Alterações na matéria orgânica e na biomassa microbiana em solo de mata natural submetido a diferentes manejos Changes in organic matter and in microbial biomass of a natural forest soil under different management

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MILTON MARCHIORI JÚNIOR

2000-06-01

Full Text Available Avaliou-se, em um Latossolo Roxo, o efeito de diferentes formas de manejo do solo sobre a matéria orgânica do solo e na biomassa microbiana. Os tratamentos usados foram: mata natural; mata natural até 1976 e café até 1994 (amostragem na projeção da copa e na entrelinha; mata natural até 1976, café até 1991 e milho até 1994; mata natural até 1940, café até 1960, citros até 1978, e cana-de-açúcar até 1994 (amostragem na linha e na entrelinha. A mata natural apresentou os maiores valores de C orgânico no solo e na fração humina e os menores valores foram obtidos nas áreas com cana-de-açúcar, que apresentaram os maiores valores de C microbiano em relação à mata natural. O uso agrícola do solo aumentou a porcentagem de C orgânico na forma de ácidos húmicos e fúlvicos, em relação à mata natural. Em geral, o solo apresentou mais de 74% do C orgânico na forma de húmus residual.The effect of soil management on forms of carbon and microbial biomass was studied in a Typic Euthortox soil. The treatments tested were: natural forest; natural forest till 1976 and coffee till 1994 (sampling on the shoot projection and between lines ; natural forest till 1976, coffee till 1991 and corn till 1994; natural forest till 1940, coffee till 1960, citrus till 1978 and sugar cane till 1994 (sampling on the planting line and between lines . The treatment with sugar cane presented the largest values of microbial carbon in relation to the natural forest. The agricultural management of soil increased the percentage of organic carbon in humic and fulvic acids forms. The soil presented more than 74% of organic carbon in the form of residual humus.

Sinergias numa fusão de empresas:estudo de caso aplicado à "Transportes Tejo à Vista. Soc.Unip.,Lda" e "Gomes&Paredes, Lda."

OpenAIRE

Jordão, Pedro Fernando Ferreira

2014-01-01

Dissertação, Mestrado, Contabilidade e Finanças, Instituto Politécnico de Santarém, Escola Superior de Gestão e Tecnologia, 2014 A principal motivação do estudo, passou por se tentar entender se a fusão das empresas em causa trará benefícios e se esta estratégia de reestruturação de empresas é vantajosa. O objetivo da realização deste estudo de caso, passa pelo cálculo dos custos e benefícios do processo de fusão de duas empresas, concluindo a presença ou não de Sinergias da fusão. Os obje...

The natural history of surgically treated but radiotherapy-naïve nonfunctioning pituitary adenomas.

LENUS (Irish Health Repository)

O'Sullivan, Eoin P

2009-11-01

Transsphenoidal surgery is indicated for patients with nonfunctioning pituitary adenomas (NFPAs) causing compressive symptoms. Previous studies attempting to define the rate of recurrence\\/regrowth of surgically treated but radiation-naïve NFPAs were somewhat limited by selection bias and\\/or small numbers and\\/or lack of consistency of findings between studies. A better understanding of the natural history of this condition could allow stratification of recurrence risk and inform future management. We aimed to define the natural history of a large, mainly unselected cohort with surgically treated, radiotherapy (RT)-naïve NFPAs and to try to identify predictors of recurrence\\/regrowth.

Tipos, Setores, Nacionalidade e Experiência: O Que Importa para o Sucesso das Estratégias De Fusão e Aquisição?

OpenAIRE

Hoffmann, Valmir Emil; de Menezes, Kim La Croix Maluf; Vieira, Daniel Pires

2017-01-01

Este estudo caracterizou os processos de Fusões e Aquisições (F&A) que criaram maior valor interno e sinergia. O tema de F&A não é novo na literatura de estratégia, o que não significa, que ele esteja consolidado, ao menos não do ponto de vista dos resultados que essa estratégia traz. O que se percebe é que existem momentos onde essa estratégia é mais comumente adotada, e em alguns setores onde ela é prevalente. A literatura traz a criação de sinergias como uma das principais razões p...

Synthesis of Zeolite NaA from Low Grade (High Impurities) Indonesian Natural Zeolite

OpenAIRE

Mustain, Asalil; Wibawa, Gede; Nais, Mukhammad Furoiddun; Falah, Miftakhul

2014-01-01

The zeolite NaA has been successfully synthesized from the low grade natural zeolite with high impurities. The synthesis method was started by mixing natural zeolite powder with NH4Cl aqueous solution in the reactor as pretreatment. The use of pretreatment was to reduce the impurities contents in the zeolite. The process was followed by alkaline fusion hydrothermal treatment to modify the framework structure of natural zeolite and reduce the SiO2/Al2O3 ratio. Finally, the synthesized zeolite ...

Synergies between Last Planner System and OHSAS 18001 - A general overview = Sinergias entre el Last Planner System y la OHSAS 18001 - Una visión general

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Xavier Brioso

2017-08-01

Full Text Available The present article’s main objective is to describe the synergies generated from the simultaneous application of the Last Planner System (LPS and OHSAS 18001. We explain the main principles, tools, techniques and practices of the Lean Construction philosophy and LPS that integrate and make synergy with the elaboration of Safety and Health Study, the implementation of the Safety and Health Plan, and with the OHSAS 18001. The LPS elements are correlated with the OHSAS 18001 requirements: (1 Policy; (2 Planning; (3 Implementation and Operation; (4 Checking; and (5 Management Review. The methodology used to validate the proposal is based in a review of the published literature in the last years, in which information was quoted from the Conferences of the International Group for Lean Construction (IGLC, Lean Construction Journal, Lean Construction Institute, among others. This paper hopes to bring integration and collaborative work from the Production and the Safety and Health Department. Resumen El presente artículo tiene como objetivo describir las sinergias generadas en la aplicación simultánea del Last Planner System (LPS y la OHSAS 18001. Se explican los principios, herramientas, técnicas y prácticas de la filosofía Lean Construction y del LPS que integran y generan sinergia con la elaboración del Estudio de Seguridad y Salud, con la implementación del Plan de Seguridad y Salud y con la OHSAS 18001. Se relacionan los elementos del LPS con los requisitos OHSAS 18001: (1 Política; (2 Planificación; (3 Implementación y operación; (4 Verificación; y (5 Revisión por la Dirección. La metodología empleada para validar la propuesta se basa en una revisión de la literatura publicada en los últimos años, en la que se citó información de la Conferencia del International Group for Lean Construction (IGLC, Lean Construction Journal, Lean Construction Institute, entre otros. Este trabajo pretende aportar en la integración y el trabajo

O EFEITO DO MÉTODO DE PILATES NA PREVENÇÃO DE LESÕES EM BAILARINOS

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S. Fernandes

2015-04-01

Full Text Available A Dança potencia a ocorrência de lesões (Meereis, Favretto, Bernardi, Peroni, & Mota, 2011, sendo mais frequentes no membro inferior (Rietveld, 2013. O centro é o ponto-chave do Método de Pilates e refere-se à sinergia muscular estabelecida entre os músculos Transverso Abdominal, Oblíquos Interno e Externo e o Multifidus. A sua estabilidade aumenta a performance, previne lesões e alivia a dor lombar. Existe uma relação entre a diminuição da estabilidade do centro e uma maior incidência de lesões do membro inferior. Existem poucos estudos que avaliem o centro em bailarinos (Rickman et al., 2012.O Método de Pilates é um exercício corpo-mente que requer estabilidade do centro dando atenção ao controlo muscular, postura e respiração (Wells, Kolt, & Bialocerkowski, 2012, o que contribui para um melhor alinhamento corporal (Cruz-Ferreira et al., 2011, e para a prevenção de lesões (Massey, 2011. Os estudos existentes em bailarinos concluíram que melhora o alinhamento corporal (Kuo et al. 2009 e previne lesões (McMillan et al., 1998. Objetivo: Determinar os efeitos de um programa do método de Pilates na estabilidade do centro, no alinhamento postural e na dor, na prevenção de lesões no membro inferior em bailarinos.

Natural variants of AtHKT1 enhance Na+ accumulation in two wild populations of Arabidopsis.

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Ana Rus

2006-12-01

Full Text Available Plants are sessile and therefore have developed mechanisms to adapt to their environment, including the soil mineral nutrient composition. Ionomics is a developing functional genomic strategy designed to rapidly identify the genes and gene networks involved in regulating how plants acquire and accumulate these mineral nutrients from the soil. Here, we report on the coupling of high-throughput elemental profiling of shoot tissue from various Arabidopsis accessions with DNA microarray-based bulk segregant analysis and reverse genetics, for the rapid identification of genes from wild populations of Arabidopsis that are involved in regulating how plants acquire and accumulate Na(+ from the soil. Elemental profiling of shoot tissue from 12 different Arabidopsis accessions revealed that two coastal populations of Arabidopsis collected from Tossa del Mar, Spain, and Tsu, Japan (Ts-1 and Tsu-1, respectively, accumulate higher shoot levels of Na(+ than do Col-0 and other accessions. We identify AtHKT1, known to encode a Na(+ transporter, as being the causal locus driving elevated shoot Na(+ in both Ts-1 and Tsu-1. Furthermore, we establish that a deletion in a tandem repeat sequence approximately 5 kb upstream of AtHKT1 is responsible for the reduced root expression of AtHKT1 observed in these accessions. Reciprocal grafting experiments establish that this loss of AtHKT1 expression in roots is responsible for elevated shoot Na(+. Interestingly, and in contrast to the hkt1-1 null mutant, under NaCl stress conditions, this novel AtHKT1 allele not only does not confer NaCl sensitivity but also cosegregates with elevated NaCl tolerance. We also present all our elemental profiling data in a new open access ionomics database, the Purdue Ionomics Information Management System (PiiMS; http://www.purdue.edu/dp/ionomics. Using DNA microarray-based genotyping has allowed us to rapidly identify AtHKT1 as the casual locus driving the natural variation in shoot Na

Cultura organizacional: sinergias e alergias entre Hofstede e Trompenaars

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Daniel Pacheco Lacerda

2011-10-01

Full Text Available Entre os diferentes elementos a serem considerados na gestão atualmente, os aspectos culturais têm se colocado na centralidade das discussões organizacionais. Essa posição deriva do fato de que a vantagem competitiva sustentável se origina da compreensão, respeito e utilização das diferenças de hábitos, práticas, pontos de vistas e competências. Empresas com atuação local ou global precisam atentar para as características oriundas de seu capital humano. O presente trabalho busca apresentar algumas evidências das implicações culturais a partir do prisma das dimensões culturais. Para isso é realizada uma breve revisão sobre o tema, em seguida são discutidas algumas repercussões para as organizações.

Comparison measure of natural radioactivity in environment specimen using HPGe and NaI(Tl) γ-ray spectrometer

International Nuclear Information System (INIS)

Zhou Chunlin; Han Feng; Li Tiantuo; Ma Wenyan; Di Yuming; Guo Huiping; Wu Yuelei

2000-01-01

The author reports the comparison results on natural radioactive nuclide contents of soil specimen from an uranium diggings with HPGe and NaI(Tl) γ-ray spectrometer. Relative method and athwart matrix method are used to analyze natural radioactive nuclide contents in samples of soil. The results are compared and are proven to be in accordance with each other

A incorporação das rotas turísticas, como complemento ao turismo religioso e ao marketing mix – 4P’s, dos hotéis localizados em Fátima e o impacto na satisfação dos turistas portugueses e estrangeiros: o caso de hotéis de 4 e 3 estrelas

OpenAIRE

Santos, Marisa Raquel Ribeiro

2017-01-01

O Turismo exerce influências económicas, sociais e culturais, sendo cada vez mais evidente as proporções deste fenómeno, tanto nos locais turísticos como nas unidades hoteleiras que acolhem os turistas. De facto, esta relação é notória na cidade de Fátima, onde o Turismo Religioso apresenta uma maior influência. Tendo em consideração que os turistas tendem a conhecer novas regiões e novas ofertas, é crucial que existam sinergias entre os locais turísticos e os hotéis. Assim, os hotéis deverão...

O álbum poético em português e em espanhol: sinergia estética entre palavras e ilustrações

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SARA RAQUEL DUARTE REIS DA SILVA

2017-01-01

Full Text Available Este estudio ha tenido como objetivo discutir la relación textual que existe entre la palabra y la imagen en un tipo texto especialmente creado para niños: el álbum poético. Para ello, utilizamos algunos ejemplos textuales significativos de un subgénero literario en emergencia tanto en Portugal cuanto en España, y hemos propuesto una definición de este subgénero y su caracterización a partir del comentario de secuencias poéticas en las cuales la imagen sustenta el contenido verbal. De hecho, centrando la atención en el álbum poético de potencial recepción infantil y juvenil, proponemos un análisis de diversos títulos de autoría portuguesa y española basado en la lectura dialógica entre el texto verbal y el texto ilustrativo. La sinergia que se establece entre estos dos componentes enunciados facilita una nueva construcción estética que da pie, en su esencia, a un tipo de poesía que, en gran medida, es deudora de los efectos expresivos de la metáfora.

Preparation of sol-gel TiO2/purified Na-bentonite composites and their photovoltaic application for natural dye-sensitized solar cells

International Nuclear Information System (INIS)

Saelim, Ni-on; Magaraphan, Rathanawan; Sreethawong, Thammanoon

2011-01-01

Highlights: → Natural dye from red cabbage was successfully employed in DSSC. → A fast sol-gel method to produce TiO 2 /clay thin film was proposed. → The sol-gel-prepared TiO 2 /clay was applied as the scattering layer on top of TiO 2 electrode. → Thicker sol-gel-prepared TiO 2 /clay electrode showed higher DSSC efficiency. - Abstract: The sol-gel TiO 2 /purified natural clay electrodes having Ti:Si molar ratios of 95:5 and 90:10 were initially prepared, sensitized with natural red cabbage dye, and compared to the sol-gel TiO 2 electrode in terms of physicochemical characteristics and solar cell efficiency. The results showed that the increase in purified Na-bentonite content greatly increased the specific surface area and total pore volume of the prepared sol-gel TiO 2 /purified Na-bentonite composites because the clay platelets prevented TiO 2 particle agglomeration. The sol-gel TiO 2 /5 mol% Si purified Na-bentonite and sol-gel TiO 2 /10 mol% Si purified Na-bentonite composites could increase the film thickness of solar cells without cracking when they were coated as a scattering layer on the TiO 2 semiconductor-based film, leading to increasing the efficiency of the natural dye-sensitized solar cells in this work.

A introdução dos estudos de história natural na reforma pombalina-o quadro cultural e o movimento das ideias

OpenAIRE

Brigola, João

2012-01-01

Idenficam-se os autores e as ideias que, no período joanino, influenciaram o movimento de reforma da Universidade de Coimbra, cujo elemento mais inovador se corporizou na criação de duas novas faculdades (a de Matemática e a de Filosofia Natural) e na alteração programática profunda na de Medicina. Referência aos nomes dos professores mais inflentes neste período, aos Estatutos e à criação de novos equipamentos pedagógicos e científicos: jardim botânico; gabinete de história natural; gabinete...

Tecnologia e "Morte Natural": o morrer na contemporaneidade Technology and "Natural Death": dying in contemporary society

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Rachel Aisengart Menezes

2003-12-01

Full Text Available O desenvolvimento de técnicas voltadas ao prolongamento da vida acarretou mudanças significativas na concepção de morte. Este artigo analisa as representações contemporâneas da "morte natural" e sua relação com o uso de tecnologias médicas. Através de revisão bibliográfica, são examinadas as concepções de "morte natural" e de "morrer bem" construídas pelos diversos atores sociais envolvidos no processo do morrer. A literatura evidencia a construção contemporânea de um ideário e de uma trajetória necessários à realização do modelo da "boa morte". Esse modelo do "morrer bem" é construído em contraposição ao uso de técnicas para o prolongamento da vida. Estudos apontam a complexidade e ambivalência presentes no que seriam a morte natural ou não-natural, pois essas representações se encontram imbricadas com a concepção da "boa morte" como escolhida e produzida pelo doente. Deste modo, a tecnologia médica torna-se intrinsecamente constitutiva do "morrer natural".The development of techniques to prolong life has brought significant changes in the conceptualization of death. This article analyzes contemporary representations of "natural death" and their relationship to the use of medical technologies. Based on a literature review, the article examines the concepts of "natural death" and "dying well" constructed by the various social actors involved in the process of dying. The literature reveals the contemporary construction of a necessary set of ideals and pathway for achieving the model of a "good death". The "dying well" model is constructed in opposition to techniques for prolonging life. The studies point to the complexity and ambivalence of what is presented as "natural" versus "unnatural" death, since such representations are intertwined with the concept of a "good death" as that which is "chosen and produced" by the patient. Thus, medical technology becomes intrinsically constitutive for a "natural death".

PROMINP (Program of Mobilization of the National Industry of Oil and Natural Gas): synergy in the national industry; PROMINP (Programa de Mobilizacao da Industria Nacional de Petroleo e Gas Natural): sinergia na industria nacional

Energy Technology Data Exchange (ETDEWEB)

Almeida, Jose Renato Ferreira de; Campos, Michel Fabianski; Lopesm Ronaldo Rangel; Lisboa, Vitor Manuel dos Santos [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil)

2008-07-01

The Federal Government identified, from the forecast of massive investments in the sector of oil and natural gas in the next years, that it was establishing a favorable environment to foment the participation of the national industry of goods and services, in competitive and sustainable bases, in the implantation of projects of oil and gas in Brazil. Thus, in 2003, it was born the Program of Mobilization of the National Industry of Oil and Natural Gas - PROMINP. From an ample diagnosis of the necessary critical resources, throughout the time, for the implementation of the planned projects, the PROMINP identifies the gaps related to the professional qualification, industrial infrastructure and supply of materials and equipment, and, to surpass these challenges, it has lead, in these five years of existence, an expressive set of action for each one of the cited sources, of form to assure the competitiveness of the Industry of Supply of Goods and services and the support of this process. Such actions are elaborated and developed of joint form it enters all the participants of the chain. Since the creation of the PROMINP, the participation of the national industry (Local Content) in the investments of the sector increased of 57% in 2003 for 75% in 2007, what it means a US$ addition 8,3 billion orders of goods and services in the national market and generated more than 390 thousand new jobs. (author)

Optically stimulated luminescence of natural NaCl mineral from Dead Sea exposed to gamma radiation

International Nuclear Information System (INIS)

Roman L, J.; Cruz Z, E.; Pina L, Y. I.; Marcazzo, J.

2016-10-01

Luminescence properties such as radioluminescence, thermoluminescence and optically stimulated luminescence have been studied on natural sodium chloride (NaCl) for dosimetric purposes in retrospective dosimetry (Timar-Gabor et al., 2013; Druzhyna et al., 2016). In this work, the optically stimulated luminescence (Cw-OSL) emissions of natural salt minerals, collected from Dead Sea in summer of 2015, were studied. The Cw-OSL dose response of natural salt was analyzed in the range between 0.2 and 10 Gy gamma dose of "6"0Co. Samples exposed at 3 Gy exhibited good repeatability with a variation coefficient of 4.6%. The thermal stability of the Cw-OSL response was analyzed to different temperatures from 50 up to 250 degrees Celsius using a heating rate of 5 degrees Celsius. The results showed that the natural Dead Sea salt minerals could be applied as natural dosimeter of gamma radiation. (Author)

Optically stimulated luminescence of natural NaCl mineral from Dead Sea exposed to gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Roman L, J.; Cruz Z, E. [UNAM, Instituto de Ciencias Nucleares, Ciudad Universitaria, 04510 Ciudad de Mexico (Mexico); Pina L, Y. I. [UNAM, Facultad de Ciencias, Ciudad Universitaria, 04510 Ciudad de Mexico (Mexico); Marcazzo, J., E-mail: jesus.roman@nucleares.unam.mx [Instituto de Fisica Arroyo Seco - UNICEN, Pinto 399, 7000 Tandil (Argentina)

2016-10-15

Luminescence properties such as radioluminescence, thermoluminescence and optically stimulated luminescence have been studied on natural sodium chloride (NaCl) for dosimetric purposes in retrospective dosimetry (Timar-Gabor et al., 2013; Druzhyna et al., 2016). In this work, the optically stimulated luminescence (Cw-OSL) emissions of natural salt minerals, collected from Dead Sea in summer of 2015, were studied. The Cw-OSL dose response of natural salt was analyzed in the range between 0.2 and 10 Gy gamma dose of {sup 60}Co. Samples exposed at 3 Gy exhibited good repeatability with a variation coefficient of 4.6%. The thermal stability of the Cw-OSL response was analyzed to different temperatures from 50 up to 250 degrees Celsius using a heating rate of 5 degrees Celsius. The results showed that the natural Dead Sea salt minerals could be applied as natural dosimeter of gamma radiation. (Author)

Calibration with MCNP of NaI detector for the determination of natural radioactivity levels in the field.

Science.gov (United States)

Cinelli, Giorgia; Tositti, Laura; Mostacci, Domiziano; Baré, Jonathan

2016-05-01

In view of assessing natural radioactivity with on-site quantitative gamma spectrometry, efficiency calibration of NaI(Tl) detectors is investigated. A calibration based on Monte Carlo simulation of detector response is proposed, to render reliable quantitative analysis practicable in field campaigns. The method is developed with reference to contact geometry, in which measurements are taken placing the NaI(Tl) probe directly against the solid source to be analyzed. The Monte Carlo code used for the simulations was MCNP. Experimental verification of the calibration goodness is obtained by comparison with appropriate standards, as reported. On-site measurements yield a quick quantitative assessment of natural radioactivity levels present ((40)K, (238)U and (232)Th). On-site gamma spectrometry can prove particularly useful insofar as it provides information on materials from which samples cannot be taken. Copyright © 2016 The Authors. Published by Elsevier Ltd.. All rights reserved.

Jundiaí (SP: transformações recentes na paisagem urbana

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Adriana Fornari Del Monte Fanelli

2014-06-01

Full Text Available O objetivo deste trabalho é analisar aspectos condicionantes das transformações e as tipologias presentes na paisagem urbana de Jundiaí na região situada às margens das rodovias Dom Gabriel P. B. Couto e João Cereser, nas proximidades da serra do Japi. A partir da conceituação de Magnoli (1982 de espaços livres, e através da análise de informações de diversas naturezas, como legislações urbanísticas, fotos aéreas e visitas in loco, pode-se afirmar que Jundiaí, cidade-polo do Aglomerado Urbano de Jundiaí (AUJ, caracteriza-se pela presença de grandes áreas de preservação ambiental, como a serra do Japi, e áreas de conservação de mananciais, que impedem a expansão urbana para os vetores sul ou leste, favorecendo o crescimento da forma urbana no sentido noroeste e oeste. Devido à sua localização, num espaço intersticial entre as Regiões Metropolitanas de São Paulo, Campinas e o Aglomerado Urbano de Sorocaba (AUS, a cidade convive com diversas influências socioeconômicas e espaciais decorrentes do processo de metropolização típico da macrometrópole paulista. Assim, as áreas de preservação ambiental, as presenças de espaços livres não urbanizados de grandes proporções e a sinergia de Jundiaí com a rede de cidades dos Aglomerados Urbanos tornaram-se os principais agentes transformadores da paisagem urbana deste território.

Radiation induced color center and colloid formation in synthetic NaCl and natural rock salt

International Nuclear Information System (INIS)

Levy, P.W.; Swyler, K.J.; Klaffky, R.W.

1979-01-01

F-center and colloid particle formation has been studied in synthetic NaCl and natural rock salt crystals with apparatus for making optical absorption measurements during irradiation. F-center and colloid formation are functions of temperature, dose, dose rate, strain applied prior to irradiation and numerous other factors. Many of the observed properties are in accord with the Jain-Lidiard theory for radiation induced F-center and colloid growth above room temperature

Florística na Reserva Particular do Patrimônio Natural Complexo Serra da Farofa, estrutura e efeitos ambientais da antropização na comunidade arbustivo-arbórea, Santa Catarina, Brasil

OpenAIRE

Floriani, Mireli Moura Pitz

2015-01-01

A Floresta Ombrófila Mista (FOM) pertence ao Bioma Mata Atlântica e trata-se de uma formação florestal rica em espécies vegetais endêmicas, ocorrente preferencialmente na região Sul do Brasil. O trabalho teve como objetivo conhecer a composição florística, a estrutura e os efeitos ambientais da antropização na comunidade arbustivo-arbórea na Reserva Particular do Patrimônio Natural Estadual Complexo Serra da Farofa (Bloco VI) no município de Rio Rufino, Santa Catarina. O ...

Regeneração natural em fragmentos de floresta ombrófila densa na Bacia do Rio Capibaribe, Pernambuco.

OpenAIRE

Aldení Silva de Lima

2011-01-01

Os fragmentos florestais ciliares são de grande importância para manutenção da diversidade biológica, pois atuam como corredores ecológicos, facilitando a dispersão animal e vegetal entre áreas, além de auxiliarem na regularização do regime hídrico e na estabilidade dos solos. Assim, o presente trabalho objetivou caracterizar a fitossociologia do componente lenhoso regenerante em áreas ciliares, visando avaliar o potencial de regeneração natural em cinco fragmentos de Floresta Ombrófila Densa...

Simbolismo sobre "natural" na alimentação Symbolism on "natural" in food

Directory of Open Access Journals (Sweden)

Maria Claudia da Veiga Soares Carvalho

2011-01-01

Full Text Available Os sentidos incorporados representam um acervo de possibilidades para a vida futura capaz de construir identidades individuais e coletivas. Este trabalho aprofunda os habitus, nos termos de Bourdieu, associados aos estilos "natural" e fast-food, fazendo uma análise interpretativa das trocas simbólicas de elementos reproduzidos nas práticas de alimentação. Consideramos que o arranjo "bricolista" desses elementos possibilita permutas e hibridismos, marcado por uma tensão que reflete a insegurança das inovações tecnológicas. O "natural" é o representante do ideal de autossustentabilidade, da produção não poluidora, que aponta para um enfrentamento da crise sanitária e ecológica do planeta, resistindo à industrialização em larga escala e à urbanização acelerada, entendidos como fatores de depredação das condições básicas de vida. As trocas se dão em um jogo simbólico articulado com o econômico global, em que os atores sociais fazem apostas, illusio, de acordo com intenções particulares na ação concreta. Há chance para reformulação das regras do jogo "no jogo", pois ainda que com um equilíbrio precário de forças, com perdas para o lado mais fraco, um agente pode ter em seu acervo a possibilidade de não reproduzir as pressões da globalização alimentar, o que está distante do que possa aparecer como sobrenatural.The incorporated senses represent a set of possibilities for future life able to build individual and collective identities. This work deepens the habitus, in Bourdieu's terms, associated with "natural" and fast-food styles, making an interpretative analysis of symbolic exchanges of elements reproduced in feeding practices. We believe that this bricolage arrangement of elements enables bartering and hybridism, marked by a tension that reflects the insecurity of technological innovations. The "natural" style represents an ideal of self-sustainability, non-polluting production, which faces the sanitary

Liberdade, lei natural e direito natural em Hobbes: limiar do direito e da política na modernidade Freedom, natural law and natural right in Hobbes: threshold of law and politics in modernity

Directory of Open Access Journals (Sweden)

Natalia Maruyama

2009-01-01

Full Text Available Liberdade e poder são dois temas que se correlacionam ao longo da história da filosofia política moderna. Nos textos de Hobbes, a ideia da liberdade como ausência de impedimentos às ações ajuda-nos a pensar o dever de obediência ao poder soberano e as relações entre política e direito. Uma situação de vácuo jurídico, em que tudo é permitido, faz-se, contudo, impossível, de modo que a solução de Hobbes consiste em sustentar a ideia do direito natural como direito originário individual vinculado à preservação da vida. Suas ideias do direito natural e da lei natural, que servem de fundamento ao dever de obediência ao soberano, amparam-se em princípios jurídicos, teológicos e biológicos. Tais princípios, entretanto, não dão conta da questão da extensão do poder soberano. Hobbes recorre à análise da linguagem. Sua teoria contratual afirma o princípio de preservação da vida na base da política e sustenta a ideia da criação e da manutenção do poder soberano no ato de linguagem implicado na estrutura representativa do pacto político.Liberty and power are two subjects correlated along the history of the political modern philosophy. In the texts of Hobbes, the idea of liberty as absence of impediments to the actions helps us to think the duty of obedience to the sovereign power and the relations between politics and right. A situation of legal vacuum, in which everything is allowed, is, nevertheless, impossible, so that the solution of Hobbes consists in supporting the idea of the natural right like original individual right linked to the preservation of the life. His ideas of the natural right and of the natural law, which serve of basis to the duty of obedience to a sovereign, lean on legal, theological and biological principles. In spite of that, such principles do not surround the question of the extension of the sovereign power. Hobbes resorts to the analysis of the language. His contractual theory affirms

Diffusion of Na(I), Cs(I), Sr(II) and Eu(III) in smectite rich natural clay.

Science.gov (United States)

Kasar, Sharayu; Kumar, Sumit; Bajpai, R K; Tomar, B S

2016-01-01

Diffusion of Na(I), Cs(I), Sr(II) and Eu(III) in smectite rich natural clay, proposed as a backfill material in the Indian geological repository, was studied using the out-diffusion method. Radiotracers (22)Na, (137)Cs, (85)Sr and (154)Eu were used; the first three are carrier-free enabling experimental work at sub-micromolar metal ion concentration, and Eu(III) tracer (154)Eu was used at sub millimolar concentration. An out-diffusion methodology, wherein a thin planar source of radioactivity placed between two clay columns diffuses out, was used to obtain the apparent diffusion coefficient (Da) values. This methodology enabled determination of diffusion coefficient even for strongly sorbing (154)Eu. Da values for (22)Na, (137)Cs, (85)Sr and (154)Eu were 2.35 (±0.14) × 10(-11), 2.65 (±0.09) × 10(-12), 3.32 (±0.15) × 10(-11) and 1.23 (±0.15) × 10(-13) m(2) s(-1), respectively. Da values were found to be in fair agreement with literature data reported for similar mineralogical sediments. Sorption of radionuclides on the clay was also determined in the present study and differences in Da values were rationalized on the basis of sorption data. Distribution ratios (Kd) for Cs(I) and Eu(III) were higher than that for Sr(II), which in turn was higher than that for Na(I). Copyright © 2015 Elsevier Ltd. All rights reserved.

Incentivos, competências e conhecimento: evidência na França e integração teórica

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Fabrice Galia

2007-06-01

Full Text Available Este artigo examina a criação do conhecimento, bem como a partilha e a transferência de processos em firmas de manufatura na perspectiva da inovação. Primeiramente, usando dados franceses, mostra a complementariedade entre a gerência de recursos humanos e as práticas de gerência do conhecimento (HRM e KM, e seu impacto na inovação. Expõe a diversidade organizational das firmas. Três conjuntos ou pacotes de práticas organizationais são identificados como "sistemas das práticas HRM e de KM". Caracterizamos, respectivamente, (i firmas tradicionais na organização do trabalho; (ii firmas usando práticas de gestão de pessoal com incentivos e (iii firmas de aprendizagem, adicionando aos incentivos práticas de gerência do conhecimento. Correspondem aos modelos organizationais teóricos, includindo arquiteturas organizationais modernas, baseadas em incentivos para desenvolver competências e conhecimento, sem deixar de lado firmas inspiradas em tayloring. Os resultados empíricos permitem concluir que os pacotes das práticas de HRM e de KM produzem significativo e positivo impacto no desempenho da inovação, quando mudanças marginais em práticas individuais dão pouco resultado. Além disso, a fim de confirmar tais complementariedades, concentramo-nos em quatro práticas específicas usadas, principalmente, por firmas: gerência da equipe, dos incentivos, do treinamento e do conhecimento. Empregamos novo procedimento, baseado no conceito de supermodularidade, para estudar a complementaridade e a substitutabilidade em casos onde práticas organizationais múltiplas afetam o desempenho inovativo. Este procedimento baseia-se na limitação múltipla da desigualdade. Nossos resultados sugerem que as firmas usam certas práticas de maneira comum e sistematicamente, que explicam sinergias existentes. O resultado confirma a noção de que a gerência do conhecimento é mais eficaz quando acompanhada pela organização da equipe e por

Efeitos da adubação com dejetos suínos, cama de aves e fosfato natural na recuperação de pastagens degradadas

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Gabriel Felipe Vogel

2014-05-01

Full Text Available Normal 0 21 false false false PT-BR X-NONE X-NONE MicrosoftInternetExplorer4 O uso inadequado de áreas exploradas pela atividade pecuária tem sido uma das principais causas do declínio na fertilidade natural dos solos destas áreas, o que leva a degradação das pastagens. Uma alternativa que vêm se destacando na busca da sustentabilidade na recuperação dos solos degradados é a utilização de adubos orgânicos. O presente trabalho tem por objetivo expor pesquisas realizadas no Brasil com relação ao uso de adubos orgânicos na recuperação de pastagens degradadas. Tanto a utilização de adubação orgânica como de fosfato natural tem se mostrado alternativas promissoras na recuperação de pastagens degradadas em avaliações a curto prazo. Porém, verifica-se a necessidade de acompanhamentos a longo prazo do efeito do uso destas fontes, em especial aos adubos orgânicos, devido a dinâmica complexa destes adubos no solo e ao efeito que podem gerar no sistema.

Nonspecific nature of the vanadate inhibition of rat ileal (Na, K)-ATPase

International Nuclear Information System (INIS)

Hajjar, J.J.; Rowe, W.A.; Tomicic, T.K.

1988-01-01

Vanadate has been suggested as an intracellular regulator of (Na+ + K+)-ATPase. To test this hypothesis the authors examined the stimulatory and inhibitory effects of vanadate on 86 Rb efflux and influx (measurements of the activity of the Na-pump) in rat ileum under conditions of normal, reduced and increased (Na+ + K+)-ATPase activity. The half maximal inhibition of the Rb efflux and the half maximal inhibition of the Rb influx were not different in the three conditions tested. This suggests that vanadate does not have a regulatory effect on the activity of the Na-K-transport enzyme. The vanadate effect seem rather, to be nonspecific in terms of being unrelated, on a mole per mole basis, to the activity of the (Na+ + K+)-ATPase enzyme

Nonspecific nature of the vanadate inhibition of rat ileal (Na, K)-ATPase

Energy Technology Data Exchange (ETDEWEB)

Hajjar, J.J.; Rowe, W.A.; Tomicic, T.K.

1988-01-01

Vanadate has been suggested as an intracellular regulator of (Na+ + K+)-ATPase. To test this hypothesis the authors examined the stimulatory and inhibitory effects of vanadate on /sup 86/Rb efflux and influx (measurements of the activity of the Na-pump) in rat ileum under conditions of normal, reduced and increased (Na+ + K+)-ATPase activity. The half maximal inhibition of the Rb efflux and the half maximal inhibition of the Rb influx were not different in the three conditions tested. This suggests that vanadate does not have a regulatory effect on the activity of the Na-K-transport enzyme. The vanadate effect seem rather, to be nonspecific in terms of being unrelated, on a mole per mole basis, to the activity of the (Na+ + K+)-ATPase enzyme.

Acesso ao cuidado na Estratégia Saúde da Família: equilíbrio entre demanda espontânea e prevenção/promoção da saúde

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Armando Henrique Norman

2015-03-01

Full Text Available Este artigo propõe algumas diretrizes para a organização do trabalho na Atenção Primária à Saúde (APS e na Estratégia Saúde da Família (ESF, relacionadas aos desafios de prover acesso e equilibrar no cotidiano dos serviços ações de prevenção de agravos e promoção da saúde com o cuidado ao adoecimento. Primeiramente, apresenta algumas ideias específicas sobre a importância do acesso para a qualidade dos serviços de saúde, seguidas de uma crítica sintética - fundamentada nos conceitos de Geoffrey Rose - à estratégia preventiva de alto risco, que tem tido alto impacto na organização das rotinas assistenciais. A seguir, contextualiza a promoção da saúde relacionada ao cuidado individual na APS/ESF, discutindo o potencial sinérgico do cuidado e da promoção da saúde, em suas dimensões individuais e coletivas, para transcender o modelo biomédico/mecanicista. Finalmente, apoiado nos tópicos anteriores, no que tange aos seus desdobramentos operacionais e utilizando um exemplo concreto, propõe algumas diretrizes para a organização do trabalho e das agendas de médicos e enfermeiros da ESF, de modo a viabilizar equilíbrio e sinergia entre acesso ao cuidado e prevenção/promoção, com vistas ao fortalecimento da ESF como coordenadora local do cuidado e principal porta de entrada do Sistema Único de Saúde.

ESTUDO DA REGENERAÇÃO NATURAL, BANCO DE SEMENTES E CHUVA DE SEMENTES NA RESERVA GENÉTICA FLORESTAL DE CAÇADOR, SC

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Solon Jonas Longhi

1996-12-01

Full Text Available Este estudo foi realizado na Reserva Genética Florestal de Caçador, no Estado de Santa Catarina no período de agosto de 1995 a janeiro de 1996. Para o estudo da regeneração natural foram instaladas 10 parcelas de 250 m² (10m x 25m. No interior das mesmas foram coletados a camada de solo juntamente com a serapilheira em até 3cm de profundidade em 40 pontos amostrais de 0,5m x 0,5m para a análise do banco de sementes no solo, e instalados 20 coletores com área de 0,5 m x 0,5 m para a avaliação da chuva de sementes. Os resultados mostram que apesar da Araucaria angustifolia ser a espécie dominante no estrato superior da floresta não apresenta indivíduos na regeneração natural e a Mimosa scabrella foi a espécie arbórea mais importante presente no banco de sementes no solo. As relações entre os três parâmetros avaliados evidenciam uma distribuição irregular das espécies na área de estudo.

Altered Na+ transport after an intracellular alpha-subunit deletion reveals strict external sequential release of Na+ from the Na/K pump.

Science.gov (United States)

Yaragatupalli, Siddhartha; Olivera, J Fernando; Gatto, Craig; Artigas, Pablo

2009-09-08

The Na/K pump actively exports 3 Na(+) in exchange for 2 K(+) across the plasmalemma of animal cells. As in other P-type ATPases, pump function is more effective when the relative affinity for transported ions is altered as the ion binding sites alternate between opposite sides of the membrane. Deletion of the five C-terminal residues from the alpha-subunit diminishes internal Na(+) (Na(i)(+)) affinity approximately 25-fold [Morth et al. (2007) Nature 450:1043-1049]. Because external Na(+) (Na(o)(+)) binding is voltage-dependent, we studied the reactions involving this process by using two-electrode and inside-out patch voltage clamp in normal and truncated (DeltaKESYY) Xenopus-alpha1 pumps expressed in oocytes. We observed that DeltaKESYY (i) decreased both Na(o)(+) and Na(i)(+) apparent affinities in the absence of K(o)(+), and (ii) did not affect apparent Na(o)(+) affinity at high K(o)(+). These results support a model of strict sequential external release of Na(+) ions, where the Na(+)-exclusive site releases Na(+) before the sites shared with K(+) and the DeltaKESYY deletion only reduces Na(o)(+) affinity at the shared sites. Moreover, at nonsaturating K(o)(+), DeltaKESYY induced an inward flow of Na(+) through Na/K pumps at negative potentials. Guanidinium(+) can also permeate truncated pumps, whereas N-methyl-D-glucamine cannot. Because guanidinium(o)(+) can also traverse normal Na/K pumps in the absence of both Na(o)(+) and K(o)(+) and can also inhibit Na/K pump currents in a Na(+)-like voltage-dependent manner, we conclude that the normal pathway transited by the first externally released Na(+) is large enough to accommodate guanidinium(+).

Silicene for Na-ion battery applications

KAUST Repository

Zhu, Jiajie; Schwingenschlö gl, Udo

2016-01-01

Na-ion batteries are promising candidates to replace Li-ion batteries in large scale applications because of the advantages in natural abundance and cost of Na. Silicene has potential as the anode in Li-ion batteries but so far has not received

Radiação gama na conservação do suco natural de laranja

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Iemma Juliana

1999-01-01

Full Text Available Este trabalho estudou o efeito da radiação gama na população microbiológica, teor de sólidos solúveis, acidez titulável, pH and conteúdo de vitamina C do suco natural de laranja. A atividade microbiana pode causar a deterioração do suco de laranja. A irradiação é um processo de conservação de alimentos através da eliminação dos microrganismos, porém pode afetar algumas características do produto. O delineamento experimental foi em esquema fatorial 4x5 referentes ao controle mais 3 doses de radiação (2,0; 4,0 and 6.0 kGy e 5 períodos de armazenamento (1, 7, 14, 21 e 28 dias com 2 repetições. As amostras de suco natural foram extraídas de laranjas da variedade "Pêra", irradiadas a uma taxa de dose de 2,0 kGy por hora (cobalto-60, e em seguida foram armazenadas sob refrigeração (5 ± 3ºC. Os resultados mostraram pequenas variações no teor de sólidos solúveis, acidez titulável e pH, em relação aos tratamentos testados. A razão sólidos solúveis/acidez titulável foi determinada e também mostrou pequena variação em todos os tratamentos. Com o aumento da dose de radiação e o prolongamento do período de armazenamento houve redução no conteúdo de vitamina C do suco. A radiação gama se mostrou eficaz na redução da população microbiana do suco de laranja.

Synthesis of Ag or Pt Nanoparticles by Hydrolysis of Either Ag2Na or PtNa

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Huabin Wang

2008-01-01

Full Text Available Ag and Pt nanoparticles have successfully been synthesized by hydrolysis of either Ag2Na or PtNa at room temperature. The oxidation of sodium in the Pt-Na pellets was much faster than that in the Ag-Na pellets since Pt is a catalyst for H2O formation reaction from hydrogen and oxygen at room temperature. The hydrolysis byproduct, NaOH, has a high solubility and easily is removed. This method offers a simple method of preparing transition metal nanoparticles. The Ag and Pt nanoparticles prepared by this method were crystalline in nature, and spherical in shape with a mean size of around 10 nm.

Responsabilidade social como estratégia corporativa: o caso da Johnson & Johnson

OpenAIRE

Rosenchan, Tatiana

2010-01-01

Trata da reorganização do espaço público/civil através de novos posicionamentos dos diferentes agentes da realidade socioeconômicas. Debate a necessidade da conscientização das possibilidades de sinergia na atuação conjunta entre os setores público, privado e terceiro setor. Enfoca, através de ilustrações e estudo de caso, o importante e estratégico papel que a empresa assume como protagonista social. Analisa impactos e conseqüências dessa atuação.

Associar os ritmos da natureza ao desenvolvimento de benefícios em pessoas com diversos tipos de dificuldade

OpenAIRE

Oliveira, José Carlos Couto

2014-01-01

Dissertação de mestrado em Agricultura Biológica, apresentada à Escola Superior Agrária do Instituto Politécnico de Viana do Castelo O trabalho na agricultura com pessoas portadoras de deficiência é uma boa forma de fomentar sinergias, onde é possível ter diversos tipos de trabalho, combinado com as rotinas diárias. Por outro lado, tem sido demonstrado que a horticultura social e terapêutica tem benefícios relacionados com uma maior autoestima, capacidades sociais, reabilitação, inclusão, ...

Effects of synthetic and naturally occurring flavonoids on Na+, K+-ATPase: Aspects of the structure-activity relationship and action mechanism

International Nuclear Information System (INIS)

Hirano, T.; Oka, K.; Akiba, M.

1989-01-01

A comparative study was made of the effects of 15 synthetic and naturally occurring flavonoids on the hydrolytic activity of Na + , K + -adenosine triphosphatase (ATPase). Twelve of the flavonoids examined were mono-hydroxy or mono-methoxy derivatives. All inhibited Na + , K + -ATPase from dog kidney cortex when present at concentrations from 40-1000 μM. Flavones possessing cyclohexyl instead of the phenyl group were the most potent with IC 50 at 257-320 μM. Structure-activity relationships were observed among the following mono-substituted flavones as: (i) 2-cyclohexyl-benzopyran-4-one much-gt 2-phenyl-benzopyran-4-one; (ii) 2-cyclohexyl-7-hydroxybenzopyran-4-one > 2-cyclohexyl-6-hydroxy-benzopyran-4-one > 2-cyclohexyl-5-hydroxybenzopyran-4-one. Some flavonoids showing potent inhibitory activity were also examined for ouabain-displacement activity on human erythrocytes. Hardly and of the flavonoids were able to block [ 3 H] ouabain binding to erythrocytes. These results suggest that the mechanism by which flavonoid block Na + , K + -ATPase is not related to the cardiac glycoside-specific binding site(s) of this enzyme

Silicene for Na-ion battery applications

KAUST Repository

Zhu, Jiajie

2016-08-19

Na-ion batteries are promising candidates to replace Li-ion batteries in large scale applications because of the advantages in natural abundance and cost of Na. Silicene has potential as the anode in Li-ion batteries but so far has not received attention with respect to Na-ion batteries. In this context, freestanding silicene, a graphene-silicene-graphene heterostructure, and a graphene-silicene superlattice are investigated for possible application in Na-ion batteries, using first-principles calculations. The calculated Na capacities of 954mAh/g for freestanding silicene and 730mAh/g for the graphenesilicene superlattice (10% biaxial tensile strain) are highly competitive and potentials of >0.3 V against the Na/Na potential exceed the corresponding value of graphite. In addition, the diffusion barriers are predicted to be <0.3 eV.

Radiation damage studies on synthetic NaCl crystals and natural rock salt for waste disposal applications

International Nuclear Information System (INIS)

Klaffky, R.W.; Swyler, K.J.; Levy, P.W.

1979-01-01

Radiation damage studies are being made on synthetic NaCl and natural rock salt crystals from various localities, including potential repository sites. Measurements are being made with equipment for recording the radiation induced F-center and colloid particle absorption bands during irradiation with 1.5 MeV electrons at various temperatures. A technique has been developed to resolve the overlapping F-center and colloid bands. The resulting spectra and curves of absorption vs. dose provide information on colloid particle size and concentration, activation energies for processes occurring during colloid formation, and additional data suggesting that both strain and radiation induced dislocations contribute to the colloid formation process

Cultivo de beterraba em ambientes protegido e natural na época de verão

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João A. Tullio

2013-10-01

Full Text Available Objetivou-se neste trabalho avaliar as respostas produtivas de beterraba cultivada em ambiente natural e sob túnel com malha de sombreamento durante a época de verão. O delineamento experimental foi blocos ao acaso com quatro repetições e os tratamentos arranjados em parcela sub-subdividida tendo, como fator primário, os ambientes de cultivo (protegido e natural, como fator secundário, as cultivares (Itapuã 202 e Tall Top Early Wonder além das épocas de colheita (13, 26, 39, 52 e 65 dias após o transplante como fator terciário. Foram avaliados número de folhas, fitomassas fresca e seca da parte aérea, fitomassa fresca da raiz tuberosa, índice de área foliar, altura da planta e presença ou não de aneis esbranquiçados na raiz tuberosa. Em cada ambiente de cultivo foram instalados sensores para medidas da radiação fotossinteticamente ativa e temperatura do ar. O cultivo de beterraba sob túnel resultou em menor fitomassa fresca da raiz tuberosa e maior fitomassa fresca da parte aérea quando comparadas àquelas do cultivo em ambiente natural. O cultivo de beterraba sob túnel coberto com telado preto 70% não apresentou vantagens em relação ao cultivo em ambiente natural no que diz respeito às características de produção e à qualidade da raiz de beterraba.

Crise ambiental e ensino de ecologia : o conflito na relação homem-mundo natural

OpenAIRE

Dorotea Cuevas Fracalanza

1992-01-01

Resumo: Há duas décadas o currículo de Biologia para as escolas de segundo grau não incluía, com o mesmo destaque de hoje, temas como a Ecologia e a Questão Ambiental. A crescente importância desses assuntos e a estreita vinculação entre eles são sinais de uma mudança de sensibilidade na relação entre o Homem e o Mundo Natural. Atualmente, esta se apresenta sob a influência de dois pontos de vista conflitantes: o domínio do Homem sobre a Natureza'e a sujeição do mesmo às leis enunciadas pela ...

A Inovação Tecnológica na Sociedade do Conhecimento e o Papel Social da Embrapa no Desenvolvimento Regional

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Fabiana Cunha Viana Leonelli

2011-06-01

Full Text Available Em um ambiente caracterizado, cada vez mais, pelo acesso a informação e, principalmente, pela transversalidade do conhecimento, faz-se necessário compreender como a inovação tecnológica pode ter reflexos tangíveis e intangíveis na organização.A inovação pode ser entendida como a capacidade que a empresa tem em gerar novas idéias, identificar oportunidades e transformar esforços em produtos comercializáveis, buscando vincular a inovação com a geração de valor para a empresa, quase sempre, financeiro. No caso da Empresa Brasileira de Pesquisa Agropecuária – Embrapa, a geração de valor advinda das inovações se expressa não apenas pela arrecadação de royalties, mas, sobretudo, pelo avanço do conhecimento e pelos benefícios sociais e ambientais que uma tecnologia pode gerar para quem a adota, para o entorno e para a sociedade. Neste sentido, pensar a inovação tecnológica nesta dimensão é complexo e envolve elementos que extrapolam os fatores tradicionais de produção. A capacidade inovadora é formada por uma sinergia entre cultura organizacional, processos internos e relacionamentos inter-organizacionais.

A relação corpo-natureza na modernidade The body-nature relation in the Modernity

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Dulce Suassuna

2005-04-01

Full Text Available O trabalho apresenta uma reflexão teórica sobre o significado da relação corpo-natureza tomando como contexto a modernidade. O debate teórico proposto subsidia-se na teoria social, seguindo como referencial o pensamento weberiano no que concerne à sua visão sobre a modernidade. Ampara-se em Habermas para mostrar que na modernidade o quadro configurado se constrói por meio de rupturas que se processam como conseqüências patológicas do mundo natural, momento em que se permite discutir a relação homem (corpo e meio ambiente (natureza. A recuperação da contribuição de Habermas ocorreu por meio do texto clássico Teoria da Ação Comunicativa e da leitura de Goldblatt no seu livro Teoria Social e Ambiente. Além desses autores, outros são utilizados dentro dessa linha de pensamento, entretanto, pretendendo-se fugir da visão instrumentalista, buscou-se em Mauss, por meio da teoria do fato social total e da noção de técnicas corporais, um esforço teórico para uma possível justificativa da perspectiva da interdisciplinaridade entre o campo disciplinar das Ciências Sociais e a Educação Física e, por conseguinte, do desporto.This paper presents a theoretical reflection about the meaning of the body-nature relation, taking Modernity as a context. The theoretical discussion proposed here is subsidized by the social theory, following the weberian thinking as a reference, where it concerns the view of Modernity. It uses Habermas to show that in modernity the shaped picture is built by means of breaches which occur as pathological consequences of the natural world; moment in which the man (body-environment (nature relation can be discussed. The recovery of the contribution of Habernas happened through the classic text Theory of the Communicative Action and the reading of Goldblatt in his book Social and Environment Theory. Besides these authors, others are used within this line of thought. However, attempting to dodge the

Natural and technologic hazardous material releases during and after natural disasters: a review.

Science.gov (United States)

Young, Stacy; Balluz, Lina; Malilay, Josephine

2004-04-25

Natural disasters may be powerful and prominent mechanisms of direct and indirect hazardous material (hazmat) releases. Hazardous materials that are released as the result of a technologic malfunction precipitated by a natural event are referred to as natural-technologic or na-tech events. Na-tech events pose unique environmental and human hazards. Disaster-associated hazardous material releases are of concern, given increases in population density and accelerating industrial development in areas subject to natural disasters. These trends increase the probability of catastrophic future disasters and the potential for mass human exposure to hazardous materials released during disasters. This systematic review summarizes direct and indirect disaster-associated releases, as well as environmental contamination and adverse human health effects that have resulted from natural disaster-related hazmat incidents. Thorough examination of historic disaster-related hazmat releases can be used to identify future threats and improve mitigation and prevention efforts.

Na+,K+ pumpen vedbliver at overraske

DEFF Research Database (Denmark)

Vilsen, Bente

2008-01-01

This article provides an overview of news about the Na+,K+ pump, an indispensable enzyme whose protein structure has been described in a recent article in Nature, 50 years after its discovery. In combination with mutational analysis, the structure reveals the binding pocket for the K+ ions...... and the regulation of Na+ transport by a strategically located C-terminus of the protein. Focus is also on the pathophysiology of two neurological disorders, familial hemiplegic migraine and rapid-onset dystonia-parkinsonism, recently shown to be caused by mutations in the Na+,K+-ATPase. Udgivelsesdato: may 19...

Definition of a short-cut methodology for assessing earthquake-related Na-Tech risk

International Nuclear Information System (INIS)

Busini, Valentina; Marzo, Enrico; Callioni, Andrea; Rota, Renato

2011-01-01

Highlights: → In industrial sites located in natural hazard-prone areas technological accidents may be triggered by natural events, generating the so-called Na-Tech accidents. → In this paper, a qualitative screening methodology for assessing the earthquake Na-Tech risk has been developed with the aim of identifying which situations deserve a much more expensive Quantitative Risk Analysis. → The simple procedure developed, which summarizes in a suitable Key Hazard Indicator the Na-Tech risk level, has been validated by comparing its results with those of some Quantitative Risk Analyses involving also Na-Tech events and previously presented in the literature. - Abstract: Na-Tech (Natural and Technological) refers to industrial accidents triggered by natural events such as storms, earthquakes, flooding, and lightning. Herein, a qualitative methodology for the initial assessment of earthquake Na-Tech risk has been developed as a screening tool to identify which situations require a much more expensive Quantitative Risk Analysis (QRA). The proposed methodology, through suitable Key Hazard Indicators (KHIs), identifies the Na-Tech risk level associated with a given situation (i.e., a process plant located in a given territory), using the Analytical Hierarchy Process as a multi-criteria decision tool for the evaluation of such KHIs. The developed methodology was validated by comparing its computational results with QRA results that involved Na-Tech events previously presented in literature.

The effect of Na+ and K+ on the thermal denaturation of Na+ and + K+-dependent ATPase.

Science.gov (United States)

Fischer, T H

1983-01-01

To increase our understanding of the physical nature of the Na+ and K+ forms of the Na+ + K+-dependent ATPase, thermal-denaturation studies were conducted in different types of ionic media. Thermal-denaturation measurements were performed by measuring the regeneration of ATPase activity after slow pulse exposure to elevated temperatures. Two types of experiments were performed. First, the dependence of the thermal-denaturation rate on Na+ and K+ concentrations was examined. It was found that both cations stabilized the pump protein. Also, K+ was a more effective stabilizer of the native state than was Na+. Secondly, a set of thermodynamic parameters was obtained by measuring the temperature-dependence of the thermal-denaturation rate under three ionic conditions: 60 mM-K+, 150 mM-Na+ and no Na+ or K+. It was found that ion-mediated stabilization of the pump protein was accompanied by substantial increases in activation enthalpy and entropy, the net effect being a less-pronounced increase in activation free energy. PMID:6309139

Non-preferential fuelling of the Na(+)/K(+)-ATPase pump.

Science.gov (United States)

Fernández-Moncada, Ignacio; Barros, L Felipe

2014-06-15

There is abundant evidence that glycolysis and the Na(+)/K(+)-ATPase pump are functionally coupled, and it is thought that the nature of the coupling is energetic, with glycolysis providing the ATP that fuels the pump. This notion has been instrumental to current models of brain energy metabolism. However, structural and biophysical considerations suggest that the pump should also have access to mitochondrial ATP, which is much more abundant. In the present study, we have investigated the source of ATP that fuels the Na(+) pump in astrocytes, taking advantage of the high temporal resolution of recently available FRET nanosensors for glucose, lactate and ATP. The activity of the Na(+) pump was assessed in parallel with the Na(+)-sensitive dye SBFI AM (Na(+)-binding benzofuran isophthalate acetoxymethyl ester). OXPHOS (oxidative phosphorylation) inhibition resulted in bulk ATP depletion and a 5-fold stimulation of glycolytic flux, in spite of which Na(+) pumping was inhibited by 90%. Mathematical modelling of ATP dynamics showed that the observed pump failure is inconsistent with preferential fuelling of the Na(+) pump by glycolytic ATP. We conclude that the nature of the functional coupling between the Na(+) pump and the glycolytic machinery is not energetic and that the pump is mainly fuelled by mitochondrial ATP.

Protecting the 'Na Plachtě' natural monument from development. A case study on the importance of public participation in environmental protection

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Vendula Záhumenská

2014-11-01

Full Text Available Na Plachtě is located at the south-eastern edge of Hradec Králové where over the past 20 years conflicts of interests between environmentalists and local developers have arisen concerning the development and commercial use of the site. This case study is concerned with the importance of public participation in  environmental issues and describes the specific opportunities for influencing environmental decision-making. The author refers to specific events which eventually resulted in the declaration of the Na Plachtě site as a “natural monument”; she also investigates opportunities for changing the landscape plan which would strengthen  protection against any construction on the site. Other possibilities for influencing decision-making about issues of concern to the general public and which have an impact on the work of regional representatives are also discussed.

Simulação computacional integrada para a consideração da luz natural na avaliação do desempenho energético de edificações

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Evelise Leite Didoné

Full Text Available A luz natural é uma importante estratégia para redução do consumo de energia em edificações. Para sua previsão, recomenda-se a utilização de programas de simulação que empregam arquivos climáticos e processam as simulações com o conceito do Daylight Coefficients. O EnergyPlus, programa para simulação termoenergética, é uma dessas ferramentas. Porém, este software possui limitações no módulo de iluminação natural que superestimam a luz natural em ambientes internos. Para contornar essas limitações, o presente trabalho propõe uma metodologia para avaliação da eficiência energética, considerando o aproveitamento da luz natural, através da utilização de dois programas. A metodologia consiste na avaliação do desempenho luminoso e energético através de simulação com os programas Daysim e EnergyPlus. O Daysim produz um relatório que descreve o controle da iluminação artificial que é utilizado na simulação energética do EnergyPlus, que calcula o consumo energético final dos ambientes analisados. Os resultados indicam que a metodologia proposta mostrou-se adequada para suprir as limitações do EnergyPlus e para a avaliação da eficiência energética em edificações, considerando o aproveitamento da luz natural. Este trabalho mostra um caminho alternativo e confiável para a consideração do aproveitamento da iluminação natural na avaliação da eficiência energética de edificações.

Effects of synthetic and naturally occurring flavonoids on Na sup + , K sup + -ATPase: Aspects of the structure-activity relationship and action mechanism

Energy Technology Data Exchange (ETDEWEB)

Hirano, T.; Oka, K.; Akiba, M. (Tokyo College of Pharmacy (Japan))

1989-01-01

A comparative study was made of the effects of 15 synthetic and naturally occurring flavonoids on the hydrolytic activity of Na{sup +}, K{sup +} -adenosine triphosphatase (ATPase). Twelve of the flavonoids examined were mono-hydroxy or mono-methoxy derivatives. All inhibited Na{sup +}, K{sup +} -ATPase from dog kidney cortex when present at concentrations from 40-1000 {mu}M. Flavones possessing cyclohexyl instead of the phenyl group were the most potent with IC{sub 50} at 257-320 {mu}M. Structure-activity relationships were observed among the following mono-substituted flavones as: (i) 2-cyclohexyl-benzopyran-4-one {much gt} 2-phenyl-benzopyran-4-one; (ii) 2-cyclohexyl-7-hydroxybenzopyran-4-one {gt} 2-cyclohexyl-6-hydroxy-benzopyran-4-one {gt} 2-cyclohexyl-5-hydroxybenzopyran-4-one. Some flavonoids showing potent inhibitory activity were also examined for ouabain-displacement activity on human erythrocytes. Hardly and of the flavonoids were able to block ({sup 3}H) ouabain binding to erythrocytes. These results suggest that the mechanism by which flavonoid block Na{sup +}, K{sup +} -ATPase is not related to the cardiac glycoside-specific binding site(s) of this enzyme.

