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Sample records for al ph salinidad

  1. Efecto de una posible interacción entre el pH y la salinidad sobre el crecimiento de Posidonia oceanica (L.) Delile, 1813

    OpenAIRE

    Fernández-Torquemada, Yolanda; Sánchez-Lizaso, José Luis

    2003-01-01

    La desalación de aguas marinas mediante ósmosis inversa es una actividad en desarrollo en la cuenca mediterránea cuyos posibles impactos ambientales son poco conocidos. El agua de rechazo de dichas plantas posee una elevada salinidad y un pH relativamente bajo. En el presente trabajo se realizaron experimentos en mesocosmos para estimar el efecto de una posible interacción entre dicho descenso del pH y el incremento de la salinidad sobre el crecimiento de la fanerógama marina Posidonia oce...

  2. La influencia del pH y de la salinidad en el crecimiento de Avicennia Germinans (L. L. en cultivo hidropónico La influencia del pH y de la salinidad en el crecimiento de Avicennia Germinans (L. L. en cultivo hidropónico

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    Schnetter Marie Luise

    1986-12-01

    Full Text Available Por sus características llamativas interpretadas como adaptación a las condiciones del medio ambiente bajo las cuales crecen en las costas tropicales, los mangles sirven como objeto de estudios botánicos desde hace mucho tiempo.Con frecuencia es importante cultivar las plantas bajo condiciones controladaspara experimentos de esta índole. Distintos autores investigaron elcrecimiento de plantas jóvenes de Auicennui marina (Forssk Vierh. ensolución nutritiva (CONNOR 1969, CLARKE & HANNON 1970, DOWNTON 1982,CLOUGH 1984. En todos estos casos figura como objetivo principal de lasinvestigaciones determinar la influencia de la salinidad del medio de cultivoen el desarrollo de las plantas.Ensayos de la autora para cultivar plantas de Auicennia qerminans en Ciesserr/ Alemania (SCHNETTER 1985 indicaron que pDr 10 visto tambien el pH del medio nutritivo tiene cierta influencia sobre el crecimiento, Para una mejor aclaración de este asunto se realizó una serie de experimentos cultivando plántulas de Asncennia qerminans en soluciones nutritivas a diferente pH y salinidad. Seedlings of Avicennia qerminans, collected at Turbo and Cartagena on the Caribbean Coast of Colombia were hydroponically grown during 28 weeks. The pH of nutrient solution containing 0.1 M NaCl ranged from 5.7 to 8.7. Additionally, one culture medium without NaCl (pH 7.7 and another containing 0.35 M NaCl (pH 8.2 were used. Biomass production depended both on salinity and pH. Highest values of dry matter were obtained for plants of both collection sites in weak basic nutrient solution containing O. 1 M NaCI. But different answers to pH conditions could be observed. Growth optimum of the plants from Cartagena occurred at pH 8, while those from Turbo remained already small at the same pH. They showed better growth in culture medium containing 0.35 M NaCl at pH 8.2 than at pH 8 and 0.1 M NaCl. Increasing salinity resulted in a higher percentage of root biomass.  General differences

  3. Injertos de tomate (Solanum lycopersicum) tolerantes a la salinidad.

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    Tlatilpa Santamaría, Ibar Felipe

    2013-01-01

    La selección de cultivares tolerantes a salinidad es uno de los métodos más efectivos para incrementar la productividad en suelos salinos. El injerto sobre patrones tolerantes a la salinidad es un método eficaz para aumentar la tolerancia de las plantas al estrés salino. Los objetivos del presente estudio fueron, es seleccionar y caracterizar accesiones de tomate silvestre con base en la respuesta de la plántula a la salinidad, y determinar la magnitud de la variabilidad fenotípica de la tole...

  4. Efecto de la salinidad en la supervivencia embrionaria de puye Galaxias maculatus (Jenyns, 1842

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    Juan Barile

    2015-05-01

    Full Text Available Se evaluó e l efecto de la salinidad en la supervivencia embrionaria, período embrionario y período de eclosión de puye, Galaxias maculatus. Se utilizaron ocho tratamientos, con salinidades de 0, 4, 8, 12, 16 y 20 obteniéndose supervivencias embrionarias promedios respectivas de 84,9; 84,0; 85,5; 86,1; 82,6 y 75,8%, sin diferencias significativas entre ellas, mientras que con salinidad de 24 se obtuvo sobrevivencia de 10,4%, significativamente diferente al resto de los tratamientos y con salinidad de 28 causó 100% de mortalidad. A diferencia del estado juvenil y adulto, el embrión es incapaz de resistir la salinidad marina y su umbral de tolerancia se encuentra entre salinidades de 24 y 28. Las mayores supervivencias promedios larvales a 10 días de vida fueron con salinidades intermedias de 8, 12 y 16 de 79,3; 80,3 y 74,6% respectivamente, sin diferencias significativas entre ellas, demostrando alta viabilidad del embrión post-eclosión. Los períodos embrionarios promedios (50% más breves fueron a bajas salinidades 0, 4, 8, 12 con 28,7; 28,0; 29,7 y 29,7 días y los más extensos en los tratamientos con salinidades de 16 y 20, con 34,0 y 34,3 días, sin diferencias significativas entre ellos. Los períodos de eclosión promedio (50% con salinidades de 0, 4, 8, 12, 16, 20 y 24 fueron de 5,0; 5,5; 7,5; 8,8; 13,0; 14,3 y 15,8 días respectivamente, sin diferencias significativas entre ellos.

  5. Tolerancia a salinidad de Persea americana Mill en cultivo in vitro.

    OpenAIRE

    Ramírez Guerrero, Leobarda Guadalupe

    2010-01-01

    El objetivo de la investigación fue conocer los efectos de salinidad en el desarrollo y anatomía de embriones maduros de dos tipos de aguacate cultivados in vitro e identificar alguna fuente de tolerancia al estrés salino. El trabajo consistió en: I) Establecimiento in vitro; II) Evaluación del desarrollo y sobrevivencia in vitro; III) Evaluación de parámetros de tolerancia a salinidad en aguacate en cultivo in vitro; IV) Cambios anatómicos en la raíz inducidos por salinidad. Se sembraron in ...

  6. Tolerancia a la salinidad del pasto Banderita [Bouteluoa curtipendula (Michx. Torr.] en la etapa de germinación en dos regímenes de temperaturas

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    Sara Lucía González Romero

    2010-01-01

    Full Text Available El pasto Banderita es un forraje nativo de México, con gran potencial socio-económico para la ganadería extensiva; sin embargo, la información sobre su tolerancia a la salinidad es escasa. Para evaluar el efecto de diferentes sales y concentraciones sobre su germinación, se utilizaron cariópsides de reciente cosecha. Las salinidades sulfático-sódica y NaHCO3 de pH alcalino, registraron el menor porcentaje de germinación, en las sales: clorhídrica y CaCl2.2H2O con pH ácido, el mayor valor. El efecto de sales combinadas fue benéfico para la germinación; ésta es inversamente proporcional al incremento de solución salina. Un incremento de temperatura favoreció la germinación, disminuyó la toxicidad de los cloruros y permitió que las semillas soportaran mayores concentraciones de salinidad.

  7. Tolerancia a la salinidad del pasto Banderita [Bouteluoa curtipendula (Michx. Torr.] en la etapa de germinación en dos regímenes de temperaturas

    Directory of Open Access Journals (Sweden)

    Sara Lucía González Romero

    2011-01-01

    Full Text Available El pasto Banderita es un forraje nativo de México, con gran potencial socio-económico para la ganadería extensiva; sin embargo, la información sobre su tolerancia a la salinidad es escasa. Para evaluar el efecto de diferentes sales y concentraciones sobre su germinación, se utilizaron cariópsides de reciente cosecha. Las salinidades sulfático-sódica y NaHCO3 de pH alcalino, registraron el menor porcentaje de germinación, en las sales: clorhídrica y CaCl2.2H2O con pH ácido, el mayor valor. El efecto de sales combinadas fue benéfico para la germinación; ésta es inversamente proporcional al incremento de solución salina. Un incremento de temperatura favoreció la germinación, disminuyó la toxicidad de los cloruros y permitió que las semillas soportaran mayores concentraciones de salinidad.

  8. Edith Stein als Phänomenologin : Betrachtungen zur Phänomenologie im Grenzbereich zur Theologie

    NARCIS (Netherlands)

    Wulf, Mariéle

    2018-01-01

    Edith Steins Phänomenologie basiert auf der Person als erkennendes Subjekt. Das ermöglicht ihr, Sinnfragen zu thematisieren – bis hinein in den theologischen Bereich. Steins phänomenologische Methode, die sie aus der philosophischen Phänomenolo-gie gewonnen hat, behält sie bei, als sie sich

  9. Respuesta de cultivares de patata a la salinidad y potencial efecto protector del metil jasmonato frente al estrés salino

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    Rodríguez Buitrón, Ricardo

    2014-01-01

    En aquesta Tesi Doctoral es van caracteritzar in vitro quatre cultivars de patata amb diferent cicle de maduració, Agata, Monalisa, Kennebec i Red Pontiac en base al desenvolupament vegetatiu i radical dels explants. L’efecte del MeJa es va avaluar en base al desenvolupament vegetatiu i radical dels explants exposats a 0,10, 50, 250 i 1250 nM de MeJa. La tolerància a l’estrès salí es va avaluar en base al desenvolupament vegetatiu i radical dels explants dels quatre cultivars exposats a 0, 30...

  10. Utilizacion del metodo de hidrolisis de los amilostatolitos para el diagnostico de resistencia al calor, la sequia y la salinidad en el tomate

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    Jorge A. Sánchez

    2000-01-01

    Full Text Available Se propone 5 indices de calidad que penni- ten estimar certerarnentel nivel de calidad y po- tencial productivo de una plantaci6n forestal. £1 primer indice es el de calidad general y debe uti- lizarse preferiblemente en plantaciones no ralea- das. £ste indiceproducira valores de 1.0-4.0. Valo- res cercanos a 1 serlin de plantaciones de la mas al- ta calidad. £1 segundo es el de calidad de cosecha y se basa en la cantidad de individuos presentes por ha de calidad 1 y 2. Una plantaci6n con 400 indi- viduos de calidad 1 +2 seria excelente y con menos de 200 individuos seria de mala calidad. £1 tercero es el de calidad maxima, que busca reflejar en que proporci6n la plantaci6n se aproxima al maximo numero posible de individuos de calidad 1 y de 40 cm de dap que puede contener una plantaci6n fo- festal ala cosecha; es basado en N 1=250 Y genera harvalores porcentuales, donde una plantaci6n con >90% seria excelente y 1600 trozas/ha de calidad 1+2 son excelentes y aquellas <800 trozas son inaceptables. Por ultimo se incluye el indice de calidad de productividad, que permite valorar la calidad de una plantaci6n en

  11. Effect of elevated Al and pH on the growth and root morphology of Al-tolerant and Al-sensitive wheat seedlings in an acid soil

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    Md. Toufiq Iqbal

    2014-03-01

    Full Text Available Aluminium ion (Al3+ toxicity and hydrogen ion (H+ activity are the major constraints for plant growth in acid soil. This study was undertaken to determine the effect of pH and Al on the growth response and changes in root morphology of Al-tolerant (ET8 and Al-sensitive (ES8 wheat seedlings. Different levels of AlCl3 and CaCO3 were added to the soils to manipulate soil pH and extractable Al. The results showed that the bulk soil pH remained constant at pH 4.1 with further applications of AlCl3, and that the seedlings died at the 200 mg AlCl3/kg treatments. The ET8 seedlings responded better than the ES8 seedlings in both low and high Al and pH. The ET8 seedlings had higher root surface areas and root tip numbers than the ES8 seedlings in the Al treatment. In contrast, the ES8 had higher root diameters than the ET8 seedlings due to the elevated Al supply. Apoplast Al increased with the increase of soil available extractable Al, and declined with the decrease of soil extractable Al. The ET8 seedlings accumulated more Al in their apoplast than the ES8 seedlings. This study concluded that accumulation of Al in the apoplast is also involved in Al tolerance mechanism with the addition of organic acid exudation.

  12. CRECIMIENTO Y DESARROLLO DE VARIEDADES DE ALBAHACA (Ocimum basilicum L.) EN CONDICIONES DE SALINIDAD

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    Bernardo Murillo Amador; Alejandra Nieto Garibay; Enrique Troyo Diéguez; Inés María Reynaldo Escobar; Edgar Omar Rueda Puente; Jairo Leonardo Cuervo Andrade

    2014-01-01

    El cultivo de albahaca (Ocimum basilicum L.) presenta amplia variabilidad en cuanto a la tolerancia al estrés salino, sin embargo es sensible durante el crecimiento inicial. El establecimiento de indicadores morfométricos que indiquen tolerancia a la salinidad por parte del cultivo es importante para recomendar a los agricultores la variedad más productiva en esas condiciones. El objetivo del estudio fue determinar el efecto del NaCl en el crecimiento y desarrollo de plantas de albahaca. Se e...

  13. Surface activity evaluation of an arabinose ester as water/oil demulsifier at severe conditions of temperature, salinity and pH; Avaliacao da atividade superficial de um ester de arabinose, como desemulsificante agua/oleo, em condicoes severas de temperatura, salinidade e pH

    Energy Technology Data Exchange (ETDEWEB)

    Borges, Mauricio Rodrigues; Garcia, Rosangela Balaban; Santos, Jaciara Alves dos; Vieira, Mariane; Silva, Luciana Carvalho; Campos, Viviane de Oliveira; Silva, Rayane Araujo da; Santos, Telma Pitanga dos [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil)

    2008-07-01

    This work had for objective to compare the superficial properties of an arabinose ester, no-ionic, nontoxic, biodegradable, with two commercial products: the first one based on sodium dodecyl sulfate and the second one based on poly-oxy alkylene phenol formaldehyde. The arabinose ester was synthesized on the Petroleum Research Laboratory - UFRN, through enzymatic catalysis by protease from Bacillus subtilis, using arabinose and vegetable oil, in organic medium. In previous work [1], this sugar ester was evaluated as a possible water/oil demulsifier and the results were compared with the results of the commercial product based on poly-oxy alkylene phenol formaldehyde, showing that, for certain reaction conditions, the sugar ester presented better acting (71%) that the commercial product (33%) as demulsifier. In this work, the stability of this arabinose ester was evaluated in severe conditions of temperature, salinity and pH, through superficial tests in a tensiometer, using Wilhelmy plate method and the results were compared with the results obtained for two commercial products above mentioned. (author)

  14. Determination of critical pH and Al concentration of acidic Ultisols for wheat and canola crops

    Science.gov (United States)

    Abdulaha-Al Baquy, M.; Li, Jiu-Yu; Xu, Chen-Yang; Mehmood, Khalid; Xu, Ren-Kou

    2017-02-01

    Soil acidity has become a principal constraint in dry land crop production systems of acidic Ultisols in tropical and subtropical regions of southern China, where winter wheat and canola are cultivated as important rotational crops. There is little information on the determination of critical soil pH as well as aluminium (Al) concentration for wheat and canola crops. The objective of this study is to determine the critical soil pH and exchangeable aluminium concentration (AlKCl) for wheat and canola production. Two pot cultures with two Ultisols from Hunan and Anhui (SE China) were conducted for wheat and canola crops in a controlled growth chamber. Aluminium sulfate (Al2(SO4)3) and hydrated lime (Ca(OH)2) were used to obtain the target soil pH levels from 3.7 (Hunan) and 3.97 (Anhui) to 6.5. Plant height, shoot dry weight, root dry weight, and chlorophyll content (SPAD value) of wheat and canola were adversely affected by soil acidity in both locations. The critical soil pH and AlKCl of the Ultisol from Hunan for wheat were 5.29 and 0.56 cmol kg-1, respectively. At Anhui, the threshold soil pH and AlKCl for wheat were 4.66 and 1.72 cmol kg-1, respectively. On the other hand, the critical soil pH for canola was 5.65 and 4.87 for the Ultisols from Hunan and Anhui, respectively. The critical soil exchangeable Al for canola cannot be determined from the experiment of this study. The results suggested that the critical soil pH and AlKCl varied between different locations for the same variety of crop, due to the different soil types and their other soil chemical properties. The critical soil pH for canola was higher than that for wheat for both Ultisols, and thus canola was more sensitive to soil acidity. Therefore, we recommend that liming should be undertaken to increase soil pH if it falls below these critical soil pH levels for wheat and canola production.

  15. Crecimiento de café (Coffea arabica L. durante la etapa de almácigo en respuesta a la salinidad generada por fertilizantes

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    Siavosh Sadeghian Khalajabadi

    2014-12-01

    Full Text Available La salinidad del suelo puede afectar negativamente el crecimiento de las plantas, e incluso causar su muerte. Esta investigación tuvo como propósito, determinar el efecto de la salinidad generada por fertilizantes en el crecimiento de café Coffea arabica L. durante la etapa de almácigo. Se recolectaron muestras de suelo en dos Estaciones Experimentales (EE de Cenicafé (Naranjal en Caldas y Timbío en Cauca y una finca cafetera (FC en Jamundí (Valle del Cauca. Bajo el diseño completamente aleatorio se evaluó para cada suelo la respuesta de café variedad Caturra a 27 tratamientos (factorial 33, resultantes de tres dosis de calcio-Ca, de magnesio-Mg y de potasio-K (0, 1 y 3 g dm-3 de suelo, empleando como fuentes sulfatos. La conductividad eléctrica (C.E., como indicador de la salinidad, se incrementó en conformidad a las dosis, con valores más altos para el Mg, seguido por K y Ca, resultado que se relacionó principalmente con el índice de salinidad de los fertilizantes y su solubilidad. Las diferencias de la C.E. entre las localidades (EE Naranjal>EE Timbío>FC Jamundí se atribuyeron a la capacidad de éstos para retener la humedad. Conforme al aumento de la salinidad disminuyó el peso de las plantas, hasta causar síntomas de toxicidad y posterior muerte. El nivel crítico de la C.E., calculado para el 90% del crecimiento relativo, correspondió en promedio a 1,1 dS m-1.

  16. Análisis del perfil de expresión de proteínas del organismo halotolerante Tistlia consotensis bajo diferentes condiciones de salinidad

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    Carolina Rubiano-Labrador

    2016-12-01

    Full Text Available En su hábitat natural, Tistlia consotensis, una bacteria halotolerante aislada de un manantial salino colombiano, está expuesta a variaciones continuas en la osmolaridad necesitando por lo tanto una respuesta efectiva frente a cambios en la salinidad. Para determinar el perfil de expresión de proteínas de T. consotensis bajo diferentes salinidades (0, 5 y 40 g·l-1 NaCl se utilizó la técnica de electroforesis bidimensional (2-DE para analizar el cambio de expresión de sus proteínas en respuesta al estrés osmótico. De acuerdo a los resultados obtenidos, se identificaron 56 manchas proteicas con cambios significativos de expresión. En ausencia de NaCl, 22 manchas se sobre-expresaron y 5 se sub-expresaron mientras que a 40 g·l-1 de NaCl seis manchas se sub-expresaron. El análisis de los perfiles de expresión de proteínas de T. consotensis permitió determinar que esta bacteria halotolerante responde a los cambios de salinidad del medio expresando un perfil diferencial de proteínas, donde a mayor salinidad disminuye el número e intensidad de proteínas expresadas. Además, se detectaron proteínas que probablemente confieren a T. consotensis la capacidad de adaptación a condiciones cambiantes de salinidad.

  17. Factors Influencing Trends in pH in the Wootton et al. (2008) Dataset

    Science.gov (United States)

    In this report, the dataset collected by Wootton at Tatoosh Island during 2000 through 2010 is analyzed to assess whether the apparent rapid decline in the pH data can be explained by other more localized processes. Specifically, we focused on the role of river discharge on pH l...

  18. RESPUESTA DIFERENCIAL A LA SALINIDAD DE GENOTIPOS DE TOMATE (Lycopersicon esculentum Mill. EN PRIMERAS ETAPAS FENOLÓGICAS

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    Francisco Higinio Ruiz Espinoza

    2014-10-01

    Full Text Available La salinidad afecta tanto el crecimiento vegetativo como el desarrollo reproductivo de las plantas: puede reducir el número de flores, incrementar la esterilidad y alterar la duración de la floración y la maduración. En México, el tomate es una de las especies hortícolas de mayor importancia económica y social, en virtud del valor de su producción y por la demanda de mano de obra que genera, por lo que el objetivo del presente trabajo fue evaluar el efecto de la salinidad en variables morfológicas, en dos etapas fenológicas (germinación y crecimiento vegetativo inicial, de ocho genotipos de tomate, “Tropic, Feroz, Ace, Super Río Grande, Yaqui, Missouri, Vita y Floradade”, los cuales fueron expuestos a estrés salino mediante la adición de NaCl en concentraciones de 0, 50, 100, 150 y 200 mM, en un diseño experimental completamente al azar con cuatro repeticiones. En la etapa de germinación se midieron las variables morfométricas: porcentaje de germinación, peso fresco y seco de parte aérea, peso fresco de raíces. En la etapa de crecimiento vegetativo inicial se midieron: longitud de tallo, peso fresco de tallo, numero de hojas y área foliar. Los resultados de la etapa de germinación muestran que conforme se incrementó la concentración salina, el porcentaje de germinación disminuyó, siendo “Tropic y Yaqui” los que mostraron valores superiores. Por su parte, “Tropic y Missouri” mostraron el mayor peso fresco y seco de parte aérea, mientras que los genotipos con menor tolerancia en esta etapa fueron “Feroz, Vita y Ace”. En la etapa de crecimiento vegetativo inicial se determinó que los cultivares que presentaron mejor respuesta o mayor tolerancia al estrés salino fueron “Missouri, Tropic, Feroz y Vita”, mientras que los genotipos con menor tolerancia a la salinidad en esta etapa fueron “Floradade y Ace”. Se concluye que en ambas etapas fenológicas existe un diferencial potencial entre los

  19. HFE p.H63D polymorphism does not influence ALS phenotype and survival

    Science.gov (United States)

    Chiò, Adriano; Mora, Gabriele; Sabatelli, Mario; Caponnetto, Claudia; Lunetta, Christian; Traynor, Bryan J.; Johnson, Janel O.; Nalls, Mike A.; Calvo, Andrea; Moglia, Cristina; Borghero, Giuseppe; Monsurrò, Maria Rosaria; Bella, Vincenzo La; Volanti, Paolo; Simone, Isabella; Salvi, Fabrizio; Logullo, Francesco O.; Nilo, Riva; Giannini, Fabio; Mandrioli, Jessica; Tanel, Raffaella; Murru, Maria Rita; Mandich, Paola; Zollino, Marcella; Conforti, Francesca L.; Penco, Silvana

    2016-01-01

    It has been recently reported that the p.His63Asp polymorphism of the HFE gene accelerates disease progression both in the SOD1 transgenic mouse and in amyotrophic lateral sclerosis (ALS) patients. We have evaluated the effect of HFE p.His63Asp polymorphism on the phenotype in 1351 Italian ALS patients (232 of Sardinian ancestry). Patients were genotyped for the HFE p.His63Asp polymorphism (CC, GC, and GG). All patients were also assessed for C9ORF72, TARDBP, SOD1, and FUS mutations. Of the 1351 ALS patients, 363 (29.2%) were heterozygous (GC) for the p.His63Asp polymorphism and 30 (2.2%) were homozygous for the minor allele (GG). Patients with CC, GC, and GG polymorphisms did not significantly differ by age at onset, site of onset of symptoms, and survival; however, in SOD1 patients with CG or GG polymorphism had a significantly longer survival than those with a CC polymorphism. Differently from what observed in the mouse model of ALS, the HFE p.His63Asp polymorphism has no effect on ALS phenotype in this large series of Italian ALS patients. PMID:26174855

  20. The effect of pH and role of Ni{sup 2+} in zinc phosphating of 2024-Al alloy

    Energy Technology Data Exchange (ETDEWEB)

    Akhtar, A.S. [Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, V6T 1Z1 (Canada); Wong, K.C. [Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, V6T 1Z1 (Canada); Mitchell, K.A.R. [Department of Chemistry, University of British Columbia, 2036 Main Mall, Vancouver, BC, V6T 1Z1 (Canada)]. E-mail: karm@chem.ubc.ca

    2006-11-15

    Coatings formed on 2024-T3 aluminum alloy were studied by X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) after dipping in zinc phosphating (ZPO) baths at different acidities, for different lengths of time, and with or without Ni{sup 2+} additive. The overall objective was to learn more about the role of Ni{sup 2+} on the ZPO coating mechanism, particularly since this additive is believed to improve corrosion protection for the Al alloy. Secondary phosphates dominate the coatings when the Ni-containing solution is adjusted to starting pH values of either 3 or 5, while tertiary phosphate is predominant at pH 4. AlF{sub 3} precipitates during the early stages of the coating process. Ni{sup 2+} has two main roles in the mechanism. First, the rate of increase in local solution pH is retarded by the slower kinetics of reactions involving Ni{sup 2+} compared to Zn{sup 2+}, leading to thinner ZPO coatings when Ni{sup 2+} is present in the coating solution. Second, most Ni{sup 2+} deposition occurs during the later stages of the coating process, by nickel phosphate deposition and/or by formation of a Ni-rich oxide.

  1. Improving the low temperature ductility of NiAl. Ph.D. Thesis

    Science.gov (United States)

    Guha, Sumit

    1992-01-01

    The intermetallic NiAl exhibits excellent potential as a structural material for application in air-breathing and single-stage-to-orbit engines. Unfortunately NiAl is brittle at ambient temperature, which is partly attributed to the lack of five independent slip systems as required by von Mises criterion for uniform, volume conserving deformation since the operative group of zone axes (100) slip offers only three independent slip systems. Isostructural FeAl, however, deforms by group of zone axes (111) slip at room temperature which provides five independent slip systems. Thus, it was decided to macroalloy NiAl with Fe to promote group of zone axes (111) slip thereby possibly improving the ductility. For Ni - 30 at. (percent) Al - 20 at. (percent) Fe having essentially bcc microstructure indicated up to 6 percent tensile elongation combined with high yield strength (about 800 MPa). The results compare favorably with those of stoichiometric Ni - 50 at. (percent) Al which, however, deforms by group of zone axes (100) slip at room temperature. The multi-phase alloy approach has proven even more successful for Ni - 20 at. (percent) Al - 30 at. (percent) Fe. The high temperature ductility of the multi-phase alloy was attributed to deformation transfer across interphase boundaries and the crack stopping action of the constituent gamma/gamma' phase. While the constituent phase became increasingly brittle, the beta' phase became more ductile at elevated temperatures. Thus the multi-phase alloy did not exhibit any elevated temperature embrittlement. Similarly, while the beta' phase became weak at high temperatures, the gamma/gamma' phase exhibited better strength retention leading to the improved elevated temperature strength of the multi-phase alloy. Thus, the multi-phase alloy benefits from both its constituent phases, with each phase alleviating the disadvantages associated with the other phase over any temperature range. The multi-phase alloy approach is suggested as a

  2. CRECIMIENTO Y DESARROLLO DE VARIEDADES DE ALBAHACA (Ocimum basilicum L. EN CONDICIONES DE SALINIDAD

    Directory of Open Access Journals (Sweden)

    Juan José Reyes Pérez

    2014-01-01

    Full Text Available El cultivo de albahaca (Ocimum basilicum L. presenta amplia variabilidad en cuanto a la tolerancia al estrés salino, sin embargo es sensible durante el crecimiento inicial. El establecimiento de indicadores morfométricos que indiquen tolerancia a la salinidad por parte del cultivo es importante para recomendar a los agricultores la variedad más productiva en esas condiciones. El objetivo del estudio fue determinar el efecto del NaCl en el crecimiento y desarrollo de plantas de albahaca. Se evaluaron veinte variedades, en condiciones de malla sombra, con los tratamientos, 0, 50 y 100 mM de NaCl. Se estableció un experimento factorial con arreglo completamente al azar con cuatro repeticiones, considerando las veinte variedades de albahaca como factor A y los tratamientos salinos como factor B. Las variables que se midieron fueron longitud de tallo (cm, longitud de raíz (cm, biomasa fresca y seca de raíz, tallo, hoja (g y área foliar (cm2. Los resultados mostraron el efecto de las sales en el crecimiento de las variedades Sweet Dani y Dolly las cuales presentaron mayor longitud de tallo y raíz, mientras que Napoletano mostró mayor biomasa fresca y seca de raíz, tallo, y hoja. La variedad Sweet Dani presentó mayor área foliar.

  3. EXAFS study of mercury(II) sorption to Fe- and Al-(hydr)oxides: I. Effects of pH

    Science.gov (United States)

    Kim, C.S.; Rytuba, J.J.; Brown, Gordon E.

    2004-01-01

    The study of mercury sorption products in model systems using appropriate in situ molecular-scale probes can provide detailed information on the modes of sorption at mineral/water interfaces. Such studies are essential for assessing the influence of sorption processes on the transport of Hg in contaminated natural systems. Macroscopic uptake of Hg(II) on goethite (??-FeOOH), ??-alumina (??-Al2O3), and bayerite (??-Al(OH)3) as a function of pH has been combined with Hg L III-edge EXAFS spectroscopy, FTIR spectroscopy, and bond valence analysis of possible sorption products to provide this type of information. Macroscopic uptake measurements show that Hg(II) sorbs strongly to fine-grained powders of synthetic goethite (Hg sorption density ??=0.39-0.42 ??mol/m2) and bayerite (??=0.39-0.44 ??mol/m2), while sorbing more weakly to ??-alumina (??=0.04-0.13 ??mol/m 2). EXAFS spectroscopy on the sorption samples shows that the dominant mode of Hg sorption on these phases is as monodentate and bidentate inner-sphere complexes. The mode of Hg(II) sorption to goethite was similar over the pH range 4.3-7.4, as were those of Hg(II) sorption to bayerite over the pH range 5.1-7.9. Conversion of the ??-Al2O3 sorbent to a bayerite-like phase in addition to the apparent reduction of Hg(II) to Hg(I), possibly by photoreduction during EXAFS data collection, resulted in enhanced Hg uptake from pH 5.2-7.8 and changes in the modes of sorption that correlate with the formation of the bayerite-like phase. Bond valence calculations are consistent with the sorption modes proposed from EXAFS analysis. EXAFS analysis of Hg(II) sorption products on a natural Fe oxyhydroxide precipitate and Al/Si-bearing flocculent material showed sorption products and modes of surface attachment similar to those for the model substrates, indicating that the model substrates are useful surrogates for the natural sediments. ?? 2003 Elsevier Inc. All rights reserved.

  4. Efectos de la salinidad sobre el desarrollo de embriones de Cryphiops caementarius (Crustacea: Palaemonidae incubados in vitro

    Directory of Open Access Journals (Sweden)

    Adelhi S. Fuentes

    2011-05-01

    Full Text Available El objetivo fue estudiar los efectos de la salinidad sobre el desarrollo de embriones de Cryphiops caementa- rius incubados in vitro. Se utilizaron embriones de desarrollo temprano procedentes de una sola hembra. Se emplearon incubadoras de 400 mL, con 4 tratamientos de salinidades de 0, 10, 20 y 30‰, tres replicas, y 200 embriones cada incubadora. El 80% del agua se renovó frecuentemente. Las salinidades entre 0 y 30‰ no afectaron el desarrollo de los embriones hasta el estadio 6. Las salinidades de 10 y 20‰ ocasionaron retraso del desarrollo de los estadios 7 y 8; y la salinidad de 30‰ ocasionó muerte del estadio 7. En agua dulce el 70,3% de los embriones supervivieron y las larvas fueron normales; en cambio en salinidad de 10‰ el 13,5% y en 20‰ solo 7,9% lograron eclosionar larvas pero con deformaciones.

  5. Sterically crowded monomeric neutral bis(benzamidinato) compounds of aluminium, [PhC(NSiMe(3))(2)](2)AlX (X=Cl, H); X-ray crystal structure of [PhC(NSiMe(3))(2)]2AlH

    NARCIS (Netherlands)

    Duchateau, R; Meetsma, A; Teuben, JH

    1996-01-01

    AlCl3 reacts with [PhC(NSiMe(3))(2)]Li(OEt(2)) to afford the bis(N,N'-bis(trimethylsilyl)benzamidinato)aluminium chloro compound which, on treatment with KBEt(3)H, yields the structurally characterized monomeric hydride derivative, [PhC(NSiMe(3))(2)]2AlH, whose reactivity towards unsaturated

  6. Changes in 22Na influx and outflux in Daphnia magna (Straus) as a function of elevated Al concentrations in soft water at low pH

    International Nuclear Information System (INIS)

    Havas, M.; Likens, G.E.

    1985-01-01

    The effects of aluminum on sodium regulation by the freshwater crustacean Daphnia magna were determined. 22 Na influx and outflux experiments were conducted in soft water adjusted to pH 4.5, 5.0, and 6.5 (reference pH) with either ambient (0.02 mg/liter) or high (1.02 mg/liter) concentrations of total Al. The results indicate that Al toxicity was pH dependent. Aluminum increased the rate of morbidity of D. magna at pH 6.5, had no additional effect to those of hydrogen ions (H + ) at pH 5.0, and reduced the rate of morbidity at pH 4.5. Both H + and total Al concentrations interfered with Na regulation, although it was possible to distinguish between their respective effects by using 22 Na. At pH 6.5, Al decreased 22 Na influx (by 46%) and increased 22 Na outflux (by 25%), which led to a net loss of Na. At pH 5.0, Al reduced 22 Na influx (by 58%) but had not additional effect to that of H + on 22 Na outflux. At pH 4.5, 22 Na influx was significantly inhibited (by 73%) compared with the reference pH 6.5 treatment even in the absence of Al. Aluminum decreased 22 Na outflux (by 31%) at pH 4.5, which reduced the net loss of Na and temporarily prolonged survival of the daphnids. These results indicate that Al affects both 22 Na influx and outflux in D. magna. The lower rate of Na uptake may involve a denaturation of the enzyme responsible for the active uptake of Na. At pH 6.5, the increased outflux of 22 Na may be due to either increased membrane permeability or increased renal losses (or both). At pH 4.5, the reduced outflux of 22 Na resembles the amelioration that occurs in the presence of elevated Ca concentrations

  7. Salinidad en Cuba y tratamientos pregerminativos de hidratación-deshidratación de semillas

    Directory of Open Access Journals (Sweden)

    Mayté Pernús

    Full Text Available La salinidad de los suelos es uno de los principales factores abióticos que afectan el establecimiento y la productividad de las plantas, efecto que se incrementa a escala global. Una ecotecnología de fácil implementación que ha probado ser eficiente para mejorar la germinación, el crecimiento y la productividad de las plantas cultivadas y silvestres, en diferentes escenarios de estrés (e.g., hídrico, calórico, ácido y salinidad, es el tratamiento de hidratación-deshidratación (HD de las semillas. En esta revisión se informa sobre el estado de salinidad de los suelos cubanos, los principales efectos de la salinidad en las plantas y las diferentes tecnologías que existen para el manejo de los suelos salinos. Se discuten los efectos positivos de los tratamientos de HD en el comportamiento de las plantas en condiciones de salinidad, así como aspectos teóricos y prácticos relacionados con la aplicación de estos procedimientos fisiológicos para facilitar su introducción en las prácticas agroforestales y silvopastoriles.

  8. Assessment of the Binding of Protons, Al and Fe to Biochar at Different pH Values and Soluble Metal Concentrations

    Directory of Open Access Journals (Sweden)

    Tan Dang

    2018-01-01

    Full Text Available Biochar can retain large amounts of protons and metals in the drainage water from acid sulfate soils and mine sites. Metal sorption can, however, be influenced by many factors, such as pH and metal composition. This study investigated proton, Al, and Fe retention capacity of eucalyptus biochar (1% w/v at different pH and metal concentrations. In the absence of metals, the biochar had a high proton binding capacity, (up to 0.035 mmol of H+, whereas its capacity to retain hydroxide ions was limited. A batch experiment was carried out at pH 4 and pH 7 with 10−6, 10−5, 10−4, 10−3, and 10−2 M of added Fe or Al. Added metals precipitated considerably prior to addition of the biochar except that Al remained highly soluble at pH 4. The biochar had a high retention capacity for Al and Fe; at high (>1 mM concentrations, over 80% of soluble metals were retained. Metal competition for binding sites of both Al and Fe at different ratios was investigated, but increasing concentrations of one metal did not reduce retention of the other. The results confirmed that biochar has high metal binding capacity under both acidic and neutral conditions.

  9. Densidade de estocagem e salinidade da água na larvicultura do pacamã

    OpenAIRE

    Luz,Ronald Kennedy; Santos,José Cláudio Epaminondas dos

    2008-01-01

    O objetivo deste trabalho foi avaliar o efeito da densidade de estocagem e da salinidade da água, na larvicultura do pacamã Lophiosilurus alexandri, alimentado com náuplios de Artemia sp. Foram utilizadas três densidades de estocagem: 20, 40 e 60 larvas L-1 (D20, D40 e D60, respectivamente). Para cada densidade testaram-se três índices de salinidade da água: água doce (S0), 2‰ (S2) e 4‰ (S4), em delineamento experimental inteiramente ao acaso, em esquema fatorial 3x3, com três repetições. For...

  10. Effect of pH on the Nitrite Hydrogenation Mechanism over Pd/Al2O3 and Pt/Al2O3: Details Obtained with ATR-IR Spectroscopy

    DEFF Research Database (Denmark)

    Ebbesen, Sune Dalgaard; Mojet, Barbara L.; Lefferts, Leon

    2011-01-01

    It is well-known that activity and selectivity to N2 during nitrite hydrogenation over noble metal catalysts in water depend on the pH of the solution, but mechanistic understanding is lacking. Attenuated total reflection infrared (ATR-IR) spectroscopy is an ideal tool to perform detailed studies...... on catalytic surfaces in water. In this paper, the influence of pH was studied on adsorption and subsequent hydrogenation of nitrite in water between pH 5 and 9 over Pd/Al2O3 and Pt/Al2O3, using ATR-IR spectroscopy. On both catalysts, pH clearly influenced the surface coverage and reaction rates...... of intermediates. For Pt/Al2O3, lowering the pH induced the increasing surface coverage of key reaction intermediates like NOsteps1620cm−1 and “HNO”(ads)1540cm−1, as well as increased hydrogenation rates, explaining the higher TOF at lower pH as reported in the literature. For Pd/Al2O3, the effect of p...

