Chemical constituents and evaluation of cytotoxic and antifungal activity of Lantana camara essential oils

Directory of Open Access Journals (Sweden)

Lídia B. P. Medeiros

2012-08-01

Full Text Available The essential oil (EO of aerial parts of Lantana camara L., Verbenaceae, from Simões, Piaui, Northeast of Brazil, were obtained by hydrodistillation and analyzed by GC-FID and GC-MS techniques. In total, 68 compounds were identified. The most representative compounds of the oil were mono and sesquiterpenes. The main compounds found in the oil of the leaves in different months were β-caryophyllene (10.5%, in June of 2009, sabinene (7.98%, in September of 2008, limonene (7.68%, in September of 2008, spathulenol (11.64%, in September of 2008. The oil from stems of L. camara was characterized by a largest amount of sesquiterpenoids, with spatulenol (15.9% and caryophyllene oxide (17.1% in June of 2009, as main components. β-Gurjunene (32.7%, in September of 2008 was the most prominent compound in the stems oils, which was absent or at very low relative abundance in leaves. L. camara essential oils from leaves were cytotoxic to V79 mammalian cells and also to Artemia salina, showing 50% lethal concentration (LC50 values from 0.23 µg/mL. The in vitro data obtained in this study suggested that EO may also be effective treating yeast infection in patients infected with fluconazole and terbinafine resistant isolates, but its toxicity must be monitored carefully.

Metal temperature monitoring in corrosive gases at high temperature and high thermal flows; Monitoreo de temperaturas de metal en gases corrosivos a alta temperatura y altos flujos termicos

Energy Technology Data Exchange (ETDEWEB)

Huerta Espino, Mario; Martinez Flores, Marco Antonio; Martinez Villafane, Alberto; Porcayo Calderon, Jesus; Gomez Guzman, Roberto; Reyes Cervantes, Fernando [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1991-12-31

The direct measurement of metal temperatures during operation in superheater, reheater, and water wall tubes in zones exposed to high thermal flows is of great interest for the operation and analysis of the correct functioning of a steam generator. The operation temperature measurement of these zones differs very much of the monitored temperature in headers in the dead chamber, since the temperature measured in this zone is the steam temperature that does not reflect the one detected in the gas zone. For this reason, the thermocouples implant in gas zones will detect the real metal temperature and the incidence that some operation variables might have on it (Martinez et al., (1990). [Espanol] La medicion directa de temperaturas de metal durante operacion en tubos de sobrecalentador, recalentador y pared de agua en zonas expuestas a altos flujos termicos es de gran interes para la operacion y analisis del buen funcionamiento de un generador de vapor. La medicion de la temperatura de operacion de estas zonas, difiere mucho de la temperatura monitoreada en cabezales en zona de camara muerta, ya que la temperatura registrada en esta zona es la de vapor que no es un reflejo de la detectada en zona de gases. Por esta razon, la implantacion de termopares en zona de gases detectara la temperatura de metal real y la incidencia que algunas variables de operacion tengan sobre esta (Martinez et al., 1990).

Metal temperature monitoring in corrosive gases at high temperature and high thermal flows; Monitoreo de temperaturas de metal en gases corrosivos a alta temperatura y altos flujos termicos

Energy Technology Data Exchange (ETDEWEB)

Huerta Espino, Mario; Martinez Flores, Marco Antonio; Martinez Villafane, Alberto; Porcayo Calderon, Jesus; Gomez Guzman, Roberto; Reyes Cervantes, Fernando [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1990-12-31

The direct measurement of metal temperatures during operation in superheater, reheater, and water wall tubes in zones exposed to high thermal flows is of great interest for the operation and analysis of the correct functioning of a steam generator. The operation temperature measurement of these zones differs very much of the monitored temperature in headers in the dead chamber, since the temperature measured in this zone is the steam temperature that does not reflect the one detected in the gas zone. For this reason, the thermocouples implant in gas zones will detect the real metal temperature and the incidence that some operation variables might have on it (Martinez et al., (1990). [Espanol] La medicion directa de temperaturas de metal durante operacion en tubos de sobrecalentador, recalentador y pared de agua en zonas expuestas a altos flujos termicos es de gran interes para la operacion y analisis del buen funcionamiento de un generador de vapor. La medicion de la temperatura de operacion de estas zonas, difiere mucho de la temperatura monitoreada en cabezales en zona de camara muerta, ya que la temperatura registrada en esta zona es la de vapor que no es un reflejo de la detectada en zona de gases. Por esta razon, la implantacion de termopares en zona de gases detectara la temperatura de metal real y la incidencia que algunas variables de operacion tengan sobre esta (Martinez et al., 1990).

LANTANA CAMARA: OVERVIEW ON TOXIC TO POTENT MEDICINAL PROPERTIES

OpenAIRE

Dr. Milindmitra K Lonare et al

2012-01-01

Lantana camara is more popular as toxic weed rather than medicinal plant in most of the countries responsible for infesting pastures, grazing lands, orchards and crops like, tea, coffee, oil palm, coconut and cotton, and reduces the economic viability of the crops. This plant can grow in even in extreme harsh climatic conditions of tropical and sub-tropical areas and has become naturalized worldwide as an ornamental plant including India. The stem, root and leaves contain many of the bioactiv...

Lantana camara invasion in urban forests of an Indo–Burma hotspot region and its ecosustainable management implication through biomonitoring of particulate matter

Directory of Open Access Journals (Sweden)

Prabhat Kumar Rai

2015-12-01

Full Text Available The present study was performed in urban forests of Aizawl, Mizoram, north east India falling under an Indo–Burma hot spot region of existing ecological relevance and pristine environment. The phytosociolology of invasive weeds has been studied, showing that Lantana camara was the most dominant invasive weed. Further, the air quality studies revealed high suspended particulate matter as well as respirable suspended particulate matter in the ambient air of Aizawl. Biomonitoring through plant leaves has been recognized as a recent thrust area in the field of particulate matter science. We aimed to investigate whether L. camara leaves may act as a biomonitoring tool hence allowing its sustainable management. The quantity of respirable suspended particulate matter and suspended particulate matter at four different sites were much higher than the prescribed limits of Central Pollution Control Board of India during the summer and winter seasons. The dust deposition of L. camara leaves was 1.01 mg/cm2 and, pertaining to the biochemical parameters: pH was 7.49; relative water content 73.74%; total chlorophyll 1.91 mg/g; ascorbic acid 7.06 mg/g; sugar 0.16 mg/g; protein 0.67 mg/g; catalase 30.76 U/mg protein; peroxidase 0.16 U/mg protein; and air pollution tolerance index was 12.91. L. camara was observed in the good category in anticipated performance index, which shows the tolerant and conditioning capacity of air pollution. Therefore, the present study recommends the use of L. camara as biomonitor that may further have sustainable management implications for an invasive plant.

Suppression of thermal and chemical nociception in rats by methanol extract and its sub-fraction from lantana camara

International Nuclear Information System (INIS)

Simjee, S.U.; Perveen, H.; Zehra, S.Q.

2016-01-01

The traditional use of Lantana camara (Verbenaceae) is reported to include anti-nociceptive, antimicrobial, and immunosuppressant activity. To our knowledge no systematic study has been carried out on the anti-nociceptive activity of L. camara. The present study was designed to delineate the analgesic activity of L. camara extract and its fractions to elucidate the traditional belief in the painkilling effects. Experimental models employed were thermal and chemical-induced nociception assays. After initial screening of the methanol extract and its fractions prepared from the aerial parts of the plant, the dose of 50,100 and 200 mg/kg were selected and route of administration was i.p. The test samples were tested against a reference drug indomethacine (i.p. 5 mg/kg). The observations were made at 15, 30, 60, and 120 seconds following the administration of the samples or reference drug. Experiments on naloxone antagonism were conducted to determine involvement of opioid receptors. Compared to concurrent controls, a significant anti-nociceptive activity was observed in methanol extract LC (ED50 50 mg/kg, P < 0.002) and its sub-fractions LCEA-AQ (ED50 50 mg/kg, P < 0.004), LCEA (ED50 100 mg/kg, P < 0.004) and LCEA-PEI (ED50 100 mg/kg, P < 0.005). No apparent acute toxicity was observed in any test groups. The anti-nociceptive activity was not precipitated by naloxone antagonism indicating that these fractions do not act through opioid receptors. The methanol extract and active fractions of Lantana camara possess anti-nociceptive activity. Further investigations are needed to elucidate the mechanism of its action. (author)

Antinociceptive and anti-inflammatory effects of Lantana camara L. extract in mice

Directory of Open Access Journals (Sweden)

T.S.C. SILVA

2015-06-01

Full Text Available ABSTRACT:he Lantana camara L. belongs to the family Verbenaceae, which contains several active compounds in leaves and roots and which are reported to have medicinal and insecticidal properties. Studies of plants within the same family show the existence of anti-inflammatory activity in paw edema induced by carrageenan, serotonin and histamine and analgesic activity in the acetic acid writhing and tail-flick tests. The present study investigated whether the L. camara extract (ACE also exerts these effects. The ACE toxicity was studied in male mice, and the percentage of mortality recorded 7 days after treatment was assessed. The ACE was evaluated as an antinociceptive agent in the hot plate, tail-flick and acetic acid writhing tests at a nontoxic dose of 1.0 g/Kg. The results showed that 1.5 g/Kg of ACE was not able to cause death, and doses of 3.0 and 4.0 g/Kg caused 50% and 60% death, respectively, in male mice. In all of the antinociceptive tests, 1 g/Kg of ACE markedly reduced responses to pain. Our findings suggest that ACE may have active anti-inflammatory and antinociceptive properties in much smaller doses than toxic.

The toxicity evaluation of prepared Lantana camara nano extract against Spodoptera litura (Lepidoptera: Noctuidae)

Science.gov (United States)

Kasmara, Hikmat; Melanie, Nurfajri, Dea Audia; Hermawan, Wawan; Panatarani, Camellia

2018-02-01

Nanotechnology plays an important role in providing opportunities and possibilities for the development of a plant extracts, particularly applied for agriculture using the organic nanoparticles extract as bioinsecticide. This paper reports the extraction of L. camaraas an insecticidal compound applied to control the S. litura larvae which is the main pest for agricultural commodities in Indonesia. The objective of this research is to evaluate the toxicity performance of nano extract to S. litura larvae. The extract was prepared by maceration and evaporation and followed by particles stabilization. The received suspension was characterized using a Particles Size Analyzer (PSA). The performance evaluation was conducted using dye feed method by observing at 24 h and 48 h. The toxicity performance of L. camara nano extract on S. litura larvae was evaluated based on the lethal concentration which was obtained at 50% of 3rd instar larvae S. litura (LC50) and the toxicity level. The larval mortality data was analyzed by probit analysis to obtain LC50 values. The results showed that the LC50 value of L. camara nano extract after 24 h was 16,347 ppm and after 48 h the LC50 value was 3,548 ppm. The smaller LC50 values indicate a stronger toxicity level, in contrast the best toxicity was LC50 after 48 h with the concentration of 3,548 ppm. Referring to toxicity category standard with LC50 pesticide value, the range 0.5-5 g/L is considered as medium toxic category. Toxicity level of L. camara nano extract to S. litura 3,548 ppm or 3,548 mg/L is considered as medium toxic category.

Photo and cathode luminescence emission in oxide silicium films implanted with silicium; Emision de foto y catodoluminiscencia en peliculas de oxido de silicio termico implantadas con silicio

Energy Technology Data Exchange (ETDEWEB)

Flores, F; Aceves, M. [Instituto Nacional de Astrofisica Optica y Electronica, Mexico, D.F. (Mexico); Carrillo, J. [Benemrita Universidad Autonoma de Puebla, Puebla (Mexico); Dominguez, C. [Universida Autonoma de Barcelona, Barcelona (Spain); Falcony, C. [Instituto Politecnico Nacional, Mexico, D.F. (Mexico)

2001-10-01

We studied the photo and cathodoluminescence of Silicon Rich Oxides (SRO) obtained by ion implant of Si in thermal oxides. Doses of 10{sup 1}6 cm{sup -}2 (low dose) and 10{sup 1}7 cm{sup -}2 (high dose) and implant energy of 150 keV were used. The films were annealed for 30, 60 and 180 minutes in nitrogen at 1100 Celsius degrees. The spectra show photo and cathodoluminescence emission in the visible range, the bands in the spectra change with the conditions of ion implant and annealing. The films without thermal treatment in both dose present photoluminescence bands around 1.9 eV (band B) and 2.4 eV (band C). With the thermal treatments, the band B disappears. In the case of the films with low dose, the band C shows a blue shift and a decrease in intensity. The high dose films have a band centered in 1.7 eV (band A) that increases its intensity with annealings. The cathodoluminescence bands in all the cases are in 2.7 eV (band D) and they present changes with the thermal treatments that it seems they depend on the variation in the implant parameters. [Spanish] Se estudian las propiedades de foto y la catodoluminiscencia de peliculas de oxidos de silicio ricos en Si (Silicon Rich Oxide SRO) obtenidas por implantacion ionica de Si en oxidos termicos. Se usaron dosis de 10{sup 1}6 cm{sup -}2 (dosis baja) y 10{sup 1}7 cm{sup -}2 (dosis alta) y energia de implantacion de 150 keV. Las peliculas se sometieron a tratamientos termicos por 30, 60 y 180 minutos en nitrogeno de 1100 grados centigrados. Se encontro emision foto y catodoluminiscente en el rango visible, las bandas en los espectros cambian con las condiciones de implantacion ionica y con los tratamientos termicos. Las peliculas sin tratamiento termico en ambas dosis presentan bandas de fotoluminiscencia alrededor de 1.9 eV (banda B) y 2.4 eV (banda C). Con los tratamientos termicos, la banda B desaparece. En el caso de las peliculas con dosis baja, la banda C muestra un corrimiento hacia el azul junto con una

High alpha cellulose from fast growing species such as Lantana camara (linn) and Hibiscus cannabinus

Energy Technology Data Exchange (ETDEWEB)

Manavalan, R.; Mithal, B.M.; Anand, S.M.; Chawla, J.S.

1980-01-01

Prehydrolysis of L. camara and kenaf with H/sub 2/O at 165 degrees, and kraft cooking gave pulp in 28-40% yield, and permanganate number 8.5-12. Bleaching of the pulps from these species by CEHED sequence gave products in 26-41% yield, and with 83-90% brightness.

Analytical model to describe the thermal behavior of a heat discharge system in roofs; Modelo analitico que describe el comportamiento termico de un sistema de descarga de calor en techos

Energy Technology Data Exchange (ETDEWEB)

Hernandez-Gomez, V.H.; Contreras-Espinosa, J.J.; Gonzalez-Ortiz, G.; Morillon-Galvez, D.; Fernandez-Zayas, J.L. [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)]. E-mail: vichugo@servidor.unam.mx; jjuancon2000@yahoo.com.mx; gilberto_gonzalez25@hotmail.com; damg@pumas.iingen.unam.mx; JFernandezZ@iingen.unam.mx

2012-01-15

The present study proposes an analytical model which describes the thermal behavior of a heat discharge system in roof, when the surfaces that constitute it are not translucent. Such a model derives from a thermal balance carried out to a heat discharge system in roofs. To validate it, an experimental prototype that allows simulating the thermal behavior of a heat discharge system in wall and roof was used, and the results were compared to those obtained with the proposed analytical model. It was found that the thermal behavior of the analytical model is similar to the thermal behavior of the experimental prototype; a worthless variation was detected among their respective outcome (The difference of temperatures can be caused by the heat transfer coefficient, of which no studies defining its behavior accurately have been found). Therefore, it can be considered that the proposed analytical model can be employed to simulate the thermal behavior of a heat discharge system in roofs when the surfaces that constitute it are opaque. [Spanish] En el presente estudio se propone un modelo analitico que describe el comportamiento termico de un sistema de descarga de calor en techo, cuando las superficies que lo componen no son translucidos. Dicho modelo surge a partir de un balance termico realizado a un sistema de descarga de calor en techos. Para validarlo, se realizaron dos corridas experimentales en un prototipo que permite simular el comportamiento termico de un sistema de descarga de calor en techo y se compararon los resultados medidos con los calculados por el modelo analitico propuesto. Se encontro que, el comportamiento termico del modelo analitico es similar al comportamiento termico del prototipo experimental, se detecto una variacion despreciable entre los valores arrojados por ambos modelos (la diferencia de temperaturas puede estar ocasionada por la obtencion del coeficiente convectivo de transferencia de calor, del cual no se han encontrado estudios que

EFEK ANTIPIRETIK KOMBINASI EKSTRAK DAUN COCOR BEBEK (Kalanchoe pinnata L. DAN EKSTRAK DAUN TEMBELEKAN(Lantana camara L. PERS.TERHADAP MARMUT (Cavia porcellus DENGAN DEMAM YANG DIINDUKSI PEPTON

Directory of Open Access Journals (Sweden)

Heni Purwitasari

2017-03-01

Full Text Available Cocor Bebek (Kalanchoe pinnata L. is a medicinal plant that has been used as traditional medicine for long period, used to fight fever, but it empirically leaves of  Tembelekan (Lantana camara L. are also generally primarily used to treat fever. Research on the effects of the combination of Cocor Bebek’s leaf extract (Kalanchoe pinnata L. and the leaf extract of tembelekan (Lantana camara L. Pers on male guinea pig (Cavia porcellus is induced peptone 5% at a dose of 150 mg / kg body weight. With the aim to determine the effect of the combination and determine the effects of the most effective as an antipyretic. Extracts prepared by maceration method using ethanol 95%. Marmots were divided into 4 groups. Each guinea pig was induced using peptone 5%. The first group was given Na CMC as a negative control group 2nd given a combination of one dose combinations (50 + 720. Group 3 was given a second dose combination (100 + 720. Group-4 were given a 3-dose combination (150 + 720. Temperature measurement is carried out for 2 hours with a 30 minute interval. Data were analyzed temperature measurements were statistically analyzed using ANOVA (Analisys Of Variance. The research result was addressing, that the combination of extracts can reduce fever. The combination is most effective as an antipyretic is cocor duck leaf extract 50 mg and 720 mg tembelekan leaf extract (50 + 720.

Impact of Lantana camara in the Indian society

Directory of Open Access Journals (Sweden)

Reshmi Chatterjee

2015-06-01

Full Text Available Lantana camara, an introduced species by the British has turned itself in to a noxious weed, which has expanded itself in almost all the possible habitats of India. It is a major threat to the ecosystem, including plants and animals. Attempt to combat the further spread of this nuisance species has been of little help. Therefore, in the present discussion an attempt on its impact, toxicity, uses and therapeutic properties have been discussed. A carefully knitted plan should be framed emphasizing on exploiting this species economically as well as on taming the present threat so that the Indian society can be benefitted by properly utilizing the plant and thereby also conserve the ecosystem with its bio resources. The present review paper focuses on the various benefitting sides of the Lantana that would create better livelihood opportunities. DOI: http://dx.doi.org/10.3126/ije.v4i2.12663 International Journal of Environment Vol.4(2 2015: 348-354

Thickness calculation software of the thermal insulation in facilities using thermal solar energy; Software para el calculo de espesores del aislante termico en instalaciones de aprovechamiento de energia solar termica

Energy Technology Data Exchange (ETDEWEB)

Portillo Jimenez, Canek [Universidad Autonoma de Sinaloa, Culiacan, Sinaloa (Mexico)]. E-mail: cnk@uas.uasnet.mx

2010-11-15

It is presented a software application for calculating the thickness of the thermal insulation used in various facilities where there are thermal systems using solar energy. The software facilitates the calculation of the thermal cover thickness over components such as pipes (flat or round), storage and other devices that require thermal protection, installed in outdoors or indoors. The software was programmed in Visual Basic by following the technical specifications of the current regulations in the field. Application examples are performed, obtaining certain results that are discussed briefly. [Spanish] Se presenta un software de aplicacion para el calculo de los espesores de los aislantes termicos, utilizados en diferentes instalaciones donde existen sistemas de aprovechamiento termico de energia solar. El software facilita el calculo del grosor del recubrimiento termico en componentes tales como: tuberias (planas o circulares), depositos acumuladores y otros aparatos que necesiten proteccion termica, instalados en exteriores o en interiores. El software fue programado en Visual Basic siguiendo las especificaciones tecnicas de la normatividad vigente en la materia. Se realizan ejemplos de aplicacion, donde se obtienen ciertos resultados de los cuales se hace una breve discusion.

2009 - Global Energy Balance - Intendente Camara - Ipatinga - Minas Gerais - Brazil - plant - Superintendence of Energy and Utilities; Balanco energetico global - 2009 - Usina Intendente Camara - Ipatinga - Minas Gerais - Superintendencia de Energia e Utilidades

Energy Technology Data Exchange (ETDEWEB)

Silveira Junior, Jose Ronaldo; Bastos, Moises Hofer [Usinas Siderurgicas de Minas Gerais S/A (USIMINAS), Ipatinga, MG (Brazil)

2010-07-01

The Global Energy Balance of the USIMINAS - Usina Intendente Camara em Ipatinga - Minas Gerais - Brazil, in 2009, is presented with the the main energy consumption indicators of the producer areas. It is highlighted during 2009 as followed: the steel demand retraction decurring from the world wild financial crisis, given as consequence the stop of the blast furnace 1 and 2; dinishing of the production of sinter, pig iron, steel, hot and cold rolled rilled mill; gradual elevation of the production rhythm at the at the plant and energy consumption during the year, motivated by the slow and gradual recovering of the steel marketing.

WIND DIRECTION, pH and other data from ALMIRANTE CAMARA and ALMIRANTE SALDANHA from 1979-01-07 to 1979-12-11 (NODC Accession 8100468)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Water depth and other station data collected from ALMIRANTE CAMARA, ALMIRANTE SALDANHA and other Platforms for one year. The data was collected between January 7,...

Characterization of leaves and flowers volatile constituents of Lantana camara growing in central region of Saudi Ar

Directory of Open Access Journals (Sweden)

Merajuddin Khan

2016-11-01

Full Text Available The chemical components of essential oils derived from leaves and flowers of Lantana camara growing in Saudi Arabia are analyzed for the first time using gas chromatography techniques (GC–MS, GC–FID, Co-GC, LRI determination, and database and literature searches on two different stationary phase columns (polar and nonpolar. This analysis led to the identification of total 163 compounds from leaves and flowers oils. 134 compounds were identified in the oil obtained from leaves of L. camara, whereas 127 compounds were identified in the oil obtained from flowers; these compounds account for 96.3% and 95.3% of the oil composition, respectively. The major components in the oil from leaves were cis-3-hexen-1-ol (11.3%, 1-octen-3-ol (8.7%, spathulenol (8.6%, caryophyllene oxide (7.5% and 1-hexanol (5.8%. In contrast, the major compounds in the flowers oil were caryophyllene oxide (10.6%, β-caryophyllene (9.7%, spathulenol (8.6%, γ-cadinene (5.6% and trans-β-farnesene (5.0%. To the best of our knowledge, cis-3-hexen-1-ol and 1-octen-3-ol that were identified as major components in this study have not been reported earlier from Lantana oils.

Optimization of air conditioning systems utilizing low temperature thermal storage; Optimizacion de sistemas de acondicionamiento de aire utilizando sistemas de almacenamiento termico de baja temperatura

Energy Technology Data Exchange (ETDEWEB)

Contreras Ramirez, J.; Dorantes Rodriguez, R. [Departamento de Energia, Universidad Autonoma Metropolitana - Unidad Azcapotzalco, Mexico, D. F. (Mexico)

1997-12-31

sistemas esta relacionado con la variabilidad de la carga termica y las posibilidades de regulacion de la o las maquinas termicas, de tal manera de lograr, a lo largo del dia, un adecuado uso y optimizacion de la carga total instalada, con los mejores beneficios economicos posibles. Entre las estrategias que permiten optimizar la capacidad de la instalacion y la variacion de la carga termica esta el almacenamiento termico de baja temperatura, por ejemplo, el almacenamiento de hielo, el cual se produce y se almacena durante las horas en que normalmente las maquinas de refrigeracion estan paradas, y con el fin de usar esta energia almacenada durante el horario pico y durante las horas de operacion normal del equipo, pero disminuyendo en forma importante la demanda electrica de la instalacion al satisfacer la carga termica con una combinacion almacen termico-maquina de refrigeracion. En este trabajo se presentan algunos antecedentes y tipos de almacenes termicos utilizados comunmente, se discute una metodologia que permite dimensionar un almacen termico, tanto tecnica como economicamente, y se plantean algunos de los problemas en el control y operacion de estos sistemas termicos.

Optimization of air conditioning systems utilizing low temperature thermal storage; Optimizacion de sistemas de acondicionamiento de aire utilizando sistemas de almacenamiento termico de baja temperatura

Energy Technology Data Exchange (ETDEWEB)

Contreras Ramirez, J; Dorantes Rodriguez, R [Departamento de Energia, Universidad Autonoma Metropolitana - Unidad Azcapotzalco, Mexico, D. F. (Mexico)

1998-12-31

sistemas esta relacionado con la variabilidad de la carga termica y las posibilidades de regulacion de la o las maquinas termicas, de tal manera de lograr, a lo largo del dia, un adecuado uso y optimizacion de la carga total instalada, con los mejores beneficios economicos posibles. Entre las estrategias que permiten optimizar la capacidad de la instalacion y la variacion de la carga termica esta el almacenamiento termico de baja temperatura, por ejemplo, el almacenamiento de hielo, el cual se produce y se almacena durante las horas en que normalmente las maquinas de refrigeracion estan paradas, y con el fin de usar esta energia almacenada durante el horario pico y durante las horas de operacion normal del equipo, pero disminuyendo en forma importante la demanda electrica de la instalacion al satisfacer la carga termica con una combinacion almacen termico-maquina de refrigeracion. En este trabajo se presentan algunos antecedentes y tipos de almacenes termicos utilizados comunmente, se discute una metodologia que permite dimensionar un almacen termico, tanto tecnica como economicamente, y se plantean algunos de los problemas en el control y operacion de estos sistemas termicos.

Development of an electro-thermal model for ZnO surge arrester under contamination; Desarrollo de un modelo electro-termico para apartarrayos de ZnO bajo contaminacion

Energy Technology Data Exchange (ETDEWEB)

Guardado Zavala, J.L.; Moreno Barraza, M.; Zazueta Pena, H.; Venegas Rebollar, V.; Melgoza Vazquez, E. [Instituto Tecnologico de Morelia, Morelia, Michoacan (Mexico)]. E-mail: lguarda@prodigy.net.mx; hzazuetapea@yahoo.com; vvenegas@yahoo.com; emelgoza@iimorelia.edu.mx

2010-01-15

An electro-thermal model for a Zinc Oxide (ZnO) surge arrester under contamination test is presented. The model is based in three sub-models: electrical, thermal and contamination, which interact in order to obtain the surge arrester performance under contamination tests. The electrical model is obtained from measurements and is based on a capacitance and a non-linear resistor. The thermal model takes into account the heat generated and dissipated by the column of varistors and its surroundings. The contamination is represented by dynamic impedance obtained from measurements in the arrester column during contamination tests. The full model is validated by calculating the temperature increase during contamination tests carried out in a two units ZnO surge arrester, class 190 kV. Finally, the results of the effect of several design and construction parameters in the voltage and temperature distribution in the arrester column during contamination tests are presented. [Spanish] Se presenta el modelo electro-termico para un apartarrayos de Oxido de Zinc (ZnO) durante pruebas de contaminacion. El modelo esta compuesto de tres sub-modelos: electrico, termico y de contaminacion, los cuales interactuan armonicamente para obtener el comportamiento del apartarrayos durante pruebas de contaminacion. El modelo electrico se obtiene de mediciones y esta compuesto de una capacitancia y una resistencia no-lineal. El modelo termico considera el calor generado y disipado en la columna de varistores y su entorno. La contaminacion se representa como una impedancia dinamica, cuyos valores se obtienen de mediciones en la columna del apartarrayos durante pruebas de contaminacion. El modelo se valida determinando el incremento de temperatura durante pruebas de contaminacion en un apartarrayos de ZnO de dos unidades clase 1990 kV. Finalmente, se presentan los resultados del impacto de diversos parametros de diseno y construccion en la distribucion de voltaje y temperatura en el apartarrayos

Integration of a thermal stresses supervisory system and useful life of steam turbine rotors; Integracion de un sistema supervisorio de esfuerzos termicos y vida util de rotores de turbinas de vapor

Energy Technology Data Exchange (ETDEWEB)

Carnero, Antonio; Serrano, Luis E. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico); Nebradt, G. Jesus; Leyva, M. Luis [Comision Federal de Electricidad, Mexico, D.F. (Mexico)

2007-11-15

The turbine wheels undergo high thermal and mechanical stresses caused by the requirements of their operation. This causes a mechanical damage (fatigue) that is accumulated according to the frequency whereupon the different operation ways (cold starts, lukewarm or hot) happen. On the other hand, the greater efficiency of power stations of combined cycle with respect to conventional power stations is reflected in a greater production cost of the electrical energy, which has forced to that conventional generation units designed to operate on base load, now are used as variable load units to satisfy the demand during the peak hours. The former, rebounds in a greater frequency of operations of shut downs and hot starts of turbines, reason why the fatigue damage will be increased when changing its operating range. In Mexico turbines there are turbines that have been 15 or 20 years in operation and that do not have a thermal stresses supervisor, reason why when changing their load operation from base load to variable load it is essential to install a rotor supervisor of thermal efforts, with the purpose of limiting or reducing the thermal stresses and in this way reduce the fatigue damage to extend their useful life. The article deals over the integration of a supervisory system of thermal stresses, that from the operation parameters of the turbine, determines the temperature gradient in the labyrinth seals zone between the control passage and the first passage of the high pressure section of the rotor, the thermal and mechanical stresses and the fatigue are calculated, determining the consumption of the useful life for each operation cycle (shutdown and starting). [Spanish] Los rotores de turbina experimentan altas esfuerzos termicos y mecanicos causados por los requerimientos de su operacion. Esto causa un dano mecanico (fatiga) que se acumula de acuerdo a la frecuencia con que los diferentes modos de operacion (arranques en frio, tibio o caliente) suceden. Por otro

Supervisory system for real time monitoring of transient thermal stresses in turbines rotors; Sistema supervisorio para el monitoreo en tiempo real de esfuerzos termicos transitorios en rotores de turbinas

Energy Technology Data Exchange (ETDEWEB)

Urquiza Beltran, Gustavo; Rios Miranda, Edmundo; Venegas Guzman, Ricardo; Alvarez Garcia, Gabriela [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1991-12-31

This article presents a supervisory system that, as its main functions, assists the operator on base of the thermal stresses, monitoring in real time the high pressure (HP) and intermediate pressure rotors (IP) of a steam turbine during the start, shut down and/or sudden load changes. The system is based on a thermal model uni-dimensional integrated to the SIMPER (Information System for the Predictive Maintenance of Rotating Equipment), tested in a 300 MW unit of Comision Federal de Electricidad (CFE). [Espanol] En este articulo se presenta un sistema supervisorio que, como funciones principales, asiste al operador con base en el monitoreo de esfuerzos termicos en tiempo real en los rotores de presion alta (PA) y presion intermedia (PI) de una turbina de vapor durante un arranque, paro y/o variaciones bruscas de carga. El sistema esta basado en un modelo termico unidimensional integrado al SIMPER (sistema informatico para el mantenimiento predictivo de equipo rotatorio), experimentado en una unidad de 300 MW de la Comision Federal de Electricidad (CFE).

Supervisory system for real time monitoring of transient thermal stresses in turbines rotors; Sistema supervisorio para el monitoreo en tiempo real de esfuerzos termicos transitorios en rotores de turbinas

Energy Technology Data Exchange (ETDEWEB)

Urquiza Beltran, Gustavo; Rios Miranda, Edmundo; Venegas Guzman, Ricardo; Alvarez Garcia, Gabriela [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1992-12-31

This article presents a supervisory system that, as its main functions, assists the operator on base of the thermal stresses, monitoring in real time the high pressure (HP) and intermediate pressure rotors (IP) of a steam turbine during the start, shut down and/or sudden load changes. The system is based on a thermal model uni-dimensional integrated to the SIMPER (Information System for the Predictive Maintenance of Rotating Equipment), tested in a 300 MW unit of Comision Federal de Electricidad (CFE). [Espanol] En este articulo se presenta un sistema supervisorio que, como funciones principales, asiste al operador con base en el monitoreo de esfuerzos termicos en tiempo real en los rotores de presion alta (PA) y presion intermedia (PI) de una turbina de vapor durante un arranque, paro y/o variaciones bruscas de carga. El sistema esta basado en un modelo termico unidimensional integrado al SIMPER (sistema informatico para el mantenimiento predictivo de equipo rotatorio), experimentado en una unidad de 300 MW de la Comision Federal de Electricidad (CFE).

Are there evidences of a complex mimicry system among Asclepias curassavica (Apocynaceae), Epidendrum fulgens (Orchidaceae), and Lantana camara (Verbenaceae) in Southern Brazil?

OpenAIRE

Fuhro, Daniela; Araújo, Aldo Mellender de; Irgang, Bruno Edgar

2010-01-01

The goal of this paper was to test the presence of mimicry in Asclepias curassavica L., Epidendrum fulgens Brong., and Lantana camara L. The study was carried out at the Parque Estadual de Itapeva, RS, southern Brazil, from 2004 to 2006. Flowering period of each of the three species was followed up; focal observations of butterflies visiting flowers, from fixed point and during random walks were carried out. We also estimated the frequency of pollinaria removal in the orchid, as well as its m...

Antioxidant, antibacterial and cytotoxic potential of silver nanoparticles synthesized using terpenes rich extract of Lantana camara L. leaves

Directory of Open Access Journals (Sweden)

Patil Shriniwas P.

2017-07-01

Full Text Available Several attempts have been made for green synthesis of silver nanoparticles (AgNPs using different plant extracts. Present study revealed that, antioxidant, antibacterial and cytotoxic AgNPs were synthesized using terpenes-rich extract (TRE of environmentally notorious Lantana camara L. leaves. AgNPs were characterized by advanced techniques like UV–Visible and Infra red spectroscopy; XRD, SEM techniques as terpenes coated sphere shaped NPs with average diameter 425 nm. Further, on evaluation, AgNPs were found to exhibit dose – dependent antioxidant potential, good to moderate antibacterial activity against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa; and toxicity on Brine shrimp (A. salinanauplii with LD50 value 514.50 µg/ml.

The thermal insulating materials and its coatings for underground piping; Los aislamientos termicos y sus recubrimientos para tuberias subterraneos

Energy Technology Data Exchange (ETDEWEB)

Salcido Lopez, Salvador [Aislantes Minerales, S. A. de C. V. Mexico, D. F. (Mexico)

1994-12-31

Energy Saving through the adequate selection and application of the thermal insulating materials, as well as its coatings for underground piping conducting fluids, both at high and at low temperature. The benefits are outlined at economical level for the investor as well as at ecological level (of vital importance today) and are observed as practical examples in industrial and commercial processes. [Espanol] Ahorro de energeticos mediante la adecuada seleccion y aplicacion de los aislamientos termicos, asi como de sus recubrimientos para tuberias subterraneas que conducen fluidos tanto en alta como en baja temperatura. Los beneficios son destacados tanto a nivel economico para el inversionista, como a nivel ecologico (de vital importancia en la actualidad), y son observados con ejemplos practicos en procesos industriales y comerciales.

Energy saving by means of air conditioning equipment replacement and the household application of thermal insulation; Ahorro de energia electrica por reemplazo de equipos de aire acondicionado y aplicacion de aislamiento termico en viviendas

Energy Technology Data Exchange (ETDEWEB)

Peralta Solorio, Jose Luis [Fideicomiso para el Ahorro de la Energia (Mexico)

2005-07-15

An extension study of the Financing Program for Energy Saving looked for the evaluation of the electric energy saving potential obtained by the replacement of air conditioning equipment and the application of thermal insulation in 30 houses of two Mexican cities with warmth climate. In a joint effort with Comision Federal de Electricidad the consumption files of the users were analyzed and field measurements of electric demand and of refrigeration were made. As a following step the change of the refrigeration necessities derived from the application of thermal insulation were evaluated as well as the energy efficiency improvement obtained by the substitution of the air conditioning equipment and the favorable results obtained by the implementation of both measures - thermal insulation and change of air conditioning equipment in a joint form. This way, as a conclusion, the optimum sequence of application of these measures is revealed. [Spanish] Un estudio extension del Programa de Financiamiento para el Ahorro de Energia Electrica busco evaluar el potencial de ahorro de energia electrica alcanzado por el reemplazo de equipos de aire acondicionado y la aplicacion de aislamiento termico en 30 viviendas de dos ciudades mexicanas con clima calido. En un esfuerzo conjunto con la Comision Federal de Electricidad se analizaron los historiales de consumo de los usuarios y se efectuaron las mediciones de campo de demanda electrica y de refrigeracion. Como paso siguiente se valoro el cambio en las necesidades de refrigeracion derivado de la aplicacion de aislamiento termico al igual que la mejora en eficiencia energetica obtenida por la sustitucion de aire acondicionado y se identificaron los resultados favorecedores arrojados por la implementacion de ambas medidas -aislamiento termico y cambio de equipo de aire acondicionado- en forma conjunta. De esta manera, como conclusion, se devela la mas optima secuencia de aplicacion de estas medidas.

Evaluación de la actividad antioxidante bioautográfica de cinco variedades de aceites esenciales andinos (Aristeguietia glutinosa; Myrcianthes rhopaloides; Ambrosia arborescens; Lantana camara; Minthostachys mollis)

OpenAIRE

Guerrero Toapanta, Priscila Pamela; Pozo Morales, Karla Natalia

2016-01-01

This experimental work had the goal of assessing the antioxidant capabilities of five essential oils: Minthostachys mollis, Aristeguietia glutinosa, Ambrosia arborescens, Myrcianthes rhopaloides and Lantana camara; all of which were obtained from the Ecuadorian Andes. This work used the DPPH and ABTS methods to assess free radical-capturing capacity, and it used the β-carotene Test to determine the antioxidant activity of each essential oil. The natural referent used herein...

Study of thermal behavior of three different housing prototypes, for a desertic climate; Estudio de comportamiento termico de tres prototipos de vivienda, para un clima desertico

Energy Technology Data Exchange (ETDEWEB)

Bojorquez, Gonzalo; Gallegos, Ricardo; Luna, Anibal [Universidad Autonoma de Baja Callifornia, Mexicali, Baja California (Mexico)

2000-07-01

The design of housing in Mexico, does not considers the thermal simulation as a support tool. This situation generates projects that are not thermally apt for the natural environment. The use of the thermal simulation to evaluate a building doesn't represents by itself the possibility of internal thermal comfort for the user, but rather it determines the saving levels of energy on air conditioning. The objective of this work is to quantitatively show how a proposal formally designed for a specific climate, plus the use of environmental strategies to adapt it to the climate, has minor climatic requirements than when these factors are not considered. For the development purposes of this work, three different housing prototypes were selected. Two of them where designed according to the climate and using environmental adequation strategies. The thermal behavior was simulated for each case, and the maximum climatic requirement was calculated according to the construction volume. In near future, the use of the thermal simulation to evaluate design proposals and existing buildings must be considered as a basic tool in Mexico, not just for specialists in the area of thermal evaluation, but for all those implicated in the architecture and construction. [Spanish] El diseno de vivienda en Mexico, no considera como herramienta de apoyo la simulacion termica, lo que genera proyectos no aptos termicamente al medio ambiente. El uso de la modelacion termica para la evaluacion de un edificio, no solo representa la posibilidad de confort termico del usuario, sino que determina el nivel de ahorro energetico por climatizacion artificial. El objetivo de este trabajo es mostrar cuantitativamente como una vivienda disenada con estrategias de adecuacion ambiental, tiene un requerimiento de climatizacion menor que aquella donde su diseno no considera el clima donde se proyecta. Para el desarrollo del trabajo se seleccionaron tres prototipos de vivienda diferentes, en dos de los cuales

[Microscopic anatomy and volatile secondary metabolites at three stages of development of the inflorescences of Lantana camara (Verbenaceae)].

Science.gov (United States)

Caroprese Araque, José Fernando; Parra Garcés, María Isabel; Arrieta Prieto, Dagoberto; Stashenko, Elena

2011-03-01

Plants of the Verbenaceae family, like L. camara, have called the attention of researchers, not only because of its high diversity and its distribution around the world, but also for its variable use as popular medicine to treat diseases like tetanus, rheumatism and malaria, and as bactericide and insecticide. To assess this, the morphology and ontogeny of the inflorescences of Lantana camara and the chemical composition of volatile secondary metabolites were analyzed at three different ontogeny stages. Plants were collected from the experimental crop area in CENIVAM, Bucaramanga, Colombia. Fresh inflorescence stages were established and analyzed using a stereoscopic microscope, fixed in FAA and included in parafine. Transversal and longitudinal 10 microm thick sections were prepared using a rotative microtome, safranine-fastgreen stained and were observed and photographed using a light microscope. The chemical composition of volatile secondary metabolites were analyzed for each stage. The analytes, obtained from 0.7 g of plant, were isolated by solid phase micro-extraction in the headspace mode (HS-SPME) and were placed in 20 ml vials. The components were analyzed by gas chromatography coupled to mass spectrometry (GC-MS). Stage I was microscopically characterized by an immature development in which the meristematic differentiation begins with a mass of cells. In Stage II, the morphogenetic movement gives way to the formation of the respective floral sexual structures, calyx and corolla. In Stage III, the different organs are conspicuous: four stamens epipetals and didynamous, monocarpelar, biloculate and globose gynoecium, upper ovary and lateral stigma; the flowers are hermaphroditic. The main secondary metabolites detected by GC-MS were bicyclosesquiphellandrene, E-beta-farnesene, E-beta-caryophyllene, gamma-muurolene + gamma-curcumene and alpha-zingiberene. Nevertheless, this study reports for the first time in plant species alpha-gurjunene, gamma

Lantana camara Linn leaf extract mediated green synthesis of gold nanoparticles and study of its catalytic activity

Science.gov (United States)

Dash, Shib Shankar; Bag, Braja Gopal; Hota, Poulami

2015-03-01

A facile one-step green synthesis of stable gold nanoparticles (AuNPs) has been described using chloroauric acid (HAuCl4) and the leaf extract of Lantana camara Linn (Verbenaceae family) at room temperature. The leaf extract enriched in various types of plant secondary metabolites is highly efficient for the reduction of chloroaurate ions into metallic gold and stabilizes the synthesized AuNPs without any additional stabilizing or capping agents. Detailed characterizations of the synthesized gold nanoparticles were carried out by surface plasmon resonance spectroscopy, transmission electron microscopy, dynamic light scattering, Zeta potential, X-ray diffraction and Fourier transform-infrared spectroscopy studies. The synthesized AuNPs have been utilized as a catalyst for the sodium borohydride reduction of 4-nitrophenol to 4-aminophenol in water at room temperature under mild reaction condition. The kinetics of the reduction reaction has been studied spectrophotometrically.

