 90% decay for NaF:Ca,Cu is 0.3 times as that of OSL phosphor LMP. NaF:Ca,Cu thus deserves much more attention than it has received up till now.

  2. New solid conductors of Na/+/ and K/+/ ions

    NASA Technical Reports Server (NTRS)

    Singer, J.; Fielder, W. L.; Kautz, H. E.; Fordyce, J. S.

    1976-01-01

    About 40 structure types for solid conductors of Na(+) and K(+) ions are surveyed. Five compounds in three structure types are discovered to be good solid conductors of alkali metal ions, capable of ion transport with conductivities in the vicinity of 0.00001/ohm-cm at 25 C. These compounds are a bcc form of NaSbO3, an orthorhombic layer structure of the composition 2M2O.3Nb2O5 with M equal to Na or K, and the Na pyrochlores NaTa2O5F and NaTaWO6. Ion exchange is required to produce each of these Na compounds. Only the 2K2O.3Nb2O5 can so far be synthesized directly from the oxides and thus is the only one which can be sintered readily. The niobate is about as good a conductor of K(+) ion as is K-beta alumina. The NaSbO3 compares well with Na beta at 280 C. A number of phase diagrams are developed.

  3. Transcriptional regulators of Na,K-ATPase subunits

    PubMed Central

    Li, Zhiqin; Langhans, Sigrid A.

    2015-01-01

    The Na,K-ATPase classically serves as an ion pump creating an electrochemical gradient across the plasma membrane that is essential for transepithelial transport, nutrient uptake and membrane potential. In addition, Na,K-ATPase also functions as a receptor, a signal transducer and a cell adhesion molecule. With such diverse roles, it is understandable that the Na,K-ATPase subunits, the catalytic ?-subunit, the ?-subunit and the FXYD proteins, are controlled extensively during development and to accommodate physiological needs. The spatial and temporal expression of Na,K-ATPase is partially regulated at the transcriptional level. Numerous transcription factors, hormones, growth factors, lipids, and extracellular stimuli modulate the transcription of the Na,K-ATPase subunits. Moreover, epigenetic mechanisms also contribute to the regulation of Na,K-ATPase expression. With the ever growing knowledge about diseases associated with the malfunction of Na,K-ATPase, this review aims at summarizing the best-characterized transcription regulators that modulate Na,K-ATPase subunit levels. As abnormal expression of Na,K-ATPase subunits has been observed in many carcinoma, we will also discuss transcription factors that are associated with epithelial-mesenchymal transition, a crucial step in the progression of many tumors to malignant disease. PMID:26579519

  4. Electrode potential studies of liquid-solid equilibrium in Na{sub 3}Bi-saturated Na-Bi melts

    SciTech Connect

    Yan, X.Y.; Langberg, D.E.; Rankin, W.J.

    2000-04-01

    Liquid binary Na-Bi alloys have been studied extensively because of the interest in possible uses as electrochemically active couples in regenerative electrochemical cells, in high-energy batteries, and as potential heat-transfer media in nuclear reaction processes. Techniques used previously for thermodynamic measurements on the system have included the transpiration method, quasi-static and boiling point methods, the electromotive force (emf) method using molten salt mixtures and various solid electrolytes, and thermal analysis. Most of the thermodynamic data on Bi-Na alloys were recently assessed by Sangster and Pelton. However, no experimental thermodynamic data for liquid-solid equilibrium in liquid Na-Bi alloys saturated with solid Na{sub 3}Bi have been reported in the literature. The aim of the present work was to investigate experimentally the equilibrium between Na-Bi melts and solid Na{sub 3}Bi by the emf method in the range 638 to 973 K.

  5. Na/sup +/-H/sup +/ exchange and Na/sup +/-dependent transport systems in streptozotocin diabetic rat kidneys

    SciTech Connect

    El-Seifi, S.; Freiberg, J.M.; Kinsella, F.J.; Cheng, L.; Sacktor, B.

    1987-01-01

    The streptozotocin-induced diabetic rat was used to test the hypothesis that Na/sup +/-H/sup +/ exchange activity in the proximal tubule luminal membrane would be increased in association with renal hypertrophy, altered glomerular hemodynamics, enhanced filtered load and tubular reabsorption of /sup 22/Na/sup +/, and stimulated /sup 22/Na= pump activity in the basolateral membrane, previously reported characteristics of this experimental animal model. Amiloride-sensitive H/sup +/ gradient-dependent Na/sup +/ uptake and Na/sup +/ gradient-dependent H/sup +/ flux were increased in brush-border membrane vesicles from the streptozotocin-treated animals. Na/sup +/ gradient-dependent uptakes of phosphate, D-glucose, L-proline, and myoinositol were decreased in the drug-induced diabetic animals. These membrane transport alterations were not found when the streptozotocin-diabetic animals were treated with insulin.

  6. Colorimetric Assays of Na,K-ATPase.

    PubMed

    Sweadner, Kathleen J

    2016-01-01

    The Na,K-ATPase is a plasma membrane enzyme that catalyzes active ion transport by the hydrolysis of ATP. Its activity in vivo is determined by many factors, particularly the concentration of intracellular sodium ions. It is the target of the cardiac glycoside class of drugs and of endogenous regulators. Its assay is often an endpoint in the investigation of physiological processes, and it is a promising drug target. As described in this unit, its enzymatic activity can be determined in extracts from tissues by test tube assay using a spectrophotometer or (32)P-ATP. The protocols in this chapter measure inorganic phosphate as the end product of hydrolysis of ATP. PMID:26695025

  7. Pion and kaon freezeout in NA44

    SciTech Connect

    NA44 Collaboration

    1994-12-01

    The NA44 spectrometer is optimized for the study of single and two-particle particle spectra near mid-rapidity for transverse momenta below {approx} 1 GeV/c. A large fraction of all pairs in the spectrometer`s acceptance are at low relative momenta, resulting in small statistical uncertainties on the extracted size parameters. In addition, the spectrometer`s clean particle identification allows the authors to measure correlation functions for pions, kaons, and protons. This contribution will concentrate on the source size parameters determined from pion and kaon correlation functions. These size parameters will be compared to calculations from the RQMD event generator and also interpreted in the context of a hydrodynamic model. Finally, the measured single particle spectra will be examined from the viewpoint of hydrodynamics.

  8. RNA adducts with Na 2SeO 4 and Na 2SeO 3 - Stability and structural features

    NASA Astrophysics Data System (ADS)

    Nafisi, Shohreh; Manouchehri, Firouzeh; Montazeri, Maryam

    2011-12-01

    Selenium compounds are widely available in dietary supplements and have been extensively studied for their antioxidant and anticancer properties. Low blood Se levels were found to be associated with an increased incidence and mortality from various types of cancers. Although many in vivo and clinical trials have been conducted using these compounds, their biochemical and chemical mechanisms of efficacy are the focus of much current research. This study was designed to examine the interaction of Na 2SeO 4 and Na 2SeO 3 with RNA in aqueous solution at physiological conditions, using a constant RNA concentration (6.25 mM) and various sodium selenate and sodium selenite/polynucleotide (phosphate) ratios of 1/80, 1/40, 1/20, 1/10, 1/5, 1/2 and 1/1. Fourier transform infrared, UV-Visible spectroscopic methods were used to determine the drug binding modes, the binding constants, and the stability of Na 2SeO 4 and Na 2SeO 3-RNA complexes in aqueous solution. Spectroscopic evidence showed that Na 2SeO 4 and Na 2SeO 3 bind to the major and minor grooves of RNA ( via G, A and U bases) with some degree of the Se-phosphate (PO 2) interaction for both compounds with overall binding constants of K(Na 2SeO 4-RNA) = 8.34 × 10 3 and K(Na 2SeO 3-RNA) = 4.57 × 10 3 M -1. The order of selenium salts-biopolymer stability was Na 2SeO 4-RNA > Na 2SeO 3-RNA. RNA aggregations occurred at higher selenium concentrations. No biopolymer conformational changes were observed upon Na 2SeO 4 and Na 2SeO 3 interactions, while RNA remains in the A-family structure.

  9. Enhancement of the sulfur capture capacity of limestones by the addition of Na2CO3 and NaCl.

    PubMed

    Laursen, K; Grace, J R; Lim, C J

    2001-11-01

    The ability of Na2CO3 and NaCl to enhance the sulfur capture capacity of three limestones was evaluated via fixed-bed calcination and sulfation experiments. The tested limestones represent three different sulfation morphologies: unreacted-core, network, and uniformly sulfated. Treatment with aqueous or powdered Na2CO3 significantly increased the Ca-utilization for two stones which normally sulfate in an unreacted-core pattern (20% to 45%) and network pattern (33% to 49%). The increase was lower for the uniformly sulfated stone (44% to 48%). Na2CO3 treatment increased the number of macropores leading to uniform sulfation of all particles, nearly eliminating the normal strong dependence of utilization on limestone type and particle size. The effect of Na2CO3 is believed to be associated with formation of a eutectic melt which enhances ionic diffusion and accelerates molecular rearrangement of the CaO. Treatment with aqueous NaCl solution caused a decrease in utilization, probably due to formation of large grains and plugging of pores caused by formation of a large amount of eutectic melt. The effect of Na2CO3 is less sensitive than that of NaCl to the amount added and the combustion environment (temperature and gas composition). In addition, Na2CO3 neither promotes corrosion nor forms chlorinated byproducts, which are main concerns associated with NaCl. Thus, Na2CO3 appears to have significant advantages over NaCl for enhancement of limestone sulfur capture capacity in fluidized-bed combustors. PMID:11718362

  10. Questões mais freqüentes na área de astronomia

    NASA Astrophysics Data System (ADS)

    Segundo, H. A. S.; Garcia, G. C.; Caretta, C. A.; Lima, F. P.

    2003-08-01

    É amplamente reconhecido que as pessoas em geral têm grande fascínio e interesse pela Astronomia. Por outro lado, o conteúdo dessa área incluído no ensino formal está longe de ser abrangente e suficiente para suprir a demanda. Esse interesse permite otimizar a divulgação e o ensino não formal de Astronomia aliando a adequação do conteúdo à expectativa das pessoas. Nesse intuito, nosso trabalho busca mapear que assuntos da Astronomia despertam mais a atenção e o interesse das pessoas e o quanto disso é estimulado pela mídia, que freqüentemente aproveita-se desse interesse de forma sensacionalista, trazendo contribuições positivas e negativas. Para esta avaliação, utilizamos as pesquisas específicas e de caracterização do público que freqüentou o MAst nos anos de 2001 a 2003, pesquisa das matérias de Astronomia veiculadas na mídia escrita da cidade do Rio de Janeiro no mesmo período, além da base de dados do programa Pergunte a um astrônomo, realizado no Observatório Nacional nos anos de 1997 a 1999. Para a análise dos dados, dividimos as perguntas em dez categorias, cada uma com suas subcategorias, tomando como referência as divisões, comissões e grupos de trabalho da IAU. Apresentamos neste trabalho os resultados dessa pesquisa, que incluem, entre outros, a predominância de questões nas categorias Observação do Céu e Sistemas Planetários enquanto nos jornais dominam as notícias de Sistemas Planetários e Espaço & Astronáutica. Outro resultado interessante indicou que as dúvidas de crianças do ensino fundamental se concentram em algumas categorias enquanto as questões de adultos são mais distribuídas por todas as categorias. Os resultados dessa pesquisa serão aplicados diretamente no aperfeiçoamento das atividades do Programa de Observação de Céu, bem como na elaboração de novos projetos e eventos realizados no MAst.

  11. Mercury's Na Exosphere from MESSENGER Data

    NASA Technical Reports Server (NTRS)

    Killen, Rosemary M.; Burger, M. H.; Cassidy, T. A.; Sarantos, M.; Vervack, R. J.; McClintock, W. El; Merkel, A. W.; Sprague, A. L.; Solomon, S. C.

    2012-01-01

    MESSENGER entered orbit about Mercury on March 18, 2011. Since then, the Ultraviolet and Visible Spectrometer (UWS) channel of MESSENGER's Mercury Atmospheric and Surface Composition Spectrometer (MASCS) has been observing Mercury's exosphere nearly continuously. Daily measurements of Na brightness were fitted with non-uniform exospheric models. With Monte Carlo sampling we traced the trajectories of a representative number of test particles, generally one million per run per source process, until photoionization, escape from the gravitational well, or permanent sticking at the surface removed the atom from the simulation. Atoms were assumed to partially thermally accommodate on each encounter with the surface with accommodation coefficient 0.25. Runs for different assumed source processes are run separately, scaled and co-added. Once these model results were saved onto a 3D grid, we ran lines of sight from the MESSENGER spacecraft :0 infinity using the SPICE kernels and we computed brightness integrals. Note that only particles that contribute to the measurement can be constrained with our method. Atoms and molecules produced on the nightside must escape the shadow in order to scatter light if the excitation process is resonant-light scattering, as assumed here. The aggregate distribution of Na atoms fits a 1200 K gas, with a PSD distribution, along with a hotter component. Our models constrain the hot component, assumed to be impact vaporization, to be emitted with a 2500 K Maxwellian. Most orbits show a dawnside enhancement in the hot component broadly spread over the leading hemisphere. However, on some dates there is no dawn/dusk asymmetry. The portion of the hot/cold source appears to be highly variable.

  12. Ab initio variational calculations of the vibrational properties of Li + 3, Li2Na + , LiNa + 2, and KLiNa +

    NASA Astrophysics Data System (ADS)

    Searles, D. J.; von Nagy-Felsobuki, E. I.

    1991-07-01

    A rovibrational Hamiltonian has been derived in terms of rectilinear displacement coordinates which is based on the Watson Hamiltonian. Moreover, it is a generalization of the Carney and Porter analysis for D3h triatomic systems [J. Chem. Phys. 65, 3547 (1976)] and Carney et al. analysis for C2v triatomic systems [J. Chem. Phys. 66, 3724 (1977)]. It is therefore the most general form of the Watson Hamiltonian which is applicable to a bent triatomic system. Ab initio variational calculations using this Hamiltonian are presented for vibrational properties of Li+3, Li2Na+, LiNa+2, and KLiNa+.

  13. Expression of diverse Na+ channel messenger RNAs in rat myocardium. Evidence for a cardiac-specific Na+ channel.

    PubMed Central

    Sills, M N; Xu, Y C; Baracchini, E; Goodman, R H; Cooperman, S S; Mandel, G; Chien, K R

    1989-01-01

    This study examined the diversity of Na+ channel gene expression in intact cardiac tissue and purified myocardial cells. The screening of neonatal rat myocardial cell cDNA libraries with a conserved rat brain Na+ channel cDNA probe, resulted in the isolation and characterization of a putative rat cardiac Na+ channel cDNA probe (pCSC-1). The deduced amino acid sequence of pCSC-1 displayed a striking degree of homology with the eel, rat brain-1, and rat brain-2 Na+ channel, thereby identifying pCSC-1 as a related member of the family of Na+ channel genes. Northern blot analysis revealed the expression of a 7-kb CSC-1 transcript in rat cardiac tissue and purified myocardial cells, but little or no detectable expression of CSC-1 in rat brain, skeletal muscle, denervated skeletal muscle, or liver. Using RNase protection and Northern blot hybridization with specific rat brain Na+ channel gene probes, expression of the rat brain-1 Na+ channel was observed in rat myocardium, but no detectable expression of the rat brain-2 gene was found. This study provides evidence for the expression of diverse Na+ channel mRNAs in rat myocardium and presents the initial characterization of a new, related member of the family of Na+ channel genes, which appears to be expressed in a cardiac-specific manner. Images PMID:2544627

  14. The process of GaN single crystal growth by the Na flux method with Na vapor

    NASA Astrophysics Data System (ADS)

    Yamada, Takahiro; Yamane, Hisanori; Iwata, Hirokazu; Sarayama, Seiji

    2006-01-01

    Ga melts were heated in a boron nitride crucible at 800 °C and 5 MPa of N 2 for 8-200 h with Na vapor. Colorless and transparent prismatic GaN single crystals grew from a Na-Ga melt which was formed by dissolution of Na from the gas phase. Nitrogen was probably introduced into the melt with Na. The time dependence of the Na fraction ( rNa=Na/(Na+Ga)) in the melts and the yields of GaN were investigated. rNa increased to 0.39-0.43 within 100 h, and then became almost constant at this value. The yield of GaN was less than 2% at 50 h. The yield increased linearly with heating time after 75 h, and reached 57% at 200 h. GaN single crystals with a size of 1.5 mm long were obtained on the bottom of the crucible wall. The largest crystals (3.0 mm-long and 1.2 mm-wide) grew at the edges of the melt and of the GaN crystal formation area near the bottom wall of the crucible.

  15. Alternative cycling modes of the Na(+)/K(+)-ATPase in the presence of either Na(+) or Rb(+).

    PubMed

    Monti, José L E; Montes, Mónica R; Rossi, Rolando C

    2013-05-01

    A comprehensive study of the interaction between Na(+) and K(+) with the Na(+)/K(+)-ATPase requires dissecting the incidence of alternative cycling modes on activity measurements in which one or both of these cations are absent. With this aim, we used membrane fragments containing pig-kidney Na(+)/K(+)-ATPase to perform measurements, at 25°C and pH=7.4, of ATPase activity and steady-state levels of (i) intermediates containing occluded Rb(+) at different [Rb(+)] in media lacking Na(+), and (ii) phosphorylated intermediates at different [Na(+)] in media lacking Rb(+). Most relevant results are: (1) Rb(+) can be occluded through an ATPasic cycling mode that takes place in the absence of Na(+) ions, (2) the kinetic behavior of the phosphoenzyme formed by ATP in the absence of Na(+) is different from the one that is formed with Na(+), and (3) binding of Na(+) to transport sites during catalysis is not at random unless rapid equilibrium holds. PMID:23357355

  16. Synthesis of NaYF4 and NaLuF4 Based Upconversion Nanocrystals and Comparison of Their Properties.

    PubMed

    Ouyang, Juan; Yin, Dongguang; Song, Kailin; Wang, Chengcheng; Liu, Bing; Wu, Minghong

    2015-04-01

    In this study, four kinds of upconversion nanocrystals (UCNs) have been successfully synthesized by a facile solvothermal method. The morphology, crystalline phase, composition, grain size, upconversion luminescence and cell image of the UCNs were investigated. The properties of the NaLuF4-based UCNs were compared with the counterparts of NaYF4-based UCNs. It is found that the NaLuF4-based UCNs are apt to form hexagonal phase structures, while NaYF4-based UCNs of NaYF4:Yb, Er and NaYF4:Gd, Yb, Er are cubic and hexagonal phases respectively. The upconversion emission intensities of the NaLuF4-based UCNs are higher than that of NaYF4-based UCNs, and Gd3+ presented UCNs are higher than that of Gd3+ absented UCNs. The bioimaging application of NaLuF4:Gd, Yb, Er shows that bright upconversion luminescence can be observed when UCNs-labeled HeLa cells are excited with 980 nm light. PMID:26353495

  17. Branching ratios for the beta decay of Na-21 

    E-print Network

    Iacob, V. E.; Hardy, John C.; Gagliardi, Carl A.; Goodwin, J.; Nica, N.; Park, H. I.; Tabacaru, G.; Trache, L.; Tribble, Robert E.; Zhai, Y.; Towner, I. S.

    2006-01-01

    We have measured the beta-decay branching ratio for the transition from Na-21 to the first excited state of Ne-21. A recently published test of the standard model, which was based on a measurement of the beta-nu correlation in the decay of Na-21...

  18. Temporal changes in intestinal Na+ -ATPase activity and in vitro

    E-print Network

    Young, Graham

    Temporal changes in intestinal Na+ , K+ -ATPase activity and in vitro responsiveness to cortisol+ , K+ -ATPase activity were measured in pyloric ceca and posterior intestine of juvenile chinook salmon pronounced increases in endogenous Na+ , K+ -ATPase activity in summer for both intestinal regions

  19. Moderate temperature rechargeable NaNiS2 cells

    NASA Technical Reports Server (NTRS)

    Abraham, K. M.

    1983-01-01

    A rechargeable sodium battery of the configuration, liquid Na/beta double prime -Al2O3/molten NaAlCl4, NiS2, operating in the temperature range of 170 to 190 C, is described. This battery is capable of delivering or = to 50 W-hr/1b and 1000 deep discharge/charge cycles.

  20. Transepithelial Na+ transport and the intracellular fluids: a computer study.

    PubMed

    Civan, M M; Bookman, R J

    1982-01-01

    Computer simulations of tight epithelia under three experimental conditions have been carried out, using the rheogenic nonlinear model of Lew, Ferreira and Moura (Proc. Roy. Soc. London. B 206:53-83, 1979) based largely on the formulation of Koefoed-Johnsen and Ussing (Acta Physiol. Scand. 42: 298-308. 1958). First, analysis of the transition between the short-circuited and open-circuited states has indicated that (i) apical Cl- permeability is a critical parameter requiring experimental definition in order to analyze cell volume regulation, and (ii) contrary to certain experimental reports, intracellular Na+ concentration (ccNa) is expected to be a strong function of transepithelial clamping voltage. Second, analysis of the effects of lowering serosal K+ concentration (csK) indicates that the basic model cannot simulate several well-documented observations; these defects can be overcome, at least qualitatively, by modifying the model to take account of the negative feedback interaction likely to exist between the apical Na+ permeability and ccNa. Third, analysis of the strongly supports the concept that osmotically induced permeability changes in the apical intercellular junctions play a physiological role in conserving the body's stores of NaCl. The analyses also demonstrate that the importance of Na+ entry across the basolateral membrane is strongly dependent upon transepithelial potential, cmNa and csK; under certain conditions, net Na+ entry could be appreciably greater across the basolateral than across the apical membrane. PMID:7057462

  1. Performances of the NA48 Liquid Krypton calorimeter

    E-print Network

    Guillaume Unal

    2000-12-05

    The NA48 experiments aims at a precise measurement of direct CP violation in the neutral Kaon system. This puts stringent requirements on the electromagnetic calorimeter used to detect photons of average energy 25 GeV. The choice of NA48 is a quasi homogeneous Liquid Krypton calorimeter with fast readout. The operation of this device and the performances achieved are described.

  2. Identification of Hydroxyxanthones as Na/K-ATPase Ligands

    PubMed Central

    Zhang, Zhongbing; Li, Zhichuan; Tian, Jiang; Jiang, Wei; Wang, Yin; Zhang, Xiaojin; Li, Zhuorong; You, Qidong; Shapiro, Joseph I.; Si, Shuyi

    2010-01-01

    We have screened a chemical library and identified several novel structures of Na/K-ATPase inhibitors. One group of these inhibitors belongs to polyphenolic xanthone derivatives. Functional characterization reveals the following properties of this group of inhibitors. First, like ouabain, they are potent inhibitors of the purified Na/K-ATPase. Second, their effects on the Na/K-ATPase depend on the number and position of phenolic groups. Methylation of these phenolic groups reduces the inhibitory effect. Third, further characterization of the most potent xanthone derivative, MB7 (3,4,5,6-tetrahydroxyxanthone), reveals that it does not change either Na+ or ATP affinity of the enzyme. Finally, unlike that of ouabain, the inhibitory effect of MB7 on Na/K-ATPase is not antagonized by K+. Moreover, MB7 does not activate the receptor Na/K-ATPase/Src complex and fails to stimulate protein kinase cascades in cultured cells. Thus, we have identified a group of novel Na/K-ATPase ligands that can inhibit the pumping function without stimulating the signaling function of Na/K-ATPase. PMID:20335388

  3. Direct Measurement of {sup 21}Na+{alpha} Stellar Reaction

    SciTech Connect

    Binh, D. N.; Kubono, S.; Yamaguchi, H.; Hayakawa, S.; Hashimoto, T.; Kahl, D.; Teranishi, T.; Iwasa, N.; Kume, N.; Kato, S.; Khiem, L. H.; Tho, N. T.; Wakabayashi, Y.

    2010-08-12

    The measurement of the resonant alpha scattering and the {sup 21}Na({alpha}, p) reaction were performed for the first time in inverse kinematics with the thick target method using a {sup 21}Na radioisotope (RI) beam. This paper reports the current result of alpha scattering measurement and its astrophysics implication.

  4. Kinetics of Na-ATPase activity by the Na,K pump. Interactions of the phosphorylated intermediates with Na+, Tris+, and K+

    PubMed Central

    1983-01-01

    To determine the biochemical events of Na+ transport, we studied the interactions of Na+, Tris+, and K+ with the phosphorylated intermediates of Na,K-ATPase from ox brain. The enzyme was phosphorylated by incubation at 0 degrees C with 1 mM Mg2+, 25 microM [32P]ATP, and 20-600 mM Na+ with or without Tris+, and the dephosphorylation kinetics of [32P]EP were studied after addition of (1) 1 mM ATP, (2) 2.5 mM ADP, (3) 1 mM ATP plus 20 mM K+, and (4) 2.5 mM ADP plus Na+ up to 600 mM. In dephosphorylation types 2-4, the curves were bi- or multiphasic. "ADP-sensitive EP" and "K+-sensitive EP" were determined by extrapolation of the slow phase of the curves to the ordinate and their sum was always larger than Etotal. These results required a minimal model consisting of three consecutive EP pools, A, B, and C, where A was ADP sensitive and both B and C were K+ sensitive. At high [Na+], B was converted rapidly to A (type 4 experiment). The seven rate coefficients were dependent on [Na+], [Tris+], and [K+], and to explain this we developed a comprehensive model for cation interaction with EP. The model has the following features: A, B, and C are equilibrium mixtures of EP forms; EP in A has two to three Na ions bound at high-affinity (internal) sites, pool B has three, and pool C has two to three low-affinity (external) sites. The putative high- affinity outside Na+ site may be on E2P in pool C. The A leads to B conversion is blocked by K+ (and Tris+). We conclude that pool A can be an intermediate only in the Na-ATPase reaction and not in the normal operation of the Na,K pump. PMID:6319537

  5. Feasibility study for a secondary Na/S battery

    NASA Technical Reports Server (NTRS)

    Abraham, K. M.; Schiff, R.; Brummer, S. B.

    1979-01-01

    The feasibility of a moderate temperature Na battery was studied. This battery is to operate at a temperature in the range of 100-150 C. Two kinds of cathode were investigated: (1) a soluble S cathode consisting of a solution of Na2Sn in an organic solvent and (2) an insoluble S cathode consisting of a transition metal dichalcogenide in contact with a Na(+)ion conducting electrolyte. Four amide solvents, dimethyl acetamide, diethyl acetamide, N-methyl acetamide and acetamide, were investigated as possible solvents for the soluble S cathode. Results of stability and electrochemical studies using these solvents are presented. The dialkyl substituted amides were found to be superior. Although the alcohol 1,3-cyclohexanediol was found to be stable in the presence of Na2Sn at 130 C, its Na2Sn solutions did not appear to have suitable electrochemical properties.

  6. Pressure-Stabilized Sodium Polyhydrides: NaHn (n>1)

    NASA Astrophysics Data System (ADS)

    Baettig, Pio; Zurek, Eva

    2011-06-01

    Computations on NaHn, n=6-12, show that NaH9 is stable by P=25GPa. Cmc21-NaH9 containing both H2 and H- units is metallic at P>250GPa. Other phases with only H2 units metallize at lower pressures as a result of the partial filling of the H2 ?u* bands by the Na 3s electrons. Pressure induced overlap of the Na 2p cores forestalls closure of the band gap in the odd phases with H- atoms, but the even phases remain good metals up to 300 GPa. The lower the IP of the metal, the lower the pressure at which MHn with n>1 become stable. The larger the radius of M, the greater the optimal value of n.

  7. Persistent human cardiac Na+ currents in stably transfected mammalian cells

    PubMed Central

    Wang, Ging Kuo; Russell, Gabriella; Wang, Sho-Ya

    2013-01-01

    Miniature persistent late Na+ currents in cardiomyocytes have been linked to arrhythmias and sudden death. The goals of this study are to establish a stable cell line expressing robust persistent cardiac Na+ currents and to test Class 1 antiarrhythmic drugs for selective action against resting and open states. After transient transfection of an inactivation-deficient human cardiac Na+ channel clone (hNav1.5-CW with L409C/A410W double mutations), transfected mammalian HEK293 cells were treated with 1 mg/ml G-418. Individual G-418-resistant colonies were isolated using glass cylinders. One colony with high expression of persistent Na+ currents was subjected to a second colony selection. Cells from this colony remained stable in expressing robust peak Na+ currents of 996 ± 173 pA/pF at +50 mV (n = 20). Persistent late Na+ currents in these cells were clearly visible during a 4-second depolarizing pulse albeit decayed slowly. This slow decay is likely due to slow inactivation of Na+ channels and could be largely eliminated by 5 ?M batrachotoxin. Peak cardiac hNav1.5-CW Na+ currents were blocked by tetrodotoxin with an IC50 value of 2.27 ± 0.08 ?M (n = 6). At clinic relevant concentrations, Class 1 antiarrhythmics are much more selective in blocking persistent late Na+ currents than their peak counterparts, with a selectivity ratio ranging from 80.6 (flecainide) to 3 (disopyramide). We conclude that (1) Class 1 antiarrhythmics differ widely in their resting- vs. open-channel selectivity, and (2) stably transfected HEK293 cells expressing large persistent hNav1.5-CW Na+ currents are suitable for studying as well as screening potent open-channel blockers. PMID:23695971

  8. Many-body perturbation theory calculations on the electronic states of Li 2, LiNa and Na 2

    NASA Astrophysics Data System (ADS)

    Davies, D. W.; Jones, G. J. R.

    1981-07-01

    Quasi-degenerate many-body perturbation theory with a multi-configuration reference space is used to obtain potential curves for the ground and excited electronic states of Li 2, LiNa and Na 2. Correlation contributions are analyzed and the effect of potential curve crossing on laser action is discussed.

  9. Studying Human Face Recognition with the Gaze-Contingent Window Technique Naing Naing Maw (nnmaw@cs.umb.edu)

    E-print Network

    Pomplun, Marc

    Studying Human Face Recognition with the Gaze-Contingent Window Technique Naing Naing Maw (nnmaw this technique to a face recognition task. By varying the size of the window, we gain insight into face recognition processes in humans and characterize the visual information on which face recognition relies

  10. Genome Sequences of Cupriavidus metallidurans Strains NA1, NA4, and NE12, Isolated from Space Equipment

    PubMed Central

    Monsieurs, Pieter; Mijnendonckx, Kristel; Provoost, Ann; Venkateswaran, Kasthuri; Ott, C. Mark; Leys, Natalie

    2014-01-01

    Cupriavidus metallidurans NA1, NA4, and NE12 were isolated from space and spacecraft-associated environments. Here, we report their draft genome sequences with the aim of gaining insight into their potential to adapt to these environments. PMID:25059868

  11. Direct measurements of 22Na(p,g)23Mg resonances and consequences for 22Na production in classical novae

    E-print Network

    A. L. Sallaska; C. Wrede; A. Garcia; D. W. Storm; T. A. D. Brown; C. Ruiz; K. A. Snover; D. F. Ottewell; L. Buchmann; C. Vockenhuber; D. A. Hutcheon; J. A. Caggiano

    2010-09-24

    The radionuclide 22Na is a potential astronomical observable that is expected to be produced in classical novae in quantities that depend on the thermonuclear rate of the 22Na(p,g)23Mg reaction. We have measured the strengths of low-energy 22Na(p,g)23Mg resonances directly and absolutely using a radioactive 22Na target. We find the strengths of resonances at E_p = 213, 288, 454, and 610 keV to be higher than previous measurements by factors of 2.4 to 3.2, and we exclude important contributions to the rate from proposed resonances at E_p = 198, 209, and 232 keV. The 22Na abundances expected in the ejecta of classical novae are reduced by a factor of ~ 2.

  12. The C Terminus of Na+,K+-ATPase Controls Na+ Affinity on Both Sides of the Membrane through Arg935*?

    PubMed Central

    Toustrup-Jensen, Mads S.; Holm, Rikke; Einholm, Anja Pernille; Schack, Vivien Rodacker; Morth, J. Preben; Nissen, Poul; Andersen, Jens Peter; Vilsen, Bente

    2009-01-01

    The Na+,K+-ATPase C terminus has a unique location between transmembrane segments, appearing to participate in a network of interactions. We have examined the functional consequences of amino acid substitutions in this region and deletions of the C terminus of varying lengths. Assays revealing separately the mutational effects on internally and externally facing Na+ sites, as well as E1-E2 conformational changes, have been applied. The results pinpoint the two terminal tyrosines, Tyr1017 and Tyr1018, as well as putative interaction partners, Arg935 in the loop between transmembrane segments M8 and M9 and Lys768 in transmembrane segment M5, as crucial to Na+ activation of phosphorylation of E1, a partial reaction reflecting Na+ interaction on the cytoplasmic side of the membrane. Tyr1017, Tyr1018, and Arg935 are furthermore indispensable to Na+ interaction on the extracellular side of the membrane, as revealed by inability of high Na+ concentrations to drive the transition from E1P to E2P backwards toward E1P and inhibit Na+-ATPase activity in mutants. Lys768 is not important for Na+ binding from the external side of the membrane but is involved in stabilization of the E2 form. These data demonstrate that the C terminus controls Na+ affinity on both sides of the membrane and suggest that Arg935 constitutes an important link between the C terminus and the third Na+ site, involving an arginine-? stacking interaction between Arg935 and the C-terminal tyrosines. Lys768 may interact preferentially with the C terminus in E1 and E1P forms and with the loop between transmembrane segments M6 and M7 in E2 and E2P forms. PMID:19416970

  13. Preparation of Al-La Master Alloy by Thermite Reaction in NaF-NaCl-KCl Molten Salt

    NASA Astrophysics Data System (ADS)

    Jang, Poknam; Li, Hyonmo; Kim, Wenjae; Wang, Zhaowen; Liu, Fengguo

    2015-05-01

    A NaF-NaCl-KCl ternary system containing La2O3 was investigated for the preparation of Al-La master alloy by the thermite reaction method. The solubility of La2O3 in NaF-NaCl-KCl molten salt was determined by the method of isothermal solution saturation. Inductively coupled plasma-optical emission spectroscopy and x-ray diffraction (XRD) analyses were used to consider the content of La2O3 in molten salt and the supernatant composition of molten salt after dissolution of La2O3, respectively. The results showed that the content of NaF had a positive influence on the solubility of La2O3 in NaF-NaCl-KCl molten salts, and the solubility of La2O3 could reach 8.71 wt.% in molten salts of 50 wt.%NaF-50 wt.% (44 wt.%NaCl + 56 wt.%KCl). The XRD pattern of cooling molten salt indicated the formation of LaOF in molten salt, which was probably obtained by the reaction between NaF and La2O3. The kinetic study showed that the thermite reaction was in accord with a first-order reaction model. The main influence factors on La content in the Al-La master alloy product, including molten salt composition, amount of Al, concentration of La2O3, stirring, reduction time and temperature, were investigated by single-factor experimentation. The content of La in the Al-La master alloy could be reached to 10.1 wt.%.

  14. Hormonal regulation of Na -K -ATPase in cultured epithelial cells

    SciTech Connect

    Johnson, J.P.; Jones, D.; Wiesmann, W.P.

    1986-08-01

    Aldosterone and insulin stimulate Na transport through mechanisms involving protein synthesis. Na -K -ATPase has been implicated in the action of both hormones. The authors examined the effect of aldosterone and insulin on Na -K -ATPase in epithelial cells in culture derived from toad urinary bladder (TB6C) and toad kidney (A6). Aldosterone, but not insulin, increases short-circuit current (I/sub sc/) in TB6C cells. Aldosterone increases Na -K -(TSP)ATPase activity after 18 h of incubation, but no effect can be seen at 3 and 6 h. Amiloride, which inhibits aldosterone-induced increases in I/sub sc/, has no effect on either basal or aldosterone stimulated enzyme activity. Both aldosterone and insulin increase I/sub sc/ in A6 cells and when added together are synergistic. Aldosterone stimulates enzyme activity in A6 cells, but insulin alone has no effect. However, aldosterone and insulin together stimulate enzyme activity more than aldosterone alone. It appears that stimulation of Na -K -ATPase activity is involved in aldosterone action in both cell lines but does not appear to be due to increased Na entry, since enhanced enzyme activity is not inhibited by amiloride. In contrast, insulin alone has no direct effect on Na -K -ATPase, although the increased enzyme activity following both agents in combination may explain their synergism on I/sub sc/.

  15. Targeting Na?/K? -translocating adenosine triphosphatase in cancer treatment.

    PubMed

    Durlacher, Cameron T; Chow, Kevin; Chen, Xiao-Wu; He, Zhi-Xu; Zhang, Xueji; Yang, Tianxin; Zhou, Shu-Feng

    2015-05-01

    The Na(+) /K(+) -translocating adenosine triphosphatase (ATPase) transports sodium and potassium across the plasma membrane and represents a potential target in cancer chemotherapy. Na(+) /K(+) -ATPase belongs to the P-type ATPase family (also known as E1-E2 ATPase), which is involved in transporting certain ions, metals, and lipids across the plasma membrane of mammalian cells. In humans, the Na(+) /K(+) -ATPase is a binary complex of an ?-subunit that has four isoforms (?1 -?4 ) and a ?-subunit that has three isoforms (?1 -?3 ). This review aims to update our knowledge on the role of Na(+) /K(+) -ATPase in cancer development and metastasis, as well as on how Na(+) /K(+) -ATPase inhibitors kill tumour cells. The Na(+) /K(+) -ATPase has been found to be associated with cancer initiation, growth, development, and metastasis. Cardiac glycosides have exhibited anticancer effects in cell-based and mouse studies via inhibition of the Na(+) /K(+) -ATPase and other mechanisms. Na(+) /K(+) -ATPase inhibitors may kill cancer cells via induction of apoptosis and autophagy, radical oxygen species production, and cell cycle arrest. They also modulate multiple signalling pathways that regulate cancer cell survival and death, which contributes to their antiproliferative activities in cancer cells. The clinical evidence supporting the use of Na(+) /K(+) -ATPase inhibitors as anticancer drugs is weak. Several phase I and phase II clinical trials with digoxin, Anvirzel, and huachansu (an intravenous formulated extract of the venom of the wild toad), either alone or more often in combination with other anticancer agents, have shown acceptable safety profiles but limited efficacy in cancer patients. Well-designed randomized clinical trials with reasonable sample sizes are certainly warranted to confirm the efficacy and safety of cardiac glycosides for the treatment of cancer. PMID:25739707

  16. Electron scattering in graphene with adsorbed NaCl nanoparticles

    SciTech Connect

    Drabi?ska, Aneta Ka?mierczak, Piotr; Bo?ek, Rafa?; Karpierz, Ewelina; Wysmo?ek, Andrzej; Kami?ska, Maria; Wo?o?, Agnieszka; Krajewska, Aleksandra

    2015-01-07

    In this work, the results of contactless magnetoconductance and Raman spectroscopy measurements performed for a graphene sample after its immersion in NaCl solution were presented. The properties of the immersed sample were compared with those of a non-immersed reference sample. Atomic force microscopy and electron spin resonance experiments confirmed the deposition of NaCl nanoparticles on the graphene surface. A weak localization signal observed using contactless magnetoconductance showed the reduction of the coherence length after NaCl treatment of graphene. Temperature dependence of the coherence length indicated a change from ballistic to diffusive regime in electron transport after NaCl treatment. The main inelastic scattering process was of the electron-electron type but the major reason for the reduction of the coherence length at low temperatures was additional, temperature independent, inelastic scattering. We associate it with spin flip scattering, caused by NaCl nanoparticles present on the graphene surface. Raman spectroscopy showed an increase in the D and D? bands intensities for graphene after its immersion in NaCl solution. An analysis of the D, D?, and G bands intensities proved that this additional scattering is related to the decoration of vacancies and grain boundaries with NaCl nanoparticles, as well as generation of new on-site defects as a result of the decoration of the graphene surface with NaCl nanoparticles. The observed energy shifts of 2D and G bands indicated that NaCl deposition on the graphene surface did not change carrier concentration, but reduced compressive biaxial strain in the graphene layer.

  17. Electron scattering in graphene with adsorbed NaCl nanoparticles

    NASA Astrophysics Data System (ADS)

    Drabi?ska, Aneta; Ka?mierczak, Piotr; Bo?ek, Rafa?; Karpierz, Ewelina; Wo?o?, Agnieszka; Wysmo?ek, Andrzej; Kami?ska, Maria; Pasternak, Iwona; Krajewska, Aleksandra; Strupi?ski, W?odek

    2015-01-01

    In this work, the results of contactless magnetoconductance and Raman spectroscopy measurements performed for a graphene sample after its immersion in NaCl solution were presented. The properties of the immersed sample were compared with those of a non-immersed reference sample. Atomic force microscopy and electron spin resonance experiments confirmed the deposition of NaCl nanoparticles on the graphene surface. A weak localization signal observed using contactless magnetoconductance showed the reduction of the coherence length after NaCl treatment of graphene. Temperature dependence of the coherence length indicated a change from ballistic to diffusive regime in electron transport after NaCl treatment. The main inelastic scattering process was of the electron-electron type but the major reason for the reduction of the coherence length at low temperatures was additional, temperature independent, inelastic scattering. We associate it with spin flip scattering, caused by NaCl nanoparticles present on the graphene surface. Raman spectroscopy showed an increase in the D and D' bands intensities for graphene after its immersion in NaCl solution. An analysis of the D, D', and G bands intensities proved that this additional scattering is related to the decoration of vacancies and grain boundaries with NaCl nanoparticles, as well as generation of new on-site defects as a result of the decoration of the graphene surface with NaCl nanoparticles. The observed energy shifts of 2D and G bands indicated that NaCl deposition on the graphene surface did not change carrier concentration, but reduced compressive biaxial strain in the graphene layer.

  18. In Situ Observation of Dehydration-Induced Phase Transformation from Na2Nb2O6-H2O to NaNbO3

    E-print Network

    Wang, Zhong L.

    In Situ Observation of Dehydration-Induced Phase Transformation from Na2Nb2O6-H2O to NaNbO3 Jong the phase transformation from a Sandia octahedral molecular sieve Na2Nb2O6-H2O to a piezoelectric NaNbO3 at high temperatures. After dehydration at 288 °C, the Na2Nb2O6-H2O becomes significantly destabilized

  19. Phyla- and Subtype-Selectivity of CgNa, a Na+ Channel Toxin from the Venom of the Giant Caribbean Sea Anemone Condylactis Gigantea

    PubMed Central

    Billen, Bert; Debaveye, Sarah; Béress, Lászlo; Tytgat, Jan

    2010-01-01

    Because of their prominent role in electro-excitability, voltage-gated sodium (NaV) channels have become the foremost important target of animal toxins. These toxins have developed the ability to discriminate between closely related NaV subtypes, making them powerful tools to study NaV channel function and structure. CgNa is a 47-amino acid residue type I toxin isolated from the venom of the Giant Caribbean Sea Anemone Condylactis gigantea. Previous studies showed that this toxin slows the fast inactivation of tetrodotoxin-sensitive NaV currents in rat dorsal root ganglion neurons. To illuminate the underlying NaV subtype-selectivity pattern, we have assayed the effects of CgNa on a broad range of mammalian isoforms (NaV1.2–NaV1.8) expressed in Xenopus oocytes. This study demonstrates that CgNa selectively slows the fast inactivation of rNaV1.3/?1, mNaV1.6/?1 and, to a lesser extent, hNaV1.5/?1, while the other mammalian isoforms remain unaffected. Importantly, CgNa was also examined on the insect sodium channel DmNaV1/tipE, revealing a clear phyla-selectivity in the efficacious actions of the toxin. CgNa strongly inhibits the inactivation of the insect NaV channel, resulting in a dramatic increase in peak current amplitude and complete removal of fast and steady-state inactivation. Together with the previously determined solution structure, the subtype-selective effects revealed in this study make of CgNa an interesting pharmacological probe to investigate the functional role of specific NaV channel subtypes. Moreover, further structural studies could provide important information on the molecular mechanism of NaV channel inactivation. PMID:21833172

  20. NA61/SHINE physics program -- first results and future plans

    E-print Network

    Tobiasz Czopowicz; for the NA61/SHINE Collaboration

    2012-01-27

    The NA61/SHINE experiment aims to discover the critical point of strongly interacting matter and study properties of the onset of deconfinement. These goals are to be achieved by performing a twodimensional phase diagram (T - {\\mu}B) scan measurements of hadron production as a function of collision energy and system size. With its large acceptance and good particle identification NA61/SHINE also performs detailed and precise particle production measurements for the T2K, Pierre Auger Observatory and KASCADEGrande experiments. This contribution summarizes current status and future plans as well as presents the first physics results of the NA61/SHINE experiment.

  1. Two-frequency lidar technique for mesospheric Na temperature measurements

    NASA Technical Reports Server (NTRS)

    She, C. Y.; Latifi, H.; Yu, J. R.; Alvarez, R. J., II; Bills, R. E.

    1990-01-01

    This paper describes a new two-frequency lidar for measuring Na temperature profiles. The laser oscillator is tuned to the two operating frequencies by observing the Doppler-free structure of the Na D2 fluorescence spectrum in a vapor cell. The lidar technique and initial observations of the temperature profile between 82 and 102 km are described. Absolute temperature accuracies at the Na layer peak of better than + or - 3 K with a vertical resolution of 1 km and an integration period of approximately 5 min were achieved.

  2. Ion Program of Na61/Shine at the CERN SPS

    E-print Network

    M. Gazdzicki; for the NA61/SHINE Collaboration

    2009-01-06

    The NA61/SHINE experiment at the CERN SPS aims to discover the critical point of strongly interacting matter and study properties of the onset of deconfinement. These goals will be reached by measurements of hadron production properties in nucleus-nucleus, proton-proton and proton-lead interactions as a function of collision energy and size of the colliding nuclei. Furthermore, NA61/SHINE will perform numerous precision measurements needed for neutrino (T2K) and cosmic-ray (Pierre Auger Observatory and KASCADE) experiments. This paper summarizes physics arguments for the NA61/SHINE ion program and presents the status and plans of the experiment.

  3. Desensitization by external Na of the cyclic AMP-dependent Na+/H+ antiporter in trout red blood cells

    PubMed Central

    1988-01-01

    The erythrocytes of the trout, Salmo gairdneri, react to beta- adrenergic stimulation by activating a cyclic AMP-dependent and amiloride-sensitive Na+/H+ antiporter (see Borgese, F., F. Garcia- Romeu, and R. Motais, Journal of General Physiology, 1986, 87:551-566). The present study traces the kinetic behavior of the unidirectional Na fluxes after stimulation by isoproterenol. A very considerable increase (100-fold) of the unidirectional Na influx (JNa(in)) follows the addition of isoproterenol to the erythrocyte suspension. After 1.5 min, JNa(in) falls suddenly, and asymptotically diminishes toward the nonstimulated flux level. The unidirectional Na efflux (JNa(out)) proceeds according to similar kinetics. The decrease of JNa(in) and JNa(out)is not linked to either a change in the driving forces of the transported ions or a decrease of the cyclic AMP concentration but to a desensitization of the Na+/H+ antiporter. This desensitization is dependent on the external Na concentration and is not controlled by internal Na, cell swelling, or external Ca. PMID:2839593

  4. NA49/NA61: results and plans on beam energy and system size scan at the CERN SPS

    E-print Network

    M. Gazdzicki; for the NA49; NA61/SHINE Collaborations

    2011-07-12

    This paper presents results and plans of the NA49 and NA61/SHINE experiments at the CERN Super Proton Synchrotron concerning the study of relativistic nucleus-nucleus interactions. First, the NA49 evidence for the energy threshold of creating quark-gluon plasma, the onset of deconfinement, in central lead-lead collisions around 30A GeV is reviewed. Then the status of the NA61/SHINE systematic study of properties of the onset of deconfinement is presented. Second, the search for the critical point of strongly interacting matter undertaken by both experiments is discussed. NA49 measured large fluctuations at the top SPS energy, 158A GeV, in collisions of light and medium size nuclei. They seem to indicate that the critical point exists and is located close to baryonic chemical potential of about 250 MeV. The NA61/SHINE beam energy and system size scan started in 2009 will provide evidence for the existence of the critical point or refute the interpretation of the NA49 fluctuation data in terms of the critical point.

  5. Characterization and antibacterial activity of silver exchanged regenerated NaY zeolite from surfactant-modified NaY zeolite.

    PubMed

    Salim, Mashitah Mad; Malek, Nik Ahmad Nizam Nik

    2016-02-01

    The antibacterial activity of regenerated NaY zeolite (thermal treatment from cetyltrimethyl ammonium bromide (CTAB)-modified NaY zeolite and pretreatment with Na ions) loaded with silver ions were examined using the broth dilution minimum inhibitory concentration (MIC) method against Escherichia coli (E. coli ATCC 11229) and Staphylococcus aureus (S. aureus ATCC 6538). X-ray diffraction (XRD), attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) and chemical elemental analyses were used to characterize the regenerated NaY and AgY zeolites. The XRD patterns indicated that the calcination and addition of silver ions on regenerated NaY zeolite did not affect the structure of the regenerated NaY zeolite as the characteristic peaks of the NaY zeolite were retained, and no new peaks were observed. The regenerated AgY zeolite showed good antibacterial activity against both bacteria strains in distilled water, and the antibacterial activity of the samples increased with increasing Ag loaded on the regenerated AgY zeolite; the regenerated AgY zeolite was more effective against E. coli than S. aureus. However, the antibacterial activity of the regenerated AgY was not effective in saline solution for both bacteria. The study showed that CTAB-modified NaY zeolite materials could be regenerated to NaY zeolite using thermal treatment (550°C, 5h) and this material has excellent performance as an antibacterial agent after silver ions loading. PMID:26652350

  6. Determinants of substrate and cation transport in the human Na+/dicarboxylate cotransporter NaDC3.

    PubMed

    Schlessinger, Avner; Sun, Nina N; Colas, Claire; Pajor, Ana M

    2014-06-13

    Metabolic intermediates, such as succinate and citrate, regulate important processes ranging from energy metabolism to fatty acid synthesis. Cytosolic concentrations of these metabolites are controlled, in part, by members of the SLC13 gene family. The molecular mechanism underlying Na(+)-coupled di- and tricarboxylate transport by this family is understood poorly. The human Na(+)/dicarboxylate cotransporter NaDC3 (SLC13A3) is found in various tissues, including the kidney, liver, and brain. In addition to citric acid cycle intermediates such as ?-ketoglutarate and succinate, NaDC3 transports other compounds into cells, including N-acetyl aspartate, mercaptosuccinate, and glutathione, in keeping with its dual roles in cell nutrition and detoxification. In this study, we construct a homology structural model of NaDC3 on the basis of the structure of the Vibrio cholerae homolog vcINDY. Our computations are followed by experimental testing of the predicted NaDC3 structure and mode of interaction with various substrates. The results of this study show that the substrate and cation binding domains of NaDC3 are composed of residues in the opposing hairpin loops and unwound portions of adjacent helices. Furthermore, these results provide a possible explanation for the differential substrate specificity among dicarboxylate transporters that underpin their diverse biological roles in metabolism and detoxification. The structural model of NaDC3 provides a framework for understanding substrate selectivity and the Na(+)-coupled anion transport mechanism by the human SLC13 family and other key solute carrier transporters. PMID:24808185

  7. 23 Na and 17O NMR studies of hyperkagome Na4Ir3O8

    NASA Astrophysics Data System (ADS)

    Shockley, Abigail; Bert, Fabrice; Orain, Jean-Christophe; Okamoto, Yoshihiko; Mendels, Philippe

    2015-03-01

    Na4Ir3O8 is a unique case of a 3D corner sharing triangular lattice which can be decorated with quantum spins. It has spurred a lot of theoretical interest as a spin liquid candidate of a new kind where the Hamiltonian might not be thought in terms of a simple Heisenberg case because of spin orbit coupling on the Ir 5d element. We present a comprehensive set of NMR data taken on both the 23Na and 17O sites. We have found that magnetic freezing of all Ir sites sets in below Tf ~ 7.5K ~ 0 . 019 J with a clear hyperfine field transferred from Ir moments and a drastic decrease of 1 /T1 . Above Tf, physical properties are expected to be a landmark of frustration in this exotic geometry. We will discuss our shift and relaxation data in the temperature range of 300K to 7.5 K in the light of published thermodynamic measurements (Y. Okamotoa et al, PRL 99 137207, 2007 and Y. Singh et al, PRB 88 220413(R), 2013) and comment on their implications for the already existing large body of theoretical work.

  8. Influence of NaCl and NaNO3 on sinigrin hydrolysis by foodborne bacteria.

    PubMed

    Herzallah, S; Lledó, M Lara; Holley, R

    2011-12-01

    The glucosinolate sinigrin (SNG) is converted by endogenous plant myrosinase or by bacterial myrosinase-like activity to form the potent antimicrobial allyl isothiocyanate. In order to use SNG as a natural antimicrobial precursor in food, it became important to better understand the ability of bacteria to synthesize the enzyme(s) and understand factors influencing this synthesis at a constant SNG concentration. Eight spoilage, pathogenic, or starter culture bacteria were grown separately in medium containing individual or combined salts with SNG. SNG degradation by the bacteria and the formation of its major degradation product, allyl isothiocyanate, were followed for 12 days at 30 or 35°C. The bacterial strains varied in their ability to metabolize SNG, and this was enhanced by NaCl and/or NaNO(3). SNG hydrolysis took place after 4 days, and the greatest amount occurred by day 12. At 12 days, Escherichia coli O157:H7 showed the greatest capacity to hydrolyze SNG (45.3% degradation), followed by Staphylococcus carnosus (44.57%), while Pseudomonas fluorescens was not active against SNG. The ability of tested strains to metabolize SNG, in decreasing order, was as follows: Escherichia coli O157:H7 > Staphylococcus carnosus > Staphylococcus aureus > Pediococcus pentosaceus > Salmonella Typhimurium > Listeria monocytogenes > Enterococcus faecalis > Pseudomonas fluorescens. PMID:22186059

  9. ?-synuclein assemblies sequester neuronal ?3-Na+/K+-ATPase and impair Na+ gradient.