Planejamento de redes logísticas: um estudo de caso na indústria petroquímica brasileira.

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Luiz Felipe de Medeiros Frias

2013-08-01

Full Text Available O planejamento de redes logísticas emerge como decisão estratégica a ser tomada na busca da manutenção da competitividade empresarial. O presente estudo desenvolveu um modelo de Programação Não Linear Inteira Mista contemplando os principais componentes de custo envolvidos no processo de planejamento de redes associados à realidade brasileira: transportes, estoques e tributos. O modelo foi testado na empresa Nova Braskem. Foram realizadas análises de sensibilidade em que se apreciaram os principais trade-offs relativos às premissas assumidas. Constatou-se que, no caso estudado, o modelo desenvolvido proporciona economia nos custos tributários e nos custos logísticos de transporte, e, consequentemente, nos custos totais. Mais precisamente, os resultados apontam que, apesar da importância dos custos de transporte ante os demais, o aspecto fiscal se apresentou como o principal potencial de retorno financeiro a ser perseguido, e, dessa maneira, foi possível demonstrar o valor associado à questão dentro da atmosfera empresarial brasileira. Para o design ótimo de uma rede, confirma-se, portanto, a tese de que não é plausível a dissociação entre logística e planejamento tributário. Ademais, dada a natureza do estudo de caso, é factível a consideração do planejamento de redes logísticas como um importante ferramental capaz de subsidiar a busca de sinergias em operações de fusões e aquisições de empresas. Há, por exemplo, diversos outros casos recentes no cenário empresarial brasileiro, como a fusão entre Sadia e Perdigão e entre outras empresas do agronegócio. Para dar continuidade aos estudos dos trade-offs entre logística e os aspectos tributários brasileiros, sugere-se a inclusão de novos tributos (PIS, Cofins etc. e a concessão de benefícios fiscais na modelagem de redes logísticas futuras. Especificamente com relação ao estudo de caso, observa-se que a forma de agregação dos mercados consumidores

Diffusion and the dynamics of displacive phase transitions in cryolite (Na3AlF6) and chiolite (Na5Al3F14): Multi-nuclear NMR studies

Science.gov (United States)

Spearing, Dane R.; Stebbins, Jonathan F.; Farnan, Ian

1994-10-01

Cryolite is a mixed-cation perovskite (Na2(NaAl)F6) which undergoes a monoclinic to orthorhombic displacive phase transition at ˜550° C. Chiolite (Na5Al3F14) is associated with cryolite in natural deposits, and consists of sheets of corner sharing [AlF6] octahedra interlayered with edge-sharing [NaF6] octahedra. Multi-nuclear NMR line shape and relaxation time (T1) studies were performed on cryolite and chiolite in order to gain a better understanding of the atomic motions associated with the phase transition in cryolite, and Na diffusion in cryolite and chiolite. 27Al, 23Na, and 19F static NMR spectra and T1's in cryolite suggest that oscillatory motions of the [AlF6] octahedra among four micro-twin and anti-phase domains in α-cryolite begin at least 150° C below the transition temperature and persist above it. Variable temperature 23Na MAS NMR further indicates diffusional exchange at a rate of at least 13 kHz between the Na sites by the time the transition temperature is reached. 27Al and 23Na T1's show the same behavior with increasing temperature, indicating the same relaxation mechanisms are responsible for both. The first order nature of the cryolite transition is apparent as a jump in the 23Na and 27Al T1's. Above the transition temperature, the T1's decrease slightly indicating that the motions responsible for the drop in T1, are still present above the transition, further supporting the dynamic nature of the high temperature phase of cryolite. Chiolite 23Na static spectra decrease in linewidth with increasing temperature, indicating increased Na diffusion, which is interpreted as occurring within the [NaF6] sheets in the chiolite structure, but not between the two different Na sites. 27Al and 23Na T1's show similar behavior as in cryolite, but there is no discontinuity due to a phase transition. 19F T1's are constant from room temperature to 150° C indicating no oscillatory motion of the [AlF6] octahedra in chiolite.

God, design, and naturalism: Implications of methodological naturalism in science for science-religion relation

OpenAIRE

Piotr Bylica; Dariusz Sagan

2015-01-01

The aim of this paper is to analyze the implications flowing from adopting methodological naturalism in science, with special emphasis on the relation between science and religion. Methodological naturalism, denying supernatural and teleological explanations, influences the content of scientific theories, and in practice leads to vision of science as compatible with ontological naturalism and in opposition to theism. Ontological naturalism in turn justifies the acceptance of methodological na...

Estratégias para luz natural: sistemas inovadores.

Directory of Open Access Journals (Sweden)

Juliana Saiter Garrocho

2007-07-01

Full Text Available Diversos sistemas, estratégias e componentesinovadores de alta tecnologia paraa otimização do uso da luz natural noprojeto de arquitetura têm se desenvolvidoatualmente, principalmente na EuropaCentral, nos Estados Unidos e na Austrália.Este artigo apresenta algumas dessasestratégias descrevendo suas principaiscaracterísticas. Palavras-chave: luz natural, estratégias deprojeto, sistemas inovadores de alta tecnologia.

Synthesis of high capacity cation exchangers from a low-grade Chinese natural zeolite

International Nuclear Information System (INIS)

Wang Yifei; Lin Feng

2009-01-01

The Chinese natural zeolite, in which clinoptilolite coexists with quartz was treated hydrothermally with NaOH solutions, either with or without fusion with NaOH powder as pretreatment. Zeolite Na-P, Na-Y and analcime were identified as the reacted products, depending on the reaction conditions such as NaOH concentration, reaction time and hydrothermal temperature. The products were identified by X-ray diffraction, and characterized by Fourier transform IR and ICP. With hydrothermal treatment after fusion of natural zeolite with NaOH, high purity of zeolite Na-Y and Na-P can be selectively formed, their cation exchange capacity (CEC) are 275 and 355 meq/100 g respectively, which are greatly higher than that of the natural zeolite (97 meq/100 g). Furthermore, the ammonium removal by the synthetic zeolite Na-P in aqueous solution was also studied. The equilibrium isotherms have been got and the influence of other cations present in water upon the ammonia uptake suggested an order of preference Ca 2+ > K + > Mg 2+ .

Removal of emulsified and dissolved traces of organic compounds from industrial wastewaters using nature and synthesized (Na A and Nam) zeolites

International Nuclear Information System (INIS)

Modirshahla, N.; Tabatabaii, S.

2004-01-01

The main object of this study was to compare the natural and synthetic (Na A and Nam) zeolites as absorbents in removing emulsified and dissolved traces of organic compounds, which appear in the wastewater of power plants, refinery and petrochemical complexes. The specific objections of the work was: a) to select the best species that have the highest amount of absorption; b) to measure the rate of absorption of traces organic compounds and emulsions on the natural and synthesized zeolites; c) to establish the absorption isotherms for the organics and emulsions with selected samples; d) to select readily available regenerants, and e ) to examine the ph dependence of the process and to establish a simple and practical method to detect and to measure the pollution after the treatment process. The BOD and COD of the treated and feed waters were compared

THERMODYNAMICS OF ION-EXCHANGED NATURAL CLINOPTILOLITE

Science.gov (United States)

Natural clinoptilolite from Castle Creek, Idaho, and its cation-exchanged variants (Na-Cpt, NaK-Cpt, K-Cpt, and Ca-Cpt) were studied by high-temperature calorimetry. The hydration enthalpy for all clinoptilolites is about -30 kJ/mol H2O (liquid water reference state) at 25 C. T...

Geotecnologias como suporte para análise da vegetação natural na sub-bacia hidrográfica do Rio Gavião (1988 a 2015

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Carlos Magno Santos Clemente

2017-06-01

Full Text Available O histórico de ocupação da sub-bacia do rio Gavião passou por transformações socioeconômicas expressivas nos últimos 30 anos. Desse modo, preocupações com preservação ou recuperação da cobertura vegetal influência, positivamente, na manutenção do ciclo hidrológico da sub-bacia. A presente pesquisa tem como objetivo analisar a modificação da vegetal natural entre os anos de 1988 a 2015 na sub-bacia hidrográfico do rio Gavião (semiárido brasileiro. Foram utilizadas as como suporte técnico o sensoriamento remoto, Processamento Digital de Imagens - PDI e o Sistema de Informações Geográficas - SIG (satélites landsat 5 e landsat 8. Os resultados indicam redução da cobertura vegetal de 751,69 km², entre os anos de 1988 a 2015. Também, manchas de desmatamento em áreas de nascentes, na parte alta da rede de drenagem e no dessegue do canal principal. Assim, a presente pesquisa chama atenção para os efeitos da mudança da vegetação natural para outros usos da terra (solo exposto, plantio, entre outros, a concentração do desmatamento em áreas de fragilidade ambiental.

Mudanças das rotinas familiares na transição inesperada por desastre natural Cambios sobre las rutinas familiares en la transición inesperada por desastre natural Family routines changes in the unexpected transition due to natural disasters

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Gisele Cristina Manfrini Fernandes

2013-03-01

Full Text Available Desastres naturais são eventos disruptivos às rotinas e rituais familiares e promovem mudanças significativas na vida e na saúde. O objetivo deste artigo foi discutir as rotinas diárias ao longo das trajetórias na transição familiar pela ocorrência de um desastre natural ocorrido em uma área rural. Trata-se de um estudo qualitativo de múltiplos casos, realizado com seis famílias com crianças. Os dados foram coletados em 2010, com técnicas de observação participante, entrevista narrativa, genograma, ecomapa e o calendário de rotinas familiares. Foi feita a análise das narrativas, e os resultados revelaram a mudança nas rotinas e rituais nas trajetórias entre o pré, o pós-desastre e atualidade. A transição abrupta gerou reações estressantes, afetando a saúde dos membros. São necessários mais estudos sobre a saúde no pós-desastre que contribuam ao conhecimento, ao ensino e à prática do cuidado de enfermagem, especialmente na estratégia de saúde da família.Los desastres naturales son eventos disruptivos a las rutinas y rituales familiares y promueven cambios significativos en la vida y en la salud. El objetivo de este artículo es discutir las rutinas diarias a lo largo de las trayectorias en la transición familiar debido a un desastre natural ocurrido en un área rural. Se trata de un estudio cualitativo de múltiples casos, realizado con seis familias con niños. Los datos fueron obtenidos en 2010, con técnicas de observación participante, entrevista narrativa, genograma, ecomapa y el calendario de rutinas familiares. Se realizó un análisis de las narrativas y los resultados revelaron cambios en las rutinas y rituales, en las trayectorias entre el pre y el post desastre y la actualidad. La transición abrupta generó reacciones estresantes, afectando la salud de los miembros. Se hace necesario más estudios sobre la salud en el post desastre, que contribuyan al conocimiento, enseñanza y práctica del

Crystallographic characterization of cement pastes hydrated with NaCl; Caracterizacao cristalografica de pastas de cimento hidratadas com NaCl

Energy Technology Data Exchange (ETDEWEB)

Melo, Carina Gabriela de Melo e; Martinelli, Antonio Eduardo; Melo, Dulce Maria Araujo; Melo, Marcus Antonio de Freitas; Melo, Vitor Rodrigo de Melo e [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

2012-07-01

One of the major current challenges faced by oil companies is the exploration of pre salt basins. Salt layers deposited upon the evaporation of ocean water and continental separation are mainly formed by NaCl and isolate immense oil reservoirs. The mechanical stability and zonal isolation of oil wells that run through salt layers must be fulfilled by cement sheaths saturated with NaCl to assure chemical compatibility between cement and salt layer. The present study aimed at evaluating the effect of NaCl addition on the hydration of oil well cement slurries as well as identifying the nature of crystalline phases present in the hardened cement. To that end, cement slurries containing NaCl were mixed, hardened and characterized by X-ray diffraction. The results revealed that the presence of NaCl affects the formation of hydration products by the presence of Friedel's salt. The intensity of the corresponding peaks increase as the contents of NaCl in the slurry increase. High concentrations of NaCl in Portland slurries increase the setting time of cement and the presence of Friedel's salt decreases the strength of the hardened cement. (author)

A model to investigate the optimal seeder-to-naïve ratio for successful natural Mycoplasma hyopneumoniae gilt exposure prior to entering the breeding herd.

Science.gov (United States)

Roos, Luiza R; Fano, Eduardo; Homwong, Nitipong; Payne, Brian; Pieters, Maria

2016-02-29

Due to the significance of Mycoplasma hyopneumoniae as a swine respiratory pathogen, acclimation measures are taken into consideration when obtaining replacement gilts from negative sources to be introduced to endemically infected herds. The aim of this study was to evaluate the optimum seeder-to-naïve gilt ratio in a 4-week period for successful natural exposure to M. hyopneumoniae. Sixty gilts were divided in two groups, 21 2-week old seeder gilts were inoculated with M. hyopneumoniae, and 39 aged-matched naïve gilts were exposed to the seeders during a 4-week period. The exposure was set by dividing the gilts into six groups of 10 with different ratios of seeder-to-naïve, from 1:9 until 6 seeders and 4 naïve gilts. Laryngeal swabs, oral fluids and blood samples were collected from all gilts prior to, during and after inoculation and exposure. Infection in seeders was confirmed by development of clinical signs, seroconversion post-inoculation, and detection of M. hyopneumoniae genetic material. Naïve were considered positive after 4 weeks if M. hyopneumoniae was detected on bronchial swab or fixed lung tissue. As result, 33% (3/9) naïve gilts were positive in the 1:9 ratio, 75% (6/8) in 2:8, 28% (2/7) in 3:7, 33% (2/6) in 4:6, 80% (4/5) in 5:5 and 100% (4/4) in the 6:4 ratio. The estimated transmission rate (β) and expected probability of infection (ψ) were 1.28 per pig/week and 0.6, respectively. In this study, six seeders were required in a group of 10 gilts for successful exposure to M. hyopneumoniae in a 4-week exposure period. Copyright © 2016 Elsevier B.V. All rights reserved.

Programas educativos e práticas integradas ao patrimônio cultural: atualizando o debate

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Marian Helen da Silva Gomes Rodrigues

2016-12-01

Full Text Available O artigo apresenta uma reflexão sobre a relevância do desenvolvimento de programas educativos voltados para o ensino do patrimônio cultural, para promover a integração e apropriação das comunidades locais aos conhecimentos patrimoniais. Para tanto, teceremos sobre os principais certames legais na política de preservação patrimonial no Brasil, tendo a inserção da educação como principal indutora. Em seguida, abrindo o horizonte da discussão apresentam-se quatro experiências educacionais desenvolvidas por instituições não governamentais em regiões (continentes socioculturais e geograficamente distintas do globo terrestre, são elas: Europa, América do Norte e América do Sul, com o objetivo de ilustrar a sinergia dessas experiências, pois mesmo em contexto distintos, vem promovendo a integração e o engajamento social na defesa e difusão do patrimônio cultural nas suas nações e/ou regiões.

Parametri za procena na kvalitetot na polietilenska i na polipropilenska ambalaza i na gumeni zatvoraci nameneti za farmacevtski preparati

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Liljana Ugrinova

2002-03-01

Full Text Available Napraven e pregled na parametrite za procena na kvalitetot na polietilenska i na polipropilenska ambalaza i na gumeni zatvoraci nameneti za farmacevtski preparati. Za procena na kvalitetot na ispituvaniot materijal bea izvrseni fizicki, hemiski i bioloski ispituvanja spored postapkite dadeni vo Ph. Eur., DIN i spored DIN ISO standardite. Baranjata za kvalitet na ovoj vid ambalaza propisani spored Ph. Eur., DIN i DIN ISO standardite se razlikuvaat vo odnos na predvidenite parametri za fizicki, za hemiski i za bioloski ispituvanja. Isto taka, propisani se i razlicni granici na dozvoleno otstapuvanje na oddelni parametri.

Prediction of Intrinsic Cesium Desorption from Na-Smectite in Mixed Cation Solutions.

Science.gov (United States)

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.

An enhancement to the NA4 gear vibration diagnostic parameter

Science.gov (United States)

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.

Distinction of [220] and [204] textures of Cu(In,Ga)Se{sub 2} film and their growth behaviors depending on substrate nature and Na incorporation

Energy Technology Data Exchange (ETDEWEB)

Cho, Dae-Hyung, E-mail: dhcho@etri.re.kr [IT Components and Materials Industry Technology Research Department, Electronics and Telecommunications Research Institute (ETRI), 218 Gajeongno, Yuseong-gu, Daejeon 305-700 (Korea, Republic of); Kim, Jeha [Department of Solar & Energy Engineering, Cheongju University, 298 Daeseongro, Sangdang-gu, Cheongju, Chungbuk 360-764 (Korea, Republic of); Chung, Yong-Duck [IT Components and Materials Industry Technology Research Department, Electronics and Telecommunications Research Institute (ETRI), 218 Gajeongno, Yuseong-gu, Daejeon 305-700 (Korea, Republic of); Korea University of Science and Technology (UST), 217 Gajeongno, Yuseong-gu, Daejeon 305-350 (Korea, Republic of)

2015-08-31

For better understanding of the structural property of polycrystalline tetragonal Cu(In,Ga)Se{sub 2} (CIGS) thin films grown on soda-lime glass, it is necessary to characterize the [220]- and [204]-oriented textures clearly that are related to the different physical properties. However, the distinction between the [220]- and [204]-oriented textures is very difficult because of their nearly identical plane spacings and atomic arrangements. Using X-ray diffraction techniques of high resolution θ–2θ scanning and reciprocal space mapping, we distinguished the [220]- and [204]-oriented textures of CIGS films and observed that the behaviors of [220] and [204] textures independently depended on both substrate nature and Na presence. We report the Na- and substrate-related dependence of the physical properties of the CIGS film was attributed to the independent growth behaviors of the [220] and [204] textures in the CIGS. - Highlights: • We investigated [220]- and [204]-oriented textures of Cu(In,Ga)Se{sub 2} (CIGS) films. • X-ray diffraction methods distinguished two textures. • The growth behaviors were influenced by underlying substrate and Na. • The [220] and [204] textures in CIGS should be differentially observed.

Načrtovan porod na domu

OpenAIRE

Todorović, Tamara; Takač, Iztok

2017-01-01

Izhodišča: Porod na domu je sicer star toliko kot človeštvo, pa vendar v veliki večini srednje in visoko razvitih držav prevladuje mnenje, da so zaradi nepredvidljivosti zapletov porodnišnice najbolj varno okolje za rojevanje. Kljub temu obstaja peščica držav, v katerih je porod na domu integriran v sistem zdravstvenega varstva (npr. Nizozemska, Velika Britanija, Kanada). Pri porodih na domu ločimo nenačrtovane in načrtovane porode na domu, slednje pa lahko nadalje razdelimo še na porode s sp...

Exploring Natural and Social Scientists' Views of Nature of Science

Science.gov (United States)

Bayir, Eylem; Cakici, Yilmaz; Ertas, Ozge

2014-01-01

Science education researchers recently turned their attention to exploring views about nature of science (NOS). A large body of research indicates that both students and teachers have many naïve views about the NOS. Unfortunately, less attention has been directed at the issue of exploring the views of the scientists. Also, the little research in…

Radiation induced F-center and colloid formation in synthetic NaCl and natural rock salt: applications to radioactive waste repositories

International Nuclear Information System (INIS)

Levy, P.W.; Loman, J.M.; Kierstead, J.A.

1983-01-01

Radiation damage, particularly Na metal colloid formation, has been studied in synthetic NaCl and natural rock salt using unique equipment for making optical absorption, luminescence and other measurements during irradiation with 1 to 3 MeV electrons. Previous studies have established the F-center and colloid growth phenomenology. At temperatures where colloids form most rapidly, 100 to 250 C, F-centers appear when the irradiation is initiated and increase at a decreasing rate to a plateau, reached at doses of 10 6 to 10 7 rad. Concomitant colloid growth is described by classical nucleation and growth curves with the transition to rapid growth occurring at 10 6 to 10 7 rad. The colloid growth rate is low at 100 C, increases markedly to a maximum at 150 to 175 C and decreases to a negligible rate at 225 C. At 1.2x10 8 rad/h the induction period is >10 4 sec at 100 C, 10 4 sec at 275 C. The colloid growth in salt from 14 localities is well described by C(dose)/sup n/ relations. Data on WIPP site salt (Los Medanos, NM, USA) has been used to estimate roughly the colloid expected in radioactive waste repositories. Doses of 1 to 2x10 10 rad, which will accumulate in salt adjacent to lightly shielded high level canisters in 200 to 500 years, will convert between 1 and 100% of the salt to Na colloids (and Cl) if back reactions or other limiting reactions do not occur. Each high level lightly shielded canister may ultimately be surrounded by 200 to 300 kg of colloid sodium. Low level or heavily shielded canisters may produce as little as 1 kg sodium

Ibn Kamm´na on the Nature of Knowledge | Alper | Journal for ...

African Journals Online (AJOL)

philosopher Sa>d b. Man§´r Ibn Kamm´na (d. 683/1284), who is one of the most important and influential philosophers of the post-Avicennan period. In order to accomplish this aim, the article begins with a brief look at his view on the conception of ...

Efeito do conteúdo e da natureza da lignina residual na eficiência e na seletividade do branqueamento com ozônio Effect of residual lignin content and nature on the efficiency and selectivity of ozone bleaching

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Elenice Pereira Maia

2003-04-01

Full Text Available Neste estudo foram avaliados os efeitos do conteúdo e da natureza da lignina residual na eficiência e na seletividade do branqueamento com ozônio de polpa kraft convencional (kraft e pré-deslignificada com oxigênio (kraft-O. Constatou-se que a eficiência do branqueamento com ozônio se eleva com o aumento do conteúdo de lignina residual da polpa. O tratamento com ozônio é mais seletivo para polpas kraft-O, mas para um mesmo tipo de polpa a seletividade de branqueamento com ozônio se eleva com o aumento de lignina residual. A eficiência do branqueamento com ozônio aumenta com o teor de lignina fenólica na polpa, entretanto a seletividade é negativamente afetada pela presença destas estruturas.This study aimed to evaluate the effect of residual lignin content and nature on the efficiency and selectivity of ozone bleaching of conventional (kraft and oxygen delignified (kraft-O pulps. Ozone bleaching efficiency was found to be enhanced by increasing pulp residual lignin content. Ozone treatment is more selective for kraft-O pulps, but for a given type of pulp (kraft or kraft-O, ozone bleaching selectivity increases with increasing pulp lignin content. Ozone bleaching efficiency increases with increasing pulp lignin phenolic hydroxyl content whereas selectivity is negatively affected by these structures.

Especiarias como antioxidantes naturais: aplicações em alimentos e implicação na saúde Spices as natural antioxidants: their application in food and implication for health

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P.V Del Ré

2012-01-01

Full Text Available O crescente interesse na substituição de antioxidantes sintéticos por naturais em alimentos tem fomentado a pesquisa sobre fontes vegetais, caracterização de matérias-primas e identificação de novos compostos antioxidantes. As reações de oxidação não são uma preocupação exclusiva das indústrias alimentícias, seu estudo é também amplamente necessário para evitar implicações indesejáveis na saúde humana. O objetivo desta revisão, depois de apresentar aspectos gerais sobre a oxidação, é concentrar-se nos benefícios da utilização das especiarias como antioxidantes naturais, em especial as da família Labiatae, amplamente utilizadas na culinária brasileira.The growing interest in replacing synthetic antioxidants by natural antioxidants in food has stimulated research on vegetable sources, raw material characterization and identification of new antioxidant compounds. Oxidation reactions are not an exclusive preoccupation of the food industry; studies regarding this issue are widely necessary in order to prevent undesired implications for human health. The aim of this review, after presenting overall aspects about oxidation, is to concentrate on the benefits of using spices as natural antioxidants, especially those from the Labiatae family, which are widely used in the Brazilian cuisine.

Effect of alkali-treatment on the characteristics of natural zeolites with different compositions.

Science.gov (United States)

Ates, Ayten

2018-08-01

A series of natural zeolites with different compositions were modified by post-synthesis modification with sodium hydroxide (NaOH) solution. Natural and modified zeolites were characterized by XRD, SEM, nitrogen adsorption, FTIR, zeta potential and temperature programmed desorption of ammonia (NH 3 -TPD). The adsorption capacities of these samples were evaluated by the adsorption of manganese from aqueous solution. The treatment with NaOH led to a decrease in the surface area and microporosity of all natural zeolites as well as partly damage of the zeolite structure depending on zeolite composition. In addition, the amount of weak, medium and strong acid sites in the zeolites was changed significantly by NaOH treatment depending on zeolite composition. The NaOH treatment resulted in a four-fold improvement in adsorption capacity of natural zeolite originated from Bigadic and a twofold decrease in that of the natural zeolite originated from Manisa-Gordes. Although the improved adsorption capacity might be mainly due to modification of porosity in the zeolites and formation of hydroxysodalite, the reduced adsorption capacity of the zeolite might be mainly due to a significant deformation of the zeolite structure. The pseudo-second-order kinetic model for the adsorption of manganese on all natural and modified zeolites fits well. Copyright © 2018 Elsevier Inc. All rights reserved.

Inhibitory efficacy of bufadienolides on Na+,K+-pump activity versus cell proliferation.

Science.gov (United States)

Xu, Yinfang; Liu, Xuan; Schwarz, Silvia; Hu, Lihong; Guo, Dean; Gu, Quanbao; Schwarz, Wolfgang

2016-07-01

Bufadienolides are cytotoxic drugs that may form the basis for anticancer agents. Due to structural and functional similarity to cardiotonic glycosides, application is restricted. We, therefore, investigated correlation of their putative anticancer effects with inhibition of Na + ,K + pumps. The natural bufalin and three derivatives were tested. The anticancer effects of the drugs were checked by observing their inhibitory effects on proliferation of rat liver cancer cells using MTT assay. Inhibition of Na + ,K + -pump was determined by measuring pump-mediated current of rat α1/β1 and α2/β1 Na + ,K + pumps expressed in Xenopus oocytes. All tested bufadienolides inhibited cell proliferation and Na + ,K + pump activity. An activity coefficient A =100x IC 50 Na,K pump /IC 50 pr o liferation was used to describe drug effectivity as anticancer drug. Natural bufalin exhibited lowest effectivity on cell proliferation, and also the A value for rat α1 isoform was the lowest (0.08), the α2 isoform was much less sensitive ( A =1.00). The highest A values were obtained for the BF238 derivative with A =0.88 and 2.64 for the α1 and α2 isoforms, respectively. Therefore, we suggest that search for bufalin derivatives with high anticancer effect and low affinity for both Na + ,K + pump isoforms may be a promising strategy for development of anticancer drugs.

Parâmetros nutricionais da pastagem natural em diferentes tipos de solos na APA do Ibirapuitã, Rio Grande do Sul - Brasil Nutritional parameters of natural pasture in different soils at APA of Ibirapuitã, Rio Grande do Sul - Brazil

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Vicente Celestino Pires Silveira

2006-12-01

Full Text Available O desempenho de ruminantes domésticos é influenciado por fatores intrínsecos ao animal, ao alimento e pela interação entre animal e alimento. O trabalho foi realizado na Estância do 28, pertencente à Fundação Maronna, Alegrete - RS, dentro da APA do Ibirapuitã. Para representar o fator solo, foram escolhidos os três tipos predominantes da APA do Ibirapuitã: Basalto Superficial, Basalto Profundo e Arenito. As amostras da pastagem natural foram retiradas por simulação de pastejo, através de coleta manual. Os parâmetros nutricionais avaliados foram: proteína bruta, fibra em detergente neutro e taxa de degradação da matéria seca. A forragem da pastagem natural oriunda do solo Basalto Superficial apresentou diferença significativa (PIntrinsic animal and food factors and the interaction between them influence the performance of domestic ruminants. This study was done at Estância do 28, property of the Maronna Foundation, Alegrete - RS, inside the Ibirapuitã Area of Environmental Protection. In order to represent soil as a factor, the three main soil types were chosen: Superficial Basalt, Deep Basalt and Sandy. Hand plucking methods were used to obtain samples of natural pasture. Nutritional parameters considered were crude protein, neutral detergent fiber and dry matter degradation rate. The forage from natural pasture of the Superficial Basalt presented significant difference (P<0.05 in crude protein rates over the other two types of soil, which did not differ amongst themselves. The highest rate of neutral detergent fibre (84.54% was obtained in pasture originated from Sandy soil, in relation to Superficial and Deep Basalt, with values of 74.53% and 77.98%, respectively. There was also a significant difference in the degradation rate of dry matter (P<0.05. Sandy soil pasture presented an intermediate degradation value (3.61% h-1, not differing from other soils. The forage from natural pastures present similar degradation rates

Naturally occurring mutations associated with resistance to HCV NS5B polymerase and NS3 protease inhibitors in treatment-naïve patients with chronic hepatitis C.

Science.gov (United States)

Costantino, Angela; Spada, Enea; Equestre, Michele; Bruni, Roberto; Tritarelli, Elena; Coppola, Nicola; Sagnelli, Caterina; Sagnelli, Evangelista; Ciccaglione, Anna Rita

2015-11-14

The detection of baseline resistance mutations to new direct-acting antivirals (DAAs) in HCV chronically infected treatment-naïve patients could be important for their management and outcome prevision. In this study, we investigated the presence of mutations, which have been previously reported to be associated with resistance to DAAs in HCV polymerase (NS5B) and HCV protease (NS3) regions, in sera of treatment-naïve patients. HCV RNA from 152 naïve patients (84 % Italian and 16 % immigrants from various countries) infected with different HCV genotypes (21,1a; 21, 1b; 2, 2a; 60, 2c; 22, 3a; 25, 4d and 1, 4k) was evaluated for sequence analysis. Amplification and sequencing of fragments in the NS5B (nt 8256-8640) and NS3 (nt 3420-3960) regions of HCV genome were carried out for 152 and 28 patients, respectively. The polymorphism C316N/H in NS5B region, associated with resistance to sofosbuvir, was detected in 9 of the 21 (43 %) analysed sequences from genotype 1b-infected patients. Naturally occurring mutations V36L, and M175L in the NS3 protease region were observed in 100 % of patients infected with subtype 2c and 4. A relevant proportion of treatment naïve genotype 1b infected patients evaluated in this study harboured N316 polymorphism and might poorly respond to sofosbuvir treatment. As sofosbuvir has been approved for treatment of HCV chronic infection in USA and Europe including Italy, pre-treatment testing for N316 polymorphism on genotype 1b naïve patients should be considered for this drug.

Effects of different NaCl Concentrations on germination and ...

African Journals Online (AJOL)

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Salinity refers to the salt content of any given system. By nature, arid .... Effect of varying concentrations of NaCl on seed germination of Amaranthus hybridus in percentages. .... Osmotic differences could explain this phenomenon where by ...

Implantación CRM en la FAS (Fundació Autònoma Solidària)

OpenAIRE

Cuevas Mayo, Ricart

2015-01-01

El propósito de este documento es el de consignar detalladamente la implantación de un CRM (Customer Relationship Management) en la Fundación Autònoma Solidària (FAS). El CRM se ha llevado a cabo por el proyecto SinergiaCRM a partir de una iniciativa de la Asociación SinergiaTIC, entidad sin ánimo de lucro, cuya misión es favorecer el desarrollo colaborativo de herramientas tecnológicas adaptadas a las necesidades del Tercer Sector. En concreto mis funciones han sido las de unificar todos los...

Chemical modifications of liquid natural rubber

Science.gov (United States)

Azhar, Nur Hanis Adila; Rasid, Hamizah Md; Yusoff, Siti Fairus M.

2016-11-01

Liquid natural rubber (LNR) was synthesized via photosentisized degradation of natural rubber (NR). LNR was modified into epoxidized liquid natural rubber (LENR) and hydroxylated liquid natural rubber (LNR-OH) using Na2WO4/CH3COOH/H2O2 catalytic system. Chemical structures of LNR and modified LNRs were characterized using Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) and 1H Nuclear Magnetic Resonance (NMR) spectroscopies. Integration of 1H NMR was used to calculate the epoxy content (%) of LENR. 1H NMR detected the formation of LNR-OH after prolonged heating and increased of catalyst in oxidation reaction.

Measuring naturally occurring uranium in soil and minerals by analysing the 352 keV gamma-ray peak of 214Pb using a NaI(Tl)-detector

International Nuclear Information System (INIS)

Bezuidenhout, J.

2013-01-01

This article investigates the prospect of utilising the 351.9 keV gamma-ray of 214 Pb when determining the concentration of uranium. Soil samples were collected from various locations around South Africa and laboratory gamma ray spectra for each were obtained by means of a NaI(Tl)-detector (7.62×7.62 cm 2 ). The potassium, uranium and thorium concentrations where extracted by analysing gamma ray peaks that are associated with these radionuclides. Two separate uranium concentrations were extracted; one by means of the 214 Pb decay and the other one by means of the 214 Bi decay. These uranium concentrations were compared in terms of accuracies and detection limits. - Highlights: • Investigated a method to improve uranium concentrations measurements. • Expansion on an existing method that analyses naturally occurring radionuclides. • Utilise pill containers opposed to Marrinelli beakers. • Possible application to in situ measurements. • The method utilise NaI(Tl)-detectors with relative high efficiency

Florística e classificação da regeneração natural em Floresta Ombrófila Mista na Floresta Nacional de São Francisco de Paula, RS.

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Igor da Silva Narvaes

2009-10-01

Full Text Available Normal 0 21 MicrosoftInternetExplorer4 Na floresta Ombrófila Mista, a regeneração natural é pouco estudada. No Rio Grande do Sul, em conseqüência da ação antrópica, essas florestas se encontram sob diferentes condições de alteração, em alguns casos formando fragmentos. O estudo teve como objetivo analisar a florística da regeneração natural e verificar a ocorrência de grupos florísticos de uma área onde não foram constatadas alterações intensas. A área com 1606,69 ha localiza-se na Floresta Nacional de São Francisco de Paula (entre 29° 23' e 29° 27' S; 50° 23' e 50° 25' W, no município de São Francisco de Paula, RS. No estudo, foram selecionadas seis parcelas permanentes de crescimento do PELD (Projeto Ecológico de Longa Duração cuja vegetação foi inventariada, utilizando-se dez faixas paralelas entre si e perpendiculares à direção da posição topográfica, as quais apresentaram 10 m de largura e 100 m de comprimento, subdivididas em dez unidades de 100 m² onde foram sorteadas três unidades amostrais por faixa para identificação e medição (altura e circunferência de indivíduos com Cap maior ou igual a 3 cm e menor de 30 cm. Os cipós, trepadeiras e ervas também tiveram suas circunferências medidas e identificados até o nível de espécie, quando possível. Os dados de densidade por espécie formaram uma matriz (180x70 utilizada na análise multivariada. A presença de agrupamento de vegetação em estado de regeneração natural no interior da floresta foi testada pelo Método TWINSPAN (Two-way indicator species analysis. Constatou-se a existência de três grupos ecológicos (G-1, G-2 e G-3. O G-1 foi caracterizado por boa disponibilidade hídrica, por possuir características ambientais intermediárias e por situar-se na posição topográfica referente à encosta média; G-2 ocorreu na encosta inferior da floresta, apresentando forte influência da umidade e sujeita a alagamentos espor

A água na Ilha da Madeira

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João Manuel de Lemos Baptista

2014-02-01

Full Text Available Este artigo aborda a problemaÅLtica da aÅLgua na Madeira, desde a origem do povoamento ateÅL aos nossosdias, com especial atencao para a exploracao e salvaguarda deste recurso natural.Na Madeira, a aÅLgua existe em abunda^ncia, gracas aos fenoÅLmenos climaÅLticos que ocorrem na ilha, devidotambeÅLm ao relevo e a` natureza das rochas serem predominantemente basaÅLlticas (impermeaÅLveis etambeÅLm devido aos investimentos que o Governo Regional tem efetuado, nomeadamente a niÅLvel daexploracao, atraveÅLs da construcao de furos e de galerias para extrair a aÅLgua subterra^nea, como forma desatisfazer as necessidades da populacao no seu todo e dos turistas que nos visitam.Nao obstante, eÅL fundamental continuar com uma gestao equilibrada e sisteÅLmica da aÅLgua, para que nofuturo este liÅLquido continue nas nossas vidas. Felizmente que na Madeira, a empresa de capitaispuÅLblicos IGA – Investimentos e Gestao da AÅLgua, S.A. tem realizado um trabalho excelente em termosde exploracao, tratamento e abastecimentos a`s populacoes da Madeira e do Porto Santo, assim comouma gestao sustentaÅLvel deste recurso.This article discusses the problem of water in the wood, from the origin of the settlement to the presentday, with special attention to the exploitation and protection of this natural resource. In Madeira, waterexists in abundance, thanks to the weather phenomena that occur on the island, also due to relief andthe nature of the rocks are predominantly basaltic (waterproof and also due to the investments thatthe Regional Government has made, particularly in terms of the exploration, through the constructionof boreholes and galleries to extract groundwater as a way to meet the needs of the whole populationand the tourists who visit us.Nevertheless, it is essential to continue with a balanced and systematic management of water, so thatin future this fluid continues in our lives. Fortunately in Madeira, the company —owned IGA�

Radiation Processing of Natural Polymers for Industrial Applications

International Nuclear Information System (INIS)

Hegazy, E.A.

2008-01-01

Radiation induced degradation technology is a new and promising application of ionizing radiation to develop viscose, pulp, paper, food preservation, pharmaceutical production, and natural bioactive agents industries. Controlling the degree of degradation, uniform molecular weight distribution, saving achieved in the chemicals (used in conventional methods) on a cost basis, and environmentally friendly process are the beneficial effects of using radiation technology in these industries. However, for some development countries such technology is not economic. Therefore, a great effort should be done to reduce the cost required for such technologies. One of the principle factors for reducing the cost is achieving the degradation at low irradiation doses. The addition of some additives such as potassium per-sulfate (KPS), ammonium per-sulfate (APS), or H 2 O 2 to natural polymers (carboxy-methylcellulose (CMC), chitosan, carrageenan and Na-alginate) during irradiation process accelerates their degradation. The highest degradation rate of polysaccharides obtained when APS was used. The end product of irradiated CMC, chitosan, carrageenan and Na-alginate may be used as food additive or benefited in agricultural purposes. On the other hand, radiation crosslinking of PAAm or PNIPAAm is affected by the presence of natural polymer like CMC-Na and carrageenan due to their degradability which could be controlled according to its concentration in the bulk medium and irradiation dose. Accordingly, the gel content, thermo-sensitivity (LCST) and swelling properties of PNIPAAm based natural polymers could be controlled. The swelling of the prepared copolymer hydrogels was investigated for its possible use in personal care articles particularly diapers or as carriers for drug delivery systems. The prepared crosslinked copolymers possessed high and fast swelling properties in simulated urine media and the swelling ratios of CMC-Na /PAAm gels in urine are acceptable for diaper

Adsorption of Free Fatty Acid (FFA) in Low-Grade Cooking Oil Used Activated Natural Zeolite as Adsorbent

Science.gov (United States)

Larasati Tres Ayu Putranti, Monika; Kompiang Wirawan, Sang; Made Bendiyasa, I.

2018-01-01

Adsorption of free fatty acid (FFA) in low-grade cooking oil using active natural zeolite adsorbent was done as an effort to improve the quality of low-grade cooking oil so that it can fulfill the standard of fried oil which has been set on SNI 01-3741-2013. Adsorption was carried out with natural zeolite which activated with HCl and NaOH solution followed by the calcination process. The results showed that the NaOH activated zeolite decreased FFA content in low-grade cooking oil more than the HCl activated natural zeolite, with optimum NaOH concentration was 0.75 M. In the adsorption equilibrium analysis with temperature variation (25 °C, 40 °C, 80 °C ), obtained that adsorption of FFA with NaOH activated natural zeolite follows Adsorption Isotherm Freundlich Model with equilibrium constant value was 20,5873; 0,9629 dan 0,8053.

Environmental background level of cosmic ray produced 22Na

International Nuclear Information System (INIS)

Tokuyama, H.; Oonishi, M.; Matsuura, H.

1993-01-01

The annual deposition rate of cosmogenic 22 Na has been studied at Fukui City, Japan, to obtain the current background level. The deposition rate was found to range from 0.16 to 0.22 Bq m -2 y -1 with a mean value of 0.20 Bq m -2 y -1 for the years 1986-1990. The author's results agree fairly well with those observed for the years 1975-1977 in Tokyo. The 22 Na concentration in rain water was also estimated. The mean value for this period was found to be 0.09 mBq litre -1 , which is about one-third of that detected during the latter half of the 1950's. The high levels of environmental 22 Na in the 1950's are attributed to the many nuclear weapon tests conducted at that time. At present, however, the 22 Na from these weapons tests has practically decayed and the concentration in rain water has decreased to the natural background level. (Author)

Development of Na/sup 123/I pharmaceutical from antimony target

Energy Technology Data Exchange (ETDEWEB)

Yongjian, L.; Qixun, S.; Dequn, S. (Shanghai Inst. of Nuclear Research, Academia Sinica, Shanghai (China))

A new method for the production of Na/sup 123/I is described. It is produced by the /sup 121/Sb(..cap alpha..,2n)/sup 123/I nuclear reaction and using a natural antimony target prepared by electroplating in a bath of antimony oxide and hydrofluoric acid. The target is irradiated with 32MeV ..cap alpha..-beams then transferred to a dry distillation apparatus and the iodide evolved and absorbed in NaOH. Quality control is by paper chromatography.

Simbolismo sobre "natural" na alimentação

OpenAIRE

Carvalho,Maria Claudia da Veiga Soares; Luz,Madel Therezinha

2011-01-01

Os sentidos incorporados representam um acervo de possibilidades para a vida futura capaz de construir identidades individuais e coletivas. Este trabalho aprofunda os habitus, nos termos de Bourdieu, associados aos estilos "natural" e fast-food, fazendo uma análise interpretativa das trocas simbólicas de elementos reproduzidos nas práticas de alimentação. Consideramos que o arranjo "bricolista" desses elementos possibilita permutas e hibridismos, marcado por uma tensão que reflete a inseguran...

Na+-stimulated ATPase of alkaliphilic halotolerant cyanobacterium Aphanothece halophytica translocates Na+ into proteoliposomes via Na+ uniport mechanism

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Soontharapirakkul Kanteera

2010-08-01

Full Text Available Abstract Background When cells are exposed to high salinity conditions, they develop a mechanism to extrude excess Na+ from cells to maintain the cytoplasmic Na+ concentration. Until now, the ATPase involved in Na+ transport in cyanobacteria has not been characterized. Here, the characterization of ATPase and its role in Na+ transport of alkaliphilic halotolerant Aphanothece halophytica were investigated to understand the survival mechanism of A. halophytica under high salinity conditions. Results The purified enzyme catalyzed the hydrolysis of ATP in the presence of Na+ but not K+, Li+ and Ca2+. The apparent Km values for Na+ and ATP were 2.0 and 1.2 mM, respectively. The enzyme is likely the F1F0-ATPase based on the usual subunit pattern and the protection against N,N'-dicyclohexylcarbodiimide inhibition of ATPase activity by Na+ in a pH-dependent manner. Proteoliposomes reconstituted with the purified enzyme could take up Na+ upon the addition of ATP. The apparent Km values for this uptake were 3.3 and 0.5 mM for Na+ and ATP, respectively. The mechanism of Na+ transport mediated by Na+-stimulated ATPase in A. halophytica was revealed. Using acridine orange as a probe, alkalization of the lumen of proteoliposomes reconstituted with Na+-stimulated ATPase was observed upon the addition of ATP with Na+ but not with K+, Li+ and Ca2+. The Na+- and ATP-dependent alkalization of the proteoliposome lumen was stimulated by carbonyl cyanide m - chlorophenylhydrazone (CCCP but was inhibited by a permeant anion nitrate. The proteoliposomes showed both ATPase activity and ATP-dependent Na+ uptake activity. The uptake of Na+ was enhanced by CCCP and nitrate. On the other hand, both CCCP and nitrate were shown to dissipate the preformed electric potential generated by Na+-stimulated ATPase of the proteoliposomes. Conclusion The data demonstrate that Na+-stimulated ATPase from A. halophytica, a likely member of F-type ATPase, functions as an electrogenic Na

Effect of salts (NaCl and Na2CO3) on callus and suspension culture of Stevia rebaudiana for Steviol glycoside production.

Science.gov (United States)

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 μmol 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.

Polarization dependence of Na* + Na* associative ionization revisited

NARCIS (Netherlands)

Meijer, H.A.J.; Meulen, H.P. v.d.; Morgenstern, R.; Hertel, I.V.; Meyer, E.; Witte, R.

1986-01-01

The dependence of the associative ionization process Na 3 2P3/2 + Na 3 2P3/2 → Na2+ + e- on the polarization of the laser light used for Na excitation was independently investigated in Utrecht and Berlin. The purpose of this paper is to clarify discrepancies between two other earlier experimental

O serviço social em indústrias de grande porte do Rio Grande do Sul = Social work in big companies in Rio Grande do Sul

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Ziliotto, Denise Macedo

2010-01-01

Full Text Available A temática deste artigo centra-se na prática profissional do assistente social na área empresarial, especialmente em indústrias de grande porte. Pretende contribuir na explicitação da especificidade do exercício profissional do Serviço Social nas organizações, entendido como uma atividade inserida na divisão sociotécnica do trabalho e sendo perpassada pelas transformações que estão ocorrendo no mundo laboral nas últimas décadas. A pesquisa foi realizada com profissionais atuantes no contexto investigado através de entrevistas pessoais, avaliadas pela análise de conteúdo. Os resultados obtidos sugerem a atuação predominante de mulheres com formação em universidades privadas, com trajetória profissional majoritária no setor empresarial. Os processos desenvolvidos pelas entrevistadas buscam reverter a imagem assistencialista do campo, valorizando as relações no trabalho e a sinergia com a organização como um todo. A importância do conhecimento multidisciplinar como instrumento para as intervenções e do posicionamento crítico diante das demandas que lhe são dirigidas na dinâmica organizacional foram evidenciados na pesquisa. O caráter recente e ainda restrito da presença dos profissionais no segmento industrial sinaliza um processo de inserção e reconhecimento ainda em construção

Influenza neuraminidase: a druggable target for natural products.

Science.gov (United States)

Grienke, Ulrike; Schmidtke, Michaela; von Grafenstein, Susanne; Kirchmair, Johannes; Liedl, Klaus R; Rollinger, Judith M

2012-01-01

The imminent threat of influenza pandemics and repeatedly reported emergence of new drug-resistant influenza virus strains demonstrate the urgent need for developing innovative and effective antiviral agents for prevention and treatment. At present, influenza neuraminidase (NA), a key enzyme in viral replication, spread, and pathogenesis, is considered to be one of the most promising targets for combating influenza. Despite the substantial medical potential of NA inhibitors (NAIs), only three of these drugs are currently on the market (zanamivir, oseltamivir, and peramivir). Moreover, sudden changes in NAI susceptibility revealed the urgent need in the discovery/identification of novel inhibitors. Nature offers an abundance of biosynthesized compounds comprising chemical scaffolds of high diversity, which present an infinite pool of chemical entities for target-oriented drug discovery in the battle against this highly contagious pathogen. This review illuminates the increasing research efforts of the past decade (2000-2011), focusing on the structure, function and druggability of influenza NA, as well as its inhibition by natural products. Following a critical discussion of publications describing some 150 secondary plant metabolites tested for their inhibitory potential against influenza NA, the impact of three different strategies to identify and develop novel NAIs is presented: (i) bioactivity screening of herbal extracts, (ii) exploitation of empirical knowledge, and (iii) computational approaches. This work addresses the latest developments in theoretical and experimental research on properties of NA that are and will be driving anti-influenza drug development now and in the near future.

Ion Exchange Properties of Georgian Natural Zeolites

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Vladimer Tsitsishvili

2017-06-01

Full Text Available Ion-exchange properties of natural zeolites of Georgia with a relatively low Si/Al ratio have been studied: analcimes are characterized by selectivity series: Na+>K+>Ag+>NH4+>Ca+2>Sr+2>Li+; for phillipsites selectivity sequences are different for calcium- and potassium forms; selectivity sequence for scolecite is: Sr+2>Ba+2>Rb+>Ca+2>Cs+>K+>NH4+>Na+>Mg+2>Li+>Cd+2>Cu+2> Mn+2> Zn+2>Co+2>Ni+2.

Terminação de novilhos de corte Angus e mestiços em pastagem natural na região da Campanha do RS Finishing of Angus and crossbred beef cattle on native pasture in the Campanha region of RS

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Eduardo Tonet Ferreira

2011-09-01

Full Text Available Avaliou-se a viabilidade de abater animais de distintos grupos raciais com até quatro dentes em diferentes tipos de pastagem: natural, adubada, e melhorada por fertilização e sobressemeadura de espécies hiberno-primaveris. O delineamento experimental utilizado foi o de blocos ao acaso, com três repetições. Os dados foram agrupados em estações do ano (inverno e primavera e submetidos à análise de variância. Foram utilizados novilhos de corte Angus e mestiços, ambos com média de idade inicial de 20 meses. A massa de forragem total e a altura do pasto apresentaram diferenças entre os tipos de pastagem e as estações do ano. A taxa de lotação e a massa de forragem verde sofreram interação entre o tipo de pastagem e a estação do ano. O ganho por área ao longo do experimento foi maior na pastagem adubada (259 kg/ha e melhorada (263 kg/ha em comparação à pastagem natural (126 kg/ha. O ganho médio diário foi maior para os novilhos Angus (1,087 kg/dia e na estação de inverno (1,251 kg/dia. Não houve diferença para a área de olho-de-lombo entre o tipo de pastagem e grupo racial na data do abate. A espessura de gordura subcutânea sofreu interação entre o tipo de manejo e o grupo racial, uma vez que novilhos mestiços depositaram mais gordura na pastagem adubada e novilhos Angus na melhorada. Animais mestiços atingiram menor peso ao abate (505 kg, porém maior rendimento de carcaça (51,6%. Somente os animais mantidos na pastagem natural não atingiram acabamento suficiente para a comercialização. A utilização de fertlizantes e sementes na pastagem natural possibilita o abate de novilhos precoces independente do grupo racial. O ambiente pastoril determina diferentes respostas produtivas conforme a genética utilizada. O cruzamento é uma alternativa para incrementar atributos importantes da carcaça e diminuir o tempo de terminação.The viability for slaughtering steers of distinct breeds with four teeth at most, on

Spectrographic analysis of metallic silicium and natural quartz

International Nuclear Information System (INIS)

Grigoletto, T.; Lordello, A.R.

1985-01-01

A method has been developed for the spectrographic determination of B, Mg, Al, Ca, Ti, Mn, Fe, Ni, Cu and Ag in silicon metal and other for Al, Ca, Mg, Ti, Cr, Mn, and Fe in natural quartz. A mixture of the matrix with a proper buffer is excited directly in a dc-arc. High-current (25A) and argon atmosphere are used for both the methods. Silicon metal is blended with 8% NaF and after 1:1 (w/w) with graphite. For natural quartz 20% NaF and 30% graphite by weight is the buffer mixture employed. The lower values in the determinations varies from 0.5 to 40 μg/g and the precision of the analysis from 7% to 45%. (Author) [pt

Sinergia natural en la globalización: Suite ofimática y organizaciones flexibles e inteligentes

OpenAIRE

Alix Aguirre Andrade; Nelly Manasía Fernández

2009-01-01

Los servicios que presta la suite ofimática facilitan los procesos en las organizaciones, realizándolos en el espacio virtual, superando las limitaciones que impone la contextualización física. Las nuevas formas de emprender tareas utilizando componentes de la suite ofimática, incentivan la aplicación de las tecnologías de la información y comunicación como instrumentos estratégicos en suministrar respuestas a las organizaciones, en sectores públicos y privados. El objetivo de este artículo e...

Pseudo-ternary phase diagram in the Na2O-Na2O2-NaOH system

International Nuclear Information System (INIS)

Saito, Jun-ichi; Tendo, Masayuki; Aoto, Kazumi

1997-10-01

Generally, the phase diagrams are always used to understand the present state of compounds at certain temperature. In order to understand the corrosion behavior of structural material for FBR by main sodium compounds (Na 2 O, Na 2 O 2 and NaOH), it is very important to comprehend the phase diagrams of their compounds. However, only Na 2 O-NaOH pseudo-binary phase diagram had been investigated previously in this system. There is no study of other pseudo-binary or ternary phase diagrams in the Na 2 O-Na 2 O 2 -NaOH system. In this study, in order to clarify the present states of their compounds at certain temperatures, the pseudo-binary and ternary phase diagrams in the Na 2 O-Na 2 O 2 -NaOH system were prepared. A series of thermal analyses with binary and ternary component system has been carried out using the differential scanning calorimetry (DSC). The liquidus temperature and ternary eutectic temperatures were confirmed by these measurements. The beneficial indications for constructing phase diagrams were obtained from these experiments. On the basis of these results, the interaction parameters between compounds which were utilized for the Thermo-Calc calculation were optimized. Thermo-Calc is one of thermodynamic calculation software. Consequently the accurate pseudo-binary and ternary phase diagrams were indicated using the optimized parameters. (author)

Integrated treatment process using a natural Wyoming clinoptilolite for remediating produced waters from coalbed natural gas operations

Science.gov (United States)

Zhao, H.; Vance, G.F.; Urynowicz, M.A.; Gregory, R.W.

2009-01-01

Coalbed natural gas (CBNG) development in western U.S. states has resulted in an increase in an essential energy resource, but has also resulted in environmental impacts and additional regulatory needs. A concern associated with CBNG development relates to the production of the copious quantities of potentially saline-sodic groundwater required to recover the natural gas, hereafter referred to as CBNG water. Management of CBNG water is a major environmental challenge because of its quantity and quality. In this study, a locally available Na-rich natural zeolite (clinoptilolite) from Wyoming (WY) was examined for its potential to treat CBNG water to remove Na+ and lower the sodium adsorption ratio (SAR, mmol1/2 L- 1/2). The zeolite material was Ca-modified before being used in column experiments. Column breakthrough studies indicated that a metric tonne (1000??kg) of Ca-WY-zeolite could be used to treat 60,000??L of CBNG water in order to lower SAR of the CBNG water from 30 to an acceptable level of 10??mmol1/2 L- 1/2. An integrated treatment process using Na-WY-zeolite for alternately treating hard water and CBNG water was also examined for its potential to treat problematic waters in the region. Based on the results of this study, use of WY-zeolite appears to be a cost-effective water treatment technology for maximizing the beneficial use of poor-quality CBNG water. Ongoing studies are evaluating water treatment techniques involving infiltration ponds lined with zeolite. ?? 2008 Elsevier B.V. All rights reserved.

Extracting natural dyes from wool--an evaluation of extraction methods.

Science.gov (United States)

Manhita, Ana; Ferreira, Teresa; Candeias, António; Dias, Cristina Barrocas

2011-05-01

The efficiency of eight different procedures used for the extraction of natural dyes was evaluated using contemporary wool samples dyed with cochineal, madder, woad, weld, brazilwood and logwood. Comparison was made based on the LC-DAD peak areas of the natural dye's main components which had been extracted from the wool samples. Among the tested methods, an extraction procedure with Na(2)EDTA in water/DMF (1:1, v/v) proved to be the most suitable for the extraction of the studied dyes, which presented a wide range of chemical structures. The identification of the natural dyes used in the making of an eighteenth century Arraiolos carpet was possible using the Na(2)EDTA/DMF extraction of the wool embroidery samples and an LC-DAD-MS methodology. The effectiveness of the Na(2)EDTA/DMF extraction method was particularly observed in the extraction of weld dye components. Nine flavone derivatives previously identified in weld extracts could be identified in a single historical sample, confirming the use of this natural dye in the making of Arraiolos carpets. Indigo and brazilwood were also identified in the samples, and despite the fact that these natural dyes were referred in the historical recipes of Arraiolos dyeing, it is the first time that the use of brazilwood is confirmed. Mordant analysis by ICP-MS identified the widespread use of alum in the dyeing process, but in some samples with darker hues, high amounts of iron were found instead.

Efficient removal of cesium from low-level radioactive liquid waste using natural and impregnated zeolite minerals.

Science.gov (United States)

Borai, E H; Harjula, R; Malinen, Leena; Paajanen, Airi

2009-12-15

The objective of the proposed work was focused to provide promising solid-phase materials that combine relatively inexpensive and high removal capacity of some radionuclides from low-level radioactive liquid waste (LLRLW). Four various zeolite minerals including natural clinoptilolite (NaNCl), natural chabazite (NaNCh), natural mordenite (NaNM) and synthetic mordenite (NaSM) were investigated. The effective key parameters on the sorption behavior of cesium (Cs-134) were investigated using batch equilibrium technique with respect to the waste solution pH, contacting time, potassium ion concentration, waste solution volume/sorbent weight ratio and Cs ion concentration. The obtained results revealed that natural chabazite (NaNCh) has the higher distribution coefficients and capacity towards Cs ion rather than the other investigated zeolite materials. Furthermore, novel impregnated zeolite material (ISM) was prepared by loading Calix [4] arene bis(-2,3 naphtho-crown-6) onto synthetic mordenite to combine the high removal uptake of the mordenite with the high selectivity of Calix [4] arene towards Cs radionuclide. Comparing the obtained results for both NaSM and the impregnated synthetic mordenite (ISM-25), it could be observed that the impregnation process leads to high improvement in the distribution coefficients of Cs+ ion (from 0.52 to 27.63 L/g). The final objective in all cases was aimed at determining feasible and economically reliable solution to the management of LLRLW specifically for the problems related to the low decontamination factor and the effective recovery of monovalent cesium ion.

Efficient removal of cesium from low-level radioactive liquid waste using natural and impregnated zeolite minerals

International Nuclear Information System (INIS)

Borai, E.H.; Harjula, R.; Malinen, Leena; Paajanen, Airi

2009-01-01

The objective of the proposed work was focused to provide promising solid-phase materials that combine relatively inexpensive and high removal capacity of some radionuclides from low-level radioactive liquid waste (LLRLW). Four various zeolite minerals including natural clinoptilolite (NaNCl), natural chabazite (NaNCh), natural mordenite (NaNM) and synthetic mordenite (NaSM) were investigated. The effective key parameters on the sorption behavior of cesium (Cs-134) were investigated using batch equilibrium technique with respect to the waste solution pH, contacting time, potassium ion concentration, waste solution volume/sorbent weight ratio and Cs ion concentration. The obtained results revealed that natural chabazite (NaNCh) has the higher distribution coefficients and capacity towards Cs ion rather than the other investigated zeolite materials. Furthermore, novel impregnated zeolite material (ISM) was prepared by loading Calix [4] arene bis(-2,3 naphtho-crown-6) onto synthetic mordenite to combine the high removal uptake of the mordenite with the high selectivity of Calix [4] arene towards Cs radionuclide. Comparing the obtained results for both NaSM and the impregnated synthetic mordenite (ISM-25), it could be observed that the impregnation process leads to high improvement in the distribution coefficients of Cs + ion (from 0.52 to 27.63 L/g). The final objective in all cases was aimed at determining feasible and economically reliable solution to the management of LLRLW specifically for the problems related to the low decontamination factor and the effective recovery of monovalent cesium ion.