Analysis of the indices of thermal comfort for the conditions of the Mexican Republic; Analisis de los indices de confort termico para las condiciones de la republica mexicana

Energy Technology Data Exchange (ETDEWEB)

Fuentes Freixanet, Victor; Rodriguez Viqueira, Manuel [Universidad Autonoma Metropolitana - Unidad Azcapotzalco (Mexico)

2009-07-15

The objective of this article is to analyze different indices of thermal comfort for the Mexican Republic. Among them the Fanger (PMV and PPD) physiological methods of comfort and the new effective temperature index are included. The standard effective temperature (SET), as well as the adaptive methods of Humphreys and Nicol, Auliciems, De Dear and Brager. A comparative analysis is done of the different indices through thematic maps determined by interpolation, using a climatic data base of 700 cities obtained from the observatories and stations of the National Meteorological Service. This article pretends to establish general criteria of the thermal comfort to later define design strategies for each one of the climatic regions of the Mexican Republic. [Spanish] El objetivo de este articulo es analizar distintos indices de confort termico para la Republica Mexicana. Entre ellos se incluyen los metodos fisiologicos de confort de Fanger (PMV y PPD), el indice de nueva temperatura efectiva. La temperatura efectiva estandar (SET), asi como los metodos adaptativos de Humphreys y Nicol, Auliciems, De Dear y Brager. Se hace un analisis comparativo de los distintos indices a traves de mapas tematicos determinados por interpolacion, usando una base de datos climaticos de 700 ciudades obtenidos de los observatorios y estaciones del Servicio Meteorologico Nacional. Este articulo presenta establecer criterios generales del confort termico para posteriormente definir estrategias de diseno para cada una de las regiones climaticas de la Republica Mexicana.

EFECTOS TOXICOLÓGICOS DE EXTRACTOS DE MOLLE (Schinus molle) Y LANTANA (Lantana camara) SOBRE Chrysoperla externa (NEUROPTERA: CHRYSOPIDAE), Trichogramma pintoi (HYMENOPTERA: TRICHOGRAMMATIDAE) Y Copidosoma koehleri (HYMENOPTERA: ENCYRTIDAE) EN EL PERÚ

OpenAIRE

Iannacone O., José; Lamas M., Gerardo

2003-01-01

Extractos de dos plantas; el molle (Schinus molle L., Anacardiaceae) y la lantana (Lantana camara L., Verbenaceae), se evaluaron sobre huevos, larvas de primer estadio y pupas de Chrysoperla externa Hagen (Neuroptera: Chrysopidae), y sobre estados inmaduros y adultos de los microhimenopteros Trichogramma pintoi Voegelé (Trichogrammatidae) y Copidosoma koehleri Blanchard (Encyrtidae), en bioensayos toxicológicos bajo condiciones de laboratorio. Los extractos acuosos (F1) del molle y la lantana...

Monitoring and assessment of thermical comfort in hygrothermically moderate offices and laboratories; Monitoraggio e valutazione del comfort termico negli ambienti di lavoro termoigrometricamente moderati

Energy Technology Data Exchange (ETDEWEB)

Speranza, A. [ENEA, Centro Ricerche `Ezio Clementel`, Bologna (Italy). Dip. Ambiente

1998-12-31

This study reports the results of the micro climatic measurements carried out in some ENEA work environments. The work conditions in the surveyed areas, have been evaluated following welfare indexes or thermical comfort: PMV= Predicted Mean Vote (ISO recommendation 7730); PPD= Predicted Percentage of Dissatisfied (ISO recommendation 7730). [Italiano] In questo studio sono riportati i risultati delle misure microclimatiche eseguite in alcuni ambienti di lavoro dei centri ENEA di Bologna. Le condizioni di lavoro (delle zone che sono state sottoposte ad indagine) sono state valutate mediante i seguenti indici di benessere o `comfort` termico: Voto Medio Previsto (PMV= Predicted Mean Vote) - raccomandazione ISO 7730; Percentuale Prevista di Insoddisfatti (PPD= Predicted Percentage of Dissatisfied) - raccomandazione ISO 7730.

Monitoring and assessment of thermical comfort in hygrothermically moderate offices and laboratories; Monitoraggio e valutazione del comfort termico negli ambienti di lavoro termoigrometricamente moderati

Energy Technology Data Exchange (ETDEWEB)

Speranza, A [ENEA, Centro Ricerche ` Ezio Clementel` , Bologna (Italy). Dip. Ambiente

1999-12-31

This study reports the results of the micro climatic measurements carried out in some ENEA work environments. The work conditions in the surveyed areas, have been evaluated following welfare indexes or thermical comfort: PMV= Predicted Mean Vote (ISO recommendation 7730); PPD= Predicted Percentage of Dissatisfied (ISO recommendation 7730). [Italiano] In questo studio sono riportati i risultati delle misure microclimatiche eseguite in alcuni ambienti di lavoro dei centri ENEA di Bologna. Le condizioni di lavoro (delle zone che sono state sottoposte ad indagine) sono state valutate mediante i seguenti indici di benessere o `comfort` termico: Voto Medio Previsto (PMV= Predicted Mean Vote) - raccomandazione ISO 7730; Percentuale Prevista di Insoddisfatti (PPD= Predicted Percentage of Dissatisfied) - raccomandazione ISO 7730.

Technologies for the treatment of the sulfur dioxide and nitrogen oxides generated by the combustion in open chamber; Tecnologias para el tratamiento de dioxido de azufre y oxidos de nitrogeno generados por la combustion en camara abierta

Energy Technology Data Exchange (ETDEWEB)

Salazar Villalpando, Maria Dolores [Instituto Mexicano del Petroleo, Mexico, D. F. (Mexico)

1993-12-31

In general terms, there are only three ways of avoiding the sulfur dioxide and the nitrogen oxides, generated by the combustion in open chamber, from contaminating the air; the first one is utilizing low sulfur and nitrogen content fuels, the second one is by controlling the parameters that affect the combustion and the third one to treat and/or clean the gases before exhausting them to the air. In this document, some of the treatments for diminishing the pollutant emissions generated by the combustion in open chamber, are presented. [Espanol] En terminos generales, solo existen 3 maneras de evitar que el dioxido de azufre y oxidos de nitrogeno generados por la combustion en camara abierta sigan contaminando el aire, la primera es utilizar un combustible de bajo contenido de azufre y nitrogeno, la segunda es controlar los parametros que afectan la combustion, y la tercera es tratar y/o limpiar los gases antes de emitirlos a la atmosfera. En este documento se presentan algunos tratamientos para disminuir las emisiones de contaminantes generados por la combustion en camara abierta.

Preliminary experiments with a solid-state ionization chamber; Experiences preliminaires au moyen d'une chambre d'ionisation a milieu solide; Predvaritel'nye opyty s tverdoj ionizatsionnoj kameroj; Experimentos preliminares con una camara de ionizacion en estado solido

Energy Technology Data Exchange (ETDEWEB)

Griffiths, R J; Batty, C J [National Institute for Research and Nuclear Science, Harwell (United Kingdom); Gibbons, P E; Northrop, D C [Service' s Electronics Research Laboratory, Baldock, Didcot (United Kingdom)

1962-04-15

A solid-state ionization chamber has been made by diffusing phosphorus into high-resistivity silicon to form ohmic contacts. Such a detector has been successfully used to detect 30-MeV protons. Preliminary results are given and discussed. (author) [French] Une chambre d'ionisation a milieu solide a ete realisee par diffusion de phosphore dans du silicium de haute resistivite pour former des contacts ohmiques. Un detecteur de cette nature a ete utilise avec succes pour detecter des protons de 30 MeV. Les auteurs presentent les resultats preliminaires obtenus. (author) [Spanish] Se ha construido una camara de ionizacion en estado solido, por difusion de fosforo en silicio de elevada resistividad para formar contactos ohmicos. Con esta camara se han logrado detectar protones de 30 MeV. Los autores presentan y examinan los resultados preliminares obtenidos. (author) [Russian] Tverdaya ionizatsionnaya kamera izgotovlena putem vklyucheniya fosfora v kremnij s vysokoj udel'noj soprotivlyaemost'yu dlya obrazovaniya omicheskikh kontaktov. Takoj detektor uspeshno primenyaetsya dlya obnaruzheniya protonov v 30 mehv. Predstavleny i obsuzhdayutsya predvaritel'nye rezul'taty. (author)

Technologies for the treatment of the sulfur dioxide and nitrogen oxides generated by the combustion in open chamber; Tecnologias para el tratamiento de dioxido de azufre y oxidos de nitrogeno generados por la combustion en camara abierta

Energy Technology Data Exchange (ETDEWEB)

Salazar Villalpando, Maria Dolores [Instituto Mexicano del Petroleo, Mexico, D. F. (Mexico)

1992-12-31

In general terms, there are only three ways of avoiding the sulfur dioxide and the nitrogen oxides, generated by the combustion in open chamber, from contaminating the air; the first one is utilizing low sulfur and nitrogen content fuels, the second one is by controlling the parameters that affect the combustion and the third one to treat and/or clean the gases before exhausting them to the air. In this document, some of the treatments for diminishing the pollutant emissions generated by the combustion in open chamber, are presented. [Espanol] En terminos generales, solo existen 3 maneras de evitar que el dioxido de azufre y oxidos de nitrogeno generados por la combustion en camara abierta sigan contaminando el aire, la primera es utilizar un combustible de bajo contenido de azufre y nitrogeno, la segunda es controlar los parametros que afectan la combustion, y la tercera es tratar y/o limpiar los gases antes de emitirlos a la atmosfera. En este documento se presentan algunos tratamientos para disminuir las emisiones de contaminantes generados por la combustion en camara abierta.

Creams formulated with Ocimum gratissimum L. and Lantana camara L. crude extracts and fractions as mosquito repellents against Aedes aegypti L. (Diptera: Culicidae).

Science.gov (United States)

Keziah, Ezeike Amarachi; Nukenine, Elias Nchiwan; Danga, Simon Pierre Yinyang; Younoussa, Lame; Esimone, Charles Okechukwu

2015-01-01

Mosquitoes are the most deadly vectors of parasites that cause diseases such as malaria, yellow fever, and filariasis. In view of the recent increased interest in developing plant origin insecticides as an alternative to chemical insecticides, the objective of this study was to determine the repellent activity of creams formulated with methanol crude extract (MCE), hexane fraction (HF), and ethyl acetate fractions (EAFs) of Ocimum gratissimum and Lantana camara leaves in single and combined actions against female Aedes aegypti. Evaluation was carried out in the net cages (30 by 30 by 30 cm) containing 60 blood-starved female mosquitoes each and were assayed in the laboratory condition following World Health Organization 2009 protocol. All formulations (single and mixture) were applied at 2, 4, 6, and 8 mg/cm(2) in the exposed area of human hands. Only acetone + white soft paraffin served as negative control and odomos (12% DEET) as positive control. All the formulations presented good protection against mosquito bites without any allergic reaction by the human volunteers. The repellent activity was dependent on the strength of the extracts and fractions. Among the tested formulations, the maximum protection time was observed in MCE (120 min) and EAF (150 min) of O. gratissimum; MCE:MCE (150 min) and HF:HF (120 min) mixtures of both plants. In addition, MCE:MCE and HF:HF mixtures from both plants showed possible synergistic effect. From the results, the combination of O. gratissimum and L. camara to formulate natural mosquito repellent using small amount of extracts can be encouraging to be an alternative to conventional DEET. © The Author 2015. Published by Oxford University Press on behalf of the Entomological Society of America.

Valorization of Toxic Weed Lantana camara L. Biomass for Adsorptive Removal of Lead

Directory of Open Access Journals (Sweden)

Vipin Kumar Saini

2017-01-01

Full Text Available Valorization of Lantana camara L., which is a recognized invasive plant, as a potential source of activated carbon is proposed in this study. Its stem and leaf have been utilized for the preparation of activated carbon (ACL and ACS by following acid-impregnation technique, followed by thermal treatment. The developed activated carbon samples were characterized for their structural and surface related properties by low-temperature nitrogen adsorption isotherm, SEM techniques, and pHPZC method. The samples show reasonable high surface area and pore volume; nonetheless, these properties are higher in case of ACL as compraed to ACS. Both of these samples developed negative charge on their surface due to acid treatment that resulted in an increase in adsorption at pH > 5. The batch adsorption studies on these samples shows the Pb(II ion adsorption capacities of ACL and ACS were 36.01 and 32.24 mg·g−1, respectively, at 25°C. The kinetics of adsorption with both the sample systems follow the pseudo-second-order model, whereas the experimental equilibrium isotherm data of ACL and ACS were explained by Freundlich and Langmuir models, respectively. For these samples, the HCl shows maximum desorption with which the recycling test on these samples shows that ACS has better recycling potential over ACL samples.

Casca de arroz e palhada de soja na compostagem de carcaças de frangos de corte = Rice husks and soy straw as substrate for composting of broiler carcasses

Directory of Open Access Journals (Sweden)

Paulo Giovanni de Abreu

2011-01-01

Full Text Available Avaliou-se a atuacao da casca de arroz e da palhada de soja como substrato para compostagem de carcaca de frangos de corte, observando a degradacao dos dois substratos e das carcacas pelo monitoramento da temperatura, peso das carcacas e dos substratos e analise fisicoquimica do produto final. As camaras foram montadas com carcacas de 10 aves recem abatidas, com quatro repeticoes no tempo. Instalou-se em cada camara um termopar para registro da temperatura. O substrato e as carcacas foram pesadas separadamente, no inicio, aos 15 e aos 30 dias de compostagem. Ao final de cada periodo, foram realizadas analises fisico-quimica de amostras de cada camara, avaliando-se o pH e os teores de materia seca, cinzas, P, N, K, Cu, Zn, Mn, Fe e carbono organico. Concluiu-se que a palhada de soja pode ser usada como alternativa para substrato de compostagem de carcacas de aves, atendendo a relacao C/N exigida pela legislacao ao final da terceira reutilizacao. A casca de arroz, da mesma forma, pode ser utilizada na compostagem de carcacas de aves, porem reutilizada por maior numero de vezes. A decomposicao das carcacas foi significativamente maior, em percentual, na palhada de soja aofinal do quarto periodo de compostagem (p „Tƒn0,05.The performance of rice husks and of soy straw were evaluated as substrate for on-farm poultry carcass composting, observing the degradation of the two substrate and of the carcasses through monitoring the temperature, weight of the carcasses and of the substrate and physiochemical analysis of the final product. The piles were arranged with carcasses of 10 recently slaughtered birds, with four repetitions in time. A thermo pair was installed in each pile to register the temperature. The substrate and the carcasses were weighed separately, in the beginning, day 15 and day 30 of composting. At the end of each period, the physiochemical analysis of samples were made from each pile, evaluating the pH, the dry material, ashes, P, N

Genetic diversity and population structure of Lantana camara in India indicates multiple introductions and gene flow.

Science.gov (United States)

Ray, A; Quader, S

2014-05-01

Lantana camara is a highly invasive plant, which has spread over 60 countries and island groups of Asia, Africa and Australia. In India, it was introduced in the early nineteenth century, since when it has expanded and gradually established itself in almost every available ecosystem. We investigated the genetic diversity and population structure of this plant in India in order to understand its introduction, subsequent range expansion and gene flow. A total of 179 individuals were sequenced at three chloroplast loci and 218 individuals were genotyped for six nuclear microsatellites. Both chloroplasts (nine haplotypes) and microsatellites (83 alleles) showed high genetic diversity. Besides, each type of marker confirmed the presence of private polymorphism. We uncovered low to medium population structure in both markers, and found a faint signal of isolation by distance with microsatellites. Bayesian clustering analyses revealed multiple divergent genetic clusters. Taken together, these findings (i.e. high genetic diversity with private alleles and multiple genetic clusters) suggest that Lantana was introduced multiple times and gradually underwent spatial expansion with recurrent gene flow. © 2013 German Botanical Society and The Royal Botanical Society of the Netherlands.

Energy consumption and the use of thermal insulating materials. A comparative analysis on the tendencies over the time; Consumo de energia y uso de aislamientos termicos - un analisis comparativo de tendencias en el tiempo

Energy Technology Data Exchange (ETDEWEB)

Ordonez C, Luis Felipe [Aislantes Minerales, S. A. de C. V. Mexico, D. F. (Mexico)

1994-12-31

positivas y son semejantes a las tendencias en el consumo de aislamientos termicos y a cifras semejantes de otros paises. El analisis de estas cifras nos permiten detectar si se pueden correlacionar los esfuerzos de ahorro de energia con el consumo de aislamientos termicos y con el nivel de vida de un pais (determinado por su ingreso per capita), y establecer un indice futuro de efectividad de conservacion de energia por el uso adecuado de materiales de espesor economico. El indice propuesto en esta ponencia sirve este proposito y nos arroja resultados interesantes. A lo largo de los anos recientes y como resultado del cambio en el nivel de industrializacion y de vida en Mexico, el consumo de energeticos ha aumentado en proporcion mayor al crecimiento de poblacion, tomando como base las cifras de 1980. En ese mismo periodo, el producto interno bruto per capita ha aumentado en proporcion tambien ligeramente menor al crecimiento poblacional. Esto significa que la cifra de Intensidad Energetica, definida como la proporcion de consumo de energeticos sobre el producto interno bruto, ha aumentado ligeramente en el mismo periodo en consideracion, significando que el pais se ha vuelto mas ineficiente en anos recientes. Al mismo tiempo, la capacidad de produccion de materiales aislantes termicos ha permanecido constante desde 1980 hasta principios de 1994. Esto compara desfavorablemente con todos los paises desarrollados, en los cuales la intensidad energetica ha disminuido considerablemente en los ultimos anos, al tiempo que la produccion de materiales aislantes termicos ha crecido a un ritmo de proporciones semejantes.

The impact of the use of thermal insulating materials in the global climatic change; El impacto del uso de los aislamientos termicos en el cambio de los climas globales

Energy Technology Data Exchange (ETDEWEB)

Ordonez C, Luis Felipe [Aislantes Minerales, S.A. de C.V. (Mexico)

1996-12-31

One of the technologies for energy saving easier to understand and one of the fastest and economical to install in the dwelling, commercial and industrial, construction is represented by the use of thermal insulation for the thermal energy losses control. As a result of the application of this technology in direct form for the smaller consumption of energy fuels, will have the effect of a lesser emission of pollution gases that produce the green house effect of the earth atmosphere. The thermal insulating materials, made from a variety of raw materials, many of which utilize large amounts of recycled products in the benefit of the smaller use of natural resources, offer annually and permanently reductions in the energy consumption much higher than the energy resources utilized just once in its manufacture. Therefore, they are also an economical way in contributing in the reduction of atmospheric pollutants of the so-called greenhouse gases. [Espanol] Una de las tecnologias para el ahorro de energia mas faciles de comprender y de las mas rapidas y economicas de instalar en la edificacion de vivienda, comercial e industrial, es la que representa el uso de aislamientos termicos para el control de las perdidas de energia termica. Como resultado de la aplicacion de esta tecnologia, en forma directa por el menor consumo de energeticos combustibles, tendra como efecto la menor emision de gases contaminantes que producen el efecto de invernadero en la atmosfera terrestre. Los aislamientos termicos, fabricados de una gran variedad de materiales, muchos de los cuales utilizan grandes cantidades de productos reciclados en beneficio del menor uso de los recursos naturales, ofrecen anualmente y permanentemente reducciones de consumo de energia muy superiores a los recursos energeticos utilizados una sola vez en su manufactura. Por ende, tambien son una forma economica a coadyuvar en la reduccion de contaminantes atmosfericos de los llamados gases de invernadero.

The impact of the use of thermal insulating materials in the global climatic change; El impacto del uso de los aislamientos termicos en el cambio de los climas globales

Energy Technology Data Exchange (ETDEWEB)

Ordonez C, Luis Felipe [Aislantes Minerales, S.A. de C.V. (Mexico)

1997-12-31

One of the technologies for energy saving easier to understand and one of the fastest and economical to install in the dwelling, commercial and industrial, construction is represented by the use of thermal insulation for the thermal energy losses control. As a result of the application of this technology in direct form for the smaller consumption of energy fuels, will have the effect of a lesser emission of pollution gases that produce the green house effect of the earth atmosphere. The thermal insulating materials, made from a variety of raw materials, many of which utilize large amounts of recycled products in the benefit of the smaller use of natural resources, offer annually and permanently reductions in the energy consumption much higher than the energy resources utilized just once in its manufacture. Therefore, they are also an economical way in contributing in the reduction of atmospheric pollutants of the so-called greenhouse gases. [Espanol] Una de las tecnologias para el ahorro de energia mas faciles de comprender y de las mas rapidas y economicas de instalar en la edificacion de vivienda, comercial e industrial, es la que representa el uso de aislamientos termicos para el control de las perdidas de energia termica. Como resultado de la aplicacion de esta tecnologia, en forma directa por el menor consumo de energeticos combustibles, tendra como efecto la menor emision de gases contaminantes que producen el efecto de invernadero en la atmosfera terrestre. Los aislamientos termicos, fabricados de una gran variedad de materiales, muchos de los cuales utilizan grandes cantidades de productos reciclados en beneficio del menor uso de los recursos naturales, ofrecen anualmente y permanentemente reducciones de consumo de energia muy superiores a los recursos energeticos utilizados una sola vez en su manufactura. Por ende, tambien son una forma economica a coadyuvar en la reduccion de contaminantes atmosfericos de los llamados gases de invernadero.

Experimental determination about thermal comfort conditions in buildings; Determinacion experimental de las condiciones de confort termico en edificaciones

Energy Technology Data Exchange (ETDEWEB)

Ambriz Garcia, Juan Jose; Garcia Chavez, Jose Roberto; Paredes Rubio, Hernando Romero [Universidad Autonoma Metropolitana (Mexico)]. E-mail: agj@xanum.uam.mx; jgc@correo.azc.uam.mx; hrp@xanum.uam.mx

2006-04-15

This paper analyzes the thermal comfort importance in a building. And the influence it exerts on quality of life as well as the efficiency of people work activities. There are comments about some models which better help to estimate the recommended temperature levels. The experimental evaluation results from a Mexico City population sampler are presented. This work was done in a Controlled Environment Laboratory; the obtained outcomes proved the preferences occupants exceed the comfort zone greatest limit accepted in the reference international standards. The meaning of this conclusion is thermal comfort can be reached with higher temperatures and consequently an energy consumption and an environment impact decrease. [Spanish] En este trabajo se analiza la importancia que tiene el confort termico en la calidad de vida de las personas que ocupan una edificacion y en la eficiencia de sus actividades. Se comentan algunos modelos con los cuales se estiman los niveles de temperatura recomendados y se presentan los resultados de una evaluacion experimental realizada en un Laboratorio de Ambiente Controlado con una muestra de la poblacion del Distrito Federal. Los resultados que se obtuvieron demuestran que los ocupantes tienen preferencias que rebasan el limite superior de la zona de confort comunmente aceptada en los estandares internacionales de referencia. Esto quiere decir que el confort puede lograrse con mayores temperaturas, lo que se traduce en menor consumo de energia y menor impacto en el ambiente.

Efeitos do tratamento termico UHT em um leite modificado

OpenAIRE

Juan Manuel Valdivia Velasquez

1992-01-01

Resumo: Fizeram-se formulações de leite modificado, a partir de leite integral de vaca, com a diluição do mesmo com água potável. Tentou-se aproximar a composição do leite modificado ao do um leite humano, principalmente no que refere aos componentes principais: (proteína, gordura e lactose), algumas vitaminas (A, B1, B2 e C) e alguns minerais (ferro, zinco e potássio). 0 uso de fórmulas sugeridas na presente pesquisa, utilizando os dados das análises rápidas rotineiras de planta de laticínio...

Experimental and theoretical investigations of Lantana camara oil diffusion from polyacrylonitrile membrane for pulsatile drug delivery system

Energy Technology Data Exchange (ETDEWEB)

Verma, Vivek [Department of Chemistry, Indian Institute of Science Education and Research (IISER), Pune 411008 (India); Balasubramanian, K., E-mail: meetkbs@gmail.com [Department of Materials Engineering, Defence Institute of Advance Technology (DIAT), Ministry of Defence, Girinagar, Pune 411025 (India)

2014-08-01

Porous composite membrane of polyacrylonitrile (PAN) and Lantana camara essential oil was synthesized by solvent casting method. Stability of oil in PAN solution was measured by XiGo nano tool indicating constant relaxation time of 1487 time/s. Pore size of few microns confirmed by electron microscopy was supported by atomic force microscopy indicating roughness factor of 0.9 nm. Contact angle of 2° inveterates superhydrophilicity of the composite membrane. Membrane showed excellent antibacterial activity against both Gram-positive Bacillus subtilis and Gram-negative Escherichia coli with a 7–10 mm zone of inhibition. In vitro release of Lantana oil from the composite membrane was carried out in isotonic phosphate buffer solution (pH = 7.4). Lantana oil was released for 9 h, lag time of 3 h with constant 33% release confirmed PAN membranes as potential system for pulsatile drug delivery applications. Diffusion of E-caryophyllene (antibacterial component of oil) which was studied through molecular simulation using Material Studio software ensued diffusion coefficient value of 1.11 ∗ 10{sup −9} m{sup 2}/s. Biocompatibility of the composite membrane was assessed by mouse embryonic fibroblast cell line (NIH 3T3) through MTT assay indicating more than 91% viable cell even at 200 μg/mL concentration. Such membranes can be efficiently used in biomedical applications as antibacterial and antifungal agent. - Highlights: • Pulsatile release • Lantana oil–PAN composite membrane as antibacterial material • Enhanced bactericidal activity of the membrane.

Effect of time and temperature of storage on the activity of the etanolic extracts of Lantana camara L. and Heliotropium indicum L. on Colletotrichum gloeosporioides

Directory of Open Access Journals (Sweden)

Rafael Alejandro Infante

2015-10-01

Full Text Available The effect of time and temperature of storage of ethanolic extracts (EE of Lantana camara and Heliotropium indicum on Colletotrichum gloeosporioides was investigated. The EE were stored at 8±2 and 26±2°C, during one year. Every 2 months they were diluted in potato dextrose agar (PDA at 0; 0.5; 1 y 1.5% (v/v concentrations, fungus disks were placed onto the media, mycelial growth (ICM and sporulation (IE inhibition were measured, as well as conidia germination. The EE stored at 8±2°C maintained their effectiveness on all variables during the 12 months storage, while those stored at 26±2°C started to lose their effectiveness at 6 to 8 months, ending up to 3% ICM, 4% IE and 18% conidia germination at 1.5% concentration. Results indicated that storage temperature and time are determinant for extracts effectiveness.

Thermal fracturing of the well H-40, Los Humeros, Pue., geothermal field; Fracturamiento termico del pozo H-40 del campo geotermico de Los Humeros, Pue.

Energy Technology Data Exchange (ETDEWEB)

Flores Armenta, Magaly; Tovar Aguado, Rigoberto [Comision Federal de Electricidad (Mexico)]. E-mail: magaly.flores@cfe.gob.mx

2007-01-15

Well H-40 was drilled for production in 1997, but the well was not able to sustain flow. After it was monitored to assess its injection capacity, the well was changed to an injection well, but the well did not accept more than 5 tons of fluid per hour (t/h). The well was stimulated by thermal fracturing in three tests made in October 2005. As a result, the well can accept up to 110t/h and can be used as an injection well. [Spanish] El pozo H-40 se perforo con objetivos de produccion en 1997. Sin embargo, el pozo resulto incapaz de mantenerse fluyendo. Despues de un periodo de monitoreo se evaluo su capacidad de aceptacion para tratar de utilizarlo como pozo inyector, observandose que no aceptaba mas de 5 toneladas por hora (t/h) de fluido. Por lo tanto, se decidio estimularlo mediante fracturamiento termico con tres pruebas que se realizaron en octubre de 2005, lograndose que el pozo llegara a aceptar hasta 110 t/h, lo que permitira que el pozo pueda ser usado como inyector.

Study of thermal behavior of the adobe with the simulator DOE 2.1E; Estudio de comportamiento termico del adobe con el simulador DOE 2.1E

Energy Technology Data Exchange (ETDEWEB)

Luna, Anibal; Gallegos, Ricardo; Bojorquez, Gonzalo [Universidad Autonoma de Baja California, Mexicali, Baja California (Mexico)

2000-07-01

A thermal analysis of the envelope of one of the most used housing models for low income groups, as those offered by the Mexican Government is presented in this report. The building's thermal gain in walls was determined, using: concrete block, brick and adobe; and considering concrete of roofing, concrete floors, windows and doors equal in all the cases. The objective of this study is to know the contribution to the building's thermal load of each one of the materials applied. The calculation was conducted using the Doe 2.1E thermal simulator software, using meteorological data for the city of El Centro, California, USA. This was so, because there is no reliable weather data for the city of Mexicali, B.C., where the housing units are. Because of geographical proximity between of these cities the same data was used. The properties for each one of the three building materials were taken from specialized bibliography. It was determined that the housing built with adobe walls has thermal advantages over the units built with concrete block and brick. The adobe unit has a lower thermal load of 13% over the concrete block, and of 3.44% over the clay brick unit. [Spanish] Se presenta el analisis termico de la envolvente de uno de los modelos de casas mas utilizados en la construccion de viviendas de interes social en Mexico. Se determino la ganancia, termica del edificio por muros, aplicando: bloque de concreto, ladrillo de barro y adobe. Se considero techo, piso, ventanas y puertas iguales en todos los casos. El objetivo del estudio es conocer la distribucion de la carga termica segun los materiales aplicados. El calculo se realizo con el simulador termico DOE 2.1E con datos meteorologicos de la ciudad de El Centro, California, E. U., por no contar con datos de Mexicali, B. C.: debido a la proximidad y similitud topografica entre ambas ciudades se uso la misma informacion. Las propiedades aplicadas para cada uno de los tres materiales fueron tomadas de

Thermodynamic methodology for the design of solar dryers operated with flat solar collectors; Metodologia termodinamica para el diseno de secadores operados con calentadores solares planos

Energy Technology Data Exchange (ETDEWEB)

Torres Reyes, Ernestina; Navarrete Gonzalez, Jose L; Ibarra Salazar, Beatriz A; Picon Nunez, Martin [Instituto de Investigaciones Cientificas, Universidad de Guanajuato, Guanjuato, Guanajuato (Mexico)

2000-07-01

In this paper a thermal performance analysis of solar drying process at operating varying conditions is presented. It is described semi-empirical models to thermal characterization of an experimental device. A simulator of thermal performance for operating varying conditions was developed as a part of the procedure of thermal design of solar dryers. On the other hand, it is described a simplified method to design solar collectors based on the determination of minimum entropy generation during the thermal conversion of the solar device by using the thermal analysis procedure established and the method derived of the second law of the Thermodynamics are finally presented. [Spanish] En este trabajo se presenta el analisis termico del comportamiento del sistema -colector solar camara de secado-. Se describen los modelos semi-empiricos con los que se caracterizo termicamente un secador solar experimental del tipo indirecto. Se presenta tambien un procedimiento de diseno de equipo de secado que toma en cuenta las condiciones variables de operacion que presentan los dispositivos solares. Por otro lado se describe un procedimiento simplificado de diseno, basado en un analisis derivado de la segunda ley de la Termodinamica. Esta metodologia se fundamenta en la minima generacion de entropia durante la conversion termica de la energia solar, utilizando colectores solares planos. Finalmente se presentan los resultados del diseno preliminar de equipo de secado utilizando los dos procedimientos mencionados.

Energy saving in the auxiliaries consumption for circulation water pumps optimizing the thermal regime; Ahorro en el consumo de auxiliares por bombas de agua de circulacion optimando el regimen termico

Energy Technology Data Exchange (ETDEWEB)

Orozco Martinez, Roni [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1999-12-31

A methodology is proposed that should be followed in any thermal electric power plant to determine the load value at which a unit requires a second circulation water pump without affecting the thermal regime and avoiding an excessive auxiliaries consumption in partial loads. In applying this method the power plant would have an energy saving equivalent to the auxiliaries consumption during an hour, when the unit as operating at full load. [Espanol] Se propone una metodologia que debe seguirse en cualquier central termoelectrica para determinar el valor de la carga en la cual una unidad requiere de la segunda bomba de agua de circulacion sin afectar el regimen termico y evitadose un excesivo consumo de auxiliares en cargas parciales. Al aplicar este metodo la central tendria un ahorro de energia equivalente al consumo de auxiliares durante una hora cuando la unidad esta generando su maxima carga.

Energy saving in the auxiliaries consumption for circulation water pumps optimizing the thermal regime; Ahorro en el consumo de auxiliares por bombas de agua de circulacion optimando el regimen termico

Energy Technology Data Exchange (ETDEWEB)

Orozco Martinez, Roni [Instituto de Investigaciones Electricas, Cuernavaca (Mexico)

1998-12-31

A methodology is proposed that should be followed in any thermal electric power plant to determine the load value at which a unit requires a second circulation water pump without affecting the thermal regime and avoiding an excessive auxiliaries consumption in partial loads. In applying this method the power plant would have an energy saving equivalent to the auxiliaries consumption during an hour, when the unit as operating at full load. [Espanol] Se propone una metodologia que debe seguirse en cualquier central termoelectrica para determinar el valor de la carga en la cual una unidad requiere de la segunda bomba de agua de circulacion sin afectar el regimen termico y evitadose un excesivo consumo de auxiliares en cargas parciales. Al aplicar este metodo la central tendria un ahorro de energia equivalente al consumo de auxiliares durante una hora cuando la unidad esta generando su maxima carga.

Pyrolysis of Lantana camara and Mimosa pigra: Influences of temperature, other process parameters and incondensable gas evolution on char yield and higher heating value.

Science.gov (United States)

Mundike, Jhonnah; Collard, François-Xavier; Görgens, Johann F

2017-11-01

Pyrolysis of invasive non-indigenous plants, Lantana camara (LC) and Mimosa pigra (MP) was conducted at milligram-scale for optimisation of temperature, heating rate and hold time on char yield and higher heating value (HHV). The impact of scaling-up to gram-scale was also studied, with chromatography used to correlate gas composition with HHV evolution. Statistically significant effects of temperature on char yield and HHV were obtained, while heating rate and hold time effects were insignificant. Milligram-scale maximised HHVs were 30.03MJkg -1 (525°C) and 31.01MJkg -1 (580°C) for LC and MP, respectively. Higher char yields and HHVs for MP were attributed to increased lignin content. Scaling-up promoted secondary char formation thereby increasing HHVs, 30.82MJkg -1 for LC and 31.61MJkg -1 for MP. Incondensable gas analysis showed that temperature increase beyond preferred values caused dehydrogenation that decreased HHV. Similarly, CO evolution profile explained differences in optimal HHV temperatures. Copyright © 2017 Elsevier Ltd. All rights reserved.

Simulation and analysis of the tangential flow in the combustion chamber of a steam generator; Simulacion y analisis del flujo tangencial en la camara de combustion de un generador de vapor

Energy Technology Data Exchange (ETDEWEB)

Hernandez Ramirez, Isaias

1997-06-01

supplying ducts, were obtained, with a maximum discrepancy of 5.5 m/s between the data published by McKenty and Gravel (1997) and this analysis, for the case of combustion gases in the interior of the furnace. Temperature profiles were obtained, which were overestimated in the order of 417 Celsius degrees for the case of the temperature of gases in the center of the combustion chamber, when comparing them with the corresponding ones obtained by McKenty and Gravel (1997). It is speculated that this discrepancy must to be due to the omission of the connection of the radiation model to the global computational model and; the contours of concentration of species for the combustion products in the chamber were considered (carbon dioxide, oxygen and nitrogen), obtaining only the qualitative behavior of these. It is proposed as conclusion that the computational model developed in this thesis work can be used for the estimation of flow of fluids patterns, heat transference and transference of mass of a steam generator VU-60 of the tangential type and similar to the one taken as a base for this analysis. One improvement to the computational model developed could be achieved including the radiation effect, which requires a larger memory capacity of the computer hardware than the one available during the elaboration of this thesis. [Espanol] El presente trabajo de tesis describe la simulacion y analisis de la camara de combustion de un generador de vapor VU-60 del tipo tangencial, el cual esta basado en la solucion de la ecuacion generalizada de transporte, empleando modelos matematicos desarrollados para la caracterizacion de fenomenos fisicos para cerrar los sistemas de ecuaciones gobernantes. Para la solucion de los modelos matematicos y ecuaciones gobernantes se empleo el metodo de volumen finito, el cual se basa en el concepto de volumen de control. Se desarrollo un modelo computacional tridimensional por medio del cual se estimaron los perfiles de velocidad, presion, temperatura

Critical heat flux, post dry-out and their augmentation

Energy Technology Data Exchange (ETDEWEB)

Celata, G.P.; Mariani, A. [ENEA, Centro Ricerche Casaccia, S. Maria di Galeria, RM (Italy). Dipt. Energia

1999-07-01

The report shows the state of art review on the critical heat flux and the post-dryout heat transfer. The work, which is a merge of original researches carried out at the Institute of Thermal Fluid Dynamic of ENEA (National Agency for New Technology, Energy and the Environment) and a thorough review of the recent literature, is divided in four chapters: critical heat flux in subcooled flow boiling; critical heat flux in saturated flow boiling; post-dryout heat transfer; enhancement of critical heat flux and post-dryout heat transfer. [Italian] Si passa in rassegna lo stato dell'arte sulla crisi termica e sullo scambio termico post-crisi, che compendia studi tradizionali condotti dall'ENEA. Il rapporto e' suddiviso in quattro parti: crisi termica in ebollizione sottoraffreddata; crisi termica in ebollizione satura; scambio termico dopo la crisi termica; incremento del flusso termico critico e dello scambio termico post-crisi.

Critical heat flux, post dry-out and their augmentation

Energy Technology Data Exchange (ETDEWEB)

Celata, G P; Mariani, A [ENEA, Centro Ricerche Casaccia, S. Maria di Galeria, RM (Italy). Dipt. Energia

1999-07-01

The report shows the state of art review on the critical heat flux and the post-dryout heat transfer. The work, which is a merge of original researches carried out at the Institute of Thermal Fluid Dynamic of ENEA (National Agency for New Technology, Energy and the Environment) and a thorough review of the recent literature, is divided in four chapters: critical heat flux in subcooled flow boiling; critical heat flux in saturated flow boiling; post-dryout heat transfer; enhancement of critical heat flux and post-dryout heat transfer. [Italian] Si passa in rassegna lo stato dell'arte sulla crisi termica e sullo scambio termico post-crisi, che compendia studi tradizionali condotti dall'ENEA. Il rapporto e' suddiviso in quattro parti: crisi termica in ebollizione sottoraffreddata; crisi termica in ebollizione satura; scambio termico dopo la crisi termica; incremento del flusso termico critico e dello scambio termico post-crisi.

Thermal analysis for energy consumption reduction in cooling water systems; Analisis termico para la reduccion del consumo de energia en sistemas de agua de enfriamiento

Energy Technology Data Exchange (ETDEWEB)

Picon Nunez, Martin [Instituto de Investigaciones Cientificas, Universidad de Guanajuato, Guanajuato (Mexico); Quillares Vargas, Luis [Tecnopinch, S. A. de C. V., (Mexico)

1998-12-31

This paper presents the fundamental principles for the thermal analysis of cooling water systems in processing plants. In existing heat dissipating networks this methodology application allows the identification of opportunities for reducing the energy consumption used for cooling water pumping. The methodology is based on the determination of the minimum cooling water flow as a function of the installed heat exchange capacity, subjected to the restrictions of the maximum allowed temperature elevation. The methodology application to real systems, has resulted in saving 20% of the total energy consumed in cooling water pumping. [Espanol] En este trabajo se presentan los principios fundamentales para el analisis termico de sistemas de enfriamiento en plantas de proceso. En redes de eliminacion de calor existentes, la aplicacion de esta metodologia permite identificar oportunidades para reducir el consumo de energia utilizada para el bombeo del fluido enfriante. La metodologia se basa en la determinacion del flujo minimo de agua de enfriamiento en funcion de la capacidad de transferencia de calor instalada, sujeta a las restricciones de maximo incremento de temperatura permitido. La aplicacion de la metodologia a sistemas reales, ha resultado en ahorros del 20% del total de la energia que se consume en el bombeo del agua de enfriamiento.

Thermal analysis for energy consumption reduction in cooling water systems; Analisis termico para la reduccion del consumo de energia en sistemas de agua de enfriamiento

Energy Technology Data Exchange (ETDEWEB)

Picon Nunez, Martin [Instituto de Investigaciones Cientificas, Universidad de Guanajuato, Guanajuato (Mexico); Quillares Vargas, Luis [Tecnopinch, S. A. de C. V., (Mexico)

1999-12-31

This paper presents the fundamental principles for the thermal analysis of cooling water systems in processing plants. In existing heat dissipating networks this methodology application allows the identification of opportunities for reducing the energy consumption used for cooling water pumping. The methodology is based on the determination of the minimum cooling water flow as a function of the installed heat exchange capacity, subjected to the restrictions of the maximum allowed temperature elevation. The methodology application to real systems, has resulted in saving 20% of the total energy consumed in cooling water pumping. [Espanol] En este trabajo se presentan los principios fundamentales para el analisis termico de sistemas de enfriamiento en plantas de proceso. En redes de eliminacion de calor existentes, la aplicacion de esta metodologia permite identificar oportunidades para reducir el consumo de energia utilizada para el bombeo del fluido enfriante. La metodologia se basa en la determinacion del flujo minimo de agua de enfriamiento en funcion de la capacidad de transferencia de calor instalada, sujeta a las restricciones de maximo incremento de temperatura permitido. La aplicacion de la metodologia a sistemas reales, ha resultado en ahorros del 20% del total de la energia que se consume en el bombeo del agua de enfriamiento.

Vermicomposting eliminates the toxicity of Lantana (Lantana camara) and turns it into a plant friendly organic fertilizer

Energy Technology Data Exchange (ETDEWEB)

Hussain, N.; Abbasi, Tasneem; Abbasi, S.A., E-mail: prof.s.a.abbasi@gmail.com

2015-11-15

Highlights: • It is shown for the first time that Lantana can lose its toxicity when vermicomposted. • The Lantana vermicompost is shown to be a good organic fertilizer. • FTIR studies identified Lantana’s toxic constituents destroyed by vermicomposting. • The findings have far-reaching implications in the gainful use of harmful weeds. - Abstract: In evidently the first study of its kind, vermicompost derived solely from a weed known to possess plant and animal toxicity was used to assess its impact on the germination and early growth of several plant species. No pre-composting or supplementation of animal manure was done to generate the vermicompost in order to ensure that the impact is clearly attributable to the weed. Whereas the weed used in this study, Lantana (Lantana camara), is known to possess strong negative allelopathy, besides plant/animal toxicity in other forms, its vermicompost was seen to be a good organic fertilizer as it increased germination success and encouraged growth of all the three botanical species explored by the authors – green gram (Vigna radiata), ladies finger (Abelmoschus esculentus) and cucumber (Cucumis sativus). In terms of several physical, chemical and biochemical attributes that were studied, the vermicompost appeared plant-friendly, giving best results in general when employed at concentrations of 1.5% in soil (w/w). Fourier transform infrared spectrometry revealed that the phenols and the sesquiterpene lactones that are responsible for the allelopathic impact of Lantana were largely destroyed in the course of vermicomposting. There is also an indication that lignin content of Lantana was reduced during its vermicomposting. The findings open up the possibility that the billions of tons of phytomass that is generated annually by Lantana and other invasives can be gainfully utilized in generating organic fertilizer via vermicomposting.