  11. Fe/Al bimetallic particles for the fast and highly efficient removal of Cr(VI) over a wide pH range: Performance and mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Fenglian, E-mail: fufenglian2006@163.com [School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Environmental Engineering and Science Program, Department of Biomedical, Chemical and Environmental Engineering (DBCEE), University of Cincinnati, OH 45221-0012 (United States); Cheng, Zihang [School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Dionysiou, Dionysios D., E-mail: dionysios.d.dionysiou@uc.edu [Environmental Engineering and Science Program, Department of Biomedical, Chemical and Environmental Engineering (DBCEE), University of Cincinnati, OH 45221-0012 (United States); Tang, Bing [School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006 (China)

    2015-11-15

    Highlights: • Bimetallic particles with different Fe/Al mass ratios were prepared. • High removal rate of Cr(VI) was achieved in acidic, neutral, and alkaline pH. • No total iron ions at pH 3.0–11.0 and nearly no Al{sup 3+} at pH 3.0–7.0 were released. • Galvanic cell effect and high specific surface area contributed to Cr(VI) removal. - Abstract: The iron/aluminum (Fe/Al) bimetallic particles with high efficiency for the removal of Cr(VI) were prepared. Fe/Al bimetallic particles were characterized by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), SEM mapping, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). SEM mapping showed that the core of bimetal was Al, and the planting Fe was deposited on the surface of Al. In acidic and neutral conditions, Fe/Al bimetal can completely remove Cr(VI) from wastewater in 20 min. Even at pH 11.0, the Cr(VI) removal efficiency achieved was 93.5%. Galvanic cell effect and high specific surface area are the main reasons for the enhanced removal of Cr(VI) by bimetallic particles. There were no iron ions released in solutions at pH values ranging from 3.0 to 11.0. The released Al{sup 3+} ions concentrations in acidic and neutral conditions were all less than 0.2 mg/L. The bimetal can be used 4 times without losing activity at initial pH 3.0. XPS indicated that the removed Cr(VI) was immobilized via the formation of Cr(III) hydroxide and Cr(III)–Fe(III) hydroxide/oxyhydroxide on the surface of Fe/Al bimetal. The Fe/Al bimetallic particles are promising for further testing for the rapid and effective removal of contaminants from water.

  12. Aluminium uptake and translocation in Al hyperaccumulator Rumex obtusifolius is affected by low-molecular-weight organic acids content and soil pH.

    Directory of Open Access Journals (Sweden)

    Stanislava Vondráčková

    Full Text Available High Al resistance of Rumex obtusifolius together with its ability to accumulate Al has never been studied in weakly acidic conditions (pH > 5.8 and is not sufficiently described in real soil conditions. The potential elucidation of the role of organic acids in plant can explain the Al tolerance mechanism.We established a pot experiment with R. obtusifolius planted in slightly acidic and alkaline soils. For the manipulation of Al availability, both soils were untreated and treated by lime and superphosphate. We determined mobile Al concentrations in soils and concentrations of Al and organic acids in organs.Al availability correlated positively to the extraction of organic acids (citric acid < oxalic acid in soils. Monovalent Al cations were the most abundant mobile Al forms with positive charge in soils. Liming and superphosphate application were ambiguous measures for changing Al mobility in soils. Elevated transport of total Al from belowground organs into leaves was recorded in both lime-treated soils and in superphosphate-treated alkaline soil as a result of sufficient amount of Ca available from soil solution as well as from superphosphate that can probably modify distribution of total Al in R. obtusifolius as a representative of "oxalate plants." The highest concentrations of Al and organic acids were recorded in the leaves, followed by the stem and belowground organ infusions.In alkaline soil, R. obtusifolius is an Al-hyperaccumulator with the highest concentrations of oxalate in leaves, of malate in stems, and of citrate in belowground organs. These organic acids form strong complexes with Al that can play a key role in internal Al tolerance but the used methods did not allow us to distinguish the proportion of total Al-organic complexes to the free organic acids.

  13. Processing and Mechanical Properties of NiAl-Based In-Situ Composites. Ph.D. Thesis Final Report

    Science.gov (United States)

    Johnson, David Ray

    1994-01-01

    In-situ composites based on the NiAl-Cr eutectic system were successfully produced by containerless processing and evaluated. The NiAl-Cr alloys had a fibrous microstructure while the NiAl-(Cr,Mo) alloys containing 1 at. percent or more molybdenum exhibited a lamellar structure. The NiAl-28Cr-6Mo eutectic displays promising high temperature strength while still maintaining a reasonable room temperature fracture toughness when compared to other NiAl-based materials. The Laves phase NiAlTa was used to strengthen NiAl and very promising creep strengths were found for the directionally solidified NiAl-NiAlTa eutectic. The eutectic composition was found to be near NiAl-15.5Ta (at. percent) and well aligned microstructures were produced at this composition. An off-eutectic composition of NiAl-14.5Ta was also processed, consisting of NiAl dendrites surrounded by aligned eutectic regions. The room temperature toughness of these two phase alloys was similar to that of polycrystalline NiAl even with the presence of the brittle Laves phase NiAlTa. Polyphase in-situ composites were generated by directional solidification of ternary eutectics. The systems investigated were the Ni-Al-Ta-X (X=Cr, Mo, or V) alloys. Ternary eutectics were found in each of these systems and both the eutectic composition and temperature were determined. Of these ternary eutectics, the one in the NiAl-Ta-Cr system was found to be the most promising. The fracture toughness of the NiAl-(Cr,Al)NiTa-Cr eutectic was intermediate between those of the NiAl-NiAlTa eutectic and the NiAl-Cr eutectic. The creep strength of this ternary eutectic was similar to or greater than that of the NiAl-Cr eutectic.

  14. Microstructure of Al2O3 scales formed on NiCrAl alloys. Ph.D. Thesis - Case Western Reserve Univ.

    Science.gov (United States)

    Smialek, J. L.

    1981-01-01

    The structure of transient scales formed on pure and Y or Zr-doped Ni-15Cr-13Al alloys oxidized for 0.1 hr at 1100 C was studied by the use of transmission electron microscopy. Crystallographically oriented scales were found on all three alloys, but especially for the Zr-doped NiCrAl. The oriented scales consisted of alpha-(Al,Cr)2O3, Ni(Al,Cr)2O4 and gamma-Al2O3. They were often found in intimate contact with each other such that the close-packed planes and directions of one oxide phase were aligned with those of another. The prominent structural features of the oriented scales were approximately equal to micrometer subgrains; voids, antiphase domain boundaries and aligned precipitates were also prevalent. Randomly oriented alpha-Al2O3 was also found and was the only oxide ever observed at the immediate oxide metal interface. These approximately 0.15 micrometer grains were populated by intragranular voids which decreased in size and number towards the oxide metal interface. A sequence of oxidation was proposed in which the composition of the growing scale changed from oriented oxides rich in Ni and Cr to oriented oxides rich in Al. At the same time the structure changed from cubic spinels to hexagonal corundums with apparent precipitates of one phase in the matrix of the other. Eventually randomly oriented pure alpha-Al2O3 formed as the stable oxide with an abrupt transition: there was no gradual loss of orientation, no gradual compositional change or no gradual decrease in precipitate density.

  15. Arsenic Scavenging by Al-Substituted Ferrihydrites in a Circumneutral pH River Impacted by the Acid Mine Drainage of Carnoulès, Gard, France

    Science.gov (United States)

    ADRA, A.; Morin, G.; ona-Nguema, G.; Maillot, F.; Casiot, C.; Bruneel, O.

    2013-12-01

    Ferrihydrite (Fh) is a nanocrystalline ferric oxyhydroxide involved in the retention of pollutants in natural systems and in water-treatment processes. The status and properties of major chemical impurities in natural Fh is however still scarcely documented. Here we investigated the structure and reactivity of aluminum-rich Fh from river-bed sediments collected in a circumneutral river (pH 6-7) impacted by an arsenic-rich acid mine drainage (AMD). Extended X-ray absorption fine structure (EXAFS) spectroscopy at the Fe K-edge shows that Fh is the predominant mineral phase forming after neutralization of the AMD, in association with minor amount of schwertmannite transported from the AMD. EXAFS analysis indicates that Al(III) substitutes for Fe(III) ions into the Fh structure in the natural sediment samples, with local aluminum concentration within the 20-37×7 mol%Al range, in agreement with bulk chemical compositions. Synthetic aluminous Fh analogues prepared in the present study are found to be less Al-substituted (14-18×4 mol%Al). Finally, EXAFS analysis at the arsenic K-edge indicates that As(V) form similar inner-sphere surface complexes on the natural and synthetic Al-substituted Fh studied. Our results provide direct evidences for the scavenging of arsenic by natural Al- Fh, with possible implications for other pollutants in natural or engineered systems.

  16. Adsorption of tetracycline on Fe (hydr)oxides: effects of pH and metal cation (Cu2+, Zn2+ and Al3+) addition in various molar ratios

    Science.gov (United States)

    Hsu, Liang-Ching; Liu, Yu-Ting; Syu, Chien-Hui; Huang, Mei-Hsia; Teah, Heng Yi

    2018-01-01

    Iron (Fe) (hydr)oxides control the mobility and bioavailability of tetracycline (TC) in waters and soils. Adsorption of TC on Fe (hydr)oxides is greatly affected by polyvalent metals; however, impacts of molar metal/TC ratios on TC adsorptive behaviours on Fe (hydr)oxides remain unclear. Results showed that maximum TC adsorption on ferrihydrite and goethite occurred at pH 5–6. Such TC adsorption was generally promoted by the addition of Cu2+, Zn2+ and Al3+. The greatest increase in TC adsorption was found in the system with molar Cu/TC ratio of 3 due to the formation of Fe hydr(oxide)–Cu–TC ternary complexes. Functional groups on TC that were responsible for the complexation with Cu2+shifted from phenolic diketone groups at Cu/TC molar ratio adsorption at a molar Al/TC ratio of 1. However, TC adsorption decreased for Al/TC molar ratio > 1 as excess Al3+ led to the competitive adsorption with Al/TC complexes. For the Zn2+ addition, no significant correlation was found between TC adsorption capacity and molar Zn/TC ratios. PMID:29657795

  17. Efecto de la aplicaci??n N-K en condiciones de salinidad, sobre algunos parametros fisiol??gicos y bioqu??micos en plantas de pimiento (capsicum annuum L. cv. Lamuyo)

    OpenAIRE

    S??nchez Prados, Agust??n

    1993-01-01

    Debido al avance en las t??cnicas de cultivo, aplicaci??n de fertilizantes, mejora de la calidad de las semillas, uso de h??bridos resistentes a enfermedades, etc..., el cultivo bajo pl??stico ha sufrido en los ??ltimos a??os un incremento bastante importante, sobre todo en el sureste espa??ol. una de las especies que su cultivo se ha visto incrementado, es el pimiento (capsicum annuum l.). Adem??s se requiere un conocimiento mas adecuado de las relaciones fertilizaci??n- salinidad debido a l...

  18. The preparation of nanosized polyethylene particles via novel heterogeneous non-metallocene catalyst (m-CH3PhO)TiCl3/CNTs/AlEt3

    Science.gov (United States)

    Wang, J.; Guo, J. P.; Yi, J. J.; Huang, Q. G.; Li, H. M.; Li, Y. F.; Gao, K. J.; Yang, W. T.

    2014-08-01

    This paper reports the preparation of coral-shaped topological morphology nascent polyethylene (PE) particles promoted by the novel heterogeneous non-metallocene catalyst (m-CH3PhO)TiCl3/carbon nanotubes (CNTs), with AlEt3 used as a cocatalyst. Scanning electron microscope (SEM), high resolution transmission electron microscope (HR-TEM) and inductively coupled plasma (ICP) emission spectroscopy were used to determine the morphology of the catalyst particles and the content of (m-CH3PhO)TiCl3. The carbon nanotube surface was treated with Grignard Reagent prior to reacting with (m-CH3PhO)TiCl3. The catalyst system could effectively catalyze ethylene polymerization and ethylene with 1- hexene copolymerization, the catalytic activity could reach up to 5.8 kg/((gTi)h). Morphology of the obtained polymer particles by SEM and HR-TEM technique revealed that the nascent polyethylene particles looked like coral shape in micro-size. The multiwalled carbon nanotubes (MWCNTs) supported catalysts polymerized ethylene to form polymer nanocomposite in situ. The microscopic examination of this nanocomposite revealed that carbon nanoparticles in PE matrix had a good distribution and the cryogenically fractured surface was ductile-like when polymerization time was 2 min.

  19. The preparation of nanosized polyethylene particles via novel heterogeneous non-metallocene catalyst (m-CH3PhO)TiCl3/CNTs/AlEt3

    International Nuclear Information System (INIS)

    Wang, J; Guo, J P; Huang, Q G; Li, Y F; Yang, W T; Yi, J J; Li, H M; Gao, K J

    2014-01-01

    This paper reports the preparation of coral-shaped topological morphology nascent polyethylene (PE) particles promoted by the novel heterogeneous non-metallocene catalyst (m-CH 3 PhO)TiCl 3 /carbon nanotubes (CNTs), with AlEt 3 used as a cocatalyst. Scanning electron microscope (SEM), high resolution transmission electron microscope (HR-TEM) and inductively coupled plasma (ICP) emission spectroscopy were used to determine the morphology of the catalyst particles and the content of (m-CH 3 PhO)TiCl 3 . The carbon nanotube surface was treated with Grignard Reagent prior to reacting with (m-CH 3 PhO)TiCl 3 . The catalyst system could effectively catalyze ethylene polymerization and ethylene with 1- hexene copolymerization, the catalytic activity could reach up to 5.8 kg/((gTi)h). Morphology of the obtained polymer particles by SEM and HR-TEM technique revealed that the nascent polyethylene particles looked like coral shape in micro-size. The multiwalled carbon nanotubes (MWCNTs) supported catalysts polymerized ethylene to form polymer nanocomposite in situ. The microscopic examination of this nanocomposite revealed that carbon nanoparticles in PE matrix had a good distribution and the cryogenically fractured surface was ductile-like when polymerization time was 2 min

  20. Germinación de Diferentes cultivos en condiciones de salinidad cuantitativa y cualitativa

    OpenAIRE

    González Romero, Sara Lucia

    2012-01-01

    El presente estudio se llevó a cabo en dos fases. La primera fue con el propósito de evaluar, en la etapa de germinación de algunos cultivos, la tolerancia a la salinidad en siete niveles de conductividad eléctrica (CE) constante para cada sal. En la segunda fase se evaluó la tolerancia del pasto Banderita a temperatura contante y en soluciones isosmóticas. Los resultados obtenidos en la primera fase mostraron que las sales con predominio de Cl- generaron una CE mayor, y u...

  1. Estudio de la interacción salinidad x fitorregulador en "Chrysanthemum coronarium" L. cultivado en maceta

    OpenAIRE

    Pastor Pérez, Yolanda

    2009-01-01

    En la producción viverística de la regiones afectadas por la salinidad es frecuente regar con aguas salinas, lo que puede ocasionar problemas de crecimiento y desarrollo en las especies cultivadas, que repercuten negativamente en la calidad de la planta. Los síntomas más comunes de la salinidad en la producción de plantas ornamentales son la reducción del crecimiento, la manifestación de clorosis y necrosis foliares, y la caída de las hojas. Algunos autores han estudiado si la ...

  2. POLIAMINAS COMO MARCADORES BIOQUÍMICOS DE SALINIDADE EM CALOS DE Eucalyptus urograndis

    Directory of Open Access Journals (Sweden)

    Giuseppina Pace Pereira Lima

    2002-11-01

    Full Text Available Marcadores bioquímicos têm sido usados na análise de plantas submetidas a vários tipos de estresse, entre eles a salinidade. Este trabalho teve como objetivo analisar o estresse salino em calos de Eucalyptus urograndis em relação ao conteúdo de poliaminas. Explantes (hipocótilos obtidos de sementes foram inoculados em meio indutivo de calos e foram submetidos a diferentes níveis de NaCl e analisados aos 10, 20 e 30 dias de inoculação. As poliaminas livres foram extraídas, isoladas e quantificadas usando TLC (Cromatografia de Camada Delgada. O conteúdo de putrescina foi maior, enquanto que o conteúdo de espermidina apresentou decréscimo, em calos submetidos a condições salinas. Os resultados mostram que o acúmulo de putrescina está relacionado com a exposição a NaCl em calos de Eucalyptus urograndis. A diminuição do conteúdo de espermina pode ser usada como marcador bioquímico de calos de Eucalyptus sujeitos à salinidade.

  3. Balanço hídrico e da salinidade do solo na bananeira irrigada com água de diferentes salinidades = Soil water and salinity balance on banana irrigated with water of varied salinity

    Directory of Open Access Journals (Sweden)

    Ancélio Ricardo de Oliveira Gondim

    2009-01-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito de diferentes níveis de salinidade de água de irrigação no uso consultivo na fase reprodutiva da bananeira e evolução da salinidade do solo. Adotou-se o delineamento inteiramente casualizado em parcelas subdivididas, totalizando oito tratamentos com quatro repetições por tratamento. Os níveis de salinidade foram obtidos a partir de águas naturais de poços dos aquíferos arenito e calcário e foram misturadas em tanques de alvenaria para a obtenção das concentrações de salinidade desejada. Verificou-se que a área do bulbo com umidade superior a 8% representa aproximadamente 50% do volume do solo. A evapotranspiração da cultura diminuiu com o aumento da salinidade entre os tratamentos, o kc médio no período variou de 1,01 a 1,09 em águas de salinidade extremas. Comparando os perfis da salinidade do solo, verificou-se quea concentração de sais foi superior na camada superficial aos 440 dias após plantio.The objective this work was to evaluate the advisory use of two cultivars banana and the salinity of the soil in different water salinity levels (0.55; 1.70; 2.85; and 4.00 dS m-1 during the reproductive phase. The experimental design chosen was randomizedcomplete blocks in subdivided plots, totaling eight treatments with four repetitions per treatment. The salinity levels were obtained from natural waters of wells from sandstone and calcareous aquifers and were mixed in masonry tanks in order to obtain the desiredsalinity concentrations. It was verified that the area of the bulb with moisture greater than 8% represents approximately 50% of the volume of the soil. The evapotranspiration of the culture decreased with the increase in the salinity among the treatments; the average kc in the period varied from 1.01 to 1.09 in waters of extreme salinity. Comparing the salinity profiles of the soil, it was verified that the concentration of salts was highest on the surfacelayer at 440

  4. Ein abgründiges Thema – Inzest als historisches Phänomen An Abysmal Issue—Incest as Historical Phenomenon

    Directory of Open Access Journals (Sweden)

    Pascal Eitler

    2004-11-01

    Full Text Available Der vorliegende Sammelband bietet einen vielschichtigen, aber ergänzungsbedürftigen Überblick zur Geschichte der Inzestproblematik vom 13. bis zum 20. Jahrhundert. Er beinhaltet interdisziplinäre Studien sowohl zu dem sich historisch wandelnden Inzestbegriff als auch zu der sich verändernden Umgangsweise mit dem Phänomen Inzest. Im Zentrum des Interesses stehen dabei die unterschiedlichen Verwandtschaftsvorstellungen und Sexualitätsnormen, die im Rahmen der Inzestthematik verhandelt werden.The collection at hand offers a multilayered historical overview, though in need of some addition, of the incest problematic from the Thirteenth to the Twentieth Century. It contains interdisciplinary studies on the historically changing definition of incest as well as the changing ways of approaching the phenomenon of incest itself. Differing perceptions of familial relations and sexual norms, negotiated within the framework of the incest thematic, form the core concern of the study.

  5. La salinidad y la distribución espacial de la ictiofauna en el estuario del Río de la Plata

    OpenAIRE

    Rico, M.R.

    2000-01-01

    Los ecosistemas estuariales se caracterizan por su alta productividad, baja diversidad biológica y fluctuaciones impredecibles de salinidad. A su vez, la distribución espacial de su ictiofauna resulta en general suficientemente explicada por los patrones de distribución de la salinidad. En particular, en el estuario del Río de la Plata (35° 00' S y 55° 30' W) que presenta una marcada estratificación vertical de densidad, dominada por la salinidad, se analizó cuantitativamente la relación entr...

  6. AJUSTAMENTO OSMÓTICO EM MUDAS DE JATOBÁ SUBMETIDAS À SALINIDADE EM MEIO HIDROPÔNICO

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    Hugo Henrique Costa do Nascimento

    2015-08-01

    Full Text Available RESUMOEm ambientes naturais, a salinidade representa grande empecilho ao desenvolvimento dos vegetais. Visando à melhor compreensão dos efeitos que ela provoca na fisiologia de espécies arbóreas nativas, este trabalho objetivou avaliar o comportamento fisiológico de mudas de jatobá (Hymenaea courbaril L. submetidas à salinidade em meio hidropônico. Portanto, um experimento foi realizado em casa de vegetação do Laboratório de Fisiologia Vegetal da Universidade Federal Rural de Pernambuco, adotando-se um delineamento experimental inteiramente casualizado em arranjo fatorial 3 x 2, composto por três tratamentos salinos: Controle (solução nutritiva sem adição de NaCl, Estresse moderado (adição de 50 mM de NaCl e Estresse severo (adição de 100 mM de NaCl e duas épocas de avaliação (1ª época: constatação do fechamento estomático; e 2ª época: após a verificação da abertura estomática das plantas submetidas à salinidade, com 20 repetições em cada tratamento. Durante o estudo, foram verificadas as trocas gasosas, as relações hídricas, os teores de pigmentos fotossintéticos e o acúmulo de solutos orgânicos e inorgânicos. Ao final do experimento, observou-se que as mudas de jatobá se ajustaram osmoticamente após a indução do estresse severo, uma vez que acumularam solutos orgânicos que promoveram a elevação da turgescência foliar, resultando na estabilização das trocas gasosas, mesmo após a submissão ao estresse severo.

  7. Tolerancia de plantas de feijoa (Acca sellowiana [Berg] Burret a la salinidad por NaCl

    Directory of Open Access Journals (Sweden)

    Casierra-Posada Fánor Ernesto

    2006-12-01

    Full Text Available

    Los efectos de la salinidad por NaCl sobre la producción y la distribución de la biomasa, la toma de agua y el área foliar total fueron investigados en plantas de feijoa (Acca sellowiana [Berg] Burret cultivadas en materas con suelo bajo condiciones de invernadero, durante ocho meses. Los tratamientos con la sal comenzaron 60 d después del transplante. El NaCl fue agregado en diferentes concentraciones: 0, 20, 40, 60, 80 mM de NaCl en el suelo. Estas concentraciones correspondieron a conductividades eléctricas de 2,8; 4,6; 6,1; 8,4 y 11,1 dS· m-1, respectivamente. Para evitar el choque osmótico, el tratamiento salino fue impuesto progresivamente, aumentando la concentración de sal cada semana hasta alcanzar la

  8. Fotossíntese e acúmulo de solutos em feijoeiro caupi submetido à salinidade

    Directory of Open Access Journals (Sweden)

    Rogéria Pereira Souza

    2011-06-01

    Full Text Available O objetivo deste trabalho foi determinar as respostas fotossintéticas e a acumulação de carboidratos, íons salinos e prolina em feijoeiro caupi (Vigna unguiculata submetido à salinidade. As plantas foram submetidas à quatro tratamentos, dos 28 aos 35 dias de idade: 0, 50, 100 e 200 mmol L-1 de NaCl. Avaliaramse as trocas gasosas, a emissão de fluorescência pela clorofila a, o potencial hídrico foliar, e as concentrações de carboidratos, Na+, Cl- e prolina nas folhas. Os tratamentos não tiveram efeito sobre a eficiência quântica potencial do fotossistema II, mas causaram leve diminuição na eficiência quântica efetiva e maior dissipação do excesso de energia de excitação por processos não fotoquímicos. As concentrações foliares de amido diminuíram, e as de sacarose e prolina aumentaram nas maiores concentrações de NaCl. Ocorreu exclusão do Na+ e acúmulo do Cl- nas folhas, e as relações hídricas das folhas foram pouco afetadas, exceto no tratamento mais severo. O acúmulo de Cl- esteve envolvido na redução da assimilação de CO2, decorrente da queda na condutância estomática e na eficiência de carboxilação da Rubisco. O feijoeiro caupi apresenta características fisiológicas que favorecem a manutenção da atividade fotossintética sob curta exposição à salinidade.

  9. Effect of pH on the Water/{alpha}-Al{sub 2}O{sub 3} (1{bar 1}02) interface structure studied by sum-frequency vibrational spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Sung, J.; Zhang, L.; Tian, C.; Shen, Y. R.; Waychunas, G. A.

    2011-08-01

    Sum frequency vibrational spectroscopy (SFVS) was used to study the structure of water/{alpha} - Al{sub 2}O{sub 3} (1{bar 1}02 ) interfaces at different pH values. The OH stretch spectra are dominated by interfacial water contributions at lower frequencies, and by bonded hydroxyls on the Al{sub 2}O{sub 3} surface at higher frequencies. Protonation and deprotonation of various oxide functional groups at the {alpha}-Al{sub 2}O{sub 3} surface as pH varies can be monitored quantitatively by changes of the spectrum, allowing their pK reaction values can be estimated. The point of zero charge of the interface is found to be at pH ~ 6.7.

  10. Besprechung: W. SEIBT-J. PREISER-KAPELLER (Hgg., Die Entstehung der kaukasischen Alphabete als kulturhistorisches Phänomen, Wien 2011

    Directory of Open Access Journals (Sweden)

    Nino DOBORJGINIDZE

    2014-01-01

    Full Text Available Normal 0 false false false EL X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Κανονικός πίνακας"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Besprechung:W. Seibt – J. Preiser-Kapeller (Hgg., Die Entstehung der kaukasischen Alphabete als kulturhistorisches Phänomen. Referate des Internationalen Symposions (Wien, 1.-4. Dezember 2005, Verlag der Österreichischen Akademie der Wissenschaften, Wien 2011 (=Österreichische Akademie der Wissenschaften. Phil.-hist. Kl. Denkschriften, 430. Band; Veröffentlichungen zur Byzanzforschung, Band 28. ISBN 978-3-7001-7088-4

  11. Evaluación general de la salinidad y modelación de los riesgos de salinización en suelos del Valle del Cauca: uso práctico del modelo PLA para evaluar el riesgo de salinización en tierras bajo riego en la parte plana del Valle del Cauca (Colombia)

    OpenAIRE

    Ramírez Alzate, Jorge Armando

    2011-01-01

    La investigación se desarrolló basándose en evidencias y estudios previos de salinidad. Se muestrearon 100 suelos y aguas de riego utilizados en caña de azúcar entre los municipios de Zarzal y El Cerrito. Los suelos a cuatro profundidades (0-20, 20-40, 40-60, 60-80 cm.) y las aguas de riego de diferentes fuentes. Tanto en las aguas como en los extractos de saturación se determinó pH, conductividad eléctrica (C.E.), calcio (Ca2+), magnesio (Mg2+), potasio (K+), sodio (Na+), cloruros (Cl-), sul...

  12. Influencia de la salinidad edáfica sobre la calidad del aceite de oliva cv. Arbequina

    Directory of Open Access Journals (Sweden)

    Aragüés, R.

    2005-03-01

    Full Text Available This work analyzes the effect of soil salinity on olive oil quality. The chemical composition of oils extracted from young ‘Arbequina' olives subject in the field to three soil salinity levels (low-L, medium-M and high-H was determined throughout a period of three years. A total of 30 parameters were analyzed (moisture, oil content, acidity, peroxides, ultraviolet absorbances, poliphenols, aliphatic alcohols, sterols, waxes, and fatty acid composition. Soil salinity was measured on fourteen different dates with an electromagnetic sensor. Overall, salinity increased oil content (+15 % in H with respect to L and decreased aliphatic alcohols (-29 % and palmitoleic acid (-32 % (values significant at P0,05. In summary, olive oil quality was practically independent of soil salinity and, according to the prevailing legislation, all the oils were classified as “extra virgin”.Este trabajo analiza el efecto de la salinidad edáfica sobre la calidad del aceite de oliva. Durante tres campañas se determinó la composición química de aceites provenientes de olivos jóvenes ‘Arbequina' sujetos en campo a tres niveles de salinidad (baja-B, media-M y alta-A. En total se analizaron 30 parámetros (humedad, grasa, acidez, peróxidos, lecturas en el ultravioleta, polifenoles, alcoholes alifáticos, esteroles, ceras y composición de ácidos grasos. La salinidad edáfica se midió en catorce fechas con un sensor electromagnético. La salinidad produjo un aumento del porcentaje de grasa (+15 % en A respecto a B, y un descenso de los alcoholes alifáticos (-29 % y del ácido palmitoleico (-32 % (valores significativos a P0,05. En conclusión, la calidad del aceite de oliva fue prácticamente independiente de la salinidad, clasificándose en todos los casos como “virgen extra” según la normativa vigente.

  13. Efeito da salinidade no crescimento inicial do maracujazeiro amarelo (Passiflora edulis f. flavicarpa Deg

    Directory of Open Access Journals (Sweden)

    Aureliano Albuquerque Ribeiro

    2014-06-01

    Full Text Available : O presente estudo teve como objetivo os efeitos de cinco níveis de salinidade da água de irrigação (T1 = testemunha= 0,27; T2 = 1,5; T3 = 2,5; T4 = 3,5 e T5 = 4,5 dS m-1 , sobre o crescimento inicial do maracujazeiro amarelo. O trabalho foi conduzido em condições de laboratório e campo (Telado Agrícola no Instituto Federal de Educação, Ciência e Tecnologia do Ceará – Campus de Sobral. Utilizou-se o delineamento experimental em blocos casualizados, com quatro repetições, colocando-se 32 sementes por unidade experimental. As variáveis analisadas foram: altura das plantas (AP, número de folhas (NF, diâmetro do caule (DC, massa seca da parte aérea (MSPA e massa seca da raiz (MSR.  O maracujazeiro amarelo apresentou elevada sensibilidade aos sais, sendo que com exceção do diâmetro do caule, as demais variáveis avaliadas foram afetadas de maneira significativa pelo estresse salino  a partir de 1,5 dSm-1.

  14. Corrosion Kinetics of AlMg2 Alloy in Water With pH From 4 to 9 at Temperature of 40-800C

    International Nuclear Information System (INIS)

    Chaidir, A; Sungkono

    1998-01-01

    The research of ALMg2 corrosion has been done to study kinetics and mechanism corrosion. Corrosion experiment was carried out using water under controlled pH from 4 up to 9 at temperature of 40-80 0 C within 5-30 days by discontinue gravimetric method. The result shows that increasing rate of weight over the surface area unit of ALMg2 occurs logarithmically in the pH of 4 at temperature of 40 and 60 0 C. In the other hand that rate of weight over the surface area unit is decreasing linearly at temperature of 80 0 C. The rate of change weight over the surface area unit of ALMg2 increase logarithmically in pH of 6,5 and temperature from 40 up to 80 0 C so do that of condition in pH of 9 at temperatures of 40 and 60 0 C. Meanwhile,the rate of changed weight over the surface area unit increase linearly toward corrosion time within 5-15 days and then that decrease linearly in 20-30 days duration at constant temperature of 80 0 C. The corrosion mechanisms on ALMg2 surface occurred in the pH solution from 4 up to 9 and at temperature of 40-60 0 C, pH of 6,5 at temperature of 80 0 C and that pH of 9 at temperature of 80 0 C within 5-15 days. Erosion process on ALMg2 surface occurs in both solution of pH 4 and 9 at temperature of 80 0 C during 20-30 days

  15. Efeito da salinidade na germinação de sementes de pinhão manso

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    José Marcelo Cordeiro Possas

    2014-12-01

    Full Text Available Objetivou-se, na presente pesquisa, avaliar o comportamento da germinação em sementes de pinhão manso (Jatropha curcas L. quando submetidas a níveis crescentes de salinidade da água utilizada para embebição. Para tanto, o teste de geminação foi realizado com quatro repetições de 25 sementes para cada tratamento. Os tratamentos foram dispostos em delineamento inteiramente casualizado em esquema fatorial 6 x 2 (seis níveis de salinidade da água 0,6; 2,1; 3,6; 5,1; 6,6 e 8,1 dS m-1, e duas procedências de sementes, nativas dos municípios de Patos e Itaporanga, PB. A semeadura foi realizada em sistema rolo (papel germitest, umedecidos com volumes da solução salina (mL, equivalentes a 2,5 vezes o peso do papel seco (g. Os tratamentos foram instalados em câmara de germinação do tipo BOD (Biological Organism Development sob uma temperatura de 25 ºC em regime de escuro. Avaliou-se a germinação com contagens diárias, do 1º ao 14º dia do início do teste. Constatou-se um comprometimento no desempenho germinativo das sementes devido a condições de aumento da salinidade, porém as sementes oriundas de plantas nativas do município de Patos, mostraram-se mais tolerantes.

  16. Desenvolvimento inicial do girassol submetido a diferentes níveis de salinidade em dois tipos de solo

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    José Leôncio de Almeida Silva

    2012-09-01

    Full Text Available Considerando a importância do girassol (Helianthus annuus L. como potencial de fonte de energia renovável e a carência de resultados de pesquisas sobre a tolerância da cultura à salinidade, avaliou-se nesta pesquisa o desenvolvimento inicial do girassol cultivado sob cinco níveis de salinidade da água de irrigação (0,5, 1,5, 2,5, 4,5 e 6,5 dS m-1 em dois tipos de solo (Latossolo vermelho amarelo eutrófico – S1 e Neossolo quartizarênico – S2. O experimento foi realizado no período de setembro a novembro de 2010 em casa de vegetação do Departamento de ciências ambientais e tecnológicas da Universidade Federal Rural do Semiárido-UFERSA. Foi utilizado o delineamento inteiramente casualizado, com os tratamentos arranjados em esquema fatorial 2 x 5, com três  repetições. As análises de crescimento das planta de girassol foram feitas semanalmente, analisado-se o crescimento das plantas a partir da mensuração da altura e do diâmetro do caule e a contabilização do número de folhas.O aumento da salinidade da água de irrigação afetou o desenvolvimento do girassol, tanto para o solo Neossolo quartzarênico como para o Latossolo vermelho-amarelo.

  17. Avaliação de genótipos de caupi sob salinidade Assessment of cowpea genotypes under salinity

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    José P. Dantas

    2002-12-01

    Full Text Available Foram conduzidos ensaios em abrigo telado de vegetação com cobertura de telha de fibra de vidro com o objetivo de se avaliar a tolerância de 50 genótipos de caupi sob salinidade. Os tratamentos de salinidade aplicados no solo, em termos de condutividade elétrica do extrato de saturação (CE, foram: CE1 - 0,3, CE2 - 3,0, CE3 - 6,0, CE4 - 9,0 e CE5 - 12,0 dS m-1. Os genótipos foram classificados para tolerância à salinidade com base na redução percentual do peso de matéria seca da parte aérea. No tratamento CE2, 36 genótipos foram tolerantes (T, 12 moderadamente tolerantes (MT e 2 moderadamente sensíveis (MS; no tratamento CE3, 3 foram T, 14 MT, 30 MS e 3 sensíveis (S; no tratamento CE4, um foi MS e 49 S e, no tratamento CE5, todos foram S. O teor de proteína nos grãos foi influenciado pela salinidade e variou de genótipo para genótipo.To assess the tolerance of 50 cowpea genotypes under salinity, experiments were conducted in greenhouse covered with fiberglass sheets. The salinity treatments applied in terms of electrical conductivity of saturation extract of soil (EC were EC1 - 0.3; EC2 - 3.0; EC3 - 6.0; EC4 - 9.0 and EC5 - 12.0 dS m-1. The genotypes were classified for the salinity tolerance on the basis of the reduction in dry weight (% of shoot. Under EC2, 36 genotypes were tolerant (T, 12 moderately tolerant (MT and 2 moderately susceptible (MS; under EC3, 3 were T, 14 MT, 30 MS and 3 susceptible (S; under EC4, one was MS and 49 S and under EC5, all were S. The protein content of seed was influenced by salinity and varied with the genotype.

  18. Interação entre salinidade e biofertilizante bovino na cultura do feijão-de-corda

    OpenAIRE

    Silva,Francisco L. B. da; Lacerda,Claudivan F. de; Sousa,Geocleber G. de; Neves,Antônia L. R.; Silva,Giovana L. da; Sousa,Carlos H. C.

    2011-01-01

    Objetivou-se avaliar a interação entre salinidade e o uso de biofertilizante bovino sobre a condutividade elétrica do solo, crescimento inicial, trocas gasosas e teores de elementos minerais no feijão-de-corda. O experimento foi conduzido em ambiente protegido do Departamento de Ciências dos Solos - UFC. A semeadura foi feita em vasos, utilizando-se, como substrato, um Argissolo Vermelho Amarelo. O experimento obedeceu a um delineamento inteiramente casualizado, em esquema fatorial 5 x 2, ref...

  19. DISTRIBUCIÓN VERTICAL DE TEMPERATURA Y SALINIDAD EN EL ÁREA COSTERA DE SANTA MARTA (COLOMBIA

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    FRANCISCO GARCÍA

    2012-01-01

    Full Text Available Fueron determinados los perfi les de temperatura, salinidad y densidad en el punto de descarga del emisario submarino de Santa Marta. Se encontraron tres masas de aguas. Los periodos de estratifi cación térmica coinciden con las dos épocas de lluvias en la región (entre abril y junio la primera y agosto y diciembre la segunda. El espesor de la termoclina puede alcanzar hasta 12 metros de espesor y gradientes térmicos de 0.67 °C/m.