A Ruddlesden-Popper-type layered perovskite, Na2Ca2Nb4O13

International Nuclear Information System (INIS)

Chiba, K.; Ishizawa, N.; Oishi, S.

1999-01-01

Single crystals of disodium dicalcium tetraniobium tridecaoxide, Na 2 Ca 2 Nb 4 O 13 , were grown by the flux method. The structure was determined in space group Bb2 1 m. Perovskite-type layers with the formula [(Ca 2 Na)Nb 4 O 13 ] - are concatenated by Na + cations near the interlayer, forming a Ruddlesden-Popper-type structure. The interlayer structure, composed of Na and O atoms, can be regarded as a rocksalt-type. NbO 6 octahedra are tilted about [010] and [001]. The off-centre displacement of Nb atoms suggests a ferroelectric nature along [010], with a calculated magnitude of polarization of 0.12 C m -2 . (orig.)

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

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Emmanuelle eBerret

2014-12-01

Full Text Available 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 α1-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 α1-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.

Stability analysis for single-phase liquid metal rectangular natural circulation loops

International Nuclear Information System (INIS)

Lu, Daogang; Zhang, Xun; Guo, Chao

2014-01-01

Highlights: • The stability for asymmetric liquid metal natural circulation loops is analyzed. • The Na and NaK loops have higher critical Reynolds number than Pb and LBE loops. • Decreasing the ratio of height to width of loop can increase loop stability. • The length of heater would not affect the loop stability obviously. • Adding the length or heat transfer coefficient of cooler can increase loop stability. - Abstract: Natural circulation systems are preferred in some advanced nuclear power plants as they can simplify the designs and improve the inherent safety. The stability and steady-state characteristics of natural circulation are important for the applications of natural circulation loops (NCLs). A linear stability analysis method was used to study the stability behavior of liquid metal NCLs. The influences of the types of working fluids and loop geometry parameters on the stability of NCLs were evaluated. The liquid sodium (Na) loop and sodium–potassium alloy (NaK) loop would be more stable than lead bismuth eutectics (LBE) loop. The pressure drop could stabilize the loop behavior and also lead an increase of operating temperature for the loop. The NCL with a lower aspect ratio (ratio of vertical center distance between the heating and cooling section to the horizontal length of loop) is supposed to be more stable. It was found that the length of heating section would not have an obvious effect on the stability of NCL. However, the loop behavior could be stabilized by adding the length or heat transfer coefficient of the cooling section

A Study of the Distribution of Sodium Cations in the Zeolites NaX, NaY and ZnNaY Using Carbon Monoxide Adsorption and 23Na NMR Techniques

Science.gov (United States)

Seidel, A.; Boddenberg, B.

1995-03-01

The zeolites NaX, NaY, Zn(55)NaY, and Zn(74)NaY were investigated by means of carbon monoxide adsorption and with static and magic angle spinning (MAS) 23Na NMR spectroscopy. The Na+ distribution between the sodalite (ß)- and supercages of the fully hydrated zeolites NaX and NaY were found to agree with XRD results. In the hydrated zinc-exchanged zeolites the Na+ ions almost exclusively populate the ß-cages. The adsorption isotherms of CO in the dehydrated zeolites were analyzed quantitatively to yield the concentrations of Na+ residing in the supercages. The measured static and MAS 23Na NMR spectra were analyzed by comparing their widths and shapes with simulated central transition patterns and yield, inter alia, the concentrations of Na+ associated with the spectrum components. Arguments are put forward that 23Na NMR of dehydrated zeolites is well suited to distinguish Na+ cations in highly symmetric environments and mobile Na+ species from others located on general positions, but further resolution is hardly feasible.

HCO3(-)-coupled Na+ influx is a major determinant of Na+ turnover and Na+/K+ pump activity in rat hepatocytes

International Nuclear Information System (INIS)

Fitz, J.G.; Lidofsky, S.D.; Weisiger, R.A.; Xie, M.H.; Cochran, M.; Grotmol, T.; Scharschmidt, B.F.

1991-01-01

Recent studies in hepatocytes indicate that Na(+)-coupled HCO3- transport contributes importantly to regulation of intracellular pH and membrane HCO3- transport. However, the direction of net coupled Na+ and HCO3- movement and the effect of HCO3- on Na+ turnover and Na+/K+ pump activity are not known. In these studies, the effect of HCO3- on Na+ influx and turnover were measured in primary rat hepatocyte cultures with 22Na+, and [Na+]i was measured in single hepatocytes using the Na(+)-sensitive fluorochrome SBFI. Na+/K+ pump activity was measured in intact perfused rat liver and hepatocyte monolayers as Na(+)-dependent or ouabain-suppressible 86Rb uptake, and was measured in single hepatocytes as the effect of transient pump inhibition by removal of extracellular K+ on membrane potential difference (PD) and [Na+]i. In hepatocyte monolayers, HCO3- increased 22Na+ entry and turnover rates by 50-65%, without measurably altering 22Na+ pool size or cell volume, and HCO3- also increased Na+/K+ pump activity by 70%. In single cells, exposure to HCO3- produced an abrupt and sustained rise in [Na+]i from approximately 8 to 12 mM. Na+/K+ pump activity assessed in single cells by PD excursions during transient K+ removal increased congruent to 2.5-fold in the presence of HCO3-, and the rise in [Na+]i produced by inhibition of the Na+/K+ pump was similarly increased congruent to 2.5-fold in the presence of HCO3-. In intact perfused rat liver, HCO3- increased both Na+/K+ pump activity and O2 consumption. These findings indicate that, in hepatocytes, net coupled Na+ and HCO3- movement is inward and represents a major determinant of Na+ influx and Na+/K+ pump activity. About half of hepatic Na+/K+ pump activity appears dedicated to recycling Na+ entering in conjunction with HCO3- to maintain [Na+]i within the physiologic range

43. Calmodulin regulating calcium sensitivity of Na channels

Directory of Open Access Journals (Sweden)

R. Vegiraju

2016-07-01

Full Text Available By extrapolating information from existing research and observing previous assumptions regarding the structure of the Na Channel, this experiment was conducted under the hypothesis that the Na Channel is in part regulated by the calmodulin protein, as a result proving calcium sensitivity of the Na Channel. Furthermore, we assume that there is a one to one stoichiometry between the Na Channel and the Calmodulin. There has been extensive research into the functionality and structure of sodium ion channels (Na channels, as several diseases are associated with the lack of regulation of sodium ions, that is caused by the disfunction of these Na channels. However, one highly controversial matter in the field is the importance of the protein calmodulin (CaM and calcium in Na channel function. Calmodulin is a protein that is well known for its role as a calcium binding messenger protein, and that association is believed to play an indirect role in regulating the Na channel through the Na channel’s supposed calcium sensitivity. While there are proponents for both sides, there has been relatively little research that provides strong evidence for either case. In this experiment, the effect of calmodulin on NaV 1.5 is tested by preparing a set of cardiac cells (of the human specie with the NaV 1.5 C-Termini and CaM protein, which were then to be placed in solutions with varying concentrations of calcium. We took special care to test multiple concentrations of calcium, as previous studies have tested very low concentrations, with Manu Ben-Johny’s team from the John Hopkins laboratory in particular testing up to a meager 50 micromolar, despite producing a well-respected paper (By comparison, the average Na channel can naturally sustain a concentration of almost 1-2 millimolar and on some occasions, reaching even higher concentrations. After using light scattering and observing the signals given off by the calcium interacting with these Nav1.5/Ca

The effect of Na vapor on the Na content of chondrules

Science.gov (United States)

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

Na7 [Fe2S6 ] , Na2 [FeS2 ] and Na2 [FeSe2 ] : New 'reduced' sodium chalcogenido ferrates

Science.gov (United States)

Stüble, Pirmin; Peschke, Simon; Johrendt, Dirk; Röhr, Caroline

2018-02-01

Three new 'reduced' FeII containing sodium chalcogenido ferrates were obtained applying a reductive synthetic route. The mixed-valent sulfido ferrate Na7 [Fe2S6 ] , which forms bar-shaped crystals with metallic greenish luster, was synthesized in pure phase from natural pyrite and elemental sodium at a maximum temperature of 800 °C. Its centrosymmetric triclinic structure (SG P 1 bar , a = 764.15(2), b = 1153.70(2), c = 1272.58(3) pm, α = 62.3325 (7) , β = 72.8345 (8) , γ = 84.6394 (8) ° , Z = 3, R1 = 0.0185) exhibits two crystallographically different [Fe2S6 ] 7 - dimers of edge-sharing [FeS4 ] tetrahedra, with somewhat larger Fe-S distances than in the fully oxidized FeIII dimers of e.g. Na6 [Fe2III S6 ] . In contrast to the localized AFM ordered pure di-ferrates(III), the Curie-Weiss behavior of the magnetic susceptibility proves the rarely observed valence-delocalized S = 9/2 state of the mixed-valent FeIII /FeII dimer. The nearly spin-only value of the magnetic moment combined with the chemical bonding not generally differing from that in pure ferrates(II) and (III), provides a striking argument, that the reduction of the local Fe spin moments observed in all condensed sulfido ferrate moieties is connected with the AFM spin ordering. The two isotypic ferrates(II) Na2 [FeS2 ] and Na2 [FeSe2 ] with chain-like structural units (SG Ibam, a = 643.54(8)/ 660.81(1), b = 1140.2(2)/1190.30(2) c = 562.90(6)/585.59(1) pm, Z = 4, R1 = 0.0372/0.0466) crystallize in the K2 [ZnO2 ] -type structure. Although representing merely further members of the common series of chalcogenido metallates(II) Na2 [MIIQ2 ] , these two new phases, together with Na6 [FeS4 ] and Li2 [FeS2 ] , are the only examples of pure FeII alkali chalcogenido ferrates. The new compounds allow for a general comparison of di- and chain ferrates(II) and (III) and mixed-valent analogs concerning the electronic and magnetic properties (including Heisenberg super-exchange and double-exchange interactions

Na/K pump inactivation, subsarcolemmal Na measurements, and cytoplasmic ion turnover kinetics contradict restricted Na spaces in murine cardiac myocytes.

Science.gov (United States)

Lu, Fang-Min; Hilgemann, Donald W

2017-07-03

Decades ago, it was proposed that Na transport in cardiac myocytes is modulated by large changes in cytoplasmic Na concentration within restricted subsarcolemmal spaces. Here, we probe this hypothesis for Na/K pumps by generating constitutive transsarcolemmal Na flux with the Na channel opener veratridine in whole-cell patch-clamp recordings. Using 25 mM Na in the patch pipette, pump currents decay strongly during continuous activation by extracellular K (τ, ∼2 s). In contradiction to depletion hypotheses, the decay becomes stronger when pump currents are decreased by hyperpolarization. Na channel currents are nearly unchanged by pump activity in these conditions, and conversely, continuous Na currents up to 0.5 nA in magnitude have negligible effects on pump currents. These outcomes are even more pronounced using 50 mM Li as a cytoplasmic Na congener. Thus, the Na/K pump current decay reflects mostly an inactivation mechanism that immobilizes Na/K pump charge movements, not cytoplasmic Na depletion. When channel currents are increased beyond 1 nA, models with unrestricted subsarcolemmal diffusion accurately predict current decay (τ ∼15 s) and reversal potential shifts observed for Na, Li, and K currents through Na channels opened by veratridine, as well as for Na, K, Cs, Li, and Cl currents recorded in nystatin-permeabilized myocytes. Ion concentrations in the pipette tip (i.e., access conductance) track without appreciable delay the current changes caused by sarcolemmal ion flux. Importantly, cytoplasmic mixing volumes, calculated from current decay kinetics, increase and decrease as expected with osmolarity changes (τ >30 s). Na/K pump current run-down over 20 min reflects a failure of pumps to recover from inactivation. Simulations reveal that pump inactivation coupled with Na-activated recovery enhances the rapidity and effectivity of Na homeostasis in cardiac myocytes. In conclusion, an autoregulatory mechanism enhances cardiac Na/K pump activity when

GESTÃO TERRITORIAL DE ÁREAS PROTEGIDAS NO LITORAL: PRIMEIRAS INCURSÕES

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Claudio Roberto Braghini

2013-06-01

Full Text Available Este artigo discute de forma preliminar a gestão territorial das unidades de conservação do litoral sergipano: Reserva Biológica (REBIO Santa Isabel, em Pirambu, Área de Proteção Ambiental (APA Morro do Urubu, em Aracaju e a Reserva Particular do Patrimônio Natural (RPPN do Caju, em Itaporanga D’Ajuda. As unidades de conservação configuram-se em novos elementos nos espaços litorâneos e trazem à dinâmica territorial uma complexidade, inclusive para o gerenciamento costeiro. O território compreendido como espaço social em transformação tende a um olhar sobre a totalidade, delimitado pela interação entre sistemas de objetos e de ações, na concepção de Milton Santos. A paisagem expõe a materialidade em um determinado território, a partir de objetos e marcas que coexistem e estabelecem certo grau de relação. Dessa maneira, discutiu-se teoricamente a gestão territorial e as imbricações com a gestão ambiental, bem como o perfil das unidades de conservação elencadas. No caráter ambiental o litoral de Sergipe abrange áreas com alto grau de prioridade na conservação da biodiversidade devido à presença de ecossistemas costeiros de grande fragilidade. Para a conservação observa-se uma complexidade na configuração territorial, nas relações de poder, que implicam níveis diferentes de indução da gestão, seja na esfera estadual, federal ou iniciativa privada. As ações podem estabelecer sinergias e conflitos de interesses sobre um mesmo espaço geográfico e por conseqüência para a governança.

CERN result provides definite answer to one of nature's most subtle secrets

CERN Multimedia

CERN Press Office. Geneva

2001-01-01

At a seminar at CERN on 10 May the NA48 collaboration announced its final result on one of nature's best-kept secrets : direct Charge Parity (CP)-violation. This subtle effect explains nature's preference for matter over antimatter.

Bulk crystal growth and electronic characterization of the 3D Dirac semimetal Na3Bi

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Satya K. Kushwaha

2015-04-01

Full Text Available 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.

The local structure of CaNa pyroxenes. I. XANES study at the Na K-edge

International Nuclear Information System (INIS)

Mottana, Annibale; Murata, T.; Wu, Ziyu; Marcelli, Augusto; Paris, E.

1996-07-01

X-ray absorption Na K-edge spectra have been recorded on synthetic end member jadeite and on a series of natural Ca-Na pyroxenes compositionally straddling the Jd-Di. The disordered C2/c members of the series are systematically different from the ordered P2/n members. These differences can be interpreted and explained by comparing the experimental spectra with theoretical spectra. These have been calculated by the multiple-scattering formalism from the atomic positional parameters determined by single-crystal X-ray diffraction structure refinement on the same samples. In the full multiple scattering region of the spectrum (1075 to 1095 eV) C-pyroxenes exhibit three features which reflect the 6-2 configuration of the O back-scattering atoms around the Na absorber located at the center of the cluster (site M2 of the jadeite structure). P-pyroxenes show more complicated spectra in which at least four features can be recognized; they reflect the two types of the configuration (6-2 and 4-2-2) of the oxygens around Na in the two independent M2 and M21 eight-fold coordinated sites of the omphacite structure. A weak, sometimes poorly resolved peak at 1079 eV diagnostic and discriminates C- from P-pyroxenes. The Garnet Ridge C2/c impure jadeite exhibits a spectrum which is intermediate between those of jadeite and omphacite. The Hedin-Lundqist potential proves best for these insulating materials and allows multiple-scattering calculations agreeing well with experiments. The assessment of the local electronic properties of compositionally and structurally complex minerals such as clinopyroxenes is thus enhanced

Radiation processing of natural polymers for industrial and agricultural applications

International Nuclear Information System (INIS)

Hegazy, El-Sayed A.; AbdEl-Rehim, H.; Diaa, D.A.; El-Barbary, A.

2008-01-01

Radiation induced degradation technology is a new and promising application of ionizing radiation to develop viscose, pulp, paper, food preservation, pharmaceutical production, and natural bioactive agents industries. Controlling the degree of degradation, uniform molecular weight distribution, saving achieved in the chemicals (used in conventional methods) on a cost basis, and environmentally friendly process are the beneficial effects of using radiation technology in these industries. However, for some development countries such technology is not economic. Therefore, a great efforts should be done to reduce the cost required for such technologies. One of the principle factors for reducing the cost is achieving the degradation at low irradiation doses. The addition of some additives such as potassium per-sulfate (KPS), ammonium per-sulfate (APS), or H 2 O 2 to natural polymers (carboxymethylcellulose (CMC), chitosan, carrageenan and Na-alginate) during irradiation process accelerates their degradation. The highest degradation rate of polysaccharides obtained when APS was used. The end product of irradiated CMC, chitosan, carrageenan and Na-alginate may be used as food additive or benefited in agricultural purposes. On the other hand, radiation crosslinking of PAAm or PNIPAAm is affected by the presence of natural polymer like CMC-Na and carrageenan due to their degradability which could be controlled according to its concentration in the bulk medium and irradiation dose. Accordingly, the gel content, thermo-sensitivity (LCST) and swelling properties of PNIPAAm based natural polymers could be controlled. The swelling of the prepared copolymer hydrogels was investigated for its possible use in personal care articles particularly diapers or as carriers for drug delivery systems. The prepared crosslinked copolymers possessed high and fast swelling properties in simulated urine media and the swelling ratios of CMC-Na/PAAm gels in urine are acceptable for diaper

Na+/Ca2+ exchange and Na+/K+-ATPase in the heart

Science.gov (United States)

Shattock, Michael J; Ottolia, Michela; Bers, Donald M; Blaustein, Mordecai P; Boguslavskyi, Andrii; Bossuyt, Julie; Bridge, John H B; Chen-Izu, Ye; Clancy, Colleen E; Edwards, Andrew; Goldhaber, Joshua; Kaplan, Jack; Lingrel, Jerry B; Pavlovic, Davor; Philipson, Kenneth; Sipido, Karin R; Xie, Zi-Jian

2015-01-01

This paper is the third in a series of 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 cardiac Na+/Ca2+ exchange (NCX) and Na+/K+-ATPase (NKA). While the relevance of Ca2+ homeostasis in cardiac function has been extensively investigated, the role of Na+ regulation in shaping heart function is often overlooked. Small changes in the cytoplasmic Na+ content have multiple effects on the heart by influencing intracellular Ca2+ and pH levels thereby modulating heart contractility. Therefore it is essential for heart cells to maintain Na+ homeostasis. Among the proteins that accomplish this task are the Na+/Ca2+ exchanger (NCX) and the Na+/K+ pump (NKA). By transporting three Na+ ions into the cytoplasm in exchange for one Ca2+ moved out, NCX is one of the main Na+ influx mechanisms in cardiomyocytes. Acting in the opposite direction, NKA moves Na+ ions from the cytoplasm to the extracellular space against their gradient by utilizing the energy released from ATP hydrolysis. A fine balance between these two processes controls the net amount of intracellular Na+ and aberrations in either of these two systems can have a large impact on cardiac contractility. Due to the relevant role of these two proteins in Na+ homeostasis, the emphasis of this review is on recent developments regarding the cardiac Na+/Ca2+ exchanger (NCX1) and Na+/K+ pump and the controversies that still persist in the field. PMID:25772291

Na-noparticles of activated natural zeolite on textiles for protection and therapy

Directory of Open Access Journals (Sweden)

Ivančica Kovaček

2009-10-01

Full Text Available Activated natural zeolite clinoptilolite is microporous hydrated aluminosilicates crystals with well-defined structures containing AlO4 and SiO4 tetrahedral linked through the common oxygen atoms. It is to point out that zeolites act as strong adsorbents and ion-exchangers but having many other useful properties. Due to its cationexchange ability, zeolites have catalytic properties and, for that, multiple uses in medicine and industry, agriculture, water purification and detergents. Zeolites are nontoxic substance, excellent for UVR and microbes protection, for proteins and small molecules such as glucose adsorption. In this paper its positive effect on the metabolism of living organisms and its anticancerogenic, antiviral, antimetastatic and antioxidant effect. The activity of natural zeolite as natural immunostimulator was presented as well as its help in healing wounds. Therefore, the present paper is an attempt to modify cotton (by mercerization and polyester (by alkaline hydrolysis fabrics for summer clothing with addition of natural zeolite nanoparticles for achieving UV and antibacterial protective textiles

Na/Cl molar ratio changes during a salting cycle and its application to the estimation of sodium retention in salted watersheds.

Science.gov (United States)

Sun, Hongbing; Huffine, Maria; Husch, Jonathan; Sinpatanasakul, Leeann

2012-08-01

Using soil column experiments and data from natural watersheds, this paper analyzes the changes in Na/Cl molar ratios during a salting cycle of aqueous-soil systems. The soil column experiments involved introducing NaCl salt at various initial concentrations into multiple soil columns. At the start of a salting cycle in the column experiments, sodium was adsorbed more than chloride due to cation exchange processes. As a result, the initial Na/Cl molar ratio in column effluent was lower than 1, but increased thereafter. One-dimensional PHREEQC geochemical transport simulations also were conducted to further quantify these trends under more diverse scenarios. The experimentally determined Na/Cl molar ratio pattern was compared to observations in the annual salting cycle of four natural watersheds where NaCl is the dominant applied road deicing salt. Typically, Na/Cl molar ratios were low from mid-winter to early spring and increased after the bulk of the salt was flushed out of the watersheds during the summer, fall and early winter. The established relationship between the Na/Cl molar ratios and the amount of sodium retention derived from the column experiments and computer simulations present an alternative approach to the traditional budget analysis method for estimating sodium retention when the experimental and natural watershed patterns of Na/Cl molar ratio change are similar. Findings from this study enhance the understanding of sodium retention and help improve the scientific basis for future environmental policies intended to suppress the increase of sodium concentrations in salted watersheds. Copyright © 2012 Elsevier B.V. All rights reserved.

Aplicação de um modelo matemático na simulação da produção e importação de gás natural no Brasil até 2017

Directory of Open Access Journals (Sweden)

Antonio Carlos Gracias

2010-08-01

Full Text Available O governo federal, por meio de política de desenvolvimento, pretende ampliar a participação do gás natural na matriz energética nos próximos anos. Essa ampliação irá produzir um aumento da capacidade de abastecimento de energia elétrica com uso da geração de energia térmica com gás natural. Um modelo matemático capaz de possibilitar uma previsão futura do consumo e importação de gás natural é fundamental para o planejamento da matriz energética do Brasil. Este trabalho compara dois modelos matemáticos, o modelo de Verhulst (modelo logístico e o modelo de Malthus (modelo exponencial, com o objetivo de analisar as possibilidades desses modelos descreverem a evolução da produção e importação de gás natural no Brasil até 2017, a partir dos dados fornecidos pelo Balanço Energético Nacional desde 1970 até 2007. Toda parte computacional, gráficos, resolução das equações diferenciais e cálculos de linearização e método dos mínimos quadrados, foi feita com o uso do software MatLabÒ. Os resultados obtidos, por meio de gráficos, mostram que os modelos de dinâmica populacional (Verhulst e Malthus podem ser aplicados na modelagem da produção e importação de gás natural do Brasil.

Functionalization of Liquid Natural Rubber via Oxidative Degradation of Natural Rubber

Directory of Open Access Journals (Sweden)

Suhawati Ibrahim

2014-12-01

Full Text Available Natural rubber (NR is a high molecular weight natural polymer and can be degraded to liquid natural rubber (LNR leaving certain functional groups at the end of chains. In this study, LNR samples prepared via oxidative degradation using H2O2 and NaNO2 as reagents were found to have different end groups depending on the pH of the reaction medium. In an acidic medium, LNR with hydroxyl terminal groups was formed as the degradation reaction was initiated by hydroxyl radicals produced from decomposition of peroxynitrite acid. In contrast, a redox reaction took place in an alkaline medium to yield LNR with carbonyl terminal groups. The mechanisms of reaction are discussed and proposed to explain the formation of different end groups when reaction carried out in acidic and alkaline media. Chain degradation in an acidic medium seems to be more effective than in an alkaline medium, and thus yields LNR with lower Mn.

Security resolution minute for natural gas distribution pipeline; Minuta de resolucao de seguranca na distribuicao do gas natural

Energy Technology Data Exchange (ETDEWEB)

Teles, Marcus de Barros [ARCE - Agencia Reguladora de Servicos Publicos Delegados do Estado do Ceara, Fortaleza, CE (Brazil)

2003-07-01

In the current scenery of natural gas distribution regulation, there is no specific resolution about security. The security is boarded in few concession contracts of some private gas companies, but not as principal theme. The security resolution minute presented in this paper aim break the direct and indirect causes of accidents, eliminating their potential. In this new point of view, the quality of services is the principal cause to guarantee the security of natural gas distribution systems. The methodology used to develop the minute was based on the research of Brazilian and American resolutions of state regulation agencies, concession contracts of private distribution gas companies, American code of federal regulation, ASME code for pressure piping B31.8 - 1999 edition and the NBR 12712 standard. The result of the research was the elaboration of an specific minute resolution of security that can be used as reference in the fiscalization of the natural gas distribution piping companies activities. This minute, can be an important instrument to avoid accidents and incidents, eliminating prejudices to the people, to properties, to environment and to the image of natural gas distribution companies and regulation agencies. (author)

Study on the natural gas utilization in the ceramic industry; Estudo sobre a utilizacao do gas natural na industria ceramica

Energy Technology Data Exchange (ETDEWEB)

NONE

1998-07-01

The production, principal applications, characteristics and properties, advantages of the gas natural is showed. A sectorial overview of the ceramic industry and the utilization of the natural gas in the ceramic industry is presented. The expectations are systematized and the impact of the natural gas utilization in the ceramic industry is evaluated. Some conclusions are withdrawn and recommendations suggested.

Preparation of Natural Zeolite for Air Dehumidification in Food Drying

Directory of Open Access Journals (Sweden)

Mohamad Djaeni

2015-03-01

Full Text Available Drying with air dehumidification with solid adsorbent improves the quality of food product as well as energy efficiency. The natural zeolite is one of adsorbent having potential to adsorb the water.  Normally, the material was activated to open the pore, remove the organic impurities, and increase Si/Al rate. Hence, it can enhance the adsorbing capacity. This research studied the activation of natural zeolite mined from Klaten, Indonesia as air dehumidification for food drying. Two different methods were used involving activation by heat and NaOH introduction.  As indicators, the porosity and water loaded were evaluated. Results showed both methods improved the adsorbing capacity significantly. With NaOH, the adsorbing capacity was higher. The simple test in onion and corn drying showed the presence of activated natural zeolite can speed up water evaporation positively. This performance was also comparable with Zeolite 3A

Peierls instability as the insulating origin of the Na/Si(111)-(3 × 1) surface with a Na coverage of 2/3 monolayers

Science.gov (United States)

Kang, Myung Ho; Kwon, Se Gab; Jung, Sung Chul

2018-03-01

Density functional theory (DFT) calculations are used to investigate the insulating origin of the Na/Si(111)-(3 × 1) surface with a Na coverage of 2/3 monolayers. In the coverage definition, one monolayer refers to one Na atom per surface Si atom, so this surface contains an odd number of electrons (i.e., three Si dangling-bond electrons plus two Na electrons) per 3 × 1 unit cell. Interestingly, this odd-electron surface has been ascribed to a Mott-Hubbard insulator to account for the measured insulating band structure with a gap of about 0.8 eV. Here, we instead propose a Peierls instability as the origin of the experimental band gap. The concept of Peierls instability is fundamental in one-dimensional metal systems but has not been taken into account in previous studies of this surface. Our DFT calculations demonstrate that the linear chain structure of Si dangling bonds in this surface is energetically unstable with respect to a × 2 buckling modulation, and the buckling-induced band gap of 0.79 eV explains well the measured insulating nature.

Temperature dependence of thermal pressure for NaCl

Science.gov (United States)

Singh, Chandra K.; Pande, Brijesh K.; Pandey, Anjani K.

2018-05-01

Engineering applications of the materials can be explored upto the desired limit of accuracy with the better knowledge of its mechanical and thermal properties such as ductility, brittleness and Thermal Pressure. For the resistance to fracture (K) and plastic deformation (G) the ratio K/G is treated as an indication of ductile or brittle character of solids. In the present work we have tested the condition of ductility and brittleness with the calculated values of K/G for the NaCl. It is concluded that the nature of NaCl can be predicted upto high temperature simply with the knowledge of its elastic stiffness constant only. Thermoelastic properties of materials at high temperature is directly related to thermal pressure and volume expansion of the materials. An expression for the temperature dependence of thermal pressure is formulated using basic thermodynamic identities. It is observed that thermal pressure ΔPth calculated for NaCl by using Kushwah formulation is in good agreement with the experimental values also the thermal pressure increases with the increase in temperature.

Status for 2018, CERN NA63

CERN Document Server

Nielsen, CF; Di Piazza, A; Wistisen, TN

2018-01-01

In the NA63 experiment of April 2018 the purpose was to look for the effect of the derivative term, the so-called Schott-term, in classical radiation reaction as described in \\cite{DiPiazza20171}. Data was taken for 20, 40 and 80 GeV electrons and positrons aligned to the $\\langle100\\rangle$ axis of a diamond crystal of thickness 1.5 mm, as well as for 40 and 80 GeV electrons on a 1.0 mm thick diamond aligned to the $\\langle100\\rangle$ axis. The data which was taken during the run shows encouraging results, but await a thorough analysis. For the 2017 data, the analysis is still ongoing, but expected to be finished within the coming few months. The results look very promising, but no final conclusion can be drawn at the present stage. For the 2016 results on quantum radiation reaction obtained by CERN NA63, the results have been published in Nature Communications \\cite{Wist17}.

The ARGO Project: assessing NA-TECH risks on off-shore oil platforms

Science.gov (United States)

Capuano, Paolo; Basco, Anna; Di Ruocco, Angela; Esposito, Simona; Fusco, Giannetta; Garcia-Aristizabal, Alexander; Mercogliano, Paola; Salzano, Ernesto; Solaro, Giuseppe; Teofilo, Gianvito; Scandone, Paolo; Gasparini, Paolo

2017-04-01

ARGO (Analysis of natural and anthropogenic risks on off-shore oil platforms) is a 2 years project, funded by the DGS-UNMIG (Directorate General for Safety of Mining and Energy Activities - National Mining Office for Hydrocarbons and Georesources) of Italian Ministry of Economic Development. The project, coordinated by AMRA (Center for the Analysis and Monitoring of Environmental Risk), aims at providing technical support for the analysis of natural and anthropogenic risks on offshore oil platforms. In order to achieve this challenging objective, ARGO brings together climate experts, risk management experts, seismologists, geologists, chemical engineers, earth and coastal observation experts. ARGO has developed methodologies for the probabilistic analysis of industrial accidents triggered by natural events (NA-TECH) on offshore oil platforms in the Italian seas, including extreme events related to climate changes. Furthermore the environmental effect of offshore activities has been investigated, including: changes on seismicity and on the evolution of coastal areas close to offshore platforms. Then a probabilistic multi-risk framework has been developed for the analysis of NA-TECH events on offshore installations for hydrocarbon extraction.

Sinergias entre Luxemburgo, ACNUR y Skype

OpenAIRE

Bertout, Antoine; Bourcy, Marc de; Faisal, Mohammad

2011-01-01

Una reciente asociación estratégica entre ACNUR, el Gobierno de Luxemburgo y el proveedor de software para comunicaciones Skype permite al personal de ACNUR en zonas de condiciones de vida difíciles mantenerse en contacto con sus familiares y amigos. Los socios evalúan de qué forma podría adaptarse la tecnología para otras organizaciones humanitarias.

Active transport of Na+ by reconstituted Na,K-ATPase

International Nuclear Information System (INIS)

Boldyrev, A.A.; Svinukhova, I.A.

1987-01-01

The ability of ATP, CTP, ITP, GTP, and UTP to support ouabain-sensitive accumulation of Na + by proteoliposomes with a reconstituted Na/K-pump was investigated. At a low [Na + ]/[K + ] ratio in the medium (20 mM/50 mM), a correlation is observed between the proton-accepting capacity of the nucleotide and its effectiveness as a substrate of active transport. To test the hypothesis of the importance of the presence of a negative charge in the 1-position of the purine (3-pyrimidine) base of the nucleotide for mutual transitions between the Na- and K-conformations of Na,K-ATPase they used two analogs of ATP: N 1 -hydroxy-ATP, possessing proton acceptor capacity, and N 1 -methoxy-ATP, in the molecule of which the negative charge is quenched by a methyl group. The first substrate supports active accumulation of Na + in proteoliposomes at the same rate as ATP, whereas the second substrate is relatively ineffective

Investigation on U - O - Na, Pu - O - Na and U,Pu - O - Na phase diagrams

International Nuclear Information System (INIS)

Pillon, S.

1989-03-01

The thermochemical interaction between the nuclear fuel (uranium and plutonium mixed oxides) and the sodium has been investigated and particularly the three phase diagrams: U - O - Na; Pu - O - Na; U,Pu - O - Na. High temperature neutron diffraction, microcalorimetry and powder X-ray diffraction were used for the characterization of the compounds synthetized. This study allowed to complete the knowledge about each of these diagrams and to measure some physical and thermal properties on the compounds. The limits on the modelization of the fuel-sodium interaction are discussed from the results of the UO 2 - Na reaction [fr

Natural radioactivity of sediments from Wei River of Shannxi province

International Nuclear Information System (INIS)

Wang Fengling; Lu Xinwei

2008-01-01

The natural radioactivity level in sediments from Wei River of Shannxi has been surveyed with a NaI(Tl) γ-spectrometer and its radiation hazards to the people has been assessed. The results indicate the natural radioactivity level in sediments from Wei River of Shaanxi is normal and the sediments can be safely used as building materials. (authors)

The initial stages of NaCl dissolution: Ion or ion pair solvation?

Science.gov (United States)

Klimes, Jiri; Michaelides, Angelos

2009-03-01

The interaction of water with rock salt (NaCl) is important in a wide variety of natural processes and human activities. A lot is known about NaCl dissolution at the macroscopic level but we do not yet have a detailed atomic scale picture of how salt crystals dissolve. Here we report an extensive series of density functional theory, forcefield and molecular dynamics studies of water clusters at flat and defective NaCl surfaces and NaCl clusters. The focus is on answering seemingly elementary questions such as how many water molecules are needed before it becomes favorable to extract an ion or a pair of ions from the crystal or the cluster. It turns out, however, that the answers to these questions are not so straightforward: below a certain number of water molecules (˜ 12) solvation of individual ions is less costly and above this number solvation of ion pairs is favored. These results reveal a hitherto unknown complexity in the NaCl dissolution process born out of a subtle interplay between water-water and water-ion interactions.

Integração entre logística e marketing: fatores críticos na perspectiva de interação e colaboração Integration between logistics and marketing: critical factors in the interaction and collaboration's perspective

Directory of Open Access Journals (Sweden)

Márcio Lopes Pimenta

2011-12-01

Full Text Available Diversos pesquisadores destacam a existência de estreita relação entre as funções de Marketing e Logística. É percebido que a integração destas funções exerce influência positiva no desempenho das organizações. A literatura sobre integração interfuncional sugere configurações de estratégias formais e informais, no intuito de estudar a sinergia dentro das organizações. O objetivo deste artigo é identificar e caracterizar elementos que facilitam ou dificultam a integração entre as funções de Logística e Marketing, no âmbito interno de organizações do setor de laticínios. O trabalho consiste em uma pesquisa bibliográfica sobre o tema, seguido de um estudo de caso múltiplo, de modo a evidenciar os conceitos e os pressupostos obtidos na literatura. Entrevistas em profundidade foram conduzidas com quatro gerentes, com base na técnica do incidente crítico (FLANAGAN, 1954, que também contribuiu para a análise e interpretação dos dados. Como resultados, tem-se que a percepção dos gerentes de Marketing e de Logística revela a existência de elementos que inibem a integração entre estas áreas, bem como elementos que facilitam a integração. Além disso, foram evidenciadas situações de integração formais (estruturas hierárquicas entre Marketing e Logística e informais (relações de confiança e sinergia entre os dois gerentes de área que, conforme a literatura pesquisada, são adotadas diante da necessidade de maiores níveis de interação ou de colaboração, respectivamente. Os elementos inibidores e facilitadores de integração, aqui mencionados, bem como suas definições, podem subsidiar futuros trabalhos no âmbito da integração interfuncional entre Marketing e Logística, e ainda, entre diversas áreas internas das organizações.Many researchers highlight the existence of a close relationship between Marketing and Logistics functions. It is perceived that the integration of these functions

Measurement of exchangeable sodium: 22Na or 24Na

International Nuclear Information System (INIS)

Smith, T.; Edmonds, C.J.

1987-01-01

A case is made for the use of 22 Na in low activities in preference to 24 Na for routine diagnostic estimation of exchangeable sodium, and is based chiefly on considerations of availability, cost and radiation dosimetry. A method in which only 37 kBq (1 μCi) 22 Na is administered orally is shown to be sufficiently accurate and to possess distinct advantages in terms of cost and convenience with a committed radiation dose no greater than that for a measurement using 24 Na. (author)

Experimental validation of kinetic inhibitor strength on natural gas hydrate nucleation

DEFF Research Database (Denmark)

Daraboina, Nagu; Pachitsas, Stylianos; von Solms, Nicolas

2015-01-01

The kinetics of natural gas hydrate formation in the presence of dissolved salts (NaCl) and crude oil ( a middle east crude with density 851.5 kg/m3 were investigated by using a standard rocking cell (RC-5) apparatus. The hydrate nucleation temperature was reduced in the presence of NaCl and oil...... management in oil and gas facilities. (C) 2014 Elsevier Ltd. All rights reserved....

Background studies for NaI(Tl) detectors in the ANAIS dark matter project

International Nuclear Information System (INIS)

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

2013-01-01

Several large NaI(Tl) detectors, produced by different companies, have been operated in the Canfranc Underground Laboratory (LSC) in the frame of the ANAIS (Annual modulation with NaI Scintillators) project devoted to the direct detection of dark matter. A complete background model has been developed for a 9.6 kg detector (referred as ANAIS-0 prototype) after a long data taking at LSC. Activities from the natural chains of 238 U and 232 Th, and 40 K in the NaI(Tl) crystal were evaluated applying different methods: discrimination of alpha particles vs beta/gamma background by Pulse Shape Analysis for quantifying the content of the natural chains and coincidence techniques for 40 K. Radioactive contaminations in the detector and shielding components were also determined by HPGe spectrometry. Monte Carlo simulations using Geant4 package were carried out to evaluate their contribution. At high energies, most of the measured background is nicely reproduced; at low energy some non-explained components are still present, although some plausible background sources have been analyzed. The 40 K content of the NaI(Tl) crystal has been confirmed to be the dominant contributor to the measured background with this detector. In addition, preliminary results of the background characterization, presently underway at the LSC, of two recently produced NaI(Tl) detectors, with 12.5 kg mass each, will be presented: cosmogenic induced activity has been clearly observed and is being quantified, and 40 K activity at a level ten times lower than in ANAIS-0 has been determined

Suppression of Na interstitials in Na-F codoped ZnO

Science.gov (United States)

Huo, Wenxing; Mei, Zengxia; Tang, Aihua; Liang, Huili; Du, Xiaolong

2018-04-01

Controlling the formation of interstitial Na (Nai) self-compensating defects has been a long-term physics problem for effective Na doping in ZnO. Herein, we present an experimental approach to the suppression of Nai defects in ZnO via Na and F codoping under an oxygen-rich condition during the molecular beam epitaxy growth process. It is found that the incorporation of such large numbers of Na and F dopants (˜1020 cm-3) does not cause an obvious influence on the lattice parameters. Hall-effect measurements demonstrate that F doping efficiently raises the Fermi level (EF) of ZnO films, which is expected to make the formation energy of Nai and NaZn increase and decrease, respectively. Most of the Na atoms occupy the substitutional Zn sites, and the formation of Nai is suppressed consequently. Secondary ion mass spectrometry measurements reveal that F and Na atoms are tightly bonded together due to their strong Coulomb interaction. The enhanced deep level emission (DLE) in ZnO:Na-F is ascribed to the considerable amount of isolated Zn vacancy (VZn) defects induced by the elevated EF and the formation of neutral (" separators="| FO + - Na Zn - ) 0 complexes. On the other hand, formation of (" separators="| FO + - VZn 2 - ) - complexes in ZnO:F exhausts most of the isolated Zn vacancies, leading to the disappearance of the DLE band.

Natural Polymorphisms Conferring Resistance to HCV Protease and Polymerase Inhibitors in Treatment-Naïve HIV/HCV Co-Infected Patients in China.

Directory of Open Access Journals (Sweden)

Kali Zhou

Full Text Available The advent of direct-acting agents (DAAs has improved treatment of HCV in HIV co-infection, but may be limited by primary drug resistance. This study reports the prevalence of natural polymorphisms conferring resistance to NS3/4A protease inhibitors and NS5B polymerase inhibitors in treatment-naïve HIV/HCV co-infected individuals in China.Population based NS3/4A sequencing was completed for 778 treatment-naïve HIV/HCV co-infected patients from twelve provinces. NS3 sequences were amplified by nested PCR using in-house primers for genotypes 1-6. NS5B sequencing was completed for genotyping in 350 sequences. Resistance-associated variants (RAVs were identified in positions associated with HCV resistance.Overall, 72.8% (566/778 of all HCV sequences had at least one RAV associated with HCV NS3/4A protease inhibitor resistance. Variants were found in 3.6% (7/193 of genotype 1, 100% (23/23 of genotype 2, 100% (237/237 of genotype 3 and 92% (299/325 of genotype 6 sequences. The Q80K variant was present in 98.4% of genotype 6a sequences. High-level RAVs were rare, occurring in only 0.8% of patients. 93% (64/69 patients with genotype 1b also carried the C316N variant associated with NS5B low-level resistance.The low frequency of high-level RAVs associated with primary HCV DAA resistance among all genotypes in HIV/HCV co-infected patients is encouraging. Further phenotypic studies and clinical research are needed.

OGLAŠEVANJE NA DRUŽBENIH OMREŽJIH NA PRIMERU FACEBOOKA

OpenAIRE

Novak, Martina

2012-01-01

V diplomskem delu obravnavamo družbene medije kot novo priložnost za promocijo in oglaševanje podjetij. Spoznali smo družbena omrežja na splošno in nekaj teh, ki jih uporabljamo tudi v Sloveniji na kratko predstavili. Podrobneje smo se osredotočili na družbeno omrežje Facebook, predvsem na samo spletno stran, njen izgled in storitve, ki jih ponuja uporabnikom. V nalogi je podrobneje opisan Facebook kot orodje za uporabo oglaševanja. Spoznali smo brezplačne in plačljive načine promocije in ogl...

CARS spectroscopy of the NaH2 collision complex: The nature of the Na(3 2P)H2 exciplex - ab initio calculations and experimental results

International Nuclear Information System (INIS)

Vivie-Riedle, R. de; Hering, P.; Kompa, K.L.

1990-01-01

CARS has been used to analyze the rovibronic state distribution of H 2 after collision with Na(3 2 P). New lines, which do not correspond to H 2 lines are observed in the CARS spectrum. The experiments point to the formation of a complex of Na(3 2 P)H 2 in A 2 B 2 symmetry. Ab initio calculations of the A 2 B 2 potential were performed. On this surface the vibrational spectra of the exciplex is evaluated. The observed lines can be attributed to vibrational transitions in the complex, in which combinational modes are involved. The connection of experimental and theoretical results indicates that a collisionally stabilized exciplex molecule is formed during the quenching process. (orig.)

Na+,K+-ATPase Na+ affinity in rat skeletal muscle fiber types

DEFF Research Database (Denmark)

Kristensen, Michael; Juel, Carsten

2010-01-01

Previous studies in expression systems have found different ion activation of the Na(+)/K(+)-ATPase isozymes, which suggest that different muscles have different ion affinities. The rate of ATP hydrolysis was used to quantify Na(+),K(+)-ATPase activity, and the Na(+) affinity of Na(+),K(+)-ATPase...

Na-smectite s in the Cala de Tomate bentonite deposit (Spain): a natural analogue of the salinity effect on the bentonite barrier of a rad waste disposal

Energy Technology Data Exchange (ETDEWEB)

Perez del Villar, L.; Pelayo, M.; Fernandez, A.M.; Cozar, J.S. [CIEMAT - Centro de Investigaciones Energeticas, Medioambientales y Tecnologicas (CIEMAT/DIRE/CEAGP), Madrid (Spain); Delgado, A.; Reyes, E. [Ciencias de la Tierra y Quimica Ambiental Estacion Experimental del Zaidin Dpt., Granada (Spain); Fernandez-Soler, J.M. [Granada Univ., Dpt. de Mineralogia y Petrologia (Spain); Tsige, M. [Facultad de Ciencias Geologicas, Dpt. de Geodinamica, Madrid (Spain)

2005-07-01

Within the framework of the ENRESA programme for the assessment of the long-term behaviour of the bentonite-engineered barrier for a deep radwaste geological repository, analogue studies on several bentonite deposits are conducted at CIEMAT. Among these analogue studies, the thermal effect induced by volcanic intrusions on bentonite deposits is highlighted. In the Cabo de Gata volcanic region, there are several analogue scenarios where these studies have been performed, such as the Cala de Tomate bentonite deposit that was intruded by a pyroxene andesite volcanic dome. However, geological, mineralogical, physicochemical, geochemical and stable isotopic data obtained from the smectites do not allow to establish any analogy with the thermal effect expected on the bentonite-engineered barrier of a deep geological repository after burial. Thus, the bentonitisation processes took place after the intrusion of the dome, as a result of meteoric diagenesis intensively developed on faulting zone affecting the parent pyroclastic acid tuffs. This faulting process occurred after the dome intrusion. However, the physicochemical characteristics of these smectites, specially the exchangeable cations, allow to consider this bentonite deposit as a natural analogue of the saline effect on the clayey barrier. This analogy has been established because Na-smectites are present in this deposit and, up to our present knowledge, it is the first time that these smectites occur naturally in the Cabo de Gata-La Serrata de Nijar volcanic region. As a consequence, the main objectives of this work are: i) to characterise these smectites; ii) to establish their genesis and processes affecting them after their formation and iii) to identify the effects on the bentonite-engineered barrier should it were affected by a Na-rich saline waterfront. (authors)

AVALIAÇÃO DA CAFEÍNA EM ASSOCIAÇÕES MEDICAMENTOSAS

OpenAIRE

Débora Mendes LOPES, João Lúcio CARDOSO, Ronilson Ferreira FREITAS, Vanessa de Andrade ROYO

2013-01-01

A cafeína é uma metilxantina de origem natural consumida mundialmente em alimentos e em associações medicamentosas, porém seus efeitos bem como o seu mecanismo de ação não são bem definidos de acordo com a literatura. O objetivo deste trabalho foi avaliar os benefícios e riscos ligados à associação da cafeína em medicamentos, bem como fazer comparação das doses citadas pela literatura com as encontradas nos medicamentos mais comercializados e nos alimentos mais consumidos no cotidiano da popu...

O cheiro das palavras: o olfato na narrativa literária

OpenAIRE

Gomes, Cristina

2009-01-01

Este trabalho, de natureza teórica e criativa, pretende realizar uma investigação para uma teoria do olfato na literatura. Para isso, deve analisar em que situação encontra-se a narrativa contemporânea quando lida com o olfato. Que papel desempenha o sentido do olfato na literatura? Quais são os métodos de escrita sobre o olfato? Como pode o cheiro ser capturado no papel? O trabalho consiste de um capítulo teórico seguido da novela literária A Rua das Laranjeiras. Ce travail, de nature thé...

IMPACTOS AMBIENTAIS DECORRENTES DE VAZAMENTO DE GÁS NATURAL DE BAIXA E MÉDIA PRESSÕES, NA ÁREA URBANA CENTRAL DO MUNICÍPIO DE SÃO PAULO

OpenAIRE

Moscardi, Jean Prost [UNESP; Araujo, Neide; Saad, Antônio Roberto

2006-01-01

Com a busca por fontes de energia alternativas, o gás natural vem adquirindo posicionamento de destaque por seu relativo baixo custo de aquisição ao consumidor final e por apresentar reduzidos impactos na implantação de dutovias, comparados com outras fontes de energia (hidroelétrica e fissão). O presente trabalho foi direcionado para a verificação de possíveis impactos oriundos de vazamentos em tubulações de gás em sua fase operacional. A área de estudo localiza-se no Município de São Paulo;...

First-Year Medical Students' Naïve Beliefs about Respiratory Physiology

Science.gov (United States)

Badenhorst, Elmi; Mamede, Silvia; Abrahams, Amaal; Bugarith, Kishor; Friedling, Jacqui; Gunston, Geney; Kelly-Laubscher, Roisin; Schmidt, Henk G.

2016-01-01

The present study explored the nature and frequency of physiology naïve beliefs by investigating novices' understanding of the respiratory system. Previous studies have shown considerable misconceptions related to physiology but focused mostly on specific physiological processes of normal respiration. Little is known about novices' broader…

Variation of Natural Gamma Radiation in Isparta

International Nuclear Information System (INIS)

Akkurt, I.

2004-01-01

There is always a radiation in the earth, and its level is generated primarily by galactic cosmic rays (GCR), consisting of energetic nuclei of all naturally occurring elements, interacting with atmospheric constituents, through atomic and nuclear collisions. The other sources of natural radiations are global average background radiation from terrestrial sources such as soils, rocks ete. Background radiation levels in the atmosphere vary in intensity with latitude, altitude and phase of the solar cycle. Variation of natural radiation as a function of altitude, geological structure etc has been investigated. The measurements were performed using portable radiation counter which connected to NaI(Tl) probe

Rentabilidade da monta natural e inseminação artificial em tempo fixo na pecuária de corte = Profitability of natural mating and fixed-time artificial insemination in beef cattle

Directory of Open Access Journals (Sweden)

Glauber dos Santos

2018-02-01

Full Text Available O futuro da pecuária de corte e consequentemente sua rentabilidade estão atrelados a otimização do uso da terra, visto que em muitos estados sua área vem sendo ocupada pela agricultura. Uma das alternativas é o uso de biotecnologias da reprodução, como a inseminação artificial em tempo fixo [IATF] que permite a inseminação de animais sem a detecção do estro. O objetivo desse estudo foi avaliar o custo por prenhez da monta natural [MN] e da IATF em fêmeas pluríparas em um rebanho de corte. Os animais foram divididos em dois grupos: MN (n = 150 e IATF (n = 150. O custo por prenhez incluiu itens como vida útil do touro, depreciação, remuneração do capital e remuneração de funcionários, entre outros. O custo na MN foi calculado a partir de um valor de compra de R$ 9.000,00, taxa de prenhez de 75% e proporção de um touro para 30 vacas. Na IATF foi baseado na taxa de prenhez de 87% e valor do serviço por animal de R$ 60,00. O custo por prenhez foi de R$ 117,62 e R$ 217,66 para a MN e a IATF, respectivamente. As vantagens da utilização da IATF foram, maior taxa de prenhez no início da estação de monta, antecipação de partos, formação de lotes de bezerros mais pesados a desmama e diminuição do descarte involuntário. Desta forma, apesar de um investimento inicial maior, a IATF teve um bom custo/benefício e rentabilidade. = The future of beef cattle and consequently its profitability are tied to the optimization of land use, since in many states its area has been occupied by agriculture. One of the alternatives is the use of breeding biotechnologies, such as fixed-time artificial insemination [FTAI], which allows the insemination of animals without the detection of estrus. The objective of the present study was to evaluate the pregnancy cost of natural mating [NM] and FTAI in pluriparous females in a beef herd. The animals were divided into two groups: NM (n = 150 and FTAI (n = 150. The cost per pregnancy included

Crystal structure of Na+, K(+)-ATPase in the Na(+)-bound state.

Science.gov (United States)

Nyblom, Maria; Poulsen, Hanne; Gourdon, Pontus; Reinhard, Linda; Andersson, Magnus; Lindahl, Erik; Fedosova, Natalya; Nissen, Poul

2013-10-04

The Na(+), K(+)-adenosine triphosphatase (ATPase) maintains the electrochemical gradients of Na(+) and K(+) across the plasma membrane--a prerequisite for electrical excitability and secondary transport. Hitherto, structural information has been limited to K(+)-bound or ouabain-blocked forms. We present the crystal structure of a Na(+)-bound Na(+), K(+)-ATPase as determined at 4.3 Å resolution. Compared with the K(+)-bound form, large conformational changes are observed in the α subunit whereas the β and γ subunit structures are maintained. The locations of the three Na(+) sites are indicated with the unique site III at the recently suggested IIIb, as further supported by electrophysiological studies on leak currents. Extracellular release of the third Na(+) from IIIb through IIIa, followed by exchange of Na(+) for K(+) at sites I and II, is suggested.

NATURAL LAW, HISTORY AND POLITICS LEY NATURAL, HISTORIA Y POLÍTICA LEI NATURAL, HISTÓRIA E POLÍTICA

Directory of Open Access Journals (Sweden)

James Drane

2002-01-01

de la medicina contemporáneas. Una perspectiva católica liberal intenta mantener en juego los aspectos universales y particulares del razonamiento de la Ley NaturalA visão filosófica básica e os princípios éticos da Lei Natural Católica buscam a universalidade. O propósito da Lei Natural aspira a objetividade e universalidade e, ao mesmo tempo, permanece aberto à contínua influência da história e da política. Os princípios que repousam na base da lei positiva recebem historicamente o nome de Lei Natural. O sofrimento e a injustiça contribuem para uma visão, tanto da estrutura da existência humana como aquilo que entendemos por lei e ética humana. Quando enfrentamos uma crise cultural, a Lei Natural não olha para o passado mas sim para o futuro. Atualmente é incomum que se considere as dimensões éticas das realidades sociais tendo como referência a Lei Natural. Isto vale tanto para a Igreja quanto para o Estado. Em bioética, os princípios com origem na estrutura universal da vida humana têm que proporcionar direção e normas no âmbito das variáveis da vida e da medicina contemporânea. Uma perspectiva liberal católica tenta manter presente os aspectos universais e particulares das razões da Lei Natural

Synergistic kinetic inhibition of natural gas hydrate formation

DEFF Research Database (Denmark)

Daraboina, Nagu; Malmos, Christine; von Solms, Nicolas

2013-01-01

Rocking cells were used to investigate the natural gas hydrate formation and decomposition in the presence of kinetic inhibitor, Luvicap. In addition, the influence of poly ethylene oxide (PEO) and NaCl on the performance of Luvicap was investigated using temperature ramping and isothermal...

The local structure of Ca{sub N}a pyroxenes. I. XANES study at the Na K-edge

Energy Technology Data Exchange (ETDEWEB)

Mottana, Annibale [Rome, Univ. III (Italy). Dipt. di Scienze Geologiche; Murata, T. [Kyoto, Univ. of Education (Japan). Dept. of Physics; Wu, Ziyu; Marcelli, Augusto [INFN, Frascati (Italy). Laboratori Nazionali di Frascati; Paris, E. [Camerino, Univ. (Italy). Dipt. di Scienze della Terra

1996-07-01

X-ray absorption Na K-edge spectra have been recorded on synthetic end member jadeite and on a series of natural Ca-Na pyroxenes compositionally straddling the Jd-Di. The disordered C2/c members of the series are systematically different from the ordered P2/n members. These differences can be interpreted and explained by comparing the experimental spectra with theoretical spectra. These have been calculated by the multiple-scattering formalism from the atomic positional parameters determined by single-crystal X-ray diffraction structure refinement on the same samples. In the full multiple scattering region of the spectrum (1075 to 1095 eV) C-pyroxenes exhibit three features which reflect the 6-2 configuration of the O back-scattering atoms around the Na absorber located at the center of the cluster (site M2 of the jadeite structure). P-pyroxenes show more complicated spectra in which at least four features can be recognized; they reflect the two types of the configuration (6-2 and 4-2-2) of the oxygens around Na in the two independent M2 and M21 eight-fold coordinated sites of the omphacite structure. A weak, sometimes poorly resolved peak at 1079 eV diagnostic and discriminates C- from P-pyroxenes. The Garnet Ridge C2/c impure jadeite exhibits a spectrum which is intermediate between those of jadeite and omphacite. The Hedin-Lundqist potential proves best for these insulating materials and allows multiple-scattering calculations agreeing well with experiments. The assessment of the local electronic properties of compositionally and structurally complex minerals such as clinopyroxenes is thus enhanced.

NaAuS chicken-wire-like semiconductor: Electronic structure and optical properties

International Nuclear Information System (INIS)

Reshak, A.H.; Khan, Saleem Ayaz; Kamarudin, H.; Bila, Jiri

2014-01-01

Highlights: • Chicken wire like semiconductor NaAuS was investigated. • Good agreement with experimental data was found. • Electronic charge density of chicken wire like semiconductor NaAuS was obtained. • The calculated uniaxial anisotropy is −0.0005, indicating the strong anisotropy. -- Abstract: The electronic structure, charge density and optical properties of NaAuS a chicken-wire-like semiconductor was calculated using full potential linear augmented plane wave based on density functional theory. The Ceperley-Alder local density approximation, Perdew Becke Ernzerhof Generalized gradient approximation and Engel Voskov Generalized Gradient Approximation were applied to solve the exchange correlation potential. The investigation of band structures and density of states elucidates that Engle Vasko Generalized Gradient Approximation shows close agreement to the experimental data. The calculated valence charge density shows pure ionic nature of Au–Au bond. It becomes partially covalent when Au is connected with two Na atoms. The linear optical susceptibilities of chicken-wire-like NaAuS semiconductor are calculated so as to obtain further insight into the electronic properties. The uniaxial anisotropy is −0.0005, indicating the strong anisotropy of the dielectric function in the NaAuS a chicken-wire-like semiconductor

NaAuS chicken-wire-like semiconductor: Electronic structure and optical properties

Energy Technology Data Exchange (ETDEWEB)

Reshak, A.H. [Institute of Complex Systems, FFPW, CENAKVA, University of South Bohemia in CB, Nove Hrady 37333 (Czech Republic); Center of Excellence Geopolymer and Green Technology, School of Material Engineering, University Malaysia Perlis, 01007 Kangar, Perlis (Malaysia); Khan, Saleem Ayaz, E-mail: sayaz_usb@yahoo.com [Institute of Complex Systems, FFPW, CENAKVA, University of South Bohemia in CB, Nove Hrady 37333 (Czech Republic); Kamarudin, H. [Center of Excellence Geopolymer and Green Technology, School of Material Engineering, University Malaysia Perlis, 01007 Kangar, Perlis (Malaysia); Bila, Jiri [Department of Instrumentation and Control Engineering, Faculty of Mechanical Engineering, CTU in Prague, Technicka 4, 166 07 Prague 6 (Czech Republic)

2014-01-05

Highlights: • Chicken wire like semiconductor NaAuS was investigated. • Good agreement with experimental data was found. • Electronic charge density of chicken wire like semiconductor NaAuS was obtained. • The calculated uniaxial anisotropy is −0.0005, indicating the strong anisotropy. -- Abstract: The electronic structure, charge density and optical properties of NaAuS a chicken-wire-like semiconductor was calculated using full potential linear augmented plane wave based on density functional theory. The Ceperley-Alder local density approximation, Perdew Becke Ernzerhof Generalized gradient approximation and Engel Voskov Generalized Gradient Approximation were applied to solve the exchange correlation potential. The investigation of band structures and density of states elucidates that Engle Vasko Generalized Gradient Approximation shows close agreement to the experimental data. The calculated valence charge density shows pure ionic nature of Au–Au bond. It becomes partially covalent when Au is connected with two Na atoms. The linear optical susceptibilities of chicken-wire-like NaAuS semiconductor are calculated so as to obtain further insight into the electronic properties. The uniaxial anisotropy is −0.0005, indicating the strong anisotropy of the dielectric function in the NaAuS a chicken-wire-like semiconductor.