Vermicomposting eliminates the toxicity of Lantana (Lantana camara) and turns it into a plant friendly organic fertilizer

International Nuclear Information System (INIS)

Hussain, N.; Abbasi, Tasneem; Abbasi, S.A.

2015-01-01

Highlights: • It is shown for the first time that Lantana can lose its toxicity when vermicomposted. • The Lantana vermicompost is shown to be a good organic fertilizer. • FTIR studies identified Lantana’s toxic constituents destroyed by vermicomposting. • The findings have far-reaching implications in the gainful use of harmful weeds. - Abstract: In evidently the first study of its kind, vermicompost derived solely from a weed known to possess plant and animal toxicity was used to assess its impact on the germination and early growth of several plant species. No pre-composting or supplementation of animal manure was done to generate the vermicompost in order to ensure that the impact is clearly attributable to the weed. Whereas the weed used in this study, Lantana (Lantana camara), is known to possess strong negative allelopathy, besides plant/animal toxicity in other forms, its vermicompost was seen to be a good organic fertilizer as it increased germination success and encouraged growth of all the three botanical species explored by the authors – green gram (Vigna radiata), ladies finger (Abelmoschus esculentus) and cucumber (Cucumis sativus). In terms of several physical, chemical and biochemical attributes that were studied, the vermicompost appeared plant-friendly, giving best results in general when employed at concentrations of 1.5% in soil (w/w). Fourier transform infrared spectrometry revealed that the phenols and the sesquiterpene lactones that are responsible for the allelopathic impact of Lantana were largely destroyed in the course of vermicomposting. There is also an indication that lignin content of Lantana was reduced during its vermicomposting. The findings open up the possibility that the billions of tons of phytomass that is generated annually by Lantana and other invasives can be gainfully utilized in generating organic fertilizer via vermicomposting

Thermal behavior of building materials based in woody fibers; Comportamiento termico de materiales constructivos a base de fibras lenosas

Energy Technology Data Exchange (ETDEWEB)

Flores Murrieta, Fernando E; Bojorquez Baez, Inocente; Llovera Esteban, Arturo; Hernandez Rodriguez, Jose [Universidad de Quintana Roo, Chetumal, Quintana Roo (Mexico); Perez Sanchez, Maria M [Universidad Autonoma de Yucatan, Merida (Mexico)

2000-07-01

A Test development to obtain the thermal conductivity and the study of thermal performance of building materials by a device of the Guarded Hot Plate (25 x 24.8 cm) according to standards ASTM C 518-91 and C 717-97, in a range of low temperatures (23-50 Celsius degrees) are presented in this work. The device consist of a structure whit: heat source system; heat dissipator system; plates and specimens fastener, and assembly of thermocouples and insulated plates. Subsequently in the experiments, will be necessary to reach a steady state to different temperatures for monitoring the thermal gradient. Another side, considering the electric power of the overall system and the modified Fouriers equation for two specimens, we can obtain the thermal conductivity, for instance: Plaster; woods and new materials based on woody fibers. [Spanish] En este trabajo se presenta el estudio del comportamiento termico y desarrollo de prueba de conductividad termica tanto en materiales de construccion como aquellos basado en fibras lenosas en un rango de bajas temperaturas (23-50 grados Celsius). De acuerdo con las normas ASTM C-518-91 y C-177-97, se utiliza un dispositivo de placa caliente guardada de 25 x 24.8 cm. que requiere de dos muestras identicas de especimenes diferentes colocadas entre una fuente de calor y una fuente fria aisladas termicamente. Se presenta el desarrollo experimental para determinar la conductividad termica en estado estacionario a varias temperaturas de operacion en materiales constructivos tales como: yeso, madera de pino y a base de fibra lenosa. Los dos primeros materiales se han utilizado como referencia en la comparacion de las propiedades termofisicas que aparecen en la bibliografia tecnica. Lo cual nos permite tener un buen grado de confiabilidad en el dispositivo utilizado en la determinacion de dichas propiedades.

C:\\Users\\AISA\\Desktop\\A. B. FANDOHAN.xps

African Journals Online (AJOL)

AISA

Lantana camara (verbenaceae) : a potential threat to the effectiveness of ... network was highly suitable for L. camara under current climate. ..... in their historical home range but also because ... environmentally friendly biocontrol protocols.

Effect of vermicast generated from an allelopathic weed lantana (Lantana camara) on seed germination, plant growth, and yield of cluster bean (Cyamopsis tetragonoloba).

Science.gov (United States)

Karthikeyan, M; Hussain, N; Gajalakshmi, S; Abbasi, S A

2014-11-01

In perhaps the first-ever study of its kind, the effect of vermicompost, derived solely from an allelopathic weed, on the germination, growth, and yield of a botanical species, has been carried out. In test plots, the soil was treated with the vermicompost of lantana (Lantana camara) at the rates of 5, 7.5, and 10 t ha(-1), and cluster bean (Cyamopsis tetragonoloba) was grown on it. The performance of these systems was compared with the systems in which the soil was fortified with inorganic fertilizers (IFs) in concentrations equivalent to those present in the respective vermicompost (VC) treatments. Additionally, a set of control was studied in which the soil was used without fortification by either VC or IF. It was seen that up to 51.5 % greater germination success occurred in the VC treatments compared to controls. VC also supported better plant growth in terms of stem diameter, shoot length, shoot mass, number of leaves, and leaf pigments. The positive impact extended up to fruit yield. In addition, vermicast application enhanced root nodule formation, reduced disease incidence, and allowed for a smaller number of stunted plants. The results indicate that allelopathic ingredients of lantana seem to have been totally eliminated during the course of its vermicomposting and that lantana vermicompost has the potential to support germination, growth, and fruit yield better than equivalent quantities of IFs.

Nonlinear analysis of thermal stresses of a of first stage nozzle of a gas turbine at full load from the results of an analysis of conjugated heat transference; Analisis no lineal de esfuerzos termicos de una tobera de primera etapa de turbina de gas a plena carga a partir de resultados de un analisis de transferencia de calor conjugado

Energy Technology Data Exchange (ETDEWEB)

Perez Hernandez, Efrain [Centro Nacional de Investigacion y Desarrollo Tecnologico (Cenidet), Cuernavaca, Morelos (Mexico); Mazur C, Zdzislaw; Garcia Illescas, R; Hernandez Rossette, Alejandro [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2007-11-15

The gas turbines operate at extremely high temperatures, at high thermal and mechanical stresses, causing that the useful life of the involved components be reduced. In the present article the results realized by previous investigations of temperatures obtained from analysis of heat transfer and flow of fluids of the nozzle by means of the Star-CD program based on finite volumes is presented. Later, the NISA program of finite elements was used to realize the analysis of thermal stresses considering the material plasticity. The methodology employed to determine the material properties variable with the temperature of the super-alloy FSX-414 and the plasticity model used in the structural analysis in the finite element program. The result will be later used in the fatigue analysis for the useful life assessment. [Spanish] Las turbinas de gas operan a temperatura extremadamente altas, a elevados esfuerzos termicos y mecanicos, ocasionando que la vida de los componentes involucrados se reduzca. En el presente articulo se presentan los resultados realizados por previas investigaciones de temperaturas obtenidas a partir de analisis de transferencia de calor y flujo de fluidos de la tobera mediante el programa Star-CD basado en volumenes finitos. Posteriormente, se utilizo el programa NISA de elementos finitos para realizar el analisis de esfuerzos termicos considerando plasticidad del material. Se muestra la metodologia empleada para determinar las propiedades del material variables con la temperatura de la superaleacion FSX-414 y el modelo de plasticidad utilizado en el analisis estructural en el programa de elemento finito. Los resultados seran empleados posteriormente en el analisis de fatiga para la estimacion de vida util.

Hydrogen absorption in Mg1.95Ti0.05Ni0.95Cu0.05 alloy prepared with mechanical alloying and thermal treatment; Absorcion de hidrogeno en la aleacion Mg1.95Ti0.05Ni0.95Cu0.05 preparada por aleado mecanico y tratamiento termico

Energy Technology Data Exchange (ETDEWEB)

Martinez, Juan Bonifacio; Urena Nunez, Fernando [Instituto Nacional de Investigaciones Nucleares, Ocoyoacac, Estado de Mexico (Mexico)]. E-mail: juan.bonifacio@inin.gob.mx

2009-09-15

This work presents hydrogen absorption in quaternary alloy Mg1.95Ti0.05Ni0.95Cu0.05 obtained by the mechanical alloying method, followed by thermal treatment in ultra-high pure argon atmosphere. The composition of the phases, microstructure and morphology of ground powders and with thermal treatment were characterized by DRX, SEM/EDS and TEM. After 20 hours of mechanical grinding and recooked at 300 degrees Celsius/1h in argon atmosphere, the quaternary alloy has a Mg{sub 2}Ni crystalline hexagonal structure with a crystallite size under 10 nm. The absorption measurements were performed under a pressure of 0.2 to 1.2 MPa at a temperature of 200 degrees Celsius in a micro-reactor. The quantification of absorption-desorption of hydrogen in the intermetallic was conducted in a TGA-DSC simultaneous calorimeter. Metallic hydride-dehydride powder was characterized with SEM and XRD. [Spanish] En este trabajo se presenta la absorcion de hidrogeno en la aleacion cuaternaria Mg1.95Ti0.05Ni0.95Cu0.05 obtenida por el metodo de aleado mecanico, seguida de tratamiento termico en atmosfera de argon de ultra alta pureza. La composicion de las fases, microestructura y morfologia de los polvos molidos y con tratamiento termico fue caracterizada por DRX, SEM/EDS y TEM. Despues de 20 h de molienda mecanica con recocido a 300 grados Celsios/1h en atmosfera de argon, la aleacion cuaternaria tiene una estructura cristalina hexagonal Mg{sub 2}Ni con tamano de cristalito menor a 10 nm. Las mediciones de absorcion fueron realizadas bajo una presion de 0.2 a 1.2 MPa a una temperatura de 200 grados Celsios en un micro-reactor. La cuantificacion de absorcion-desorcion de hidrogeno en el intermetalico se realizo en un calorimetro simultaneo TGA-DSC. Se determino que la cantidad maxima absorbida de hidrogeno en la aleacion cuaternaria fue de 3.24% en peso cuando la presion fue de 0.8 MPa a dicha temperatura. Polvos metalicos hidrurados-deshidrurados se caracterizaron por SEM y XRD.

Assessing the utility of the spot 6 sensor in detecting and mapping ...

African Journals Online (AJOL)

Lantana camara is a significant weed in South Africa which is causing severe impacts on agriculture by reducing grazing areas. This study assessed the potential of the SPOT 6 multispectral sensor and two broadband vegetation indices (NDVI and SR) for detecting and mapping Lantana camara in a community grazing ...

Thermal responses and its relation with the building outdoor conditions; Respuestas termicas y su relacion con la envolvente del edificio

Energy Technology Data Exchange (ETDEWEB)

Marincic, Irene [Universidad de Sonora, Hermosillo, Sonora (Mexico); Isalgue, Antoni [Universidad Politecnica de Cataluna, Barcelona (Spain)

2000-07-01

In order to understand and to control the indoor thermal behavior in buildings, it is necessary to know the origin of the energies coming into and outside the building, identifying the geometric factors and physical properties, that can modify the thermal balance of the system. In this work, we analyze the thermal behavior of a building experimentally, related with its exterior conditions. Specifically, we analyze the thermal response indoors at different distances from the building envelope, which implies different thermal insulation situations. Supported on temperature measurements in a residential building, which is representative of local construction styles (adjacent other buildings), we analyze the thermal response effects depending on the distances between the considered points and the envelope and on the insulation between both. Applying a methodology based on experimental transfer functions of buildings, the thermal behavior in the temporary and frequency domains is evaluated. With this methodology, it is possible to visualize certain phenomena and to obtain thermal parameters that characterize the dynamic aspects of the thermal response. The main scope is to extract information from the building analysis, in order to extrapolate the behavior conclusions to a proper thermal design of similar constructions. From the thermal responses analysis at different spatial localization, we conclude that the distance from the building envelope (and also its properties) has a great influence on thermal inertia effects, which can modify importantly the thermal response. This phenomena has a parallelism with the skin effect of the magnetic fields penetration in conductors. The spatial localization implies a certain thermal mass involved in each case, which controls the penetration of exterior thermal oscillation. [Spanish] Para poder entender y controlar los comportamientos termicos en el interior de los edificios, es necesario conocer el origen de las energias que

AP Potential™ Expectancy Tables Based on PSAT/NMSQT® and SAT® Scores on the 2015-16 Redesigned Scales. Statistical Report 2016-2

Science.gov (United States)

Ewing, Maureen; Wyatt, Jeffrey N.; Smith, Kara

2016-01-01

Historically, AP Potential™ has used PSAT/NMSQT® scores to identify students who are likely to earn a 3 or higher on a specific AP® Exam--based on research showing moderate to strong relationships between PSAT/NMSQT scores and AP Exam scores (Camara & Millsap, 1998; Ewing, Camara & Millsap, 2006; Zhang, Patel & Ewing, 2014a). For most…

AP Potential Expectancy Tables Based on PSAT/NMSQT and SAT Scores on the 2015-16 Redesigned Scales Using Final Concordance Tables. Statistical Report

Science.gov (United States)

Ewing, Maureen; Wyatt, Jeff

2017-01-01

Historically, AP Potential™ has used PSAT/NMSQT® scores to identify students who are likely to earn a 3 or higher on a specific AP Exam based on research showing moderate to strong relationships between PSAT/NMSQT scores and AP Exam scores (Camara & Millsap, 1998; Ewing, Camara, & Millsap, 2006; Zhang, Patel, & Ewing, 2014a). For most…

Incorporating Ninth-Grade PSAT/NMSQT® Scores into AP Potential™ Predictions for AP® European History and AP World History. Statistical Report 2014-1

Science.gov (United States)

Zhang, Xiuyuan; Patel, Priyank; Ewing, Maureen

2015-01-01

Historically, AP Potential™ correlations and expectancy tables have been based on 10th-and 11th-grade PSAT/NMSQT® examinees and 11th-and 12th-grade AP® examinees for all subjects (Zhang, Patel, & Ewing,2014; Ewing, Camara, & Millsap, 2006; Camara & Millsap, 1998). However, a large number of students take AP European History and AP…

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

Directory of Open Access Journals (Sweden)

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.

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...

An Investigation of the Combat Air Patrol Stationing in an Integrated Air Defense Scenario

Science.gov (United States)

1990-12-01

guided missiles, drones , decoys and short range missiles and bombs. The defensive elements include a C2 netting of early warning (EW), ground...M, 69 andar 70045 Brasilia, DF Brasil 6. Departamento de Ensino Da Aerondutica Av. Mal CAmara , 233, 10 andar 20020 Rio de Janeiro, RJ Brasil 7...Diretoria de Informdtica e Estatfstica da Aeron~utica Av. Mal CAmara , 233, 8Q andar 20020 Rio de Janeiro, RJ Brasil 11. Centro de Computagdo da Aeronutica-BR

Assessing distributions of two invasive species of contrasting habits in future climate.

Science.gov (United States)

Panda, Rajendra Mohan; Behera, Mukunda Dev; Roy, Partha Sarathi

2018-05-01

Understanding the impact of climate change on species invasion is crucial for sustainable biodiversity conservation. Through this study, we try to answer how species differing in phenological cycles, specifically Cassia tora and Lantana camara, differ in the manner in which they invade new regions in India in the future climate. Since both species occupy identical niches, exploring their invasive potential in different climate change scenarios will offer critical insights into invasion and inform ecosystem management. We use three modelling protocols (i.e., maximum entropy, generalised linear model and generalised additive model) to predict the current distribution. Projections are made for both moderate (A1B) and extreme (A2) IPCC (Intergovernmental Panel on Climate Change) scenarios for the year 2050 and 2100. The study reveals that the distributions of C. tora (annual) and L. camara (perennial) would depend on the precipitation of the warmest quarter and moisture availability. C. tora may demonstrate physiological tolerance to the mean diurnal temperature range and L. camara to the solar radiation. C. tora may invade central India, while L. camara may invade the Western Himalaya, parts of the Eastern Himalaya and the Western Ghats. The distribution ranges of both species could shift in the northern and north-eastern directions in India, owing to changes in moisture availability. The possible alterations in precipitation regimes could lead to water stress, which might have cascading effects on species invasion. L. camara might adapt to climate change better compared with C. tora. This comparative analysis of the future distributions of two invasive plants with contrasting habits demonstrates that temporal complementarity would prevail over the competition. Copyright © 2017 Elsevier Ltd. All rights reserved.

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

Directory of Open Access Journals (Sweden)

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

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

Neuronal networks for the study of buildings thermal behavior; Redes neuronales para el estudio del comportamiento termico de edificios

Energy Technology Data Exchange (ETDEWEB)

Marincic, Irene [Universidad de Sonora (Mexico); Del Rio, J. Antonio [Centro Morelense de Innovacion y Transferencia Tecnologica (Mexico)

2009-07-15

The evaluation as well as the prediction of buildings thermal behavior involves complex calculations mainly because of its enormous number of variables, many of them difficult to determine. For this type of problems, a possibility is to resort to models of the black box type, that allow the characterization of the building with very few variables, for then to be able to predict its behavior under other circumstances, with greater certainty. One of the black box models of more and more used in diverse disciplines, is the one of the artificial neuronal networks (ANN). These can be used as an alternative method of analysis and prediction, particularly for cases in which many variables take part. In this work a preliminary study is presented that analyzes the accuracy of a model of neuronal network for the prediction of the inside temperatures of a building, given the outside temperatures. A very simple network, of 3 neurons, located in 2 layers is considered. The results of the inside temperatures obtained in the learning as well as in the prediction stage are analyzed, comparing them with the ones obtained using another model of black box previously developed by the authors, the one of the function responded in the dominion of frequencies. [Spanish] Tanto la evaluacion como la prediccion del comportamiento termico de los edificios involucra calculos complejos sobre todo por su enorme numero de variables, muchas de ellas dificiles de determinar. Para este tipo de problemas, una posibilidad es recurrir a modelos del tipo caja negra, que permiten caracterizar al edificio como muy pocas variables, para luego poder predecir su comportamiento bajo otras circunstancias, como mayor certeza. Uno de los modelos de caja negra cada vez mas utilizado en diversas disciplinas, es el de las redes neuronales artificiales (ANN). Estas pueden ser usadas como metodo alternativo de analisis y sobre todo de prediccion, particularmente para los casos en que intervienen muchas variables. En

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)

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

Directory of Open Access Journals (Sweden)

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.

Thermal Neutron Spectral and Spatial Distributions in Light-Water-Moderated Uranium Lattices; Distributions Spectrale et Spatiale des Neutrons Thermiques dans des Reseaux a Uranium et a Eau Leger; Spektral'noe i prostranstvennoe raspredelenie teplovykh nejtronov v uranovykh reshetkakh s vodnym zamedlitelem; Distribuciones Espectral y Espacial de los Neutrones Termicos en los Reticulados de Uranio Moderados por Agua Ligera

Energy Technology Data Exchange (ETDEWEB)

Hardy, J.; Volpe, J. J.; Klein, D.; Schmidt, E.; Gelbard, E. [Bettis Atomic Power Laboratory, Pittsburgh, PA (United States)

1964-02-15

realizados acerca del comportamiento de los neutrones termicos en los reticulados de uranio moderados por agua ligera. Los experimentos pertenecen a dos tipos principales: mediciones del grado de utilizacion termica y mediciones, por activacion, de la distribucion espacial de los neutrones termicos en un medio acuoso uniformemente envenenado. Esos experimentos se concibieron con miras a comprobar la validez de los actuales modelos teoricos, distinguiendo los efectos espectrales de los espaciales en el interior de un reactor. Se han efectuado eomparaciones con modelos teoricos que entraflan distintas aproximaciones relacionadas con la teoria del transporte y el nucleo de dispercion de los neutrones termicos. La primera serie de experimentos consistio en medir por el procedimiento de activacion los factores de desventaja termica en distintas celdas de reticulados del conjunto TRX, que constituye un reactor de uranio ligeramente enriquecido, moderado por H{sub 2}O, con barras de combustible cilindricas dispuestas en haces hexagonales. Los autores han comparado los resultados de las mediciones del grado de utilizacion termica con los datos de calculos efectuados con arreglo al metodo de Montecarlo. Utilizaron dos nucleos, el de Radkowsky y el de N elk in. El nucleo de Radkowsky constituye una aproximacion de primer orden que se viene utilizando umversalmente en el disello de los reactores. El nucleo de Nelkin, por su parte, representa una descripcion mas reciente y mas detallada del nucleo de dispersion. Dado que los indices de absorcion calculados para los neutrones termicos dependen de la eleccion del nucleo de dispersion, especialmente si el espectro del flujo neutronico no es maxwelliano, se ideo otra serie de experimentos de activacion con ayuda del conjunto TRX para verificar de un modo mas directo la utilidad del nucleo de dispersion. Los experimentos se realizaron en condiciones tales que la deformacion espectral se debia esencialmente a un envenenamiento uniforme. Las

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

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

Biological Effects of Thermal Neutrons and the B{sup 10}(n, {alpha}) Li{sup 7} reaction; Effets Biologiques des Neutrons Thermiques et la Reaction {sup 10}B(n, {alpha}){sup 7}Li; Biologicheskoe dejstvie teplovykh nejtronov i reaktsiya B{sup 10}(n, {alpha}) Li{sup 7}; Efectos Biologicos de los Neutrones Termicos y la Reaccion {sup 10}B(n, {alpha}){sup 7}Li

Energy Technology Data Exchange (ETDEWEB)

Archambeau, J. O.; Alcober, V.; Calvo, W. G.; Brenneis, H. [Medical Research Center, Brookhaven National Laboratory, Upton, NY (United States)

1964-05-15

astrocytes et d'une alteration de l ' endothelium des capillaires. Il en resulte une deficience marquee en plaquettes, qui vient aggraver les alterations locales. Les animaux meurent d'une hemorragie et/ou d'une lesion du cerveau entre le cinquieme et le neuvieme jour apres l'expo sition. Ces effets sont attribues aux rayons gamma et aux particules alpha produits lors de la capture des neutrons par le bore {sup 10}B(n, {alpha}){sup 7}Li. L'exposition de la peau d'un porc a un flux de 5 x 10{sup 12} n/cm{sup 2} ne provoque aucune modification histologique. Lorsque la peau est irradiee par ce meme flux apres une injection intraveineuse de 35 mg de {sup 10}B/kg de matiere vivante, on constate une radioepidermite classique, qui guerit dans l'espace de 36 a 40 j. Le fractionnement du flux total en huit expositions reparties sur 12 j ne diminue pas la gravite de la reaction, comme c'est le cas pour une irradiation par les rayons gamma. Cet effet est attribue essentiellement a l'action des particules alpha provenant de la capture des neutrons thermiques par le bore. (author) [Spanish] U irradiacion de animales con neutrones termicos procedentes del reactor de investigacion medica (MRR) produce en los tejidos efectos derivados de las radiaciones gamma y otras particulas liberadas en la captura de los neutrones termicos por los elementos del tejido y los materiales protectores, asi como de las radiaciones gamma y los neutrones rapidos generados en el proceso de fision en el cuerpo del reactor. Los resultados globales de la irradiacion con neutrones termicos son funcion del flujo incidente nvt. Como el flujo de neutrones termicos decrece rapidamente dentro del tejido (capa semirreductorasl Approximately-Equal-To 8 cm), las dosis que inciden sobre la superficie deben ser grandes a fin de que la dosis profunda sea suficiente. Las reacciones consecutivas en el pulmon, el intestino, la medula osea y las mucosas se atribuyen principalmente al efe cto de los rayos gamma originados por la

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

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

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(+).

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

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)

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.

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...

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...

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.

Mesh sensitivity in the thermal analysis of a gas turbine a blade with internal cooling; Sensibilidad de malla en el analisis termico de un alabe de turbina de gas con enfriamiento interno

Energy Technology Data Exchange (ETDEWEB)

Alfaro Ayala, Jorge Arturo; Gallegos Munoz, Armando [Facultad de Ingenieria Mecanica, Electrica y Electronica (FIMEE), Universidad de Guanajuato (Mexico); Campos Amezcua, Alfonso [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2007-11-15

This article presents the methodology to generate the mesh model of the computer model of a blade by means of commands in the software of CFD Fluent, mainly in the fluid zone, since a mesh sensitivity analysis becomes too expensive in terms of human and computer resources. When geometry is too irregular, modifications are required in the mesh to avoid problems such as the divergence, instability in the solution and the dependency on the results of temperature, pressure, velocity, etc. Such is the case of a blade with internal cooling of the first stage of a gas turbine. The results are included of the generated mesh as well as of the thermal analysis of the blade. Additionally the results of temperature, pressure and velocity of the combustion gases and of the cooling air are shown. [Spanish] Este articulo presenta la metodologia para generar el mallado del modelo computacional de un alabe por medio de comandos en el software de CFD Fluent, principalmente en la zona del fluido, ya que un analisis de sensibilidad de malla se vuelve demasiado costoso en terminos de recursos humanos y computacionales. Cuando la geometria es demasiado irregular, se requiere de modificaciones en la malla para evitar problemas como son la divergencia, inestabilidad en la solucion y la dependencia de los resultados de temperatura, presion, velocidad, etc. Tal es el caso de un alabe con enfriamiento interno de la primera etapa de una turbina de gas. Se incluyen los resultados tanto de la malla generada como del analisis termico del alabe. Adicionalmente se muestran los resultados de temperatura, presion y velocidad de los gases de la combustion y del aire de enfriamiento.

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

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...

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.

Heating of a Dense Plasma in a Metallic Chamber; Chauffage d'un Plasma dense dans une Chambre Metallique; 041d 0410 0413 0420 0415 0412 041f 041b 041e 0422 041d 041e 0419 041f 041b 0410 0417 041c 042b 0412 041c 0415 0422 0410 041b 041b 0418 0427 0415 0421 041a 041e 0419 041a 0410 041c 0415 0420 0415 ; Calentamiento de un Plasma Denso en una Camara Metalica

Energy Technology Data Exchange (ETDEWEB)

Shvets, O. M.; Tarasenko, V. F.; Ovchinnikov, S. S.; Tolok, V. T. [Fiziko-Tehnicheskij Institut AN USSR, Khar' kov, USSR (Ukraine)

1966-04-15

d'alimentation a pointe d'aluminium. Les electrodes sont branchees sur un generateur haute frequence par l'intermediaire d'un condensateur isolant. La chambre est placee a l'interieur d'un soleno'ide produisant un champ magnetique dont l'intensite peut etre reglee de facon continue entre zero et 2500 Oe. Les auteurs ont choisi la configuration du champ en fonction des conditions necessaires a la generation et a l'absorption des ondes cyclotroniques des ions (le champ limite se situe au centre du solenoiede). On a utilise l'hydrogene comme gaz de travail, et sa pression a ete main- . tenue entre 10{sup -4} et 10{sup -2} Torr au moyen d'un mecanisme de fuite fonctionnant en regime stationnaire. Pour produire un plasma isole des parois de la chambre, les auteurs ont utilise une decharge haute frequence qui, en raison des qualites du plasma, cree une difference de potentiel constante entre les electrodes et la chambre. Il en resulte l'apparition entre les electrodes d'electrons qui oscillent le long des lignes de force du champ magnetique et produisent un degre eleve d'ionisation du gaz entre les electrodes. Il se forme sur l'axe de la chambre a vide une colonne de plasma dense dont le diametre est determine par le diametre des electrodes. Les auteurs font des recherches sur le spectre du rayonnement de decharge; ils determinent la densite du plasma d'apres l'elargissement de Stark de la raie H{sub {beta}} et la temperature des electrons du plasma d'apres ' le rapport des intensites du singulet et du triplet de l'helium. Les auteurs mesurent les flux d'atomes neutres rapides formes au cours de l'echange de charges des ions hydrogene sur le gaz neutre et, a l'aide de sondes speciales, les energies transversales des ions en fonction de l'intensite du champ magnetique et d'autres parametres. (author) [Spanish] En la memoria se exponen los resultados de experimentos sobre el calentamiento por alta frecuencia de un plasma en una instalacion que consiste en una camara de

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...

Fungal delignification of lignocellulosic biomass improves the saccharification of cellulosics.

Science.gov (United States)

Gupta, Rishi; Mehta, Girija; Khasa, Yogender Pal; Kuhad, Ramesh Chander

2011-07-01

The biological delignification of lignocellulosic feedstocks, Prosopis juliflora and Lantana camara was carried out with Pycnoporus cinnabarinus, a white rot fungus, at different scales under solid-state fermentation (SSF) and the fungal treated substrates were evaluated for their acid and enzymatic saccharification. The fungal fermentation at 10.0 g substrate level optimally delignified the P. juliflora by 11.89% and L. camara by 8.36%, and enriched their holocellulose content by 3.32 and 4.87%, respectively, after 15 days. The fungal delignification when scaled up from 10.0 g to 75.0, 200.0 and 500.0 g substrate level, the fungus degraded about 7.69-10.08% lignin in P. juliflora and 6.89-7.31% in L. camara, and eventually enhanced the holocellulose content by 2.90-3.97 and 4.25-4.61%, respectively. Furthermore, when the fungal fermented L. camara and P. juliflora was hydrolysed with dilute sulphuric acid, the sugar release was increased by 21.4-42.4% and the phenolics content in hydrolysate was decreased by 18.46 and 19.88%, as compared to the unfermented substrate acid hydrolysis, respectively. The reduction of phenolics in acid hydrolysates of fungal treated substrates decreased the amount of detoxifying material (activated charcoal) by 25.0-33.0% as compared to the amount required to reduce almost the same level of phenolics from unfermented substrate hydrolysates. Moreover, an increment of 21.1-25.1% sugar release was obtained when fungal treated substrates were enzymatically hydrolysed as compared to the hydrolysis of unfermented substrates. This study clearly shows that fungal delignification holds potential in utilizing plant residues for the production of sugars and biofuels.

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...

Electret ionization chamber: a new method for detection and dosimetry of thermal neutrons; Camara de ionizacao de eletretos: um novo metodo para deteccao e dosimetria de neutrons termicos

Energy Technology Data Exchange (ETDEWEB)

Ghilardi, A J.P.

1988-12-31

An electret ionization chamber with boron coated walls is presented as a new method for detecting thermal neutrons. The efficiency of electret ionization chambers with different wall materials for the external electrode was inferred from the results. Detection of slow neutrons with discrimination against the detection of {gamma}-rays and energetic neutrons was shown to depend on the selection of these materials. The charge stability over a long period of time and the charge decay owing to natural radiation were also studied. Numerical analysis was developed by the use of a micro-computer PC-XT. Both the experimental and numerical results show that the sensitivity of the electret ionization chamber for detection of thermal neutrons is comparable with that of the BF{sub 3} ionization chamber and that new technologies for deposition of the boron layer will produce higher efficiency detectors. (author). 102 refs, 32 fig, 10 tabs.

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

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.

Measurement of {beta} Emitters by the Radiated Charge; Mesure des Emetteurs {beta} par la Charge Rayonnee. Mesure de l'activite des emetteurs {beta} a partir de la charge rayonnee; Izmerenie aktivnosti izluchatelya {beta}-chaetits na osnove izluchaemogo zaryada; Medicion de la actividad de los emisores {beta} a partir de la carga irradiada

Energy Technology Data Exchange (ETDEWEB)

Engelmann, J J [Centre d' Etudes Nucleaires de Saclay (France)

1960-06-15

choix. Les theories sur la retrodiffusion permettent d'expliquer ces resultats. (author) [Spanish] El metodo se basa en el principio recientemente descrito por Failla y sus colaboradores: En un recinto en que se ha hecho el vacio se disponen paralelamente y a poca distancia entre si dos electrodos planos del mismo material. Sobre uno de ellos se deposita la fuente que se ha de medir. La retrodispersion en el electrodo portador de la fuente queda compensada por la reflexion en el otro electrodo. Un campo magnetico o electrico permite eliminar el efecto de los electrones secundarios de escasa energia. Cuando la deflexion se efectua por medios magneticos, el dispositivo experimental se completa por una camara de extrapolacion y cuando la deflexion es. electrica, por una camara de rejilla muy fina. En el caso del Sr{sup 90}-Y{sup 90} y del P{sup 32}, los resultados obtenidos concuerdan satisfactoriamente con los de las mediciones efectuadas con ayuda de un contador 4 {pi} (precision superior a {+-} 2%). En el caso del S{sup 35}, las eperiencias realizadas ponen de manifiesto la influencia ejercida por el numero atomico del soporte de la fuente, lo cual obliga a utilizar determinados soportes. Los resultados obtenidos pueden explicarse con ayuda de las teorias sobre la retrodispersion. (author) [Russian] Printsip metoda opisan nedavno g-nom Pehlla i ego sotrudnikami: Dva takikh ehlektroda, sdelannye iz odnogo materiala i raspolozhenny e parallel'no i blizko drug ot druga, pomeshchayutsya v vakuumnyj sosud. Na odnom iz ehlektrodov pomeshchayut podlezhashchij izmereniyu istochnik. Obratnaya diffuziya na ehlektrode, na kotorom nakhoditsya istochnik, kompensiruets ya otrazheniem na drugom ehlektrode. Magnitnoe ili ehlektricheskoe pole pozvolyaet ustranit' dejstvie vtorostepenny kh ehlektronov slaboj moshchnosti. EHksperimental'ny j mekhanizm sostoit, v sluchae magnitnogo otkloneniya, iz ehkstrapolyatsionno j kamery, a v sluchae ehlektricheskogo otkloneniya, iz kamery s ochen

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.

2016-01-01

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

The luminescent chamber and its use in high-energy physics experiments; La chambre a luminescence: son emploi dans les experiences de physique des hautes energies; Lyuminestsentnaya kamera i ee ispol'zovanie v ehksperimentakh, provodimykh v fizike vysokikh ehnergij; La camara luminiscente y su empleo en experimentos de fisica de elevada energia

Energy Technology Data Exchange (ETDEWEB)

Jones, L W; Perl, M L [Randall Laboratory of Physics, University of Michigan, Ann Arbor, MI (United States); Lawrence Radiation Laboratory, University of California, Berkeley, CA (United States)

1962-04-15

los protones de retroceso procedentes de la dispersion inelastica de piones (produccion de piones aislados) en tres cantidades de movimiento correspondientes a piones incidentes. En este caso se registraron tambien varios millares de sucesos. El alcance y el angulo del proton de retroceso determinaron exclusivamente la transferencia de cantidad de movimiento y la energia del centro de masa del sistema di-pion, que fueron los parametros cinematicos de interes en este problema. En estos experimentos se logro un disparo despues de cada suceso y un tiempo de resolucion de 5 {mu}s, desbloqueando el segundo tubo de imagenes al recibir una senal del circuito electronico del contador de centelleo. Los autores estudian la preparacion y la ejecucion con exito de estos experimentos, sobre todo las caracteristicas mas interesantes de los tubos de imagenes de los contadores de centelleo y de los sistemas electronicos. Se ha adquirido tambien experiencia en el analisis de fotografias de trazas, en particular respecto de la precision alcanzable y la exactitud de los datos fisicos obtenidos. Por ultimo examinan la evolucion futura de las camaras luminiscentes, en especial de los tubos intensificadores de imagenes y los centelleadores en desarrollo actualmente. Tambien analizan el papel que la camara luminiscente podra desempenar en los futuros experimentos con particulas de elevada energia, en comparacion con las camaras de chispa y otros detectores. (author) [Russian] Vpervye v ehksperimentakh v oblasti fiziki chastits vysokikh ehnergij byla ispol'zovana lyuminestsentnaya kamera. Na bevatrone radiatsionnoj laboratorii im. Lourensa s pomoshch'yu kaskadnoj sistemy trekh usilitelej yarkosti izobrazheniya byli sfotografirovany sledy chastits v aktivirovannykh jodisto-natrievykh kristallakh. Pri odnom ehksperimente uprugoe rasseyanie pi-mezonov na protonakh izuchalos' s pomoshch'yu dvukh blokov stsintillyatorov, kazhdyj iz kotorykh imel dlinu 20 sm, prichem odin ispol'zovalsya dlya

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

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

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

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)

Hybrid solar-electric oven construction prototype; Construccion de prototipo de horno hibrido solar-electrico

Energy Technology Data Exchange (ETDEWEB)

Hernandez Roman, M. A; Pineda Pinon, J; Arcos Pichardo, A [CICATA, Santiago de Queretaro, Queretaro (Mexico)

2013-03-15

The oven construction consists of a solar collector system of cylindrical parabolic type, a heating through electrical resistance and a curing chamber. The warm fluid is air, which is injected into the chamber through forced draft. The temperature required in the system is within a range of 150 to 300 degrees Celsius. [Spanish] La construccion del horno consta de un sistema de captacion solar del tipo cilindrico parabolico, un sistema de calentamiento a traves de resistencias electricas y una camara de curado. El fluido a calentar es aire, el cual es inyectado dentro de la camara a traves de tiro forzado. La temperatura solicitada en el sistema es dentro de un rango de 150 a 300 grados centigrados.

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.

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.

Equipment to evaluate in experimental form the thermal conductivity of the construction materials; Equipo para evaluar en forma experimental el coeficiente de conductividad termica de los materiales de construccion

Energy Technology Data Exchange (ETDEWEB)

Lopez C, Raymundo; Morales G, Juan R.; Diaz C, Alen; Lizardi R, Arturo [Universidad Autonoma Metropolitana-Azcapotzalco, Mexico, D. F. (Mexico); Vaca M, Mabel [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

2001-04-01

An equipment meant to obtain the thermal conductivity coefficient was designed, constructed and evaluated. Convection losses in the experimental device were reduced by means of a vacuum chamber that wraps it. Conduction losses were minimized with the proper insulation. The tested materials are the most frequently used in the construction of buildings in Mexico, such as concrete, burnt brick, adobe and gypsum. Results observed are comparable to those reported in the literature. The essays done using the vacuum chamber produced values of thermal conductivity coefficient 3% lower than those obtained without using it. [Spanish] Se diseno, construyo y evaluo un equipo, con el cual se obtiene el coeficiente de conductividad termica en diversos materiales. En este se reducen las perdidas por conveccion, colocando una camara de vacio alrededor del conjunto de prueba. Las perdidas por conduccion se minimizan con un aislamiento adecuado. Los materiales evaluados son los que mas se utilizan en la construccion en Mexico, a saber, el concreto, el ladrillo cocido, el adobe y el yeso. Los valores obtenidos, sin considerar las perdidas por conveccion, se comparan con los de la literatura. Los ensayos utilizando la camara de vacio proporcionan valores del coeficiente de conductividad termica menores en 3% a los obtenidos sin dicha camara.

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.

EVALUACION DE LA RESISTENCIA A LA CORROSION DEL SISTEMA PRIMER EPOXICO RICO EN ZINC/ACABADO POLISILOXANO POR MEDIO DE ESPECTROSCOPIA DE IMPEDANCIA ELECTROQUIMICA

Directory of Open Access Journals (Sweden)

ANDRES ALBERTO GUZMAN ROSAS

2011-01-01

Full Text Available En este trabajo fue estudiado el sistema primer epoxico rico en zinc / acabado polisiloxano aplicado sobre laminas de acero al carbono laminado en caliente y sometido a camaras de corrosion acelerada (inmersion total, niebla salina, ciclo de corrosion y prohesion por un periodo de hasta 5000 horas. Las probetas bajo estudio se evaluaron cada 20 dias por medio de espectroscopia de impedancia electroquimica y al final de la prueba se realizaron chequeos visuales y microscopia optica para ver la morfologia de la interface metal-recubrimiento y microespectroscopia Raman para identificar la presencia de posibles productos de corrosion. Los resultados de impedancia fueron simulados por medio de circuitos electricos equivalentes. Para el sistema se encontraron modulos de impedancia del orden de 1011 ¿.cm2 en prohesion, 1010 ¿.cm2 en ciclo de corrosion, 109 ¿.cm2 tanto niebla salina como en las inmersiones totales (NaCl 10-2M y Na2SO4 10-2M. Este sistema tuvo durante el tiempo de pruebas un comportamiento excelente con altas resistencias de pelicula y de transferencia de carga y bajas capacitancias de pelicula y de doble capa.

Clay-brick firing in a high-temperature solar furnace

Energy Technology Data Exchange (ETDEWEB)

Villeda-Munoz, G. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Instituto Politecnico Nacional, Unidad Queretaro, Queretaro (Mexico)]. E-mail: gvilledam@ipn.mx; Castaneda-Miranda, A. [Computation & amp; Mechatronic Studies Division, Universidad Politecnica de Queretaro, Queretaro (Mexico)]. E-mail: acastaneda@upq.edu.mx; Pless, R.C. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Instituto Politecnico Nacional, Unidad Queretaro, Queretaro (Mexico)]. E-mail: rpless@ipn.mx; Vega-Duran, J.T. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Instituto Politecnico Nacional, Unidad Queretaro, Queretaro (Mexico); Pineda-Pinon, J. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Instituto Politecnico Nacional, Unidad Queretaro, Queretaro (Mexico)]. E-mail: jpinedap@ipn.mx

2011-10-15

The firing process for clay-brick production in traditional kilns generates atmospheric pollution when industrial and domestic scrap is used as fuel. An alternative is presented here, using the solar energy for clay-brick firing. We are developing a system for clay-brick firing to reach temperatures between 900 degrees Celsius and 1050 degrees Celsius; these temperatures are sufficiently high to fire bricks or similar ceramic products. The present paper describes the design and characterization of the components of a solar furnace for clay-brick firing with inner chamber dimensions of 0.48 * 0.61 * 0.64 m. To convey the sunlight to the firing chamber, a heliostat with nine 1 * 1 m mirrors is used to send the rays of the sun to an off-axis parabolic concentrator that focuses the light on the entrance of the firing chamber. The heliostat has a solar-tracking system which makes primary and secondary adjustments to assure that the reflected solar radiation always arrives at the concentrator. The firing chamber contains a prismatic cavity that absorbs the solar radiation to generate the heat which is needed for baking the bricks inside the firing chamber. [Spanish] El proceso de coccion para la produccion de tabiques de arcilla en hornos tradicionales genera contaminacion atmosferica cuando los desechos industriales y domesticos se usan como combustibles. Aqui se presenta una alternativa, utilizando la energia solar para la coccion de tabiques de arcilla. Estamos desarrollando un sistema para la coccion de tabiques de arcilla para alcanzar temperaturas entre 900 grados centigradosy 1050 grados centigrados; estas temperaturas son suficientemente altas para cocer tabiques o productos ceramicos similares. El presente articulo describe el diseno y caracterizacion de los componentes de un horno solar para la coccion de tabiques de arcilla con una camara con dimensiones internas de 0.48 * 0.61 *× 0.64 m. Para dirigir los rayos solares a la camara de coccion, un heliostato

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

Directory of Open Access Journals (Sweden)

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...

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.