    PubMed

    Shrivastava, Amulya Nidhi; Redeker, Virginie; Fritz, Nicolas; Pieri, Laura; Almeida, Leandro G; Spolidoro, Maria; Liebmann, Thomas; Bousset, Luc; Renner, Marianne; Léna, Clément; Aperia, Anita; Melki, Ronald; Triller, Antoine

    2015-10-01

    Extracellular ?-synuclein (?-syn) assemblies can be up-taken by neurons; however, their interaction with the plasma membrane and proteins has not been studied specifically. Here we demonstrate that ?-syn assemblies form clusters within the plasma membrane of neurons. Using a proteomic-based approach, we identify the ?3-subunit of Na+/K+-ATPase (NKA) as a cell surface partner of ?-syn assemblies. The interaction strength depended on the state of ?-syn, fibrils being the strongest, oligomers weak, and monomers none. Mutations within the neuron-specific ?3-subunit are linked to rapid-onset dystonia Parkinsonism (RDP) and alternating hemiplegia of childhood (AHC). We show that freely diffusing ?3-NKA are trapped within ?-syn clusters resulting in ?3-NKA redistribution and formation of larger nanoclusters. This creates regions within the plasma membrane with reduced local densities of ?3-NKA, thereby decreasing the efficiency of Na+ extrusion following stimulus. Thus, interactions of ?3-NKA with extracellular ?-syn assemblies reduce its pumping activity as its mutations in RDP/AHC. PMID:26323479

  10. The Practice of Research of a Basic Education Teacher Involving Mental Models of the Phases of the Moon and Eclipses. (Spanish Title: La Práctica de Investigación de un Maestro de Educación BÁsica con El Uso de los Modelos Mentales de Las Fases de la Luna Y Eclipses.) A Prática de Pesquisa de um Professor do Ensino Fundamental Envolvendo Modelos Mentais de Fases da Lua e Eclipses

    NASA Astrophysics Data System (ADS)

    Pessôa Queiroz, Glória; Jubitipan Borges de Sousa, Carlos; Auxiliadora Delgado Machado, Maria

    2009-12-01

    The inclusion of basic education teachers in the survey domain is a controversial issue and fully debated in the academy. The opportunity for a collective work that incorporated school teachers from a public school to a university's group of physics teaching at university allowed us to glimpse the redefinition of the function of a science teacher (a coauthor of this paper) by himself, such that now he includes research on the knowledge construction by students in his teacher practice. The formation of inter-institutional groups for action planning and research in these areas has proved productive for the task of knowledge construction to support educational processes in school, while the university enriches its collection of experiences critically validated, and can consider the results in teachers initial and continued education. The active participation of the teacher in a research group at the university led him to reflect on the possible didactical ways to be described, analyzed and communicated to other teachers. The construction of a pedagogy that took into account the mental models of students on the basic topics of astronomy, and the changes developed resulting from the lessons taught, led to far-reaching consequences on the pedagogy adopted by the teacher, who incorporates now a new vision of science and alternative forms to dialogue with students, essential components for a researcher in Science Education. La inclusión de los maestros de la escuela básica en el universo de la investigación es polémica y está en amplio debate en el mundo académico. La oportunidad de trabajo colectivo de los maestros de una escuela pública en Río de Janeiro con un grupo universitario de enseñanza de la física nos ha permitido vislumbrar la redefinición de la función de un maestro de ciencias (uno de los coautores de este documento) por él mismo, ahora para incluir la investigación sobre la construcción del conocimiento por los alumnos en su práctica como docente. La formación de grupos interinstitucionales para la planificación de la acción y la investigación ha resultado productiva para el trabajo de construcción de conocimiento de apoyo a los procesos educativos en la escuela, mientras que la universidad enriquece su colección de experiencias validadas, considerando los resultados de la educación inicial y continua de maestros. La participación activa del maestro en un grupo de investigación en la universidad lo llevó a reflexiones sobre los posibles caminos didácticos que pueden ser descriptos, analizados y comunicados a los demás docentes. La construcción de una pedagogía propia, que tuvo en cuenta los modelos mentales de los estudiantes sobre los temas básicos de astronomía, y los cambios desarrollados a partir de las lecciones que enseñó, trajeron consecuencias de largo alcance sobre la pedagogía adoptada por el maestro, que ahora incorpora una nueva visión de la ciencia y formas alternativas al diálogo con los estudiantes, los componentes esenciales para un investigador en Educaciónen Ciencias. A inclusão do professor da escola básica no universo da pesquisa é questão controvertida e em pleno debate no meio acadêmico. A oportunidade de trabalho coletivo que incorporou professores de uma escola municipal no Rio de Janeiro a um grupo de ensino de Física da universidade nos possibilitou vislumbrar a ressignificação da função de um professor de Ciências (co-autor deste trabalho) por ele próprio, agora passando a incluir a pesquisa sobre a construção de conhecimento pelos alunos em sua prática como docente. A formação de grupos interinstitucionais para o planejamento de ações e de pesquisas tem-se mostrado produtiva para um trabalho de construção de conhecimentos a fim de subsidiar processos educativos na escola, ao mesmo tempo em que a universidade enriquece seu acervo de experiências validadas criticamente, podendo considerar seus resultados na formação inicial e continuada de professores. A participação ativa do professor num grupo de pesquisa na universidade o

  11. Coulomb interaction energy including overlap effects for the ground states of LiNa and Na 2

    NASA Astrophysics Data System (ADS)

    Bussery, B.; Achkar, Y.; Aubert-Frécon, M.

    1989-01-01

    A recently proposed method to calculate first-order electrostatic as well as second-order induction and dispersion energies including charge-overlap effects for the interaction between two atoms each with one active electron is applied to the systems Li(2s) + Na(3s) and Na(3s) + Na(3s), giving the induction energy for both systems. The variation with R of the relative contribution of the overlapping and non-overlapping configuration space regions is discussed for the largest dispersion and induction terms.

  12. Slovenski terminološki sistemi na primeru pravne terminologije

    E-print Network

    Fajfar, Tanja

    2007-01-01

    je slovenska pravna terminologija odzvala na poimenovanje pojmov iz pojmovnega sveta pravnega reda Evropskih skupnosti (acquis communautaire). Ta je nacionalnim pravnim redom držav ?lanic nadrejen ter terja enotno interpretacijo in uporabo, kar...

  13. Tb/Na tobermorite: Thermal behaviour and high temperature products

    SciTech Connect

    Garra, Walter; Marchetti, Fabio; Merlino, Stefano

    2009-06-15

    By heating a sample of Tb/Na tobermorite we obtained a phase which was identified through its X-ray diffraction (XRD) pattern, as terbium silicate apatite. Subsequently this compound has been directly prepared by solid state reaction and we carried out a structural refinement from XRD data in space group P6{sub 3}/m obtaining cell parameters a=9.39199(4) A and c=6.84041(5) A. Terbium silicate apatite heated in melted NaF led to Tb{sub 4}O{sub 7} crystals. - Graphical Abstract: By heating over 900 deg. C Tb/Na tobermorite a terbium silicate apatite was obtained. The same product has been independently prepared and structurally characterized from powder diffraction data. Attempts of crystallizing terbium silicate apatite from melted NaF led to Tb{sub 4}O{sub 7} crystals.

  14. Degradation Of Carbon/Phenolic Composites By NaOH

    NASA Technical Reports Server (NTRS)

    King, H. M.; Semmel, M. L.; Goldberg, B. E.; Clinton, Raymond G., Jr.

    1989-01-01

    Effects of sodium hydroxide contamination level on physical and chemical properties of phenolic resin and carbon/phenolic composites described in report. NaOH degrades both carbon and phenolic components of carbon/phenolic laminates.

  15. NaIrO3—A Pentavalent Post-perovskite

    SciTech Connect

    M Bremholm; S Dutton; P Stephens; R Cava

    2011-12-31

    Sodium iridium (V) oxide, NaIrO{sub 3}, was synthesized by a high pressure solid state method and recovered to ambient conditions. It is found to be isostructural with CaIrO{sub 3}, the much-studied structural analog of the high-pressure post-perovskite phase of MgSiO{sub 3}. Among the oxide post-perovskites, NaIrO{sub 3} is the first example with a pentavalent cation. The structure consists of layers of corner- and edge-sharing IrO{sub 6} octahedra separated by layers of NaO{sub 8} bicapped trigonal prisms. NaIrO{sub 3} shows no magnetic ordering and resistivity measurements show non-metallic behavior. The crystal structure, electrical and magnetic properties are discussed and compared to known post-perovskites and pentavalent perovskite metal oxides.

  16. The NA62 experiment at CERN: status and perspectives

    E-print Network

    Tommaso Spadaro

    2011-01-28

    The future program of the NA62 experiment at CERN SPS is currently in advanced stage of development. The main goal of the experiment is to measure the branching ratio of the ultra-rare decay K^+ -> pi+\

  17. Evolution of Na(+) and H(+) bioenergetics in methanogenic archaea.

    PubMed

    Schlegel, Katharina; Müller, Volker

    2013-02-01

    Methanogenic archaea live at the thermodynamic limit of life and use sophisticated mechanisms for ATP synthesis and energy coupling. The group of methanogens without cytochromes use an Na(+) current across the membrane for ATP synthesis, whereas the cytochrome-containing methanogens have additional coupling sites that also translocate protons. The ATP synthase in this group is promiscuous and uses Na(+) and H(+) simultaneously. PMID:23356322

  18. Na(+) diffusion kinetics in nanoporous metal-hexacyanoferrates.

    PubMed

    Takachi, Masamitsu; Fukuzumi, Yuya; Moritomo, Yutaka

    2015-12-22

    Metal-hexacyanoferrates (metal-HCFs) are promising candidates for cathode materials of sodium-ion secondary batteries (SIBs). Here, we systematically investigated Na(+) diffusion constants (D) and the activation energies (Ea) of metal-HCFs against the framework size (= a/2). We found that the magnitude of D (Ea) systematically increases (decreases) with increases in a, indicating that steric hindrance plays a dominant role in Na(+) diffusion. PMID:26415909

  19. g State of Na2: Vibrational Numbering and Hyperfine Structure

    E-print Network

    Huennekens, John

    The 43 g State of Na2: Vibrational Numbering and Hyperfine Structure G. Lazarov,* A. M. Lyyra,*,1 The Na2 43 g state has been studied by continuous-wave (cw) perturbation-facilitated optical of the 43 g (v, N) 4 b3 u (vb, J ) A1 u (vA, J ) 4 X1 g (v , J ) transitions show hyperfine splittings

  20. Status and plans of the NA61/SHINE physics program

    SciTech Connect

    Czopowicz, T.

    2012-06-15

    One of the NA61/SHINE experiment's goals is to discover the critical point of strongly interacting matter and study the properties of the onset of deconfinement. This is to be achieved by performing a two-dimensional phase diagram (T- Micro-Sign {sub B}) scan-measuring hadron production in collisions of various beam particles and targets at various beam energies. NA61/SHINE also collects data for the T2K experiment, which are just about to be published.

  1. An empirical NaKCa geothermometer for natural waters

    USGS Publications Warehouse

    Fournier, R.O.; Truesdell, A.H.

    1973-01-01

    An empirical method of estimating the last temperature of water-rock interaction has been devised. It is based upon molar Na, K and Ca concentrations in natural waters from temperature environments ranging from 4 to 340??C. The data for most geothermal waters cluster near a straight line when plotted as the function log ( Na K) + ?? log [ ??? (Ca) Na] vs reciprocal of absolute temperature, where ?? is either 1 3 or 4 3 depending upon whether the water equilibrated above or below 100??C. For most waters tested, the method gives better results than the Na K methods suggested by other workers. The ratio Na K should not be used to estimate temperature if ??? ( MCa) MNa is greater than 1. The Na K values of such waters generally yield calculated temperatures much higher than the actual temperature at which water interacted with the rock. A comparison of the composition of boiling hot-spring water with that obtained from a nearby well (170??C) in Yellowstone Park shows that continued water-rock reactions may occur during ascent of water even though that ascent is so rapid that little or no heat is lost to the country rock, i.e. the water cools adiabatically. As a result of such continued reaction, waters which dissolve additional Ca as they ascend from the aquifer to the surface will yield estimated aquifer temperatures that are too low. On the other hand, waters initially having enough Ca to deposit calcium carbonate during ascent may yield estimated aquifer temperatures that are too high if aqueous Na and K are prevented from further reaction with country rock owing to armoring by calcite or silica minerals. The Na-K-Ca geothermometer is of particular interest to those prospecting for geothermal energy. The method also may be of use in interpreting compositions of fluid inclusions. ?? 1973.

  2. Na+ and K+ ion imbalances in Alzheimer’s disease

    PubMed Central

    Vitvitsky, Victor M.; Garg, Sanjay K.; Keep, Richard F.; Albin, Roger L.; Banerjee, Ruma

    2012-01-01

    Alzheimer’s disease (AD) is associated with impaired glutamate clearance and depressed Na+/K+ ATPase levels in AD brain that might lead to a cellular ion imbalance. To test this hypothesis, [Na+] and [K+] were analyzed in postmortem brain samples of 12 normal and 16 AD individuals, and in cerebrospinal fluid (CSF) from AD patients and matched controls. Statistically significant increases in [Na+] in frontal (25%) and parietal cortex (20%) and in cerebellar [K+] (15%) were observed in AD samples compared to controls. CSF from AD patients and matched controls exhibited no differences, suggesting that tissue ion imbalances reflected changes in the intracellular compartment. Differences in cation concentrations between normal and AD brain samples were modeled by a 2-fold increase in intracellular [Na+] and an 8–15% increase in intracellular [K+]. Since amyloid beta peptide (A?) is an important contributor to AD brain pathology, we assessed how A? affects ion homeostasis in primary murine astrocytes, the most abundant cells in brain tissue. We demonstrate that treatment of astrocytes with the A? 25–35 peptide increases intracellular levels of Na+ (~2–3-fold) and K+ (~1.5-fold), which were associated with reduced levels of Na+/K+ ATPase and the Na+-dependent glutamate transporters, GLAST and GLT-1. Similar increases in astrocytic Na+ and K+ levels were also caused by A? 1–40, but not by A? 1–42 treatment. Our study suggests a previously unrecognized impairment in AD brain cell ion homeostasis that might be triggered by A? and could significantly affect electrophysiological activity of brain cells, contributing to the pathophysiology of AD. PMID:22820549

  3. Theoretical perspective on the NA62 physics program

    E-print Network

    Christopher Smith

    2010-12-16

    Soon the NA62 experiment will start looking for the rare K+ ---> pi+ nu nu bar decay. In this talk, its theoretical interests, together with those of the neutral rare decays KL ---> pi0 nu nu bar, KL ---> pi0 e+ e-, and KL ---> pi0 mu+ mu-, are briefly reviewed. Then, other possible targets for NA62 are discussed, among which the dominant semileptonic decays, the radiative decays, as well as the lepton-flavor violating decays.

  4. Bacterial Na+-translocating ferredoxin:NAD+ oxidoreductase

    PubMed Central

    Biegel, Eva; Müller, Volker

    2010-01-01

    The anaerobic acetogenic bacterium Acetobacterium woodii carries out a unique type of Na+-motive, anaerobic respiration with caffeate as electron acceptor, termed “caffeate respiration.” Central, and so far the only identified membrane-bound reaction in this respiration pathway, is a ferredoxin:NAD+ oxidoreductase (Fno) activity. Here we show that inverted membrane vesicles of A. woodii couple electron transfer from reduced ferredoxin to NAD+ with the transport of Na+ from the outside into the lumen of the vesicles. Na+ transport was electrogenic, and accumulation was inhibited by sodium ionophores but not protonophores, demonstrating a direct coupling of Fno activity to Na+ transport. Results from inhibitor studies are consistent with the hypothesis that Fno activity coupled to Na+ translocation is catalyzed by the Rnf complex, a membrane-bound, iron–sulfur and flavin-containing electron transport complex encoded by many bacterial and some archaeal genomes. Fno is a unique type of primary Na+ pump and represents an early evolutionary mechanism of energy conservation that expands the redox range known to support life. In addition, it explains the lifestyle of many anaerobic bacteria and gives a mechanistic explanation for the enigma of the energetic driving force for the endergonic reduction of ferredoxin with NADH plus H+ as reductant in a number of aerobic bacteria. PMID:20921383

  5. thin films grown with additional NaF layers

    NASA Astrophysics Data System (ADS)

    Kim, Gee Yeong; Kim, Juran; Jo, William; Son, Dae-Ho; Kim, Dae-Hwan; Kang, Jin-Kyu

    2014-10-01

    CZTS precursors [SLG/Mo (300 nm)/ZnS (460 nm)/SnS (480 nm)/Cu (240 nm)] were deposited by RF/DC sputtering, and then NaF layers (0, 15, and 30 nm) were grown by electron beam evaporation. The precursors were annealed in a furnace with Se metals at 590°C for 20 minutes. The final composition of the CZTSSe thin-films was of Cu/(Zn + Sn) ~ 0.88 and Zn/Sn ~ 1.05, with a metal S/Se ratio estimated at ~0.05. The CZTSSe thin-films have different NaF layer thicknesses in the range from 0 to 30 nm, achieving a ~3% conversion efficiency, and the CZTSSe thin-films contain ~3% of Na. Kelvin probe force microscopy was used to identify the local potential difference that varied according to the thickness of the NaF layer on the CZTSSe thin-films. The potential values at the grain boundaries were observed to increase as the NaF thickness increased. Moreover, the ratio of the positively charged GBs in the CZTSSe thin-films with an NaF layer was higher than that of pure CZTSSe thin-films. A positively charged potential was observed around the grain boundaries of the CZTSSe thin-films, which is a beneficial characteristic that can improve the performance of a device.

  6. Experimental and first-principles study of photoluminescent and optical properties of Na-doped CuAlO2: the role of the NaAl-2Na i complex

    NASA Astrophysics Data System (ADS)

    Liu, Ruijian; Li, Yongfeng; Yao, Bin; Ding, Zhanhui; Deng, Rui; Zhang, Ligong; Zhao, Haifeng; Liu, Lei

    2015-08-01

    We report that a band-tail emission at 3.08?eV, lower than near-band-edge energy, is observed in photoluminescence measurements of bulk Na-doped CuAlO2. The band-tail emission is attributed to Na-related defects. Electronic structure calculations based on the first-principles method demonstrate that the donor-acceptor compensated complex of NaAl-2Na i in Na-doped CuAlO2 plays a key role in leading to the band-tail emission and bandgap narrowing. Furthermore, Hall effect measurements indicates that the hole concentration in CuAlO2 is independent on Na doping, which is well understood by the donor-acceptor compensation effect of NaAl-2Na i complex.

  7. Design and implementation of the NaI (Tl)CsI (Na) detectors output signal generator

    E-print Network

    Xu Zhou; Cong-Zhan Liu; Jian-Ling Zhao; Fei Zhang; Yi-Fei Zhang; Zheng-Wei Li; Shuo Zhang; Xu-Fang Li; Xue-Feng Lu; Zhen-Ling Xu; Fang-Jun Lu

    2013-05-16

    We designed and implemented a signal generator that can simulate the output of the NaI (Tl)CsI (Na) detectors pre amplifier onboard the Hard X ray Modulation Telescope (HXMT). Using the development of FPGA (Field Programmable Gate Array) with VHDL language and adding random constituent, we have finally produced the double exponential random pulse signal generator. The statistical distribution of signal amplitude is programmable. The occurrence time intervals of adjacent signals content negative exponential distribution statistically.

  8. n-Selective Single Capture Following Xe18+ And Xe54+ Impact On Na(3s) And Na*(3p)

    NASA Astrophysics Data System (ADS)

    Otranto, S.; Olson, R. E.; Hasan, V. G.; Hoekstra, R.

    2011-06-01

    State selective single charge exchange n-level cross sections are calculated for collisions of Xe18+ and Xe54+ ions with Na(3s) and Na*(3p) over the energy range of 0.1 to 10.0 keV/amu. The CTMC method is used which includes all two-body interactions. Experimental state-selective cross sections and their corresponding transverse momentum spectra for Xe18+ are found to be in reasonable accord with the calculations.

  9. NaCl Taste Thresholds in 13 Inbred Mouse Strains

    PubMed Central

    Ishiwatari, Yutaka

    2012-01-01

    Molecular mechanisms of salty taste in mammals are not completely understood. We use genetic approaches to study these mechanisms. Previously, we developed a high-throughput procedure to measure NaCl taste thresholds, which involves conditioning mice to avoid LiCl and then examining avoidance of NaCl solutions presented in 48-h 2-bottle preference tests. Using this procedure, we measured NaCl taste thresholds of mice from 13 genealogically divergent inbred stains: 129P3/J, A/J, BALB/cByJ, C3H/HeJ, C57BL/6ByJ, C57BL/6J, CBA/J, CE/J, DBA/2J, FVB/NJ, NZB/BlNJ, PWK/PhJ, and SJL/J. We found substantial strain variation in NaCl taste thresholds: mice from the A/J and 129P3/J strains had high thresholds (were less sensitive), whereas mice from the BALB/cByJ, C57BL/6J, C57BL/6ByJ, CE/J, DBA/2J, NZB/BINJ, and SJL/J had low thresholds (were more sensitive). NaCl taste thresholds measured in this study did not significantly correlate with NaCl preferences or amiloride sensitivity of chorda tympani nerve responses to NaCl determined in the same strains in other studies. To examine whether strain differences in NaCl taste thresholds could have been affected by variation in learning ability or sensitivity to toxic effects of LiCl, we used the same method to measure citric acid taste thresholds in 4 inbred strains with large differences in NaCl taste thresholds but similar acid sensitivity in preference tests (129P3/J, A/J, C57BL/6J, and DBA/2J). Citric acid taste thresholds were similar in these 4 strains. This suggests that our technique measures taste quality–specific thresholds that are likely to represent differences in peripheral taste responsiveness. The strain differences in NaCl taste sensitivity found in this study provide a basis for genetic analysis of this phenotype. PMID:22293936

  10. Upconversion improvement by the reduction of Na?-vacancies in Mn²? doped hexagonal NaYbF?:Er³? nanoparticles.

    PubMed

    Tian, Dongping; Gao, Dangli; Chong, Bo; Liu, Xuanzuo

    2015-03-01

    Hexagonal-phase NaYbF4:Er(3+) upconversion nanoparticles (UCNPs) have been synthesized via a co-precipitation method in high-boiling-point solvents, and remarkably enhanced upconversion luminescence, particularly in red emission bands (650-670 nm) in NaYbF4:Er(3+) UCNPs, has been achieved by Mn(2+) doping. The underlying reason for luminescence enhancement by Mn(2+) doping is explored by a series of controlled experiments, and a mechanism of enhancement based on the decrease of Na(+)-vacancies and organic adsorption is proposed. The Mn(2+) substitution disturbs the equilibrium of the charge and crystal lattice in the hexagonal-phase NaYbF4:Er(3+) UCNPs, which makes the Na(+)-vacancies that quenched luminescence become filled with Na(+) or Mn(2+) to offset the imbalance of the charge and electron cloud distortion. In addition, the Mn(2+) doping at the surface of UCNPs could reduce the organic adsorption on the surface of the UCNPs by an extra F(-) ion on the grain surface resulting in luminescence enhancement. Therefore, the Mn(2+)-doping approach provides a facile strategy for improvement of luminescence, which will impact on the field of bioimaging based on UCNP nanoprobes. PMID:25622805

  11. NaN, a novel voltage-gated Na channel, is expressed preferentially in peripheral sensory neurons and down-regulated after axotomy

    PubMed Central

    Dib-Hajj, S. D.; Tyrrell, L.; Black, J. A.; Waxman, S. G.

    1998-01-01

    Although physiological and pharmacological evidence suggests the presence of multiple tetrodotoxin-resistant (TTX-R) Na channels in neurons of peripheral nervous system ganglia, only one, SNS/PN3, has been identified in these cells to date. We have identified and sequenced a novel Na channel ?-subunit (NaN), predicted to be TTX-R and voltage-gated, that is expressed preferentially in sensory neurons within dorsal root ganglia (DRG) and trigeminal ganglia. The predicted amino acid sequence of NaN can be aligned with the predicted structure of known Na channel ?-subunits; all relevant landmark sequences, including positively charged S4 and pore-lining SS1–SS2 segments, and the inactivation tripeptide IFM, are present at predicted positions. However, NaN exhibits only 42–53% similarity to other mammalian Na channels, including SNS/PN3, indicating that it is a novel channel, and suggesting that it may represent a third subfamily of Na channels. NaN transcript levels are reduced significantly 7 days post axotomy in DRG neurons, consistent with previous findings of a reduction in TTX-R Na currents. The preferential expression of NaN in DRG and trigeminal ganglia and the reduction of NaN mRNA levels in DRG after axonal injury suggest that NaN, together with SNS/PN3, may produce TTX-R currents in peripheral sensory neurons and may influence the generation of electrical activity in these cells. PMID:9671787

  12. High-NA HPCS optical fibers for medical diagnosis and treatment

    NASA Astrophysics Data System (ADS)

    Skutnik, Bolesh J.

    2010-02-01

    Hard Plastic Clad Silica (HPCS) optical fibers with pure silica cores have been developed which are robust and have NA(Numerical Aperture)>0.50. Improved clad only HPCS fibers have been produced for both new 'standard' and 'high' NA versions. Based on new cladding formulations, the 'standard' NA fiber has an NA of 0.41, while the new ultrahigh NA fiber has an NA of 0.54. Mechanical strength and preliminary fatigue data are presented along with spectral characterization data. For the first time significant results were obtained for clad only high NA fibers, The fibers are useful for diagnostic and surgical applications. Short to medium length time to failure results, indicate that the static fatigue parameters of the new high numerical aperture (NA) optical fibers are at least as good as those for former standard NA (0.37) HPCS fibers, which is an advance from previous results on the older formulation high NA fibers.

  13. Magnetism in Na-filled Fe-based skutterudites

    PubMed Central

    Xing, Guangzong; Fan, Xiaofeng; Zheng, Weitao; Ma, Yanming; Shi, Hongliang; Singh, David J.

    2015-01-01

    The interplay of superconductivity and magnetism is a subject of ongoing interest, stimulated most recently by the discovery of Fe-based superconductivity and the recognition that spin-fluctuations near a magnetic quantum critical point may provide an explanation for the superconductivity and the order parameter. Here we investigate magnetism in the Na filled Fe-based skutterudites using first principles calculations. NaFe4Sb12 is a known ferromagnet near a quantum critical point. We find a ferromagnetic metallic state for this compound driven by a Stoner type instability, consistent with prior work. In accord with prior work, the magnetization is overestimated, as expected for a material near an itinerant ferromagnetic quantum critical point. NaFe4P12 also shows a ferromagnetic instability at the density functional level, but this instability is much weaker than that of NaFe4Sb12, possibly placing it on the paramagnetic side of the quantum critical point. NaFe4As12 shows intermediate behavior. We also present results for skutterudite FeSb3, which is a metastable phase that has been reported in thin film form. PMID:26027504

  14. Links between hydrothermal environments, pyrophosphate, na(+), and early evolution.

    PubMed

    Holm, Nils G; Baltscheffsky, Herrick

    2011-10-01

    The discovery that photosynthetic bacterial membrane-bound inorganic pyrophosphatase (PPase) catalyzed light-induced phosphorylation of orthophosphate (Pi) to pyrophosphate (PPi) and the capability of PPi to drive energy requiring dark reactions supported PPi as a possible early alternative to ATP. Like the proton-pumping ATPase, the corresponding membrane-bound PPase also is a H(+)-pump, and like the Na(+)-pumping ATPase, it can be a Na(+)-pump, both in archaeal and bacterial membranes. We suggest that PPi and Na(+) transport preceded ATP and H(+) transport in association with geochemistry of the Earth at the time of the origin and early evolution of life. Life may have started in connection with early plate tectonic processes coupled to alkaline hydrothermal activity. A hydrothermal environment in which Na(+) is abundant exists in sediment-starved subduction zones, like the Mariana forearc in the W Pacific Ocean. It is considered to mimic the Archean Earth. The forearc pore fluids have a pH up to 12.6, a Na(+)-concentration of 0.7 mol/kg seawater. PPi could have been formed during early subduction of oceanic lithosphere by dehydration of protonated orthophosphates. A key to PPi formation in these geological environments is a low local activity of water. PMID:21461648

  15. Biosensor Consists of Na -- Doped Hydroxyapatite Thin Film

    NASA Astrophysics Data System (ADS)

    Nishikawa, Hiroaki; Kawashima, Masami; Kawai, Tomoji

    2005-03-01

    Hydroxyapatite (HAp) surface has an excellent ability of adsorption for functional biomolecules such as protein, DNA and so on. We have investigated the application of the HAp as a suitable material for biosensor. Thin film of the sodium -- doped HAp (Na -- HAp) is prepared in order to decrease the electric resistivity. We have studied variation of the resistance for the Na -- HAp thin films with the adsorption of the functional biomolecules. The sample were prepared by a pulsed laser deposition technique on porous alumina substrate. After the deposition, sample was post -- annealed in O2 / H2O atmosphere in order to crystallize the Na -- HAp. The powder X ray diffraction pattern shows the sample has a pure HAp structure. The gold comb electrodes were evaporated on the sample for the resistance measurement. The sample was set in pure water of 100 ml in a beaker. When Fetal Bovine Serum of 100 ?l was dropped in the beaker, the Na -- HAp shows the drastic change of the AC resistance (at 120 kHz). This result shows that the Na -- HAp will be one of the most effective materials for the biosensor applications.

  16. Effects of Osmoprotectants upon NaCl Stress in Rice.

    PubMed Central

    Garcia, A. B.; Engler, JdA.; Iyer, S.; Gerats, T.; Van Montagu, M.; Caplan, A. B.

    1997-01-01

    Plants accumulate a number of osmoprotective substances in response to NaCl stress, one of them being proline (Pro). While characterizing some of the changes in solute accumulation in NaCl-stressed rice (Oryza sativa L.), we identified several other potential osmoprotectants. One such substance, trehalose, begins to accumulate in small amounts in roots after 3 d. We performed a series of experiments to compare the effects of Pro and trehalose on ion accumulation to determine whether the two chemicals protect the same physiological processes. We found that Pro either has no effect or, in some cases, exasperates the effect of NaCl on growth inhibition, chlorophyll loss, and induction of a highly sensitive marker for plant stress, the osmotically regulated salT gene. By contrast, low to moderate concentrations of trehalose reduce Na+ accumulation, salT expression, and growth inhibition. Somewhat higher concentrations (10 mM) prevent NaCl-induced loss of chlorophyll in blades, preserve root integrity, and enhance growth. The results of this study indicate that during osmotic stress trehalose or carbohydrates might be more important for rice than Pro. PMID:12223797

  17. The Na(+) transporter, TaHKT1;5-D, limits shoot Na(+) accumulation in bread wheat.

    PubMed

    Byrt, Caitlin Siobhan; Xu, Bo; Krishnan, Mahima; Lightfoot, Damien James; Athman, Asmini; Jacobs, Andrew Keith; Watson-Haigh, Nathan S; Plett, Darren; Munns, Rana; Tester, Mark; Gilliham, Matthew

    2014-11-01

    Bread wheat (Triticum aestivum L.) has a major salt tolerance locus, Kna1, responsible for the maintenance of a high cytosolic K(+) /Na(+) ratio in the leaves of salt stressed plants. The Kna1 locus encompasses a large DNA fragment, the distal 14% of chromosome 4DL. Limited recombination has been observed at this locus making it difficult to map genetically and identify the causal gene. Here, we decipher the function of TaHKT1;5-D, a candidate gene underlying the Kna1 locus. Transport studies using the heterologous expression systems Saccharomyces cerevisiae and Xenopus laevis oocytes indicated that TaHKT1;5-D is a Na(+) -selective transporter. Transient expression in Arabidopsis thaliana mesophyll protoplasts and in situ polymerase chain reaction indicated that TaHKT1;5-D is localised on the plasma membrane in the wheat root stele. RNA interference-induced silencing decreased the expression of TaHKT1;5-D in transgenic bread wheat lines which led to an increase in the Na(+) concentration in the leaves. This indicates that TaHKT1;5-D retrieves Na(+) from the xylem vessels in the root and has an important role in restricting the transport of Na(+) from the root to the leaves in bread wheat. Thus, TaHKT1;5-D confers the essential salinity tolerance mechanism in bread wheat associated with the Kna1 locus via shoot Na(+) exclusion and is critical in maintaining a high K(+) /Na(+) ratio in the leaves. These findings show there is potential to increase the salinity tolerance of bread wheat by manipulation of HKT1;5 genes. PMID:25158883

  18. Evidence for SiO2-NaCl complexing in H2O-NaCl solutions at high pressure and temperature

    E-print Network

    Manning, Craig

    Evidence for SiO2-NaCl complexing in H2O-NaCl solutions at high pressure and temperature R. C to be Si(OH)4·2H2O. These neglected features can be incorporated into the complexing model in a revised complexes with overall NaCl:H2O = 1:6, one Na-bearing and one Cl-bearing. Their (equal) molar concentrations

  19. Accurate measurement of the 23 Na(d, p) 24 Na cross section in the 1.7-20 MeV energy range

    NASA Astrophysics Data System (ADS)

    Hirsh, T. Y.; Kreisel, Arik; Mrazek, J.; Weissman, L.; Eisen, Y.; Stefanik, M.; Simeckova, E.; Aviv, O.; Moscovici, S.; Yungrais, Z.; Berkovits, D.

    2015-11-01

    The 23 Na(d, p) 24 Na cross sections were measured in two complementary experiments using a cyclotron and a variant low-energy energy LINAC, effectively covering the 1.7-19.8 MeV energy range. The present results allow one to use the 23 Na(d, p) 24 Na process as a standard monitoring cross section in future measurements of deuteron reactions.

  20. A new low-voltage plateau of Na3V2(PO4)(3) as an anode for Na-ion batteries

    SciTech Connect

    Jian, ZL; Sun, Y; Ji, XL

    2015-01-01

    A low-voltage plateau at similar to 0.3 V is discovered for the deep sodiation of Na3V2(PO4)(3) by combined computational and experimental studies. This new low-voltage plateau doubles the sodiation capacity of Na3V2(PO4)(3), thus turning it into a promising anode for Na-ion batteries.

  1. Sodium Chloride, NaCl/? : New Force Field

    E-print Network

    Raul Fuentes-Azcatl; Marcia C. Barbosa

    2015-08-08

    A new computational model for Sodium Chloride, the NaCl/{\\epsilon}, is proposed. The Force Fields employed here for the description of the NaCl is based on a set of radial particle-particle pair potentials involving Lennard-Jones (LJ) and Coulombic forces. The parameterization is obtained fitting the density of the crystal and the density and the dielectric constant of the mixture of salt with water at diluted solution. Our model shows good agreement with the experimental values for the density and surface tension for the pure system and for the density, the viscosity, the diffusion, and the dielectric constant for the mixture with water at various molal concentrations. The NaCl/{\\epsilon} together with the water TIP4P/{\\epsilon} model provide a good approximation for studying electrolyte solutions.

  2. Binding energy and structure of e+Na

    NASA Astrophysics Data System (ADS)

    Shertzer, J.; Ward, S. J.

    2010-06-01

    We calculate the nonadiabatic binding energy and geometry of the weakly bound state of e+Na. We use the Peach model potential, which includes both the dipole and an effective quadrupole term in the polarization, to describe the interaction of the electron and positron with the ion core. The effective three-body Schrödinger equation is solved with the finite element method. Because the model potential gives rise to three spurious states, the true ground state of e+Na is embedded in a dense spectrum of spurious states. We develop a method for extracting the correct ground state for e+Na, even when the energy is nearly degenerate with a spurious level. The calculated value for the binding energy is consistent with other calculations.

  3. Binding energy and structure of e{sup +}Na

    SciTech Connect

    Shertzer, J.; Ward, S. J.

    2010-06-15

    We calculate the nonadiabatic binding energy and geometry of the weakly bound state of e{sup +}Na. We use the Peach model potential, which includes both the dipole and an effective quadrupole term in the polarization, to describe the interaction of the electron and positron with the ion core. The effective three-body Schroedinger equation is solved with the finite element method. Because the model potential gives rise to three spurious states, the true ground state of e{sup +}Na is embedded in a dense spectrum of spurious states. We develop a method for extracting the correct ground state for e{sup +}Na, even when the energy is nearly degenerate with a spurious level. The calculated value for the binding energy is consistent with other calculations.

  4. Solvation of Na+, K+, and Their Dimers in Helium

    PubMed Central

    An der Lan, Lukas; Bartl, Peter; Leidlmair, Christian; Jochum, Roland; Denifl, Stephan; Echt, Olof; Scheier, Paul

    2012-01-01

    Helium atoms bind strongly to alkali cations which, when embedded in liquid helium, form so-called snowballs. Calculations suggest that helium atoms in the first solvation layer of these snowballs form rigid structures and that their number (n) is well defined, especially for the lighter alkalis. However, experiments have so far failed to accurately determine values of n. We present high-resolution mass spectra of Na+Hen, K+Hen, Na2+Hen and K2+Hen, formed by electron ionization of doped helium droplets; the data allow for a critical comparison with several theoretical studies. For sodium and potassium monomers the spectra indicate that the value of n is slightly smaller than calculated. Na2+Hen displays two distinct anomalies at n=2 and n=6, in agreement with theory; dissociation energies derived from experiment closely track theoretical values. K2+Hen distributions are fairly featureless, which also agrees with predictions. PMID:22374575

  5. Characterization of the Na?/H? antiporter from Yersinia pestis.

    PubMed

    Ganoth, Assaf; Alhadeff, Raphael; Kohen, Dovrat; Arkin, Isaiah T

    2011-01-01

    Yersinia pestis, the bacterium that historically accounts for the Black Death epidemics, has nowadays gained new attention as a possible biological warfare agent. In this study, its Na?/H? antiporter is investigated for the first time, by a combination of experimental and computational methodologies. We determined the protein's substrate specificity and pH dependence by fluorescence measurements in everted membrane vesicles. Subsequently, we constructed a model of the protein's structure and validated the model using molecular dynamics simulations. Taken together, better understanding of the Yersinia pestis Na?/H? antiporter's structure-function relationship may assist in studies on ion transport, mechanism of action and designing specific blockers of Na?/H? antiporter to help in fighting Yersinia pestis -associated infections. We hope that our model will prove useful both from mechanistic and pharmaceutical perspectives. PMID:22102858

  6. Towards ultracold ground-state NaRb molecule

    NASA Astrophysics Data System (ADS)

    Guo, Mingyang; Zhu, Bing; Li, Xiaoke; Lu, Bo; Wang, Fudong; Ye, Xin; Wang, Dajun

    2015-05-01

    The ground-state 23Na87Rb molecule is chemically stable and has a permanent electric dipole moment as large as 3.3 Debye. These properties make it a promising candidate for investigating dipolar quantum gases. Recently, we have realized weakly bound 23Na87Rb Feshbach molecules via magneto-association. Here, we will present our results on excited-state molecular spectroscopy investigation starting with these Feshbach molecules. The prospects of transferring 23Na87Rb to the absolute ground state will also be discussed. This work is supported by Hong Kong Research Grants Council (General Research Fund Projects 403111, 404712 and the ANR/RGC Joint Research Scheme ACUHK403/13).

  7. The stability of sodalite in the system NaAlSiO sub 4 -NaCl

    SciTech Connect

    Sharp, Z.D. ); Helffrich, G.R. ); Bohlen, S.R. ); Essene, E.J. )

    1989-08-01

    The reaction sodalite = {beta}-nepheline + NaCl (s) was reversed in solid-medium apparatus and the reaction sodalite = carnegieite + NaCl (l) was reversed at 1 bar (1,649-1,652 K). The experimental reversals between 923 K and 973 K can be fit with a dP/dT of {minus}11 bar/K, suggesting that the excess entropy for sodalite is present only above 923 K. A phase diagram for the NaAlSiO{sub 4}-NaCl system that is consistent with the measured thermochemical data and the experiments between 973 and 1,650 K can be generated if the 61.7 J/mol{center dot}K entropy contribution is included in the S{sup 0}{sub 298} of sodalite. This entropy contribution must be removed below 973 K for the experiments to fit with calculations. Previously unreported thermodynamic data estimated in this study are {Delta}G{sup 0}{sub 298} for sodalite ({minus}12,697 kJ/mol) and carnegieite (NaAlSiO{sub 4}) ({minus}1,958 kJ/mol), S{sup 0}{sub 298} of carnegieite (129.6 J/mol{center dot}K) and compressibility of NaCl{sub liquid} (V{sup P}{sub 298} (cm{sup 3}) = 31.6{center dot}(1 - 24.7{center dot}10{sup {minus}3}{center dot}P + 800{center dot}10{sup {minus}6}{center dot}P{sup 2}))(T in K; P in kbar). Sodalite is a high-temperature, low-pressure phase, stable well above the solidus in sodic silica-undersaturated magmas enriched in NaCl, and its presence constrains NaCl activities in magmas. Estimates of minimum NaCl (l) activities in the Mont St-Hilaire sodalite syenites are 0.05 at 1,073 K and 0.13 at 1,273 K. Density calculations are consistent with the field observations that sodalite phenocrysts will float in a nepheline syenite liquid. This explains the enrichment of sodalite in the upper levels of the sodalite syenites at Mont St.Hilaire and elsewhere.

  8. Measurement of the low-energy Na+-Na total collision rate in an ion-neutral hybrid trap

    NASA Astrophysics Data System (ADS)

    Goodman, D. S.; Wells, J. E.; Kwolek, J. M.; Blümel, R.; Narducci, F. A.; Smith, W. W.

    2015-01-01

    We present measurements of the total elastic and resonant charge-exchange ion-atom collision rate coefficient kia of cold sodium (Na) with optically dark low-energy Na+ ions in a hybrid ion-neutral trap. To determine kia, we measured the trap loading and loss rates from both a Na magneto-optical trap (MOT) and a linear radio-frequency quadrupole Paul trap. We found the total rate coefficient to be 7.4 ±1.9 ×10-8 cm3/s for the type-I Na MOT immersed within an ?140 -K ion cloud and 1.10 ±0.25 ×10-7 cm3/s for the type-II Na MOT within an ?1070 -K ion cloud. Our measurements show excellent agreement with previously reported theoretical fully quantal ab initio calculations. In the process of determining the total rate coefficient, we demonstrate that a MOT can be used to probe an optically dark ion cloud's spatial distribution within a hybrid trap.

  9. Plant response to Na/sup +/, K/sup +/ and K/sup +//Na/sup +/ ratios under saline conditions

    SciTech Connect

    Devitt, D.A.

    1983-01-01

    This research was undertaken to more clearly determine plant response to saline-sodic waters. In the first experiment, the response of wheat and sorghum to different K/sup +//Na/sup +/ ratios at different osmotic potentials was investigated. The plants were grown in outdoor solution culture tanks containing polyethylene glycol and/or NaCl as osmoticum with 1/2 strength Hoagland as the base nutrient solution. The mass of the root system for both wheat and sorghum was determined primarily by the osmotic potential. However, root elongation was controlled primarily by the Na/sup +/ concentration. Sorghum root elongation rates decreased with increasing Na/sup +/ while those for wheat increased. Sodium was not translocated out of the sorghum root system until a critical Na/sup +/ root saturation level of .6 moles/kg was obtained. The second experiment was designed to investigate the water, nutrient and growth responses of the second crop of wheat in a wheat-sorghum-wheat rotation to zonal saline-sodic conditions.

  10. Rate-Dependent Nucleation and Growth of NaO2 in Na-O2 Batteries.

    PubMed

    Ortiz-Vitoriano, Nagore; Batcho, Thomas P; Kwabi, David G; Han, Binghong; Pour, Nir; Yao, Koffi Pierre Claver; Thompson, Carl V; Shao-Horn, Yang

    2015-07-01

    Understanding the oxygen reduction reaction kinetics in the presence of Na ions and the formation mechanism of discharge product(s) is key to enhancing Na-O2 battery performance. Here we show NaO2 as the only discharge product from Na-O2 cells with carbon nanotubes in 1,2-dimethoxyethane from X-ray diffraction and Raman spectroscopy. Sodium peroxide dihydrate was not detected in the discharged electrode with up to 6000 ppm of H2O added to the electrolyte, but it was detected with ambient air exposure. In addition, we show that the sizes and distributions of NaO2 can be highly dependent on the discharge rate, and we discuss the formation mechanisms responsible for this rate dependence. Micron-sized (?500 nm) and nanometer-scale (?50 nm) cubes were found on the top and bottom of a carbon nanotube (CNT) carpet electrode and along CNT sidewalls at 10 mA/g, while only micron-scale cubes (?2 ?m) were found on the top and bottom of the CNT carpet at 1000 mA/g, respectively. PMID:26266746

  11. Results from the NA61/SHINE Ion Program

    NASA Astrophysics Data System (ADS)

    Czopowicz, Tobiasz

    2015-03-01

    The NA61/SHINE experiment aims to discover the critical point of strongly interacting matter and study properties of the onset of deconfinement. These goals are to be achieved by performing a two dimensional phase diagram (T-?B) scan - measurements of hadron production properties in proton-proton, proton-nucleus and nucleus-nucleus interactions as a function of collision energy and system size. This contribution summarizes current the status and future plans as well as presents the first physics results of the NA61/SHINE ion program.

  12. Branching ratios for the beta decay of 21Na

    E-print Network

    V. E. Iacob; J. C. Hardy; C. A. Gagliardi; J. Goodwin; N. Nica; H. I. Park; G. Tabacaru; L. Trache; R. Tribble; Y. Zhai; I. S. Towner

    2006-08-16

    We have measured the beta-decay branching ratio for the transition from 21Na to the first excited state of 21Ne. A recently published test of the standard model, which was based on a measurement of the beta-nu correlation in the decay of 21Na, depended on this branching ratio. However, until now only relatively imprecise (and, in some cases, contradictory) values existed for it. Our new result, 4.74(4)%, reduces but does not remove the reported discrepancy with the standard model.

  13. Brain Na+, K+-ATPase Activity In Aging and Disease

    PubMed Central

    de Lores Arnaiz, Georgina Rodríguez; Ordieres, María Graciela López

    2014-01-01

    Na+/K+ pump or sodium- and potassium-activated adenosine 5’-triphosphatase (Na+, K+-ATPase), its enzymatic version, is a crucial protein responsible for the electrochemical gradient across the cell membranes. It is an ion transporter, which in addition to exchange cations, is the ligand for cardenolides. This enzyme regulates the entry of K+ with the exit of Na+ from cells, being the responsible for Na+/K+ equilibrium maintenance through neuronal membranes. This transport system couples the hydrolysis of one molecule of ATP to exchange three sodium ions for two potassium ions, thus maintaining the normal gradient of these cations in animal cells. Oxidative metabolism is very active in brain, where large amounts of chemical energy as ATP molecules are consumed, mostly required for the maintenance of the ionic gradients that underlie resting and action potentials which are involved in nerve impulse propagation, neurotransmitter release and cation homeostasis. Protein phosphorylation is a key process in biological regulation. At nervous system level, protein phosphorylation is the major molecular mechanism through which the function of neural proteins is modulted in response to extracellular signals, including the response to neurotransmitter stimuli. It is the major mechanism of neural plasticity, including memory processing. The phosphorylation of Na+, K+-ATPase catalytic subunit inhibits enzyme activity whereas the inhibition of protein kinase C restores the enzyme activity. The dephosphorylation of neuronal Na+, K+-ATPase is mediated by calcineurin, a serine / threonine phosphatase. The latter enzyme is involved in a wide range of cellular responses to Ca2+ mobilizing signals, in the regulation of neuronal excitability by controlling the activity of ion channels, in the release of neurotransmitters and hormones, as well as in synaptic plasticity and gene transcription. In the present article evidence showing Na+, K+-ATPase involvement in signaling pathways, enzyme changes in diverse neurological diseases as well as during aging, have been summarized. Issues refer mainly to Na+, K+-ATPase studies in ischemia, brain injury, depression and mood disorders, mania, stress, Alzheimer´s disease, learning and memory, and neuronal hyperexcitability and epilepsy. PMID:25018677

  14. Toward Triplet Ground State LiNa Molecules

    NASA Astrophysics Data System (ADS)

    Jamison, Alan; Rvachov, Timur; Jing, Li; Jiang, Yijun; Zwierlein, Martin; Ketterle, Wolfgang

    2015-05-01

    We present progress toward creation of ultracold ground-state triplet LiNa molecules. This molecule is expected to have a long lifetime in the triplet ground state due to its fermionic nature, large rotational constant, and weak spin-orbit coupling. The triplet state has both electric and magnetic dipole moments, affording unique opportunities in quantum simulation and ultracold chemistry. Our progress includes the first observation of triplet excited states in this molecule, achieved through photoassociation of ultracold mixtures of 6-Li and Na. We compare experimental results to a variety of near-dissociation expansions as well as ab initio potentials.

  15. Russian Scientific-Educational Project: Kazan-GeoNa-2017

    NASA Astrophysics Data System (ADS)

    Gusev, A.; Alibekova, N.

    2012-09-01

    For the further successful development of educational and scientific - educational activity of the Russian Federation, the Republic Tatarstan, Kazan is offered the national project - the International Center of the Science and the Internet of Technologies. "GeoNa" (Geometry of Nature - "GeoNa" is developed - wisdom, enthusiasm, pride, grandeur), which includes a modern complex of conference halls (up to 4 thousand places), the Center the Internet of Technologies, 3D Planetarium - development of the Moon, PhysicsLand, an active museum of natural sciences, an oceanarium, training a complex «Spheres of Knowledge», botanical and landscape oases.

  16. Precipitation of solubilized Na+/K+-ATPase by divalent cations.

    PubMed

    Esmann, M

    1988-05-01

    A method for preparation of membranous fragments of pure and highly active shark rectal gland Na+/K+-ATPase by Mn2+ precipitation of C12E8-solubilized enzyme is described. The method is rapid and inexpensive, and yields enzyme with a specific Na+/K+-ATPase activity of up to 1800 mumol/mg per h at 37 degrees C. The influence of the detergent/protein and lipid/protein ratios on the yield of membrane bound enzyme is described. PMID:2835103

  17. Upper stratospheric photolysis of NaCl and KCl

    PubMed Central

    Rowland, F. Sherwood; Rogers, Patricia J.

    1982-01-01

    Sodium chloride has been postulated to be formed in the stratosphere by the reaction of NaOH with HCl, and an analogous reaction should occur also for KOH, with the formation of KCl. Photodissociation rates have been calculated for both NaCl and KCl using the published ultraviolet absorption cross sections below 300 nm. Both molecules absorb strongly and have photodissociation lifetimes of only a few minutes in the upper stratosphere. Neither molecule is an effective sink for chlorine above an altitude of about 35 km. PMID:16593182

  18. Complex microwave conductivity of Na-DNA powders

    E-print Network

    H. Kitano; K. Ota; A. Maeda

    2006-08-01

    We report the complex microwave conductivity, $\\sigma=\\sigma_1-i\\sigma_2$, of Na-DNA powders, which was measured from 80 K to 300 K by using a microwave cavity perturbation technique. We found that the magnitude of $\\sigma_1$ near room temperature was much larger than the contribution of the surrounding water molecules, and that the decrease of $\\sigma_1$ with decreasing temperature was sufficiently stronger than that of the conduction of counterions. These results clearly suggest that the electrical conduction of Na-DNA is intrinsically semiconductive.

  19. The NA62 Liquid Krypton Electromagnetic Calorimeter Level 0 Trigger

    E-print Network

    Bonaiuto, V; Paoluzzi, G; Salamon, A; Salina, G; Santovetti, E; Sargeni, F; Scarfì, F M

    2012-01-01

    The NA62 experiment at CERN SPS aims to measure the Branching Ratio of the very rare kaon decay K+ -> pi+ nu nubar collecting O(100) events with a 10% background to make a stringent test of the Standard Model. One of the main backgrounds to the proposed measurement is represented by the K+ -> pi+ pi0 decay. To suppress this background an efficient photo veto system is foreseen. In the 1-10 mrad angular region the NA48 high performance liquid krypton electromagnetic calorimeter is used. The design, implementation and current status of the Liquid Krypton Electromagnetic Calorimeter Level 0 Trigger are presented.

  20. The NA62 Liquid Krypton Electromagnetic Calorimeter Level 0 Trigger

    E-print Network

    Vincenzo Bonaiuto; Adolfo Fucci; Giovanni Paoluzzi; Andrea Salamon; Gaetano Salina; Emanuele Santovetti; Fausto Sargeni; Francesco M. Scarfi'

    2012-01-18

    The NA62 experiment at CERN SPS aims to measure the Branching Ratio of the very rare kaon decay K+ -> pi+ nu nubar collecting O(100) events with a 10% background to make a stringent test of the Standard Model. One of the main backgrounds to the proposed measurement is represented by the K+ -> pi+ pi0 decay. To suppress this background an efficient photo veto system is foreseen. In the 1-10 mrad angular region the NA48 high performance liquid krypton electromagnetic calorimeter is used. The design, implementation and current status of the Liquid Krypton Electromagnetic Calorimeter Level 0 Trigger are presented.

  1. The NA62 Liquid Krypton Electromagnetic Calorimeter Level 0 Trigger

    E-print Network

    V. Bonaiuto; A. Fucci; G. Paoluzzi; A. Salamon; G. Salina; E. Santovetti; F. Sargeni; F. M. Scarfi'

    2012-01-16

    The NA62 experiment at CERN SPS aims to measure the Branching Ratio of the very rare kaon decay K+ -> pi+ nu nubar collecting O(100) events with a 10% background to make a stringent test of the Standard Model. One of the main backgrounds to the proposed measurement is represented by the K+ -> pi+ pi0 decay. To suppress this background an efficient photo veto system is foreseen. In the 1-10 mrad angular region the NA48 high performance liquid krypton electromagnetic calorimeter is used. The design, implementation and current status of the Liquid Krypton Electromagnetic Calorimeter Level 0 Trigger are presented.

  2. In Situ SAXS/WAXS of Zeolite Microwave Synthesis: NaY, NaA, and Beta Zeolites

    SciTech Connect

    Panzarella,B.; Tompsett, G.; Conner, W.; Jones, K.

    2007-01-01

    A custom waveguide apparatus is constructed to study the microwave synthesis of zeolites by in situ small-angle X-ray scattering (SAXS) and wide-angle X-ray scattering (WAXS). The WR-284 waveguide is used to heat precursor solutions using microwaves at a frequency of 2.45 GHz. The reaction vessels are designed to include sections of thin-walled glass, which permit X-rays to pass through the precursor solutions with minimal attenuation. Slots were machined into the waveguide to provide windows for X-ray energy to enter and scatter from solutions during microwave heating. The synthesis of zeolites with conventional heating is also studied using X-ray scattering in the same reactor. SAXS studies show that the crystallization of beta zeolite and NaY zeolite is preceded by a reorganization of nanosized particles in their precursor solutions or gels. The evolution of these particles during the nucleation and crystallization stages of zeolite formation depends on the properties of the precursor solution. The synthesis of NaA and NaX zeolites and sodalite from a single zeolite precursor is studied by microwave and conventional heating. Microwave heating shifts the selectivity of this synthesis in favor of NaA and NaX over sodalite; conventional heating leads to the formation of sodalite for synthesis from the same precursor. The use of microwave heating also led to a more rapid onset of NaA zeolite product crystallization compared to conventional heating. Pulsed and continuous microwave heating are compared for zeolite synthesis. The resulting rates of formation of the zeolite products, and the relative amounts of the products determined from the WAXS spectra, are similar when either pulsed or continuous microwave heating is applied in the reactor while maintaining the same synthesis temperature. The consequences of these results in terms of zeolite synthesis are discussed.

  3. Na2TeS3, Na2TeSe3-mP24, and Na2TeSe3-mC48: Crystal Structures and Optical and Electrical Properties of Sodium Chalcogenidotellurates(IV).

    PubMed

    Pompe, Constantin; Preitschaft, Christian; Weihrich, Richard; Pfitzner, Arno

    2015-12-01

    Pure samples of Na2TeS3 and Na2TeSe3 were synthesized by the reactions of stoichiometric amounts of the elements Na, Te, and Q (Q = S, Se) in the ratio 2:1:3. Both compounds are highly air- and moisture-sensitive. The crystal structures were determined by single-crystal X-ray diffraction. Yellow Na2TeS3 crystallizes in the space group P21/c. Na2TeSe3 exists in a low-temperature modification (Na2TeSe3-mP24, space group P21/c) and a high-temperature modification (Na2TeSe3-mC48, space group C2/c); both modifications are red. Density functional theory calculations confirmed the coexistence of both modifications of Na2TeSe3 because they are very close in energy (?E = 0.18 kJ mol(-1)). To the contrary, hypothetic Na2TeS3-mC48 is significantly less favored (?E = 1.8 kJ mol(-1)) than the primitive modification. Na2TeS3 and Na2TeSe3-mP24 are isotypic to Li2TeS3, whereas Na2TeSe3-mC48 crystallizes in its own structure type, which was first described by Eisenmann and Zagler. The title compounds have two common structure motifs. Trigonal TeQ3 pyramids form layers, and the Na atoms are surrounded by a distorted octahedral environment of chalcogen atoms. Raman spectra are dominated by the vibration modes of the TeQ3 units. The activation energies of the total conductivity of the title compounds range between 0.68 eV (Na2TeS3) and 1.1 eV (Na2TeSe3). Direct principal band gaps of 1.20 and 1.72 eV were calculated for Na2TeSe3 and Na2TeS3, respectively. The optical band gaps are in the range from 1.38 eV for Li2TeSe3 to 2.35 eV for Na2TeS3. PMID:26600068

  4. Raman spectroscopy of (K,Na)NbO3 and (K,Na)1-xLixNbO3

    NASA Astrophysics Data System (ADS)

    Trodahl, H. J.; Klein, N.; Damjanovic, D.; Setter, N.; Ludbrook, B.; Rytz, D.; Kuball, M.