  20. Miogênese do tecido muscular branquial do peixe eurialino poecilia vivipara (cyprinodontiformes, poeciliidae) exposto à salinidade

    OpenAIRE

    Antunes, Adriana Maria; Rocha, Thiago Lopes; Morais, José Oscar Rodrigues; Sabóia-Morais, Simone Maria Teixeira

    2011-01-01

    v. 12, n. 3, p.478-486, jul./set. 2011. Os teleósteos Poecilia vivipara, conhecidos popularmente como guarus, são caracterizados como eurialinos, ou seja, eles modulam o comportamento celular branquial para sobreviver em ambientes com variações de salinidade. As brânquias do P.vivipara possuem um conjunto de músculos estriados esqueléticos, os músculos adutores e abdutores, que têm papel importante no processo de respiração. O presente trabalho teve como objetivos principais descrever a mo...

  1. Efecto del aumento de salinidad en la fertilización de óvulos de erizos Strongylocentrotus franciscanus y Lytechinus anamesus

    OpenAIRE

    López Ortiz, B. Estela; Sánchez González, Alberto

    2009-01-01

    Se evaluaron los efectos del incremento de salinidad sobre la fertilización de óvulos de erizos de mar de las especies Strongylocentrotus franciscanus Agassiz, 1863 y Lytechinus anamesus Clark, 1912, los cuales fueron colectados mediante buceo libre en la bahía de Todos Santos, Ensenada, B. C., México. La fertilización de los óvulos de cada especie de erizo se llevó a cabo en un intervalo de salinidad de 33.4 a 53.4‰ estimándose para cada caso su CL50. Los resultados indicaron que la capacida...

  2. Propiedades oxido-reductoras del agua y dependencia de los potenciales redox de este disolvente frente al valor del pH

    OpenAIRE

    Milla González, Miguel

    2017-01-01

    El agua se comporta como anfótero en equilibrios redox. Se estudian los procesos redox de este disolvente y se representan los valores de los potenciales en función del pH. Los límites de estabilidad del agua determinan la estabilidad de las especies oxidantes y reductoras en el seno de este disolvente.

  3. Effect of salinity changes on the midgut gland of Artemesia longinaris(Decapoda, Penaeidae Efecto de los cambios de salinidad sobre el hepatopáncreas de Artemesia longinaris (Decapoda, Penaeidae

    Directory of Open Access Journals (Sweden)

    Ignacio Masson

    2012-07-01

    30 días, el hepatopáncreas mostró una estructura normal. Exceptuando las células E que no variaron en altura entre tratamientos, las F, R y B fueron más altas en los animales gradualmente adaptados de 33 a 29 psu. Los cambios súbitos de salinidad tuvieron un efecto significativo en la altura media de las células F, R y B solamente en animales transferidos de 33 a 25 psu (24 a 96 h después de la transferencia disminuyó la altura de las células F y R, y 96 a 144 h después hubo un aumento en la altura de las células B. El presente estudio muestra el efecto de los cambios de salinidad sobre el hepatopáncreas y explica, al menos parcialmente, la razón de la mortalidad a bajas salinidades.

  4. Effect of thermal oxidation treatment on pH sensitivity of AlGaN/GaN heterostructure ion-sensitive field-effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lei; Bu, Yuyu [Institute of Science and Technology, Tokushima University, Tokushima 770-8506 (Japan); Li, Liuan, E-mail: liliuan@mail.sysu.edu.cn [School of Electronics and Information Technology, Sun Yat-Sen University, Guangzhou 510275 (China); Ao, Jin-Ping, E-mail: jpao@ee.tokushima-u.ac.jp [Institute of Science and Technology, Tokushima University, Tokushima 770-8506 (Japan)

    2017-07-31

    Highlights: • AlGaN/GaN ISFETs were fabricated and evaluated with thermal oxidation treatment. • Sensitivity was improved to 57.7 mV/pH after 700 °C treatment. • Sensitivity became poor after 800 °C treatment. • The pure α-Al{sub 2}O{sub 3} crystal phase generated on the surface of the 700 °C treatment sample. • Ga{sub 2}O{sub 3} phase content in the metal oxide layer increased after 800 °C treatment. - Abstract: In this article, AlGaN/GaN heterostructure ion-sensitive field-effect transistors (ISFETs) were prepared and evaluated by thermal oxidation treatment on the AlGaN surface. The ISFETs were fabricated on the AlGaN/GaN heterostructure and then thermally oxidized with dry oxygen in 600, 700, and 800 °C, respectively. It indicates that the performance of the AlGaN/GaN heterostructure ISFETs, such as noise and sensitivity, has been improved owing to the thermal oxidation treatment process at different temperatures. The X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) results indicate that after thermal oxidation treatment at different temperatures, hydroxide who possesses high surface state density will transfer to oxide owing to the higher chemical stability of the latter. Moreover, a crystalline α-Al{sub 2}O{sub 3} phase generated at 700 °C can not only provide a relatively smooth surface, but also improve the sensitivity to 57.7 mV/pH for the AlGaN/GaN heterostructure ISFETs, which is very close to the Nernstian limit.

  5. Salinidade da Água e Biofertilizante Bovino: Efeito sobre a Biometria do Pimentão

    Directory of Open Access Journals (Sweden)

    Vinícius Batista Campos

    2009-10-01

    Full Text Available Objetivou-se avaliar o efeito da salinidade da água de irrigação e biofertilizante bovino no comportamento vegetativo do pimentão, cultivar “All Big”. O experimento foi conduzido em abrigo telado, utilizando como substrato material dos primeiros 10 cm de um Latossolo Amarelo Distrófico, acondicionado em vasos de 3 L, adotando-se o delineamento inteiramente casualizado, em esquema fatorial 5x2 correspondente a condutividade elétrica da água (0,5; 1,0; 2,0; 3,0 e 4,0 dS m-1, na ausência e presença de biofertilizante bovino aplicado ao solo na forma líquida, diluído em água na proporção de 1:1. Aos 60 dias após a semeadura, a salinidade da água de irrigação influenciou negativamente a altura das plantas, número de folhas e área foliar do pimentão, contudo, em menor intensidade às plantas submetidas ao biofertilizante bovino. Apenas o diâmetro do caule não foi afetado pelos sais presentes na água de irrigação, mas essas plantas apresentaram diâmetro superior quando tratadas com o insumo.

  6. Cultivo de girassol em sistema hidropônico sob diferentes níveis de salinidade Sunflower cultivation in a hydroponic system under different salinity levels

    Directory of Open Access Journals (Sweden)

    José Amilton Santos Júnior

    2011-12-01

    Full Text Available Os sistemas hidropônicos tem se constituído em uma das alternativas para equacionar os fatores naturais adversos à produção agropecuária presentes nas regiões semiáridas do Brasil, como solos rasos, pedregosos e pouco férteis, além da escassez de recursos hídricos em quantidade e qualidade (teores elevados de sais. Este trabalho buscou estudar os componentes de produção do girassol (variedade EMBRAPA 122/V-2000 destinados à obtenção de aquênios e forragem (fitomassa, cultivado em sistema hidropônico, utilizando a fibra de coco como substrato e irrigado com água salobra de diferentes salinidades. O delineamento experimental utilizado foi o inteiramente casualizado, em esquema fatorial 5 x 2 com três repetições, de modo que foram estudados cinco níveis de salinidade e duas densidades de plantio - uma ou duas plantas por vaso. As águas de irrigação foram compostas por 50% da solução nutritiva padrão e 50% de água de abastecimento, adicionada de níveis crescentes de NaCl, resultando em uma condutividade elétrica final da solução (CEs de 1,7; 4,3; 6,0; 9,0 e 11,5 dS m-1. Verificou-se que a densidade diferenciada das plantas de girassol afetou positivamente os componentes de produção de aquênios e fitomassa da cultura indicando maior viabilidade quando se utiliza duas plantas por vaso.Hydroponic systems have constituted an alternative for combating the adverse natural factors of agricultural production in the semi-arid regions of Brazil, such as shallow rocky and infertile soils, and the scarcity of good quality water resources (high salt content. This work studied the yield of the sunflower (variety EMBRAPA 122/V-2000 destined for achene and fodder (phytomass production, grown hydroponically, using coconut fiber as substrate and irrigated with brackish water of varying salinities. The experimental layout used was completely randomized into a 5 x 2 factorial design with three replications, five levels of water

  7. Comments on the paper "The Mexican Hat Wavelet Family. Application to point source detection in CMB maps" by J. Gonzalez-Nuevo et al. (astro-ph/0604376)

    OpenAIRE

    Vio, Roberto; Andreani, Paola

    2006-01-01

    The arguments presented by Gonzalez-Nuevo et. al (2006) in favour of the Mexican Hat Wavelet Family (MHWF) are critically discussed here. These authors allege the optimal properties of this new class of filters in the detection of point sources embedded in a noise background but their claim is not based upon a solid mathematical foundation and proof.

  8. Influence of CO2 exposure on pH value, electrochemical properties, and the formation of calcium-phosphate on Ti-6Al-4V under adjusted in vitro conditions in DMEM

    Science.gov (United States)

    Höhn, Sarah; Virtanen, Sannakaisa

    2015-06-01

    Immersion tests for studying biomaterials surface reactions should be carried out at a pH value of 7.4 and an adjusted blood physiological electrolyte to simulate as far as possible in vivo conditions. The present work deals with surface reactivity of the biocompatible Ti-6Al-4V alloy in Dulbecco's Modified Eagle Medium (DMEM) and the influence of different immersion conditions on the pH value of solution and thus on the surface charge and calcium-phosphate formation on the oxide covered alloy surface. More specifically, the influence of the temperature (room temperature vs. 37 °C) and atmospheric exposure (solution open-to-air vs. solution exposed to 5% CO2 in air) was investigated. Electrochemical measurements, XPS and ATR-IR studies were carried out for interface characterization. Precipitations of calcium-phosphate (Ca-P) on Ti-6Al-4V in DMEM are formed depending on the atmospheric conditions (presence or absence of CO2). In the absence of CO2 strong coverage of the surface by a Ca-P layer takes place; in solution exposed to 5% CO2, however, only minor amounts of Ca-P are found on the surface. This drastically different behavior can be explained by different surface terminations of OH and TiO2, induced by atmosphere-dependent pH change in solution. In consequence, different surface charges on Ti-6Al-4V can be formed at the interface depending on the type of hydroxides after contact with the electrolyte. Hence, the surface charge influences the interaction with adsorption of charged species and further modifies the oxide properties. The adsorption of the charged cations (Ca2 +) and anions (PO43 -, HPO42 -, H2PO4 -) leads to the formation of additional calcium phosphate layers. The pH of the solution is also important. At higher pH the titanium surface is more negatively charged leading to an increased electrostatic interaction with Ca2 + and reduced solubility of the calcium phosphates. Additional experiments indicate that the CO2 content in the atmosphere is

  9. Comment on "Fertilization and pH effects on processes and mechanisms controlling dissolved inorganic phosphorus in soils" by Nicolas Devau et al. (2011)

    Science.gov (United States)

    Lumsdon, David G.

    2012-09-01

    In a recent article by Devau et al. (2011) a mechanistic model based on a surface complexation theory is presented which aims to predict the solubility of inorganic phosphorus (P) in soils. Compared with many empirical soil studies, the surface complexation approach as applied to soils is to be encouraged since it provides a coherent and mechanistically based foundation for the interpretation of a wide range of soil chemical phenomena. Soil chemists have attempted to explain P solubility for decades, so Devau et al. (2011) have attempted a difficult task but unfortunately they have introduced a number of errors that need to be corrected. The purpose of the present contribution is to suggest some corrections to their proposed model and provide commentary on the errors and inconsistencies concerning the application and citation of the sources of thermodynamic data. Hopefully this will provide some insights for others wishing to progress this subject.

  10. Salinidade e temperatura na germinação e vigor de sementes de mutambo (Guazuma Ulmifolia Lam.) (Sterculiaceae)

    OpenAIRE

    Roseli Betoni; Silvana de Paula Quintao Scalon; Rosilda Mara Mussury

    2011-01-01

    Este trabalho teve como objetivo avaliar a germinação e o vigor de sementes e plântulas de mutambo em resposta à salinidade e a diferentes temperaturas. O experimento foi realizado em laboratório onde as sementes foram colocadas em placas de Petri com soluções salinas de KCl, NaCl e CaCl2 nos potenciais osmóticos de 0,0 (testemunha); -0,4; -0,8; -1,2; -1,6; -2,0 MPa acrescidas (CE) ou não (SE) de espermidina (100ppm). As sementes foram incubadas em BOD, nas temperaturas de 15, 20, 30 e 35ºC. ...

  11. Desenvolvimento do tomate em diferentes níveis de irrigação e de doses de salinidade

    OpenAIRE

    Silva Junior, Josué Ferreira [UNESP

    2012-01-01

    O tomate é uma das hortaliças mais importante da agroindústria brasileira. Neste estudo, foram testados os efeitos de três doses de salinidade da água de irrigação (0, 3 e 5 dS m-1) e três níveis mínimos de irrigação (-10, -30 e -60 kPa) sobre o desenvolvimento de tomateiro tipo industrial, Kátia. As mudas foram transplantadas em vasos e o cultivo foi em casa de vegetação até a maturação dos frutos. As irrigações foram procedidas por pesagem dos vasos quando atingiam os valores mínimos aproxi...

  12. Estudo comparativo do crescimento de plantas de tomate e milho sob condições de salinidade

    OpenAIRE

    Bezerra Neto,Egídio; Nogueira,Rejane Jurema Mansur Custódio

    1999-01-01

    Plantas de tomate (Lycopersicum esculentum Mill) e de milho (Zea maiz L.) foram cultivadas em meio hidropônico, em presença de 0 ou 100 mmol de NaCl por litro de solução nutritiva. Trinta dias após o início da aplicação dos tratamentos foi realizada coleta para a análise dos parâmetros de crescimento. A taxa de crescimento absoluto de ambas as espécies diminuiu com a salinidade. O tratamento salino não afetou a alocação de biomassa das folhas, provocou uma diminuição na alocação da biomassa d...

  13. Efeito da salinidade na germinação e no desenvolvimento inicial da erva-doce (Foeniculum Vulgare MILL..

    Directory of Open Access Journals (Sweden)

    Aureliano Albuquerque Ribeiro

    2013-08-01

    Full Text Available O presente estudo teve como objetivo verificar o efeito de diferentes níveis de salinidade (0,17; 1,5; 2,5; 3,5; 4,5 e 5,5 dSm-1 na germinação das sementes e no desenvolvimento inicial das plântulas de erva-doce (Foeniculum vulgare Mill.. O experimento foi conduzido em condições de laboratório e campo no Instituto Federal de Educação, Ciência e Tecnologia - IFCE, Campus de Sobral. Utilizou-se o delineamento experimental em blocos casualizados, com quatro repetições, colocando-se 32 sementes por unidade experimental.  As variáveis analisadas foram: primeira contagem, percentual de germinação, índice de velocidade de germinação (IVG, altura das plântulas, número de folhas e condutividade elétrica do substrato. As variáveis analisadas na germinação mostraram-se sensível ao estresse salino a partir da concentração 1,5 dSm-1, com exceção a primeira contagem que não sofreu influência dos sais. Entre os parâmetros de crescimento inicial (altura das plântulas e número de folhas, ambos foram afetadas negativamente pelos sais a partir da Testemunha. A condutividade elétrica do substrato apresentou aumento crescente com os níveis de salinidade da água de irrigação

  14. Informe de las condiciones oceanográficas superficiales entre Chicama y Cabo Blanco. Crucero BAP Ocoña 9510: Del 16 al 23 de Octubre de 1995.

    OpenAIRE

    Pizarro, Luis; García Díaz, Walter

    1996-01-01

    Presenta un monitoreo oceanográfico pesquero del 16 al 24 de Octubre de 1995 abarcando las zonas entre Puerto Salaverry y el norte de Cabo Blanco, a fin de analizar la variación horizontal de la temperatura y salinidad del mar.

  15. Salinity reduced growth PS2 photochemistry and chlorophyll content in radish Crescimento reduzido por salinidade, fotoquímica PS2 e conteúdo de clorofila em rabanete

    Directory of Open Access Journals (Sweden)

    Muhammad Jamil

    2007-01-01

    Full Text Available When plants are grown under saline conditions, photosynthetic activity decreases leading to reduced plant growth, leaf area, chlorophyll content and chlorophyll fluorescence. Seeds and seedlings of radish (Raphanus sativus L. were grown in NaCl solutions under controlled greenhouse conditions. The NaCl concentrations in complete nutrient solutions were 0 (control, 4.7, 9.4 and 14.1 dS m-1. The salinity reduced germination percentage and also delayed the germination rate as the salt level increased. Lengths and fresh weights of root and shoot decreased with the increasing salt concentration. Furthermore, photochemical efficiency of PS2 (Fv/Fm, photochemical quenching coefficient (qP, non photochemical quenching coefficient (qN, leaf area and chlorophyll content (SPAD value were also reduced (P Quando plantas crescem sob condições de salinidade, sua atividade fotossintética diminui levando a um crescimento reduzido, menor área foliar, conteúdo de clorofila e fluorescência de clorofila. Sementes e plântulas de rabanete (Raphanus sativus L. foram germinadas e conduzidas em soluções de NaCl sob condições controladas de casa de vegetação. As concentrações de NaCl adicionado a solução nutritiva completa foram 0 (Controle, 4,7; 9,4 e 14,1 dS m-1. A salinidade diminui a percentagem de germinação e também atrasou a taxa de germinação com o aumento do nível de sal. Comprimento e peso fresco da parte aérea e da raiz decresceram com o aumento da concentração salina. Além disso, a eficiência fotoquímica de PS2 (Fv/Fm, o coeficiente fotoquímico de 'quenchin" (q p, o coeficiente não fotoquímico de "quenching" (q n, a área foliar e o teor de clorofila (valor SPAD também foram reduzidos (P < 0,001 por estresse de sal. Ao contrário, a relação Fo/Fm aumentou com a concentração salina, ao passo que a salinidade não teve efeito sobre a eficiência de excitação capturada pelo PS2 aberto (Fv'/Fm', taxa de transporte eletr

  16. Resposta de cultivares de alface à salinidade da solução nutritiva com rejeito salino em hidroponia Response of lettuce cultivars to nutrient solution salinity with saline rejects in hydropony

    Directory of Open Access Journals (Sweden)

    Nildo da S Dias

    2011-10-01

    Full Text Available No processo de dessalinização se gera, além da água potável, um rejeito altamente salino e de poder poluente elevado, o qual pode ser utilizado na produção agrícola rentável dependendo da adoção de práticas culturais adequadas e da tolerância das plantas às condições salinas. Nos últimos anos a tendência tem sido a substituição da agricultura convencional por sistemas hidropônicos de cultivos, considerados um dos mais eficientes no uso de água. O objetivo desta pesquisa foi analisar a resposta de duas cultivares de alface sob sistema hidropônico de cultivo (Lactuca sativa L., cvs. Verônica e Babá de verão em diferentes níveis de salinidade da solução nutritiva preparadas com água de abastecimento, água de rejeito coletada no dessalinizador e da sua diluição com água de abastecimento a 75, 50 e 25%, resultando em condutividades elétricas da solução nutritiva (CEs de 1,1; 2,4; 3,6; 4,7 e 5,7 dS m-1 após as diluições e adição de fertilizantes. Ocorreu variação genotípica sob as variáveis de crescimento e produção da alface, exceto para o número de folhas, sendo a cultivar Babá de verão a que produziu maior rendimento, independentemente do nível de salinidade e, portanto, a cultivar mais tolerante à salinidade da água com rejeito salino.In desalination process, besides the potable water, highly salty and polluted water (brine is generated, which can be used for producing profitable crops depending on the adequate cultural practices as well as on the plant ability of reacting to saline conditions. The trend in recent years has been towards conversion of conventional agriculture to soilless agriculture which is considered to be a more efficient use of water system. The aim of this research was to examine the response of two lettuce cultivars (Lactuca sativa L. cvs. Veronica, Babá de verão under hydroponic system to different levels of salinity of the nutrient solutions prepared with tap water

  17. Efeito da salinidade na germinação e desenvolvimento inicial da mamona ‘BRS energia’

    Directory of Open Access Journals (Sweden)

    K. Q. D. Brito

    2015-10-01

    Full Text Available A mamoneira possui destacável importância no mundo, tem como principal produto derivado do seu óleo que pode ser utilizado como matéria prima para o biodiesel. Objetivou-se com este trabalho avaliar os níveis de tolerância das sementes de mamona ao estresse salino simulados por NaCl. A pesquisa foi desenvolvida no Laboratório de Irrigação e Salinidade na Universidade Federal de Campina Grande. Em cada tratamento foram utilizadas 100 sementes, dispostas em quatro repetições de 25 sementes. O delineamento experimental utilizado foi o inteiramente casualizado. Para a avaliação da germinação sob estresse salino utilizou-se soluções de NaCl com as seguintes condutividade elétrica: 0,4; 1,2; 2,2; 3,2 e 4,2dSm-1. Realizou-se avaliações de porcentagem de germinação, tempo médio de germinação, velocidade média de germinação, índice de velocidade de germinação e aos 15 dias realizaram o comprimento da raiz primaria, da parte aérea, e pesou a massa seca e fresca das plântulas. As sementes de mamoneira BRS Energia apresentaram tolerância às águas com níveis de salinidade de até 4,2 dS m-1 em relação ao índice de velocidade de germinação, tempo médio de germinação, velocidade média de germinação e porcentagem de germinação e o aumento da salinidade afetou o comprimento da parte aérea e da zona radicular.Effect of salinity on germination and initial development of castor bean ‘BRS energia’Abrstact: The castor bean (Ricinus communis L. is an oilseed that has detachable importance in Brazil and worldwide, its main product derived from its oil that can be used as raw material for biodiesel, therefore the aim of this study was to evaluate the tolerance levels of castor seeds to salt stress simulated by NaCl. In each treatment, 100 seeds, in four replicates of 25 seeds. For the evaluation of germination under salt stress was used NaCl solutions with the following electric conductivity: 0.4dSm-1 1.2dSm-1, 2.2d

  18. Salinidade e temperatura na germinação e vigor de sementes de mutambo (Guazuma Ulmifolia Lam. (Sterculiaceae

    Directory of Open Access Journals (Sweden)

    Roseli Betoni

    2011-06-01

    Full Text Available Este trabalho teve como objetivo avaliar a germinação e o vigor de sementes e plântulas de mutambo em resposta à salinidade e a diferentes temperaturas. O experimento foi realizado em laboratório onde as sementes foram colocadas em placas de Petri com soluções salinas de KCl, NaCl e CaCl2 nos potenciais osmóticos de 0,0 (testemunha; -0,4; -0,8; -1,2; -1,6; -2,0 MPa acrescidas (CE ou não (SE de espermidina (100ppm. As sementes foram incubadas em BOD, nas temperaturas de 15, 20, 30 e 35ºC. Para cada sal, o delineamento experimental foi inteiramente casualizado, com três repetições de 20 sementes. Não houve germinação na temperatura de 15ºC. Para os três sais ,os valores para porcentagem de germinação foram maiores a 30ºC. Os valores do índice de velocidade de germinação (IVG diminuíram com a redução dos potenciais osmóticos (PO. O IVG e a massa fresca (MF apresentaram maiores médias na temperatura de 30ºC. A relação raiz/ parte aérea foi significativamente maior na temperatura de 20ºC, não diferindo significativamente entre CE e SE. Os valores de MF de sementes CE reduziram-se com a diminuição dos PO. Os maiores valores de massa seca (MS ocorreram a 30 e 35ºC nos tratamentos com KCl e NaCl e a 30ºC com o CaCl2. Não houve diferença significativa na interação entre sal e potencial osmótico para a massa seca. Nas condições controladas deste estudo, Guazuma ulmifolia apresentou germinação e crescimento de plântula em ambiente com salinidade de -2,0MPa e temperatura em torno de 30ºC, não apresentando limite de tolerância até essa concentração em nenhum dos sais avaliados.

  19. Estudo comparativo do crescimento de plantas de tomate e milho sob condições de salinidade

    Directory of Open Access Journals (Sweden)

    Egídio Bezerra Neto

    1999-01-01

    Full Text Available Plantas de tomate (Lycopersicum esculentum Mill e de milho (Zea maiz L. foram cultivadas em meio hidropônico, em presença de 0 ou 100 mmol de NaCl por litro de solução nutritiva. Trinta dias após o início da aplicação dos tratamentos foi realizada coleta para a análise dos parâmetros de crescimento. A taxa de crescimento absoluto de ambas as espécies diminuiu com a salinidade. O tratamento salino não afetou a alocação de biomassa das folhas, provocou uma diminuição na alocação da biomassa do caule e aumento da alocação da biomassa das raízes das plantas de tomate e de milho. Ocorreu uma redução de 48,01 % na área foliar das plantas de milho e de 58,75 % nas de tomate, devido ao tratamento salino. A razão de área foliar nas plantas de milho foi reduzida em 14,07 % enquanto nas de tomate tratadas com cloreto de sódio aumentou 15,49 %. Os resultados obtidos sugerem que as plantas de milho são mais tolerantes à salinidade que as de tomate.Plants of tomato and maize were grown in hydroponic solution with and without the addition of sodium chloride in order to evaluate some growth parameters of one C3 and one C4 species. After 30 days under the saline stress treatment there was no significant difference between both species regarding to leaf biomass allocation. The stem biomass allocation decreased for both the tomato and the maize plants. This was due to salt treatment, while root biomass allocation increased. The Absolute growth rate was the most affected parameter by the NaCl treatment for which values were obtained for both species. The leaf area also decreased due to the sodium chloride treatment. The leaf area rate increased for the stressed tomato plants, while it tend to decrease for maize plants under saline treatment.

  20. Crescimento de mudas de moringa em função da salinidade da água e da posição das sementes nos frutos

    Directory of Open Access Journals (Sweden)

    Francisco de Assis de Oliveira

    2013-02-01

    Full Text Available A escolha das sementes é de fundamental importância para a obtenção de mudas de qualidade, principalmente quando são produzidas sob condições ambientais adversas. Este trabalho foi desenvolvido com o objetivo de avaliar a influencia da salinidade sobre o desenvolvimento de mudas de moringa provenientes de sementes localizadas em diferentes posições no fruto. O delineamento utilizado foi o inteiramente casualizado, com os tratamentos arranjados em esquema fatorial 3 x 4 e quatro repetições. Os tratamentos resultaram da combinação de três posições de sementes no fruto (basal, mediana e apical com quatro níveis de salinidade da água de irrigação (0,5; 2,0; 3,5; e 5,0 dS m-1. Foram avaliadas as seguintes características de crescimento: altura (ALT, diâmetro do caule (DC, diâmetro da raiz principal (DRP, número de folhas (NF, área foliar (AF, massa seca da parte aérea (MSPA, massa seca do sistema radicular (MSR e massa seca total (MST. Os dados foram submetidos à análise de variância pelo teste F e as médias, comparadas pelo teste de Tukey a 5% de probabilidade, para o efeito da posição da semente no fruto; e por análise de regressão, para os dados provenientes da salinidade. Houve interação significativa na maioria das características avaliadas. A salinidade da água de irrigação diminuiu em todas as variáveis. As mudas provenientes de sementes localizadas na porção basal dos frutos foram mais afetadas pela salinidade da água de irrigação.

  1. Tolerância da cultura do tomate à salinidade do solo em ambiente protegido Tolerance of tomato crop to salinity of soil in protected ambient

    Directory of Open Access Journals (Sweden)

    Pedro R. F. Medeiros

    2012-01-01

    Full Text Available Com o intuito de contribuir com os dados disponíveis na literatura sobre tolerância das culturas à salinidade do solo oriunda de sais fertilizantes, o presente trabalho tem, como objetivo, determinar a tolerância da cultura do tomate a salinidade do solo, a partir de dois manejos de fertirrigação e seis níveis iniciais de salinidade (1,0; 2,0; 3,0; 4,0; 5,0 e 6,0 dS m-1 a partir das variáveis produção e componentes de produção, em ambiente protegido com solo franco-argiloso. O experimento foi realizado no Departamento de Engenharia de Biossistemas da ESALQ/USP, Piracicaba,SP. O delineamento estatístico foi aleatorizado em blocos, com 4 repetições, concluindo que a produção e os componentes de produção da cultura do tomate foram afetados estatisticamente, tanto pelo tipo de manejo de fertirrigação quanto pelos níveis de salinidade do solo, com redução na tolerância da cultura do tomate, passando a ser classificada sensível à salinidade do solo.In order to contribute to data available in the literature on tolerance of crops to soil salinity derived from fertilizer salts, the present study aims to determine the tolerance of tomato crop to the soil salinity, based on two managements of fertirrigation and six initial levels of salinity (1.0; 2.0; 3.0; 4.0; 5.0 and 6.0 dS m-1 from the variables production and components of production, in a protected environment with sandy-clay soil. The experiment was conducted at the Department of Biosystems Engineering of ESALQ/USP, Piracicaba/SP. The experimental design was in randomized blocks, with 4 repetitions. Concluding that the production and the components of production of tomato crop were significantly affected both by the type of management of fertirrigation and by the levels of soil salinity, with a reduction in the tolerance of tomato crop, being classified as sensitive to soil salinity.

  2. Batimetría, salinidad, temperatura y oxígeno disuelto en aguas del Parque Nacional Marino Ballena, Pacífico, Costa Rica

    Directory of Open Access Journals (Sweden)

    Juan José Alvarado

    2009-11-01

    Full Text Available Se realizó un estudio sobre la batimetría del PNMB y del comportamiento de la temperatura, salinidad, oxígeno disuelto y porcentaje de saturación de oxígeno entre setiembre 2003 y abril 2005. El parque posee una profundidad promedio de 14.97± 9.11m y una profundidad máxima detectada de 37.33m. La sección interna de la bahía es poco profunda, no alcanzando más de 20m de profundidad, mientras que en la parte externa la pendiente es más pronunciada, alcanzando rápidamente los 37 m. A lo largo del estudio, los valores promedio superficiales de salinidad fueron de 29.1±4.3‰, de temperatura 29.7±1.3ºC, de concentración de oxígeno disuelto 6.7±1.3mg/l, y del porcentaje de saturación de oxígeno 115.6±22.1%. Entre las estaciones interna y externa solo se observaron diferencias significativas en cuanto a la salinidad y la temperatura por profundidad, como producto de la época lluviosa. Los valores más bajos de salinidad y temperatura se observaron para la época lluviosa y los más altos en la época seca, mientras que los valores de oxígeno disuelto y porcentaje de saturación de oxígeno presentaron un incremento continuo a través del tiempo. La similitud entre las estaciones y el hecho de haber encontrado diferencias significativas solamente entre la salinidad y la temperatura en cuanto a la profundidad, hacen pensar que a lo largo del tiempo las aguas del parque se comportan de manera muy similar y que es una zona muy dinámica y homogénea con corrientes lo suficientemente fuertes para mezclar la columna de agua del parque. El PNMB es una zona muy productiva debido a los altos valores de saturación de oxígeno observados a lo largo del tiempo (120%. Esto hace pensar que existen condiciones apropiadas para el desarrollo del fitoplancton, zooplancton y otros grupos tróficos.

  3. Controlo da salinidade do solo com recurso à sementeira directa Control of the soil salinity by using direct drilling

    Directory of Open Access Journals (Sweden)

    J. P. Mendes

    2009-01-01

    Full Text Available A introdução do regadio utilizando água com teores moderados de sais, em zonas de clima semi-árido e em solos com má drenagem interna, conduz, a prazo, ao inevitável aumento da salinidade do solo e, provavelmente, ao risco de alcalização do mesmo. A maior parte das áreas de regadio, a beneficiar com as águas provenientes do Alqueva, enquadram-se nesta circunstância. No presente estudo, pretende-se averiguar se, o aumento da infiltrabilidade do solo e a redução da evaporação directa, conseguida com uma elevada quantidade de resíduos à superfície do solo provenientes de uma cultura de cobertura seguida de s ementeira directa, possibilitam uma menor acumulação dos sais durante o Verão e uma maior lavagem, dos mesmos, durante o Inverno. Para testar a sementeira directa com cultura de cobertura, como tecnologia para o controlo da salinidade, a longo prazo, em clima semi-árido e solos mal drenados, instalou-se um ensaio no Alto Alentejo no perímetro de rega do Caia, em Luvissolos Cálcicos (classificação FAO. O ensaio decorreu debaixo de uma rampa rotativa e tem como tratamentos principais dois sistemas de preparação do solo: sementeira directa sobre cultura de cobertura (SD; sistema convencional (SC, subdividido em dois níveis de salinidade da água (0,7 dS m-1 e 2 dS m-1 e em dois regimes hídricos (100% e 70% da ETc do SC. O regime hídrico mais baixo foi obtido por redução do diâmetro dos bicos dos aspersores numa coroa circular da rampa rotativa e as diferentes qualidades da água foram obtidas por aplicação de cloreto de sódio e de sulfato de magnésio à superfície do solo como se se tratasse de um fertilizante de cobertura, sólido. Ao fim do segundo ano de ensaio, os valores de salinidade da solução do solo (1:2 em peso nos primeiros 0,20 m são inferiores na sementeira directa (0,63 dS m-1 para a SD e 0,75 dS m-1 para o SC e as diferenças são mais acentuadas no regime hídrico mais elevado. Os valores

  4. Oxydation catalytique du Phénol par le peroxyde d'hydrogène en présence d'argiles pontées par des espèces mixtes [Al-Cu

    Science.gov (United States)

    Abdellaoui, M.; Barrault, J.; Bouchoule, C.; Srasra, N. F.; Bergaya, F.

    1999-03-01

    Various processes can be used for the treatment of wastewater, but the one we feel to be important and more promising is the wet peroxide oxidation (WPO), in the presence of a solid catalyst, at atmospheric pressure and at room temperature. Different types of materials can be used as catalysts for such reactions, but as shown in previous studies dealing with phenol oxidation clays-based catalysts seem to be attractive. It is well known that natural clays are inactive in the phenol oxidation, but the intercalation of polymeric species changes their properties. When the clay is pillared with pure aluminum oxyhydroxides species, the d{001} spacing and the surface area increase, but the activity is very low. When the clay is pillared with mixed [Al-Cu] species, there is a strong increase of the phenol conversion. Nevertheless W (Wyoming) based solids are more active than H (Haîdoudi) or L (Laponite) based catalysts. The stability, the activity and the percentage of copper depend on the preparation method. Différentes techniques de traitements des eaux usées peuvent être utilisées, et l'une des plus prometteuses est l'oxydation voie humide par le peroxyde d'hydrogène en milieu aqueux dilué (WPO), en présence de catalyseurs supportés, à pression atmosphérique et à 25 ° C. Lors de cette étude, il a été montré que les argiles brutes sont inactives en oxydation du phénol. L'intercalation d'espèces hydroxyaluminiques conduit à une augmentation de la surface spécifique et de l'espace interlamellaire, mais la conversion du phénol reste faible. En revanche, l'insertion d'espèces mixtes [Al-Cu] confère au catalyseur une importante activité. En outre, la quantité de cuivre intercalé est très faible (argile et la méthode de préparation. Néanmoins, la comparaison des divers catalyseurs, montre que l'utilisation de l'argile Wyoming (W), conduit à une activité supérieure à celle des argiles moins bien définies (Haîdoudi) ou à celle de la Laponite

  5. Effect of calcium and magnesium silicate on the growth of the castor oil plant subjected to salinity levels Efeito de silicato de cálcio e magnésio sobre o crescimento de plantas de mamoneira submetidas a níveis de salinidade

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    José Félix Brito Neto

    2012-12-01

    Full Text Available Salt stress decreases the osmotic potential of soil solution causing water stress, causing toxic effects in the plants resulting in injuries on the metabolism and nutritional disorders, thus compromising the plant growth, resulting in lower production. The calcium silicate and magnesium can perform the same function as limestone, besides providing silicon to plants, may also contribute to the resistance of plants to salt stress. Thus, the objective of this study was to evaluate the effect of calcium and magnesium silicate on the growth of the castor oil plant BRS Energia cultivated under saline conditions. This study evaluated plant height, stem diameter, number of leaves, leaf area, dry weight of shoot and root, and soil chemical characteristics. There was no interaction between factors of salinity level and of silicate level regarding the evaluated variables. There was a direct relationship between salinity levels and plant growth in height and stem diameter. The K concentration in soil were affected by salinity levels. O estresse salino diminui o potencial osmótico da solução do solo causando estresse hídrico, provocando efeitos tóxicos nas plantas que resultam em injúrias no metabolismo e desordens nutricionais, comprometendo assim o crescimento das plantas, resultando em menor produção. O silicato de cálcio e magnésio pode desempenhar a mesma função do calcário, além de fornecer silício para as plantas, podendo ainda, contribuir para a resistência de plantas ao estresse salino. Nesse sentido, objetivou-se com esse trabalho avaliar o efeito do silicato de cálcio e magnésio no crescimento da mamoneira BRS Energia cultivada sob condições salinas. Avaliou-se a altura da planta, diâmetro do caule, número de folhas, área foliar, massa seca da parte aérea e da raiz e as características químicas do solo. Não houve interação entre os fatores níveis de salinidade e silicato sobre as variáveis analisadas. Houve rela

  6. Manejo de la salinidad en aguas asociadas de producción de la industria petrolera.

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    Carlos Alberto Guerrero Fajardo

    2005-09-01

    Full Text Available En este artIculo se presenta el diseno conceptual de una alternativa complementaria de la solución al manelo de las aguas asociadas de producción dentro de un marco ambiental y técnico factible, cuyo fin es la recuperación de la sal de mayor porcentale, mediante un proceso de cristalización fraccionada tipo I.Para plantear y analizar la alternativa de trabalo con las aguas asociadas de producción provenientes de las estaciones La Gloria, La Gloria Norte y Morichal, pertenecientes a la Asociación Casanare, dado que las anteriores producen un efluente con alto contenido de sales, la propuesta está enfocada al tratamiento del 30% del volumen de agua asociada producida, esperada para el ano 2000 (1239 m3/dIa en los campos de estudio.El proceso permite recuperar un 92% de NaCl presente, equivalente a 0.918 Ton/h, con una pureza del 97%.Para garantizar la calidad del producto final y aprovechar las facilidades del campo, se proponen sistemas de aireación y evaporación previos a la etapa de cristalización.