Second law characterization of stratified thermal storage tanks

Energy Technology Data Exchange (ETDEWEB)

Fraidenraich, N [Departamento de Energia Nuclear-UFPE (Brazil)

2000-07-01

It is well known that fluid stratification in thermal storage tanks improves the overall performance of solar thermal systems, when compared with systems operating with uniform fluid temperature. From the point of view of the first law of thermodynamics, no difference exists between storage tanks with the same mass and average temperature, even if they have different stratified thermal structures. Nevertheless, the useful thermal energy that can be obtained from them might differ significantly. In this work, we derive an expression able to characterize the stratified configuration of thermal fluid. Using results obtained by thermodynamics of irreversible processes, the procedure adopted consists in calculating the maximum work available from the tank's thermal layer is able to develop. We arrive, then, at a dimensionless expression, the stratification parameter (SP), which depends on the mass fraction and absolute temperature of each thermal layer as well as the thermal fluid average temperature. Numerical examples for different types of tank stratification are given and it is verified that the expression obtained is sensitive to small differences in the reservoir thermal configuration. For example a thermal storage with temperatures equal to 74 Celsius degrees, 64 Celsius degrees and 54 Celsius degrees, with its mass equally distributed along the tank yields, for the parameter SP, a figure equal to 0.000294. On the other hand a storage tank with the same average temperature but with different layer's temperatures 76 Celsius degrees, 64 and 52 Celsius degrees, also with uniform mass distribution, yields for SP a value equal to quantitative evaluation of the stratification structure of thermal reservoirs. [Spanish] Es bien conocido que la estratificacion fluida en tanques de almacenamiento termico mejora el rendimiento total de los sistemas termicos solares en comparacion con sistemas que operan con temperatura uniforme del fluido. Desde el punto de vista

International Development Research Centre

International Development Research Centre (IDRC) Digital Library (Canada)

... development. Learn moreArtificial intelligence and human development ... New initiative will match climate knowledge to developing country needs. Aminata Camara ... Shadow Libraries: Access to Knowledge in Global Higher Education.

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.

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

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.

INvENTAIRE FLORISTIqUE ET EFFET DE LA DENSITÉ DE ...

African Journals Online (AJOL)

KyllingaerectaSchum. var. flabelliformis (Cyperaceae). +. +. +. 92. Kyllingapumila Michaux (Cyperaceae). +. +. +. 93. Lantana camara L. (verbenaceae). +. -. -. 94. Leptoderrisfasciculata(Benth.) Dunn. (Fabaceae). -. +. -. 95. Lindernia diffusa (L.) Wettst. (Scrophulariaceae). +. -. -. 96. Ludwigiaabyssinica A. Rich. (Onagraceae).

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

Desenvolvimento de processo termico otimizado para mosto de caldo de cana na fermentação alcoolica

OpenAIRE

Jonas Nolasco Junior

2005-01-01

Resumo: Nesta pesquisa é proposto um processo de tratamento térmico do mosto, com máxima preservação do conteúdo em açúcares fermentescíveis (sacarose, glicose e frutose), a fim de promover a inativação térmica de seus contaminantes bacterianos e por extensão os da fermentação alcoólica. Com esse objetivo foram examinadas as cinéticas de degradação térmica da sacarose, glicose, frutose e açúcares redutores totais (ART) (110 ? 140ºC) e também dos esporos de B. stearothermophilus (98 ? 130ºC), ...

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.

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

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

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.)

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

Directory of Open Access Journals (Sweden)

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

Assessing effect of rainfall on rate of alien shrub expansion in a ...

African Journals Online (AJOL)

Assessing effect of rainfall on rate of alien shrub expansion in a southern African savanna. ... Keywords: aerial photography, invasion, Kyle Game Reserve, Lantana camara, patch dynamics, rainfall variability ... AJOL African Journals Online.

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

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.

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.

Some Measurements of Thermal Neutron Spectra; Mesure de Spectres de Neutrons Thermiques; Nekotorye izmereniya spektrov teplovykh nejtronov; Algunas Mediciones de Espectros de Neutrones Termicos

Energy Technology Data Exchange (ETDEWEB)

Poole, M. J.; Schofield, P.; Sinclair, R. N. [United Kingdom Atomic Energy Authority, Research Group, Atomic Energy Research Establishment, Harwell (United Kingdom)

1964-04-15

les spectres soit en geometrie critique soit en geometrie sous- critique. Les auteurs examinent les merites respectifs de ces deux methodes. (author) [Spanish] Los autores han ejecutado programas complementarios con objeto de determinar la ley de dispersion del moderador y comprobar su validez por medio de mediciones espectrales. La mayor parte de los experimentos sobre la ley de dispersion se efectuaron en Chalk River y la elaboracion de Ice dates, en el Laboratorio Nacional de Argonne; por otra pacte, su analisis y las extrapolaciones necesarias se llevaron a cabo en Harwell. Las mediciones espectrales se dividen naturalmente en dos categorias. Mediante la espectroscopia de tiempo de vuelo, los autores efectuaron amplias mediciones de los espectros de neutrones termicos en moderadores homogeneos envenenados. Estos trabajos, que complementan los realizados anteriormente por los autores, y Beyster y colaboradores, sirven para comprobar la validez de las secciones eficaces de transmision de energia o(E -> E) deducidas de la ley de dispeision. Sin embargo, los resultados experimentales son totalmente independientes del angulo de dispersion y de aquella parte de la seccion eficaz de dispersion que no implique cambio de la energia del neutron dispersado; ambos fenomenos son importantes en un problema en el que interviene un factor espacial. Por ello, los autores efectuaron otros experimentos en los que introdujeron deliberadamente discontinuidades espaciales y termicas a fin de que el espectro se rigiese por la ley de dispersion completa. En el primero de estos experimentos, que se denomina 'experimento de dos bloques', los neutrones termicos se dispersan a partir de un bloque de grafito a temperatura ambiente en un segundo bloque cuya temperatura puede llegar hasta los 400 Degree-Sign C. Los espectros neutronicos se midieron en diferentes posiciones cerca de la discontinuidad termica extrayendo un haz neutronico en cada posicion y haciendolo pasar por un espectrometro de

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 ...

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.

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.

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

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)

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.

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)

Repellent Activities of Essential Oils of Some Plants Used Traditionally to Control the Brown Ear Tick, Rhipicephalus appendiculatus

NARCIS (Netherlands)

Wanzala, W.W.; Hassanali, A.; Mukabana, W.R.; Takken, W.

2014-01-01

Essential oils of eight plants, selected after an ethnobotanical survey conducted in Bukusu community in Bungoma County, western Kenya (Tagetes minuta, Tithonia diversifolia, Juniperus procera, Solanecio mannii, Senna didymobotrya, Lantana camara, Securidaca longepedunculata, and Hoslundia

Simply architecture or bioclimatic architecture?; Arquitectura bioclimatica o simplemente Arquitectura?

Energy Technology Data Exchange (ETDEWEB)

Rodriguez Torres, Juan Manuel [Universidad de Guanajuato (Mexico)

2006-10-15

The bioclimatic architecture is the one which profits from its position in the environment and its architectonic elements for the climate benefit. With the aim of reach the internal thermal comfort without using mechanical systems. This article states the story about this singular kind of architecture during centuries. And also emphasizes the sunlight utilization, in order to achieve the desired thermal well-being in edifications. [Spanish] El tipo de arquitectura que toma ventaja de su disposicion en el entorno y sus elementos arquitectonicos para el aprovechamiento del clima, con el fin de conseguir el confort termico interior sin utilizar sistemas mecanicos, se denomina bioclimatica. En este articulo se habla de la historia de este tipo tan singular de arquitectura con el paso de los siglos, y tambien se hace hincapie acerca de la luz solar, como un medio muy eficiente a traves del cual las edificaciones pueden ser disenadas para lograr el bienestar termico deseado.

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.

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

Directory of Open Access Journals (Sweden)

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.

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.

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...

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.

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 ...

PROTECCIÓN CONTRA LA CORROSIÓN POR SALES FUNDIDAS DE UN ACERO AL CARBONO POR ROCIADO TERMICO

OpenAIRE

JOSE MARULANDA; ANDRÉS GARCÍA; JOSE VITOLA

2009-01-01

Se evaluó la corrosión por sales fundidas mediante la técnica gravimétrica en un acero de bajo carbono rociado térmicamente con una aleación de acero inoxidable, en una mezcla de sal con 20% Na2SO4 - 80% V2O5, entre 700ºC - 850ºC. Los resultados de las pruebas gravimétricas mostraron una deficiente protección de la capa rociada térmicamente y se presentó alta degradación en el recubrimiento protector, debido a que las temperaturas de exposición fueron mayores que las temperaturas de fusión de...

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

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

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

Financiranje projekata na pomorskom dobru

Directory of Open Access Journals (Sweden)

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. (...

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

Directory of Open Access Journals (Sweden)

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...

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

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.

1701-IJBCS-Article-Camara Mameri

African Journals Online (AJOL)

hp

d'Ivoire. Agronomie Africaine, 19(2):. 173-185. Gamouh A. 2005. Effets comparés et interactifs des pesticides et facteurs physiques sur la minéralisation de substrats carbonés dans le sol. Bull. Inst. Scientifique Sci. Vie, 26-27. Hartemink AE, O'Sullivan JN. 2001. Leaf litter decomposition of Piper aduncum,. Glyricidia sepium.

Alkaline protease from senesced leaves of invasive weed | Gaur ...

African Journals Online (AJOL)

step procedure involving ammonium sulfate precipitation and Sephadex G-250 gel permeation chromatography. The Sephadex-G-250 fraction of senesced leaves of Lantana camara showed 28.31 fold with a yield of 6.19%. The enzyme was ...

Finding of No Significant Impact/Finding of No Practicable Alternative: Environmental Assessment of the Privatization of Military Family Housing at MacDill Air Force Base, Florida

Science.gov (United States)

2007-10-09

mimosa (Albizia julibrissin), cattails (Typha spp.), cogon grass (Imperata cylindrical), water hyacinth (Eichhornia crassipes), lantana (Lantana camara...exotic invaders such as Australian pine, mimosa, and cogon grass . Another concern is mangrove tree invasion of drainage ditches. While mangrove

Bioclimatic conditioning places for propagation the plants; Acondicionamiento Bioclimatico de locales para programacion de plantas

Energy Technology Data Exchange (ETDEWEB)

Iriarte, Adolfo [Catamarca, (Argentina); Lesino, Gabriela [Buenos Aires, (Argentina); Matias, Cesar [Catamarca, (Argentina)

2000-07-01

A special tax reduction to promote agricultural investments in the Province of Catamarca in Argentina has created a strong demand of high quality plants of olive (Olea europea L.), walnut (Junglans regia L.) and fig (Ficus carica L.) trees. The method used for plant propagation consists of three stages: rooting of stem cuttings (two months), growth under controlled conditions in a greenhouse (four to five months) and rustication and acclimatization to outdoor conditions in a half-shadow protected area (three to four months). The plant is ready to be transferred to the field in nine to ten months. The rooting stage cannot take place outdoors in hot, arid and windy climates. This paper refers to the design, construction and monitoring of a building where the ambient temperature, humidity and illumination levels are controlled to promote the growth of roots, maintain the stem hydrated and allow restrained photosynthetic activity. Excellent thermal and agronomic results were obtained with rooting efficiencies of 43 to 75 % in summer and 30 to 60 % in winter for olive stems. [Spanish] La necesidad de produccion de olivo (Olea europea L.), nogal (Junglans regia L.) e higueras (Ficus carica L.) de alta calidad para satisfacer la demanda de los establecimientos agropecuarios, ha obligado a utilizar para la produccion de plantas la tecnica de enraizamiento de estacas semilenosas, lo que permite obtener plantas identicas a la planta madre. En regiones de climas calidos y ventosos los factores climaticos externos dificultan el control y mantenimiento de las condiciones ambientales dentro de los recintos destinados a la produccion de plantas mediante estacas. Esto exige disponer de una camara que permita controlar la temperatura y la humedad simultaneamente obtener niveles de iluminacion natural compatible con las necesidades fotosinteticas de las estacas. En el presente trabajo se describen los aspectos constructivos de una casa de vegetacion, analizandose el balance de calor

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.

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...

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.

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.

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.

All new for NA62

CERN Multimedia

Antonella Del Rosso

2012-01-01

This week sees the start of the first run of the new NA62 experiment. This will be a unique opportunity for the collaboration to test its new beam, new detectors and new data acquisition system before the physics run in 2014. Speaking to the Bulletin, the NA62 technical coordinator Ferdinand Hahn shares the many challenges that the various teams faced to be on time for beam. Ready, steady, start!   A Large Angle Veto detector (white) in place in the NA62 decay volume (blue). With components from almost all the detectors in place downstream of the decay point of the mother particles – the kaons – and of the KTAG detector that tags the kaons before they decay, NA62 is ready for its first technical run. This unique run will test all the equipment as well as the trigger and the data acquisition systems. “This year, we will have about five weeks of beam from the SPS before the long shutdown of all the CERN machines,” says Ferdinand Hahn, NA62 Technical Co-...

Effect of chloride substitution on the order–disorder transition in NaBH4 and Na11BD4

International Nuclear Information System (INIS)

Olsen, Jørn Eirik; Karen, Pavel; Sørby, Magnus H.; Hauback, Bjørn C.

2014-01-01

Graphical abstract: Interactions that order the BD 4 - tetrahedra below the order–disorder transition became increasingly frustrated by the solute in the Na( 11 BD 4 ) 1−x Cl x solid solutions, and the order disappears at x = 0.158. Highlights: • The order–disorder transition temperature for Na(BH 4 ) 1−x Cl x and Na( 11 BD 4 ) 1−x Cl x is highly dependent on the Cl-content, x. • The transition is characterized by DSC for Na( 11 BD 4 ) 1−x Cl x for x = 0, 0.10 and 0.15. • No transition is observed for x ⩾ 0.20 on cooling to 8 K. • The crystal structures are reported for Na 11 BD 4 at room temperature and 8 K and Na( 11 BD 4 ) 1−x Cl x (x = 0.10, 0.15, 0.20 and 0.25) at 8 K from powder neutron diffraction. -- Abstract: Phase transition associated with anion disordering over two orientations in Na 11 BD 4 (NaBH 4 ) and its solid solutions with NaCl, Na( 11 BD 4 ) 1−x Cl x , is investigated with powder diffraction (neutron and synchrotron radiation), differential scanning calorimetry and Raman spectroscopy. Upon heating, the transition temperature extrapolated to zero rate of heating is 192.2 K for Na 11 BD 4 , ΔS = 4.41 J/mol K, hysteresis 1.7 K and the volume increase 0.43%. Thermal parameters of the transition in Na( 11 BD 4 ) 1−x Cl x follow a colligative-property model of an ideal solution, with x = 0.158(1) as the critical concentration at which the ordering interactions and the transition itself are eliminated. On approaching this limit, the tetragonal distortion of the ordered structure decreases somewhat towards the cubic average, and this is associated with a partial disorder of the tetrahedral anions seen by diffraction methods. In fact, a 3% disorder is already present in the pure solvent of the solid solution (Na 11 BD 4 ) at 8 K

Neutron diffraction studies of the Na-ion battery electrode materials NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3}

Energy Technology Data Exchange (ETDEWEB)

Yahia, H. Ben [Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, P.O. Box 5825 Doha (Qatar); Essehli, R., E-mail: ressehli@qf.org.qa [Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, P.O. Box 5825 Doha (Qatar); Avdeev, M. [Australian Nuclear Science and Technology Organisation, New Illawarra Road, Lucas Heights NSW 2234 (Australia); Park, J-B.; Sun, Y-K. [Department of Energy Engineering Hanyang University, 17 Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Al-Maadeed, M.A. [Center for Advanced Materials (CAM), Qatar University, 2713 Doha (Qatar); Belharouak, I., E-mail: ibelharouak@qf.org.qa [Qatar Environment and Energy Research Institute, Hamad Bin Khalifa University, Qatar Foundation, P.O. Box 5825 Doha (Qatar)

2016-06-15

The new compounds NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} were synthesized by sol-gel method and their crystal structures were determined by using neutron powder diffraction data. These compounds were characterized by galvanometric cycling and cyclic voltammetry. NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} crystallize with a stuffed α-CrPO{sub 4}-type structure. The structure consists of a 3D-framework made of octahedra and tetrahedra that are sharing corners and/or edges generating channels along [100] and [010], in which the sodium atoms are located. Of significance, in the structures of NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} a statistical disorder Ni{sup 2+}/Cr{sup 3+} was observed on both the 8g and 4a atomic positions, whereas in NaCoCr{sub 2}(PO{sub 4}){sub 3} the statistical disorder Co{sup 2+}/Cr{sup 3+} was only observed on the 8g atomic position. When tested as negative electrode materials, NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} delivered specific capacities of 352, 385, and 368 mA h g{sup −1}, respectively, which attests to the electrochemical activity of sodium in these compounds. - Highlights: • NaCoCr{sub 2}(PO{sub 4}){sub 3}, NaNiCr{sub 2}(PO{sub 4}){sub 3}, and Na{sub 2}Ni{sub 2}Cr(PO{sub 4}){sub 3} were synthesized by sol-gel method. • The crystal structures were determined by using neutron powder diffraction data. • The three compounds crystallize with a stuffed α-CrPO{sub 4}-type structure. • The three compounds were tested as anodes in sodium-ion batteries. • Relatively high specific capacities were obtained for these compounds.

Evaluation of NaX and NaY packed beds for chromium uptake from multicomponent solution

Directory of Open Access Journals (Sweden)

Maria Angélica Simões Dornellas de Barros

2014-04-01

Full Text Available In this paper the removal of chromium from Cr/Ca/Mg/K and Cr/Ca/Mg/K/Na solutions was investigated in NaX and NaY packed beds. The breakthrough curves presented some overshooting phenomena where chromium ions displaced the previous exchanged cations. Length of unused bed, overall mass transfer coefficient, operational ratio and dimensionless variance were obtained. According to such mass transfer parameters it was concluded that the chromium uptake is influenced by the competition and interaction of the entering ions. Such influences were verified through some differences in the dynamic selectivity obtained for each system. NaY seemed to have a higher affinity towards Cr3+ and its sites were more efficiently used in the ion exchange process.

Water transport by the renal Na(+)-dicarboxylate cotransporter

DEFF Research Database (Denmark)

Meinild, A K; Loo, D D; Pajor, A M

2000-01-01

. This solute-coupled influx of water took place in the absence of, and even against, osmotic gradients. There was a strict stoichiometric relationship between Na(+), substrate, and water transport of 3 Na(+), 1 dicarboxylate, and 176 water molecules/transport cycle. These results indicate that the renal Na......This study investigated the ability of the renal Na(+)-dicarboxylate cotransporter, NaDC-1, to transport water. Rabbit NaDC-1 was expressed in Xenopus laevis oocytes, cotransporter activity was measured as the inward current generated by substrate (citrate or succinate), and water transport...... was monitored by the changes in oocyte volume. In the absence of substrates, oocytes expressing NaDC-1 showed an increase in osmotic water permeability, which was directly correlated with the expression level of NaDC-1. When NaDC-1 was transporting substrates, there was a concomitant increase in oocyte volume...

Pioneering instrumentation aspects of NA60

International Nuclear Information System (INIS)

David, Andre

2004-01-01

NA60 is taking data with proton and heavy-ion beams at the CERN SPS. Although building up on previous experiments, the dimuon physics programme of NA60 places very demanding requirements on its new detectors, in terms of radiation tolerance, granularity and read-out electronics speed. We start by comparing dimuon detection strategies in NA60 with those of previous experiments. We then describe the new detectors used in NA60, placing particular emphasis on their technological pioneering aspects as well as on their contributions to the overall physics performance of the experiment

Occlusion of 22Na+ and 86Rb+ in membrane-bound and soluble protomeric alpha beta-units of Na,K-ATPase

International Nuclear Information System (INIS)

Vilsen, B.; Andersen, J.P.; Petersen, J.; Jorgensen, P.L.

1987-01-01

In this work, we examined occlusion of 22 Na+ and 86 Rb+ in membranous and detergent-solubilized Na,K-ATPase from outer renal medulla. Optimum conditions for occlusion of 22 Na+ were provided by formation of the phosphorylated complex from the beta,gamma-bidentate complex of chromium (III) with ATP (CrATP). Release of occluded cations occurred at equally slow rates in soluble and membrane-bound Na,K-ATPase. Values of 22 Na+ occlusion as high as 11 nmol/mg of protein were measured, corresponding to 1.8-2.7 mol of Na+/mol of phosphorylated Na,K-ATPase as determined by 32 P incorporation from [gamma- 32 P]CrATP. Maximum capacity for phosphorylation from [gamma- 32 P]CrATP was 6 nmol/mg of protein and equal to capacities for binding of [48V]vanadate and [ 3 H]ouabain. The stoichiometry for occlusion of Rb+ was close to 2 Rb+ ions/phosphorylation site. In an analytical ultracentrifuge, the soluble Na+- or Rb+-occluded complexes showed sedimentation velocities (S20,w = 6.8-7.4) consistent with monomeric alpha beta-units. The data show that soluble monomeric alpha beta-units of Na,K-ATPase can occlude Rb+ or Na+ with the same stoichiometry as the membrane-bound enzyme. The structural basis for occlusion of cations in Na,K-ATPase is suggested to be the formation of a cavity inside a monomeric alpha beta-unit constituting the minimum protein unit required for active Na,K-transport

Transcriptional regulators of Na, K-ATPase subunits

Directory of Open Access Journals (Sweden)

Zhiqin eLi

2015-10-01

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

Sepsis does not alter red blood cell glucose metabolism or Na+ concentration: A 2H-, 23Na-NMR study

International Nuclear Information System (INIS)

Hotchkiss, R.S.; Song, S.K.; Ling, C.S.; Ackerman, J.J.; Karl, I.E.

1990-01-01

The effects of sepsis on intracellular Na+ concentration ([Na+]i) and glucose metabolism were examined in rat red blood cells (RBCs) by using 23Na- and 2H-nuclear magnetic resonance (NMR) spectroscopy. Sepsis was induced in 15 halothane-anesthetized female Sprague-Dawley rats by using the cecal ligation and perforation technique; 14 control rats underwent cecal manipulation without ligation. The animals were fasted for 36 h, but allowed free access to water. At 36 h postsurgery, RBCs were examined by 23Na-NMR by using dysprosium tripolyphosphate as a chemical shift reagent. Human RBCs from 17 critically ill nonseptic patients and from 7 patients who were diagnosed as septic were also examined for [Na+]i. Five rat RBC specimens had [Na+]i determined by both 23Na-NMR and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). For glucose metabolism studies, RBCs from septic and control rats were suspended in modified Krebs-Henseleit buffer containing [6,6-2H2]glucose and examined by 2H-NMR. No significant differences in [Na+]i or glucose utilization were found in RBCs from control or septic rats. There were no differences in [Na+]i in the two groups of patients. The [Na+]i determined by NMR spectroscopy agreed closely with measurements using ICP-AES and establish that 100% of the [Na+]i of the RBC is visible by NMR. Glucose measurements determined by 2H-NMR correlated closely (correlation coefficient = 0.93) with enzymatic analysis. These studies showed no evidence that sepsis disturbed RBC membrane function or metabolism

SPOLNO NADLEGOVANJE NA DELOVNEM MESTU

OpenAIRE

Rubič, Gašper

2016-01-01

V diplomskem delu smo v uvodu predstavili problem spolnega nadlegovanja na delovnem mestu in predstavili podjetje TEKSTIL d.d. V nadaljevanju smo z anketo raziskali, ali problem spolnega nadlegovanja na delovnem mestu v obravnavanem podjetju obstaja in če, kako se nanj odziva okolje. V teoretičnem delu smo nadaljevali in predstavili definicijo spolnega nadlegovanja, ki je kakršna koli oblika nezaželenega verbalnega in neverbalnega ali fizičnega ravnanja spolne narave z učinkom ali nameno...

Photodesorption of Na atoms from rough Na surfaces

DEFF Research Database (Denmark)

Balzer, Frank; Gerlach, R.; Manson, J.R.

1997-01-01

We investigate the desorption of Na atoms from large Na clusters deposited on dielectric surfaces. High-resolution translational energy distributions of the desorbing atoms are determined by three independent methods, two-photon laser-induced fluorescence, as well as single-photon and resonance......-enhanced two-photon ionization techniques. Upon variation of surface temperature and for different substrates (mica vs lithium fluoride) clear non-Maxwellian time-of-flight distributions are observed with a cos θ angular dependence and most probable kinetic energies below that expected of atoms desorbing from...... atoms are scattered by surface vibrations. Recent experiments providing time constants for the decay of the optical excitations in the clusters support this model. The excellent agreement between experiment and theory indicates the importance of both absorption of the laser photons via direct excitation...

Evaluation of {sup 23}Na(n,2n){sup 22}Na reaction cross-sections

Energy Technology Data Exchange (ETDEWEB)

Manokhin, V N [Institute of Physics and Power Engineering, Obninsk (Russian Federation)

1997-06-01

Using available experimental data and (n,2n) excitation function systematics {sup 23}Na(n,2n){sup 22}Na reaction cross-sections were evaluated for energies ranging from the reaction threshold to 20 MeV. (author). 21 refs, 1 fig., 2 tabs.

Formation of hydroxyl groups and exchange with deuterium on NaHX and NaHY zeolites

International Nuclear Information System (INIS)

Kubelkova, L.; Novakova, J.

1976-01-01

Deammoniation and dehydroxylation of Na(NH 4 )X and Na(NH 4 )Y zeolites were compared. With the X type, both processes overlapped and proceeded more easily than with the Y type. Both H forms contained structural OH groups and hydroxyls denoted as SiOH, to which the 3740 cm -1 band in the IR spectrum was assigned. In addition, the NaHX zeolite contained OH groups characterized by the 3700 and 3600 cm -1 bands. Certain differences in the behaviour of NaHX and NaHY zeolites during deammoniation and dehydroxylation might be attributed to the presence of ''non-localizable'' H atoms. The active sites for the D 2 -OH exchange were probably formed during dehydroxylation. Hydrogen in SiOH groups was replaced by deuterium in both zeolite types more slowly than H atoms in other OH groups, which influenced the kinetic variations in the gaseous phase. The presence of water in the gaseous phase affected the kinetics and could distort the determination of the number of H atoms bound in the zeolites. (author)

High resolution laser spectroscopy of the D lines of on-line produced 21Na, 22Na, 24Na, 25Na using a new high sensitivity method of detection of optical resonances

International Nuclear Information System (INIS)

Huber, G.; Thibault, G.; Klapisch, R.; Duong, H.T.; Vialle, J.L.; Pinard, I.; Juncar, P.; Jacquinot, P.

1975-01-01

A polyisotopic sodium beam of 21 - 25 Na, produced by spallation of Al, was illuminated by a tunable dye laser. The atomic beam, analyzed by a sixpole magnet is then ionized and detected after a mass spectrometer. The results are the isotope shifts, nuclear magnetic moment and quadrupole moment of 25 Na [fr

OGLAŠEVANJE NA SOCIALNEM OMREŽJU FACEBOOK, NA PRIMERU SPLETICNA.SI

OpenAIRE

Reisman, Nina

2011-01-01

Internet je od svojega razvoja dolgo časa obstajal kot prostor za enostransko komunikacijo. Isto se je dogajalo na televiziji, radiu in časopisih, kjer je javnost sprejemala informacije, ki jih je nekdo pripravil. Tradicionalni mediji so hitro doumeli, da takšna vrsta komunikacije ni naravna in ne predstavlja najboljšega ohranjanja gledalcev in poslušalcev. Začela se je uporabljati dvosmerna komunikacija. Trenutno v svetu najbolje poznan primer dvosmerne komunikacije je socialno omrežje F...

FTIR spectra of the solid solutions (Na0.88K0.12)VO3, (Na0.5K0.5)VO3, and Na(V0.66P0.34)O3

Science.gov (United States)

de Waal, D.; Heyns, A. M.

1992-03-01

It is known that three different solid solutions, (Na0.88K0.12)VO3, (Na0.5K0.5)VO3 and Na(V0.66P0.34)O3, form in the (Na,K)(V,P)O3 system. These compounds all have monoclinic crystal structures similar to the pure alkali metal metavanadates containing small cations, e.g. Li+ and Na+ (Space group C2/c). Metavanadates with large cations like K+, Rb+, C+s and NH+4 form orthorhombic crystals, space group Pbcm. All those are structurally related to the silicate pyroxenes. Na(V0.66P0.34)O3 and (Na0.88K0.12)VO3 have the same modified diopside structure as (alpha) - NaVO3 while (Na0.5K0.5)VO3 adopts the true diopside structure. The infrared spectra of the three solid solutions are reported here in comparison with those of (alpha) -NaVO3 and KVO3. The results are also correlated with those obtained in two independent high pressure Raman studies of NH4VO3 and RbVO3 as the introduction of a larger cation like K+ should increase the pressure in the structure.

Medetomidīna un detomidīna hidrogēnhlorīdu struktūra noteikšana

OpenAIRE

Smuļko, Irina

2012-01-01

Medetomidīna un detomidīna hidrogēnhlorīdu struktūras noteikšana. Smuļko I., zinātniskais vadītājs Dr. ķīm., asoc. prof. Actiņš A. Maģistra darbs, 52 lappuses, 37 attēli, 6 tabulas, 29 literatūras avoti. Latviešu valodā. Maģistra darbā pētītas farmaceitiski aktīvās vielas – medetomidīna un detomidīna hidrogēnhlorīdi. Veikti mēģinājumi detomidīna bezūdens formas un monohidrāta struktūras noteikšanai, kā arī medetomidīna bezūdens formu A un B struktūras noteikšanai. Struktūras noteikšanai iz...

NAKUPOVANJE NA SPLETU

OpenAIRE

Visenjak, Monika

2013-01-01

Nakupovanje na spletu je prihodnost poslovanja. Za podjetja pomeni manjše stroške, lažje prilagajanje tržnim pogojem. Hitreje lahko razvijajo odnose in analizirajo uporabnike, saj jim je dan dostop o nakupnih podatkih uporabnika. Za potrošnike je nakupovanje na spletu možnost hitrega, preprostega in učinkovitega nakupovanja od doma ali pisarne. Pomembno je, da se seznanijo z vsemi informacijami in pogoji spletnih trgovin, saj se lahko le tako izognejo nezadovoljstvu ob nakupu v spletni trgovi...

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

KAUST Repository

Byrt, Caitlin Siobhan

2014-10-01

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

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

KAUST Repository

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

2014-01-01

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

Osmotic and ionic effects of NaCl and Na₂SO₄ salinity on Phragmites australis

DEFF Research Database (Denmark)

Pagter, Majken; Bragato, Claudia; Malagoli, Mario

2009-01-01

Osmotic and ion-specific effects of NaCl and Na2SO4 on Phragmites australis (Cav.) Trin ex. Steud. were investigated in a laboratory experiment by examining effects of iso-osmotic solutions of NaCl and Na2SO4 on growth, osmolality of cell sap, proline content, elemental composition and gas exchange....... Plants were supplied with a control standard nutrient solution (Ψ = -0.09 MPa) or solutions of NaCl or Na2SO4 at water potentials of -0.50, -1.09 or -1.74 MPa. Salt treatments increased root concentrations of Na and S or Cl, whereas P. australis had efficient mechanisms for exclusion of Na and S...... and partly Cl ions from the leaves. Incomplete exclusion of Cl from the leaves may affect aboveground biomass production, which was significantly more reduced by NaCl than Na2SO4. Stomatal conductance was negatively influenced by decreasing water potentials caused by NaCl or Na2SO4, implying that a non...

Polarization and collision velocity dependence of associative ionization in cold Na (3p)-Na(3p) collisions

NARCIS (Netherlands)

Meijer, H.A.J.

1990-01-01

We studied the polarization dependence of the associative ionization (AI) process Na(3p) + Na(3p) → Na2+ at collision velocities between 100 and 700 m/s (5 and 200 K), using linearly and circularly polarized light for the excitation. We found that the polarization dependence varies strongly in the

Erythrocyte Na+/K+ ATPase activity measured with sup 23 Na NMR

Energy Technology Data Exchange (ETDEWEB)

Ouwerkerk, R.; van Echteld, C.J.; Staal, G.E.; Rijksen, G. (University Hospital, Utrecht (Netherland))

1989-11-01

A {sup 23}Na NMR assay for measurement of erythrocyte Na+/K+ ATPase activity is presented. Using the nonpermeant shift reagent dysprosium tripolyphosphate the signals of intra- and extracellular sodium are separated, enabling measurement of sodium fluxes nondestructively, without the need to physically separate the cells from their environment. By increasing membrane permeability with nystatin we have shown that the assay allows the detection of differences in membrane permeability. With low doses of nystatin the ouabain-sensitive sodium flux increased more than twofold. With high doses of nystatin the Na+/K+ pump could not prevent an almost total equilibration of intra- and extracellular sodium. All sodium that entered the cells remained NMR visible, proving that sodium influx can be measured quantitatively. {sup 31}P NMR spectra taken before and after the assay revealed a slight acidification of the cells and no significant change in ATP concentration. No evidence of Dy3+ entering the cell was observed.

Molecular dynamics investigation of Na+ in Na2Ni2TeO6

International Nuclear Information System (INIS)

Sau, Kartik; Kumar, P. Padma

2014-01-01

An inter-atomic potential for Na 2 Ni 2 TeO 6 in the Parrinello- Rahman-Vashishta (PRV) model is parameterized empirically. The potential reproduces variety of structural and transport properties of that material in good agreement with recent experimental results. The study provides fresh insights on the migration channels and mechanism of Na + in the system

Efeito do plasma de oxigênio na dentina previamente exposta ao NaOCl

Directory of Open Access Journals (Sweden)

Maíra do PRADO

Full Text Available Resumo Introdução O tratamento de plasma é uma tecnologia eficaz que pode manter as propriedades internas dos materiais inalteradas após o tratamento, modificando apenas a superfície. Objetivo Avaliar o efeito do plasma de oxigênio na dentina previamente exposta ao NaOCl 6%. Material e método Foram utilizados 60 incisivos bovinos. A coroa foi removida, a raiz foi dividida e as faces planificadas, totalizando 120 segmentos referentes ao terço cervical. As amostras foram divididas em dois grupos: controle (imersa em NaOCl 6%, lavada com água destilada, seca, imersa em EDTA 17%, lavada e seca e plasma de oxigênio (após tratamento descrito no grupo controle, plasma de oxigênio foi aplicado por 30 s. As amostras foram avaliadas qualitativamente em relação à topografia por microscopia eletrônica de varredura, utilizando-se microfotografias com ampliação de 1.000×. O goniômetro Ramé-hart foi utilizado para a mensuração do ângulo de contato entre as superfícies e as seguintes soluções foram utilizadas: água, etilenoglicol e di-iodometano. Em seguida, a energia de superfície, representada pelas componentes polar e dispersiva, foi calculada. Avaliou-se também o escoamento dos cimentos Pulp Canal Sealer EWT (PCS e Real Sal SE (RS na superfície dentinária. Os dados foram analisados estatisticamente utilizando os testes Kruskal-Wallis e Mann-Whitney U (p<0,05. Resultado O tratamento com plasma levou à formação de uma camada semelhante à smear layer na superfície dentinária. Este tratamento levou a um aumento da energia de superfície e da componente polar, favorecendo a hidrofilicidade da superfície. Entretanto, desfavoreceu o escoamento do cimento PCS e não influenciou no escoamento do cimento RS. Conclusão O plasma de oxigênio ocasionou mudanças topográficas na superfície dentinária, favorecendo a hidrofilicidade desta. Contudo, não favoreceu o escoamento dos cimentos endodônticos na dentina.

Phase formation in the systems ZrO2-H2SO4-Na2SO4 (NaCl)-H2O

International Nuclear Information System (INIS)

Sozinova, Yu.P.; Motov, D.L.; Rys'kina, M.P.

1988-01-01

Formation of solid phases in the systems ZrO 2 - H 2 SO 4 - Na 2 SO 4 (NaCl) - H 2 O at 25 and 75 deg C is studied. Three basic Na 2 Zr(OH) 2 (SO 4 ) 2 x (0.2 - 0.4)H 2 O, NaZrOH(SO 4 ) 2 x H 2 O, NaZrO 0.5 (OH) 2 SO 4 x 2H 2 O and three normal sodium sulfatozirconates Na 2 Zr(SO 4 ) 3 x 3H 2 O, Na 4 Zr(SO 4 ) 4 x 3H 2 O, Na 6 Zr(SO 4 ) 5 x 4H 2 O have been isolated, their solubility and crystal optical properties are determined

Modification of NaK (Na and K) dissolution device at the L.E.C.I

International Nuclear Information System (INIS)

Mansard, Bernard; Ducas, Serge; Riviere, Michel

1969-12-01

As three NaK dissolution devices had been operated since 1965 and as irradiation assemblies with a greater capacity (2 to 3 times) are now to be used, the modification of these dissolution devices is addressed. This requires a better control of the dissolution reaction (the NaK + alcohol reaction is highly exothermic and results in an effervescence which requires a greater volume). The objectives are therefore to delay the dissolution, to trigger it, to stop it, to control it at will, and to release heat. The new device is then described with its vessel, its cap, its ball valve, and its two tight sleeves. The operation principle is described, as well as the NaK draining process, and the NaK dissolution. Safety, time saving and raw matter saving issues are finally outlined

OGLAŠEVANJE NA FACEBOOKU V SLOVENIJI

OpenAIRE

Dobnik, Monja

2013-01-01

Danes so zahvaljujoč napredni mobilni tehnologiji družbena omrežja z nami na vsakem koraku. Facebook (FB) se po priljubljenosti uvršča v sam vrh družbenih omrežij in glede na to, da ga uporablja že več kot milijarda zemljanov, ponuja tudi odlične trg za oglaševanje. To so ugotovili tudi slovenski podjetniki. V diplomski nalogi je predstavljeno, kako na FB oglašujejo nekatera slovenska podjetja, s pomočjo spletnega vprašalnika pa je ugotovljeno tudi, kaj o oglasih na FB menijo njegovi uporabni...

Myocardial Na,K-ATPase: Clinical aspects

Science.gov (United States)

Kjeldsen, Keld

2003-01-01

The specific binding of digitalis glycosides to Na,K-ATPase is used as a tool for Na,K-ATPase quantification with high accuracy and precision. In myocardial biopsies from patients with heart failure, total Na,K-ATPase concentration is decreased by around 40%; a correlation exists between a decrease in heart function and a decrease in Na,K-ATPase concentration. During digitalization, around 30% of remaining pumps are occupied by digoxin. Myocardial Na,K-ATPase is also influenced by other drugs used for the treatment of heart failure. Thus, potassium loss during diuretic therapy has been found to reduce myocardial Na,K-ATPase, whereas angiotensin-converting enzyme inhibitors may stimulate Na,K pump activity. Furthermore, hyperaldosteronism induced by heart failure has been found to decrease Na,K-ATPase activity. Accordingly, treatment with the aldosterone antagonist, spironolactone, may also influence Na,K-ATPase activity. The importance of Na,K pump modulation with heart disease, inhibition in digitalization and other effects of medication should be considered in the context of sodium, potassium and calcium regulation. It is recommended that digoxin be administered to heart failure patients who, after institution of mortality-reducing therapy, still have heart failure symptoms, and that the therapy be continued if symptoms are revealed or reduced. Digitalis glycosides are the only safe inotropic drugs for oral use that improve hemodynamics in heart failure. An important aspect of myocardial Na,K pump affection in heart disease is its influence on extracellular potassium (Ke) homeostasis. Two important aspects should be considered: potassium handling among myocytes, and effects of potassium entering the extracellular space of the heart via the bloodstream. It should be noted that both of these aspects of Ke homeostasis are affected by regulatory aspects, eg, regulation of the Na,K pump by physiological and pathophysiological conditions, as well as by medical

Advancement of technology towards developing Na-ion batteries

Science.gov (United States)

Jamesh, Mohammed Ibrahim; Prakash, A. S.

2018-02-01

The Na-ion-batteries are considered much attention for the next-generation power-sources due to the high abundance of Na resources that lower the cost and become the alternative for the state of the art Li-ion batteries in future. In this review, the recently reported potential cathode and anode candidates for Na-ion-batteries are identified in-light-of-their high-performance for the development of Na-ion-full-cells. Further, the recent-progress on the Na-ion full-cells including the strategies used to improve the high cycling-performance (stable even up-to 50000 cycles), operating voltage (even ≥ 3.7 V), capacity (>350 mAhg-1 even at 1000 mAg-1 (based-on-mass-of-the-anode)), and energy density (even up-to 400 Whkg-1) are reviewed. In addition, Na-ion-batteries with the electrodes containing reduced graphene oxide, and the recent developments on symmetric Na-ion-batteries are discussed. Further, this paper identifies the promising Na-ion-batteries including the strategies used to assemble full-cell using hard-carbon-anodes, Na3V2(PO4)3 cathodes, and other-electrode-materials. Then, comparison between aqueous and non-aqueous Na-ion-batteries in terms of voltage and energy density has been given. Later, various types of electrolytes used for Na-ion-batteries including aqueous, non-aqueous, ionic-liquids and solid-state electrolytes are discussed. Finally, commercial and technological-developments on Na-ion-batteries are provided. The scientific and engineering knowledge gained on Na-ion-batteries afford conceivable development for practical application in near future.

Negative electrodes for Na-ion batteries.

Science.gov (United States)

Dahbi, Mouad; Yabuuchi, Naoaki; Kubota, Kei; Tokiwa, Kazuyasu; Komaba, Shinichi

2014-08-07

Research interest in Na-ion batteries has increased rapidly because of the environmental friendliness of sodium compared to lithium. Throughout this Perspective paper, we report and review recent scientific advances in the field of negative electrode materials used for Na-ion batteries. This paper sheds light on negative electrode materials for Na-ion batteries: carbonaceous materials, oxides/phosphates (as sodium insertion materials), sodium alloy/compounds and so on. These electrode materials have different reaction mechanisms for electrochemical sodiation/desodiation processes. Moreover, not only sodiation-active materials but also binders, current collectors, electrolytes and electrode/electrolyte interphase and its stabilization are essential for long cycle life Na-ion batteries. This paper also addresses the prospect of Na-ion batteries as low-cost and long-life batteries with relatively high-energy density as their potential competitive edge over the commercialized Li-ion batteries.

Corpo e sexualidade na gravidez

Directory of Open Access Journals (Sweden)

Natalúcia Matos Araújo

2012-06-01

Full Text Available Estudo etnográfico que teve como objetivo compreender como as gestantes vivenciam os processos fisiológicos do seu corpo durante a gestação e a sua repercussão na sexualidade. A pesquisa envolveu sete mulheres residentes em bairro popular de São Paulo. Na coleta de dados, utilizou-se observação participante e entrevista com questões norteadoras. Os dados foram apresentados na forma de narrativa e posteriormente organizados nas categorias: Percebendo as transformações corporais; Convivendo com as mudanças no corpo; Sentimentos e sensações na vida sexual durante a gestação e imaginando o corpo e a sexualidade após a gestação. As mulheres referiram-se às transformações do corpo como desconfortos e expressaram a preocupação de que fossem definitivas. Expressaram o desejo de que, após o parto, o corpo volte a ser como era e que volte a sentir desejo sexual. O reconhecimento destes fatos constitui-se numa ferramenta primordial na adequação das práticas profissionais.

Comparison of the effectiveness of seven amiloride congeners as inhibitors of Na/H and Na/Ca antiport in cultured smooth muscle cells

International Nuclear Information System (INIS)

Smith, L.; Higgins, B.L.; Cragoe, E.J. Jr.; Smith, J.B.