Narrativas do envelhecimento: ser velho na sociedade contemporânea

Directory of Open Access Journals (Sweden)

Sofia Aboim

2014-06-01

Full Text Available Com base em entrevistas realizadas a homens e mulheres com mais de 65 anos de idade residentes em Portugal, procura-se elaborar um retrato do que significa ser velho e de qual o impacto do processo de envelhecimento na vida e na identidade da pessoa idosa. Partindo do pressuposto de que, não obstante a maior regulação da idade na sociedade contemporânea, existe grande diversidade nas formas de viver a velhice, mobiliza-se uma perspectiva microssociológica de análise, na primeira pessoa, dos discursos sobre o envelhecimento. Além de diferenças de gênero e de estatuto social, a população idosa revela um relativo conformismo com a velhice, enquanto algo que é natural. Porém, algumas dimensões surgem como problemáticas para a identidade do idoso: o declínio do corpo e da saúde, a sexualidade, a perda de atividade, o isolamento e a discriminação social são dimensões particularmente relevantes para conceituar a pessoa idosa como ator reflexivo e portador de reflexividade.

Meltability in system of K2TaF7-NaF-NaCl-KCl

International Nuclear Information System (INIS)

Kartsev, V.E.; Kovalev, F.V.; Korshunov, B.G.

1975-01-01

Thermographic and visual-polythermal techniques were used to study the meltability in K 2 TaF 7 -NaF-NaCl-KCl system. The tetrahedron-forming sections NaF-NaCl-K 2 TaF 7 xKCl and NaF-K 2 TaF 7 xKCl-2K 2 TaF 7 xNaCl divide the concentration tetrahedron into three particular tetrahedra: NaF-K 2 TaF 7 xKCl-2K 2 TaF 7 xNaCl-K 2 TaF 7 , NaF-NaCl-K 2 TaF 7 xKCl-2K 2 TaF 7 xaCl, and NaF-NaCl-KCl-K 2 TaF 7 xKCl. Non-variant equilibrium points in all of the particular four-component systems have been determined

O Impacto de Brises na Ventilação Natural: Avaliação Integrada em uma Enfermaria em Florianópolis (SC

Directory of Open Access Journals (Sweden)

Bianca Milani de Quadros

2018-02-01

Full Text Available Resumo A principal função dos brises é o controle do ganho de calor pelas janelas. No entanto, estes elementos também podem influenciar no desempenho da ventilação natural. Em edifícios hospitalares, a ventilação natural pode reduzir o consumo de energia, proporcionar conforto térmico e controlar a infecção hospitalar por meio da renovação do ar nos ambientes onde não há obrigatoriedade do uso de sistemas de ar condicionado. Este artigo analisa o impacto de brises no desempenho da ventilação natural em uma enfermaria em Florianópolis (SC. Para uma análise detalhada, o estudo integrou simulações computacionais com modelos de rede e CFD. Foram simulados dois casos: caso 1 que reproduz o ambiente existente sem brises e o caso 2 que apresenta o mesmo ambiente com brises em todas as janelas. Os resultados demonstram que a aplicação de brises modifica o comportamento da ventilação natural com o aumento da velocidade do ar de entrada e, consequentemente, com a elevação da velocidade média do ar interno. Conclui-se que os brises apresentam não apenas a usual finalidade de redução do ganho de calor, mas também podem auxiliar na melhoria do desempenho da ventilação natural. Palavras-Chave: Conforto Ambiental; Ventilação; Brises; EnergyPlus; CFD. Abstract The main purpose of shading devices is controling windows heat gain. However, these elements can have an influence on natural ventilation control according its geometry and wind direction. In hospitals, natural ventilation can be used to reduce the energy consumption, to provide thermal comfort and to control hospital-acquired infections through air renewal for all rooms where the HVAC systems is not mandatory. This paper analyzes the impact of shading devices on the performance of natural ventilation in an infirmary room in Florianopolis, Brazil. For a detailed analysis of natural ventilation, this study combined computational simulation with Airflow Network model and

Influência da adubação fosfatada e da introdução de espécies forrageiras de inverno na oferta de forragem de pastagem natural Influence of phosphorus fertilization and introduction of winter forage species on forage offer from natural pasture

Directory of Open Access Journals (Sweden)

LUCIANO COLPO GATIBONI

2000-08-01

Full Text Available A pecuária de corte no Estado do Rio Grande do Sul é baseada na utilização de pastagens naturais, que são de baixa produtividade e sazonalidade de produção. O objetivo deste trabalho foi testar o efeito de diferentes fosfatos, solúveis e natural, associados ou não à calagem, no melhoramento de pastagem natural pela introdução de espécies forrageiras de inverno. O estudo foi conduzido na Universidade Federal de Santa Maria, em solo Argissolo Vermelho. Os tratamentos foram: foscal (superfosfato simples + calcário; superfosfato triplo + calcário; superfosfato triplo; hiperfosfato de gafsa; sem adubação fosfatada e sem calcário; testemunha de pastagem natural. Com exceção do último, todos os tratamentos receberam adubação potássica, nitrogenada e introdução de Lolium multiflorum e Trifolium vesiculosum. Foram aplicados nos tratamentos específicos 3,2 Mg ha-1 de calcário (elevação do pH-H2O a 5,5, 180 kg ha-1 de P2O5, 130 kg ha-1 de K2O e 70 kg ha-1 de N. A produtividade de matéria seca foi avaliada nos períodos do inverno, primavera, primavera-verão e verão-outono. A adubação fosfatada aumentou significativamente a produtividade de matéria seca da pastagem. Os fosfatos solúveis proporcionaram maiores produções que o fosfato natural. A calagem não aumentou a produtividade de Lolium multiflorum e da pastagem natural, mas o Trifolium vesiculosum apresentou resposta a este insumo.The beef cattle production in Rio Grande do Sul, Brazil, is based on natural pasture grazing, which are of low productivity and seasonal growth. The present work was done to test the effects of Italian ryegrass and arrowleaf clover introduction in natural pasture under different phosphorus fertilizer, soluble and natural, associated or not to the lime, on forage improvement from natural pasture. The study was conducted at Universidade Federal de Santa Maria on a Paleudalf. The treatments were: foscal (simple superphosphate + lime; triple

Lazzaro Spallanzani e os fósseis: das observações em viagens naturalísticas ao ensino de história natural Lazzaro Spallanzani and fossils: from a naturalist's travel observations to the teaching of natural history

Directory of Open Access Journals (Sweden)

Maria Elice Brzezinski Prestes

2011-12-01

Full Text Available Analisa opiniões do naturalista italiano Lazzaro Spallanzani sobre a origem e a constituição dos fósseis por ocasião de três de suas viagens naturalísticas, entremeadas a três cursos de mineralogia da disciplina de história natural que lecionou na Universidade de Pavia. Essas viagens, para Portovenere, ilha Cerigo e Duas Sicílias, permitiram que abordasse temas importantes, como a descoberta de conchas fósseis no interior de rochas vulcânicas, a de fósseis humanos, e a existência de fósseis de espécies que 'se perderam', incorporando conhecimentos que se desenvolviam na época, com base na química mineralógica. Sua preocupação com os fósseis testemunha o modo como, ao estilo do século XVIII, Spallanzani integrava os estudos dos três reinos da natureza.This article analyzes opinions expressed by Italian naturalist Lazzaro Spallanzani on the origin and constitution of fossils on three of his travels, which punctuated three courses in mineralogy he gave in the natural history discipline at the University of Pavia. These trips to Portovenere, the island of Cerigo and the Two Sicilies enabled him to address important topics, such as the discovery of fossilized shells inside volcanic rocks, the discovery of human fossils, and the existence of fossils of species that had 'been lost', incorporating knowledge being developed at the time that drew on mineral chemistry. His concern with fossils is demonstrative of how Spallanzani, in true eighteenth century fashion, integrated studies from the three kingdoms of nature.

Active transport of Na/sup +/ by reconstituted Na,K-ATPase

Energy Technology Data Exchange (ETDEWEB)

Boldyrev, A.A.; Svinukhova, I.A.

1987-02-20

The ability of ATP, CTP, ITP, GTP, and UTP to support ouabain-sensitive accumulation of Na/sup +/ by proteoliposomes with a reconstituted Na/K-pump was investigated. At a low (Na/sup +/)/(K/sup +/) ratio in the medium (20 mM/50 mM), a correlation is observed between the proton-accepting capacity of the nucleotide and its effectiveness as a substrate of active transport. To test the hypothesis of the importance of the presence of a negative charge in the 1-position of the purine (3-pyrimidine) base of the nucleotide for mutual transitions between the Na- and K-conformations of Na,K-ATPase they used two analogs of ATP: N/sub 1/-hydroxy-ATP, possessing proton acceptor capacity, and N/sub 1/-methoxy-ATP, in the molecule of which the negative charge is quenched by a methyl group. The first substrate supports active accumulation of Na/sup +/ in proteoliposomes at the same rate as ATP, whereas the second substrate is relatively ineffective.

Relationship between intracellular Na+ concentration and reduced Na+ affinity in Na+,K+-ATPase mutants causing neurological disease

DEFF Research Database (Denmark)

Toustrup-Jensen, Mads Schak; Einholm, Anja P.; Schack, Vivien

The neurological disorders familial hemiplegic migraine type 2 (FHM2), alternating hemiplegia of childhood (AHC), and rapid-onset dystonia parkinsonism (RDP) are caused by mutations of Na+,K+-ATPase α2 and α3 isoforms, expressed in glial and neuronal cells, respectively. Although these disorders......, addressing the question to what extent they cause a change of the intracellular Na+ and K+ concentrations ([Na+]i and [K+]i) in COS cells. C-terminal extension mutants generally showed dramatically reduced Na+ affinity without disturbance of K+ binding, as did other RDP mutants. No phosphorylation from ATP...

MOŽNOSTI VSTOPA NA TUJE TRGE NA PRIMERU PODJETJA AWOODTURE

OpenAIRE

Orličnik, Urša

2014-01-01

Danes pojavljanje podjetja samo na domačem trgu ni več dovolj. Spremembe okolja, naraščanje konkurence ter hiter tehnološki napredek, silijo podjetja k nenehnemu prilagajanju in iskanju novih priložnosti tako na domačem kot tudi na tujem trgu. Internacionalizacija podjetja tako postaja vedno bolj pomemembna za preživetje podjetja. Internacionalizacija se v najširšem smislu nanaša na vse oblike mednarodnega ekonomskega sodelovanja. Je dinamičen proces, kateremu nujno sledi sprememba stanja...

Ion-exchange properties of natural mordenite

International Nuclear Information System (INIS)

Chelishchev, N.F.; Volodin, V.F.

1977-01-01

Ion exchange properties are studied of natural mordenite Si(Al=4.75) exhibiting adequate mechanical characteristics and sufficient resistance to high temperature acids. Consideration is given to the pattern of exchange ions distribution among mordenite and chloride solutions of K, Cs, Rb, Sr. Mordenite shows sharp selectivity towards large alkali metal cations, particularly Cs + . In these processes the exchange isotherms are characterized by the constant selectivity towards a counterion. For the Sr 2+ -2Na + exchange the isotherm shows a change of selectivity after a definite counterion concentration has been reached in the solution. Correlation between the exchange thermodynamic constants makes it possible to propose the following range of mordenite selectivity towards the cations under study: Cs>Rb>K>Na>Sr

Na/K pump inactivation, subsarcolemmal Na measurements, and cytoplasmic ion turnover kinetics contradict restricted Na spaces in murine cardiac myocytes

OpenAIRE

Lu, Fang-Min; Hilgemann, Donald W.

2017-01-01

The Na/K pump exports cytoplasmic Na ions while importing K ions, and its activity is thought to be affected by restricted intracellular Na diffusion in cardiac myocytes. Lu and Hilgemann find instead that the pump can enter an inactivated state and that inactivation can be relieved by cytoplasmic Na.

Interaction in the NaIn(MoO4)2 - AMoO4 (A = Mg, Mn) systems

International Nuclear Information System (INIS)

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

2001-01-01

The results of investigation into NaIn(MoO 4 ) 2 - AMoO 4 (A = Mg, Mn) quasibinary cross-sections by means of X-ray diffraction and differential thermal analysis are presented. Conducted researches revealed that compounds NaMg 3 In(MoO 4 ) and NaMn 3 In(MoO 4 ) melting incongruently at 990 Deg C and 940 Deg C accordingly were formed in the NaIn(MoO 4 ) - AMoO 4 (A = Mg, Mn) systems. The data of initiation of X-ray diffraction pattern of NaMg 3 In(MoO 4 ) 5 are presented. The temperature dependences of conductivity, dielectric permeability and tangent of dielectric losses indicative on ionic-electronic nature conductivity are determined. Activation energy of conductivity in the Mg - Mn row changes moderately - from 9.91 till 5.71 eV [ru

Phonon instabilities in NaNbO3

International Nuclear Information System (INIS)

Mishra, S.K.; Gupta, M.K.; Mittal, R.; Chaplot, S.L.

2012-01-01

NaNbO 3 has antiferroelectric structure at room temperature and exhibits unusual complex sequence of temperature and pressure driven structural phase transitions. Temperature dependent measurements from 17 to 1075 K revealed that NaNbO 3 undergoes a series of phase transitions, ranging from non-polar antiferrodistortive to ferroelectric and antiferroelectric in nature. High pressure measurements carried out up to 11 GPa at ambient temperature indicate transition from antiferroelectric to paraelectric phase. These transitions are characterized by appearance and disappearance of superlattice reflections in the powder diffraction patterns. Numerous Raman and infrared measurements are also reported in literature to gain reliable insights into, and deeper understanding of phase transition behavior. The optical measurements are limited to the Brillouin zone centre, which does not give a complete picture of the dynamics. Inelastic neutron scattering and ab-initio calculations were carried out to understand the phase transitions behaviour and their relation to the phonon spectra

Natureza e cultura na paisagem amazônica: uma experiência fotográfica com ressonâncias na cosmologia ameríndia e na ecologia histórica

Directory of Open Access Journals (Sweden)

Patrick Pardini

Full Text Available Enquanto experiência artística, o projeto fotográfico "Arborescência - fisionomia do vegetal na paisagem amazônica" proporciona ao autor uma série de descobertas: a paisagem como entrelaçamento de Natureza e Cultura (a presença indireta do homem; o face a face com 'sujeitos vegetais'; as relações de continuidade, indiferenciação e equivalência entre o 'natural' (heterogêneo, espontâneo, nativo, rural e o 'cultural' (homogêneo, cultivado, exótico, urbano na experiência da paisagem vegetal; a arborescência como "imagem cósmica" (Gaston Bachelard, onde o alto (céu, luz, galhos, água celeste e o baixo (terra, sombra, raízes, água terrestre são pólos equivalentes e reversíveis. Tal experiência encontra ressonâncias na eco-cosmologia das sociedades da floresta amazônica. A cosmologia ameríndia é uma "ecologia simbólica" (Philippe Descola, pois elabora "uma complexa dinâmica de trocas e transformações entre sujeitos humanos e não humanos, visíveis e invisíveis" (Bruce Albert; a ecologia ameríndia é uma "cosmologia posta em prática" (Kaj Århem, na qual animais caçados e plantas cultivadas são 'parentes' que é preciso seduzir ou coagir. Tal modelo constitui uma forma de "socialização da natureza" (Descola, de "humanização da floresta" (Evaristo Eduardo de Miranda e de "antropização indireta" dos ecossistemas amazônicos (Descola, geradora de "matas culturais" (William Balée.

The influence of Mg/Si ratio on the negative natural aging effect in Al–Mg–Si–Cu alloys

International Nuclear Information System (INIS)

Tao, G.H.; Liu, C.H.; Chen, J.H.; Lai, Y.X.; Ma, P.P.; Liu, L.M.

2015-01-01

The effects of natural aging (NA) on subsequent artificial aging (AA) at 180 °C in Al–Mg–Si–Cu alloys with varied Mg/Si ratios (0.5, 1 and 2) were systematically studied by Vickers micro-hardness measurements, differential scanning calorimetry and transmission electron microscopy (TEM). The alloy with large Mg/Si ratio possesses a significant negative NA effect on the maximum hardness achieved during AA preceded by an extended NA, while the alloy with small Mg/Si ratio shows a negligible negative NA effect. Though few lath-like Q''/L precipitates exist, needle-like β'' precipitates are the primary hardening precipitates in all the peak-aged alloys. The negative NA effect is demonstrated to be determined by precipitate coarsening, which is manifested microscopically as the broader precipitate length distributions (PLD) and shift of PLD toward larger length range, in AA with the prolonging of NA. Our results suggest the nature of NA clusters is quite different in Al–Mg–Si–Cu alloy varying in Mg/Si ratio. Only a small fraction of NA clusters in alloy with large Mg/Si ratio are stable and could induce preferential growth of precipitates to be considerably coarsened during AA. A large fraction of stable NA clusters in alloy with low Mg/Si ratio lead to synchronous growth of β'' precipitates, thus restricting the preferential growth

Prehistory effect on dielectric properties of NaNbO3-Gd1/3NbO3

International Nuclear Information System (INIS)

Burkhanov, A.I.; Bondarenko, P.V.; Shil'nikov, A.V.; Raevskaya, S.I.; Raevskij, I.P.

2006-01-01

One studied the low- and the infralow-frequency dielectric response of 0.9NaNbO 3 -0.1Gd 1/3 NbO 3 (NNG10) composition ceramics and single crystal at the material different prehistory. One revealed the differences in the nature of dielectric aging in NaNbO 3 antiferroelectric base material with a diffused phase transition in contrast to manifestation of similar phenomena in ferroelectrics-relaxors [ru

Ion association in concentrated NaCl brines from ambient to supercritical conditions: results from classical molecular dynamics simulations

Directory of Open Access Journals (Sweden)

Collings Matthew D

2002-11-01

Full Text Available Highly concentrated NaCl brines are important geothermal fluids; chloride complexation of metals in such brines increases the solubility of minerals and plays a fundamental role in the genesis of hydrothermal ore deposits. There is experimental evidence that the molecular nature of the NaCl–water system changes over the pressure–temperature range of the Earth's crust. A transition of concentrated NaCl–H2O brines to a "hydrous molten salt" at high P and T has been argued to stabilize an aqueous fluid phase in the deep crust. In this work, we have done molecular dynamic simulations using classical potentials to determine the nature of concentrated (0.5–16 m NaCl–water mixtures under ambient (25°C, 1 bar, hydrothermal (325°C, 1 kbar and deep crustal (625°C, 15 kbar conditions. We used the well-established SPCE model for water together with the Smith and Dang Lennard-Jones potentials for the ions (J. Chem. Phys., 1994, 100, 3757. With increasing temperature at 1 kbar, the dielectric constant of water decreases to give extensive ion-association and the formation of polyatomic (NanClmn-m clusters in addition to simple NaCl ion pairs. Large polyatomic (NanClmn-m clusters resemble what would be expected in a hydrous NaCl melt in which water and NaCl were completely miscible. Although ion association decreases with pressure, temperatures of 625°C are not enough to overcome pressures of 15 kbar; consequently, there is still enhanced Na–Cl association in brines under deep crustal conditions.

CERN result provides answer to one of nature's most subtle secrets

CERN Multimedia

CERN Press Office. Geneva

1999-01-01

At a seminar at CERN on 18 June Pascal Debu, spokesman of the Laboratory's NA48 experiment, announced its preliminary result, after analysis of 10% of the expected data, on one of nature's best-kept secrets. Direct CP-violation, as it is called, is a subtle effect that betrays nature's preference for matter over antimatter, the reason why we are here.

The role of natural indigo dye in alleviation of genotoxicity of sodium dithionite as a reducing agent.

Science.gov (United States)

Bektaş, İdris; Karaman, Şengül; Dıraz, Emel; Çelik, Mustafa

2016-12-01

Indigo blue is a natural dye used for thousands of years by civilizations to dye fabric blue and it is naturally obtained from Isatis tinctoria. I. tinctoria is not only used for extraction of indigo blue color but also used medicinally in Traditional Chinese Medicine because of its active compounds. Sodium dithionite (Na 2 S 2 O 4 ) is used in dye bath for indigo blue extraction, but this reducing agent and its derivatives are major pollutants of textile industry and subsequently have hazardous influences on public health. Herein, the present study was designed to obtain the high yield of natural indigo dye but with low possible toxic effect. In this context, genotoxic effects of particular combinations of natural dye solutions obtained from Isatis tinctoria subsp. tomentolla with Na 2 S 2 O 4 as reducing agent were investigated. Dye solutions were obtained using two different pH levels (pH 9 and 11) and three different concentrations of Na 2 S 2 O 4 (2.5, 5 and 10 mg/ml). In addition to the dye solutions and reducing agent, aqueous extracts of I. tinctoria were assessed for their genotoxicity on human lymphocytes. For in vitro testing of genotoxicity, chromosomal aberrations (CAs), sister chromatid exchanges (SCEs) and mitotic indexes (MI) assays were used. Accordingly, Na 2 S 2 O 4 caused significant increases in CA and SCE as well decrease in MI but the genotoxic effects of sodium dithionite were reduced with natural indigo dye. As a result, aqueous extracts of Isatis leaves removed the toxic effects of sodium dithionite and showed anti-genotoxic effect. For the optimal and desired quality but with less toxic effects of natural dye, 2.5 mg/ml (for wool yarn) and 5 mg/ml (for cotton yarn) of Na 2 S 2 O 4 doses were found to be the best doses for reduction in the dye bath at Ph 9.

Vpliv toplotnih mostov na porabo energije za ogrevanje na primeru osnovne šole

OpenAIRE

Megušar, Primož

2015-01-01

Na primeru Osnovne šole Dobrova sem preveril, kakšen vpliv imajo dejanski toplotni mostovi na porabo energije za ogrevanje. Iz načrtov stavbe sem evidentiral vse toplotne mostove, kateri vplivajo na porabo energije. Tem toplotnim mostovom sem nato v standardu SIST EN ISO 14683 poiskal ustrezne približke. Nato sem s programom TOST izvedel tri simulacije. V prvem primeru toplotnih mostov nisem upošteval. V drugem primeru sem toplotne mostove upošteval na poenostavljen način, v zadnjem primeru p...

Na and K dependence of the Na/K pump in cystic fibrosis fibroblasts.

OpenAIRE

Reznik, V M; Schneider, J A; Mendoza, S A

1981-01-01

The Na and K dependence of the Na/K pump was measured in skin fibroblasts from patients with cystic fibrosis and age/sex-matched controls. Under basal conditions, there was no difference between control and cystic fibrosis cells in protein per cell, intracellular Na and K content, or Na/K pump activity (measured as ouabain-sensitive 86Rb uptake). There was no difference in the Na dependence of the Na/K pump between cystic fibrosis cells and control cells. In cells from patients with cystic fi...

The World of Insect Metaphors in Zofia Nałkowska’s Dzienniki czasu wojny [Diaries of Wartime

Directory of Open Access Journals (Sweden)

Piotr Krupiński

2013-01-01

Full Text Available The main aim of the article is an analysis of entomological motifs in the Nałkowska’s wartime diary. The surprising frequency of these motifs gives an opportunity for a more general discussion: the key context for an explanation of insect metaphors seems to be the tendency, common for modernist authors, to place the concept of humanity in a widely un­derstood philosophy of nature. The rule would also apply for the war, or more generally, for mechanisms of human violence, which Nałkowska subjects in her diary to a peculiar darwinistic representation. Understanding the war as a “naturalistic fact” (Hanna Kirchner’s description results in a gradual blurring of the differences between the violence of nature and the violence of history. The author of the article has identified a similar procedure in Czesław Miłosz’s work, which constitutes a specific counterpoint for Nałkowska’s wartime diary.

A teoria das restrições como balizadora das ações visando a troca rápida de ferramentas

Directory of Open Access Journals (Sweden)

José Antônio Valle Antunes Jr

1993-12-01

Full Text Available O presente artigo propõe a sinergia entre duas técnicas famosas no contexto da gestão industrial: a Troca Rápida de Ferramenta (TRF e a Teoria das Restrições (Theory of Constraints TOC. Para tanto, inicialmente, discute-se a problemática macroeconômica e sua vinculação com o aspecto microeconômico da TRF. Posteriormente, discute-se as principais vantagens potenciais decorrentes daredução dos custos e dos tempos de preparação. Na seqüência, revisa-se o método da TRF, pontuando-se que a abordagem apresenta uma deficiência no que concerne à apresentação de um procedimento de priorização que permita um plano lógico de ataque à questão. Neste ponto do texto, propõe-se a TOC como balizadora das ações visando a Troca Rápida de Ferramentas. Após uma breve revisão teórica da TOC, apresenta-se uma discussão sobre a possível sinergia da mesma com a TRF. Finalmente, apresenta-se um exemplo didático e as conclusões finais do artigo.This paper presents the relationship between two well-known techniques with in lndustrial Management: SMED and the Theory of Constraints (TOC. As a first step, it is discussed the macroeconomics environment and its relationship with microeconomics aspects of the SMED. After that, the main advantages ofcost and set-up time reductions are discussed and the TOC is proposed as away to define priorities to SMED activities. Both, SMED concepts and TOC concepts are presented in this paper. Finally, an example is built up to show the synergy between the two techniques and a conclusion is presented.

Synthesis of NaCl Single Crystals with Defined Morphologies as Templates for Fabricating Hollow Nano/micro-structures

DEFF Research Database (Denmark)

Wang, B.B.; Jin, P.; Yue, Yuanzheng

2015-01-01

. These naturally abundant NaCl single crystal templates are water-soluble, environmentally-friendly and uniform in both geometry and size, and hence are ideal for preparing high quality hollow nano/micro structures. The new approach may have the potential to replace the conventional hard or soft template...... approaches. Furthermore, this work has revealed the formation mechanism of nano/micron NaCl crystals with different sizes and geometries....

An experimental investigation of Na incorporation in cordierite in low P/high T metapelites

Science.gov (United States)

Tropper, Peter; Wyhlidal, Stefan; Haefeker, Udo A.; Mirwald, Peter W.

2018-04-01

The aim of this experimental study was to investigate the incorporation of Na in cordierite in metapelites as a function of temperature and pressure using natural quartzphyllite rocks as starting materials. The experiments were performed in a hydrothermal apparatus as well as a piston-cylinder apparatus with two natural quartzphyllite samples, which represent the protolith rocks of the hornfelses from the Brixen Granite contact aureole near Franzensfeste. Sample W shows high muscovite contents (57 wt%) and only accessory plagioclase while sample SP5 has high plagioclase (16 wt%) and lower muscovite contents (20 vol%). The experiments were done dry at pressures of 0.15, 0.3 and 0.6 GPa in a temperature range of 550 °C to 780 °C. The Na content of the newly formed cordierites shows a systematic variation and decreases linearly with increasing temperatures and no influence of pressure and melting on the Na contents of cordierite was observed. The experiments also show that the difference in mineral assemblage considerably shifts the obtained Na contents of cordierite. The P-independent temperature correlations for both sets of experiments can be described with the linear relationships: T (°C) = (Na [apfu] - 0.4052)/(-0.000487); R2 = 0.96; (±20 °C, calibration W) and T (°C) = (Na [apfu] - 0.3671)/(-0.000383); R2 = 0.94; (±15 °C, calibration SP5). The difference between the two temperatures is large and the SP5 experiments yield temperatures that are up to 100 °C higher. This is not unexpected since theoretical phase relations in the system NMASH predict different Na contents depending on the buffering assemblage (plagioclase vs. paragonite). On the other hand these T differences could also reflect disequilibrium behaviour in the SP5 experiments. Detailed micro-Raman spectroscopic investigations reveal that cordierites from both experiments show disordered structures but the SP5 experiments show a much higher degree of Si-Al disorder and the elevated Na

Vliv mikroflóry na senzorické vlastnosti vína

OpenAIRE

Petrášová, Ludmila

2014-01-01

Tato bakalářská práce se zabývá vlivem mikroflóry na senzorické vlastnosti vína. Teoretická část informuje o botanickém popisu hroznů vína Veltlínské zelené, dále o jeho složení, o technologii zpracování bílého vína a o vlivu kvasinek na aromatický profil vína. V další části popisuje metodu stanovení aromaticky aktivních látek pomocí plynové chromatografie v kombinaci s mikroextrakcí tuhou fází (SPME-GC). Cílem experimentální části bylo proměřit vzorky 4 různých moštů odrůdy Veltlínské zelené...

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

Energy Technology Data Exchange (ETDEWEB)

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

2008-01-10

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

Sorption of 60 Co in natural zeolite (clinoptilolite)

International Nuclear Information System (INIS)

Hernandez B, E.

1996-01-01

A Mexican zeolite (clinoptilolite) from Taxco, Guerrero, was partially stabilized with sodium cations. Radioactive Cobalt ( 60 Co) was used to study the Co 2+ sorption in the stabilized zeolite (Na + ). It was found that sorption in general does not favour the diffusion of cobalt between framework, it explains because of it is a natural zeolite and its composition heterogeneous decrease its exchange capacity by the generated competence to the existence other type of exchange ions. The cobalt retention reached the highest level, around 0.408 m eq Co 2+ /g in the Na-Clinoptilolite. The crystallinity of the aluminosilicates was maintained during experiments, it was verified by XRD patterns. (Author)

Salinity controls on Na incorporation in Red Sea planktonic foraminifera

Science.gov (United States)

Mezger, E. M.; de Nooijer, L. J.; Boer, W.; Brummer, G. J. A.; Reichart, G. J.

2016-12-01

Whereas several well-established proxies are available for reconstructing past temperatures, salinity remains challenging to assess. Reconstructions based on the combination of (in)organic temperature proxies and foraminiferal stable oxygen isotopes result in relatively large uncertainties, which may be reduced by application of a direct salinity proxy. Cultured benthic and planktonic foraminifera showed that Na incorporation in foraminiferal shell calcite provides a potential independent proxy for salinity. Here we present the first field calibration of such a potential proxy. Living planktonic foraminiferal specimens from the Red Sea surface waters were collected and analyzed for their Na/Ca content using laser ablation quadrupole inductively coupled plasma mass spectrometry. Using the Red Sea as a natural laboratory, the calibration covers a broad range of salinities over a steep gradient within the same water mass. For both Globigerinoides ruber and Globigerinoides sacculifer calcite Na/Ca increases with salinity, albeit with a relatively large intraspecimen and interspecimen variability. The field-based calibration is similar for both species from a salinity of 36.8 up to 39.6, while values for G. sacculifer deviate from this trend in the northernmost transect. It is hypothesized that the foraminifera in the northernmost part of the Red Sea are (partly) expatriated and hence should be excluded from the Na/Ca-salinity calibration. Incorporation of Na in foraminiferal calcite therefore provides a potential proxy for salinity, although species-specific calibrations are still required and more research on the effect of temperature is needed.

The State Policy for Natural Gas Sector / Sektor Gazu Ziemnego W Polityce Państwa

Science.gov (United States)

Szurlej, Adam

2013-09-01

This article reviews the state policy for natural gas sector. A particular attention has been given to how the assumptions of gas demand, import volumes and gas production from domestic reserves have developed in strategic documents. The restructuring of natural gas sector has been brought closer on the example of PGNiG S.A. (Polish Oil and Gas Company), and changes in the domestic gas market resulting from the implementation of EU law have been discussed as well. Major changes in the domestic gas market in the period of 1990-2011 have been presented along with the cooperation between Poland and Russia regarding the natural gas supply for the Polish market. W artykule dokonano przeglądu polityki państwa wobec sektora gazu ziemnego. W sposób szczególny przeanalizowano jak kształtowały się w dokumentach strategicznych prognozy w zakresie zapotrzebowania na gaz, wielkości importu i wydobycia gazu ze złóż krajowych. Przybliżono także restrukturyzację sektora gazu ziemnego na przykładzie PGNiG oraz zmiany na krajowym rynku gazu wynikające z implementacji prawa UE. Wskazano najważniejsze zmiany na krajowym rynku gazu ziemnego w latach 1990-2011 oraz scharakteryzowano współpracę polsko - rosyjską w zakresie dostaw gazu do Polski.

7th World Congress on Nature and Biologically Inspired Computing

CERN Document Server

Engelbrecht, Andries; Abraham, Ajith; Plessis, Mathys; Snášel, Václav; Muda, Azah

2016-01-01

World Congress on Nature and Biologically Inspired Computing (NaBIC) is organized to discuss the state-of-the-art as well as to address various issues with respect to Nurturing Intelligent Computing Towards Advancement of Machine Intelligence. This Volume contains the papers presented in the Seventh World Congress (NaBIC’15) held in Pietermaritzburg, South Africa during December 01-03, 2015. The 39 papers presented in this Volume were carefully reviewed and selected. The Volume would be a valuable reference to researchers, students and practitioners in the computational intelligence field.

Combinations of nisin with salt (NaCl) to control Listeria ...

African Journals Online (AJOL)

This study evaluated the effect of combinations of nisin with salt (NaCl) to control Listeria monocytogenes on sheep natural sausage casings. Casings were inoculated with 3.0 x 105 cfu/g final inocula of L. monocytogenes, stored at 6°C in different solutions of nisin at 0, 100, 150 and 200 ìg/g. Each combined with salt at 0, 4, ...

Study of the Na-C-O and Na-H-O ternary systems in the sodium rich corner

International Nuclear Information System (INIS)

Maupre, J.-P.

1978-02-01

The purpose of this study is to provide a contribution to the understanding of the sodium - carbon - oxygen and sodium - hydrogen - oxygen ternary systems in the sodium rich corner. In order to do this the Na-NaH-Na 2 O-NaOH phase diagram was completed and the Na-Na 2 O-Na 2 CO 3 -C phase diagram was outlined. This work is made up of two parts. The first is devoted to a critical literature survey essential to establish correct phase diagrams. The second is an experimental study followed by a discussion collating our finding to the literary data. The basic experimental technique used is differential thermal analysis (DTA) but it has been completed by quenching, X-ray and chemical analysis methods. The proposed phase diagrams imply that Na-NaH-Na 2 O-NaOH and Na-Na 2 O-Na 2 CO 3 -C systems are reciprocal ternary systems. Temperatures of stable pairs reversal are respectively 410 and 690 0 C. The stable pairs are Na-NaOH and Na-Na 2 CO 3 at elevated temperature, Na 2 O-NaH and Na 2 O-C at low temperature [fr

Variability salt stress response analysis of Tunisian natural ...

African Journals Online (AJOL)

We evaluated the responses to salt stress of 106 Medicago truncatula lines from 11 Tunisian natural populations collected from areas that varied in soil composition, salinity and water availability. Five references lines were also included in this study. Plants were cultivated in two treatments (0 and 50 mM of NaCl) during a ...

Response of saliva Na/K ratio to changing Na supply of lactating cows under tropical conditions.

Science.gov (United States)

Thiangtum, Wandee; Schonewille, J Thomas; Verstegen, Martin Wa; Arsawakulsudhi, Supot; Rukkwamsuk, Theera; Hendriks, Wouter H

2017-06-01

Factorial determination of the sodium (Na) requirement of heat-stressed lactating cows is hindered by accurate estimates of the Na losses through sweat. Direct studies, therefore, may be needed requiring information on the time course of healthy animals to become Na depleted and the subsequent rate of repletion. The rate of Na depletion and subsequent rate of Na repletion with two levels of dietary Na to lactating dairy cows housed under tropical conditions were investigated using the salivary Na/K. The 12 lactating cows (salivary Na/K ratio 14.6) rapidly developed clinical signs of Na deficiency, including pica, polyuria and polydipsia, reduced body weight and reduced milk yield when fed a low-Na ration (0.33 g kg -1 dry matter (DM)) for 3 weeks. Deficiency symptoms were associated with a rapid decrease in salivary Na/K ratio to cows with NaCl to a ration concentration of 1.1 or 1.6 g Na kg -1 DM for 5 weeks did not restore salivary Na/K ratio to values of >6. A daily Na intake of heat-stressed lactating cows to a ration intake of 1.6 g Na kg -1 DM was insufficient to restore Na deficiency. One week was sufficient to deplete heat-stressed lactating cows of Na, allowing for rapid dose-response studies utilizing the salivary Na/K ratio as a parameter for Na status of cows under tropical conditions. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Efeito de métodos e intensidades de pastejo sobre a ressemeadura natural de azevém anual = Effect of grazing methods and intensities on annual ryegrass under natural reseedling

Directory of Open Access Journals (Sweden)

Cristina Maria Pacheco Barbosa

2008-10-01

Full Text Available Este trabalho foi conduzido na E.E.A da UFRGS/RS (30°05’S e 51°39’W com o objetivo de avaliar o efeito de métodos e intensidades de pastejo na dinâmica populacional de azevém (Lolium multiflorum Lam. em ressemeadura natural. Conduziu-se a pastagem em dois métodos de pastejo (lotação contínua e rotacionada e duas intensidades de pastejo (moderada e baixa, em um delineamento em blocos casualizados, em esquema fatorial com três repetições (2x2x3. No ano seguinte, após um ciclo de lavoura de soja no verão, foi contado o número de perfilhos de azevém estabelecidos via essemeadura natural. Os resultados demonstraram não ter havido interação (p > 0,05 entre os métodos e as intensidades de pastejo, e seus efeitos foram analisados de forma independente. Enquanto os diferentes métodos de pastejo não afetaram a ressemeadura do azevém (p = 0,4636, asdiferentes intensidades de pastejo a influenciaram significativamente (p = 0,0003. O número de perfilhos de azevém estabelecidos via ressemeadura natural, na intensidade de pastejo baixa, foi maior (6.776 perfilhos m-2 do que na intensidade de pastejo moderada(211 perfilhos m-2. O controle da intensidade de pastejo é um fator determinante para a manutenção do azevém em sistemas de produção baseados na persistência dessa forrageira via ressemeadura natural.This work was conducted at EEA/UFRGS, in Eldorado do Sul, RioGrande do Sul state, Brazil (30°05’S e 51°39’W, to evaluate the effects of different grazing intensities and methods on the population dynamics of ryegrass (Lolium multiflorum Lam. under natural reseedling. Two grazing intensities (moderate and low were used, under continuous and rotational grazing. The experimental design included randomized blocks with 2x2x3 factorial arrangements (2 grazing intensities x 2 grazing methods x 3 replicates.The following year, the fields were desiccated with herbicides and a soybean plant crop cycle was established during the

A Teoria de Benveniste sobre a pessoalidade e seus desdobramentos na enunciação infantil

Directory of Open Access Journals (Sweden)

José Temístocles FERREIRA JÚNIOR

2015-12-01

Full Text Available Neste trabalho, objetivamos discutir a teoria de (Benveniste 1988 e 1989 sobre a categoria de pessoa na linguagem e examinar suas implicações na enunciação infantil. Para isso, iremos revisitar a abordagem enunciativa de Benveniste, destacando algumas questões correlacionadas à teoria da pessoalidade. Após isso, buscaremos apresentar dados ilustrativos para discutir a emergência e o funcionamento dos índices de pessoa na fala da criança. O corpus de que dispomos é formado por dados de interação envolvendo três crianças diferentes (e suas respectivas mães em situações naturalísticas, presentes na pesquisa de Ferreira Júnior (2009. As análises dos nossos dados mostram que há mecanismos enunciativos subjacentes à fala da criança que comportam modos de apropriação do sistema da língua e de engajamento do sujeito na relação discursiva com o outro.

Chemical behaviour of americium in natural aquatic solutions: Hydrolysis, radiolysis and redox reactions

International Nuclear Information System (INIS)

Stadler, S.; Kim, J.I.

1988-06-01

Hydrolysis and redox reactions of the Am(III) and Am(V) ions have been investigated in NaClO 4 and NaCl solutions as well as in natural saline groundwaters. The hydrolysis constants of Am(OH) n 3-n species and the solubility product of Am(OH) 3 (s) have been determined in 0.1 M NaClO 4 , 0.1 M NaCl and 0.6 M NaCl solutions. As observed in concentrated NaCl solutions (> 3 M), the α-radiation induces the radiolytic oxidation of the Cl - -ion to produce Cl 2 , HClO, ClO - and other oxidized species, which result in a strongly oxidizing medium. Consequently Am(III) is oxidized to Am(V). Under these conditions the hydrolysis constants of AmO 2 (OH) n 1-n species and the solubility product are also determined. The α-radiation induced radiolysis reactions in NaCl solution and the subsequent oxidation reaction of Am(III) have been systematically investigated by varying pH, NaCl concentration and specific α-activity. Also included in the investigation are a few selected groundwaters of relatively high salinity from the Gorleben aquifer systems. (orig.) [de

Glutathionylation-Dependence of Na+-K+-Pump Currents Can Mimic Reduced Subsarcolemmal Na+ Diffusion

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Garcia, Alvaro; Liu, Chia-Chi; Cornelius, Flemming; Clarke, Ronald J.; Rasmussen, Helge H.

2016-01-01

The existence of a subsarcolemmal space with restricted diffusion for Na+ in cardiac myocytes has been inferred from a transient peak electrogenic Na+-K+ pump current beyond steady state on reexposure of myocytes to K+ after a period of exposure to K+-free extracellular solution. The transient peak current is attributed to enhanced electrogenic pumping of Na+ that accumulated in the diffusion-restricted space during pump inhibition in K+-free extracellular solution. However, there are no known physical barriers that account for such restricted Na+ diffusion, and we examined if changes of activity of the Na+-K+ pump itself cause the transient peak current. Reexposure to K+ reproduced a transient current beyond steady state in voltage-clamped ventricular myocytes as reported by others. Persistence of it when the Na+ concentration in patch pipette solutions perfusing the intracellular compartment was high and elimination of it with K+-free pipette solution could not be reconciled with restricted subsarcolemmal Na+ diffusion. The pattern of the transient current early after pump activation was dependent on transmembrane Na+- and K+ concentration gradients suggesting the currents were related to the conformational poise imposed on the pump. We examined if the currents might be accounted for by changes in glutathionylation of the β1 Na+-K+ pump subunit, a reversible oxidative modification that inhibits the pump. Susceptibility of the β1 subunit to glutathionylation depends on the conformational poise of the Na+-K+ pump, and glutathionylation with the pump stabilized in conformations equivalent to those expected to be imposed on voltage-clamped myocytes supported this hypothesis. So did elimination of the transient K+-induced peak Na+-K+ pump current when we included glutaredoxin 1 in patch pipette solutions to reverse glutathionylation. We conclude that transient K+-induced peak Na+-K+ pump current reflects the effect of conformation-dependent β1 pump subunit

Glutathionylation-Dependence of Na(+)-K(+)-Pump Currents Can Mimic Reduced Subsarcolemmal Na(+) Diffusion.

Science.gov (United States)

Garcia, Alvaro; Liu, Chia-Chi; Cornelius, Flemming; Clarke, Ronald J; Rasmussen, Helge H

2016-03-08

The existence of a subsarcolemmal space with restricted diffusion for Na(+) in cardiac myocytes has been inferred from a transient peak electrogenic Na(+)-K(+) pump current beyond steady state on reexposure of myocytes to K(+) after a period of exposure to K(+)-free extracellular solution. The transient peak current is attributed to enhanced electrogenic pumping of Na(+) that accumulated in the diffusion-restricted space during pump inhibition in K(+)-free extracellular solution. However, there are no known physical barriers that account for such restricted Na(+) diffusion, and we examined if changes of activity of the Na(+)-K(+) pump itself cause the transient peak current. Reexposure to K(+) reproduced a transient current beyond steady state in voltage-clamped ventricular myocytes as reported by others. Persistence of it when the Na(+) concentration in patch pipette solutions perfusing the intracellular compartment was high and elimination of it with K(+)-free pipette solution could not be reconciled with restricted subsarcolemmal Na(+) diffusion. The pattern of the transient current early after pump activation was dependent on transmembrane Na(+)- and K(+) concentration gradients suggesting the currents were related to the conformational poise imposed on the pump. We examined if the currents might be accounted for by changes in glutathionylation of the β1 Na(+)-K(+) pump subunit, a reversible oxidative modification that inhibits the pump. Susceptibility of the β1 subunit to glutathionylation depends on the conformational poise of the Na(+)-K(+) pump, and glutathionylation with the pump stabilized in conformations equivalent to those expected to be imposed on voltage-clamped myocytes supported this hypothesis. So did elimination of the transient K(+)-induced peak Na(+)-K(+) pump current when we included glutaredoxin 1 in patch pipette solutions to reverse glutathionylation. We conclude that transient K(+)-induced peak Na(+)-K(+) pump current reflects the effect

Processing bulk natural wood into a high-performance structural material

Science.gov (United States)

Song, Jianwei; Chen, Chaoji; Zhu, Shuze; Zhu, Mingwei; Dai, Jiaqi; Ray, Upamanyu; Li, Yiju; Kuang, Yudi; Li, Yongfeng; Quispe, Nelson; Yao, Yonggang; Gong, Amy; Leiste, Ulrich H.; Bruck, Hugh A.; Zhu, J. Y.; Vellore, Azhar; Li, Heng; Minus, Marilyn L.; Jia, Zheng; Martini, Ashlie; Li, Teng; Hu, Liangbing

2018-02-01

Synthetic structural materials with exceptional mechanical performance suffer from either large weight and adverse environmental impact (for example, steels and alloys) or complex manufacturing processes and thus high cost (for example, polymer-based and biomimetic composites). Natural wood is a low-cost and abundant material and has been used for millennia as a structural material for building and furniture construction. However, the mechanical performance of natural wood (its strength and toughness) is unsatisfactory for many advanced engineering structures and applications. Pre-treatment with steam, heat, ammonia or cold rolling followed by densification has led to the enhanced mechanical performance of natural wood. However, the existing methods result in incomplete densification and lack dimensional stability, particularly in response to humid environments, and wood treated in these ways can expand and weaken. Here we report a simple and effective strategy to transform bulk natural wood directly into a high-performance structural material with a more than tenfold increase in strength, toughness and ballistic resistance and with greater dimensional stability. Our two-step process involves the partial removal of lignin and hemicellulose from the natural wood via a boiling process in an aqueous mixture of NaOH and Na2SO3 followed by hot-pressing, leading to the total collapse of cell walls and the complete densification of the natural wood with highly aligned cellulose nanofibres. This strategy is shown to be universally effective for various species of wood. Our processed wood has a specific strength higher than that of most structural metals and alloys, making it a low-cost, high-performance, lightweight alternative.

Recent advances in enhanced luminescence upconversion of lanthanide-doped NaYF4 phosphors

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Kumar, Deepak; Verma, Kartikey; Verma, Shefali; Chaudhary, Babulal; Som, Sudipta; Sharma, Vishal; Kumar, Vijay; Swart, Hendrik C.

2018-04-01

NaYF4 is regarded as the best upconversion (UC) matrix owing to its low phonon energy, more chemical stability, and a superior refractive index. This review reports on the various synthesis techniques of lanthanide-doped NaYF4 phosphors for UC application. The UC intensity depends on different properties of the matrix and those are discussed in detail. Plasmon-enhanced luminescence UC of the lanthanide-doped NaYF4 core-shells structure is discussed based on a literature survey. The present review provides the information about how the UC intensity can be enhanced. The idea about the UC is then deliberately used for versatile applications such as luminescent materials, display devices, biomedical imaging and different security appliances. In addition, the present review demonstrates the recent trends of NaYF4 UC materials in solar cell devices. The role of NaYF4 phosphor to eradicate the spectral variance among the incident solar spectrum, semiconductor as well as the sub-band gap nature of the semiconductor materials is also discussed in detail. Considering the fact that the research status on NaYF4 phosphor for photovoltaic application is now growing, the present review is therefore very important to the researchers. More importantly, this may promote more interesting research platforms to investigate the realistic use of UC nanophosphors as spectral converters for solar cells.

Domain configuration changes under electric field-induced antiferroelectric-ferroelectric phase transitions in NaNbO3-based ceramics

International Nuclear Information System (INIS)

Guo, Hanzheng; Randall, Clive A.; Shimizu, Hiroyuki; Mizuno, Youichi

2015-01-01

We recently developed a feasible crystal chemistry strategy to stabilize the antiferroelectricity in NaNbO 3 through a chemical substitution to decrease the tolerance factor and increase the average electronegativity of the system [Shimizu et al., Dalton Trans. 44, 10763 (2015) and Guo et al., J. Appl. Phys. 117, 214103 (2015)]. Two novel lead-free antiferroelectric (AFE) solid solutions, (1-x)NaNbO 3 -xCaZrO 3 and (1-x)NaNbO 3 -xSrZrO 3 , have been found to exhibit the double polarization hysteresis typical of a reversible AFE ↔ ferroelectric (FE) phase transition. In this study, as demonstrated by (1-x)NaNbO 3 -xCaZrO 3 system, the influence of chemical modification and electrical poling on the AFE/FE phase stability was investigated, primarily focusing on the microstructural and crystallographic evolutions. Together with the macroscopic polarization hysteresis measurements, a well-demonstrated structure-property relationship was presented. It was found that the CaZrO 3 substitution into NaNbO 3 can effectively destabilize the FE Q phase and correspondingly lead to a spontaneous reverting to AFE P phase. In contrast to the reversible AFE ↔ FE phase transition, the domain morphology evolution exhibits irreversible nature with a growing process of the orientational domains after applying electric field. Moreover, a multiple-zone axes electron diffraction map of P and Q phases has been summarized and is believed to be an efficient diagram to determine the AFE/FE nature of the NaNbO 3 -based systems

The separation of uranium ions by natural and modified diatomite from aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Sprynskyy, Myroslav, E-mail: sprynsky@yahoo.com [Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, 7 Gagarina Str., 87-100 Torun (Poland); Kovalchuk, Iryna [Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, 7 Gagarina Str., 87-100 Torun (Poland); Institute of Adsorption and Problem of Endoecology, National Academy of Sciences of Ukraine, 13 General Naumov Str., 03164 Kyiv (Ukraine); Buszewski, Boguslaw [Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus Copernicus University, 7 Gagarina Str., 87-100 Torun (Poland)

2010-09-15

In this work the natural and the surfactant modified diatomite has been tested for ability to remove uranium ions from aqueous solutions. Such controlling factors of the adsorption process as initial uranium concentration, pH, contact time and ionic strength have been investigated. Effect of ionic strength of solution has been examined using the solutions of NaCl, Na{sub 2}CO{sub 3} and K{sub 2}SO{sub 4}. The pseudo-first order and the pseudo-second order models have been used to analyze the adsorption kinetic results, whereas the Langmuir and the Freundlich isotherms have been used to the equilibrium adsorption data. The effects of the adsorbent modification as well as uranium adsorption on the diatomite surface have been studied using X-ray powder diffraction, scanning electron microscopy and FTIR spectroscopy. The maximum adsorption capacities of the natural and the modified diatomite towards uranium were 25.63 {mu}mol/g and 667.40 {mu}mol/g, respectively. The desorptive solutions of HCl, NaOH, Na{sub 2}CO{sub 3}, K{sub 2}SO{sub 4}, CaCO{sub 3}, humic acid, cool and hot water have been tested to recover uranium from the adsorbent. The highest values of uranium desorption (86%) have been reached using 0.1 M HCl.

The separation of uranium ions by natural and modified diatomite from aqueous solution.

Science.gov (United States)

Sprynskyy, Myroslav; Kovalchuk, Iryna; Buszewski, Bogusław

2010-09-15

In this work the natural and the surfactant modified diatomite has been tested for ability to remove uranium ions from aqueous solutions. Such controlling factors of the adsorption process as initial uranium concentration, pH, contact time and ionic strength have been investigated. Effect of ionic strength of solution has been examined using the solutions of NaCl, Na(2)CO(3) and K(2)SO(4). The pseudo-first order and the pseudo-second order models have been used to analyze the adsorption kinetic results, whereas the Langmuir and the Freundlich isotherms have been used to the equilibrium adsorption data. The effects of the adsorbent modification as well as uranium adsorption on the diatomite surface have been studied using X-ray powder diffraction, scanning electron microscopy and FTIR spectroscopy. The maximum adsorption capacities of the natural and the modified diatomite towards uranium were 25.63 micromol/g and 667.40 micromol/g, respectively. The desorptive solutions of HCl, NaOH, Na(2)CO(3), K(2)SO(4), CaCO(3), humic acid, cool and hot water have been tested to recover uranium from the adsorbent. The highest values of uranium desorption (86%) have been reached using 0.1M HCl. Copyright 2010 Elsevier B.V. All rights reserved.

Src-independent ERK signaling through the rat α3 isoform of Na/K-ATPase.

Science.gov (United States)

Madan, Namrata; Xu, Yunhui; Duan, Qiming; Banerjee, Moumita; Larre, Isabel; Pierre, Sandrine V; Xie, Zijian

2017-03-01

The Na/K-ATPase α1 polypeptide supports both ion-pumping and signaling functions. The Na/K-ATPase α3 polypeptide differs from α1 in both its primary structure and its tissue distribution. The expression of α3 seems particularly important in neurons, and recent clinical evidence supports a unique role of this isoform in normal brain function. The nature of this specific role of α3 has remained elusive, because the ubiquitous presence of α1 has hindered efforts to characterize α3-specific functions in mammalian cell systems. Using Na/K-ATPase α1 knockdown pig kidney cells (PY-17), we generated the first stable mammalian cell line expressing a ouabain-resistant form of rat Na/K-ATPase α3 in the absence of endogenous pig α1 detectable by Western blotting. In these cells, Na/K-ATPase α3 formed a functional ion-pumping enzyme and rescued the expression of Na/K-ATPase β1 and caveolin-1 to levels comparable with those observed in PY-17 cells rescued with a rat Na/K-ATPase α1 (AAC-19). The α3-containing enzymes had lower Na + affinity and lower ouabain-sensitive transport activity than their α1-containing counterparts under basal conditions, but showed a greater capacity to be activated when intracellular Na + was increased. In contrast to Na/K-ATPase α1, α3 could not regulate Src. Upon exposure to ouabain, Src activation did not occur, yet ERK was activated through Src-independent pathways involving PI3K and PKC. Hence, α3 expression confers signaling and pumping properties that are clearly distinct from that of cells expressing Na/K-ATPase α1. Copyright © 2017 the American Physiological Society.

THE BALNEOCLIMATIC RESORT STÂNA DE VALE - PAST, PRESENT, PERSPECTIVES

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Mihai VLAICU

2016-06-01

Full Text Available Stâna de Vale balneoclimatic resort, located in the Apuseni Mountains, is very little valorised. The special natural setting, with the picturesque landscapes, the tourist trails of various difficulty degrees, the oligomineral waters, the numerous waterfalls, the fresh air intensely ionized, without pollutants and allergens, generated by the deciduous and coniferous forests, the exciting-soliciting bioclimate etc. recommend Stâna de Vale as a resort having a remarkable touristic potential, but very little harnessed and this is why it is necessary to identify solutions for its tourist valorisation. This paper highlights the periods of development and of decline of this resort which used to be emblematic for the Apuseni Mountains and for Bihor County and in the end, it suggests some simple solutions to revitalize the resort.

Crystal structure of a Na+-bound Na+,K+-ATPase preceding the E1P state.

Science.gov (United States)

Kanai, Ryuta; Ogawa, Haruo; Vilsen, Bente; Cornelius, Flemming; Toyoshima, Chikashi

2013-10-10

Na(+),K(+)-ATPase pumps three Na(+) ions out of cells in exchange for two K(+) taken up from the extracellular medium per ATP molecule hydrolysed, thereby establishing Na(+) and K(+) gradients across the membrane in all animal cells. These ion gradients are used in many fundamental processes, notably excitation of nerve cells. Here we describe 2.8 Å-resolution crystal structures of this ATPase from pig kidney with bound Na(+), ADP and aluminium fluoride, a stable phosphate analogue, with and without oligomycin that promotes Na(+) occlusion. These crystal structures represent a transition state preceding the phosphorylated intermediate (E1P) in which three Na(+) ions are occluded. Details of the Na(+)-binding sites show how this ATPase functions as a Na(+)-specific pump, rejecting K(+) and Ca(2+), even though its affinity for Na(+) is low (millimolar dissociation constant). A mechanism for sequential, cooperative Na(+) binding can now be formulated in atomic detail.

Na+-H+ exchange and Na+-dependent transport systems in streptozotocin diabetic rat kidneys

International Nuclear Information System (INIS)

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 + -H + 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 22 Na + , and stimulated 22 Na= pump activity in the basolateral membrane, previously reported characteristics of this experimental animal model. Amiloride-sensitive H + gradient-dependent Na + uptake and Na + gradient-dependent H + flux were increased in brush-border membrane vesicles from the streptozotocin-treated animals. Na + 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

Sacralidade e crueldade no direito natural segundo Hobbes e Agamben = Sacredness and cruelty in natural right according to Hobbes and Agamben

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Costa, Gilcilene Dias da

2011-01-01

Full Text Available O presente texto visa discutir o sentido da sacralidade e da crueldade no direito natural e na cena política a partir de Hobbes e Agamben. Relaciona o conceito hobbesiano de estado de natureza às figuras do direito romano arcaico, homo lupus (homem lobo e homo sacer (homem sagrado em seu duplo processo de inclusão/exclusão da vida nua (zoé na vida política (bíos. Adentra nos limites da natureza e da condição humana, a fim de perceber as flutuações de sentido implicadas na situação de abandono que acerca um malfeitor ou bando junto à comunidade, com sua exposição à morte ou desaparecimento social sem as formas sancionadas pela lei. Reitera a permanente fronteira entre animal e humano, limite paradoxal e intransponível, situado entre polidez e nudez, crueldade e sacralidade, bem e mal

Analysis of natural milk and milk powder samples by NAA

International Nuclear Information System (INIS)

Al-Jobori, S.M.; Itawi, R.K.; Saad, A.; Shihab, K.M.; Jalil, M.; Farhan, S.S.

1990-01-01

As a part of the Iraqi Food Analysis Programme the concentration of Na, Mg, P, Cl, K, Ca, Zn, Se, Br, Rb and I in natural milk collected from different regions of Iraq, and in milk powder samples was determined by NAA technique. It was found that except for the elements I, Rb and Br the concentration of the elements was approximately identical in both natural milk and milk powders. (author) 4 refs.; 3 figs.; 5 tabs

Analysis of natural milk and milk powder samples by NAA

International Nuclear Information System (INIS)

Al-Jobori, S. M.; Itawi, R. K.; Saad, A; Shihab, K. M.; Jalil, M.; Farhan, S. S.