  7. Germinação e crescimento inicial de meloeiro submetido ao osmocondicionamento da semente com NACl e níveis de salinidade da água

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    Auderlan de Macena Pereira

    2012-11-01

    Full Text Available A salinização dos solos tem contribuído para afetar o rendimento das plantas em termos de produtividade das culturas. O objetivo deste trabalho foi avaliar a germinação e o crescimento de mudas de meloeiro submetidas ao osmocondicionamento da semente com solução de NaCl e de níveis de salinidade da água de irrigação. O experimento foi realizado no delineamento de blocos casualizados em parcelas subdivididas do tipo 5 x 2, com quatro repetições. Na parcela constou de cinco níveis de salinidade da água de irrigação (1,0; 2,0; 3,0; 4,0 e 5,0 dS m-1 e na sub-parcela de sementes tratadas (com e sem pré-embebição em solução salina de NaCl. O aumento da salinidade da água de 1,0 para 5,0 dS m-1 proporcionou resposta linear decrescente na porcentagem de germinação, altura de plantas, número de folhas por planta, área foliar e no acúmulo de massa seca nas plantas nos diferentes órgãos da planta (raiz e parte aérea e resposta linear crescente com a elevação no índice de velocidade de emergência; o tratamento pré germinativo da semente com solução de NaCl apresentou uma resposta linear crescente favorecendo uma maior porcentagem de germinação, altura de plantas, área foliar e o acúmulo de massa seca total da planta e um menor índice de velocidade de emergência.

  8. Ação da irradiância e salinidade no processo fotossintético em ecotipos de feijoeiro

    OpenAIRE

    Giraldo, Carolina Jaramillo

    2007-01-01

    O centro de domesticação do Phaseolus vulgaris se encontra em diferentes regiões ecológicas e geográficas de América Latina, tendo uma alta variabilidade genética e versatilidade de adaptação à diferentes condições ambientais. Estresses ambientais diferentes podem induzir nas plantas respostas fisiológica, bioquímicas e moleculares semelhantes. Plantas adaptadas a um tipo de estresse, como irradiância de altitude, poderiam resistir a outro diferente, como salinidade. cultivar Cargamanto, ecot...

  9. Salinidad del recurso hídrico sobterráneo del Altiplano Central

    Directory of Open Access Journals (Sweden)

    1995-01-01

    Full Text Available SALINITE DE LA RESSOURCE EN EAU SOUTERRAINE DE L’ALTIPLANO. Le bilan hydrologique actuel de l’aquifère de l’Altiplano central bolivien (6 000 km2 montre une alimentation annuelle de 50 106 m3 par le rio Desaguadero et par infiltration près des piedmonts. Les sorties sont l’évaporation et l’écoulement vers les salars. Près des piedmonts, l’eau souterraine est douce (<0,5 mS cm-1 et pauvre en isotopes lourds comme la pluie de la saison humide ( 180<-14‰. Près de la zone de recharge par le Desaguadero, l’eau souterraine a des caractéristiques proches de la moyenne de celles du rio (2 mS cm-1 et  18O ≈ -10‰. Plus à l’aval, une zone plus salée (3-6 mS cm-1 présente un signal isotopique d’eau évaporée et un âge (14C et modèle hydraulique d’environ 3 500 B.P. Elle pourrait être liée au lac Tauca, antérieur à 8 000 ans, ou à un paléolac plus récent. El balance hidrológico actual del acuífero del Altiplano central boliviano (6 000 km2 muestra una alimentación anual de 50 106 m3 por el río Desaguadero y por infiltración cerca de los montes. Las pérdidas son por evaporación y por flujo hacia los salares. Cerca de los montes, el agua subterránea es dulce (<0,5 mS cm-1 y empobrecida, como la lluvia del verano, en isótopos pesados ( 180<-14‰. En el área de influencia del Desaguadero, el agua subterránea tiene características salinas y isotópicas similares a las del río (2 mS cm-1 y  18O ≈ -10‰. Aguas abajo, una zona salina (3-6 mS cm-1 tiene una señal isotópica de agua evaporada y una edad (14C y modelo hidráulico de aproximadamente 3 500 años. Podría ser relacionada al lago Tauca, anterior a 8 000 años, o a un paleolago más reciente. SALINITY OF THE GROUNDWATER ON THE CENTRAL ALTIPLANO. Present hydrological balance of the aquifer on the central Bolivian Altiplano (6 000 km2 shows an input of 50 106 m3 by the Rio Desaguadero and by infiltration of rainfall runoff

  10. Tolerância aguda e crônica de adultos de beta, Betta splendens, à salinidade da água Acute and chronic salinity tolerance in adult siamese fighting fish, Betta splendens

    Directory of Open Access Journals (Sweden)

    Jener Alexandre Sampaio Zuanon

    2009-11-01

    Full Text Available Com o objetivo de avaliar a tolerância de Betta splendens à salinidade da água, realizou-se um experimento em delineamento inteiramente casualizado, com seis concentrações de sal na água (0; 3; 6; 9; 12 e 15 g de sal comum/L de água, cada uma com cinco repetições (1 peixe/repetição. Fêmeas adultas de Betta splendens foram alojadas individualmente em aquários mantidos em estufa incubadora, a 26 ± 0,2 ºC e fotoperíodo de 12 horas. Os peixes foram alimentados até a saciedade, uma vez ao dia, com ração comercial. Foram mensurados o consumo diário de ração e a sobrevivência dos peixes a cada 12 horas. Para avaliar o efeito agudo da salinidade, foram calculados o tempo médio de sobrevivência e a salinidade letal mediana-96 horas, enquanto o efeito crônico (18 dias foi avaliado pelo cálculo da salinidade máxima de sobrevivência e da salinidade letal mediana. O tempo médio de sobrevivência foi significativamente menor na salinidade de 15 g/L. A salinidade letal mediana-96 horas estimada foi de 11,88 g/L, a salinidade máxima de sobrevivência entre 6 e 7 g/L, e a salinidade letal mediana de 9,35 g/L. Observou-se interação significativa entre as salinidades da água e o tempo de alimentação. Considerando que é uma espécie de água doce, o beta possui alta tolerância à salinidade da água.Salinity tolerance of Betta splendens was evaluated in a complete randomized design, with six salt concentrations in the water (0; 3; 6; 9; 12 and 15 g common salt/L with five replications (1 fish/replication. Adult female B. splendens were individually placed in aquariums in an incubation chamber at 26 ± 0.2ºC and 12-hour photoperiod. Fish were fed to satiation, once a day, with commercial diet. Feed intake and survival rate were measured every 12 hours. To evaluate the effect of acute salinity, the mean survival time and median lethal salinity-96 h were calculated, while the chronic effect (18 days was assessed by calculating

  11. EFECTO DE LA SALINIDAD Y DEL TAMAÑO DE LA SEMILLA SOBRE LA GERMINACIÓN Y CRECIMIENTO DE PLÁNTULAS DE MAÍZ (Zea mays L. BAJO CONDICIONES DE LABORATORIO

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    José A. Laynez-Garsaball

    2008-01-01

    Full Text Available Se estudió la germinación y el crecimiento de plántulas a partir de dos tamaños de semillas, de dos cultivares de maíz, utilizando como sustrato papel absorbente y regados con tres soluciones salinas preparadas con cloruro de sodio. El diseño estadístico fue de parcelas divididas con cuatro repeticiones, en la parcela principal se midieron los potenciales osmóticos (0, - 0.328 y - 0.547 MPa, en las subparcelas los cultivares de maíz (Himeca 95 y Pioneer 361 y en las sub-sub-parcelas los tamaños de las semillas (¿ 0.32 – 0.36 ¿ g y > 0.36 g. Se realizó un análisis de varianza y la prueba de rangos múltiples de Duncan. El nivel de inferencia fue de 5%. Las disminuciones en el potencial osmótico también disminuyeron la germinación y el crecimiento de las plántulas en dos cultivares. La tolerancia a la salinidad sólo se pudo evaluar en la etapa de germinación con potenciales osmóticos de -0.328 y -0.547 MPa (Pioneer 361 más tolerante que Himeca 95. Se tuvo mayor crecimiento de plántulas (volumen radicular y peso fresco del vástago a partir de semillas grandes, aunque este crecimiento se perdió al disminuir el potencial osmótico, sugiriendo que el uso de semillas grandes puede representar una ventaja en suelos no salinos.

  12. Performance of rocket cultivars under different nutritive solutions with salinity different. = Desempenho de cultivares de rúcula sob soluções nutritivas com diferentes salinidades.

    Directory of Open Access Journals (Sweden)

    Francisco de Assis de Oliveira

    2013-08-01

    Full Text Available The use of saline water for vegetable production is a major challenge for researchers and farmers. Cultivation in inert substrate can be an alternative, since the low matric potential can reduce the effect of salinity on plants. This study was conducted in a greenhouse at the Departamento de Ciências Ambientais e Tecnológicas da Universidade Federal Rural do Semi-Árido, Mossoró-RN, in order to evaluate the performance of two cultivars of rocket grown in substrate and fertilized with nutrient solutions of different salinities . Ten treatments were evaluated in a factorial 2 x 5, two cultivars (C1-Cultivada e C2-Folha Larga and five salinity levels of the nutrient solutions (S1-1.2; S2-2.2; S3-3.2; S4-4.2 and S5-5.2 dS m-1, usinga randomized design. Harvesting was performed at 30 days after sowing and evaluated the following variables: number of leaves, height, leaf area, total fresh and total dry mass. The salinity of the nutrient solution adversely affected the development of rocket, grown on a substrate, however, cultivation rocket substrate may be performed using electrical conductivity of the nutritive solution to 2.36 dS m-1 without loss in yield fresh pasta. The Folha Larga cultivar produced more total fresh and dry weight in relation to cultivar Cultivada, but to cultivar Cultivada has increased tolerance to salinity than cultivar Folha Larga. = O uso de água salina na produção de hortaliças é um dos principais desafios de pesquisadores e produtores rurais. O cultivo em substrato inerte pode ser uma alternativa, uma vez que o reduzido potencial matricial pode reduzir o efeito da salinidade sobre as plantas. O trabalho foi desenvolvido em ambiente protegido no Departamento de Ciências Ambientaise Tecnológicas da Universidade Federal Rural do Semi-Árido, Mossoró-RN, e objetivou-se avaliar o desempenho de duas cultivares de rúcula cultivadas em substrato e fertirrigadas com soluções nutritivas de diferentes salinidades. Foram

  13. Variabilidade espacial da salinidade de um solo aluvial no semi-árido Paraibano Spatial variability of soil salinity in an alluvial soil of the semi-arid region of Paraíba state

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    Lázaro Costa de Souza

    2000-04-01

    Full Text Available O objetivo deste trabalho foi estudar a variabilidade espacial do pH da pasta de saturação (pHps, condutividade elétrica do extrato de saturação (CEes e porcentagem de sódio trocável (PST de um solo aluvial afetado por sais. Foram coletadas amostras de solo nas camadas 0-20, 20-40 e 40-60 cm, numa área do Projeto de Irrigação Capoeira, localizado em São José do Bonfim, Estado da Paraíba, utilizando-se um esquema sistemático de amostragem numa malha regular de 10 x 15 m. Os dados foram analisados através da estatística descritiva e geoestatística. Verificou-se baixa variabilidade para o pHps (CV 60 %. Modelos esférico e gaussiano foram ajustados aos semivariogramas das variáveis que apresentaram estrutura de dependência espacial, tendo-se obtido alcances variando de 20 a 40 m. Os mapas de isolinhas da combinação da CEes e PST permitiram visualizar o padrão de variabilidade da salinidade e sodicidade, constituindo-se em uma ferramenta para a definição de estratégias de manejo edáfico e recuperação da área afetada.The objective of this work was to study the spatial variability of pH of saturation paste (pHsp, the electrical conductivity of saturation extract (ECe and the exchangeable sodium percentage (ESP in an alluvial salt affected soil. Soil samples were collected in 0 - 20, 20 - 40 and 40 - 60 cm depths, in an area of the Irrigation Project of Capoeira, located in São José do Bonfim - Paraíba (Brazil, following a systematic scheme of sampling in a 10 x 15 m mesh. The data were analyzed through the descriptive statistics and geostatistics. Low variability was observed for the pHsp (CV 60%. Spherical and gaussian models were adjusted to the experimental semivariograms of the variables that presented a spatial dependence structure. Structures of spatial dependence, with range varying from 20 to 40 m were observed. The maps of isohypsas of the combination of ECe and ESP allowed the visualization of the pattern of

  14. Sweet pepper production in substrate in response to salinity, nutrient solution management and training system Produção de pimentão cultivado em substrato em resposta à salinidade, manejo da solução nutritiva e sistema de condução

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    José S Rubio

    2011-09-01

    . Um experimento no delineamento de blocos casualizados em parcelas sub-subdivididas, com quatro repetições, foi utilizado para testar os efeitos da concentração da solução nutritiva (Hoagland completa ou meia-força iônica, sistemas de condução (dois ou três ramos por planta e a salinidade da água (salina ou não salina sobre o rendimento total e comercial, a qualidade dos frutos e a concentração de nutrientes minerais nos frutos. A salinidade diminuiu o rendimento dos frutos devido à menor massa da matéria fresca dos frutos, mas não diminuiu o número de frutos por planta. Tanto na presença como na ausência da salinidade, o maior rendimento de frutos foi obtido pelas plantas irrigadas com solução nutritiva de Hoagland meia força e conduzidas com três hastes por planta. A incidência de podridão apical aumentou com o aumento da condutibilidade elétrica na solução nutritiva e diminuiu na solução de Hoagland meia força. A salinidade diminuiu a qualidade dos frutos em todos os tratamentos devido à diminuição nos teores de PO4(2-, SO4(2-, Fe2+;3+, Cu1+;2+ e Mn2+, além do índice de formato do fruto. Da mesma maneira, as plantas salinizadas e irrigadas com a solução de Hoagland meia força e conduzidas com três hastes apresentaram menor concentração de glicose e de frutose na polpa do fruto. Com base nestes resultados, o rendimento comercial poderia ser aumentado com água não salina ou com salinidade moderada mediante a implementação de práticas culturais adequadas.

  15. Omeike et al. (13)

    African Journals Online (AJOL)

    was used for sorption of Al ions at low concentrations of 10-50 mg/L. Effect of contact time and pH on biosorption of aluminium ions from solution was also evaluated. The result showed that highest aluminium sorption was obtained at pH 6 after 24 hours. Langmuir and Freundlich isotherm constants described a feasible.

  16. Efeito da salinidade e modo de aplicação da água de irrigação no crescimento e produção de alho

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    Amorim Júlio Roberto de Araújo

    2002-01-01

    Full Text Available Na Paraíba é comum a irrigação do alho por aspersão utilizando águas salinas, o que pode causar sérios danos às plantas. Este trabalho, realizado em casa de vegetação, teve por objetivo avaliar os efeitos sobre crescimento e produção do alho a partir de dois modos de aplicação de água, molhando ou não a folhagem das plantas, combinados com cinco níveis de salinidade da água de irrigação, que variaram entre 0,6 e 3,0 dS m-1. O desenvolvimento das plantas foi avaliado aos 30, 60, 90 e 120 dias após o plantio (DAP. As plantas de alho foram relativamente tolerantes à salinidade na brotação de bulbilhos e crescimento até 30 DAP. No final do ciclo (90-120 DAP, a parte aérea da planta e a formação dos bulbos foram afetadas pelo molhamento da folhagem das plantas. A salinidade começou a afetar a parte aérea das plantas entre 30-60 dias, enquanto o bulbo passou a ser afetado entre 60-90 DAP. A fase final de formação do bulbo (últimos 30 dias do ciclo foi a mais sensível à salinidade. A razão bulbar não pode ser utilizada como parâmetro de avaliação de tolerância do alho à salinidade.

  17. Ph3CCOOSnPh3.Ph3PO AND Ph3CCOOSnPh3.Ph3AsO: SYNTHESIS AND INFRARED STUDY

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    ABDOU MBAYE

    2014-08-01

    Full Text Available The mixture of ethanolic solutions of Ph3CCOOSnPh3 and Ph3PO or Ph3AsO gives Ph3CCOOSnPh3.Ph3PO and Ph3CCOOSnPh3.Ph3AsO adducts which have been characterized by infrared spectroscopy. A discrete structure is suggested for both, the environment around the tin centre being trigonal bipyramidal, the triphenylacetate anion behaving as a mondentate ligand.

  18. EVALUACIÓN DE TECNOLOGÍAS PARA LA RECUPERACIÓN DE SUELOS DEGRADADOS POR SALINIDAD EVALUATION OF TECHNOLOGIES FOR THE RECOVERY OF SOILS DEGRADED BY SALINITY

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    Orlando Zúñiga Escobar

    2011-06-01

    Full Text Available La presencia de salinidad y sodio en los suelos interfiere en el crecimiento adecuado de la mayoría de los cultivos y por lo tanto constituye uno de los problemas más serios que enfrenta la agricultura sostenible. Se evaluaron una serie de tecnologías no convencionales utilizadas en recuperación de suelos afectados por salinidad según la respuesta agronómica de un cultivo de maíz. Se planteó la aplicación de 3 tratamientos alternativos: 1 Biofertilizantes, 2 Biopolimeros y 3 Electromagnetismo comparados frente a la propuesta: 4 Convencional con base en la teoría del USDA (United States Departament of Agriculture de enmiendas químicas (yeso - azufre. Además de un testigo absoluto (Sólo drenaje. Los tratamientos más efectivos en cuanto respuesta fisiológica y productividad fueron los biológicos con uso de microorganismos (biofertlizantes y electromagnetismo, se incluyó la estimulación electromagnética la cual acelera la actividad microbiana para disminuir el tiempo de recuperación de suelos afectados por salinidad del suelo.Salinity and sodium content in soils interferes with proper growth of most crops and therefore constitutes a serious problem facing sustainable agriculture. The objective of this research was to evaluate a series of unconventional technologies used in recovery of salt-affected soils according to the agronomic response of a maize crop. The application of three alternative treatments with Biofertilizers, Biopolymers and Electromagnetism were proposed to make a comparison with the USDA-based conventional theory approach (United States Department of Agriculture of chemical amendments (gypsum - sulfur. In addition to an absolute control (drainage only. The most effective treatments in terms of physiological response and productivity were the biological using microorganisms (biofertilizers and electromagnetism, clarifying that electromagnetic stimulation was included to accelerate microbial activity and lower soil

  19. Hongos ectomicorrícicos y la tolerancia a la salinidad en plantas Ectomycorrhizal fungi and tolerance to salinity in plants

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    SELENE AGUILAR-AGUILAR

    2009-03-01

    Full Text Available El proceso de salinización de los suelos constituye un problema generalizado a nivel global. En este sentido, los hongos ectomicorrícicos tienen una importante participación en la recuperación de suelos forestales ya que involucran una serie de mecanismos celulares que pueden contribuir a la tolerancia a la salinidad en plantas que habitan los bosques templados o boreales. La participación de los hongos ectomicorrícicos en la tolerancia a la salinidad involucra la regulación homeostática de los iones, la mejora de captación de agua y la inducción de genes específicos en las raíces colonizadas. Los hongos ectomicorrícicos pueden estimular la presencia de osmolitos como la prolina, azúcares y polioles que contribuyen en la protección de las células vegetales. Además, estos organismos inducen la síntesis de enzimas antioxidantes y glutatión que participan en la disminución de especies reactivas de oxígeno. Esta revisión ofrece una descripción de la participación de los hongos ectomicorrícicos en la tolerancia a la salinidad en plantas.The process of salinization of the soil is a widespread problem at the global level. In this sense, ectomycorrhizal fungi have an important role in the recovery of forest soil, as it involves a number of cellular mechanisms that may contribute to the salinity tolerance in plants that inhabit temperate and boreal forests. The participation of ectomycorrhizal fungi on the salinity tolerance involves the ion-homeostasis regulation, improving uptake water and inducing specific gene in roots colonized. Likewise ectomycorrhizal fungi can stimulate the presence of osmolytes as proline, sugars and polyols that contribute to the protection of plant cells. Additionally, these organisms stimulate the synthesis of glutathione and antioxidant enzymes involved in the decrease of reactive oxygen species. This review provides an overview of participation of ectomycorrhizal fungi in the salinity tolerance in

  20. Crescimento e produção de manjericão em sistema hidropônico NFT sob salinidade

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    Maria A. A. Bione

    2014-12-01

    Full Text Available No semiárido brasileiro a falta de água de boa qualidade tem justificado o desenvolvimento de pesquisas científicas no aproveitamento de águas salobras. No presente trabalho avaliaram-se os efeitos de águas salobras em relação ao crescimento e à produção de plantas de manjericão em hidroponia, de outubro a novembro de 2012. Os tratamentos consistiram de quatro níveis de salinidade da água (1,45; 3,80; 6,08 e 8,48 dS m-1 obtidos pela adição de NaCl à água doce local, de um tratamento controle com essa água doce (0,29 dS m-1 e de um rejeito de osmose reversa (8,39 dS m-1 de um município do semiárido. Foram usadas 36 parcelas experimentais aleatorizadas em seis blocos. Os dados foram analisados mediante análise de variância e de regressão. Houve redução linear da produção de massa de matéria fresca e seca da parte aérea (MFPA e MSPA, com o aumento da salinidade, de 7,86 e 6,76% por acréscimo unitário na condutividade elétrica da água (dS m-1, respectivamente; não ocorreu diferença entre águas isosmóticas de NaCl e rejeito de dessalinização em referência à produção de MFPA. A altura de planta e a taxa de crescimento não indicaram a influência da salinidade no manjericão. As águas salobras não produziram sintomas depreciativos nas plantas.

  1. EFECTO DEL OIL PULLING CON ACEITE DE COCO VIRGEN PRENSADO AL FRIO Y EL COLUTORIO DE BICARBONATO EN EL PH ÁCIDO DE PACIENTES ADULTOS. CONSULTA PRIVADA. AREQUIPA, 2015

    OpenAIRE

    CÁRDENAS VARGAS, ANGELA GRETEL

    2016-01-01

    ACEITE DE COCO HISTORIA COMPOSICIÓN CARACTERÍSTICAS FÍSICAS PROPIEDADES DEL ACEITE DE COCO LENJUAGUE CON ACEITE DE COCO (OIL PULLING) MECANISMO DE ACCIÓN PROCEDIMIENTO PARA REALIZAR EL OIL PULLING CON ACEITE DE COCO BENEFICIOS DEL OIL PULLING BICARBONATO DE SODIO CARACTERÍSTICAS FÍSICAS PROPIEDADES DEL BICARBONATO DE SODIO PH SALIVAL PH SALIVAL Y METABOLISMO BACTERIANO ACIDES EN LA CAVIDAD BUCAL ANTECEDENTES INVESTIGATIVOS

  2. Densidade de estocagem e salinidade da água na larvicultura do pacamã Stocking density and water salinity on pacamã larviculture

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    Ronald Kennedy Luz

    2008-07-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito da densidade de estocagem e da salinidade da água, na larvicultura do pacamã Lophiosilurus alexandri, alimentado com náuplios de Artemia sp. Foram utilizadas três densidades de estocagem: 20, 40 e 60 larvas L-1 (D20, D40 e D60, respectivamente. Para cada densidade testaram-se três índices de salinidade da água: água doce (S0, 2‰ (S2 e 4‰ (S4, em delineamento experimental inteiramente ao acaso, em esquema fatorial 3x3, com três repetições. Foram analisados: crescimento, sobrevivência, mortalidade, canibalismo, produtividade e níveis de amônia não ionizada. As concentrações de amônia não ionizada foram maiores nas densidades D40 e D60. Aos dez dias de alimentação, o peso foi afetado negativamente em D40 e D60 associado à maior salinidade da água (S4. A maior sobrevivência foi obtida no tratamento D20S2, enquanto os menores valores foram registrados em relação à salinidade S4, independentemente da densidade testada. Foram verificadas baixas taxas de mortalidade e ausência de canibalismo. A produção de juvenis também foi influenciada pelos fatores avaliados. Larvas de L. alexandri podem ser criadas, durante os dez primeiros dias de alimentação exógena, em água doce ou a 2‰ com maior produção de juvenis na densidade D60.The objective of this work was to evaluate the effect of stocking density and water salinity levels on Lophiosilurus alexandri (pacamã larvae rearing fed with Artemia sp. nauplii. Three stocking densities were used: 20, 40 and 60 larvae L-1 (D20, D40 and D60, respectively. For each density, three different levels of salinity were tested: freshwater (S0, 2‰ (S2 and 4‰ (S4, in a completely randomized design, in a 3x3 factorial scheme, with three replications. The growth, survival, mortality, cannibalism, production and nonionized ammonia levels were evaluated. The nonionized ammonia levels were higher at D40 and D60. At 10 days of feeding, the

  3. Estimación de la salinidad de los suelos utilizando una imagen espectrozonal y el sistema de información geográfica Telemap

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    Andrés Lau Quan; Eduardo Garea Llano; María Elena Ruiz

    2005-01-01

    A partir de una foto espectrozonal de alta resolución espacial y una base de datos de conductividad eléctrica de más de 800 puntos, se desarrolló una Metodología para la estimación de la salinidad de los suelos utilizando la teledetección, un Sistema de información geográfica, la Geoestadística y Sensores eléctricos. Este resultado constituye uno de los primeros en el ámbito internacional en esta temática que utiliza imagen espectrozonal y el primero en Cuba. El área, sembrada de cañ...

  4. Produção do algodoeiro em função da salinidade e tratamento de sementes com regulador de crescimento

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    Oliveira,Francisco de Assis de; Medeiros,José Francismar de; Oliveira,Francisco Ronaldo Alves de; Freire,Alcione Guimarães; Soares,Leonardo Cirilo da Silva

    2012-01-01

    Este trabalho foi realizado com o objetivo de avaliar o efeito de diferentes níveis de salinidade da água de irrigação e sementes tratadas com regulador de crescimento na produção do algodoeiro. O delineamento experimental adotado foi inteiramente ao acaso, arranjados em esquema fatorial 5 x 2 com quatro repetições. Os tratamentos resultaram da combinação de cinco níveis de condutividade elétrica da água de irrigação (S1-0,5; S2-2,0; S3-3,5; S4-5,0 e S5-6,5 dS m-1) em sementes tratadas e não ...

  5. Sobrevivência de alevinos de Jundiá (Rhamdia quelen Quoy & Gaimard, 1824) à variação de salinidade da água

    OpenAIRE

    Marchioro, Maria Ignez; Baldisserotto, Bernardo

    1999-01-01

    O objetivo deste trabalho foi testar a sobrevivência de alevinos de jundiá a diferentes concentrações de salinidade (sal marinho comum e água do mar), pois o sal é indicado no tratamento de algumas doenças e também para reduzir o estresse durante o manuseio e transporte de peixes. Os alevinos (1,68 ± 0,87g) permaneceram de 3 a 7 dias em tanques de 1400l, com água corrente e temperatura entre 23 e 25°C, sendo alimentados diariamente. Após esse período, foram colocados 50 alevinos em tanques de...

  6. Sobrevivência de alevinos de Jundiá (Rhamdia quelen Quoy & Gaimard, 1824) à variação de salinidade da água

    OpenAIRE

    Marchioro,Maria Ignez; Baldisserotto,Bernardo

    1999-01-01

    O objetivo deste trabalho foi testar a sobrevivência de alevinos de jundiá a diferentes concentrações de salinidade (sal marinho comum e água do mar), pois o sal é indicado no tratamento de algumas doenças e também para reduzir o estresse durante o manuseio e transporte de peixes. Os alevinos (1,68 ± 0,87g) permaneceram de 3 a 7 dias em tanques de 1400l, com água corrente e temperatura entre 23 e 25°C, sendo alimentados diariamente. Após esse período, foram colocados 50 alevinos em...

  7. Crescimento de híbridos e variedades porta-enxerto de citros sob salinidade = Growth of hybrids and rootstock varieties of citrus under salinity.

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    Pedro Dantas Fernandes

    2011-04-01

    Full Text Available A salinidade da água e do solo afeta o crescimento, o desenvolvimento e a produção de espécies frutíferas, dentre as quais os citros. O uso de porta-enxertos tolerantes pode garantir a sustentabilidade do agronegócio citrícola em tais condições. Assim, estudou-se a sensibilidade à salinidade durante a fase de formação de portaenxertoscompreendendo variedades e híbridos selecionados. O experimento foirealizado em casa-de-vegetação, considerando cinco níveis de salinidade da água de irrigação [testemunha, irrigação com água de abastecimento local, condutividade elétrica da água (CEa de 0,41 dS m-1 e água com CEa de 1,0; 2,0; 3,0 e 4,0 dS m-1] e sete genótipos, utilizando delineamento em blocos casualizados, com cinco repetiçõesem esquema fatorial e quatro plantas úteis por parcela, durante o período de 150 dias. Avaliaram-se variáveis de crescimento e fisiológicas. A redução mais expressiva foi observada na fitomassa seca total da parte aérea com aumento unitário da CEa. Observou-se redução linear no crescimento com aumento da salinidade nos híbridosLVK x LVA-009 e TSK x TRENG-256. Dentre os genótipos avaliados, o limoeiro ‘Volkameriano’ foi o menos sensível ao estresse salino.Water and soil salinity affects the growth, development and production of fructiferous species, such as citrus. The use of tolerant rootstocks can guarantee the agribusiness of citrus under such conditions. Thus, the sensibility to salinity during the phase of rootstock formation of varieties and selected hybrids was studied. The experiment was carried out in a greenhouse, with five levels of irrigation water salinity [control, tap water with electrical conductivity (ECw of 0.41 dS m-1, and water with ECw of 1.0, 2.0, 3.0 and 4.0 dS m-1] and seven genotypes, in a randomized block designand five replications each consisting of four plants, during 150 day period. Growth and physiologic variables were evaluated. Significant effects

  8. PhD Dissertations

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    Redazione Reti Medievali (a cura di

    2004-06-01

    Full Text Available Report of PhD Dissertations. Francesco Barone Istituzioni, società ed economia a Catania nel tardo medioevo (XIV-XV secolo, Tesi di dottorato in Storia medievale (XVI ciclo, Università degli Studi di Firenze, 2004   Laura Berti Ceroni Il territorio e le strutture di Cesarea e Classe tra tarda antichità e alto medioevo in rapporto con Ravenna, Tesi di dottorato di ricerca in Storia e Informatica, Università degli studi di Bologna, 2002-2003.   Marco Bicchierai Poppi dalla signoria dei conti Guidi al vicariato del Casentino (1360-1480, Tesi di dottorato in Storia medievale (XIV ciclo, Università degli Studi di Firenze, 2004   Emanuela Garimberti Spatiosa ad habitandum loca. Luoghi e identità nella Historia Langobardorum di Paolo Diacono, Tesi di dottorato in Storia medievale (XV ciclo, Università degli Studi di Bologna, 2004   Lorenzo Tanzini Sistemi normativi e pratiche istituzionali a Firenze dalla fine del XIII all’inizio del XV secolo, Tesi di dottorato di ricerca in Storia medievale (XVI ciclo, Università degli Studi di Firenze, 2004   Stefania Tarquini Pellegrinaggio e asseto urbano di Roma, Tesi di dottorato di ricerca in Storia dei centri, delle vie e della cultura dei pellegrinaggi nel Medioevo euro mediterraneo (XV ciclo, Università degli studi di Lecce, 2003

  9. Batimetría, salinidad, temperatura y oxígeno disuelto en aguas del Parque Nacional Marino Ballena, Pacífico, Costa Rica

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    Juan José Alvarado

    2009-11-01

    Full Text Available Se realizó un estudio sobre la batimetría del PNMB y del comportamiento de la temperatura, salinidad, oxígeno disuelto y porcentaje de saturación de oxígeno entre setiembre 2003 y abril 2005. El parque posee una profundidad promedio de 14.97± 9.11m y una profundidad máxima detectada de 37.33m. La sección interna de la bahía es poco profunda, no alcanzando más de 20m de profundidad, mientras que en la parte externa la pendiente es más pronunciada, alcanzando rápidamente los 37 m. A lo largo del estudio, los valores promedio superficiales de salinidad fueron de 29.1±4.3‰, de temperatura 29.7±1.3ºC, de concentración de oxígeno disuelto 6.7±1.3mg/l, y del porcentaje de saturación de oxígeno 115.6±22.1%. Entre las estaciones interna y externa solo se observaron diferencias significativas en cuanto a la salinidad y la temperatura por profundidad, como producto de la época lluviosa. Los valores más bajos de salinidad y temperatura se observaron para la época lluviosa y los más altos en la época seca, mientras que los valores de oxígeno disuelto y porcentaje de saturación de oxígeno presentaron un incremento continuo a través del tiempo. La similitud entre las estaciones y el hecho de haber encontrado diferencias significativas solamente entre la salinidad y la temperatura en cuanto a la profundidad, hacen pensar que a lo largo del tiempo las aguas del parque se comportan de manera muy similar y que es una zona muy dinámica y homogénea con corrientes lo suficientemente fuertes para mezclar la columna de agua del parque. El PNMB es una zona muy productiva debido a los altos valores de saturación de oxígeno observados a lo largo del tiempo (120%. Esto hace pensar que existen condiciones apropiadas para el desarrollo del fitoplancton, zooplancton y otros grupos tróficos.Batimetry, salinity, temperature, and dissolved oxigen water of the Marino Ballena National Park, Pacific, Costa Rica. Between September 2003 and April

  10. Evolución del desarrollo del color en sistema modelo de composición similar al dulce de leche. Influencia del tiempo de calentamiento y del Ph

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    Analía Rodríguez Blanco

    2013-01-01

    Full Text Available El color es un atributo importante en la elección del producto dulce de leche por parte del consumidor. El mismo se desarrolla en el proceso de elaboración debido principalmente a las reacciones de pardeamiento no enzimático, las cuales se ven influenciadas por varios factores. En este trabajo se evaluó el desarrollo de color, con el tiempo de tratamiento térmico y el pH inicial como variables tecnológicas, en un sistema modelo compuesto de caseinato, lactosa, sacarosa y agua destilada cuya composición fue similar a la del dulce de leche comercial. El estudio del color se realizó utilizando los parámetros de medición de color del sistema CIELAB y el índice de Kubelka Munk (K/S. Con ambos métodos se constató un aumento significativo del dE*ab y del K/S con el tiempo de tratamiento térmico y el pH inicial. Con el sistema CIELAB además se observó una tendencia a disminuir la luminosidad con el tiempo y el aumento del pH inicial, y el aumento de a* con el tiempo.