    2008-12-01

    We report Raman spectroscopy in all four phases of a (K0.5+?Na0.5-?)NbO3 (?˜0.03) crystal and ((K0.5+?Na0.5-?)1-xLix)NbO3 for x =0.02 and 0.03. The phase transitions in the Li-free crystal are homogeneous and hysteretic, with no mixed-phase region between the rhombohedral and orthorhombic phases. Raman spectra in the lowest-temperature phase in the Li-doped material differ significantly from those at x =0 and suggest a structural phase boundary at a Li concentration of less than 2%.

  5. Laser vaporized Li2, Na2, K2, and LiNa molecules observed by cavity ring-down spectroscopy

    NASA Astrophysics Data System (ADS)

    Labazan, I.; Miloševi?, S.

    2003-09-01

    Laser ablation of solid lithium, sodium, potassium, and lithium-sodium alloy was performed using a 308-nm excimer laser at fluences close to 1 J cm-2. Frequency and time resolved A-X and B-X electronic transitions of 6,7Li2, Na2, LiNa and K2 respectively, were observed. Lithium atom, dimer velocities, and influence of the background gas on dimer content of the plume have been measured. The origin of dimers at high densities, with subthermal internal energy, is discussed.

  6. Electron transfer and ionization in collisions of He-like ions with Na(3s) and Na(3p)

    NASA Astrophysics Data System (ADS)

    Blank, I.; Otrantcr, S.; Meinema, C.; Olson, R. E.; Hoekstra, R.

    2012-11-01

    Single electron transfer and ionization in collisions of He-like ions (N5+, O6+, Ne8+) and Na has been investigated both experimentally and theoretically at energies around the matching velocity of the valence electron (2 to 10 keV/amu). State selective cross sections and scattering angle distributions were obtained using recoil-ion momentum spectroscopy in combination with a magneto-optically cooled Na atom target. A strong dependence of the relative cross sections on the collision energy is observed. The results are compared with Classical-Trajectory Monte Carlo (CTMC) calculations and show an overall very good agreement.

  7. Spin assignments to excited states in 22Na through a 24Mg(p,3He)22Na reaction measurement

    SciTech Connect

    Chae, K. Y.; Bardayan, Daniel W; Blackmon, Jeff C; Chipps, K.; Hatarik, Robert; Jones, K. L.; Kozub, R. L.; Liang, J Felix; Matei, Catalin; Moazen, Brian; Nesaraja, Caroline D; O'Malley, Patrick; Pain, S. D.; Pittman, S. T.; Smith, Michael Scott

    2010-10-01

    The level structure of 22Na has been studied at the Holifield Radioactive Ion Beam Facility in Oak Ridge National Laboratory using the 24Mg(p,3He)22Na reaction. 41 and 41.5 MeV proton beams were generated by 25 MV tandem accelerator and bombarded isotopically enriched 24Mg targets. Angular distributions of recoiling 3He particles were extracted by using a segmented annular silicon strip detector array. Spins and parities for ten levels were constrained through a distorted wave Born approximation analysis of angular distributions including three above the proton threshold at 6.739 MeV.

  8. Multiple quantum filtered 23Na NMR in the Langendorff perfused mouse heart: Ratio of triple/double quantum filtered signals correlates with [Na]i

    PubMed Central

    Eykyn, Thomas R.; Aksentijevi?, Dunja; Aughton, Karen L.; Southworth, Richard; Fuller, William; Shattock, Michael J.

    2015-01-01

    We investigate the potential of multiple quantum filtered (MQF) 23Na NMR to probe intracellular [Na]i in the Langendorff perfused mouse heart. In the presence of Tm(DOTP) shift reagent the triple quantum filtered (TQF) signal originated largely from the intracellular sodium pool with a 32 ± 6% contribution of the total TQF signal arising from extracellular sodium, whilst the rank 2 double-quantum filtered signal (DQF), acquired with a 54.7° flip-angle pulse, originated exclusively from the extracellular sodium pool. Given the different cellular origins of the 23Na MQF signals we propose that the TQF/DQF ratio can be used as a semi-quantitative measure of [Na]i in the mouse heart. We demonstrate a good correlation of this ratio with [Na]i measured with shift reagent at baseline and under conditions of elevated [Na]i. We compare the measurements of [Na]i using both shift reagent and TQF/DQF ratio in a cohort of wild type mouse hearts and in a transgenic PLM3SA mouse expressing a non-phosphorylatable form of phospholemman, showing a modest but measurable elevation of baseline [Na]i. MQF filtered 23Na NMR is a potentially useful tool for studying normal and pathophysiological changes in [Na]i, particularly in transgenic mouse models with altered Na regulation. PMID:26196304

  9. Multiple quantum filtered (23)Na NMR in the Langendorff perfused mouse heart: Ratio of triple/double quantum filtered signals correlates with [Na]i.

    PubMed

    Eykyn, Thomas R; Aksentijevi?, Dunja; Aughton, Karen L; Southworth, Richard; Fuller, William; Shattock, Michael J

    2015-09-01

    We investigate the potential of multiple quantum filtered (MQF) (23)Na NMR to probe intracellular [Na]i in the Langendorff perfused mouse heart. In the presence of Tm(DOTP) shift reagent the triple quantum filtered (TQF) signal originated largely from the intracellular sodium pool with a 32±6% contribution of the total TQF signal arising from extracellular sodium, whilst the rank 2 double-quantum filtered signal (DQF), acquired with a 54.7° flip-angle pulse, originated exclusively from the extracellular sodium pool. Given the different cellular origins of the (23)Na MQF signals we propose that the TQF/DQF ratio can be used as a semi-quantitative measure of [Na]i in the mouse heart. We demonstrate a good correlation of this ratio with [Na]i measured with shift reagent at baseline and under conditions of elevated [Na]i. We compare the measurements of [Na]i using both shift reagent and TQF/DQF ratio in a cohort of wild type mouse hearts and in a transgenic PLM(3SA) mouse expressing a non-phosphorylatable form of phospholemman, showing a modest but measurable elevation of baseline [Na]i. MQF filtered (23)Na NMR is a potentially useful tool for studying normal and pathophysiological changes in [Na]i, particularly in transgenic mouse models with altered Na regulation. PMID:26196304

  10. Effects of Na2MoO4 and Na2WO4 on molybdenum and tungsten electrodes for the alkali metal thermoelectric converter (AMTEC)

    NASA Astrophysics Data System (ADS)

    Williams, R. M.; Wheeler, B. L.; Jeffries-Nakamura, B.; Loveland, M. E.; Bankston, C. P.

    1988-11-01

    The effects of adding Na2MoO4 and Na2WO4 to porous Mo and W electrodes, respectively, on the performance and impedance characteristics of the electrodes in an alkali metal thermoelectric converter (AMTEC) were investigated. It was found that corrosion of the porous electrode by Na2MoO4 or Na2WO4 to form Na2MO3O6 and WO2, respectively, and recrystallization of the Mo or W as the salt evaporates, result in major morphological changes including a loss of columnar structure and a significant increase in porosity. This effect is more pronounced in Na2MoO4/Mo electrodes, due to the lower stability of Na2MoO4.

  11. Effects of Na2MoO4 and Na2WO4 on molybdenum and tungsten electrodes for the alkali metal thermoelectric converter (AMTEC)

    NASA Technical Reports Server (NTRS)

    Williams, R. M.; Wheeler, B. L.; Jeffries-Nakamura, B.; Loveland, M. E.; Bankston, C. P.

    1988-01-01

    The effects of adding Na2MoO4 and Na2WO4 to porous Mo and W electrodes, respectively, on the performance and impedance characteristics of the electrodes in an alkali metal thermoelectric converter (AMTEC) were investigated. It was found that corrosion of the porous electrode by Na2MoO4 or Na2WO4 to form Na2MO3O6 and WO2, respectively, and recrystallization of the Mo or W as the salt evaporates, result in major morphological changes including a loss of columnar structure and a significant increase in porosity. This effect is more pronounced in Na2MoO4/Mo electrodes, due to the lower stability of Na2MoO4.

  12. Functional identification and characterization of sodium binding sites in Na symporters

    PubMed Central

    Loo, Donald D. F.; Jiang, Xuan; Gorraitz, Edurne; Hirayama, Bruce A.; Wright, Ernest M.

    2013-01-01

    Sodium cotransporters from several different gene families belong to the leucine transporter (LeuT) structural family. Although the identification of Na+ in binding sites is beyond the resolution of the structures, two Na+ binding sites (Na1 and Na2) have been proposed in LeuT. Na2 is conserved in the LeuT family but Na1 is not. A biophysical method has been used to measure sodium dissociation constants (Kd) of wild-type and mutant human sodium glucose cotransport (hSGLT1) proteins to identify the Na+ binding sites in hSGLT1. The Na1 site is formed by residues in the sugar binding pocket, and their mutation influences sodium binding to Na1 but not to Na2. For the canonical Na2 site formed by two –OH side chains, S392 and S393, and three backbone carbonyls, mutation of S392 to cysteine increased the sodium Kd by sixfold. This was accompanied by a dramatic reduction in the apparent sugar and phlorizin affinities. We suggest that mutation of S392 in the Na2 site produces a structural rearrangement of the sugar binding pocket to disrupt both the binding of the second Na+ and the binding of sugar. In contrast, the S393 mutations produce no significant changes in sodium, sugar, and phlorizin affinities. We conclude that the Na2 site is conserved in hSGLT1, the side chain of S392 and the backbone carbonyl of S393 are important in the first Na+ binding, and that Na+ binding to Na2 promotes binding to Na1 and also sugar binding. PMID:24191006

  13. Free Energy for the Permeation of Na+ Ions and Their

    E-print Network

    Lu, Benzhuo

    to exhibit a characteristic pH-dependence.5 A number of attempts have been made to deconvolute the details to that in water as a function of the bilayer permeation depth. Despite the fact that the bilayer boosts the Na-pairing in fluid anisotropic media and details the ion permeation mechanism on atomic level. Introduction Lipid

  14. Sustainable Li/Na-Ion Batteries Chunsheng Wang

    E-print Network

    Zeng, Ning

    Sustainable Li/Na-Ion Batteries Chunsheng Wang 1223C Chemical and Nuclear Engineering Department of Chemical & Biomolecular Engineering Email: cswang@umd.edu Phone: (301) 405-0352 #12;2 Application of Li-ion batteries https://www.google.com/search?q=electric+vehicle&sourc e=lnms&tbm=isch&sa=X&ei=7stVU7Kx

  15. Results from NA60 experiment at the CERN SPS

    SciTech Connect

    Usai, G.; Cicalo, C.; De Falco, A.; Floris, M.; Masoni, A.; Puddu, G.; Serci, S.; Arnaldi, R.; Colla, A.; Cortese, P.; Ferretti, A.; Oppedisano, C.; Averbeck, R.; Drees, A.; Banicz, K.; Castor, J.; Devaux, A.; Force, P.; Manso, F.; Chaurand, B.

    2006-07-11

    The NA60 experiment studies open charm and prompt dimuon production in proton-nucleus and nucleus-nucleus collisions at the CERN SPS. During 2003 the experiment collected data in Indium-Indium collisions at 158 GeV per nucleon. In this paper the first results on low mass dimuons, intermediate mass dimuons and J/{psi} suppression are presented.

  16. Substituting KCl for NaCl in fresh Queso Fresco

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reducing the sodium level in cheese is challenging when a signature salty flavor is expected, such as in high-moisture Queso Fresco (QF). Fresh starter-free QF was fine milled and dry salted at different levels of NaCl and KCl to obtain total salt levels of 1.5 to 2.0%. The treatments contained 1....

  17. Integrating Provenance Information in Reservoir Engineering Jing Zhao, Na Chen

    E-print Network

    Hwang, Kai

    Integrating Provenance Information in Reservoir Engineering Jing Zhao, Na Chen Computer Science in the area of reservoir engineering. An important metric that determines the overall effectiveness of data objects, has emerged as an invaluable asset in evaluating data quality. The reservoir facilities

  18. Ouabain Assembles Signaling Cascades through the Caveolar Na /K -ATPase*

    E-print Network

    Abraham, Nader G.

    trans- membrane pump that transports Na and K across the plasma membrane by hydrolyzing ATP (1 first identified as flask-shaped vesic- ular invagination of plasma membrane and are enriched and stimulated tyrosine phosphoryl- ation of caveolin-1 in LLC-PK1 cells. When added to the isolated membrane

  19. Species differences in bacterial NhaA Na+ Octavian Clinescua

    E-print Network

    Just, Armin

    value [2]. More recently, an alternate model of pH regulation in EcNhaA was introduced [6], following+ and Na+ . We show that Helicobacter pylori NhaA only has a small acidic shift of its pH-dependent activity profile compared to the other transporters and discuss why a more drastic change in its pH

  20. S. Typhimurium NhaA Molecular characterization of the Na+

    E-print Network

    Just, Armin

    and in every kingdom of life. They are essential for the regulation of intracellular pH-value, Na+ stoichiometry. Transport activity was low at pH 7 and up-regulation above this pH value was accompanied remains high at pH values above 8.5. The antiporter from S. Typhimurium is a promising candidate

  1. Lattice dynamics and melting features of Li and Na

    NASA Astrophysics Data System (ADS)

    Lepeshkin, S. V.; Magnitskaya, M. V.; Maksimov, E. G.

    2009-08-01

    The high-pressure melting of Li and Na has been studied using ab initio calculations of the lattice dynamics. It has been shown that the recently discovered anomalous melting of Na is adequately explained by the phonon spectrum behavior and, accordingly, the thermal vibration amplitudes under compression. In a simple approach using the Lindemann criterion, the nonmonotonic behavior of the melting curve T m( p) of Na has been quantitatively described within very wide pressure and temperature ranges, and, in particular, the melting temperature drop at p ˜ 1 Mbar down to values lower than those at normal pressure. This approach leads to a nonphysical discontinuity of the melting curve T m( p) of Li near the bcc-fcc-liquid triple point. This is due to the “softness” of the phonon spectrum of the bcc phase of Li that is the necessary condition for the existence of the high-temperature bcc phase. The melting of Na and Li is used as an example to determine why the Lindemann criterion is efficient in some situations and is inapplicable in the other cases.

  2. Stainless Steel NaK Circuit Integration and Fill Submission

    NASA Technical Reports Server (NTRS)

    Garber, Anne E.

    2006-01-01

    The Early Flight Fission Test Facilities (EFF-TF) team has been tasked by the Marshall Space Flight Center Nuclear Systems Office to design, fabricate, and test an actively pumped alkali metal flow circuit. The system, which was originally designed to hold a eutectic mixture of sodium potassium (NaK), was redesigned to hold lithium; but due to a shift in focus, it is once again being prepared for use with NaK. Changes made to the actively pumped, high temperature loop include the replacement of the expansion reservoir, addition of remotely operated valves, and modification of the support table. Basic circuit components include: reactor segment, NaK to gas heat exchanger, electromagnetic (EM) liquid metal pump, load/drain reservoir, expansion reservoir, instrumentation, and a spill reservoir. A 37-pin partial-array core (pin and flow path dimensions are the same as those in a full design) was selected for fabrication and test. This document summarizes the integration and fill of the pumped liquid metal NaK flow circuit.

  3. Altered erythrocyte Na-K pump in anorectic patients

    SciTech Connect

    Pasquali, R.; Strocchi, E.; Malini, P.; Casimirri, F.; Ambrosioni, E.; Melchionda, N.; Labo, G.

    1985-07-01

    The status of the erythrocyte sodium pump was evaluated in a group of patients suffering from anorexia nervosa and a group of healthy female control subjects. Anorectic patients showed significantly higher mean values of digoxin-binding sites/cell (ie, the number of Na-K-ATPase units) with respect to control subjects while no differences were found in the specific /sup 86/Rb uptake (which reflects the Na-K-ATPase activity) between the two groups. A significant correlation was found between relative weight and the number of Na-K-ATPase pump units (r = -0.66; P less than 0.0001). Anorectic patients showed lower serum T3 concentrations (71.3 +/- 53 ng/dL) with respect to control subjects (100.8 +/- 4.7 ng/dL; P less than 0.0005) and a significant negative correlation between T3 levels and the number of pump units (r = -0.52; P less than 0.003) was found. This study therefore shows that the erythrocyte Na-K pump may be altered in several anorectic patients. The authors suggest that this feature could be interrelated with the degree of underweight and/or malnutrition.

  4. Project ELaNa and NASA's CubeSat Initiative

    NASA Technical Reports Server (NTRS)

    Skrobot, Garrett Lee

    2010-01-01

    This slide presentation reviews the NASA program to use expendable lift vehicles (ELVs) to launch nanosatellites for the purpose of enhancing educational research. The Education Launch of Nanosatellite (ELaNa) project, run out of the Launch Services Program is requesting proposals for CubeSat type payload to provide information that will aid or verify NASA Projects designs while providing higher educational research

  5. Promiscuous archaeal ATP synthase concurrently coupled to Na+ translocation

    E-print Network

    Huang, Ching-Tsan

    Promiscuous archaeal ATP synthase concurrently coupled to Na+ and H+ translocation Katharina98B02057 Chii-Shen Yang, PhD December 25, 2012 The 6th Classroom ATP (adenosine triphosphate) synthase ATP ATP ATP synthase ATP synthase ATP synthase ATP synthase Methanosarcina acetivorans

  6. Neutral Na in comets tails: a chemical story

    NASA Astrophysics Data System (ADS)

    Ellinger, Y.; Pauzat, F.; Mousis, O.; Guilbert-Lepoutre, A.; Leblanc, F.; Ali-Dib, M.; Doronin, M.; Zicler, E.; Doressoundiram, A.

    2015-10-01

    The origin of the neutral sodium comet tail discovered in comet Hale-Bopp in 1997 is still a matter of discussion. Here we propose a scenario which is based on chemical grounds. The starting point is the chemical trapping of the Na+ ion in the refractory material during the condensation phase of the protosolar nebula, followed by its incorporation in the building blocks of the comets parent bodies. In the next step, the Na+ ions are washed out of the refractory material by the water formed by the melting of the ice due to the heat released in the radioactive decay of short period elements. When the water freezes again, the Na+ ion looses its positive charge to evolve progressively toward a neutral atom when approaching the surface of the ice. As shown by high-level numerical simulations based on first principle periodic density functional theory (DFT) to describe the solid structure of the ice, it is a neutral Na that is ejected with the sublimation of the ice top layer.

  7. O, Na, Ba and Eu abundance patterns in open clusters

    NASA Astrophysics Data System (ADS)

    MacLean, B. T.; De Silva, G. M.; Lattanzio, J.

    2015-02-01

    Open clusters are historically regarded as single-aged stellar populations representative of star formation within the Galactic disc. Recent literature has questioned this view, based on discrepant Na abundances relative to the field, and concerns about the longevity of bound clusters contributing to a selection bias: perhaps long-lived open clusters are chemically different to the star formation events that contributed to the Galactic disc. We explore a large sample of high-resolution Na, O, Ba and Eu abundances from the literature, homogenized as much as reasonable including accounting for non-local thermodynamic equilibrium (NLTE) effects, variations in analysis and choice of spectral lines. Compared to a template globular cluster and representative field stars, we find no significant abundance trends, confirming that the process producing the Na-O anticorrelation in globular clusters is not present in open clusters. Furthermore, previously reported Na enhancement of open clusters is found to be an artefact of NLTE effects, with the open clusters matching a subset of chemically tagged field stars.

  8. Regulation of Intracellular Cholesterol Distribution by Na/K-ATPase*

    E-print Network

    Toledo, University of

    Regulation of Intracellular Cholesterol Distribution by Na/K-ATPase* Received for publication/K-ATPase 1 subunit produces a parallel decrease in both caveolin-1 and cholesterol in light fractions of LLC redistribution of cholesterol from the plasma membrane to intracellular compartments in the knockdown cells

  9. Mechanism of two types of Na emission observed in sonoluminescence

    NASA Astrophysics Data System (ADS)

    Nakajima, Ryota; Hayashi, Yuichi; Choi, Pak-Kon

    2015-07-01

    The sonoluminescence (SL) spectrum of Na atoms revealed that the Na line consists of two components, one of which is a broadened component (broad component) which is shifted from the original D lines, and the other is an unshifted narrow component (narrow component). We spatially separated the continuum, broad, and narrow components by capturing SL images using different optical filters. We also temporally separated these components by measuring SL pulses using respective band-pass filters. The SL image distribution and the timing of the SL pulses were different between the broad and narrow components. The results suggested that the broad and narrow components of Na emission are generated from different bubble populations. The dependences of SL spectra on ultrasonic frequency and dissolved rare gas (He, Ne, Ar, Kr, and Xe) were also investigated. It is concluded that the broad component and a blue satellite peak at 558 nm originate from van der Waals molecules composed of Na and rare-gas atoms. The narrow component was predicted to occur under temperature conditions at bubble collapse higher than that for the broad component.

  10. A Lepton Universality Test at CERN NA62 Experiment

    E-print Network

    Evgueni Goudzovski

    2010-05-07

    The NA62 experiment at CERN collected a large sample of K+ --> enu decays during a dedicated run in 2007, aiming at a precise test of lepton universality by measurement of the helicity suppressed ratio RK = BR(K+ --> enu)/BR(K+ --> munu). A preliminary result of the analysis of a partial data sample of 51089 K+ --> enu candidates is presented.

  11. Apical Na+ conductance in maturing rabbit principal cell.

    PubMed

    Satlin, L M; Palmer, L G

    1996-03-01

    Net Na+ absorption in microperfused rabbit cortical collecting ducts (CCDs) is low during the 1st wk of postnatal life, increasing substantially thereafter [L. M. Satlin. Am. J. Physiol. 266 (Renal Fluid Electrolyte Physiol. 35): F57-F65, 1994]. To establish whether the low rate of Na+ absorption observed immediately after birth is due to a low apical Na+ permeability of the neonatal principal cell, we used the patch-clamp technique in split-open CCDs isolated from maturing rabbits to estimate conductance, number (N), and open probability (Po) of apical Na+ channels in principal cells. With LiCl in the pipette and a NaCl or potassium gluconate solution, warmed to 37 degrees C, in the bath, inward currents with a conductance of approximately 11 pS (n = 23) were observed in 17% of cell-attached patches at 1 wk, 41% of patches at 2 wk, and 43% of patches at 5 wk. The mean N per patch in the 1st wk (0.22 +/- 0.09; n = 36) was significantly less than that observed in the 2nd (1.38 +/- 0.39; n = 34) and 5th (1.24 +/- 0.37; n = 21) wk of life. Po, studied at positive pipette voltages, was significantly lower in the 1st wk (0.085 +/- 0.035; n = 5) than in the 2nd wk (0.345 +/- 0.063; n = 9) and 5th wk (0.291 +/- 0.058; n = 4). To confirm that the 11-pS channel represented the amiloride-sensitive apical Na+ channel, cell-attached patches in CCDs isolated from 2-wk-old rabbits were studied with 0.5 microM amiloride added to the LiCl pipette solution. Amiloride led to > 90% reductions in mean open and closed times of the 11-pS conductance, consistent with blockade of the channel. These data indicate that N and Po of apical amiloride-sensitive Na+ channels in principal cells increase significantly after birth. PMID:8780239

  12. Light-Driven Na+ Pump from Gillisia limnaea: A High-Affinity Na+ Binding Site Is Formed Transiently in the Photocycle

    PubMed Central

    2015-01-01

    A group of microbial retinal proteins most closely related to the proton pump xanthorhodopsin has a novel sequence motif and a novel function. Instead of, or in addition to, proton transport, they perform light-driven sodium ion transport, as reported for one representative of this group (KR2) from Krokinobacter. In this paper, we examine a similar protein, GLR from Gillisia limnaea, expressed in Escherichia coli, which shares some properties with KR2 but transports only Na+. The absorption spectrum of GLR is insensitive to Na+ at concentrations of ?3 M. However, very low concentrations of Na+ cause profound differences in the decay and rise time of photocycle intermediates, consistent with a switch from a “Na+-independent” to a “Na+-dependent” photocycle (or photocycle branch) at ?60 ?M Na+. The rates of photocycle steps in the latter, but not the former, are linearly dependent on Na+ concentration. This suggests that a high-affinity Na+ binding site is created transiently after photoexcitation, and entry of Na+ from the bulk to this site redirects the course of events in the remainder of the cycle. A greater concentration of Na+ is needed for switching the reaction path at lower pH. The data suggest therefore competition between H+ and Na+ to determine the two alternative pathways. The idea that a Na+ binding site can be created at the Schiff base counterion is supported by the finding that upon perturbation of this region in the D251E mutant, Na+ binds without photoexcitation. Binding of Na+ to the mutant shifts the chromophore maximum to the red like that of H+, which occurs in the photocycle of the wild type. PMID:25375769

  13. Semi-volatiles at Mercury: Sodium (Na) and potassium (K)

    NASA Technical Reports Server (NTRS)

    Sprague, A.

    1994-01-01

    Several lines of evidence now suggest that Mercury is a planet rich in moderately-volatile elements such as Na and K. Recent mid-infrared spectral observations of Mercury's equatorial and mid-latitude region near 120 degrees mercurian longitude indicate the presence of plagioclase feldspar. Spectra of Mercury's surface exhibit spectral activity similar to labradorite (plagioclase feldspar with NaAlSi3O8: 30-50 percent) and bytownite (NaAlSi3O8: 10-30 percent). These surface studies were stimulated by the relatively large abundance of Na and K observed in Mercury's atmosphere. An enhanced column of K is observed at the longitudes of Caloris Basin and of the antipodal terrain. Extreme heating at these 'hot' longitudes and severe fracturing suffered from the large impact event could lead to enhanced outgassing from surface or subsurface materials. Alternatively, sputtering from a surface enriched in K could be the source of the observed enhancement. Recent microwave measurements of Mercury also give indirect evidence of a mercurian regolith less FeO-rich than the Moon. An anomalously high index of refraction derived from the whole-disk integrated phase curve of Danjon may also be indicative of surface sulfides contributing to a regolith that is moderately volatile-rich. The recent exciting observations of radar-bright spots at high latitudes also indicate that a substance of high volume scattering, like ice, is present in shadowed regions. Other radar-bright spots have been seen at locations of Na enhancements on the atmosphere. All combined, these pieces of evidence point to a planet that is not severely depleted in volatiles or semi-volatiles.

  14. Molecular dynamics simulation of aqueous NaF and NaI solutions near a hydrophobic surface.

    PubMed

    Pal, Sandeep; Müller-Plathe, Florian

    2005-04-01

    We present results from molecular dynamics simulation of aqueous solutions of alkali halide salts (NaI and NaF) at the interface with hydrophobic objects. The primary objective of this study is to investigate the structural properties of the salt solutions at the hydrophobic surface. An alkane crystal has been taken as the parent model for a hydrophobic surface. A hexagonal hole was created on it, which was half a nm deep and 2.5 nm wide. The density distributions of different species (water, anions, and cations) are studied as a function of distance from the surface. While iodide prefers the interface, the fluoride ions stay inside the bulk water region. The higher concentration of iodide ions at the interface drags sodium counterions to the interface. It also decreases the water density at the interface because of steric effects of the iodide ions. The number of contacts between the surface carbons and water decreases in the case of NaI solutions but is unchanged for NaF solutions. The orientation of the water-ion and the water-water hydrogen bond vector orientations near the interface is discussed in detail. PMID:16851713

  15. Validation of estimating food intake in gray wolves by 22Na turnover

    USGS Publications Warehouse

    DelGiudice, G.D.; Duquette, L.S.; Seal, U.S.; Mech, L.D.

    1991-01-01

    We studied 22sodium (22Na) turnover as a means of estimating food intake in 6 captive, adult gray wolves (Canis lupus) (2 F, 4 M) over a 31-day feeding period. Wolves were fed white-tailed deer (Odocoileus virginianus) meat only. Mean mass-specific exchangeable Na pool was 44.8 .+-. 0.7 mEq/kg; there was no differeence between males and females. Total exchangeable Na was related (r2 = 0.85, P < 0.009) to body mass. Overall, 22Na turnover overestimated Na intake by 9.8 .+-. 2.4% after 32 days. Actual Na intake was similar in males and females; however, Na turnover (P < 0.05) and the discrepancy (P < 0.01) between turnover and actual Na intake were greater in females than males. From Day 8 to the end of the study, the absolute difference (mEq) between Na intake and Na turnover remained stable. Sodium turnover (mEq/kg/day) was a reliable (r2 = 0.91, P < 0.001) estimator of food consumption (g/kg/day) in wolves over a 32-day period. Sampling blood and weighing wolves every 1-4 days permitted identification of several potential sources of error, including changes in size of exchangeable Na pools, exchange of 22Na with gastrointestinal and bone Na, and rapid loss of the isotope by urinary excretion.

  16. Na-O Anticorrelation and Horizontal Branches. V. The Na-O anticorrelation in NGC 6441 from Giraffe spectra

    E-print Network

    R. G. Gratton; S. Lucatello; A. Bragaglia; E. Carretta; S. Cassisi; Y. Momany; E. Pancino; E. Valenti; V. Caloi; R. Claudi; F. D'Antona; S. Desidera; P. Fran{ç}ois; G. James; S. Moehler; S. Ortolani; L. Pasquini; G. Piotto; A. Recio-Blanco

    2007-01-08

    We present an analysis of FLAMES-Giraffe spectra for several bright giants in NGC 6441, to investigate the presence and extent of the Na-O anticorrelation in this anomalous globular cluster. The field of NGC 6441 is very crowded, with severe contamination by foreground (mainly bulge) field stars. Appropriate membership criteria were devised to identify a group of 25 likely cluster members among the about 130 stars observed. Combined with the UVES data obtained with the same observations, high dispersion abundance analyses are now available for a total of 30 stars in NGC 6441, 29 of them having data for both O and Na. The spectra were analyzed by a standard line analysis procedure; care was taken to minimize the impact of the differential interstellar reddening throughout the cluster, and to extract reliable information from crowded, and moderately high S/N (30-70), moderately high resolution (R ~ 23,000) spectra. NGC 6441 is very metal-rich ([Fe/H]=$-0.34\\pm 0.02\\pm0.04$ dex). There is no clear sign of star-to-star scatter in the Fe-peak elements. The alpha-elements Mg, Si, Ca, and Ti are overabundant by rather large factors, suggesting that the cluster formed from material enriched by massive core collapse SNe. The O-Na anticorrelation is well defined, with about 1/4 of the stars being Na-rich and O-poor. One of the stars is a Ba-rich and moderately C-rich star. The distribution of [Na/O] ratios among RGB stars in NGC 6441 appears similar to the distribution of colors of stars along the horizontal branch. The fraction of Na-poor, O-rich stars found in NGC 6441 agrees well with that of stars on the red horizontal branch of this cluster (in both cases about 80%), with a sloping distribution toward lower values of [O/Na] (among RGB stars and bluer colors (among HB stars).

  17. INTEX-NA: Intercontinental Chemical Transport Experiment - North America

    NASA Technical Reports Server (NTRS)

    Singh, Hanwant B.; Jacob, D.; Pfister, L.; Hipskind, R. Stephen (Technical Monitor)

    2002-01-01

    INTEX-NA is an integrated atmospheric chemistry field experiment to be performed over North America using the NASA DC-8 and P-3B aircraft as its primary platforms. It seeks to understand the exchange of chemicals and aerosols between continents and the global troposphere. The constituents of interest are ozone and its precursors (hydrocarbons, NOX and HOX), aerosols, and the major greenhouse gases (CO2, CH4, N2O). INTEX-NA will provide the observational database needed to quantify inflow, outflow, and transformations of chemicals over North America. INTEX-NA is to be performed in two phases. Phase A will take place during the period of May-August 2004 and Phase B during March-June 2006. Phase A is in summer when photochemistry is most intense and climatic issues involving aerosols and carbon cycle are most pressing, and Phase B is in spring when Asian transport to North America is at its peak. INTEX-NA will coordinate its activities with concurrent measurement programs including satellites (e. g. Terra, Aura, Envisat), field activities undertaken by the North American Carbon Program (NACP), and other U.S. and international partners. However, it is being designed as a 'stand alone' mission such that its successful execution is not contingent on other programs. Synthesis of the ensemble of observation from surface, airborne, and space platforms, with the help of global/regional models is an important It is anticipated that approximately 175 flight hours for each of the aircraft (DC-8 and P-3B) will be required for each Phase. Principal operational sites are tentatively selected to be Bangor, ME; Wallops Island, VA; Seattle, WA; Rhinelander, WI; Lancaster, CA; and New Orleans, LA. These coastal and continental sites can support large missions and are suitable for INTEX-NA objectives. The experiment will be supported by forecasts from meteorological and chemical models, satellite observations, surface networks, and enhanced O3,-sonde releases. In addition to characterizing Atlantic-outflow and Pacific-inflow, INTEX-NA will characterize air masses transported between the U.S., Canada, and Mexico. INTEX-NA will be the first continental scale inflow, outflow, and transformation experiment to be performed over North America. It will provide the most comprehensive observational data set to date to understand the O3/NOX/HOX/aerosol photochemical system and the carbon cycle. One of the critical needs of the carbon cycle research is to obtain large-scale vertical and horizontal concentration gradients of CO2, throughout the troposphere over continental source/sink regions. INTEX-NA is ideally suited to perform this role. Coastal and continental operational sites will allow us to develop a curtain profile of greenhouse gases (e. g. CO2,) and other key pollutants across North America. Such information is central to our quantitative understanding of chemical budgets on the continental scale. We expect to provide a number of satellite under-flights over land and water to test and validate observations from the appropriate satellite platform (e. g. Aura). We plan to develop strong collaborations with other national and international observational programs. Results from INTEX-NA should directly benefit the development of environmental policy for air quality and climate change.

  18. Cell volume regulation during hyperosmotic shrinkage is mediated by Na+/K+-ATPase and Na+-K+-2Cl- cotransporter in Necturus gastrics surface epithelial cells.

    PubMed

    Nylander-Koski, Outi; Mustonen, Harri; Kiviluoto, Tuula; Kivilaakso, Eero

    2005-11-01

    Cell volume regulation was investigated in gastric surface epithelial cells during hypertonic conditions. Isolated Necturus antral mucosa was perfused on the serosal side with Ringer's solution (pH 7.25, 95%O2/5%CO2) and on the mucosal side successively with 150-500 mM NaCl. Amiloride, ouabain, and bumetanide were used to experimentally inhibit Na+/H+, Na+/K+ ATPase or Na+-K+-2Cl- ion transporters. Intracellular sodium activity and cell volume changes were measured with liquid sensor microelectrodes. The increase in intracellular sodium activity caused by luminal hyperosmolar exposure was mainly due to cell shrinkage. Inhibition of Na+/K+ ATPase or Na+-K+-2Cl- cotransporter increased hyperosmotic cell shrinkage (-52 +/- 5%, -85 +/- 19%, and -77 +/- 9% for control, ouabain, and bumetanide, respectively). Inhibition of Na+/K+ ATPase increased intracellular sodium activity (from 18 +/- 4 to 52 +/- 12 mM). Cell volume regulation in gastric epithelial surface cells during mucosal hyperosmolar exposure is maintained by the basolateral Na+-K+-2Cl- cotransporter, while Na+/K+ ATPase maintains sodium balance, but Na+/H+ antiport seems to have a less important role. PMID:16240213

  19. Analysis of cardiovascular responses to the H2S donors Na2S and NaHS in the rat.

    PubMed

    Yoo, Daniel; Jupiter, Ryan C; Pankey, Edward A; Reddy, Vishwaradh G; Edward, Justin A; Swan, Kevin W; Peak, Taylor C; Mostany, Ricardo; Kadowitz, Philip J

    2015-08-15

    Hydrogen sulfide (H2S) is an endogenous gaseous molecule formed from L-cysteine in vascular tissue. In the present study, cardiovascular responses to the H2S donors Na2S and NaHS were investigated in the anesthetized rat. The intravenous injections of Na2S and NaHS 0.03-0.5 mg/kg produced dose-related decreases in systemic arterial pressure and heart rate, and at higher doses decreases in cardiac output, pulmonary arterial pressure, and systemic vascular resistance. H2S infusion studies show that decreases in systemic arterial pressure, heart rate, cardiac output, and systemic vascular resistance are well-maintained, and responses to Na2S are reversible. Decreases in heart rate were not blocked by atropine, suggesting that the bradycardia was independent of parasympathetic activation and was mediated by an effect on the sinus node. The decreases in systemic arterial pressure were not attenuated by hexamethonium, glybenclamide, N(w)-nitro-L-arginine methyl ester hydrochloride, sodium meclofenamate, ODQ, miconazole, 5-hydroxydecanoate, or tetraethylammonium, suggesting that ATP-sensitive potassium channels, nitric oxide, arachidonic acid metabolites, cyclic GMP, p450 epoxygenase metabolites, or large conductance calcium-activated potassium channels are not involved in mediating hypotensive responses to the H2S donors in the rat and that responses are not centrally mediated. The present data indicate that decreases in systemic arterial pressure in response to the H2S donors can be mediated by decreases in vascular resistance and cardiac output and that the donors have an effect on the sinus node independent of the parasympathetic system. The present data indicate that the mechanism of the peripherally mediated hypotensive response to the H2S donors is uncertain in the intact rat. PMID:26071540

  20. Synthesis of NaB5C bulk ceramics by reaction sintering

    NASA Astrophysics Data System (ADS)

    Morito, Haruhiko; Anzai, Jun; Kimura, Takuma; Yamane, Hisanori

    2015-09-01

    Bulk ceramics of NaB5C were prepared by heating compact bodies of amorphous boron (B) and carbon black (C) powders with Na at 1073 K. The obtained bulk ceramics retained the rectangular shape of their original compacts. The obtained samples had a density of 80.1 ± 0.6% of the theoretical density of NaB5C. NaB5C bulk ceramics were also prepared by heating compacts comprised of B and C powders and Na. The addition of Na to the starting compact bodies increased the relative bulk density to 83.5 ± 0.4%. A fracture bending strength of 195 MPa was measured for the NaB5C bulk sample prepared from the compact of Na, B, and C.

  1. Preferential Interaction of Na+ over K+ to Carboxylate-functionalized Silver Nanoparticles

    EPA Science Inventory

    Elucidating mechanistic interactions between specific ions (Na+/ K+) and nanoparticle surfaces to alter particle stability in polar media has received little attention. We investigated relative preferential binding of Na+ and K+ to carboxylate-functionalized silver nanoparticles ...

  2. A Versatile Low Temperature Synthetic Route to Zintl Phase Precursors: Na4Si4, Na4Ge4 and K4Ge4 as Examples

    PubMed Central

    Ma, Xuchu; Xu, Fen; Atkins, Tonya; Goforth, Andrea M.; Neiner, Doinita; Navrotsky, Alexandra; Kauzlarich, Susan M.

    2010-01-01

    Na4Si4 and Na4Ge4 are ideal chemical precursors for inorganic clathrate structures, clusters, and nanocrystals. The monoclinic Zintl phases, Na4Si4 and Na4Ge4, contain isolated homo-tetrahedranide [Si4]4? and [Ge4]4? clusters surrounded by alkali metal cations. In this study, a simple scalable route has been applied to prepare Zintl phases of composition Na4Si4 and Na4Ge4 using the reaction between NaH and Si or Ge at low temperature (420 °C for Na4Si4 and 270 °C for Na4Ge4). The method was also applied to K4Ge4, using KH and Ge as raw materials, to show the versatility of this approach. The influence of specific reaction conditions on the purity of these Zintl phases has been studied by controlling five factors: the method of reagent mixing (manual or ball milled), the stoichiometry between raw materials, the reaction temperature, the heating time and the gas flow rate. Moderate ball-milling and excess NaH or KH facilitate the formation of pure Na4Si4, Na4Ge4 or K4Ge4 at 420 °C (Na4Si4) or 270 °C (both M4Ge4 compounds, M = Na, K). TG/DSC analysis of the reaction of NaH and Ge indicates that ball milling reduces the temperature for reaction and confirms the formation temperature. This method provides large quantities of high quality Na4Si4 and Na4Ge4 without the need for specialized laboratory equipment, such as Schlenk lines, niobium/tantalum containers, or an arc welder, thereby expanding the accessibility and chemical utility of these phases by making them more convenient to prepare. This new synthetic method may also be extended to lithium-containing Zintl phases (LiH is commercially available) as well as to alkali metal-tetrel Zintl compounds of other compositions, e.g. K4Ge9. PMID:19921060

  3. Caustic Recycle from Hanford Tank Waste Using Large Area NaSICON Structures (LANS)

    SciTech Connect

    Fountain, Matthew S.; Sevigny, Gary J.; Balagopal, S.; Bhavaraju, S.

    2009-03-31

    This report presents the results of a 5-day test of an electrochemical bench-scale apparatus using a proprietary (NAS-GY) material formulation of a (Na) Super Ion Conductor (NaSICON) membrane in a Large Area NaSICON Structures (LANS) configuration. The primary objectives of this work were to assess system performance, membrane seal integrity, and material degradation while removing Na from Group 5 and 6 tank waste from the Hanford Site.

  4. Density distributions of OH, Na, water vapor, and water mist in atmospheric-pressure dc helium glow plasmas in contact with NaCl solution

    NASA Astrophysics Data System (ADS)

    Sasaki, Koichi; Ishigame, Hiroaki; Nishiyama, Shusuke

    2015-07-01

    This paper reports the density distributions of OH, Na, water vapor and water mist in atmospheric-pressure dc helium glow plasmas in contact with NaCl solution. The densities of OH, Na and H2O had different spatial distributions, while the Na density had a similar distribution to mist, suggesting that mist is the source of Na in the gas phase. When the flow rate of helium toward the electrolyte surface was increased, the distributions of all the species densities concentrated in the neighboring region to the electrolyte surface more significantly. The densities of all the species were sensitive to the electric polarity of the power supply. In particular, we never detected Na and mist when the electrolyte worked as the anode of the dc discharge. Contribution to the topical issue "The 14th International Symposium on High Pressure Low Temperature Plasma Chemistry (HAKONE XIV)", edited by Nicolas Gherardi, Ronny Brandenburg and Lars Stollenwark

  5. Robert K. Crane—Na+-glucose cotransporter to cure?

    PubMed Central

    Hamilton, Kirk L.

    2013-01-01

    Dr. Robert K. Crane made major contributions to our understanding of carbohydrate metabolism and transport of the intestine over a very long and productive career. This Perspective examines, briefly, his early life and academic positions, but more importantly, this Perspective highlights his contributions to the understanding of coupled Na+-glucose absorption by the small intestine. I discuss how his early hypothesis of a “cotransport” of sodium and glucose ushered in and provided the physiological explanation for the clinical treatment of acute diarrhea and cholera when using oral rehydration therapy (ORT). ORT saves millions of lives each year. Certainly, humankind is better off because of Crane's hypothesis of the Na+-glucose cotransporter that he put forth over 50 years ago? PMID:23525627

  6. First principles molecular dynamics of molten NaCl

    NASA Astrophysics Data System (ADS)

    Galamba, N.; Costa Cabral, B. J.

    2007-03-01

    First principles Hellmann-Feynman molecular dynamics (HFMD) results for molten NaCl at a single state point are reported. The effect of induction forces on the structure and dynamics of the system is studied by comparison of the partial radial distribution functions and the velocity and force autocorrelation functions with those calculated from classical MD based on rigid-ion and shell-model potentials. The first principles results reproduce the main structural features of the molten salt observed experimentally, whereas they are incorrectly described by both rigid-ion and shell-model potentials. Moreover, HFMD Green-Kubo self-diffusion coefficients are in closer agreement with experimental data than those predicted by classical MD. A comprehensive discussion of MD results for molten NaCl based on different ab initio parametrized polarizable interionic potentials is also given.

  7. Imaging performance of the EUV high NA anamorphic system

    NASA Astrophysics Data System (ADS)

    van Ingen Schenau, Koen; Bottiglieri, Gerardo; van Schoot, Jan; Neumann, Jens-Timo; Roesch, Matthias

    2015-09-01

    This paper presents the predicted imaging performance for an anamorphic EUV high NA (>0.5) exposure system with a 4x magnification in X orientation and a 8x magnification in Y orientation. It has a half field size with which the productivity requirements can be maintained. The main findings of the study are that horizontal and vertical features have very similar process window sizes despite magnification difference. A new definition of the Mask Error Factor (MEF) is introduced that is more relevant for anamorphic imaging; it shows that reticle CD errors have 2x larger impact for vertical compared to horizontal features. For dark field horizontal two-bar trenches relatively small mask induced focus shift was observed compared to the 0.33NA case, probably due to the relatively small Mask Angle of Incidence in the Y orientation with the 8x magnification. Finally a Ni type absorber has potential to further improve imaging performance.

  8. Study of the K±??±?? decay by the NA62 experiment

    NASA Astrophysics Data System (ADS)

    Lazzeroni, C.; Romano, A.; Ceccucci, A.; Danielsson, H.; Falaleev, V.; Gatignon, L.; Goy Lopez, S.; Hallgren, B.; Maier, A.; Peters, A.; Piccini, M.; Riedler, P.; Frabetti, P. L.; Gersabeck, E.; Kekelidze, V.; Madigozhin, D.; Misheva, M.; Molokanova, N.; Movchan, S.; Potrebenikov, Yu.; Shkarovskiy, S.; Zinchenko, A.; Rubin, P.; Baldini, W.; Cotta Ramusino, A.; Dalpiaz, P.; Fiorini, M.; Gianoli, A.; Norton, A.; Petrucci, F.; Savrié, M.; Wahl, H.; Bizzeti, A.; Bucci, F.; Iacopini, E.; Lenti, M.; Veltri, M.; Antonelli, A.; Moulson, M.; Raggi, M.; Spadaro, T.; Eppard, K.; Hita-Hochgesand, M.; Kleinknecht, K.; Renk, B.; Wanke, R.; Winhart, A.; Winston, R.; Bolotov, V.; Duk, V.; Gushchin, E.; Ambrosino, F.; Di Filippo, D.; Massarotti, P.; Napolitano, M.; Palladino, V.; Saracino, G.; Anzivino, G.; Imbergamo, E.; Piandani, R.; Sergi, A.; Cenci, P.; Pepe, M.; Costantini, F.; Doble, N.; Giudici, S.; Pierazzini, G.; Sozzi, M.; Venditti, S.; Balev, S.; Collazuol, G.; DiLella, L.; Gallorini, S.; Goudzovski, E.; Lamanna, G.; Mannelli, I.; Ruggiero, G.; Cerri, C.; Fantechi, R.; Kholodenko, S.; Kurshetsov, V.; Obraztsov, V.; Semenov, V.; Yushchenko, O.; D'Agostini, G.; Leonardi, E.; Serra, M.; Valente, P.; Fucci, A.; Salamon, A.; Bloch-Devaux, B.; Peyaud, B.; Engelfried, J.; Coward, D.; Kozhuharov, V.; Litov, L.; Arcidiacono, R.; Bifani, S.; Biino, C.; Dellacasa, G.; Marchetto, F.; Numao, T.; Retière, F.

    2014-05-01

    A study of the dynamics of the rare decay K±??±?? has been performed on a sample of 232 decay candidates, with an estimated background of 17.4±1.1 events, collected by the NA62 experiment at CERN in 2007. The results are combined with those from a measurement conducted by the NA48/2 Collaboration at CERN. The combined model-independent branching ratio in the kinematic range z=(>0.2 is BMI(z>0.2)=(0.965±0.063)×10-6, and the combined branching ratio in the full kinematic range assuming a Chiral Perturbation Theory description is B(K)=(1.003±0.056)×10-6. A detailed comparison of the results with the previous measurements is performed.

  9. Interaction of NaCl with limestones during calcination

    SciTech Connect

    Shearer, J.A.; Johnson, I.; Turner, C.B.

    1980-05-01

    The interaction of small quantities of NaCl with limestone during calcination is shown to increase the average pore diameters of the lime particles. For twenty-eight limestones pore diameters increased from an overall average of 0.14 to 1.8 ..mu..m for 2.0 wt % NaCl addition. These structural changes are thought to result from the formation of trace amounts of liquid phase at high temperatures, which increases the ionic diffusion of the system. Controlled use of salt additives can result in a pore structure favorable to subsequent reactions involving gas or liquid phases. The effectiveness of the salt addition in promoting changes in pore distribution is dependent on the impurity content of the original limestone.

  10. Na8Au9.8(4)Ga7.2 and Na17Au5.87(2)Ga46.63: The diversity of pseudo 5-fold symmetries in the Na-Au-Ga system

    NASA Astrophysics Data System (ADS)

    Smetana, Volodymyr; Corbett, John D.; Miller, Gordon J.

    2013-11-01

    The Na-rich part (~30% Na) of the Na-Au-Ga system between NaAu2, NaGa4, and Na22Ga39 has been found to contain the ternary phases Na8Au9.8(4)Ga7.2 (I) and Na17Au5.87(2)Ga46.63 (II), according to the results of single crystal X-ray diffraction measurements. I is orthorhombic, Cmcm, a=5.3040(1), b=24.519(5), c=14.573(3) Å, and contains a network of clusters with local 5-fold symmetry along the a-axis. Such clusters are frequent building units in decagonal quasicrystals and their approximants. II is rhombohedral, R3¯m, a=16.325(2), c=35.242(7) Å, and contains building blocks that are structurally identical to the Bergman-type clusters as well as fused icosahedral units known with active metals, triels and late transition elements. II also contains a polycationic network with elements of the clathrate V type structure. Tight-binding electronic structure calculations using linear muffin-tin-orbital (LMTO) methods on idealized models of I and II indicate that both compounds are metallic with evident pseudogaps at the corresponding Fermi levels. The overall Hamilton bond populations are generally dominated by Au-Ga and Au-Au bonds in I and by Ga-Ga bonds in II; moreover, the Na-Au and Na-Ga contributions in I are unexpectedly large, ~20% of the total. A similar involvement of sodium in covalent bonding has also been found in the electron-richer i-Na13Au12Ga15 quasicrystal approximant.

  11. Effect of cation substitution on structural transition: synthesis, characterization and theoretical studies of NaCa4B3O9, NaCaBO3, NaSrBO3 and Li4CaB2O6.

    PubMed

    Yang, Yun; Su, Xin; Pan, Shilie; Yang, Zhihua

    2015-10-21

    Single crystals of NaCa4B3O9, NaCaBO3, NaSrBO3 and Li4CaB2O6 have been successfully synthesized through conventional high-temperature solid-state reactions. They are structurally characterized by single crystal X-ray diffraction and exhibit three-dimensional crystal structures consisting of isolated planar BO3 as fundamental building blocks. Interestingly, for the centrosymmetric crystal structure of NaCaBO3 (Na3Ca3B3O9), as 2/3 of the Na(+) ions are substituted by Ca(2+) ions, NaCa4B3O9 is obtained and crystallizes in the noncentrosymmetric space group Ama2 (crystal class mm2). A second harmonic generation (SHG) test of the title compound by the Kurtz-Perry method shows that NaCa4B3O9 can be phase matchable with an effective SHG coefficient approximately one-half that of KH2PO4 (KDP). Studies of their optical properties as well as band structure calculations based on density functional theory methods have been also performed. NaCa4B3O9 possesses a moderate birefringence of about 0.05 at 1064 nm. To explain the difference in optical nonlinearity we compared the electronic structures of NaCa4B3O9, KCa4B3O9 and KSr4B3O9 crystals, in particular at the bottom of the conduction band (CB) and the top of the valence band (VB), since they are known to play a primary role in SHG. These electronic structures are responsible for the optical-nonlinearity of NaCa4B3O9, KCa4B3O9 and KSr4B3O9 crystals. PMID:26387438

  12. Condensed Lecture Notes, Part 2 Bond energy of NaCl

    E-print Network

    6 Condensed Lecture Notes, Part 2 Bond energy of NaCl If NaCl were diatomic molecule of the type Na that satisfy the octet (duplet) rule. If multiple structures are ok, then the rule of thumb is that the lowest, not OFF. 7. If there are multiple equivalent structures which satisfy the octet rule, then we say

  13. Complete Genome Sequence of Bacillus subtilis subsp. subtilis Strain 3NA

    PubMed Central

    Reuß, Daniel R.; Schuldes, Jörg; Daniel, Rolf

    2015-01-01

    Bacillus subtilis 3NA reaches high cell densities during fed-batch fermentation and is an interesting target for further optimization as a production strain. Here, we announce the full genome of B. subtilis 3NA. The presence of specific Bacillus subtilis 168 and W23 genetic features suggests that 3NA is a hybrid of these strains. PMID:25767229

  14. Regulation of SOS1, a plasma membrane Na H exchanger in Arabidopsis thaliana, by SOS2

    E-print Network

    Schumaker, Karen

    ions across the plasma membrane. To dem- onstrate the transport capability of SOS1, we studied Na H of sos2 and sos3 plants had reduced plasma membrane Na H -exchange activity, transport activity in both membranes, respectively (4­6). Na H exchangers are membrane proteins that transport protons (H ) across

  15. Comparison of meteor radar and Na Doppler lidar measurements of winds in the mesopause region

    E-print Network

    Chu, Xinzhao

    Comparison of meteor radar and Na Doppler lidar measurements of winds in the mesopause region above 29 January 2005. [1] Simultaneous sodium (Na) Doppler lidar and meteor radar measurements/s at altitudes below 96 km. This is smaller than the RMS differences observed in a previous Na lidar and meteor

  16. Voltage-gated sodium channel (NaV) protein dissection creates a set of

    E-print Network

    Lim, Wendell

    Voltage-gated sodium channel (NaV) protein dissection creates a set of functional pore voltage- gated sodium channel (NaVSp1) PD forms a stand-alone, ion selec- tive pore (NaVSp1p) that is tetrameric, -helical, and that forms functional, sodium-selective channels when reconstituted into lipid

  17. Na?-functionalized carbon quantum dots: a new draw solute in forward osmosis for seawater desalination.

    PubMed

    Guo, Chun Xian; Zhao, Dieling; Zhao, Qipeng; Wang, Peng; Lu, Xianmao

    2014-07-14

    A new type of biocompatible draw solute, Na(+)-functionalized carbon quantum dots (Na_CQDs) with ultra-small size and rich ionic species, in forward osmosis (FO) is developed for seawater desalination. The aqueous dispersion of Na_CQDs demonstrates a high osmotic pressure, which allows high FO water flux and negligible reverse solute permeation. PMID:24870226

  18. Cooling polar NaCs molecules in an electrostatic trap

    NASA Astrophysics Data System (ADS)

    Haruza, Marek; Jayaseelan, Maitreyi; Bigelow, Nicholas P.

    2015-05-01

    We present our scheme for creating an ultracold and dense sample of polar NaCs molecules. The molecules are photoassociated from laser cooled atoms and held in an electrostatic trap in their vibrational ground state and the lowest trappable rotational states. The trap depth dependance on the rotational quantum numbers can be exploited to cool the motion of the molecules by optical pumping between rotational levels.

  19. Cosmogenic radionuclide production in NaI(Tl) crystals

    NASA Astrophysics Data System (ADS)

    Amaré, J.; Cebrián, S.; Cuesta, C.; García, E.; Ginestra, C.; Martínez, M.; Oliván, M. A.; Ortigoza, Y.; Ortiz de Solórzano, A.; Pobes, C.; Puimedón, J.; Sarsa, M. L.; Villar, J. A.; Villar, P.