1993-01-01

As a part of the Iraqi food analysis program (IFAP) the concentration of Na, Mg, P, Cl, K, Ca, Zn, Se, Br, Rb, and I in natural milk collected from different regions of Iraq, and in milk powder samples have been determined by using the NAA techniques. It was found that except for the elements I, Rb, and Br the concentrations of the elements was approximately identical in both the natural milk and milk powder. (author)

The two C-terminal tyrosines stabilize occluded Na/K pump conformations containing Na or K ions.

Science.gov (United States)

Vedovato, Natascia; Gadsby, David C

2010-07-01

Interactions of the three transported Na ions with the Na/K pump remain incompletely understood. Na/K pump crystal structures show that the extended C terminus of the Na,K-adenosine triphosphatase (ATPase) alpha subunit directly contacts transmembrane helices. Deletion of the last five residues (KETYY in almost all Na/K pumps) markedly lowered the apparent affinity for Na activation of pump phosphorylation from ATP, a reflection of cytoplasmic Na affinity for forming the occluded E1P(Na3) conformation. ATPase assays further suggested that C-terminal truncations also interfere with low affinity Na interactions, which are attributable to extracellular effects. Because extracellular Na ions traverse part of the membrane's electric field to reach their binding sites in the Na/K pump, their movements generate currents that can be monitored with high resolution. We report here electrical measurements to examine how Na/K pump interactions with extracellular Na ions are influenced by C-terminal truncations. We deleted the last two (YY) or five (KESYY) residues in Xenopus laevis alpha1 Na/K pumps made ouabain resistant by either of two kinds of point mutations and measured their currents as 10-mM ouabain-sensitive currents in Xenopus oocytes after silencing endogenous Xenopus Na/K pumps with 1 microM ouabain. We found the low affinity inhibitory influence of extracellular Na on outward Na/K pump current at negative voltages to be impaired in all of the C-terminally truncated pumps. Correspondingly, voltage jump-induced transient charge movements that reflect pump interactions with extracellular Na ions were strongly shifted to more negative potentials; this signals a several-fold reduction of the apparent affinity for extracellular Na in the truncated pumps. Parallel lowering of Na affinity on both sides of the membrane argues that the C-terminal contacts provide important stabilization of the occluded E1P(Na3) conformation, regardless of the route of Na ion entry into the

Arctigenin antagonizes mineralocorticoid receptor to inhibit the transcription of Na/K-ATPase.

Science.gov (United States)

Cheng, Ye; Zhou, Meili; Wang, Yan

2016-01-01

Hypertension is one of the most important risk factors in cardiovascular disease and is the most common chronic disease. Mineralocorticoid receptor (MR) antagonists have been successfully used in clinic for the treatment of hypertension. Our study aims to investigate whether Arctigenin can antagonize MR and inhibit the transcription of Na/K-ATPase. The yeast two-hybrid assay was used to screen natural products and Arctigenin was identified as an MR antagonist. The direct binding of Arctigenin to MR was determined using assays based on surface plasmon resonance, differential scanning calorimetry and fluorescence quenching. Furthermore, results from mammalian one-hybrid and transcriptional activation experiments also confirmed that Arctigenin can potently antagonize MR in cells. We demonstrated that Arctigenin can decrease the level of Na/K-ATPase mRNA by antagonizing MR in HK-2 cells. Our findings show that Arctigenin can effectively decrease Na/K-ATPase transcription; thus highlight its potential as an anti-hypertensive drug lead compound. Our current findings demonstrate that Arctigenin is an antagonist of MR and effectively decreases the Na/K-ATPase 1 gene expression. Our work provides a hint for the drug discovery against cardiovascular disease.

Hardware Development and Locomotion Control Strategy for an Over-Ground Gait Trainer: NaTUre-Gaits.

Science.gov (United States)

Luu, Trieu Phat; Low, Kin Huat; Qu, Xingda; Lim, Hup Boon; Hoon, Kay Hiang

2014-01-01

Therapist-assisted body weight supported (TABWS) gait rehabilitation was introduced two decades ago. The benefit of TABWS in functional recovery of walking in spinal cord injury and stroke patients has been demonstrated and reported. However, shortage of therapists, labor-intensiveness, and short duration of training are some limitations of this approach. To overcome these deficiencies, robotic-assisted gait rehabilitation systems have been suggested. These systems have gained attentions from researchers and clinical practitioner in recent years. To achieve the same objective, an over-ground gait rehabilitation system, NaTUre-gaits, was developed at the Nanyang Technological University. The design was based on a clinical approach to provide four main features, which are pelvic motion, body weight support, over-ground walking experience, and lower limb assistance. These features can be achieved by three main modules of NaTUre-gaits: 1) pelvic assistance mechanism, mobile platform, and robotic orthosis. Predefined gait patterns are required for a robotic assisted system to follow. In this paper, the gait pattern planning for NaTUre-gaits was accomplished by an individual-specific gait pattern prediction model. The model generates gait patterns that resemble natural gait patterns of the targeted subjects. The features of NaTUre-gaits have been demonstrated by walking trials with several subjects. The trials have been evaluated by therapists and doctors. The results show that 10-m walking trial with a reduction in manpower. The task-specific repetitive training approach and natural walking gait patterns were also successfully achieved.

Anion-coupled Na efflux mediated by the human red blood cell Na/K pump

International Nuclear Information System (INIS)

Dissing, S.; Hoffman, J.F.

1990-01-01

The red cell Na/K pump is known to continue to extrude Na when both Na and K are removed from the external medium. Because this ouabain-sensitive flux occurs in the absence of an exchangeable cation, it is referred to as uncoupled Na efflux. This flux is also known to be inhibited by 5 mM Nao but to a lesser extent than that inhibitable by ouabain. Uncoupled Na efflux via the Na/K pump therefore can be divided into a Nao-sensitive and Nao-insensitive component. We used DIDS-treated, SO4-equilibrated human red blood cells suspended in HEPES-buffered (pHo 7.4) MgSO4 or (Tris)2SO4, in which we measured 22Na efflux, 35SO4 efflux, and changes in the membrane potential with the fluorescent dye, diS-C3 (5). A principal finding is that uncoupled Na efflux occurs electroneurally, in contrast to the pump's normal electrogenic operation when exchanging Nai for Ko. This electroneutral uncoupled efflux of Na was found to be balanced by an efflux of cellular anions. (We were unable to detect any ouabain-sensitive uptake of protons, measured in an unbuffered medium at pH 7.4 with a Radiometer pH-STAT.) The Nao-sensitive efflux of Nai was found to be 1.95 +/- 0.10 times the Nao-sensitive efflux of (SO4)i, indicating that the stoichiometry of this cotransport is two Na+ per SO4=, accounting for 60-80% of the electroneutral Na efflux. The remainder portion, that is, the ouabain-sensitive Nao-insensitive component, has been identified as PO4-coupled Na transport and is the subject of a separate paper. That uncoupled Na efflux occurs as a cotransport with anions is supported by the result, obtained with resealed ghosts, that when internal and external SO4 was substituted by the impermeant anion, tartrate i,o, the efflux of Na was inhibited 60-80%. This inhibition could be relieved by the inclusion, before DIDS treatment, of 5 mM Cli,o

The modulation of erythrocyte Na+/K+-ATPase activity by curcumin

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Prabhakar Singh

2015-11-01

Full Text Available Curcumin, an active biphenolic molecule present in turmeric (Curcuma longa, has been reported to elicit plethora of health protective effects. The present study was carried out in vitro, in vivo and in silico to investigate the modulatory effects of curcumin on erythrocyte membrane Na+/K+-ATPase activity. In vitro curcumin (10−5 M to 10−8 M was incubated with human erythrocytes membrane. In vivo curcumin (340 mg/kg b.w. and 170 mg/kg b.w. was supplemented to wistar rats for 21 days. In silico, catalytic unit α of Na+/K+-ATPase (3b8e.pdb protein was used as a receptor for the natural ligand ATP to study curcumin-mediated docking simulation using AutoDock4. The in vitro effect of curcumin on the Na+/K+-ATPase activity in human erythrocytes was biphasic. An inhibitory response was observed at 10−5 M (p < 0.001. An activation of the Na+/K+-ATPase activity was observed at 10−7 and 10−8 M (p < 0.001 and p < 0.01. In vivo, curcumin supplementation to rats increased the Na+/K+-ATPase activity at doses 340 mg/kg b.w. (p < 0.001 as well as at 170 mg/kg b.w., (p < 0.01. AutoDock4 docking simulation study showed that both ligands curcumin and ATP actively interacted with amino acids Glu214, Ser215, Glu216, Thr371, Asn377, Arg378, Met379, Arg438, Val440, Ala444, Lys451 and Asp586 at the catalytic cavity of Na+/K+-ATPase. ATP had more H bonding and hydrophobic interaction with active site amino acid residues compared to curcumin. These finding may explain some of the health beneficial properties of curcumin associated with deregulated Na+/K+-ATPase activity or ions homeostasis.

Removal of uranium ions from synthetic wastewater using ZnO/Na-clinoptilolite nanocomposites

International Nuclear Information System (INIS)

Aghadavoud, Azadeh; Saraee, Khadijeh Rezaee Ebrahim; Shakur, Hamid Reza; Sayyari, Rasol

2016-01-01

Uranium is one of the heavy metals that is found in industrial wastewater and is very toxic for human and environment. In this work, natural clinoptilolite is used as a low-cost adsorbent for uranium removal from aqueous solutions. The sodium form of clinoptilolite and ZnO/Na-clinoptilolite nanocomposite were prepared. The sample sorption capacities for uranium removal from simulated drinking water in the presence of other anions and cations were investigated. Natural zeolite and its modified forms were characterized by XRD, XRF, FTIR, TEM and BET. Batch experiments were used to determine the best adsorption conditions. The effects of various parameters such as contact time, pH, initial uranium concentration, temperature and mass sorbent on the removal efficiency of uranium ions were studied. The equilibration was attained after 2 and 6 h for the Na-clinoptilolite and ZnO/Na-clinoptilolite nanocomposite, respectively. Both adsorbents showed relatively fast adsorption. Effective removal of uranium was demonstrated at pH values of 4-8 for both forms of zeolite. Temperature had no significant effect on adsorption. The maximum removal efficiency of uranium by the ZnO/Na-clinoptilolite nanocomposite in pH=7.2 and room temperature was 98.55%. Langmuir, Freundlich and Sips models were used for describing the equilibrium isotherms for uranium uptake. The Sips model corresponded well with the experimental data. The thermodynamic parameters, such as ΔG , ΔH and ΔS , have been calculated and interpreted. The pseudo-first order and pseudo-second order models were applied to describe the kinetic data. The pseudo-second order kinetic model had excellent kinetic data fitting (R2=1).

Removal of uranium ions from synthetic wastewater using ZnO/Na-clinoptilolite nanocomposites

Energy Technology Data Exchange (ETDEWEB)

Aghadavoud, Azadeh; Saraee, Khadijeh Rezaee Ebrahim; Shakur, Hamid Reza [Isfahan Univ. (Iran, Islamic Republic of). Dept. of Nuclear Engineering; Sayyari, Rasol

2016-07-01

Uranium is one of the heavy metals that is found in industrial wastewater and is very toxic for human and environment. In this work, natural clinoptilolite is used as a low-cost adsorbent for uranium removal from aqueous solutions. The sodium form of clinoptilolite and ZnO/Na-clinoptilolite nanocomposite were prepared. The sample sorption capacities for uranium removal from simulated drinking water in the presence of other anions and cations were investigated. Natural zeolite and its modified forms were characterized by XRD, XRF, FTIR, TEM and BET. Batch experiments were used to determine the best adsorption conditions. The effects of various parameters such as contact time, pH, initial uranium concentration, temperature and mass sorbent on the removal efficiency of uranium ions were studied. The equilibration was attained after 2 and 6 h for the Na-clinoptilolite and ZnO/Na-clinoptilolite nanocomposite, respectively. Both adsorbents showed relatively fast adsorption. Effective removal of uranium was demonstrated at pH values of 4-8 for both forms of zeolite. Temperature had no significant effect on adsorption. The maximum removal efficiency of uranium by the ZnO/Na-clinoptilolite nanocomposite in pH=7.2 and room temperature was 98.55%. Langmuir, Freundlich and Sips models were used for describing the equilibrium isotherms for uranium uptake. The Sips model corresponded well with the experimental data. The thermodynamic parameters, such as ΔG , ΔH and ΔS , have been calculated and interpreted. The pseudo-first order and pseudo-second order models were applied to describe the kinetic data. The pseudo-second order kinetic model had excellent kinetic data fitting (R2=1).

Enhancement of Biogas Production from Rice Husk by NaOH and Enzyme Pretreatment

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Syafrudin

2018-01-01

Full Text Available Biogas is a renewable energy source that can be used as an alternative fuel to replace fossil fuel such as oil and natural gas. This research aims to analyze the impact of NaOH (Sodium hydroxide and enzyme usage on the production of rice husk biogas using Solid State Anaerobic Digestion (SS-AD. Generally, SS-AD occurs at solid concentrations higher than 15%. The waste of rice husk are used as substrate with a C/N ratio of 25% and the total of solid that are used is 21%. Rice husk contains high lignin, therefore it is handled with chemical and biological treatment. The chemical preliminary treatment was using NaOH with various concentrations from 3%, 6% and 9% while the biological preliminary treatment was using enzyme with various concentration from 5%, 8%, and 11%. The biogas that is produced then measured every two days during 60 days of research with the biogas volume as a parameter observed. The result of the research shows that preliminary treatment with NaOH and enzyme can increase the production of biogas. The highest biogas production was obtained by the NaOH pretreatment using 6% NaOH which was 497 ml and by enzyme pretreatment using 11% enzyme which was 667,5 ml.

Enhancement of Biogas Production from Rice Husk by NaOH and Enzyme Pretreatment

Science.gov (United States)

Syafrudin; Nugraha, Winardi Dwi; Agnesia, Shandy Sarima; Matin, Hashfi Hawali Abdul; Budiyono

2018-02-01

Biogas is a renewable energy source that can be used as an alternative fuel to replace fossil fuel such as oil and natural gas. This research aims to analyze the impact of NaOH (Sodium hydroxide) and enzyme usage on the production of rice husk biogas using Solid State Anaerobic Digestion (SS-AD). Generally, SS-AD occurs at solid concentrations higher than 15%. The waste of rice husk are used as substrate with a C/N ratio of 25% and the total of solid that are used is 21%. Rice husk contains high lignin, therefore it is handled with chemical and biological treatment. The chemical preliminary treatment was using NaOH with various concentrations from 3%, 6% and 9% while the biological preliminary treatment was using enzyme with various concentration from 5%, 8%, and 11%. The biogas that is produced then measured every two days during 60 days of research with the biogas volume as a parameter observed. The result of the research shows that preliminary treatment with NaOH and enzyme can increase the production of biogas. The highest biogas production was obtained by the NaOH pretreatment using 6% NaOH which was 497 ml and by enzyme pretreatment using 11% enzyme which was 667,5 ml.

Determination of inorganic ions in natural water by ion chromatography

International Nuclear Information System (INIS)

Nazaratul Ashifa Abdullah Salim; Mohd Suhaimi Hamzah; Eewiat Edin Put; Abdul Khalik Wood; Shamsiah Abdul Rahman; Md Suhaimi Elia

2010-01-01

Ion chromatography (IC) is a well established methodology for analysis of ionic species. The concentration of ionic species was determined using suppressed IC with conductivity detection. Anion species were determined in a single 15-min run with Na 2 CO 3 and NaHCO 3 eluent. Cation species were analysed by direct injection of 1 ml and isocratic elution with a methanesulfonic acid (MSA) eluent. Natural water were collected from various sources such as rainwater, lake, river and groundwater. Analysis performance of IC system was validated by evaluating the linear regression of calibration curve, recovery of spike sample and quality control sample. (author)

Na5NbO5 and Na5TaO5 phases

International Nuclear Information System (INIS)

Darriet, J.; Maazaz, A.; Bouloux, J.C.; Delmas, C.

1982-01-01

New ternary oxides of formulas Na 5 NbO 5 and Na 5 TaO 5 have been prepared. They crystallize in the monoclinic system (space group C2/c). The crystal structure of Na 5 NbO 5 has been determined. It derives from a NaCl-type structure by ordering of the cations and of the oxygen vacancies in the anionic sublattice, the corresponding formula being Nasub(5/6)Nbsub(1/6)Osub(5/6)vacant sub(1/6). Sodium and niobium have a distorted square-pyramidal surrounding. (author)

Natural latex graft in lamellar and penetrating sclerectomies in rabbits Enxerto de látex natural na cicatrização de esclerectomias lamelar e penetrante em coelhos

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Ivia Carmem Talieri

2009-09-01

Full Text Available The objective of study was to investigate the effects of natural latex with 0.1% of polylysine on lamellar and penetrating scleroctomies in rabbits. Two groups of twelve rabbits each (lamellar GI and penetrating GII were studied. Scleral square incisions near the limbus were performed on the left eye of each animal. The latex biomembrane was fixed to the recipient sclera and it covered with a conjunctival flap. The clinical evaluations were followed for 60 days. Aplannation tonometry, binocular indirect ophthalmoscopy and slit-lamp biomicroscopy were performed during evaluation. Bright field microscopy and polarization microscopy were employed. Blepharospasm, graft infection, mucoid ocular discharge and chemosis were not observed in either treatment group. The conjunctival hyperemia varied from moderate to hardly noticeable. The postoperative IOP was not statiscally significant, comparing to the preoperative IOP, for GI and GII. The histopathology by polarization microscopy showed that the neoformed tissue was primarily dependent on adjacent vascularized tissues and was constituted by collagen type III. Both groups presented optimum graft adhesion to the receiving sclera. The natural latex biomembrane with 0.1% polylysine constitutes a new alternative for scleral reconstruction. Furthermore, this is a durable material, easy to obtain and manipulate.Este trabalho teve como objetivo investigar os efeitos do látex natural com polilisina a 0,1% na cicatrização de esclerectomias lamelar e penetrante em coelhos. Foram estudados dois grupos de 12 coelhos (GI - lamelar e GII - penetrante. As esclerectomias foram realizadas no olho esquerdo de cada animal. A biomembrana de látex foi fixada à esclera receptora e foi recoberta com conjuntiva bulbar. As avaliações clínicas foram realizadas durante 60 dias. Para tal, empregaram-se a tonometria de aplanação, a oftalmoscopia indireta binocular e a biomicroscopia em lâmpada de fenda. Realizou-se an

Phase transitions on dehydration of the natural zeolite thomsonite

DEFF Research Database (Denmark)

Ståhl, Kenny

2001-01-01

The dehydration of the natural zeolite thomsonite, Na4CasAl20Si20O80 24H(2)O, has been studied using a combination of conventional and synchrotron X-ray powder diffraction. A preliminary in situ dehydration study revealed two distinct unit cell changes at approximately 540 and 570 K, respectively...

Dinâmica vegetacional em pastagem natural submetida a diferentes sistemas de manejo Vegetation dynamics of natural grassland under different management systems

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Marcos da Silva Brum

2007-06-01

Full Text Available A dinâmica da composição florística de uma pastagem natural foi avaliada para estimar os efeitos de sistemas de pastejo e introdução de espécies hibernais. O experimento foi realizado em São Gabriel, na região da Depressão Central, Rio Grande do Sul. O período de pastejo foi entre 01/11/2004 e 23/12/2004, totalizando 53 dias. Foram realizados dois levantamentos da composição florística, sendo o primeiro antes do início do pastejo (23/09/2004 e o segundo após o término do período experimental (27/01/2005. Os tratamentos testados foram: pastagem natural melhorada com introdução de espécies hibernais sob pastejo rotativo (CNM; pastagem natural sob pastejo contínuo (CNC e pastagem natural sob pastejo rotativo (CNR, sendo distribuídos em delineamento inteiramente casualizado, com duas repetições. Os animais utilizados no pastejo foram ovelhas com cordeiros da raça Corriedale. Os dados foram submetidos à análise multivariada baseada em ordenação e testes de aleatorização. No primeiro levantamento botânico, o tratamento CNM diferiu (P=0,0001 do CNC e CNR pela elevada participação das espécies introduzidas, enquanto CNC e do CNR foram semelhantes (P=0,6742 na composição de espécies. Os tratamentos CNM e CNC foram diferentes (P=0,0017 no segundo levantamento. O efeito do pastejo rotativo, a introdução de espécies e a adubação são determinantes para mudanças na composição da vegetação. A vegetação sob efeito de pastejo rotativo apresentou trajetórias que convergem para uma situação de semelhança na composição de espécies.Floristic composition's dynamics of a natural grassland was evaluated to estimate the effects of grazing systems and introduction of cool season species. The experiment was held in São Gabriel, in the region of Depressão Central, Rio Grande do Sul, Brazil. The grazing period was from 01/11/2004 to 23/12/2004, totaling 53 days. Floristic composition were evaluated before the

OPTIMISATION OF HIBISCUS SABDARIFFA AS A NATURAL COAGULANT TO TREAT CONGO RED IN WASTEWATER

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MUN Y. YONG

2016-02-01

Full Text Available The process of coagulation is commonly practiced in water and wastewater treatment to reduce level of dissolved chemical, turbidity and so on with the usage of coagulant. Aluminium sulphate (alum is the most commonly used coagulant, however, recent studies show that residual aluminium in drinking water and sludge may induce Alzheimer’s disease and environmental issues. Natural coagulant which is environmental friendly and non-toxic is developed as an alternative to overcome these issues. In this work, Hibiscus Sabdariffa was studied as natural coagulant to treat dye wastewater containing Congo red. The seeds were extracted with different solvent such as distilled water, 0.5 M NaCl and 0.05 M NaOH to extract the coagulation agent. The working parameters were optimised using Response Surface Methodology (RSM. 0.5 M NaCl was found to have highest colour removal of 95.1 % among the solvents. In addition, Hibiscus Sabdariffa seed was found to be an effective coagulant that has 91.2 % colour removal at the optimal working condition of pH 2, 190 mg/L coagulant dosage at 400 ppm of dye concentration. It was also been identified that the performance of natural coagulant is comparable with conventional coagulant, aluminium sulphate with colour removal of 91.2 % and 92.3 % respectively.

Cymbopogon citratus and NaNO2 Behaviours in 3.5% NaCl-Immersed Steel-Reinforced Concrete: Implications for Eco-Friendly Corrosion Inhibitor Applications for Steel in Concrete

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Joshua Olusegun Okeniyi

2018-01-01

Full Text Available This paper studies behaviours of Cymbopogon citratus leaf-extract and NaNO2, used as equal-mass admixture models, in 3.5% NaCl-immersed steel-reinforced concrete by nondestructive electrochemical methods and by compressive-strength improvement/reduction effects. Corrosion-rate, corrosion-current, and corrosion-potential constitute electrochemical test-techniques while compressive-strength effect investigations followed ASTM C29 and ASTM C33, in experiments using positive-controls for the electrochemical and compressive-strength studies. Analyses of the different electrochemical test-results mostly portrayed agreements on reinforcing-steel anticorrosion effects by the concentrations of natural plant and of chemical admixtures in the saline/marine simulating-environment and in the distilled H2O (electrochemical positive control of steel-reinforced concrete immersions. These indicated that little amount (0.0833% cement for concrete-mixing of Cymbopogon citratus leaf-extract was required for optimal inhibition efficiency, η = 99.35%, on reinforcing-steel corrosion, in the study. Results of compressive-strength change factor also indicated that the 0.0833% Cymbopogon citratus concentration outperformed NaNO2 admixture concentrations also in compressive-strength improvement effects on the NaCl-immersed steel-reinforced concrete. These established implications, from the study, on the suitability of the eco-friendly Cymbopogon citratus leaf-extract for replacing the also highly effective NaNO2 inhibitor of steel-in-concrete corrosion in concrete designed for the saline/marine service-environment.

A politicidade do cuidado na crítica aos estereótipos de gênero

OpenAIRE

Pires, Maria Raquel Gomes Maia; Fonseca, Rosa Maria Godoy Serpa da; Padilla, Beatriz

2016-01-01

RESUMO Objetivos: analisar as desigualdades de gênero entre mulheres brasileiras em Portugal e na enfermagem moderna, a partir da politicidade do cuidado na perspectiva do gênero; explicitar a opressão sobre o feminino reproduzida pelos estereótipos que essencializam a mulher como cuidadora natural; apontar politicidades para a desconstrução dos estereótipos de gênero. Método: reflexão teórica com revisão narrativa de literatura com o propósito de analisar as referências clássicas da episte...

Luz natural na micropropagação do abacaxizeiro (Ananas comosus L. Merr)

OpenAIRE

Bortolotti da Silva, Adriano; Pasqual, Moacir; Mauro de Castro, Evaristo; Yuriko Miyata, Luzia; Amaral de Melo, Lucas; Tavares Braga, Francyane

2008-01-01

Brotações de Ananas comosus cv. Imperial, foram enraizadas in vitro em diferentes condições ambientais (luz artificial e natural) e após dois meses as plântulas foram transferidas para substrato comercial (Plantmax®) em casa de vegetação. O crescimento das plantas e anatomia foliar foram avaliados em diferentes tempos (0, 7, 15, 30 e 60 dias) do processo de aclimatização. O emprego de luz natural durante a fase de enraizamento in vitro proporciona melhor desempenho agronômico e anatômico das ...

Synthesis of Na-A and/or Na-X zeolite/porous carbon composites from carbonized rice husk

International Nuclear Information System (INIS)

Katsuki, Hiroaki; Komarneni, Sridhar

2009-01-01

Na-A and/or Na-X zeolite/porous carbon composites were prepared under hydrothermal conditions by NaOH dissolution of silica first from carbonized rice husk followed by addition of NaAlO 2 and in situ crystallization of zeolites i.e., using a two-step process. When a one-step process was used, both Na-A and Na-X zeolites crystallized on the surface of carbon. Na-A or Na-X zeolite crystals were prepared on the porous carbonized rice husk at 90 deg. C for 2-6 h by changing the SiO 2 /Al 2 O 3 , H 2 O/Na 2 O and Na 2 O/SiO 2 molar ratios of precursors in the two-step process. The surface area and NH 4 + -cation exchange capacity (CEC) of Na-A zeolite/porous carbon were found to be 171 m 2 /g and 506 meq/100 g, respectively, while those of Na-X zeolite/porous carbon composites were 676 m 2 /g and 317 meq/100 g, respectively. Na-A and Na-X zeolites are well-known microporous and hydrophilic materials while carbonized rice husk was found to be mesoporous (pores of ∼3.9 nm) and hydrophobic. These hybrid microporous-mesoporous and hydrophilic-hydrophobic composites are expected to be useful for decontamination of metal cations as well as organic contaminants simultaneously. - Graphical Abstract: Novel Na-X zeolite/porous carbon composite.

Equilibrium chemical transformations in NaPO3 + NaCl melts

International Nuclear Information System (INIS)

Kovarskaya, E.N.; Rodionov, Yu.I.

1988-01-01

Because of the problems of the burial of solidified radioactive wastes into different geological rock formations, in particular into massives of rock-salt, the state of molten polyphosphate-chloride mixtures (taking into account the chemical character of the interaction of their components) for a prolonged period of time. The equilibrium products of the reaction in the NaPO 3 -NaCl system were studied in melts in air in the composition range of 30-70 mole % NaCl. It was shown that with increase in the NaCl content in the mixtures, the polyphosphate gradually depolymerizes to sodium tri-, di-, and monophosphates, and the composition of the equilibrium melts is dependent only on the ratio between the components in the initial molten mixtures. The time until the equilibrium is attained is shorter, the higher is the experimental temperature

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

Science.gov (United States)

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.

Interaction between Na+/K+-pump and Na+/Ca2+-exchanger modulates intercellular communication.

Science.gov (United States)

Matchkov, Vladimir V; Gustafsson, Helena; Rahman, Awahan; Briggs Boedtkjer, Donna M; Gorintin, Sarah; Hansen, Anne Kirstine; Bouzinova, Elena V; Praetorius, Helle A; Aalkjaer, Christian; Nilsson, Holger

2007-04-13

Ouabain, a specific inhibitor of the Na(+)/K(+)-pump, has previously been shown to interfere with intercellular communication. Here we test the hypothesis that the communication between vascular smooth muscle cells is regulated through an interaction between the Na(+)/K(+)-pump and the Na(+)/Ca(2+)-exchanger leading to an increase in the intracellular calcium concentration ([Ca(2+)](i)) in discrete areas near the plasma membrane. [Ca(2+)](i) in smooth muscle cells was imaged in cultured rat aortic smooth muscle cell pairs (A7r5) and in rat mesenteric small artery segments simultaneously with force. In A7r5 coupling between cells was estimated by measuring membrane capacitance. Smooth muscle cells were uncoupled when the Na(+)/K(+)-pump was inhibited either by a low concentration of ouabain, which also caused a localized increase of [Ca(2+)](i) near the membrane, or by ATP depletion. Reduction of Na(+)/K(+)-pump activity by removal of extracellular potassium ([K(+)](o)) also uncoupled cells, but only after inhibition of K(ATP) channels. Inhibition of the Na(+)/Ca(2+)-exchange activity by SEA0400 or by a reduction of the equilibrium potential (making it more negative) also uncoupled the cells. Depletion of intracellular Na(+) and clamping of [Ca(2+)](i) at low concentrations prevented the uncoupling. The experiments suggest that the Na(+)/K(+)-pump may affect gap junction conductivity via localized changes in [Ca(2+)](i) through modulation of Na(+)/Ca(2+)-exchanger activity.

Core--strategy leading to high reversible hydrogen storage capacity for NaBH4.

Science.gov (United States)

Christian, Meganne L; Aguey-Zinsou, Kondo-François

2012-09-25

Owing to its high storage capacity (10.8 mass %), sodium borohydride (NaBH(4)) is a promising hydrogen storage material. However, the temperature for hydrogen release is high (>500 °C), and reversibility of the release is unachievable under reasonable conditions. Herein, we demonstrate the potential of a novel strategy leading to high and stable hydrogen absorption/desorption cycling for NaBH(4) under mild pressure conditions (4 MPa). By an antisolvent precipitation method, the size of NaBH(4) particles was restricted to a few nanometers (hydrogen at 400 °C. Further encapsulation of these nanoparticles upon reaction of nickel chloride at their surface allowed the synthesis of a core--shell nanostructure, NaBH(4)@Ni, and this provided a route for (a) the effective nanoconfinement of the melted NaBH(4) core and its dehydrogenation products, and (b) reversibility and fast kinetics owing to short diffusion lengths, the unstable nature of nickel borohydride, and possible modification of reaction paths. Hence at 350 °C, a reversible and steady hydrogen capacity of 5 mass % was achieved for NaBH(4)@Ni; 80% of the hydrogen could be desorbed or absorbed in less than 60 min, and full capacity was reached within 5 h. To the best of our knowledge, this is the first time that such performances have been achieved with NaBH(4). This demonstrates the potential of the strategy in leading to major advancements in the design of effective hydrogen storage materials from pristine borohydrides.

Evaluation of photocatalytic activities of supported catalysts on NaX zeolite or activated charcoal

Energy Technology Data Exchange (ETDEWEB)

Brites-Nóbrega, Fernanda F. de [Chemical Engineering Department, Universidade Estadual de Maringá (UEM), Av. Colombo, 5790, CEP 87020-900 Maringá, PR (Brazil); Sanitary and Environmental Engineering Department, Universidade Federal de Minas Gerais (UFMG), Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, MG (Brazil); Polo, Aldino N.B.; Benedetti, Angélica M. [Chemical Engineering Department, Universidade Estadual do Oeste do Paraná (UNIOESTE), Rua da Faculdade, 645, CEP 85903-000 Toledo, PR (Brazil); Leão, Mônica M.D. [Sanitary and Environmental Engineering Department, Universidade Federal de Minas Gerais (UFMG), Av. Antônio Carlos, 6627, Campus Pampulha, Belo Horizonte, MG (Brazil); Slusarski-Santana, Veronice, E-mail: veronice.santana@unioeste.br [Chemical Engineering Department, Universidade Estadual do Oeste do Paraná (UNIOESTE), Rua da Faculdade, 645, CEP 85903-000 Toledo, PR (Brazil); Fernandes-Machado, Nádia R.C. [Chemical Engineering Department, Universidade Estadual de Maringá (UEM), Av. Colombo, 5790, CEP 87020-900 Maringá, PR (Brazil)

2013-12-15

Highlights: • The synergic effect between ZnO and NaX was positive, which increased its activity. • The best results were obtained at pH 3 and 9 with ZnO/NaX and at pH 3 with Nb{sub 2}O{sub 5}/AC. • High degradation and considerable mineralization were attained with 10% ZnO/NaX. • ZnO and Nb{sub 2}O{sub 5} supported on NaX and AC are promising alternatives as photocatalysts. -- Abstract: This study aimed to evaluate the photocatalytic activity of ZnO and Nb{sub 2}O{sub 5} catalysts, both supported on NaX zeolite and activated charcoal (AC). The synergistic effect between oxide and support and the influence of solution pH (3, 7 and 9) on photocatalytic degradation of reactive blue 5G (C.I. 222) were analyzed. The catalysts Nb{sub 2}O{sub 5}/NaX, Nb{sub 2}O{sub 5}/AC and ZnO/NaX, ZnO/AC with 5 and 10% (wt%) were prepared by wet impregnation. The results showed that the catalysts exhibit quite different structural and textural properties. The synergic effect between ZnO and NaX support was higher than that with the activated charcoal, showing that these catalysts were more efficient. The most photoactive catalyst was 10% ZnO/NaX which showed 100% discoloration of the dye solution at pH 3, 7 and 9 after 0.5, 5 and 2 h of irradiation, respectively. The hydrolytic nature of zeolite favored the formation of surface hydroxyl radicals, which increased the activity of the photocatalyst. Thus, catalysts supported on NaX zeolite are promising for use in photocatalysis.

Fósforo microbiano em solos sob pastagem natural submetida à queima e pastejo

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Leandro Bittencourt de Oliveira

2011-10-01

Full Text Available Em ecossistemas de pastagens naturais deficientes em P disponível, a imobilização temporária do P na biomassa microbiana e sua posterior mineralização podem ser considerados mecanismo potencial de suprimento de P às plantas. O objetivo deste trabalho foi avaliar a influência da queima e do pastejo da vegetação campestre sobre a dinâmica do P no solo, com ênfase no conteúdo de P imobilizado na biomassa microbiana. Os tratamentos consistiram da associação do pastejo (presença ou ausência e da queima (ausência ou presença numa pastagem natural manejada há 13 anos com histórico de queimadas e de pastejo nas posições de relevo de encosta (Argissolo e de baixada (Planossolo. A queima e o pastejo foram arranjados em delineamento completamente casualizado com quatro repetições. Coletaram-se amostras de solo na camada de 0-10 cm em duas épocas, durante a estação de crescimento da pastagem natural, sempre logo após o pastejo. A carga animal utilizada foi calculada adotando-se uma taxa de utilização de 20-35 % da massa de forragem. Determinaram-se o teor de P armazenado na biomassa microbiana do solo, o teor de P total e o de P orgânico total. A análise estatística dos resultados foi baseada em análise de variância via testes de aleatorização. O teor de P microbiano do solo sob pastagem natural variou de 11,4 a 57,3 mg kg-1, representando, em média, 38 e 32 % do P orgânico total do solo, na primeira e na segunda coleta, respectivamente. O P imobilizado na biomassa microbiana constitui a reserva potencial de P capaz de suprir a demanda de espécies nativas nas pastagens naturais, além de ser indicador mais sensível que o teor de P orgânico total do solo para detectar as alterações promovidas pelo pastejo. O manejo das pastagens naturais com fogo diminui a amplitude do incremento de P microbiano decorrente do pastejo.

Culpa e prazer: imagens do consumo na cultura de massa

Directory of Open Access Journals (Sweden)

Everardo Rocha

2008-09-01

Full Text Available O objetivo deste artigo é estudar algumas das principais representações do consumo no senso comum e na cultura de massa. Essas representações tendem a classificar o consumo como algo hedonista, ou exercer sobre ele um discurso moralista, ou vê-lo como algo natural ou, ainda, como utilitário. Ao estudar as implica ções ideológicas dessas visões, este artigo pretende contribuir para o estudo do consumo como um sistema cultural central na sociedade moderno-contemporânea. Palavras-chave: Cultura e consumo; cultura de massa e ideologia; Teoria da comunicação; Antropologia do consumo. ABSTRACT The objective of this article is to study some of the main representations of consumption in the general sense and in mass culture. These representations tend to classify consumption as something hedonist, or answer to it with a moralistic rhetoric, or to see it as something natural or even as something utilitarian. While studying the ideological implications of these views, this article intends to contribute to the study of consumption as a central cultural system in the modern contemporary society. Keywords: Culture and consumption; mass culture and ideology; Theory of communication; Anthropology of consumption.

Intracellular Na(+) and metabolic modulation of Na/K pump and excitability in the rat suprachiasmatic nucleus neurons.

Science.gov (United States)

Wang, Yi-Chi; Yang, Jyh-Jeen; Huang, Rong-Chi

2012-10-01

Na/K pump activity and metabolic rate are both higher during the day in the suprachiasmatic nucleus (SCN) that houses the circadian clock. Here we investigated the role of intracellular Na(+) and energy metabolism in regulating Na/K pump activity and neuronal excitability. Removal of extracellular K(+) to block the Na/K pump excited SCN neurons to fire at higher rates and return to normal K(+) to reactivate the pump produced rebound hyperpolarization to inhibit firing. In the presence of tetrodotoxin to block the action potentials, both zero K(+)-induced depolarization and rebound hyperpolarization were blocked by the cardiac glycoside strophanthidin. Ratiometric Na(+) imaging with a Na(+)-sensitive fluorescent dye indicated saturating accumulation of intracellular Na(+) in response to pump blockade with zero K(+). The Na(+) ionophore monensin also induced Na(+) loading and hyperpolarized the membrane potential, with the hyperpolarizing effect of monensin abolished in zero Na(+) or by pump blockade. Conversely, Na(+) depletion with Na(+)-free pipette solution depolarized membrane potential but retained residual Na/K pump activity. Cyanide inhibition of oxidative phosphorylation blocked the Na/K pump to depolarize resting potential and increase spontaneous firing in most cells, and to raise intracellular Na(+) levels in all cells. Nonetheless, the Na/K pump was incompletely blocked by cyanide but completely blocked by iodoacetate to inhibit glycolysis, indicating the involvement of both oxidative phosphorylation and glycolysis in fueling the Na/K pump. Together, the results indicate the importance of intracellular Na(+) and energy metabolism in regulating Na/K pump activity as well as neuronal excitability in the SCN neurons.

Spatial distribution of Na+-K+-ATPase in dendritic spines dissected by nanoscale superresolution STED microscopy

Directory of Open Access Journals (Sweden)

Bondar Alexander

2011-01-01

Full Text Available Abstract Background The Na+,K+-ATPase plays an important role for ion homeostasis in virtually all mammalian cells, including neurons. Despite this, there is as yet little known about the isoform specific distribution in neurons. Results With help of superresolving stimulated emission depletion microscopy the spatial distribution of Na+,K+-ATPase in dendritic spines of cultured striatum neurons have been dissected. The found compartmentalized distribution provides a strong evidence for the confinement of neuronal Na+,K+-ATPase (α3 isoform in the postsynaptic region of the spine. Conclusions A compartmentalized distribution may have implications for the generation of local sodium gradients within the spine and for the structural and functional interaction between the sodium pump and other synaptic proteins. Superresolution microscopy has thus opened up a new perspective to elucidate the nature of the physiological function, regulation and signaling role of Na+,K+-ATPase from its topological distribution in dendritic spines.

Supercooling of aqueous NaCl and KCl solutions under acoustic levitation.

Science.gov (United States)

Lü, Y J; Wei, B

2006-10-14

The supercooling capability of aqueous NaCl and KCl solutions is investigated at containerless state by using acoustic levitation method. The supercooling of water is obviously enhanced by the alkali metal ions and increases linearly with the augmentation of concentrations. Furthermore, the supercooling depends on the nature of ions and is 2-3 K larger for NaCl solution than that for KCl solution in the present concentration range: Molecular dynamics simulations are performed to reveal the intrinsic correlation between supercoolability and microstructure. The translational and orientational order parameters are applied to quantitatively demonstrate the effect of ionic concentration on the hydrogen-bond network and ice melting point. The disrupted hydrogen-bond structure determines essentially the concentration dependence of supercooling. On the other hand, the introduced acoustic pressure suppresses the increase of supercooling by promoting the growth and coalescence of microbubbles, the effective nucleation catalysts, in water. However, the dissolved ions can weaken this effect, and moreover the degree varies with the ion type. This results in the different supercoolability for NaCl and KCl solutions under the acoustic levitation conditions.

Characteristics of injury and recovery of net NO3- transport of barley seedlings from treatments of NaCl

Science.gov (United States)

Klobus, G.; Ward, M. R.; Huffaker, R. C.

1988-01-01

The nature of the injury and recovery of nitrate uptake (net uptake) from NaCl stress in young barley (Hordeum vulgare L, var CM 72) seedlings was investigated. Nitrate uptake was inhibited rapidly by NaCl, within 1 minute after exposure to 200 millimolar NaCl. The duration of exposure to saline conditions determined the time of recovery of NO3- uptake from NaCl stress. Recovery was dependent on the presence of NO3- and was inhibited by cycloheximide, 6-methylpurine, and cerulenin, respective inhibitors of protein, RNA, and sterol/fatty acid synthesis. These inhibitors also prevented the induction of the NO3- uptake system in uninduced seedlings. Uninduced seedlings exhibited endogenous NO3- transport activity that appeared to be constitutive. This constitutive activity was also inhibited by NaCl. Recovery of constitutive NO3- uptake did not require the presence of NO3-.

Structure and properties of new natural cellulose fabrics from Cordia dichotoma

CSIR Research Space (South Africa)

Jayaramudu, J

2011-10-01

Full Text Available Natural cellulose fabrics were newly identified from the branches of the Cordia dichotoma. The structure of the fabrics was analysed by FTIR and X-ray diffraction. The net-like morphologies of the untreated, bleached and 5% NaOH (alkali) treated...

Analysis of the natural gas market in Fortaleza metropolitan region (Brazil); Analise do mercado de gas natural na regiao metropolitana de Fortaleza

Energy Technology Data Exchange (ETDEWEB)

Barroso, Carlos Andre M.; Rabelo, Clarice A.C.; Santana, Lana L.P.; Sucupira, Marcos L.L. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil)

2004-07-01

Natural gas has become one of the most important energy sources, as we can observe in most countries' energy sector, where its presence is very significant. In Brazil, natural gas corresponds to 7,5% of all energy Also available, and the government has plans to increase this number to 12% until 2010. However, in order to reach this goal, it is important to understand how market works, evaluating all the aspects that have some influence on it. This paper goal is to analyze the natural gas market in Fortaleza metropolitan region, emphasizing the industrial sector, the biggest consumer in Ceara State. The main aspects are characterized here, like professionals qualification in the area, service quality, from equipment and maintenance suppliers until gas distributors, legal aspects, and other factors that are also relevant to a possible future expansion of different natural gas market segments (industry, residence, commerce and transport). (author)

Synthesis of zeolites Na-A and Na-X from tablet compressed and calcinated coal fly ash

Science.gov (United States)

Hu, Tao; Gao, Wenyan; Liu, Xin; Zhang, Yifu; Meng, Changgong

2017-10-01

Zeolites Na-A and Na-X are important synthetic zeolites widely used for separation and adsorption in industry. It is of great significance to develop energy-efficient routines that can synthesize zeolites Na-A and Na-X from low-cost raw materials. Coal fly ash (CFA) is the major residue from the combustion of coal and biomass containing more than 85% SiO2 and Al2O3, which can readily replace the conventionally used sodium silicate and aluminate for zeolite synthesis. We used Na2CO3 to replace the expensive NaOH used for the calcination of CFA and showed that tablet compression can enhance the contact with Na2CO3 for the activation of CFA through calcination for the synthesis of zeolites Na-A and Na-X under mild conditions. We optimized the control variables for zeolite synthesis and showed that phase-pure zeolite Na-A can be synthesized with CFA at reactant molar ratio, hydrothermal reaction temperature and reaction time of 1.3Na2O: 0.6Al2O3: 1SiO2: 38H2O at 80°C for 6 h, respectively, while phase-pure zeolite Na-X can be synthesized at 2.2Na2O: 0.2Al2O3: 1SiO2: 88H2O at 100°C for 8 h, respectively. The composition, morphology, specific surface area, vibration spectrum and thermogravimetry of synthesized Na-A and Na-X were further characterized.

The CERES / NA45 experiment

CERN Multimedia

Laurent Guiraud

2000-01-01

Ceres is one of the second generation heavy ion experiments at CERN's SPS. It is dedicated to the study of electron-positron pairs in relativistic nuclear collisions. NA45 is one of the seven experiments (NA44, NA45, NA49, NA50, NA52, WA97/NA57 and WA98) involved in CERN's Heavy Ion programme which provided evidence for the existence of a new state of matter, the quark-gluon plasma. In this state, quarks, instead of being bound up into more complex particles such as protons and neutrons, are liberated and roam freely. Theory predicts that this state must have existed at about 10 microseconds after the Big Bang, before the formation of matter as we know it today.

The rapid-onset dystonia parkinsonism mutation D923N of the Na+, K+-ATPase alpha3 isoform disrupts Na+ interaction at the third Na+ site.

Science.gov (United States)

Einholm, Anja Pernille; Toustrup-Jensen, Mads S; Holm, Rikke; Andersen, Jens Peter; Vilsen, Bente

2010-08-20

Rapid-onset dystonia parkinsonism (RDP), a rare neurological disorder, is caused by mutation of the neuron-specific alpha3-isoform of Na(+), K(+)-ATPase. Here, we present the functional consequences of RDP mutation D923N. Relative to the wild type, the mutant exhibits a remarkable approximately 200-fold reduction of Na(+) affinity for activation of phosphorylation from ATP, reflecting a defective interaction of the E(1) form with intracellular Na(+). This is the largest effect on Na(+) affinity reported so far for any Na(+), K(+)-ATPase mutant. D923N also affects the interaction with extracellular Na(+) normally driving the E(1)P to E(2)P conformational transition backward. However, no impairment of K(+) binding was observed for D923N, leading to the conclusion that Asp(923) is specifically associated with the third Na(+) site that is selective toward Na(+). The crystal structure of the Na(+), K(+)-ATPase in E(2) form shows that Asp(923) is located in the cytoplasmic half of transmembrane helix M8 inside a putative transport channel, which is lined by residues from the transmembrane helices M5, M7, M8, and M10 and capped by the C terminus, recently found involved in recognition of the third Na(+) ion. Structural modeling of the E(1) form of Na(+), K(+)-ATPase based on the Ca(2+)-ATPase crystal structure is consistent with the hypothesis that Asp(923) contributes to a site binding the third Na(+) ion. These results in conjunction with our previous findings with other RDP mutants suggest that a selective defect in the handling of Na(+) may be a general feature of the RDP disorder.

Recikliranje plastenk na kreativen način

OpenAIRE

Pavlin, Suzana

2017-01-01

Plastenke, poleg ostalih plastičnih izdelkov, v zadnjih letih predstavljajo pravo katastrofo za okolje. Domnevamo, da se le redko kdo vpraša, kaj se zgodi z njo po tem, ko je iz nje zaužil še zadnjo kapljico vode. Plastenka je lahko kot večina ostalih komunalnih odpadkov ponovno uporabljena, reciklirana, sežgana ali odložena na deponijo. V primeru nespoštovanja Zakona o varstvu okolja pa pristane v naravi, pogosto v morju, kjer prav počasi razpada in negativno vpliva na celoten ekosistem. V d...

Plant Defensins NaD1 and NaD2 Induce Different Stress Response Pathways in Fungi

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Peter M. Dracatos

2016-09-01

Full Text Available Nicotiana alata defensins 1 and 2 (NaD1 and NaD2 are plant defensins from the ornamental tobacco that have antifungal activity against a variety of fungal pathogens. Some plant defensins interact with fungal cell wall O-glycosylated proteins. Therefore, we investigated if this was the case for NaD1 and NaD2, by assessing the sensitivity of the three Aspergillus nidulans (An O-mannosyltransferase (pmt knockout (KO mutants (An∆pmtA, An∆pmtB, and An∆pmtC. An∆pmtA was resistant to both defensins, while An∆pmtC was resistant to NaD2 only, suggesting NaD1 and NaD2 are unlikely to have a general interaction with O-linked side chains. Further evidence of this difference in the antifungal mechanism was provided by the dissimilarity of the NaD1 and NaD2 sensitivities of the Fusarium oxysporum f. sp. lycopersici (Fol signalling knockout mutants from the cell wall integrity (CWI and high osmolarity glycerol (HOG mitogen-activated protein kinase (MAPK pathways. HOG pathway mutants were sensitive to both NaD1 and NaD2, while CWI pathway mutants only displayed sensitivity to NaD2.

Glutamate Water Gates in the Ion Binding Pocket of Na(+) Bound Na(+), K(+)-ATPase

DEFF Research Database (Denmark)

Han, Minwoo; Kopec, Wojciech; Solov'yov, Ilia A

2017-01-01

III is always protonated. Glutamic acid residues in the three binding sites act as water gates, and their deprotonation triggers water entry to the binding sites. From DFT calculations of Na(+) binding energies, we conclude that three protons in the binding site are needed to effectively bind Na......The dynamically changing protonation states of the six acidic amino acid residues in the ion binding pocket of the Na(+), K(+) -ATPase (NKA) during the ion transport cycle are proposed to drive ion binding, release and possibly determine Na(+) or K(+) selectivity. We use molecular dynamics (MD......(+) from water and four are needed to release them in the next step. Protonation of Asp926 in site III will induce Na(+) release, and Glu327, Glu954 and Glu779 are all likely to be protonated in the Na(+) bound occluded conformation. Our data provides key insights into the role of protons in the Na...

Controlling Radiation Degradation of Natural Polymers for Industrial and Agricultural application

International Nuclear Information System (INIS)

Hegazy, E.A.; AbdEl-Rehim, H

2008-01-01

Radiation induced degradation technology is a new and promising application of ionizing radiation to develop viscose, pulp, paper, food preservation, pharmaceutical production, and natural bioactive agents industries. Controlling the degree of degradation, uniform molecular weight distribution, saving achieved in the chemicals (used in conventional methods) on a cost basis, and environmentally friendly process are the beneficial effects of using radiation technology in these industries. However, for some development countries such technology is not economic. Therefore, a great effort should be done to reduce the cost required for such technologies. One of the principle factors for reducing the cost is achieving the degradation at low irradiation doses. The addition of some additives such as potassium per-sulfate (KPS), ammonium per-sulfate (APS), or H 2O2 to natural polymers such as chitosan and Na-alginate during irradiation process accelerates their degradation. The highest degradation rate of polysaccharides obtained when APS was used. The end product of irradiated chitosan, and Na-alginate may be used as food additive or benefited in agricultural purposes. The prepared crosslinked copolymers possessed high and fast swelling properties in simulated urine media and the swelling ratios of CMC-Na /PAAm gels in urine are acceptable for diaper application. (author)

Salinity and cationic nature of irrigation water on castor bean cultivation

Directory of Open Access Journals (Sweden)

Geovani S. de Lima

Full Text Available ABSTRACT This study aimed to evaluate the water relations, cell damage percentage and growth of the castor bean cv. ‘BRS Energia’ as a function of salinity and cationic nature of the water used in irrigation. The experiment was conducted in drainage lysimeters under greenhouse conditions in eutrophic Grey Argisol of sandy loam texture. Six combinations of water salinity and cations were studied (S1 - Control; S2 - Na+, S3 - Ca2+, S4 - Na+ + Ca2+; S5 - K+ and S6 - Na+ + Ca2+ + Mg2+, in a randomized block design with four replicates. In the control (S1, plants were irrigated with 0.6 dS m-1 water, whereas the other treatments received 4.5 dS m-1 water, obtained by adding different salts, all in the chloride form. Higher relative water content in the leaf blade of plants irrigated with K+-salinized water associated with leaf succulence are indicative of tolerance of the castor bean cv. ‘BRS Energia’ to salinity. Saline stress negatively affected castor bean growth, regardless of cationic nature of water. Among the ions studied, ‘BRS Energia’ castor bean was more sensitive to the presence of sodium in the irrigation water, in terms of both water relations and leaf succulence.

Structural Stability and Electronic Properties of Na2C6O6 for a Rechargeable Sodium-ion Battery

Science.gov (United States)

Yamashita, Tomoki; Fujii, Akihiro; Momida, Hiroyoshi; Oguchi, Tamio

2014-03-01

Sodium-ion batteries have been explored as a promising alternative to lithium-ion batteries owing to a significant advantage of a natural abundance of sodium. Recently, it has been reported that disodium rhodizonate, Na2C6O6, exhibit good electrochemical properties and cycle performance as a minor-metal free organic cathode for sodium-ion batteries. However, its crystal structures during discharge/charge cycle still remain unclear. In this work, we theoretically propose feasible crystal structures of Na2+xC6O6 using first principles calculations. A structural phase transition has been found: Na4C6O6 has a different C6O6 packing arrangement from Na2C6O6. Electronic structures of Na2+xC6O6 during discharge/charge cycle are also discussed. Our predictions could be the key to understanding the discharge/charge process of Na2C6O6. Supported by MEXT program ``Elements Strategy Initiative to Form Core Rersearch Center'' (since 2012), MEXT; Ministry of Education Culture, Sports, Science and Technology, Japan.

NA62 and NA48/2 results on search for Heavy Neutral Leptons

Directory of Open Access Journals (Sweden)

Lamanna Gianluca

2018-01-01

Full Text Available In this paper we present new results on upper limits for the search of Heavy Neutral Leptons (HNL with data collected by NA48/2 (2003-2004, NA62-RK (2007 and NA62 (2015 CERN experiments. The data collected with different trigger configuration allow to search for both long and short living heavy neutrinos in the mass range below the kaon mass. In addition the status of the search for K+ → π+vv with the NA62 detector will be briefly presented.

Heteroaggregation of titanium dioxide nanoparticles with natural clay colloids.

Science.gov (United States)

Labille, Jérôme; Harns, Carrie; Bottero, Jean-Yves; Brant, Jonathan

2015-06-02

To better understand and predict the fate of engineered nanoparticles in the water column, we assessed the heteroaggregation of TiO2 nanoparticles with a smectite clay as analogues for natural colloids. Heteroaggregation was evaluated as a function of water salinity (10(-3) and 10(-1) M NaCl), pH (5 and 8), and selected nanoparticle concentration (0-4 mg/L). Time-resolved laser diffraction was used, coupled to an aggregation model, to identify the key mechanisms and variables that drive the heteroaggregation of the nanoparticles with colloids. Our data show that, at a relevant concentration, nanoparticle behavior is mainly driven by heteroaggregation with colloids, while homoaggregation remains negligible. The affinity of TiO2 nanoparticles for clay is driven by electrostatic interactions. Opposite surface charges and/or high ionic strength favored the formation of primary heteroaggregates via the attachment of nanoparticles to the clay. The initial shape and dispersion state of the clay as well as the nanoparticle/clay concentration ratio also affected the nature of the heteroaggregation mechanism. With dispersed clay platelets (10(-3) M NaCl), secondary heteroaggregation driven by bridging nanoparticles occurred at a nanoparticle/clay number ratio of greater than 0.5. In 10(-1) M NaCl, the clay was preaggregated into larger and more spherical units. This favored secondary heteroaggregation at lower nanoparticle concentration that correlated to the nanoparticle/clay surface area ratio. In this latter case, a nanoparticle to clay sticking efficiency could be determined.

A politicidade do cuidado na crítica aos estereótipos de gênero

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Maria Raquel Gomes Maia Pires

Full Text Available RESUMO Objetivos: analisar as desigualdades de gênero entre mulheres brasileiras em Portugal e na enfermagem moderna, a partir da politicidade do cuidado na perspectiva do gênero; explicitar a opressão sobre o feminino reproduzida pelos estereótipos que essencializam a mulher como cuidadora natural; apontar politicidades para a desconstrução dos estereótipos de gênero. Método: reflexão teórica com revisão narrativa de literatura com o propósito de analisar as referências clássicas da epistemologia feminista na articulação com a tese da politicidade do cuidado. Resultados: as similitudes entre os estereótipos das Evas-brasileiras e das Marias-portuguesas com a enfermeira sexualizada ou santificada se inscrevem na genealogia da moral judaico-cristã que reitera a subserviência do feminino ao masculino. Conclusão: ao priorizar um cuidado que precisa do descuidado para ampliar as possibilidades cuidativas, a premissa teórica da politicidade do cuidado pode contribuir para subverter as imagens essencializadas das brasileiras em solo lusitano e na enfermagem contemporânea.

Determination of boron in natural waters using atomic-absorption spectrometry with electrothermal atomization

International Nuclear Information System (INIS)

Usenko, S.I.; Prorok, M.M.

1992-01-01

A method of direct determination of boron in natural waters using atomic-absorption spectrometry with electrothermal atomization was developed. Concomitant elements Si, K, Mg, Na, present in natural waters in the concentration of 0.05-100 mg/cv 3 , do not produce effect on the value of boron atomic absorption. Boron determination limit constituted 0.02 mg/cm 3 for 25 ml of solution introduced

Natural and improved natural pastures on the reproductive performance of first-calf beef cows Pastagens naturais e melhoradas no desempenho reprodutivo de vacas de corte primíparas

Directory of Open Access Journals (Sweden)

Soraya Tanure

2011-03-01

Full Text Available This work evaluated the reproductive performance of first-calf cows at three years of age, submitted or not to protein supplementation at yearling on natural pastures. After calving, cows were managed on natural or improved pastures. The feeding managements were the following: on natural pastures as yearlings and during pregnancy, post-calving period and breeding season; on natural pastures with protein supplement as yearlings and only natural pasture during pregnancy, post-calving and breeding season; on natural pastures as yearlings and during pregnancy and on improved natural pastures (Lolium multiflorum L., Trifolium repens cv. Yi and Lotus corniculatus cv. São Gabriel during the post-calving period and breeding season; on natural pastures with protein supplement at yearling, on natural pastures during pregnancy, and on improved natural pasture during post-calving period and breeding season. Cows did not differ on body weight, but from calving to the beginning of breeding season, cows on improved natural pastures presented higher weight gain than those on natural pastures (0.203 vs. 0.109 kg/day. Cows in post-calving on natural pastures lost 1.0 point of body condition score during mating, determinant of the lowest pregnancy rate and later conception in relation to cows on improved natural pasture. Pregnant cows presented higher body weight (440 vs. 413 kg and body condition score (4.14 vs. 3.66 points than open cows at the end of the breeding season.O trabalho avaliou o desempenho reprodutivo de vacas primíparas aos três anos de idade, submetidas previamente ou não à suplementação protéica no sobreano sobre pastagens naturais. Após o parto, foram manejadas em pastagens naturais ou naturais melhoradas. Os manejos alimentares foram: em pastagem natural na recria e nos períodos de gestação, pós-parto e reprodutivo; em pastagem natural com suplemento protéico na recria e somente pastagem natural durante os períodos de gesta

Natural pozzolan-and granulated blast furnace slag-based binary geopolymers

Directory of Open Access Journals (Sweden)

Robayo, R. A.