  11. Evapotranspiração da cultura da melancia irrigada com água de diferentes salinidades Evapotranspiration of watermelon irrigated with different salinity waters

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    Vladimir B. Figueirêdo

    2009-06-01

    Full Text Available Sabe-se que a determinação precisa da evapotranspiração da cultura (ETc é de grande importância para o uso eficiente da água, principalmente em regiões áridas e semiáridas onde se faz necessária a utilização de água salina para irrigação. O objetivo deste trabalho foi determinar a evapotranspiração da melancia, cultivar Mickylee, com o uso de diferentes níveis de salinidade da água de irrigação. O experimento foi conduzido na Fazenda Experimental da Alagoinha, pertencente à Universidade Federal Rural do Semiárido, Mossoró - RN. Os níveis de salinidade da água de irrigação foram: S1 = 0,55; S2 = 1,65; S3 = 2,35; S4 = 3,5, e S5 = 4,5 dS m-1, sendo os tratamentos dispostos no delineamento de blocos ao acaso, com quatro repetições. A determinação da evapotranspiração de referência (ETo foi realizada pelo método FAO-Penmam-Monteith, e a ETc, pelas leituras obtidas em lisímetros de pesagem, instalados nos tratamentos S1 e S5. Os resultados mostraram que a ETc da melancia diminui com o aumento da salinidade da água aplicada e que a evapotranspiração total durante o ciclo foi de 245 e 214 mm, respectivamente, para os tratamentos S1 e S5. Os valores médios de Kc obtidos para cada fase fenológica foram 0,23; 0,68; 1,12; 0,90 e 0,24; 0,61; 0,98 e 0,78, respectivamente, para as águas S1 e S5.The knowledge of crop evapotranspiration (ETc is very important for efficient water use in irrigated crops, mainly in arid and semi-arid regions, where the use of saline water is common. The objective of this study was to determine watermelon crop evapotranspiration (cv. Mickylee in plants submitted to different irrigation water salinity levels. The experiment was carried out at the Experimental field of the Semi-Arid Federal Rural University, Mossoró, RN, Brazil. The irrigation water salinity levels were of S1 = 0.55; S2 = 1.65; S3 = 2.35; S4 = 3.5 and S5 = 4.5 dS m-1, with the treatments set up in randomized blocks with

  12. Interação entre salinidade e bioestimulante na cultura do feijão caupi Interaction between water salinity and biostimulant in the cowpea plants

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    Francisco de A. de Oliveira

    2013-05-01

    Full Text Available Objetivou-se, neste trabalho, avaliar a interação entre salinidade e o uso de bioestimulante (Stimulate® sobre o desenvolvimento do feijão caupi. A semeadura foi feita em vasos utilizando-se, como substrato, um Argissolo Vermelho Amarelo. O experimento obedeceu a um delineamento inteiramente casualizado em esquema fatorial 2 x 7. Os tratamentos se constituíram da combinação de dois níveis de sais da água de irrigação e seis formas de aplicação de bioestimulante (Ausência, Tratamento de sementes, Foliar aos 20 dias após semeadura (DAS, Foliar aos 40 DAS, Tratamentos de sementes + Foliar aos 20 DAS, Tratamento de sementes + foliar aos 40 DAS e Aplicação foliar aos 20 e 40 DAS. Foram realizadas duas avaliações não destrutivas (20 e 40 DAS e uma destrutiva (60 DAS e avaliados a altura, o número de folhas, a área foliar e a massa seca de folhas, de caule e da parte aérea. Todos os parâmetros fisiológicos avaliados foram afetados pela salinidade. Nas formas de aplicação adotadas o bioestimulante não proporcionou melhorias no desenvolvimento das plantas quando submetidas ao estresse salino; a salinidade inibiu o efeito benéfico do bioestimulante sobre o desenvolvimento do feijão caupi; enfim, o uso de bioestimulante não é viável em plantas cultivadas sob estresse salino.The objective of this study was to evaluate the interaction between salinity levels of the water and the use of biostimulant (Stimulate® in the initial development stage of cowpea plants. The sowing of seeds was done in pots, using as a substrate Alfissol and two plants per pot. The experimental design was completely randomized in a 2 x 7 factorial scheme. The treatments consisted of combination of two salinity levels (0.5 and 5.0 dS m-1 with seven biostimulant application forms (without application, seed treatment, sprinkled 20 days after sowing (DAS, sprinkled 40 DAS, seed treatment + sprinkled 20 DAS, seed treatment + sprinkled 40 DAS and sprinkled

  13. Tolerância de bactérias diazotróficas simbióticas à salinidade in vitro Tolerance of diazotrophic symbiotic bacteria to salinity

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    Rafaela Simão Abrahão Nóbrega

    2004-08-01

    Full Text Available A busca de estirpes de bactérias diazotróficas simbióticas tolerantes à salinidade, em conjunto com a seleção de hospedeiros, tem por objetivo aumentar o desempenho da simbiose e manter a produtividade vegetal de forma sustentada em condições de estresse salino. Doze estirpes de bactérias diazotróficas de diferentes procedências foram estudadas quanto à tolerância a diferentes concentrações de NaCl em meios de cultura 79 e LB. As estirpes que apresentaram maior tolerância à salinidade (30 g L-1 em meio 79 foram: BR 6806 e BR 4007, ambas de crescimento rápido isoladas de solos do nordeste brasileiro, UFLA 03-51 e UFLA 03-65, de crescimento rápido e UFLA 03-84, de crescimento lento, sendo as três últimas oriundas da região Amazônica. Essas também estiveram entre as mais tolerantes em meio de cultura LB. A estirpe UFLA 03-84, selecionada em trabalhos prévios por sua alta eficiência para caupi (Vigna unguiculata, pode ser indicada para estudos de inoculação, visando a aumentar o rendimento dessa cultura em solos salinos. Os meios de cultura 79 e LB foram eficientes para avaliar a tolerância relativa de rizóbio a NaCl, mas o meio 79 é mais indicado, pois permite o crescimento de todas as estirpes. Pelos resultados, infere-se haver relação entre tolerância in vitro à salinidade e origem dos microssimbiontes, pois as estirpes BR 4007 e BR 6806, oriundas do Ceará, estiveram entre as mais tolerantes.Tolerance to salinity of diazotrophic bacteriaand their host species could increase plant growth and sustainability in salt stressed soils. Twelve diazotrophic bacteria strains were studied regarding their tolerance to different NaCl concentrations in 79 and LB media. More tolerant (30 g L-1 strains in 79 medium were: the fast growers BR 6806 and BR 4007, isolated from northeast Brazil, UFLA 03-51 and UFLA 03-65, and slow growing strain UFLA03-84, being these last three isolated from Amazon region. These strains were among

  14. PIGMENTOS FOTOSSITETICOS E PRODUÇÃO DE FEIJÃO Vigna ungüiculada L. Walp SOB SALINIDADE E ADUBAÇÃO NITROGENADA

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    Guilherme de Freitas Furtado

    2014-08-01

    Full Text Available Estudaram-se acúmulo de pigmentos foliares e a produção do feijão vigna cv. BRS Pajeú submetidos diferentes níveis de salinidade da água de irrigação e doses de nitrogênio. O experimento foi desenvolvido em lisímetros de drenagem, no período de junho a setembro de 2013 em ambiente protegido da UEAg/CTRN/UFCG. Utilizou-se o delineamento experimental em blocos casualizados, em esquema fatorial 5 x 5, com três repetições, testando-se cinco níveis de condutividade elétrica da água de irrigação - CEa (0,9; 1,8; 2,7; 3,6 e 4,5 dS m-1 e cinco doses de adubação nitrogenada (70; 100; 130; 160 e 190% da recomendação indicada para ensaio em vaso. Avaliaram-se o teor de clorofila ‘a’ (CL a, teor de clorofila ‘b’ (CL b teor de clorofila total (CLT, razão clorofila ‘a’ e clorofila ‘b’ (CL a/CL b, teor de carotenóides (CAT, o conteúdo relativo de água (CRA, florescimento inicial (FI, o número de flores por planta (NFP, a taxa de abortamento (TA, o número de grãos por vagens (NGV e o número de grãos por planta (NGP. O teor de CL a não foi influenciada pelos tratamentos aplicados, sendo em média 13,66 µg g-1 MF-1. A irrigação com água salina proporcionou redução no teor de CL b, CLT, CL a/CL b, CAT e o CRA. A adubação nitrogenada promoveu decréscimo da razão CL a/CL b. A salinidade retardou o florescimento inicial, reduziu o número de flores por planta, o número de grãos por vagem e o número de grãos por planta. A taxa de abortamento de flores foi elevada com o incremento da condutividade elétrica da água. O nitrogênio proporcionou efeito significativo para o número de grãos por vagem. Não houve interação entre a salinidade da água de irrigação e a fertilização nitrogenada para nenhuma variável analisada.

  15. Nutrição mineral de mudas de pupunheira sob diferentes níveis de salinidade Mineral nutrition of peach palm seedlings under different salinity levels

    Directory of Open Access Journals (Sweden)

    Antonio Rodrigues Fernandes

    2002-11-01

    Full Text Available O potencial produtivo das plantas pode ser afetado por desordens nutricionais, induzidas pelo estresse salino. O objetivo deste trabalho foi estudar a influência de diferentes níveis de salinidade na nutrição mineral de mudas de pupunheira (Bactris gasipaes H.B.K., mediante o uso de solução nutritiva, em casa de vegetação. O experimento foi instalado em blocos ao acaso, com sete tratamentos e quatro repetições. Os tratamentos constaram das seguintes doses (mmol L-1: 0,0 de Na e 0,5 de Cl; 1,0 de Na e 0,5 de Cl (controle; e 5,0, 15,0, 30,0, 60,0 e 120,0 de NaCl. Os teores dos macronutrientes variaram em razão da salinidade, e verificou-se que o P e K apresentaram seus teores reduzidos nas raízes, o K e o Ca, nas folhas e o S, nas diferentes partes, enquanto o Na e o Cl apresentaram teores incrementados nas diferentes partes da planta. As relações Na/K, Na/Ca, Na/Mg, Cl/N, Cl/P e Cl/S aumentaram, causando um desbalanço nutricional na planta.The productive potential of plants may be affected by nutritional disorders induced by saline stress. The objective was to study the influence of different salinity levels on mineral nutrition of peach palm (Bactris gasipaes H.B.K. seedlings in greenhouse conditions with nutritive solution. The experimental design was in randomized blocks, with seven treatments and four replications. The treatments consisted of the following dosages (mmol L-1: 0.0 of Na and 0.5 of Cl; 1.0 of Na and 0.5 of Cl (control; and 5.0, 15.0, 30.0, 60.0 and 120.0 of NaCl. The content of the macronutrients varied with the salinity, there was reduction of P and K in the roots, K and Ca in the leaves, and S in different parts of the plants. Therefore, there was increase of Na and Cl in different parts of the plant. The enhancement of the ratios Na/K, Na/Ca, Na/Mg, Cl/N, Cl/P and Cl/S induced a nutritional imbalance in the plant.

  16. Efeito de liberadores de óxido nítrico na qualidade fisiológica de sementes de repolho sob salinidade

    Directory of Open Access Journals (Sweden)

    Ingrid Schimidt Kaiser

    2016-02-01

    Full Text Available RESUMO Estudos realizados com Brassica sp. demonstram que o estresse salino afeta a qualidade fisiológica e o vigor das sementes. Assim, a busca por substâncias que minimizem os efeitos provocados pelo estresse salino durante a germinação são de grande importância. Objetivou-se com este trabalho avaliar a ação de substâncias liberadoras de óxido nítrico durante a germinação de sementes de repolho cultivado sob condições de salinidade. As sementes foram pré-embebidas em soluções de nitrato de potássio (KNO3 e nitroprus siato de sódio (SNP nas concentrações de zero (controle, 0,01, 0,10, 1,00 e 10,00 mmol L-1, por 30 minutos. Posteriormente, distribuídas sobre papel germitest em placas de Petri, umedecido com solução salina de NaCl nos potenciais de zero, -0,6 e -1,2 MPa. Foram avaliados a germinação, primeira contagem de germinação, índice de velocidade de germinação, tempo médio de germinação, comprimento de parte aérea, comprimento de raiz e massa seca das plântulas. Não houve germinação no potencial osmótico de -1,2 MPa. O potencial de -0,6 MPa reduz a germinação e o desenvolvimento das plântulas de repolho. Os resultados sugerem que houve ação positiva do KNO3 e do SNP na concentração de 0,01 mmol L-1, revertendo o estresse provocado pela salinidade (-0,6 MPa de NaCl.

  17. Development of Hybrid pH sensor for long-term seawater pH monitoring.

    Science.gov (United States)

    Nakano, Y.; Egashira, T.; Miwa, T.; Kimoto, H.

    2016-02-01

    We have been developing the in situ pH sensor (Hybrid pH sensor: HpHS) for the long-term seawater pH monitoring. We are planning to provide the HpHS for researchers and environmental consultants for observation of the CCS (Carbon dioxide Capture and Storage) monitoring system, the coastal environment monitoring system (e.g. Blue Carbon) and ocean acidification. The HpHS has two types of pH sensors (i.e. potentiometric pH sensor and spectrophotometric pH sensor). The spectrophotometric pH sensor can measure pH correctly and stably, however it needs large power consumption and a lot of reagents in a long period of observation. The pH sensor used m-cresol purple (mCP) as an indicator of pH (Clayton and Byrne, 1993 and Liu et al., 2011). We can choose both coefficients before deployment. On the other hand, although the potentiometric pH sensor is low power consumption and high-speed response (within 10 seconds), drifts in the pH of the potentiometric measurements may possibly occur for a long-term observation. The HpHS can measure in situ pH correctly and stably combining advantage of both pH sensors. The HpHS consists of an aluminum pressure housing with optical cell (main unit) and an aluminum silicon-oil filled, pressure-compensated vessel containing pumps and valves (diaphragm pump and valve unit) and pressure-compensated reagents bags (pH indicator, pure water and Tris buffer or certified reference material: CRM) with an ability to resist water pressure to 3000m depth. The main unit holds system control boards, pump drivers, data storage (micro SD card), LED right source, photodiode, optical cell and pressure proof windows. The HpHS also has an aluminum pressure housing that holds a rechargeable lithium-ion battery or a lithium battery for the power supply (DC 24 V). The HpHS is correcting the value of the potentiometric pH sensor (measuring frequently) by the value of the spectrophotometric pH sensor (measuring less frequently). It is possible to calibrate in

  18. Germinação da vinagreira em função de cinco níveis de salinidade da água de irrigação

    Directory of Open Access Journals (Sweden)

    Mariana Alexandre de Lima Sales

    2014-04-01

    Full Text Available Normalmente, problemas de salinidade surgem quando os sais contidos na água de irrigação se acumulam na região do solo onde se encontra o sistema radicular das culturas e, com isto, seus rendimentos são afetados negativamente. Este ensaio teve por objetivo avaliar a germinação de vinagreira em função de cinco níveis de salinidade da água de irrigação. O trabalho foi realizado Laboratório de Análises de Solos e Água e em casa de vegetação, ambos localizados no IFCE, Campus de Sobral. No Ensaio I realizou-se testes preliminares que possibilitaram a construção de curvas artificiais de salinidade e no Ensaio II estudou-se os efeitos destes diferentes níveis de salinidade da água de irrigação, (T1 = testemunha – 0,17; T2=1,5; T3=2,5; T4=3,5; T5=4,5 e T6=5,5 dS m-1. As variáveis analisadas foram primeira contagem da germinação (PCG, porcentagem de germinação (%Germ, índice de velocidade de germinação (IVG e tempo médio de germinação (TMG. De posse dos resultados verifica-se que a elevação da condutividade elétrica da água de irrigação, reduziu o vigor da germinação das sementes de vinagreira; a condutividade elétrica do substrato apresentou aumento crescente com os níveis de salinidade da água de irrigação. Normal 0 21 false false false PT-BR X-NONE X-NONE

  19. Evolução e variabilidade espacial da salinidade em Neossolo Flúvico cultivado com cenoura sob irrigação Evolution and spatial variability of salinity in a Fluvic Neossol cropped with irrigated carrot

    Directory of Open Access Journals (Sweden)

    Edivan R. de Souza

    2008-12-01

    Full Text Available Desenvolveu-se um experimento de campo com o intuito de verificar o efeito da irrigação por microaspersão, utilizando-se água de condutividade elétrica média de 1,42 dS m-1, sob as propriedades químicas de um Neossolo Flúvico cultivado com cenoura cv. Brasília. A área foi dividida em dois setores (S1 e S2, com 900 m² cada um (30 x 30 m e texturas contrastantes; no S2 adicionou-se cobertura morta aos 23 dias após a semeadura (DAS e se adotou uma fração de lixiviação de 0,20 para os dois setores. Realizaram-se duas amostragens de solo, antes da semeadura e a 96 DAS, nas camadas de 0-20 e 20-40 cm, em 49 pontos no S1 e 52 pontos no S2, segundo uma malha de 5 x 5 m. No extrato da pasta saturada foram medidos o pH e a condutividade elétrica (CEes, e determinadas as bases solúveis; determinou-se, ainda, as bases trocáveis, calculando-se a relação de adsorção de sódio e a percentagem de sódio trocável. Os dados foram analisados por estatística descritiva e geoestatística. Considerando-se a camada de 0-40 cm, a área salina no S1, inicialmente de 7,98%, aumentou para 15,09% ao final do ciclo cultural. Para o S2, a área salina passou de 5,97 para 5,52%; verificou-se, assim, a influência decisiva da textura e da cobertura morta no controle da salinidade do solo.A field experiment was carried out aiming to verify the effect of micro sprinkler irrigation, using water with an average electrical conductivity of 1.42 dS m-1, on the chemical properties of a Fluvic Neossol cropped with carrot, variety Brasília. The area was divided into two sectors (S1 and S2, each one with 900 m² (30 x 30 m and contrasting textures; at S2 mulch was added at day 23 after sowing (DAS. A leaching fraction of 0.20 was adopted for both sectors. Two soil sampling schemes were carried out, before sowing and at 96 DAS, in the 0-20 and 20-40 cm layers, at 49 points in S1 and 52 points in S2, according to a regular 5 x 5 m mesh. In the extract of saturated

  20. Effect of the salinity in the e fi science in the use of the water and the production of dry matter in guayabo Efecto de la salinidad en la eficiencia en el uso del agua y la producción de materia seca en guayabo

    Directory of Open Access Journals (Sweden)

    González M Ing. Agr.; Leonardo A.

    2006-09-01

    Full Text Available

    Effect of salinity on water use efficiency and dry matter production of guava plants. To study the salt tolerance of guava cultivars (Psidium guajava I L.cvs RS 980 and Cimpa 00916, the effect os salinity on growth, dry matter production and agronomic water use efficiency were evaluated. Seedlings were grown in a glasshouse experiment in 3-1 post filled with soil in Tunja, Colombia. Plants were exposed to either non-saline (ECe: 1.2 dS.m-1 or saline conditions using 20, 40, 60 and 80 mM NaCl based to air dry soil (ECe: 3.0, 5.4, 7.9 and 10.5 dS.m-1 respectly of a saturated soil extract 3 months after germination. Plants were harvested 7 months after the NaCl exposure. The evapotranspiration rate (cm3, dry matter production (g, agronomic water use efficiency (g1-1 and leaf area (cm2 of both cultivars was reduced by salinity. Dry matter partitioning in roots shoot and leaves and root: shoot ratio based on dry matter were little affected by salinity. In comparison to the control plants, the agronomic water use efficiency was reduced 29.5% in cultivar RS 980 and 10.0% in Cimpa 00196 by 80 mM NaCl; similarly, 80 mM NaCl reduced the total dry matter production 50.8% in RS 980 and 29.8% in Cimpa 00196 in comparison to the control plants. Thus, it appears that RS 980 was more salt-sensitive than Cimpa 00196.

    En plantas de guayaba (Psidium guajava L. cvs. RS 980 y Cimpa 00916 se evaluó el efecto de la salinidad sobre el crecimiento, la producción de materia seca y la eficacia agronómica en el uso del agua. Las plantas se obtuvieron a partir de semilla, crecieron en un invernadero en materas (tres litros y se expusieron a condiciones no salinas (ECe: 1.2 dS.m-1 o salinas mediante la adición de 20; 40; 60 y 80 mM de NaCl con base en suelo seco al aire (ECe:3.0, 5.4, 7.9 y 10.5 dS.m-1

  1. SALINIDADE DO SUBSTRATO CONTENDO BIOFERTILIZANTE PARA FORMACÃO DE MUDAS DE MARACUJAZEIRO IRRIGADO COM ÁGUA SALINA

    Directory of Open Access Journals (Sweden)

    Gasparino Batista de Sousa

    2008-01-01

    Full Text Available An experiment was carried out, in order to evaluate the saline aspect of the substrate with biofertilizer on seedling formation of yellow passion fruit irrigated with different saline water. A completely randomized design was used, with treatments distributed in a factorial arrangement 5 x 3 x 2, referring to water salinity levels (0.5; 1.0; 2.0; 3.0 and 4,0 dS m-1, substrate volumes (1, 2 and 3 L, in absence and presence of biofertilizer bovine. The following variables were registered at the end of the experiment: pH, electrical conductivity of water and exchangeable sodium percentage. The increase of irrigation water salinity, independently of biofertilizer use, drastically enhanced the substrate salinity, from not saline to saline and strongly saline. No there was definition of the values of PST among substrate volumes. Electrical conductivity values of the saturation extract were higher for substrate with lower volume.

  2. Esuuman et al (17)

    African Journals Online (AJOL)

    big timmy

    ether (Sathe et al., 2002). Various extraction conditions such as pH, solvent types (NaOH, NaCl or Ethanol), solvent concentration, extraction time, solvent/flour ratio, may affect the final properties of the extracted protein. When many factors and interactions affect desired responses in a certain process design, Response.

  3. Hydrodeoxygenation of Phenolic Compounds by Sulfided (CoMo/Al2O3 Catalysts, a Combined Experimental and Theoretical Study Hydrodésoxygénation de composés phénoliques en présence de catalyseurs sulfurés (CoMo/Al2O3 : une étude expérimentale et théorique

    Directory of Open Access Journals (Sweden)

    Badawi M.

    2013-04-01

    Full Text Available The hydrodeoxygenation of model phenol compounds (phenol and 2-ethylphenol was carried over unpromoted Mo/Al2O3 and promoted CoMo/Al2O3 catalysts. Hydrodeoxygenation proceeds by two pathways: – hydrogenation of the aromatic ring followed by Csp3-O bond cleavage (HYD pathway, (hydrogenation of the aromatic ring followed by Csp3-O bond cleavage; – direct cleavage of the Csp2-O bond (DDO pathway. Both routes were favored by the presence of Co on the catalyst, while the presence of the alkyl substituent on the phenolic ring favors the DDO route but inhibits the HYD pathway. IR (InfraRed spectroscopy shows that while phenol mostly dissociates on these catalysts, a significant fraction of 2-ethylphenol remains non dissociated. The adsorption energies of both reactants and possible reaction intermediates on promoted and non-promoted sulfide phases as computed by DFT (Density-Functional Theory confirm these findings and allow rationalizing the catalytic activity trends observed experimentally. L’hydrodésoxygénation de deux composés phénoliques modèles (phénol et 2-éthylphénol a été étudiée sur deux catalyseurs Mo/Al2O3 et CoMo/Al2O3 sulfurés. La désoxygénation de ces molécules fait intervenir deux voies parallèles et indépendantes, à savoir : – l’hydrogénation du noyau aromatique suivie par la rupture de la liaison Csp3-O (voie HYD, (hydrogenation of the aromatic ring followed by Csp3-O bond cleavage; – la rupture directe de la liaison Csp2-O (voie de DésOxygénation Directe – DOD. Ces deux voies sont favorisées en présence du catalyseur promu par le cobalt (CoMo/Al2O3. La présence du groupe éthyle permet d’améliorer la voie DOD mais conduit à une diminution de la voie HYD. Les études menées par spectroscopie IR (InfraRouge montrent que le phénol est majoritairement dissocié sur ces catalyseurs alors que le 2-éthylphénol semble plutôt adsorbé de façon non-dissociative. Les énergies d’adsorption de

  4. PH og modernismen

    DEFF Research Database (Denmark)

    Ahnfeldt-Mollerup, Merete

    2012-01-01

    Artiklen kaster et kritisk blik på Poul Henningsens samfundsanalyse og dennes sammenhæng med hans design. PH ses i en bredere national og international sammenhæng. Diskussion af designmetoder, æstetik og Bauhaus.......Artiklen kaster et kritisk blik på Poul Henningsens samfundsanalyse og dennes sammenhæng med hans design. PH ses i en bredere national og international sammenhæng. Diskussion af designmetoder, æstetik og Bauhaus....

  5. Crescimento e tolerância à salinidade em três espécies medicinais do gênero Plectranthus expostas a diferentes níveis de radiação

    Directory of Open Access Journals (Sweden)

    M.A.C. Freitas

    2014-12-01

    Full Text Available No cultivo de plantas medicinais as condições de salinidade e de luz podem exercer influência no rendimento e na qualidade final da produção de biomassa. O objetivo deste trabalho foi avaliar o efeito de diferentes luminosidades e níveis de salinidade na água de irrigação sobre o crescimento e tolerância de três espécies de plantas do gênero Plectranthus. O ensaio foi conduzido em parcelas subsubdivididas com cinco repetições, sendo as parcelas referente ao fator ambiente (pleno sol e telado, as subparcelas aos níveis de salinidade na água de irrigação - CEa (0,7; 1,9; 3,1; 4,3 e 5,5 dS m-1, e as subsubparcelas às três espécies do gênero Plectranthus (P. amboinicus, P. barbatus e P. grandis. As variáveis de resposta foram: índice relativo de clorofila (IRC, área foliar (AF, razão de área foliar (RAF, área foliar específica (AFE, matéria seca da parte aérea (MSPA, matéria seca das raízes (MSR, matéria seca total (MST, relação MSR/MSPA, grau de tolerância à salinidade, e teor dos íons Na+ e K+. O estresse salino reduziu o crescimento das plantas, sendo as maiores reduções observadas nas plantas expostas a pleno sol. A salinidade influenciou a partição de matéria seca, sendo as raízes mais afetadas do que a parte aérea. Com o aumento da CEa houve aumento expressivo no teor foliar de Na+, enquanto o teor de K+ e o IRC foram reduzidos. Entretanto, o acúmulo de Na+ foi menor em P. grandis. Considerando-se a MST, verificou-se que as três espécies se mostraram moderadamente tolerantes à salinidade de até 3,1 dS m-1, exceto P. grandis cultivada em telado, classificada como tolerante. Em relação ao grau de redução na produção MSPA (parte de interesse comercial, poderia se recomendar o cultivo de P. grandis quando a água de irrigação contiver CEa de até 3,1 dS m-1.

  6. Tolerância de juvenis do pampo Trachinotus marginatus (Teleostei, Carangidae ao choque agudo de salinidade em laboratório Acute salinity tolerance of juvenile pompano Trachinotus marginatus (Teleostei, Carangidae under laboratory conditions

    Directory of Open Access Journals (Sweden)

    Luís André Sampaio

    2003-08-01

    Full Text Available O pampo Trachinotus marginatus é uma espécie com potencial para piscicultura, mas a sua utilização pode ser limitada pelas variações de salinidade comuns em estuários ou em ambientes super-salinos. Este trabalho foi realizado com o objetivo de determinar a tolerância à salinidade de juvenis de T. marginatus em laboratório. Foram testadas 12 salinidades em duplicata (0, 6, 8, 10, 15, 25, 45, 55, 58, 61, 65 e 75‰ e um tratamento controle (35‰. Dez peixes (comprimento total: 20,7±2,3mm e peso úmido: 427±113mg foram colocados em tanques plásticos de 3L. A temperatura da água foi mantida em 24ºC com um banho termostatisado, aeração constante e, a cada 24 horas, os meios experimentais foram completamente renovados. Após 96 horas de exposição, as salinidades letais médias inferior e superior, com os respectivos intervalos de confiança (IC 95%, foram estimadas em 6,99‰ (IC 95% = 6,86-7,13‰ e 58,50‰ (IC 95% = 56,81-60,24‰, respectivamente. Estes resultados permitem caracterizar esta espécie como eurialina. O estudo da influência da salinidade sobre T. marginatus deve ser aprofundado, buscando avaliar principalmente os efeitos sobre o crescimento, de modo que seja possível determinar o potencial do seu cultivo em ambientes com diferentes salinidades.The pompano Trachinotus marginatus shows good potential for aquaculture, but the success of its culture might be limited by the salinity fluctuations common in estuaries or in hyper-saline environments. The objective of this work was to establish the salinity tolerance of juvenile T. marginatus under laboratory conditions. Twelve salinities (0, 6, 8, 10, 15, 25, 45, 55, 58, 61, 65, and 75‰ plus a control (35‰ were tested in duplicate. Groups of ten fish (total length: 20.7±2,3mm and wet weight: 427±113mg were placed in plastic tanks with 3L of water. A water bath was set to control the temperature at 24ºC, water was continuously aerated, and completely exchanged

  7. Efeitos da lixiviação e salinidade da água sobre um solo salinizado cultivado com beterraba Effects of leaching and water salinity on a saline soil cultivated with sugar beet

    Directory of Open Access Journals (Sweden)

    Paulo A. Ferreira

    2006-09-01

    Full Text Available Os efeitos de cinco lâminas de lixiviação e quatro níveis de salinidade da água de irrigação sobre a salinidade de um Neossolo Flúvico e a produtividade da cultura da beterraba (Beta vulgaris L. foram estudados em lisímetros de drenagem. Os tratamentos foram dispostos em arranjo fatorial com quatro níveis de condutividade elétrica da água de irrigação (1,0, 2,0, 3,0 e 4,0 dS m-1, a 25 °C e cinco lâminas de lixiviação equivalente a 0,25, 0,50, 0,75, 1,00 e 1,25 do volume de poros do solo ou 53, 106, 159, 206 e 248 mm, respectivamente, no delineamento inteiramente casualizado, com quatro repetições. Os componentes avaliados foram a produtividade da cultura e as salinidades no solo e no lixiviado. Os resultados obtidos mostraram incrementos da salinidade no lixiviado com o decréscimo das lâminas de lixiviação. Os maiores índices de salinidade no perfil do solo, ao final do ciclo da cultura, corresponderam aos tratamentos que receberam as menores lâminas de lixiviação e condutividade elétrica da água de irrigação. A produtividade total da beterraba e a produção das raízes com diâmetros maiores que 3, 4, 5, 6 e 7 cm, não foram influenciadas pelos níveis de salinidade da água de irrigação e lâminas de lixiviação.The effects of five leaching depths and four salinity levels of the irrigation water on the salinity of a Neossol Fluvent and the productivity of sugar beet crop were studied using drainage lysimeters. A completely randomized experimental design was used with four replications, the treatments being displayed in a factorial scheme with four electrical conductivity levels of the irrigation water (1.0, 2.0, 3.0 and 4.0 dS m-1 at 25 °C and five leaching depths equivalent to 0.25, 0.50, 0.75, 1.00 and 1.25 of the soil pores volume or 53, 106, 159, 206 e 248 mm, respectively. The crop productivity and the salinity of soil and leachate were evaluated. The results showed increased salinity in the leachate

  8. Crescimento do melão Pele de Sapo, em níveis de salinidade e estágio de desenvolvimento da planta Growth of 'Pele de Sapo' muskmelon under salinity levels and development stage of plant

    Directory of Open Access Journals (Sweden)

    Damiana C. de Medeiros

    2012-06-01

    Full Text Available As áreas de cultivo com intensa evaporação, deficiência em drenagem e uso inadequado de fertilizantes, têm aumentado os problemas com a salinidade, prejudicando o rendimento das culturas. O experimento foi conduzido com o objetivo de se avaliar a alocação de massa seca do meloeiro, em função dos diferentes níveis de salinidade da água de irrigação e estágios de desenvolvimento da planta, em Mossoró, RN. O delineamento experimental utilizado foi o de blocos ao acaso, em parcelas subdivididas apresentando, nas parcelas, cinco níveis de salinidade da água de irrigação (0,54, 1,48, 2,02, 3,03 e 3,90 dS m-1 e, nas subparcelas, quatro épocas de coleta de plantas em função dos estágios de seu desenvolvimento (15, 30, 45 e 60 dias após o transplante - DAT correspondendo às fases de crescimento inicial, floração plena, frutificação plena e anterior ao início da colheita, respectivamente, com quatro repetições. Todos os parâmetros de crescimento avaliados foram afetados pela salinidade da água de irrigação. O efeito da salinidade da água sobre a área foliar específica e a massa seca das folhas, foi variável de acordo com a fase de desenvolvimento das plantas. As variáveis mais afetadas pela salinidade da água de irrigação foram a área foliar e a massa seca de frutos, com redução de 28,9 e 24,6%, respectivamente. O maior acúmulo de massa seca no meloeiro Pele de Sapo ocorreu no período entre 30 e 45 dias após o transplantio.The region of Mossoró, RN, Brazil, underwent increasing problems with soil salinity and melon crop yields, mainly in areas with intense evaporation, deficient drainage and inadequate fertilizer use. With this concern, dry mass accumulation in different muskmelon plant organs was evaluated in a trial combining different irrigation water salinity levels and crop growth stages. The experiment was conducted in completely randomized block design with split plot arrangement, having four

  9. DESENVOLVIMENTO INICIAL DA GRAVIOLEIRA SOB FONTES E NÍVEIS DE SALINIDADE DA ÁGUA INITIAL DEVELOPMENT OF SOURSUP PLANTS UNDER SOURCE AND WATER SALINITY LEVELS

    Directory of Open Access Journals (Sweden)

    LOURIVAL FERREIRA CAVALCANTE

    2001-08-01

    Full Text Available No período de fevereiro a julho de 1999, estudaram-se os efeitos de fontes salinas através da irrigação com água de barragem, rica em cloreto de sódio e em cloreto de magnésio, com níveis de condutividade elétrica de 0,5; 1,0; 2,0; 3,0; 6,0 e 9,0 dSm-1 sobre o crescimento inicial da gravioleira, Annona muricata L., cultivar Morada. Os resultados nos primeiros 150 dias, independentemente das fontes, indicam que área foliar e sua fitomassa cresceram com o aumento da salinidade das águas de 0,5 para 2,0 e até 3,0 dSm-1. No mesmo período, o índice de salinidade do substrato foi elevado para até fortemente salino, revelando que a gravioleira comportou-se como planta moderadamente tolerante aos sais durante o crescimento inicial. Apesar de a água rica em cloreto de magnésio ser a fonte que menos elevou a condutividade elétrica do substrato, foi a que mais contribuiu para a redução das variáveis estudadas, indicando que as plantas foram mais sensíveis a sua toxidade em relação à água de barragem e rica em cloreto de sódio.This Work was carried out on period of February to July of year 1999, in order to evaluate the effects of three salinity sources from water irrigation (dam water, water rich in sodium chloride and rich in magnesium chloride to electric conductivity levels 0.5;1.0;2.0;3.0;6.0 and 9.0 dSm-1, on initial growth of soursup plants Annona muricata L, cultivate Morada. During the first fifty days in any one salinity sources studied data of leaves area and dry matter production of leaves plants increased with increment of water salinity level of 0.5 to 2.0 and till 3.0 dSm-1. In same period the substratum salinity index was expressively increased and soursup plants presented it as moderately tolerant to soil salinity during it initial growth. In spite of water rich in magnesium chloride to be the saline source that least contributed to increase of substratum salinity level was the salt source that more induced

  10. Influência de diferentes níveis de salinidade nas características sensoriais do tomate Influence of different levels of salinity on sensory characteristics of tomato

    Directory of Open Access Journals (Sweden)

    Waleska M. Eloi

    2011-01-01

    Full Text Available Objetivou-se, com este trabalho, avaliar o efeito de diferentes níveis de salinidade no solo provocados pelo uso da fertirrigação, nas características sensoriais de frutos do tomateiro. O experimento foi conduzido em duas etapas, a primeira desenvolvida em laboratório e a segunda realizada em estufa plástica. A primeira etapa consistiu de testes preliminares que possibilitaram a construção de curvas artificiais de salinização, visando à realização do processo de salinização artificial do solo; na segunda etapa estudou-se a evolução dos diferentes níveis iniciais de salinidade do solo, implementados por meio da aplicação de fertilizantes, de acordo com a marcha de absorção de nutrientes pela cultura. Os níveis iniciais de salinidade utilizados foram: 1,5; 2,5; 3,5; 4,5; 5,5 e 6,5 dS m-1. Para a análise sensorial dos frutos realizou-se o teste hedônico com 39 provadores. Verificou-se que os índices de salinidade utilizados não interferiram na aceitação do produto.With the objective of evaluating the effect of different salinity levels in the soil provoked by the use of fertigation, on the sensory characteristics of tomato fruits, an experiment was conducted in two stages, being the first developed in laboratory and the second one accomplished in plastic greenhouse. The first stage consisted of preliminary tests that made possible the construction of artificial curves of salinization, seeking accomplishment of the process of artificial salinization of the soil. In the second stage the evolution of the different initial levels of soil salinity was studied, implemented through the application of fertilizers in agreement with the absorption of nutrients for the crop. The levels of salinity used were: 1.5, 2.5, 3.5, 4.5, 5.5 and 6.5 dS m-1. For the fruit sensory analysis the hedonic test with 39 individuals was performed. It was found that the levels of salinity used did not interfer in the acceptance of the product.

  11. Mecanismos bioqu??micos y moleculares de tolerancia a la salinidad en especies cultivada y silvestre de tomate : papel de los enzimas translocadores de iones de plasmalema y tonoplasto

    OpenAIRE

    Kerkeb, Badea

    2000-01-01

    Para disminuir el impacto de la salinidad en agricultura, una estrategia importante para ayudar a la selecci??n de las plantas mas tolerantes y productivas, se basa en el conocimiento de los mecanismos bioqu??micos y moleculares de resistencia en medios salinos. En especies tolerantes, la capacidad para regular los flujos i??nicos constituye un mecanismo de tolerancia, por lo que la identificaci??n y caracterizaci??n bioqu??mica y g??nica de los mecanismos fisiol??gicos que controlan esta res...

  12. Efecto de la salinidad sobre algunas variables bioquímicas, inmunológicas, fisiológicas y productivas del camarón litopenaeus vannamei cultivado experimentalmente

    OpenAIRE

    Cervantes Cervantes, Carlos Miguel

    2014-01-01

    La camaronicultura es una de las industrias de mayor crecimiento tanto a nivel mundial como nacional, pero en la última década el desarrollo de ésta se ha visto limitado por la aparición de enfermedades infecciosas provocadas principalmente por virus. Existen condiciones físico-químicas y biológicas dentro de los sistemas de cultivo que pueden provocar estrés y aumentar la susceptibilidad de los camarones a enfermedades infecciosas. Dentro de las variables físico-químicas, la salinidad es una...

  13. Uso de un modelo semi-empírico de emisividad del mar para la estimación aproximada de la salinidad superficial a partir de medidas realizadas con un radiómetro aerotransportado

    OpenAIRE

    Gabarró, Carolina; Font, Jordi; Miller, Jerry; Camps, Adriano; Burrage, Derek; Wesson, Joe; Piola, Alberto A.

    2008-01-01

    [ES] Para preparar la misión satelital SMOS (Soil Moisture and Ocean Salinity) de la Agencia Espacial Europea, varias medidas radiométricas y oceanográficas se llevaron a cabo en el año 2000 y 2001 desde una plataforma fija en el Mediterráneo noroccidental. El objetivo de estas campañas era mejorar los modelos de la emisividad superficial del mar en banda L y de ellas se derivaron varios modelos semi-empíricos. Ahora, unos de estos modelos se ha usado para el cálculo de la salinidad superfici...

  14. Seleção de genótipos de arroz tolerantes à salinidade durante a fase vegetativa Selection of genotypes of salinity tolerance rice during the vegetative phase

    Directory of Open Access Journals (Sweden)

    Palmira Cabral Sales de Melo

    2006-02-01

    Full Text Available O objetivo deste trabalho foi avaliar o grau de tolerância e sensibilidade à salinidade de genótipos de arroz durante a fase vegetativa da planta. O experimento foi conduzido sob condições de telado, nas dependências da Empresa Pernambucana de Pesquisa Agropecuária-IPA (Recife-PE, em 1996. Foram avaliados doze genótipos de arroz, sendo dez tolerantes e dois sensíveis à salinidade no estádio de desenvolvimento vegetativo. O delineamento experimental foi em blocos ao acaso com arranjo fatorial (doze genótipos x quatro níveis de NaCl, em três repetições. Os resultados constataram existência de variabilidade entre os genótipos de arroz na população estudada para tolerância e sensibilidade à salinidade. As linhagens PR492, PR504, CNA8250, CNA8262 e CNA8267 são tolerantes e a CNA8270, CNA8258, CNA8269, PR475 e PR477 são sensíveis à salinidade dos solos durante a fase vegetativa.The objective of this work was to evaluate the degree of tolerance and sensibility to the salinity of genoty,pes of rice (Oryza sativa L. during the vegetative phase of the plant. The experiment was lead under greenhouse conditions at IPA (Empresa Pernambucana de Pesquisa Agropecuária, in 1996. Twelve genotypes of rice had been evaluated, being ten tolerant and two sensible ones to salinity in the vegetative development stadium. The randomized blocks design were performed into three repetitions of factorials arrangements (twelve genotypes x four levels of NaCl. Results had evidenced variability existence among the genotypes of rice, in the specific population, for tolerance and sensitivity to the salinity. Samples PR492, PR504, CNA8250, CNA8262 and CNA8267 can be considered tolerant to salinity, while the genotypes CNA8270, CNA8258, CNA8269, PR475 and PR477 are sensible to salinity of soil during the vegetative phase.