    2015-02-01

    The production of long-lived radioactive isotopes in materials due to the exposure to cosmic rays on Earth surface can be an hazard for experiments demanding ultra-low background conditions, typically performed deep underground. Production rates of cosmogenic isotopes in all the materials present in the experimental set-up, as well as the corresponding cosmic rays exposure history, must be both well known in order to assess the relevance of this effect in the achievable sensitivity of a given experiment. Although NaI(Tl) scintillators are being used in experiments aiming at the direct detection of dark matter since the first nineties of the last century, very few data about cosmogenic isotopes production rates have been published up to date. In this work we present data from two 12.5 kg NaI(Tl) detectors, developed in the frame of the ANAIS project, which were installed inside a convenient shielding at the Canfranc Underground Laboratory just after finishing surface exposure to cosmic rays. The very fast start of data taking allowed to identify and quantify isotopes with half-lives of the order of tens of days. Initial activities underground have been measured and then production rates at sea level have been estimated following the history of detectors; values of about a few tens of nuclei per kg and day for Te isotopes and 22Na and of a few hundreds for I isotopes have been found. These are the first direct estimates of production rates of cosmogenic nuclides in NaI crystals. A comparison of the so deduced rates with calculations using typical cosmic neutron flux at sea level and a carefully selected description of excitation functions will be also presented together with an estimate of the corresponding contribution to the background at low and high energies, which can be relevant for experiments aiming at rare events searches.

  20. Redetermination of durangite, NaAl(AsO4)F

    PubMed Central

    Downs, Gordon W.; Yang, Betty N.; Thompson, Richard M.; Wenz, Michelle D.; Andrade, Marcelo B.

    2012-01-01

    The crystal structure of durangite, ideally NaAl(AsO4)F (chemical name sodium aluminium arsenate fluoride), has been determined previously [Kokkoros (1938). Z. Kristallogr. 99, 38–49] using Weissenberg film data without reporting displacement parameters of atoms or a reliability factor. This study reports the redetermination of the structure of durangite using single-crystal X-ray diffraction data from a natural sample with composition (Na0.95Li0.05)(Al0.91Fe3+ 0.07Mn3+ 0.02)(AsO4)(F0.73(OH)0.27) from the type locality, the Barranca mine, Coneto de Comonfort, Durango, Mexico. Durangite is isostructural with minerals of the titanite group in the space group C2/c. Its structure is characterized by kinked chains of corner-sharing AlO4F2 octa­hedra parallel to the c axis. These chains are cross-linked by isolated AsO4 tetra­hedra, forming a three-dimensional framework. The Na+ cation (site symmetry 2) occupies the inter­stitial sites and is coordinated by one F? and six O2? anions. The AlO4F2 octa­hedron has symmetry -1; it is flattened, with the Al—F bond length [1.8457?(4)?Å] shorter than the Al—O bond lengths [1.8913?(8) and 1.9002?(9)?Å]. Examination of the Raman spectra for arsenate minerals in the titanite group reveals that the position of the band originating from the As—O symmetric stretching vibrations shifts to lower wavenumbers from durangite, maxwellite [ideally NaFe(AsO4)F], to tilasite [CaMg(AsO4)F]. PMID:23284315

  1. Lepton flavour universality test at the CERN NA62 experiment

    E-print Network

    Evgueni Goudzovski

    2010-08-06

    A precision test of lepton universality by measurement of the ratio RK of K-->e nu to K-->mu nu decay rates was performed using a sample of 59963 K-->e nu candidates with 8.8% background contamination collected by the CERN NA62 experiment. The result RK = (2.486 +- 0.013)*10^{-5} is in agreement with the Standard Model expectation.

  2. Cosmogenic radionuclide production in NaI(Tl) crystals

    E-print Network

    J. Amaré; S. Cebrián; C. Cuesta; E. García; C. Ginestra; M. Martínez; M. A. Oliván; Y. Ortigoza; A. Ortiz de Solórzano; C. Pobes; J. Puimedón; M. L. Sarsa; J. A. Villar; P. Villar

    2015-01-16

    The production of long-lived radioactive isotopes in materials due to the exposure to cosmic rays on Earth surface can be an hazard for experiments demanding ultra-low background conditions, typically performed deep underground. Production rates of cosmogenic isotopes in all the materials present in the experimental set-up, as well as the corresponding cosmic rays exposure history, must be both well known in order to assess the relevance of this effect in the achievable sensitivity of a given experiment. Although NaI(Tl) scintillators are being used in experiments aiming at the direct detection of dark matter since the first nineties of the last century, very few data about cosmogenic isotopes production rates have been published up to date. In this work we present data from two 12.5 kg NaI(Tl) detectors, developed in the frame of the ANAIS project, which were installed inside a convenient shielding at the Canfranc Underground Laboratory just after finishing surface exposure to cosmic rays. The very fast start of data taking allowed to identify and quantify isotopes with half-lives of the order of tens of days. Initial activities underground have been measured and then production rates at sea level have been estimated following the history of detectors; values of about a few tens of nuclei per kg and day for Te isotopes and 22Na and of a few hundreds for I isotopes have been found. These are the first direct estimates of production rates of cosmogenic nuclides in NaI crystals. A comparison of the so deduced rates with calculations using typical cosmic neutron flux at sea level and a carefully selected description of excitation functions will be also presented together with an estimate of the corresponding contribution to the background at low and high energies, which can be relevant for experiments aiming at rare events searches.

  3. Prospects for observation at CERN in NA62

    NASA Astrophysics Data System (ADS)

    Hahn, F.; the NA62 Collaboration; Aglieri Rinella, G.; Aliberti, R.; Ambrosino, F.; Angelucci, B.; Antonelli, A.; Anzivino, G.; Arcidiacono, R.; Azhinenko, I.; Balev, S.; Bendotti, J.; Biagioni, A.; Biino, C.; Bizzeti, A.; Blazek, T.; Blik, A.; Bloch-Devaux, B.; Bolotov, V.; Bonaiuto, V.; Bragadireanu, M.; Britton, D.; Britvich, G.; Brook, N.; Bucci, F.; Butin, F.; Capitolo, E.; Capoccia, C.; Capussela, T.; Carassiti, V.; Cartiglia, N.; Cassese, A.; Catinaccio, A.; Cecchetti, A.; Ceccucci, A.; Cenci, P.; Cerny, V.; Cerri, C.; Chikilev, O.; Ciaranfi, R.; Collazuol, G.; Cooke, P.; Cooper, P.; Corradi, G.; Cortina Gil, E.; Costantini, F.; Cotta Ramusino, A.; Coward, D.; D'Agostini, G.; Dainton, J.; Dalpiaz, P.; Danielsson, H.; Degrange, J.; De Simone, N.; Di Filippo, D.; Di Lella, L.; Dixon, N.; Doble, N.; Duk, V.; Elsha, V.; Engelfried, J.; Enik, T.; Falaleev, V.; Fantechi, R.; Federici, L.; Fiorini, M.; Fry, J.; Fucci, A.; Fulton, L.; Gallorini, S.; Gatignon, L.; Gianoli, A.; Giudici, S.; Glonti, L.; Goncalves Martins, A.; Gonnella, F.; Goudzovski, E.; Guida, R.; Gushchin, E.; Hahn, F.; Hallgren, B.; Heath, H.; Herman, F.; Hutchcroft, D.; Iacopini, E.; Jamet, O.; Jarron, P.; Kampf, K.; Kaplon, J.; Karjavin, V.; Kekelidze, V.; Kholodenko, S.; Khoriauli, G.; Khudyakov, A.; Kiryushin, Yu; Kleinknecht, K.; Kluge, A.; Koval, M.; Kozhuharov, V.; Krivda, M.; Kudenko, Y.; Kunze, J.; Lamanna, G.; Lazzeroni, C.; Leitner, R.; Lenci, R.; Lenti, M.; Leonardi, E.; Lichard, P.; Lietava, R.; Litov, L.; Lomidze, D.; Lonardo, A.; Lurkin, N.; Madigozhin, D.; Maire, G.; Makarov, A.; Mannelli, I.; Mannocchi, G.; Mapelli, A.; Marchetto, F.; Massarotti, P.; Massri, K.; Matak, P.; Mazza, G.; Menichetti, E.; Mirra, M.; Misheva, M.; Molokanova, N.; Morant, J.; Morel, M.; Moulson, M.; Movchan, S.; Munday, D.; Napolitano, M.; Newson, F.; Norton, A.; Noy, M.; Nuessle, G.; Obraztsov, V.; Padolski, S.; Page, R.; Palladino, V.; Pardons, A.; Pedreschi, E.; Pepe, M.; Perez Gomez, F.; Perrin-Terrin, M.; Petrov, P.; Petrucci, F.; Piandani, R.; Piccini, M.; Pietreanu, D.; Pinzino, J.; Pivanti, M.; Polenkevich, I.; Popov, I.; Potrebenikov, Yu; Protopopescu, D.; Raffaelli, F.; Raggi, M.; Riedler, P.; Romano, A.; Rubin, P.; Ruggiero, G.; Russo, V.; Ryjov, V.; Salamon, A.; Salina, G.; Samsonov, V.; Santovetti, E.; Saracino, G.; Sargeni, F.; Schifano, S.; Semenov, V.; Sergi, A.; Serra, M.; Shkarovskiy, S.; Sotnikov, A.; Sougonyaev, V.; Sozzi, M.; Spadaro, T.; Spinella, F.; Staley, R.; Statera, M.; Sutcliffe, P.; Szilasi, N.; Tagnani, D.; Valdata-Nappi, M.; Valente, P.; Vasile, M.; Vassilieva, V.; Velghe, B.; Veltri, M.; Venditti, S.; Vormstein, M.; Wahl, H.; Wanke, R.; Wertelaers, P.; Winhart, A.; Winston, R.; Wrona, B.; Yushchenko, O.; Zamkovsky, M.; Zinchenko, A.

    2015-07-01

    The rare decays are excellent processes to probe the Standard Model and indirectly search for new physics complementary to the direct LHC searches. The NA62 experiment at CERN SPS aims to collect and analyse O(1013) kaon decays before the CERN long-shutdown 2 (in 2018). This will allow to measure the branching ratio to a level of 10% accuracy. The experimental apparatus has been commissioned during a first run in autumn 2014.

  4. Probabilistic Models to Predict the Growth Initiation Time for Pseudomonas spp. in Processed Meats Formulated with NaCl and NaNO2

    PubMed Central

    Park, Beomyoung; Oh, Mihwa

    2014-01-01

    This study developed probabilistic models to determine the initiation time of growth of Pseudomonas spp. in combinations with NaNO2 and NaCl concentrations during storage at different temperatures. The combination of 8 NaCl concentrations (0, 0.25, 0.5, 0.75, 1, 1.25, 1.5, and 1.75%) and 9 NaNO2 concentrations (0, 15, 30, 45, 60, 75, 90, 105, and 120 ppm) were prepared in a nutrient broth. The medium was placed in the wells of 96-well microtiter plates, followed by inoculation of a five-strain mixture of Pseudomonas in each well. All microtiter plates were incubated at 4, 7, 10, 12, and 15? for 528, 504, 504, 360 and 144 h, respectively. Growth (growth initiation; GI) or no growth was then determined by turbidity every 24 h. These growth response data were analyzed by a logistic regression to produce growth/no growth interface of Pseudomonas spp. and to calculate GI time. NaCl and NaNO2 were significantly effective (p<0.05) on inhibiting Pseudomonas spp. growth when stored at 4-12?. The developed model showed that at lower NaCl concentration, higher NaNO2 level was required to inhibit Pseudomonas growth at 4-12?. However, at 15?, there was no significant effect of NaCl and NaNO2. The model overestimated GI times by 58.2±17.5 to 79.4±11%. These results indicate that the probabilistic models developed in this study should be useful in calculating the GI times of Pseudomonas spp. in combination with NaCl and NaNO2 concentrations, considering the over-prediction percentage.

  5. Actinic EUV mask inspection beyond 0.25 NA

    SciTech Connect

    Goldberg, Kenneth A.; Mochi, Iacopo; Anderson, Erik H.; Rekawa, Seno. B.; Kemp, Charles D.; Huh, S.; Han, H.-S.; Naulleau, P.; Huh, S.

    2008-03-24

    The SEMATECH Berkeley Actinic Inspection Tool (AIT) is an EUV-wavelength mask inspection microscope designed for direct aerial image measurements, and pre-commercial EUV mask research. Operating on a synchrotron bending magnet beamline, the AIT uses an off-axis Fresnel zoneplate lens to project a high-magnification EUV image directly onto a CCD camera. We present the results of recent system upgrades that have improved the imaging resolution, illumination uniformity, and partial coherence. Benchmarking tests show image contrast above 75% for 100-nm mask features, and significant improvements and across the full range of measured sizes. The zoneplate lens has been replaced by an array of user-selectable zoneplates with higher magnification and NA values up to 0.0875, emulating the spatial resolution of a 0.35-NA 4x EUV stepper. Illumination uniformity is above 90% for mask areas 2-{micro}m-wide and smaller. An angle-scanning mirror reduces the high coherence of the synchrotron beamline light source giving measured {sigma} values of approximately 0.125 at 0.0875 NA.

  6. Factors dominating adhesion of NaCl onto potato chips.

    PubMed

    Buck, V E; Barringer, S A

    2007-10-01

    In this study, the adhesion factors examined were time between frying and coating, surface oil content, chip temperature, oil composition, NaCl size, NaCl shape, and electrostatic coating. Three different surface oil content potato chips, high, low, and no, were produced. Oils used were soybean, olive, corn, peanut, and coconut. After frying, chips were coated immediately, after 1 d, and after 1 mo. NaCl crystals of 5 different particle sizes (24.7, 123, 259, 291, and 388 microm) were coated both electrostatically and nonelectrostatically. Adhesion of cubic, dendritic, and flake crystals was examined. Chips were coated at different temperatures. Chips with high surface oil had the highest adhesion of salt, making surface oil content the most important factor. Decreasing chip temperature decreased surface oil and adhesion. Increasing time between frying and coating reduced adhesion for low surface oil chips, but did not affect high and no surface oil chips. Changing oil composition did not affect adhesion. Increasing salt size decreased adhesion. Salt size had a greater effect on chips with lower surface oil content. When there were significant differences, cubic crystals gave the best adhesion followed by flake crystals then dendritic crystals. For high and low surface oil chips, electrostatic coating did not change adhesion of small size crystals but decreased adhesion of large salts. For no surface oil content chips, electrostatic coating improved adhesion for small salt sizes but did not affect adhesion of large crystals. PMID:17995602

  7. Sonochemical synthesis of zeolite NaP from clinoptilolite.

    PubMed

    Behin, Jamshid; Kazemian, Hossein; Rohani, Sohrab

    2016-01-01

    In the present work, natural clinoptilolite was converted to zeolite NaP using ultrasonic energy, in which the transformation time shortened remarkably. The effect of post-synthesis treatment using conventional hydrothermal was also investigated. The synthesized powders were characterized by XRD, TGA/DTA, SEM, and PSD analysis. The results showed that, increasing the sonication time (energy) has no significant effect on the product's morphology. The crystallinity of the synthesized samples increased slightly with increasing sonication time, but their yield remained relatively unchanged. Furthermore, post-synthesis hydrothermal treatment showed very little influence on properties of the final product. Because the ultrasonic irradiation creates acoustic cavitation cracks on the surface structure of clinoptilolite particulates and increases the concentration of soluble alumino-silicate species, which favors the prevailing super-saturation, crystallization and crystal growth of zeolite NaP happen faster. The particles of zeolite NaP synthesized by ultrasonic irradiation consist of small crystallites of uniform size. PMID:26341462

  8. Benchmarking EUV mask inspection beyond 0.25 NA

    SciTech Connect

    Goldberg, Kenneth A.; Mochi, Iacopo; Anderson, Erik H.; Rekawa, Seno B.; Kemp, Charles D.; Huh, S.; Han, H.-S.; Naulleau, P.; Gunion, R.F.

    2008-09-18

    The SEMATECH Berkeley Actinic Inspection Tool (AIT) is an EUV-wavelength mask inspection microscope designed for direct aerial image measurements, and pre-commercial EUV mask research. Operating on a synchrotron bending magnet beamline, the AIT uses an off-axis Fresnel zoneplate lens to project a high-magnification EUV image directly onto a CCD camera. We present the results of recent system upgrades that have improved the imaging resolution, illumination uniformity, and partial coherence. Benchmarking tests show image contrast above 75% for 100-nm mask features, and significant improvements and across the full range of measured sizes. The zoneplate lens has been replaced by an array of user-selectable zoneplates with higher magnification and NA values up to 0.0875, emulating the spatial resolution of a 0.35-NA 4 x EUV stepper. Illumination uniformity is above 90% for mask areas 2-{micro}m-wide and smaller. An angle-scanning mirror reduces the high coherence of the synchrotron beamline light source giving measured {sigma} values of approximately 0.125 at 0.0875 NA.

  9. Potentials of the first excited ( A) state of LiNa, Na 2, and K 2 by the generalized reduced potential curve method

    NASA Astrophysics Data System (ADS)

    Jen?, F.; Brandt, B. A.

    1992-03-01

    Rydberg-Klein-Rees potentials for the first excited ( A) state of LiNa, Na 2, and K 2 are extended by the generalized reduced potential curve method from 50 to 60% of the depth of the potential well up to the dissociation limit. The method is tested on the potentials of the ground state. The error limit in the extensions in the attractive limb should be essentially smaller than 3 cm -1 for LiNa, smaller than 10 and 15 cm -1 for Na 2 and K 2, respectively, and smaller than 0.001 Å in the repulsive limb for all three molecules.

  10. A study of the reaction NaO2 + O yields NaO + O2: Implications for the chemistry of sodium in the upper atmosphere

    SciTech Connect

    Helmer, M.; Plane, J.M.C.

    1993-12-01

    Sodium superoxide (NaO2) is believed to be a major sink for meteor-ablated Na in the upper atmosphere. However, the rate constant for the reaction between NaO2 and O is not known, and its determination is the subject of this study. NaO2 was produced by the reaction between Na vapor, an excess of O2, and the carrier gas N2 in the upstream section of a fast flow tube reactor. Excess atomic O was then added, so that a steady state developed in which the sodium was partitioned between its atomic form and a variety of oxides. The steady state fraction of atomic Na, monitored by laser-induced fluorescence, was then observed as a function of (O) and (O2), from which it was deduced that k(NaO2 + O) = (2.2 +/- 1.0) x 10(exp -11) cu cm/molecule/s at 300 K (3 sigma uncertainty). As a prelude to this experiment, the recombination reaction between O2 and Na was studied by the conventional flow tube technique, yielding k(Na + O2 + N2) = (3.14 +/- 0.20) x 10(exp -30)(300/T)(exp -1.52 +/- 0.27)cm(exp 6)/molecule(exp 2)/s. These experimental results were then incorporated into a one-dimensional model of sodium in the upper atmosphere between 65 and 110 km. It is shown that formation of NaHCO3 rather than NaO2 is the dominant removal process for atomic Na below 90 km. This new model, whole only important assumption is the rate constant for the reaction NaHCO3 + H yields Na + H2CO3, predicts a seasonal variation of the atomic Na layer in excellent agreement with recent lidar observations at 40 deg and 69 deg N and also demonstrates that temperature fluctuations produced by gravity waves should induce significant chemical responses in the Na layer below 88 km.

  11. Na sup + and H sup + transport in human jejunal brush-border membrane vesicles

    SciTech Connect

    Kleinman, J.G.; Harig, J.M.; Barry, J.A.; Ramaswamy, K. )

    1988-08-01

    The authors have examined pH gradient-driven Na{sup +} uptake and Na{sup +}-driven H{sup +} transport in brush-border membrane vesicles prepared from jejunal tissue obtained from organ donors by measuring the influx of {sup 22}Na and the fluorescence quenching of acridine orange (AO). Vesicle preparation by either Ca{sup 2+} or Mg{sup 2+} precipitation showed no difference in {sup 22}Na uptake or AO fluorescence quenching and dissipation. An outward H{sup +} gradient induced a Na{sup +} uptake overshoot of threefold over equilibrium, whereas the absence of an H{sup +} gradient did not produce an overshoot. The initial rate of pH-driven Na{sup +} uptake in voltage-clamped vesicles was related to (Na{sup +}{sub o}). Amiloride inhibited this uptake in voltage-clamped vesicles. Dissipation of AO fluorescence quench in vesicles with a preformed internal acid gradient was hastened by Na{sup +}{sub o} as well as voltage clamping in the absence of Na{sup +}. In vesicles without a pH gradient, internal Na{sup +}, as well as a diffusion potential in the absence of Na{sup +}, induced AO quenching. External Na{sup +} and Li{sup +}, but not choline, acted to dissipate AO quenching induced by a diffusion potential, and the rate of dissipation was unaffected by the presence of Cl{sup {minus}}. Li{sup +} and NH{sup +}{sub 4}, but not Cs{sup +}, K{sup +}, Rb{sup +}, or choline{sup +}, inhibited pH gradient-driven {sup 22}Na uptake. They conclude that human jejunal brush-border membrane vesicles contain conductive pathways for both Na{sup +} and H{sup +} and an Na{sup +}-H{sup +} exchanger.

  12. Evidence of sympathetic cooling of Na+ ions by a Na magneto-optical trap in a hybrid trap

    NASA Astrophysics Data System (ADS)

    Sivarajah, I.; Goodman, D. S.; Wells, J. E.; Narducci, F. A.; Smith, W. W.

    2012-12-01

    A hybrid ion-neutral trap provides an ideal system to study collisional dynamics between ions and neutral atoms. This system provides a general cooling method that can be applied to species that do not have optically accessible transitions and can also potentially cool internal degrees of freedom. The long-range polarization potentials (V?-?/r4) between ions and neutrals result in large scattering cross sections at cold temperatures, making the hybrid trap a favorable system for efficient sympathetic cooling of ions by collisions with neutral atoms. We present experimental evidence of sympathetic cooling of trapped Na+ ions, which are closed shell and therefore do not have a laser-induced atomic transition from the ground state, by equal-mass cold Na atoms in a magneto-optical trap.

  13. Evolution of magnetism in the Na3-?(Na1-xMgx)Ir2O6 series of honeycomb iridates

    NASA Astrophysics Data System (ADS)

    Wallace, David C.; Brown, Craig M.; McQueen, Tyrel M.

    2015-04-01

    The structural and magnetic properties of a new series of iridium-based honeycomb lattices with the formula Na3-?(Na1-xMgx)Ir2O6(0 ? x ? 1) are reported. As x and ? are increased, the honeycomb lattice contracts and the strength of the antiferromagnetic interactions decreases systematically due to a reduction in Ir-O-Ir bond angles. Samples with imperfect stoichiometry exhibit disordered magnetic freezing at temperatures Tf between 3.4 K and 5 K. This glassy magnetism likely arises due to the presence of non-magnetic Ir3+, which are distributed randomly throughout the lattice, with a possible additional contribution from stacking faults. Together, these results demonstrate that chemical defects and non-stoichiometry have a significant effect on the magnetism of compounds in the A2IrO3 materials family.

  14. Search for solid conductors of Na/+/ and K/+/ ions - Five new conductors

    NASA Technical Reports Server (NTRS)

    Singer, J.; Kautz, H.; Fielder, W.; Fordyce, J.

    1975-01-01

    Five new conductors of positive Na and K ions, for use as separators in high energy secondary batteries, have been discovered. They include: (1) the pyrochlores NaTaWO6 and NaTa2O5F; (2) the bcc form of NaSbO3; and (3) the niobates 2Na2O-3Nb2O5 and 2K2O-3Nb2O5, with the alkali ions probably in open layers of the completely determined structure. On the basis of approximately 40 structure types, generalizations have been made regarding the relation between structure and ionic transport.

  15. Conductivity of aqueous HCl, NaOH and NaCl solutions: Is water just a substrate?

    NASA Astrophysics Data System (ADS)

    Artemov, V. G.; Volkov, A. A.; Sysoev, N. N.; Volkov, A. A.

    2015-01-01

    According to the Arrhenius theory, the ionic conductivity of aqueous electrolytes is realized by the electrolyte ions. Water is considered to be a chemically inactive environmental media. Here, we succeeded in modeling the ionic dc conductivity and dielectric constant of aqueous HCl, NaOH and NaCl solutions without considering Na+ and Cl- ions. Instead, we assumed that i) water has a high concentration of the intrinsic H3O+ and OH- ions (much larger than it is implied by p\\text{H}=7 ), masked in the dc conductivity by the electrophoretic effect, i.e. by a strong ion-ion attraction, and ii) the chemical interaction between the electrolyte molecules and the water ions happens to break down the electrophoretic effect, thus “activating” the water ions for the dc conductivity. The hypothesis about the active role of water in the conductivity of electrolytes may look controversial, but nevertheless it consistently accounts for a set of basic empirical data and is therefore worth examining.

  16. Threshold oxygen levels in Na(I) for the formation of NaCrO 2(s) on 18-8 stainless steels from accurate thermodynamic measurements

    NASA Astrophysics Data System (ADS)

    Sreedharan, O. M.; Madan, B. S.; Gnanamoorthy, J. B.

    1983-12-01

    The compound NaCrO 2(s) is an important corrosion product in sodium-cooled LMFBRs. The standard Gibbs energy of formation of NaCrO 2(s) is required for the computation of threshold oxygen levels in Na(1) for the formation of NaCrO 2(s) on 18-8 stainless steels. For this purpose the emf of the galvanic cell: Pt, NaCrO 2, Cr 2O 3, Na 2CrO 4/15 YSZ/O 2 ( P O 2 = 0.21 atm, air), Pt was measured over 784-1012 K to be: (E±4.4)(mV) = 483.67-0.34155 T(K). From this, the standard Gibbs energy of formation of NaCrO 2(s) from the elements ( ?G f,T0) and from the oxides ( ?G f,OX,T0) was calculated to be: [?G f,T0(NaCrO 2, s)±1.86] (kJ/mol) =-869.98 + 0.18575 T(K) , [?G f,OX,T0(NaCr0 2, s)±4.8] (kJ/mol) = -104.25-0.00856 T(K) . The molar heat capacity, C P0, of NaCrO 2(s) was measured by DSC to be (350-600 K): C P0(NaCrO 2, s) (J/K mol) = 27.15 + 0.1247 T (K) , From these data, values of -99.3 kJ/mol and 91.6 J/K mol were computed for ?H f,2980 and S 2980 of NaCrO 2(s). The internal consistency was checked with the use of enthalpy data on Na 2CrO 4(s). From the standard Gibbs energy of formation of NaCrO 2(s) the equation logC 0(wppm) = 3.9905-3147.6 T(K) was derived, where C 0 is the threshold oxygen level for the formation of NaCrO 2(s) on 18-8 stainless steels.

  17. Synthesis of Na2Mg3X2 (X = Sn, Pb) and Na4Mg4Sn3 and their crystal structures and thermoelectric properties

    NASA Astrophysics Data System (ADS)

    Yamada, Takahiro; Ishiyama, Ryo; Yamane, Hisanori

    2015-07-01

    Novel ternary stannides and a plumbide, Na2Mg3X2 (X = Sn, Pb) and Na4Mg4Sn3, were synthesized by heating the corresponding elements. The crystal structures were determined by single-crystal X-ray diffraction analysis, and the electrical conductivities and Seebeck coefficients were measured. The crystal structures of Na2Mg3X2 [orthorhombic, a = 7.3066(9) Å, b = 14.4559(13) Å, c = 6.6433(7) Å for X = Sn, a = 7.4272(11), b = 14.770(3), c = 6.6852(11) Å for X = Pb] are based on the Mg5Ga2-type structure (space group Ibam, Z = 4). Na4Mg4Sn3 crystallizes in an orthorhombic cell [a = 6.879(3) Å, b = 7.154(2) Å, c = 22.285(7) Å, space group Fmmm, Z = 4] with layers of disordered Na atom arrangement with defects. The electrical conductivities measured for the polycrystalline sintered samples of Na2Mg3Sn2, Na4Mg4Sn3, and Na2Mg3Pb2 were 1.9 × 105 S m-1 at 300 K, 1.6 × 105 S m-1 at 307 K and 3.3 × 105 S m-1 at 300 K, respectively. The Seebeck coefficients (S) of Na2Mg3Sn2, Na4Mg4Sn3, and Na2Mg3Pb2 were +47 to +72, +29 to +67, and +10 to +24 µV K-1, respectively, and increased with increasing temperature of 300-600 K.

  18. Preparation of zeolite NaA for CO2 capture from nickel laterite residue

    NASA Astrophysics Data System (ADS)

    Du, Tao; Liu, Li-ying; Xiao, Penny; Che, Shuai; Wang, He-ming

    2014-08-01

    Zeolite NaA was successfully prepared from nickel laterite residue for the first time via a fusion-hydrothermal procedure. The structure and morphology of the as-synthesized zeolite NaA were characterized with a range of experimental techniques, such as X-ray diffraction, scanning electronic microscopy, and infrared spectroscopy. It was revealed that the structures of the produced zeolites were dependent on the molar ratios of the reactants and hydrothermal reaction conditions, so the synthesis conditions were optimized to obtain pure zeolite NaA. Adsorption of nitrogen and carbon dioxide on the prepared zeolite NaA was also measured and analyzed. The results showed that zeolite NaA could be prepared with reasonable purity, it had physicochemical properties comparable with zeolite NaA made from other methods, and it had excellent gas adsorption properties, thus demonstrating that zeolite NaA could be prepared from nickel laterite residue.

  19. Ubiquitination Participates in the Lysosomal Degradation of Na,K-ATPase in Steady-State Conditions

    PubMed Central

    Lecuona, Emilia; Sun, Haiying; Vohwinkel, Christine; Ciechanover, Aaron; Sznajder, Jacob I.

    2009-01-01

    The alveolar epithelial cell (AEC) Na,K-ATPase contributes to vectorial Na+ transport and plays an important role in keeping the lungs free of edema. We determined, by cell surface labeling with biotin and immunofluorescence, that approximately 30% of total Na,K-ATPase is at the plasma membrane of AEC in steady-state conditions. The half-life of the plasma membrane Na,K-ATPase was about 4 hours, and the incorporation of new Na,K-ATPase to the plasma membrane was Brefeldin A sensitive. Both protein kinase C (PKC) inhibition with bisindolylmaleimide (10 ?M) and infection with an adenovirus expressing dominant-negative PKC? prevented Na,K-ATPase degradation. In cells expressing the Na,K-ATPase ?1-subunit lacking the PKC phosphorylation sites, the plasma membrane Na,K-ATPase had a moderate increase in half-life. We also found that the Na,K-ATPase was ubiquitinated in steady-state conditions and that proteasomal inhibitors prevented its degradation. Interestingly, mutation of the four lysines described to be necessary for ubiquitination and endocytosis of the Na,K-ATPase in injurious conditions did not have an effect on its half-life in steady-state conditions. Lysosomal inhibitors prevented Na,K-ATPase degradation, and co-localization of Na,K-ATPase and lysosomes was found after labeling and chasing the plasma membrane Na,K-ATPase for 4 hours. Accordingly, we provide evidence suggesting that phosphorylation and ubiquitination are necessary for the steady-state degradation of the plasma membrane Na,K-ATPase in the lysosomes in alveolar epithelial cells. PMID:19286978

  20. Characterization of NaCl tolerance in Desulfovibrio vulgaris Hildenborough through experimental evolution

    PubMed Central

    Zhou, Aifen; Baidoo, Edward; He, Zhili; Mukhopadhyay, Aindrila; Baumohl, Jason K; Benke, Peter; Joachimiak, Marcin P; Xie, Ming; Song, Rong; Arkin, Adam P; Hazen, Terry C; Keasling, Jay D; Wall, Judy D; Stahl, David A; Zhou, Jizhong

    2013-01-01

    Desulfovibrio vulgaris Hildenborough strains with significantly increased tolerance to NaCl were obtained via experimental evolution. A NaCl-evolved strain, ES9-11, isolated from a population cultured for 1200 generations in medium amended with 100?mM NaCl, showed better tolerance to NaCl than a control strain, EC3-10, cultured for 1200 generations in parallel but without NaCl amendment in medium. To understand the NaCl adaptation mechanism in ES9-11, we analyzed the transcriptional, metabolite and phospholipid fatty acid (PLFA) profiles of strain ES9-11 with 0, 100- or 250?mM-added NaCl in medium compared with the ancestral strain and EC3-10 as controls. In all the culture conditions, increased expressions of genes involved in amino-acid synthesis and transport, energy production, cation efflux and decreased expression of flagellar assembly genes were detected in ES9-11. Consistently, increased abundances of organic solutes and decreased cell motility were observed in ES9-11. Glutamate appears to be the most important osmoprotectant in D. vulgaris under NaCl stress, whereas, other organic solutes such as glutamine, glycine and glycine betaine might contribute to NaCl tolerance under low NaCl concentration only. Unsaturation indices of PLFA significantly increased in ES9-11. Branched unsaturated PLFAs i17:1 ?9c, a17:1 ?9c and branched saturated i15:0 might have important roles in maintaining proper membrane fluidity under NaCl stress. Taken together, these data suggest that the accumulation of osmolytes, increased membrane fluidity, decreased cell motility and possibly an increased exclusion of Na+ contribute to increased NaCl tolerance in NaCl-evolved D. vulgaris. PMID:23575373

  1. Na/sup +/-K/sup +/ pump in chronic renal failure

    SciTech Connect

    Deepak, K.; Kahn, T.

    1987-05-01

    This review summarizes the evidence for the defect in Na/sup +/-K/sup +/ pump in chronic renal failure, considers the role of various factors in causing this defect, and discusses the clinical implications thereof. Intracellular Na is elevated in erythrocytes, leukocytes, and muscle cells from some patients with chronic renal failure (CRF). Recent evidence suggest that this elevation of cell Na may be, in large part, a consequence of decreased number of Na/sup +/-K/sup +/ pump units per cell. Maintenance dialysis over a period of weeks ameliorates the defect in intracellular Na/sup +/, and this improvement is contemporaneous with an increase in the number of Na/sup +/-K/sup +/ pump sites per cell. In erythrocytes with normal cell Na/sup +/, acute hemodialysis increases the rate of /sup 22/Na/sup +/ and /sup 42/K/sup +/ transport. Many factors such as the presence of retained toxic metabolite or circulating inhibitor in the uremic plasma, or biochemical changes produced by acute hemodialysis, may explain this finding. In cells with high cell Na/sup +/, the pump-mediated /sup 42/K/sup +/ transport is normalized at the expense of a raised cell Na/sup +/. The decreased muscle membrane potential in uremic subjects has been attributed to a decreased activity of Na/sup +/-K/sup +/ pump. The authors discuss the role of hormonal abnormalities and circulating inhibitors, which may cause an acute inhibition of the pump and of other factors such as K/sup +/ depletion, which may cause more chronic alterations. The implications of alteration of Na/sup +/ and K/sup +/ pump transport and raised cell Na/sup +/ on other non-pump-mediated transport pathways are discussed. Raised cell Na/sup +/ may be a marker for the adequacy of maintenance dialysis in patients with end-stage renal failure.

  2. Na+/H+ Exchange Activity in the Plasma Membrane of Arabidopsis1

    PubMed Central

    Qiu, Quan-Sheng; Barkla, Bronwyn J.; Vera-Estrella, Rosario; Zhu, Jian-Kang; Schumaker, Karen S.

    2003-01-01

    In plants, Na+/H+ exchangers in the plasma membrane are critical for growth in high levels of salt, removing toxic Na+ from the cytoplasm by transport out of the cell. The molecular identity of a plasma membrane Na+/H+ exchanger in Arabidopsis (SOS1) has recently been determined. In this study, immunological analysis provided evidence that SOS1 localizes to the plasma membrane of leaves and roots. To characterize the transport activity of this protein, purified plasma membrane vesicles were isolated from leaves of Arabidopsis. Na+/H+ exchange activity, monitored as the ability of Na to dissipate an established pH gradient, was absent in plants grown without salt. However, exchange activity was induced when plants were grown in 250 mm NaCl and increased with prolonged salt exposure up to 8 d. H+-coupled exchange was specific for Na, because chloride salts of other monovalent cations did not dissipate the pH gradient. Na+/H+ exchange activity was dependent on Na (substrate) concentration, and kinetic analysis indicated that the affinity (apparent Km) of the transporter for Na+ is 22.8 mm. Data from two experimental approaches supports electroneutral exchange (one Na+ exchanged for one proton): (a) no change in membrane potential was measured during the exchange reaction, and (b) Na+/H+ exchange was unaffected by the presence or absence of a membrane potential. Results from this research provide a framework for future studies into the regulation of the plant plasma membrane Na+/H+ exchanger and its relative contribution to the maintenance of cellular Na+ homeostasis during plant growth in salt. PMID:12805632

  3. Analysis of exercise-induced Na+-K+ exchange in rat skeletal muscle in vivo.

    PubMed

    Murphy, K T; Nielsen, O B; Clausen, T

    2008-12-01

    We aimed to quantify the Na(+)-K(+) exchange occurring during exercise in rat skeletal muscle in vivo. Intracellular Na(+) and K(+) content, Na(+) permeability ((22)Na(+) influx), Na(+)-K(+) pump activity (ouabain-sensitive (86)Rb(+) uptake) and Na(+)-K(+) pump alpha(2) subunit content ([(3)H]ouabain binding) were measured. Six-week-old rats rested (control animals) or performed intermittent running for 10-60 min and were then killed or were killed at 15 or 90 min following 60 min exercise. In the soleus muscle, intracellular Na(+) was 80% higher than in control rats after 60 min exercise, was still elevated (38%) after 15 min rest and returned to control levels after 90 min rest. Intracellular K(+) showed corresponding decreases after 15-60 min exercise, returning to control levels 90 min postexercise. Exercise induced little change in Na(+) and K(+) in the extensor digitorum longus muscle (EDL). In soleus, the exercise-induced rise in Na(+) and reduction in K(+) were augmented by pretreatment with ouabain or by reducing the content of muscular Na(+)-K(+) pumps by prior K(+) depletion of the animals. Fifteen minutes after 60 min exercise, ouabain-sensitive (86)Rb(+) uptake in the soleus was increased by 30% but was unchanged in EDL, and there was no effect of exercise on [(3)H]ouabain binding measured in vitro or in vivo in either muscle. In conclusion, in the soleus, in vivo exercise induces a rise in intracellular Na(+), which reflects the excitation-induced increase in Na(+) influx and leads to augmented Na(+)-K(+) pump activity without apparent change in Na(+)-K(+) pump capacity. PMID:18586859

  4. Quantification of Na+,K+ pumps and their transport rate in skeletal muscle: Functional significance

    PubMed Central

    2013-01-01

    During excitation, muscle cells gain Na+ and lose K+, leading to a rise in extracellular K+ ([K+]o), depolarization, and loss of excitability. Recent studies support the idea that these events are important causes of muscle fatigue and that full use of the Na+,K+-ATPase (also known as the Na+,K+ pump) is often essential for adequate clearance of extracellular K+. As a result of their electrogenic action, Na+,K+ pumps also help reverse depolarization arising during excitation, hyperkalemia, and anoxia, or from cell damage resulting from exercise, rhabdomyolysis, or muscle diseases. The ability to evaluate Na+,K+-pump function and the capacity of the Na+,K+ pumps to fill these needs require quantification of the total content of Na+,K+ pumps in skeletal muscle. Inhibition of Na+,K+-pump activity, or a decrease in their content, reduces muscle contractility. Conversely, stimulation of the Na+,K+-pump transport rate or increasing the content of Na+,K+ pumps enhances muscle excitability and contractility. Measurements of [3H]ouabain binding to skeletal muscle in vivo or in vitro have enabled the reproducible quantification of the total content of Na+,K+ pumps in molar units in various animal species, and in both healthy people and individuals with various diseases. In contrast, measurements of 3-O-methylfluorescein phosphatase activity associated with the Na+,K+-ATPase may show inconsistent results. Measurements of Na+ and K+ fluxes in intact isolated muscles show that, after Na+ loading or intense excitation, all the Na+,K+ pumps are functional, allowing calculation of the maximum Na+,K+-pumping capacity, expressed in molar units/g muscle/min. The activity and content of Na+,K+ pumps are regulated by exercise, inactivity, K+ deficiency, fasting, age, and several hormones and pharmaceuticals. Studies on the ?-subunit isoforms of the Na+,K+-ATPase have detected a relative increase in their number in response to exercise and the glucocorticoid dexamethasone but have not involved their quantification in molar units. Determination of ATPase activity in homogenates and plasma membranes obtained from muscle has shown ouabain-suppressible stimulatory effects of Na+ and K+. PMID:24081980

  5. Tcnicas em Transies de Fase Mtodo do aglomerado variacional

    E-print Network

    Stariolo, Daniel Adrián

    é uma desigualdade, co- nhecida como desigualdade de Bogoliubov, que estabelece que a energia livre a energia livre de Helmholtz. Usando a identidade anterior e a desigualdade (1.2), podemos escrever: e-F e- H - ln (1.6) ou F F = H + kBT ln = Tr ( H) + kBT Tr ( ln ), (1.7) onde F é uma energia livre

  6. A double-tuned 1H/23Na dual resonator system for tissue sodium concentration measurements in the rat brain via Na-MRI

    NASA Astrophysics Data System (ADS)

    Wetterling, Friedrich; Tabbert, Martin; Junge, Sven; Gallagher, Lindsay; Mhairi Macrae, I.; Fagan, Andrew J.

    2010-12-01

    A method for quantifying the tissue sodium concentration (TSC) in the rat brain from 23Na-MR images was developed. TSC is known to change in a variety of common human diseases and holds considerable potential to contribute to their study; however, its accurate measurement in small laboratory animals has been hindered by the extremely low signal to noise ratio (SNR) in 23Na images. To address this, the design, construction and characterization of a double-tuned 1H/23Na dual resonator system for 1H-guided quantitative 23Na-MRI are described. This system comprises an SNR-optimized surface detector coil for 23Na image acquisition, and a volume resonator producing a highly homogeneous B1 field (<5% inhomogeneity) for the Na channel across the rat head. The resonators incorporated channel-independent balanced matching and tuning capabilities with active decoupling circuitry at the 23Na resonance frequency. A quantification accuracy of TSC of <10 mM was achieved in Na-images with 1.2 µl voxel resolution acquired in 10 min. The potential of the quantification technique was demonstrated in an in vivo experiment of a rat model of cerebral stroke, where the evolution of the TSC was successfully monitored for 8 h after the stroke was induced.

  7. Probabilistic models to describe the effect of NaNO2 in combination with NaCl on the growth inhibition of Lactobacillus in frankfurters.

    PubMed

    Lee, Soomin; Lee, Heeyoung; Kim, Sejeong; Lee, Jeeyeon; Ha, Jimyeong; Gwak, Eunji; Oh, Mi-Hwa; Park, Beom-Young; Kim, Jin-Seok; Choi, Kyoung-Hee; Yoon, Yohan

    2015-12-01

    Probabilistic models were developed to describe the antimicrobial effect of NaNO2 (0-210ppm) in combination with NaCl (0-1.75%) on Lactobacillus growth under aerobic and anaerobic conditions. Growth (1) or no growth (0) was assessed every 24h as turbid or not turbid, respectively. The growth response data were analyzed by logistic regression to select significant variables (P<0.05) for Lactobacillus growth inhibition, and these variables were used to generate a probabilistic model. The model was then validated with observed data from frankfurters (a model system). NaNO2 and NaCl inhibited (P<0.05) Lactobacillus growth at all temperatures under aerobic and anaerobic conditions, and the antimicrobial effect of NaNO2 increased as the NaCl concentration increased. Validation showed that the performance of the developed model was appropriate. These results indicate that the models developed in this study should be useful for describing the antimicrobial effect of NaNO2 in combination with NaCl on Lactobacillus. PMID:26410421

  8. Composition and evolution of the solid-electrolyte interphase in Na2Ti3O7 electrodes for Na-ion batteries: XPS and Auger parameter analysis.

    PubMed

    Muñoz-Márquez, Miguel A; Zarrabeitia, Maider; Castillo-Martínez, Elizabeth; Eguía-Barrio, Aitor; Rojo, Teófilo; Casas-Cabanas, Montse

    2015-04-15

    Na2Ti3O7 is considered a promising negative electrode for Na-ion batteries; however, poor capacity retention has been reported and the stability of the solid-electrolyte interphase (SEI) could be one of the main actors of this underperformance. The composition and evolution of the SEI in Na2Ti3O7 electrodes is hereby studied by means of X-ray photoelectron spectroscopy (XPS). To overcome typical XPS limitations in the photoelectron energy assignments, the analysis of the Auger parameter is here proposed for the first time in battery materials characterization. We have found that the electrode/electrolyte interface formed upon discharge, mostly composed by carbonates and semicarbonates (Na2CO3, NaCO3R), fluorides (NaF), chlorides (NaCl) and poly(ethylene oxide)s, is unstable upon electrochemical cycling. Additionally, solid state nuclear magnetic resonance (NMR) studies prove the reaction of the polyvinylidene difluoride (PVdF) binder with sodium. The powerful approach used in this work, namely Auger parameter study, enables us to correctly determine the composition of the electrode surface layer without any interference from surface charging or absolute binding energy calibration effects. As a result, the suitability for Na-ion batteries of binders and electrolytes widely used for Li-ion batteries is questioned here. PMID:25811538

  9. Measurements of the liquidus surface and solidus transitions of the NaCl-UCl3 and NaCl-UCl3-CeCl3 phase diagrams

    NASA Astrophysics Data System (ADS)

    Sooby, E. S.; Nelson, A. T.; White, J. T.; McIntyre, P. M.

    2015-11-01

    NaCl-UCl3-PuCl3 is proposed as the fuel salt for a number of molten salt reactor concepts. No experimental data exists for the ternary system, and limited data is available for the binary compositions of this salt system. Differential scanning calorimetry is used in this study to examine the liquidus surface and solidus transition of a surrogate fuel-salt (NaCl-UCl3-CeCl3) and to reinvestigate the NaCl-UCl3 eutectic phase diagram. The results of this study show good agreement with previously reported data for the pure salt compounds used (NaCl, UCl3, and CeCl3) as well as for the eutectic points for the NaCl-UCl3 and NaCl-CeCl3 binary systems. The NaCl-UCl3 liquidus surface produced in this study predicts a 30-40 °C increase on the NaCl-rich side of the binary phase diagram. The increase in liquidus temperature could prove significant to molten salt reactor modeling.

  10. Impact of surface roughness on the electrical parameters of industrial high efficiency NaOH-NaOCl textured multicrystalline silicon solar cell

    SciTech Connect

    Basu, P.K.; Pujahari, R.M.; Kaur, Harpreet; Singh, Devi; Varandani, D.; Mehta, B.R.

    2010-09-15

    Sodium hydroxide (NaOH) and sodium hypochlorite (NaOCl) solution (1:1 ratio by volume) based texturization process at 80-82 C is an easy, low cost and comparatively new and convenient option for fabrication of any multicrystalline silicon (mC-Si) solar cell. In the present study atomic force microscope is used to observe the intragrain surface in a miniscule area (3 {mu}m x 3 {mu}m) of NaOH-NaOCl textured surface by two and three dimensional analysis, roughness analysis and section analysis. The r.m.s value of the surface parameter of 7.0 nm ascertains the smoothness of the textured surface and further the surface reflectivity is minimized to 4-6% in the 500-1000 nm wavelength range by a proper silicon nitride anti-reflection coating. Comparing with the standard HF-HNO{sub 3}-CH{sub 3}COOH acid textured cell, the NaOH-NaOCl textured cell shows a comparatively lower value of series resistance of 7.17 m{omega}, higher value of shunt resistance of 18.4 {omega} to yield a fill factor of 0.766 leading to more than 15% cell efficiency in the industrial cell processing line. This AFM study yields different surface roughness parameters for the NaOH-NaOCl textured wafers which can be used as a reference standard for optimized texturing. (author)

  11. Red blood cell Na pump: Insights from species differences.

    PubMed

    Gatto, Craig; Milanick, Mark

    2009-01-01

    The red blood cell membrane is specialized to exchange chloride and bicarbonate; usually the pH gradient, the chloride ratio, and the membrane potential are tightly coupled. We review the evidence that led to the ability to separately vary inside and outside pH in red cells. The effect of pH on Na pump activity and on the selectivity of the inside and the outside transport sites is reviewed. In red blood cells, at high pH, the outside site is not selective. An increase in protons leads to an increase in K(+) affinity, thus making the site more selective. The pK for this site is different in rats and humans; because of the high conservation of residues in these two species, there are only a few possible residues that can account for this difference. On the inside, work from unsided preparations suggests that, at high pH, the transport site is highly selective for Na(+). Once again, an increase in protons leads to an increase in K(+) affinity, but now the result is a less selective site. During their maturation, reticulocytes lose many membrane proteins. The type and fractional loss is species dependent. For example, most reticulocytes lose most of their Na pumps, retaining about 100 pumps per cell, but animals from the order Carnivora lose all their pumps. We review some of the evidence that PKC phosphorylation of N-terminus serines is responsible for endocytosis in other cell types and species variation in this region. PMID:19268612

  12. Topological analysis of the Na+/H+ exchanger.

    PubMed

    Liu, Yongsheng; Basu, Arghya; Li, Xiuju; Fliegel, Larry

    2015-10-01

    The mammalian Na+/H+ exchanger isoform 1 (NHE1) is a ubiquitously expressed integral membrane protein present in mammalian cells. It is made up of a hydrophobic 500 amino acid membrane domain that transports and removes protons from within cells, and a regulatory intracellular cytosolic domain made of approximately 315 amino acids. Determining the structure of NHE1 is critical for both an understanding of the Na+/H+ exchange mechanism of transport, and in the design of new improved inhibitors for use in treatment of several diseases in which it is involved. Differing models of the NHE1 protein have been proposed. The first model suggested by two groups proposes that amino acids 1-500 form a 12 transmembrane segment spanning region in which amino acids 1-127 form two transmembrane segments, and amino acids 315-411 form a single transmembrane segment with membrane associated segments. A second model based on the structure of the Escherichia coli Na+/H+ exchanger protein proposes an overall similar topology, but suggests amino acids 1-127 are removed as a signal sequence and are not present in the mature protein. It also suggests a different topology of amino acids 315-411 to form three transmembrane segments. We used cysteine scanning accessibility and examination of glycosylation of the mature protein to characterize the NHE1 protein. Our results demonstrate that the model of NHE1 is correct which suggests that amino acids 1-127 form two transmembrane segments that remain connected to the mature protein, and the segment between amino acids 315-411 is one transmembrane segment. PMID:26215741

  13. Detailed investigation of Na2.24FePO4CO3 as a cathode material for Na-ion batteries

    PubMed Central

    Huang, Weifeng; Zhou, Jing; Li, Biao; Ma, Jin; Tao, Shi; Xia, Dingguo; Chu, Wangsheng; Wu, Ziyu

    2014-01-01

    Na-ion batteries are gaining an increased recognition as the next generation low cost energy storage devices. Here, we present a characterization of Na3FePO4CO3 nanoplates as a novel cathode material for sodium ion batteries. First-principles calculations reveal that there are two paths for Na ion migration along b and c axis. In-situ and ex-situ Fe K-edge X-ray absorption near edge structure (XANES) point out that in Na3FePO4CO3 both Fe2+/Fe3+ and Fe3+/Fe4+ redox couples are electrochemically active, suggesting also the existence of a two-electron intercalation reaction. Ex-situ X-ray powder diffraction data demonstrates that the crystalline structure of Na3FePO4CO3 remains stable during the charging/discharging process within the range 2.0–4.55?V. PMID:24595232

  14. Detailed investigation of Na2.24FePO4CO3 as a cathode material for Na-ion batteries

    NASA Astrophysics Data System (ADS)

    Huang, Weifeng; Zhou, Jing; Li, Biao; Ma, Jin; Tao, Shi; Xia, Dingguo; Chu, Wangsheng; Wu, Ziyu

    2014-03-01

    Na-ion batteries are gaining an increased recognition as the next generation low cost energy storage devices. Here, we present a characterization of Na3FePO4CO3 nanoplates as a novel cathode material for sodium ion batteries. First-principles calculations reveal that there are two paths for Na ion migration along b and c axis. In-situ and ex-situ Fe K-edge X-ray absorption near edge structure (XANES) point out that in Na3FePO4CO3 both Fe2+/Fe3+ and Fe3+/Fe4+ redox couples are electrochemically active, suggesting also the existence of a two-electron intercalation reaction. Ex-situ X-ray powder diffraction data demonstrates that the crystalline structure of Na3FePO4CO3 remains stable during the charging/discharging process within the range 2.0-4.55 V.

  15. Uptake and Loss of Na+, Rb+, and Cs+ in Relation to an Active Mechanism for Extrusion of Na+ in Scenedesmus 1

    PubMed Central

    Kylin, Anders

    1966-01-01

    The mechanism for extrusion of Na+ from Scenedesmus cells is characterized physiologically. It is stimulated by phosphate but oxygen is not necessary. Rb+ and Cs+ may also be extruded, but in the presence of Na+ they cannot compete for the sites on the inside of the transport system. When Na+ is extruded, Rb+ and, by inference, K+ seems to be transported as counter ion from the outside, and sodium ions compete only weakly for this external site. The parallelism between these findings and the Na+-K+-activated adenosine triphosphatases known from animal tissues is pointed out. With low additions of phosphate, the extrusion mechanism can keep the cells practically free from Na+. Increasing the concentrations of external phosphate stimulates uptake more than extrusion, and a net uptake occurs. As for Rb+ and Cs+, they are taken up in the absence of external phosphate, but additions of P will greatly enhance the amounts absorbed. Two different ways of uptake are indicated. PMID:5932402

  16. Hybrid functional study of the NASICON-type Na3V2(PO4)3: crystal and electronic structures, and polaron-Na vacancy complex diffusion.

    PubMed

    Bui, Kieu My; Dinh, Van An; Okada, Susumu; Ohno, Takahisa

    2015-11-11

    The crystal and electronic structures, electrochemical properties and diffusion mechanism of NASICON-type Na3V2(PO4)3 have been investigated based on the hybrid density functional Heyd-Scuseria-Ernzerhof (HSE06). A polaron-Na vacancy complex model for revealing the diffusion mechanism is proposed for the first time in the field of Na-ion batteries. The bound polaron is found to favorably form at the first nearest V site to the Na vacancy. Consequently, the movement of the Na vacancy will be accompanied by the polaron. Three preferable diffusion pathways are revealed; these are two intra-layer diffusion pathways and one inter-layer pathway. The activation barriers for the intra-layer and inter-layer pathways are 353 meV and 513 meV, respectively. For further comparison, the generalized gradient approximation with an onsite Coulomb Hubbard U (GGA+U) is also employed. PMID:26509737

  17. Precursor Routes to Complex Ternary Intermetallics: Single-Crystal and Microcrystalline Preparation of Clathrate-I Na8Al8Si38 from NaSi + NaAlSi.