2016-03-01

Full Text Available This study describes the synthesis at ambient temperature (25±3 °C of binary geopolymer systems based on natural volcanic pozzolan and granulated blast furnace slag. Na2SiO3 and NaOH were used as alkaline activators. The effects of the SiO2/Al2O3, Na2O/Al2O3 ratio and the amount of slag added (from 0 to 30% on the reaction kinetics, compressive strength and microstructure of the final product were studied. To characterise the geopolymer pastes, techniques such as X-ray diffraction (XRD, infrared spectroscopy (FTIR and scanning electron microscopy (SEM were used. The results indicate the possibility of obtaining a geopolymer cement with a compressive strength of up to 48.11 MPa after 28 days of curing at ambient temperature whose characteristics are comparable to those of commercial portland cement.Este trabajo describe la síntesis a temperatura ambiente (25±3 °C de sistemas geopoliméricos de tipo binario basados en una puzolana natural de origen volcánico y escoria siderúrgica de alto horno usando activadores alcalinos basados en la combinación de Na2SiO3 y NaOH. Se estudió el efecto de la relación SiO2/Al2O3, Na2O/Al2O3 y la cantidad de escoria adicionada en niveles entre el 0 y 30% sobre la cinética de reacción, la resistencia a la compresión y la microestructura del producto final. Para la caracterización de las pastas geopoliméricas se utilizaron técnicas como difracción de rayos X (DRX, espectroscopia infrarroja (FTIR y microscopia electrónica de barrido (MEB. Los resultados conseguidos revelan la posibilidad de obtener un cementante geopolimérico con una resistencia a la compresión de hasta 48,11 MPa a los 28 días de curado a temperatura ambiente cuyas características son comparables a las de un cemento portland comercial.

Transmural gradients in Na/K pump activity and [Na+]I in canine ventricle.

Science.gov (United States)

Gao, J; Wang, W; Cohen, I S; Mathias, R T

2005-09-01

There are well-documented differences in ion channel activity and action potential shape between epicardial (EPI), midmyocardial (MID), and endocardial (ENDO) ventricular myocytes. The purpose of this study was to determine if differences exist in Na/K pump activity. The whole cell patch-clamp was used to measure Na/K pump current (I(P)) and inward background Na(+)-current (I(inb)) in cells isolated from canine left ventricle. All currents were normalized to membrane capacitance. I(P) was measured as the current blocked by a saturating concentration of dihydro-ouabain. [Na(+)](i) was measured using SBFI-AM. I(P)(ENDO) (0.34 +/- 0.04 pA/pF, n = 17) was smaller than I(P)(EPI) (0.68 +/- 0.09 pA/pF, n = 38); the ratio was 0.50 with I(P)(MID) being intermediate (0.53 +/- 0.13 pA/pF, n = 19). The dependence of I(P) on [Na(+)](i) or voltage was essentially identical in EPI and ENDO (half-maximal activation at 9-10 mM [Na(+)](i) or approximately -90 mV). Increasing [K(+)](o) from 5.4 to 15 mM caused both I(P)(ENDO) and I(P)(EPI) to increase, but the ratio remained approximately 0.5. I(inb) in EPI and ENDO were nearly identical ( approximately 0.6 pA/pF). Physiological [Na(+)](i) was lower in EPI (7 +/- 2 mM, n = 31) than ENDO (12 +/- 3 mM, n = 29), with MID being intermediate (9 +/- 3 mM, n = 22). When cells were paced at 2 Hz, [Na(+)](i) increased but the differences persisted (ENDO 14 +/- 3 mM, n = 10; EPI 9 +/- 2 mM, n = 10; and MID intermediate, 11 +/- 2 mM, n = 9). Based on these results, the larger I(P) in EPI appears to reflect a higher maximum turnover rate, which implies either a larger number of active pumps or a higher turnover rate per pump protein. The transmural gradient in [Na(+)](i) means physiological I(P) is approximately uniform across the ventricular wall, whereas transporters that utilize the transmembrane electrochemical gradient for Na(+), such as Na/Ca exchange, have a larger driving force in EPI than ENDO.

Some studies about the NaCl:Ca2+ :Mn2+ and NaCl: Cd2+ :Mn2+ dosemeters

International Nuclear Information System (INIS)

Verdiguel G, H.; Flores J, C.; Camarillo G, E.; Espejel P, R.; Cabrera B, E.; Hernandez A, J.; Murrieta S, H.; Cruz Z, E.; Ramos B, S.; Negron, A.

2002-01-01

Nowadays, a great interest by counting with dosemeters of characteristics such as a high stability, of easy operation and easier production exists. Looking for a commitment with all these characteristics,a possibility to use the system NaCl: Ca 2+ :Mn 2+ and NaCl: Cd 2+ :Mn 2+ as dosemeters was studied. The studies were realized irradiating with gamma radiation from a 60 Co source. The crystals that were used as samples did not suffer any thermal treatment previous to irradiation. The supplied doses were 10, 30, 60, 100, 300, and 600 rads. 24 hours after irradiation the thermoluminescent response was obtained. In the case of the system NaCl: Ca 2+ :Mn 2+ several thermoluminescent bands were observed (BTL). Two concentrations of Mn 2+ with only one concentration of Ca 2+ (1%) were studied. For the case of the smaller concentration of Mn 2+ (0.1%) 4 BTL were observed, whereas for a greater concentration (0.3%) just 2 BTL were detected. The positions of the maximum of the BTL peaks differ for both concentrations, this possible due to what the nature of the traps for both cases differs by the type of precipitates present in the net. For the case of the system NaCl: Cd 2+ (1%) :Mn 2+ (0.1% and 0.5%) a similar situation to the previous was found, although in this case for both manganese concentrations just 2 BTL were observed; however all the peaks seem to be the superposition of several bands. Despite the apparent complexity of the thermoluminescent response, such response as function of the dose shows that both systems present a stable response to gamma radiation in the interval from 10 to 600 rads. In the case of calcium it is had a response of linear type of the Tl intensity depending on the dose, whereas for the cadmium system a supra linear response seems to exist. Nowadays, studies for determining the BTL origin being carried out. (Author)

Reactions of metal oxides with molten NaPO3 + NaCl mixtures

International Nuclear Information System (INIS)

Kovarskaya, E.N.; Mityakhina, V.S.; Rodionov, Yu.I.; Silin, M.Yu.

1988-01-01

We consider the dissolution mechanism for iron (III), europium(III), and tin(IV) oxides in molten NaPO 3 + NaCl that are responsible for the peak solubilities. We chose Fe 2 O 3 as the basic material since this occurs in large amounts around damaged metal structures in rock salt mines in a proposed zone for storing vitrified radioactive wastes. Solubility measurement and paper chromatography show that Fe 2 O 3 dissolves in molten NaPO 3 + NaCl in air by reaction with the solvent to give double iron and sodium diphosphates and monophosphates in accordance with the initial solution-in-the-melt composition, the degree of equilibration, and the temperature. The elevated solubilities for initial NaCl contents close to 30 mole % are due to sodium triphosphates and tricyclophosphates present in these melts. Moessbauer spectroscopy confirms that double iron, europium and tin diphosphates and monophosphates containing sodium occur in these chloride-polyphosphate melts

Na(+),K (+)-ATPase as a docking station: protein-protein complexes of the Na(+),K (+)-ATPase.

Science.gov (United States)

Reinhard, Linda; Tidow, Henning; Clausen, Michael J; Nissen, Poul

2013-01-01

The Na(+),K(+)-ATPase, or sodium pump, is well known for its role in ion transport across the plasma membrane of animal cells. It carries out the transport of Na(+) ions out of the cell and of K(+) ions into the cell and thus maintains electrolyte and fluid balance. In addition to the fundamental ion-pumping function of the Na(+),K(+)-ATPase, recent work has suggested additional roles for Na(+),K(+)-ATPase in signal transduction and biomembrane structure. Several signaling pathways have been found to involve Na(+),K(+)-ATPase, which serves as a docking station for a fast-growing number of protein interaction partners. In this review, we focus on Na(+),K(+)-ATPase as a signal transducer, but also briefly discuss other Na(+),K(+)-ATPase protein-protein interactions, providing a comprehensive overview of the diverse signaling functions ascribed to this well-known enzyme.

Characterization of Na+-linked and Na+-independent Cl-/HCO3- exchange systems in Chinese hamster lung fibroblasts

International Nuclear Information System (INIS)

Cassel, D.; Scharf, O.; Rotman, M.; Cragoe, E.J. Jr.; Katz, M.

1988-01-01

The PS120 variant of Chinese hamster lung fibroblasts which lacks Na + /H + exchange activity was used to investigate bicarbonate transport systems and their role in intracellular pH (pH/sub i/) regulation. When pH/sub i/ was decreased by acid load, bicarbonate caused pH/sub i/ increase and stimulated 36 Cl - efflux from the cells, both in a Na + -dependent manner. These results together with previous findings that bicarbonate stimulates 22 Na + uptake in PS120 cells demonstrate the presence of a Na + -linked Cl - /HCO 3 - exchange system. In cells with normal initial pH/sub i/, bicarbonate caused Na + -independent pH/sub i/ increase in Cl - -free solutions and stimulated Na + -independent 36 Cl - efflux, indicating that a Na + -independent Cl - /HCO 3 - exchanger is also present in the cell. Na + -linked and Na + -independent Cl - /HCO 3- exchange is apparently mediated by two distinct systems, since a [(tetrahydrofluorene-7-yl)oxy]acetic acid derivative selectively inhibits the Na + -independent exchanger. An additional distinctive features is a 10-fold lower affinity for chloride of the Na + -linked exchanger. The Na + -linked and Na + -independent Cl - /HCO 3 - exchange systems are likely to protect the cell from acid and alkaline load, respectively

NaA zeolite derived from blast furnace slag: its application for ammonium removal.

Science.gov (United States)

Guo, Hongwei; Tang, Lizhen; Yan, Bingji; Wan, Kang; Li, Peng

2017-09-01

In this paper, high value added NaA zeolite material was prepared from blast furnace (BF) slag by hydrothermal method and its adsorption behavior on the removal of ammonium ion was investigated. It was found out that the synthetic NaA cubic zeolite with smaller crystal size obtained at nSiO 2 /nAl 2 O 3 = 2 and nH 2 O/nNaOH = 20 showed better adsorption performance. The kinetics of the adsorption of ammonium ion by synthesized NaA zeolite was fitted by the pseudo-second-order kinetic model. The intra-particle diffusion modeling reveals that two mixed rate-controlling mechanisms were involved in the adsorption process. The relatively high value of activation energy of 92.3 kJ·mol -1 indicates a high impact of temperature on the adsorption rate, and the nature of ammonium adsorption is chemical reaction rather than physisorption. Based on the thermodynamics calculations, the adsorption of ammonium was found to be an endothermic, spontaneous process. The adsorption isothermal analysis showed that the Langmuir model could be well fitted and a maximum adsorption capacity of 83.3 mg·g -1 of NH 4 + was obtained. Thus, it was demonstrated that by forming low cost NaA zeolite and using it for environmental remediation, the synchronous minimization of BF slag and ammonia nitrogen contamination could be achieved.

NaDeA: A Natural Deduction Assistant with a Formalization in Isabelle

DEFF Research Database (Denmark)

Villadsen, Jørgen; Jensen, Alexander Birch; Schlichtkrull, Anders

2017-01-01

We present a new software tool for teaching logic based on natural deduction. Its proof system is formalized in the proof assistant Isabelle such that its definition is very precise. Soundness of the formalization has been proved in Isabelle. The tool is open source software developed in TypeScript...

NaDeA: A Natural Deduction Assistant with a Formalization in Isabelle

DEFF Research Database (Denmark)

Villadsen, Jørgen; Jensen, Alexander Birch; Schlichtkrull, Anders

2015-01-01

We present a new software tool for teaching logic based on natural deduction. Its proof system is formalized in the proof assistant Isabelle such that its definition is very precise. Soundness of the formalization has been proved in Isabelle. The tool is open source software developed in TypeScript...

Half-metallicity and giant magneto-optical Kerr effect in N-doped NaTaO3

KAUST Repository

Saeed, Yasir

2012-09-01

We use density functional theory and the modified Becke-Johnson (mBJ) approach to analyze the electronic and magneto-optical properties of N-doped NaTaO 3. The mBJ results show a half-metallic nature of NaTaO 2N, in contrast to the generalized gradient approximation. We find a giant polar Kerr rotation of 2.16°at 725 nm wave length (visible region), much higher than in other half-metallic perovskites and the prototypical half-metal PtMnSb. We explain the physical origin of this unexpected property. © 2012 Elsevier B.V. All rights reserved.

Removal of Na+ from Ionic Liquids by Zeolite for High Quality Electrolyte Manufacture

International Nuclear Information System (INIS)

Cho, Wonje; Seo, Yongseong; Jung, Soon Jae; Lee, Won Gil; Kim, Byung Chul; Yu, Kookhyun

2013-01-01

This study develops a novel method to remove the free cations created during the synthesis of ionic liquid. The cations are removed from the ionic liquid by size-selective adsorption onto chemically surface-modified Zeolite. The porous crystal nano-structure of Zeolite has several electron-rich Al sites to attract cations. While large cations of an ionic liquid cannot access the Zeolite nano-structure, small cations like Na + have ready access and are adsorbed. This study confirms that: Na + can be removed from ionic liquid effectively using Zeolite; and, in contrast to the conventional and extensively applied ion exchange resin method or solvent extraction methods, this can be done without changing the nature of the ionic liquid

Na/K Pump and Beyond: Na/K-ATPase as a Modulator of Apoptosis and Autophagy

Directory of Open Access Journals (Sweden)

Cassiano Felippe Gonçalves-de-Albuquerque

2017-04-01

Full Text Available Lung cancer is a leading cause of global cancer deaths. Na/K-ATPase has been studied as a target for cancer treatment. Cardiotonic steroids (CS trigger intracellular signalling upon binding to Na/K-ATPase. Normal lung and tumour cells frequently express different pump isoforms. Thus, Na/K-ATPase is a powerful target for lung cancer treatment. Drugs targeting Na/K-ATPase may induce apoptosis and autophagy in transformed cells. We argue that Na/K-ATPase has a role as a potential target in chemotherapy in lung cancer treatment. We discuss the effects of Na/K-ATPase ligands and molecular pathways inducing deleterious effects on lung cancer cells, especially those leading to apoptosis and autophagy.

Na/K Pump and Beyond: Na/K-ATPase as a Modulator of Apoptosis and Autophagy.

Science.gov (United States)

Felippe Gonçalves-de-Albuquerque, Cassiano; Ribeiro Silva, Adriana; Ignácio da Silva, Camila; Caire Castro-Faria-Neto, Hugo; Burth, Patrícia

2017-04-21

Lung cancer is a leading cause of global cancer deaths. Na/K-ATPase has been studied as a target for cancer treatment. Cardiotonic steroids (CS) trigger intracellular signalling upon binding to Na/K-ATPase. Normal lung and tumour cells frequently express different pump isoforms. Thus, Na/K-ATPase is a powerful target for lung cancer treatment. Drugs targeting Na/K-ATPase may induce apoptosis and autophagy in transformed cells. We argue that Na/K-ATPase has a role as a potential target in chemotherapy in lung cancer treatment. We discuss the effects of Na/K-ATPase ligands and molecular pathways inducing deleterious effects on lung cancer cells, especially those leading to apoptosis and autophagy.

Subnitride chemistry: A first-principles study of the NaBa3N, Na5Ba3N, and Na16Ba6N phases

International Nuclear Information System (INIS)

Oliva, Josep M.

2005-01-01

An ab initio study on the electronic structure of the subnitrides NaBa 3 N, Na 5 Ba 3 N, and Na 16 Ba 6 N is performed for the first time. The NaBa 3 N and Na 5 Ba 3 N 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 16 Ba 6 N 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(5p) electrons in the lower energy region for NaBa 3 N and Na 5 Ba 3 N. However, no dispersion is observed for the N(2s) and Ba(5p) bands in the cubic phase Na 16 Ba 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 l 6s m 6p n barium orbitals which interact with hybridized 3s n 3p 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 1 ∞ [NBa 6/2 ] strands of the NaBa 3 N and Na 5 Ba 3 N phases, and within the isolated [NBa 6 ] octahedra of the Na 16 Ba 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 16 Ba 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

Ion exchange reactions of major inorganic cations (H+, Na+, Ca2+, Mg2+ and K+) on beidellite: Experimental results and new thermodynamic database. Toward a better prediction of contaminant mobility in natural environments

International Nuclear Information System (INIS)

Robin, Valentin; Tertre, Emmanuel; Beaufort, Daniel; Regnault, Olivier; Sardini, Paul; Descostes, Michael

2015-01-01

Highlights: • Multi-site ion exchange model for beidellite for Na + , Ca 2+ , Mg 2+ , K + and H + . • Validity over the 1–7 pH range and total normality >5 × 10 −3 mol/L. • Application to equilibrium between smectite and acidic solution from mining sites. • Impact of crystal chemistry of smectites on their sorption properties. - Abstract: To our knowledge, no thermodynamic database is available in the literature concerning ion-exchange reactions occurring in low-charge smectite with tetrahedral charge (beidellite). The lack of this information makes it difficult to predict the mobility of contaminants in environments where beidellite and major cations, which act as competitors with contaminants for sorption on the clay phase, are present. The present study proposes a multi-site ion exchange model able to describe experimental data obtained for H + and the four major cations (Na + , Ca 2+ , Mg 2+ and K + ) found in natural waters interacting with a <0.3 μm size fraction of Na-beidellite. The nature of the sites involved in the sorption processes is assessed using qualitative structural data. Moreover, the effect of the charge location in the smectite on the selectivity coefficient values is discussed by comparison with the results reported in the literature for smectite characterized by octahedral charge (montmorillonite). The new thermodynamic database proposed in this study is based on the same total sorption site density and distribution of sites regardless of the cations investigated. This database is valid for a large range of physico-chemical conditions: a [1–7] pH range, a total normality higher than 5 × 10 −3 mol/L corresponding to a flocculated state for water/clay systems, and when sorption of ions pairs can be neglected. Note that this study provides evidence that a thermodynamic database describing ion exchange reactions between H + and the four major cations of natural water for smectite cannot be valid irrespective of the total

WPŁYW WIEKU NA WYTRZYMAŁOŚĆ NA ŚCISKANIE BETONU MODYFIKOWANEGO DODATKIEM METAKAOLINITU

Directory of Open Access Journals (Sweden)

Janusz KONKOL

Full Text Available W artykule przedstawiono wyniki badań wytrzymałości na ściskanie betonów modyfikowanych dodatkiem metakaolinitu po 2, 3, 7, 14, 28 i 56 dniach dojrzewania. Dodatek metakaolinitu użyto jako częściowy substytut cementu, dokonując wymiany 10% masy cementu na metakaolinit. Udział ten uznawany jest za optymalny z uwagi na inne niż wytrzymałość na ściskanie właściwości betonu, w tym trwałość betonu modyfikowanego metakaolinitem. Badania przeprowadzono także dla betonu tła, betonu bez dodatku metakaolinitu. Betony wykonano przy założeniu stałego stosunku woda/spoiwo, względnie woda/cement wynoszącego 0,45 oraz przy użyciu cementu portlandzkiego CEM I 32,5R, piasku kwarcowego frakcji do 2 mm oraz grysu bazaltowego frakcji do 16 mm. W celu uzyskania pożądanej konsystencji mieszanki betonowej zastosowano upłynniacz na bazie estrów polikarboksylowych. Uzyskane rezultaty badań potwierdziły wysoką aktywność pucolanową metakaolinitu już we wczesnym okresie dojrzewania betonu. W okresie między 3 a 7 dniem dojrzewania stwierdzono wolniejszy przyrost wytrzymałości na ściskanie w betonie niemodyfikowanym metakaolinitem, podczas gdy w betonie, w którym 10% masy cementu zastąpiono metakaolinitem uwidocznił się znaczący przyrost wytrzymałości na ściskanie. Po 2 dniach dojrzewania wytrzymałość na ściskanie betonu tła była nieznacznie wyższa od wytrzymałości na ściskanie betonu modyfikowanego. Korzystny wpływ dodatku metakaolinitu wynikający z jego wysokiej aktywności pucolanowej, jak również z uszczelniającego charakteru tego dodatku obserwowano jest zwłaszcza w okresie między 3 a 14 dniem dojrzewania. W tym okresie obserwowano znaczny przyrost wytrzymałości na ściskanie betonu modyfikowanego w porównaniu z wytrzymałością na ściskanie betonu tła. Po 7 i 14 dniach dojrzewania stwierdzono odpowiednio prawie 25% i 21% wzrost wytrzymałości na ściskanie na skutek użycia metakaolinitu.

The importance of flexibility in supply and demand in the natural gas market - The Brazilian case; A importancia da flexibilidade na oferta e na demanda de gas natural - o caso do mercado brasileiro

Energy Technology Data Exchange (ETDEWEB)

Almeida, Jose Ricardo Uchoa Cavalcanti

2008-05-15

The objective of this dissertation is to identify and discuss the main tools in implementing flexibility in supply and demand in the natural gas market, as well as highlight those which are the most appropriate for the Brazilian market. Flexibility, in this context, means the ability to guarantee a balance of supply versus demand without deficits, considering, mainly, the seasonal variations (winter-summer). From there, the study analyzes these flexibility tools in detail. Next, it discusses which of these flexibility tools are currently being used in more mature foreign markets and which tools could be feasibly applied to the Brazilian market. This dissertation also addresses how the natural gas thermoelectric market in Brazil shows a wide range of seasonality due to this segment's nature of complementing the Brazilian hydroelectric complex. This occurs because the capacity to generate hydroelectricity depends on rainfall for supplying reservoirs. Because of this interdependence, it examines how each the natural gas industry and the power industry operate, and their convergence. The flexibility tools which are already implemented here in Brazil are then presented. Finally, additional relevant new concepts and information are discussed to support the conclusions and final comments about the flexibility tools evolution and new applications. (author)

The importance of flexibility in supply and demand in the natural gas market - The Brazilian case; A importancia da flexibilidade na oferta e na demanda de gas natural - o caso do mercado brasileiro

Energy Technology Data Exchange (ETDEWEB)

Almeida, Jose Ricardo Uchoa Cavalcanti

2008-05-15

The objective of this dissertation is to identify and discuss the main tools in implementing flexibility in supply and demand in the natural gas market, as well as highlight those which are the most appropriate for the Brazilian market. Flexibility, in this context, means the ability to guarantee a balance of supply versus demand without deficits, considering, mainly, the seasonal variations (winter-summer). From there, the study analyzes these flexibility tools in detail. Next, it discusses which of these flexibility tools are currently being used in more mature foreign markets and which tools could be feasibly applied to the Brazilian market. This dissertation also addresses how the natural gas thermoelectric market in Brazil shows a wide range of seasonality due to this segment's nature of complementing the Brazilian hydroelectric complex. This occurs because the capacity to generate hydroelectricity depends on rainfall for supplying reservoirs. Because of this interdependence, it examines how each the natural gas industry and the power industry operate, and their convergence. The flexibility tools which are already implemented here in Brazil are then presented. Finally, additional relevant new concepts and information are discussed to support the conclusions and final comments about the flexibility tools evolution and new applications. (author)

Teratological studies of DTPA-CaNa3, DTPA-ZnNa3 and quinamic acid in mice

International Nuclear Information System (INIS)

Luo Meichu; Ruan Tianming; Tong Shungao

1989-01-01

DTPA-CaNa 3 , DTPA-ZnNa 3 and quinamic acid are effective chelating agents for removing actinide elements from the body. In this experiment, different doses of DTPA-CaNa 3 , DTPA-ZnNa 3 and quinamic acid were given to mice on gestation days 6-10. Eight groups of mice received 0.8 and 2.0 mM/kg of DTPA-CaNa 3 , 3.8, 7.6, and 11.4 mM/kg of DTPA-ZnNa 3 and 0.42, 2.1, and 4.2 mM/kg of quinamic acid. Hypetonic saline and isotonic saline were given to two control groups. DTPA-CaNa 3 and quinamidic acid were found to be much more toxic to fetus of mice than DTPA-ZnNa 3 . When the doses of DTPA-CaMa 3 and quinamidic acid were 20 times higher than the human dose, the number of resorbed fetus was increased and the number and weight of live fetus were reduced. The result of injection with 7.6 mM/kg (200 times of human dose)DTPA-ZnNa 3 and that of injection with isotonic saline are the same. Therefore, we suggest that the DTPA-CaNa 3 and quinamidic acid should not be given to pregnant woman, if chelation therapy is needed, while the much safer DTPA-ZnNa 3 could be used

[Different NaCl-dependence of the circadian CO2-gas-exchange of some halophil growing coastal plants].

Science.gov (United States)

Treichel, Siegfried; Bauer, Peter

1974-03-01

CO 2 -exchange, diurnal changes in malate- and ion concentrations of the halophytes Carpobrotus edulis, Crithmum maritimum, Mesembryanthemum nodiflorum, Salicornia fruticosa, Suaeda maritima, and Trifolium fragiferum were investigated after culture at different NaCl concentrations. In Carp. edulis and Mes. nodiflorum the diurnal rhythm of CO 2 -exchange is in accordance with that of crassulacean acid metabolism (CAM), in Sal. fruticosa, Crithm. maritimum, Suaeda maritima, and Trif. fragiferum with that of Benson-Calvin metabolism (C 3 ). Malate concentration and CO 2 uptake in the sap latter group are not influenced. On the other hand, Carp. edulis and Mes. nodiflorum show an accumulation of malate during the night, which can be interpreted as a further indication of CAM.The two species most resistant to NaCl, Carp. edulis and Sal. fruticosa, greatly differ very much in their NaCl content. NaCl concentration in Salicornia is four times higher than in Carpobrotus.The different metabolic properties studied might be of ecological importance for the plants in their natural habitats. The effect of NaCl on metabolic processes is discussed.

Na-ion dynamics in Quasi-1D compound NaV2O4

International Nuclear Information System (INIS)

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

2014-01-01

We have used the pulsed muon source at ISIS to study high-temperature Na-ion dynamics in the quasi-one-dimensional (Q1D) metallic antiferromagnet NaV 2 O 4 . By performing systematic zero-field and longitudinal-field measurements as a function of temperature we clearly distinguish that the hopping rate increases exponentially above T diff ≈ 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 T diff . 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 NaV 2 O 4 and related compounds in energy related applications

A topofilia dos cidadãos para com o patrimônio natural urbano: O caso da cidade de Coimbra The citizens topophilia and the natural urban patrimony: Coimbra’s case study

Directory of Open Access Journals (Sweden)

Gabriel Salles Maria de Macedo Rego

2012-07-01

Full Text Available O trabalho em questão analisa, segundo o prisma da Geografia, a importância do patrimônio natural em ambiente urbano. Como objetivo principal, pretende compreender a percepção que os residentes na cidade de Coimbra (Portugal têm da natureza e do papel que o património natural pode desempenhar na qualidade de vida da cidade. Para alcançar esses objetivos, inicia-se o texto com uma reflexão teórica que percorre conceitos como a topofilia e os olhares sociais sobre o ambiente e a natureza em contexto citadino. Depois, seguem-se dois procedimentos diferentes, mas complementares: (1 Como forma de registro da presença e do estado de conservação da natureza em Coimbra e da interação entre os cidadãos e o patrimônio natural naquele espaço geográfico, fez-se uma análise de campo com a montagem de um banco de dados fotográficos que representam excertos deste território; (2 Inquéritos por meio de entrevistas, em dois bairros da cidade – Vale das Flores e Monte Formoso – privilegiando adultos com idades superiores aos 30 anos. Apesar de a pesquisa ter revelado algumas contradições entre a prática e o discurso na percepção e na relação topofílica para com as áreas verdes urbanas, concluiu-se que a presença do patrimônio natural no ambiente urbano ainda se apresenta como uma questão secundária. Contudo, também se verificou que, para reforço desta relação simbólica e/ou funcional, o patrimônio natural deve estar presente em todo o contínuo urbano e não ficar restrito aos bairros mais elitizados ou aos parques.This paper analyzes the importance of natural patrimony in the urban environment, under the prism of geography. The main objective of this study is to understand how nature is perceived in the city of Coimbra (Portugal and the role that green areas and natural patrimony has in the quality of urban life. To achieve these objectives, this article discusses the conceptual argument about environmental perception

Reference price of natural gas produced in Bacia dos Solimoes; Preco de referencia do gas natural produzido na Bacia do Solimoes

Energy Technology Data Exchange (ETDEWEB)

Valim, Leandro S.; Ferreira, Leticia P.; Correia, Irina S.; Guimaraes, Maria Jose de O.C.; Seidl, Peter R. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica; Bispo, Luiz Henrique de Oliveira [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica; Agencia Nacional do Petroleo, Gas Natural e Biocombustiveis (ANP), Rio de Janeiro, RJ (Brazil)

2012-07-01

Oil and natural gas are exhaustible resources. Thus, exploitation of these energy sources can lead to shortages and even the absence for future generations. In this context, royalties are included as a way to financially compensate future generations through a monthly payment made by the explorer. In Brazil, the control of the royalties and their distribution is charge of the National Agency of Petroleum, Natural Gas and Biofuels (ANP). Its function is to establish reference prices used for the payment of royalties on oil and natural gas. In this study, three methods were used to calculate royalties, using data from Leste do Urucu field, located in Solimoes Basin. The first one is imposed by Resolution ANP No. 40/2009 that uses the calculation of the reference price of natural gas produced in Brazil. The second one is an alternative method of calculating royalties produced by Bispo, 2011, considering the different compositions of the gas produced and injected. And finally, the Resolution ANP RD No. 983/2011 that uses the calculation of the price of gas injected, considering this as the price of gas processed. When performing the calculation of royalties through the proposed methodologies by Bispo, 2011, and the ANP (Resolution No. 40/2009 and RD 983/2011), the results were similar to each other, and the methodology proposed by Resolution No. 40/2009 was the most different from the others. (author)

Photoelectrochemical solar cell using extract of Eugenia jambolana Lam as a natural sensitizer

Directory of Open Access Journals (Sweden)

Christian G. Garcia

2003-06-01

Full Text Available The extract of Jambolão (java plum, Eugenia jambolana Lam, was used as a natural sensitizer of a wide band-gap semiconductor (TiO2 in photoelectrochemical solar cells. The natural dye, adsorbed onto the semiconductor surface, absorbs visible light and promotes electron transfer across the dye/semiconductor interface. Photogenerated current and voltage as high as 2.3 mA and 711 mV, respectively, were obtained and effective conversion of visible light into electricity was achieved. The use of a natural product as the semiconductor sensitizer enables a faster and simpler production of cheaper and environmentally friendly solar cells.O extrato de Jambolão, Eugenia jambolana Lam, foi utilizado como um sensibilizador natural de um semicondutor com separação grande de bandas (TiO2 nas células solares fotoeletroquímica. O corante natural, adsorvido na superfície do semicondutor, absorve luz visível e promove transferência eletrônica na interface corante/semicondutor. A corrente e o potencial fotogerados tão altos como 2,3 mA e 711 mV, respectivamente, foram obtidos observando-se conversão eficiente de luz visível em eletricidade. O uso de um produto natural como o sensibilizador de semicondutor possibilita uma produção mais rápida e simples de células solares mais baratas que não agridem o meio ambiente.

O Passeio Público do Rio de Janeiro na Literatura, na Pintura e na Fotografia do Século XIX

Directory of Open Access Journals (Sweden)

Solange de Aragão

2012-06-01

Full Text Available Este artigo tem como objetivo geral e mais amplo chamar a atenção dos pesquisadores para a importância da literatura, da pintura e da fotografia como fontes documentais para a construção da História do Paisagismo no Brasil por meio de um estudo de caso muito particular: o Passeio Público do Rio de Janeiro no século XIX. São objetivos específicos apresentar e analisar o modo como esse espaço livre público aparece na literatura, na pintura e na fotografia desse período, considerando suas transformações paisagísticas.

Solubility of NaNd(CO3)2.6H2O(c) in concentrated Na2CO3 and NaHCO3 solutions

International Nuclear Information System (INIS)

Rao, L.; Rai, D.; Felmy, A.R.; Fulton, R.W.; Novak, C.F.

1996-01-01

NaNd(CO 3 ) 2 x 6 H 2 O(c) was identified to be the final equilibrium solid phase in suspensions containing concentrated sodium carbonate (0.1 to 2.0 M) and sodium bicarbonate (0.1 to 1.0 M), with either NaNd(CO 3 ) 2 x 6 H 2 O(c) or Nd 2 (CO 3 ) 3 x xH 2 O(s) as initial solids. A thermodynamic model, based on Pitzer's specific into-interaction approach, was developed to interpret the solubility of NaNd(CO 3 ) 2 x 6 H 2 O(c) as functions of sodium carbonate and sodium bicarbonate concentrations. In this model, the solubility data of NaNd(CO 3 ) 2 x 6 H 2 O(c) were explained by assuming the formation of NdCO 3 + , Nd(CO 3 ) 2 - and Nd(CO 3 ) 3 3- species and invoking the specific ion interactions between Na + and Nd(CO 3 ) 3 3- . Ion interaction parameters for Na + -Nd(CO 3 ) 3 3- were developed to fit the solubility data. Based on the model calculations, Nd(CO 3 ) 3 3- was the predominant aqueous neodymium species in 0.1 to 2 M sodium carbonate and 0.1 to 1 M sodium bicarbonate solutions. The logarithm of the NaNd(CO 3 ) 2 x 6 H 2 O solubility product (NaNd(CO 3 ) 2 x 6 H 2 O(c)=Na + +Nd 3+ +2 CO 3 2- +6 H 2 O) was calculated to be -21.39. This model also provided satisfactory interpretation of the solubility data of the analogous Am(III) system in less concentrated carbonate and bicarbonate solutions. (orig.)

FREEZE-THAW AND FIRE RESISTANCE OF GEOPOLYMER MORTAR BASED ON NATURAL AND WASTE POZZOLANS

Directory of Open Access Journals (Sweden)

F.Nurhayat Degirmenci

2017-12-01

Full Text Available The purpose of this research was to investigate the resistance of pozzolan-based geopolymer mortars subjected to high temperatures and freeze-thaw cycles. Low calcium fly ash and granulated blast furnace slag as waste pozzolans and natural zeolite as a natural pozzolan were used as base materials for producing geopolymer mortar. The other purpose the research was to study the effect of alkaline activator ratio (Na₂SiO₃/NaOH on the performance of pozzolan-based geopolymer mortar specimens subjected to extreme temperatures. The influence of high temperatures on the properties of mortars was investigated at 300°C, 600°C, and 900°C. Fire and freeze-thaw and resistance of mortars were investigated in terms of visual appearance, weight loss and residual compressive strength. The minimal values of the residual compressive strength were obtained at 900°C for all mixtures. The residual compressive strength of all specimens was lower than the values obtained for specimens not subjected to any freeze-thaw resistance test, except those containing GGBS. The Na₂SiO₃/NaOH ratios of the alkaline activator solution used to prepare the geopolymer mortars have an effect on the weight losses and residual compressive strengths of the specimens subjected to high temperatures and freeze-thaw cycles. As the Na2SiO3/NaOH ratios increased, the weight and strength losses decreased.

Nature of weak inter- and intramolecular interactions in crystals. Communication 5. Interactions Na...H-B in a crystal of sodium salt of charge compensated nido-carborane [9-SMe2-7,8-C2B9H10]-

International Nuclear Information System (INIS)

Lysenko, K.A.; Golovanov, D.G.; Meshcheryakov, V.I.; Kudinov, A.R.; Antipin, M.Yu.

2005-01-01

The character of electron density distribution in the C 2 B 3 open face, the influence of the SMe 2 group on the character of electron density distribution, and the nature of the sodium-anion interaction were studied based on the data of high-resolution X-ray diffraction study of crystals of the sodium salt of charge-compensated nido-carborane [9-SMe 2 -7,8- C 2 B 9 H 10 ] - and quantum-chemical calculations for the Na...H-B-bonded dimer, the isolated [9-SMe 2 -7,8-C 2 B 9 H 10 ] - anion, and the [7,8-C 2 B 9 H 10 ] 2- dianion. The character of electron density distribution in the C 2 B 3 open face is analogous to the electron distribution in the cyclopentadienyl ligand. In nido-carborane, a substantial charge redistribution takes place compared to that observed in the closo analogs. The topological analysis of the electron density distribution function demonstrated that the cation-anion interactions are determined predominantly by Na...H-B contacts. The total energy of these contacts in the {[9-SMe 2 -7,8-C 2 B 9 H 10 ]Na(thf) 2 } 2 dimer estimated from X-ray diffraction data is 11.74 kcal mol -1 [ru

Monitoring of Natural Soil Radioactivity with Portable Gamma-Ray Spectrometers

DEFF Research Database (Denmark)

Bøtter-Jensen, Lars; Løvborg, Leif; Kirkegaard, Peter

1979-01-01

Two portable NaI(Tl) spectrometers with four energy windows were used for the recording of gamma-ray counts over soil and rock of differing natural radioactivity. The exposure rates at the field sites were simultaneously measured with a high-pressure argon ionization chamber. Background measureme......Two portable NaI(Tl) spectrometers with four energy windows were used for the recording of gamma-ray counts over soil and rock of differing natural radioactivity. The exposure rates at the field sites were simultaneously measured with a high-pressure argon ionization chamber. Background...... measurements at sea were carried out in order to estimate the non-terrestrial contributions to the instrument readings. Counts recorded in the three high-energy windows of the spectrometers were converted into radiometrically equivalent concentrations of thorium, uranium, and potassium in the ground. Large....... The theoretical exposure rates deducible from the experimental radioelement concentrations at the field sites were in good agreement both with the ionization-chamber readings (corrected for cosmic-ray background) and with the exposure rates measured by total gamma-ray counting. From this and other results...

Effect of the raw material type and the reaction time on the synthesis of halloysite based Zeolite Na-P1

Directory of Open Access Journals (Sweden)

Mahdi Meftah

Full Text Available Zeolites are currently one of the most important classes of inorganic materials because of their multiple applications not only as ions exchangers and molecular sieves, but also as catalysts. This works focus the synthesis and the characterization of Zeolite Na-P1 using halloysite (collected near Ain Khemouda, western Tunisia as the starting material. Two parameters, such as the host materials type (natural or treated and the reaction time, involved in the synthesis process are investigated. The intermediate phases and final products were characterized by X-ray diffraction, Infrared IR spectroscopy, scanning electron microscopy and high-resolution 29Si and 27Al MAS NMR. Obtained results show that the hydrothermal synthesis from natural and heated-halloysite leads to formation of homogenous Zeolite Na-P1. The difference in the crystallization/transformation time process is explained by the effect of the dissolution rate of the starting materials in sodium hydroxide solution. In the case of heated halloysite, the synthesis reaction with alkali solution occurs very readily and achieved without prior thermal activation at high temperature. The optimal conditions of Zeolite Na-P1 crystallization, from heated-halloysite, are reached at 120 °C. Keywords: Zeolite Na-P1, Halloysite, X-ray, FTIR spectroscopy, SEM, 29Si and 27Al MAS NMR spectroscopy

Determination of boron and lithium in diverse biological matrices using neutron activation-mass spectrometry (NA-MS)

International Nuclear Information System (INIS)

Iyengar, G.V.; Downing, R.G.; Clarke, W.B.

1990-01-01

Essential features of the neutron activation-mass Spectrometry (NA-MS) technique are described. Applicability of this technique for the simultaneous determination of boron and lithium is demonstrated for a diverse group of biomaterials. NA-MS is a nondestructive analytical technique, and dynamic in nature since its coverage extends to a broad range of concentration levels. Contamination after the irradiation step, extraneous by natural lithium or boron is inconsequential, since only the activation products are the analyted assayed. Coupling the nuclear activation phenomenon which generates 4 He and 3 He (from 10 B and 6 Li, respectively), with the high precision potential of mass spectrometry forms the bases of this technique. Under ideal conditions the detection limit is extendable to pg g -1 concentration ranges and therefore, it is extremely well suited to investigate the natural concentration levels of boron and lithium in biomaterials. The potential of this method for the determination of lithium in biomedical trace element research is of special significance since determination of sub-ppb levels of lithium by other analytical techniques faces serious analytical difficulties mainly due to contamination control and in some cases to insufficiently low detection limits. (orig.)

Dependence of chlorine isotope separation in ion exchange chromatography on the nature and concentration of the eluent

International Nuclear Information System (INIS)

Heumann, K.G.; Baier, K.

1980-01-01

In a heterogeneous electrolyte system of a strongly basic anion exchanger and solutions of NaBF 4 or NaClO 4 we established the influence of the nature and concentration of the eluent in chromatographic experiments on chlorine isotope separation. Results show that when the elctrolyte concentration is increased the degree of isotope separation decreases. With NaBF 4 the separation factor is greater than with NaClO 4 under conditions which are otherwise the same. For electrolyte solutions containing ClO 4 -, NO 3 - and BF 4 - there is a linear relation between the separation factor of the chlorine isotopes and the logarithm of the heat of anion hydration of the elution electrolyte. (orig.)

The effects of sulfur intercalation on the optical properties of artificial 'hackmanite', Na8[Al6Si6O24]Cl1.8S0.1; 'sulfosodalite', Na8[Al6Si6O24]S; and natural tugtupite, Na8

DEFF Research Database (Denmark)

Warner, Terence Edwin; Hutzen Andersen, Jan

2012-01-01

.8S0.1 destroys the tenebrescence and induces a permanently pale blue and, at higher temperature, a pale green coloration. The effect on Na8[Al6Si6O24]S induced similar colorations but of a deeper hue. Annealing tugtupite, Na8[Be2Al2Si8O24](Cl,S)2-x under a sulfur atmosphere over the range 600-700 °C......, destroyed the tenebrescence and resulted in a colourless tugtupite; but did not effect the photoluminescence. This suggests that the chemical species responsible for the tenebrescence in tugtupite is unlikely to be the same as that for the luminescence....

Mechanism of μ-conotoxin PIIIA binding to the voltage-gated Na+ channel NaV1.4.

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Rong Chen

Full Text Available Several subtypes of voltage-gated Na+ (NaV channels are important targets for pain management. μ-Conotoxins isolated from venoms of cone snails are potent and specific blockers of different NaV channel isoforms. The inhibitory effect of μ-conotoxins on NaV channels has been examined extensively, but the mechanism of toxin specificity has not been understood in detail. Here the known structure of μ-conotoxin PIIIA and a model of the skeletal muscle channel NaV1.4 are used to elucidate elements that contribute to the structural basis of μ-conotoxin binding and specificity. The model of NaV1.4 is constructed based on the crystal structure of the bacterial NaV channel, NaVAb. Six different binding modes, in which the side chain of each of the basic residues carried by the toxin protrudes into the selectivity filter of NaV1.4, are examined in atomic detail using molecular dynamics simulations with explicit solvent. The dissociation constants (Kd computed for two selected binding modes in which Lys9 or Arg14 from the toxin protrudes into the filter of the channel are within 2 fold; both values in close proximity to those determined from dose response data for the block of NaV currents. To explore the mechanism of PIIIA specificity, a double mutant of NaV1.4 mimicking NaV channels resistant to μ-conotoxins and tetrodotoxin is constructed and the binding of PIIIA to this mutant channel examined. The double mutation causes the affinity of PIIIA to reduce by two orders of magnitude.

Muscle K+, Na+, and Cl- disturbances and Na+-K+ pump inactivation: implications for fatigue

DEFF Research Database (Denmark)

McKenna, Michael J; Bangsbo, Jens; Renaud, Jean-Marc

2008-01-01

(+)-ATPase activity during exercise stabilizes Na(+) and K(+) concentration gradients and membrane excitability and thus protects against fatigue. However, during intense contraction some Na(+)-K(+) pumps are inactivated and together with further ionic disturbances, likely precipitate muscle fatigue.......Membrane excitability is a critical regulatory step in skeletal muscle contraction and is modulated by local ionic concentrations, conductances, ion transporter activities, temperature, and humoral factors. Intense fatiguing contractions induce cellular K(+) efflux and Na(+) and Cl(-) influx......, causing pronounced perturbations in extracellular (interstitial) and intracellular K(+) and Na(+) concentrations. Muscle interstitial K(+) concentration may increase 1- to 2-fold to 11-13 mM and intracellular K(+) concentration fall by 1.3- to 1.7-fold; interstitial Na(+) concentration may decline by 10 m...

Route, mechanism, and implications of proton import during Na+/K+ exchange by native Na+/K+-ATPase pumps

Science.gov (United States)

Vedovato, Natascia

2014-01-01

A single Na+/K+-ATPase pumps three Na+ outwards and two K+ inwards by alternately exposing ion-binding sites to opposite sides of the membrane in a conformational sequence coupled to pump autophosphorylation from ATP and auto-dephosphorylation. The larger flow of Na+ than K+ generates outward current across the cell membrane. Less well understood is the ability of Na+/K+ pumps to generate an inward current of protons. Originally noted in pumps deprived of external K+ and Na+ ions, as inward current at negative membrane potentials that becomes amplified when external pH is lowered, this proton current is generally viewed as an artifact of those unnatural conditions. We demonstrate here that this inward current also flows at physiological K+ and Na+ concentrations. We show that protons exploit ready reversibility of conformational changes associated with extracellular Na+ release from phosphorylated Na+/K+ pumps. Reversal of a subset of these transitions allows an extracellular proton to bind an acidic side chain and to be subsequently released to the cytoplasm. This back-step of phosphorylated Na+/K+ pumps that enables proton import is not required for completion of the 3 Na+/2 K+ transport cycle. However, the back-step occurs readily during Na+/K+ transport when external K+ ion binding and occlusion are delayed, and it occurs more frequently when lowered extracellular pH raises the probability of protonation of the externally accessible carboxylate side chain. The proton route passes through the Na+-selective binding site III and is distinct from the principal pathway traversed by the majority of transported Na+ and K+ ions that passes through binding site II. The inferred occurrence of Na+/K+ exchange and H+ import during the same conformational cycle of a single molecule identifies the Na+/K+ pump as a hybrid transporter. Whether Na+/K+ pump–mediated proton inflow may have any physiological or pathophysiological significance remains to be clarified. PMID

Route, mechanism, and implications of proton import during Na+/K+ exchange by native Na+/K+-ATPase pumps.

Science.gov (United States)

Vedovato, Natascia; Gadsby, David C

2014-04-01

A single Na(+)/K(+)-ATPase pumps three Na(+) outwards and two K(+) inwards by alternately exposing ion-binding sites to opposite sides of the membrane in a conformational sequence coupled to pump autophosphorylation from ATP and auto-dephosphorylation. The larger flow of Na(+) than K(+) generates outward current across the cell membrane. Less well understood is the ability of Na(+)/K(+) pumps to generate an inward current of protons. Originally noted in pumps deprived of external K(+) and Na(+) ions, as inward current at negative membrane potentials that becomes amplified when external pH is lowered, this proton current is generally viewed as an artifact of those unnatural conditions. We demonstrate here that this inward current also flows at physiological K(+) and Na(+) concentrations. We show that protons exploit ready reversibility of conformational changes associated with extracellular Na(+) release from phosphorylated Na(+)/K(+) pumps. Reversal of a subset of these transitions allows an extracellular proton to bind an acidic side chain and to be subsequently released to the cytoplasm. This back-step of phosphorylated Na(+)/K(+) pumps that enables proton import is not required for completion of the 3 Na(+)/2 K(+) transport cycle. However, the back-step occurs readily during Na(+)/K(+) transport when external K(+) ion binding and occlusion are delayed, and it occurs more frequently when lowered extracellular pH raises the probability of protonation of the externally accessible carboxylate side chain. The proton route passes through the Na(+)-selective binding site III and is distinct from the principal pathway traversed by the majority of transported Na(+) and K(+) ions that passes through binding site II. The inferred occurrence of Na(+)/K(+) exchange and H(+) import during the same conformational cycle of a single molecule identifies the Na(+)/K(+) pump as a hybrid transporter. Whether Na(+)/K(+) pump-mediated proton inflow may have any physiological or

A data base for thermodynamic modeling of +III actinide solubility in concentrated Na-Cl-SO4-CO3-PO4 electrolytes

International Nuclear Information System (INIS)

Novak, C.F.; Crafts, C.C.; Dhooge, N.J.

1995-01-01

The literature contains thermodynamic parameters for describing the chemical behavior of the following: Am(III) in dilute NaHCO 3 media; Nd(III) in dilute to concentrated Na 2 CO 3 and NaHCO 3 media; Pu(III) in dilute to concentrated NaCl media; Nd(III)/Am(III) in dilute to concentrated Na 2 SO 4 media; and Am(III) in NaH 2 PO 4 media. We have combined this information into a thermodynamic data base for the general +III actinide, An(III), using the analogy for chemical behavior of f-elements in the same oxidation state. This internally consistent data base is based on equilibrium thermodynamics and the specific ion interaction activity coefficient formalism of Pitzer. This data base forms the basis for the prediction of potential Am(III) and Pu(III) dissolved concentrations in the concentrated natural brines associated with the Waste Isolation Pilot Plant (WIPP) in Southeastern New Mexico, USA

Extraction of natural coagulant from peanut seeds for treatment of turbid water

International Nuclear Information System (INIS)

Birima, A H; Desa, M N M; Muda, Z C; Hammad, H A

2013-01-01

This study investigates the potential of peanut seeds as an environmental friendly and natural coagulant for the treatment of high turbid water. The peanut seeds have been used after oil extraction; and the active coagulation component was extracted by distilled water and salt solution of different salt concentrations. The salts used were NaCl, KNO 3 , KCl, NH 4 Cl and NaNO 3 . Synthetic water with 200 NTU turbidity was used. Peanut extracted with NaCl (PC-NaCl) could effectively remove 92% of the 200 NTU turbidity using only 20 mg/l, while peanut seeds extracted with distilled water (PC-DW) could remove only 31.5% of the same turbidity with the same dosage. The coagulant dosage did not affected by the concentration of the salt solution, however, residual turbidity decreased with increasing the concentration of the salt; and the relationship was found to be a second order polynomial curve with R 2 of 0.9312. The other salts tested were also found to be good solvents to extract the active coagulation component with no much difference from NaCl solution in terms of efficiency.

Growth mechanism of NaClO 3 and NaBrO 3 crystals from aqueous ...

Indian Academy of Sciences (India)

A study of growth rates of NaClO3 and NaBrO3 has been carried out using a small growth cell by in situ observation. Normal growth rates of {100} faces of NaClO3 and {111} faces of NaBrO3 along ⟨ 110 ⟩ direction are measured under relatively high supersaturation ranging from 3–8%. In the initial stages of growth, {100}, ...

Rescue of Na+ affinity in aspartate 928 mutants of Na+,K+-ATPase by secondary mutation of glutamate 314.

Science.gov (United States)

Holm, Rikke; Einholm, Anja P; Andersen, Jens P; Vilsen, Bente

2015-04-10

The Na(+),K(+)-ATPase binds Na(+) at three transport sites denoted I, II, and III, of which site III is Na(+)-specific and suggested to be the first occupied in the cooperative binding process activating phosphorylation from ATP. Here we demonstrate that the asparagine substitution of the aspartate associated with site III found in patients with rapid-onset dystonia parkinsonism or alternating hemiplegia of childhood causes a dramatic reduction of Na(+) affinity in the α1-, α2-, and α3-isoforms of Na(+),K(+)-ATPase, whereas other substitutions of this aspartate are much less disruptive. This is likely due to interference by the amide function of the asparagine side chain with Na(+)-coordinating residues in site III. Remarkably, the Na(+) affinity of site III aspartate to asparagine and alanine mutants is rescued by second-site mutation of a glutamate in the extracellular part of the fourth transmembrane helix, distant to site III. This gain-of-function mutation works without recovery of the lost cooperativity and selectivity of Na(+) binding and does not affect the E1-E2 conformational equilibrium or the maximum phosphorylation rate. Hence, the rescue of Na(+) affinity is likely intrinsic to the Na(+) binding pocket, and the underlying mechanism could be a tightening of Na(+) binding at Na(+) site II, possibly via movement of transmembrane helix four. The second-site mutation also improves Na(+),K(+) pump function in intact cells. Rescue of Na(+) affinity and Na(+) and K(+) transport by second-site mutation is unique in the history of Na(+),K(+)-ATPase and points to new possibilities for treatment of neurological patients carrying Na(+),K(+)-ATPase mutations. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

The system NaVO3-Na2WO4-Na2W2O7

International Nuclear Information System (INIS)

Kazanbekov, V.R.; Gasanaliev, A.M.; Kazanbekov, R.G.

1994-01-01

Phase diagrams of sodium metavanadate-sodium ditungstate, sodium metavanadate-sodium tungstate systems and surface of primary crystallization of sodium metavabadate-sodium tungstate-sodium ditungstate system were studied. The system sodium metavanadate-sodium ditungstate is eutectic one. Compound NaVO 3 x2Na 2 WO 4 is formed in solid state in sodium metavanadate-sodium tungstate system. Liquidus surface of sodium metavanadate-sodium tungstate-sodium ditungstate is presented by three crystallization fields of initial components. Composition and melting point of ternary eutectics are determined

Summer sudden Na number density enhancements measured with the ALOMAR Weber Na Lidar

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D. Heinrich

2008-05-01

Full Text Available We present summer Na-densities and atmospheric temperatures measured 80 to 110 km above the Arctic Lidar Observatory for Middle Atmosphere Research (ALOMAR. The Weber Na Lidar is part of ALOMAR, located at 69° N in Norway, 150 km north of the Arctic Circle. The sun does not set here during the summer months, and measurements require a narrowband Faraday Anomalous Dispersion Optical Filter (FADOF.

We discuss an observed sudden enhancement in the Na number density around 22:00 UT on 1 to 2 June 2006. We compare this observation with previous summer measurements and find a frequent appearance of Na number density enhancements near local midnight. We describe the time of appearance, the altitude distribution, the duration and the strength of these enhancements and compare them to winter observations. We investigate possible formation mechanisms and, as others before, we find a strong link between these Na number density enhancements and sporadic E layers.

Summer sudden Na number density enhancements measured with the ALOMAR Weber Na Lidar

Directory of Open Access Journals (Sweden)

D. Heinrich

2008-05-01

Full Text Available We present summer Na-densities and atmospheric temperatures measured 80 to 110 km above the Arctic Lidar Observatory for Middle Atmosphere Research (ALOMAR. The Weber Na Lidar is part of ALOMAR, located at 69° N in Norway, 150 km north of the Arctic Circle. The sun does not set here during the summer months, and measurements require a narrowband Faraday Anomalous Dispersion Optical Filter (FADOF. We discuss an observed sudden enhancement in the Na number density around 22:00 UT on 1 to 2 June 2006. We compare this observation with previous summer measurements and find a frequent appearance of Na number density enhancements near local midnight. We describe the time of appearance, the altitude distribution, the duration and the strength of these enhancements and compare them to winter observations. We investigate possible formation mechanisms and, as others before, we find a strong link between these Na number density enhancements and sporadic E layers.

Solution dynamics of synthetic and natural polyelectrolytes

Science.gov (United States)

Krause, Wendy E.

Polyelectrolytes are abundant in nature and essential to life, and used extensively in industry. This work discussed two polyelectrolytes: sodium poly(2-acrylamido-2-methylpropanesulfonate) (NaPAMS), synthetic polyelectrolyte, and sodium hyaluronate (NaHA), a glycosaminoglycan. Rheological data of NaPAMS solutions of variable chain length and concentration were reported. A strong dependence of viscosity eta on chain length: eta ˜ M2.4 was found. The comparison of the rheological data with two proposed scaling theories (Dobrynin 1995, Witten 1987) forces the conclusion that neither theory is correct. A possible interpretation of the viscosity data falling between the predictions of the two scaling theories is that some chain rigidity may persist beyond the correlation length. A sample model for the conductivity of semidilute polyelectrolytes with no added salt was presented. The model correctly describes the logarithmic decrease of specific conductance observed for many polyelectrolytes at low concentration (below ca. 10-2M), and is in good agreement with data from NaPAMS solutions. NaHA in phosphate buffered saline behaves as a typical polyelectrolyte in the high-salt limit, as Newtonian viscosities are observed over a wide range of shear rates. There is no evidence of intermolecular hydrogen bonding causing gel formation in NaHA solutions without protein present. The viscosity of 3 mg/mL NaHA was measured in the presence of the selected anti-inflammatory agents. Of the seven additives investigated only (D)-penicillamine significantly altered the rheology of HA. (D)-Penicillamine dramatically reduced the viscosity of HA, probably by disrupting intramolecular hydrogen bonding. The plasma proteins albumin and gamma-globulins bind to HA in solution to form a weak reversible gel. The rheology and osmotic pressure of the simple model for synovial fluid, consisting of 3mg/mL NaHA, 11 mg/mL albumin, and 7 mg/mL gamma-globulins in phosphate buffered saline, were studied

Células natural killer e vigilância imunológica Natural killer cells and immune surveillance

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Mariana Jobim

2008-08-01

Full Text Available OBJETIVOS: Analisar a importância das células natural killer, de seus receptores killer immunoglobulin-like receptors e correspondentes genes (KIR na vigilância imunológica do organismo contra agentes infecciosos, transplantes de células-tronco hematopoiéticas, assim como sua participação na auto-imunidade. As características e o polimorfismo dos genes e receptores KIR na população brasileira serão descritos. FONTES DOS DADOS: Livros, artigos de revisão e artigos científicos recentes são citados e listados na bibliografia. A experiência pessoal é também apresentada. SÍNTESE DOS DADOS: Identificamos o perfil de genes e haplótipos KIR na população caucasóide brasileira, sendo de importância esse conhecimento para a análise da relação desse sistema com doenças. Examinamos 116 indivíduos doadores voluntários de medula óssea, identificando-se 32 genótipos e a presença de 51 e 49% de haplótipos A e B, respectivamente. Foi realizado estudo comparativo entre os nossos genótipos e os de outras populações. CONCLUSÕES: A imunidade inata é uma barreira antiinfecciosa de importância em pediatria. Ela atua de maneira independente da imunidade celular e humoral, sendo mais rápida que as demais fontes de proteção do organismo. Ao mesmo tempo, ela estimula os linfócitos T CD8 a agirem e amplificarem a rede de proteção imunológica. Entretanto, como na maioria das vezes em que a imunidade atua, ela também pode ser prejudicial, agredindo o organismo por mecanismos auto-imunes ou mesmo, na sua ausência, oferecer espaço aos agentes infecciosos para agirem de forma impune.OBJECTIVES: To analyze the importance of natural killer cells, their killer immunoglobulin-like receptors (KIR and genes in autoimmunity and in the immune surveillance against infectious agents and stem cells transplantation. The characteristics and polymorphisms of the KIR genes and receptors in the Brazilian population is described. SOURCES

Criptococose pulmonar: aspectos na tomografia computadorizada

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Silva Ana Carina Gamboa da

2003-01-01

Full Text Available A criptococose pulmonar é uma doença causada pelo Criptococcus neoformans, um fungo unimórfico que possui distribuição mundial, existindo na mesma forma tanto no seu habitat natural quanto em animais e humanos. A doença possui apresentações clínica e patológica variáveis e pode manifestar-se tanto em pacientes com a imunidade normal como em imunocomprometidos, que representam a maioria dos casos. Neste trabalho são analisados os aspectos encontrados nas tomografias computadorizadas do tórax de 14 pacientes com criptococose pulmonar confirmada. Os achados mais freqüentes na tomografia do tórax foram as massas e os nódulos pulmonares. Outros aspectos observados foram as áreas de escavação, as consolidações, o espessamento do interstício peribroncovascular e o reticulado difuso. Massa pulmonar foi o achado isolado mais comum (64,2%, seguido dos nódulos isolados ou múltiplos (35,7%. Doença pulmonar difusa foi vista em apenas 14,2% dos casos. Os lobos superiores foram os mais comprometidos, sendo a doença mais comum nas regiões anteriores. A tomografia do tórax permitiu avaliar com precisão o grau de comprometimento do parênquima pulmonar.