  15. Plant Habitat (PH)

    Science.gov (United States)

    Onate, Bryan

    2016-01-01

    The International Space Station (ISS) will soon have a platform for conducting fundamental research of Large Plants. Plant Habitat (PH) is designed to be a fully controllable environment for high-quality plant physiological research. PH will control light quality, level, and timing, temperature, CO2, relative humidity, and irrigation, while scrubbing ethylene. Additional capabilities include leaf temperature and root zone moisture and oxygen sensing. The light cap will have red (630 nm), blue (450 nm), green (525 nm), far red (730 nm) and broad spectrum white LEDs. There will be several internal cameras (visible and IR) to monitor and record plant growth and operations.

  16. ALS Association

    Science.gov (United States)

    ... toward a world without ALS! Walk to Defeat ALS® Walk to Defeat ALS® draws people of all ... We need your help. I Will Advocate National ALS Registry The National ALS Registry is a congressionally ...

  17. pH matters

    DEFF Research Database (Denmark)

    Inaba, Masanori; Quinson, Jonathan; Arenz, Matthias

    2017-01-01

    to home-made catalysts does not lead to satisfying results, although reported work could be reproduced using commercial catalyst samples. It is demonstrated that the pH of the catalyst ink, which has not been addressed in previous TF-RDE studies, is an important parameter that needs to be carefully...

  18. pH Basics

    Science.gov (United States)

    Lunelli, Bruno; Scagnolari, Francesco

    2009-01-01

    The exposition of the pervasive concept of pH, of its foundations and implementation as a meaningful quantitative measurement, in nonspecialist university texts is often not easy to follow because too many of its theoretical and operative underpinnings are neglected. To help the inquiring student we provide a concise introduction to the depth just…

  19. Familial ALS

    Science.gov (United States)

    Boylan, Kevin

    2015-01-01

    Synopsis Genes linked to ALS susceptibility are being identified at an increasing rate owing to advances in molecular genetic technology. Genetic mechanisms in ALS pathogenesis appear to exert major effects in ~10% of patients, but genetic factors at some level may be important components of disease risk in most ALS patients. Identification of gene variants associated with ALS has informed concepts of the pathogenesis of ALS, aided the identification of therapeutic targets, facilitated research to develop new ALS biomarkers, and supported the establishment of clinical diagnostic tests for ALS-linked genes. Translation of this knowledge to ALS therapy development is ongoing. PMID:26515623

  20. ATIVIDADE DE PEROXIDASES (EC 1.11.1.7 E TEOR DE PROLINA NO EMBRIÃO E COTILÉDONES DE FEIJOEIRO Phaseolus vulgaris L. EM CONDIÇÕES DE SALINIDADE

    Directory of Open Access Journals (Sweden)

    G.P.P. LIMA

    1997-09-01

    Full Text Available Os efeitos da salinidade sobre a atividade de peroxidases foram acompanhadas no embrião e em cotilédones de feijoeiro Phaseolus vulgaris L. cv. Carioca, observando-se em ambos, aumento na atividade das enzimas. Com relação ao teor de prolina, ocorreu decréscimo constante no embrião de feijoeiro cultivado em condições salinas, entretanto, nos cotilédones, verificou-se aumento progressivo em condições de presença ou ausência de salinidade.Changes in proline level and peroxidase activity in bean embryo and cotiledon were studied in response to salinity conditions. Activity of peroxidases (EC 1.11.1.7 in bean embryo and cotiledon (Phaseolus vulgaris L. cv. Carioca was higher than in seedlings growing in the absence of NaCl. Proline level decresead constantly in bean embryo growing in saline conditions. However, in cotiledon the proline content increased progressively in the absence and presence of NaCl in growth solution.

  1. Effects of salinity on seed germination, seedling growth and survival of Spartina ciliata Brong Efeitos da salinidade sobre a germinação, crescimento e sobrevivência das plântulas de Spartina ciliata Brong

    Directory of Open Access Journals (Sweden)

    César Vieira Cordazzo

    1999-12-01

    Full Text Available The effects of different salinities on the germination of Spartina ciliata seeds were tested during 40 days in the laboratory, using six concentrations of NaCl (0,45, 80, 130, 170 and 215 mM besides three concentrations of seawater (25,30 and 35‰. In addition, the survival and growth of seedlings were tested in five constant salinity regimes (0,45, 80 and 170 mM NaCl as well as in five regimes of simulating seawater overwash. The results showed that seeds possed a high germination capacity over a wide range of salinities (0 to 215 mM NaCl. Although concentrations close to full-strength seawater completely inhibited seed germination, the transfer of the ungerminated seeds to freshwater immediately stimulated this. The effects of salinity on seedling growth showed that shoot height and root length were the variables most sensitive to salt stress. Frequent overwash with seawater significantly reduced the survival and growth of Spartina ciliata seedlings. The success in seed germination, survival, and growth of Spartina ciliata in salinities above those normally found in the natural environment could explain the species being distributed throughout salt-stressed foredune habitats in southern Brazil.O efeito de diferentes salinidades sobre a germinação das sementes de Spartina ciliata foi testado em laboratório ao longo de 40 dias, usando seis concentrações de NaCl (0,45, 80, 130, 170 e 215 mM NaCl e em três concentrações de água do mar (25, 30 e 35‰. Adicionalmente a sobrevivência e crescimento das plântulas foram testados em cinco regimes de salinidade (0,45,80,130 e 170 mM NaCl assim como, em cinco regimes de inundação com água do mar. Os resultados mostraram que as sementes apresentam alta capacidade germinativa numa grande amplitude de salinidades (0 a 215 mM NaCl. Apesar de concentrações próximas as da água do mar terem inibido completamente a germinação, a transferencia das sementes que não germinaram para água doce

  2. Salinity tolerance of halophyte Atriplex nummularia L. grown under increasing NaCl levels Tolerância à salinidade da halófita Atriplex nummularia L. cultivada em níveis crescentes de NaCl

    Directory of Open Access Journals (Sweden)

    Sandro A.M. de Araújo

    2006-12-01

    Full Text Available The current study reports effects of salt stress on growth, K+ nutrition and organic composition of Atriplex nummularia. The upper limit of the NaCl gradient imposed on the plants was close to seawater salinity (600 mM. An external NaCl of 150 mM improved the growth of this species, which corroborates its halophytic nature. Evidence show that Atriplex nummularia was responsive to NaCl, but the mechanisms of this response are still not known. In such stress condition, Na+ and Cl- accumulation in leaves was far greater than that in roots; therefore salinity tolerance of Atriplex nummularia is not due to ion exclusion mechanism. In spite of a reduction of K+ content of tissues under salinity conditions, no corresponding physiological relevance of this in terms of growth was found. The high affinity of root cells for Na+ during uptake and, probably, its subsequent sequestration into cell vacuoles and structures of protection seems to contribute to osmotic adjustment as an increase in relative water content (RWC of leaves was observed. NaCl caused a decrease in total soluble proteins and chlorophylls; the relevance of this is discussed in terms of mechanisms of salinity tolerance. The ability of Atriplex nummularia plants to keep Na+ and Cl- away from enzymes and cytosolic structures, together with an effective osmotic adjustment, is suggested as having a role in its tolerance to high salinity.O presente estudo relata os efeitos do estresse salino no crescimento, na nutrição de K+ e na composição orgânica de Atriplex nummularia. A maior concentração de NaCl imposta às plantas foi similar a da salinidade da água do mar (600 mM. Uma concentração externa de 150 mM de NaCl estimulou o crescimento da espécie o que, em parte, explica seu caráter halofítico. As evidências mostram que a Atriplex nummularia foi receptiva ao NaCl, porém os mecanismos envolvidos são ainda esperados. Em tais condições de estresse a acumulação de Na+ e Cl

  3. Interação entre salinidade e biofertilizante bovino na cultura do feijão-de-corda Interaction between water salinity and bovine biofertilizer on the cowpea plants

    Directory of Open Access Journals (Sweden)

    Francisco L. B. da Silva

    2011-04-01

    Full Text Available Objetivou-se avaliar a interação entre salinidade e o uso de biofertilizante bovino sobre a condutividade elétrica do solo, crescimento inicial, trocas gasosas e teores de elementos minerais no feijão-de-corda. O experimento foi conduzido em ambiente protegido do Departamento de Ciências dos Solos - UFC. A semeadura foi feita em vasos, utilizando-se, como substrato, um Argissolo Vermelho Amarelo. O experimento obedeceu a um delineamento inteiramente casualizado, em esquema fatorial 5 x 2, referente a cinco níveis de sais da água de irrigação e dois de biofertilizante bovino. O aumento dos níveis salinos da água de irrigação inibiu o crescimento inicial das plantas, sendo menos afetado no solo com o biofertilizante. O aumento da salinidade da água aliado à aplicação do biofertilizante, resultou no aumento da salinidade do solo. O aumento do teor salino da água de irrigação provocou redução nas trocas gasosas, mas em menor proporção nas plantas desenvolvidas nos tratamentos com o biofertilizante. A extração dos elementos essenciais e de sódio obedeceu a seguinte ordem: Ca > K > Na > P. A aplicação de biofertilizante bovino foi eficiente ao aumentar os teores de P na planta e de aumentar os totais extraídos de K, P e Ca, independente no nível de salinidade aplicado. Entretanto, os efeitos benéficos da aplicação de biofertilizante bovino sobre o crescimento, trocas gasosas e extração de nutrientes, são menos expressivos nos maiores níveis de salinidade da água de irrigação.The objective of this study was to evaluate the interaction between salinity levels of the water and the use of biofertilizer soil electrical conductivity of soil, initial growth, gas exchange and mineral content in cowpea plants. The experiment was performed conducted under greenhouse of the Department of Soil Science - UFC. The sowing of seeds was done in pots, using as a substrate Alfissol and two plants per pot. The experimental design

  4. Germinação de duas espécies da caatinga sob déficit hídrico e salinidade

    Directory of Open Access Journals (Sweden)

    Cibele Alves dos Santos

    2016-09-01

    Full Text Available A germinação é uma das etapas de desenvolvimento do vegetal e para que a mesma ocorra, a presença da água é de fundamental importância. Porém, plantas que precisam se desenvolver em solos de regiões áridas e semiáridas se deparam com solos salinizados ou com pouca água disponível. Portanto, a presente pesquisa objetivou avaliar a germinação de sementes de catingueira e angico submetidas a condições de estresse salino e hídrico. Foram utilizadas sementes de Poincianella pyramidalis e Anadenanthera colubrina submetidas à salinidade, induzida pelos cloretos de cálcio e de sódio e à deficiência hídrica, induzida pelo PEG 6000, tendo o rolo de papel como substrato. Os tratamentos foram: controle (água destilada, -0,4MPa (NaCl, CaCl2 e PEG, -0,8MPa (NaCl, CaCl2 e PEG e -1,2MPa (NaCl, CaCl2 e PEG. Avaliou-se a %G, o IVG e o TMG. Em ambas espécies não houve germinação no potencial osmótico mais negativo (-1,2MPa de CaCl2 e de PEG 6000. Foi verificado também que a germinação nas duas espécies foi mais afetada pelo CaCl2, não havendo germinação a partir de -0,8MPa de CaCl2. As sementes de catingueira evidenciaram uma maior tolerância ao estresse salino, enquanto que as sementes de angico suportaram melhor a condição de deficiência hídrica.

  5. Tolerância à salinidade em feijão (Phaseolus vulgaris L Salt tolerance in bean (Paseolus vulgaris cell culture

    Directory of Open Access Journals (Sweden)

    F. Broetto

    1995-04-01

    Full Text Available Uma das aplicações das técnicas da cultura de tecidos no melhoramento é a identificação de linhas de células que apresentam tolerância à salinidade. Vários autores obtiveram linhas de células tolerantes ao estresse salino; e estudo de mecanismos bioquímicos da tolerância a sais em plantas tem demonstrado altas correlações entre estes e o acúmulo de macromoléculas em tecido de plantas superiores. Para verificar essas correlações em feijão (Phaseolus vulgaris cv IAC carioca, calos oriundos de eixos embrionários foram cultivados em meio sólido, suplementado com NaCl nas concentrações de 0 a 60 mM. Após 13 dias de incubação, os calos foram coletados e analisados quanto ao crescimento relativo, teor de proteínas, teor de prolina e atividade da peroxidase. Os parâmetros analisados mostraram decréscimo no crescimento relativo e no de proteínas em resposta ao NaCl. Paralelamente, observou-se aumento significativo no conteúdo de prolina e atividade da enzima peroxidase.One of the applications of the tissue culture technique in plant improvement is the identification of cell lines which show salinity tolerance. Several authors were able to obtain saline stress-tolerant cell lines and show that mechanisms of tolerance to salts have a strong correlation between this phenomenon and a high macromolecule concentration in plant tissues. Callus obtained from embrionic axis of Phaseolus vulgarís cv. IAC carioca in solid medium, supplemented with 0 to 60 mM NaCl, as the salt treatment, were used. Callus harvesting was done on the 13th day, when they were processed for relative growth, protein, proline content and peroxidase acivity. The results show both, a decrease of the relative growth and of protein content in response to the NaCl treatment, as compared to controls. However, there was a significant increase on the proline content and on the peroxidase activity.

  6. Low pH Cements

    Energy Technology Data Exchange (ETDEWEB)

    Savage, David; Benbow, Steven [Quintessa Ltd., Henley-on-Thames (United Kingdom)

    2007-05-15

    speciation of silicon at pH 10 has a significant impact upon the solubility of montmorillonite and would thus constitute a logical choice of pH limit for cement-derived pore fluids, but it is unlikely that cement-based grouts could be developed to meet this limit. Control of mass transport by diffusion processes serves as a significant constraint over the amount of bentonite that can be degraded. Computer simulations indicate that porosity reduction is likely at the interface between cement and bentonite. However, it is not clear how the transport properties of bentonite may be modified due to mineral alteration processes. There are considerable uncertainties concerning the precise mechanism of the rate of montmorillonite dissolution at elevated pH. The rate of dissolution may be inhibited by the presence of dissolved Si (and perhaps Al), but this mechanism has yet to be confirmed at high pH. The type of secondary minerals assumed to form from cement-bentonite interaction will also have a significant impact upon the rate of montmorillonite dissolution. Low-pH cement systems have received little attention thus far regarding the development of models for the chemical evolution of pore fluids. Low Ca/Si CSH gels show preferential leaching of Si, which is in marked contrast with gels of greater Ca/Si ratio. Models apparently capable of predicting pore fluid composition coexisting with low Ca/Si CSH gels are a modified Berner model and a solid-solution model proposed by Sugiyama and Fujita. The solubility of silica in pore fluids coexisting with low Ca/Si gels may exceed that of amorphous silica, and may pose problems regarding the stability of montmorillonite in relation to framework silicates such as feldspars. However, the potential rate of conversion of montmorillonite to feldspar under repository conditions is uncertain. It is necessary to use additives such as super plasticiser to improve the workability of low-pH cements. These organic additives have the potential to

  7. Low pH Cements

    International Nuclear Information System (INIS)

    Savage, David; Benbow, Steven

    2007-05-01

    speciation of silicon at pH 10 has a significant impact upon the solubility of montmorillonite and would thus constitute a logical choice of pH limit for cement-derived pore fluids, but it is unlikely that cement-based grouts could be developed to meet this limit. Control of mass transport by diffusion processes serves as a significant constraint over the amount of bentonite that can be degraded. Computer simulations indicate that porosity reduction is likely at the interface between cement and bentonite. However, it is not clear how the transport properties of bentonite may be modified due to mineral alteration processes. There are considerable uncertainties concerning the precise mechanism of the rate of montmorillonite dissolution at elevated pH. The rate of dissolution may be inhibited by the presence of dissolved Si (and perhaps Al), but this mechanism has yet to be confirmed at high pH. The type of secondary minerals assumed to form from cement-bentonite interaction will also have a significant impact upon the rate of montmorillonite dissolution. Low-pH cement systems have received little attention thus far regarding the development of models for the chemical evolution of pore fluids. Low Ca/Si CSH gels show preferential leaching of Si, which is in marked contrast with gels of greater Ca/Si ratio. Models apparently capable of predicting pore fluid composition coexisting with low Ca/Si CSH gels are a modified Berner model and a solid-solution model proposed by Sugiyama and Fujita. The solubility of silica in pore fluids coexisting with low Ca/Si gels may exceed that of amorphous silica, and may pose problems regarding the stability of montmorillonite in relation to framework silicates such as feldspars. However, the potential rate of conversion of montmorillonite to feldspar under repository conditions is uncertain. It is necessary to use additives such as super plasticiser to improve the workability of low-pH cements. These organic additives have the potential to

  8. Produção do algodoeiro em função da salinidade e tratamento de sementes com regulador de crescimento Cotton yield as a function of salinity and seeds treatment with growth regulator

    Directory of Open Access Journals (Sweden)

    Francisco de Assis de Oliveira

    2012-06-01

    Full Text Available Este trabalho foi realizado com o objetivo de avaliar o efeito de diferentes níveis de salinidade da água de irrigação e sementes tratadas com regulador de crescimento na produção do algodoeiro. O delineamento experimental adotado foi inteiramente ao acaso, arranjados em esquema fatorial 5 x 2 com quatro repetições. Os tratamentos resultaram da combinação de cinco níveis de condutividade elétrica da água de irrigação (S1-0,5; S2-2,0; S3-3,5; S4-5,0 e S5-6,5 dS m-1 em sementes tratadas e não tratadas com regulador de crescimento. As variáveis avaliadas foram: produção de algodão em caroço, produção de sementes e de fibra, peso de 100 sementes e porcentagem de fibra. Não houve interação entre os níveis de salinidades e as sementes tratadas com regulador de crescimento. Os parâmetros produtivos do algodoeiro são reduzidos com uso de água de salinidade a partir de 3,5 dS m-1, independente das sementes serem tratadas com regulador de crescimento. As características agronômicas: peso de 100 sementes, porcentagem de fibra e produção de algodão em caroço não são influenciadas pelo cloreto de mepiquat. O tratamento das sementes com regulador de crescimento não afeta o efeito adverso da salinidade.This study was conducted to evaluate the effect of different salinity levels of irrigation water and seed treated with growth regulator on the yield of cotton. It was used an entirely statistical randomized design, in a factorial scheme 5 x 2, with four replications. The treatments resulted from the combination of four salinity levels of irrigation water (S1-0.5; S2-2.0; S3-3.5; S4-5.0 and S5-6.5 dS m-1 in treated and untreated seeds with growth regulator. The variables were: production of cotton, seed and fiber, 100 seed weight and percentage of fiber. There was not interaction between salinity levels and seed treated. The parameters of cotton production are reduced with the use of water salinity from 3.5 dS m-1

  9. Estimation of leaf area for greenhouse cucumber by linear measurements under salinity and grafting Estimativa da área foliar do pepino em ambiente protegido por medidas lineares sob salinidade e enxertia

    Directory of Open Access Journals (Sweden)

    Flávio Favaro Blanco

    2005-08-01

    Full Text Available The measurement of leaf area by linear parameters is a useful tool when plants cannot be destroyed for direct measurement. The objectives of this study were to establish equations to estimate the leaf area of greenhouse-cucumber and to evaluate the effects of salinity and grafting on this estimative. Non-grafted cucumber seedlings, cv. 'Hokushin', were transplanted in a greenhouse and were irrigated with water of different salinities (1.0, 3.2 and 5.0 dS m-1. In the second growing period, the same cultivar was grafted on Cucurbita spp. and the plants were irrigated with water of 1.4, 3.0 and 5.3 dS m-1. Leaves of different sizes were collected from both experiments and leaf area was determined by an integrating area meter. Leaf length (L and width (W were also recorded. An equation for estimating the leaf area from L and W was developed for a given salinity level or grafting condition and estimated well the area of leaves collected in the other treatments. The leaf area (LA of cucumber 'Hokushin' could be estimated using the equation LA = 0.88LW - 4.27, for any grafting and salinity conditions.A determinação da área foliar por medidas lineares é uma ferramenta útil quando as plantas não podem ser destruídas para que a medição direta seja realizada. Os objetivos desse trabalho foram definir equações para a estimativa da área foliar do pepino em ambiente protegido e avaliar os efeitos da salinidade e da a enxertia nessa estimativa. Mudas de pepino, cv. 'Hokushin', não enxertadas, foram transplantadas em um ambiente protegido e irrigadas com água de diferentes salinidades (1,0, 3,2 e 5,0 dS m-1. No segundo período de cultivo, a mesma cultivar foi enxertada sobre Cucurbita spp., sendo as plantas irrigadas com água de 1,4, 3,0 e 5,3 dS m-1. Foram coletadas folhas de diferentes tamanhos dos dois cultivos e dos três tratamentos e a área foliar foi determinada por um medidor de área foliar. O comprimento (C e a largura (L da folha

  10. Effects of salinity on the development of rocket grown on different substrates hydroponic. = Efeitos da salinidade sobre o desenvolvimento de rúcula cultivada em diferentes substratos hidropônicos.

    Directory of Open Access Journals (Sweden)

    Maria Lilia de Souza Neta

    2013-08-01

    Full Text Available This study evaluated the effects of salinity on the nutrient solution on the production of rocket, grown on different substrates. The test was developed in an environment protected by the Department of Environmental Sciences and Technology, Federal Rural University of the Semi-Arid in Mossoró-RN, housed in a completely randomized design in a factorial 3 x 5 with three replications. Five salinity levels of nutrient solution were used, obtained with or without the fish farming wastewater (S1-0.5, S2-2.0, S3-3.5, S4-5.0 and S5-6.5 dS m-1 and three substrates (SUB1-Mix coconut fibre + sand + rice husk (1:1:1, SUB2-Cambisol and SUB3-SUB1 reused in the previous experiment. Harvesting of rocket was performed at 35 days aftersowing and evaluated the following variables: plant height, leaf number, leaf area, fresh weight, and dry weight. The salinityof the nutrient solution negatively affected the development of the rocket grown, having effect varying according to the type of substrate used. The plants grown on the substrate formed by the mixture of coconut fibre + sand + rice hulls (1:1:1 showed higher tolerance to salinity. The substrate formed by mixing coir + sand + rice husk can be recommended for growing rocket containers, but cannot be reused without treatment. = Objetivou-se com este trabalho avaliar o efeito da salinidade na solução nutritiva sobre a produção de rúcula, cultivada em diferentes substratos. O ensaio foi desenvolvido em ambiente protegido do Departamento de Ciências Ambientais e Tecnológicas da Universidade Federal Rural do Semi-Árido em Mossoró-RN, e instalado em delineamento experimental inteiramente casualizado, em esquema fatorial 5 x 3, com três repetições. Foram utilizados cinco níveis de salinidade na solução nutritiva, obtidos com ou sem uso de água residuária da piscicultura (S1-0,5; S2-2,0; S3-3,5; S4-5,0 e S5-6,5 dS m-1 e três substratos (SUB1-Mistura de fibra de coco + areia + casca de arroz (1

  11. pH dependent dissolution of sediment aluminum in six Danish lakes treated with aluminum

    DEFF Research Database (Denmark)

    Reitzel, Kasper; Jensen, Henning S.; Egemose, Sara

    2013-01-01

    The possible pH dependent dissolution of aluminum hydroxides (Al(OH)(3)) from lake sediments was studied in six lakes previously treated with Al to bind excess phosphorus (P). Surface sediment was suspended for 2 h in lake water of pH 7.5, 8.5, or 9.5 with resulting stepwise increments in dissolv...

  12. Compostos nitrogenados e carboidratos em sorgo submetido à salinidade e combinações de nitrato e amônio Nitrogenous compounds and carbohydrates in sorghum subjected to salinity and combinations of nitrate and ammonium

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    Ana Karla Moreira Lobo

    2011-06-01

    Full Text Available O objetivo do trabalho foi avaliar os efeitos de combinações de nitrato e amônio no meio, na acumulação de compostos nitrogenados e carboidratos, na presença e ausência de salinidade em plantas de sorgo. Sementes do genótipo CSF 20 foram cultivadas em casa de vegetação, em solução nutritiva com três concentrações de nitrato e amônio (100% NO3-: 0% NH4+, 75% NO3-: 25% NH4+ e 0% NO3-: 100% NH4+, na presença e ausência de salinidade. A salinidade reduziu a concentração de nitrato nas folhas e colmo, nos tratamentos 100:0 e 75:25. O amônio acumulou-se mais nas plantas com NaCl, nas folhas e colmo. Os teores de aminoácidos livres totais nas folhas não se alteraram, mas, no colmo, aumentaram na presença de sal e aumento do amônio. A concentração de prolina livre nas folhas e colmo elevou-se nas plantas sob salinidade. O conteúdo de nitrogênio total foi maior nas folhas, entretanto não houve grandes alterações com a presença do sal. A concentração de carboidratos solúveis totais foi maior nas plantas tratadas com sal, exceto no colmo 0:100. Nas folhas, o teor de sacarose foi reduzido na presença do NaCl e aumento de amônio, enquanto, no colmo, foi maior no tratamento 75:25 com NaCl. O teor de amido não sofreu alterações com as diferentes combinações nas formas de N e salinidade. Conclui-se que combinações de NO-3 e NH4+ no meio afetam a acumulação de compostos nitrogenados e carboidratos em folhas e colmo, com presença ou ausência de salinidade, em plantas de sorgo forrageiro.The objective of this study was to evaluate the effects of combinations of nitrate and ammonium in the medium, on the accumulation of nitrogen compounds and carbohydrates, in the presence and absence of salinity in sorghum plants. CSF 20 genotype sorghum seeds, were grown in the greenhouse and supplied with a nutritive solution at three different concentrations of nitrate and ammonium (100% NO3-: 0% NH4+, 75% NO3-: 25% NH4+ e 0% NO3

  13. PhD Dissertations

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    Redazione Reti Medievali (a cura di

    2010-06-01

    Full Text Available Report of PhD dissertations. Andrea Brugnoli Una storia locale: l’organizzazione del territorio veronese nel medioevo: trasformazioni della realtà e schemi notarili (IX-metà XII secolo, Tesi di dottorato di ricerca in Scienze Storiche e Antropologiche (XXII ciclo, Università degli Studi di Verona, 2010   Luca Filangieri Famiglie e gruppi dirigenti a Genova (secoli XII-metà XIII, Tesi di dottorato di ricerca in Storia medievale (XXII ciclo, Università degli Studi di Firenze, 2010   Jakub Kujawi ski Wernakularna kolekcja historiograficzna z rękopisu francuskiego nr 688 z Biblioteki Narodowej w Paryżu. Studium źródłoznawcze (La raccolta dei volgarizzamenti delle opere storiografiche nel manoscritto francese 688 della Biblioteca Nazionale di Parigi, Tesi di dottorato, Università “Adam Mickiewicz”, Facoltà di Storia, Pozna, a.a. 2009/2010   Marta Longhi I signori “de Radicata”. Strategie di affermazione familiare e patrimoniale nel Piemonte dei secoli XII-XIV, Tesi di dottorato di ricerca in Istituzioni, Società, Religioni dal Tardo Antico alla fine del Medioevo (XX ciclo, Università di Torino, 2008

  14. Requerimientos de proteína y energía bruta en juveniles de camarón rosado Farfantepenaeus paulensis (Pérez-Farfante, 1967 sometidos a diferentes salinidades Gross protein and energy requirements for pink shrimp Farfantepenaeus paulensis (Pérez-Farfante, 1967 juvenile under different salinities

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    Roberto Ramos

    2011-11-01

    Full Text Available Se determinó el requerimiento de proteína (PB y energía bruta (EB y su relación óptima en dietas prácticas para juveniles de camarón rosado Farfantepenaeus paulensis en diferentes salinidades. Se sembraron camarones con peso promedio de 0,353 g en 54 estanques de PVC con densidad inicial de 40 ind m-2. El experimento fue factorial, con tres niveles de proteína bruta 24, 35 y 48%, tres salinidades 10, 20 y 30 psu y dos niveles de energía bruta 3200 y 4200 kcal kg-1 de dieta, con tres réplicas, en un período experimental de 25 días. Los resultados indicaron que la salinidad y la proteína tuvieron un efecto significativo (P 0,05 sobre la sobrevivencia, tasa de crecimiento específica y ganancia en peso. La respuesta de los camarones a las necesidades de proteína y energía bruta en las salinidades probadas fue diferente. En la salinidad de 10 psu los requerimientos fueron 35% PB y 4200 kcal kg-1 (83,3 mg PB kcal-1, mientras que en salinidades de 20 y 30 psu fueron 25% de PB y 3200 kcal kg-1 (75,0 mg PB kcal-1.The requirement of gross protein and energy and the optimal ratio of these in practical diets for pink shrimp (Farfantepenaeus paulensis juveniles in different salinities were determined. Shrimp with a mean initial weight of 0.353 g were stocked in 54 plastic tanks at initial densities of 40 ind m-2. The experiment was factorial, with three levels of gross protein (24, 35, 48%, three levels of salinities (10, 20, 30 psu, and two levels of gross energy (3200, 4200 kcal kg-1; the experiment lasted 25 days and considered three replicates. The results showed that salinity and protein had a significant effect (P < 0.05 on weight gain and the specific growth rate, but did not influence on survival. The energy had no significant effect on survival, growth rate, or weight gain. The response of the shrimp to the gross energy and protein level showed different requirements according to the different salinities tested. At salinity of 10 psu

  15. Ti, Al

    Indian Academy of Sciences (India)

    In the present study, authors report on the effect that substrate bias voltage has on the microstructure and mechanical properties of (Ti, Al)N hard coatings deposited with cathodic arc evaporation (CAE) technique. The coatings were deposited from a Ti0.5Al0.5 powder metallurgical target in a reactive nitrogen atmosphere at ...

  16. PhD Dissertations

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    Redazione Reti Medievali (a cura di

    2002-06-01

    Full Text Available Report of PhD dissertation. Laura Baietto Una politica per le città. Rapporti fra papato, vescovi e comuni nell'Italia centro-settentrionale da Innocenzo III a Gregorio IX, Tesi di dottorato di ricerca in Storia Medievale, Università degli Studi di Torino, 2002   Giuseppe Banfo Compresenze e sovrapposizioni di poteri territoriali di qualità diversa tra X e XIII: il caso del basso Monferrato, Tesi di dottorato di ricerca in Storia medievale, Università degli Studi di Torino, 2002   Francesca Dell'Acqua La vetrata tra l'età tardo imperiale e l'altomedioevo: le fonti, l'archeologia, Tesi di Perfezionamento in Storia dell'Arte Medievale, Scuola Normale Superiore di Pisa, 2001   Primo Giovanni Embriaco I vescovi di Albenga e gli sviluppi signorili nella Liguria occidentale (secoli XI-XIII, Tesi di dottorato di ricerca in Storia medievale, Università degli Studi di Torino, 2001   Antonella Ghignoli Documenti e proprietà altomedievali. Fondamenti e problemi dell'esegesi storica delle fonti documentarie nello specchio della tradizione delle carte pisane dei secoli VIII-XI, Tesi di dottorato di ricerca in Storia medievale, Università degli Studi di Firenze, 2002   Vito Loré Espansione monastica e mutamenti politici. La Trinità di Cava nei suoi rapporti con i sovrani longobardi e normanni e con l'aristocrazia territoriale. Secoli XI-XII, Tesi di dottorato di ricerca in Storia medievale, Università degli Studi di Firenze, 2002   Rosaria Stracuzzi Messina nel '400, Tesi di dottorato di ricerca in Storia medievale, Università degli Studi di Palermo, 2001   Stefania Tamburini Le "portate" ecclesiastiche nel piviere di San Giovanni in Firenze nel 1427. Spunti per una riflessione sul patrimonio ecclesiastico della diocesi fiorentina,Tesi di dottorato di ricerca in Storia e informatica, Università degli Studi di Bologna, 2001

  17. Interview als Text vs. Interview als Interaktion

    Directory of Open Access Journals (Sweden)

    Arnulf Deppermann

    2013-09-01

    Full Text Available Das Interview ist nach wie vor das beliebteste sozialwissenschaftliche Verfahren des Datengewinns. Ökonomie der Erhebung, Vergleichbarkeit und die Möglichkeit, Einsicht in Praxisbereiche und historisch-biografische Dimensionen zu erhalten, die der direkten Beobachtung kaum zugänglich sind, machen seine Attraktivität aus. Zugleich mehren sich Kritiken, die seine Leistungsfähigkeit problematisieren, indem sie auf die begrenzte Reichweite der Explikationsfähigkeiten der Befragten, die Reaktivität der Erhebung oder die Differenz zwischen Handeln und dem Bericht über Handeln verweisen. Im Beitrag wird zwischen Ansätzen, die das Interview als Text, und solchen, die es als Interaktion verstehen, unterschieden. Nach dem Text-Verständnis werden Interviews unter inhaltlichen Gesichtspunkten analysiert und als Zugang zu einer vorgängigen sozialen oder psychischen Wirklichkeit angesehen. Das Interaktions-Verständnis versteht Interviews dagegen als situierte Praxis, in welcher im Hier und Jetzt von InterviewerInnen und Befragten gemeinsam soziale Sinnstrukturen hergestellt werden. Anhand ubiquitärer Phänomene der Interviewinteraktion – Fragen, Antworten und die Selbstpositionierung von InterviewerInnen und Befragten – werden Praktiken des interaktiv-performativen Handelns im Interview dargestellt. Ihre Relevanz für die Interviewkonstitution und ihre Erkenntnispotenziale für die Interviewauswertung werden aufgezeigt. Es wird dafür plädiert, die interaktive Konstitutionsweise von Interviews empirisch zu erforschen und methodisch konsequent zu berücksichtigen. URN: http://nbn-resolving.de/urn:nbn:de:0114-fqs1303131

  18. al junctions

    African Journals Online (AJOL)

    Preferred Customer

    Bruan and Heeger,. 1991), Schottky barrier devices (Gardner and Tan,. 1989; Bantikassegn Workalemahu and Inganas,. 1997; Granstrom et al., 1998), organic solar cells. (Abay Gadisa and ... the capacitance per unit area of the cell as well as.

  19. Variación de la composición de ácidos grasos de membrana celular de Rhodococcus rodochrous GNP-OHP-38r en respuesta a la temperatura y salinidad Variation in the composition of Rhodococcus rodochrous GNP-OHP-38r cell membrane fatty acids in response to temperature and salinity

    Directory of Open Access Journals (Sweden)

    G.N. Pucci

    2004-06-01

    Full Text Available Los integrantes del género Rhodococcus son habitantes frecuentes y abundantes de áreas contaminadas con hidrocarburos y resisten la creciente salinidad que se presenta en la Patagonia central. Este género tiene buena capacidad de eliminar contaminantes hidrocarburos que constituyen el mayor contaminante de la región. En el presente trabajo se estudió la respuesta en la composición de sus ácidos grasos de una cepa aislada de un sistema de landfarming, ante la acción combinada de diferentes temperaturas y concentraciones salinas. La estrategia de la cepa Rhodococcus rodochrous GNP-OHP-38r frente al incremento de temperatura, es el aumento del porcentaje de los ácidos grasos saturados totales (n:0; ácidos grasos ramificados en el carbono terminal con grupos oxidrilo en posición 2 (n:0 iso 2 OH y saturados con grupo metilo en carbono 10 (n:0 10 metil, a expensas de la disminución del porcentaje de los n:1 cis.The members of the genus Rhodococcus are frequent and abundant inhabitants of polluted areas with hydrocarbons and they resist the salinity present in the central Patagonia. This genus has good capacity to eliminate pollution produced by hydrocarbons that constitutes the biggest pollutant agent in the region. The present work studies the answer in the composition of its fatty acids under the combined action of the temperature and saline concentration of an isolated stump of a landfarming system. The strategy of Rhodococcus rodochrous strain GNP-OHP-38r in front of the thermal-osmotic stress is the increase of the percentage of the total saturated fatty acids (n:0; fatty acids branched in the terminal carbon with hidroxyl group in position 2 (n:0 iso 2 OH and saturated with group methyl in carbon 10 (n:0 10 metil when the temperature is increased. These acids increase while the percentage of n:1 cis decrease.

  20. A PhD is a PhD is a PhD

    OpenAIRE

    Ostrow, Deborah Anne

    2017-01-01

    A PhD is a PhD is a PhD is a practice-based project that interrogates the process of an artist undertaking PhD research under established criteria. It consists of an exegesis, an original screenplay, and a digital film made for online viewing, with images drawn from a range of documentaries and films found on YouTube. They have been dissected, re-assembled and then re-embedded to YouTube. The source material covers topics such as medicalization of madness, the conspicuous appropriation of uni...

  1. Interacção da salinidade e da fertilização azotada na produtividade do milho-grão Relationship between different levels of salinity and nitrogen and maize production

    Directory of Open Access Journals (Sweden)

    M.C. Gonçalves

    2007-01-01

    Full Text Available Instalaram-se, em 2004 e 2005, dois ensaios de campo (Évora e Alvalade, em solos diferentes, com mobilização convencional e a cultura de milho-grão regada com sistema gota-a-gota, em fonte tripla linear. Neste sistema existem 3 fontes: água salina, água de rega e solução fertilizante, de modo a obter dois gradientes, um de salinidade (adiç��o de NaCl, e outro de fertilizante (adição de solução azotada. Pretende-se avaliar o efeito da interacção da aplicação da água da rega salina e da fertilização azotada, sem deixar de se conseguir níveis de produção aceitáveis. Cada área experimental integrava 4 grupos (I a IV, com três repetições, tendo-se utilizado um gradiente decrescente de fertilizante do Grupo I para o IV, sem solução azotada neste último grupo. Dentro de cada grupo estabeleceram-se 4 modalidades de salinidade em 2004 e apenas 3 em 2005, através da distribuição de diferentes quantidades de água salina ao longo das linhas da cultura. O conjunto de gotejadores debitava 18 L/h em cada ponto de rega e cada metro linear de cultura de milho. Nos dois anos em estudo, as regas com as soluções salina e azotada decorreram de Junho a Setembro, com frequência trissemanal no início, passando a diária. Nos dois anos monitorizou-se a solução do solo (condutividade eléctrica, teores em catiões solúveis e nitratos às profundidades de 20, 40 e 60 cm. Recolheram-se amostras de solo antes, durante e no fim dos ciclos de rega, nos 4 Grupos a 3 profundidades (0-20 cm; 20-40 cm; 40-60 cm, para determinação de vários parâmetros do solo, entre os quais a condutividade eléctrica do extracto de saturação do solo. Avaliou-se a produtividade do milho-grão nas diferentes modalidades e determinaram-se funções de produção e as curvas de resposta em função das quantidades totais de sais e de fertilizante azotado aplicados nos dois anos do ensaio (R²=0.62 n=55. Os resultados apontam para um efeito positivo

  2. Majorization and extremal PH distributions

    NARCIS (Netherlands)

    He, Q.M.; Zhang, H.; Vera, J.C.; Latouche, G.; Ramaswami, V.; Sethuraman, J.; Sigman, K.; Squillante, M.S.; Yao, D.D.