    PubMed

    Dong, Yongkwan; Chai, Ping; Beekman, Matt; Zeng, Xiaoyu; Tritt, Terry M; Nolas, George S

    2015-06-01

    Single crystals of the ternary clathrate-I Na8Al8Si38 were synthesized by kinetically controlled thermal decomposition (KCTD), and microcrystalline Na8Al8Si38 was synthesized by spark plasma sintering (SPS) using a NaSi + NaAlSi mixture as the precursor. Na8AlxSi46-x compositions with x ? 8 were also synthesized by SPS from precursor mixtures of different ratios. The crystal structure of Na8Al8Si38 was investigated using both Rietveld and single-crystal refinements. Temperature-dependent transport and UV/vis measurements were employed in the characterization of Na8Al8Si38, with diffuse-reflectance measurement indicating an indirect optical gap of 0.64 eV. Our results indicate that, when more than one precursor is used, both SPS and KCTD are effective methods for the synthesis of multinary inorganic phases that are not easily accessible by traditional solid-state synthesis or crystal growth techniques. PMID:25985168

  18. The CERES/NA45 Radial Drift Time Projection Chamber

    E-print Network

    The CERES Collaboration

    2008-03-26

    The design, calibration, and performance of the first radial drift Time Projection Chamber (TPC) are presented. The TPC was built and installed at the CERES/NA45 experiment at the CERN SPS in the late nineties, with the objective to improve the momentum resolution of the spectrometer. The upgraded experiment took data twice, in 1999 and in 2000. After a detailed study of residual distortions a spatial resolution of 340 um in the azimuthal and 640 um in the radial direction was achieved, corresponding to a momentum resolution of Dp/p = sqrt{(1% * p/GeV)^2 + (2%)^2}.

  19. Digital pulse processing for NaI(Tl) detectors

    NASA Astrophysics Data System (ADS)

    Di Fulvio, A.; Shin, T. H.; Hamel, M. C.; Pozzi, S. A.

    2016-01-01

    We apply two different post-processing techniques to digital pulses induced by photons in a NaI(Tl) detector and compare the obtained energy resolution to the standard analog approach. Our digital acquisition approach is performed using a single-stage acquisition with a fast digitizer. Both the post-processing techniques we propose rely on signal integration. In the first, the pulse integral is calculated by directly numerically integrating the pulse digital samples, while in the second the pulse integral is estimated by a model-based fitting of the pulse. Our study used a 7.62 cm×7.62 cm cylindrical NaI(Tl) detector that gave a 7.60% energy resolution (at 662 keV), using the standard analog acquisition approach, based on a pulse shaping amplifier. The new direct numerical integration yielded a 6.52% energy resolution. The fitting approach yielded a 6.55% energy resolution, and, although computationally heavier than numerical integration, is preferable when only the early samples of the pulse are available. We also evaluated the timing performance of a fast-slow detection system, encompassing an EJ-309 and a NaI(Tl) scintillator. We use two techniques to determine the pulse start time: constant fraction discrimination (CFD) and adaptive noise threshold timing (ANT), for both the analog and digital acquisition approach. With the analog acquisition approach, we found a system time resolution of 5.8 ns and 7.3 ns, using the constant fraction discrimination and adaptive noise threshold timing, respectively. With the digital acquisition approach, a time resolution of 1.2 ns was achieved using the ANT method and 3.3 ns using CFD at 50% of the maximum, to select the pulse start time. The proposed direct digital readout and post-processing techniques can improve the application of NaI(Tl) detectors, traditionally considered 'slow', for fast counting and correlation measurements, while maintaining a good measurement of the energy resolution.

  20. Ferroelectricity in antiferroelectric NaNbO3 crystal.

    PubMed

    Tyunina, M; Dejneka, A; Rytz, D; Gregora, I; Borodavka, F; Vondracek, M; Honolka, J

    2014-03-26

    Sodium niobate (NaNbO3, or NNO) is known to be antiferroelectric at temperatures between 45 and 753 K. Here we show experimentally the presence of the ferroelectric phase at temperatures between 100 and 830 K in the NNO crystals obtained by top-seeded solution growth. The ferroelectric phase and new phase transitions are evidenced using a combination of thermo-optical studies by variable angle spectroscopic ellipsometry, Raman spectroscopy analysis, and photoelectron emission microscopy. The possibility for strain-induced ferroelectricity in NNO is suggested. PMID:24594846

  1. New NA48 Results on Kaon and Hyperon Decays

    E-print Network

    R. Wanke

    2006-10-22

    The NA48 Collaboration has obtained several new results on kaon and neutral hyperon decays. For hyperons we present new, very precise measurements on the Xi0 lifetime and the decay asymmetries of Xi0 -> Lamda gamma and Xi0 -> Sigma0 gamma. On kaon decays, we report on the first observation of the interference term between Inner Bremsstrahlung and Direct Emission in K+- -> pi+- pi0 gamma and on a new, accurate measurement of the form factor slopes in the semileptonic decay KL -> pi+- mu-+ nu.

  2. Slovaropisje klasi?nih jezikov na Slovenskem v 16. stoletju

    E-print Network

    Hriberšek, Matej

    2008-02-01

    - na v Bistri, ki po oceni Milka Kosa (1931: 71–73) izvira iz 14. do 15. stoletja. Vklju?uje ve? manjših latinskih vokabularjev in nekaj odlomkov o latinski slovnici.3 Najobsežnejši je prvi vokabular v kodeksu, ki obsega 40 strani (f. 103–122’) in je... obseg besedja in 1 Signatura: Narodna knjižnica sv. Marka, Mss. latini Vl. 6, No 59; manoscritti marciani 2548. 2 Rokopis slovarja hranijo v Gradcu (Ms 988). 3 Za natan?nejšo predstavitev kodeksa in v njem ohranjenega gradiva gl. Gantar 1970. —??79...

  3. Analysis of Defects Induced Melting in NaCl Crystal

    NASA Astrophysics Data System (ADS)

    Chauhan, R. S.; Snehlata, K.; Singh, C. P.

    2011-07-01

    In the present work we study the pressure dependence of melting of NaCl crystal. Values of pressure derivatives of melting temperature have been calculated at elevated pressures to determine the rate of change of melting temperature with the increase in pressure using the data on vacancy formation energy aqnd effective volume of Schottky defects. The melting curves have also been obtained and found to compare well with the results based on the molecular dynamics simulation and experimental data reported in the recent literature.

  4. Enhanced Infrared Surveillance Imaging Report for NA-22

    SciTech Connect

    Carrano, C J

    2005-10-04

    The purpose of this report is to describe our work on enhanced infrared (IR) surveillance using speckle imaging for NA-22. Speckle imaging in this context is an image post-processing algorithm that aims to solve the atmospheric blurring problem of imaging through horizontal or slant path turbulence. We will describe the IR imaging systems used in our data collections and show imagery before and after speckle processing. We will also compare IR imagery with visible wavelength imagery of the same target in the same conditions and demonstrate how going to longer wavelengths can be beneficial in the presence of strong turbulence.

  5. Observation of {sup 19}Na states by inelastic scattering

    SciTech Connect

    Pellegriti, M. G.; Angulo, C.; Casarejos, E.; Couder, M.; Achouri, N. L.; Angelique, J. C.; Orr, N. A.; Berthoumieux, E.; Descouvemont, P.; Ray, I.; Stefan, I. G.

    2007-11-30

    The low-energy levels of {sup 19}Na were studied in the center-of-mass energy (E{sub CM}) range from 2.6 to 3.4 MeV, by using the elastic and inelastic scattering methods in inverse kinematics. The {sup 18}Ne+p scattering reactions, leading to the ground state and the first excited state of {sup 18}Ne, were investigated by using a 66 MeV radioactive {sup 18}Ne beam and a polyethylene (CH{sub 2}){sub n} target. The experimental methods and the set-up are described and preliminary results are presented.

  6. Analysis of Cl and Na in Hyperimmune Sera by NAA

    NASA Astrophysics Data System (ADS)

    Baptista, T. S.; Zamboni, C. B.; Marcelino, J. R.

    2011-08-01

    The Cl and Na concentration values in four types of hyperimmune sera (anti-Bothrops, anti-Diphtheria, anti-Rabies and anti-Tetanus) used for immunological therapy were determined using Neutron Activation Analysis (NAA). These data were compatible with the specifications established by the Word Health Organization (WHO-OMS) and with the Brazilian Official Pharmacopea (Pharmaceutical Code Official of the Country). These data are an important support for quality control of hyperimmune sera production at Butantan Institute (São Paulo city, Brazil), responsible for supplying the Brazilian market.

  7. Fluorescence spectra of the NaI molecule

    NASA Astrophysics Data System (ADS)

    Ragone, Anthony S.; Levy, Donald H.; Berry, R. Stephen

    1982-10-01

    The fluorescence excitation spectrum and fluorescence emission spectra of sodium iodide vapor are reported for the first time. The emission spectrum contains a v = 0 progression and v = 1 progression of a transition of the NaI molecule, as well as many other bands due to other species. The spectrum is taken from a seeded hypersonic nozzle beam excited by a tunable laser. A vibrational analysis is given, part of the upper state potential is constructed, and the results are related to photodissociation studies.

  8. Purification of Na,K-ATPase from Pig Kidney.

    PubMed

    Fedosova, Natalya U

    2016-01-01

    The method of purification of Na,K-ATPase from pig kidney is based on a differential centrifugation and SDS-treatment of a microsomal preparation. The yield is 0.4 mg protein per 1 g tissue with the specific (ouabain-sensitive) activity of 25-28 ?mol Pi/min per mg protein and nucleotide binding capacity of 3 nmol/mg. The protein/lipid ratio is 1/1 (mg/mg) with a protein purity of ~80 %. PMID:26695017

  9. Reconstitution of Na(+),K(+)-ATPase in Nanodiscs.

    PubMed

    Gregersen, Jonas Lindholt; Fedosova, Natalya U; Nissen, Poul; Boesen, Thomas

    2016-01-01

    Nanodiscs are disc-shaped self-assembled lipid bilayers encircled by membrane scaffolding proteins derived from Apolipoprotein A-1 (apo A-1). They constitute a versatile tool for studying membrane proteins since reconstitution into nanodiscs allows studies of the membrane proteins in detergent-free aqueous solutions in a lipid bilayer. Here, we apply the technique to the Na(+),K(+)-ATPase (NKA) from pig kidney using Membrane Scaffolding Protein 1 D1 (MSP1D1). Contrary to other reports, the nanodiscs obtained by our protocol are built up of the native lipids originally present in the detergent solubilized sample together with the NKA. PMID:26695051

  10. Cell Degradation of a Na-NiCl2 (ZEBRA) Battery

    SciTech Connect

    Li, Guosheng; Lu, Xiaochuan; Kim, Jin Yong; Lemmon, John P.; Sprenkle, Vincent L.

    2013-11-01

    In this work, the parameters influencing the degradation of a Na-NiCl2 (ZEBRA) battery were investigated. Planar Na-NiCl2 cells using ?”-alumina solid electrolyte (BASE) were tested with different C-rates, Ni/NaCl ratios, and capacity windows, in order to identify the key parameters for the degradation of Na-NiCl2 battery. The morphology of NaCl and Ni particles were extensively investigated after 60 cycles under various test conditions using a scanning electron microscope. A strong correlation between the particle size (NaCl and Ni) and battery degradation was observed in this work. Even though the growth of both Ni and NaCl can influence the cell degradation, our results indicate that the growth of NaCl is a dominant factor in cell degradation. The use of excess Ni seems to play a role in tolerating the negative effects of particle growth on degradation since the available active surface area of Ni particles can be still sufficient even after particle growth. For NaCl, a large cycling window was the most significant factor, of which effects were amplified with decrease in Ni/NaCl ratio.

  11. Morphological, Physiological, and Structural Responses of Two Species of Artemisia to NaCl Stress

    PubMed Central

    Guan, Zhi-Yong; Su, Yi-Ji; Teng, Nian-Jun; Chen, Su-Mei; Sun, Hai-Nan; Li, Chu-Ling; Chen, Fa-Di

    2013-01-01

    Effects of salt stress on Artemisia scoparia and A. vulgaris “Variegate” were examined. A. scoparia leaves became withered under NaCl treatment, whereas A. vulgaris “Variegate” leaves were not remarkably affected. Chlorophyll content decreased in both species, with a higher reduction in A. scoparia. Contents of proline, MDA, soluble carbohydrate, and Na+ increased in both species under salt stress, but A. vulgaris “Variegate” had higher level of proline and soluble carbohydrate and lower level of MDA and Na+. The ratios of K+/Na+, Ca2+/Na+, and Mg2+/Na+ in A. vulgaris “Variegate” under NaCl stress were higher. Moreover, A. vulgaris “Variegate” had higher transport selectivity of K+/Na+ from root to stem, stem to middle mature leaves, and upper newly developed leaves than A. scoparia under NaCl stress. A. vulgaris “Variegate” chloroplast maintained its morphological integrity under NaCl stress, whereas A. scoparia chloroplast lost integrity. The results indicated that A. scoparia is more sensitive to salt stress than A. vulgaris “Variegate.” Salt tolerance is mainly related to the ability of regulating osmotic pressure through the accumulation of soluble carbohydrates and proline, and the gradient distribution of K+ between roots and leaves was also contributed to osmotic pressure adjustment and improvement of plant salt tolerance. PMID:24235883

  12. Na-doped hydroxyapatite coating on carbon/carbon composites: Preparation, in vitro bioactivity and biocompatibility

    NASA Astrophysics Data System (ADS)

    Li, Hejun; Zhao, Xueni; Cao, Sheng; Li, Kezhi; Chen, Mengdi; Xu, Zhanwei; Lu, Jinhua; Zhang, Leilei

    2012-12-01

    Na-doped hydroxyapatite (Na-HA) coating was directly prepared onto carbon/carbon (C/C) composites using electrochemical deposition (ECD) and the mean thickness of the coating is approximately 10 ± 2 ?m. The formed Na-HA crystals which are Ca-deficient, are rod-like with a hexagonal cross section. The Na/P molar ratios of the coating formed on C/C substrate is 0.097. During the deposition, the Na-HA crystals grow in both radial and longitudinal directions, and faster along the longitudinal direction. The pattern formation of crystal growth leads to dense coating which would help to increase the bonding strength of the coating. The average shear bonding strength of Na-HA coating on C/C is 5.55 ± 0.77 MPa. The in vitro bioactivity of the Na-HA coated C/C composites were investigated by soaking the samples in a simulated body fluid (SBF) for 14 days. The results indicate that the Na-HA coated C/C composites can rapidly induce bone-like apatite nucleation and growth on its surface in SBF. The in vitro cellular biocompatibility tests reveal that the Na-HA coating was better to improve the in vitro biocompatibility of C/C composites compared with hydroxyapatite (HA) coating. It was suggested that the Na-HA coating might be an effective method to improve the surface bioactivity and biocompatibility of C/C composites.

  13. Regulation of Electroneutral NaCl Absorption by the Small Intestine

    PubMed Central

    Kato, Akira; Romero, Michael F.

    2014-01-01

    Na+ and Cl? movement across the intestinal epithelium occurs by several interconnected mechanisms: (1) nutrient coupled Na+ absorption; (2) electroneutral NaCl absorption; (3) electrogenic Cl? secretion by CFTR; and (4) electrogenic Na+ absorption by ENaC. All of these transport modes require a favorable electrochemical gradient maintained by the basolateral Na+-K+-ATPase, a Cl? channel and K+ channels. Electroneutral NaCl absorption is observed from the small intestine to distal colon. This transport is mediated by apical Na+/H+ (NHE2/3) and Cl?/HCO3 ? (Slc26a3/a6, others) exchangers that provide the major route of NaCl absorption. Electroneutral NaCl absorption and Cl? secretion by CFTR are oppositely regulated by the autonomic nerve system, immune system, and endocrine system via PKA?, PKC?, cGKII, and/or SGK1. This integrated regulation requires the formation of macromolecular complexes, which mediated by NHERF family of scaffold proteins, and involve internalization of NHE3. Using knockout mice and human mutations, a more detailed understanding of the integrated as well as subtle regulation of electroneutral NaCl absorption by the mammalian intestine has emerged. PMID:21054167

  14. Crystal and electronic structures of nitridophosphate compounds as cathode materials for Na-ion batteries

    NASA Astrophysics Data System (ADS)

    Debbichi, M.; Lebègue, S.

    2015-08-01

    Using density-functional theory, we have studied the electronic and magnetic properties of two promising compounds that can be used as cathode materials, namely, Na2Fe2P3O9N and Na3TiP3O9N . When Na is extracted, we found the volume change to be quite small, with values of ˜-0.6 % for Na3TiP3O9N and -5 % for Na2Fe2P3O9N . Our calculated voltages with the Hubbard-type correction (GGA+U) approximation are 2.93 V for Na3TiP3O9N /Na2TiP3O9N and 2.68 V for Na2Fe2P3O9N /NaFe2P3O9N , in good agreement with the experimental data. Our results confirm that these compounds are very promising for rechargeable Na-ion batteries.

  15. Formation of titanate nanostructures under different NaOH concentration and their application in wastewater treatment

    SciTech Connect

    Huang Jiquan; Cao Yongge; Deng Zhonghua; Tong Hao

    2011-03-15

    The effects of the concentration of NaOH on the formation and transformation of various titanate nanostructures were studied. With increasing NaOH concentration, three different formation mechanisms were proposed. Nanotubes can only be obtained under moderate NaOH conditions, and should transform into nanowires with prolonged hydrothermal treatment, and their formation rate is accelerated by increasing NaOH concentration. Low concentration of NaOH results in the direct formation of nanowires, while extra high concentration of NaOH leads to the formation of amorphous nanoparticles. Adsorption and photocatalysis studies show that titanate nanowires and nanotubes might be potential adsorbents for the removal of both heavy metal ions and dyes and photocatalysts for the removal of dyes from wastewater. -- Graphical abstract: The morphologies of the titanates depend deeply on the concentration of NaOH. With increasing NaOH concentration, three different formation mechanisms were proposed. The application of these titanate nanostructures in the wastewater treatment was studied. Display Omitted Research highlights: {yields} Effect of NaOH concentration on the structures of various titanates was reported. {yields} Three different formation mechanisms were presented with increasing NaOH concentration. {yields} Various titanates were used as adsorbents/photocatalysts in wastewater treatment.

  16. Fabrication and formation studies on single-walled CA/NaCS-WSC microcapsules.

    PubMed

    Wu, Qing-Xi; Lin, Dong-Qiang; Yao, Shan-Jing

    2016-02-01

    The micron-sized calcium alginate/sodium cellulose sulfate-water soluble chitosan (CA/NaCS-WSC) microcapsules were prepared by membrane emulsification method using sodium alginate (NaAlg), NaCS and WSC as raw materials. The CA/NaCS microspheres prepared dispersed well and held spherical shape with an emulsifier volume ratio of 7:3 (Span 80:Tween 80) and a concentration of cross-linking agent of 1.5% (w/v) calcium chloride and 5% (w/v) sodium chloride. The CA/NaCS-WSC microcapsules had a spherical shape with average diameter of 62.36±13.87?m. A fluorescent ring could be seen obviously on the surface of CA/NaCS-WSC microcapsules under confocal microscope, when WSC was labeled by fluorescein isothiocyanate. The discussion on the formation studies implied that Ca(2+) could diffuse into the droplets of NaAlg/NaCS forming CA/NaCS microspheres, while NaCS could react with WSC forming a polyelectrolyte complexes film. The microcapsules prepared with typical wall-capsule/core structure could be used to develop micron-sized drug delivery carriers. PMID:26652447

  17. Pressure solution compaction of sodium chlorate and implications for pressure solution in NaCl

    NASA Astrophysics Data System (ADS)

    den Brok, Bas; Zahid, Mohsine; Passchier, Cees W.

    1999-06-01

    Sodium chloride (NaCl) has been extensively used as a material to develop, test and improve pressure solution (PS) rock deformation models. However, unlike silicate and carbonate rocks, NaCl can deform plastically at very low stresses (˜0.5 MPa). This could mean that NaCl is less suitable for use as an analogue for rocks that do not deform plastically at conditions where PS is important. In order to test the reliability of NaCl as a rock analogue, we carried out a series of uniaxial compaction experiments on sodium chlorate (NaClO 3) at room pressure and temperature (P-T) conditions and applied effective stresses of 2.4 and 5.0 Mpa. NaClO 3 is a very soluble, elastic-brittle salt, that cannot be deformed plastically at room P-T conditions. The results were compared with experiments on NaCl at similar conditions and show that NaClO 3 behaves in a strikingly similar way to NaCl, despite its brittleness. Like NaCl, it most likely compacts by a grain boundary diffusion controlled PS mechanism. Mechanical data were fitted to a power law in the form: ???? -?? nd -m (with volumetric strain rate ??, volumetric strain ?, effective stress ? and grain size d). A reasonable fit was obtained, with ?=2 to 4, n=1.6±0.5, and m=2.8±0.5. The similarity in mechanical behaviour of the two materials (NaCl plastic, NaClO 3 brittle) suggests that plasticity does not play a key role in PS compaction deformation of NaCl. This means that its plasticity is not a drawback for its use as a PS analogue for rocks or for deriving PS creep laws for salt from compaction experiments.

  18. Linking salinity stress tolerance with tissue-specific Na+ sequestration in wheat roots

    PubMed Central

    Wu, Honghong; Shabala, Lana; Liu, Xiaohui; Azzarello, Elisa; Zhou, Meixue; Pandolfi, Camilla; Chen, Zhong-Hua; Bose, Jayakumar; Mancuso, Stefano; Shabala, Sergey

    2015-01-01

    Salinity stress tolerance is a physiologically complex trait that is conferred by the large array of interacting mechanisms. Among these, vacuolar Na+ sequestration has always been considered as one of the key components differentiating between sensitive and tolerant species and genotypes. However, vacuolar Na+ sequestration has been rarely considered in the context of the tissue-specific expression and regulation of appropriate transporters contributing to Na+ removal from the cytosol. In this work, six bread wheat varieties contrasting in their salinity tolerance (three tolerant and three sensitive) were used to understand the essentiality of vacuolar Na+ sequestration between functionally different root tissues, and link it with the overall salinity stress tolerance in this species. Roots of 4-day old wheat seedlings were treated with 100 mM NaCl for 3 days, and then Na+ distribution between cytosol and vacuole was quantified by CoroNa Green fluorescent dye imaging. Our major observations were as follows: (1) salinity stress tolerance correlated positively with vacuolar Na+ sequestration ability in the mature root zone but not in the root apex; (2) contrary to expectations, cytosolic Na+ levels in root meristem were significantly higher in salt tolerant than sensitive group, while vacuolar Na+ levels showed an opposite trend. These results are interpreted as meristem cells playing a role of the “salt sensor;” (3) no significant difference in the vacuolar Na+ sequestration ability was found between sensitive and tolerant groups in either transition or elongation zones; (4) the overall Na+ accumulation was highest in the elongation zone, suggesting its role in osmotic adjustment and turgor maintenance required to drive root expansion growth. Overall, the reported results suggest high tissue-specificity of Na+ uptake, signaling, and sequestration in wheat roots. The implications of these findings for plant breeding for salinity stress tolerance are discussed. PMID:25750644

  19. Na 2O solubility in CaO-MgO-SiO 2 melts

    NASA Astrophysics Data System (ADS)

    Mathieu, R.; Libourel, G.; Deloule, E.; Tissandier, L.; Rapin, C.; Podor, R.

    2011-01-01

    The sodium solubility in silicate melts in the CaO-MgO-SiO 2 (CMS) system at 1400 °C has been measured by using a closed thermochemical reactor designed to control alkali metal activity. In this reactor, Na (g) evaporation from a Na 2O- xSiO 2 melt imposes an alkali metal vapor pressure in equilibrium with the molten silicate samples. Because of equilibrium conditions in the reactor, the activity of sodium-metal oxide in the molten samples is the same as that of the source, i.e., aNa 2O (sample) = aNa 2O (source). This design also allows to determine the sodium oxide activity coefficient in the samples. Thirty-three different CMS compositions were studied. The results show that the amount of sodium entering from the gas phase (i.e., Na 2O solubility) is strongly sensitive to silica content of the melt and, to a lesser extent, the relative amounts of CaO and MgO. Despite the large range of tested melt compositions (0 < CaO and MgO < 40; 40 < SiO 2 < 100; in wt%), we found that Na 2O solubility is conveniently modeled as a linear function of the optical basicity ( ?) calculated on a Na-free basis melt composition. In our experiments, ?Na 2O (sample) ranges from 7 × 10 -7 to 5 × 10 -6, indicating a strongly non-ideal behavior of Na 2O solubility in the studied CMS melts (?Na 2O (sample) ? 1). In addition to showing the effect of sodium on phase relationships in the CMS system, this Na 2O solubility study brings valuable new constraints on how melt structure controls the solubility of Na in the CMS silicate melts. Our results suggest that Na 2O addition causes depolymerization of the melt by preferential breaking of Si-O-Si bonds of the most polymerized tetrahedral sites, mainly Q 4.

  20. Dissociation energy of the ground state of NaH

    SciTech Connect

    Huang, Hsien-Yu; Lu, Tsai-Lien; Whang, Thou-Jen; Chang, Yung-Yung; Tsai, Chin-Chun

    2010-07-28

    The dissociation energy of the ground state of NaH was determined by analyzing the observed near dissociation rovibrational levels. These levels were reached by stimulated emission pumping and fluorescence depletion spectroscopy. A total of 114 rovibrational levels in the ranges 9{<=}v{sup ''}{<=}21 and 1{<=}J{sup ''}{<=}14 were assigned to the X {sup 1}{Sigma}{sup +} state of NaH. The highest vibrational level observed was only about 40 cm{sup -1} from the dissociation limit in the ground state. One quasibound state, above the dissociation limit and confined by the centrifugal barrier, was observed. Determining the vibrational quantum number at dissociation v{sub D} from the highest four vibrational levels yielded the dissociation energy D{sub e}=15 815{+-}5 cm{sup -1}. Based on new observations and available data, a set of Dunham coefficients and the rotationless Rydberg-Klein-Rees curve were constructed. The effective potential curve and the quasibound states were discussed.

  1. Microstructural characterization of catalyzed NaAlH{sub 4}

    SciTech Connect

    Thomas, G.J.; Gross, K.J.; Yang, N.Y.C.; Jensen, C.

    2000-10-01

    A number of laboratories have now demonstrated that catalyst-assisted NaAlH{sub 4} can reversibly absorb and desorb hydrogen in the solid state at moderate temperatures. An understanding of the mechanisms by which bulk decomposition and reformation of the compound can occur in the presence of a surface catalyst is important to improving the kinetic and thermodynamic properties of alanates for use in hydrogen storage applications. Using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), the authors have examined the microstructure and elemental composition of Na alanate samples, doped using a liquid Ti/Zr catalyst precursor, for a number of conditions. First, microscopy and compositional analyses were performed at different stages of the decomposition process within the first desorption cycle. Second, the material was characterized after multiple absorption/desorption cycles (5 cycles). Finally, the effects of the catalyst doping procedure on particle size, surface morphology and surface composition were examined. Significant changes in particle morphology and in elemental distribution were found to be induced by the desorption and cycling processes. Importantly, the measurements indicate that the initial dehydriding reactions were accompanied by significant enhancement of Al concentration toward the surface of particles and that elemental segregation occurred with repeated absorption/desorption cycles.

  2. Inhibition of renal Na+, K+-adenosine triphosphatase by gentamicin

    SciTech Connect

    Williams, P.D.; Trimble, M.E.; Crespo, L.; Holohan, P.D.; Freedman, J.C.; Ross, C.R.

    1984-11-01

    Inhibition of renal Na+,K+-adenosine triphosphatase is an early biochemical manifestation of gentamicin treatment in rats. Studies with isolated, perfused rat kidneys in filtering and nonfiltering modes indicate that gentamicin is transported across the brush border membrane before enzyme inhibition. The drug caused enzyme inhibition (42%) only in filtering kidneys, and this inhibition was blocked by spermine, an inhibitor of gentamicin binding. In purified rat renal basolateral membranes, bound (/sup 3/H)gentamicin was displaced 88% by unlabeled gentamicin. After in vivo exposure to (/sup 3/H)gentamicin, the radioactivity associated with the isolated basolateral membranes was displaced only 46% by unlabeled drug. These results suggest that inhibition of renal Na+,K+-adenosine triphosphatase by gentamicin is probably due to an interaction at the cytoplasmic face of the basolateral membrane. Scatchard plots of (/sup 3/H)gentamicin binding to basolateral and brush border membranes revealed a single class of noninteracting sites in each membrane. Gentamicin did not change the bulk membrane lipid fluidity, as estimated by the fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene.

  3. Correction of the Caulobacter crescentus NA1000 Genome Annotation

    PubMed Central

    Ely, Bert; Scott, LaTia Etheredge

    2014-01-01

    Bacterial genome annotations are accumulating rapidly in the GenBank database and the use of automated annotation technologies to create these annotations has become the norm. However, these automated methods commonly result in a small, but significant percentage of genome annotation errors. To improve accuracy and reliability, we analyzed the Caulobacter crescentus NA1000 genome utilizing computer programs Artemis and MICheck to manually examine the third codon position GC content, alignment to a third codon position GC frame plot peak, and matches in the GenBank database. We identified 11 new genes, modified the start site of 113 genes, and changed the reading frame of 38 genes that had been incorrectly annotated. Furthermore, our manual method of identifying protein-coding genes allowed us to remove 112 non-coding regions that had been designated as coding regions. The improved NA1000 genome annotation resulted in a reduction in the use of rare codons since noncoding regions with atypical codon usage were removed from the annotation and 49 new coding regions were added to the annotation. Thus, a more accurate codon usage table was generated as well. These results demonstrate that a comparison of the location of peaks third codon position GC content to the location of protein coding regions could be used to verify the annotation of any genome that has a GC content that is greater than 60%. PMID:24621776

  4. Covering surface nanobubbles with a NaCl nanoblanket.

    PubMed

    Berkelaar, Robin P; Zandvliet, Harold J W; Lohse, Detlef

    2013-09-10

    By letting a NaCl aqueous solution of low (0.01 M) concentration evaporate on a highly oriented pyrolytic graphite (HOPG) surface, it is possible to form a thin film of salt. However, pre-existing surface nanobubbles prevent the homogeneous coverage of the surface with the salt, keeping the footprint areas on the substrate pristine. Comparing the surface nanobubbles in the salt solution with their associated footprint after drying, provides information on the shrinkage of nanobubbles during the hours-long process of drying the liquid film. At a slightly higher NaCl concentration and thus salt layer thickness, the nanobubbles are covered with a thin blanket of salt. Once the liquid film has evaporated until a water film remains that is smaller than the height of the nanobubbles, the blanket of salt cracks and unfolds into a flower-like pattern of salt flakes that is located at the rim of the nanobubble footprint. The formation of a blanket of salt covering the nanobubbles is likely to considerably or even completely block the gas out-flux from the nanobubble, partially stabilizing the nanobubbles against dissolution. PMID:23937683

  5. MINOS Calibration and NA49 Hadronic Production Studies

    SciTech Connect

    Morse, Robert James

    2003-08-01

    An overview of the current status of the Main Injector Neutrino Oscillation Search (MINOS) is presented. MINOS is a long-baseline experiment with two detectors situated in North America. The near detector is based at the emission point of the NuMI beam at Fermilab, Chicago, the far detector is 735 km downstream in a disused iron mine in Soudan, Minnesota. A third detector, the calibration detector, is used to cross-calibrate these detectors by sampling different particle beams at CERN. A detailed description of the design and construction of the light-injection calibration system is included. Also presented are experimental investigations into proton-carbon collisions at 158 GeV/c carried out with the NA49 experiment at CERN. The NA49 experiment is a Time Projection Chamber (TPC) based experiment situated at CERN's North Area. It is a well established experiment with well known characteristics. The data gained from this investigation are to be used to parameterize various hadronic production processes in accelerator and atmospheric neutrino production. These hadronic production parameters will be used to improve the neutrino generation models used in calculating the neutrino oscillation parameters in MINOS.

  6. Phosphorylation and ubiquitination are necessary for Na,K-ATPase endocytosis during hypoxia

    PubMed Central

    Dada, Laura A.; Welch, Lynn C.; Zhou, Guofei; Ben-Saadon, Ronen; Ciechanover, Aaron; Sznajder, Jacob I.

    2007-01-01

    As a cellular adaptative response, hypoxia decreases Na,K-ATPase activity by triggering the endocytosis of its ?1 subunit in alveolar epithelial cells. Here, we present evidence that the ubiquitin conjugating system is important in the Na,K-ATPase endocytosis during hypoxia and ubiquitination of Na,K-ATPase ?1 subunit occurs at the basolateral membrane. Endocytosis and ubiquitination were prevented when the Ser 18 in the PKC phosphorylation motif of the Na,K-ATPase ?1 subunit was mutated to an alanine, suggesting that phosphorylation at Ser-18 is required for ubiquitination. Mutation of the four lysines surrounding Ser 18 to arginine prevented Na,K-ATPase ubiquitination and endocytosis during hypoxia; however, only one of them was sufficient to restore hypoxia-induced endocytosis. We provide evidence that ubiquitination plays an important role in cellular adaptation to hypoxia by regulating Na,K-ATPase ?1-subunit endocytosis. PMID:17532187

  7. On the formation of Na nanoparticles in femtosecond-laser irradiated glasses

    SciTech Connect

    Jiang Nan; Su Dong; Spence, John C. H.; Qiu Jianrong

    2010-03-15

    This work discusses the response of Na to both high-energy electrons and femtosecond-laser (fs-laser) pulses in the soda-lime glass. The evidence for different responses of Na to high-energy electron irradiation between glasses with and without fs-laser irradiation suggests that the chemical and/or physical states of Na in the fs-laser irradiated glass are different from those in the original glass. Fs-laser pulses in the glass may be able to neutralize Na, which may form clusters. These results suggest that close attention should be paid to the defects associated with Na when optical or physical data are interpreted in fs-laser irradiated Na glasses.

  8. Mechanism of potassium ion uptake by the Na(+)/K(+)-ATPase.

    PubMed

    Castillo, Juan P; Rui, Huan; Basilio, Daniel; Das, Avisek; Roux, Benoît; Latorre, Ramon; Bezanilla, Francisco; Holmgren, Miguel

    2015-01-01

    The Na(+)/K(+)-ATPase restores sodium (Na(+)) and potassium (K(+)) electrochemical gradients dissipated by action potentials and ion-coupled transport processes. As ions are transported, they become transiently trapped between intracellular and extracellular gates. Once the external gate opens, three Na(+) ions are released, followed by the binding and occlusion of two K(+) ions. While the mechanisms of Na(+) release have been well characterized by the study of transient Na(+) currents, smaller and faster transient currents mediated by external K(+) have been more difficult to study. Here we show that external K(+) ions travelling to their binding sites sense only a small fraction of the electric field as they rapidly and simultaneously become occluded. Consistent with these results, molecular dynamics simulations of a pump model show a wide water-filled access channel connecting the binding site to the external solution. These results suggest a mechanism of K(+) gating different from that of Na(+) occlusion. PMID:26205423

  9. NaSrCo2F7, a Co(2+) pyrochlore antiferromagnet.

    PubMed

    Krizan, J W; Cava, R J

    2015-07-29

    We report the crystal growth, by the Bridgeman-Stockbarger method, and the basic magnetic properties of a new cobalt-based pyrochlore, NaSrCo2F7. Single-crystal structure determination shows that Na and Sr are completely disordered on the non-magnetic large atom A sites, while magnetic [Formula: see text] Co(2+) fully occupies the pyrochlore lattice B sites. NaSrCo2F7 displays strong antiferromagnetic interactions ([Formula: see text]), a large effective moment ([Formula: see text]), and no spin freezing until 3?K. Thus, NaSrCo2F7 is a geometrically frustrated antiferromagnet with a frustration index [Formula: see text]. Ac susceptibility, dc susceptibility, and heat capacity are utilized to characterize the spin freezing. We argue that NaSrCo2F7 and the related material NaCaCo2F7 are examples of frustrated pyrochlore antiferromagnets with weak bond disorder. PMID:26154596

  10. Mechanism of potassium ion uptake by the Na+/K+-ATPase

    PubMed Central

    Castillo, Juan P.; Rui, Huan; Basilio, Daniel; Das, Avisek; Roux, Benoît; Latorre, Ramon; Bezanilla, Francisco; Holmgren, Miguel

    2015-01-01

    The Na+/K+-ATPase restores sodium (Na+) and potassium (K+) electrochemical gradients dissipated by action potentials and ion-coupled transport processes. As ions are transported, they become transiently trapped between intracellular and extracellular gates. Once the external gate opens, three Na+ ions are released, followed by the binding and occlusion of two K+ ions. While the mechanisms of Na+ release have been well characterized by the study of transient Na+ currents, smaller and faster transient currents mediated by external K+ have been more difficult to study. Here we show that external K+ ions travelling to their binding sites sense only a small fraction of the electric field as they rapidly and simultaneously become occluded. Consistent with these results, molecular dynamics simulations of a pump model show a wide water-filled access channel connecting the binding site to the external solution. These results suggest a mechanism of K+ gating different from that of Na+ occlusion. PMID:26205423

  11. Formation of Frustrated Lewis Pairs in Ptx -Loaded Zeolite?NaY.

    PubMed

    Lee, Heeju; Choi, Yong Nam; Lim, Dae-Woon; Rahman, Md Mahbubur; Kim, Yong-Il; Cho, In Hwa; Kang, Hyun Wook; Seo, Jung-Hye; Jeon, Cheolho; Yoon, Kyung Byung

    2015-10-26

    The formation of a frustrated Lewis pair consisting of sodium hydride (Na(+) H(-) ) and a framework-bound hydroxy proton O(H(+) ) is reported upon H2 treatment of zeolite?NaY loaded with Pt nanoparticles (Ptx /NaY). Frustrated Lewis pair formation was confirmed using in?situ neutron diffraction and spectroscopic measurements. The activity of the intrazeolite NaH as a size-selective catalyst was verified by the efficient esterification of acetaldehyde (a small aldehyde) to form the corresponding ester ethyl acetate, whereas esterification of the larger molecule benzaldehyde was unsuccessful. The frustrated Lewis pair (consisting of Na(+) H(-) and O(H(+) )) generated within zeolite?NaY may be a useful catalyst for various catalytic reactions which require both H(-) and H(+) ions, such as catalytic hydrogenation or dehydrogenation of organic compounds and activation of small molecules. PMID:26480339

  12. Phosphorylation of the catalytic subunit of Na+,K(+)-ATPase inhibits the activity of the enzyme.

    PubMed

    Bertorello, A M; Aperia, A; Walaas, S I; Nairn, A C; Greengard, P

    1991-12-15

    We have examined two distinct protein kinases, cAMP-dependent protein kinase and protein kinase C, for their ability to phosphorylate and regulate the activity of three different types of Na+,K(+)-ATPase preparation. cAMP-dependent protein kinase phosphorylated purified shark rectal gland Na+,K(+)-ATPase to a stoichiometry of approximately 1 mol of phosphate per mol of alpha subunit. Protein kinase C phosphorylated purified shark rectal gland Na+,K(+)-ATPase to a stoichiometry of approximately 2 mol of phosphate per mol of alpha subunit. The phosphorylation by each of the kinases was associated with an inhibition of Na+,K(+)-ATPase activity of about 40-50%. These two protein kinases also inhibited the activity of a partially purified preparation of Na+,K(+)-ATPase from rat renal cortex and the activity of Na+,K(+)-ATPase present in preparations of basolateral membrane vesicles from rat renal cortex. PMID:1662394

  13. Mechanism of potassium ion uptake by the Na+/K+-ATPase

    NASA Astrophysics Data System (ADS)

    Castillo, Juan P.; Rui, Huan; Basilio, Daniel; Das, Avisek; Roux, Benoît; Latorre, Ramon; Bezanilla, Francisco; Holmgren, Miguel

    2015-07-01

    The Na+/K+-ATPase restores sodium (Na+) and potassium (K+) electrochemical gradients dissipated by action potentials and ion-coupled transport processes. As ions are transported, they become transiently trapped between intracellular and extracellular gates. Once the external gate opens, three Na+ ions are released, followed by the binding and occlusion of two K+ ions. While the mechanisms of Na+ release have been well characterized by the study of transient Na+ currents, smaller and faster transient currents mediated by external K+ have been more difficult to study. Here we show that external K+ ions travelling to their binding sites sense only a small fraction of the electric field as they rapidly and simultaneously become occluded. Consistent with these results, molecular dynamics simulations of a pump model show a wide water-filled access channel connecting the binding site to the external solution. These results suggest a mechanism of K+ gating different from that of Na+ occlusion.

  14. Photoemission study of the electronic structure and charge density waves of Na?Ti?Sb?O

    DOE PAGESBeta

    Tan, S. Y.; Jiang, J.; Ye, Z. R.; Niu, X. H.; Song, Y.; Zhang, C. L.; Dai, P. C.; Xie, B. P.; Lai, X. C.; Feng, D. L.

    2015-04-30

    The electronic structure of Na?Ti?Sb?O single crystal is studied by photon energy and polarization dependent angle-resolved photoemission spectroscopy (ARPES). The obtained band structure and Fermi surface agree well with the band structure calculation of Na?Ti?Sb?O in the non-magnetic state, which indicates that there is no magnetic order in Na?Ti?Sb?O and the electronic correlation is weak. Polarization dependent ARPES results suggest the multi-band and multi-orbital nature of Na?Ti?Sb?O. Photon energy dependent ARPES results suggest that the electronic structure of Na?Ti?Sb?O is rather two-dimensional. Moreover, we find a density wave energy gap forms below the transition temperature and reaches 65 meV atmore »7 K, indicating that Na?Ti?Sb?O is likely a weakly correlated CDW material in the strong electron-phonon interaction regime. (author)« less

  15. Growth responses and ion accumulation in the halophytic legume Prosopis strombulifera are determined by Na2 SO4 and NaCl.

    PubMed

    Reginato, M; Sosa, L; Llanes, A; Hampp, E; Vettorazzi, N; Reinoso, H; Luna, V

    2014-01-01

    Halophytes are potential gene sources for genetic manipulation of economically important crop species. This study addresses the physiological responses of a widespread halophyte, Prosopis strombulifera (Lam.) Benth to salinity. We hypothesised that increasing concentrations of the two major salts present in soils of central Argentina (Na2 SO4 , NaCl, or their iso-osmotic mixture) would produce distinct physiological responses. We used hydroponically grown P. strombulifera to test this hypothesis, analysing growth parameters, water relations, photosynthetic pigments, cations and anions. These plants showed a halophytic response to NaCl, but strong general inhibition of growth in response to iso-osmotic solutions containing Na2 SO4 . The explanation for the adaptive success of P. strombulifera in high NaCl conditions seems to be related to a delicate balance between Na(+) accumulation (and its use for osmotic adjustment) and efficient compartmentalisation in vacuoles, the ability of the whole plant to ensure sufficient K(+) supply by maintaining high K(+) /Na(+) discrimination, and maintenance of normal Ca(2+) levels in leaves. The three salt treatments had different effects on the accumulation of ions. Findings in bi-saline-treated plants were of particular interest, where most of the physiological parameters studied showed partial alleviation of SO4 (2-) -induced toxicity by Cl(-) . Thus, discussions on physiological responses to salinity could be further expanded in a way that more closely mimics natural salt environments. PMID:23869994

  16. Effects of NaBF4 + NaF on the Tensile and Impact Properties of Al-Si-Mg-Fe Alloys

    NASA Astrophysics Data System (ADS)

    Chen, Zongning; Wang, Tongmin; Zhao, Yufei; Zheng, Yuanping; Kang, Huijun

    2015-05-01

    NaBF4 + NaF were found to play three roles, i.e., Fe-eliminator, grain refiner, and eutectic modifier, in treating A356 alloy with a high Fe content. The joint effects led to significant improvement in both tensile and impact properties of thus treated alloy. The multiple reactions between the NaBF4 + NaF and Al-Si-Mg-Fe system are suggested to form Fe2B, AlB2, and Na in the melt, as per thermodynamic analysis. The three are responsible for Fe removal, grain refinement, and eutectic modification, respectively. When NaBF4 and NaF are mixed in weight ratio of 1:1, an optimum addition rate is in the range between 1.0 and 2.0 wt pct for treating AlSi7Mg0.3Fe0.65 alloy, based on the results of tensile and impact tests. Excessive addition of the salt may deteriorate the mechanical properties of the alloy, basically owing to overmodification of Si and contamination of salt inclusions.

  17. Na8Au9.8(4)Ga7.2 and Na17Au15.87(2)Ga46.63: The diversity of pseudo 5-fold 0 Cross Mark symmetries in the Na-Au-Ga system

    SciTech Connect

    Smetana, Volodymyr; Corbett, John D.; Miller, Gordon J.

    2013-08-29

    The Na-rich part (similar to 30% Na) of the Na-Au-Ga system between NaAu2, NaGa4, and Na(22)Ga39 has been found to contain the ternary phases NasAug(8)(4)Ga-7.2 (I) and NavAu(5.87(2))Ga46.63 (II), according to the results of single crystal X-ray diffraction measurements. I is orthorhombic, Cmcm, a= 5.3040(1), b=24.519(5), c=14.573(3) A, and contains a network of clusters with local 5-fold symmetry along the a-axis. Such clusters are frequent building units in decagonal quasicrystals and their approximants. II is rhombohedral, a =16.325(2), c=35.242(7) A, and contains building blocks that are structurally. identical to the Bergman-type clusters as well as fused icosahedral units known with active metals, triels and late transition elements. II also contains a polycationic network with elements of the clathrate V type structure. Tight-binding electronic structure calculations using linear muffin-tin-orbital (LMTO) methods on idealized models of I and II indicate that both compounds are metallic with evident pseudogaps at the corresponding Fermi levels. The overall Hamilton bond populations are generally dominated by Au-Ga and Au-Au bonds in I and by Ga-Ga bonds in II; moreover, the Na-Au and Na-Ga contributions in I are unexpectedly large, 20% of the total. A similar involvement of sodium in covalent bonding has also been found in the electron-richer i-Nai(3)Aui(2)Gai(5) quasicrystal approximant. (C) 2013 Elsevier Inc. All rights reserved.

  18. Complexation of pectin with macro- and microelements. Antianemic activity of Na, Fe and Na, Ca, Fe complexes.

    PubMed

    Minzanova, S T; Mironov, V F; Vyshtakalyuk, A B; Tsepaeva, O V; Mironova, L G; Mindubaev, A Z; Nizameev, I R; Kholin, K V; Milyukov, V A

    2015-12-10

    New water-soluble pectin complexes with Ca(2+), Mg(2+), Co(2+), Cu(2+), Fe(2+), Mn(2+), Zn(2+) on the basis of pectin biopolymer have been synthesized and successfully tested on white rats. For a starting, we have obtained a sodium pectate to enhance solubility of target complexes as a whole. Shortly afterwards, running the reaction of ligand exchange of N?(+) ions with corresponding s-, d- metal cations we were able to synthesize new pectin complexes. The ranges of s-, d-metals salts concentrations were detected experimentally, in which the selective formation of water-soluble complexes occurred. Antianemic effect of new pectin complexes with Na, Fe and Na, Ca, Fe was investigated on white rats with posthemorrhagic anemia. Under the effect of complexes, the improvement of animals and prevention of erythropoiesis disorders were observed. Antianemic effect of the complexes manifested itself in the doses equivalent to 25% or 50% of the iron daily rate, recommended in the treatment of iron-deficiency anemia with the drugs based on iron sulphate. PMID:26428154

  19. Above threshold dissociation of LiNa +: monitoring an avoided crossing with femtosecond spectroscopy

    NASA Astrophysics Data System (ADS)

    Magnier, S.; Toniolo, A.

    2001-04-01

    Computer simulations of one- and two-color experiments in above threshold dissociation (ATD) are reported for the first heteronuclear alkali ion LiNa +. We focus on the 1 2? +?1 2??4,5 2? + process, with dissociation to Li ++Na(3p) or Li(3s)+Na +. The product yields are determined by the presence of an avoided crossing between the 4 and 5 2? + potential curves, according to the frequency and delay of the second laser pulse.

  20. Regulation of Na+-K+-ATPase activity in kidney proximal tubules: involvement of GTP binding proteins.

    PubMed

    Bertorello, A; Aperia, A

    1989-01-01

    This study evaluates the involvement of GTP-dependent regulatory proteins (G-proteins) in the regulation of Na+-K+-ATPase activity in proximal convoluted tubule (PCT) segments. Single PCT segments were dissected from rat kidney and permeabilized to allow nucleotides and medium free access to the interior of the cell. A GDP analogue that blocks GTP-dependent activation of the G-protein, GDP beta S (400 microM) significantly inhibited PCT Na+-K+-ATPase activity when Na in the medium (Nam) was greater than or equal to 70 mM. The inhibition was attenuated when Nam was 55 and 35 mM and was no longer significant when Nam was 25 mM. GDP beta S had no inhibitory effect on the activity of purified Na+-K+-ATPase. A nonhydrolyzable GTP analogue, GppNHp (50 microM) significantly increased Na+-K+-ATPase activity when Nam was 25 and 35 mM, but not when Nam was 55-140 mM. Dopamine (DA) and DA1 plus DA2 agonists significantly inhibit Na+-K+-ATPase activity. DA inhibition was competitively abolished by GppNHp. In PCT segments from rats pretreated with pertussis toxin, DA and DA1 plus DA2 agonist inhibition of Na+-K+-ATPase activity was abolished. In PCT segments from rats pretreated with cholera toxin, basal Na+-K+-ATPase activity was increased, but DA significantly inhibited Na+-K+-ATPase activity. Na+-K+-ATPase activity in PCT segments is regulated via a G-protein that stimulates Na+-K+-ATPase activity and a DA-activated pertussis toxin-sensitive G-protein that inhibits Na+-K+-ATPase activity.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2563204

  1. Effect of salt stress on growth, Na+ accumulation and proline metabolism in potato (Solanum tuberosum) cultivars.

    PubMed

    Jaarsma, Rinse; de Vries, Rozemarijn S M; de Boer, Albertus H

    2013-01-01

    Potato (Solanum tuberosum) is a major crop world-wide and the productivity of currently used cultivars is strongly reduced at high soil salt levels. We compared the response of six potato cultivars to increased root NaCl concentrations. Cuttings were grown hydroponically and treated with 0 mM, 60 mM and 180 mM NaCl for one week. Growth reduction on salt was strongest for the cultivars Mozart and Mona Lisa with a severe senescence response at 180 mM NaCl and Mozart barely survived the treatment. The cultivars Desiree and Russett Burbank were more tolerant showing no senescence after salt treatment. A clear difference in Na(+) homeostasis was observed between sensitive and tolerant cultivars. The salt sensitive cultivar Mozart combined low Na(+) levels in root and stem with the highest leaf Na(+) concentration of all cultivars, resulting in a high Na(+) shoot distribution index (SDI) for Mozart as compared to Desiree. Overall, a positive correlation between salt tolerance and stem Na(+) accumulation was found and the SDI for Na(+) points to a role of stem Na(+) accumulation in tolerance. In stem tissue, Mozart accumulated more H2O2 and less proline compared to the tolerant cultivars. Analysis of the expression of proline biosynthesis genes in Mozart and Desiree showed a clear reduction in proline dehydrogenase (PDH) expression in both cultivars and an increase in pyrroline-5-carboxylate synthetase 1 (P5CS1) gene expression in Desiree, but not in Mozart. Taken together, current day commercial cultivars show promising differences in salt tolerance and the results suggest that mechanisms of tolerance reside in the capacity of Na(+) accumulation in stem tissue, resulting in reduced Na(+) transport to the leaves. PMID:23533673

  2. Bulk and track etch properties of CR-39 SSNTD etched in NaOH/ethanol

    E-print Network

    Yu, Peter K.N.

    Bulk and track etch properties of CR-39 SSNTD etched in NaOH/ethanol K.F. Chan, F.M.F. Ng, D. described the use of NaOH/ethanol as an etchant for the CR-39 detector, and have determined the corre and track etch properties of CR- 39 in NaOH/ethanol were derived from direct measurements. The bulk etch

  3. Effects of Na on the electrical and structural properties of CuInSe2

    NASA Astrophysics Data System (ADS)

    Wei, Su-Huai; Zhang, S. B.; Zunger, Alex

    1999-05-01

    We found theoretically that Na has three effects on CuInSe2: (1) If available in stoichiometric quantities, Na will replace Cu, forming a more stable NaInSe2 compound having a larger band gap (higher open-circuit voltage) and a (112)tetra morphology. The ensuing alloy NaxCu1-xInSe2 has, however, a positive mixing enthalpy, so NaInSe2 will phase separate, forming precipitates. (2) When available in small quantities, Na will form defect on Cu site and In site. Na on Cu site does not create electric levels in the band gap, while Na on In site creates acceptor levels that are shallower than CuIn. The formation energy of Na(InCu) is very exothermic, therefore, the major effect of Na is the elimination of the InCu defects and the resulting increase of the effective hole densities. The quenching of InCu as well as VCu by Na reduces the stability of the (2VCu-+InCu2+), thus suppressing the formation of the "Ordered Defect Compounds." (3) Na on the surface of CuInSe2 is known to catalyze the dissociation of O2 into atomic oxygen that substitutes Se vacancy (shallow donors), converting them into OSe. We find, however, that OSe is an (isovalent) deep rather than shallow acceptor. We also find that having removed the donors, O atoms in CuInSe2 form Cu2O and In2O3 compounds, and phase separate, forming precipitates at the surfaces and grain boundaries. Our results are compared with previous models and provide new insights into the defect physics of Na in CIS.

  4. WIMPs search by exclusive measurements with thin multilayer NaI(Tl) scintillators (PICO-LON)

    E-print Network

    K. Fushimi; H. Kawasuso; K. Yasuda; Y. Kameda; N. Koori; S. Nakayama; K. Ichihara; M. Nomachi; S. Umehara; R. Hazama; S. Yoshida; H. Ejiri; K. Imagawa; H. Ito

    2006-12-01

    The WIMPs search project PICO-LON has been started with multilayer thin NaI(Tl) crystals. The thin (0.05cm) and wide area (5cmx5cm) NaI(Tl) crystals was successfully developed. The performances of thin NaI(Tl) scintillator was measured and they showed good energy resolution (20% at 60keV) and good position resolution (20% in 5cmx5cm wider area).

  5. Daytime operation of Na temperature lidar using a dispersive Faraday vapor filter

    SciTech Connect

    Chen, H.; White, M.; Krueger, D.A.; She, C.Y.

    1996-12-31

    A novel ultra-narrow Na Faraday vapor filter was developed and is in use with the Na temperature lidar system for daytime measurements of the atmospheric temperature near the mesopause. The first 34 hour continuous observation was carried out from 1 pm, Oct. 10 to 11 pm Oct. 12, 1995, terminated by clouds. Signal to background ratio at high noon was about 15 at Na D2a peak frequency.

  6. Optimization of NaOH Molarity, LUSI Mud/Alkaline Activator, and Na2SiO3/NaOH Ratio to Produce Lightweight Aggregate-Based Geopolymer

    PubMed Central

    Abdul Razak, Rafiza; Abdullah, Mohd Mustafa Al Bakri; Hussin, Kamarudin; Ismail, Khairul Nizar; Hardjito, Djwantoro; Yahya, Zarina

    2015-01-01

    This paper presents the mechanical function and characterization of an artificial lightweight geopolymer aggregate (ALGA) using LUSI (Sidoarjo mud) and alkaline activator as source materials. LUSI stands for LU-Lumpur and SI-Sidoarjo, meaning mud from Sidoarjo which erupted near the Banjarpanji-1 exploration well in Sidoarjo, East Java, Indonesia on 27 May 2006. The effect of NaOH molarity, LUSI mud/Alkaline activator (LM/AA) ratio, and Na2SiO3/NaOH ratio to the ALGA are investigated at a sintering temperature of 950 °C. The results show that the optimum NaOH molarity found in this study is 12 M due to the highest strength (lowest AIV value) of 15.79% with lower water absorption and specific gravity. The optimum LUSI mud/Alkaline activator (LM/AA) ratio of 1.7 and the Na2SiO3/NaOH ratio of 0.4 gives the highest strength with AIV value of 15.42% with specific gravity of 1.10 g/cm3 and water absorption of 4.7%. The major synthesized crystalline phases were identified as sodalite, quartz and albite. Scanning Electron Microscope (SEM) image showed more complete geopolymer matrix which contributes to highest strength of ALGA produced. PMID:26006238

  7. Optimization of NaOH Molarity, LUSI Mud/Alkaline Activator, and Na2SiO3/NaOH Ratio to Produce Lightweight Aggregate-Based Geopolymer.