1987-01-01

The authors cultured smooth muscle cells from rat aorta and assayed Na/Ca antiport by measuring the initial rate of 45 Ca influx in Na-loaded cells. Na/H antiport was assayed by measuring the initial rate of 22 Na influx in acid-loaded cells. The external medium was the same for both assays except Na was 10 mM for Na/H antiport and O for the Na/Ca antiport assay. The dose of each congener that caused 50% inhibition (I 50 ) was calculated using a log-log median effect plot. The linear regression coefficients ranged from 0.916 to 0.998. Of all the compounds tested only dimethylbenzamil is more potent as an inhibitor of Na/Ca compared to Na/H antiport

Presoja notranjih kontrol pri obračunu davka na dodano vrednost na primeru "Podjetja x"

OpenAIRE

Majcen, Borut

2016-01-01

Poslovanje podjetja si je ob odsotnosti notranjih kontrol nemogoče predstavljati. Podjetja so podvržena raznim tveganjem, še posebej v današnjih razmerah globalnega poslovanja, ko se podjetja soočajo z vedno novimi izzivi, kar prinaša tudi nova tveganja. Najučinkovitejši ukrep za obvladovanje tveganj predstavlja vzpostavitev sistema notranjih kontrol. Obvladovanje tveganj pa ne poteka samo na ravni podjetja kot celote, ampak je prisotno na vseh področjih delovanja podjetja, torej tudi na p...

Culturas morais e políticas de desenvolvimento na noruega e na união europeia

Directory of Open Access Journals (Sweden)

Maria Macedo Barroso

2014-06-01

Full Text Available A partir de um diálogo entre os casos da Noruega e da União Europeia, pretendemos analisar a combinação de diferentes fatores e escalas de processos sociais (individuais, institucionais e de unidades políticas nacionais e supranacionais, estruturantes na formação dos sentidos sociais do desenvolvimento, notadamente das relações entre princípios morais e trocas interessadas, constitutivas das "culturas morais" dos universos analisados. Na perspectiva dos indivíduos, observaremos pela lente do caso da UE as motivações, vocações e histórias de vida dos "profissionais do desenvolvimento", bem como as razões da adesão da opinião pública às ações de cooperação internacional. Na escala institucional, abordaremos, nos dois casos, os modelos político-administrativos utilizados pela burocracia do desenvolvimento, e as lógicas dos diferentes grupos organizados para disputar seus recursos, no caso da Noruega. Na dimensão dos Estados, analisaremos a lógica das políticas nacionais e internacionais sob as quais são negociadas as intervenções de cooperação bilateral e/ou multilaterais tanto na Noruega quanto na UE.

Intermittent Hypoxia Inhibits Na+-H+ Exchange-Mediated Acid Extrusion Via Intracellular Na+ Accumulation in Cardiomyocytes

Directory of Open Access Journals (Sweden)

Huai-Ren Chang

2018-04-01

Full Text Available Background/Aims: Intermittent hypoxia (IH has been shown to exert preconditioning-like cardioprotective effects. It also has been reported that IH preserves intracellular pH (pHi during ischemia and protects cardiomyocytes against ischemic reperfusion injury. However, the exact mechanism is still unclear. Methods: In this study, we used proton indicator BCECF-AM to analyze the rate of pHi recovery from acidosis in the IH model of rat neonatal cardiomyocytes. Neonatal cardiomyocytes were first treated with repetitive hypoxia-normoxia cycles for 1-4 days. Cells were then acid loaded with NH4Cl, and the rate of pHi recovery from acidosis was measured. Results: We found that the pHi recovery rate from acidosis was much slower in the IH group than in the room air (RA group. When we treated cardiomyocytes with Na+-H+ exchange (NHE inhibitors (Amiloride and HOE642 or Na+-free Tyrode solution during the recovery, there was no difference between RA and IH groups. We also found intracellular Na+ concentration ([Na+]i significantly increased after IH exposure for 4 days. However, the phenomenon could be abolished by pretreatment with ROS inhibitors (SOD and phenanathroline, intracellular calcium chelator or Na+-Ca2+ exchange (NCX inhibitor. Furthermore, the pHi recovery rate from acidosis became faster in the IH group than in the RA group when inhibition of NCX activity. Conclusions: These results suggest that IH would induce the elevation of ROS production. ROS then activates Ca2+-efflux mode of NCX and results in intracellular Na+ accumulation. The rise of [Na+]i further inhibits the activity of NHE-mediated acid extrusion and retards the rate of pHi recovery from acidosis during IH.

Elastic Coulomb breakup of 34Na

Science.gov (United States)

Singh, G.; Shubhchintak, Chatterjee, R.

2016-08-01

Background: 34Na is conjectured to play an important role in the production of seed nuclei in the alternate r -process paths involving light neutron rich nuclei very near the β -stability line, and as such, it is important to know its ground state properties and structure to calculate rates of the reactions it might be involved in, in the stellar plasma. Found in the region of `island of inversion', its ground state might not be in agreement with normal shell model predictions. Purpose: The aim of this paper is to study the elastic Coulomb breakup of 34Na on 208Pb to give us a core of 33Na with a neutron and in the process we try and investigate the one neutron separation energy and the ground state configuration of 34Na. Method: A fully quantum mechanical Coulomb breakup theory within the architecture of post-form finite range distorted wave Born approximation extended to include the effects of deformation is used to research the elastic Coulomb breakup of 34Na on 208Pb at 100 MeV/u. The triple differential cross section calculated for the breakup is integrated over the desired components to find the total cross-section, momentum, and angular distributions as well as the average momenta, along with the energy-angular distributions. Results: The total one neutron removal cross section is calculated to test the possible ground state configurations of 34Na. The average momentum results along with energy-angular calculations indicate 34Na to have a halo structure. The parallel momentum distributions with narrow full widths at half-maxima signify the same. Conclusion: We have attempted to analyze the possible ground state configurations of 34Na and in congruity with the patterns in the `island of inversion' conclude that even without deformation, 34Na should be a neutron halo with a predominant contribution to its ground state most probably coming from 33Na(3 /2+)⊗ 2 p3 /2ν configuration. We also surmise that it would certainly be useful and rewarding to test our

Osmotic and activity coefficients of aqueous NaTcO4 and NaReO4 solutions at 250C

International Nuclear Information System (INIS)

Boyd, G.E.

1978-01-01

Isopiestic vapor-pressure comparison experiments were performed with aqueous binary sodium perchlorate, pertechnetate, and perrhenate solutions to concentrations of approximately 8.5 m. Osmotic coefficients for these solutions and mean molal ionic activity coefficients for NaTcO 4 and NaReO 4 were derived from the isotonic molalities. Pitzer's treatment was applied to describe the concentration dependence of the osmotic coefficients of NaClO 4 , NaTcO 4 , and NaReO 4 , and the implications of the parameters derived from a least-squares fit are discussed in terms of solvent structure and interionic forces. 4 tables, 1 figure

Energy levels of the single excited states in NaI and Na-like ions

International Nuclear Information System (INIS)

El-Sherbini, T.M.; Wahby, A.S.

1987-08-01

Energy levels of the single excited 1s 2 2s 2 2p 6 ns( 2 S), 1s 2 2s 2 2p 6 mp( 2 P), 1s 2 2s 2 2p 6 md( 2 D) and 1s 2 2s 2 2p 6 nf( 2 F); n=4-7, m=3-6 states for NaI and Na-like ions are calculated using the one configuration Hartree-Fock method. Good agreement is obtained between our results for the higher members of the NaI sequence and previous data from photo-absorption and beam foil experiments. (author). 11 refs, 3 figs, 9 tabs

Fabrication of implanted $^{22}$Na targets

CERN Multimedia

2002-01-01

A knowledge of the $^{22}$Na(p,$\\gamma$)$^{23}$ Mg reaction rate is of significant astrophysical interest. In order to complete previous studies of this reaction, radioactive $^{22}$Na targets of high purity are required. We ask for support to fabricate these targets via the implantation technique at ISOLDE GPS (off—line mode) using $^{22}$Na nuclides in an Al matrix produced in Nov. 1990 at the PSI (Zürich). The $^{22}$Na nuclides are released and ionized in a surface ionisation source, mass-analyzed at ISOLDE GPS, and implanted in a Ni-Ta backing and a C—foil in a special implantation setup.

Painful Na-channelopathies: an expanding universe.

Science.gov (United States)

Waxman, Stephen G

2013-07-01

The universe of painful Na-channelopathies--human disorders caused by mutations in voltage-gated sodium channels--has recently expanded in three dimensions. We now know that mutations of sodium channels cause not only rare genetic 'model disorders' such as inherited erythromelalgia and channelopathy-associated insensitivity to pain but also common painful neuropathies. We have learned that mutations of NaV1.8, as well as mutations of NaV1.7, can cause painful Na-channelopathies. Moreover, recent studies combining atomic level structural models and pharmacogenomics suggest that the goal of genomically guided pain therapy may not be unrealistic. Copyright © 2013 Elsevier Ltd. All rights reserved.

Usmerjanje urbanega razvoja na mestni ravni

Directory of Open Access Journals (Sweden)

Mojca Šašek Divjak

1999-01-01

Full Text Available Kot je poudarjeno v predstavljenem načrtu Kopenhagna, mestni načrt ne more rešiti vseh planskih problemov mesta. Predstavljal naj bi predvideni red, ki pa se pogosto sproti podira glede na nepredvidena dogajanja v prostoru. Probleme je velikokrat treba reševati šele, ko se pokažejo. Zato mora biti mestni načrt zastavljen dovolj prilagodljivo in fleksibilno, da dovoljuje potrebne spremembe. Vendar mora kljub temu dati mestu trdne glavne usmeritve in s tem omogočiti, da meščani lahko izkoristijo priložnosti, ki jih nudi nova doba in uveljavljajo nove kvalitete bivanja.

Velocity distribution and dimer formation in a Na/Na2 beam

International Nuclear Information System (INIS)

Bergmann, K.; Hefter, U.; Hering, P.

1977-01-01

Using the TOF via optical pumping method and the Doppler-shifted laser induced emission described previously, the authors have measured the parallel and perpendicular velocity distribution respectively for Na atoms and Na 2 molecules in a variety of individual quantum states. In addition they monitored the flux of molecules in specific states while changing the stagnation pressure. In all cases a significant dependence on the internal energy of the molecules was found. The goal of these experiments is to improve understanding of the beam dynamics and the dimer formation process. (Auth.)

Angular distributions of photoelectrons from free Na clusters

International Nuclear Information System (INIS)

Wopperer, P.; Dinh, P. M.; Faber, B.; Reinhard, P.-G.; Suraud, E.

2010-01-01

We explore, from a theoretical perspective, photoelectron angular distributions (PADs) of the Na clusters Na 8 , Na 10 , Na 12 , Na 18 , Na 3 + , Na 11 + , Na 13 + , and Na 19 + . The basis of the description is the time-dependent local-density approximation (TDLDA), augmented by a self-interaction correction (SIC) to describe ionization properties correctly. The scheme is solved on a numerical grid in coordinate space with absorbing bounds. We assume for each cluster system an isotropic ensemble of free clusters and develop for the case of one-photon emission analytical formulas for computing the orientation-averaged PAD on the basis of a few TDLDA-SIC calculations for properly chosen reference orientations. It turns out that all the information in the averaged PAD is contained in one anisotropy parameter. We find that this parameter varies very little with system size, but as a whole is crucially influenced by the detailed ionic structure. We also make comparisons with direct orientation averaging and consider one example reaching outside the perturbative regime.

The Na+ transport in gram-positive bacteria defect in the Mrp antiporter complex measured with 23Na nuclear magnetic resonance.

Science.gov (United States)

Górecki, Kamil; Hägerhäll, Cecilia; Drakenberg, Torbjörn

2014-01-15

(23)Na nuclear magnetic resonance (NMR) has previously been used to monitor Na(+) translocation across membranes in gram-negative bacteria and in various other organelles and liposomes using a membrane-impermeable shift reagent to resolve the signals resulting from internal and external Na(+). In this work, the (23)Na NMR method was adapted for measurements of internal Na(+) concentration in the gram-positive bacterium Bacillus subtilis, with the aim of assessing the Na(+) translocation activity of the Mrp (multiple resistance and pH) antiporter complex, a member of the cation proton antiporter-3 (CPA-3) family. The sodium-sensitive growth phenotype observed in a B. subtilis strain with the gene encoding MrpA deleted could indeed be correlated to the inability of this strain to maintain a lower internal Na(+) concentration than an external one. Copyright © 2013 Elsevier Inc. All rights reserved.

Quatenary Na//F, Cl, CO3, MoO4 system

International Nuclear Information System (INIS)

Kochkarov, Zh.A.; Lok''yaeva, S.M.; Shurdumov, G.K.; Gasanaliev, A.M.; Trunin, A.S.

1999-01-01

Perspective in applied respect quatenary system (NaF) 2 -(NaCl)-Na 2 CO 3 -Na 2 MoO 4 being element of narrowing of more complex six-membered mutual Na//F, Cl, CO 3 , MoO 4 (WO 4 ) system is investigated by differential thermal analysis with the use of projection-thermographic method for the first time. Crystallization tree of Na//F, Cl, CO 3 , MoO 4 system is established. It is shown that this system by tetrahedrating (NaF) 2 -Na 2 CO 3 -Na 3 ClMoO 4 section is triangulated on two stable system: (NaF) 2 -Na 3 ClMoO 4 -Na 2 CO 3 -(NaCl) 2 and (NaF) 2 -Na 3 ClMoO 4 -Na 2 CO 3 -Na 2 MoO 4 . Phase single units are determined too. Coordinates of desired quatenary nonvariant points are calculated on analytical models of surfaces by mutual crystallization of two phases and are refined by differential thermal analysis [ru

Experimental Study of Na based Titanium Nanofluid-Water Reaction

Energy Technology Data Exchange (ETDEWEB)

Park, Gunyeop; Kim, Soo Jae; Baek, Jehyun; Kim, Hyun Soo; Oh, Sun Ryung; Park, Hyun Sun; Kim, Moo Hwan [POSTECH, Pohang (Korea, Republic of)

2015-10-15

In KALIMER-600, a sodium-cooled fast reactor designed by KAERI, thermal energy is transported from high-temperature liquid Na (526 .deg. C at 0.1 MPa) to low temperature water (230 .deg. C at - 19.5 MPa) through a heat exchanger. If any leakage or rupture occurs during the operation of this heat exchanger, highly pressurized liquid water can penetrate into the liquid Na channels; this contact should instantly cause SWR. As reaction continues, liquid water is soon vaporized by pressure drop and huge amount of reaction heat. This generated water vapor expands large reaction area and increases sodium-water vapor reaction process. Therefore, the rapid generation of reaction product (like H{sub 2}) and water vapor increases the system pressure that can cause the system failure in SFR. To reduce this strong chemical reaction phenomena between Na and water, some we have focused on suppressing the chemical reactivity of liquid Na by dispersing nanoparticles (NPs). For the real application of NaTiNF, the pressure change induced by NaTiNF-water reaction is compared with Na-water reaction in the present study. NaTiNF contains 100nm of Ti NPs at 0.2 vol. %. The reaction rate of NaTiNF-water reaction is also investigated as reaction temperature increases. Sodium-water vapor reaction (SVR) will occur when an SWR accident occurs in SFR. In this manner, NaTiNF-water vapor reaction is experimentally performed for ensuring the suppression of chemical reactivity of NaTiNF in contact with water vapor. In the basic step for reducing risk of an SWR in SFR, we have experimentally verified the suppressed chemical reactivity of liquid sodium using Ti NPs through SWR and SVR experiments. In SWR, Na based titanium nanofluid (NaTiNF) shows lower pressure change than Na. As T{sub R} increases, P{sub max} in Na-water reaction increases while NaTiNF does not. The reaction rate of NaTiNF shows twice slower than that of Na. In SVR, NaTiNF shows slower temperature increase than Na. The distinct

Phase equilibria in the NaF-CdO-NaPO{sub 3} system at 873 K and crystal structure and physico-chemical characterizations of the new Na{sub 2}CdPO{sub 4}F fluorophosphate

Energy Technology Data Exchange (ETDEWEB)

Aboussatar, Mohamed [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS, BP 10448, F-63000 Clermont-Ferrand (France); Laboratoire de Physico-Chimie de l’État Solide, Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000 Sfax (Tunisia); Mbarek, Aïcha [Laboratoire de Chimie Industrielle, Ecole Nationale d’Ingénieurs de Sfax, Université de Sfax, BP W3038, 3000 Sfax (Tunisia); Naili, Houcine [Laboratoire de Physico-Chimie de l’État Solide, Faculté des Sciences de Sfax, Université de Sfax, BP 1171, 3000 Sfax (Tunisia); El-Ghozzi, Malika [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS, BP 10448, F-63000 Clermont-Ferrand (France); Chadeyron, Geneviève [Université Clermont Auvergne, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS/UBP/SIGMA, BP 10448, F-63000 Clermont-Ferrand (France); Avignant, Daniel [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS, BP 10448, F-63000 Clermont-Ferrand (France); Zambon, Daniel, E-mail: Daniel.Zambon@univ-bpclermont.fr [Université Clermont Auvergne, Université Blaise Pascal, Institut de Chimie de Clermont-Ferrand, UMR 6296 CNRS, BP 10448, F-63000 Clermont-Ferrand (France)

2017-04-15

Isothermal sections of the diagram representing phase relationships in the NaF-CdO-NaPO{sub 3} system have been investigated by solid state reactions and powder X-ray diffraction. This phase diagram investigation confirms the polymorphism of the NaCdPO{sub 4} side component and the structure of the ß high temperature polymorph (orthorhombic, space group Pnma and unit cell parameters a=9.3118(2), b=7.0459(1), c=5.1849(1) Å has been refined. A new fluorophosphate, Na{sub 2}CdPO{sub 4}F, has been discovered and its crystal structure determined and refined from powder X-ray diffraction data. It exhibits a new 3D structure with orthorhombic symmetry, space group Pnma and unit cell parameters a=5.3731(1), b=6.8530(1), c=12.2691(2) Å. The structure is closely related to those of the high temperature polymorph of the nacaphite Na{sub 2}CaPO{sub 4}F and the fluorosilicate Ca{sub 2}NaSiO{sub 4}F but differs essentially in the cationic repartition since the structure is fully ordered with one Na site (8d) and one Cd site (4c). Relationships with other Na{sub 2}M{sup II}PO{sub 4}F (M{sup II}=Mg, Ca, Mn, Fe, Co, Ni) have been examined and the crystal-chemical and topographical analysis of these fluorophosphates is briefly reviewed. IR, Raman, optical and {sup 19}F, {sup 23}Na, {sup 31}P MAS NMR characterizations of Na{sub 2}CdPO{sub 4}F have been investigated. - Graphical abstract: The structure of the compound Na{sub 2}CdPO{sub 4}F, discovered during the study of the phase relationships in the NaF-CdO-NaPO{sub 3} system, has been determined and compared with other Na{sub 2}M{sup II}PO{sub 4}F fluorophosphates. - Highlights: • XRD analysis of the isothermal section of the NaF-CdO-NaPO{sub 3} system at 923 K. • Rietveld refinement of the high temperature polymorph β-NaCdPO{sub 4}. • Crystal structure of the new Na{sub 2}CdPO{sub 4}F fluorophosphate determined from powder XRD. • Crystal structure - composition relationships of Na{sub 2}M{sup II}PO{sub 4}F compounds

Mechanochemical transformations in Li(Na)AlH4-Li(Na)NH2 systems

International Nuclear Information System (INIS)

Dolotko, Oleksandr; Zhang Haiqiao; Ugurlu, Ozan; Wiench, Jerzy W.; Pruski, Marek; Scott Chumbley, L.; Pecharsky, Vitalij

2007-01-01

Mechanochemical transformations of tetrahydroaluminates and amides of lithium and sodium have been investigated using gas volumetric analysis, X-ray powder diffraction, solid-state nuclear magnetic resonance (NMR) and transmission electron microscopy. In a transformation of LiAlH 4 and LiNH 2 taken in an 1:1 molar ratio, the amount of released hydrogen (6.6 wt.% after 30 min ball milling) was higher than in any known one pot mechanochemical process involving a hydrogen-containing solid. A total of 4.3 wt.% of hydrogen is released by the NaAlH 4 -NaNH 2 system after 60 min ball milling; and 5.2 wt.% H 2 is released when LiAlH 4 and NaNH 2 or NaAlH 4 and LiNH 2 are ball milled for 90 min and 120 min, respectively. All transformations proceed at room temperature. The mechanism of the overall transformation MAlH 4 (s) + MNH 2 (s) → 2MH(s) + AlN(s) + 2H 2 (g) was identified based on detailed spectroscopic analysis of the intermediate (M 3 AlH 6 ) and final products of the ball milling process

Makosa Yanayofanywa na Wanafunzi Wanaojifunza Kiswahili kama ...

African Journals Online (AJOL)

Makala haya, yanashughulika na makosa ambayo hufanywa na wanafunzi wanaojifunza Kiswahili kama lugha ya pili katika shule za sekondari nchini Uganda. Mtafiti ameyaainisha makosa mbalimbali na kuyaeleza kiusahihi. Makala yanaeleza namna ambavyo makosa hayo hutokea. Yaani, kama ni makosa ...

Učinak video igre "Flappy Bird" na adolescente

OpenAIRE

Horvat, Marija

2018-01-01

Ovaj diplomski rad nastoji predstaviti uvid u učinke videoigre Flappy Bird na adolescente, fokusirajući se pritom na to potiče li ona nasilno ponašanje te nastoji odgovoriti na pitanje koliko je ta videoigra bila popularna među adolescentima u Hrvatskoj te po čemu je smatraju posebnom, tj. specifičnom. U tu svrhu provedeno je anketno istraživanje, a isti anketni upitnik proveden je na terenu i putem interneta te su uspoređeni rezultati. Anketni upitnik konstruiran je na način da se prvi dio u...

Perinatal Na+ Overload Programs Raised Renal Proximal Na+ Transport and Enalapril-Sensitive Alterations of Ang II Signaling Pathways during Adulthood

Science.gov (United States)

Cabral, Edjair V.; Vieira-Filho, Leucio D.; Silva, Paulo A.; Nascimento, Williams S.; Aires, Regina S.; Oliveira, Fabiana S. T.; Luzardo, Ricardo; Vieyra, Adalberto; Paixão, Ana D. O.

2012-01-01

Background High Na+ intake is a reality in nowadays and is frequently accompanied by renal and cardiovascular alterations. In this study, renal mechanisms underlying perinatal Na+ overload-programmed alterations in Na+ transporters and the renin/angiotensin system (RAS) were investigated, together with effects of short-term treatment with enalapril in terms of reprogramming molecular alterations in kidney. Methodology/Principal Findings Male adult Wistar rats were obtained from dams maintained throughout pregnancy and lactation on a standard diet and drinking water (control) or 0.17 M NaCl (saline group). Enalapril (100 mg/l), an angiotensin converting enzyme inhibitor, was administered for three weeks after weaning. Ninety day old offspring from dams that drank saline presented with proximal tubules exhibiting increased (Na++K+)ATPase expression and activity. Ouabain-insensitive Na+-ATPase activity remained unchanged but its response to angiotensin II (Ang II) was lost. PKC, PKA, renal thiobarbituric acid reactive substances (TBARS), macrophage infiltration and collagen deposition markedly increased, and AT2 receptor expression decreased while AT1 expression was unaltered. Early treatment with enalapril reduced expression and activity of (Na++K+)ATPase, partially recovered the response of Na+-ATPase to Ang II, and reduced PKC and PKA activities independently of whether offspring were exposed to high perinatal Na+ or not. In addition, treatment with enalapril per se reduced AT2 receptor expression, and increased TBARS, macrophage infiltration and collagen deposition. The perinatally Na+-overloaded offspring presented high numbers of Ang II-positive cortical cells, and significantly lower circulating Ang I, indicating that programming/reprogramming impacted systemic and local RAS. Conclusions/Significance Maternal Na+ overload programmed alterations in renal Na+ transporters and in its regulation, as well as severe structural lesions in adult offspring. Enalapril

alpha-Adducin mutations increase Na/K pump activity in renal cells by affecting constitutive endocytosis: implications for tubular Na reabsorption.

Science.gov (United States)

Torielli, Lucia; Tivodar, Simona; Montella, Rosa Chiara; Iacone, Roberto; Padoani, Gloria; Tarsini, Paolo; Russo, Ornella; Sarnataro, Daniela; Strazzullo, Pasquale; Ferrari, Patrizia; Bianchi, Giuseppe; Zurzolo, Chiara

2008-08-01

Genetic variation in alpha-adducin cytoskeletal protein is implicated in the polymerization and bundling of actin and alteration of the Na/K pump, resulting in abnormal renal sodium transport and hypertension in Milan hypertensive rats and humans. To investigate the molecular involvement of alpha-adducin in controlling Na/K pump activity, wild-type or mutated rat and human alpha-adducin forms were, respectively, transfected into several renal cell lines. Through multiple experimental approaches (microscopy, enzymatic assays, coimmunoprecipitation), we showed that rat and human mutated forms increased Na/K pump activity and the number of pump units; moreover, both variants coimmunoprecipitate with Na/K pump. The increased Na/K pump activity was not due to changes in its basolateral localization, but to an alteration of Na/K pump residential time on the plasma membrane. Indeed, both rat and human mutated variants reduced constitutive Na/K pump endocytosis and similarly affected transferrin receptor trafficking and fluid-phase endocytosis. In fact, alpha-adducin was detected in clathrin-coated vesicles and coimmunoprecipitated with clathrin. These results indicate that adducin, besides its modulatory effects on actin cytoskeleton dynamics, might play a direct role in clathrin-dependent endocytosis. The constitutive reduction of the Na/K pump endocytic rate induced by mutated adducin variants may be relevant in Na-dependent hypertension.

VPLIV OSEBNOSTI NA STILE VODENJA

OpenAIRE

Vučak, Petra

2009-01-01

Nekatere naše vrline krasijo zlate lastnosti, druge pa kvarijo sivi odtenki. Če bi ljudje razumeli in spoznali svojo osebnost, ter osebnostne tipe drugih ljudi, bi se problemi pri komunikaciji občutno zmanjšali. Takrat bi namreč lažje uvideli, zakaj je nekdo reagiral na način, kot je ali zakaj je nekdo dejal to, kar je. Smisel tega je, da spoznamo svoje dobre lastnosti, ki jih lahko še bolj razvijemo, slabe pa poskušamo nadzorovati in tako zmanjšati njihov vpliv. Iskanje uspešnih in učink...

VPLIV CENE NA ZADOVOLJSTVO IN ZVESTOBO UPORABNIKOV TELEKOMUNIKACIJSKIH STORITEV

OpenAIRE

Majcen, Mateja

2016-01-01

Cena izdelka ali storitve, ki jo plača uporabnik, ima pomemben vpliv na zadovoljstvo ali nezadovoljstvo uporabnika z uporabo tega izdelka ali storitve in posledično na zadovoljstvo do podjetja. Glede na to, da se različni avtorji strinjajo in to tudi dokazujejo z raziskavami, zadovoljstvo nedvoumno vpliva na zvestobo uporabnika, zvestoba pa na dolgoročno uspešnost podjetja, smo v delu ugotavljali, kako sama cena storitve vpliva na zadovoljstvo in kako posredno preko zadovoljstva vpliva na zve...

NaI(Tl) electron energy resolution

CERN Document Server

Mengesha, W

2002-01-01

NaI(Tl) electron energy resolution eta sub e was measured using the Modified Compton Coincidence Technique (MCCT). The MCCT allowed detection of nearly monoenergetic internal electrons resulting from the scattering of incident 662 keV gamma rays within a primary NaI(Tl) detector. Scattered gamma rays were detected using a secondary HPGe detector in a coincidence mode. Measurements were carried out for electron energies ranging from 16 to 438 keV, by varying the scattering angle. Measured HPGe coincidence spectra were deconvolved to determine the scattered energy spectra from the NaI(Tl) detector. Subsequently, the NaI(Tl) electron energy spectra were determined by subtracting the energy of scattered spectra from the incident source energy (662 keV). Using chi-squared minimization, iterative deconvolution of the internal electron energy spectra from the measured NaI(Tl) spectra was then used to determine eta sub e at the electron energy of interest. eta sub e values determined using this technique represent va...

Quantitative (23) Na MRI of human knee cartilage using dual-tuned (1) H/(23) Na transceiver array radiofrequency coil at 7 tesla.

Science.gov (United States)

Moon, Chan Hong; Kim, Jung-Hwan; Zhao, Tiejun; Bae, Kyongtae Ty

2013-11-01

To develop quantitative dual-tuned (DT) (1) H/(23) Na MRI of human knee cartilage in vivo at 7 Tesla (T). A sensitive (23) Na transceiver array RF coil was developed at 7T. B1 fields generated by the transceiver array coil were characterized and corrected in the (23) Na images. Point spread function (PSF) of the (23) Na images was measured, and the signal decrease due to partial-volume-effect was compensated in [(23) Na] quantification of knee cartilage. SNR and [(23) Na] in anterior femoral cartilage were measured from seven healthy subjects. SNR of (23) Na image with the transceiver array coil was higher than that of birdcage coil. SNR in the cartilage at 2-mm isotropic resolution was 26.80 ± 3.69 (n = 7). B1 transmission and reception fields produced by the DT coil at 7T were similar to each other. Effective full-width-half-maximum of (23) Na image was ∼5 mm at 2-mm resolution. Mean [(23) Na] was 288.13 ± 29.50 mM (n = 7) in the anterior femoral cartilage of normal subjects. We developed a new high-sensitivity (23) Na RF coil for knee MRI at 7T. Our (1) H/(23) Na MRI allowed quantitative measurement of [(23) Na] in knee cartilage by measuring PSF and cartilage thickness from (23) Na and (1) H image, respectively. Copyright © 2013 Wiley Periodicals, Inc.

Razvitak naselja na kvarnerskim otocima - primjer Dobrinja

Directory of Open Access Journals (Sweden)

Marijan Bradanović

2012-12-01

Full Text Available Na dosad slabo poznatom i sa stajališta povijesti umjetnosti još posve neobrađenom primjeru Dobrinja na otoku Krku, raspravlja se o razvitku naselja na kvarnerskim otocima. Uz isticanje štetnosti dosad prevladavajućih uopćavanja, karakteristični položaj i razvitak Dobrinja tumače se u širem, komparativnom kontekstu. Analiziraju se prostiranje i obilježja pojedinih dijelova ovog naselja, a naglasak je na vremenu kasnog srednjeg i ranijeg novog vijeka. Tada je najuži dio povijesnog središta Dobrinja poprimio čvrstu, na tlorisnoj osnovi i danas, usprkos opsežnim pregradnjama i arhitektonskim preinakama, jasno uočljivu, urbanu fizionomiju.

Browse Title Index

African Journals Online (AJOL)

O Diallo, D Kanikomo, M Camara, M Dama, O Coulibaly, B Kane, MS Diarra, Y Sogoba, H Traore, SB Badiane ... S Ghroubi, I Miladi, S Mefteh, O Kharrat, M Guermazi, E Turki, C Mhiri, M Elleuch .... VB Patel, A Motala, C Connally, IDP Burger.

Investigation of sodalites for conditioning halide salts (NaCl and NaI): Comparison of two synthesis routes

Energy Technology Data Exchange (ETDEWEB)

Bardez, Isabelle; Campayo, Lionel; Rigaud, Danielle; Chartier, Myriam; Calvet, Aurelie [CEA, Laboratoire d' Etudes des Materiaux Ceramiques pour le Conditionnement, Site de Marcoule, Batiment 208, B.P. 17171, 30207 Bagnols sur Ceze cedex (France)

2008-07-01

Sodalites with the general formula Na{sub 8}Al{sub 6}Si{sub 6}O{sub 24}X{sub 2} (where X = Cl or I) were investigated for ceramic conditioning of halide salts (NaCl and NaI). Because of the tendency of halides to volatilize at high temperature, two synthesis routes were tested to optimize the halide content in the sodalite phase. The first is based on heating at high temperature of a [nepheline NaAlSiO{sub 4} + salt] mixture prepared by a dry process. The second, performed at low temperature, consists of the reaction in aqueous media between kaolinite (Al{sub 2}Si{sub 2}O{sub 5}(OH){sub 4}), sodium hydroxide (NaOH) and the salt. The present study compares these two syntheses and examines differences between chloro-sodalite and iodo-sodalite based on X-ray diffraction and infrared spectroscopy. The next step will consist in sintering the resulting powder samples to obtain dense ceramics. (authors)

Dissolution of targets for the production of Mo-99: Part 1. Influence of NaOH concentration and the addition of NaNO3 and NaNO2 on the dissolution time

International Nuclear Information System (INIS)

Camilo, Ruth L.; Araujo, Izilda da C.; Mindrisz, Ana C.; Forbicini, Christina A.L.G. de O.

2011-01-01

Faced with global crisis in the production of radioisotope 99 Mo, which product of decay, 99 mTc, is the tracer element most often used in nuclear medicine and accounts for about 80% of all diagnostic procedures in vivo, since September 2008 Brazil is developing the project called Brazilian Multipurpose Reactor (RMB). Within the Brazilian Nuclear Program (PNB) the construction of the RMB, is seen as a long term solution to meet all domestic demand relative to the supply of radioisotopes and radiopharmaceuticals. In the process to be studied to obtain 99 Mo from irradiated UA1 x -A1 LEU targets employing alkaline dissolution, processing time should be minimized, considering the short half life of 99 Mo and 99 mTc, about 66 h and 6 h, respectively. That makes dissolution time a significant factor in the development of the process. This paper presents the results of alkaline dissolution of scraps of Al, used to simulate the dissolution process of UA1 x -A1 targets. Al corresponds to about 79% of the total weight of the UA1 x -A1 target. The effect of NaOH concentration on dissolution time for the interval of 1 to 3.5 mol.L-1 was studied, keeping the molar ratio in 1Al:2.16NaOH and the initial temperature of 88 degree C. The influence of reagent composition over dissolution time was studied using three different solutions: a) 3 mol.L -1 NaOH, b) 3 mol.L -1 NaOH/NaNO 3 and c) 3 mol.L -1 NaOH/NaNO 2 , keeping the same molar ratio and temperature. The results showed that the dissolution time decreases with increasing NaOH concentration and the addition of NaNO 3 or NaNO 2 in the NaOH solution reduces both dissolution time and volume of gases released. (author)

Magnetic upconverting fluorescent NaGdF4:Ln3+ and iron-oxide@NaGdF4:Ln3+ nanoparticles

Science.gov (United States)

Shrivastava, Navadeep; Rocha, Uéslen; Muraca, Diego; Jacinto, Carlos; Moreno, Sergio; Vargas, J. M.; Sharma, S. K.

2018-05-01

Microwave assisted solvothermal method has been employed to synthesize multifunctional upconverting β-NaGdF4:Ln3+ and magnetic-upconverting Fe3O4/γ-Fe2O3@NaGdF4:Ln3+ (Ln = Yb and Er) nanoparticles. The powder x-ray diffraction data confirms the hexagonal structure of NaGdF4:Ln3+ and high resolution transmission electron microscopy shows the formation of rod shaped NaGdF4:Ln3+ (˜ 20 nm) and ovoid shaped Fe3O4/γ-Fe2O3@NaGdF4:Ln3+ (˜ 15 nm) nanoparticles. The magnetic hysteresis at 300 K for β-NaGdF4:Ln3+ demonstrates paramagnetic features, whereas iron-oxide@β-NaGdF4:Ln3+ exhibits superparamagnetic behavior along with a linear component at large applied field due to paramagnetic NaGdF4 matrix. Both nanoparticle samples provide an excellent green emitting [(2H11/2, 4S3/2)→4I15/2 (˜ 540 nm)] upconversion luminescence emission under excitation at 980 nm. The energy migration between Yb and Er in NaGdF4 matrix has been explored from 300-800 nm. Intensity variation of blue, green and red lines and the observed luminescence quenching due to the presence of Fe3O4/γ-Fe2O3 in the composite has been proposed. These kinds of materials contain magnetic and luminescence characteristics into single nanoparticle open new possibility for bioimaging applications.

The plant vacuolar Na+/H+ antiport.

Science.gov (United States)

Barkla, B J; Apse, M P; Manolson, M F; Blumwald, E

1994-01-01

Salt stress imposes severe limitations on plant growth, however, the extent of growth reduction depends upon the soil salinity level and the plant species. One of the mechanisms employed by salt tolerant plants is the effective vacuolar compartmentalization of sodium. The sequestration of sodium into the vacuole occurs by the operation of a Na+/H+ antiport located at the tonoplast. Evidence for a plant vacuolar Na+/H+ antiport has been demonstrated in tissues, intact vacuoles and isolated tonoplast vesicles. In sugar beet cell suspensions, the activity of the vacuolar Na+/H+ antiport increased with increasing NaCl concentrations in the growth medium. This increased activity was correlated with the increased synthesis of a 170 kDa tonoplast polypeptide. In vivo labelling of tonoplast proteins showed the enhanced synthesis of the 170 kDa polypeptide not only upon exposure of the cells to salt, but also when the cells were grown in the presence of amiloride. Exposure of the cells to amiloride also resulted in increased vacuolar Na+/H+ antiport activity. Polyclonal antibodies raised against the 170 kDa polypeptide almost completely inhibited the antiport activity, suggesting the association of this protein with the plant vacuolar Na+/H+ antiport. Antibodies against the Na+/H+ antiport-associated polypeptide were used to screen a Beta lambda ZAP expression library. A partial clone of 1.65 kb was sequenced and found to encode a polypeptide with a putative transmembrane domain and a large hydrophilic C terminus. This clone showed no homology to any previously cloned gene at either the nucleic acid or the amino acid level.

Correlation of the Na2SiO3 to NaOH Ratios and Solid to Liquid Ratios to the Kedah’s Soil Strength

Directory of Open Access Journals (Sweden)

Nur Hamzah Hazamaah

2016-01-01

Full Text Available Geopolymer was used for the soil stabilization of Kedah’s soil at different ratios of solid to liquid and Na2SiO3 to NaOH in order to achieve the desired compressive strength. The geopolymerization process which produces an aluminosilicate gel was occurred due to the mixing of Kedah’s soil and fly ash with Na2SiO3 and NaOH. Soil stabilization by geopolymer was synthesized by the activation of fly ash and Kedah’s soil with Na2SiO3 and NaOH at different ratios of solid to liquid (1.5, 2.0, 2.5 and 3.0 and Na2SiO3 to NaOH (0.5, 1.0, 1.5, 2.0, 2.5 and 3.0 at a specific constant concentration of NaOH solution of 6M. The compressive strength up to 5.12 MPa was obtained at 3.0 of solid to liquid ratio and 2.5 of Na2SiO3 to NaOH ratio in 7 days curing at room temperature.

Near resonant charge transfer in Na(4D)+K+ → Na++K*: Optical pumping of the Na(4D) state and energy dependence of rank 4 alignment

International Nuclear Information System (INIS)

Campbell, E.E.B.; Huelser, H.; Witte, R.; Hertel, I.V.

1990-01-01

Rank 4 alignment has been observed in a quasi one electron system. Relative charge transfer cross sections of the Na 4dσ, 4dπ and 4dδ sublevels for the K + +Na(4D)→K * +Na + system have been measured. A strong energy dependence is observed. The results at energies less than 1 keV may be attributed to rotational coupling of the Na 4dπ state to the K 4fδ state. The Na atom is excited in a two-step process, the first step being excitation to the 3 2 P 3/2 level with a two-mode laser to pump from both hyperfine levels of the ground state simultaneously. This two-mode laser is described in detail. The optical pumping problem is solved using rate equations. The general formula for describing the scattering intensity for cylindrical symmetry, in terms of multipole moments, for atoms excited by two linearly polarised lasers is derived and used to evaluate the experimental results. (orig.)

Thermodynamic description of Tc(iv) solubility and carbonate complexation in alkaline NaHCO3-Na2CO3-NaCl systems.

Science.gov (United States)

Baumann, A; Yalçıntaş, E; Gaona, X; Polly, R; Dardenne, K; Prüßmann, T; Rothe, J; Altmaier, M; Geckeis, H

2018-03-28

The solubility of 99 Tc(iv) was investigated in dilute to concentrated carbonate solutions (0.01 M ≤ C tot ≤ 1.0 M, with C tot = [HCO 3 - ] + [CO 3 2- ]) under systematic variation of ionic strength (I = 0.3-5.0 M NaHCO 3 -Na 2 CO 3 -NaCl-NaOH) and pH m (-log[H + ] = 8.5-14.5). Strongly reducing conditions (pe + pH m ≈ 2) were set with Sn(ii). Carbonate enhances the solubility of Tc(iv) in alkaline conditions by up to 3.5 log 10 -units compared to carbonate-free systems. Solvent extraction and XANES confirmed that Tc was kept as +IV during the timeframe of the experiments (≤ 650 days). Solid phase characterization performed by XAFS, XRD, SEM-EDS, chemical analysis and TG-DTA confirmed that TcO 2 ·0.6H 2 O(am) controls the solubility of Tc(iv) under the conditions investigated. Slope analysis of the solubility data in combination with solid/aqueous phase characterization and DFT calculations indicate the predominance of the species Tc(OH) 3 CO 3 - at pH m ≤ 11 and C tot ≥ 0.01 M, for which thermodynamic and activity models are derived. Solubility data obtained above pH m ≈ 11 indicates the formation of previously unreported Tc(iv)-carbonate species, possibly Tc(OH) 4 CO 3 2- , although the likely formation of additional complexes prevents deriving a thermodynamic model valid for this pH m -region. This work provides the most comprehensive thermodynamic dataset available for the system Tc 4+ -Na + -Cl - -OH - -HCO 3 - -CO 3 2- -H 2 O(l) valid under a range of conditions relevant for nuclear waste disposal.

Stimulation of Na+/K+ ATPase activity and Na+ coupled glucose transport by β-catenin

International Nuclear Information System (INIS)

Sopjani, Mentor; Alesutan, Ioana; Wilmes, Jan; Dermaku-Sopjani, Miribane; Lam, Rebecca S.; Koutsouki, Evgenia; Jakupi, Muharrem; Foeller, Michael; Lang, Florian

2010-01-01

Research highlights: → The oncogenic transcription factor β-catenin stimulates the Na + /K + -ATPase. → β-Catenin stimulates SGLT1 dependent Na + , glucose cotransport. → The effects are independent of transcription. → β-Catenin sensitive transport may contribute to properties of proliferating cells. -- Abstract: β-Catenin is a multifunctional protein stimulating as oncogenic transcription factor several genes important for cell proliferation. β-Catenin-regulated genes include the serum- and glucocorticoid-inducible kinase SGK1, which is known to stimulate a variety of transport systems. The present study explored the possibility that β-catenin influences membrane transport. To this end, β-catenin was expressed in Xenopus oocytes with or without SGLT1 and electrogenic transport determined by dual electrode voltage clamp. As a result, expression of β-catenin significantly enhanced the ouabain-sensitive current of the endogeneous Na + /K + -ATPase. Inhibition of vesicle trafficking by brefeldin A revealed that the stimulatory effect of β-catenin on the endogenous Na + /K + -ATPase was not due to enhanced stability of the pump protein in the cell membrane. Expression of β-catenin further enhanced glucose-induced current (Ig) in SGLT1-expressing oocytes. In the absence of SGLT1 Ig was negligible irrespective of β-catenin expression. The stimulating effect of β-catenin on both Na + /K + ATPase and SGLT1 activity was observed even in the presence of actinomycin D, an inhibitor of transcription. The experiments disclose a completely novel function of β-catenin, i.e. the regulation of transport.