    2013-01-01

    This chapter presents majorization results for PH generators. Based on the majorization results, bounds on the moments and Laplace–Stieltjes transforms of phase-type distributions are found. Exponential distributions and Coxian distributions are identified to be extremal PH distributions with

  3. Crescimento de bananeiras sob diferentes níveis de salinidade da água de irrigação Growth in banana cultivars under different salinity levels of irrigation water

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    Gilcimar Alves do Carmo

    2003-12-01

    Full Text Available Avaliaram-se os efeitos do uso de diferentes níveis de salinidade da água de irrigação (S1 = 0,55 dS/m, S2 = 1,70 dS/m, S3 = 2,85 dS/m e S1 = 4,00 dS/m no crescimento vegetativo de bananeiras Pacovan (AAB e Marmelo (ABB, utilizando-se um solo Argissolo Crômico, textura franco-argilo-arenosa e adotando-se um delineamento experimental em blocos completos casualizados, com parcelas subdivididas e quatro repetições. As parcelas experimentais foram compostas de uma fileira com 10 plantas, sendo cinco de cada cultivar, com as três plantas centrais de cada sub-parcela consideradas úteis. As irrigações foram feitas diariamente ou a cada dois dias de modo a proporcionar uma fração de lixiviação ao redor de 0,15%, colocando-se volumes aproximados de água para manter o solo próximo à capacidade de campo. Os resultados obtidos aos 110, 160, 220, 300 e 360 dias após o plantio mostraram que o incremento nos níveis de salinidade diminuiu significativamente a altura da planta, o número de folhas e a área foliar com o aumento do nível de salinidade da água até no máximo 240 dias do desenvolvimento, havendo uma equiparação depois do período chuvoso.The effects of different salinity levels of irrigation water (S1 = 0.55 dS/m, S2 = 1.70 dS/m, S3 = 2.85 dS/m e S4 = 4.00 dS/m on vegetative growth in bananas Pacovan (AAB and Marmelo (ABB were evaluated. The experiment was carried out on a sandy clay loam Chromic Argisol in a split-plot scheme arranged in a randomized block design with four replications. The whole plots were composed of a row with 10-plants, five plants of each cultivar (subplot, and the data were collected from the three central ones. The irrigations were applied either dayly or every each two-days period in order to maintain a lixiviation fraction of 0.15, using approximate water sheets to keep the soil at field capacity. The data obtained at 110, 160, 220, 300, and 360 days after planting indicated that the water

  4. Avaliação de diploides de bananeira (Musa spp. quanto à tolerância a salinidade Evaluation of banana diploids plants (Musa spp. to salinity tolerance

    Directory of Open Access Journals (Sweden)

    Roberta Lane de Oliveira Silva

    2009-12-01

    Full Text Available A salinidade é um fator comum de estresse abiótico que afeta a produção agrícola onde ela existe. Uma das estratégias para promover a reincorporação de áreas salinizadas e o aumento da produtividade consiste no desenvolvimento e na seleção de genótipos tolerantes, o que permitirá a identificação de parentais a serem utilizados em cruzamentos. Esta pesquisa teve como objetivo identificar genótipos diploides de bananeira tolerantes à salinidade a serem utilizados em futuros trabalhos de melhoramento genético, visando à obtenção de cultivares adaptados a solos salinos. Foram avaliados nove genótipos diploides (AA de bananeira. Para a avaliação dos parâmetros de crescimento, foram feitas medições de área foliar, altura e contagem do número de folhas. As plantas foram tratadas durante 21 dias com 0 e 100 mM de NaCl, num delineamento experimental inteiramente casualizado, com três repetições. Aos 21 dias, foi feita a determinação do peso da matéria fresca, utilizando-se balança analítica. A obtenção do peso da matéria seca das partes limbo foliar, pseudocaule e raízes+rizoma de cada planta foi feita após secagem em estufa a 60ºC até peso constante. o genótipo Tjau Lagada, que sofreu menor redução da área foliar, possivelmente apresentará uma produção relativamente superior aos genótipos avaliados neste estudo. o genótipo 0116-01, por ter apresentado maior tolerância à salinidade, poderá ser utilizado em futuros cruzamentos, disponibilizando genes a serem incorporados em cultivares produtivas utilizadas em programas de melhoramento que visem à obtenção de cultivares adaptadas às regiões de solos salinos no Nordeste brasileiro.The salinity is a common factor of abiotic stress that seriously affects the agricultural production where it is found. one of the strategies to promote reincorporation of salinity areas and the productivity increasing consists in development and selection of tolerant

  5. Necessidade hídrica do meloeiro irrigado com água de diferentes salinidades e cultivado com ou sem cobertura do solo Water requirements of melon irrigated with different water salinities, cultivated with and without mulching

    Directory of Open Access Journals (Sweden)

    Francisco A. S. B. de Medeiros

    2005-06-01

    Full Text Available A necessidade hídrica das culturas pode ser estimada a partir da evapotranspiração de referência (ETo e do coeficiente de cultura (kc. Com o objetivo de se estimar a necessidade hídrica de duas cultivares de melão (Gold mine e Trusty cultivadas com e sem cobertura do solo com filme de polietileno e irrigadas por gotejamento com água de diferentes salinidades (1,2, 2,5 e 4,4 dS m-1 instalou-se um experimento no município de Mossoró, RN, em um Argissolo Vermelho Amarelo. Para se obter a necessidade hídrica da cultura, realizou-se o balanço hídrico nas parcelas, obtendo-se os coeficientes de cultura. Para medir a variação de armazenamento de água no perfil do solo e o fluxo subterrâneo, foram instaladas baterias com três tensiômetros em cada parcela de dois blocos experimentais. A lâmina de irrigação foi estimada pela metodologia FAO e ajustada de acordo com o monitoramento da umidade do solo. A água de maior salinidade diminuiu a evapotranspiração do meloeiro em 14%, a cobertura de solo reduziu em 18% e a cultivar Trusty evapotranspirou 11% a menos que a Gold mine. O balanço hídrico permitiu que se estimassem os coeficientes de cultura do meloeiro para diferentes salinidades, cobertura de solo e cultivares.The water requirement of the crops can be estimated from the reference evapotranspiration (ETo and crop coefficients (kc. Aiming to estimate the water requirement of two cultivars of melon (Gold mine and Trusty cultivated with and without soil covering with polyethylene film and irrigated by trickle irrigation with water of different salinities (1.2, 2.5 and 4.4 dS m-1, an experiment was installed in the municipal district of Mossoró, RN, in an Alfissol. To obtain the water requirement of the crop the water balance was accomplished in the plots, obtaining the crop coefficients. To obtain the variation in water storage in the soil profile and the subsurface flow three tensiometers were installed in each plot of two

  6. Efecto de la temperatura y salinidad sobre la germinación y crecimiento de plántulas de dos variedades de Chenopodium quinoa Temperature and salinity effects on germination and seedling growth on two varieties of Chenopodium quinoa

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    G. Chilo

    2009-06-01

    Full Text Available Se estudió el efecto de la temperatura y salinidad sobre la germinación y crecimiento de plántulas de dos variedades de Chenopodium quinoa. Se diseñó un experimento factorial con tres factores: 1 variedad, con dos niveles (Cica y Real; 2 temperatura, con tres niveles (5 ºC, 10 ºC y 20 ºC; y 3 salinidad, con cinco niveles (0,0; 0,1; 0,2; 0,3 y 0,4M de cloruro de sodio. Los ensayos se realizaron según normas ISTA, las variables de respuesta fueron: poder germinativo como porcentaje de plántulas normales, velocidad de germinación y crecimiento de plántulas. Se determinaron porcentajes de plántulas normales, anormales y semillas muertas; además, peso seco y contenido de sodio y potasio. En las variedades Cica y Real el descenso de temperatura y aumento de salinidad produjeron una disminución del poder germinativo, de la velocidad de germinación y del crecimiento de las plántulas; además, afectaron el peso seco y los porcentajes de plántulas normales, anormales y semillas muertas. Las variedades acumularon solutos en las vacuolas de las células epidérmicas del tallo y hojas. La variedad Cica presentó mejor respuesta a la germinación y crecimiento de plántulas en comparación con la variedad Real.The effect of temperature and salinity on germination and seedling growth was studied in two varieties of Chenopodium quinoa. A factorial experiment with three factors was designed: 1 variety (two levels: Cica and Real; 2 temperature, (three levels: 5 ºC, 10 ºC and 20 ºC and 3 salinity (five levels: 0.0, 0.1, 0.2, 0.3 and 0.4M of sodium chloride. The tests were carried out according to ISTA rules. The response variables were: germination rate as a percentage of normal seedlings; germination speed and seedling growth. Percentage of normal seedlings, abnormal and dead seeds, together with dry weight and sodium and potassium content were determined. In Cica and Real varieties, decreasing temperature and increasing salinity caused a

  7. Produção de alface em condições de salinidade a partir de mudas produzidas com e sem estresse salino Production of lettuce under salinity conditions using seedlings produced with and without saline stress

    Directory of Open Access Journals (Sweden)

    Sergio B.A. Viana

    2001-04-01

    Full Text Available Objetivando-se estudar o efeito da salinidade da água de irrigação sobre a produção da alface cv. 'Elba', conduziu-se um experimento em ambiente protegido, no delineamento inteiramente casualizado, testando-se cinco níveis de condutividade elétrica da água de irrigação (CEa: 0,3, 1,0, 1,7, 2,4 e 3,1 dS m-1, a 25 ºC e dois tipos de mudas (produzidas com água de 0,3 e 3,1 dS m-1. Foram avaliados os efeitos sobre as variáveis fitomassa verde e seca da parte aérea, número de folhas, diâmetro da cabeça e fitomassa seca de raízes. Concluiu-se que a maioria das variáveis estudadas foi influenciada tanto pelo efeito da concentração de sais na água de irrigação como pelo fator tipo de muda sem, entretanto, haver efeito interativo dos fatores. No trabalho são apresentadas equações, obtidas através de regressão polinomial, relacionando as variáveis estudadas com os níveis de salinidade. O rendimento relativo final da cultivar estudada, em termos de fitomassa fresca, decresce 9,0% para cada incremento unitário de CEa.With the objective of studying the effect of water salinity on the productivity of lettuce, cv. 'Elba', an experiment was carried out in a completely randomized design, under a protected environment. Five levels of water salinity (ECw: 0.3, 1.0, 1.7, 2.4 and 3.1 dS m-1 at 25 ºC and two types of seedlings (produced using water of 0.3 and 3.1 dS m-1 were tested. The effects of the factors on the fresh and dry weight of the aerial parts, number of leaves, diameter of the head, and dry weight of roots, were evaluated. It was concluded that the studied variables were influenced by ECw and by the seedling types, without being influenced by the factor interaction. The equations, obtained through polynomial regression, relating the variables studied with the salinity levels are also, presented. The relative production (fresh weight of the cultivar studied, decreased 9.0% for each unitary increment of ECw.

  8. CE e RAS do extrato de saturação do solo sob diferentes níveis de salinidade e doses de nitrogênio no cultivo da abobora

    Directory of Open Access Journals (Sweden)

    Max Venicius Teixeira da Silva

    2014-07-01

    Full Text Available 800x600 A agricultura irrigada depende tanto da quantidade como da qualidade da água; no entanto, o aspecto qualidade tem sido desprezado devido ao fato de que, no passado, em geral as fontes de água, eram abundantes, de boa qualidade. O trabalho teve como objetivo estudar a condutividade elétrica e razão de adsorção do sódio no extrato de saturação do solo no cultivo da abobora sob diferentes níveis salinos da água de irrigação e doses de nitrogênio. A água de irrigação disponível na Fazenda Experimental é proveniente de um poço perfurado do aqüífero Arenito Açu, com profundidade aproximada de 800 m, com água de boa qualidade, e condutividade elétrica da água (CEa em torno de0,5 dS m-1. Adotou-se o delineamento experimental em blocos ao acaso, em esquema de parcelas subdivididas 5 x 3, com quatro repetições. Os tratamentos foram constituídos dos cinco níveis de salinidade (0,5, 1,5, 2,5, 3,5 e 4,5 dS m-1, e três níveis de nitrogênio: N1 = 27,37; N2 = 91,25 e N3 = 155,12 kg ha-1 correspondente a 30%, 100% e 170%, da recomendação de nitrogênio. Houve um aumento da salinidade do extrato de saturação com incremento dos níveis salinos da água e adubação nitrogenada. Os maiores valores de CEes foram verificados na CE (4,5 dS.m-1 e 170% da dose  de nitrogênio recomendada pelos produtores de abobora. A razão de adsorção de Sódio (RASes cresceu proporcional com os valores da condutividade elétrica da água de irrigação Normal 0 21 false false false PT-BR X-NONE X-NONE

  9. Evaluación de la relación entre composición química del agua de lluvia y el grado de salinidad y sodicidad de distintos suelos

    OpenAIRE

    Lavado, Raúl Silvio

    1983-01-01

    p.135-139 Se estudió la composición del agua de lluvia en la localidad de A. Korn, unos kilómetros al sur de Buenos Aires, y su relación con suelos circundantes. La composición media del agua pluvial fue la siguiente, en mmolc L-1 Ca: 0,20; Mg: 0,13; Na: 0,14; K: 0,03, Cl: 0,15; CO3H: 0,31; SO4 : vest. El pH fue 5,95 y la conductividad eléctrica 0,046 dS m-1. El aporte iónico estuvo determinado por aerosoles marinos y-o polvos terrestres, según los iones. La composición de la solución del ...

  10. Exercise and Pulmonary Hypertension (PH)

    Science.gov (United States)

    Facebook Twitter Instagram YouTube About PHA Contact Join Careers Store My Account Donate Patients About PH Diagnosis Treatments Newly ... areas © 2017 Pulmonary Hypertension Association. All Rights Reserved. Facebook Twitter Instagram YouTube

  11. Urine pH test

    Science.gov (United States)

    ... urine test Male urinary tract References Bose A, Monk RD, Bushinsky DA. Kidney stones. In: Melmed S, Polonsky ... and its influence on urine pH. J Am Diet Assoc . 1995;95(7):791-797. PMID: 7797810 ...

  12. Neuronal pH regulation

    DEFF Research Database (Denmark)

    Vorstrup, S; Jensen, K E; Thomsen, C

    1989-01-01

    The intracellular pH in the brain was studied in six healthy volunteers before and immediately after the administration of 2 g of acetazolamide. Phosphorus-31 nuclear magnetic resonance spectroscopy by a 1.5 tesla whole-body scanner was used. The chemical shift between the inorganic phosphate...... and the phosphocreatine resonance frequencies was used for indirect assessment of the intracellular pH. The mean baseline intracellular pH was 7.05 +/- 0.04 (SD). The mean pH changes obtained at 15-min intervals within the first hour of acetazolamide administration were -0.03 +/- 0.04 (SD), -0.02 +/- 0.03 (SD), and 0...

  13. et al

    African Journals Online (AJOL)

    Schalk Cloete

    experienced (Bath, 2006), while indications are that no new drenches are in the process of being developed. Existing strategies for the control of these pathogens are thus challenged (Bath, 2006), and alternative strategies need to be formulated (Vatta et al., 2000). A possible avenue for dealing with the challenge of ...

  14. Programmable pH buffers

    Science.gov (United States)

    Gough, Dara Van; Huber, Dale L.; Bunker, Bruce C.; Roberts, Mark E.

    2017-01-24

    A programmable pH buffer comprises a copolymer that changes pK.sub.a at a lower critical solution temperature (LCST) in water. The copolymer comprises a thermally programmable polymer that undergoes a hydrophobic-to-hydrophilic phase change at the LCST and an electrolytic polymer that exhibits acid-base properties that are responsive to the phase change. The programmable pH buffer can be used to sequester CO.sub.2 into water.

  15. PhEDEx Data Service

    International Nuclear Information System (INIS)

    Egeland, Ricky; Wildish, Tony; Huang, Chih-Hao

    2010-01-01

    The PhEDEx Data Service provides access to information from the central PhEDEx database, as well as certificate-authenticated managerial operations such as requesting the transfer or deletion of data. The Data Service is integrated with the 'SiteDB' service for fine-grained access control, providing a safe and secure environment for operations. A plug-in architecture allows server-side modules to be developed rapidly and easily by anyone familiar with the schema, and can automatically return the data in a variety of formats for use by different client technologies. Using HTTP access via the Data Service instead of direct database connections makes it possible to build monitoring web-pages with complex drill-down operations, suitable for debugging or presentation from many aspects. This will form the basis of the new PhEDEx website in the near future, as well as providing access to PhEDEx information and certificate-authenticated services for other CMS dataflow and workflow management tools such as CRAB, WMCore, DBS and the dashboard. A PhEDEx command-line client tool provides one-stop access to all the functions of the PhEDEx Data Service interactively, for use in simple scripts that do not access the service directly. The client tool provides certificate-authenticated access to managerial functions, so all the functions of the PhEDEx Data Service are available to it. The tool can be expanded by plug-ins which can combine or extend the client-side manipulation of data from the Data Service, providing a powerful environment for manipulating data within PhEDEx.

  16. Effect of salinity on growth and chemical composition of the diatom Thalassiosira weissflogii at three culture phases Efecto de la salinidad en el crecimiento y composición química de la diatomea Thalassiosira weissflogii en tres fases de cultivo

    Directory of Open Access Journals (Sweden)

    Norma García

    2012-07-01

    Full Text Available The estuarine diatom Thalassiosira weissflogii (Fryxell & Hasle, 1977 has been widely used as live feed in aquaculture. The growth rate and biochemical composition of microalgae are highly influenced by environmental factors such as, light, salinity and nutrient availability. Salinity is difficult to control in some shrimp laboratories specialized in larvae production, because these laboratories depend upon the levels measured in estuaries or coastal lagoons, which are the water sources for larvae culture. The present study evaluated the effect of different salinities (25, 30, 35, 40, 45 and 50 psu, on the growth and chemical composition of T. weisflogii at three culture phases, under laboratory conditions. The highest growth rate and maximum cell density were found at 25 psu. Decrease in size and striking changes in morphology of the cells were observed at the higher salinities and drastic changes occurred at 50 psu. Protein and carbohydrate content were higher at low salinities (25 and 30 psu during the stationary phase. The lipid production was higher at low salinities, but diminished as the phase changes occurred; in contrast, the lipid content was unaffected by the growth phase at higher salinities (≥ 35 psu. The higher growth rate and better biochemical composition were obtained at 25 and 30 psu.La diatomea estuarina Thalassiosira weissflogii (Fryxell & Hasle, 1977 ha sido utilizada como alimento vivo en acuacultura. La composición bioquímica del alimento vivo afecta la nutrición de los organismos durante su cultivo. La tasa de crecimiento y composición bioquímica de las microalgas están altamente influenciadas por factores ambientales como luz, salinidad y disponibilidad de nutrientes. En algunos laboratorios productores de larvas de camarón, es difícil controlar la salinidad, debido a que éstos dependen de los niveles presentes en estuarios o lagunas costeras, los cuales son la fuente de agua para el cultivo larvario. El

  17. Germinação e crescimento inicial de híbridos de meloeiro em função da salinidade Germination and initial growth stage of melon plant hybrids due to salinity

    Directory of Open Access Journals (Sweden)

    Roberto Cleiton F de Queiroga

    2006-09-01

    Full Text Available As áreas de cultivo com intensa evaporação, deficiência em drenagem e uso inadequado de fertilizantes têm aumentado os problemas com a salinidade prejudicando o rendimento das culturas. No meloeiro as elevadas concentrações de sais no solo e na água ocasionam modificações morfológicas, estruturais e metabólicas, que inibem o seu crescimento e desenvolvimento. Portanto, o objetivo deste trabalho foi avaliar a germinação e o crescimento inicial de híbridos de meloeiro em diferentes níveis de salinidade da água de irrigação e submetidas a um estresse salino através da embebição. Os tratamentos foram instalados no delineamento inteiramente casualizado em esquema fatorial 2x3x5 (sementes tratadas com e sem pré-embebição em solução salina de NaCl (6 g/L, três híbridos de meloeiro (Hy Mark, Honey Dew Red Flesh e Daimiel, e cinco níveis de condutividade elétrica da água de irrigação (0,45; 1,30; 2,15; 3,00 e 3,85 dS m-1, com três repetições. Foram feitas avaliações da porcentagem de germinação, velocidade de emergência, área foliar, altura e massa seca da parte aérea. O tratamento pré-germinativo de sementes de meloeiro com solução salina (6 g/L proporcionou maior massa seca da parte aérea das plântulas e um aumento significativo na porcentagem de germinação. Por outro lado, a salinidade da água de irrigação reduziu a área foliar, a massa seca da parte aérea da plântula e a altura da plântula. A cultivar Daimiel destacou-se como a mais tolerante a salinidade em razão das maiores estimativas da área foliar, massa seca da parte aérea e altura da plântula.Cultivation sites with intense evaporation rates, drainage deficit and inadequate use of fertilizers have increased the problems with salinity by impairing the good development of cultures. In melon plants, the high concentration of salts in both soil and water bring about morphological, structural and metabolic changes and inhibit their growth

  18. AL Amyloidosis

    Directory of Open Access Journals (Sweden)

    Desport Estelle

    2012-08-01

    Full Text Available Abstract Definition of the disease AL amyloidosis results from extra-cellular deposition of fibril-forming monoclonal immunoglobulin (Ig light chains (LC (most commonly of lambda isotype usually secreted by a small plasma cell clone. Most patients have evidence of isolated monoclonal gammopathy or smoldering myeloma, and the occurrence of AL amyloidosis in patients with symptomatic multiple myeloma or other B-cell lymphoproliferative disorders is unusual. The key event in the development of AL amyloidosis is the change in the secondary or tertiary structure of an abnormal monoclonal LC, which results in instable conformation. This conformational change is responsible for abnormal folding of the LC, rich in β leaves, which assemble into monomers that stack together to form amyloid fibrils. Epidemiology AL amyloidosis is the most common type of systemic amyloidois in developed countries with an estimated incidence of 9 cases/million inhabitant/year. The average age of diagnosed patients is 65 years and less than 10% of patients are under 50. Clinical description The clinical presentation is protean, because of the wide number of tissues or organs that may be affected. The most common presenting symptoms are asthenia and dyspnoea, which are poorly specific and may account for delayed diagnosis. Renal manifestations are the most frequent, affecting two thirds of patients at presentation. They are characterized by heavy proteinuria, with nephrotic syndrome and impaired renal function in half of the patients. Heart involvement, which is present at diagnosis in more than 50% of patients, leading to restrictive cardiopathy, is the most serious complication and engages prognosis. Diagnostic methods The diagnosis relies on pathological examination of an involved site showing Congo red-positive amyloid deposits, with typical apple-green birefringence under polarized light, that stain positive with an anti-LC antibody by immunohistochemistry and

  19. Dissolution kinetics of heulandite at pH 2--12 and 25 degrees C

    International Nuclear Information System (INIS)

    Ragnarsdottir, K.V.

    1993-01-01

    Because of their favourable cation exchange reactions, heulandite and clinoptilolite have been suggested as being capable of immobilizing radionuclides and therefore could possibly act as an important barrier for nuclear waste. Recent studies of laboratory-reacted minerals indicate, however, that hydrated surface layers tend to accumulate highly hydrolyzable heavy elements. These hydrated layers may therefore be the most important retardants for radionuclides. The dissolution rate of heulandite depends strongly on pH. Based on silica release, the logarithm of the steady-state dissolution rate at pH 2 is -13.1 mol cm -2 s -1 . The logarithm of the rate decreases to -15.8 mol cm -2 s -1 at pH 7.2 and increases again to -14.6 mol cm -2 s -1 at pH 12.2. At low pH, Al is released preferentially to silica; but at intermediate and high pH, the release of silica appears to be congruent relative to Al. The change in dissolution rate with pH indicates that at low pH, the dissolution mechanism is controlled by the detachment of a positively charged Al species, >Al-OH 2 + . Below pH 5, however, a silica-rich surface layer is formed requiring diffusion through the layer. At intermediate and high pH, it is likely that the dissolution rate is controlled by the detachment of a negatively charged silica species, >Si - O - . The reaction order of the hydrogen ion under low pH conditions is 0.7, and the reaction order of the OH - ion is 0.3 at high pH. The measured dissolution rates indicate that a 1 mm heulandite crystal would dissolve in 300,000 yrs if the solution composition is maintained undersaturated. 75 refs., 11 figs., 3 tabs

  20. Estudio de laboratorio del efecto de las concentraciones de calcio y caseína, el pH y la temperatura sobre la incorporación de proteínas lácteas al coágulo obtenido por acción enzimática

    Directory of Open Access Journals (Sweden)

    Pires Miryam S.

    1999-01-01

    Full Text Available The effect of casein concentration, Ca2+ concentration, temperature and pH on the amount and size of protein aggregates (fines in the whey produced by enzimic coagulation of nonfat milk was studied in laboratory conditions. Casein concentrations about 0.3 g/L showed a minimal amount of caseins in the whey, with presence of small aggregates of casein micellles. Ca2+ concentrations higher than 5 mM were neccesary to reduce the whey protein to a minimum constituted by protein particles smaller than casein micelles. The coagulation temperature, in the 35 - 45oC range, produced almost no variations in the whey proteins. The obtention of a minimum amount of whey proteins was possible only in a narrow pH range around 6.4. These results pointed to casein concentration and pH as important variables to be controlled in connection with the process yield.

  1. Long-term effects of water pH changes on hematological parameters ...

    African Journals Online (AJOL)

    Yomi

    2012-02-14

    Feb 14, 2012 ... Stock solution of sodium bicarbonate (Na2CO3) and glacial acetic acid with sodium acetate. (4%) were used to create the different alkaline and acidic conditions, respectively, in water of the experimental tanks (Das et al., 2006). The pH was measured with the help of a digital pH meter. (Elico, L1-120).

  2. Lead ion adsorption on montmorillonite-Al hydroxide polymer systems

    NARCIS (Netherlands)

    Janssen, R.P.T.; Bruggenwert, M.G.M.; Dijk, van G.; Riemsdijk, van W.H.

    2007-01-01

    Clay¿Al hydroxide polymer systems (CAlHO) can bind heavy metals effectively. Their adsorption behaviour depends on the type of metal. We studied the dependence of Al-loading and pH on the adsorption of Pb to Na-saturated montmorillonite¿Al hydroxide polymer systems. The available binding sites on

  3. Zinc ion adsorption on montmorillonite-Al hydroxide polymer systems

    NARCIS (Netherlands)

    Janssen, R.P.T.; Bruggenwert, M.G.M.; Riemsdijk, van W.H.

    2003-01-01

    Clay¿Al hydroxide polymers (CAlHO) can bind heavy metals effectively and may play an important role in the adsorption behaviour and metal binding capacity of soils. We studied the dependence of Al loading and pH on the adsorption of Zn on Na-saturated montmorillonite¿Al hydroxide polymer systems.

  4. pH in Action

    NARCIS (Netherlands)

    Tijskens, L.M.M.; Biekman, E.S.A.

    2001-01-01

    Based on fundamental chemical relations, well-established in chemical engineering and chemical technology over almost a century, the effects of pH in food and agricultural products will be deduced for different situations and processes. Based on simple equilibria and dissociation of water, salts,

  5. Tenkir Bonger , (PhD)

    African Journals Online (AJOL)

    Users

    ... of the market. As the ultimate beneficiaries of the process, employers, students and patients can enrich the institutional package. 1 Tenkir Bonger PhD(London). Professor of Development Economics &Dean of the School os Business Studies Mulunguhi. University, Kabwe ZAMBIA e-mail:kelemu70agere@yahoo.com ...

  6. Obtención y evaluación de plantas de olivo tolerantes a la salinidad mediante empleo de métodos biotecnológicos

    OpenAIRE

    Troncoso Mendoza, Javier

    2008-01-01

    Tesis descargada desde CSIC El olivo ha estado y está presente en la evolución de la cultura mediterránea. Junto con la palmera datilera, la higuera y la vid, forma parte de los árboles de fruto más característicos y antiguos del Mediterráneo. Pero a diferencia de aquellos, que fundamentalmente proporcionan alimento, el olivo además regala al hombre medicamentos, ungüentos, perfumes, lubrificantes, condimentos, luz, calor, madera y alimento para el ganado. Si a esto, se une su gra...

  7. Lou Gehrig's Disease (ALS)

    Science.gov (United States)

    ... for Educators Search English Español Lou Gehrig's Disease (ALS) KidsHealth / For Kids / Lou Gehrig's Disease (ALS) What's ... with ALS in the 1930s. What Happens in ALS? ALS damages motor neurons in the brain and ...

  8. The impact of oxygen consumption by the shrimp Litopenaeus vannamei according to body weight, temperature, salinity and stocking density on pond aeration: a simulation = Impacto do consumo de oxigênio do camarão Litopenaeus vannamei em relação ao peso corporal, temperatura, salinidade na aeração do viveiro: uma simulação

    Directory of Open Access Journals (Sweden)

    Luis Vinatea

    2011-04-01

    Full Text Available A simulation was conducted to determinate the impact caused by thecombination of Litopenaeus vannamei respiratory rate (mg O2 shrimp-1 h-1, the behavior of SOTR (kg O2 h-1 of mechanical aerators as a function of salinity, as well as the oxygen consumption rate of the pond water and soil (mg O2 L-1 h-1 on the aeration of shrimp ponds (1, 10, 50 and 100 ha stocked with different densities (10, 40 and 120 shrimp m-2, salinities (1, 13, 25 and 37 ppt, temperatures (20, 25 and 30°C, and shrimp wet weight (5, 10, 15 and 20 g. Results showed that under lower salinity, with larger shrimp, and higher stocking density, higher will be the quantity of required 2-HP aerators to keep dissolved oxygen over 50% saturation. In addition, under low salinity, with 5 and 10 g shrimp, independent of stocking density, more aerators per hectare are required and electricity cost is higher at 20°C and salinity 1 ppt. Less aerators and lower electricity cost was observed at 30°C, salinities of 25 and 37 ppt, and shrimp of 15 and 20 g. Baseado em estudos de respiração de Litopenaeus vannamei (mg O2 camarão-1 h-1, comportamento do Standard Oxygen Transfer Rate (SOTR, kg O2 h-1 de aeradores mecânicos em função da salinidade, assim como as taxas de respiração da água e do solo (mg O2 L-1 h-1, uma simulação foi realizada a fim de determinar o impacto que estas três variáveis juntas têm sobre a aeração de viveiros (1, 10, 50 e 100 ha, estocados com diferentes densidades (10, 40 e 120 camarões m-2 em salinidades de 1, 13, 25 e 37 ppm, temperaturas de 20, 25 e 30°C e peso úmido dos camarões de 5, 10, 15 e 20 g. Os resultados mostraram que em salinidades mais baixas, com animais maiores e maiores densidades de estocagem, maior será a quantidade de aeradores de 2 cvnecessários para manter o oxigênio dissolvido acima de 50% da saturação. Igualmente, em baixas salinidades e com camarões de 5 e 10 g, independente da densidade de estocagem, mais aeradores

  9. Impacto da salinidade no desenvolvimento e crescimento de mudas de carnaúba (Copernicia prunifera (Miller H.E.Moore Impact of salinity on development and growing of ‘carnaúba’ (Copernicia prunifera (Miller H.E. Moore seedlings

    Directory of Open Access Journals (Sweden)

    Samia J. R. Holanda

    2011-01-01

    Full Text Available Identificar o impacto da salinidade no desenvolvimento e crescimento de espécies resistentes a altas concentrações salinas é de fundamental importância para a recuperação de áreas salinizadas do semiárido nordestino brasileiro. Visando contribuir para a resolução desta problemática, o presente trabalho avaliou o efeito de diferentes níveis de salinidade para o desenvolvimento e o crescimento da carnaúba, espécie nativa e de extremo valor econômico para a região. Os níveis analisados foram: 0, 25, 50, 100 mM de NaCl, correspondente a uma condutividade elétrica de 2.0, 4.6, 7.1, 9.6, 12 dS m-1, respectivamente. Utilizou-se o delineamento inteiramente casualisado, com cinco tratamentos e quatro repetições, e se analisaram as variáveis altura da parte aérea, largura da parte aérea da folha, comprimento da raiz principal, peso da matéria seca, razão da matéria seca parte aérea/raiz e taxa de sobrevivência. Os tratamentos com 25 e 50 mM de NaCl não afetaram a sobrevivência inicial da planta. Concentrações maiores ou iguais que 75 mM de NaCl reduziram a produção de biomassa e a taxa de sobrevivência, em quase 50%; portanto, a produção de plantas nesses níveis de sal não é recomendada.To identify the impact of salinity on the development and growth of species resistant to high salt concentration is fundamental for restoration of salty areas in the Northeast brazilian semi-arid region. Seeking to solve this problem this work evaluated the effect of different salt levels on the development and growth of ‘carnauba’, a native species with high economical value to the region. The levels analyzed were: 0, 25, 50, 75 and 100 mM of NaCl, corresponding to an electrical conductivity of 2.0, 4.6, 7.1, 9.6 and 12 dS m-1, respectively. A completely randomized experimental design with five treatments and four replicates was used. The analyzed variables were aerial height, aerial width, main root length, dry weight, aerial

  10. Germination and seedlings development of the butterfly pea as influenced salinity Germinação e desenvolvimento de plântulas de cunhã em função da salinidade

    Directory of Open Access Journals (Sweden)

    João Domingos Rodrigues

    2011-06-01

    Embrapa Semiárido, no município de Petrolina no estado de Pernambuco. O delineamento experimental foi o inteiramente casualizado, com sete soluções aquosas de NaCl, nas concentrações de condutividade elétrica em água de 0; 2; 4; 6; 8; 10 e 12dS/m com quatro repetições. A elevada concentração salina influencia na germinação da cunhã, que foi afetada com salinidade a partir de 2dS/m. A salinidade altera as características de germinação e vigor das plântulas com diferentes intensidades. De maneira geral, o aumento da concentração de NaCl interfere, de forma prejudicial no processo de germinação e desenvolvimento de plântulas de cunhã, com efeitos acentuados a partir da concentração de 2 dS/m.