Muziki wa Hip Hop na Haki Za Kijamii: Dhima, Changamoto na ...

African Journals Online (AJOL)

Ni dhahiri kuwa haki za kijamii zinaweza kuwasilishwa kwa jamii pana kupitia sanaa ya hip hop. Makala haya basi, yanabainisha dhima na mchango wa muziki wa hip hop katika masuala ya haki za kijamii, yanafafanua changamoto za muziki huu katika kuwasilisha haki za kijamii na kutoa mapendekezo kwa makundi ...

Transcriptomic and functional analysis of NaCl-induced stress in Enterococcus faecalis.

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Margrete Solheim

Full Text Available The robust physiology of Enterococcus faecalis facilitates tolerance to various stresses. We here report the transcriptional response of E. faecalis V583 to growth in the presence of 6.5% NaCl. Among the early responses observed was an immediate down-regulation of mscL, accompanied by an up-regulation of genes predicted to be involved in uptake of extracellular potassium and glycine betaine. The high NaCl concentration also induced expression of chaperons and cell envelope related traits, such as the enterococcal polysaccharide antigen (epa locus. Functional genetic analysis revealed reduced salt stress resistance in both epaB and epaE mutants. The reduced salt resistance phenotype associated with the epaB mutant was restored by complementation, hence demonstrating a role of Epa in the physiological robustness of E. faecalis. Furthermore, we demonstrate that Epa confers increased resistance towards multiple cell envelope stress-inducing factors. Accordingly, these findings delineate a potential link between the robust nature of E. faecalis and its ability to perform as a human pathogen, and provide a new perspective on the mechanisms by which Epa contributes to virulence. Notably, the high NaCl concentration also resulted in strict repression of the gelE-sprE operon and impaired gelatinase activity. We demonstrate that NaCl antagonize the GBAP-pheromone dependent induction in a concentration dependent manner.

Effect of cation nature of zeolite on carbon replicas and their electrochemical capacitance

International Nuclear Information System (INIS)

Zhou, Jin; Li, Wen; Zhang, Zhongshen; Wu, Xiaozhong; Xing, Wei; Zhuo, Shuping

2013-01-01

Graphical abstract: Cation nature of zeolite influences the porosity, surface chemical properties of carbon replicas of zeolite, resulting in different electrochemical capacitance. Highlights: ► The porosity of carbon replica strongly depends on zeolite's effective pore size. ► The surface chemical properties influence by the cation nature of zeolite. ► The N-doping introduces large pseudo-capacitance. ► The HYC800 carbon showed a high capacitance of up to 312 F g −1 in 1 M H 2 SO 4 . ► The prepared carbons show good durability of galvanostatic cycle. -- Abstract: N-doped carbon replicas of zeolite Y are prepared, and the effect of cation nature of zeolite (H + or Na + ) on the carbon replicas is studied. The morphology, structure and surface properties of the carbon materials are investigated by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), N 2 adsorption, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FT-IR). The pore regularity, pore parameter and surface chemical properties of the carbons may strongly depend on the cation nature of the zeolite Y. The carbon replicas of zeolite HY (H-form of zeolite Y) possesses higher pore regularity and much larger surface area than those of zeolite NaY (Na-form of zeolite Y), while the latter carbons seem to possess higher carbonization degrees. Electrochemical measurements show a large faradaic capacitance related to the N- or O-containing groups for the prepared carbons. Owing to the large specific surface area, high pore regularity and heteroatom-doping, the HYC800 sample derived from zeolite HY presents very high gravimetric capacitance, up to 312.4 F g −1 in H 2 SO 4 electrolyte, and this carbon can operate at 1.2 V with good retention ratio in the range of 0.25 to 10 A g −1

Sequential growth of sandwiched NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb core–shell–shell nanoparticles for photodynamic therapy

Energy Technology Data Exchange (ETDEWEB)

Peng, Huang-Yong; Ding, Bin-Bin; Ma, Yin-Chu [Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology, Hefei 230009 (China); Sun, Shi-Qi [State Key Laboratory of Veterinary Etiological Biology and Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Lanzhou, Gansu 730046 (China); Tao, Wei [Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology, Hefei 230009 (China); Guo, Yan-Chuan [Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190 (China); Guo, Hui-Chen, E-mail: ghch-2004@hotmail.com [State Key Laboratory of Veterinary Etiological Biology and Key Laboratory of Animal Virology of Ministry of Agriculture, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Xujiaping 1, Lanzhou, Gansu 730046 (China); Yang, Xian-Zhu, E-mail: yangxz@hftu.edu.cn [Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology, Hefei 230009 (China); Qian, Hai-Sheng, E-mail: shqian@hfut.edu.cn [Department of Medical Materials and Rehabilitation Engineering, School of Medical Engineering, Hefei University of Technology, Hefei 230009 (China)

2015-12-01

Graphical abstract: The monodisperse elliptical NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb core–shell–shell nanoparticles have been synthesized successfully by a facile sequential growth process, which can be used as transducer for photodynamic therapy of cancer cells. - Highlights: • The NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb nanoparticles have been fabricated successfully. • The as-prepared nanoparticles show strong fluorescence excited at 980 or 808 nm. • The nanoparticles were transferred into the aqueous phase via a facile process. • Photosensitizers were loaded into the composites for photodynamic therapy. - Abstract: Upconversion (UC) nanostructures have attracted much interest for their extensive biological applications. In this work, we describe a sequential synthetic route to prepare sandwiched NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb core–shell upconversion nanoparticles. The as-prepared products were investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM, JEM 2100F), respectively. The as-prepared core–shell nanoparticles of NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb are composed of elliptical nanoparticles with a length of 80 nm and width of 42 nm, which show efficient upconversion fluorescence excited at 808 nm indicating the formation of core–shell–shell sandwiched nanostructures. In addition, the as-prepared sandwiched NaYF{sub 4}:Yb/Er@NaYF{sub 4}:Yb@NaNdF{sub 4}:Yb core–shell upconversion nanoparticles also show strong upconversion fluorescence excited at 980 nm. Amphiphilic mPEG{sub 2k}-b-PEBEP{sub 6K} copolymers (denoted as PPE) were chosen to transfer these hydrophobic UCNPs into the aqueous phase for biological application. In vitro photodynamic therapy of cancer cells show that the viability of cells incubated with the nanoparticles loaded with MC 540 was significantly lower as compared to the nanoparticles without photosensitizers exposed to NIR laser.

Intracellular Na+ regulation of Na+ pump sites in cultured vascular smooth muscle cells

International Nuclear Information System (INIS)

Allen, J.C.; Navran, S.S.; Seidel, C.L.; Dennison, D.K.; Amann, J.M.; Jemelka, S.K.

1989-01-01

Enzymatically dispersed cells from canine saphenous vein and femoral artery were grown in fetal calf serum and studied at day 0 (freshly dispersed) through confluence in primary culture. Intracellular Na levels (Nai), but not intracellular K (Ki), were increased after 24 h in culture and then decreased to a steady state by 4 days. Na+ pump site number [( 3 H] ouabain binding) increased through day 3 and remained elevated. Nai was still elevated at 2 days when the Na+ pump site number began to increase. Total pump turnover (maximum ouabain-inhibited 86 Rb uptake) reflected the increase in Na+ pump site number. These key events precede the observed increases in both protein production and cellular proliferation. If the same cells are maintained in defined medium, without fetal calf serum, Nai, Ki, and the number of [ 3 H]ouabain binding sites do not change with time. These data are consistent with the suggestion that the initial mitogenic response of vascular smooth muscle cells to fetal calf serum involves an increased Na+ influx, and a Nai accumulation, caused by low Na+ pump density. The synthesis of new pump sites effects a decrease in the accumulated Nai, which may be related to cell proliferation

On the Stability of NaO2 in Na-O2 Batteries.

Science.gov (United States)

Liu, Chenjuan; Carboni, Marco; Brant, William R; Pan, Ruijun; Hedman, Jonas; Zhu, Jiefang; Gustafsson, Torbjörn; Younesi, Reza

2018-04-25

Na-O 2 batteries are regarded as promising candidates for energy storage. They have higher energy efficiency, rate capability, and chemical reversibility than Li-O 2 batteries; in addition, sodium is cheaper and more abundant compared to lithium. However, inconsistent observations and instability of discharge products have inhibited the understanding of the working mechanism of this technology. In this work, we have investigated a number of factors that influence the stability of the discharge products. By means of in operando powder X-ray diffraction study, the influence of oxygen, sodium anode, salt, solvent, and carbon cathode were investigated. The Na metal anode and an ether-based solvent are the main factors that lead to the instability and decomposition of NaO 2 in the cell environment. This fundamental insight brings new information on the working mechanism of Na-O 2 batteries.

NaK handling and removal

International Nuclear Information System (INIS)

Desreumaux, J.; Rodriguez, G.; Guigon, A.; Verdelli, J.; Thomine, G.

1997-01-01

Sodium-potassium alloy is used in specific application in French Fast Breeder Reactors as: cold traps, NaK bubbler for argon purification, valves and also in experimental irradiation devices. lt has been preferred to sodium because it is liquid from + 7 deg. C for the most common peritectic alloy. After its use, NaK is considered as a hazardous waste (nuclear or not) due to its high reactivity with air and water. The most important risk remains in handling NaK systems which have not been operated for some time. The NaK will be covered with a crust of the superoxide K02 which is a strong oxidising agent. Thermodynamically, K02 will react with most organic material or metallic dust or swarfs and can also react with additional NaK to give sufficient heat to boil part of the NaK, resulting in a sudden increase in pressure and small explosions. We describe the formation given to experimenters in our Sodium School and the CEA's experience in treating specific devices for transportation, decanting of tanks, tank opening and NaK removal. (author)

Angiotensin II-induced hypertension increases plasma membrane Na pump activity by enhancing Na entry in rat thick ascending limbs.

Science.gov (United States)

Gonzalez-Vicente, Agustin; Garvin, Jeffrey L

2013-11-01

Thick ascending limbs (TAL) reabsorb 30% of the filtered NaCl load. Na enters the cells via apical Na-K-2Cl cotransporters and Na/H exchangers and exits via basolateral Na pumps. Chronic angiotensin II (ANG II) infusion increases net TAL Na transport and Na apical entry; however, little is known about its effects on the basolateral Na pump. We hypothesized that in rat TALs Na pump activity is enhanced by ANG II-infusion, a model of ANG II-induced hypertension. Rats were infused with 200 ng·kg(-1)·min(-1) ANG II or vehicle for 7 days, and TAL suspensions were obtained. We studied plasma membrane Na pump activity by measuring changes in 1) intracellular Na (Nai) induced by ouabain; and 2) ouabain-sensitive oxygen consumption (QO2). We found that the ouabain-sensitive rise in Nai in TALs from ANG II-infused rats was 12.8 ± 0.4 arbitrary fluorescent units (AFU)·mg(-1)·min(-1) compared with only 9.9 ± 1.1 AFU·mg(-1)·min(-1) in controls (P Na pump expression, the number of Na pumps in the plasma membrane, or the affinity for Na. When furosemide (1.1 mg·kg(-1)·day(-1)) was coinfused with ANG II, no increase in plasma membrane Na pump activity was observed. We concluded that in ANG II-induced hypertension Na pump activity is increased in the plasma membrane of TALs and that this increase is caused by the chronically enhanced Na entry occurring in this model.

A crise da Liga das Nações de 1926: realismo neoclássico, multilateralismo e a natureza da política externa brasileira The League of Nations crisis of 1926: neoclassical realism, multilateralism, and the nature of Brazilian foreign policy

Directory of Open Access Journals (Sweden)

Braz Baracuhy

2006-12-01

Full Text Available O artigo analisa a natureza da política externa brasileira na crise da Liga das Nações (1926, a partir de modelo teórico do realismo neoclássico. As dinâmicas por posições de poder nos tabuleiros geopolítico e multilateral do sistema internacional e as percepções e estratégias diplomáticas da elite de política externa brasileira são consideradas no estudo teórico.The article analyzes the nature of Brazilian foreign policy in the crisis of the League of Nations (1926 from a neoclassical-realist theoretical perspective. Within this theoretical framework, the dynamics of power positioning in the geopolitical and multilateral chessboards of the international system and the perceptions and diplomatic strategies of the Brazilian foreign-policy elite are taken into account.

Cooperative down-conversion of UV light in disordered scheelitelike Yb-doped NaGd(MoO4)2 and NaLa(MoO4)2 crystals

Science.gov (United States)

Subbotin, K. A.; Osipova, Yu. N.; Lis, D. A.; Smirnov, V. A.; Zharikov, E. V.; Shcherbakov, I. A.

2017-07-01

Concentration series of disordered scheelitelike Yb:NaGd(MoO4)2 and Yb:NaLa(MoO4)2 single crystals are grown by the Czochralski method. The actual concentrations of Yb3+ ions in the crystals are determined by optical-absorption spectroscopy. The luminescence of Yb3+ ions in these crystals in the region of 1 μm is studied under UV and IR excitation. In the case of UV excitation, this luminescence appears as a result of nonradiative excited state energy transfer from donor centers of unknown nature to ytterbium. The character of the concentration dependence of Yb3+ luminescence indicates that the energy transfer at high Yb concentrations occurs with active participation of a cooperative mechanism, according to which the excitation energy of one donor center is transferred simultaneously to two Yb3+ ions. In other words, the quantum yield of this transfer exceeds unity, which can be used to increase the efficiency of crystalline silicon (c-Si) solar cells.

Natural Radioactivity in Bananas

Science.gov (United States)

Zagatto, V. A. B.; Medina, N. H.; Okuno, E.; Umisedo, N. K.

2008-08-01

The content of 40K natural radionuclide in bananas (Musa sapientum) from the Vale do Ribeira region, São Paulo, Brazil, has been measured. We have collected several samples of bananas prata and nanica, its peels, leaves, and also different soils where the banana tree was planted, such as soil with a standard amount of fertilizer, the fertilizer itself and also soil without fertilizer for comparison. We have used the gamma-ray spectroscopy technique with a NaI(T1) crystal inside a 12 cm thick lead shield to detect the gamma-radiation. The results indicate that only part of the available potassium is absorbed by the plant, which is mainly concentrated in the banana peel.

Natural Radioactivity in Bananas

International Nuclear Information System (INIS)

Zagatto, V. A. B.; Medina, N. H.; Okuno, E.; Umisedo, N. K.

2008-01-01

The content of 40 K natural radionuclide in bananas (Musa sapientum) from the Vale do Ribeira region, Sao Paulo, Brazil, has been measured. We have collected several samples of bananas prata and nanica, its peels, leaves, and also different soils where the banana tree was planted, such as soil with a standard amount of fertilizer, the fertilizer itself and also soil without fertilizer for comparison. We have used the gamma-ray spectroscopy technique with a NaI(T1) crystal inside a 12 cm thick lead shield to detect the gamma-radiation. The results indicate that only part of the available potassium is absorbed by the plant, which is mainly concentrated in the banana peel

Hydrolysis of Rice Straw Pretreated by Na2SO3 Over Fe-resin/NaCl

Directory of Open Access Journals (Sweden)

YANG Hui

2017-05-01

Full Text Available To increase the conversion of rice straw(RS and the yield of products, we employed three methods, which were ultrasonic wave, steam explosion and Na2SO3 pretreatment to pretreat RS(the treated RS noted as CS-RS, ZQ-RS and Na2SO3-RS, respectively and found that Na2SO3 treatment was the best pretreatment method based on XRD, SEM, elemental analysis and content of cellulose, hemicellulose and lignin. The conversion of Na2SO3-RS and the yield of total reducing sugar(TRS and levulinic acid(LA were 97.3%, 29.6% and 13.5%, respectively by 10% Fe-resin in 3.3% NaCl solution under 200 ℃.

Na+/H+ and Na+/NH4+ exchange activities of zebrafish NHE3b expressed in Xenopus oocytes

Science.gov (United States)

Ito, Yusuke; Kato, Akira; Hirata, Taku; Hirose, Shigehisa

2014-01-01

Zebrafish Na+/H+ exchanger 3b (zNHE3b) is highly expressed in the apical membrane of ionocytes where Na+ is absorbed from ion-poor fresh water against a concentration gradient. Much in vivo data indicated that zNHE3b is involved in Na+ absorption but not leakage. However, zNHE3b-mediated Na+ absorption has not been thermodynamically explained, and zNHE3b activity has not been measured. To address this issue, we overexpressed zNHE3b in Xenopus oocytes and characterized its activity by electrophysiology. Exposure of zNHE3b oocytes to Na+-free media resulted in significant decrease in intracellular pH (pHi) and intracellular Na+ activity (aNai). aNai increased significantly when the cytoplasm was acidified by media containing CO2-HCO3− or butyrate. Activity of zNHE3b was inhibited by amiloride or 5-ethylisopropyl amiloride (EIPA). Although the activity was accompanied by a large hyperpolarization of ∼50 mV, voltage-clamp experiments showed that Na+/H+ exchange activity of zNHE3b is electroneutral. Exposure of zNHE3b oocytes to medium containing NH3/NH4+ resulted in significant decreases in pHi and aNai and significant increase in intracellular NH4+ activity, indicating that zNHE3b mediates the Na+/NH4+ exchange. In low-Na+ (0.5 mM) media, zNHE3b oocytes maintained aNai of 1.3 mM, and Na+-influx was observed when pHi was decreased by media containing CO2-HCO3− or butyrate. These results provide thermodynamic evidence that zNHE3b mediates Na+ absorption from ion-poor fresh water by its Na+/H+ and Na+/NH4+ exchange activities. PMID:24401990

Structural simulation of natural zeolites

International Nuclear Information System (INIS)

Sanchez P, E.; Carrera G, L.M.

1997-01-01

The application of X-ray diffraction (XRD) in the study of crystalline structures of the natural and modified zeolites allows the identification, lattice parameter determination and the crystallinity grade of the sample of interest. Until two decades ago, simulation methods of X-ray diffraction patterns were developed with which was possible to do reliable determinations of their crystalline structure. In this work it is presented the first stage of the crystalline structure simulation of zeolitic material from Etla, Oaxaca which has been studied for using it in the steam production industry and purification of industrial water. So that the natural material was modified for increasing its sodium contents and this material in its turn was put in contact with aqueous solutions of Na, Mg and Ca carbonates. All the simulations were done with the Lazy-Pulverix method. The considered phase was clinoptilolite. It was done the comparison with three clinoptilolite reported in the literature. (Author)

The relation between aging, aortic NaF avidity and coronary artery NaF avidity: A NaF PET CT study

DEFF Research Database (Denmark)

Blomberg, Björn; Thomassen, Anders; Hildebrandt, Malene

2013-01-01

volunteers without traditional cardiovascular risk factors were prospectively assessed by Sodium 18-Fluoride (Na-18F) PET CT imaging. Global aortic uptake of Na-18F was determined by calculating the average aortic blood pool subtracted maximum standardized uptake value (cSUV) [maximum SUVaorta - mean...

Rescue of Na+ and H+ binding in Na+,K+-ATPase M8 aspartate mutants by secondary mutation

DEFF Research Database (Denmark)

Holm, Rikke; Einholm, Anja P.; Andersen, Jens Peter

A mutation replacing the aspartate in transmembrane segment M8 in the a3-isoform of Na,K-ATPase with asparagine has been found in patients with rapid-onset dystonia parkinsonism or alternating hemiplegia of childhood. This aspartate may be a critical Na+ coordinating residue, but the crystal......-isoforms of Na,K-ATPase, and much smaller effects were seen for other mutations to the M8 aspartate, which were less disruptive of Na+ binding than mutations to other residues related to Na+ site III. The D928 (rat a1 numbering) mutations strongly diminished the cooperativity of Na+ binding. Moreover the p......H optimum of Na,K-ATPase activity was left-shifted, again with D928N being most disruptive. The reduced affinity for activating Na+ and for inhibitory protons, caused by D928N and D928A mutations, could be rescued by introduction of an additional mutation of a glutamate located far away from D928....

Salinity tolerance in barley (hordeum vulgare l.): effects of varying NaCl, K/sup +/ Na/sup +/ and NaHCO/sub 3/ levels on cultivars differing in tolerance

International Nuclear Information System (INIS)

Mahmood, K.

2011-01-01

Although barley (Hordeum vulgare L.) is regarded as salt tolerant among crop plants, its growth and plant development is severely affected by ionic and osmotic stresses in salt-affected soils. To elucidate the tolerance mechanism, growth and ion uptake of three barley cultivars, differing in salt tolerance, were examined under different levels of NaCl, K/sup +/ Na/sup +/ and NaHCO/sub 3/ in the root medium. The cultivars differed greatly in their responses to varying root medium conditions. Plant growth was more adversely affected by NaHCO/sub 3/ than NaCl. In general, biomass yields were comparable under control and 100 mM NaCl. However, growth of all three cultivars was significantly inhibited by NaHCO/sub 3/ even at low concentration (10 mM). Improved K/sup +/ supply in saline medium increased K/sup +/ uptake and growth of less tolerant cultivars. K/sup +/ uptake was more adversely affected by NaHCO/sub 3/ than NaCl salinity. Selective K/sup +/ uptake and lower Cl/sup -/ in shoots seemed to be associated with the growth responses. K application would help better growth of these cultivars on K-deficient saline-sodic soils and under irrigation with poor quality water having high Residual Sodium Carbonate (RSC) and/or Sodium Adsorption Ratio (SAR). (author)

Determination of naturally occurring radionuclides in soil samples of Ayranci, Turkey

Science.gov (United States)

Agar, Osman; Eke, Canel; Boztosun, Ismail; Emin Korkmaz, M.

2015-04-01

The specific activity, radiation hazard index and the annual effective dose of the naturally occurring radioactive elements (238U, 232Th and 40K) were determined in soil samples collected from 12 different locations in Ayranci region by using a NaI(Tl) gamma-ray spectrometer. The measured activity concentrations of the natural radionuclides in studied soil samples were compared with the corresponding results of different countries and the internationally reported values. From the analysis, it is found that these materials may be safely used as construction materials and do not pose significant radiation hazards.

The effect of CaNa{sub 2}EDTA on excretion of {sup 210}PB, {sup 210}Po and stable lead in cases of chronic lead intoxication

Energy Technology Data Exchange (ETDEWEB)

Knezevic, I.; Milacic, S.; Novak, Lj.; Uzelac, V.; Nesic, V

1998-07-01

The study describes the effect of CaNa{sub 2}EDTA on the excretion of the naturally occurring radionuclides {sup 210}Pb, {sup 210}Po and stable lead in workers' urine. The CaNa{sub 2}EDTA was administered intravenously to workers in the morning for five days. The results show that CaNa{sub 2}EDTA mobilises biologically active {sup 210}Pb, {sup 210}Po and stable lead, appreciably increasing their concentration in urine. (author)

Glutathionylation-Dependence of Na+-K+-Pump Currents Can Mimic Reduced Subsarcolemmal Na+ Diffusion

OpenAIRE

Garcia, Alvaro; Liu, Chia-Chi; Cornelius, Flemming; Clarke, Ronald?J.; Rasmussen, Helge?H.

2016-01-01

The existence of a subsarcolemmal space with restricted diffusion for Na+ in cardiac myocytes has been inferred from a transient peak electrogenic Na+-K+ pump current beyond steady state on reexposure of myocytes to K+ after a period of exposure to K+-free extracellular solution. The transient peak current is attributed to enhanced electrogenic pumping of Na+ that accumulated in the diffusion-restricted space during pump inhibition in K+-free extracellular solution. However, there are no know...

Myocardial Na,K-ATPase: Clinical aspects

OpenAIRE

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...

Down-Regulation of the Na+-Coupled Phosphate Transporter NaPi-IIa by AMP-Activated Protein Kinase

Directory of Open Access Journals (Sweden)

Miribane Dërmaku-Sopjani

2013-11-01

Full Text Available Background/Aims: The Na+-coupled phosphate transporter NaPi-IIa is the main carrier accomplishing renal tubular phosphate reabsorption. It is driven by the electrochemical Na+ gradient across the apical cell membrane, which is maintained by Na+ extrusion across the basolateral cell membrane through the Na+/K+ ATPase. The operation of NaPi-IIa thus requires energy in order to avoid cellular Na+ accumulation and K+ loss with eventual decrease of cell membrane potential, Cl- entry and cell swelling. Upon energy depletion, early inhibition of Na+-coupled transport processes may delay cell swelling and thus foster cell survival. Energy depletion is sensed by the AMP-activated protein kinase (AMPK, a serine/threonine kinase stimulating several cellular mechanisms increasing energy production and limiting energy utilization. The present study explored whether AMPK influences the activity of NAPi-IIa. Methods: cRNA encoding NAPi-IIa was injected into Xenopus oocytes with or without additional expression of wild-type AMPK (AMPKα1-HA+AMPKβ1-Flag+AMPKγ1-HA, of inactive AMPKαK45R (AMPKα1K45R+AMPKβ1-Flag+AMPKγ1-HA or of constitutively active AMPKγR70Q (AMPKα1-HA+AMPKβ1-Flag+AMPKγ1R70Q. NaPi-IIa activity was estimated from phosphate-induced current in dual electrode voltage clamp experiments. Results: In NaPi-IIa-expressing, but not in water-injected Xenopus oocytes, the addition of phosphate (1 mM to the extracellular bath solution generated a current (Ip, which was significantly decreased by coexpression of wild-type AMPK and of AMPKγR70Q but not of AMPKαK45R. The phosphate-induced current in NaPi-IIa- and AMPK-expressing Xenopus ooocytes was significantly increased by AMPK inhibitor Compound C (20 µM. Kinetic analysis revealed that AMPK significantly decreased the maximal transport rate. Conclusion: The AMP-activated protein kinase AMPK is a powerful regulator of NaPi-IIa and thus of renal tubular phosphate transport.

Evaluation of the potentiality of a Mexican natural zeolite chabazite-type in the lead removal in water; Evaluacion de la potencialidad de una chabasita natural mexicana en la remocion de plomo en agua

Energy Technology Data Exchange (ETDEWEB)

Alvarado I, J.; Sotelo L, M.; Meza F, D.; Paz M, F. A. [Universidad de Sonora, Blvd. Luis Encinas y Rosales s/n, Col. Centro, Hermosillo, Sonora (Mexico); Maubert F, M., E-mail: msotelo@guaymas.uson.mx [Universidad Autonoma Metropolitana, Unidad Azcapotzalco, Av. San Pablo 180, Col. Reynosa-Tamaulipas, 02200 Mexico D. F. (Mexico)

2013-06-01

The intention of this paper is to present the characterization of a natural zeolite, chabazite-type, from the Mexican reservoir La Palma, at Divisaderos, Sonora, where their potential use as ion exchange material to remove lead in water is assessed. The chabazite was characterized through X-ray diffraction, Icp-OES, Icp-Ms, EDX, Bet and TG/TGD. The results indicate the presence of Ba(1930 ppm) and Sr(1220 ppm), which are characteristic of aluminium rich phases. A chabazite modification treatment is proposed by using solutions of NaOH (0.1 M) and NH{sub 4}NO{sub 3} (1 M). The lead removal kinetics both in natural zeolite as in their chemically modified forms was obtained by using the ion exchange process in a batch reactor. The results show how unnecessary natural zeolite homo ionization is for the removal of lead, thereby obtaining the equilibrium concentration of unmodified zeolite for plotting the adsorption isotherm, which was adjusted to Langmuir model. The Langmuir isotherm has a good fit of the results at equilibrium (R{sup 2}=0.92), which demonstrates that natural zeolites studied, in its natural form, contains exchangeable cations required (Ca{sup +2}, Mg{sup 2+} and Na{sup +}) for potentially be used as an adsorbent material/ion exchanger for water treatment impacted by lead. (Author)

Efeito da adição de Na2O na viscosidade e devitrificação do vidro obtido a partir de cinzas volantes e Li2O Influence of Na2O on the viscosity and devitrification behavior of glasses obtained from fly ashes and Li2O

Directory of Open Access Journals (Sweden)

Etney Neves

1998-07-01

Full Text Available Glass-ceramic materials can be produced by the addition of LiO2 to fly ashes disposible in Southern Brazil. These glass-ceramics are based on the Al2O3-SiO2-Li 2O system. The high viscosity of the obtained glasses, however, makes forming useful articles with these materials difficult. In this study we investigate the effect of adding low cost Na2CO3 on the melt viscosity and on the nature of the developed crystalline phases. It was intended that the ultimate crystalline phase (LiAlSi3O8 should not be altered. With additions up to 3 wt. % Na2CO3, the viscosity was apparently lowered and no new crystalline phase were detected.

Thermodynamic study of NaFe complex oxides. High temperature properties of Na sub 5 FeO sub 4 and Na sub 3 FeO sub 3

CERN Document Server

Furukawa, T

2002-01-01

In order to contribute the investigation into corrosion mechanism of the structural materials by leakage sodium, thermodynamic study of Na-Fe complex oxides formed by the reactions was carried out. Na sub 5 FeO sub 4 and Na sub 3 FeO sub 3 were used as the sample. Its high temperature properties (i.e. melting, solidification and transformation) were observed by Differential Scanning Calorimetry, DSC. Moreover, the original test named 'melting point confirmation test' was performed for the observation of traces of melting and solidification after the tests. Following contents have been obtained by this study. (1) Na sub 5 FeO sub 4 was stably as the solid without phase transformation and melting until 800degC. However, the compound was showing a tendency to change into Na sub 4 FeO sub 3 with temperature increasing under the low oxygen potential. (2) The stability of Na sub 3 FeO sub 3 is the same as that of Na sub 5 FeO sub 4 until 700degC. Over the temperature, the compound was changed differential compound ...

Metallic Na formation in NaCl crystals with irradiation of electron or vacuum ultraviolet photon

Energy Technology Data Exchange (ETDEWEB)

Owaki, Shigehiro [Osaka Prefecture Univ., Sakai, Osaka (Japan). Coll. of Integrated Arts and Sciences; Koyama, Shigeko; Takahashi, Masao; Kamada, Masao; Suzuki, Ryouichi

1997-03-01

Metallic Na was formed in NaCl single crystals with irradiation of a variety of radiation sources and analyzed the physical states with several methods. In the case of irradiation of 21 MeV electron pulses to the crystal blocks, the optical absorption and lifetime measurement of positron annihilation indicated appearance of Na clusters inside. Radiation effects of electron beam of 30 keV to the crystals in vacuum showed the appearance of not only metallic Na but atomic one during irradiation with Auger electron spectroscopy. Intense photon fluxes in vacuum ultraviolet region of synchrotron radiation were used as another source and an analyzing method of ultraviolet photoelectron spectroscopy. The results showed the metallic Na layered so thick that bulk plasmon can exist. (author)

Reducing agent (NaBH4) dependent structure, morphology and magnetic properties of nickel ferrite (NiFe2O4) nanorods

International Nuclear Information System (INIS)

Saravanakumar, B.; Rani, B. Jansi; Ravi, G.; Thambidurai, M.; Yuvakkumar, R.

2017-01-01

Nickel ferrite (Ni-Fe 2 O 4 ) nanorods were synthesized employing a simple chemical reduction method. Reducing agent (NaBH 4 ) influence on structural, morphological and magnetic properties of NiFe 2 O 4 nanorods was investigated. XRD results clearly revealed the presence of inverse cubic spinel nickel ferrite structure characteristic peaks and confirmed the site inversion of inverse spinel structure of Fe 3+ tetrahedral A site and Ni 2+ octahedral B site. The observed Raman characteristic peak at 488 and 683 cm −1 were corresponded to E 1 g and A 1 g mode whereas A and B site respectively corresponded to tetrahedral and octahedral site of NiFe 2 O 4 inverse spinel structure. The obtained PL peaks at 530 and 542 nm were attributed to the emission spectra of Fe 3+ ions in site A of inverse spinel structure and Ni 2+ ions in site B of inverse spinel structure respectively. SEM result clearly revealed that increase in NaBH 4 concentration had remarkable impact on nanorods formation, nano-octahedron structure, homogeneity and regularity of Ni-Ferrites. VSM studies clearly revealed the soft ferromagnetic nature of NiFe 2 O 4 and increase in NaBH 4 concentration further induced raise in metal cations concentration in A- and B- site which might impact the resultant magnetization of ferrites. - Highlights: • Nano rod formation has been initiated while increase of NaBH 4 concentration. • Further increasing NaBH 4 concentration favors nano-octahedron formation. • VSM studies revealed soft ferromagnetic nature of NiFe 2 O 4 .

Spatial variation of natural terrestrial gamma-ray dose rates in Brunei

International Nuclear Information System (INIS)

Hu, S.J.; Lai, K.K.; Manato, S.; Kodaira, K.

1998-01-01

A carbon survey of natural terrestrial gamma-rat dose rates along the main roads of the western part of Brunei Darussalam was carried out using two portable type 1.5 φ x 4 NaI(TI) and 1 φ x 2 NaI(TI) scintillation counters. A series of semicontinuous count rates measurements were performed inside a moving vehicle. This yielded equal-distance data which were analysed statistically to obtain the spatial variation of the natural terrestrial gamma-ray dose rates. The equal-distance data of dose rates were obtained by correcting for shielding effect of the car. The thickness of the pavement and the contribution from the pavement material were estimated from a correlation curve between the dose rates measured on pavements and on the nearby soils. A spectral analysis of the equal-distance data enabled us to clarify the structure of the spatial variation in dose rates. The data could be reasonably smoothened by removing the random noise components in a higher wave number region. (author). 6 refs., 7 figs., 1 tab

Spatial variation of natural terrestrial γ-ray dose rates in Brunei

International Nuclear Information System (INIS)

Hu, S.J.; Lai, K.K.

1998-01-01

A carborne survey of natural terrestrial y-ray dose rates along the main roads of the western part of Brunei Darussalam was carried out using two portable type 1.5'φx4' NaI(T1) and 1'φx2' NaI(T1) scintillation counters. A series of semicontinuous count rates measurements were performed inside a moving vehicle. This yielded equal-distance data which were analysed statistically to obtain the spatial variation of the natural terrestrial γ-ray dose rates. The equal-distance data of dose rates were obtained by correcting for shielding effect of the car. The thickness of the pavement and the contribution from the pavement material were estimated from a correlation curve between the dose rates measured on pavements and on the nearby soils. A spectral analysis of the equal-distance data enabled us to clarify the structure of the spatial variation in dose rates. The data could be reasonably smoothened by removing the random noise components in a higher wave number region

Changes in the repertoire of natural antibodies caused by immunization with bacterial antigens

DEFF Research Database (Denmark)

Shilova, N V; Navakouski, M J; Huflejt, M

2011-01-01

The repertoire of natural anti-glycan antibodies in naïve chickens and in chickens immunized with bacteria Burkholderia mallei, Burkholderia pseudomallei, and Francisella tularensis as well as with peptides from an outer membrane protein of B. pseudomallei was studied. A relatively restricted pat...... pattern of natural antibodies (first of all IgY against bacterial cell wall peptidoglycan fragments, L-Rha, and core N-acetyllactosamine) shrank and, moreover, the level of detectable antibodies decreased as a result of immunization....

Reuse of nuclear byproducts, NaF and HF in metal glass industries

Energy Technology Data Exchange (ETDEWEB)

Park, J.W.; Lee, H.W. [Korea Power Engineering Co., Inc., Kyunggi-do (Korea, Republic of); Yoo, S.H.; Moon, H.S.; Cho, N.C. [Korea Nuclear Fuel Co., Ltd., Daejon (Korea, Republic of)

1997-02-01

A study has been performed to evaluate the radiological safety and feasibility associated with reuse of NaF(Sodium Fluoride) and HF(Hydrofluoric Acid) which are generated as byproducts from the nuclear fuel fabrication process. The investigation of oversea`s experience reveals that the byproduct materials are most often used in the metal and glass industries. For the radiological safety evaluation, the uranium radioactivities in the byproduct materials were examined and shown to be less than radioactivities in natural materials. The radiation doses to plant personnel and the general public were assessed to be very small and could be ignored. The Korea nuclear regulatory body permits the reuse of NaF in the metal industry on the basis of associated radioactivity being {open_quote}below regulatory concern{close_quote}. HF is now under review for reuse acceptability in the steel and glass industries.

Scintillation efficiency measurement of Na recoils in NaI(Tl) below the DAMA/LIBRA energy threshold

Energy Technology Data Exchange (ETDEWEB)

Xu, Jingke; Shields, Emily; Calaprice, Frank; Westerdale, Shawn; Froborg, Francis; Suerfu, Burkhant; Alexander, Thomas; Aprahamian, Ani; Back, Henning O.; Casarella, Clark; Fang, Xiao; Gupta, Yogesh K.; Ianni, Aldo; Lamere, Edward; Lippincott, W. Hugh; Liu, Qian; Lyons, Stephanie; Siegl, Kevin; Smith, Mallory; Tan, Wanpeng; Kolk, Bryant Vande

2015-07-01

The dark matter interpretation of the DAMA modulation signal depends on the NaI(Tl) scintillation efficiency of nuclear recoils. Previous measurements for Na recoils have large discrepancies, especially in the DAMA/LIBRA modulation energy region. We report a quenching effect measurement of Na recoils in NaI(Tl) from 3 to 52 keVnr, covering the whole DAMA/LIBRA energy region for dark matter-Na scattering interpretations. By using a low-energy, pulsed neutron beam, a double time-of-flight technique, and pulse-shape discrimination methods, we obtained the most accurate measurement of this kind for NaI(Tl) to date. The results differ significantly from the DAMA reported values at low energies but fall between the other previous measurements. We present the implications of the new quenching results for the dark matter interpretation of the DAMA modulation signal.

Distribution of natural radioactive elements in Western Carpathians granitoids

International Nuclear Information System (INIS)

Katlovsky, V.

1979-01-01

The content of natural radioactive elements was determined using the 1024-channel analyser NTA-512 B with NaI(Tl) scintillators or with a Ge(Li) detector. The following groups of samples were processed: 1. granitoids, pegmatites and weathered rocks in the Small Carpathians; 2. acid magmatites of exotic rocks of the klippen zone; 3. granitoids of the Western Carpathians. The results of the measurements are summed up. (Ha)

Dynamic polarizabilities and Van der Waals coefficients for alkali atoms Li, Na and alkali dimer molecules Li2, Na2 and NaLi

Science.gov (United States)

Mérawa, M.; Dargelos, A.

1998-07-01

The present paper gives an account of investigations of the polarizability of the alkali atoms Li, Na, diatomics homonuclear and heteronuclear Li2, Na2 and NaLi at SCF (Self Consistent Field) level of approximation and at correlated level, using a time Time-Dependent Gauge Invariant method (TDGI). Our static polarizability values agree with the best experimental and theoretical determinations. The Van der Waals C6 coefficients for the atom-atom, atom-dimer and dimer-dimer interactions have been evaluated. Les polarisabilités des atomes alcalins Li, Na, et des molécules diatomiques homonucléaires et hétéronucléaire Li2, Na2 et NaLi, ont été calculées au niveau SCF (Self Consistent Field) et au niveau corrélé à partir d'une méthode invariante de jauge dépendante du temps(TDGI). Nos valeurs des polarisabilités statiques sont en accord avec les meilleurs déterminations expérimentales et théoriques. Les coefficients C6 de Van de Waals pour les interactions atome-atome, atome-dimère et dimère-dimère ont également été évalués.

Alkali-Activated Natural Pozzolan/Slag Binder for Sustainable Concrete

Science.gov (United States)

Najimi, Meysam

alkali-activated concretes, workability and setting times were in the acceptable ranges. Overall, a 50/50 combination of natural Pozzolan and slag developed the highest strengths. Increasing slag content to 70%, however, was useful for mixtures with high NaOH concentrations (2.5M) and for acceleration of initial reactions. The strength of alkali-activated concretes improved with increases in sodium silicate portion of activator. Regarding effects of sodium hydroxide concentration on strength properties, there were optimum NaOH molarities which increased with an increase in slag portion of the binder. A 50/50 combination of natural Pozzolan and slag also proved to be the optimum combination for the results of absorption test. NaOH concentration and sodium silicate dosage had marginal effects on the absorption and volume of permeable voids. The chloride penetration depth reduced with decreases in natural Pozzolan portion of the binder (particularly from 70 to 50%), sodium silicate dosage, and NaOH concentration. A nearly similar trend was seen for the drying shrinkage of studied alkali-activated natural Pozzolan/slag concretes, as reduction of these variables also reduced the drying shrinkage. The mass loss of alkali-activated concretes subjected to acid attack increased with increases in slag content, sodium silicate dosage, and sodium hydroxide concentration. The failure time in corrosion test improved (increased) with increases in natural Pozzolan content, sodium silicate dosage, and sodium hydroxide concentration. The frost resistance of alkali-activated concretes improved as slag portion of the binder was increased. An increase in sodium silicate dosage was beneficial in improving frost resistance of concretes made with binders having 50 and 70% slag. An opposite trend was seen when slag portion of the binder was reduced to 30%. The mechanical properties (compressive strength, tensile strength and elastic modulus) of alkali-activated concretes made with activators

Structure-function relationships of Na+, K+, ATP, or Mg2+ binding and energy transduction in Na,K-ATPase

DEFF Research Database (Denmark)

Jorgensen, Peter L.; Pedersen, Per Amstrup

2000-01-01

Na,K-ATPase; Mutagenesis; Na+ binding; K+ binding; Tl+ binding; Mg2+ binding; ATP binding; Cation binding site; Energy transduction......Na,K-ATPase; Mutagenesis; Na+ binding; K+ binding; Tl+ binding; Mg2+ binding; ATP binding; Cation binding site; Energy transduction...

Measurement of the carbon 14 activity at natural level in air samples

International Nuclear Information System (INIS)

Olivier, A.; Tenailleau, L.; Baron, Y.; Maro, D.

2004-01-01

The aim of the study was to measure the carbon 14 activity at natural level in air samples using classical methods of radiochemistry and beta counting. Three different methods have been tested in order to minimise the detection limit. In the three methods, the first step consists in trapping the atmospheric carbon 14 into NaOH (1N) using a bubbling chamber. The atmospheric carbon dioxide reacts with NaOH to form Na 2 CO 3 . In the first method the Na 2 CO 3 solution is mixed with a liquid scintillate and is directly analysed by liquid scintillation counting (LSC). The detection limit is approximately 1 Bq/m 3 of air samples. The second method consists in evaporating the carbonate solution and then counting the solid residue with a proportional gas circulation counter. The detection limit obtained is lower than the first method (0.4 Bq/m 3 of air samples). In the third method, Na 2 CO 3 is precipitated into CaCO 3 in presence of CaCl 2 . CaCO 3 is then analysed by LSC. This method appear to be the most appropriate, the detection limit is 0.05 Bq/m 3 of air samples. (author)

Avaliação de compostos de borracha natural utilizados em equipamentos de segurança Evaluation of natural rubber compounds used in line-life equipment

Directory of Open Access Journals (Sweden)

Emilio M. de Paz Jr.

2010-09-01

Full Text Available No setor elétrico, a borracha natural (BN tem sido amplamente utilizada na confecção de ferramentas isolantes. Esses são itens essenciais para a segurança e proteção de trabalhadores da área de manutenção de redes de distribuição de energia elétrica. A boa conservação dessas ferramentas deve ser assegurada com o objetivo de garantir o isolamento elétrico e resistência mecânica adequados, portanto a avaliação dos processos de degradação se torna importante. Neste trabalho duas formulações de borracha natural comerciais, utilizadas na confecção de equipamentos de proteção coletiva (EPC's, foram caracterizadas por envelhecimento térmico, ensaios mecânicos, termogravimétricos, análise termo-dinâmico mecânica, inchamento e extração.Electrical engineering sector make use of natural rubber to manufacture line-life equipment, utilized to promote safety and protection for those who work in the electrical networks maintenance. A good conservation of the equipment must be assured in order to guarantee the necessary insulation. Thus, the assessment of the degradation processes becomes important. In this study two commercial types of natural rubber commonly employed to produce collective protective equipment (CPE, were evaluated using artificial thermal ageing through mechanical, swelling tests, thermogravimetric analysis, dynamic mechanical thermal analysis and solvent extraction.

O encontro entre dança e educação somática como uma interface de questionamento epistemológico sobre as teorias do corpo The encounter of dance and somatic education as a new epistemological interface on body theories

Directory of Open Access Journals (Sweden)

Eloisa Domenici

2010-08-01

Full Text Available Neste artigo, destaco a sinergia entre a educação somática e a dança, como um subespaço de produção de conhecimento qualificado sobre o corpo. Considero que as práticas de educação somática possibilitaram novos caminhos de investigação e criação, alterando profundamente os modos de fazer dança, para além da clássica epistemologia mecanicista em que se pauta o treinamento corporal tradicional. Minha hipótese é de que essa zona híbrida entre arte e ciência vem desestabilizando concepções importantes, tais como memória, cognição, movimento, hábito, natureza, cultura, entre outros, produzindo importantes subsídios na direção de novas epistemologias sobre o corpo.This article focuses on the collaboration between somatic education and dance as a sub-space for production of qualified knowledge on the body. It is argued that the practices of somatic education have provided new kinds of investigation and creation, making significant changes in the ways of making dance and producing new aesthetic concepts that present other ideas than the ones from the classical mechanist epistemology. Our hypothesis is that this hybrid zone between art and science has been mobilizing important conceptions, such as memory, cognition, movement, habit, nature, and culture, among others, producing an important support for new epistemologies on the body.

The chronic toxicity of sodium bicarbonate, a major component of coal bed natural gas produced waters

Science.gov (United States)

Farag, Aïda M.; Harper, David D.

2014-01-01

Sodium bicarbonate (NaHCO3) is the principal salt in coal bed natural gas produced water from the Powder River Structural Basin, Wyoming, USA, and concentrations of up to 3000 mg NaHCO3/L have been documented at some locations. No adequate studies have been performed to assess the chronic effects of NaHCO3 exposure. The present study was initiated to investigate the chronic toxicity and define sublethal effects at the individual organism level to explain the mechanisms of NaHCO3 toxicity. Three chronic experiments were completed with fathead minnows (Pimephales promelas), 1 with white suckers (Catostomus commersoni), 1 with Ceriodaphnia dubia, and 1 with a freshwater mussel, (Lampsilis siliquoidea). The data demonstrated that approximately 500 mg NaHCO3/L to 1000 mg NaHCO3/L affected all species of experimental aquatic animals in chronic exposure conditions. Freshwater mussels were the least sensitive to NaHCO3 exposure, with a 10-d inhibition concentration that affects 20% of the sample population (IC20) of 952 mg NaHCO3/L. The IC20 for C. dubia was the smallest, at 359 mg NaHCO3/L. A significant decrease in sodium–potassium adenosine triphosphatase (Na+/K+ ATPase) together with the lack of growth effects suggests that Na+/K+ ATPase activity was shut down before the onset of death. Several histological anomalies, including increased incidence of necrotic cells, suggested that fish were adversely affected as a result of exposure to >450 mg NaHCO3/L.

At NA2

CERN Multimedia

1977-01-01

One of the NA2 calorimeter sections is moved in. The NA2 calorimeter was divided in two halves, to the left and the right of the beam, each half consisting of sheets of passive high Z material interleaved with blades of plastic scintillators. The photo shows on the right, the upstream 'electron' module with eleven lead plates for a total radiation length of 20.

Equilibrium CO{sub 2} adsorption on zeolite 13X prepared from natural clays

Energy Technology Data Exchange (ETDEWEB)

Garshasbi, Vahid [Faculty of Chemical, Petroleum and Gas Eng., Semnan University, P.O. Box 35196-45399, Semnan, Islamic Republic of Iran (Iran, Islamic Republic of); Jahangiri, Mansour, E-mail: mjahangiri@semnan.ac.ir [Faculty of Chemical, Petroleum and Gas Eng., Semnan University, P.O. Box 35196-45399, Semnan, Islamic Republic of Iran (Iran, Islamic Republic of); Anbia, Mansoor [Research Laboratory of Nanoporous Materials, Faculty of Chemistry, Iran University of Science and Technology, Tehran 16846-13114, Islamic Republic of Iran (Iran, Islamic Republic of)

2017-01-30

Highlights: • Zeolite 13X was successfully synthesized by hydrothermal treatment using natural kaolin, natural bentonite and natural feldspath. • The optimum conditions of synthesis zeolite 13X were found to be NaOH concentration = 4 M and crystallized at 65 °C for 72 h after homogenization by agitated at room temperature for 120 h. • The prepared zeolite 13X from natural kaolin (13X-K) showed a high BET surface area of 591 m{sup 2}/g and high micropore volume (0.250 cm{sup 3}/g) than other materials in this study. • The adsorption behavior of carbon dioxide and methane on zeolite 13X sample at different temperature from 298 K to 328 K was investigated. • It was found that the Langmuir–Freundlich model was more suitable than the others for description of CO{sub 2} adsorption isotherms. - Abstract: Zeolite 13X was successfully synthesized by hydrothermal treatment using natural clays extracted from Iranian resources. The preliminary natural materials and the final zeolite 13X samples were characterized by X-ray Diffraction (XRD), Fourier-Transfer Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM) and N{sub 2} adsorption–desorption isotherm. The effects of various factors such as NaOH addition amount and aging time on the crystalline products were studied during the synthesis process. The optimum conditions related to the synthesis of zeolite 13X were set. Accordingly, NaOH concentration was equal to 4 M. It was further crystallized at 65 °C for 72 h after its homogenization by agitation at room temperature for 120 h. In this study, the zeolite 13X prepared from natural kaolin (13X-K) showed a high BET surface area of 591 m{sup 2}/g with higher micropore volume (0.250 cm{sup 3}/g) than other materials. Adsorption equilibrium isotherms of CO{sub 2} were investigated using a static, volumetric method. In addition, pressures for the pure component data extended up to 20 bar. The adsorption equilibrium data of CO{sub 2} was fitted to

Látex de amapá (Parahancornia fasciculata (Poir Benoist, Apocynaceae: remédio e renda na floresta e na cidade

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Murilo da Serra Silva

Full Text Available O estudo abordou a cadeia de produção e de comercialização e os aspectos do consumo do látex medicinal de amapá amargoso (Parahancornia fasciculata em Belém e Ponta de Pedras, no Pará. Nosso objetivo foi investigar diversos aspectos do manejo e uso desse produto, revelando a sua importância na vida de seus produtores e consumidores. Foram utilizados a abordagem da 'cadeia de produção ao consumo' e métodos qualitativos e quantitativos de pesquisa, incluindo pesquisa de mercado, entrevistas com extrativistas, comerciantes e consumidores, oficinas, turnês guiadas e inventário florestal. Os oito mil litros de látex de amapá comercializados anualmente na região de Belém beneficiam, principalmente, consumidores de baixa renda, que têm tradição secular do uso desse látex. A renda obtida com esse produto representa 42% da renda total dos extrativistas com produtos florestais não madeireiros. A grande abundância da espécie e a distribuição diamétrica das árvores indicam possibilidade de regeneração natural. A melhoria na técnica de extração do látex realizada por alguns extrativistas revela que eles têm conhecimento da anatomia da árvore. A tradição de uso e manejo do látex e as características ecológicas da espécie sugerem grande potencial para programas de produção sustentável.

Natural radioactivity concentration of peanuts in Osmaniye-Turkey

Energy Technology Data Exchange (ETDEWEB)

Akkurt, Iskender; Guenoglu, Kadir; Mavi, Betuel; Kara, Ayhan [Suleyman Demirel University Isparta (Turkey); Amasya University Amasya (Turkey); Osmaniye Korkut Ata University Osmaniye (Turkey)

2012-09-06

The peanut is grown in Osmaniye where located in southern Turkey. Due to it is grown underground, the measurements of natural radioactivity of peanuts become important. For this reason some peanut samples have been collected from different places of Osmaniye and the measurements of natural activity concentrations for {sup 40}K, {sup 226}Ra and {sup 232}Th in some peanuts samples have been carried out using a NaI(Tl) gamma-ray spectrometer. Activity of {sup 40}K was measured from its intensive line at 1460 keV, for {sup 226}Ra activity peak from {sup 214}Bi at 1760 keV and {sup 232}Th activity, peak from {sup 208}Tl at energy of 2610 keV was used.

Na+-K+ pump in chronic renal failure

International Nuclear Information System (INIS)

Deepak, K.; Kahn, T.

1987-01-01

This review summarizes the evidence for the defect in Na + -K + 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 + -K + pump units per cell. Maintenance dialysis over a period of weeks ameliorates the defect in intracellular Na + , and this improvement is contemporaneous with an increase in the number of Na + -K + pump sites per cell. In erythrocytes with normal cell Na + , acute hemodialysis increases the rate of 22 Na + and 42 K + 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 + , the pump-mediated 42 K + transport is normalized at the expense of a raised cell Na + . The decreased muscle membrane potential in uremic subjects has been attributed to a decreased activity of Na + -K + 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 + depletion, which may cause more chronic alterations. The implications of alteration of Na + and K + pump transport and raised cell Na + on other non-pump-mediated transport pathways are discussed. Raised cell Na + may be a marker for the adequacy of maintenance dialysis in patients with end-stage renal failure

Pozitivni in negativni vplivi risank na otroke

OpenAIRE

Povše, Nika

2017-01-01

V tej diplomski nalogi smo raziskovali pozitivne in negativne vplive risank na otroke. Začeli smo z zgodovino televizije, tako svetovno zgodovino kot zgodovino televizije na Slovenskem. Na isti način smo pregledali tudi zgodovino risank. Raziskovali smo otrokov razvoj, predvsem tiste vidike, ki so izpostavljeni vplivom risank, kot so morala, jezik, domišljija in učenje. Sledilo je raziskovanje negativnih in pozitivnih vplivov, ki jih imajo risanke na otroke, kar je tudi naš glavni problem te ...

Active Ti Species in TiCl3-Doped NaAlH4. Mechanism for Catalyst Deactivation

NARCIS (Netherlands)

Balde, C.P.; Stil, H.A.; van der Eerden, A.M.J.; de Jong, K.P.; Bitter, J.H.

2007-01-01

The nature of the active Ti species in TiCl3-doped NaAlH4, a promising hydrogen storage material, was studied as a function of the desorption temperature with Ti K-edge extended X-ray absorption fine structure (EXAFS) spectroscopy, Ti K-edge X-ray absorption near-edge structure (XANES) spectroscopy,

Naïve Conceptions About Multimedia Learning:A Study on Primary School Textbooks

OpenAIRE

Barbara eColombo; Alessandro eAntonietti

2013-01-01

An interview study, based on specific pictures taken from textbooks used in primary schools, was carried out to investigate illustrators’, teachers’, students’, and common people’s beliefs about the role that illustrations play in facilitating learning. Participants’ responses were internally coherent, indicating a systematic nature of the underlying naïve conceptions. Findings disprove Mayer’s pessimistic claim that laypersons’ conceptions of multimedia learning fail to match experiment...

Sinergia sostenida: las polillas y el Dr. Wolcott

Science.gov (United States)

Frank H. Wadsworth

2007-01-01

The synergy between an insect colony and a curious entomologist is described. Together they determine the relative preference of insects to over 80 woody species. The relationship between wood resistance and insect attacks and wood density and chemical composition of wood is also determined. Finally, a series of chemicals is tested to increase wood resistance to attack...

Vpliv konfucija na sodobno izobraževanje na Kitajskem

Directory of Open Access Journals (Sweden)

Katja Skitek

2009-12-01

Full Text Available Izobraževanje na Kitajskem je bilo vedno trdno povezano s Konfucijem in konfucianizmom, kar pa ni čudno, saj je bil Konfucij prvi, ki je poudarjal moč z nanja in izobraževanja. LR Kitajska je v zadnjih petdesetih letih počasi in postopoma začela uveljavljati določene spremembe v vzgojno-izobraževalni sistem. Kakšne so te spremembe in koliko nanje še vedno vpliva konfucianizem, bo osrednja tema pričujočega članka. Konfucianizem danes na Kitajskem ni preveč popularen, izobraženci pa so se razporedili v dve skupini: eni trdijo, da je njegov vpliv še vedno velik, drugi pa zatrjujejo, da nima več nobenega vpliva na sodobno življenje. Katera stran ima prav? Konfucij je v prvi vrsti poudarjal pomembnost moralnih vrednot vsakega človeka in prav moralne vrednote, za katere se je zavzemal, so še danes trdno zasidrane v kitajski kulturi. Ali je torej sploh mogoče popolnoma izriniti Konfucija iz sodobnega izobraževanja?

Low-spin states of 23Na

International Nuclear Information System (INIS)

Bakkum, E.L.

1987-01-01

A study of 23 Na via the 22 Ne(p,γ) 23 Na and 23 Na(γ,γ) 23 Na reactions is presented. Only a limited number of resonances has been studied, selected on the basis of strong excitation of the lowest levels of which the spin was unknown. As a result the spins are now known of all levels of 23 Na with excitation energies up to 7 MeV, except for a few high-spin states which are too weakly excited in the decay of the known 22 Ne(p,γ) resonances. The mean lifetimes of the 23 Na levels at 4.43 and 7.89 MeV were found to be 350±70 and 220±17 attoseconds (1 attosecond = 10 -18 seconds) respectively. 97 refs.; 22 figs.; 12 tabs

Relations between fluxes and concentrations of Na in cell suspensions of Acer pseudoplatanus

International Nuclear Information System (INIS)

Pennarun, A.-M.

1978-01-01

Taking in account the data provided by preliminary compartmental analysis, the net influxes of 24 Na measured in Acer cells after a short loading period (45 minutes) followed by a short wash (1 minute) represent the influx across the plasmalemma (phi sub(0c)) and, after a long loading period (4 hours) followed by a long wash (2 hours) represent the quasi-steady influx from the external solution to the vacuole (phi sub(0v). At flux equilibrium and when the external Na concentration is high enough, the other unidirectional fluxes - phi sub(c0), phi sub(cv) and phi sub(vc) - can be determined from these measurements. This method was used to study the variation of Na flux in terms of the external concentrations and the resulting internal concentrations. The kinetics obtained confirm the active nature of the efflux phi sub(vc) across the tonoplast according to the conclusions given by the application of the USSING-TEORELL criterion to the results of compartmental analysis. On the contrary, they suggest a passive character for the efflux phi sub(c0) accross the plasmalemma which could be considered as active according to the USSING-TEORELL criterion. The contradiction could be eliminated by taking into consideration the important underestimation of the Na activity coefficient in the cytoplasm, due to the neglecting of water binding [fr

Response of saliva Na/K ratio to changing Na supply of lactating cows under tropical conditions

NARCIS (Netherlands)

Thiangtum, Wandee; Schonewille, J Thomas; Verstegen, Martin Wa; Arsawakulsudhi, Supot; Rukkwamsuk, Theera; Hendriks, Wouter H

BACKGROUND: Factorial determination of the sodium (Na) requirement of heat-stressed lactating cows is hindered by accurate estimates of the Na losses through sweat. Direct studies, therefore, may be needed requiring information on the time course of healthy animals to become Na depleted and the

Response of saliva Na/K ratio to changing Na supply of lactating cows under tropical conditions

NARCIS (Netherlands)

Thiangtum, Wandee; Schonewille, Thomas J.; Verstegen, Martin W.A.; Arsawakulsudhi, Supot; Rukkwamsuk, Theera; Hendriks, Wouter H.