    PubMed

    Razak, Rafiza Abdul; Abdullah, Mohd Mustafa Al Bakri; Hussin, Kamarudin; Ismail, Khairul Nizar; Hardjito, Djwantoro; Yahya, Zarina

    2015-01-01

    This paper presents the mechanical function and characterization of an artificial lightweight geopolymer aggregate (ALGA) using LUSI (Sidoarjo mud) and alkaline activator as source materials. LUSI stands for LU-Lumpur and SI-Sidoarjo, meaning mud from Sidoarjo which erupted near the Banjarpanji-1 exploration well in Sidoarjo, East Java, Indonesia on 27 May 2006. The effect of NaOH molarity, LUSI mud/Alkaline activator (LM/AA) ratio, and Na2SiO3/NaOH ratio to the ALGA are investigated at a sintering temperature of 950 °C. The results show that the optimum NaOH molarity found in this study is 12 M due to the highest strength (lowest AIV value) of 15.79% with lower water absorption and specific gravity. The optimum LUSI mud/Alkaline activator (LM/AA) ratio of 1.7 and the Na2SiO3/NaOH ratio of 0.4 gives the highest strength with AIV value of 15.42% with specific gravity of 1.10 g/cm3 and water absorption of 4.7%. The major synthesized crystalline phases were identified as sodalite, quartz and albite. Scanning Electron Microscope (SEM) image showed more complete geopolymer matrix which contributes to highest strength of ALGA produced. PMID:26006238

  8. Collisional transfer of population and orientation in NaK.

    PubMed

    Wolfe, C M; Ashman, S; Bai, J; Beser, B; Ahmed, E H; Lyyra, A M; Huennekens, J

    2011-05-01

    Collisional satellite lines with |?J| ? 58 have been identified in recent polarization spectroscopy V-type optical-optical double resonance (OODR) excitation spectra of the Rb(2) molecule [H. Salami et al., Phys. Rev. A 80, 022515 (2009)]. Observation of these satellite lines clearly requires a transfer of population from the rotational level directly excited by the pump laser to a neighboring level in a collision of the molecule with an atomic perturber. However to be observed in polarization spectroscopy, the collision must also partially preserve the angular momentum orientation, which is at least somewhat surprising given the extremely large values of ?J that were observed. In the present work, we used the two-step OODR fluorescence and polarization spectroscopy techniques to obtain quantitative information on the transfer of population and orientation in rotationally inelastic collisions of the NaK molecules prepared in the 2(A)(1)?(+)(v' = 16, J' = 30) rovibrational level with argon and potassium perturbers. A rate equation model was used to study the intensities of these satellite lines as a function of argon pressure and heat pipe oven temperature, in order to separate the collisional effects of argon and potassium atoms. Using a fit of this rate equation model to the data, we found that collisions of NaK molecules with potassium atoms are more likely to transfer population and destroy orientation than collisions with argon atoms. Collisions with argon atoms show a strong propensity for population transfer with ?J = even. Conversely, collisions with potassium atoms do not show this ?J = even propensity, but do show a propensity for ?J = positive compared to ?J = negative, for this particular initial state. The density matrix equations of motion have also been solved numerically in order to test the approximations used in the rate equation model and to calculate fluorescence and polarization spectroscopy line shapes. In addition, we have measured rate coefficients for broadening of NaK 3(1)? ? 2(A)(1)?(+)spectral lines due to collisions with argon and potassium atoms. Additional broadening, due to velocity changes occurring in rotationally inelastic collisions, has also been observed. PMID:21548681

  9. Collisional transfer of population and orientation in NaK

    NASA Astrophysics Data System (ADS)

    Wolfe, C. M.; Ashman, S.; Bai, J.; Beser, B.; Ahmed, E. H.; Lyyra, A. M.; Huennekens, J.

    2011-05-01

    Collisional satellite lines with |?J| ? 58 have been identified in recent polarization spectroscopy V-type optical-optical double resonance (OODR) excitation spectra of the Rb2 molecule [H. Salami et al., Phys. Rev. A 80, 022515 (2009)]. Observation of these satellite lines clearly requires a transfer of population from the rotational level directly excited by the pump laser to a neighboring level in a collision of the molecule with an atomic perturber. However to be observed in polarization spectroscopy, the collision must also partially preserve the angular momentum orientation, which is at least somewhat surprising given the extremely large values of ?J that were observed. In the present work, we used the two-step OODR fluorescence and polarization spectroscopy techniques to obtain quantitative information on the transfer of population and orientation in rotationally inelastic collisions of the NaK molecules prepared in the 2(A)1?+(v' = 16, J' = 30) rovibrational level with argon and potassium perturbers. A rate equation model was used to study the intensities of these satellite lines as a function of argon pressure and heat pipe oven temperature, in order to separate the collisional effects of argon and potassium atoms. Using a fit of this rate equation model to the data, we found that collisions of NaK molecules with potassium atoms are more likely to transfer population and destroy orientation than collisions with argon atoms. Collisions with argon atoms show a strong propensity for population transfer with ?J = even. Conversely, collisions with potassium atoms do not show this ?J = even propensity, but do show a propensity for ?J = positive compared to ?J = negative, for this particular initial state. The density matrix equations of motion have also been solved numerically in order to test the approximations used in the rate equation model and to calculate fluorescence and polarization spectroscopy line shapes. In addition, we have measured rate coefficients for broadening of NaK 31? ? 2(A)1?+spectral lines due to collisions with argon and potassium atoms. Additional broadening, due to velocity changes occurring in rotationally inelastic collisions, has also been observed.

  10. Influence of NaA Zeolite Crystal Expansion/Contraction on Zeolite Membrane Separations

    SciTech Connect

    Sorenson, Stephanie G; Payzant, E Andrew; Gibbons, Will T; Soydas, Belma; Kita, Hidetoshi; Noble, Richard D; Falconer, John L.

    2011-01-01

    In-situ powder XRD measurements showed that the NaA zeolite unit cell contracts and expands upon adsorption, and these changes in zeolite crystal size correlate with permeation changes through NaA zeolite membranes. These membranes had high pervaporation selectivities, even though gas permeation was mainly through defects, as indicated by Knudsen selectivities for gases. At 300 K and a thermodynamic activity of 0.03, water contracted the NaA crystals by 0.22 vol%, and this contraction increased the helium flux through two NaA membranes by approximately 80%. Crystal contraction also increased the fluxes of i-butane during vapor permeation and i-propanol (IPA) during pervaporation (~ 0.03 wt% water). At activities above 0.07, water expanded NaA crystals and correspondingly decreased the membrane fluxes of helium, i-butane, and IPA. Similarly, methanol contracted NaA crystals by 0.05 vol% at an activity of 0.02, and this contraction slightly increased the helium and i-butane fluxes through a NaA membrane. Above an activity of 0.06, methanol expanded the crystals, and the fluxes of helium and i-butane through a NaA membrane decreased. The adsorbate-induced changes explain some pervaporation behavior reported by others, and they indicate that crystal expansion and contraction may increase or decrease zeolite NaA membrane selectivity by changing the defect sizes.

  11. CRMP2 protein SUMOylation modulates NaV1.7 channel trafficking.

    PubMed

    Dustrude, Erik T; Wilson, Sarah M; Ju, Weina; Xiao, Yucheng; Khanna, Rajesh

    2013-08-23

    Voltage-gated sodium channel (NaV) trafficking is incompletely understood. Post-translational modifications of NaVs and/or auxiliary subunits and protein-protein interactions have been posited as NaV-trafficking mechanisms. Here, we tested if modification of the axonal collapsin response mediator protein 2 (CRMP2) by a small ubiquitin-like modifier (SUMO) could affect NaV trafficking; CRMP2 alters the extent of NaV slow inactivation conferred by the anti-epileptic (R)-lacosamide, implying NaV-CRMP2 functional coupling. Expression of a CRMP2 SUMOylation-incompetent mutant (CRMP2-K374A) in neuronal model catecholamine A differentiated (CAD) cells did not alter lacosamide-induced NaV slow inactivation compared with CAD cells expressing wild type CRMP2. Like wild type CRMP2, CRMP2-K374A expressed robustly in CAD cells. Neurite outgrowth, a canonical CRMP2 function, was moderately reduced by the mutation but was still significantly higher than enhanced GFP-transfected cortical neurons. Notably, huwentoxin-IV-sensitive NaV1.7 currents, which predominate in CAD cells, were significantly reduced in CAD cells expressing CRMP2-K374A. Increasing deSUMOylation with sentrin/SUMO-specific protease SENP1 or SENP2 in wild type CRMP2-expressing CAD cells decreased NaV1.7 currents. Consistent with a reduction in current density, biotinylation revealed a significant reduction in surface NaV1.7 levels in CAD cells expressing CRMP2-K374A; surface NaV1.7 expression was also decreased by SENP1 + SENP2 overexpression. Currents in HEK293 cells stably expressing NaV1.7 were reduced by CRMP2-K374A in a manner dependent on the E2-conjugating enzyme Ubc9. No decrement in current density was observed in HEK293 cells co-expressing CRMP2-K374A and NaV1.1 or NaV1.3. Diminution of sodium currents, largely NaV1.7, was recapitulated in sensory neurons expressing CRMP2-K374A. Our study elucidates a novel regulatory mechanism that utilizes CRMP2 SUMOylation to choreograph NaV1.7 trafficking. PMID:23836888

  12. Fast discharge process of layered cobalt oxides due to high Na+ diffusion

    PubMed Central

    Shibata, Takayuki; Fukuzumi, Yuya; Kobayashi, Wataru; Moritomo, Yutaka

    2015-01-01

    Sodium ion secondary battery (SIB) is a low-cost and ubiquitous secondary battery for next-generation large-scale energy storage. The diffusion process of large Na+ (ionic radius is 1.12 Å), however, is considered to be slower than that of small Li+ (0.76 Å). This would be a serious disadvantage of SIB as compared with the Lithium ion secondary battery (LIB). By means of the electrochemical impedance spectroscopy (EIS), we determined the diffusion constant (D) of Na+ in thin films of O3- and P2-type NaCoO2 with layered structures. We found that the D values (~ 0.5–1.5 × 10?10?cm2/s) of Na+ are higher than those (< 1 × 10?11?cm2/s) of Li+ in layered LiCoO2. Especially, the D values of O3-NaCoO2 are even higher than those of P2-NaCoO2, probably because O3-NaCoO2 shows successive structural phase transitions from the O3, O’3, P’3, to P3 phases with Na+ deintercalation. We further found that the activation energy (ED ~ 0.4?eV) for the Na+ diffusion is significantly low in these layered cobalt oxides. We found a close relation between the relative capacity and the renormalized discharge rate ( = L2/DT, where L and T are the film thickness and discharge time, respectively). PMID:25758962

  13. The non-steroidal anti-inflammatory drug, diclofenac, inhibits Na(+) current in rat myoblasts.

    PubMed

    Fei, Xiao-Wei; Liu, Lin-Yun; Xu, Jian-Guang; Zhang, Zhi-Hong; Mei, Yan-Ai

    2006-08-11

    The inhibitory effect of diclofenac, a non-steroidal anti-inflammatory drug (NSAID), on the voltage-gated inward Na+ current (I(Na)) in cultured rat myoblasts was investigated using the whole-cell voltage-clamp technique. At concentrations of 10 nM-100 microM, diclofenac produced a dose-dependent and reversible inhibition of I(Na) with an IC50 of 8.51 microM, without modulating the fast activation and inactivation process. The inhibitory effect of diclofenac took place at resting channels and increased with more depolarizing holding potential. In addition to inhibiting the Na+ current amplitude, diclofenac significantly modulated the steady-state inactivation properties of the Na+ channels, but did not alter the steady-state activation. The steady-state inactivation curve was significantly shifted towards the hyperpolarizing potential in the presence of diclofenac. Furthermore, diclofenac treatment resulted in a fairly slow recovery from inactivation of the Na+ channel. The inhibitory effect of diclofenac was enhanced by repetitive pulses and was inflected by changing frequency; the blocking effect at higher frequency was significantly greater than at lower frequency. Both intracellular and extracellular application of diclofenac could inhibit I(Na), indicating that diclofenac may exert its channel inhibitory action both inside and outside the channel sites. Our data directly demonstrate that diclofenac can inhibit the inward Na+ channels in rat myoblasts. Some different inhibitory mechanisms from that in neuronal Na+ channels are discussed. PMID:16806078

  14. Bulk crystal growth and electronic characterization of the 3D Dirac semimetal Na3Bi

    NASA Astrophysics Data System (ADS)

    Kushwaha, Satya K.; Krizan, Jason W.; Feldman, Benjamin E.; Gyenis, András; Randeria, Mallika T.; Xiong, Jun; Xu, Su-Yang; Alidoust, Nasser; Belopolski, Ilya; Liang, Tian; Zahid Hasan, M.; Ong, N. P.; Yazdani, A.; Cava, R. J.

    2015-04-01

    High quality hexagon plate-like Na3Bi crystals with large (001) plane surfaces were grown from a molten Na flux. The freshly cleaved crystals were analyzed by low temperature scanning tunneling microscopy and angle-resolved photoemission spectroscopy, allowing for the characterization of the three-dimensional (3D) Dirac semimetal (TDS) behavior and the observation of the topological surface states. Landau levels were observed, and the energy-momentum relations exhibited a linear dispersion relationship, characteristic of the 3D TDS nature of Na3Bi. In transport measurements on Na3Bi crystals, the linear magnetoresistance and Shubnikov-de Haas quantum oscillations are observed for the first time.

  15. Mutant N143P Reveals How Na[superscript +] Activates Thrombin

    SciTech Connect

    Niu, Weiling; Chen, Zhiwei; Bush-Pelc, Leslie A.; Bah, Alaji; Gandhi, Prafull S.; Di Cera, Enrico

    2010-01-12

    The molecular mechanism of thrombin activation by Na{sup +} remains elusive. Its kinetic formulation requires extension of the classical Botts-Morales theory for the action of a modifier on an enzyme to correctly account for the contribution of the E*, E, and E:Na{sup +} forms. The extended scheme establishes that analysis of k{sub cat} unequivocally identifies allosteric transduction of Na{sup +} binding into enhanced catalytic activity. The thrombin mutant N143P features no Na{sup +}-dependent enhancement of k{sub cat} yet binds Na{sup +} with an affinity comparable to that of wild type. Crystal structures of the mutant in the presence and absence of Na{sup +} confirm that Pro{sup 143} abrogates the important H-bond between the backbone N atom of residue 143 and the carbonyl O atom of Glu{sup 192}, which in turn controls the orientation of the Glu{sup 192}-Gly{sup 193} peptide bond and the correct architecture of the oxyanion hole. We conclude that Na{sup +} activates thrombin by securing the correct orientation of the Glu{sup 192}-Gly{sup 193} peptide bond, which is likely flipped in the absence of cation. Absolute conservation of the 143-192 H-bond in trypsin-like proteases and the importance of the oxyanion hole in protease function suggest that this mechanism of Na{sup +} activation is present in all Na{sup +}-activated trypsin-like proteases.

  16. Study of ethylene adsorption on zeolite NaY modified with group I metal ions

    NASA Astrophysics Data System (ADS)

    Sue-aok, Niramai; Srithanratana, Tipaporn; Rangsriwatananon, Kunwadee; Hengrasmee, Sunantha

    2010-04-01

    The adsorption of ethylene by zeolite NaY and zeolite NaY modified by cation exchange with potassium, rubidium, and cesium ions was studied. Cation exchanges were carried out using KNO 3, RbNO 3, and CsNO 3 in the concentration ranges of 0.2-10 mM. XRD patterns and specific surface areas illustrated that modification of NaY zeolite by very dilute solutions containing K +, Rb + and Cs + did not lead to significant changes in the crystallinity. Analysis of metals content (ICP-OES) showed that Cs + can replace Na + better than Rb + and K +. Particle analysis indicated slight decreases in surface area but pore volumes and pore diameters remained unchanged. Ethylene adsorption isotherms indicated that Na-Y zeolite which was modified by 5.0 mM KNO 3, 0.5 mM RbNO 3 and 1.0 mM CsNO 3 could adsorb ethylene better than zeolite Na-Y. K-NaY zeolite adsorbed up to 102.45 cm 3/g ethylene, while Rb-NaY and Cs-NaY zeolites adsorbed up to 98.50 cm 3/g and 90.15 cm 3/g ethylene, respectively. Ethylene adsorption capacities depended on number of adsorption sites and surface interactions.

  17. Origin of intergranular embrittlement of Al alloys induced by Na and Ca segregation: Grain boundary weakening

    SciTech Connect

    Lu Guanghong; Zhang Ying; Deng Shenghua; Wang Tianmin; Kohyama, Masanori; Yamamoto, Ryoichi; Liu Feng; Horikawa, Keitaro; Kanno, Motohiro

    2006-06-01

    Using a first-principles computational tensile test, we show that the ideal tensile strength of an Al grain boundary (GB) is reduced with both Na and Ca GB segregation. We demonstrate that the fracture occurs in the GB interface, dominated by the break of the interfacial bonds. Experimentally, we further show that the presence of Na or Ca impurity, which causes intergranular fracture, reduces the ultimate tensile strength when embrittlement occurs. These results suggest that the Na/Ca-induced intergranular embrittlement of an Al alloy originates mainly from the GB weakening due to the Na/Ca segregation.

  18. First-principles study on structure stabilities of ?-S and Na-S battery systems

    NASA Astrophysics Data System (ADS)

    Momida, Hiroyoshi; Oguchi, Tamio

    2014-03-01

    To understand microscopic mechanisms of charge and discharge reactions in Na-S batteries, there has been increasing needs to study fundamental atomic and electronic structures of elemental S as well as that of Na-S phases. The most stable form of S is known to be an orthorhombic ?-S crystal at ambient temperature and pressure, and ?-S consists of puckered S8 rings which crystallize in space group Fddd . In this study, the crystal structure of ?-S is examined by using first-principles calculations with and without the van der Waals interaction corrections of Grimme's method, and results clearly show that the van der Waals interactions between the S8 rings have crucial roles on cohesion of ?-S. We also study structure stabilities of Na2S, NaS, NaS2, and Na2S5 phases with reported crystal structures. Using calculated total energies of the crystal structure models, we estimate discharge voltages assuming discharge reactions from 2Na+ xS -->Na2Sx, and discharge reactions in Na/S battery systems are discussed by comparing with experimental results. This work was partially supported by Elements Strategy Initiative for Catalysts and Batteries (ESICB) of Ministry of Education, Culture, Sports, Science, and Technology (MEXT), Japan.

  19. A new high-energy cathode for a Na-ion battery with ultrahigh stability.

    PubMed

    Park, Young-Uk; Seo, Dong-Hwa; Kwon, Hyung-Soon; Kim, Byoungkook; Kim, Jongsoon; Kim, Haegyeom; Kim, Inkyung; Yoo, Han-Ill; Kang, Kisuk

    2013-09-18

    Large-scale electric energy storage is a key enabler for the use of renewable energy. Recently, the room-temperature Na-ion battery has been rehighlighted as an alternative low-cost technology for this application. However, significant challenges such as energy density and long-term stability must be addressed. Herein, we introduce a novel cathode material, Na1.5VPO4.8F0.7, for Na-ion batteries. This new material provides an energy density of ~600 Wh kg(-1), the highest value among cathodes, originating from both the multielectron redox reaction (1.2 e(-) per formula unit) and the high potential (~3.8 V vs Na(+)/Na) of the tailored vanadium redox couple (V(3.8+)/V(5+)). Furthermore, an outstanding cycle life (~95% capacity retention for 100 cycles and ~84% for extended 500 cycles) could be achieved, which we attribute to the small volume change (2.9%) upon cycling, the smallest volume change among known Na intercalation cathodes. The open crystal framework with two-dimensional Na diffusional pathways leads to low activation barriers for Na diffusion, enabling excellent rate capability. We believe that this new material can bring the low-cost room-temperature Na-ion battery a step closer to a sustainable large-scale energy storage system. PMID:23952799

  20. Maturation of proximal straight tubule NaCl transport: role of thyroid hormone

    PubMed Central

    SHAH, MEHUL; QUIGLEY, RAYMOND; BAUM, MICHEL

    2014-01-01

    We have recently demonstrated that the rates of both active and passive proximal straight tubule (PST) NaCl transport in neonatal rabbits were less than in adults. In this segment NaCl entry across the apical membrane is via parallel Na+/H+ and Cl?/OH? exchangers, which increases in activity with maturation. The present in vitro microperfusion study examined whether thyroid hormone plays a role in the maturational increase in PST NaCl transport. Neonatal and adult PST were perfused with a high-chloride-low bicarbonate solution without organic solutes, simulating late proximal tubule fluid. Thyroid hormone-treated neonates had a higher rate of PST total and passive NaCl transport. In 8-wk-old animals that were hypothyroid since birth, the maturational increase in total and passive NaCl transport was prevented. Thyroid treatment for 4 days in hypothyroid 8-wk-old rabbits increased the rate of both total and passive NaCl transport. The maturational increases in both Na+/H+ and Cl?/OH? exchange activities were blunted in 8-wk-old hypothyroid animals and increased to control levels with thyroid treatment. This study demonstrates that thyroid hormone is a factor responsible for the maturational increase in both active and passive PST NaCl transport. PMID:10751220

  1. Keeping It Simple, Transport Mechanism and pH Regulation in Na+/H+ Exchangers*

    PubMed Central

    C?linescu, Octavian; Paulino, Cristina; Kühlbrandt, Werner; Fendler, Klaus

    2014-01-01

    Na+/H+ exchangers are essential for regulation of intracellular proton and sodium concentrations in all living organisms. We examined and experimentally verified a kinetic model for Na+/H+ exchangers, where a single binding site is alternatively occupied by Na+ or one or two H+ ions. The proposed transport mechanism inherently down-regulates Na+/H+ exchangers at extreme pH, preventing excessive cytoplasmic acidification or alkalinization. As an experimental test system we present the first electrophysiological investigation of an electroneutral Na+/H+ exchanger, NhaP1 from Methanocaldococcus jannaschii (MjNhaP1), a close homologue of the medically important eukaryotic NHE Na+/H+ exchangers. The kinetic model describes the experimentally observed substrate dependences of MjNhaP1, and the transport mechanism explains alkaline down-regulation of MjNhaP1. Because this model also accounts for acidic down-regulation of the electrogenic NhaA Na+/H+ exchanger from Escherichia coli (EcNhaA, shown in a previous publication) we conclude that it applies generally to all Na+/H+ exchangers, electrogenic as well as electroneutral, and elegantly explains their pH regulation. Furthermore, the electrophysiological analysis allows insight into the electrostatic structure of the translocation complex in electroneutral and electrogenic Na+/H+ exchangers. PMID:24644283

  2. Fast discharge process of layered cobalt oxides due to high Na+ diffusion

    NASA Astrophysics Data System (ADS)

    Shibata, Takayuki; Fukuzumi, Yuya; Kobayashi, Wataru; Moritomo, Yutaka

    2015-03-01

    Sodium ion secondary battery (SIB) is a low-cost and ubiquitous secondary battery for next-generation large-scale energy storage. The diffusion process of large Na+ (ionic radius is 1.12 Å), however, is considered to be slower than that of small Li+ (0.76 Å). This would be a serious disadvantage of SIB as compared with the Lithium ion secondary battery (LIB). By means of the electrochemical impedance spectroscopy (EIS), we determined the diffusion constant (D) of Na+ in thin films of O3- and P2-type NaCoO2 with layered structures. We found that the D values (~ 0.5-1.5 × 10-10 cm2/s) of Na+ are higher than those (< 1 × 10-11 cm2/s) of Li+ in layered LiCoO2. Especially, the D values of O3-NaCoO2 are even higher than those of P2-NaCoO2, probably because O3-NaCoO2 shows successive structural phase transitions from the O3, O'3, P'3, to P3 phases with Na+ deintercalation. We further found that the activation energy (ED ~ 0.4 eV) for the Na+ diffusion is significantly low in these layered cobalt oxides. We found a close relation between the relative capacity and the renormalized discharge rate ( = L2/DT, where L and T are the film thickness and discharge time, respectively).

  3. The use of Na-22 as a tracer for long-term bone mineral turnover studies.

    NASA Technical Reports Server (NTRS)

    Palmer, H. E.; Rieksts, G. A.; Palmer, R. F.; Gillis, M. F.

    1979-01-01

    Sodium-22 has been studied as a tracer for bone mineral metabolism in rats and dogs. When incorporated into bone during growth from birth to adulthood, the bone becomes uniformly tagged with Na-22, which is released through the metabolic turnover of the bone. The Na-22 not incorporated in the bone matrix is rapidly excreted within a few days when animals are fed high, but nontoxic levels of NaCl. The Na-22 tracer can be used to measure bone mineral loss in animals during space flight and in research on bone disease.

  4. Nucleation and Growth of Eutectic Si in Al-Si Alloys with Na Addition

    NASA Astrophysics Data System (ADS)

    Li, J. H.; Barrirero, J.; Engstler, M.; Aboulfadl, H.; Mücklich, F.; Schumacher, P.

    2015-03-01

    Al-5 wt pct Si-based alloys with Na additions (19 and 160 ppm) have been produced by controlled sand casting and melt spinning. Entrained droplet technique and differential scanning calorimetry were employed to investigate the nucleation behavior of eutectic Si. High-resolution transmission electron microscopy and atom probe tomography were used to investigate the distribution of Na atoms within eutectic Si and at the interfaces between eutectic Si and eutectic Al. It was found that (i) only 19 ppm Na addition results into a high undercooling (49 K (49 °C)) of the entrained eutectic droplet. However, further increasing Na addition up to 160 ppm exerts no positive effect on the nucleation of eutectic Si, instead a decreased undercooling (29 K (29 °C)) was observed. (ii) Na addition suppresses the growth of eutectic Si due to the Na segregation at the interface between eutectic Si and eutectic Al, and (iii) Na addition promotes significant multiple Si twins, which can be attributed to the proposed adsorption of Na atoms at the intersection of Si twins and along the <112>Si growth direction of Si. The present investigation demonstrates, for the first time, a direct observation on the distribution of Na atoms within eutectic Si and thereby provides strong experimental supports to the well-accepted impurity-induced twinning growth mechanism and poisoning of the twin plane re-entrant edge growth mechanism.

  5. First-principles study of amorphous carbon: a promising candidate for Na-ion batteries

    NASA Astrophysics Data System (ADS)

    Kotsis, Konstantinos; Legrain, Fleur; Manzhos, Sergei

    2015-03-01

    The perspective of a widespread use of clean but intermittent sources of electricity (wind and solar) as well as that of hybrid electric vehicles calls for alternatives to Li-ion batteries as Li resources are limited. Na being abundant, cheap, and a relatively light and small atom, Na-ion batteries have attracted a lot of interest the past few years. However, while most of the Na-ion batteries studies focus on the positive electrode, the negative electrode remains little investigated and an efficient anode providing all a good capacity, a high cycle life, and a descent rate of charge/discharge, is still not available. The efficient electrode materials for Li, in particular diamond Si and graphite C, have been shown to not allow the intercalation of Na [1, 2]. Computational studies report positive intercalation energies [3, 4] and therefore suggest that the insertion of Na into the crystalline framework (C and Si) is thermodynamically not favored: Na atoms prefer to gather into Na clusters rather than to intercalate into the crystalline phase. Amorphization of Si was found to be a valid strategy to improve the interaction between Si and Na [3]. We investigate here the effects of amorphization of C on its storage properties vis-à-vis Na (as well as Li for reference).

  6. Conservation of Ca2+/Calmodulin Regulation across Na and Ca2+ channels

    PubMed Central

    Ben-Johny, Manu; Yang, Philemon S.; Niu, Jacqueline; Yang, Wanjun; Joshi-Mukherjee, Rosy; Yue, David T.

    2014-01-01

    SUMMARY Voltage-gated Na and Ca2+channels comprise distinct ion-channel superfamilies, yet the carboxy tails of these channels exhibit high homology hinting at a long-shared and purposeful module. For different Ca2+ channels, carboxyl-tail inter actions with calmodulin do elaborate robust and similar forms of Ca2+ regulation. However, Na channels have only shown subtler Ca2+modulation that differs among reports, challenging attempts at unified understanding. Here, by rapid Ca2+photoreleaseon to Na channels, we reset this view of Na channel regulation. For cardiac muscle channels (NaV1.5), reported effects from which most mechanistic proposals derive, we observe no Ca2+modulation. Conversely, for skeletal-muscle channels (NaV1.4), we uncover fast Ca2+ regulation eerily similar to that of Ca2+ channels. Channel opathic myotonia mutations halve NaV1.4 Ca2+ regulation, and transplanting the NaV1.4 carboxy tail onto Ca2+ channels recapitulates Ca2+ regulation. Thus we argue for the persistence and physiological relevance of an ancient Ca2+ regulatory module across Na and Ca2+ channels. PMID:24949975

  7. Functional Interaction Between Na/K-ATPase and NMDA Receptor in Cerebellar Neurons.

    PubMed

    Akkuratov, Evgeny E; Lopacheva, Olga M; Kruusmägi, Markus; Lopachev, Alexandr V; Shah, Zahoor A; Boldyrev, Alexander A; Liu, Lijun

    2015-12-01

    NMDA receptors play a crucial role in regulating synaptic plasticity and memory. Activation of NMDA receptors changes intracellular concentrations of Na(+) and K(+), which are subsequently restored by Na/K-ATPase. We used immunochemical and biochemical methods to elucidate the potential mechanisms of interaction between these two proteins. We observed that NMDA receptor and Na/K-ATPase interact with each other and this interaction was shown for both isoforms of ? subunit (?1 and ?3) of Na/K-ATPase expressed in neurons. Using Western blotting, we showed that long-term exposure of the primary culture of cerebellar neurons to nanomolar concentrations of ouabain (a cardiotonic steroid, a specific ligand of Na/K-ATPase) leads to a decrease in the levels of NMDA receptors which is likely mediated by the ?3 subunit of Na/K-ATPase. We also observed a decrease in enzymatic activity of the ?1 subunit of Na/K-ATPase caused by NMDA receptor activation. This effect is mediated by an increase in intracellular Ca(2+). Thus, Na/K-ATPase and NMDA receptor can interact functionally by forming a macromolecular complex which can be important for restoring ionic balance after neuronal excitation. Furthermore, this interaction suggests that NMDA receptor function can be regulated by endogenous cardiotonic steroids which recently have been found in cerebrospinal fluid or by pharmacological drugs affecting Na/K-ATPase function. PMID:25381029

  8. Organophosphate inhibition of avian salt gland Na, K-ATPase activity

    USGS Publications Warehouse

    Eastin, W.C., Jr.; Fleming, W.J.; Murray, H.C.

    1982-01-01

    1. Adult black ducks (Anas rubripes) were given freshwater or saltwater (1.5% NaCl) for 11 days and half of each group was also given an organophosphate (17 p.p.m. fenthion) in the diet on days 6-11. 2. After 11 days, ducks drinking saltwater had lost more weight and had higher plasma Na and uric acid concentrations and osmolalities than birds drinking freshwater. 3. Saltwater treatment stimulated the salt gland to increased weight and Na, K-ATPase activity. 4. Fenthion generally reduced plasma and brain cholinesterase activity and depressed cholinesterase and Na, K-ATPase activities in salt glands of birds drinking saltwater.

  9. Subnitride chemistry: A first-principles study of the NaBa{sub 3}N, Na{sub 5}Ba{sub 3}N, and Na{sub 16}Ba{sub 6}N phases

    SciTech Connect

    Oliva, Josep M. . E-mail: J.M.Oliva@iqfr.csic.es

    2005-04-15

    An ab initio study on the electronic structure of the subnitrides NaBa{sub 3}N, Na{sub 5}Ba{sub 3}N, and Na{sub 16}Ba{sub 6}N is performed for the first time. The NaBa{sub 3}N and Na{sub 5}Ba{sub 3}N phases consist of infinite {sup 1}{sub {infinity}}[NBa{sub 6/2}] strands composed of face-sharing NBa{sub 6} octahedra surrounded by a 'sea' of sodium atoms. The Na{sub 16}Ba{sub 6}N phase consist of discrete [NBa{sub 6}] octahedra arranged in a body-cubic fashion, surrounded by a 'sea' of sodium atoms. Our calculations suggest that the title subnitrides are metals. Analysis of the electronic structure shows partial interaction of N(2s) with Ba(5p) electrons in the lower energy region for NaBa{sub 3}N and Na{sub 5}Ba{sub 3}N. However, no dispersion is observed for the N(2s) and Ba(5p) bands in the cubic phase Na{sub 16}Ba{sub 6}N. The metallic band below the Fermi level shows a strong mixing of N(2p), Ba(6s), Ba(5d), Ba(6p), Na(3s) and Na(3p) orbitals. The metallic character in these nitrides stems from delocalized electrons corresponding to hybridized 5d{sup l}6s{sup m}6p{sup n} barium orbitals which interact with hybridized 3s{sup n}3p{sup m} sodium orbitals. Analysis of the electron density and electronic structure in these nitrides shows two different regions: a metallic matrix corresponding to the sodium atoms and the regions around them and heteropolar bonding between nitrogen and barium within the infinite {sup 1}{sub {infinity}}[NBa{sub 6/2}] strands of the NaBa{sub 3}N and Na{sub 5}Ba{sub 3}N phases, and within the isolated [NBa{sub 6}] octahedra of the Na{sub 16}Ba{sub 6}N phase. The nitrogen atoms inside the strands and octahedra are negatively charged, the anionic character of nitrogens being larger in the isolated octahedra of the cubic phase Na{sub 16}Ba{sub 6}N, due to the lack of electron delocalization along one direction as opposed to the other phases. The sodium and barium atoms appear to be slightly negatively and positively charged, the latter to a larger extent. From the computed Ba-N overlap populations as well as the analysis of the contour maps of differences between total density and superposition of atomic densities, we suggest partial covalent bonding between nitrogen and barium atoms along the infinite {sup 1}{sub {infinity}}[NBa{sub 6/2}] strands and within isolated [NBa{sub 6}] octahedra.

  10. Structure and properties of ?-NaFeO{sub 2}-type ternary sodium iridates

    SciTech Connect

    Baroudi, Kristen; Yim, Cindi; Wu, Hui; Huang, Qingzhen; Roudebush, John H.; Vavilova, Eugenia; Grafe, Hans-Joachim; Kataev, Vladislav; Buechner, Bernd; Ji, Huiwen; Kuo, Changyang; Hu, Zhiwei; Pi, Tun-Wen; Pao, Chiwen; Lee, Jyhfu; Mikhailova, Daria; Hao Tjeng, Liu; Cava, R.J.

    2014-02-15

    The synthesis, structure, and elementary magnetic and electronic properties are reported for layered compounds of the type Na{sub 3?x}MIr{sub 2}O{sub 6} and Na{sub 3?x}M{sub 2}IrO{sub 6}, where M is a transition metal from the 3d series (M=Zn, Cu, Ni, Co, Fe and Mn). The rhombohedral structures, in space group R?3m, were determined by refinement of neutron and synchrotron powder diffraction data. No clear evidence for long range 2:1 or 1:2 honeycomb-like M/Ir ordering was found in the neutron powder diffraction patterns except in the case of M=Zn, and thus in general the compounds are best designated as sodium deficient ?-NaFeO{sub 2}-type phases with formulas Na{sub 1?x}M{sub 1/3}Ir{sub 2/3}O{sub 2} or Na{sub 1?x}M{sub 2/3}Ir{sub 1/3}O{sub 2}. Synchrotron powder diffraction patterns indicate that several of the compounds likely have honeycomb in-plane metal–iridium ordering with disordered stacking of the layers. All the compounds are sodium deficient under our synthetic conditions and are black and insulating. Weiss constants derived from magnetic susceptibility measurements indicate that Na{sub 0.62}Mn{sub 0.61}Ir{sub 0.39}O{sub 2}, Na{sub 0.80}Fe{sub 2/3}Ir{sub 1/3}O{sub 2}, Na{sub 0.92}Ni{sub 1/3}Ir{sub 2/3}O{sub 2}, Na{sub 0.86}Cu{sub 1/3}Ir{sub 2/3}O{sub 2}, and Na{sub 0.89}Zn{sub 1/3}Ir{sub 2/3}O{sub 2} display dominant antiferromagnetic interactions. For Na{sub 0.90}Co{sub 1/3}Ir{sub 2/3}O{sub 2} the dominant magnetic interactions at low temperature are ferromagnetic while at high temperatures they are antiferromagnetic; there is also a change in the effective moment. Low temperature specific heat measurements (to 2 K) on Na{sub 0.92}Ni{sub 1/3}Ir{sub 2/3}O{sub 2} indicate the presence of a broad magnetic ordering transition. X-ray absorption spectroscopy shows that iridium is at or close to the 4+ oxidation state in all compounds. {sup 23}Na nuclear magnetic resonance measurements comparing Na{sub 2}IrO{sub 3} to Na{sub 0.92}Ni{sub 1/3}Ir{sub 2/3}O{sub 2} and Na{sub 0.89}Zn{sub 1/3}Ir{sub 2/3}O{sub 2} provide strong indications that the electron spins are short-range ordered in the latter two materials. Na{sub 0.62}Mn{sub 0.61}Ir{sub 0.39}O{sub 2}, Na{sub 0.80}Fe{sub 2/3}Ir{sub 1/3}O{sub 2}, Na{sub 0.90}Co{sub 1/3}Ir{sub 2/3}O{sub 2}, Na{sub 0.92}Ni{sub 1/3}Ir{sub 2/3}O{sub 2}, Na{sub 0.86}Cu{sub 1/3}Ir{sub 2/3}O{sub 2} and Na{sub 0.89}Zn{sub 1/3}Ir{sub 2/3}O{sub 2} are spin glasses. (CSD-numbers: Na{sub 0.62}Mn{sub 0.61}Ir{sub 0.39}O{sub 2}: 426657, Na{sub 0.80}Fe{sub 2/3}Ir{sub 1/3}O{sub 2}: 426659, Na{sub 0.90}Co{sub 1/3}Ir{sub 2/3}O{sub 2}: 426658, Na{sub 0.92}Ni{sub 1/3}Ir{sub 2/3}O{sub 2}: 426656, Na{sub 0.86}Cu{sub 1/3}Ir{sub 2/3}O{sub 2}: 426655, and Na{sub 2.8}ZnIr{sub 2}O{sub 6}: 426660.) - Graphical abstract: Diffraction patterns of Na{sub 0.92}Ni{sub 1/3}Ir{sub 2/3}O{sub 2}, Na{sub 0.86}Cu{sub 1/3}Ir{sub 2/3}O{sub 2} and Na{sub 0.89}Zn{sub 1/3}Ir{sub 2/3}O{sub 2}: neutron diffraction patterns in the main panel and synchrotron diffraction in the insets. The patterns show a small amount of ordering in the transition metal iridium layer. Display Omitted - Highlights: • We report six ternary sodium iridates with the ?-NaFeO{sub 2} structure. • Compounds Na{sub 1?x}M{sub 1/3}Ir{sub 2/3}O{sub 2}, M=Co, Ni, Cu, Zn and Na{sub 1?x}M{sub 2/3}Ir{sub 1/3}O{sub 2}, M=Mn, Fe. • Rietveld refinement of powder neutron diffraction data. • All compounds are spin glasses. • NMR comparison to Na{sub 2}IrO{sub 3}.

  11. Melting of Na at high pressure from ab initio calculations

    NASA Astrophysics Data System (ADS)

    Ko?i, L.; Ahuja, R.; Vitos, L.; Pinsook, U.

    2008-04-01

    The alkali metals continue to attract attention due to their enigmatic melting behavior at high pressure. In this study, ab initio molecular dynamics (AIMD) calculations for Na using the projector augmented waves method and the generalized gradient approximation as exchange-correlation energy were performed. The melting temperature (Tm) results from the AIMD at extreme conditions confirm the recent findings of a Tm maximum and show a decrease of ˜200K between 45 and 120GPa . Furthermore, from elastic constant calculations using the exact muffin-tin orbitals method, a Lindemann model curve was calculated. The model reproduces the trend of the experimental results of Gregoryanz [Phys. Rev. Lett. 94, 185502 (2005)] who reported an extraordinarily big melting temperature drop of ˜700K between 31 and 118GPa .

  12. NaNog: A pluripotency homeobox (master) molecule

    PubMed Central

    Allouba, Mona H.; ElGuindy, Ahmed M.; Krishnamoorthy, Navaneethakrishnan; Yacoub, Magdi H.; Aguib, Yasmine E.

    2015-01-01

    One of the most intriguing aspects of cell biology is the state of pluripotency, where the cell is capable of self-renewal for as many times as deemed “necessary”, then at a specified time can differentiate into any type of cell. This fundamental process is required during organogenesis in foetal life and importantly during tissue repair in health and disease. Pluripotency is very tightly regulated, as any dysregulation can result in congenital defects, inability to repair damage, or cancer. Fuelled by the relatively recent interest in stem cell biology and tissue regeneration, the molecules implicated in regulating pluripotency have been the subject of extensive research. One of the important molecules involved in pluripotency, is NaNog, the subject of this article. PMID:26566529

  13. Long Life Na/NiCl2 Cells

    NASA Technical Reports Server (NTRS)

    Bugga, Ratnakumar V. (Inventor); Surampudi, Subbarao (Inventor); Halpert, Gerald (Inventor)

    1996-01-01

    The premature capacity failure of Na/NiCl2 secondary cells due to agglomeration of nickel particles on the surface of the NiCl2 cathode is prevented by addition of a minor amount such as 10 percent by weight of a transition metal such as Co, Fe or Mn to the cathode. The chlorides of the transition metals have lower potentials than nickel chloride and chlorinate during charge. A uniform dispersion of the transition metals in the cathodes prevents agglomeration of nickel, maintains morphology of the electrode, maintains the electrochemical area of the electrode and thus maintains capacity of the electrode. The additives do not effect sintering. The addition of sulfur to the liquid catholyte is expected to further reduce agglomeration of nickel in the cathode.

  14. The NA48 Liquid Krypton Calorimeter Description and Performances

    E-print Network

    Jose Ocariz

    1999-01-11

    The NA48 experiment at CERN aims at making a precision study of direct CP violation in the neutral kaons, by measuring $Re(\\epsilon'/\\epsilon)$ with an accuracy better than 0.02%. To achieve this goal, the experiment requires a neutral detector with fast response, high efficiency in a high-rate environment (\\sim MHz), long-term stability, sub-nanosecond time resolution, millimetric space precision, and an excellent energy resolution (1%) in the $5 \\to 100$ GeV range. To achieve these performances, a quasi-homogeneous Liquid Krypton calorimeter has been chosen, designed with a projective tower geometry, high transversal segmentation, and fast digital readout. The calorimeter was operative during the '97 data taking period, its performances were thoroughly studied, and found to be in agreement with design requirements. A detector description and performances analysis are here presented.

  15. Formation of Ultracold LiH and NaH

    NASA Astrophysics Data System (ADS)

    Taylor-Juarros, E.; Côté, R.; Kirby, K.

    2003-05-01

    Novel effects are predicted to occur in samples of ultracold polar molecules.(L. Santos et al.), Phys. Rev. Lett. 85, 1791 (2000). We are studying the formation of ultracold LiH and NaH molecules using 1-photon and 2-photon processes. We show that these polar molecules can be produced in selected vibrational and rotational states by stimulated radiative association in a mixture of ultracold hydrogen and lithium or sodium atoms. We also present a detailed analysis of the lifetimes of the vibrational levels of the ground and excited singlet states. We have calculated the photoabsorption rate coefficients for populating various vibrational levels and have found that significant molecule formation rates can be realized with laser intensities and MOT densities that are attainable experimentally.

  16. Beyond Conventional Cathode Materials for Li-ion Batteries and Na-ion Batteries Nickel fluoride conversion materials and P2 type Na-ion intercalation cathodes /

    E-print Network

    Lee, Dae Hoe

    2013-01-01

    to the Li-ion battery. However, more work still needs to bework reversibly as a cathode in the rechargeable Na-ion battery [battery……………………………………134 Chapter 9. Concluding remarks and future work………………………. ………

  17. ATLETAS PARALMPICOS DE GOALBALL NA FEF Realizou-se na FEF/UNICAMP no dia 20 de Junho a 2 Etapa do

    E-print Network

    de Aguiar, Marcus A. M.

    diferentes cidades do estado de São Paulo, nos jogos, estiveram presentes no evento, atletas da delegação. Esses mesmos atletas que estiveram na FEF/UNICAMP se preparam para representar o Brasil nos Jogos Para

  18. Physical properties of liquid NaF-LiF-LaF3 and NaF-LiF-NdF3 eutectic alloys

    NASA Astrophysics Data System (ADS)

    Bulavin, L.; Plevachuk, Yu.; Sklyarchuk, V.; Shtablavyy, I.; Faidiuk, N.; Savchuk, R.

    2013-02-01

    Electrical conductivity, thermoelectric power and viscosity measurements were carried out for the ionic liquid mixtures, formed after melting of the NaF-LiF-LaF3 and NaF-LiF-NdF3 eutectics in the wide temperature intervals above the melting points. It was found that temperature coefficient of the thermoelectric power of the both ionic mixtures changes a sign, at 948 ± 5 K in NaF-LiF-LaF3 and at 973 ± 5 K in NaF-LiF-NdF3. It was shown that temperature dependence of viscosity correlates with electrophysical data. The results can be used in choosing a blanket for the liquid salt reactor.

  19. Ab initio configuration interaction study of excited states of LiNa3 and Li2Na2 clusters: Interpretation of absorption spectra

    NASA Astrophysics Data System (ADS)

    Bona?i?-Koutecký, V.; Gaus, J.; Guest, M. F.; Koutecký, J.

    1992-04-01

    The ab initio configuration-interaction (CI) study of excited states of mixed alkali metal tetramers LiNa3 and Li2Na2 accounts for spectroscopic patterns obtained from the depletion spectra of neutral species, reproduces observed excitation energies and intensities for allowed transitions, and permits an assignment of cluster structures. For both mixed tetramers, the rhombic forms with a Li atom or atoms on the short diagonal are the most stable structures and give rise to predicted spectra in full agreement with the measured ones. The exact location of Li atoms seems to be more important in Li2Na2 than in LiNa3 since in the former case, only one isomer reproduces all features of the recorded spectrum.

  20. Interstellar Lines NaI 5890 (D2), NaI 5896 (D1) in the Spectra of the Wolf-Rayet Type Star HD 192163

    NASA Astrophysics Data System (ADS)

    Rustamov, J. N.; Abdulkerimova, A. F.

    2012-08-01

    Results of spectral investigations of the interstellar absorption lines NaI 5890 (D2) and NaI 5896 (D1) in a spectrum of a Wolf-Rayet type star HD 192163 are presented. Observations carried out at Cassegrain focus of 2- meter "Zeiss-2000" telescope of N.Tusi Shamakhy Astrophysical observatory (ShAO) of NAS Azerbaijan in 2005-2010. 46 eshelle-spectrograms of star HD 192163, and also 4 eshelle-spectrograms of star HD 191765 and standard star HD 18947 for the purpose of comparative research of lines of doublet NaI 5890 (D2) and NaI 5896 (D1) were investigated. The asymmetry of profiles of these interstellar absorption lines had been revealed only in the spectra of HD 192163 and this asymmetry is interpreted by the contribution of genetic associated with the star HD 192163 ring nebula NGC 6888, in formation of these lines.

  1. NaAlF{sub 4}: Preparation, crystal structure and thermal stability

    SciTech Connect

    Kirik, Sergei D.; Zaitseva, Julia N.

    2010-02-15

    The compound NaAlF{sub 4} has been obtained in the form of thin fibrous crystals or fine colorless powder by condensation at 18 deg. C of vapors arising over chiolite Na{sub 5}Al{sub 3}F{sub 14} or NaCaAlF{sub 6}, heated up to 800 deg. C. Thermal stability has been investigated by the methods of thermal analysis and high temperature X-ray diffraction. When heated in air, NaAlF{sub 4} is stable up to 390-400 deg. C, then there is an exothermal solid state decay into Na{sub 5}Al{sub 3}F{sub 14}(s) and AlF{sub 3}(s). At higher temperature Na{sub 5}Al{sub 3}F{sub 14}(s) decays into Na{sub 3}AlF{sub 6}(s) and NaAlF{sub 4}(g). The crystal structure (space group Cmcm, a=3.6124(1) A, b=14.9469(7) A, c=5.2617(3) A, V=284.10 A{sup 3}) has been determined by X-ray powder diffraction method. In the crystal structure of NaAlF{sub 4} the octahedrons [AlF{sub 6}] are joined through vertices and form corrugated layers, sodium ion layers being located between them. The distances between the atoms of Al-F are in the range 1.791-1.814 A, and those for Na...F are in the range 2.297-2.439 A. In spite of limited thermal stability of the crystal form, the compound NaAlF{sub 4} is the main component of the gas mixture over solid and molten salts in the ternary system NaF-AlF{sub 3}-CaF{sub 2} and participates in chemical transformations between the phases at high temperature. - Graphical abstract: The compound NaAlF{sub 4} was for the first time described 55 years ago, but until now it was not properly studied. Meantime the phase is responsible for the most low-melting part of the NaF-AlF{sub 3} system, which is the great importance for the aluminum production. The lack of information about NaAlF{sub 4} is due to narrow interval of stability which is close to liquid part of the system.

  2. Identification of the Intracellular Na+ Sensor in Slo2.1 Potassium Channels.

    PubMed

    Thomson, Steven J; Hansen, Angela; Sanguinetti, Michael C

    2015-06-01

    Slo2 potassium channels have a very low open probability under normal physiological conditions, but are readily activated in response to an elevated [Na(+)]i (e.g. during ischemia). An intracellular Na(+) coordination motif (DX(R/K)XXH) was previously identified in Kir3.2, Kir3.4, Kir5.1, and Slo2.2 channel subunits. Based loosely on this sequence, we identified five potential Na(+) coordination motifs in the C terminus of the Slo2.1 subunit. The Asp residue in each sequence was substituted with Arg, and single mutant channels were heterologously expressed in Xenopus oocytes. The Na(+) sensitivity of each of the mutant channels was assessed by voltage clamp of oocytes using micropipettes filled with 2 M NaCl. Wild-type channels and four of the mutant Slo2.1 channels were rapidly activated by leakage of NaCl solution into the cytoplasm. D757R Slo2.1 channels were not activated by NaCl, but were activated by the fenamate niflumic acid, confirming their functional expression. In whole cell voltage clamp recordings of HEK293 cells, wild-type but not D757R Slo2.1 channels were activated by a [NaCl]i of 70 mM. Thus, a single Asp residue can account for the sensitivity of Slo2.1 channels to intracellular Na(+). In excised inside-out macropatches of HEK293 cells, activation of wild-type Slo2.1 currents by 3 mM niflumic acid was 14-fold greater than activation achieved by increasing [NaCl]i from 3 to 100 mM. Thus, relative to fenamates, intracellular Na(+) is a poor activator of Slo2.1. PMID:25903137

  3. Na 6B 13O 22.5, a new noncentrosymmetric sodium borate

    NASA Astrophysics Data System (ADS)

    Penin, N.; Touboul, M.; Nowogrocki, G.

    2005-03-01

    Na 6B 13O 22.5 (B/Na=2.17) single crystals were obtained by heating, melting and appropriately cooling borax, Na 2[B 4O 5(OH) 4]·8H 2O. Its formula has been determined by the resolution of the structure from single-crystal X-ray diffraction data. The compound crystallizes in the noncentrosymmetric orthorhombic Iba2 space group, with the following unit cell parameters: a=33.359(11) Å, b=9.554(3) Å, c=10.644(4) Å; V=3392.4(19) Å 3; Z=8. The crystal structure was solved from 3226 reflections until R1=0.0385. It exhibits a three-dimensional framework built up from BO 3 triangles (?) and BO 4 tetrahedra (T). Two kinds of borate groups can be considered forming two different double B 3O 3 rings: two B 4O 9 (linkage by two boron atoms) and one B 5O 11 (linkage by one boron atom); the shorthand notation of the new fundamental building block (FBB) existing in this compound is: 13: ?3 [(5: 3?+2T)+2(4: 2?+2T)]. The discovery of this new borate questions the real number of Na 2B 4O 7 varieties. The existence of Na 6B 13O 22.5 (B/Na=2.17) and of another recently discovered borate, Na 3B 7O 12 (B/Na=2.33; FBB 7: ?3 [(3: 2?+T)+(3: ?+2T)+(1: ?)], with a composition close to the long-known borate ?-Na 2B 4O 7 (B/Na=2; FBB 8: ?3 [(5: 3?+2T)+(3: 2?+T)], may explain the very complex equilibria reported in the Na 2O-B 2O 3 phase diagram, especially in this range of composition.

  4. Rapid activation of gill Na+,K+-ATPase in the euryhaline teleost Fundulus heteroclitus

    USGS Publications Warehouse

    Mancera, J.M.; McCormick, S.D.

    2000-01-01

    The rapid activation of gill Na+,K+-ATPase was analyzed in the mummichog (Fundulus heteroclitus) and Atlantic salmon (Salmo salar) transferred from low salinity (0.1 ppt) to high salinity (25-35 ppt). In parr and presmolt, Salmo salar gill Na+,K+-ATPase activity started to increase 3 days after transfer. Exposure of Fundulus heteroclitus to 35 ppt seawater (SW) induced a rise in gill Na+,K+-ATPase activity 3 hr after transfer. After 12 hr, the values dropped to initial levels but showed a second significant increase 3 days after transfer. The absence of detergent in the enzyme assay resulted in lower values of gill Na+,K+-ATPase, and the rapid increase after transfer to SW was not observed. Na+,K+-ATPase activity of gill filaments in vitro for 3 hr increased proportionally to the osmolality of the culture medium (600 mosm/kg > 500 mosm/kg > 300 mosm/kg). Osmolality of 800 mosm/kg resulted in lower gill Na+,K+-ATPase activity relative to 600 mosm/kg. Increasing medium osmolality to 600 mosm/kg with mannitol also increased gill Na+,K+-ATPase. Cycloheximide inhibited the increase in gill Na+,K+-ATPase activity observed in hyperosmotic medium in a dose-dependent manner (10-4 M > 10-5 M > 10-6 M). Actinomycin D or bumetanide in the culture (doses of 10-4 M, 10-5 M, and 10-6 M) did not affect gill Na+,K+-ATPase. Injection of fish with actinomycin D prior to gill organ culture, however, prevented the increase in gill Na+,K+-ATPase activity in hyperosmotic media. The results show a very rapid and transitory increase in gill Na+,K+-ATPase activity in the first hours after the transfer of Fundulus heteroclitus to SW that is dependent on translational and transcriptional processes. (C) 2000 Wiley-Liss, Inc.

  5. Regulation of Na-Cl absorption in rabbit proximal colon in vitro

    SciTech Connect

    Sellin, J.H.; De Siognie, R.