Explosive phenomena in heavily irradiated NaCl

NARCIS (Netherlands)

denHartog, HW; Vainshtein, DI; Matthews, GE; Williams, RT

1997-01-01

In heavily irradiated NaCl crystals explosive phenomena can be initiated during irradiation or afterwards when samples are heated to temperatures between 100 and 250 degrees C. During irradiation of NaCl Na and Cl-2 precipitates and void structures are produced along with the accumulation of stored

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)

Estereótipos na comunicação intercultural: o caso do intercâmbio cultural na PUCRS

OpenAIRE

Espindola, Polianne Merie

2010-01-01

Este é um estudo da estereotipia existente na comunicação intercultural. O objetivo é entender a natureza do estereótipo mental e seu papel na comunicação entre interlocutores de culturas distintas. Para tanto, observa os estudantes estrangeiros em programas de intercâmbio no campus da Pontifícia Universidade Católica do Rio Grande do Sul. O estudo define o conceito de estereótipo e explicita seu papel na comunicação intercultural; verifica sua relevância na construção das narrativas entre cu...

VPLIV ULCEROZNEGA KOLITISA NA KAKOVOST ŽIVLJENJA

OpenAIRE

Dugi, Maja

2015-01-01

Pri vsaki bolezni je zelo pomembna kakovost življenja pacientov. Ulcerozni kolitis je kronična bolezen, ki je znana po obdobjih mirovanja in izbruhov, kar definitivno vpliva na posameznika, ki se s tem spopada. Sooča se z raznimi omejitvami, ki vplivajo na njegov vsakdan. Rezultati raziskave so pokazali, da je kakovost življenja bolnikov z ulceroznim kolitisom izrazito okrnjena. Ne le, da se spopadajo z bolečino, ampak tudi s psihičnimi in socialnimi posledicami, ki vplivajo na fizične aktivn...

Análise do efeito imunomodulador da ouabaína na inflamação e nocicepção

OpenAIRE

Vasconcelos, Danielle Ingrid Bezerra de

2011-01-01

A Ouabaína é um glicosídeo cardiotônico, inibidor da Na+/K+-ATPase, utilizada na clínica para o tratamento de insuficiência cardíaca. Atualmente, sabe-se que essa substância é endógena, e capaz de interferir em várias funções fisiológicas, inclusive em diversos aspectos do sistema imunológico. Apesar disso, pouco se sabe sobre seu envolvimento em processos inflamatórios e nociceptivos. Neste trabalho, foi avaliada a atividade da Ouabaína na inflamação aguda desencadeada pela ad...

Erythrocyte 22Na+ influx in hypertension

International Nuclear Information System (INIS)

Shalev, O.; Eaton, J.W.; Ben-Ishay, D.

1984-01-01

We assessed 22Na+ uptake by erythrocytes (RBC) from 38 individuals with essential hypertension and 37 healthy controls. All subjects were male, white, non-obese and with normal renal function, obviating sex, race, hormonal, ponderal and renal factors known to influence RBC Na+ handling. The mean +/- sem 22Na+ uptake of the patients was 284 +/- 16 mumole/liter RBC/hour while that of normal controls was 249 +/- 11 mumole/liter RBC/hour; although the difference reached borderline significance, individual values showed considerable overlap. Consequently, in our population, RBC 22Na+ uptake is not a reliable marker for essential hypertension. We believe that previous studies should be reassessed with regard to patients' characteristics and future studies employ rigorous criteria in selection of subjects

O grotesco na imagem publicitária

OpenAIRE

Silva, Maria João Barros

2013-01-01

O significado da palavra grotesco teve um começo puramente artístico numa descoberta, de imagens de figuras humanas deformadas e alteradas. No entanto, este foi evoluindo e adotando novos significados mais amplos e concretos na atualidade. É possível encontrar vários exemplos do grotesco em várias plataformas, como no cinema, na televisão e na literatura. Neste sentido, para se poder proceder ao estudo desta temática é fundamental a conquista do conhecimento sobre o estatuto do grotesco na pu...

Gravidez na adolescência: tendência na produção científica de enfermagem

OpenAIRE

Gurgel, Maria Glêdes Ibiapina; Alves, Maria Dalva Santos; Vieira, Neiva Francenely Cunha; Pinheiro, Patrícia Neyva da Costa; Barroso, Grasiela Teixeira

2008-01-01

A gravidez em adolescentes tem implicações biológica, psicológica, social, econômica e cultural. O estudo exploratório, descritivo e bibliográfico objetivou identificar as concepções da gravidez na adolescência, sujeito, vulnerabilidade e gênero, presentes na produção científica de Enfermagem. Foram selecionados intencionalmente quatro periódicos brasileiros e dois da América Latina indexados de 2002 a 2006 na Scientific Electronic Library. Dos 1.472 artigos identificados, 43 tinham como temá...

Neutralization of Na2PO4: Reaction between Na3PO4 and CaCL2

International Nuclear Information System (INIS)

Xia Shenglan; Wang Luning

1990-01-01

The results of reaction Na 3 PO 4 with CaCl 2 in water at ambient and higher temperature are described. The reaction rate of Na 3 PO 4 with CaCl 2 is slow at ambient temperature and the reaction is complete at 260 deg C after 2 h. The products are Ca(OH) 2 and Ca 5 (PO 4 ) 3 (OH). The quantity of them is dependent upon the quanity of Na 3 PO 4 and CaCl 2 contained in water, all of them control pH of water

Raman scattering and lattice stability of NaAlH{sub 4} and Na{sub 3}AlH{sub 6}

Energy Technology Data Exchange (ETDEWEB)

Yukawa, H. [Department of Materials Science and Engineering, Graduate School of Engineering, Nagoya University, Chikusa-Ku, Nagoya 464-8603 (Japan)], E-mail: hiroshi@numse.nagoya-u.ac.jp; Morisaku, N.; Li, Y.; Komiya, K.; Rong, R.; Shinzato, Y. [Department of Materials Science and Engineering, Graduate School of Engineering, Nagoya University, Chikusa-Ku, Nagoya 464-8603 (Japan); Sekine, R. [Department of Chemistry, Faculty of Science, Shizuoka University, 836 Ohya, Shizuoka 422-8529 (Japan); Morinaga, M. [Department of Materials Science and Engineering, Graduate School of Engineering, Nagoya University, Chikusa-Ku, Nagoya 464-8603 (Japan)

2007-10-31

In situ Raman spectroscopy measurements have been performed during the decomposition of NaAlH{sub 4} in order to investigate the transition from the four-coordinated complex anion, [AlH{sub 4}]{sup -}, in NaAlH{sub 4} to the six-coordinated complex anion, [AlH{sub 6}]{sup 3-}, in Na{sub 3}AlH{sub 6}. Also, the local geometry and the Al-H vibrations are analyzed theoretically by the first-principle calculations of the electronic structures. It is found that the Raman sift at 1765 cm{sup -1} for the Al-H stretching vibration in NaAlH{sub 4} shifts towards the higher frequency side, 1801 cm{sup -1} upon melting. This Raman spectrum for the liquid phase recovers to the original position when it is cooled down to room temperature before Na{sub 3}AlH{sub 6} start to appear. The Raman peak around 1800 cm{sup -1} is still observed after the decomposition of NaAlH{sub 4} occurs to precipitate Na{sub 3}AlH{sub 6}. However, this peak does not recover to its original position by cooling, but still persists in the sample cooled down to room temperature. From these results, the intermediate transition state during the decomposition of NaAlH{sub 4} into Na{sub 3}AlH{sub 6} is discussed. In addition, it is shown from a series of calculation that the highest frequency of the Al-H vibration correlates with the shortest Al-H bond length in the MAlH{sub 4}-type and its derivative complex hydrides.

Predstave o seksu u filmovima na temu postapokalipse

Directory of Open Access Journals (Sweden)

Ana Banić-Grubišić

2016-03-01

Full Text Available Rad se bavi načinima predstavljanja seksualnih odnosa u filmovima na temu postapokalipse. Razmatraju se različiti oblici/vrste seksualnih veza, koje se javljaju u postkataklizmičnom okruženju, u odnosu na dva tipa zajednica/društava koja nastaju nakon kraja sveta. Ti filmovi pokazuju koliko je ideja o nagonskoj, prirodnoj, biološkoj seksualnosti raširena u popularnoj imaginaciji – seks je u postapokalipsi predstavljen kao pokretačka sila, na isti način kao što je to i glad.

Calculation of the temperature distribution and thermal stresses in a gas turbine nozzle cooled by air film; Calculo de la distribucion de temperaturas y esfuerzos termicos en una tobera de turbina de gas enfriada por pelicula de aire

Energy Technology Data Exchange (ETDEWEB)

Hernandez R, Alejandro; Garcia I, Rafael; Mazur C, Zdislaw [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)

2004-07-01

temperaturas. Con las temperaturas correctamente importadas, se realizaron las simulaciones para el calculo de los esfuerzos termicos en la tobera.

23Na and 35/37Cl as NMR probes of growth and shape of sodium taurodeoxycholate micellar aggregates in the presence of NaCl.

Science.gov (United States)

Asaro, Fioretta; Feruglio, Luigi; Galantini, Luciano; Nardelli, Alessia

2013-02-15

The growth of the aggregates of the dihydroxylated bile salt sodium taurodeoxycholate (NaTDC) upon NaCl addition and the involvement of the counterion were investigated by NMR spectroscopy of monoatomic ionic species. (23)Na T(1) values from 0.015, 0.100, and 0.200 mol kg(-1) NaTDC solutions in D(2)O, at variable NaCl content, proved to be sensitive to the transition from primary to secondary aggregates, which occurs in the former sample, and to intermicellar interaction. Some (79)Br NMR measurements were performed on a 0.100 mol kg(-1) NaTDC sample added by NaBr in place of NaCl for comparison purposes. The (23)Na, (35)Cl, and (37)Cl double quantum filtered (DQF) patterns, from the 0.100 mol kg(-1) NaTDC sample, and (23)Na ones also from the 0.200 mol kg(-1) NaTDC one, in the presence of 0.750 mol kg(-1) NaCl, are a clear manifestation of motional anisotropy. Moreover, the DQF spectra of (23)Na and (37)Cl, which possess close quadrupole moments, display a striking similarity. The DQF lineshapes were simulated exploiting the Scilab environment to obtain an estimate of the residual quadrupole splitting magnitude. These results support the description of NaTDC micelles as cylindrical aggregates, strongly interacting at high ionic strengths, and capable of association with added electrolytes. Copyright © 2012 Elsevier Inc. All rights reserved.

Robust high pressure stability and negative thermal expansion in sodium-rich antiperovskites Na3OBr and Na4OI2

International Nuclear Information System (INIS)

Wang, Yonggang; Wen, Ting; Park, Changyong; Kenney-Benson, Curtis; Pravica, Michael; Zhao, Yusheng; Yang, Wenge

2016-01-01

The structure stability under high pressure and thermal expansion behavior of Na 3 OBr and Na 4 OI 2 , two prototypes of alkali-metal-rich antiperovskites, were investigated by in situ synchrotron X-ray diffraction techniques under high pressure and low temperature. Both are soft materials with bulk modulus of 58.6 GPa and 52.0 GPa for Na 3 OBr and Na 4 OI 2 , respectively. The cubic Na 3 OBr structure and tetragonal Na 4 OI 2 with intergrowth K 2 NiF 4 structure are stable under high pressure up to 23 GPa. Although being a characteristic layered structure, Na 4 OI 2 exhibits nearly isotropic compressibility. Negative thermal expansion was observed at low temperature range (20–80 K) in both transition-metal-free antiperovskites for the first time. The robust high pressure structure stability was examined and confirmed by first-principles calculations among various possible polymorphisms qualitatively. The results provide in-depth understanding of the negative thermal expansion and robust crystal structure stability of these antiperovskite systems and their potential applications

Thermoluminescence and F centers of manganese doped NaCl and NaCl-CKl crystals exposed to gamma radiation

International Nuclear Information System (INIS)

Somera, L.; Cruz Z, E.; Roman L, J.; Hernandez A, J. M.; Murrieta S, H.

2015-10-01

Alkali halides crystals doped with rare earths or transition metals have been widely studied due to the luminescence properties. In particular, NaCl and KCl single crystals present thermally stimulated luminescence (Tl) after gamma irradiation. The NaCl and the NaCl KCl mixed crystal doped with manganese (MnCl 2 ) impurity were grown by using the Czochralski method. The emission characteristic of Mn 2+ was observed at 543 nm. The crystals were exposed between 0.02 and 10 kGy gamma dose from 60 Co irradiator. Optical absorption at room temperature shows the peaked band at 452 nm corresponding to the manganese impurity. The F bands, was ascribed to the electron trapped in the anion vacancy in the lattice, were obtained at 452 nm and 455 nm belonging to NaCl:Mn and NaCl KCl:Mn, respectively. The F band increases as the doses increase and it was bleaching by the UV light at 470 nm. The glow curves of the samples show the first glow peak between 92-103 degrees C, while the second main peak was observed at 183 degrees C for the undoped NaCl and at 148 and 165 degrees C for the NaCl:Mn and NaCl-KCl:Mn, respectively. The main peak was slowly bleaching when the irradiated sample was illuminated with F (470 nm) light. Optical bleaching confirms that the F center has an important participation in the thermoluminescent response. The glow curves structure from the thermal bleaching suggests the participation of different kind of traps. Also, the kinetics parameters such as activation energy (E), frequency factor (s) and the kinetic order (b) were investigated. (Author)

Thermoluminescence and F centers of manganese doped NaCl and NaCl-CKl crystals exposed to gamma radiation

Energy Technology Data Exchange (ETDEWEB)

Somera, L.; Cruz Z, E.; Roman L, J. [UNAM, Instituto de Ciencias Nucleares, Circuito Exterior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico); Hernandez A, J. M.; Murrieta S, H., E-mail: ecruz@nucleares.unam.mx [UNAM, Instituto de Fisica, Circuito Exterior, Ciudad Universitaria, 04510 Mexico D. F. (Mexico)

2015-10-15

Alkali halides crystals doped with rare earths or transition metals have been widely studied due to the luminescence properties. In particular, NaCl and KCl single crystals present thermally stimulated luminescence (Tl) after gamma irradiation. The NaCl and the NaCl KCl mixed crystal doped with manganese (MnCl{sub 2}) impurity were grown by using the Czochralski method. The emission characteristic of Mn{sup 2+} was observed at 543 nm. The crystals were exposed between 0.02 and 10 kGy gamma dose from {sup 60}Co irradiator. Optical absorption at room temperature shows the peaked band at 452 nm corresponding to the manganese impurity. The F bands, was ascribed to the electron trapped in the anion vacancy in the lattice, were obtained at 452 nm and 455 nm belonging to NaCl:Mn and NaCl KCl:Mn, respectively. The F band increases as the doses increase and it was bleaching by the UV light at 470 nm. The glow curves of the samples show the first glow peak between 92-103 degrees C, while the second main peak was observed at 183 degrees C for the undoped NaCl and at 148 and 165 degrees C for the NaCl:Mn and NaCl-KCl:Mn, respectively. The main peak was slowly bleaching when the irradiated sample was illuminated with F (470 nm) light. Optical bleaching confirms that the F center has an important participation in the thermoluminescent response. The glow curves structure from the thermal bleaching suggests the participation of different kind of traps. Also, the kinetics parameters such as activation energy (E), frequency factor (s) and the kinetic order (b) were investigated. (Author)

Occlusion of /sup 22/Na+ and /sup 86/Rb+ in membrane-bound and soluble protomeric alpha beta-units of Na,K-ATPase

Energy Technology Data Exchange (ETDEWEB)

Vilsen, B.; Andersen, J.P.; Petersen, J.; Jorgensen, P.L.

1987-08-05

In this work, we examined occlusion of /sup 22/Na+ and /sup 86/Rb+ in membranous and detergent-solubilized Na,K-ATPase from outer renal medulla. Optimum conditions for occlusion of /sup 22/Na+ were provided by formation of the phosphorylated complex from the beta,gamma-bidentate complex of chromium (III) with ATP (CrATP). Release of occluded cations occurred at equally slow rates in soluble and membrane-bound Na,K-ATPase. Values of /sup 22/Na+ occlusion as high as 11 nmol/mg of protein were measured, corresponding to 1.8-2.7 mol of Na+/mol of phosphorylated Na,K-ATPase as determined by /sup 32/P incorporation from (gamma-/sup 32/P)CrATP. Maximum capacity for phosphorylation from (gamma-/sup 32/P)CrATP was 6 nmol/mg of protein and equal to capacities for binding of (48V)vanadate and (/sup 3/H)ouabain. The stoichiometry for occlusion of Rb+ was close to 2 Rb+ ions/phosphorylation site. In an analytical ultracentrifuge, the soluble Na+- or Rb+-occluded complexes showed sedimentation velocities (S20,w = 6.8-7.4) consistent with monomeric alpha beta-units. The data show that soluble monomeric alpha beta-units of Na,K-ATPase can occlude Rb+ or Na+ with the same stoichiometry as the membrane-bound enzyme. The structural basis for occlusion of cations in Na,K-ATPase is suggested to be the formation of a cavity inside a monomeric alpha beta-unit constituting the minimum protein unit required for active Na,K-transport.

Europlanet NA2 Science Networking

Science.gov (United States)

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

2013-04-01

Europlanet RI / NA2 Science Networking [1] focused on determining the major goals of current and future European planetary science, relating them to the Research Infrastructure that the Europlanet RI project [2] developed, and placing them in a more global context. NA2 also enhanced the ability of European planetary scientists to participate on the global scene with their own agenda-setting projects and ideas. The Networking Activity NA2 included five working groups, aimed at identifying key science issues and producing reference books on major science themes that will bridge the gap between the results of present and past missions and the scientific preparation of the future ones. Within the Europlanet RI project (2009-2012) the NA2 and NA2-WGs organized thematic workshops, an expert exchange program and training groups to improve the scientific impact of this Infrastructure. The principal tasks addressed by NA2 were: • Science activities in support to the optimal use of data from past and present space missions, involving the broad planetary science community beyond the "space club" • Science activities in support to the preparation of future planetary missions: Earth-based preparatory observations, laboratory studies, R&D on advanced instrumentation and exploration technologies for the future, theory and modeling etc. • Develop scientific activities, joint publications, dedicated meetings, tools and services, education activities, engaging the public and industries • Update science themes and addressing the two main scientific objectives • Prepare and support workshops of the International Space Science Institute (ISSI) in Bern and • Support Trans National Activities (TNAs), Joined Research Activities (JRAs) and the Integrated and Distributed Information Service (IDIS) of the Europlanet project These tasks were achieved by WG workshops organized by the NA2 working groups, by ISSI workshops and by an Expert Exchange Program. There were 17 official WG

Tanzania Journal of Health Research - Vol 20, No 2 (2018)

African Journals Online (AJOL)

Socio-demographic determinants of dengue infection during an outbreak in Dar es Salaam City, Tanzania · EMAIL FREE FULL TEXT EMAIL FREE FULL TEXT DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT. Neema Camara, Billy Ngasala, Germana Leyna, Ahmed Abade, Susan F. Rumisha, Ndekya M. Oriyo, Leonard ...

NA61/SHINE ion program

CERN Document Server

Mackowiak, Maja

2010-01-01

The Super Proton Synchrotron (SPS) at CERN covers one of the most interesting regions of the phase diagram (T - \\mu_{B}) of strongly interacting matter. The study of central Pb+Pb collisions by NA49 indicate that the threshold for deconfinement is reached already at the low SPS energies. Theoretical considerations predict a critical point of strongly interacting matter at energies accessible at the SPS. The NA61/SHINE experiment, a successor of the NA49 project, will study hadron production in p+p, p+A, h+A, and A+A reactions at various energies. The broad physics program includes the investigation of the properties of strongly interacting matter, as well as precision measurements of hadron spectra for the T2K neutrino experiment and for the Pierre Auger Observatory and KASCADE cosmic-ray projects. The main physics goals of the NA61/SHINE ion program are to study the properties of the onset of deconfinement at low SPS energies and to find signatures of the critical point of strongly interacting matter. To ach...

Armas na escola: que fazer?

Directory of Open Access Journals (Sweden)

Raymundo de Lima

2010-09-01

Full Text Available

Um aluno portava um revólver na sala de aula de uma escola de Maringá (O Diário, 30/07/2010. Ele pegou arma do pai, sem que este soubesse, para se proteger de garotos que o intimidavam. Trata-se de um caso isolado ou é hora de a escola tomar medidas preventivas? Semanas antes, tiros foram disparados dentro de uma faculdade da mesma cidade. O autor dos disparos está preso, e a faculdade tenta apagar as marcas com publicidade positiva na Tv. Em Campo Mourão, cidade a cerca de uma hora de Maringá, duas meninas foram mortas e enterradas na escola.

Imperfections study of the smoky quartz from Bahia by X-ray diffraction

International Nuclear Information System (INIS)

D'Aguiar Neto, M.M.F.

1974-01-01

X-ray diffraction techniques were used to study the type of point defects in Smoky quartz from Itambe and Vitoria da Conquista in Bahia. The power method, using the Seemann Bohlin camara (back refletion), was utilized in the analysis of the policrystals, while the monocrystals were studied by means of the precession camara. The positions occupied by the defects in the crystal net were calculated. The results show that while the defects of substitutional impurities predominate in the quartz from Itambe, in the quartz from Vitoria da Conquista the substitutional defects exist in comparable proportions that the interstital ones. Isochronous annealing curves, for both type of smoky quartz indicate an increase in the net parameter to temperature values above the annealing temperatures. Was formulated the hypothesis that providing a thermal energy greater than that of annealing is used, new interstitial defects would be created as a result of a thermic diffusion mechanism. (C.D.G.) [pt

Microbiological Studies on the Influence of Combined Processes of Heat and Irradiation on the Survival of Saccharomyces Cerevisiae Var. Ellipsoideus; Etudes Microbiologiques sur l'Influence d'un Traitement Mixte par Chauffage et Irradiation sur la Survie de Saccharomyces Cerevisiae Var. Ellipsoideus; Mikrobiologicheskie issledovaniya vliyaniya sovmestnykh protsessov nagreva i oblucheniya na vyzhivanie saccharomyces Cerevisiae Var. Ellipsoideus; Estudios Microbiologicos de la Influencia del Calentamiento e Irradiacion Combinados Sobre la Supervivencia del Saccharomyces Cerevisiae Var. Ellipsoideus

Energy Technology Data Exchange (ETDEWEB)

Stehlik, G.; Kaindl, K. [Institute for Biology and Agriculture, Reaktorzentrum, Seibersdorf (Austria)

1966-11-15

survie obtenues a des temperatures differentes, on constate que, dans le cas d'une irradiation a une temperature superieure a 40 Degree-Sign C, le traitement simultane produit un effet synergique prononce, qui atteint deux ordres de grandeur pour 150 krad. En partant de ces resultats, on procede actuellement a une etude des possibilites techniques de ce traitement sur des jus de pomme et de raisin. (author) [Spanish] Uno de los principales temas de investigacion incluidos en el programa internacional relativo a la irradiacion de frutas y zumos de fruta que se viene ejecutando en Seibersdorf se refiere al problema de la radio- sensibilizacion de microorganismos. Para estudiar los efectos del tratamiento termico y del tratamiento por irradiacion sobre la supervivencia de las celulas de levadura (formacion de colonias), se sometio a un tratamiento combinado de aplicacion de calor y de irradiacion gamma (fuente: {sup 60}Co), al comienzo de su fase de desarrollo logaritmico, una cepa de elevada radiorresistencia -Saccharomyces cerevisiae var. ellipsoideus - cultivada en un medio nutritivo semisintetico. El calor se aplico inmediatamente antes de la irradiacion, durante esta o inmediatamente despues. Las temperaturas estuvieron comprendidas entre 20 y 52,5 Degree-Sign C. La irradiacion se realizo con dosis de hasta 0,3 x 10{sup 6} rad, en un tubo de vidrio, bien aireado. El efecto inhibidor de este tratamiento combinado depende del orden en que se suceden la aplicacion del calor y la irradiacion, habiendose llegado a las siguientes conclusiones: la combinacion mas eficaz consiste en simultanear el tratamiento termico con el tratamiento por irradiacion; esta combinacion resulta menos eficaz cuando la irradiacion a la temperatura ambiente tiene lugar a continuacion del tratamiento termico; la combinacion de eficacia minima consiste en proceder al tratamiento termico despues de haberse efectuado la irradiacion a la temperatura ambiente. El tratamiento termico combinado con la

Isotope separation of 22Na and 24Na with using light induced drift effect

International Nuclear Information System (INIS)

Hradecny, C.; Tethal, T.; Ermolaev, I.M.; Zemlyanoj, S.G.; Zuzaan, P.

1993-01-01

The LIDIS (Light Drift Isotope Separation) separator without a gas flow is discussed. It is shown, that atomization degree of the separated isotopes limited real separation coefficient. The better buffer gas purification allowed to increase the experimental separation factor of 22 Na and 24 Na isotopes up to 25. The new experimental set up allow to increase the separation efficiency up to 50%. 12 refs.; 5 figs

MOBILNO POSLOVANJE NA PRIMERU UPORABE MICROSOFT DYNAMICS CRM

OpenAIRE

Duh, Tamara

2016-01-01

Hitro razvijajoči se svet nas spodbuja k hitremu reagiranju na novosti, ki se pojavljajo na trgu. Prav zaradi tega je danes zelo pomembno upravljati z mobilnimi napravami, da se lahko hitro in brez težav soočimo z morebitnimi težavami oz. zagatami. Prav iz tega razloga je mobilno poslovanje ena izmed inovativnih rešitev, ki ljudem omogoča seznanjenost z informacijami na vsakem koraku in omogoča hiter odziv na spremembe. Prav ta rešitev omogoča podjetjem, da so konkurenčna in hkrati lahko hitr...

Usando a antimatéria na medicina moderna

OpenAIRE

Machado,A.C.B.; Pleitez,V.; Tijero,M.C.

2006-01-01

Neste artigo, fazemos uma breve exposição de como um dos conceitos fundamentais da física moderna, a existência de antimatéria, tem aplicação na medicina, na chamada tomografia por emissão de pósitrons (PET na sigla em inglês). Ela consiste na produção de imagens tomográficas digitais do organismo que são obtidas pela detecção da radiação produzida na aniquilação do pósitron com o elétron.

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

In vivo PTH provokes apical NHE3 and NaPi2 redistribution and Na-K-ATPase inhibition

DEFF Research Database (Denmark)

Zhang, Y; Norian, J M; Magyar, C E

1999-01-01

and to determine whether the same cellular signals drive the changes in apical and basolateral transporters. PTH-(1-34) (20 U), which couples to adenylate cyclase (AC), phospholipase C (PLC), and phospholipase A2 (PLA2), or [Nle8,18,Tyr34]PTH-(3-34) (10 U), which couples to PLC and PLA2 but not AC, were given....../diuresis and NHE3 and NaPi2 internalization, and that Na-K-ATPase inhibition is not secondary to depressed apical Na+ transport....

Aspectos valorizados por porfissionais de enfermagem na higiene pessoal e na higiene corporal do paciente

Directory of Open Access Journals (Sweden)

Elóide André Oliveira

2003-10-01

Full Text Available Survey descritivo, com o qual se objetivou identificar que aspectos da higiene corporal são valorizados pelos componentes da equipe de enfermagem, na higiene corporal pessoal e na higiene corporal do paciente. A pesquisa foi desenvolvida em oito instituições públicas de saúde e a amostra foi composta por 126 profissionais de enfermagem, correspondendo a 12,8% do total de 986 componentes das equipes de enfermagem destas instituições. Na higiene corporal pessoal, chamou a atenção o fato de que os cuidados com as unhas e com os cabelos tenham suplantado, no número de citações dos profissionais de enfermagem, aspectos básicos como o cuidado com as mãos. Na higiene corporal do paciente, o banho foi o aspecto considerado mais importante pelas três categorias profissionais; a higiene oral, pelas(os enfermeiras(os e auxiliares de enfermagem; e as unhas, pelas(os enfermeiras(os e técnicas(os de enfermagem.

Modulation of contraction by intracellular Na+ via Na(+)-Ca2+ exchange in single shark (Squalus acanthias) ventricular myocytes.

Science.gov (United States)

Näbauer, M; Morad, M

1992-01-01

1. The effect of direct alteration of intracellular Na+ concentration on contractile properties of whole-cell clamped shark ventricular myocytes was studied using an array of 256 photodiodes to monitor the length of the isolated myocytes. 2. In myocytes dialysed with Na(+)-free solution, the voltage dependence of Ca2+ current (ICa) and contraction were similar and bell shaped. Contractions activated at all voltages were completely suppressed by nifedipine (5 microM), and failed to show significant tonic components, suggesting dependence of the contraction on Ca2+ influx through the L-type Ca2+ channel. 3. In myocytes dialysed with 60 mM Na+, a ICa-dependent and a ICa-independent component of contraction could be identified. The Ca2+ current-dependent component was prominent in voltages between -30 to +10 mV. The ICa-independent contractions were maintained for the duration of depolarization, increased with increasing depolarization between +10 to +100 mV, and were insensitive to nifedipine. 4. In such myocytes, repolarization produced slowly decaying inward tail currents closely related to the time course of relaxation and the degree of shortening prior to repolarization. 5. With 60 mM Na+ in the pipette solution, positive clamp potentials activated decaying outward currents which correlated to the size of contraction. These outward currents appeared to be generated by the Na(+)-Ca(2+)-exchanger since they depended on the presence of intracellular Na+, and were neither suppressed by nifedipine nor by K+ channel blockers. 6. The results suggest that in shark (Squalus acanthias) ventricular myocytes, which lack functionally relevant Ca2+ release pools, both Ca2+ channel and the Na(+)-Ca2+ exchanger deliver sufficient Ca2+ to activate contraction, though the effectiveness of the latter mechanism was highly dependent on the [Na+]i. PMID:1338467

KANDUNGAN NATRIUM (Na DAN GARAM (NaCl DALAM IKAN ASIN KERING MENTAH DAN GORENG DI PASAR ANYAR BOGOR

Directory of Open Access Journals (Sweden)

Heru Yuniati

2012-11-01

Full Text Available Telah dilakukan penelitian untuk mengetahui kandungan natrium (Na dan garam (NaCl dalam 10 jenis ikan asin kering yang beredar di Pasar Anyar Bogor. Analisis natrium dilakukan terhadap ikan asin mentah, setelah dicuci, dan setelah digoreng dengan menggunakan flamefometer. Analisis garam dilakukan dengan titrasi argentometri terhadap ikan asin mentah. Hasil analisis menunjukkan, kandungan Na dan garam dalam ikan asin sangat beragam besarnya berturut-turut berkisar antara 0,3-8,1% dan 5,7-21,2%. Ikan asin yang mempunyai kadar Na dan garam tinggi adalah ikan sepat, peda putih dan gabus. Jumlah air dalam ikan asin juga bervariasi, berkisar antara 10,3-46,8%. pencucian dan penggorengan dapat menurunkan kadar garam ataupun natrium sebesar 37,4%.

Aprendizagem como/na prática

Directory of Open Access Journals (Sweden)

Jean Lave

2015-12-01

Full Text Available ResumoEste artigo considera como o estudo da cultura e da aprendizagem pode ser de particular relevância para o campo da antropologia sociocultural em geral. O termo mais importante na expressão “cultura & aprendizagem” talvez seja o logograma “&” – ou seja, coloca-se a questão sobre o que conecta cultura e aprendizagem, perguntando-se como esses termos estão relacionados. Como devemos compreender cultura e aprendizagem como instâncias produtoras delas próprias, e uma da outra, na prática? Recalibrando em termos relacionais, podemos dizer que não é possível abordar a “aprendizagem” ou “cultura e aprendizagem” sem o seu emaranhamento na vida político-econômica, nas lutas e disputas históricas, em suas coerências e incoerências, e na produção relacional e histórica da vida cotidiana. Através das lentes da teoria da prática social, os estudos etnográficos sobre aprendizagem na prática oferecem diferentes entendimentos sobre como certa vida e certas disputas e incoerências são produzidas.

Metodologija analize stroškov in koristi za investicije v prometno infrastrukturo na osnovi Poročila vplivov na okolje

OpenAIRE

Podvornik, Nina

2016-01-01

Povečane potrebe po prometnem omrežju vodijo k dodatnim prometnim investicijam, ki so ne glede na njihov obseg, postavitev v prostor ter učinkovitost pomemben dejavnik gospodarskega razvoja. Investicije v prometno infrastrukturo lahko na sam razvoj vplivajo pozitivno (dvig gospodarske rasti, kakovost življenja, dostopnost idr.) in tudi negativno (različni vplivi na okolje). Ker so prometne investicije zelo obsežne, je vsestranska ocena le-teh ključnega pomena pri samem prometnem načrtovanju v...

Agmag Igbo dka Ngwar n'kwalite Ezi Nchekwa na Nkwsiike haobodo

African Journals Online (AJOL)

Ka Najira nwerechara onwe ya n'af 1960, olileanya tt mamala ya b na ihe ga-adz mma. Mana ka oge na-aga, a chptara na ihe na-akawanye nj. Usoro chch d iche iche daptara. Nd am na nd nkt achala mana nd gara n'ihu na-akawanye nj. O bu ihe doro anya na chch ha b nke nchgbu na fnfju akpa. N'agbanyegh na ...

Regulation of Epithelial Sodium Transport via Epithelial Na+ Channel

Science.gov (United States)

Marunaka, Yoshinori; Niisato, Naomi; Taruno, Akiyuki; Ohta, Mariko; Miyazaki, Hiroaki; Hosogi, Shigekuni; Nakajima, Ken-ichi; Kusuzaki, Katsuyuki; Ashihara, Eishi; Nishio, Kyosuke; Iwasaki, Yoshinobu; Nakahari, Takashi; Kubota, Takahiro

2011-01-01

Renal epithelial Na+ transport plays an important role in homeostasis of our body fluid content and blood pressure. Further, the Na+ transport in alveolar epithelial cells essentially controls the amount of alveolar fluid that should be kept at an appropriate level for normal gas exchange. The epithelial Na+ transport is generally mediated through two steps: (1) the entry step of Na+ via epithelial Na+ channel (ENaC) at the apical membrane and (2) the extrusion step of Na+ via the Na+, K+-ATPase at the basolateral membrane. In general, the Na+ entry via ENaC is the rate-limiting step. Therefore, the regulation of ENaC plays an essential role in control of blood pressure and normal gas exchange. In this paper, we discuss two major factors in ENaC regulation: (1) activity of individual ENaC and (2) number of ENaC located at the apical membrane. PMID:22028593

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...

Risbjerg: Historisk stemmeskred med NA

DEFF Research Database (Denmark)

Thomsen, Søren Risbjerg

2007-01-01

ANALYSE: NA flytter 12,3 pct. af stemmerne i majs meningsmålinger - historisk mange vælgere på en måned, skriver professor Risbjerg. Udgivelsesdato: 3. juni 2007......ANALYSE: NA flytter 12,3 pct. af stemmerne i majs meningsmålinger - historisk mange vælgere på en måned, skriver professor Risbjerg. Udgivelsesdato: 3. juni 2007...

Dissolution of targets for the production of Mo-99: Part 1. Influence of NaOH concentration and the addition of NaNO{sub 3} and NaNO{sub 2} on the dissolution time

Energy Technology Data Exchange (ETDEWEB)

Camilo, Ruth L.; Araujo, Izilda da C.; Mindrisz, Ana C.; Forbicini, Christina A.L.G. de O., E-mail: rcamilo@ipen.br, E-mail: icaraujo@ipen.br, E-mail: acmindri@ipen.br, E-mail: cforbici@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN/SP), Sao Paulo, SP (Brazil)

2011-07-01

Faced with global crisis in the production of radioisotope {sup 99}Mo, which product of decay, {sup 99}mTc, is the tracer element most often used in nuclear medicine and accounts for about 80% of all diagnostic procedures in vivo, since September 2008 Brazil is developing the project called Brazilian Multipurpose Reactor (RMB). Within the Brazilian Nuclear Program (PNB) the construction of the RMB, is seen as a long term solution to meet all domestic demand relative to the supply of radioisotopes and radiopharmaceuticals. In the process to be studied to obtain {sup 99}Mo from irradiated UA1{sub x}-A1 LEU targets employing alkaline dissolution, processing time should be minimized, considering the short half life of {sup 99}Mo and {sup 99}mTc, about 66 h and 6 h, respectively. That makes dissolution time a significant factor in the development of the process. This paper presents the results of alkaline dissolution of scraps of Al, used to simulate the dissolution process of UA1{sub x}-A1 targets. Al corresponds to about 79% of the total weight of the UA1{sub x}-A1 target. The effect of NaOH concentration on dissolution time for the interval of 1 to 3.5 mol.L-1 was studied, keeping the molar ratio in 1Al:2.16NaOH and the initial temperature of 88 degree C. The influence of reagent composition over dissolution time was studied using three different solutions: a) 3 mol.L{sup -1} NaOH, b) 3 mol.L{sup -1} NaOH/NaNO{sub 3} and c) 3 mol.L{sup -1} NaOH/NaNO{sub 2}, keeping the same molar ratio and temperature. The results showed that the dissolution time decreases with increasing NaOH concentration and the addition of NaNO{sub 3} or NaNO{sub 2} in the NaOH solution reduces both dissolution time and volume of gases released. (author)

Crystal Structure of Na3MoCl6

Directory of Open Access Journals (Sweden)

Martin Beran

2011-07-01

Full Text Available The ternary chloride Na3MoCl6 is obtained as red crystals from a disproportionation reaction of molybdenum dichloride, {Mo6}Cl12, in an acidic NaCl/AlCl3 melt at 350 °C. The crystal structure (trigonal, P-31c, a = 687.1(1, c = 1225.3(2 pm, Z = 2, V = 501,0(1 106 pm3 is that of Na3CrCl6: within a hexagonal closest-packing of chloride ions two thirds of the octahedral voids are filled between the AB double layers with Na+/Mo3+, and between the BA layers with Na+.

The Case of Exploding Lantana and the Lessons it Can Teach Us

Indian Academy of Sciences (India)

Invasive alien species are a growing conservation problem,worldwide. There are over 200 invasive plants in India, ofwhich Lantana camara is one of the best known. This articlelooks at a brief history of Lantana's arrival and spread acrossthe Indian subcontinent and the lessons that conservation biologistscan learn from it.

934 Snippets of Physics

Indian Academy of Sciences (India)

Young to old inflorescences of a colour variant of the pernicious weed Lantana camara. Freshly opened flowers are yellow and change gradu- ally to orange, scarlet and magenta. See p.1003. Eugene Paul Wigner. (1902–1995). ( Illustration: Subhankar Biswas ). Front Cover. Back Cover. 931. Classroom. An Easily Con-.

Biological activities of four essential oils against Anopheles gambiae ...

African Journals Online (AJOL)

The control of malaria is still a challenge partly due to mosquito's resistance to current available insecticides. The aim of this work was to evaluate the ovicidal, larvicidal and repellent activities of Lantana camara, Hyptis suaveolens, Hyptis spicigera and Ocimum canum essential oils against Anopheles gambiae s.l. ...

NEWS: Conference diary

Science.gov (United States)

2000-03-01

18 - 20 October 2000 Santa Fe, Argentina 5th Symposium of Investigators in Physics Education. Info: Ing Cristina Camara, GIDEAF Departamento de Fisica, Facultad de Ingenieria Quimica - UNL, Santiago del Estero 2829, 3000 Santa Fe, Argentina (ccamara@fiqus.unl.edu.ar or www.unl.edu.ar/sief5 )

Diffusion of calcium in pure and doped NaCl; Diffusion du calcium dans NaCl pur et dope

Energy Technology Data Exchange (ETDEWEB)

Slifkin, L; Brebec, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1969-07-01

We have determined, by diffusion experiments of Ca in pure and doped NaCl, the activation energy for the calcium jumps and the binding energy between calcium ion and vacancy. (authors) [French] Nous avons determine, par des mesures de diffusion du Ca dans NaCl pur et NaCl dope avec CaCl{sub 2}, l'energie d'activation relative aux sauts du calcium et l'energie de liaison lacune-calcium. (auteurs)

Wizerunek ateisty i jego miejsce na konfesyjnej mapie świata na Śląsku Cieszyńskim

Directory of Open Access Journals (Sweden)

Zbigniew Greń

2017-12-01

Full Text Available The image of the atheist and his place on the confessional map of the world in Cieszyn Silesia The aim of this article is to create an image of the atheist based on historical and contemporary sources. The history of the concept of the atheist is described on the basis of the regional press, the contemporary picture of the concept – on the basis of the results of a questionnaire and discussions on religious topics on regional websites. The analysis showed that the concept of the atheist is treated as a term equivalent to the terms of members of different churches. The research shows not only the image of the atheist, but also its place in the system of perception of religious differences.   Wizerunek ateisty i jego miejsce na konfesyjnej mapie świata na Śląsku Cieszyńskim Celem niniejszego artykułu jest stworzenie obrazu ateisty na podstawie źródeł historycznych i współczesnych. Historia pojęcia ateisty została opisana na podstawie prasy regionalnej, współczesny obraz – na podstawie wyników ankiet i dyskusji na tematy religijne na regionalnych stronach internetowych. Analiza wykazała, że pojęcie ateisty jest traktowane jako pojęcie równorzędne z określeniami członków różnych Kościołów. W wyniku badań przedstawiono nie tylko wizerunek ateisty, lecz także jego miejsce w systemie postrzegania różnic wyznaniowych.

Mabadiliko Ya Kifonolojia Na Kimofolojia Wakati Wa Utohozi Wa ...

African Journals Online (AJOL)

Mwingiliano wa lugha ya Kiswahili na Kiarabu una historia ndefu kidogo. Inasemekana Waarabu walianza muwasala na 'Waswahili' tangu karne ya kwanza (BK) (Polome 1967:9). Kutokana na muwasala huo wa muda mrefu, lugha hizi mbili (Kiarabu na Kiswahili) zimeathiriana sana. Lakini kuna maoni kwamba Kiarabu ...

Aqueous partial molar heat capacities and volumes for NaReO4 and NaTcO4

International Nuclear Information System (INIS)

Lemire, R.J.; Saluja, P.P.S.; Campbell, A.B.