2017-01-01

BACKGROUND: Factorial determination of the sodium (Na) requirement of heat-stressed lactating cows is hindered by accurate estimates of the Na losses through sweat. Direct studies, therefore, may be needed requiring information on the time course of healthy animals to become Na depleted and the

Clues to NaCN formation

Science.gov (United States)

Quintana-Lacaci, G.; Cernicharo, J.; Velilla Prieto, L.; Agúndez, M.; Castro-Carrizo, A.; Fonfría, J. P.; Massalkhi, S.; Pardo, J. R.

2017-11-01

Context. ALMA is providing us essential information on where certain molecules form. Observing where these molecules emission arises from, the physical conditions of the gas, and how this relates with the presence of other species allows us to understand the formation of many species, and to significantly improve our knowledge of the chemistry that occurs in the space. Aims: We studied the molecular distribution of NaCN around IRC +10216, a molecule detected previously, but whose origin is not clear. High angular resolution maps allow us to model the abundance distribution of this molecule and check suggested formation paths. Methods: We modeled the emission of NaCN assuming local thermal equilibrium (LTE) conditions. These profiles were fitted to azimuthal averaged intensity profiles to obtain an abundance distribution of NaCN. Results: We found that the presence of NaCN seems compatible with the presence of CN, probably as a result of the photodissociation of HCN, in the inner layers of the ejecta of IRC +10216. However, similar as for CH3CN, current photochemical models fail to reproduce this CN reservoir. We also found that the abundance peak of NaCN appears at a radius of 3 × 1015 cm, approximately where the abundance of NaCl, suggested to be the parent species, starts to decay. However, the abundance ratio shows that the NaCl abundance is lower than that obtained for NaCN. We expect that the LTE assumption might result in NaCN abundances higher than the real ones. Updated photochemical models, collisional rates, and reaction rates are essential to determine the possible paths of the NaCN formation. Based on observations carried out with ALMA and the IRAM 30 m Telescope. ALMA is a partnership of ESO (representing its member states), NSF (USA) and NINS (Japan), together with NRC (Canada) and NSC and ASIAA (Taiwan), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. IRAM is supported by INSU/CNRS (France

[A mobile sensor for remote detection of natural gas leakage].

Science.gov (United States)

Zhang, Shuai; Liu, Wen-qing; Zhang, Yu-jun; Kan, Rui-feng; Ruan, Jun; Wang, Li-ming; Yu, Dian-qiang; Dong, Jin-ting; Han, Xiao-lei; Cui, Yi-ben; Liu, Jian-guo

2012-02-01

The detection of natural gas pipeline leak becomes a significant issue for body security, environmental protection and security of state property. However, the leak detection is difficult, because of the pipeline's covering many areas, operating conditions and complicated environment. A mobile sensor for remote detection of natural gas leakage based on scanning wavelength differential absorption spectroscopy (SWDAS) is introduced. The improved soft threshold wavelet denoising was proposed by analyzing the characteristics of reflection spectrum. And the results showed that the signal to noise ratio (SNR) was increased three times. When light intensity is 530 nA, the minimum remote sensitivity will be 80 ppm x m. A widely used SWDAS can make quantitative remote sensing of natural gas leak and locate the leak source precisely in a faster, safer and more intelligent way.

Effect of the raw material type and the reaction time on the synthesis of halloysite based Zeolite Na-P1

Science.gov (United States)

Meftah, Mahdi; Oueslati, Walid; Chorfi, Nejmeddine; Ben Haj Amara, Abdesslem

Zeolites are currently one of the most important classes of inorganic materials because of their multiple applications not only as ions exchangers and molecular sieves, but also as catalysts. This works focus the synthesis and the characterization of Zeolite Na-P1 using halloysite (collected near Ain Khemouda, western Tunisia) as the starting material. Two parameters, such as the host materials type (natural or treated) and the reaction time, involved in the synthesis process are investigated. The intermediate phases and final products were characterized by X-ray diffraction, Infrared IR spectroscopy, scanning electron microscopy and high-resolution 29Si and 27Al MAS NMR. Obtained results show that the hydrothermal synthesis from natural and heated-halloysite leads to formation of homogenous Zeolite Na-P1. The difference in the crystallization/transformation time process is explained by the effect of the dissolution rate of the starting materials in sodium hydroxide solution. In the case of heated halloysite, the synthesis reaction with alkali solution occurs very readily and achieved without prior thermal activation at high temperature. The optimal conditions of Zeolite Na-P1 crystallization, from heated-halloysite, are reached at 120 °C.

ECONOMIA POLÍTICA DO TERRITÓRIO E ESTRATÉGIAS DE ATRAÇÃO DE INVESTIMENTOS – A GEOGRAFIA DA SUBVENÇÃO INDUSTRIAL NO CEARÁ COMO EXEMPLO

Directory of Open Access Journals (Sweden)

Edilson Alves Pereira Júnior

2013-12-01

Full Text Available A tentativa de afirmar um projeto de industrialização pautado numa proposta política de integração irrestrita ao mercado foi um dos fatos mais marcantes a atingir o Ceará nas duas últimas décadas. O componente central que deve ser destacado na leitura dos acontecimentos é o papel decisivo das forças públicas na consolidação do processo. A participação dos governos estaduais não só se apresentou necessária como determinou os rumos da mudança, sobretudo ao proporcionar densidade técnica ao território e incentivar a mobilidade dos capitais através de programas políticos. Este artigo procura apresentar algumas reflexões acerca do tema, seguindo os caminhos da reestruturação espacial como instrumento da acumulação capitalista pela via da indústria. O conjunto articulado das ações e dos objetos formou a síntese estrutural de uma industrialização que logrou sucesso por combinar manifestações particulares e universais unificadas num plano concreto, o próprio território, que desde então não pode mais ser entendido sem que se considere a sinergia interescalar que o caracteriza.

Financiranje projekata na pomorskom dobru

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Zoran Tasić

2018-02-01

Full Text Available Koncesije otvaraju vrlo osjetljiva politička, ekonomska i pravna pitanja u mnogim državama svijeta. Samo definiranje pojma koncesije često je komplicirana i ne sasvim jasna zadaća. OECD je prihvatila definiciju koncesije kao: ’’davanje prava privatnom trgovačkom društvu da može gospodarski upravljati određenom infrastrukturnim uslugama i za to zarađivati naknadu. Koncesionar dobija u posjed određene objekte (ali vlasništvo na tim objektima ostaje u rukama države te ih koristi u svrhu obavljanja određene djelatnosti ili usluge sukladno odredbama ugovora’’. Hrvatsko pravo definira koncesije načelno kao pravo stečeno temeljem ugovora o koncesiji, a sukladno uvjetima sadržanim u odluci o davanju koncesije (koju je donijelo odgovarajuće upravno tijelo, a u odnosu na pomorsko dobro, specifično, kao pravo državne vlasti da može dio pomorskog dobra, koje je inače dobro izvan pravnog prometa (res extra commercium, isključiti iz opće uporabe bilo dijelom ili u cijelosti, i dati ga fizičkoj ili pravnoj osobi na gospodarsko korištenje sukladno određenim prostornim planovima. Građevine i drugi objekti izgrađeni na pomorskom dobru čine njegov sastavni dio. Zakonom je jasno određeno da nikakva stvarna prava nisu dopuštena na pomorskom dobru, uključivo i na objektima izgrađenima na njemu. Projekti na pomorskom dobru često uključuju velike infrastrukturne projekte, razvoje luka i marina, koji iziskuju značajna financijska sredstva. Banke koje financiraju takve projekte zahtijevaju organiziran i transparentan zakonski okvir koncesija, slobodu ugovaranja, pravnu zaštitu svih strana uključenih u projekt (uključivo i mogućnost međunarodne arbitraže. (...

ESPÉCIES VEGETAIS UTILIZADAS NA ALIMENTAÇÃO DE Podocnemis unifilis, Troschel 1948 (REPTILIA, TESTUDINAE, PELOMEDUSIDAE NA REGIÃO DO PRACUÚBA -AMAPÁ-BRASIL

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Yeda Soares de Lucena Bataus

2006-10-01

Full Text Available Foram obtidas, junto às comunidades que vivem às margens dos rios e lagos da região do Pracuúba, Estado do Amapá, informações sobre 35 espécies vegetais que fazem parte da alimentação natural de Podocnemis unifilis (tracajá. Após a identificação dos vegetais, procedeu-se à coleta de suas partes comestíveis, para posteriores classificação taxonômica e análise química. Foram encontrados vegetais de 21 famílias botânicas, sendo que as famílias Leguminosae e Graminae ocorreram em 22,81% e 8,57% do total. A caracterização físico-química mostrou a composição centesimal quanto aos níveis de proteína, lipídios, cálcio, fósforo, potássio e magnésio, fibra bruta e de resíduo mineral fixo. Dentre os vegetais analisados, 12 espécies mostraram teores de proteína superiores a 10%. Dentre estas, oito espécies apresentaram boa possibilidade de servirem como ingredientes de uma ração regional, em função de suas propriedades nutricionais e de sua disponibilidade na natureza. São elas: Commelina longicaulis (maria-mole (20,78%, Polyganum acuminatum (pimenteira brava (20,19%; Aschymene sensitiva (corticeira (19,93%; Macrolobium acaiae folium (jandaruá (17,06%; Oryza glandiglumes (canarana grande (15,00%; Thalia geniculata (14,14%; Nymphaeae rudgeana (11,55% e Hymenachine amplexicaulis (10,11%. PALAVRAS-CHAVE: Podocnemis unifilis, tracajá, alimentação de quelônios na natureza.

O uso da gestão de projetos para a implantação de uma gestão da informação integrada e participativa: a experiência da coordenadoria de educação aberta e a distância da Universidade Federal de Viçosa-MG

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Leo Jaime Ribeiro Faria

2012-01-01

Full Text Available http://dx.doi.org/10.5007/1983-4535.2012v5n4p78   A gerência da Educação a Distância exige que seus gestores executem tarefas de planejamento, sistematização, organização, direção e controle de processos e projetos e por isso não pode prescindir de um gerenciamento da informação que atenda aos requisitos de integração, de responsabilidade coletiva e de participação. Sendo assim, este trabalho teve como objetivo a implementação da gestão da informação na Coordenadoria de Educação Aberta e a Distância da Universidade Federal de Viçosa (CEAD-UFV, seguindo a metodologia de gerenciamento de projetos com base numa modificação dodotProject, um software livre de código aberto. Para tanto, foi desenvolvido e implementado um sistema de gerenciamento da informação na Coordenadoria, com base na metodologia da gestão de projetos para organizações de tecnologia da informação e comunicação. Constatou-se que o modelo implantado ofereceu à CEAD-UFV uma visão sistêmica de seus projetos e dinamizou o fluxo de informações. A experiência mostrou ainda que a gestão baseada nagerência de projetos permite enfatizar a sinergia entre grupos necessária no contexto de EaD.

Research with a Natural-Uranium Light-Water Subcritical Assembly; Recherches au Moyen d'un Ensemble Sous-Critique a Uranium Naturel et a Eau Ordinaire; Issledovaniya na podkriticheskoj sborke,rabotayushchej na prirodnom urane i obychnoj vode; Investigaciones con un Conjunto Subcritico de Uranio Natural y Agua Ligera

Energy Technology Data Exchange (ETDEWEB)

Koskinen, H. [Institute of Technical Physics, Otaniemi (Finland)

1964-02-15

natural-agua ligera, en especial de la validez de los modelos de frenado de pocos grupos para cuerpos de estructura uniforme y no uniforme. Los conjuntos con una sola fuente de fision espontanea se consideran particularmente adecuados para las investigaciones de esta clase, aunque la estadistica solo abarca un numero reducido de observaciones. Esto se debe a dos hechos: 1. El espectro de la fuente primaria se puede considerar identico al de la fision inducida, por lo que no existen fluctuaciones transitorias de energia como en el caso de una fuente puntiforme de neutrones rapidos. 2. La intensidad de la fuente primaria en cada punto del espacio es proporcional a la seccion eficaz de fision del combustible cuando esta ultima se considera en funcion de las coordenadas espaciales. Esta particularidad contribuye a simplificar las ecuaciones de flujo y permite, en muchos casos, hallar una analogia con los sistemas criticos. Un analisis minucioso de las distribuciones de flujo en sistemas de esta clase proporciona datos sobre la validez de modelos especiales de frenado. Tambien es posible obtener algunas aclaraciones sobre problemas como la fision rapida por interaccion y la probabilidad de escape por resonancia en funcion del espacio. El autor estima que, debido a sus multiples aplicaciones y a su seguridad intrinseca, los conjuntos subcriticos con moderador liquido constituyen casi la unica posibilidad de estudiar sistematicamente reticulados no uniformes. Existe el proposito de anadir a ese conjunto elementos enriquecidos. Ello permitira proceder al estudio sistematico de reticulados mixtos, y debido al flujo mas elevado, facilitara tambien el estudio de otros factores no uniformes. La memoria expone algunos aspectos de ese programa futuro. (author) [Russian] Soobshhaetsja ob issledovanijah na podkriticheskoj sborke, rabotajushhej na prirodnom urane i obychnoj vode. Predstavleny takzhe nekotorye temy iz programmy budushhih issledovanij. Material bol'shej chast'ju javljaetsja

Controlled phase stability of highly Na-active triclinic structure in nanoscale high-voltage Na2-2xCo1+xP2O7 cathode for Na-ion batteries

Science.gov (United States)

Song, Hee Jo; Kim, Jae-Chan; Dar, Mushtaq Ahmad; Kim, Dong-Wan

2018-02-01

With the increasing demand for high energy density in energy-storage systems, a high-voltage cathode is essential in rechargeable Li-ion and Na-ion batteries. The operating voltage of a triclinic-polymorph Na2CoP2O7, also known as the rose form, is above 4.0 V (vs. Na/Na+), which is relatively high compared to that of other cathode materials. Thus, it can be employed as a potential high-voltage cathode material in Na-ion batteries. However, it is difficult to synthesize a pure rose phase because of its low phase stability, thus limiting its use in high-voltage applications. Herein, compositional-engineered, rose-phase Na2-2xCo1+xP2O7/C (x = 0, 0.1 and 0.2) nanopowder are prepared using a wet-chemical method. The Na2-2xCo1+xP2O7/C cathode shows high electrochemical reactivity with Na ions at 4.0 V, delivering high capacity and high energy density.

Optimization of NaOH Molarity, LUSI Mud/Alkaline Activator, and Na2SiO3/NaOH Ratio to Produce Lightweight Aggregate-Based Geopolymer

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Rafiza Abdul Razak

2015-05-01

Full Text Available 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.

Optimization of NaOH Molarity, LUSI Mud/Alkaline Activator, and Na2SiO3/NaOH Ratio to Produce Lightweight Aggregate-Based Geopolymer

Science.gov (United States)

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

UTJECAJ POZITIVNE DISKRIMINACIJE NA UKLJUČIVANJE ŽENA NA TRŽIŠTE RADA U REPUBLICI HRVATSKOJ

OpenAIRE

Dovranić, Dora; Katavić, Ivica

2016-01-01

U početku 21. stoljeća često se koristi pojam pozitivne (afirmativne) diskriminacije. Pozitivna diskriminacija mjera je koju poduzima vlada, neka organizacija ili korporacija s ciljem da se smanje nejednakosti u društvu nastale upravo diskriminacijom, na način da se pružaju određene povlastice onima koji su pretrpjeli neku vrstu diskriminacije. Nastala je u Sjedinjenim Američkim Državama na inicijativu predsjednika Kennedyja, Johnsona i Nixona. Diskriminacija, nažalost, ima mnogo oblika, a ne...

Natural lectin activity in the haemolymph of Panstrogylus megistus (Heteroptera: Reduvidae Atividade lectínica na hemolinfa de Panstrongylus megistus (Heteroptera: Reduviidae

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Y. M. Gomes

1988-12-01

Full Text Available The haemolymph of Panstrongylus megistus showed a natural lectin activity for a wide range of vertebrate erythocytes. Agglutination was observed against all vertebrate erythrocytes tested (human ABO, duck, rabbit, mouse, sheep, chicken and cow. Cow erythrocytes showed the lowest titre. Concerning human erythrocytes, the lectin activity was similar in the types A+,B+ and AB+ while the highest activity was observed in the type O+. Determination of minimal inhibitory concentrations was carried out with human erythrocytes type O+. Agglutination was inhibited by several carbohydrates (rhamnose. D-galatose, raffinose, D-lactose and D-fucose. Rhamnose wasreported as the strongest inhibitor (0.78mM. The results suggest the presence of more than one lection in the haemolymph of P. megistus.A hemolinfa de Panstrongylus megistus mostrou uma atividade lectínica natural para eritrócitos de vários vertebrados e não mostrou especificidade para os diversos tipos de eritrócitos testados (humano ABO, pato, coelho,c amundongo,carneiro, galinha e boi. Com relação aos eritrócitos humanos a atividade lectínica foi similar nos tipos A+, B+ e AB+ enquanto a atividade mais alta foi observada no tipo O+. O título de aglutinação entre eritrócitos animais não mostrou diferença apreciável, excluindo eritrócitos de boi, que apresentaram o título mmais baixo. A determinação da concentração mínima de inibição foi realizada com eritrócitos humanos O+. A aglutinação foi inibida por vários carboidratos (ramnose, D-dalactose, rafinose, D-lactose e D-fucose. A ramnose foi o inibidor mais potente (0,78 mM. Os resultados sugerem a presença de mais de uma lectina na hemolinfa de P. megistus.

Natural radioactivity levels in soils of Fiji

International Nuclear Information System (INIS)

Garimella, S.; Kumar, A.; Prasad, U.; Jafar, M.

1998-01-01

A 10 cm (diameter) x 7.5 cm NaI(Tl) gamma-ray spectrometer with a low background shield has been used to measure the natural radioactivity levels in soils of Viti Levu, the main island of Fiji. From this, the external gamma-dose which is likely to be delivered to the local population in this region is computed and found to be 99 μGy a -1 . This is well below the world average, but it is comparable to that observed in Marshall Islands and the Micronesia

Measurements of natural radioactivity inside Dandara temple

International Nuclear Information System (INIS)

Ahmed, N.K.; Saied, M.H.; Abbady, A.; El-Kamel, A.H.

1994-01-01

The natural radioactivities inside Dandara temple are studied by using a NaI(Tl) scintillation spectrometer. The variation of these activities with location is investigated. Average values of the identified radionuclides inside the halls, sanctuary and crypt of the temple are examined. It is estimated that the mean value lies in the range 37.9-90.1 for 212 Pb, 70.0-36.0 for 214 Bi, 52.6-76.2 for 228 Ac, 1.6-5.9 for 208 Tl, while for 40 K it is 169.3-286.6. (author)

Natural radioactivity levels in soils of Fiji

International Nuclear Information System (INIS)

Garimella, S.; Kumar, A.; Prasad, U.; Jafar, M.

1998-01-01

A 10 cm (diameter) x 7.5 cm NaI(TI) gamma-ray spectrometer with a low background shield has been used to measure the natural radioactivity levels in soils of Viti Levu, the main island of Fiji. From this, the external gamma-dose which is likely to be delivered to the local population in this region is computed and found to be 99 microG a -1 . This is well below the world average, but it is comparable to that observed in Marshall Islands and the Micronesia. (author). 17 refs., 3 figs., 5 tabs

Adsorção de ácidos húmicos em latossolo roxo natural e tratado com oxalato de amônio

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D. P. Dick

2000-06-01

Full Text Available A interação de substâncias húmicas com minerais no solo pode influir na dinâmica da decomposição da matéria orgânica e na sua estabilidade. A adsorção de dois ácidos húmicos em Latossolo Roxo natural (LR natural e tratado com oxalato de amônio (LR tratado foi efetuada, com vistas em investigar os mecanismos de adsorção e os principais grupos funcionais envolvidos, bem como relacionar a capacidade adsortiva de acordo com as características químicas e moleculares dos adsorbatos. Os ácidos húmicos extraídos com solução de NaOH 0,5 N de uma amostra de carvão (AHc e de um solo Brunizém (AHs foram caracterizados por análise elementar e espectroscopia de 13C-RMN. A parametrização dos dados experimentais das isotermas de adsorção foi do tipo y = A tanh Bx, e o modelo de Langmuir também foi aplicado. As amostras adsorvidas foram analisadas por espectroscopia no Infra-Vermelho por Reflectância Difusa com Transformada de Fourier (DRIFT. A adsorção dos ácidos húmicos no LR natural foi de natureza química, sendo evidenciado por DRIFT que a reação de troca de ligantes das carboxilas com a superfície dos minerais foi um mecanismo importante. O AHc, que apresentou caráter aromático mais elevado e maior teor de carboxilas na molécula, foi adsorvido em maior quantidade do que o AHs nos dois adsorventes, o que indica a possível participação de estruturas aromáticas na interação organomineral. No LR tratado, cuja área superficial específica foi superior (ASE = 140,9 m² g-1, a adsorção foi mais elevada do que no LR natural (ASE = 66,1 m² g-1. A maior ASE no LR tratado foi relacionada com o rompimento de microagregados no tratamento com oxalato de amônio que extraiu a porção cimentante dos óxidos de ferro que unia os minerais. A interação neste tipo de adsorvente, estimada segundo a equação y = A tanh Bx, foi mais forte do que na amostra natural, o que pode estar relacionado com a presença de sítios de

Reaction of metal oxides with molten mixtures NaPO3+NaCl

International Nuclear Information System (INIS)

Kovarskaya, E.N.; Mityakhina, V.S.; Rodionov, Yu.I.; Silin, M.Yu.

1988-01-01

By methods of solubility determination and paper chromatography it is shown, that Fe 2 O 3 solution in NaPO 3 +NaCl melts in the air relizes due to its chemical interaction with solvent resulting in formation of iron and sodium binary di- and monophosphates depending on melt-solvent initial composition, its attainment of equilibrium state and experiment temperature. It is established, that oxides increased solubility in melts with NaCl initial content ∼30 mol.% is specified by sodium tri- and tricyclophosphates presence in the melts. On this basis of NGR-spectroscopy data the presence of iron, europium, tin and sodium binary di- and monophosphates in some chloride-polyphosphate melts is confirmed

Crystal structure of polyphosphates NaCd(PO3)3 and NaMn(PO3)3

International Nuclear Information System (INIS)

Murashova, E.V.; Chudinova, N.N.

1997-01-01

Crystal structure of NaCd(PO 3 ) 3 (1) and NaMn(PO 3 ) 3 (2) isostructural polyphosphates was determined for twin samples. Rhombic lattice parameters of (1): a = 14.678, b = 14.669, c = 14.705 A, sp. gr. P2 1 2 1 2 1 , Z = 16. The structure of compounds is of frame type. Polyphosphate chain with repetition period of 24 PO 4 tetrahedrons contacts with NaO 6 and M 2 O 6 octahedrons by means of common oxygen vertices. Similarities and differences in structure of mentioned polyphosphates and earlier analyzed NaMg(PO 3 ) 3 polyphosphate are noted [ru

Gamma ray doses proceeding from natural occurring radionuclides in closed environments

International Nuclear Information System (INIS)

Aguiar, Vitor Angelo P. de; Medina, Nilberto H.; Silveira, Marcilei A. Guazzelli da; Moreira, Ramon H.

2009-01-01

In this work we report on the application of gamma-ray spectrometry in the study of the effective dose coming from terrestrial natural elements present in building materials such as sand, cement, lime (CaO) and milled granitic stones. The major contribution to annual gamma-ray radiation effective dose is due to the natural occurring radionuclides 40 K, 232 Th and 238 U. Two spectrometry systems were employed to measure the gamma radiation: one with a 60% efficient GeHP detector and the second one with a 2''x2'' NaI(Tl) scintillator. The estimated effective dose coming from the three reference rooms assumed is 0.63 mSv/yr, proceeding from terrestrial natural elements. The principal gamma radiation sources are cement, sand and bricks. (author)

Capabilities of laser ablation mass spectrometry in the differentiation of natural and artificial opal gemstones.

Science.gov (United States)

Erel, Eric; Aubriet, Frédéric; Finqueneisel, Gisèle; Muller, Jean-François

2003-12-01

The potentialities of laser ablation coupled to ion cyclotron resonance Fourier transform mass spectrometry are evaluated to distinguish natural and artificial opals. The detection of specific species in both ion detection modes leads us to obtain relevant criteria of differentiation. In positive ions, species including hafnium and large amounts of zirconium atoms are found to be specific for artificial opal. In contrast, aluminum, titanium, iron, and rubidium are systematically detected in the study of natural opals. Moreover, some ions allow us to distinguish between natural opal from Australia and from Mexico. Australian gemstone includes specifically strontium, cesium, and barium. Moreover, it is also found that the yield of (H2O)0-1(SiO2)nX- (X- = O-, OH-, KO-, NaO-, SiO2-, AlO1-2-, FeO2-, ZrO2-, and ZrO3-) and (Al2O3)(SiO2)nAlO2- ions depends on the composition of the sample when opals are laser ablated. Ions, which include zirconium oxide species, are characteristics of artificial gem. In contrast, natural opals lead us, after laser ablation, to the production of ions including H2O, Al2O3 motifs and AlO-, KO-, NaO-, and FeO2- species.

Effect of growth in lithium on ouabain binding, Na-K-ATPase and Na and K transport in hela cells.

Science.gov (United States)

Boardman, L J; Hume, S P; Lamb, J F; Polson, J

1975-01-01

1. HeLa cells were grown for 24 hr in growth medium in which part of the Na was replaced with Li. Ion contents, cell volumes and numbers, Na-K-ATPase and specific ouabain binding were measured. In some experiments the Na efflux and net Na transport was also measured. 2. Growth in Li caused a rise in the specific ouabain binding and membrane Na-K-ATPase of these cells. The Li concentrations in the cells necessary to produce this effect ranged up to 50 mM. 3. It is suggested that Li, like Na, acts on the genetic material of the cells to cause the production of more Na pumps within the membrane. PMID:124350

Effects of EDTA-Na (Na ethylenediaminetetraacetate) upon the metabolism of radiostrontium and radioyttrium in mice

Energy Technology Data Exchange (ETDEWEB)

Kikuchi, T; Wakisaka, G; Kono, T; Hiroaki, A; Yamamasu, T; Sugawa, I

1954-01-01

The toxicity of EDTA-Na, inert Sr (NO/sub 3/)/sub 2/ and Ba (NO/sub 3/)/sub 2/ has been examined. Simultaneous injection of EDTA-Na showed no significant effect upon the distribution of radio-Sr in the bones of mice. The distribution of radio-Y in the bones of mice tended to decrease following the simultaneous subcutaneous injection of /sup 91/Y and EDTA-Na.

Uranium ISR Mine Closure — General Concepts and Model-Based Simulation of Natural Attenuation for South-Australian Mine Sites

Energy Technology Data Exchange (ETDEWEB)

Jeuken, B.; Märten, H.; Woods, P., E-mail: horst.maerten@heathgate.com.au [Heathgate Resources Pty. Ltd. (Heathgate), Adelaide (Australia); Kalka, H.; Nicolai, J. [Umwelt- und Ingenieurtechnik GmbH Dresden (UIT), Dresden (Germany)

2014-05-15

Heathgate has demonstrated the effect of natural attenuation (NA) in post in-situ recovery (ISR) aquifer regions during the operation of the Beverley mine since 2001. Enhanced natural attenuation (ENA) has been considered as the key component of the mine closure concept for the new Beverley Four Mile (BFM) project, complemented by an extensive monitoring program. Data from batch and column tests for BFM core samples was used to calibrate a reactive transport model, whose application in conjunction with the hydrological modelling of the BFM aquifer has shown that NA will result in the restoration of the aquifer in time. ENA within a staged mine development program under the site-specific circumstances is discussed. (author)

Naturally radioactivity in common building materials used in Thiruvannamalai city, Tamilnadu, India

International Nuclear Information System (INIS)

Ravisankar, R.; Vanasundari, K.; Suganya, M.; Sivakumar, S.; Senthilkumar, G.; Chandramohan, J.; Vijayagopal, P.; Venkatraman, B.

2012-01-01

The radioactivity of some building materials used in Thiruvannamalai city has been measured using a NaI(Tl) detector based gamma ray spectrometer. The distribution of natural occurring radionuclides ( 226 Ra, 232 Th and 40 K) in the building materials was studied. The radium equivalent activity (Ra eq ), external hazard index (H ex ) internal radiation hazard index (H in ) and the activity utilization index (I) associated with the natural radionuclide are calculated to assess the radiation hazard of the natural radioactivity in the building materials. The present work shows that the natural radioactivity levels in the building construction materials used in Thiruvannamalai city is well below the acceptable limits. From the analysis, it was found that these materials may be safely used as construction materials and do not pose significant radiation hazards. (author)

Situação atual da filariose bancroftiana na cidade de Maceió, estado de Alagoas, Brasil

Directory of Open Access Journals (Sweden)

Gilberto Fontes

1994-07-01

Full Text Available Com o objetivo de determinar a prevalência e a distribuição da filariose linfática bancroftiana na área urbana de Maceió, estado de Alagoas, assim como identificar os insetos vetores na região, foram realizados inquéritos hemoscópicos e entomológicos. Foram examinadas, pelo método da gota espessa, amostras de sangue de 10.450 escolares oriundos de diferentes regiões da cidade, sendo detectado 0,66% de indivíduos microfilarêmicos por Wuchereria bancrofti. A parasitose tem distribuição focal com 80% dos indivíduos com infecção patente detectados em duas regiões vizinhas, cujas prevalências atingiram 1,24% e 5,25%. Estudos paralelos feitos em amostras populacionais com indivíduos de diferentes faixas etárias mostraram prevalências semelhantes às detectadas entre os escolares. No entanto, o exame dos familiares de indivíduos infectados pela W. bancrofti mostrou prevalência seis vezes mais alta, sugerindo maior transmissão no intradomicílio. A percentagem de parasitados foi maior no grupo etário mais jovem (< 20 anos. Mosquitos Culex quinquefasciatus capturados nos bairros onde a parasitose foi detectada apresentavam taxas de infecção natural de 0,28% até 4,62%. Esses dados descrevem a ocorrência da transmissão natural da filariose bancroftiana na área urbana de Maceió, Alagoas. Baseadas nesses dados, medidas de controle da filariose foram planejadas para conter sua expansão na região analisada.

Evaluation of the potentiality of a Mexican natural zeolite chabazite-type in the lead removal in water

International Nuclear Information System (INIS)

Alvarado I, J.; Sotelo L, M.; Meza F, D.; Paz M, F. A.; Maubert F, M.

2013-01-01

The intention of this paper is to present the characterization of a natural zeolite, chabazite-type, from the Mexican reservoir La Palma, at Divisaderos, Sonora, where their potential use as ion exchange material to remove lead in water is assessed. The chabazite was characterized through X-ray diffraction, Icp-OES, Icp-Ms, EDX, Bet and TG/TGD. The results indicate the presence of Ba(1930 ppm) and Sr(1220 ppm), which are characteristic of aluminium rich phases. A chabazite modification treatment is proposed by using solutions of NaOH (0.1 M) and NH 4 NO 3 (1 M). The lead removal kinetics both in natural zeolite as in their chemically modified forms was obtained by using the ion exchange process in a batch reactor. The results show how unnecessary natural zeolite homo ionization is for the removal of lead, thereby obtaining the equilibrium concentration of unmodified zeolite for plotting the adsorption isotherm, which was adjusted to Langmuir model. The Langmuir isotherm has a good fit of the results at equilibrium (R 2 =0.92), which demonstrates that natural zeolites studied, in its natural form, contains exchangeable cations required (Ca +2 , Mg 2+ and Na + ) for potentially be used as an adsorbent material/ion exchanger for water treatment impacted by lead. (Author)

Synthesis and characterization of NaSbS2 thin film for potential photodetector and photovoltaic application

Institute of Scientific and Technical Information of China (English)

Zhe Xia; Jiang Tang; Feng-Xin Yu; Shuai-Cheng Lu; Ding-Jiang Xue; Yi-Su He; Bo Yang; Chong Wang; Rui-Qing Ding; Jie Zhong

2017-01-01

Solution-processed semiconductors such as perovskite compounds have attracted tremendous attention to photovoltaic research due to the significantly higher energy conversion efficiencies and lower processing costs.However,concerns over stability and the toxicity on lead in CH3NH3PbI3 create the need for still easily-accessible but more stable and environmentally friendly materials.Here,we present NaSbS2 as a non-toxic,earth-abundant promising material consisting of densely packed (1/∞) [SbS2-] polymeric chains and sodium ions.The ionic nature makes it sharing the similar dissolution superiority with perovskite,providing great potential for low-cost and large-scale fabrication.Phase pure NaSbS2 thin film was successfully fabricated using spray-pyrolysis method,and its photovoltaic relevant material,optical and electrical properties were carefully studied.Finally,a prototype NaSbS2-based thinfilm solar cell has been successfully demonstrated,yielding a power conversion efficiency of 0.13％.The systematic experimental and theoretical investigations,combined with proof-of-principle device results,indicate that NaSbS2 is indeed very promising for photovoltaic application.

Novel aspects of Na+,K+-ATPase

OpenAIRE

Aizman, Oleg

2002-01-01

Na,K-ATPase, an integral membrane protein expressed in each eukaryotic cell, serves as the major determinant of intracellular ion composition. In the current study we investigated novel aspects of Na,K-ATPase function and regulation. It is well established that Na,K-ATPase activity is regulated by reversible phosphorylation. New findings in this study are: 1) the level of intracellular Ca 2. concentration determines the functional effects of PKA and PKC-mediated Na,K-ATP...

High-Performance Na-O2 Batteries Enabled by Oriented NaO2 Nanowires as Discharge Products.

Science.gov (United States)

Khajehbashi, S Mohammad B; Xu, Lin; Zhang, Guobin; Tan, Shuangshuang; Zhao, Yan; Wang, Lai-Sen; Li, Jiantao; Luo, Wen; Peng, Dong-Liang; Mai, Liqiang

2018-06-13

Na-O 2 batteries are emerging rechargeable batteries due to their high theoretical energy density and abundant resources, but they suffer from sluggish kinetics due to the formation of large-size discharge products with cubic or irregular particle shapes. Here, we report the unique growth of discharge products of NaO 2 nanowires inside Na-O 2 batteries that significantly boosts the performance of Na-O 2 batteries. For this purpose, a high-spin Co 3 O 4 electrocatalyst was synthesized via the high-temperature oxidation of pure cobalt nanoparticles in an external magnetic field. The discharge products of NaO 2 nanowires are 10-20 nm in diameter and ∼10 μm in length, characteristics that provide facile pathways for electron and ion transfer. With these nanowires, Na-O 2 batteries have surpassed 400 cycles with a fixed capacity of 1000 mA h g -1 , an ultra-low over-potential of ∼60 mV during charging, and near-zero over-potential during discharging. This strategy not only provides a unique way to control the morphology of discharge products to achieve high-performance Na-O 2 batteries but also opens up the opportunity to explore growing nanowires in novel conditions.

Cultivo de beterraba em ambientes protegido e natural na época de verão

OpenAIRE

João A. Tullio; Rosana F. Otto; Adriane Boer; Silvana Ohse

2013-01-01

Objetivou-se neste trabalho avaliar as respostas produtivas de beterraba cultivada em ambiente natural e sob túnel com malha de sombreamento durante a época de verão. O delineamento experimental foi blocos ao acaso com quatro repetições e os tratamentos arranjados em parcela sub-subdividida tendo, como fator primário, os ambientes de cultivo (protegido e natural), como fator secundário, as cultivares (Itapuã 202 e Tall Top Early Wonder) além das épocas de colheita (13, 26, 39, 52 e 65 dias ap...

Insight to the Thermal Decomposition and Hydrogen Desorption Behaviors of NaNH2-NaBH4 Hydrogen Storage Composite.

Science.gov (United States)

Pei, Ziwei; Bai, Ying; Wang, Yue; Wu, Feng; Wu, Chuan

2017-09-20

The lightweight compound material NaNH 2 -NaBH 4 is regarded as a promising hydrogen storage composite due to the high hydrogen density. Mechanical ball milling was employed to synthesize the composite NaNH 2 -NaBH 4 (2/1 molar ratio), and the samples were investigated utilizing thermogravimetric-differential thermal analysis-mass spectroscopy (TG-DTA-MS), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) analyses. The full-spectrum test (range of the ratio of mass to charge: 0-200) shows that the released gaseous species contain H 2 , NH 3 , B 2 H 6 , and N 2 in the heating process from room temperature to 400 °C, and possibly the impurity gas B 6 H 12 also exists. The TG/DTA analyses show that the composite NaNH 2 -NaBH 4 (2/1 molar ratio) is conductive to generate hydrogen so that the dehydrogenation process can be finished before 400 °C. Moreover, the thermal decomposition process from 200 to 400 °C involves two-step dehydrogenation reactions: (1) Na 3 (NH 2 ) 2 BH 4 hydride decomposes into Na 3 BN 2 and H 2 (200-350 °C); (2) remaining Na 3 (NH 2 ) 2 BH 4 reacts with NaBH 4 and Na 3 BN 2 , generating Na, BN, NH 3 , N 2 , and H 2 (350-400 °C). The better mechanism understanding of the thermal decomposition pathway lays a foundation for tailoring the hydrogen storage performance of the composite complex hydrides system.

Distinct pH dependencies of Na+/K+ selectivity at the two faces of Na,K-ATPase.

Science.gov (United States)

Cornelius, Flemming; Tsunekawa, Naoki; Toyoshima, Chikashi

2018-02-09

The sodium pump (Na,K-ATPase) in animal cells is vital for actively maintaining ATP hydrolysis-powered Na + and K + electrochemical gradients across the cell membrane. These ion gradients drive co- and countertransport and are critical for establishing the membrane potential. It has been an enigma how Na,K-ATPase discriminates between Na + and K + , despite the pumped ion on each side being at a lower concentration than the other ion. Recent crystal structures of analogs of the intermediate conformations E2·Pi·2K + and Na + -bound E1∼P·ADP suggest that the dimensions of the respective binding sites in Na,K-ATPase are crucial in determining its selectivity. Here, we found that the selectivity at each membrane face is pH-dependent and that this dependence is unique for each face. Most notable was a strong increase in the specific affinity for K + at the extracellular face ( i.e. E2 conformation) as the pH is lowered from 7.5 to 5. We also observed a smaller increase in affinity for K + on the cytoplasmic side (E1 conformation), which reduced the selectivity for Na + Theoretical analysis of the p K a values of ion-coordinating acidic amino acid residues suggested that the face-specific pH dependences and Na + /K + selectivities may arise from the protonation or ionization of key residues. The increase in K + selectivity at low pH on the cytoplasmic face, for instance, appeared to be associated with Asp 808 protonation. We conclude that changes in the ionization state of coordinating residues in Na,K-ATPase could contribute to altering face-specific ion selectivity. © 2018 by The American Society for Biochemistry and Molecular Biology, Inc.

OGLAŠEVANJE NA FACEBOOKU

OpenAIRE

Renko, Katica

2013-01-01

V magistrskem delu smo se seznanili z oglaševanjem na Facebooku. S pregledom gradiva, ki nam je ponujeno, smo preverili pogoje, načine, oblike … oglaševanja, ki pa smo jih s pregledom situacije v praksi preverili in dopolnili. Ob zaključku dela lahko rečemo, da je oglaševanje preko FB enostavnejše, cenejše, dostopnejše, omogoča nam ažurnost in samo komunikacijo z naslovniki, ki so potencialni kupci naših ponudb. Množični mediji nam omogočajo mnogotero obliko oglaševanja. Izbrana oblika ponuja...

Synchrotron-Radiation X-Ray Investigation of Li+/Na+ Intercalation into Prussian Blue Analogues

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Yutaka Moritomo

2013-01-01

Full Text Available Prussian blue analogies (PBAs are promising cathode materials for lithium ion (LIB and sodium ion (SIB secondary batteries, reflecting their covalent and nanoporous host structure. With use of synchrotron-radiation (SR X-ray source, we investigated the structural and electronic responses of the host framework of PBAs against Li+ and Na+ intercalation by means of the X-ray powder diffraction (XRD and X-ray absorption spectroscopy (XAS. The structural investigation reveals a robust nature of the host framework against Li+ and Na+ intercalation, which is advantageous for the stability and lifetime of the batteries. The spectroscopic investigation identifies the redox processes in respective plateaus in the discharge curves. We further compare these characteristics with those of the conventional cathode materials, such as, LiCoO2, LiFePO4, and LiMn2O4.

Resposta de pastagens perenes à adubação com chorume suíno: pastagem natural Response of perennial pasture to fertilization with pig slurry: natural pasture

Directory of Open Access Journals (Sweden)

Simone Meredith Scheffer-Basso

2008-02-01

Full Text Available Este trabalho foi realizado com o objetivo de verificar a resposta de uma pastagem natural na Depressão Central do Rio Grande do Sul à adubação com chorume suíno nas doses de 0, 15, 30 e 45 m³/ha, equivalentes a 76,8; 153,7 e 230,5 kg N/ha/corte depois de cada um dos quatro cortes, realizados no período de outubro de 2003 e fevereiro de 2004, totalizando 0, 60, 120 e 180 m³/ha de chorume. A massa seca (MS da pastagem aumentou de forma linear de acordo com as doses de chorume. Na pastagem testemunha, com aplicação de 45 m³/ha/corte, houve aumento de 108% na produção de MS (1.137 kg/ha/corte; 4.549 kg/ha no total dos cortes e de 42% na altura da pastagem (21 cm e redução de 8% no conteúdo de fibra em detergente ácido (FDA (41,8%. A eficiência da aplicação do chorume foi, em média, de 16,9 kg MS/m³/corte. Com as aplicações do fertilizante, verificou-se aumento na concentração de nutrientes no solo (máximo: K = 200 mg/L; P = 52 mg/L; Ca = 1,8 cmol c/dm-3; Mg = 1,4 cmol c/dm-3. A dose de 30 m³/ha/corte pode ser um valor-referência para as pastagens naturais na primavera-verão.The work had the objective to verify the response of a natural pasture, in the "Depressão Central of Rio Grande do Sul", Brazil, to pig slurry fertilization, in the doses of 0, 15, 30 and 45 m³/ha, equivalent to total application of 0, 76.5, 153.3, and 230.5 kg N/ha/cutting of N after each one of the four cuttings, between October/03 and February/04, totalizing 0, 60, 120, and 180 m³/ha of slurry. There was a linear increase of dry matter (DM as function of pig slurry application. Compared to the control treatment, application of 45 m³/ha/cutting resulted in: a 108% increase in the DM production (1.137 kg/ha/cutting; 4.549 kg/ha in total of the cuttings and 42% in the pasture height (21 cm; b 8% decrease in the ADF concentration (41.8%. The pig slurry application efficiency was, on average, 16.9 kg DM/m³/cutting. There was addition of soil

Laser-induced ionization of Na vapor

International Nuclear Information System (INIS)

Wu, R.C.Y.; Judge, D.L.; Roussel, F.; Carre, B.; Breger, P.; Spiess, G.

1982-01-01

The production of Na 2 + ions by off-resonant laser excitation in the 5800-6200A region mainly results from two-photon absorption by the Na 2 molecule to highly excited gerade states followed by (a) direct ionization by absorbing a third photon or (b) coupling to the molecular Na 2 D 1 PIμ Rydberg state which is subsequently ionized by absorbing a third photon. This mechanism, i.e., a two-photon resonance three photon ionization process, explains a recent experimental observation of Roussel et al. It is suggested that the very same mechanism is also responsible for a similar observation reported by Polak-Dingels et al in their work using two crossed Na beams. In the latter two studies the laser-induced associative ionization processes were reported to be responsible for producing the Na 2 + ion. From the ratio of molecular to atomic concentration in the crossed beam experiment of Polak-Dingels et al we estimate that the cross section for producing Na 2 + through laser-induced associative ionization is at least four orders of magnitude smaller than ionization through the two-photon resonance three photon ionization process in Na 2 molecules

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

Energy Technology Data Exchange (ETDEWEB)

Salim, Mashitah Mad; Malek, Nik Ahmad Nizam Nik, E-mail: niknizam@fbb.utm.my

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, 5 h) and this material has excellent performance as an antibacterial agent after silver ions loading. - Highlights: • Thermal treatment was used to regenerate surfactant modified zeolite. • The regenerated NaY zeolite formed was added with different silver loadings. • Regenerated AgY zeolite was tested for antibacterial activity on E. coli and S. aureus. • The antibacterial activity increased with increased of the amount of silver loadings. • The zeolite structure did not change with thermal and modification

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

International Nuclear Information System (INIS)

Salim, Mashitah Mad; Malek, Nik Ahmad Nizam Nik

2016-01-01

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, 5 h) and this material has excellent performance as an antibacterial agent after silver ions loading. - Highlights: • Thermal treatment was used to regenerate surfactant modified zeolite. • The regenerated NaY zeolite formed was added with different silver loadings. • Regenerated AgY zeolite was tested for antibacterial activity on E. coli and S. aureus. • The antibacterial activity increased with increased of the amount of silver loadings. • The zeolite structure did not change with thermal and modification

Carbon dioxide sequestration using NaHSO4 and NaOH: A dissolution and carbonation optimisation study.

Science.gov (United States)

Sanna, Aimaro; Steel, Luc; Maroto-Valer, M Mercedes

2017-03-15

The use of NaHSO 4 to leach out Mg fromlizardite-rich serpentinite (in form of MgSO 4 ) and the carbonation of CO 2 (captured in form of Na 2 CO 3 using NaOH) to form MgCO 3 and Na 2 SO 4 was investigated. Unlike ammonium sulphate, sodium sulphate can be separated via precipitation during the recycling step avoiding energy intensive evaporation process required in NH 4 -based processes. To determine the effectiveness of the NaHSO 4 /NaOH process when applied to lizardite, the optimisation of the dissolution and carbonation steps were performed using a UK lizardite-rich serpentine. Temperature, solid/liquid ratio, particle size, concentration and molar ratio were evaluated. An optimal dissolution efficiency of 69.6% was achieved over 3 h at 100 °C using 1.4 M sodium bisulphate and 50 g/l serpentine with particle size 75-150 μm. An optimal carbonation efficiency of 95.4% was achieved over 30 min at 90 °C and 1:1 magnesium:sodium carbonate molar ratio using non-synthesised solution. The CO 2 sequestration capacity was 223.6 g carbon dioxide/kg serpentine (66.4% in terms of Mg bonded to hydromagnesite), which is comparable with those obtained using ammonium based processes. Therefore, lizardite-rich serpentinites represent a valuable resource for the NaHSO 4 /NaOH based pH swing mineralisation process. Copyright © 2016 Elsevier Ltd. All rights reserved.

Density functional theory study of neutral and singly-charged (NaBH{sub 4}){sub n} (n = 1–6) nanoclusters

Energy Technology Data Exchange (ETDEWEB)

Yang, Yongpeng [State Key Laboratory of Organic–Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Wu, Xiangming [Ping Xiang Sports School, Jiangxi 337000 (China); Liu, Chuan [State Key Laboratory of Organic–Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China); Huang, Shiping, E-mail: huangsp@mail.buct.edu.cn [State Key Laboratory of Organic–Inorganic Composites, Beijing University of Chemical Technology, Beijing 100029 (China)

2014-10-31

Highlights: • Structures of (NaBH{sub 4}){sub n} (n = 1–6) clusters are optimized by DFT calculation. • The Kubas interaction is observed in each cationic cluster. • Hydrogen molecule interacts with attached boron atom by Kubas interaction. • Cationic NaBH{sub 4} nanoclusters exhibit more easily H{sub 2} desorption. - Abstract: We report the global minimum structures of (NaBH{sub 4}){sub n} (n = 1–6) clusters by combining the particle swarm optimization algorithm with density functional theory. A newly formed hydrogen molecule is observed in each cationic structure, and the H{sub 2} interacts with adjacent boron atom by Kubas interaction. The results of localized orbital locator and natural bond orbital analysis reveal that the hydrogen molecule interacts with attached boron atom by the σ-bond and σ{sup ∗}-antibond of H{sub 2} in [NaBH{sub 4}]{sub n}{sup +} (n = 1, 2, 3 and 5), and the σ{sup ∗}-antibond dominates this interaction in [NaBH{sub 4}]{sub 4}{sup +} and [NaBH{sub 4}]{sub 6}{sup +}. The desorption energy of the hydrogen molecule is relatively small for [NaBH{sub 4}]{sup +} (1.05 eV), [NaBH{sub 4}]{sub 2}{sup +} (0.99 eV) and [NaBH{sub 4}]{sub 3}{sup +} (0.97 eV). It is also found that the negative desorption energy of the [NaBH{sub 4}]{sub 4}{sup +} (−0.26 eV), [NaBH{sub 4}]{sub 5}{sup +} (−0.26 eV) and [NaBH{sub 4}]{sub 6}{sup +} (−0.54 eV) shows that the hydrogen molecule can be released easily.

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

Science.gov (United States)

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. Copyright © 2015 Elsevier B.V. All rights reserved.

Composition and thermochemistry of the equilibrium vapour of the systems NaI-FeI2 and NaI-PbI2

International Nuclear Information System (INIS)

Hilpert, K.; Gerads, H.; Koberts, D.; Miller, M.

1987-01-01

The vaporization of NaI/FeI 2 and NaI/PbI 2 samples of equimolar composition was investigated was investigated in the temperature ranges between 574 to 683 K and 562 to 669 K, respectively, by using the mass spectrometric Knudsen effusion method. The gaseous species I, I 2 , NaI, (NaI) 2 , FeI 2 , (FeI 2 ) 2 , FeI 3 , NaFeI 3 , and Na 2 FeI 4 (NaI-FeI 2 system) as well as NaI, (NaI) 2 , PbI 2 , (PbI 2 ) 2 , and NaPbI 3 (NaI-PbI 2 system) are present in the equilibrium vapours. The equilibrium partial pressures of these species were determined with the exception of I, I 2 , and FeI 3 . Enthalpies and entropies of dissociation resulted for the reactions NaFeI 3 (g) ↔ NaI(g)+FeI 2 (g) (1), Na 2 FeI 4 (g) ↔ 2NaI(g)+FeI 2 (g) and (2) NaPbI 3 (g) ↔ NaI(g)+PbI 2 (g) (3) as Δ d H 298 0 (Eq. (1)) = 184±5 kJ mol -1 , Δ d S 298 0 (Eq. (1)) = 143±8 J mol -1 K -1 ; Δ d H 298 0 (Eq. (2)) = 333±9 kJ mol -1 , Δ d S 298 0 (Eq. (2)) = 274±14 J mol -1 K -1 ; and Δ d H 298 0 (Eq. (3)) = 168±5 kJ mol -1 , Δ d S 298 0 (Eq. (3)) = 151±9 J mol -1 K -1 . Equilibrium constants for these reactions are additionally given. The pressures of NaFeI 3 (g) and NaPbI 3 (g) as all as their enthalpies of dissociation are discussed with respect to their significance of semi empirical rules. (orig.)

Adsorption and Formation of Small Na Clusters on Pristine and Double-Vacancy Graphene for Anodes of Na-Ion Batteries.

Science.gov (United States)

Liang, Zhicong; Fan, Xiaofeng; Zheng, Weitao; Singh, David J

2017-05-24

Layered carbon is a likely anode material for Na-ion batteries (NIBs). Graphitic carbon has a low capacity of approximately 35 (mA h)/g due to the formation of NaC 64 . Using first-principles methods including van der Waals interactions, we analyze the adsorption of Na ions and clusters on graphene in the context of anodes. The interaction between Na ions and graphene is found to be weak. Small Na clusters are not stable on the surface of pristine graphene in the electrochemical environment of NIBs. However, we find that Na ions and clusters can be stored effectively on defected graphene that has double vacancies. In addition, the adsorption energy of small Na clusters near a double vacancy is found to decrease with increasing cluster size. With high concentrations of vacancies the capacity of Na on defective graphene is found to be as much as 10-30 times higher than that of graphitic carbon.

Comparison of Polycyclic Aromatic Hydrocarbon (PAHs concentrations in urban and natural forest soils in the Atlantic Forest (São Paulo State

Directory of Open Access Journals (Sweden)

Christine Bourotte

2009-03-01

elevada na área urbana do que na área natural. Acenaftileno, acenafteno, fluoreno, fenantreno e fluoranteno foram detectados, em concentrações similares, nos solos das duas áreas. Acenafteno e fluoreno foram os compostos mais abundantes. O pireno foi duas vezes mais abundante no solo da área natural (15 µg.kg-1, e o fluoranteno foi o composto dominante (203 µg.kg-1 na área urbana (6,8 vezes mais elevado que na área natural. Alguns compostos de alto peso molecular, traçadores de emissões veiculares, foram detectados em quantidades significativas no solo da área urbana. O pireno representou 79% da ΣHPAs, enquanto que não foi detectado na área natural. Estes resultados evidenciaram que os solos de floresta em áreas urbanas são caracterizados pela acumulação de HPAs pesados oriundos de emissões industriais e veiculares.

Epoxidação "in situ" aplicada ao látex de borracha natural "In situ" epoxidation of natural rubber latex

Directory of Open Access Journals (Sweden)

Cristiane K. Santin

2012-01-01

Full Text Available O comportamento da borracha natural na forma látex frente à reação de epoxidação foi avaliado visando estabelecer as melhores condições reacionais sem a ocorrência de reações laterais, que promovem a coagulação do látex e o desenvolvimento de um aglomerado de borracha. Grupos epóxidos foram gerados através da reação de epoxidação a partir da formação in situ do ácido perfórmico. As amostras foram caracterizadas qualitativamente por espectroscopia de infravermelho (FTIR e o grau de modificação determinado por ressonância magnética nuclear de hidrogênio (1H-RMN. Análises de calorimetria exploratória diferencial (DSC demonstraram que a mobilidade da cadeia polimérica foi influenciada pela presença de grupos epóxidos, com aumento linear na temperatura de transição vítrea (Tg. Os resultados indicaram que a epoxidação do látex de borracha natural, sem a ocorrência de reações laterais, é possível e dependente das condições reacionais.Natural rubber latex was submitted to epoxidation reaction to establish the best reaction conditions without the occurrence of side reactions, which promote coagulation of the latex and development of an agglomerate of rubber. Epoxy groups were produced by in situ epoxidation with formic acid and hydrogen peroxide. The samples were characterized qualitatively by Fourier Transform Infrared (FTIR analysis and the degree of modification determined by Hydrogen Nuclear Magnetic Resonance Spectroscopy (1H-NMR analysis. A linear increase in the glass transition temperature (Tg was observed. The results show that the epoxidation of natural rubber latex is possible and depends on the reaction conditions.

Novel regulation of cardiac Na pump via phospholemman.

Science.gov (United States)

Pavlovic, Davor; Fuller, William; Shattock, Michael J

2013-08-01

As the only quantitatively significant Na efflux pathway from cardiac cells, the Na/K ATPase (Na pump) is the primary regulator of intracellular Na. The transmembrane Na gradient it establishes is essential for normal electrical excitability, numerous coupled-transport processes and, as the driving force for Na/Ca exchange, thus setting cardiac Ca load and contractility. As Na influx varies with electrical excitation, heart rate and pathology, the dynamic regulation of Na efflux is essential. It is now widely recognized that phospholemman, a 72 amino acid accessory protein which forms part of the Na pump complex, is the key nexus linking cellular signaling to pump regulation. Phospholemman is the target of a variety of post-translational modifications (including phosphorylation, palmitoylation and glutathionation) and these can dynamically alter the activity of the Na pump. This review summarizes our current understanding of the multiple regulatory mechanisms that converge on phospholemman and govern NA pump activity in the heart. The corrected Fig. 4 is reproduced below. The publisher would like to apologize for any inconvenience caused. [corrected]. Copyright © 2013. Published by Elsevier Ltd.

Rabies virus infection in Eptesicus fuscus bats born in captivity (naïve bats.

Directory of Open Access Journals (Sweden)

April D Davis

Full Text Available The study of rabies virus infection in bats can be challenging due to quarantine requirements, husbandry concerns, genetic differences among animals, and lack of medical history. To date, all rabies virus (RABV studies in bats have been performed in wild caught animals. Determining the RABV exposure history of a wild caught bat based on the presence or absence of viral neutralizing antibodies (VNA may be misleading. Previous studies have demonstrated that the presence of VNA following natural or experimental inoculation is often ephemeral. With this knowledge, it is difficult to determine if a seronegative, wild caught bat has been previously exposed to RABV. The influence of prior rabies exposure in healthy, wild caught bats is unknown. To investigate the pathogenesis of RABV infection in bats born in captivity (naïve bats, naïve bats were inoculated intramuscularly with one of two Eptesicus fuscus rabies virus variants, EfV1 or EfV2. To determine the host response to a heterologous RABV, a separate group of naïve bats were inoculated with a Lasionycteris noctivagans RABV (LnV1. Six months following the first inoculation, all bats were challenged with EfV2. Our results indicate that naïve bats may have some level of innate resistance to intramuscular RABV inoculation. Additionally, naïve bats inoculated with the LnV demonstrated the lowest clinical infection rate of all groups. However, primary inoculation with EfV1 or LnV did not appear to be protective against a challenge with the more pathogenic EfV2.

Natural autoantibodies and complement promote the uptake of a self antigen, human thyroglobulin, by B cells and the proliferation of thyroglobulin-reactive CD4(+) T cells in healthy individuals

DEFF Research Database (Denmark)

Nielsen, C H; Leslie, R G; Jepsen, B S

2001-01-01

Serum from normal individuals contains substantial amounts of natural antibodies (NA) capable of recognizing self antigens. However, the physiological implications of this autoreactivity remain unclear. We have examined the role of self-reactive NA and complement in mediating the uptake of human...... cells are prerequisites for the proliferation of Tg-reactive CD4(+) T cells, suggesting a novel role for natural autoantibodies and complement in the regulation of autoreactivity under physiological conditions....

In situ bioremediation (natural attenuation) at a gas plant waste site

International Nuclear Information System (INIS)

Ginn, J.S.; Sims, R.C.

1995-01-01

A former manufactured gas plant (MGP) waste site in New York was evaluated with regard to natural attenuation of polycyclic aromatic hydrocarbons (PAHs). Parent-compound concentrations of PAHs within an aquifer plume were observed to decrease with time subsequent to source removal of coal tar. Biotransformation-potential studies indicated that indigenous microorganisms in soil from the site were capable of degrading naphthalene and phenanthrene. A biochemical metabolite of phenanthrene degradation, 1-hydroxy-2-naphthoic acid (1H2NA), was tentatively characterized in coal-tar-contaminated soil from the site-based on liquid chromatographic retention time. Kinetic information was developed for the disappearance of phenanthrene and 1H2NA in nonspiked contaminated soil at the site. The Microtox trademark bioassay was used to evaluate toxicity trends in contaminated soil at the site. Results from the Microtox trademark indicated a decreasing trend in toxicity with respect to time in contaminated site soil. Research results were evaluated with regard to the National Research Council's guidelines for evaluating in situ bioremediation, and were used to enhance site characterization and monitoring information for evaluating the role of bioremediation as part of natural attenuation of PAHs at coal-tar-contaminated sites

All new for NA62

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