    1987-01-01

    Ion transport in rabbit proximal colon (PC) in vitro is dominated by a Na-Cl cotransport system stimulated by epinephrine. To further characterize the regulation of Na-Cl transport, the authors tested the effects of specific adrenergic agonists on ion fluxes under short-circuit conditions. Additionally, they tested the effects of the transport inhibitors bumetanide, furosemide, and 4-acetamido-4'-isothiocyanostilbene-2,2'-disulfonic acid (SITS). Basal Na and Cl absorption were essentially nil. The ..cap alpha../sub 2/-agonist clonidine significantly increased net Na and Cl absorption. The ..cap alpha../sub 1/-agonist phenylephrine and the ..beta..-agonist isoproterenol did not alter ion transport. The ..cap alpha../sub 2/-blocker yohimbine (YOH) had a complex, concentration-dependent effect. Propranolol (10/sup -5/ M) and pracozin (10/sup -6/ M) did not significantly alter either basal or stimulated ion transport. Neither bumetanide (10/sup -6/ or 10/sup -4/ M) nor furosemide (10/sup -4/ M) blocked epinephrine-stimulated Na absorption. SITS (10/sup -4/ M) and removal of mucosal K did not have a significant effect on ion transport. Conclusions: 1) Na-Cl cotransport in rabbit PC is primarily under ..cap alpha../sub 2/-adrenergic control, 2) YOH at high concentrations acts as an agonist in PC, 3) ..cap alpha../sub 2/-adrenergic agonists stimulate Na-Cl absorption in both rabbit ileum and PC. In PC, however, the process is electrically quiet and therefore does not appear to be associated with electrogenic HCO/sub 3/ secretion as found in ileum, 4) the lack of effect of bumetanide, furosemide, and 0 K on Na transport suggests that a single Na-Cl (or Na-K-2Cl) carrier is not involved in Na-Cl cotransport in proximal colon.

  6. Metagenomic cloning and characterization of Na? transporters from Huamachi Salt Lake in China.

    PubMed

    Gao, Miao; Tao, Li; Chen, Sanfeng

    2013-02-22

    Moderately halophilic bacteria are a kind of extreme environment microorganism that can tolerate moderate salt concentrations ranging from 0.5M to 2.5M. Here, via a metagenomic library screen, we identified four putative Na(+) transporters, designated H7-Nha, H16-Mppe, H19-Cap and H35-Mrp, from moderately halophilic community in the hypersaline soil of Huamachi Salt Lake, China. Functional complementation observed in a Na(+)(Ca(2+))/H(+) antiporter-defective Escherichia coli mutant (KNabc) suggests that the four putative Na(+) transporters could confer cells a capacity of Na(+) resistance probably by enhancing Na(+) or Ca(2+) efflux, but not Li(+) or K(+) exchange. Blastp analysis of the deduced amino-acid sequences indicates that H7-Nha has 71% identity to the NhaG Na(+)/H(+) antiporter of Bacillus subtilis, while H19-Cap shows 99% identity to Enterobacter cloacae Ca(2+) antiporter. Interestingly, H16-Mppe shares 59% identity to the metallophosphoesterase of Bacillus cellulosilyticus and H35-Mrp shows 68% identity to multidrug resistance protein of Lysinibacillus sphaericus. This is the first report that predicts a potential role of metallophosphoesterase in Na(+) resistance in halophilic bacteria. Furthermore, everted membrane vesicles prepared from E. coli cells harboring H7-Nha exhibit Na(+)/H(+) antiporter activity, but not Li(+) (K(+))/H(+) antiporter activity, confirming that H7-Nha supports Na(+) resistance mainly via Na(+)/H(+) antiport. Our report also demonstrates that metagenomic library screen is a convenient and effective way to explore more novel types of Na(+) transporters. PMID:23218230

  7. K+ congeners that do not compromise Na+ activation of the Na+,K+-ATPase: hydration of the ion binding cavity likely controls ion selectivity.

    PubMed

    Mahmmoud, Yasser A; Kopec, Wojciech; Khandelia, Himanshu

    2015-02-01

    The Na(+),K(+)-ATPase is essential for ionic homeostasis in animal cells. The dephosphoenzyme contains Na(+) selective inward facing sites, whereas the phosphoenzyme contains K(+) selective outward facing sites. Under normal physiological conditions, K(+) inhibits cytoplasmic Na(+) activation of the enzyme. Acetamidinium (Acet(+)) and formamidinium (Form(+)) have been shown to permeate the pump through the outward facing sites. Here, we show that these cations, unlike K(+), are unable to enter the inward facing sites in the dephosphorylated enzyme. Consistently, the organic cations exhibited little to no antagonism to cytoplasmic Na(+) activation. Na(+),K(+)-ATPase structures revealed a previously undescribed rotamer transition of the hydroxymethyl side chain of the absolutely conserved Thr(772) of the ?-subunit. The side chain contributes its hydroxyl to Na(+) in site I in the E1 form and rotates to contribute its methyl group toward K(+) in the E2 form. Molecular dynamics simulations to the E1·AlF4 (-)·ADP·3Na(+) structure indicated that 1) bound organic cations differentially distorted the ion binding sites, 2) the hydroxymethyl of Thr(772) rotates to stabilize bound Form(+) through water molecules, and 3) the rotamer transition is mediated by water traffic into the ion binding cavity. Accordingly, dehydration induced by osmotic stress enhanced the interaction of the congeners with the outward facing sites and profoundly modified the organization of membrane domains of the ?-subunit. These results assign a catalytic role for water in pump function, and shed light on a backbone-independent but a conformation-dependent switch between H-bond and dispersion contact as part of the catalytic mechanism of the Na(+),K(+)-ATPase. PMID:25533461

  8. Effect of salts (NaCl and Na2CO3) on callus and suspension culture of Stevia rebaudiana for Steviol glycoside production.

    PubMed

    Gupta, Pratibha; Sharma, Satyawati; Saxena, Sanjay

    2014-03-01

    Steviol glycosides are natural non-caloric sweeteners which are extracted from the leaves of Stevia rebaudiana plant. Present study deals the effect of salts (NaCl and Na2CO3) on callus and suspension culture of Stevia plant for steviol glycoside (SGs) production. Yellow-green and compact calli obtained from in vitro raised Stevia leaves sub-cultured on MS medium supplemented with 2.0 mg l(-1) NAA and different concentrations of NaCl (0.05-0.20%) and Na2CO3 (0.0125-0.10%) for 2 weeks, and incubated at 24 ± 1 °C and 22.4 ?mol m(-2) s(-1) light intensity provided by white fluorescent tubes for 16 h. Callus and suspension biomass cultured on salts showed less growth as well as browning of medium when compared with control. Quantification of SGs content in callus culture (collected on 15th day) and suspension cultures (collected at 10th and 15th days) treated with and without salts were analyzed by HPLC. It was found that abiotic stress induced by the salts increased the concentration of SGs significantly. In callus, the quantity of SGs got increased from 0.27 (control) to 1.43 and 1.57% with 0.10% NaCl, and 0.025% Na2CO3, respectively. However, in case of suspension culture, the same concentrations of NaCl and Na2CO3 enhanced the SGs content from 1.36 (control) to 2.61 and 5.14%, respectively, on the 10th day. PMID:24449376

  9. Molecular dynamics investigation of Na{sup +} in Na{sub 2}Ni{sub 2}TeO{sub 6}

    SciTech Connect

    Sau, Kartik Kumar, P. Padma

    2014-04-24

    An inter-atomic potential for Na{sub 2}Ni{sub 2}TeO{sub 6} in the Parrinello- Rahman-Vashishta (PRV) model is parameterized empirically. The potential reproduces variety of structural and transport properties of that material in good agreement with recent experimental results. The study provides fresh insights on the migration channels and mechanism of Na{sup +} in the system.

  10. n-Selective Single Capture Following Xe{sup 18+} And Xe{sup 54+} Impact On Na(3s) And Na*(3p)

    SciTech Connect

    Otranto, S.; Olson, R. E.; Hasan, V. G.; Hoekstra, R.

    2011-06-01

    State selective single charge exchange n-level cross sections are calculated for collisions of Xe18+ and Xe54+ ions with Na(3s) and Na*(3p) over the energy range of 0.1 to 10.0 keV/amu. The CTMC method is used which includes all two-body interactions. Experimental state-selective cross sections and their corresponding transverse momentum spectra for Xe18+ are found to be in reasonable accord with the calculations.

  11. Species-dependent adaptation of the cardiac Na+/K+ pump kinetics to the intracellular Na+ concentration

    PubMed Central

    Lewalle, Alexandre; Niederer, Steven A; Smith, Nicolas P

    2014-01-01

    The Na+/K+ ATPase (NKA) plays a critical role in maintaining ionic homeostasis and dynamic function in cardiac myocytes, within both the in vivo cell and in silico models. Physiological conditions differ significantly between mammalian species. However, most existing formulations of NKA used to simulate cardiac function in computational models are derived from a broad range of experimental sources spanning many animal species. The resultant inability of these models to discern species-specific features is a significant obstacle to achieving a detailed quantitative and comparative understanding of physiological behaviour in different biological contexts. Here we present a framework for characterising the steady-state NKA current using a biophysical mechanistic model specifically designed to provide a mechanistic explanation of the NKA flux supported by self-consistent species-specific data. We thus compared NKA kinetics specific to guinea- pig and rat ventricular myocytes. We observe that the apparent binding affinity for sodium in the rat is significantly lower, whereas the overall pump cycle rate is doubled, in comparison to the guinea pig. This sensitivity of NKA to its regulatory substrates compensates for the differences in Na+ concentrations between the cell types. NKA is thereby maintained within its dynamic range over a wide range of pacing frequencies in these two species, despite significant disparities in sodium concentration. Hence, by replacing a conventional generic NKA model with our rat-specific NKA formula into a whole-cell simulation, we have, for the first time, been able to accurately reproduce the action potential duration and the steady-state sodium concentration as functions of pacing frequency. PMID:25362154

  12. 75 FR 57911 - Application To Export Electric Energy; GDF SUEZ Energy Marketing NA, Inc.

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-23

    ... Application To Export Electric Energy; GDF SUEZ Energy Marketing NA, Inc. AGENCY: Office of Electricity Delivery and Energy Reliability, DOE. ACTION: Notice of application. SUMMARY: GDF SUEZ Energy Marketing NA... utilities, Federal power marketing agencies and other entities within the United States. The...

  13. Physiological sodium concentrations enhance the iodide affinity of the Na+/I- symporter

    NASA Astrophysics Data System (ADS)

    Nicola, Juan P.; Carrasco, Nancy; Mario Amzel, L.

    2014-06-01

    The Na+/I- symporter (NIS) mediates active I- transport—the first step in thyroid hormonogenesis—with a 2Na+:1I- stoichiometry. NIS-mediated 131I- treatment of thyroid cancer post-thyroidectomy is the most effective targeted internal radiation cancer treatment available. Here to uncover mechanistic information on NIS, we use statistical thermodynamics to obtain Kds and estimate the relative populations of the different NIS species during Na+/anion binding and transport. We show that, although the affinity of NIS for I- is low (Kd=224??M), it increases when Na+ is bound (Kd=22.4??M). However, this Kd is still much higher than the submicromolar physiological I- concentration. To overcome this, NIS takes advantage of the extracellular Na+ concentration and the pronounced increase in its own affinity for I- and for the second Na+ elicited by binding of the first. Thus, at physiological Na+ concentrations, ~79% of NIS molecules are occupied by two Na+ ions and ready to bind and transport I-.

  14. Measurement of (n,a) reactions on 147 Sm using a lead

    E-print Network

    Danon, Yaron

    Measurement of (n,a) reactions on 147 Sm and 149 Sm using a lead slowing-down spectrometer J December 2011 Accepted 4 January 2012 Available online 12 January 2012 Keywords: (n,a) Lead slowing-down spectrometer Digitizer Compensated detectors Samarium Sm-147 Sm-149 a b s t r a c t The lead slowing

  15. The ground state of metallic nano-structures in heavily irradiated NaCl-KBF4

    NASA Astrophysics Data System (ADS)

    Cherkasov, F. G.; L'Vov, S. G.; Tikhonov, D. A.; den Hartog, H. W.; Vainshtein, D. I.

    ESR, NMR and static magnetic susceptibility measurements of heavily irradiated NaCl-K and NaCl-KBF4 are reported. Up to 10% of the NaCl-molecules are transformed into metallic Na nanoparticles and Cl-2 precipitates. In addition, there are paramagnetic F- and F-aggregates, which are coupled by exchange interactions to the conduction electrons in the nanoparticles. Above 160 K the NMR and ESR signals of NaCl-K and NaCl-KBF4 show Pauli paramagnetism and the properties of the Na nanoparticles are similar to bulk sodium. A single ESR line is observed revealing exchange interaction between conduction electrons in the nano-particles and F-aggregates. The observed decrease of the ESR susceptibility with decreasing temperature is due to a metal-insulator transition. The conduction electrons are localized below 40 K and the above mentioned F-aggregate centers contribute significantly to the overall ESR signal. For NaCl-KBF4 we observed that with decreasing temperature the ESR line shifts towards lower fields due to antiferromagnetic ordering and internal magnetic fields.

  16. Graphitic Phase of NaCl. Bulk Properties and Nanoscale Stability Alexander G. Kvashnin,,,

    E-print Network

    Tománek, David

    Graphitic Phase of NaCl. Bulk Properties and Nanoscale Stability Alexander G. Kvashnin,,,§ Pavel B approach to evaluate the stability and physical properties of the nanometer-thickness NaCl layered films and found that the rock salt films with a (111) surface become unstable with thickness below 1 nm

  17. Numerical Simulation of Ethanol-Water-NaCl Droplet Evaporation Xingmao Jiang,,

    E-print Network

    Brinker, C. Jeffrey

    -assisted evaporation-induced self-assembly and the formation mechanism for single-crystal NaCl core/hexagonally ordered /cm3 , it takes only tens of milliseconds to reach phase equilibrium after adiabatic or isothermal the initial NaCl nucleation and crystallization happens as a result of relatively quick evaporation

  18. Identification and Characterization of Inorganic Pyrophosphatase and PAP Phosphatase from Thermococcus onnurineus NA1?

    PubMed Central

    Lee, Hyun Sook; Kim, Yun Jae; Lee, Jung-Hyun; Kang, Sung Gyun

    2009-01-01

    Two hypothetical genes were functionally verified to be a pyrophosphatase and a PAP phosphatase in Thermococcus onnurineus NA1. This is the first report of the pyrophosphatases and the PAP phosphatases being organized in the gene clusters of the sulfate activation system only in T. onnurineus NA1 and “Pyrococcus abyssi.” PMID:19286799

  19. Portugal lidera consrcio envolvido na produo de "energia limpa, segura e abundante"

    E-print Network

    Instituto de Sistemas e Robotica

    Portugal lidera consórcio envolvido na produção de "energia limpa, segura e abundante" Autor: Data) - A produção de eletricidade a partir de fusão nuclear, considerada uma fonte de energia limpa, abundante e lidera consórcio envolvido na produção de "energia limpa, seg... http://sicnoticias.sapo.pt/Lusa/2013

  20. New-concept Batteries Based on Aqueous Li+/Na+ Mixed-ion Electrolytes

    PubMed Central

    Chen, Liang; Gu, Qingwen; Zhou, Xufeng; Lee, Saixi; Xia, Yonggao; Liu, Zhaoping

    2013-01-01

    Rechargeable batteries made from low-cost and abundant materials operating in safe aqueous electrolytes are attractive for large-scale energy storage. Sodium-ion battery is considered as a potential alternative of current lithium-ion battery. As sodium-intercalation compounds suitable for aqueous batteries are limited, we adopt a novel concept of Li+/Na+ mixed-ion electrolytes to create two batteries (LiMn2O4/Na0.22MnO2 and Na0.44MnO2/TiP2O7), which relies on two electrochemical processes. One involves Li+ insertion/extraction reaction, and the other mainly relates to Na+ extraction/insertion reaction. Two batteries exhibit specific energy of 17?Wh kg?1 and 25?Wh kg?1 based on the total weight of active electrode materials, respectively. As well, aqueous LiMn2O4/Na0.22MnO2 battery is capable of separating Li+ and Na+ due to its specific mechanism unlike the traditional “rocking-chair” lithium-ion batteries. Hence, the Li+/Na+ mixed-ion batteries offer promising applications in energy storage and Li+/Na+ separation. PMID:23736113

  1. Novel Localization of a Na /H Exchanger in a Late Endosomal Compartment of Yeast

    E-print Network

    Rao, Rajini

    movement of salt, water, and acid-base equivalents, and are therefore critical for Na tolerance, cell to a predicted membrane topology based on the hydropathy profile of the amino acid sequence: there are 12, differentiation, essential hyperten- sion, gastric and kidney disease, and epilepsies. Na /H exchange activity has

  2. Expression of a highly basic peroxidase gene in NaCl-adapted tomato cell suspensions

    E-print Network

    Málaga, Universidad de

    Expression of a highly basic peroxidase gene in NaCl-adapted tomato cell suspensions Mar|èa I 12 March 1997 Abstract A tomato peroxidase gene, TPX2, that is only weakly expressed in the roots of young tomato seedlings is highly expressed in tomato suspension cells adapted to high external Na

  3. Cation Transport Coupled to ATP Hydrolysis by the (Na, K)-ATPase: An Integrated, Animated Model

    ERIC Educational Resources Information Center

    Leone, Francisco A.; Furriel, Rosa P. M.; McNamara, John C.; Horisberger, Jean D.; Borin, Ivana A.

    2010-01-01

    An Adobe[R] animation is presented for use in undergraduate Biochemistry courses, illustrating the mechanism of Na[superscript +] and K[superscript +] translocation coupled to ATP hydrolysis by the (Na, K)-ATPase, a P[subscript 2c]-type ATPase, or ATP-powered ion pump that actively translocates cations across plasma membranes. The enzyme is also…

  4. Formation of Alumina Nanocapsules by High-Energy-Electron Irradiation of Na-dawsonite Nanorods

    PubMed Central

    Duan, Xiaochuan; Kim, Tongil; Han, Lili; Ma, Jianmin; Du, Xiwen; Zheng, Wenjun

    2013-01-01

    We report the synthesis of unique Al2O3 nanocapsules by high-energy-electron irradiation of Na-dawsonite and a formation mechanism different from thermal decomposition which usually produces NaAlO2. The novel decomposition process may open up a shortcut for fabricating hollow nanostructures. PMID:24225738

  5. Glucocorticoids Suppress Renal Cell Carcinoma Progression by Enhancing Na,K-ATPase Beta-1 Subunit Expression

    PubMed Central

    Huynh, Thu P.; Barwe, Sonali P.; Lee, Seung J.; McSpadden, Ryan; Franco, Omar E.; Hayward, Simon W.; Damoiseaux, Robert; Grubbs, Stephen S.; Petrelli, Nicholas J.; Rajasekaran, Ayyappan K.

    2015-01-01

    Glucocorticoids are commonly used as palliative or chemotherapeutic clinical agents for treatment of a variety of cancers. Although steroid treatment is beneficial, the mechanisms by which steroids improve outcome in cancer patients are not well understood. Na,K-ATPase beta-subunit isoform 1 (NaK-?1) is a cell-cell adhesion molecule, and its expression is down-regulated in cancer cells undergoing epithelial-to mesenchymal-transition (EMT), a key event associated with cancer progression to metastatic disease. In this study, we performed high-throughput screening to identify small molecules that could up-regulate NaK-?1 expression in cancer cells. Compounds related to the glucocorticoids were identified as drug candidates enhancing NaK-?1 expression. Of these compounds, triamcinolone, dexamethasone, and fluorometholone were validated to increase NaK-?1 expression at the cell surface, enhance cell-cell adhesion, attenuate motility and invasiveness and induce mesenchymal to epithelial like transition of renal cell carcinoma (RCC) cells in vitro. Treatment of NaK-?1 knockdown cells with these drug candidates confirmed that these compounds mediate their effects through up-regulating NaK-?1. Furthermore, we demonstrated that these compounds attenuate tumor growth in subcutaneous RCC xenografts and reduce local invasiveness in orthotopically-implanted tumors. Our results strongly indicate that the addition of glucocorticoids in the treatment of RCC may improve outcome for RCC patients by augmenting NaK-?1 cell-cell adhesion function. PMID:25836370

  6. Energetics of cobalt phosphate frameworks: {alpha}, {beta}, and red NaCoPO{sub 4}

    SciTech Connect

    Le, So-Nhu; Eng, Hank W.; Navrotsky, Alexandra . E-mail: anavrotsky@ucdavis.edu

    2006-12-15

    Thermal behavior, relative stability, and enthalpy of formation of {alpha} (pink phase), {beta} (blue phase), and red NaCoPO{sub 4} are studied by differential scanning calorimetry, X-ray diffraction, and high-temperature oxide melt drop solution calorimetry. Red NaCoPO{sub 4} with cobalt in trigonal bipyramidal coordination is metastable, irreversibly changing to {alpha} NaCoPO{sub 4} at 827 K with an enthalpy of phase transition of -17.4{+-}6.9 kJ mol{sup -1}. {alpha} NaCoPO{sub 4} with cobalt in octahedral coordination is the most stable phase at room temperature. It undergoes a reversible phase transition to the {beta} phase (cobalt in tetrahedra) at 1006 K with an enthalpy of phase transition of 17.6{+-}1.3 kJ mol{sup -1}. Enthalpy of formation from oxides of {alpha}, {beta}, and red NaCoPO{sub 4} are -349.7{+-}2.3, -332.1{+-}2.5, and -332.3{+-}7.2 kJ mol{sup -1}; standard enthalpy of formation of {alpha}, {beta}, and red NaCoPO{sub 4} are -1547.5{+-}2.7, -1529.9{+-}2.8, and -1530.0{+-}7.3 kJ mol{sup -1}, respectively. The more exothermic enthalpy of formation from oxides of {beta} NaCoPO{sub 4} compared to a structurally related aluminosilicate, NaAlSiO{sub 4} nepheline, results from the stronger acid-base interaction of oxides in {beta} NaCoPO{sub 4} (Na{sub 2}O, CoO, P{sub 2}O{sub 5}) than in NaAlSiO{sub 4} nepheline (Na{sub 2}O, Al{sub 2}O{sub 3}, SiO{sub 2}). - Graphical abstract: Relative stability of NaCoPO{sub 4} polymorphs compared to the most stable phase, {alpha} NaCoPO{sub 4}.

  7. Superior Na-Storage Performance of Low-Temperature-Synthesized Na3(VO(1-x)PO4)2F(1+2x) (0?x?1) Nanoparticles for Na-Ion Batteries.

    PubMed

    Qi, Yuruo; Mu, Linqin; Zhao, Junmei; Hu, Yong-Sheng; Liu, Huizhou; Dai, Sheng

    2015-08-17

    Na-ion batteries are becoming comparable to Li-ion batteries because of their similar chemical characteristics and abundant sources of sodium. However, the materials production should be cost-effective in order to meet the demand for large-scale application. Here, a series of nanosized high-performance cathode materials, Na3(VO(1-x)PO4)2F(1+2x) (0?x?1), has been synthesized by a solvothermal low-temperature (60-120?°C) strategy without the use of organic ligands or surfactants. The as-synthesized Na3(VOPO4)2F nanoparticles show the best Na-storage performance reported so far in terms of both high rate capability (up to 10?C rate) and long cycle stability over 1200 cycles. To the best of our knowledge, the current developed synthetic strategy for Na3(VO(1-x)PO4)2F(1+2x) is by far one of the least expensive and energy-consuming methods, much superior to the conventional high-temperature solid-state method. PMID:26179243

  8. Concentration and precipitation of NaCl and KCl from salt cake leach solutions by electrodialysis

    SciTech Connect

    Sreenivasarao, K; Patsiogiannis, F.; Hryn, J.N.

    1997-02-09

    Electrodialysis was investigated for cost-effective recovery of salt from salt cake leach solutions. (Salt cake is a waste stream generated by the aluminum industry during treatment of aluminum drosses and scrap.) We used a pilot-scale electrodialysis stack of 5 membrane pairs, each with an effective area of 0.02 m{sup 2}. The diluate stream contained synthetic NaCl, KCl,mixtures of NaCl and KCl, and actual salt cake leach solutions (mainly NaCl and KCl, with small amounts of MgCl{sub 2}). We concentrated and precipitated NaCl and KCl salts from the concentrate steam when the initial diluate stream concentration was 21.5 to 28.8 wt% NaCl and KCl. We found that water transferring through the membranes was a significant factor in overall efficiency of salt recovery by electrodialysis.

  9. Synthèse et étude structurale de Na9Cr(MoO4)6

    PubMed Central

    Dridi, Wassim; Ennajeh, Ines; Zid, Mohamed Faouzi

    2015-01-01

    The title compound, nona­sodium chromium(III) hexa­kis[molybdate(VI)], Na9Cr(MoO4)6 was prepared by solid-state reactions. The basic structure units are isolated polyhedral clusters composed of a central CrO6 octa­hedron sharing vertices with six MoO4 tetrahedra to form an open framework in which the Na+ cations are bound to the free vertices of the MoO4 tetra­hedra. The Cr3+ cation has site symmetry of 32 (6a), one Na atom sits on a twofold axis (18e), and all other atoms are at general positions. The bond-valance-sum model confirms the expected values of ion charges. The title compound is isotypic with Na9Sc(MoO4)6 and Na9Fe(MoO4)6. It is compared and discussed with similar structures. PMID:25995849

  10. The (111) Surface of NaAu 2. Structure, Composition, and Stability

    DOE PAGESBeta

    Kwolek, Emma J.; Widmer, Roland; Gröning, Oliver; Deniz, Okan; Walen, Holly; Yuen, Chad D.; Huang, Wenyu; Schlagel, Deborah L.; Wallingford, Mark; Thiel, Patricia A.

    2014-12-17

    The (111) surface of single-crystal NaAu2 is a model for catalytically active, powdered NaAu2. We prepare and characterize this surface with a broad suite of techniques. Preparation in ultrahigh vacuum consists of the traditional approach of ion bombardment (to remove impurities) and thermal annealing (to restore surface order). Both of these steps cause loss of sodium (Na), and repeated treatments eventually trigger conversion of the surface and near-surface regions to crystalline gold. The bulk has a limited ability to repopulate the surface Na. Under conditions where Na depletion is minimized, electron diffraction patterns are consistent with the bulk-terminated structure, andmore »scanning tunneling microscopy reveals mesa-like features with lateral dimensions of a few tens of nanometers. The tops of the mesas do not possess fine structure characteristic of a periodic lattice, suggesting that the surface layer is disordered under the conditions of these experiments.« less

  11. Solubility of NaCl in aqueous electrolyte solutions from 10 to 100°C

    USGS Publications Warehouse

    Clynne, M.A.; Potter, R.W., II; Haas, J.L., Jr.

    1981-01-01

    The solubilities of NaCl in aqueous KCl, MgCl2, CaCl2, and mixed CaCl2-KCl solutions have been determined from 10 to 100??C. The data were fit to an equation, and the equation was used to calculate values of the change in solubility of NaCl, ???[NaCl]/???T. These values are required for calculations of the rate of migration of fluids in a thermal gradient in rock salt. The data obtained here indicate that the values of ???[NaCl]/???T are 36-73% greater for solutions containing divalent ions than for the NaCl-H2O system.

  12. [The Na+/H+ antiport: a target for new antihypertensive agents].

    PubMed

    Denolle, T; Plouin, P F

    1989-01-01

    The sodium-hydrogen (Na+/H+) antiport is electroneutral and amiloride-sensitive. It exchanges Na+ for H+ with a coupling ratio of 1:1 and therefore, it has important cellular functions: intracellular pH and cell volume regulation, control of the cell differentiation and growth. Its activity is increased in hypertension. The responsibility of the Na+/H+ antiport in essential hypertension may result in increased vascular tone and vascular hyperplasia. Amiloride is a specific inhibitor of this exchanger but under physiological conditions, very high concentrations of this drug (that are unlikely to be attained in vivo) are required to inhibit the activity of the Na+/H+ antiport. Certain of its analogues are much more potent in vitro than amiloride. Therefore, the Na+/H+ antiport may become a target for new antihypertensive drugs. PMID:2551056

  13. Population transfer in the Na s-p Rydberg ladder by a chirped microwave pulse

    SciTech Connect

    Maeda, H.; Gurian, J. H.; Gallagher, T. F.

    2011-12-15

    While quantum defects of nl Rydberg states of Na with l{>=}2 are nearly equal to zero, the quantum defects of ns and np states of Na are quite large due to the finite size of its ionic core. Since the Na ns and np states are energetically isolated from the higher angular momentum states of the same n, we can think of the Na ns and np Rydberg states as a specific example of a simple multilevel ladder system consisting of only alternating s and p angular momentum states. Here we report that population transfer in the Na s-p Rydberg ladder can be effectively achieved using a frequency-chirped microwave pulse, which couples only s and p states under suitable conditions.

  14. Discharge Reaction Mechanisms in Na/FeS2 Batteries: First-Principles Calculations

    NASA Astrophysics Data System (ADS)

    Momida, Hiroyoshi; Kitajou, Ayuko; Okada, Shigeto; Yamashita, Tomoki; Oguchi, Tamio

    2015-12-01

    We have studied microscopic discharge reaction mechanisms in Na/FeS2 batteries by first-principles calculations. The calculated Na-Fe-S phase diagram shows that the discharge reactions can proceed by converting 4Na and FeS2 into 2Na2S and Fe as a fully discharged state. As an intermediate discharge reaction, we find that NaxFeS2 (x ˜ 1.5) intermediate products can be generated in the cathode, giving two major plateaus in voltage-capacity curves. The calculated voltage-capacity characteristics and X-ray absorption spectra at S and Fe K-edges of Na-discharged FeS2 cathode materials are compared with experimental results, showing that theoretically determined reaction formulas can account for the experimental discharge reactions.

  15. The (111) Surface of NaAu2. Structure, Composition, and Stability

    DOE PAGESBeta

    Kwolek, Emma J.; Widmer, Roland; Gröning, Oliver; Deniz, Okan; Walen, Holly; Yuen, Chad D.; Huang, Wenyu; Schlagel, Deborah L.; Wallingford, Mark; Thiel, Patricia A.

    2014-12-17

    The (111) surface of single-crystal NaAu2 is a model for catalytically active, powdered NaAu2. We prepare and characterize this surface with a broad suite of techniques. Preparation in ultrahigh vacuum consists of the traditional approach of ion bombardment (to remove impurities) and thermal annealing (to restore surface order). Both of these steps cause loss of sodium (Na), and repeated treatments eventually trigger conversion of the surface and near-surface regions to crystalline gold. The bulk has a limited ability to repopulate the surface Na. Under conditions where Na depletion is minimized, electron diffraction patterns are consistent with the bulk-terminated structure, andmore »scanning tunneling microscopy reveals mesa-like features with lateral dimensions of a few tens of nanometers. The tops of the mesas do not possess fine structure characteristic of a periodic lattice, suggesting that the surface layer is disordered under the conditions of these experiments.« less

  16. The (111) Surface of NaAu2. Structure, Composition, and Stability

    SciTech Connect

    Kwolek, Emma J.; Widmer, Roland; Gröning, Oliver; Deniz, Okan; Walen, Holly; Yuen, Chad D.; Huang, Wenyu; Schlagel, Deborah L.; Wallingford, Mark; Thiel, Patricia A.

    2014-12-17

    The (111) surface of single-crystal NaAu2 is a model for catalytically active, powdered NaAu2. We prepare and characterize this surface with a broad suite of techniques. Preparation in ultrahigh vacuum consists of the traditional approach of ion bombardment (to remove impurities) and thermal annealing (to restore surface order). Both of these steps cause loss of sodium (Na), and repeated treatments eventually trigger conversion of the surface and near-surface regions to crystalline gold. The bulk has a limited ability to repopulate the surface Na. Under conditions where Na depletion is minimized, electron diffraction patterns are consistent with the bulk-terminated structure, and scanning tunneling microscopy reveals mesa-like features with lateral dimensions of a few tens of nanometers. The tops of the mesas do not possess fine structure characteristic of a periodic lattice, suggesting that the surface layer is disordered under the conditions of these experiments.

  17. Search for solid conductors of Na(+) and K(+) ions: Five new conductors

    NASA Technical Reports Server (NTRS)

    Singer, J.; Kautz, H.; Fielder, W. L.; Fordyce, J.

    1975-01-01

    Five conductors of three structure types were discovered which, as solids, can transport Na(+) or K(+) ions with conductivities of approximately .00001/(omega cm) at 300 K. These compounds are: (1) the pyrochlores NaTaWO6 and NaTa2O5F, both with an activation energy for conduction delta E of 21 kJ/mole; (2) the bodycentered cubic form of NaSbO3, with delta E = 42 kJ/mole; and (3) the niobates 2Na2O with 3Nb2O5 and 2K2O with 3Nb2O5, with the alkali ions probably in open layers of the incompletely determined structure; delta E = 17 kJ/mole. On the basis of approximately 40 structure types, some generalizations were made regarding the relation between structure and ionic transport.

  18. Design of a Mechanical NaK Pump for Fission Space Power

    NASA Technical Reports Server (NTRS)

    Mireles, Omar R.; Bradley, David E.; Godfroy, Thomas

    2011-01-01

    Alkali liquid metal cooled fission reactor concepts are under development for spaceflight power requirements. One such concept utilizes a sodium-potassium eutectic (NaK) as the primary loop working fluid, which has specific pumping requirements. Traditionally, electromagnetic linear induction pumps have been used to provide the required flow and pressure head conditions for NaK systems but they can be limited in performance, efficiency, and number of available vendors. The objective of the project was to develop a mechanical NaK centrifugal pump that takes advantages of technology advances not available in previous liquid metal mechanical pump designs. This paper details the design, build, and performance test of a mechanical NaK pump developed at NASA Marshall Space Flight Center. The pump was designed to meet reactor cooling requirements using commercially available components modified for high temperature NaK service.

  19. Crystallization and spectroscopic properties in Er3+ doped oxyfluorogermanate glass ceramics containing Na

    NASA Astrophysics Data System (ADS)

    Hu, Yuebo; Qiu, Sawei; Gao, Yuan; Qiu, Jianbei

    2015-07-01

    The Er3+ doped oxyfluorogermanate glasses, with a composition containing Na element, were synthesized by the conventional melting-quenching technique. When Na element was introduced into the composition of oxyfluorogermanate glass, the crystals behavior was investigated in details. Depending on the annealing procedure supplied, thermal annealing of precursor glasses in the system GeO2/BaF2/AlF3/Na2O/NaF/ZnO/GdF3/ErF3 led to the precipitation of different crystal phase nanocrystals. It was confirmed the nanocrystals in GC600 is orthorhombic NaBaAlF6 which led to enhance obviously in the UC luminescence of Er3+. However, the nanocrystals in G585 led to decrease in the UC luminescence, which indicated few Er ions enter into the lattice of this nanocrystal phase. The reason of the decrease in UC emission intensity of GC585 was analyzed.

  20. Sodium manganese oxide thin films as cathodes for Na-ion batteries

    SciTech Connect

    Baggetto, Loic; Carroll, Kyler J; Unocic, Raymond R; Bridges, Craig A; Meng, Ying Shirley; Veith, Gabriel M

    2014-01-01

    This paper presents the fabrication and characterization of sodium manganese oxide cathode thin films for rechargeable Na-ion batteries. Layered oxide compounds of nominal compositions Na0.6MnO2 and Na1.0MnO2 have been prepared by radio frequency magnetron sputtering and post-annealing at high temperatures under various conditions. The Na0.6MnO2 thin films possess either a hexagonal or orthorhombic structure while the Na1.0MnO2 films crystallize in a monoclinic structure, as shown by X-ray diffraction and X-ray absorption spectroscopy results. The potential profiles of the film cathodes are characterized by features similar to those measured for the powders and exhibit reversible storage capacities in the range of 50-60 Ah cm-2 m-1, which correspond to about 120-140 mAh g-1, and are maintained over 80 cycles.

  1. CONHECIMENTO DA LEI GERAL DE SAÚDE – RESPEITO ÀS TRANSFUSÕES SANGUÍNEAS EM MÉDICOS E PACIENTES TESTEMUNHAS DE JEOVÁ DO HOSPITAL DR. DARÍO CONTRERAS DA REPÚBLICA DOMINICANA

    PubMed Central

    SANTANA, ELSA DÍAZ

    2010-01-01

    Este estudo avalia quanto o corpo médico do Hospital Dr. Darío Contreras de República Dominicana conhece, respeita, informa e aplica a Lei Geral de Saúde em relação aos direitos do paciente Testemunha de Jeová de negar-se a ser transfundido (respeito a sua autonomia); também se os Testemunhas de Jeová conhecem a Lei Geral de Saúde e até que ponto têm se beneficiado diante dessa proposição. O estudo revelou que nem médicos, nem Testemunhas de Jeová conhecem de fato essa lei. PMID:20689657

  2. Sodium Transport Is Modulated by p38 Kinase–Dependent Cross-Talk between ENaC and Na,K-ATPase in Collecting Duct Principal Cells

    PubMed Central

    Wang, Yu-Bao; Leroy, Valérie; Maunsbach, Arvid B.; Doucet, Alain; Hasler, Udo; Dizin, Eva; Ernandez, Thomas; de Seigneux, Sophie; Martin, Pierre-Yves

    2014-01-01

    In relation to dietary Na+ intake and aldosterone levels, collecting duct principal cells are exposed to large variations in Na+ transport. In these cells, Na+ crosses the apical membrane via epithelial Na+ channels (ENaC) and is extruded into the interstitium by Na,K-ATPase. The activity of ENaC and Na,K-ATPase must be highly coordinated to accommodate variations in Na+ transport and minimize fluctuations in intracellular Na+ concentration. We hypothesized that, independent of hormonal stimulus, cross-talk between ENaC and Na,K-ATPase coordinates Na+ transport across apical and basolateral membranes. By varying Na+ intake in aldosterone-clamped rats and overexpressing ?-ENaC or modulating apical Na+ availability in cultured mouse collecting duct cells, enhanced apical Na+ entry invariably led to increased basolateral Na,K-ATPase expression and activity. In cultured collecting duct cells, enhanced apical Na+ entry increased the basolateral cell surface expression of Na,K-ATPase by inhibiting p38 kinase-mediated endocytosis of Na,K-ATPase. Our results reveal a new role for p38 kinase in mediating cross-talk between apical Na+ entry via ENaC and its basolateral exit via Na,K-ATPase, which may allow principal cells to maintain intracellular Na+ concentrations within narrow limits. PMID:24179170

  3. The IMF-sensitive 1.14-?m Na I doublet in early-type galaxies

    NASA Astrophysics Data System (ADS)

    Smith, Russell J.; Alton, Padraig; Lucey, John R.; Conroy, Charlie; Carter, David

    2015-11-01

    We present J-band spectroscopy of passive galaxies focusing on the Na I doublet at 1.14 ?m. Like the Na I 0.82 ?m doublet, this feature is strong in low-mass stars and hence may provide a useful probe of the initial mass function (IMF). From high signal-to-noise composite spectra, we find that Na I 1.14 ?m increases steeply with increasing velocity dispersion, ?, and for the most massive galaxies (? ? 300 km s-1) is much stronger than predicted from synthetic spectra with Milky Way-like IMFs and solar abundances. Reproducing Na I 1.14 ?m at high ? likely requires either a very high [Na/H], or a bottom-heavy IMF, or a combination of both. Using the Na D line to break the degeneracy between IMF and abundance, we infer [Na/H] ? +0.5 and a steep IMF (single-slope-equivalent x ? 3.2, where x = 2.35 for Salpeter), for the high-? galaxies. At lower mass (? = 50-100 km s-1), the line strengths are compatible with Milky Way (MW)-like IMFs and near-solar [Na/H]. We highlight two galaxies in our sample where strong gravitational lensing masses favour MW-like IMFs. Like the high-? sample on average, these galaxies have strong Na I 1.14 ?m; taken in isolation their sodium indices imply bottom-heavy IMFs which are hard to reconcile with the lensing masses. An alternative full-spectrum-fitting approach, applied to the high-? sample, recovers an IMF less heavy than Salpeter, but under-predicts the Na I 1.14 ?m line at the 5? level. We conclude that current models struggle to reproduce this feature in the most massive galaxies without breaking other constraints, and caution against over-reliance on the sodium lines in spectroscopic IMF studies.

  4. Presynaptic Na+ channels: locus, development, and recovery from inactivation at a high-fidelity synapse.

    PubMed

    Leão, Ricardo M; Kushmerick, Christopher; Pinaud, Raphael; Renden, Robert; Li, Geng-Lin; Taschenberger, Holger; Spirou, George; Levinson, S Rock; von Gersdorff, Henrique

    2005-04-01

    Na+ channel recovery from inactivation limits the maximal rate of neuronal firing. However, the properties of presynaptic Na+ channels are not well established because of the small size of most CNS boutons. Here we study the Na+ currents of the rat calyx of Held terminal and compare them with those of postsynaptic cells. We find that presynaptic Na+ currents recover from inactivation with a fast, single-exponential time constant (24 degrees C, tau of 1.4-1.8 ms; 35 degrees C, tau of 0.5 ms), and their inactivation rate accelerates twofold during development, which may contribute to the shortening of the action potential as the terminal matures. In contrast, recordings from postsynaptic cells in brainstem slices, and acutely dissociated, reveal that their Na+ currents recover from inactivation with a double-exponential time course (tau(fast) of 1.2-1.6 ms; tau(slow) of 80-125 ms; 24 degrees C). Surprisingly, confocal immunofluorescence revealed that Na+ channels are mostly absent from the calyx terminal but are instead highly concentrated in an unusually long (approximately 20-40 microm) unmyelinated axonal heminode. Outside-out patch recordings confirmed this segregation. Expression of Na(v)1.6 alpha-subunit increased during development, whereas the Na(v)1.2alpha-subunit was not present. Serial EM reconstructions also revealed a long pre-calyx heminode, and biophysical modeling showed that exclusion of Na+ channels from the calyx terminal produces an action potential waveform with a shorter half-width. We propose that the high density and polarized locus of Na+ channels on a long heminode are critical design features that allow the mature calyx of Held terminal to fire reliably at frequencies near 1 kHz. PMID:15814803

  5. Heterologous expression of NaV1.9 chimeras in various cell systems.

    PubMed

    Goral, R Oliver; Leipold, Enrico; Nematian-Ardestani, Ehsan; Heinemann, Stefan H

    2015-12-01

    SCN11A encodes the voltage-gated sodium channel NaV1.9, which deviates most strongly from the other eight NaV channels expressed in mammals. It is characterized by resistance to the prototypic NaV channel blocker tetrodotoxin and exhibits slow activation and inactivation gating. Its expression in dorsal root ganglia neurons suggests a role in motor or pain signaling functions as also recently demonstrated by the occurrence of various mutations in human SCN11A leading to altered pain sensation syndromes. The systematic investigation of human NaV1.9, however, is severely hampered because of very poor heterologous expression in host cells. Using patch-clamp and two-electrode voltage-clamp methods, we show that this limitation is caused by the C-terminal structure of NaV1.9. A chimera of NaV1.9 harboring the C terminus of NaV1.4 yields functional expression not only in neuronal cells but also in non-excitable cells, such as HEK 293T or Xenopus oocytes. The major functional difference of the chimeric channel with respect to NaV1.9 is an accelerated activation and inactivation. Since the entire transmembrane domain is preserved, it is suited for studying pharmacological properties of the channel and the functional impact of disease-causing mutations. Moreover, we demonstrate how mutation S360Y makes NaV1.9 channels sensitive to tetrodotoxin and saxitoxin and that the unusual slow open-state inactivation of NaV1.9 is also mediated by the IFM (isoleucine-phenylalanine-methionine) inactivation motif located in the linker connecting domains III and IV. PMID:25916202

  6. Fluid dilution and efficiency of Na+ transport in a mathematical model of a thick ascending limb cell

    PubMed Central

    Clausen, Chris; Marcano, Mariano; Layton, Anita T.; Layton, Harold E.; Moore, Leon C.

    2013-01-01

    Thick ascending limb (TAL) cells are capable of reducing tubular fluid Na+ concentration to as low as ?25 mM, and yet they are thought to transport Na+ efficiently owing to passive paracellular Na+ absorption. Transport efficiency in the TAL is of particular importance in the outer medulla where O2 availability is limited by low blood flow. We used a mathematical model of a TAL cell to estimate the efficiency of Na+ transport and to examine how tubular dilution and cell volume regulation influence transport efficiency. The TAL cell model represents 13 major solutes and the associated transporters and channels; model equations are based on mass conservation and electroneutrality constraints. We analyzed TAL transport in cells with conditions relevant to the inner stripe of the outer medulla, the cortico-medullary junction, and the distal cortical TAL. At each location Na+ transport efficiency was computed as functions of changes in luminal NaCl concentration ([NaCl]), [K+], [NH4+], junctional Na+ permeability, and apical K+ permeability. Na+ transport efficiency was calculated as the ratio of total net Na+ transport to transcellular Na+ transport. Transport efficiency is predicted to be highest at the cortico-medullary boundary where the transepithelial Na+ gradient is the smallest. Transport efficiency is lowest in the cortex where luminal [NaCl] approaches static head. PMID:23097469

  7. Relationship between sodium-dependent phosphate transporter (NaPi-IIc) function and cellular vacuole formation in opossum kidney cells.

    PubMed

    Shiozaki, Yuji; Segawa, Hiroko; Ohnishi, Saori; Ohi, Akiko; Ito, Mikiko; Kaneko, Ichiro; Kido, Shinsuke; Tatsumi, Sawako; Miyamoto, Ken-ichi

    2015-01-01

    NaPi-IIc/SLC34A3 is a sodium-dependent inorganic phosphate (Pi) transporter in the renal proximal tubules and its mutations cause hereditary hypophosphatemic rickets with hypercalciuria (HHRH). In the present study, we created a specific antibody for opossum SLC34A3, NaPi-IIc (oNaPi-IIc), and analyzed its localization and regulation in opossum kidney cells (a tissue culture model of proximal tubular cells). Immunoreactive oNaPi-IIc protein levels increased during the proliferative phase and decreased during differentiation. Moreover, stimulating cell growth upregulated oNaPi-IIc protein levels, whereas suppressing cell proliferation downregulated oNaPi-IIc protein levels. Immunocytochemistry revealed that endogenous and exogenous oNaPi-IIc proteins localized at the protrusion of the plasma membrane, which is a phosphatidylinositol 4,5-bisphosphate (PIP2) rich-membrane, and at the intracellular vacuolar membrane. Exogenous NaPi-IIc also induced cellular vacuoles and localized in the plasma membrane. The ability to form vacuoles is specific to electroneutral NaPi-IIc, and not electrogenic NaPi-IIa or NaPi-IIb. In addition, mutations of NaPi-IIc (S138F and R468W) in HHRH did not cause cellular PIP2-rich vacuoles. In conclusion, our data anticipate that NaPi-IIc may regulate PIP2 production at the plasma membrane and cellular vesicle formation. PMID:26399350

  8. Microstructural evolution in NaNbO3-based antiferroelectrics

    NASA Astrophysics Data System (ADS)

    Guo, Hanzheng; Shimizu, Hiroyuki; Randall, Clive A.

    2015-11-01

    Our recent study found that CaZrO3 doping can effectively enhance the antiferroelectric P phase in NaNbO3 ceramics, leading to a double polarization hysteresis loop characteristic of a reversible antiferroelectric ? ferroelectric phase transition [Shimizu et al., Dalton Trans. 44, 10763 (2015)]. Here, a thorough transmission electron microscope study was performed to illustrate the CaZrO3 doping-assisted antiferroelectricity stabilization. In parallel to the bright-field imaging and selected area electron diffraction from multiple zone axes, detailed dark-field imaging was utilized to determine the superlattice structural origins, from either oxygen octahedral tilting or antiparallel cation displacements. By analogy with Pb(Zr1-xTix)O3 and rare-earth doped BiFeO3 systems, the chemical substitutions are such as to an induced polar-to-antipolar transition that is consistent with a tolerance factor reduction. The resultant chemical pressure has a similar effect to the compressive hydrostatic pressure where the antiferroelectric state is favored over the ferroelectric state.

  9. Higher-spin structures in 21F and 25Na

    NASA Astrophysics Data System (ADS)

    VonMoss, J. M.; Tabor, S. L.; Tripathi, Vandana; Volya, A.; Abromeit, B.; Bender, P. C.; Caussyn, D. D.; Dungan, R.; Kravvaris, K.; Kuchera, M. P.; Lubna, R.; Miller, S.; Parker, J. J.; Tai, P.-L.

    2015-09-01

    Excited states were investigated in 21F and 25Na using the 9Be(14C,p n ? ) reaction at 30, 35, and 45 MeV and the 9Be(18O,p n ? ) reaction at 35 MeV. Protons were detected and identified in an E -? E telescope at 0? in coincidence with one or more ? radiations in the FSU Compton-suppressed Ge detector array. Many new levels and electromagnetic decays were observed, especially among the higher spin states. Angular distributions and mean lifetimes were measured wherever possible in both nuclei. The energy levels of the positive-parity states in the two nuclei agree rather well with shell model calculations using both the USDA and WBP interactions up to the highest spins observed of 13 /2 ? . Both a weak coupling approximation and shell model calculations using the WBP interaction generally reproduce the negative-parity states in 21F. The shell model calculations reproduce relatively well the measured M 1 and E 2 transitions in both nuclei, but overpredict the parity-changing E 1 transitions in 21F, the only nucleus in which negative-parity states were observed in the present experiment.

  10. Na-22 decay gamma rays from classical novae

    NASA Technical Reports Server (NTRS)

    Truran, James W.

    1993-01-01

    NASA Grant NAG 5-1565 has provided support for a program of theoretical research in nuclear astrophysics and related areas, focusing upon the possibility of detecting gamma rays from nearby novae. Particular attention has been given to the evaluation of the theoretical expectations for gamma ray emission from four possible sources: (1) the positron decays of the unstable CNO and fluorine isotopes that are transported to the surface regions of the envelope in the earliest stages of the outbursts; (2) Be-7 decay gamma rays, (3) Na-22 decay gamma rays released in the later stages of the outbursts; and (4) Al-26 decay gamma rays from novae and their possible contribution to Galactic emission. The critical questions of (1) the frequency of occurrence of ONeMg-enriched novae; (2) the expected Galactic distribution of the novae that produce 26Al; and (3) the nature of the observed soft X-ray emission from classical novae, have also been addressed. Considerable progress in research has been achieved on many of these fronts. Brief summaries of the results of several research projects are presented.

  11. Intercomparison of Chemically Independent Peroxide Observations During INTEX-NA

    NASA Astrophysics Data System (ADS)

    O'Sullivan, D. W.; Shen, H.; Heikes, B. G.; Crounse, J. D.; Kwan, A. J.; Wennberg, P. O.; Pippin, M. R.; Crawford, J. H.

    2005-12-01

    Gas phase peroxide measurements were preformed with two analytical techniques during the INTEX-NA field project. In the first method peroxides were partitioned into an aqueous phase in cyclone separators, the aqueous collection solution was injected on to an HPLC to separate hydrogen peroxide and organic peroxides. Separated peroxides were quantified by a post column derivatization reaction with p-hydroxyphenyl acetic acid and horse radish peroxidase forming a fluorescent dimer. This method is capable of identification and quantification of C1 and C2 organic peroxides. With the dual HPLC system a 30 sec integrated sample was analyzed every 90 sec. The second method employed chemical ionization mass spectrometry to quantify the peroxides via a direct gas phase ion-molecule reaction between the peroxide and a CFO3- ion. The Caltech CIMS technique makes a 0.5 sec measurement every 5 sec. Comparison of the observations of hydrogen peroxide by both techniques on the same time base results in nearly a 90% correspondence between the techniques. Both systems also quantified peroxyacetic acid (PAA) with a 72% correspondence between observations. The majority of discrepancies between the techniques occur for observations approaching the respective detection limits. The PAA observations are the first measurements for this compound in the troposphere. The specificity of the enzyme catalyzed technique for the peroxide moiety and the characteristic retention time, coupled to the unique mass number identification using CIMS lends confidence to the correct identification and quantification of PAA.

  12. Potencja? turystyczny Lublina jako czynnik rozwoju miasta na przestrzeni wieków

    NASA Astrophysics Data System (ADS)

    Kociuba, Dagmara; Kociuba, Waldemar

    2009-01-01

    Lublin is situated on eastern border of Na??czów Plateau at three rivers' confluence, it is the very picturesque city with beautiful panoramic sights. On touristic attractiveness of city influence both the natural as well cultural values, in peculiarity the objects of the material culture which are the heritage of men of different nationalities and religions living here over the centuries. The touristic potential of Lublin showed the large changeability in time. It structural and functional supplies were changed. The division into periods of city's popularity was marked, from very large in XV-XVI and XIX-XXI century to smaller in period of the XVIII century. Last years the touristic policy activation was noticed which manifesting the intensification of marketing actings having on aim the enlargement the touristic attractiveness of city e.g. creating the mark of Lublin and the projects in frames of the Bug Euroregion. They are effective of elevation of the rank of cultural output e.g. acknowledgement of the Lublin's historical town-planning complex the title of Monument History, inclusion of Lublin to European programme "Intercultural Cities", or trying about acknowledgement in 2016 r. the title of European Capital of Culture.

  13. Adsorbates effects in H^- - Na/Cu(111) collisions

    NASA Astrophysics Data System (ADS)

    Bahrim, Bogdana; Yu, Song

    2008-03-01

    The (111) faces of Cu, Ag and Au present a band gap that extends just below the vacuum level at the ? gpoint [1]. The effect is to forbid electrons with energies in a certain range to be transferred into the metal along the surface normal. Thus, the presence of a band gap should dramatically influence various experiments in ion-surface collisions involving electron capture or loss. In recent years, this topic received a great interest [2 -- 4]. Adsorbates deposition makes the electron dynamics at such surfaces to be even more complex. We analyze some interesting adsorbates effects: (1) projectile energy levels and widths are strongly perturbed when this approaches close to an adsorbate atom; (2) scattering by adsorbates may be used to laterally confine surface state electrons; (3) adsorbates may enhance the band gap effect; (4) adsorbates tend to couple the surface states to the bulk states. Results for the H^- projectile interacting with a Na/Cu(111) surface are reported. [1] E.V. Chulkov, V.M. Silkin and P.M. Echenique 1999 Surf. Sci. 437, 330. [2] A.G. Borisov, A.K. Kazansky and J.P. Gauyacq 1999 Phys. Rev. B. 59, 10935. [3] H.S. Chakraborty, T. Niederhausen and U. Thumm 2004 Phys. Rev. A. 70, 052903. [4] B. Bahrim, B. Makarenko and J.W. Rabalais 2005 Surface Sci. 594, 62.

  14. Inelastic Proton Scattering on 21Na in Inverse Kinematics

    NASA Astrophysics Data System (ADS)

    Austin, Roby

    2009-10-01

    R.A.E. Austin, R. Kanungo, S. Reeve, Saint Mary's University; D.G. Jenkins, C.Aa.Diget, A. Robinson, A.G. Tuff, O. Roberts, University of York, UK; P.J. Woods, T. Davinson, G. J. Lotay, University of Edinburgh; C.-Y. Wu, Lawrence Livermore National Laboratory; H. Al Falou, G.C. Ball, M. Djongolov, A. Garnsworthy, G. Hackman, J.N. Orce, C.J. Pearson, S. Triambak, S.J. Williams, TRIUMF; C. Andreiou, D.S. Cross, N. Galinski, R. Kshetri, Simon Fraser University; C. Sumithrarachchi, M.A. Schumaker, University of Guelph; M.P. Jones, S.V. Rigby, University of Liverpool; D. Cline, A. Hayes, University of Rochester; T.E. Drake, University of Toronto; We describe an experiment and associated technique [1] to measure resonances of interest in astrophysical reactions. At the TRIUMF ISAC-II radioactive beam accelerator facility in Canada, particles inelastically scattered in inverse kinematics are detected with Bambino, a ?E-E silicon telescope spanning 15-40 degrees in the lab. We use the TIGRESS to detect gamma rays in coincidence with the charged particles to cleanly select inelastic scattering events. We measured resonances above the alpha threshold in ^22Mg of relevance to the rate of break-out from the hot-CNO cycle via the reaction ^ 18Ne(?,p)^21Na. [1] PJ Woods et al. Rex-ISOLDE proposal 424 Cern (2003).