1989-01-01

As part of the Canadian Nuclear Fuel Waste Management Program, data are required to model the equilibrium thermodynamic behavior of key radionuclides at temperatures above 25 degree C. A flow microcalorimeter/densimeter system has been commissioned to measure heat capacities and densities of solutions containing radioactive species. Measurements for solutions of aqueous NaReO 4 (a common analogue for NaTcO 4 ) were made at seven temperatures (15 to 100 degree C) over the concentration range 0.05 to 0.2 mol·kg -1 . Subsequently, measurements were made for NaTcO 4 solutions under similar conditions. The heat capacity and density data are analyzed using Pitzer's ion-interaction model, and values of the NaReO 4 partial molar heat capacities are compared to literature values based on integral heats of solution. The agreement between the two sets of NaReO 4 data is good below 75 degree C, but only fair at the higher temperatures. Values of the partial molar volumes have also been derived. The uncertainties introduced by using thermodynamic data for ReO 4 - , in the absence of data for TcO 4 - , are discussed

Effects of dietary Na+ deprivation on epithelial Na+ channel (ENaC, BDNF, and TrkB mRNA expression in the rat tongue

Directory of Open Access Journals (Sweden)

Stähler Frauke

2009-03-01

Full Text Available Abstract Background In rodents, dietary Na+ deprivation reduces gustatory responses of primary taste fibers and central taste neurons to lingual Na+ stimulation. However, in the rat taste bud cells Na+ deprivation increases the number of amiloride sensitive epithelial Na+ channels (ENaC, which are considered as the "receptor" of the Na+ component of salt taste. To explore the mechanisms, the expression of the three ENaC subunits (α, β and γ in taste buds were observed from rats fed with diets containing either 0.03% (Na+ deprivation or 1% (control NaCl for 15 days, by using in situ hybridization and real-time quantitative RT-PCR (qRT-PCR. Since BDNF/TrkB signaling is involved in the neural innervation of taste buds, the effects of Na+ deprivation on BDNF and its receptor TrkB expression in the rat taste buds were also examined. Results In situ hybridization analysis showed that all three ENaC subunit mRNAs were found in the rat fungiform taste buds and lingual epithelia, but in the vallate and foliate taste buds, only α ENaC mRNA was easily detected, while β and γ ENaC mRNAs were much less than those in the fungiform taste buds. Between control and low Na+ fed animals, the numbers of taste bud cells expressing α, β and γ ENaC subunits were not significantly different in the fungiform, vallate and foliate taste buds, respectively. Similarly, qRT-PCR also indicated that Na+ deprivation had no effect on any ENaC subunit expression in the three types of taste buds. However, Na+ deprivation reduced BDNF mRNA expression by 50% in the fungiform taste buds, but not in the vallate and foliate taste buds. The expression of TrkB was not different between control and Na+ deprived rats, irrespective of the taste papillae type. Conclusion The findings demonstrate that dietary Na+ deprivation does not change ENaC mRNA expression in rat taste buds, but reduces BDNF mRNA expression in the fungiform taste buds. Given the roles of BDNF in survival of

Hydrogen production by sodium borohydride in NaOH aqueous solution

Science.gov (United States)

Wang, Q.; Zhang, L. F.; Zhao, Z. G.

2018-01-01

The kinetics of hydrolysis reaction of NaBH4 in NaOH aqueous solution is studied. The influence of pH of the NaOH aqueous solution on the rate of hydrogen production and the hydrogen production efficiency are studied for the hydrolysis reaction of NaBH4. The results show that the activation energy of hydrolysis reaction of NaBH4 increased with the increase of the initial pH of NaOH aqueous solution.With the increasing of the initial pH of NaOH aqueous solution, the rate of hydrogen production and hydrogen production efficiency of NaBH4 hydrolysis decrease.

Altered Regulation of type 3 Na+/H+ exchanger, type 1 Na+/HCO3- cotransporter, and Na+,K+-ATPase in the Kidney of Rats with Experimental Rhabdomyolysis

Science.gov (United States)

Ma, Seong Kwon; Bae, Eun Hui; Lee, JongUn; Kim, Sun Young; Kim, Sung Zoo; Choi, Ki Chul

2007-01-01

Metabolic acidosis was shown to correlate with deterioration of renal function in patients with rhabdomyolysis. The present study was aimed to investigate whether the changes of type 3 Na+/H+ exchanger (NHE3), type 1 Na+/HCO3- cotransporter (NBC1), and Na+,K+-ATPase α1 subunit may play a role in the pathogenesis of metabolic acidosis in glycerol-induced experimental rhabdomyolysis. Male Sprague-Dawley rats were deprived of fluid intake for 24 hours, and then were injected with 50% glycerol in normal saline (10 mL/kg, intramuscularly). At 24 hours after the glycerol injection, rats were sacrificed by decapitation. Control rats were injected with normal saline. The protein expression of NHE3, NBC1 and Na+,K+-ATPase α1 subunit was determined in the cortex of the kidney by immunoblotting and immunohistochemistry. Following the treatment of glycerol, creatinine clearance was significantly decreased, and high anion gap metabolic acidosis developed. In the experimental group, the expression of Na+,K+-ATPase α1 subunit was significantly decreased in the cortex of the kidney. On the contrary, the expression of NHE3 and NBC1 was significantly increased. Immunohistochemical analyses confirmed the immunoblotting data. In conclusion, the coordinate up-regulation of NHE3 and NBC1 may play an adaptive role against the metabolic acidosis in glycerol-induced rhabdomyolysis. PMID:24459502

K⁺ congeners that do not compromise Na⁺ activation of the Na⁺,K⁺-ATPase

DEFF Research Database (Denmark)

Mahmmoud, Yasser A; Kopec, Wojciech; Khandelia, Himanshu

2015-01-01

The Na(+),K(+)-ATPase is essential for ionic homeostasis in animal cells. The dephosphoenzyme contains Na(+) selective inward facing sites, whereas the phosphoenzyme contains K(+) selective outward facing sites. Under normal physiological conditions, K(+) inhibits cytoplasmic Na(+) activation...

Kupokelewa Zaidi Kwa Simu Ya Mkononi Kuliko Kompyuta Na ...

African Journals Online (AJOL)

Mtandao wa tovuti ni nyenzo ya msingi katika maendeleo ya uwanja wa mawasiliano unaounganisha watu na jamii mbalimbali katika ulimwengu wa leo unaotandawaa. Katika “ulimwengu wa kwanza na wa pili”, yaani mabara ya Amerika, Uropa na Asia, maendeleo na mapinduzi makubwa katika uwanja wa teknolojia ya ...

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

Coulomb excitation of radioactive 20, 21Na

Science.gov (United States)

Schumaker, M. A.; Cline, D.; Hackman, G.; Pearson, C.; Svensson, C. E.; Wu, C. Y.; Andreyev, A.; Austin, R. A. E.; Ball, G. C.; Bandyopadhyay, D.; Becker, J. A.; Boston, A. J.; Boston, H. C.; Buchmann, L.; Churchman, R.; Cifarelli, F.; Cooper, R. J.; Cross, D. S.; Dashdorj, D.; Demand, G. A.; Dimmock, M. R.; Drake, T. E.; Finlay, P.; Gallant, A. T.; Garrett, P. E.; Green, K. L.; Grint, A. N.; Grinyer, G. F.; Harkness, L. J.; Hayes, A. B.; Kanungo, R.; Lisetskiy, A. F.; Leach, K. G.; Lee, G.; Maharaj, R.; Martin, J.-P.; Moisan, F.; Morton, A. C.; Mythili, S.; Nelson, L.; Newman, O.; Nolan, P. J.; Orce, J. N.; Padilla-Rodal, E.; Phillips, A. A.; Porter-Peden, M.; Ressler, J. J.; Roy, R.; Ruiz, C.; Sarazin, F.; Scraggs, D. P.; Waddington, J. C.; Wan, J. M.; Whitbeck, A.; Williams, S. J.; Wong, J.

2009-12-01

The low-energy structures of the radioactive nuclei 20, 21Na have been examined using Coulomb excitation at the TRIUMF-ISAC radioactive ion beam facility. Beams of ˜ 5×106 ions/s were accelerated to 1.7MeV/A and Coulomb excited in a 0.5mg/cm^2 natTi target. Two TIGRESS HPGe clover detectors perpendicular to the beam axis were used for γ -ray detection, while scattered nuclei were observed by the Si detector BAMBINO. For 21Na , Coulomb excitation from the 3/2+ ground state to the first excited 5/2+ state was observed, while for 20Na , Coulomb excitation was observed from the 2+ ground state to the first excited 3+ and 4+ states. For both beams, B ( λ L) values were determined using the 2+ rightarrow 0+ de-excitation in 48Ti as a reference. The resulting B( E2) ↓ value for 21Na is 137±9 e^2fm^4, while the resulting B( λ L) ↓ values for 20Na are 55±6 e^2fm^4 for the 3+ rightarrow 2+ , 35.7±5.7 e^2 fm^4 for the 4+ rightarrow 2+ , and 0.154±0.030 μ_ N^2 for the 4+ rightarrow 3+ transitions. This analysis significantly improves the measurement of the 21Na B( E2) value, and provides the first experimental determination of B( λ L) values for the proton dripline nucleus 20Na .-1

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

Science.gov (United States)

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

2014-01-01

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

Artesanato na terceira idade: um estudo na cidade de Sinop no ano de 2011

Directory of Open Access Journals (Sweden)

Rosane Marlene Weber

2015-04-01

Full Text Available Essa pesquisa tem como objetivo mostrar a importância do artesanato na Terceira Idade como atividade educacional e de autonomia para os idosos. Por existir uma preocupação com a qualidade de vida da Terceira Idade e sua autonomia, nesta fase que muitos acabam ficando dependentes dos membros da família, espera-se encontrar através da arte uma motivação e uma forma de demonstrar a autoria por meio do fazer, criar e recriar com o artesanato. Aprender e ensinar são um processo contínuo na vida do ser humano, independente da idade, para Paulo Freire precisamos ter consciência de que somos inacabados, e sendo conscientes de nossa inconclusão, devemos viver num permanente movimento de busca. Essa é uma das causas pelas quais será pesquisada a prática formativa/educacional por meio do artesanato na Terceira Idade. Os motivos que levaram a escolha desta pesquisa com o artesanato na Terceira Idade é o fato de ter vivido uma experiência de trabalho na ala geriátrica de um hospital. Já o artesanato é a arte que fascina, e acreditamos que sempre há tempo para recomeçar, para descobrir algo que possa trazer qualidade para nossa vida. Devido ao crescimento cada vez maior da expectativa de vida em nosso país, cria-se uma preocupação com a qualidade de vida das pessoas da Terceira Idade. Em relação aos aspectos educacionais e culturais, esta pesquisa deseja compreender como o artesanato pode trazer motivação para as pessoas da Terceira Idade como forma de autoria e autonomia, nesta fase da vida, na cidade de Sinop, e quais os motivos que os levam a realizar esse tipo de atividade. Para investigação teórica desta pesquisa do Artesanato na Terceira Idade: um estudo na cidade de Sinop em 2011 usaremos bibliografia de vários autores, mas em especial os que dedicam seus estudos a esta faixa etária, como a coleção de Vivaidade, que tem como organizadora principal Anita Liberalesso Neri. Os autores desta coleção nos trazem a reflex

Biphasic voltage-dependent inactivation of human NaV 1.3, 1.6 and 1.7 Na+ channels expressed in rodent insulin-secreting cells.

Science.gov (United States)

Godazgar, Mahdieh; Zhang, Quan; Chibalina, Margarita V; Rorsman, Patrik

2018-05-01

Na + current inactivation is biphasic in insulin-secreting cells, proceeding with two voltage dependences that are half-maximal at ∼-100 mV and -60 mV. Inactivation of voltage-gated Na + (Na V ) channels occurs at ∼30 mV more negative voltages in insulin-secreting Ins1 and primary β-cells than in HEK, CHO or glucagon-secreting αTC1-6 cells. The difference in inactivation between Ins1 and non-β-cells persists in the inside-out patch configuration, discounting an involvement of a diffusible factor. In Ins1 cells and primary β-cells, but not in HEK cells, inactivation of a single Na V subtype is biphasic and follows two voltage dependences separated by 30-40 mV. We propose that Na V channels adopt different inactivation behaviours depending on the local membrane environment. Pancreatic β-cells are equipped with voltage-gated Na + channels that undergo biphasic voltage-dependent steady-state inactivation. A small Na + current component (10-15%) inactivates over physiological membrane potentials and contributes to action potential firing. However, the major Na + channel component is completely inactivated at -90 to -80 mV and is therefore inactive in the β-cell. It has been proposed that the biphasic inactivation reflects the contribution of different Na V α-subunits. We tested this possibility by expression of TTX-resistant variants of the Na V subunits found in β-cells (Na V 1.3, Na V 1.6 and Na V 1.7) in insulin-secreting Ins1 cells and in non-β-cells (including HEK and CHO cells). We found that all Na V subunits inactivated at 20-30 mV more negative membrane potentials in Ins1 cells than in HEK or CHO cells. The more negative inactivation in Ins1 cells does not involve a diffusible intracellular factor because the difference between Ins1 and CHO persisted after excision of the membrane. Na V 1.7 inactivated at 15--20 mV more negative membrane potentials than Na V 1.3 and Na V 1.6 in Ins1 cells but this small difference is insufficient to solely

A neural network potential energy surface for the NaH2 system and dynamics studies on the H(2S) + NaH(X1Σ+) → Na(2S) + H2(X1Σg+) reaction.

Science.gov (United States)

Wang, Shufen; Yuan, Jiuchuang; Li, Huixing; Chen, Maodu

2017-08-02

In order to study the dynamics of the reaction H( 2 S) + NaH(X 1 Σ + ) → Na( 2 S) + H 2 (X 1 Σ g + ), a new potential energy surface (PES) for the ground state of the NaH 2 system is constructed based on 35 730 ab initio energy points. Using basis sets of quadruple zeta quality, multireference configuration interaction calculations with Davidson correction were carried out to obtain the ab initio energy points. The neural network method is used to fit the PES, and the root mean square error is very small (0.00639 eV). The bond lengths, dissociation energies, zero-point energies and spectroscopic constants of H 2 (X 1 Σ g + ) and NaH(X 1 Σ + ) obtained on the new NaH 2 PES are in good agreement with the experiment data. On the new PES, the reactant coordinate-based time-dependent wave packet method is applied to study the reaction dynamics of H( 2 S) + NaH(X 1 Σ + ) → Na( 2 S) + H 2 (X 1 Σ g + ), and the reaction probabilities, integral cross-sections (ICSs) and differential cross-sections (DCSs) are obtained. There is no threshold in the reaction due to the absence of an energy barrier on the minimum energy path. When the collision energy increases, the ICSs decrease from a high value at low collision energy. The DCS results show that the angular distribution of the product molecules tends to the forward direction. Compared with the LiH 2 system, the NaH 2 system has a larger mass and the PES has a larger well at the H-NaH configuration, which leads to a higher ICS value in the H( 2 S) + NaH(X 1 Σ + ) → Na( 2 S) + H 2 (X 1 Σ g + ) reaction. Because the H( 2 S) + NaH(X 1 Σ + ) → Na( 2 S) + H 2 (X 1 Σ g + ) reaction releases more energy, the product molecules can be excited to a higher vibrational state.

Effect of chloride substitution on the order–disorder transition in NaBH{sub 4} and Na{sup 11}BD{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Olsen, Jørn Eirik [Institute for Energy Technology, Physics Department, P.O. Box 40, NO-2027 Kjeller (Norway); Karen, Pavel [University of Oslo, Department of Chemistry, P.O. Box 1033 Blindern, NO-0315 Oslo (Norway); Sørby, Magnus H. [Institute for Energy Technology, Physics Department, P.O. Box 40, NO-2027 Kjeller (Norway); Hauback, Bjørn C., E-mail: bjorn.hauback@ife.no [Institute for Energy Technology, Physics Department, P.O. Box 40, NO-2027 Kjeller (Norway)

2014-02-25

Graphical abstract: Interactions that order the BD{sub 4}{sup -} tetrahedra below the order–disorder transition became increasingly frustrated by the solute in the Na({sup 11}BD{sub 4}){sub 1−x}Cl{sub x} solid solutions, and the order disappears at x = 0.158. Highlights: • The order–disorder transition temperature for Na(BH{sub 4}){sub 1−x}Cl{sub x} and Na({sup 11}BD{sub 4}){sub 1−x}Cl{sub x} is highly dependent on the Cl-content, x. • The transition is characterized by DSC for Na({sup 11}BD{sub 4}){sub 1−x}Cl{sub x} for x = 0, 0.10 and 0.15. • No transition is observed for x ⩾ 0.20 on cooling to 8 K. • The crystal structures are reported for Na{sup 11}BD{sub 4} at room temperature and 8 K and Na({sup 11}BD{sub 4}){sub 1−x}Cl{sub x} (x = 0.10, 0.15, 0.20 and 0.25) at 8 K from powder neutron diffraction. -- Abstract: Phase transition associated with anion disordering over two orientations in Na{sup 11}BD{sub 4} (NaBH{sub 4}) and its solid solutions with NaCl, Na({sup 11}BD{sub 4}){sub 1−x}Cl{sub x}, is investigated with powder diffraction (neutron and synchrotron radiation), differential scanning calorimetry and Raman spectroscopy. Upon heating, the transition temperature extrapolated to zero rate of heating is 192.2 K for Na{sup 11}BD{sub 4}, ΔS = 4.41 J/mol K, hysteresis 1.7 K and the volume increase 0.43%. Thermal parameters of the transition in Na({sup 11}BD{sub 4}){sub 1−x}Cl{sub x} follow a colligative-property model of an ideal solution, with x = 0.158(1) as the critical concentration at which the ordering interactions and the transition itself are eliminated. On approaching this limit, the tetragonal distortion of the ordered structure decreases somewhat towards the cubic average, and this is associated with a partial disorder of the tetrahedral anions seen by diffraction methods. In fact, a 3% disorder is already present in the pure solvent of the solid solution (Na{sup 11}BD{sub 4}) at 8 K.

TweetNaCl : a crypto library in 100 tweets

NARCIS (Netherlands)

Bernstein, D.J.; van Gastel, B.; Janssen, W.; Lange, T.; Schwabe, P.; Smetsers, S.; Aranha, D.F.; Menezes, A.

2015-01-01

This paper introduces TweetNaCl, a compact reimplementation of the NaCl library, including all 25 of the NaCl functions used by applications. TweetNaCl is published on Twitter and fits into just 100 tweets; the tweets are available from anywhere, any time, in an unsuspicious way. Distribution via

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

ZAZNAVA IN VPLIV BARV NA PRIMERU TISKANIH OGLASOV

OpenAIRE

Spes, Katja

2015-01-01

V diplomski nalogi smo s pomočjo literature opisali simboliko osnovnih barv, vpliv, ki ga imajo na ljudi, ter njihov pomen v oglasnih sporočilih. Omejili smo se na tiskane oglase (plakate, časopise, revije, neposredno pošto in embalažo) in opisali njihove prednosti in slabosti. Z anketnim vprašalnikom smo ugotavljali, na katere barve smo najbolj pozorni in katerim lastnostim se posamezne barve bolj približajo. Osredotočili smo se na sedem barv

Lipopolysaccharide hyperpolarizes guinea pig airway epithelium by increasing the activities of the epithelial Na(+) channel and the Na(+)-K(+) pump.

Science.gov (United States)

Dodrill, Michael W; Fedan, Jeffrey S

2010-10-01

Earlier, we found that systemic administration of lipopolysaccharide (LPS; 4 mg/kg) hyperpolarized the transepithelial potential difference (V(t)) of tracheal epithelium in the isolated, perfused trachea (IPT) of the guinea pig 18 h after injection. As well, LPS increased the hyperpolarization component of the response to basolateral methacholine, and potentiated the epithelium-derived relaxing factor-mediated relaxation responses to hyperosmolar solutions applied to the apical membrane. We hypothesized that LPS stimulates the transepithelial movement of Na(+) via the epithelial sodium channel (ENaC)/Na(+)-K(+) pump axis, leading to hyperpolarization of V(t). LPS increased the V(t)-depolarizing response to amiloride (10 μM), i.e., offset the effect of LPS, indicating that Na(+) transport activity was increased. The functional activity of ENaC was measured in the IPT after short-circuiting the Na(+)-K(+) pump with basolateral amphotericin B (7.5 μM). LPS had no effect on the hyperpolarization response to apical trypsin (100 U/ml) in the Ussing chamber, indicating that channel-activating proteases are not involved in the LPS-induced activation of ENaC. To assess Na(+)-K(+) pump activity in the IPT, ENaC was short-circuited with apical amphotericin B. The greater V(t) in the presence of amphotericin B in tracheas from LPS-treated animals compared with controls revealed that LPS increased Na(+)-K(+) pump activity. This finding was confirmed in the Ussing chamber by inhibiting the Na(+)-K(+) pump via extracellular K(+) removal, loading the epithelium with Na(+), and observing a greater hyperpolarization response to K(+) restoration. Together, the findings of this study reveal that LPS hyperpolarizes the airway epithelium by increasing the activities of ENaC and the Na(+)-K(+) pump.

Redetermination of Na(3)TaF(8).

Science.gov (United States)

Langer, Vratislav; Smrcok, Lubomír; Boca, Miroslav

2010-09-01

The crystal structure of trisodium octafluoridotantalate, Na(3)TaF(8), has been redetermined using diffractometer data collected at 153 K, resulting in more accurate bond distances and angles than obtained from a previous structure determination based on film data. The structure is built from layers running along [101], which are formed by distorted [TaF(8)] antiprisms and [NaF(6)] rectangular bipyramids sharing edges and corners. The individual layers are separated by eight-coordinated Na ions. Two atoms in the asymmetric unit are in special positions: the Ta atom is on a twofold axis in Wyckoff position 4e and one of the Na ions lies on an inversion centre in Wyckoff site 4d.

ser precoce na intervenção

OpenAIRE

Bernardo, Ana Carolina Couto

2013-01-01

Dissertação apresentada à Universidade Fernando Pessoa como parte dos requisitos para obtenção do grau de Mestre em Ciências da Educação: Educação Especial, área de especialização em Domínio da Intervenção Precoce na Infância Este estudo centra-se na implementação de uma Escola de Mães, programa de educação parental realizado em seis sessões na freguesia de Calhetas, ilha de S. Miguel, e na avaliação comparativa, anterior e posterior ao programa, das três mães participantes no que...

Na+/H+ exchange activity in the plasma membrane of Arabidopsis.

Science.gov (United States)

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

2003-06-01

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

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

International Nuclear Information System (INIS)

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

2009-01-01

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

Effect of hydrocarbons and nitrogen oxides on ozone formation in smog chambers exposed to solar irradiance of Mexico City

Energy Technology Data Exchange (ETDEWEB)

Sandoval F, J; Marroquin de la R, O; Jaimes L, J. L; Zuniga L, V. A; Gonzalez O, E; Guzman Lopez-Figueroa, F [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico)

2001-01-01

Outdoor smog chambers experiments were performed on air to determine the answer of maximum ozone levels, to changes in the initial hydrocarbons, HC, and nitrogen oxide NO{sub x}. These captive-air experiments under natural irradiation were carried out. Typically, eight chambers were filled with Mexico city air in the morning. In some of those chambers, the initial HC and/or Nox concentrations were varied by {+-}25% to {+-}50% by adding various combinations of a mixture of HC, clean air, or NO{sub x} (perturbed chambers). The O{sub 3} and NO{sub x} concentration in each chamber was monitored throughout the day to determine O{sub 3} (max). The initial HC and NO{sub x} concentration effects were determined by comparing the maximum ozone concentrations measured in the perturbed and unperturbed chambers. Ozone isopleths were constructed from the empirical model obtained of measurements of the eight chambers and plotted in a graph whose axe were the initial HC and NO{sub x} values. For the average initial conditions that were measured in Mexico City, it was found that the most efficient strategy to reduce the maximum concentration of O{sub 3} is the one that reduces NO{sub x}. [Spanish] Se realizaron experimentos de camaras de esmog con el aire de la ciudad de Mexico para determinar las respuestas de los niveles maximos de ozono a los cambios en las concentraciones iniciales de hidrocarburos, HC y oxido de nitrogeno, NO{sub x}. Por lo general, se llenaron 8 bolsas con aire matutino de la Ciudad de Mexico. En algunas camaras, las concentraciones iniciales fueron cambiadas de 25% a 50%, anadiendo varias concentraciones de una mezcla de HC, aire limpio y/o NO{sub x}. La concentracion de O{sub 3} y NO{sub x}, en cada camara, fueron monitoreadas a lo largo del dia para determinar el maximo de O{sub 3}. El efecto de los HC y el NO{sub x} fue determinado por comparacion del maximo de ozono formado en las camaras, que fueron perturbadas por adicion o reduccion de HC y/o Nox

In volo con l’occhio termico

Directory of Open Access Journals (Sweden)

Emanuele De Angelis

2012-04-01

Full Text Available Il Laboratorio di Meccanica del Volo (MDVLab dell’Università di Bologna nasce nel 2006 presso la Seconda Facoltà di Ingegneria e la sua attività di ricerca riguarda principalmente problematiche di modellazione, simulazione e controllo del volo atmosferico e spaziale. Un'intensa collaborazione con l’Istituto Nazionale di Geofisica e Vulcanologia (INGV  ha consentito di estendere le proprie conoscenze al di fuori del settore aerospaziale, presentando oggi un’ampia offerta di tecnologie per l’Osservazione della Terra nell'ambito di progetti in cui MDVLab è coinvolto insieme ad INGV per l’impiego di velivoli non abilitati per applicazioni di gestione del rischio sismico, vulcanico ed ambientale. Flight testing with thermal cameraRemote sensing from satellites or aircraft represents an impor-tant tool for the monitoring and management of catastrophic events. For some rapidly  evolving phenomena (e.g. volcanic events,  wildfires    they  both  show  two  relevant    limits:  long revisiting time (satellites and the high cost and high human risk for monitoring. Unmanned Aircraft Veicle (UAV because of their autonomous flight and  real time telemetry transmis-sion   offer a good solution to these limitations.To explore the operational aspects of such UAV deployments for example in volcanology, INGV in partnership with MavLab department of University of Bologna (Unibo developed  a UAV system and actually are carrying on integration  studies  and testing of sci-entific payloads. The payload is thermal camera. it has a  light weight of 67.5g while the spectral response  is in the 7-14mi-cron spectral range.  The integration activities, the on board installation and  results of the first in flight thermal acquisition experiment realized on July 30 2011, in Italy, are presented.

Optimization and kinetics decomposition of monazite using NaOH

International Nuclear Information System (INIS)

MV Purwani; Suyanti; Deddy Husnurrofiq

2015-01-01

Decomposition of monazite with NaOH has been done. Decomposition performed at high temperature on furnace. The parameters studied were the comparison NaOH / monazite, temperature and time decomposition. From the research decomposition for 100 grams of monazite with NaOH, it can be concluded that the greater the ratio of NaOH / monazite, the greater the conversion. In the temperature influences decomposition 400 - 700°C, the greater the reaction rate constant with increasing temperature greater decomposition. Comparison NaOH / monazite optimum was 1.5 and the optimum time of 3 hours. Relations ratio NaOH / monazite with conversion (x) following the polynomial equation y = 0.1579x 2 – 0.2855x + 0.8301 (y = conversion and x = ratio of NaOH/monazite). Decomposition reaction of monazite with NaOH was second orde reaction, the relationship between temperature (T) with a reaction rate constant (k), k = 6.106.e - 1006.8 /T or ln k = - 1006.8/T + 6.106, frequency factor A = 448.541, activation energy E = 8.371 kJ/mol. (author)

The loss of Na and Cl during the pyrolysis of a NaCl-loaded brown coal sample

Energy Technology Data Exchange (ETDEWEB)

Mody, D.; Li, C.Z.

1999-07-01

A Victorian brown coal was physically loaded with NaCl and pyrolyzed in a quartz fluidized-bed reactor. The fluidized-bed reactor was equipped with a quartz frit in the freeboard zone to enable the total devolatilization of the coal particles. The introduction of NaCl into the coal has caused only minor reductions in the weight loss. A significant amount of chlorine was volatilized during pyrolysis at temperatures as low as 200 C. At temperatures around 400--500 C where the loss of sodium was not very significant, about 70% of chlorine was volatilized from the coal particles. With the volatilization of chlorine at this temperature level, sodium must have been bonded to the char matrix. With increasing temperature, the volatilization of chlorine decreased and then increased again, whereas the volatilization of sodium increased monotonically with increasing temperature. Almost all the Na in coal could be volatilized at temperatures higher than about 800 C. These experimental results clearly indicate that chlorine and Na interacted strongly with coal/char at high temperatures. Na and Cl in the coal did not volatilize as NaCl molecules. Significant amounts of species containing a COO-group such as acetate, formate and oxalate were observed in the pyrolysis products although the exact forms of these species (i.e., as acids, salts or esters) in the pyrolysis product remain unknown. The yields of the species containing a COO-group decreased with increasing temperature, possibly due to the intensified thermal cracking reactions at high temperatures.

Avaliação do tratamento térmico na composição química e na qualidade da cajuína Evaluation of the thermal treatment on the chemical composition and quality of "cajuína" beverage

Directory of Open Access Journals (Sweden)

Ronaldo Ferreira do Nascimento

2003-08-01

Full Text Available Neste trabalho foi estudado o efeito do processo de tratamento térmico na qualidade e composição química da bebida cajuína quando submetida ao cozimento sob temperatura constante de 100ºC durante 1:00, 1:30, 2:00, 2:30, 3:00 e 4:00 horas. Alíquotas foram coletadas em cada tempo de aquecimento e analisadas por cromatografia líquida de alta eficiência (CLAE em relação aos ácidos (cítrico e ascórbico, aldeídos furânicos (5-hidroximetilfurfural e furfural e açúcares (frutose, glicose e frutose. Os resultados foram reprodutíveis e indicaram que as cajuínas comerciais do estado do Ceará apresentam uma grande diversidade quanto ao processo de cozimento e ao teor de vitamina C, causados principalmente por processos térmicos inadequados. O tempo mais adequado sugerido para o "cozimento" da cajuína está em torno de 2:00h. O trabalho também aponta a combinação das análises de 5-HMF, furfural, ácido ascórbico e teor de ácido ascórbico/ácido cítrico como uma metodologia alternativa para a avaliação da qualidade da cajuína.In this work the effect of the thermal process on the quality and chemical composition of the beverage cajuína was studied. Cajuína is basically clarified cashew juice. Samples of cajuína were submitted to thermal processes, of constant heating (100ºC for 1:00, 1:30, 2:00, 2:30, 3:00 and 4:00 hours. The samples were subsequently analyzed by HPLC for glucose, fructose, citric acid, ascorbic acid, hydroxymethylfurfural (5-HMF and furfural. The results showed that the commercial cajuína beverage of Ceará State presented a great diversity in process standardization and vitamin C content, caused by inadequate thermal processing. The process is more efficient with a time period of 2:00hs. The work also indicates a combination of the analyses of 5-HMF, furfural and ascorbic acid and the ratio ascorbic acid/citric acid, as an alternative methodology for the evaluation of cajuína quality.

Measurement and modeling of CO2 solubility in NaCl brine and CO2–saturated NaCl brine density

DEFF Research Database (Denmark)

Yan, Wei; Huang, Shengli; Stenby, Erling Halfdan

2011-01-01

over climate change and energy security. This work is an experimental and modeling study of two fundamental properties in high pressure CO2–NaCl brine equilibrium, i.e., CO2 solubility in NaCl brine and CO2–saturated NaCl brine density. A literature review of the available data was presented first...

Five ab initio potential energy and dipole moment surfaces for hydrated NaCl and NaF. I. Two-body interactions

International Nuclear Information System (INIS)

Wang, Yimin; Bowman, Joel M.; Kamarchik, Eugene

2016-01-01

We report full-dimensional, ab initio-based potentials and dipole moment surfaces for NaCl, NaF, Na + H 2 O, F − H 2 O, and Cl − H 2 O. The NaCl and NaF potentials are diabatic ones that dissociate to ions. These are obtained using spline fits to CCSD(T)/aug-cc-pV5Z energies. In addition, non-linear least square fits using the Born-Mayer-Huggins potential are presented, providing accurate parameters based strictly on the current ab initio energies. The long-range behavior of the NaCl and NaF potentials is shown to go, as expected, accurately to the point-charge Coulomb interaction. The three ion-H 2 O potentials are permutationally invariant fits to roughly 20 000 coupled cluster CCSD(T) energies (awCVTZ basis for Na + and aVTZ basis for Cl − and F − ), over a large range of distances and H 2 O intramolecular configurations. These potentials are switched accurately in the long range to the analytical ion-dipole interactions, to improve computational efficiency. Dipole moment surfaces are fits to MP2 data; for the ion-ion cases, these are well described in the intermediate- and long-range by the simple point-charge expression. The performance of these new fits is examined by direct comparison to additional ab initio energies and dipole moments along various cuts. Equilibrium structures, harmonic frequencies, and electronic dissociation energies are also reported and compared to direct ab initio results. These indicate the high fidelity of the new PESs.

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

Science.gov (United States)

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

1983-12-01

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

Maternal and Child Health Services in the Context of the Ebola Virus ...

African Journals Online (AJOL)

Maternal and Child Health Services in the Context of the Ebola Virus Disease: Health Care Workers' Knowledge, Attitudes and Practices in Rural Guinea. Alexandre Delamou, Sidikiba Sidibé, Alison Marie El Ayadi, Bienvenu Salim Camara, Thérèse Delvaux, Bettina Utz, Abdoulaye II Toure, Sah D. Sandouno, Alioune ...

A Cultural Resource Inventory of Portions of Lake Oahe, Corson County, South Dakota. Volume 1.

Science.gov (United States)

1987-07-01

Dakota Twilight. Exposition Press, Hicksville, New York. Moran, S. R., M. Arndt, J. P. Bluemle, M. Camara, L. Clayton, M. M. Fenton , K. L. Harris, H. C...89 35 116 89 *Piscellaneous, a - smoking material. b - gum, c - sap. d - ceremonial or play. a - cosmetic . References: 6 - Gilmore 1919. 6 - Grinnell

C:\\Users\\AISA\\Desktop\\PDF 26(2)\\SENOU.xps

African Journals Online (AJOL)

AISA

cadmium (Cd) des lixisols et vertisols a été évaluée en station. Les sols ... camara (Tea of Gambia) to accumulate heavy metals such as the Copper (Cu), Lead (Pb), Zinc (Zn) and. Cadmium ... métaux lourds, un procédé de phytoremédiation.

PRIMERJAVA GEODETSKIH METOD NA ZAHTEVNEM GRADBENEM OBJEKTU

OpenAIRE

Reberčnik, Matic

2017-01-01

V projektni nalogi smo v uvodnih poglavjih predstavili različne načine izvajanja geodetskih meritev, ki jih v gradbeništvu uporabljamo pri analizi pomikov in deformacij gradbenih konstrukcij ter terena, na katerem so le-te postavljene. V nadaljevanju opisujemo terestične in GNSS (globalni navigacijski satelitski sistem) metode, ki smo jih uporabljali pri izvajanju meritev na izbranem premostitvenem objektu avtocestnega odseka v Sloveniji (zaradi varovanja podatkov ga imenujemo Objekt 1). Pod...

Synthesis of Li(x)Na(2-x)Mn2S3 and LiNaMnS2 through redox-induced ion exchange reactions

International Nuclear Information System (INIS)

Luthy, Joshua A.; Goodman, Phillip L.; Martin, Benjamin R.

2009-01-01

Na 2 Mn 2 S 3 was oxidatively deintercalated using iodine in acetonitrile to yield Na 1.3 Mn 2 S 3 , with lattice constants nearly identical to that of the reactant. Lithium was then reductively intercalated into the oxidized product to yield Li 0.7 Na 1.3 Mn 2 S 3 . When heated, this metastable compound decomposed to form a new crystalline compound, LiNaMnS 2 , along with MnS and residual Na 2 Mn 2 S 3 . Single crystal X-ray diffraction structural analysis of LiNaMnS 2 revealed that this compound crystallizes in P-3m1 with cell parameters a=4.0479(6) A, c=6.7759(14) A, V=96.15(3) A 3 (Z=1, wR2=0.0367) in the NaLiCdS 2 structure-type. - Graphical abstract: Structure of LiNaMnS 2 . Li and Mn are statistically distributed in edge-shared tetrahedral environments linked into infinite planes. Sodium ions occupy interlayer sites

Número de amostras na análise geoestatística e na krigagem de mapas de atributos do solo

Directory of Open Access Journals (Sweden)

Zigomar Menezes de Souza

2014-02-01

Full Text Available O objetivo deste trabalho foi analisar diferentes intensidades de amostragem do solo com relação à precisão na análise geoestatística e interpolação de mapas, para fins de agricultura de precisão em área de cana-de-açúcar. O solo foi coletado em duas grades regulares na profundidade de 0,00-0,20m para análise granulométrica (área 1 e da fertilidade do solo (área 2. Foram comparadas intensidades de amostragem do solo: 208, 105, 58 e 24 pontos na área 1 e 206, 102 e 53 pontos na área 2. Os dados foram submetidos à análise descritiva e geoestatística. Os variogramas construídos com 105 pontos não diferem dos variogramas com 208 pontos, fato que não ocorre para 58 e 24 pontos. O aumento do intervalo de amostragem e a redução do número de pontos promovem o maior erro na estimativa por krigagem. As amostragens com mais de 100 pontos por área não resultaram em melhorias significativas no erro da estimativa por krigagem, nem diferiram na quantidade de insumos aplicados em campo.

Corpo-escrita na esquizofrenia

OpenAIRE

Bialer, Marina

2014-01-01

Este artigo aborda a importância do trabalho de escrita na esquizofrenia. Toma-se como ponto de partida a formulação lacaniana sobre o esquizofrênico como aquele que não tem as funções dos órgãos do seu corpo dadas pelos discursos estabelecidos. A hipótese de que o trabalho sobre a letra pode permitir o tratamento do gozo debordante na esquizofrenia é analisada pelo estudo da obra do escritor esquizofrênico Robert Walser, a qual evidencia a viabilidade da construção de um corpo pela escrita n...

Chemisorption of Na on the Ti Nanoparticle surface and its effects on the Na-H{sub 2}O reaction reactivity

Energy Technology Data Exchange (ETDEWEB)

Kim, Soo Jae; Park, Gunyeop; Baek, Jehyun; Park, Hyun Sun [POSTECH, Pohang (Korea, Republic of); Kim, Moo Hwan [Korea institute of Nuclear Safety, Daejeon (Korea, Republic of)

2015-10-15

This accident showed that elimination of SWR risk should be one of the most significant design criteria for the development of safe SFRs. Design solutions to ensure isolation of the Na from the water have been proposed; these include double-walled structures in the steam generator and at coolant boundaries and guard vessels or guard piping lines filled with inert gas. However, those methods cannot be ultimate solutions because the system still has a possibility of failure. An alternative approach to reduce the severity of the SWR is to reduce the reactivity of Na. Recently, this goal has been achieved by suspending a small amount of Ti nanoparticles (NPs) in liquid Na. Adding 2 at% of 10-nm Ti NPs in liquid Na reduced the heat of the reaction up to 80% and H{sub 2} production rate by 10%. The number of adsorbed Na atoms onto Ti NPs with respect to the various temperature and pressure was calculated by using ab-initio and thermodynamics. Furthermore, the model which relates the Na chemisorption and SWR reactivity was proposed. The repression of SWR by Ti NPs was expected to be caused by strong chemical interaction between Ti NP surface and Na atoms; ab initio calculation using density functional theory and atomistic thermodynamic approach were conducted to test this hypothesis. Adsorption of 0.25ML Na at hcp hollow sites was the most favorable adsorption surface state and strong chemical adsorption was confirmed by the adsorption energy of -1.65 eV. A covalent-like metallic bond was confirmed between adsorbed Na and Ti atoms on the Ti(0001) surface; this bond affects the hydration energy of Na atoms and the activation barrier of the SWR. Using adsorption energy from the ab-initio calculation and atomistic thermodynamics, the thermodynamically most stable adsorption state at (T,P) was determined Na chemisorption effect on the SWR reactivity regression rate is modeled. The model predict χ variation with respect to time well especially dramatic reduction of χ; the �

O apelo ecológico na propaganda como fator de influência na atitude de compra do consumidor: um estudo experimental

OpenAIRE

Santos, João Maurício

2010-01-01

Este estudo examinou o apelo ecológico utilizado na propaganda como influenciador na atitude de compra do consumidor, tendo em vista que nas duas últimas décadas houve um crescimento nos anúncios que utilizam este tipo de apelo, demonstrando que, pelo surgimento de um novo nicho de mercado, empresas têm se valido do marketing verde e da influência normativa na sua estratégia de marketing. Buscou-se investigar se efetivamente o uso do apelo ecológico na propaganda influencia pos...

Dejavniki psihološkega nasilja na delovnem mestu

OpenAIRE

Ilc, Teja

2011-01-01

Raziskave na področju delovnih razmer kažejo, da je danes pereč problem ravno psihološko nasilje na delovnem mestu. Posebna oblika psihološkega nasilja na delovnem mestu je mobing, s katerim se v praksi srečujemo vsak dan, vendar se ga pogosto ne zavedamo. Namen magistrske naloge je pojasniti pojem in pomen mobinga v delovnih organizacijah, poiskati možne vzroke in posledice, ki vplivajo na ta pojav, ter predlagati rešitve. Poznavanje mehanizmov, ki povzročajo mobing, njegovih vzrokov in...

Anisotropy and polarization in charge changing collisions of C4+ with Na(3s) and laser aligned Na(3p)

NARCIS (Netherlands)

Hoekstra, R; Morgenstern, R; Olson, RE

1996-01-01

Absolute cross sections for C3+(6-->5) emission at 465.7 nm after collisions of C4+ ions with ground state Na(3s) and laser excited aligned Na(Sp) atoms are measured over the collision energy range of 3-7 keV amu(-1). For Na(3s) polarizations are observed by measuring the linear polarization of the

Efeito da dexametasona e do cetoprofeno na osteogênese e na resistência óssea em ratos

Directory of Open Access Journals (Sweden)

Patrícia Costa dos Santos da Silva

2012-04-01

Full Text Available O presente estudo teve como objetivo avaliar o efeito do cetoprofeno e da dexametasona na osteogênese ao redor de implante de hidroxiapatita densa (HAD na tíbia, no osso parietal, e na resistência óssea. Utilizaram-se 15 ratos Wistar, pesando 250±30 g, com 50 dias de idade. Após a anestesia com quetamina/xilazina IM, produziuse no osso parietal e na epífise proximal da tíbia uma cavidade de 3 mm, sendo implantada a HAD. Após a cirurgia os animais foram divididos em três grupos (n=5: controle (CT, anti-inflamatório não esteroidal (AINES e anti-inflamatório esteroidal (AIES. O grupo AINES foi submetido ao tratamento com cetoprofeno na dose de 12 mg/Kg/dia, o AIES recebeu doses de 0,10 mg/kg/dia de dexametasona o grupo CT recebeu solução fisiológica 0,9% (SF por via subcutânea durante 30 dias. Todos os grupos receberam a mesma dieta sólida e água ad libitum. Após 30 dias de experimento os animais sofreram eutanásia, os fêmures coletados, para teste mecânico, e os locais do implante das tíbias e o osso parietal, para análise histomorfométrica. Os grupos AINES e AIES apresentaram menor volume de osso neoformado na falha óssea e ao redor do implante de HAD , como também, menor força máxima para a ruptura completa dos fêmures, quando comparados com o grupo CT. O uso do cetoprofeno e a dexametasona interferiram na osteogênese ao redor do implante de HAD e no osso parietal, diminuindo a resistência óssea principalmente pela inibição da COX2 e diminuição das prostaglandinas, comprometendo a estabilidade e manutenção do implante.

Nalaz tombusvirusa na vrsti Erigeron canadensis L.