  15. Precise Double-Photoionization Data for Na and K

    NASA Astrophysics Data System (ADS)

    Jurani?, P. N.; Nordberg, J. C.; Wehlitz, R.

    2006-05-01

    We have measured precise double-to-single photoionization ratios and double-photoionization cross-sections of sodium and potassium near threshold. A previously discovered scaling law allows us to conveniently compare the energy dependence of the double-to-single photoionization ratio by scaling the energy axis. Recently, we have also found a scaling law that enables us to predict the absolute double-to-single photoionization ratio. We have applied this scaling law to our new data and found excellent agreement. Previous tests of this scaling law were limited to systems where electrons were emitted from s-shells. However, in the cases of Na and K a p electrons is participating in the double-ionization process. Interestingly and in spite of the different orbital, the scaling law is still valid. R. Wehlitz and S. B. Whitfield, J. Phys. B 34, L719 (2001). J.B. Bluett, D. Luki'c, S.B. Whitfield, and R. Wehlitz, Nucl. Instrum. Methods B, 241, 114 (2005).

  16. Use of the discrete variable representation in the quantum dynamics by a wave packet propagation: Predissociation of NaI(1Sigma + 0) --> NaI(0 + ) --> Na(2S)+I(2P)

    NASA Astrophysics Data System (ADS)

    Choi, Seung E.; Light, J. C.

    1989-03-01

    Using the Gauss-Chebyshev discrete variable representation (DVR), the dissociative quantum dynamics for a wave packet evolving under the influence of the Hamiltonian for two interacting diabatic states of a diatomic molecule is calculated. The split time evolution operator method is used to obtain the solutions to the time-dependent Schrödinger equation. A specific example of the numerical calculation is shown for the predissociation process of NaI?Na(2S)+I(2P) from its first excited electronic state (0+). The numerical results are compared with the experimental observations from the femtosecond laser photofragmentation, recently reported by Zewail and co-workers.

  17. Calcite dissolution and Ca/Na ion-exchange reactions in columns with different flow rates through high ESR soil 

    E-print Network

    Navarre, Audrey

    1999-01-01

    -exchange complex. Following elution with deionized water, the columns were sectioned and analyzed for residual Na. In all cases, the eluate exhibited approximate thermodynamic equilibrium with respect to calcite. Calcite dissolution and Na?/Ca²? ion exchange...

  18. Role of Na+/H+ exchanger regulatory factor 1 in forward trafficking of the type IIa Na+-Pi cotransporter.

    PubMed

    Ketchem, Corey J; Khundmiri, Syed J; Gaweda, Adam E; Murray, Rebecca; Clark, Barbara J; Weinman, Edward J; Lederer, Eleanor D

    2015-07-15

    Na+/H+ exchanger regulatory factor (NHERF1) plays a critical role in the renal transport of phosphate by binding to Na+-Pi cotransporter (NpT2a) in the proximal tubule. While the association between NpT2a and NHERF1 in the apical membrane is known, the role of NHERF1 to regulate the trafficking of NpT2a has not been studied. To address this question, we performed cell fractionation by sucrose gradient centrifugation in opossum kidney (OK) cells placed in low-Pi medium to stimulate forward trafficking of NpT2a. Immunoblot analysis demonstrated expression of NpT2a and NHERF1 in the endoplasmic reticulum (ER)/Golgi. Coimmunoprecipitation demonstrated a NpT2a-NHERF1 interaction in the ER/Golgi. Low-Pi medium for 4 and 8 h triggered a decrease in NHERF1 in the plasma membrane with a corresponding increase in the ER/Golgi. Time-lapse total internal reflection fluorescence imaging of OK cells placed in low-Pi medium, paired with particle tracking and mean square displacement analysis, indicated active directed movement of NHERF1 at early and late time points, whereas NpT2a showed active movement only at later times. Silence of NHERF1 in OK cells expressing green fluorescent protein (GFP)-NpT2a resulted in an intracellular accumulation of GFP-NpT2a. Transfection with GFP-labeled COOH-terminal (TRL) PDZ-binding motif deleted or wild-type NpT2a in OK cells followed by cell fractionation and immunoprecipitation confirmed that the interaction between NpT2a and NHERF1 was dependent on the TRL motif of NpT2a. We conclude that appropriate trafficking of NpT2a to the plasma membrane is dependent on the initial association between NpT2a and NHERF1 through the COOH-terminal TRL motif of NpT2a in the ER/Golgi and requires redistribution of NHERF1 to the ER/Golgi. PMID:25995109

  19. X-ray Diffraction, Mössbauer Spectroscopy, Magnetic Susceptibility, and Specific Heat Investigations of Na4NpO5 and Na5NpO6.

    PubMed

    Smith, Anna L; Hen, Amir; Raison, Philippe E; Colineau, Eric; Griveau, Jean-Christophe; Magnani, Nicola; Sanchez, Jean-Pierre; Konings, Rudy J M; Caciuffo, Roberto; Cheetham, Anthony K

    2015-05-01

    The hexavalent and heptavalent sodium neptunate compounds Na4NpO5 and Na5NpO6 have been investigated using X-ray powder diffraction, Mössbauer spectroscopy, magnetic susceptibility, and specific heat measurements. Na4NpO5 has tetragonal symmetry in the space group I4/m, while Na5NpO6 adopts a monoclinic unit cell in the space group C2/m. Both structures have been refined for the first time using the Rietveld method. The valence states of neptunium in these two compounds, i.e., Np(VI) and Np(VII), respectively, have been confirmed by the isomer shift values of their Mössbauer spectra. The local structural properties obtained from the X-ray refinements have also been related to the quadrupole coupling constants and asymmetry parameters determined from the Mössbauer studies. The absence of magnetic ordering has been confirmed for Na4NpO5. However, specific heat measurements at low temperatures have suggested the existence of a Schottky-type anomaly at around 7 K in this Np(VI) phase. PMID:25859629

  20. Experimental Na/K exchange between alkali feldspar and an NaCl-KCl salt melt: chemically induced fracturing and element partitioning

    NASA Astrophysics Data System (ADS)

    Neusser, G.; Abart, R.; Fischer, F. D.; Harlov, D.; Norberg, N.

    2012-08-01

    The exchange of Na+ and K+ between alkali feldspar and a NaCl-KCl salt melt has been investigated experimentally. Run conditions were at ambient pressure and 850 °C as well as 1,000 °C. Cation exchange occurred by interdiffusion of Na+ and K+ on the feldspar sub-lattice, while the Si-Al framework remained unaffected. Due to the compositional dependence of the lattice parameters compositional heterogeneities resulting from Na+/K+ interdiffusion induced coherency stress and associated fracturing. Depending on the sense of chemical shift, different crack patterns developed. For the geometrically most regular case that developed when potassic alkali feldspar was shifted toward more sodium-rich compositions, a prominent set of cracks corresponding to tension cracks opened perpendicular to the direction of maximum tensile stress and did not follow any of the feldspar cleavage planes. The critical stress needed to initiate fracturing in a general direction of the feldspar lattice was estimated at ?0.35 GPa. Fracturing provided fast pathways for penetration of salt melt or vapor into grain interiors enhancing overall cation exchange. The Na/K partitioning between feldspar and the salt melt attained equilibrium values in the exchanged portions of the grains allowing for extraction of the alkali feldspar mixing properties.

  1. Structural investigation of Na3NpO4 and Na3PuO4 using X-ray diffraction and (237)Np Mössbauer spectroscopy.

    PubMed

    Smith, A L; Raison, P E; Hen, A; Bykov, D; Colineau, E; Sanchez, J-P; Konings, R J M; Cheetham, A K

    2015-11-14

    ?-Na3NpO4 and ?-Na3PuO4 exhibit an orthorhombic structure (Z = 8), in space group Fmmm, with lattice parameters a = 13.352(2) Å, b = 9.629(2) Å, and c = 6.673(2) Å for the neptunium compound, and a = 13.302(2) Å, b = 9.634(2) Å, and c = 6.651(2) Å for the plutonium analogue. The corresponding structure has been solved ab initio as no structural analogue could be found in the literature. The pentavalent state of neptunium has moreover been confirmed by (237)Np Mössbauer spectroscopy, and the local structural properties inferred from the X-ray Rietveld refinement have been related to the fitted quadrupole coupling constant and asymmetry parameters. The existence of a low temperature metastable m phase of Na3NpO4 and Na3PuO4, of the NaCl type, has also been suggested. PMID:26369476

  2. Noninvasive (1)H and (23)Na nuclear magnetic resonance imaging of ancient Egyptian human mummified tissue.

    PubMed

    Münnemann, Kerstin; Böni, Thomas; Colacicco, Giovanni; Blümich, Bernhard; Rühli, Frank

    2007-11-01

    Historic mummies are a unique example of the human desire for immortality. Therefore, it is not surprising that modern diagnostic imaging has been widely applied to study them. Yet, magnetic resonance imaging (MRI) of such old remains has never been successfully achieved in a noninvasive way without rehydration. Furthermore, the impact of artificial mummification as done in ancient Egypt by natron (a blend of NaCl, Na(2)CO(3), NaHCO(3) and NaP(2)SO(4)) on human tissue with a particular focus on the sodium spatial distribution has never been addressed. Here, we show for the very first time completely noninvasive (1)H and (23)Na imaging of an ancient Egyptian mummified finger by nuclear magnetic resonance (NMR). Protons could be visualized by NMR only in the tissue close to surface and sodium primarily in the bone, while computer tomography images both, soft tissue and bone but does not distinguish between different chemical elements. The selective enrichment of sodium in the bone may by due to postmortem incorporation of (23)Na into the tissue by natron-based mummification because our reference measurement of a historical finger not subjected to artificial mummification showed no sodium signal at all. Our results demonstrate not only the general feasibility of nonclinical MRI to visualize historic dry human tissues but also shows the specific (1)H and (23)Na spatial distributions in such mummy tissue, which is particularly interesting for archeology and may open up a new application for MRI. PMID:17490843

  3. Inactivation of tannins in milled sorghum grain through steeping in dilute NaOH solution.

    PubMed

    Adetunji, Adeoluwa I; Duodu, Kwaku G; Taylor, John R N

    2015-05-15

    Steeping milled sorghum in up to 0.4% NaOH was investigated as a method of tannin inactivation. NaOH steeping substantially reduced assayable total phenols and tannins in both Type III and Type II sorghums and with Type III sorghum caused a 60-80% reduction in ?-amylase inhibition compared to a 20% reduction by water steeping. NaOH treatment also reduced starch liquefaction time and increased free amino nitrogen. Type II tannin sorghum did not inhibit ?-amylase and consequently the NaOH treatment had no effect. HPLC and LC-MS of the tannin extracts indicated a general trend of increasing proanthocyanidin/procyanidin size with increasing NaOH concentration and steeping time, coupled with a reduction in total area of peaks resolved. These show that the NaOH treatment forms highly polymerised tannin compounds, too large to assay and to interact with the ?-amylase. NaOH pre-treatment of Type III sorghums could enable their utilisation in bioethanol production. PMID:25577074

  4. Reduced Na-K-Cl cotransport in vascular smooth muscle cells from spontaneously hypertensive rats

    SciTech Connect

    O'Donnell, M.E.; Owen, N.E. )

    1988-08-01

    The authors have previously demonstrated the presence of a prominent, cyclic nucleotide-sensitive Na-K-Cl cotransport in vascular smooth muscle cells (VSMC). Others have observed that Na-K-Cl cotransport levels are reduced in erythrocytes of patients with essential hypertension and have proposed that a defect in this Na transport system may play a role in the pathogenesis of the disease. However, such a defect has not been demonstrated in the putative target tissue for essential hypertension, i.e., the VSMC. In the present study, they compared Na-K-Cl cotransport of VSMC from spontaneously hypertensive rats (SHR) with Na-K-Cl cotransport of VSMC from normotensive Wistar-Kyoto rats (WKY). They found that Na-K-Cl cotransport of SHR VSMC is significantly reduced relative to that of WKY VSMC. The apparent ion affinities for Na-K-Cl cotransport of SHR VSMC did not differ from those determined for WKY VSMC. Furthermore, cyclic nucleotide regulation of cotransport also appeared to be the same for the two types of VSMC. In contrast, maximal saturable binding of ({sup 3}H)bumetanide observed in SHR VSMC was markedly reduced compared with that of WKY VSMC, but the K{sub d} values were similar. The data suggest that the reduction in cotransport observed in SHR VSMC is the result of a decrease in the number of available cotransport sites.

  5. Rigidification of the autolysis loop enhances Na[superscript +] binding to thrombin

    SciTech Connect

    Pozzi, Nicola; Chen, Raymond; Chen, Zhiwei; Bah, Alaji; Di Cera, Enrico

    2011-09-20

    Binding of Na{sup +} to thrombin ensures high activity toward physiological substrates and optimizes the procoagulant and prothrombotic roles of the enzyme in vivo. Under physiological conditions of pH and temperature, the binding affinity of Na{sup +} is weak due to large heat capacity and enthalpy changes associated with binding, and the K{sub d} = 80 mM ensures only 64% saturation of the site at the concentration of Na{sup +} in the blood (140 mM). Residues controlling Na{sup +} binding and activation have been identified. Yet, attempts to improve the interaction of Na{sup +} with thrombin and possibly increase catalytic activity under physiological conditions have so far been unsuccessful. Here we report how replacement of the flexible autolysis loop of human thrombin with the homologous rigid domain of the murine enzyme results in a drastic (up to 10-fold) increase in Na{sup +} affinity and a significant improvement in the catalytic activity of the enzyme. Rigidification of the autolysis loop abolishes the heat capacity change associated with Na{sup +} binding observed in the wild-type and also increases the stability of thrombin. These findings have general relevance to protein engineering studies of clotting proteases and trypsin-like enzymes.

  6. A Mechanism for Intracellular Release of Na+ by Neurotransmitter: Sodium Symporters

    PubMed Central

    Malinauskaite, Lina; Reinhard, Linda; Lyons, Joseph A.; Yano, Hideaki; Javitch, Jonathan A.

    2015-01-01

    Neurotransmitter:sodium symporters (NSS) terminate synaptic signal transmission by Na+-dependent reuptake of released neurotransmitters, with key conformational states reported for a bacterial homolog LeuT and an inhibitor-bound Drosophila dopamine transporter. However, a coherent mechanism of Na+-driven transport has not been described. Here, we present two crystal structures of MhsT, a NSS member from Bacillus halodurans, in occluded inward-facing states with bound Na+ ions and L-Trp that provide insight into the cytoplasmic release of Na+. The switch from outward- to inward-oriented states is centered on the partial unwinding of transmembrane helix 5, which is facilitated by a conserved GlyX9Pro motif that opens an intracellular pathway for water to access the Na2 site. Based on our structural and functional findings we propose a mechanism according to which solvation through the TM5 pathway facilitates Na+ release from Na2 and the transition to an inward-open state. PMID:25282149

  7. Role of protein dynamics in ion selectivity and allosteric coupling in the NaK channel.

    PubMed

    Brettmann, Joshua B; Urusova, Darya; Tonelli, Marco; Silva, Jonathan R; Henzler-Wildman, Katherine A

    2015-12-15

    Flux-dependent inactivation that arises from functional coupling between the inner gate and the selectivity filter is widespread in ion channels. The structural basis of this coupling has only been well characterized in KcsA. Here we present NMR data demonstrating structural and dynamic coupling between the selectivity filter and intracellular constriction point in the bacterial nonselective cation channel, NaK. This transmembrane allosteric communication must be structurally different from KcsA because the NaK selectivity filter does not collapse under low-cation conditions. Comparison of NMR spectra of the nonselective NaK and potassium-selective NaK2K indicates that the number of ion binding sites in the selectivity filter shifts the equilibrium distribution of structural states throughout the channel. This finding was unexpected given the nearly identical crystal structure of NaK and NaK2K outside the immediate vicinity of the selectivity filter. Our results highlight the tight structural and dynamic coupling between the selectivity filter and the channel scaffold, which has significant implications for channel function. NaK offers a distinct model to study the physiologically essential connection between ion conduction and channel gating. PMID:26621745

  8. Experimental Studies of NaK in a Simulated Space Environment

    NASA Technical Reports Server (NTRS)

    Gibons, Marc; Sanzi, James; Ljubanovic, Damir

    2011-01-01

    Space fission power systems are being developed at the National Aeronautics and Space Administration (NASA) and Department of Energy (DOE) with a short term goal of building a full scale, non-nuclear, Technology Demonstration Unit (TDU) test at NASA's Glenn Research Center. Due to the geometric constraints, mass restrictions, and fairly high temperatures associated with space reactors, liquid metals are typically used as the primary coolant. A eutectic mixture of sodium (22 percent) and potassium (78 percent), or NaK, has been chosen as the coolant for the TDU with a total system capacity of approximately 55 L. NaK, like all alkali metals, is very reactive, and warrants certain safety considerations. To adequately examine the risk associated with the personnel, facility, and test hardware during a potential NaK leak in the large scale TDU test, a small scale experiment was performed in which NaK was released in a thermal vacuum chamber under controlled conditions. The study focused on detecting NaK leaks in the vacuum environment as well as the molecular flow of the NaK vapor. This paper reflects the work completed during the NaK experiment and provides results and discussion relative to the findings.

  9. NA61/SHINE facility at the CERN SPS: beams and detector system

    NASA Astrophysics Data System (ADS)

    Abgrall, N.; Andreeva, O.; Aduszkiewicz, A.; Ali, Y.; Anticic, T.; Antoniou, N.; Baatar, B.; Bay, F.; Blondel, A.; Blumer, J.; Bogomilov, M.; Bogusz, M.; Bravar, A.; Brzychczyk, J.; Bunyatov, S. A.; Christakoglou, P.; Cirkovic, M.; Czopowicz, T.; Davis, N.; Debieux, S.; Dembinski, H.; Diakonos, F.; Di Luise, S.; Dominik, W.; Drozhzhova, T.; Dumarchez, J.; Dynowski, K.; Engel, R.; Efthymiopoulos, I.; Ereditato, A.; Fabich, A.; Feofilov, G. A.; Fodor, Z.; Fulop, A.; Ga?dzicki, M.; Golubeva, M.; Grebieszkow, K.; Grzeszczuk, A.; Guber, F.; Haesler, A.; Hasegawa, T.; Hierholzer, M.; Idczak, R.; Igolkin, S.; Ivashkin, A.; Jokovic, D.; Kadija, K.; Kapoyannis, A.; Kaptur, E.; Kielczewska, D.; Kirejczyk, M.; Kisiel, J.; Kiss, T.; Kleinfelder, S.; Kobayashi, T.; Kolesnikov, V. I.; Kolev, D.; Kondratiev, V. P.; Korzenev, A.; Koversarski, P.; Kowalski, S.; Krasnoperov, A.; Kurepin, A.; Larsen, D.; Laszlo, A.; Lyubushkin, V. V.; Ma?kowiak-Paw?owska, M.; Majka, Z.; Maksiak, B.; Malakhov, A. I.; Maletic, D.; Manglunki, D.; Manic, D.; Marchionni, A.; Marcinek, A.; Marin, V.; Marton, K.; Mathes, H.-J.; Matulewicz, T.; Matveev, V.; Melkumov, G. L.; Messina, M.; Mrówczy?ski, St.; Murphy, S.; Nakadaira, T.; Nirkko, M.; Nishikawa, K.; Palczewski, T.; Palla, G.; Panagiotou, A. D.; Paul, T.; Peryt, W.; Petukhov, O.; Pistillo, C.; P?aneta, R.; Pluta, J.; Popov, B. A.; Posiadala, M.; Pu?awski, S.; Puzovic, J.; Rauch, W.; Ravonel, M.; Redij, A.; Renfordt, R.; Richter-Was, E.; Robert, A.; Röhrich, D.; Rondio, E.; Rossi, B.; Roth, M.; Rubbia, A.; Rustamov, A.; Rybczy?ski, M.; Sadovsky, A.; Sakashita, K.; Savic, M.; Schmidt, K.; Sekiguchi, T.; Seyboth, P.; Sgalaberna, D.; Shibata, M.; Sipos, R.; Skrzypczak, E.; S?odkowski, M.; Sosin, Z.; Staszel, P.; Stefanek, G.; Stepaniak, J.; Stroebele, H.; Susa, T.; Szuba, M.; Tada, M.; Tereshchenko, V.; Tolyhi, T.; Tsenov, R.; Turko, L.; Ulrich, R.; Unger, M.; Vassiliou, M.; Veberic, D.; Vechernin, V. V.; Vesztergombi, G.; Vinogradov, L.; Wilczek, A.; W?odarczyk, Z.; Wojtaszek-Szwarz, A.; Wyszy?ski, O.; Zambelli, L.; Zipper, W.

    2014-06-01

    NA61/SHINE (SPS Heavy Ion and Neutrino Experiment) is a multi-purpose experimental facility to study hadron production in hadron-proton, hadron-nucleus and nucleus-nucleus collisions at the CERN Super Proton Synchrotron. It recorded the first physics data with hadron beams in 2009 and with ion beams (secondary 7Be beams) in 2011. NA61/SHINE has greatly profited from the long development of the CERN proton and ion sources and the accelerator chain as well as the H2 beamline of the CERN North Area. The latter has recently been modified to also serve as a fragment separator as needed to produce the Be beams for NA61/SHINE. Numerous components of the NA61/SHINE set-up were inherited from its predecessors, in particular, the last one, the NA49 experiment. Important new detectors and upgrades of the legacy equipment were introduced by the NA61/SHINE Collaboration. This paper describes the state of the NA61/SHINE facility — the beams and the detector system — before the CERN Long Shutdown I, which started in March 2013.

  10. NaIrO{sub 3}-A pentavalent post-perovskite

    SciTech Connect

    Bremholm, M.; Dutton, S.E.; Stephens, P.W.; Cava, R.J.

    2011-03-15

    Sodium iridium (V) oxide, NaIrO{sub 3,} was synthesized by a high pressure solid state method and recovered to ambient conditions. It is found to be isostructural with CaIrO{sub 3}, the much-studied structural analog of the high-pressure post-perovskite phase of MgSiO{sub 3}. Among the oxide post-perovskites, NaIrO{sub 3} is the first example with a pentavalent cation. The structure consists of layers of corner- and edge-sharing IrO{sub 6} octahedra separated by layers of NaO{sub 8} bicapped trigonal prisms. NaIrO{sub 3} shows no magnetic ordering and resistivity measurements show non-metallic behavior. The crystal structure, electrical and magnetic properties are discussed and compared to known post-perovskites and pentavalent perovskite metal oxides. -- Graphical abstract: Sodium iridium(V) oxide, NaIrO{sub 3}, synthesized by a high pressure solid state method and recovered to ambient conditions is found to crystallize as the post-perovskite structure and is the first example of a pentavalent ABO{sub 3} post-perovskite. Research highlights: {yields} NaIrO{sub 3} post-perovskite stabilized by pressure. {yields} First example of a pentavalent oxide post-perovskite. {yields} Non-metallic and non-magnetic behavior of NaIrO{sub 3}.

  11. Musa paradisica RCI complements AtRCI and confers Na+ tolerance and K+ sensitivity in Arabidopsis.

    PubMed

    Liu, Bing; Feng, Dongru; Zhang, Bipei; Mu, Peiqiang; Zhang, Yang; He, Yanming; Qi, Kangbiao; Wang, Jinfa; Wang, Hongbin

    2012-03-01

    The mechanisms involved in Na?/K? uptake and extrusion are important in plant salt tolerance. In this study, we investigated the physiological role of a plasma membrane (PM)-localized protein, MpRCI, from plantain in transgenic Arabidopsis under NaCl and KCl stress and determined its effect on PM fluidity and H?-ATPase activity. The MpRCI gene exhibited high homology to the AtRCI2 gene family in Arabidopsis and was therefore able to complement for loss of the yeast AtRCI2-related PMP3 gene. Results of phenotypic espial and atomic emission spectrophotometer (AES) assays indicated that MpRCI overexpression in the AtRCI2A knockout mutant with reduced shoot Na? and increased K? exhibited increased Na?-tolerance and K?-sensitivity under NaCl or KCl treatments, respectively. Furthermore, comparisons of PM fluidity and H?-ATPase activity in shoots, with expression or absence of MpRCI/AtRCI2A expression under NaCl or KCl stress, showed MpRCI maintained PM fluidity and H?-ATPase activity under stress conditions. Results suggest that MpRCI plays an essential role in Na?/K? flux in plant cells. PMID:22284714

  12. Solvation structure and dynamics of Na+ in liquid ammonia studied by ONIOM-XS MD simulations

    NASA Astrophysics Data System (ADS)

    Sripradite, Jarukorn; Tongraar, Anan; Kerdcharoen, Teerakiat

    2015-12-01

    The molecular dynamics (MD) technique based on the ONIOM-XS method, known as the ONIOM-XS MD, has been applied to investigate the solvation structure and dynamics of Na+ in liquid ammonia. Regarding the ONIOM-XS MD results, it is observed that Na+ is able to order the surrounding ammonia molecules to form its specific first and second solvation shells with the average coordination numbers of 5.1 and 11.2, respectively. The first solvation shell of Na+ is rather well-defined, forming a preferred 5-fold coordinated complex with a distorted square pyramidal geometry. In this respect, the most preferential Na+(NH3)5 species could convert back and forth to the lower probability Na+(NH3)6 and Na+(NH3)4 configurations. The second solvation shell of Na+ is detectable, in which a number of ammonia molecules, ranging from 7 to 14, are involved in this layer and they are arranged according to recognizable influence of the ion.

  13. Prediction of Intrinsic Cesium Desorption from Na-Smectite in Mixed Cation Solutions.

    PubMed

    Fukushi, Keisuke; Fukiage, Tomo

    2015-09-01

    Quantitative understanding of the stability of sorbed radionuclides in smectite is necessary to assess the performance of engineering barriers used for nuclear waste disposal. Our previous study demonstrated that the spatial organization of the smectite platelets triggered by the divalent cations led to the apparent fixation of intrinsic Cs in smectite, because some Cs is retained inside the formed tactoids. Natural water is usually a mixture of Na(+) and divalent cations (Ca(2+) and Mg(2+)). This study therefore investigated the desorption behavior of intrinsic Cs in Na-smecite in mixed Na(+)-divalent cation solutions under widely various cation concentrations using batch experiments, grain size measurements, and cation exchange modeling (CEM). Results show that increased Na(+) concentrations facilitate Cs desorption because Na(+) serves as the dispersion agent. A linear relation was obtained between the logarithm of the Na(+) fraction and the accessible Cs fraction in smectite. That relation enables the prediction of accessible Cs fraction as a function of solution cationic compositions. The corrected CEM considering the effects of the spatial organization suggests that the stability of intrinsic Cs in the smectite is governed by the Na(+) concentration, and suggests that it is almost independent of the concentrations of divalent cations in natural water. PMID:26206200

  14. New double molybdate Na9Fe(MoO4)6: Synthesis, structure, properties

    NASA Astrophysics Data System (ADS)

    Savina, Aleksandra A.; Solodovnikov, Sergey F.; Basovich, Olga M.; Solodovnikova, Zoya A.; Belov, Dmitry A.; Pokholok, Konstantin V.; Gudkova, Irina A.; Stefanovich, Sergey Yu.; Lazoryak, Bogdan I.; Khaikina, Elena G.

    2013-09-01

    A new double molybdate Na9Fe(MoO4)6 was synthesized using solid state reactions and studied with X-ray powder diffraction, second harmonic generation (SHG) technique, differential scanning calorimetry, X-ray fluorescence analysis, Mössbauer and dielectric impedance spectroscopy. Single crystals of Na9Fe(MoO4)6 were obtained and its structure was solved (the space group R3¯, a=14.8264(2), c=19.2402(3) Å, V=3662.79(9) Å3, Z=6, R=0.0132). The structure is related to that of sodium ion conductor II-Na3Fe2(AsO4)3. The basic structure units are polyhedral clusters composed of central Fe?6 octahedron sharing edges with three Na(1)?6 octahedra. The clusters share common vertices with bridging ???4 tetrahedra to form an open 3D framework where the cavities are occupied by Na(2) and Na(3) atoms. The compound melts incongruently at 904.7±0.2 K. Arrhenius type temperature dependence of electric conductivity ? has been registered in solid state (?=6.8×10-2 S ?m-1 at 800 K), thus allowing considering Na9Fe(MoO4)6 as a new sodium ion conductor.

  15. Investigation of the Effects of Biodiesel-based Na on Emissions Control Components

    SciTech Connect

    Brookshear, D. William; Nguyen, Ke; Toops, Todd J; Bunting, Bruce G; Howe, Janet E

    2012-01-01

    A single-cylinder diesel engine was used to investigate the impact of biodiesel-based Na on emissions control components using specially blended 20% biodiesel fuel (B20). The emissions control components investigated were a diesel oxidation catalyst (DOC), a Cu-zeolite-based NH{sub 3}-SCR (selective catalytic reduction) catalyst, and a diesel particulate filter (DPF). Both light-duty vehicle, DOC-SCR-DPF, and heavy-duty vehicle, DOC-DPF-SCR, emissions control configurations were employed. The accelerated Na aging is achieved by introducing elevated Na levels in the fuel, to represent full useful life exposure, and periodically increasing the exhaust temperature to replicate DPF regeneration. To assess the validity of the implemented accelerated Na aging protocol, engine-aged lean NO{sub x} traps (LNTs), DOCs and DPFs are also evaluated. To fully characterize the impact on the catalytic activity the LNT, DOC and SCR catalysts were evaluated using a bench flow reactor. The evaluation of the aged DOC samples and LNT show little to no deactivation as a result of Na contamination. However, the SCR in the light-duty configuration (DOC-SCR-DPF) was severely affected by Na contamination, especially when NO was the only fed NO{sub x} source. In the heavy-duty configuration (DOC-DPF-SCR), no impact is observed in the SCR NO{sub x} reduction activity. Electron probe micro-analysis (EPMA) reveals that Na contamination on the LNT, DOC, and SCR samples is present throughout the length of the catalysts with a higher concentration on the washcoat surface. In both the long-term engine-aged DPF and the accelerated Na-aged DPFs, there is significant Na ash present in the upstream channels; however, in the engine-aged sample lube oil-based ash is the predominant constituent.

  16. In Vitro Demonstration of Dual Light-Driven Na?/H? Pumping by a Microbial Rhodopsin.

    PubMed

    Li, Hai; Sineshchekov, Oleg A; da Silva, Giordano F Z; Spudich, John L

    2015-10-01

    A subfamily of rhodopsin pigments was recently discovered in bacteria and proposed to function as dual-function light-driven H(+)/Na(+) pumps, ejecting sodium ions from cells in the presence of sodium and protons in its absence. This proposal was based primarily on light-induced proton flux measurements in suspensions of Escherichia coli cells expressing the pigments. However, because E. coli cells contain numerous proteins that mediate proton fluxes, indirect effects on proton movements involving endogenous bioenergetics components could not be excluded. Therefore, an in vitro system consisting of the purified pigment in the absence of other proteins was needed to assign the putative Na(+) and H(+) transport definitively. We expressed IAR, an uncharacterized member from Indibacter alkaliphilus in E. coli cell suspensions, and observed similar ion fluxes as reported for KR2 from Dokdonia eikasta. We purified and reconstituted IAR into large unilamellar vesicles (LUVs), and demonstrated the proton flux criteria of light-dependent electrogenic Na(+) pumping activity in vitro, namely, light-induced passive proton flux enhanced by protonophore. The proton flux was out of the LUV lumen, increasing lumenal pH. In contrast, illumination of the LUVs in a Na(+)-free suspension medium caused a decrease of lumenal pH, eliminated by protonophore. These results meet the criteria for electrogenic Na(+) transport and electrogenic H(+) transport, respectively, in the presence and absence of Na(+). The direction of proton fluxes indicated that IAR was inserted inside-out into our sealed LUV system, which we confirmed by site-directed spin-label electron paramagnetic resonance spectroscopy. We further demonstrate that Na(+) transport by IAR requires Na(+) only on the cytoplasmic side of the protein. The in vitro LUV system proves that the dual light-driven H(+)/Na(+) pumping function of IAR is intrinsic to the single rhodopsin protein and enables study of the transport activities without perturbation by bioenergetics ion fluxes encountered in vivo. PMID:26445445

  17. Solubility of NaCl in CO 2 at high pressure and temperature: First experimental measurements

    NASA Astrophysics Data System (ADS)

    Zakirov, I. V.; Sretenskaja, N. G.; Aranovich, L. Y.; Volchenkova, V. A.

    2007-09-01

    NaCl solubility in gaseous carbon dioxide has been measured in the pressure range from 30 to 70 MPa at 623 and 673 K. Our originally-designed high pressure apparatus allows in situ sampling of a portion of the fluid phase for chemical analysis. The results indicate that the solubility of NaCl increases with both temperature and pressure, and is about 4-5 orders of magnitude higher than saturated NaCl pressure values at the same temperature conditions (6.02 × 10 -12 at 623 K and 1.51 × 10 -10 at 673 K). It is also 1-2 orders of magnitude greater than predictions according to the Equation of State of the ternary H 2O-CO 2-NaCl system by Duan, Moeller and Weare [Duan, Z., Moller, N., and Weare, J. H. (1995) Equation of state for the NaCl-H 2O-CO 2 system: prediction of phase equilibria and volumetric properties. Geochim. Cosmochim. Acta59, 2869] and has the opposite pressure dependence. The activity values of NaCl in the vapor phase, calculated from the experiments (with pure molten NaCl as a standard state in the vapor), have been fitted to the Darken Quadratic Formalism: RTlna=RTlnx-2WNaCl-COG·x+BNaCl-COG, where, xNaCl,v is mole the fraction of NaCl in the vapor phase, WNaCl-COG=(1936.3-43.669·P)×106, BNaCl-COG=83,754-420.1·P, where P is the pressure in MPa and T the absolute temperature. Caution should be exerted while extrapolating this empirical equation far beyond the experimental P- T-compositional range.

  18. Intestinal inhibition of the Na+/H+ exchanger 3 prevents cardiorenal damage in rats and inhibits Na+ uptake in humans.

    PubMed

    Spencer, Andrew G; Labonte, Eric D; Rosenbaum, David P; Plato, Craig F; Carreras, Christopher W; Leadbetter, Michael R; Kozuka, Kenji; Kohler, Jill; Koo-McCoy, Samantha; He, Limin; Bell, Noah; Tabora, Jocelyn; Joly, Kristin M; Navre, Marc; Jacobs, Jeffrey W; Charmot, Dominique

    2014-03-12

    The management of sodium intake is clinically important in many disease states including heart failure, kidney disease, and hypertension. Tenapanor is an inhibitor of the sodium-proton (Na(+)/H(+)) exchanger NHE3, which plays a prominent role in sodium handling in the gastrointestinal tract and kidney. When administered orally to rats, tenapanor acted exclusively in the gastrointestinal tract to inhibit sodium uptake. We showed that the systemic availability of tenapanor was negligible through plasma pharmacokinetic studies, as well as autoradiography and mass balance studies performed with (14)C-tenapanor. In humans, tenapanor reduced urinary sodium excretion by 20 to 50 mmol/day and led to an increase of similar magnitude in stool sodium. In salt-fed nephrectomized rats exhibiting hypervolemia, cardiac hypertrophy, and arterial stiffening, tenapanor reduced extracellular fluid volume, left ventricular hypertrophy, albuminuria, and blood pressure in a dose-dependent fashion. We observed these effects whether tenapanor was administered prophylactically or after disease was established. In addition, the combination of tenapanor and the blood pressure medication enalapril improved cardiac diastolic dysfunction and arterial pulse wave velocity relative to enalapril monotherapy in this animal model. Tenapanor prevented increases in glomerular area and urinary KIM-1, a marker of renal injury. The results suggest that therapeutic alteration of sodium transport in the gastrointestinal tract instead of the kidney--the target of current drugs--could lead to improved sodium management in renal disease. PMID:24622516

  19. 77 FR 51589 - ReconTrust Company, N.A., et al.; Notice of Application and Temporary Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-24

    ... COMMISSION ReconTrust Company, N.A., et al.; Notice of Application and Temporary Order August 20, 2012... Act, with respect to an injunction entered against ReconTrust Company, N.A. (``ReconTrust'') on August... certain circumstances.\\4\\ \\2\\ State of Washington v. ReconTrust Company, N.A. No. 2:11-cv- 1460 (W.D....

  20. 78 FR 48918 - Wells Fargo Bank, N.A., et al.; Notice of Application and Temporary Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-08-12

    ... COMMISSION Wells Fargo Bank, N.A., et al.; Notice of Application and Temporary Order August 6, 2013. AGENCY... injunction effective July 15, 2013, entered against Wells Fargo Bank, N.A. (``Wells Fargo Bank'') by the... 15, 2013, as the effective date of the Injunction. \\2\\ Gutierrez v. Wells Fargo Bank, N.A., Case...

  1. 77 FR 70193 - Wells Fargo Bank, N.A., et al.; Notice of Application and Temporary Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-11-23

    ... COMMISSION Wells Fargo Bank, N.A., et al.; Notice of Application and Temporary Order November 16, 2012... Act, with respect to an injunction entered against Wells Fargo Bank, N.A. (``Wells Fargo Bank'') on... adherence to fair lending practices. \\2\\ United States v. Wells Fargo Bank, N.A., No. 1:12-cv-01150...

  2. 76 FR 78052 - Wells Fargo Bank, N.A., et al.; Notice of Application and Temporary Order

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-12-15

    ... COMMISSION Wells Fargo Bank, N.A., et al.; Notice of Application and Temporary Order December 9, 2011. AGENCY... respect to an injunction entered against Wells Fargo Bank, N.A. (``Wells Fargo Bank'') on December 9, 2011... is a national banking association. On March 20, 2010, Wachovia Bank, N.A. (``Wachovia Bank'')...

  3. Growth of NaCl on thin epitaxial KCl films on Ag(100) studied by SPA-LEED

    NASA Astrophysics Data System (ADS)

    Marquardt, Christian; Paulheim, Alexander; Sokolowski, Moritz

    2015-11-01

    We investigated the growth of NaCl on thin (100)-oriented films of KCl by spot profile analysis of low energy electron diffraction (SPA-LEED). The underlying question of this investigation was how the system accommodates to the misfit of - 10% between the NaCl and KCl lattices. The KCl films (3 atomic layers thick) were epitaxially grown on a Ag(100) single crystal. We studied the heteroepitaxial growth of NaCl on KCl at 300 K and at 500 K, respectively. At 300 K, the first NaCl monolayer (ML) grows pseudomorphically on the KCl film. From the second layer onward, the NaCl lattice relaxes. The NaCl multilayers roughen, and a small rotational disorder (± 4°) of the NaCl domains is observed. The roughening results from the formation of multilayer islands of limited lateral size due to the misfit to the pseudomorphic first NaCl layer. At a growth temperature of 500 K, no pseudomorphic NaCl layer forms, instead relaxed multilayer island growth of NaCl is observed from the first layer onward. Similarly to the growth at 300 K, we find NaCl multilayer islands of limited lateral size. For both temperatures, we explain this growth behavior by the misfit that makes the adsorption sites at the island edges of the first relaxed NaCl layer less favorable for larger islands, promoting nucleation of multilayer islands.

  4. Non-oxidative reactions of propane on Zn/Na-ZSM5 Joseph A. Biscardi and Enrique Iglesia*

    E-print Network

    Iglesia, Enrique

    Non-oxidative reactions of propane on Zn/Na-ZSM5 Joseph A. Biscardi and Enrique Iglesia* Department rates during propane conversion at 773 K on Zn/Na-ZSM5 are about ten times higher than on Zn/H-ZSM5 catalysts with similar Zn content. The total rate of propane conversion is also higher on Zn/Na-ZSM5

  5. Balancing SoNaR: IPR versus Processing Issues in a 500-Million-Word Written Dutch Reference Corpus

    E-print Network

    Theune, Mariët

    Balancing SoNaR: IPR versus Processing Issues in a 500-Million-Word Written Dutch Reference Corpus during the creation of the SoNaR Corpus. Based on recent developments in traditional corpus compiling and new web harvesting approaches, SoNaR is designed to contain 500 million words, balanced over 36 text

  6. A human Na /H antiporter sharing evolutionary origins with bacterial NhaA may be a candidate

    E-print Network

    Rao, Rajini

    a previously unknown clade of genes in metazoan genomes, including two previously uncharacterized human iso for cations (Na or K ). In bacteria, an array of Na /H antiporters convert the proton motive force programs have identified 550 sequence entries as putative Na /H exchangers. In an effort to understand

  7. "JCE" Classroom Activity Connections: NaCl or CaCl[subscript 2], Smart Polymer Gel Tells More

    ERIC Educational Resources Information Center

    Chen, Yueh-Huey; Lin, Jia-Ying; Wang, Yu-Chen; Yaung, Jing-Fun

    2010-01-01

    This classroom activity connection demonstrates the differences between the effects of NaCl (a salt of monovalent metal ions) and CaCl[subscript 2] (a salt of polyvalent metal ions) on swollen superabsorbent polymer gels. Being ionic compounds, NaCl and CaCl[subscript 2] both collapse the swollen polymer gels. The gel contracted by NaCl reswells…

  8. Preparation of active enzyme samples for IR studies of Na+/K+-ATPase.

    PubMed

    Thoenges, Detlef; Zscherp, Christian; Grell, Ernst; Barth, Andreas

    2002-01-01

    In the case of the integral membrane protein Na+/K+-ATPase, preparation of highly concentrated samples for IR difference spectroscopy often leads to inactivation of the enzyme. Therefore, we compared the activity of Na+/K+-ATPase using different techniques of sample preparation. The loss of activity can be minimized by cooling the sample to 10 degrees C and by the addition of glycerol and dithiothreitol. The activity of Na+/K+-ATPase isolated from pig kidney is independent of the protein concentration whereas the enzyme from shark rectal gland is inactivated at concentrations above 1 microg/microL and is thus unsuitable for IR experiments. PMID:12012445

  9. An Application of Specific Sensors For The Monitoring of NaCl in Soft Cheeses

    NASA Astrophysics Data System (ADS)

    Lvova, Larisa; Mielle, Patrick; Salles, Christian; Denis, Sylvain; Vergoignan, Catherine; Barra, Aurélien; Di Natale, Corrado; Paolesse, Roberto; Temple-Boyer, Pierre; Feron, Gilles

    2011-09-01

    The commercial sensors and prototype ISEs array (Ion Selective Electrodes array) were utilized for NaCl concentration measurements in soft cheeses, in particular in vitro gut process and in commercial Italian mozzarella cheeses. The values obtained from the sensors were compared with HPLC analysis. The results showed the feasibility of the ISE array application to monitor NaCl in soft cheese during the breakdown in the digester. The best results were obtained with the use of ISEs array combining, in particular, Cl- and Na+ detections. The salinity of commercial mozzarella cheese samples and the originally utilized milk type (cow or buffalo) were also satisfactory determined with the developed ISE array.

  10. Na+,K+-ATPase as the Target Enzyme for Organic and Inorganic Compounds

    PubMed Central

    Vasi?, Vesna; Momi?, Tatjana; Petkovi?, Marijana; Krsti?, Danijela

    2008-01-01

    This paper gives an overview of the literature data concerning specific and non specific inhibitors of Na+,K+-ATPase receptor. The immobilization approaches developed to improve the rather low time and temperature stability of Na+,K+-ATPase, as well to preserve the enzyme properties were overviewed. The functional immobilization of Na+,K+-ATPase receptor as the target, with preservation of the full functional protein activity and access of various substances to an optimum number of binding sites under controlled conditions in the combination with high sensitive technology for the detection of enzyme activity is the basis for application of this enzyme in medical, pharmaceutical and environmental research.

  11. Ameloblast Modulation and Transport of Cl-, Na+, and K+ during Amelogenesis.

    PubMed

    Bronckers, A L J J; Lyaruu, D; Jalali, R; Medina, J F; Zandieh-Doulabi, B; DenBesten, P K

    2015-12-01

    Ameloblasts express transmembrane proteins for transport of mineral ions and regulation of pH in the enamel space. Two major transporters recently identified in ameloblasts are the Na(+)K(+)-dependent calcium transporter NCKX4 and the Na(+)-dependent HPO4 (2-) (Pi) cotransporter NaPi-2b. To regulate pH, ameloblasts express anion exchanger 2 (Ae2a,b), chloride channel Cftr, and amelogenins that can bind protons. Exposure to fluoride or null mutation of Cftr, Ae2a,b, or Amelx each results in formation of hypomineralized enamel. We hypothesized that enamel hypomineralization associated with disturbed pH regulation results from reduced ion transport by NCKX4 and NaPi-2b. This was tested by correlation analyses among the levels of Ca, Pi, Cl, Na, and K in forming enamel of mice with null mutation of Cftr, Ae2a,b, and Amelx, according to quantitative x-ray electron probe microanalysis. Immunohistochemistry, polymerase chain reaction analysis, and Western blotting confirmed the presence of apical NaPi-2b and Nckx4 in maturation-stage ameloblasts. In wild-type mice, K levels in enamel were negatively correlated with Ca and Cl but less negatively or even positively in fluorotic enamel. Na did not correlate with P or Ca in enamel of wild-type mice but showed strong positive correlation in fluorotic and nonfluorotic Ae2a,b- and Cftr-null enamel. In hypomineralizing enamel of all models tested, 1) Cl(-) was strongly reduced; 2) K(+) and Na(+) accumulated (Na(+) not in Amelx-null enamel); and 3) modulation was delayed or blocked. These results suggest that a Na(+)K(+)-dependent calcium transporter (likely NCKX4) and a Na(+)-dependent Pi transporter (potentially NaPi-2b) located in ruffle-ended ameloblasts operate in a coordinated way with the pH-regulating machinery to transport Ca(2+), Pi, and bicarbonate into maturation-stage enamel. Acidification and/or associated physicochemical/electrochemical changes in ion levels in enamel fluid near the apical ameloblast membrane may reduce the transport activity of mineral transporters, which results in hypomineralization. PMID:26403673

  12. Besedje stare kme?ke delovne šege na Koroškem – steljeraje

    E-print Network

    Benko, Anja

    2010-01-01

    ?ra:jo za?si:?ko, da je do?l?:?o, na ?ki:ri k?raj bo ?pa:dwa. SSKJ + Plet. + žajfa || ?ž?:fa -e ž milo ?Na:jprej se za?že:nejo ?pu:?bi za g?wa:tko o?lu:pleno ?r?:po, na?ma:zano z ?ž?:fo, da je s?p?:u?ska. [izposojeno iz zgodnjesrvnem. bav. ?aife ‘milo... obi?aja in njegovi jezikovni podobi. 1 Prispevek je nastal v okviru raziskovalnega projekta J6-2238 z naslovom Slovenski je- zik v stiku evropskega podonavskega in alpskega prostora, ki ga financira Agencija za raziskovalno dejavnost RS; odgovorni...

  13. A magnesium correction for the Na-K-Ca chemical geothermometer

    USGS Publications Warehouse

    Fournier, R.O.; Potter, Robert W.

    1978-01-01

    Graphs and equations have been devised to correct for the adverse effects of magnesium upon the Na-K-Ca geothermometer. Either the graphs or equations can be used to determine temperature corrections when given waters have Na-K-Ca calculated temperatures above 70? C and values of R less than 50, where R = {Mg/(Mg + Ca + K)} x 100 in equivalents. Waters with values of R greater than 50 probably come from relatively cool aquifers with temperatures about equal to the measured spring temperature, irrespective of much higher calculated Na-K-Ca temperatures.

  14. Reactions of chromium with gaseous NaCl in an oxygen environment

    NASA Technical Reports Server (NTRS)

    Stearns, C. A.; Kohl, F. J.; Fryburg, G. C.

    1976-01-01

    Target collection techniques and high pressure mass spectrometric sampling have been used to study the formation of volatile chromium-containing species in the reaction of Cr2O3 in the condensed state with gaseous O2 and NaCl. Experiments were performed at atmospheric pressure as a function of chromium temperature, oxygen pressure, and NaCl concentration. The major chromium-containing vapor species were found to be (NaCl)xCrO3, with x = 1,2, and 3, which are products of heterogeneous reactions on the surface. The kinetics indicate first order dependence on oxygen and sodium chloride pressures.

  15. Design of a Mechanical NaK Pump for Fission Space Power Systems

    NASA Technical Reports Server (NTRS)

    Mireles, Omar R.; Bradley, David; Godfroy, Thomas

    2010-01-01

    Alkali liquid metal cooled fission reactor concepts are under development for mid-range spaceflight power requirements. One such concept utilizes a sodium-potassium eutectic (NaK) as the primary loop working fluid. Traditionally, linear induction pumps have been used to provide the required flow and head conditions for liquid metal systems but can be limited in performance. This paper details the design, build, and check-out test of a mechanical NaK pump. The pump was designed to meet reactor cooling requirements using commercially available components modified for high temperature NaK service.

  16. Hadro-production measurements for T2K by NA61/SHINE at the CERN SPS

    E-print Network

    Claudia Strabel for the NA61/SHINE Collaboration

    2010-06-04

    In this article the NA61/SHINE detector will be presented which is a large acceptance hadron spectrometer at the CERN SPS. It allows for a precise study of particle production from interactions of a 30 GeV proton beam in a carbon target in order to predict the neutrino flux of the T2K experiment at J-PARC, Japan. Requirements for the T2K experiment will be discussed together with the ongoing NA61 measurements. In particular preliminary NA61 results on pion production and cross section measurements from the 2007 pilot run will be shown.

  17. Reactions of chromium with gaseous NaCl in an oxygen environment

    NASA Technical Reports Server (NTRS)

    Stearns, C. A.; Kohl, F. J.; Fryburg, G. C.

    1976-01-01

    Target collection techniques and high pressure mass spectrometric sampling have been used to study the formation of volatile chromium-containing species in the reaction of Cr2O3 with O2 and NaCl gases. Experiments were performed at atmospheric pressure as a function of chromium temperature, oxygen pressure, and NaCl gas concentration. The major chromium-containing vapor species were found to be (NaCl)x CrO3 gas, with x = 1,2, and 3, which are products of heterogeneous reactions on the surface. The kinetics indicate first order dependence on oxygen and sodium chloride pressures.

  18. Spectroscopy of 28Na : Shell evolution toward the drip line

    NASA Astrophysics Data System (ADS)

    Lepailleur, A.; Wimmer, K.; Mutschler, A.; Sorlin, O.; Thomas, J. C.; Bader, V.; Bancroft, C.; Barofsky, D.; Bastin, B.; Baugher, T.; Bazin, D.; Bildstein, V.; Borcea, C.; Borcea, R.; Brown, B. A.; Caceres, L.; Gade, A.; Gaudefroy, L.; Grévy, S.; Grinyer, G. F.; Iwasaki, H.; Khan, E.; Kröll, T.; Langer, C.; Lemasson, A.; Llidoo, O.; Lloyd, J.; Lunderberg, E.; Negoita, F.; de Oliveira Santos, F.; Perdikakis, G.; Recchia, F.; Redpath, T.; Roger, T.; Rotaru, F.; Saenz, S.; Saint-Laurent, M.-G.; Smalley, D.; Sohler, D.; Stanoiu, M.; Stroberg, S. R.; Vandebrouck, M.; Weisshaar, D.; Westerberg, A.

    2015-11-01

    Excited states have been studied in 28Na using the ? -decay of implanted 28Ne ions at the Grand Accélérateur National d'Ions Lourds/LISE as well as the in-beam ? -ray spectroscopy at the National Superconducting Cyclotron Laboratory/S800 facility. New states of positive (J?=3+,4+ ) and negative (J?=1--5- ) parity are proposed. The former arise from the coupling between 0 d5 /2 protons and 0 d3 /2 neutrons, while the latter are attributable to couplings of 0 d5 /2 protons with 1 p3 /2 or 0 f7 /2 neutrons. While the relative energies between the J?=1+-4+ states are well reproduced with the USDA interaction in the N =17 isotones, a progressive shift in the ground-state binding energy (by about 500 keV) is observed between 26F and 30Al . This points to a possible change in the proton-neutron 0 d5 /2 -0 d3 /2 effective interaction when moving from stability to the drip line. The presence of J?=1--4- negative-parity states around 1.5 MeV as well as of a candidate for a J?=5- state around 2.5 MeV give further support to the collapse of the N =20 gap and to the inversion between the neutron 0 f7 /2 and 1 p3 /2 levels below Z =12 . These features are discussed in the framework of shell-model and energy-density-functional calculations, leading to predicted negative-parity states in the low-energy spectra of the 26F and 25O nuclei.

  19. Bonding in scandium monosulfide a NaCl crystal type

    SciTech Connect

    Merrick, J.A.

    1980-08-01

    The transition temperature of an order-disorder transition in Sc/sub 0/ /sub 81/S (R anti 3m to Fm3m) occurs at 700/sup 0/C. A group of ordered sublattices on the NaCl-type lattice (Fm3m) was generated and a Madelung energy and configurational entropy were calculated for each sublattice assuming the ions to be Sc/sup 2/ /sup 48 +/ and S/sup 2 -/. Mean field and pair interaction approximations were used to model long-range and short-range orderings, respectively. The electrostatic model fails to predict the observed short-range and long-range orderings. The high temperature vaporization of ScP was investigated by mass spectrometry and target collection Knudsen effusion at 1767 to 2209K. The composition ScP/sub 1/ /sub 00/ vaporizes congruently to the gaseous species Sc, P, and P/sub 2/. A temperature independent third law enthalpy of atomization (..delta..H/sup 0//sub atom,298/ = 252.2 +- 2.8 kcal mole/sup -1/) has a value approx. 12 kcal larger than that reported for ScS. Nonrelativistic, nonself-consistent LAPW band structure calculations are reported for ScS. XPS and UPS measurements are reported for Sc/sub 2/S/sub 3/ and several compositions Sc/sub 1-x/S (0.0 less than or equal to x less than or equal to 0.2). The Sc and S 2p binding energies (XPS) obtained for the defect scandium monosulfides are very close to those found in the pure elements, suggesting covalent bonding. The Sc 2p energy region has an interesting satellite structure.

  20. Infrared thermography monitoring of the NaCl crystallisation process

    NASA Astrophysics Data System (ADS)

    Vázquez, Patricia; Thomachot-Schneider, Céline; Mouhoubi, Kamel; Fronteau, Gilles; Gommeaux, Maxime; Benavente, David; Barbin, Vincent; Bodnar, Jean-Luc

    2015-07-01

    In this work, we describe the growth of NaCl crystals by evaporating droplets of aqueous solution while monitoring them with infrared thermography. Over the course of the evaporation experiments, variations in the recorded signal were observed and interpreted as being the result of evaporation and crystallisation. In particular, we observed sharp and transient decreases in the thermosignal during the later stages of high-concentration drop evaporation. The number of such events per experiment, referred to as "pop-cold events", varied from 1 to over 100 and had durations from 1 to 15 s. These events are interpreted as a consequence from the top-supplied creeping (TSC) of the solution feeding the growth of efflorescence-like crystals. This phenomenon occurred when the solution was no longer macroscopically visible. In this case, efflorescence-like crystals with a spherulite shape grew around previously formed cubic crystals. Other crystal morphologies were also observed but were likely fed by mass diffusion or bottom-supplied creeping (BSC) and were not associated with "pop-cold events"; these morphologies included the cubic crystals at the centre, ring-shaped at the edge of droplets and fan-shaped crystals. After complete evaporation, an analysis of the numbers and sizes of the different types of crystals was performed using image processing. Clear differences in their sizes and distribution were observed in relation to the salt concentration. Infrared thermography permitted a level of quantification that previously was only possible using other techniques. As example, the intermittent efflorescence growth process was clearly observed and measured for the first time using infrared thermography.