OpenAIRE

Jeknić, Zoran; Erić, Živojin; Grbelja, Julijana

1988-01-01

Iz listova zaraženih primjeraka korovne biljke Erigeron canadensis L. koji su rasli na nekoliko lokaliteta u Sarajevu izoliran je virus iz skupine tombusvirusi. Identifikacija virusa izvršena je na osnovi reakcije pokusnih biljaka, analize ultratankih presjeka kroz zaraženo tkivo, morfologije i veličine virusnih čestica, te na osnovi seroloških reakcija metodom dvostruke imunodifuzije u agarskom gelu i čvrsto fazne imunoelektronske mikroskopije (SPIEM). U serološkim pokusima upotrijebljen je ...

Transcriptional regulators of Na, K-ATPase subunits

OpenAIRE

Zhiqin eLi; Sigrid A Langhans

2015-01-01

The Na,K-ATPase classically serves as an ion pump creating an electrochemical gradient across the plasma membrane that is essential for transepithelial transport, nutrient uptake and membrane potential. In addition, Na,K-ATPase also functions as a receptor, a signal transducer and a cell adhesion molecule. With such diverse roles, it is understandable that the Na,K-ATPase subunits, the catalytic alpha-subunit, the beta-subunit and the FXYD proteins, are controlled extensively during developme...

NaIrO3-A pentavalent post-perovskite

International Nuclear Information System (INIS)

Bremholm, M.; Dutton, S.E.; Stephens, P.W.; Cava, R.J.

2011-01-01

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

LiVO/sub 3/-Li/sub 2/Mo(W)O/sub 4/ and NaVO/sub 3/-Na/sub 2/Cr(Mo)O/sub 4/ systems

Energy Technology Data Exchange (ETDEWEB)

Belyaev, I N; Lupeiko, T G; Vyalikova, V I [Rostovskij-na-Donu Gosudarstvennyj Univ. (USSR)

1975-09-01

The systems LiVO/sub 3/-Li/sub 2/MoO/sub 4/, LiVO/sub 3/-Li/sub 2/WO/sub 4/, NaNO/sub 3/-Na/sub 2/CrO/sub 4/, NaNO/sub 3/-Na/sub 2/MoO/sub 4/ were studied with thermographic and partially visual polythermal methods of physical and chemical analyses. Except NaVO/sub 3/-Na/sub 2/MoO/sub 4/ all investigated systems are eutectic ones with limited solid solutions on the basis of some component; the eutectics melt at 542, 544, 550/sup 0/C and contain 25, 20 and 26% of Li/sub 2/MoO/sub 4/, Li/sub 2/WO/sub 4/ and Na/sub 2/CrO/sub 4/ respectively. The system NaNO/sub 3/-Na/sub 2/MoO/sub 4/ contains compound 18 NaVO/sub 3/.11Na/sub 2/MoO/sub 4/ congruently melting at 570/sup 0/C. Two eutectics of the system have melting points at 542 and 548/sup 0/C and contain 47 and 67% of Na/sub 2/MoO/sub 4/.

DRUŽBENA OMREŽJA NA INTERNETU

OpenAIRE

Ploj, Alen

2013-01-01

Družbena omrežja na spletu so zadnje čase zelo popularen način posredne komunikacije in predstavljajo naš vsakdan. Uporaba je enostavna in hitra, učinkovitost pa neverjetna. Zaradi priljubljenosti družbenih omrežij se njihove uporabe poslužujejo tudi različne organizacije, ki z njihovo pomočjo širijo obseg svojega delovanja ter obveščanja uporabnikov o svojih izdelkih/storitvah (marketing). Kot vsako donosno tržišče je tudi internetno tržišče nasičeno z družbenimi omrežji, ki ponujajo najr...

O Platonismo de Russell na metafísica e na matemática

Directory of Open Access Journals (Sweden)

Guido Imaguire

2005-06-01

Full Text Available Neste artigo, analiso o surgimento e a superação do Platonismo em B. Russell, tanto na sua filosofia da matemática como na sua metafísica. Começo por explicitar os argumentos que levaram Russell a aderir ao chamado "Platonismo Proposicional" - posição que será tecnicamente relevante na definição de números. Na seção seguinte, discutirei até que ponto a teoria das descrições definidas determina, necessariamente, uma adesão ao nominalismo, e as dificuldades que surgem para o logicismo conseqüentes do abandono do platonismo. Finalmente, mostrarei como a posição madura de Russell caracteriza-se mais como um reducionismo do que propriamente como um nominalismo, e como este é fundado no princípio do mínimo vocabulário.In this paper, I analyze the emergence and the overcoming of Platonism both in Russell's philosophy of mathematics and his metaphysics. I begin by examining the arguments which led Russell to endorse a position that I term "Propositional Platonism" - this position proves to be relevant for Russell's definition of numbers. In the following section, I address the question of the extent to which Russell's theory of descriptions implies the acceptance of nominalism. Moreover, I examine the difficulties which arise for logicism, if it no longer goes hand in hand with platonism. Finally, I argue argue that Russell's mature position is to be characterized as a form of reductionism rather than as a variant of nominalism

Five ab initio potential energy and dipole moment surfaces for hydrated NaCl and NaF. I. Two-body interactions

Energy Technology Data Exchange (ETDEWEB)

Wang, Yimin, E-mail: yimin.wang@emory.edu; Bowman, Joel M., E-mail: jmbowma@emory.edu [Department of Chemistry, Cherry L. Emerson Center for Scientific Computation, Emory University, Atlanta, Georgia 30322 (United States); Kamarchik, Eugene, E-mail: eugene.kamarchik@gmail.com [Quantum Pomegranate, LLC, 2604 Kings Lake Court NE, Atlanta, Georgia 30345 (United States)

2016-03-21

We report full-dimensional, ab initio-based potentials and dipole moment surfaces for NaCl, NaF, Na{sup +}H{sub 2}O, F{sup −}H{sub 2}O, and Cl{sup −}H{sub 2}O. The NaCl and NaF potentials are diabatic ones that dissociate to ions. These are obtained using spline fits to CCSD(T)/aug-cc-pV5Z energies. In addition, non-linear least square fits using the Born-Mayer-Huggins potential are presented, providing accurate parameters based strictly on the current ab initio energies. The long-range behavior of the NaCl and NaF potentials is shown to go, as expected, accurately to the point-charge Coulomb interaction. The three ion-H{sub 2}O potentials are permutationally invariant fits to roughly 20 000 coupled cluster CCSD(T) energies (awCVTZ basis for Na{sup +} and aVTZ basis for Cl{sup −} and F{sup −}), over a large range of distances and H{sub 2}O intramolecular configurations. These potentials are switched accurately in the long range to the analytical ion-dipole interactions, to improve computational efficiency. Dipole moment surfaces are fits to MP2 data; for the ion-ion cases, these are well described in the intermediate- and long-range by the simple point-charge expression. The performance of these new fits is examined by direct comparison to additional ab initio energies and dipole moments along various cuts. Equilibrium structures, harmonic frequencies, and electronic dissociation energies are also reported and compared to direct ab initio results. These indicate the high fidelity of the new PESs.

Recovery of the heavy elements by NaY AND NaZSM-5 sorbant materials

International Nuclear Information System (INIS)

Nibou, D.; Lebail, S.

1997-04-01

Porous sorbants as zeolites have a several applications in differents fiels: industrial gas purification, catalysis, transformation hydrocarbures prosesses and exchange ions. The hiogh capacity to exchange their cations with those of aqueous solutions was known (1). Since the accession of synthetic zeolites, these silicates have invaded the market and the firstindustrial applications were in exchange field. Studies at Battelle Northwest in Rchland, Washington have shown that zeolites may be used in treatment of radioactive wastes (2). The used method for storing the isotopes is based on selective removal by ion exchange. Clinoptilolite, zeolite (modernite), NaA, and AW-500 have been used. In this context, the present work deals with the recovery of heavy metals like lead and uranium using some microporous materials. The obtained results show that NaY faujasite and NaZSM-5 of the FAU- and MFI-type structure respectively are very effective in removing these elements from waste water

Hali ya taaluma ya ukalimani Tanzania: jana, leo na kesho ...

African Journals Online (AJOL)

Umuhimu wa ukalimani katika mawasiliano umeongezeka kutokana na utandawazi. Utandawazi umerahisisha kukutanika na kuwasiliana kwa watu wazungumzao lugha tofauti kupitia wakalimani. Kutokana na ongezeko hilo la umuhimu wa ukalimani, kumekuwa na jitihada mbalimbali katika nchi mbalimbali kuhakikisha ...

Minimizing Load Effects on NA4 Gear Vibration Diagnostic Parameter

Science.gov (United States)

Dempsey, Paula J.; Zakrajsek, James J.

2001-01-01

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

Secretory NaCl and volume flow in renal tubules.

Science.gov (United States)

Beyenbach, K W

1986-05-01

This review attempts to give a retrospective survey of the available evidence concerning the secretion of NaCl and fluid in renal tubules of the vertebrate kidney. In the absence of glomerular filtration, epithelial secretory mechanisms, which to this date have not been elucidated, are responsible for the renal excretion of NaCl and water in aglomerular fish. However, proximal tubules isolated from glomerular fish kidneys of the flounder, killifish, and the shark also have the capacity to secrete NaCl and fluid. In shark proximal tubules, fluid secretion appears to be driven via secondary active transport of Cl. In another marine vertebrate, the sea snake, secretion of Na (presumably NaCl) and fluid is observed in freshwater-adapted and water-loaded animals. Proximal tubules of mammals can be made to secrete NaCl in vitro together with secretion of aryl acids. An epithelial cell line derived from dog kidney exhibits secondary active secretion of Cl when stimulated with catecholamines. Tubular secretion of NaCl and fluid may serve a variety of renal functions, all of which are considered here. The occurrence of NaCl and fluid secretion in glomerular proximal tubules of teleosts, elasmobranchs, and reptiles and in mammalian renal tissue cultures suggests that the genetic potential for NaCl secretion is present in every vertebrate kidney.

Mechanochemical transformations in Li(Na)AlH{sub 4}-Li(Na)NH{sub 2} systems

Energy Technology Data Exchange (ETDEWEB)

Dolotko, Oleksandr [Ames Laboratory of the U.S. DOE, Iowa State University, Ames, IA 50011-3020 (United States); Zhang Haiqiao [Ames Laboratory of the U.S. DOE, Iowa State University, Ames, IA 50011-3020 (United States); Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011-2300 (United States); Ugurlu, Ozan [Ames Laboratory of the U.S. DOE, Iowa State University, Ames, IA 50011-3020 (United States); Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011-2300 (United States); Wiench, Jerzy W. [Ames Laboratory of the U.S. DOE, Iowa State University, Ames, IA 50011-3020 (United States); Pruski, Marek [Ames Laboratory of the U.S. DOE, Iowa State University, Ames, IA 50011-3020 (United States); Scott Chumbley, L. [Ames Laboratory of the U.S. DOE, Iowa State University, Ames, IA 50011-3020 (United States); Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011-2300 (United States); Pecharsky, Vitalij [Ames Laboratory of the U.S. DOE, Iowa State University, Ames, IA 50011-3020 (United States) and Department of Materials Science and Engineering, Iowa State University, Ames, IA 50011-2300 (United States)]. E-mail: vitkp@ameslab.gov

2007-05-15

Mechanochemical transformations of tetrahydroaluminates and amides of lithium and sodium have been investigated using gas volumetric analysis, X-ray powder diffraction, solid-state nuclear magnetic resonance (NMR) and transmission electron microscopy. In a transformation of LiAlH{sub 4} and LiNH{sub 2} taken in an 1:1 molar ratio, the amount of released hydrogen (6.6 wt.% after 30 min ball milling) was higher than in any known one pot mechanochemical process involving a hydrogen-containing solid. A total of 4.3 wt.% of hydrogen is released by the NaAlH{sub 4}-NaNH{sub 2} system after 60 min ball milling; and 5.2 wt.% H{sub 2} is released when LiAlH{sub 4} and NaNH{sub 2} or NaAlH{sub 4} and LiNH{sub 2} are ball milled for 90 min and 120 min, respectively. All transformations proceed at room temperature. The mechanism of the overall transformation MAlH{sub 4}(s) + MNH{sub 2}(s) {sup {yields}} 2MH(s) + AlN(s) + 2H{sub 2}(g) was identified based on detailed spectroscopic analysis of the intermediate (M{sub 3}AlH{sub 6}) and final products of the ball milling process.

Ética na pesquisa em Administração

OpenAIRE

Leite, Ana Patrícia Rodrigues

2012-01-01

A ética na pesquisa científica é um tema abordado e muito discutido em diversas áreas do conhecimento ligadas à saúde. Na área da Administração, são raros os estudos que abordam o tema da ética na pesquisa. O presente estudo buscou preencher esta lacuna na produção do conhecimento sobre o tema, investigando como os princípios éticos encontrados na literatura e nos códigos de conduta são percebidos e considerados nas atividades de pesquisa em Administração, desenvolvidas por pes...

NA48 experiment : view along the NA48 beamline with the detector in the distance.

CERN Multimedia

Hans Taureg

1996-01-01

Photo 02: Side view of the NA48 experiment showing the LKR calorimeter cryostat No one is sure why the Universe wound up the way it has: all matter and no antimatter. According to prevailing theories, the early universe had equal amounts of matter and antimatter. To see what might be missing from the theories, physicists search for the rare cases in which matter and antimatter behave differently. One such imbalance, called direct CP violation, showed up in the NA 31 experiment at CERN. The results from this experiment, first presented in 1993, showed that when K mesons and their antimatter cousins decay, they show a slight preference for matter over antimatter. Later experiments with neutral K mesons, including NA48 at CERN and KTeV at Fermilab in the United States, showed direct CP violation is real.

Microhardness studies on as-grown faces of NaClO3 and NaBrO3 ...

Indian Academy of Sciences (India)

Unknown

studies are made on as-grown faces of these crystals at various loads. Typical cracks are ... crystals is around 1⋅6 suggesting that these are moderately harder samples. ... the values of elastic constants (C44) and are found to be close to the experimental results. ..... the structure of NaClO3 and NaBrO3 is not as simple as.

Thermodiffusive behaviour of NaCl and KCl aqueous solutions a model for the Na-K pump

International Nuclear Information System (INIS)

Gaeta, F.S.; Mita, D.G.; Perna, G.; Scala, G.

1975-01-01

In NaCl and KCl aqueous nonisothermal solutions K + inverts its sense of migration within the physiological concentration range; Na + behaves similarly at much lower concentrations. These findings are discussed in relation to solute induced modifications of water structure and of their influence on thermal diffusion. A possible evolutionary model of a thermodiffusive mechanism for the sodium potassium pump is also suggested

ANALIZA UPORABNIŠKIH VMESNIKOV NA MOBILNIH NAPRAVAH

OpenAIRE

Bohak, Gregor

2012-01-01

V diplomskem delu smo predstavili pravila in smernice oblikovanja uporabniških vmesnikov na mobilnih napravah. Omejili smo se na platforme Google Android, Nokia Symbian, Nokia MeeGo, Apple iOS ter Microsoft Windows Phone 7. Za vsako izmed platform smo predstavili splošen model uporabniškega vmesnika, splošen model uporabniškega vmesnika aplikacije, navigacijske vzorce ter gradnike. Vse skupaj tudi smo obogatili z veliko grafičnega materiala. V drugem delu smo na podlagi pridobljenega znanja p...

Role of alkali carbonate and salt in topochemical synthesis of K1/2Na1/2NbO3 and NaNbO3 templates

Science.gov (United States)

Lee, Jae-Seok; Jeon, Jae-Ho; Choi, Si-Young

2013-11-01

Since the properties of lead-free piezoelectric materials have thus far failed to meet those of lead-based materials, either chemical doping or morphological texturing should be employed to improve the piezoelectric properties of lead-free piezoelectric ceramics. The goal of this study was to synthesize plate-like K1/2Na1/2NbO3 and NaNbO3 particles, which are the most favorable templates for morphological texturing of K1/2Na1/2NbO3 ceramics. To achieve this goal, Bi2.5Na3.5Nb5O18 precursors in a plate-like shape were first synthesized and subsequently converted into K1/2Na1/2NbO3 or NaNbO3 particles that retain the morphology of Bi2.5Na3.5Nb5O18. In this study, we found that sodium or potassium carbonate does not play a major role in converting the Bi2.5Na3.5Nb5O18 precursor to K1/2Na1/2NbO3 or NaNbO3, on the contrary to previous reports; however, the salt contributes to the conversion reaction. All synthesis processes have been performed via a molten salt method, and scanning electron microscopy, scanning probe microscopy, and inductively coupled plasma mass spectroscopy were used to characterize the synthesized K1/2Na1/2NbO3 or NaNbO3 templates.

Evaluation of the antidiarrhoeal activity of 80% methanol extract and ...

African Journals Online (AJOL)

Lantana camara L. is one of the medicinal plants traditionally used for the treatment of diarrhoea in Ethiopia. The aim of this study was to evaluate antidiarrhoeal activity of the 80% methanol extract and solvent fractions using mice model of diarrhoea. The 80% methanol extract was prepared by maceration and the fractions ...

High Power Microwaves (HPM) (les Micro-ondes de forte puissance (MFP).

Science.gov (United States)

1995-03-01

admittances is less than zero. Varying the 1PM weapon source to blind C(I drones and satellites, intensity of the auxiliary magnetic field will...This camara provides an in-situ measurement and it has a dynamic range up to 1000 C. - Overview Video: One video camera was placed to record the entire

Marketingový mix Restaurace Na chalupě

OpenAIRE

Kubíková, Martina

2013-01-01

Bakalářská práce se zaměřuje na rozbor marketingu a především marketingového mixu. Tedy na známé definice marketingu, marketingová prostředí a rozbor marketingového mixu, kde jsou zmapovány všechny jeho části (Produkt, Cena, Distribuce, Propagace, Fyzický důkaz, Lidé, Procesy). Z teoretických poznatků, které byly zjištěny v odborné literatuře, je vypracována praktická část. Zde je rozebrán marketingový mix Restaurace Na chalupě a zároveň tak i porovnání dvou provozovatelů, kteří se zde vystří...

Co-intercalation of Mg(2+) and Na(+) in Na(0.69)Fe2(CN)6 as a High-Voltage Cathode for Magnesium Batteries.

Science.gov (United States)

Kim, Dong-Min; Kim, Youngjin; Arumugam, Durairaj; Woo, Sang Won; Jo, Yong Nam; Park, Min-Sik; Kim, Young-Jun; Choi, Nam-Soon; Lee, Kyu Tae

2016-04-06

Thanks to the advantages of low cost and good safety, magnesium metal batteries get the limelight as substituent for lithium ion batteries. However, the energy density of state-of-the-art magnesium batteries is not high enough because of their low operating potential; thus, it is necessary to improve the energy density by developing new high-voltage cathode materials. In this study, nanosized Berlin green Fe2(CN)6 and Prussian blue Na(0.69)Fe2(CN)6 are compared as high-voltage cathode materials for magnesium batteries. Interestingly, while Mg(2+) ions cannot be intercalated in Fe2(CN)6, Na(0.69)Fe2(CN)6 shows reversible intercalation and deintercalation of Mg(2+) ions, although they have the same crystal structure except for the presence of Na(+) ions. This phenomenon is attributed to the fact that Mg(2+) ions are more stable in Na(+)-containing Na(0.69)Fe2(CN)6 than in Na(+)-free Fe2(CN)6, indicating Na(+) ions in Na(0.69)Fe2(CN)6 plays a crucial role in stabilizing Mg(2+) ions. Na(0.69)Fe2(CN)6 delivers reversible capacity of approximately 70 mA h g(-1) at 3.0 V vs Mg/Mg(2+) and shows stable cycle performance over 35 cycles. Therefore, Prussian blue analogues are promising structures for high-voltage cathode materials in Mg batteries. Furthermore, this co-intercalation effect suggests new avenues for the development of cathode materials in hybrid magnesium batteries that use both Mg(2+) and Na(+) ions as charge carriers.

Efeito do corte como dano mecânico na qualidade e na fisiologia de mamões 'golden'

Directory of Open Access Journals (Sweden)

Jaqueline Visioni Tezotto

2011-10-01

Full Text Available A redução na qualidade pós-colheita do mamão deve-se em grande parte aos danos mecânicos, especialmente àqueles do tipo corte. O objetivo deste trabalho foi reproduzir este dano mecânico e avaliar os efeitos do número de cortes na qualidade e na fisiologia pós-colheita de mamões 'Golden'. Os cortes foram obtidos com o uso de uma lâmina de aço de 30 mm de comprimento e 5 mm de profundidade. Os tratamentos consistiram na reprodução de 1 a 4 cortes na região mediana dos frutos. Mamões sem cortes foram utilizados como controle. Após a reprodução dos danos, os frutos foram armazenados em câmara a 22ºC e 80-90% de UR por 10 dias. As análises de qualidade foram realizadas a cada dois dias, e as fisiológicas, diariamente. Os resultados demonstraram que a firmeza, o teor de sólidos solúveis e de ácido ascórbico, a atividade respiratória e a produção de etileno foram influenciados pelo número de cortes, de forma que a perda de qualidade dos frutos foi diretamente proporcional ao número de cortes.

Hydrothermal crystallization of Na2Ti6O13, Na2Ti3O7, and Na16Ti10O28 in the NaOH-TiO2-H2O system at a temperature of 500 deg. C and a pressure of 0.1 GPa: The structural mechanism of self-assembly of titanates from suprapolyhedral clusters

International Nuclear Information System (INIS)

Hyushin, G. D.

2006-01-01

An increase in the NaOH concentration in the NaOH-TiO 2 (rutile)-H 2 O system at a temperature of 500 deg. C and a pressure of 0.1 GPa leads to the crystallization R-TiO 2 + Na 2 Ti 6 O 13 → Na 2 Ti 3 O 7 → Na 16 Ti 10 O 28 . Crystals of the Na 2 Ti 6 O 13 titanate (space group C2/m) have the three-dimensional framework structure Ti 6 O 13 . The structure of the Na 2 Ti 3 O 7 titanate (space group P2 1 /m) contains the two-dimensional layers Ti 3 O 7 . The structure of the Na 16 Ti 10 O 28 titanate (space group P-1) is composed of the isolated ten-polyhedron cluster precursors Ti 10 O 28 . In all the structures, the titanium atoms have an octahedral coordination (MTiO 6 ). The matrix self-assembly of the Na 2 Ti 6 O 13 and Na 2 Ti 3 O 7 (Na 4 Ti 6 O 14 ) crystal structures from Na 4 M 12 invariant precursors is modeled. These precursors are clusters consisting of twelve M polyhedra linked through the edges. It is demonstrated that the structurally rigid precursors Na 4 M 12 control all processes of the subsequent evolution of the crystal-forming titanate clusters. The specific features of the self-assembly of the Na 2 Ti 3 O 7 structure that result from the additional incorporation of twice the number of sodium atoms into the composition of the high-level clusters are considered

NA48: Wiring up for Change

CERN Multimedia

2001-01-01

The NA48 Collaboration is rebuilding its drift chambers ready for the experiment to start up again this coming July. An intricate task involving the soldering of over 24,000 wires! The future of the NA48 experiment is coming right down to the wire, that is, the wires which the Collaboration is installing in the clean room of Hall 887 on the Prévessin site. Six days a week, technicians are working in shifts to rebuild the experiment's drift chambers. The original chambers were damaged when a section of a vacuum tube imploded at the end of 1999. A year ago, CERN gave the green light for this essential part of the spectrometer to be rebuilt, so the NA48 experiment, which studies CP violation (see box), still has a bright future ahead of it. Three years of data-taking ahead The NA48 experiment aims to penetrate the secrets of CP (Charge Parity) violation. Charge and parity are two parameters which distinguish a particle from an antiparticle. In other words, an electron possesses a negative electric ...

Impact of childhood stress on psychopathology Impacto de estresse na infância na psicopatologia

Directory of Open Access Journals (Sweden)

Elisa Brietzke

2012-12-01

Full Text Available OBJECTIVE: Advances in our knowledge of mental disorder (MD genetics have contributed to a better understanding of their pathophysiology. Nonetheless, several questions and doubts persist. Recent studies have focused on environmental influences in the development of MDs, and the advent of neuroscientific methodologies has provided new perspectives. Early life events, such as childhood stress, may affect neurodevelopment through mechanisms such as gene-environment interactions and epigenetic regulation, thus leading to diseases in adulthood. The aim of this paper is to review the evidence regarding the role of the environment, particularly childhood stress, in the pathophysiology of MD. METHODOLOGY: We reviewed articles that evaluated environmental influences, with a particular focus on childhood trauma, brain morphology, cognitive functions, and the development of psychopathology and MD. RESULTS AND CONCLUSION: MRI studies have shown that exposure to trauma at an early age can result in several neurostructural changes, such as the reduction of the hippocampus and corpus callosum. Cognitive performance and functioning are also altered in this population. Finally, childhood stress is related to an increased risk of developing MD such as depression, bipolar disorder, schizophrenia and substance abuse. We conclude that there is robust evidence of the role of the environment, specifically adverse childhood experiences, in various aspects of MD.OBJETIVO: Avanços no conhecimento da genética dos transtornos mentais (TM contribuíram para um melhor entendimento de suas bases fisiopatológicas. No entanto, dúvidas e questões ainda persistem. Estudos recentes têm se concentrado nas influências do ambiente no desenvolvimento de TM, e o advento de metodologias neurocientíficas oferece novas perspectivas. Eventos precoces de vida, como estresse na infância, podem ser capazes de alterar o neurodesenvolvimento através de mecanismos como intera

Oxidation of ethanol on NaX zeolite modified with transition metals

Science.gov (United States)

Mirzai, J. I.; Nadirov, P. A.; Velieva, A. D.; Muradkhanli, V. G.

2017-06-01

NaLaX, NaX + Co, and NaPdX catalysts are synthesized by modification of NaX zeolite with transition metals (La, Co, Pd). The activity of the prepared materials in catalytic ethanol oxidation is studied in the temperature range of 423-723 K. It is shown that NaPdX and NaX + Co accelerate the reactions of partial and complete oxidation of ethanol as the temperature rises. NaLaX accelerates both intramolecular and intermolecular dehydration of alcohol. It is shown that the NaPdX (1.0% Pd) sample has the highest activity in the complete oxidation of alcohol with the formation of CO2.

Design and construction of a new furnace combustion pilot in IIE; Diseno y construccion de un nuevo horno experimental de combustion en el IIE

Energy Technology Data Exchange (ETDEWEB)

Martinez Flores, Marco Antonio; Tamayo Flores, G. A. [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)]. E-mail: mamf@iie.org.mx; gatamayo@iie.org.mx

2010-11-15

To expand the scope of studies and technological developments in the Laboratory of Combustion of the Thermal Process Management a new experimental furnace with a capacity of 1.5 MWt was designed and built. Spray design studies with real operational evaluation (comparison of emission of Combustion products and thermal behavior) as well as information on the behavior of the NO{sub x} emissions will be produced. An automatic control system using a water cooling jacket provides the cooling of the furnace. The furnace design is modular, consisting of six sections. Currently three trials to its maximum load of operation have been performed. The results show that the global energy balance of the furnace matches the design. The flue gas residence time and temperature also match those at the exit of steam generators of big capacity. [Spanish] Para ampliar las posibilidades de estudios y desarrollos tecnologicos del laboratorio de combustion de la Gerencia de Procesos Termicos, se diseno y construyo un nuevo horno experimental con capacidad maxima de 1.5 MegaWatts termicos (MWt). Este horno permitira realizar estudios de diseno de atomizadores con evaluacion de operacion real (comparacion de emision de productos de combustion y comportamiento termico), asi como ampliar la informacion que se tiene en el comportamiento de la emision de los oxidos de nitrogeno (NO{sub x}) que se producen en el horno. El diseno del horno es modular, compuesto por seis secciones, las cuales se enfrian de forma independiente a traves de un sistema de control automatico, empleando una chaqueta de enfriamiento por la cual circula agua. Actualmente se han realizado tres encendidos hasta alcanzar su carga maxima de operacion, los resultados obtenidos muestran que el balance de energia global del horno experimental es practicamente el de diseno y cumple con las caracteristicas de tiempo de residencia y temperatura de gases a la salida del horno de Generadores de Vapor de gran capacidad.

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.

Atletismo na escola : realidade?

OpenAIRE

Sampaio, Alessandro Oliveira de

2012-01-01

O correr, saltar, lançar e arremessar são elementos básicos do atletismo, sendo fundamentais para o ser humano, devido ao favorecimento do desenvolvimento físico e motor. Sendo um dos conteúdos principais do desporto e da educação física escolar, foi realizado um estudo relacionado à prática do atletismo na escola, na qual o objetivo desta pesquisa foi verificar se entre os professores de educação física da rede pública de ensino fundamental de 5ª a 8ª séries, da cidade satélite de Samambaia ...

Influence of NaCl and NaHCO/sub 3/ on reduction of phytic acid in red kidney bean

International Nuclear Information System (INIS)

Shahnawaz, M.; Khan, T.U.

2007-01-01

Influence of sodium chloride (NaCI) and sodium bicarbonate (NaHCO/sub 3/) was studied on phytic acid in Red kidney bean (phaseolus sp). Two varieties of Red Kidney bean VI (Orakzai Korkha) and V2 (Kurram Korkha) were obtained from NWFP Agriculture University, Peshawar. The amount of phytic acid in V1 and V2 of Red kidney bean was 10 mg and 9.80 mg, respectively. Red kidney-bean flour soaked for 6 and 12 hrs. in water and in pH4 and 6 solutions has significantly reduced (70%) amount of phytic acid. Solution of pH6 was found most effective, while pH4 and water was less effective in lowering the phytic acid in Red kidney bean. Mixed food additives (1% NaCI + 2% NaHCO/sub 3/) in water, and pH4 and 6 solutions, reduced the level of phytic acid in Red kidney bean to 40%, 54% and 58% for 6 hrs, and 50%, 57% and 70% for 12 hrs. in respective solutions. Results revealed that soaking Red kidney bean flour in pH6 solution with the presence of NaCI and NaHCO/sub 3/, the action of phytase enzyme was well activated to hydrolyze phytic acid. It has been observed that soaking of flour in the respective solutions is a simple inexpensive method of lowering phytic acid in bean. The treatment with such a sophisticated combination of food additives will improve the nutritional status of Red kidney bean, which is used in many food products. (author)

Na2SO4-based solid electrolytes for SOx sensors

DEFF Research Database (Denmark)

Rao, N.; Schoonman, J.; Toft Sørensen, O.

1992-01-01

on the phases present and the structure of the specimens. From a point of view of practical application as SOx sensor material, the Na2SO4 + 5 mol% Y2(SO4)3 + Na2WO4 and Na2SO4+ 4 mol% La2(SO4)3 + Na2WO4 materials are better than undoped Na2SO4 because of their higher conductivity, and absence of a phase...

Kinetin Reversal of NaCl Effects

Science.gov (United States)

Katz, Adriana; Dehan, Klara; Itai, Chanan

1978-01-01

Leaf discs of Nicotiana rustica L. were floated on NaCl in the presence of kinetin or abscisic acid. On the 5th day 14CO2 fixation, [3H]leucine incorporation, stomatal conductance, and chlorophyll content were determined. Kinetin either partially or completely reversed the inhibitory effects of NaCl while ABA had no effect. PMID:16660618

Combined Effects of Boron and NaCl on Wheat Seedlings

Directory of Open Access Journals (Sweden)

ZHEN Mei-nan

2015-08-01

Full Text Available To investigate the combined effects of boron(Band NaCl on the growth of wheat, a pot experiment was conducted using wheat (Triticum aestivum Linn.seedlings. Boron concentrations of culture medium were set as 0, 50 mg·kg-1 and 100 mg·kg-1, and NaCl concentrations were 0, 1 g·kg-1 and 2 g·kg-1. The results showed that both boron and NaCl could significantly inhibit wheat growth. At 50 mg B·kg-1, NaCl aggravated growth inhibition caused by boron. At 100 mg B·kg-1, however, NaCl alleviated the inhibition caused by boron. The combined stress of boron and NaCl significantly increased the root to shoot ratio of wheat. NaCl inhibited the uptake of boron by wheat. It suggests that under severe boron stress, NaCl is able to alleviate boron toxicity in wheat by increasing root to shoot ratio and reducing boron uptake.

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.

A metodologia de projecto na aprendizagem da biodiversidade e geodiversidade na praia da concha

OpenAIRE

Rosa, Marina Maria Filipe

2012-01-01

Dissertação de mestrado em Biologia e de Geologia, apresentada ao Departamento de Ciências da Terra e ao Departamento de Ciências da Vida Este trabalho consistiu na implementação e avaliação da metodologia de projeto no estudo da Biodiversidade e Geodiversidade na Praia da Concha, Portugal Central, dando ênfase ao trabalho prático, através de uma aula de campo e de aulas laboratoriais. O trabalho foi realizado numa escola da Marinha Grande, com 11 alunos do 10º ano de escolaridade. Sendo a...

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

International Nuclear Information System (INIS)

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

2008-01-01

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

Recoil Processes of Cr{sup 51} in Mixed Inorganic Systems; Processus de Recul de {sup 51}Cr dans des Melanges Inorganique; 041f 0420 041e 0426 0415 0421 0421 042b 0421 042f 0414 0420 0410 041c 0418 041e 0422 0414 0410 0427 0418 0425 0420 041e 041c 0410 -51 0412 0421 041c 0415 III 0410 041d 041d 042b 0425 041d 0415 041e 0420 0413 0410 041d 0418 0427 0415 0421 041a 0418 0425 0421 0418 0421 0422 0415 041c 0410 0425 ; Procesos de Retroceso del {sup 51}Cr en Sistemas Inorganicos Mixtos

Energy Technology Data Exchange (ETDEWEB)

Veljkovic, S. R.; Milenkovic, S. M.; Ratkovic, M. R. [Boris Kidric Institute of Nuclear Sciences, Vinca, Yugoslavia (Serbia); Faculty Of Natural Sciences, Belgrade University, Belgrade, Yugoslavia (Serbia)

1965-04-15

paralelamente los efectos termicos para poder evaluar los efectos puramente termicos en el reactor y el posible calentamiento interno de las sustancias empleadas como blanco. En el sistema en el que los cromatos se depositaron sobre MgO, se observo una reduccion considerable a ion cromo. Los efectos neutronicos son mas importantes que los procesos termicos a la temperatura de irradiacion y por mero calentamiento por encima de 600 Degree-Sign C se observaron efectos analogos. El ion cromo no experimento ningun cambio durante la irradiacion. El aumento de la concentracion de cromatos se tradujo en la retencion bien conocida de {sup 51}CrO{sub 4}{sup =}. Los cromatos adsorbidos en Al{sub 2}O{sub 3} conservaron la misma forma oxidada que en el caso del SiO{sub 2}. Los efectos termicos acusaron la misma tendencia. El ion cromo adsorbido en estos oxidos se comporto de manera distinta. En el sistema con Al{sub 2}O{sub 3} se observo una oxidacion considerablemente mayor que en el caso del proceso termico. Al comparar la irradiacion con el calentamiento, los autores hallaron una pequeuea diferencia en el sistema con SiO{sub 2}, si bien observaron un notable empobrecimiento, por difusion, del ion cromo en la superficie. La propiedad comun a todos estos sistemas es la exigua concentracion de los compuestos de cromo. En la mayor parte de los casos, las caracteristicas quimicas de las capas finas parecen diferir del comportamiento normal en grandes volumenes de cromatos, tanto en lo que atane a los procesos termicos como a los de retroceso. Ello podria significar que los procesos que se desarrollan en puntos calientes, al depender de todos los componentes, originarian productos quimicos sensibles a la naturaleza de la sustancia utilizada como blanco. Al parecer, para poder efectuar una descripcion general de los procesos de retroceso en compuestos solidos, es preciso tener debidamente en cuenta el material de la matriz. (author) [Russian] Izuchalis' jeffekty nejtronnogo obluchenija v

UM OLHAR SOBRE O DIABETES NA INFÂNCIA E NA JUVENTUDE: NEM TODOS SÃO TIPO 1

Directory of Open Access Journals (Sweden)

ANGHEBEM-OLIVEIRA

2013-12-01

Full Text Available O Diabetes mellitus (DM é caracterizado como um quadro de hiperglicemia crônica, que com os anos causa disfunção endotelial e sérias complicações vasculares, como a retinopatia, nefropatia e o infarto agudo do miocárdio. À medida que a ciência avança na compreensão da fisiopatologia e das características clínico-laboratoriais do diabetes, sua classificação tem sido adaptada, justamente porque a correta classificação do diabetes vai impactará no prognóstico e tratamento do paciente. Atualmente, o diabetes é classificado em DM tipo 1, DM tipo 2, DM gestacional e Outros Tipos Específicos, que inclui a categoria MODY (do inglês, Maturity Onset Diabetes of the Young ou diabetes da maturidade com início na juventude. O que esta revisão pretende mostrar é quem nem todo diabetes diagnosticado na infância e na juventude é DM tipo 1

Hexagonal-layered Na{sub 0.7}MnO{sub 2.05} via solvothermal synthesis as an electrode material for aqueous Na-ion supercapacitors

Energy Technology Data Exchange (ETDEWEB)

Hou, Yan; Tang, Hongwei; Li, Bao; Chang, Kun [Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan, 453007 (China); Chang, Zhaorong, E-mail: czr_56@163.com [Collaborative Innovation Center of Henan Province for Green Manufacturing of Fine Chemicals, Key Laboratory of Green Chemical Media and Reactions, Ministry of Education, School of Chemistry and Chemical Engineering, Henan Normal University, Xinxiang, Henan, 453007 (China); Yuan, Xiao-Zi; Wang, Haijiang [National Research Council of Canada, V6T 1W5, Vancouver, BC (Canada)

2016-03-01

The layered sodium manganese oxides Na{sub 0.7}MnO{sub 2.05} material was synthesized using Na{sub 2}CO{sub 3} and Mn{sub 3}O{sub 4} precursors via a solvothermal method at different temperatures. The X-ray diffraction (XRD) shows that the Na{sub 0.7}MnO{sub 2.05} sample has a high crystallinity with hexagonal crystal system. The electrochemical performance was characterized by cyclic voltammetry (CV), impedance measurements and galvanostatic charge–discharge tests in symmetric Na-ion supercapacitors with 1 mol L{sup −1} Na{sub 2}SO{sub 4} solution as electrolyte. The Na{sub 0.7}MnO{sub 2.05} material shows a high specific capacity of about 162.5 F g{sup −1} at a current density of 50 mA g{sup −1} and a high coulombic efficiency approaching 100%. Even at a current density of 200 mA g{sup −1}, the discharge capacity of the material can reach to 146 F g{sup −1}. This electrode material holds great promise for practical applications. - Highlights: • Novel electrode material for supercapacitor: hexagonal-layered Na{sub 0.7}MnO{sub 2.05}. • Na{sub 0.7}MnO{sub 2.05} is synthesized using Mn{sub 3}O{sub 4} precursors via solvothermal method. • Obtained Na{sub 0.7}MnO{sub 2.05} exhibits superior electrochemical performance.

22 Na positron source for annihilation positron spectroscopy

International Nuclear Information System (INIS)

Cimpeanu, Catalina; Craciun, L.; Dragulescu, E.; Dudu, D.; Racolta, P. M.; Voiculescu, Dana; Miron, N.

2003-01-01

To extend the nuclear physics applications and to perform the study of vacancy - type defects in metals, semiconductors, polymers etc., we decided to promote positron annihilation techniques. In order to achieve this goal we started a project of dedicated positron sources produced at the IFIN-HH U-120 Cyclotron. We have used the nuclear reaction: 24 Mg(d,α) 22 Na with deuterons of 13 MeV energy. The paper presents the main characteristics of this procedure, as follows: general conditions asked for 22 NaCl sources, reactive chamber and characteristics of Mg target, parameters for the irradiation, radiochemical procedures for separating Na from Mg after the irradiation and geometrical or mechanical requirements for dedicated NaCl source for positron annihilation spectrometry. In the e + lifetime measurements, the e + end - start signals may be obtained from prompt γ -quanta emitted from the NaCl source (1. 275 MeV photons). The 22 NaCl stock solution obtained by radiochemical separation will be kept in quartz sealed ampoules in dry places and will be dropped between the study materials before the use in positron spectrometry. (authors)

22 Na positron source for annihilation positron spectroscopy

International Nuclear Information System (INIS)

Cimpeanu, Catalina; Craciun, Liviu; Dragulescu, Emilian; Dudu, Dorin; Racolta, Petre Mihai; Voiculescu, Dana; Miron, N.

2005-01-01

To extend the nuclear physics applications and to perform the study of vacancy - type defects in metals, semiconductors, polymers, etc., we developed new positron annihilation techniques. In line with this goal we started a project for production of positron sources at the IFIN-HH U-120 Cyclotron. We made use of the nuclear reaction: 24 Mg(d,α) 22 Na with deuterons of 13 MeV energy. The paper present the main steps of this procedure which are: establishing the conditions required for 22 NaCl sources, for the parameters of reaction chamber and the characteristics of Mg target, parameters for the irradiation, radiochemical procedures for separation of Na from Mg after irradiation as well as the geometrical and mechanical requirements for the NaCl source. In the e + lifetime measurements the e + 'stop' signals are always provided by gamma - quanta generated by the e + e - annihilation and the 'start' signals are obtained from 'prompt' gamma - quanta emitted by the NaCl source (1.275 MeV photons). The 22 NaCl stock solution obtained by radiochemical separation will be kept in quartz sealed ampoules. (authors)

O outro na relação

Directory of Open Access Journals (Sweden)

Reinoldo Marquezan

2012-03-01

Full Text Available O texto aborda as contribuições de Meirieu em relação ao outro que se estabelece na relação pedagógica e de Maturana que refere o outro como legítimo outro da convivência. Aponta ser necessário estabelecer o outro na relação como legítimo outro para a consecução do ato pedagógica.Palavras-chave: O Outro na Relação. Relação Pedagógica.

MODELI MERJENJA KAKOVOSTI STORITEV NA MEDORGANIZACIJSKEM TRGU

OpenAIRE

Cestnik, Dušan

2011-01-01

Vse večja konkurenca na medorganizacijskih trgih sili tako storitvena podjetja, kot tudi podjetja, ki tržijo izdelke, da svoje delo opravljajo vse bolj kakovostno na vseh ravneh svojega delovanja. Podjetja morajo svoje odjemalce obdržati, prav tako pa morajo delovati tudi na pridobivanju novih odjemalcev. Da pa podjetja svoje odjemalce obdržijo morajo nenehno delovati tako, da uživajo zaupanje svojih odjemalcev. Odjemalec že z odločitvijo za neko določeno podjetje XY pričakuje, da bodo storit...

Lattice sites of Na dopants in ZnO

CERN Document Server

AUTHOR|(CDS)2069243; Martins Correia, Joao; Amorim, Lígia; Decoster, Stefan; Ribeiro da Silva, Manuel; Da Costa Pereira, Lino Miguel

2016-01-01

The angular distribution of beta− particles emitted by the radioactive isotope 24Na was monitored following implantation into ZnO single crystals at fluences above 5E12 cm−2 at CERN’s ISOLDE facility. We identified sodium on two distinct sites: on substitutional Zn sites and on interstitial sites that are close to the so-called octahedral site. The interstitial Na was to large extent converted to substitutional Na already for annealing at 200°C, from which an activation energy of 0.8−1.3 eV, most likely around 1.2 eV, is estimated for the migration of interstitial Na in ZnO.