  11. Concentração salina e fases de exposição à salinidade do meloeiro cultivado em substrato de fibra de coco Salt concentration and phases of exposure tosalinity of melon grown in coconut fiber substrate

    Directory of Open Access Journals (Sweden)

    Nildo da Silva Dias

    2011-09-01

    Full Text Available No semiárido, a escassez de água de boa qualidade faz com que os produtores utilizem água salobra para preparar a solução nutritiva. Com o objetivo de investigar a utilização de água salobra na irrigação de meloeiro (Cucumis melo L., cv. AF 015 cultivado em substrato de fibra de coco em casa de vegetação, plantas foram nutridas com soluções salinas de condutividades elétricas (CEs 1,1 (testemunha; 2,5; 4,0 e 5,5 dS m-1 aplicadas durante as fases: crescimento vegetativo (10-30 dias após o transplantio-DAT; florescimento (31-50 DAT e frutificação e maturação (51-70 DAT. O delineamento experimental foi o inteiramente casualizado, com 12 tratamentos arranjados em um esquema fatorial 4x3 (níveis de salinidade x tempo de exposição dos sais, com três repetições. Houve correlação na perda relativa por incremento de CEs das variáveis de crescimento e de produção do meloeiro em função da salinidade da solução nutritiva para cada fase de exposição. As soluções nutritivas preparadas com água salobra podem ser utilizadas no cultivo do meloeiro em substrato de fibra de coco com o mínimo de perdas relativas de massa média de frutos por incremento de CEs, quando aplicadas na fase de florescimento.Scarcity of good water quality in semiarid region causes producers to use brackish water to prepare the nutrient solution. In order to investigate the use of brackish water in irrigation of greenhouse-melon (Cucumis melo L., cv. AF 015 grown in coconut fiber substrate, plants were irrigated with saltine nutrient solutions of electrical conductivities (ECs of 1.1 (control, 2.5, 4.0 and 5.5 dS m-1, applied during the phases of vegetative growth (10-30 days after transplanting, DAT, flowering (31-50 DAT and fruiting and ripening (51-70 DAT. The design was completely randomized, with 12 treatments arranged in a 4x3 factorial design (salinity levels x exposure time of the salts, with three replications. There was a correlation in

  12. Germinação e crescimento inicial de genótipos de cajueiro anão-precoce em condições de salinidade Germination and initial growth of precocious dwarf cashew genotypes under saline conditions

    Directory of Open Access Journals (Sweden)

    Paulo T. Carneiro

    2002-01-01

    Full Text Available Foram avaliados, em casa-de-vegetação, os efeitos de quatro níveis de condutividade elétrica da água de irrigação (CEa: 0,7; 1,4; 2,1 e 2,8 dS m-1, a 25 ºC contendo Na:Ca:Mg na proporção equivalente 7:2:1, sobre a germinação e o crescimento inicial, durante 50 dias, de cinco clones de cajueiro anão-precoce (Anacardium occidentale L.: CCP06, CCP09, CCP1001, EMBRAPA50 e EMBRAPA51. O experimento foi conduzido em blocos ao acaso e esquema fatorial 4 x 5, com 4 repetições. Avaliaram-se, também, as variáveis de germinação (dias e percentagens de plântulas emergidas e de crescimento (altura de planta, número de folhas, área foliar e fitomassa de raízes, da parte aérea e total. A maioria das variáveis estudadas foi influenciada pela salinidade da água de irrigação e variou entre clones sem, entretanto, haver efeito interativo desses fatores. Em CEa de 1,48 dS m-1 foi obtida uma produção relativa de 90% da fitomassa total, podendo este valor ser considerado limite de tolerância à salinidade, para o crescimento inicial do cajueiro anão-precoce. Em geral, os clones EMBRAPA51 e CCP1001 foram os de menor e maior desenvolvimento, respectivamente, em todo o período de estudo.The effects of four levels of electrical conductivity of irrigation water (ECw: 0.7; 1.4; 2.1 and 2.8 dS m-1, at 25 ºC, containing Na:Ca:Mg in equivalent proportions of 7:2:1, on germination and initial growth stages of five clones of precocious dwarf cashew (Anacardium occidentale L.: CCP06, CCP09, CCP1001, EMBRAPA50 and EMBRAPA51, during the first 50 days were studied in greenhouse. The experiment was carried out in a randomized block design and 4 x 5 factorial scheme with 4 replications. The germination (days and percentage of emergence and growth variables (plant height, number of leaves, leaf area and dry weight of root, shoot and total were evaluated. The majority of variables were found to be influenced by ECw and clones, however no significant

  13. Salinidade, sodicidade e propriedades microbiológicas de Argissolo cultivado com erva-sal e irrigado com rejeito salino Salinity, sodicity and microbiological properties of an Ultisol cultivated with saltbush and irrigated with saline effluents

    Directory of Open Access Journals (Sweden)

    Célia Maria Maganhotto de Souza Silva

    2008-10-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito da irrigação com rejeito da dessalinização, oriundo de tanques de produção de tilápia-rosa, sobre as propriedades químicas e microbiológicas de solos cultivados com erva-sal (Atriplex nummularia Lindl.. Quatro áreas foram usadas, das quais duas foram irrigadas com rejeito salino e cultivadas, durante um e cinco anos, com erva-sal. As outras duas áreas foram conduzidas sem irrigação: uma cultivada com vegetação natural e outra com a halófita. Avaliaram-se os parâmetros relativos à salinidade e sodicidade do solo, e também as seguintes características: carbono da biomassa microbiana (Cmic; relação Cmic/carbono orgânico; atividade das enzimas fosfatase ácida, fosfatase alcalina, beta-glucosidase, protease, L-asparaginase, L-glutaminase. A adição de sais afetou as propriedades físicas e químicas dos solos irrigados com rejeito salino, com tendência à salinização e sodificação. A salinidade afetou as propriedades microbiológicas nos solos irrigados, mas o cultivo da halófita favoreceu a produção das enzimas estudadas. O cultivo da erva-sal em áreas que recebem rejeito salino pela irrigação melhora a qualidade biológica dos solos e sua fertilidade, mas não impede a salinização.The objective of this work was to evaluate the effects of irrigation with saline effluents, from red tilapia production ponds, on chemical and microbiological properties of soils cultivated with saltbush (Atriplex nummularia Lindl. Four areas were used, from which two were irrigated with saline waste and cultivated with A. nummularia, during one and five years. The other two areas were not irrigated, and one was cultivated with natural vegetation and the other with the halophyte. The parameters related to soil salinity and sodicity were evaluated, as well as the following characteristics: microbial biomass carbon (Cmic; Cmic/organic carbon; the activity of acid and alcaline phosphatase

  14. pH, alkalinity, temperature, salinity and other variables collected from time series profile observations using Alkalinity titrator, CTD and other instruments from the Al Amir Moulay Abdellah in the North Atlantic Ocean and Strait of Gibraltar from 2005-05-04 to 2007-05-08 (NODC Accession 0112928)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0112928 includes chemical, discrete sample, physical and time series profile data collected from Al Amir Moulay Abdellah in the North Atlantic Ocean...

  15. Avaliação do processo germinativo das sementes e o crescimento inicial de plântulas de girassol (Helliantus annus L. submetidas a diferentes níveis de salinidade

    Directory of Open Access Journals (Sweden)

    Ademir Silva Menezes

    2014-09-01

    Full Text Available Objetivou-se avaliar a influência de diferentes níveis de salinidade no processo de germinação e crescimento inicial na cultura do girassol. O processo foi conduzido em ambiente telado, no IFCE/Campus Sobral, Ceará, em delineamento inteiramente casualizado, 5 X 4, sendo cinco níveis de sais (CEa = 0,27; 1,5; 3,0; 4,5 e 6,0 dS m-1 com quatro repetições, avaliando-se a porcentagem de emergência – %E, índice de velocidade de emergência – IVE, tempo médio de germinação – TMG, alturas das plântulas – AP, número de folhas – NF e potencial osmótico do solo, que, em seguida, foram submetidas à análise de variância. A percentagem de emergência média dos tratamentos mostrou um aumento linear, de 65% para 67,5%, com relação ao IVE. Também houve um aumento linear expressando valores entre 0,95 (CEa = 0,5 dS m-1 a 1,26 (CEa = 6,0 dS m-1. Verificou-se que o incremento dos sais presente na água de irrigação não influenciou na altura das plântulas, mas provocou reduções no número de folhas e do potencial osmótico do solo. Os níveis de sais testados não influenciaram estatisticamente na germinação do girassol.

  16. Industrial PhD report: Sustainable Innovation

    DEFF Research Database (Denmark)

    Olesen, Gitte Gylling Hammershøj

    2011-01-01

    Erhvervs PhD rapport udarbejdet i tilknytning til Erhvervs PhD kurset der er obligatorisk for Erhvervs PhD studerende. Rapporten omhandler relationer melllem den akademiske verden og industrien i sammenhæng med PhD projektet, betragtet og analyseret gennem teori om bæredygtig innovation....

  17. Differential dissolution of biogenic carbonates: Implications of secretion at higher pH

    Digital Repository Service at National Institute of Oceanography (India)

    Saraswat, R.

    state and thus a more enhanced calcite precipitation than the bicarbonate ions (Lopez et al., 2009). It also helps in dissipation of respired CO 2 into high pH vacuolar seawater thus further increasing the availability of carbonate ions (Nooijer et al...

  18. Reduction of exchangeable calcium and magnesium in soil with increasing pH

    Directory of Open Access Journals (Sweden)

    Miyazawa Mário

    2001-01-01

    Full Text Available A laboratory study was conducted with soil samples and synthetic solutions to investigate possible mechanisms related with reduction in KCl exchangeable Ca and Mg with increasing pH. Increasing soil pH over 5.3 with CaCO3 added to the soil and with NaOH solution added to soil/KCl suspension increased adsorptions of Ca and Mg. The reduction of Mg was greater than Ca and was related to the concentration of soil exchangeable Al. The decreases of soluble Ca and Mg following addition of Al in synthetic solution were at pH > 7.5. The isomorphic coprecipitation reaction with Al compounds may be the most possible mechanism responsible for the decrease of exchangeable Ca and Mg with increasing pH. Possible chemical reactions are presented.

  19. Influence of pH on wetting kinetics of a pine forest soil

    Science.gov (United States)

    Amer, Ahmad; Schaumann, Gabriele; Diehl, Dörte

    2014-05-01

    Water repellent properties of organic matter significantly alter soil water dynamics. Various environmental factors control appearance and breakup of repellency in soil. Beside water content and temperature also pH exerts an influence on soil water repellency although investigations achieved partly ambiguous results; some found increasing repellency with increasing pH (Terashima et al. 2004; Duval et al. 2005), other with decreasing pH (Karnok et al. 1993; Roper 2005) and some found repellency maxima at intermediate pH and an increase with decreasing and with increasing pH (Bayer and Schaumann 2007; Diehl et al. 2010). The breakup of repellency may be observed via the time dependent sessile drop contact angle (TISED). With water contact time, soil-water contact angle decreases until complete wetting is reached. Diehl and Schaumann (2007) calculated the activation energy of the wetting process from the rate of sessile drop wetting obtained at different temperatures and draw conclusions on chemical or physical nature of repellency. The present study aims at the influence of pH on the wetting kinetics of soil. Therefore, TISED of soil was determined as a function of pH and temperature. We used upper soil samples (0 - 10 cm) from a pine forest in the southwest of Germany (Rheinland-Pfalz). Samples were air-dried, sieved Geoderma 158(3-4): 375-384. Diehl, D. and G. E. Schaumann (2007). Hydrol. Processes 21(17): 2255 - 2265. Duval, J. F. L., K. J. Wilkinson, et al. (2005). Environ Sci Technol 39(17): 6435-6445. Karnok, K. A., E. J. Rowland, et al. (1993). Agron J 85(5): 983-986. Roper, M. M. (2005). Aust J Soil Res 43: 803-810. Terashima, M., M. Fukushima, et al. (2004). Colloids and Surfaces, A: Physicochemical and Engineering Aspects 247(1-3): 77-83.

  20. Abu al-Layth al-Libi

    Science.gov (United States)

    2015-02-01

    opponents were the stringent militants in the Khaldan camp and its Institute of the Faith Brigades (Ma`had Kata`ib al-Iman), where the virulent ...local fighter remembered that al-Libi used to live together with Hamza al- Rabi `a, the former head of al-Qa`ida’s external operations, and Abu Khabbab

  1. Characterization of size, strength and structure of aluminum-polymer dual-coagulant flocs under different pH and hydraulic conditions.

    Science.gov (United States)

    Rong, Hongyan; Gao, Baoyu; Dong, Min; Zhao, Yanxia; Sun, Shenglei; Yanwang; Yue, Qinyan; Li, Qian

    2013-05-15

    The objectives of this study are to investigate the impact of papermaking sludge product (LA) on coagulation performance and floc properties under different solution pH and hydraulic conditions. LA was synthetized by grafting acrylamide onto the lignin that contained in papermaking sludge. Characterization of LA, such as FTIR, SEM, zeta potential and molecular weight, showed that target product was obtained successfully. LA was used in combination with aluminum sulfate or polyaluminum chloride, namely Al-LA (Al was dosed firstly) and LA-Al (LA was dosed firstly), in humic acid water treatment. Floc properties and coagulation behaviors of aluminum salts and the dual-coagulants were comparatively evaluated. Results showed that DOC removal was improved by LA at pH 4 ~ 9 and the removal variations caused by different pH were decreased. Flocs formed at pH 5 and pH 8 gave quite large floc size. Floc recoverability declined as initial pH increased. Floc size, growth rate and recoverability were in the order of Al-LA>LA-Al>Al. Furthermore, flocs formed at pH 7 showed the weakest resistance to increasing shear force. Fractal dimension was rather high at pH 7 and 8 and it was in the following order: Al>LA-Al>Al-LA. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Riots - Zur Verortung eines unscharfen Phänomens

    Directory of Open Access Journals (Sweden)

    Janna Frenzel

    2016-05-01

    Full Text Available Bei riots handelt es sich um unscharfe Phänomene, die von urbanen Jugendaufständen bis zu gewaltvoll eskalierenden Demonstrationen reichen. Auch der Begriff riot ist trotz seiner teils regen Verwendung in Medien und Wissenschaft nach wie vor diffus und unscharf. Neben diesen konzeptionellen Leerstellen gibt es in den Sozialwissenschaften bisher kein klar umrissenes Forschungsfeld zu riots. Auch der Sozialen Bewegungsforschung gelingt es nicht, riots als Protestphänomene zu fassen. Vor dem Hintergrund dieser Lücken im Forschungsstand versucht sich der vorliegende Text an einer wissenschaftlichen Verortung von riot als Phänomen und als Begriff. Dabei werden zwei zentrale Aspekte der bisherigen sozialwissenschaftlichen Debatte zu riots untersucht: das Verhältnis zwischen riots und Gewalt sowie das Verhältnis zwischen riots und dem Politischen. Normal 0 21 false false false DE X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Normale Tabelle"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:""; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} Bei riots handelt es sich um unscharfe Phänomene, die von urbanen Jugendaufständen bis zu gewaltvoll eskalierenden Demonstrationen reichen. Auch der Begriff riot ist trotz seiner teils regen Verwendung in Medien und Wissenschaft nach wie vor diffus und unscharf. Neben diesen konzeptionellen Leerstellen gibt es in den Sozialwissenschaften bisher kein klar umrissenes Forschungsfeld zu riots. Auch der Sozialen Bewegungsforschung gelingt es nicht, riots als Protestphänomene zu fassen. Vor dem Hintergrund dieser Lücken im Forschungsstand versucht sich der vorliegende Text an einer wissenschaftlichen Verortung von riot als Phänomen und als Begriff. Dabei werden zwei zentrale Aspekte der

  3. Acid loading test (pH)

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003615.htm Acid loading test (pH) To use the sharing features on this page, please enable JavaScript. The acid loading test (pH) measures the ability of the ...

  4. pH sensor calibration procedure

    OpenAIRE

    Artero Delgado, Carola; Nogueras Cervera, Marc; Manuel Lázaro, Antonio; Prat Tasias, Jordi; Prat Farran, Joana d'Arc

    2013-01-01

    This paper describes the calibration of pH sensor located at the OBSEA marine Observatory. This instrument is based on an industrial pH electrode that is connected to a CTD instrument (Conductivity, Temperature, and Depth ). The calibration of the pH sensor has been done using a high precision spectrophotometer pH meter from Institute of Marine Sciences (ICM), and in this way it has been obtained a numerical function for the p H sensor propor...

  5. Crescimento de mudas de moringa em função da salinidade da água e da posição das sementes nos frutos Growth of moringa seedlings as function of salinity and seed position in the fruits

    Directory of Open Access Journals (Sweden)

    Francisco de Assis de Oliveira

    2013-02-01

    Full Text Available A escolha das sementes é de fundamental importância para a obtenção de mudas de qualidade, principalmente quando são produzidas sob condições ambientais adversas. Este trabalho foi desenvolvido com o objetivo de avaliar a influencia da salinidade sobre o desenvolvimento de mudas de moringa provenientes de sementes localizadas em diferentes posiç��es no fruto. O delineamento utilizado foi o inteiramente casualizado, com os tratamentos arranjados em esquema fatorial 3 x 4 e quatro repetições. Os tratamentos resultaram da combinação de três posições de sementes no fruto (basal, mediana e apical com quatro níveis de salinidade da água de irrigação (0,5; 2,0; 3,5; e 5,0 dS m-1. Foram avaliadas as seguintes características de crescimento: altura (ALT, diâmetro do caule (DC, diâmetro da raiz principal (DRP, número de folhas (NF, área foliar (AF, massa seca da parte aérea (MSPA, massa seca do sistema radicular (MSR e massa seca total (MST. Os dados foram submetidos à análise de variância pelo teste F e as médias, comparadas pelo teste de Tukey a 5% de probabilidade, para o efeito da posição da semente no fruto; e por análise de regressão, para os dados provenientes da salinidade. Houve interação significativa na maioria das características avaliadas. A salinidade da água de irrigação diminuiu em todas as variáveis. As mudas provenientes de sementes localizadas na porção basal dos frutos foram mais afetadas pela salinidade da água de irrigação.Choosing seeds is crucial for obtaining good quality seedlings, especially when the seedlings are grown under adverse environmental conditions. This work was carried out to evaluate the influence of salinity on the development of moringa seedlings from seeds located at different positions in the pod. The design used in this study was a completely randomized design with treatments arranged in 3 x 4 factorial scheme, with four replications. The treatments resulted from

  6. Fluorescência da clorofila como uma ferramenta possível para seleção de tolerância à salinidade em girassol Chlorophyll fluorescence as a possible tool for salt-stress tolerance screening in the sunflower

    Directory of Open Access Journals (Sweden)

    André Dias de Azevedo Neto

    2011-12-01

    Full Text Available O efeito do estresse salino de intensidade e duração conhecida nos parâmetros de fluorescência da clorofila em plantas de girassol foi estudado objetivando selecionar genótipos tolerantes e sensíveis à salinidade. O delineamento experimental utilizado foi o inteiramente casualizado em um arranjo fatorial entre 10 genótipos e 2 níveis de salinidade, com quatro repetições. As sementes foram semeadas em areia lavada e, após a germinação, foram transplantadas para vasos contendo solução nutritiva ou solução nutritiva com 100 mM de NaCl, em casa de vegetação. Após 27 dias nessas condições, foram avaliadas a fluorescência basal (F0, a eficiência quântica potencial do fotossistema 2 - PS2 (Fv/Fm, a razão Fv/F0 e a eficiência quântica efetiva do PS2 (Y. Os coeficientes dos "quenching" fotoquímico (qP e não fotoquímico (qN, qCN e NPQ também foram calculados. O estresse salino aumentou F0 e diminuiu Fv/Fm, Fv/F0 e Y, sugerindo injúrias na estrutura dos tilacóides causadas pela salinidade. Esses efeitos foram mais pronunciados no genótipo AG-960 e menos pronunciados no AG-975. O genótipo AG-960 também apresentou os maiores aumentos em qN, qCN e NPQ, em contraste com o observado para o AG-975. Dessa forma, AG-975 e AG-960 foram caracterizados como tolerante e sensível à salinidade, respectivamente. Os demais genótipos apresentaram tolerância intermediária ao estresse salino. Os resultados indicam que a fluorescência da clorofila pode ser utilizada como uma ferramenta para a seleção de genótipos de girassol tolerantes à salinidade.The effect of salt stress of known intensity and duration on chlorophyll fluorescence in sunflower plants was studied aiming to identify salt-tolerant and salt-sensitive genotypes. The experimental design was a completely randomized in a factorial arrangement among 10 genotypes and two salt levels, with four replications. Seeds were sown in sand, and after germination were

  7. Níveis de salinidade e manejo da fertirrigação sobre características da berinjela cultivada em ambiente protegido Levels of salinity and fertigation management on the characteristics of the eggplant when grown in a protected environment

    Directory of Open Access Journals (Sweden)

    Everaldo Moreira da Silva

    2013-03-01

    Full Text Available Objetivou-se estudar os efeitos de diferentes níveis de salinidade do solo sobre as variáveis fenológicas e de produção da berinjela, cultivada em vasos e em ambiente protegido. O estudo foi conduzido na área experimental do Departamento de Engenharia de Biossistemas da ESALQ/USP, Piracicaba, SP. Os tratamentos foram compostos da combinação de dois fatores: 6 níveis de salinidade inicial do solo (S1 = 1,3; S2 = 2,4; S3 = 3,6; S4 = 4,5; S5 = 5,6 e S6 = 6,4 dS m-1 e dois manejos de fertirrigação: com controle da condutividade elétrica da solução do solo (M1, e o tradicional (M2, obedecendo a curva de absorção de nutrientes da cultura. O delineamento estatístico adotado foi o de blocos casualizados completos, com quatro repetições, arranjados no esquema fatorial 6 x 2. Os resultados revelaram que os níveis de salinidade do solo afetaram diretamente as variáveis, produção de matéria seca, produção de frutos e índice de área foliar das plantas. Verificou-se que a redução média na produção da cultura da berinjela, em estufa, foi da ordem de 8,65% para o incremento de 1 dS m-1 na salinidade do solo, acima da salinidade limiar, que foi de 1,71 dS m-1.The objective was to study the effects of different levels of soil salinity on the phenological variables and production of the eggplant when grown in pots in a protected environment. The study was carried out at the experimental site of the Department of Biosystems Engineering ESALQ/USP in Piracicaba, São Paulo. The treatments consisted of a combination of two factors: six initial levels of soil salinity (S1 = 1.3, S2 = 2.4, S3 = 3.6, S4 = 4.5, S5 = 5.6 and S6 = 6.4 dS m-1 and two fertigation management: with the electrical conductivity of the soil solution being controlled (M1 and traditional (M2, following the absorption curve of nutrients from the culture. The statistical design adopted was a randomized complete-block design with four replications, arranged in a 6 x 2

  8. PhD students and integrative research

    NARCIS (Netherlands)

    Fry, G.; Tress, B.; Tress, G.

    2006-01-01

    The training of PhD students is currently very dynamic and varies widely from place to place. We present some examples of this variation and comment on how it may affect the way PhD students cope with integrative studies. Our focus is on the training needs of PhD students studying integrative

  9. Leaching of Al2O3 in simulated repository conditions

    International Nuclear Information System (INIS)

    Svensson, B.-M.; Dahl, L.

    1978-06-01

    Al 2 O 3 material has been leached at 90 deg C in: simulated ground water at pH 8.5, embedded in bentonite + silica sand saturated with the same water, and in simulated ground water at pH 6 and pH 10. Leaching periods varied from 30 days to 300 days. We observed slight weight increments in all cases from deposits on samples from the environment. These mask weight losses from Al 2 O 3 that may have occurred. (author)

  10. Acidez potencial pelo método do pH SMP no Estado do Amazonas Potential acidity by pH SMP method in Amazonas State, Brazil

    Directory of Open Access Journals (Sweden)

    Adônis Moreira

    2004-01-01

    Full Text Available O objetivo deste trabalho foi definir um modelo matemático que estime o H+Al a partir do pH SMP medido em água e em solução de CaCl2 0,01 mol L-1 nas condições edafoclimáticas locais. Foram utilizadas 246 amostras de solo provenientes de diversas localidades. Mesmo apresentando menor coeficiente da correlação (r = 0,89*, a equação H+Al = 30,646 - 3,848pH SMP obtida em H2O foi mais eficiente que a obtida em solução CaCl2 (H+Al = 30,155 - 3,834pH SMP, r = 0,91*, a qual subestima os valores da acidez potencial.The objective of this work was to determine a mathematic model that estimates the potential acidity with pH SMP measured in water and in solution of CaCl2 0.01 mol L-1. Two hundred and forty six soil samples from several localities were utilized. Despite presenting a lower correlation coefficient (r = 0.89*, the equation H+Al = 30.646 - 3.848pH SMP, obtained in H2O, was more efficient than in the CaCl2 solution (H+Al = 30.155 -3.834pH SMP, r = 0.91*, since this last one underestimates the values of the potential acidity.

  11. Aluminium impact on freshwater invertebrates at low pH: A review

    Science.gov (United States)

    Herrmann, Jan

    The state of knowledge on aluminium (Al) impact on freshwater invertebrates at low pH is reviewed. Mainly inorganic ions seem to be biologically harmful. Published effect/mechanism descriptions may seem somewhat contradictory, but this can be due to the heterogeneity of "the invertebrate group", as well as the multitude and complexity of occurring Al species, thereby also Al analysis problems. Addition of Al to streams has in some cases increased drift and death of mainly some "surface-dependent" species (chironomids, mayflies, dance flies, dixid midges), but also some strictly benthic animals (isopods, stoneflies), while other studies on a variety of animals do not record any change in neither drift, mortality nor biomass. In laboratory exposures Al has been shown to cause raised mortality for some daphnids and blackfly larvae at pH around 5; in the latter animals the effect was however mitigated by humus. A variety of other freshwater invertebrates were not affected. Moreover, at pH 4, Al has even been shown to improve the survival of mayfly nymphs and daphnids, otherwise impaired by the low pH in itself. The reason for this is not clear. Proofs for "food chain accumulation" of Al are still weak. Very high additions of Al have caused a decreased respiration rate in a dragonfly nymph, while a more field-relevant exposure level increased respiration in mayfly nymphs. This suggests a stress situation, probably due to impaired osmoregulation, indicating chemical or mechanical Al impact. The lowered oxygen uptake is then compensated for by improved respiration rate. A model for this is presented. Studies on crayfish, daphnids, mayflies and waterbugs indicate that Al can lower osmoregulatory efficiency and thereby affect the ion balance maintaining mechanisms of the animals. Such sublethal effects are important and should be studied further. The review also critically discusses the concepts mortality and bioavailability.

  12. Competitive and synergistic effects in pH dependent phosphate adsorption in soils: LCD modeling.

    Science.gov (United States)

    Weng, Liping; Vega, Flora Alonso; Van Riemsdijk, Willem H

    2011-10-01

    The pH dependency of soluble phosphate in soil was measured for six agricultural soils over a pH range of 3-10. A mechanistic model, the LCD (ligand charge distribution) model, was used to simulate this change, which considers phosphate adsorption to metal (hydr)oxides in soils under the influence of natural organic matter (NOM) and polyvalent cations (Ca(2+), Al(3+), and Fe(3+)). For all soils except one, the description in the normal pH range 5-8 is good. For some soils at more extreme pH values (for low P-loading soils at low pH and for high P-loading soils at high pH), the model over predicts soluble P. The calculation shows that adsorption is the major mechanism controlling phosphate solubility in soils, except at high pH in high P-loading soils where precipitation of calcium phosphate may take place. NOM and polyvalent cations have a very strong effect on the concentration level of P. The pattern of pH dependency of soluble P in soils differs greatly from the pH effects on phosphate adsorption to synthetic metal (hydr)oxides in a monocomponent system. According to the LCD model, the pH dependency in soil is mainly caused by the synergistic effects of Ca(2+) adsorption to oxides. Adsorption of Al(3+) to NOM adsorbed plays an important role only at a pH < 4.5. Presence of NOM coating strongly competes with phosphate for the adsorption and is an important factor to consider in modeling phosphate adsorption in natural samples.

  13. Effects of Al(III) and nano-Al13 species on malate dehydrogenase activity.

    Science.gov (United States)

    Yang, Xiaodi; Cai, Ling; Peng, Yu; Li, Huihui; Chen, Rong Fu; Shen, Ren Fang

    2011-01-01

    The effects of different aluminum species on malate dehydrogenase (MDH) activity were investigated by monitoring amperometric i-t curves for the oxidation of NADH at low overpotential using a functionalized multi-wall nanotube (MWNT) modified glass carbon electrode (GCE). The results showed that Al(III) and Al(13) can activate the enzymatic activity of MDH, and the activation reaches maximum levels as the Al(III) and Al(13) concentration increase. Our study also found that the effects of Al(III) and Al(13) on the activity of MDH depended on the pH value and aluminum speciation. Electrochemical and circular dichroism spectra methods were applied to study the effects of nano-sized aluminum compounds on biomolecules.

  14. [Effects of thiourea on pH and availability of metal ions in acid red soil].

    Science.gov (United States)

    Yang, Bo; Wang, Wen; Zeng, Qing-Ru; Zhou, Xi-Hong

    2014-03-01

    Through the simulation research, the effects of application of thiourea and urea on pH and availability of metal ions in acid red soil were studied, and the results showed that after applying urea, the soil pH increased in the first experimental stage and then reduced gradually to a low level, however, decreased trends of soil pH values were inhibited by the application of thiourea, especially when the concentration of thiourea reached to 5.0 mmol x kg(-1) dry soil, the soil pH was stable at high level, which exceeded to 6.0. It proved that the application of thiourea could inhibit the soil acidification due to urea application. After applying urea with different concentrations of thiourea, the available contents of Zn and Al decreased with the increasing concentration of thiourea, nevertheless, when the concentration of thiourea reached to 5.0 mmol x kg(-1), the available content of Mn was stable at high level which was over 110 mg x kg(-1). In addition, the results showed a highly significant negative correlation between the soil pH and the available content of Cu, Zn and Al, but for Mn, no discipline was found between the soil pH and the availability after applying thiourea. Moreover, the soil pH became higher after applying urea with thiourea compared to add urea only, which led to the decreasing of available content of Al, and it was benefited for the control of the phytotoxic effect of Al. The available content of Mn in the soil not only depended on soil pH but also the content of thiourea due to its redox and complexing reaction with Mn.

  15. All About ALS

    Science.gov (United States)

    ... Subscribe August 2015 Print this issue All About ALS Understanding a Devastating Disorder En español Send us ... Sports Concussions Wise Choices How Can I Help ALS Research? If you have ALS, join the National ...

  16. Sources and levels of salinity of water on seedlings of papaya tree cv. sunrise soloFontes e níveis da salinidade da água na formação de mudas de mamoeiro cv. sunrise solo

    Directory of Open Access Journals (Sweden)

    Ítalo Herbert Lucena Cavalcante

    2010-02-01

    Full Text Available From January to March of 2005 one experiment was developed in a screen house to evaluate the effect of sources and levels of water salinity on emergence and initial development of papaya seedlings cv. Sunrise Solo. A completely randomized experimental design was used and treatments were distributed in a factorial arrangement 3×5, corresponding to three sources (dam water, water salinized with sodium and water salinized with sodium sulfate and five water saline levels (0.4; 2.0; 4.0; 6.0 e 8.0 dS.m-1 and five replications. At 60 days after seedling emergence the following variables were evaluated: soil electrical conductivity, seedling emergence, plant height, stem diameter and dry mass of shoots and roots. The soil electrical conductivity increased independently of salt source, with more expressiveness for dam water, and all evaluated variables of plant growth were inhibited with water salinity increase. No período, de janeiro a março de 2005, foi desenvolvido um experimento em abrigo telado para avaliar o efeito de fontes e níveis de salinidade sobre a emergência e desenvolvimento inicial de plântulas de mamão Havaí cv. Sunrise Solo. Os tratamentos foram distribuídos em delineamento inteiramente casualizado, em esquema fatorial 3×5, correspondente a três fontes (água salina de barragem (AS, água concentrada em cloreto de sódio (NaCl e água rica em sulfato de sódio (Na2SO4 e cinco níveis de salinidade (0,4; 2,0; 4,0; 6,0 e 8,0 dS m-1 em cinco repetições. Aos 60 dias após a emergência foram avaliadas as seguintes variáveis: Condutividade elétrica do extrato de saturação do solo (CEes, % de emergência de sementes, altura de plantas, diâmetro caulinar na altura do colo e biomassa seca de parte aérea e raízes. A CEes do substrato foi elevada, independentemente da fonte utilizada, com maior expressividade para a água de barragem, e as variáveis de crescimento vegetativo avaliadas foram inibidas, independentemente da

  17. Crescimento e desenvolvimento da cultura do melão sob diferentes lâminas de irrigação e salinidade da água Growth and development of the melon crop under different irrigation depths and water salinity

    Directory of Open Access Journals (Sweden)

    Carlos H. de A. Farias

    2003-12-01

    Full Text Available Avaliar o crescimento, o desenvolvimento foliar e o acúmulo de matéria seca da cultura de melão ‘Gold mine’, submetido a diferentes lâminas de irrigação, utilizando-se água com dois níveis de salinidade, foi o objetivo deste trabalho. O experimento foi conduzido em condições de campo, na Fazenda São João, município de Mossoró, RN, cujo delineamento experimental adotado foi o de blocos casualizados, em esquema fatorial 6 x 2. Os tratamentos consistiram na introdução de seis lâminas de irrigação (0,55; 0,70; 0,85; 1,00; 1,15 e 1,30 da evapotranspiração máxima da cultura e dois níveis de salinidade da água de irrigação 0,55 e 2,65 dS m-1. A falta de água no período crítico afetou significativamente o restante do ciclo da cultura, causando decréscimo, no peso da fitomassa seca, para lâminas abaixo do tratamento da lâmina padrão (266 mm. O acúmulo de fitomassa foi afetado pela água de maior salinidade (2,65 dS m-1 ao longo de todo ciclo.The aim of this study was to evaluate the growth, vegetative development and accumulation of dry matter of the "Gold mine" melon submitted to different depths of irrigation using two levels of salinity. The experiment was conducted under field conditions at Fazenda São João, Mossoró, RN, in random blocks and 6 x 2 factorial experimental design. The treatments consisted of 6 depths of irrigation (0.55; 0.70; 0.85; 1.00; 1.15; 1.3 of the maximum crop evapotranspiration and two levels of salinity of the irrigation water (0.55 and 2.65 dS m-1. The absence of water in the critical period significantly affected the rest of the cycle, causing decrease in the dry weight in the treatment of irrigation depth considered as of the most appropriate depth (266 mm. The water of higher salinity (2.65 dS m-1 affected the accumulation of dry matter in the cycle.

  18. Aluminum elution and precipitation in glass vials: effect of pH and buffer species.

    Science.gov (United States)

    Ogawa, Toru; Miyajima, Makoto; Wakiyama, Naoki; Terada, Katsuhide

    2015-02-01

    Inorganic extractables from glass vials may cause particle formation in the drug solution. In this study, the ability of eluting Al ion from borosilicate glass vials, and tendencies of precipitation containing Al were investigated using various pHs of phosphate, citrate, acetate and histidine buffer. Through heating, all of the buffers showed that Si and Al were eluted from glass vials in ratios almost the same as the composition of borosilicate glass, and the amounts of Al and Si from various buffer solutions at pH 7 were in the following order: citrate > phosphate > acetate > histidine. In addition, during storage after heating, the Al concentration at certain pHs of phosphate and acetate buffer solution decreased, suggesting the formation of particles containing Al. In citrate buffer, Al did not decrease in spite of the high elution amount. Considering that the solubility profile of aluminum oxide and the Al eluting profile of borosilicate glass were different, it is speculated that Al ion may be forced to leach into the buffer solution according to Si elution on the surface of glass vials. When Al ions were added to the buffer solutions, phosphate, acetate and histidine buffer showed a decrease of Al concentration during storage at a neutral range of pHs, indicating the formation of particles containing Al. In conclusion, it is suggested that phosphate buffer solution has higher possibility of forming particles containing Al than other buffer solutions.

  19. pH distribution in human tumors

    International Nuclear Information System (INIS)

    Thistlethwaite, A.J.; Leeper, D.B.; Moylan, D.J.; Nerlinger, R.E.

    1984-01-01

    pH distribution in human tumors is being determined to evaluate this parameter as a prognostic indicator of hyperthermia response. pH is measured by a modified glass pH electrode (21g, model MI 408, Microelectrodes, Inc., Londonderry, NH) inserted through an 18g open-ended Angiocath. Eight tumors have been evaluated to date; and of those, 3 were also assayed after the first heat treatment coincident with determination of blood flow. Tumors were between 2-5 cm, of various histologies, and of primary, recurrent, or metastatic origin. 2-4 measurements were made per tumor. Pretreatment readings were between 6.4 and 7.2 pH units. As tumor blood flow increased after 1 hr heating (41.5 - 43 0 ) pH rose 0.1 - 0.3 units. Normal rat muscle yields pH readings of 7.35 - 7.45. Although there was considerable heterogeneity of pH within tumors, accuracy and drift were not a problem. 5-15 min were required for pH stabilization after catheter insertion and <5 min after electrode insertion. A saline wheal was used for anesthesia to preclude modification of pH by anesthetics. Patient tolerance has not been a problems. This study suggests that human tumor tissue has a preponderance of areas more acidic than normal tissue. This may serve to sensitize tumor cells to hyperthermia and provide a prognostic indicator of tumor response

  20. PIXE analysis of mineral composition of alfalfa root-tip exposed to low pH or aluminum stress condition

    International Nuclear Information System (INIS)

    Yokota, Satoshi; Mae, Tadahiko; Ojima, Kunihiko; Ishii, Keizo.

    1994-01-01

    PIXE analysis was applied to study alteration of mineral composition (Al, P, K, and Cl) of alfalfa root-tip exposed to low pH or aluminum stress. These minerals were detectable using one or two pieces of root-tips. Short-term (within 4 h) decreases in K/P and Cl/P ratios were observed under low pH and aluminum stress conditions. However, degree of the decrease was not same. Differences in toxic effects of low pH and Al on the root-tip of alfalfa are discussed. (author)

  1. Influence of Scandium Addition on Stress Corrosion Cracking Susceptibility of Al-Zn-Mg Alloy in Different Corrosive Environments

    Directory of Open Access Journals (Sweden)

    Zhaoming Li

    2018-03-01

    Full Text Available Stress corrosion cracking (SCC susceptibilities of Al-Zn-Mg alloys without and with Scandium addition were evaluated in 3.5% NaCl solution at different pH and different strain rate, using slow strain rate test technique. The results indicate that Sc addition reduces grain size and width of precipitation free zones, and transforms grain boundary precipitates from continuous distribution into interrupted distribution by inhibiting recrystallization. In solution at pH 1, pH 3 and pH 7, Sc addition reduces the degree of localized corrosion of alloy surface and SCC susceptibility of Al-Zn-Mg alloy. However, in solution at pH 10 and pH 12, grain refinement significantly promotes the diffusion of hydrogen atoms into matrix, thus Sc addition increases SCC susceptibility of Al-Zn-Mg alloy. Under different strain rate conditions, Sc addition can all reduce SCC susceptibility of Al-Zn-Mg alloy in solution at pH 1, pH 3 and pH 7, and can all increase SCC susceptibility of Al-Zn-Mg alloy in solution at pH 10 and pH 12. As a result, Sc modified Al-Zn-Mg alloy in practical applications should be avoided in alkaline environments.

  2. Growth and composition of the essential oil off malvariço grown under salinity and biofertilizer doses = Crescimento e composição do óleo essencial de malvariço cultivado sob salinidade e doses de biofertilizante

    Directory of Open Access Journals (Sweden)

    Sergiane Beatriz da Silva Mesquita

    2017-10-01

    Full Text Available The effects of salinity of the soil and water on crops can be overcome with the use of biofertilisers. The aim of this study therefore, was to evaluate the effect of salinity and bovine biofertiliser on growth, the production of essential oils, and the carbohydrate and chloride levels in plants of Plectranthus amboinicus, known locally as malvariço. The experiment was carried out in a greenhouse from March to May 2013, in plastic pots with a capacity of 7.5 L. The experimental design utilized was fully randomized in a factorial arrangement 2 x 4, with two levels of water salinity (S1= 0.7 and S2=3.1 dS m-1 and four levels of liquid bovine biofertilizer applied to the soil, corresponding to (B1=0, B2=10, B3=20 and B4=30% the volume of the soil, with five replications. The following variables were evaluated: root, stem and leaf dry weight, and foliar levels of carbohydrates, chlorides and essential oils. Salinity reduced the dry biomass of the roots; however, the application of biofertiliser, and the interaction between factors did not influence biometric variables, or the levels of carbohydrates or chlorides. Under all the conditions being evaluated, the essential oil of Plectranthus amboinicus showed esters, alcohols, phenols, ketones and terpenoids. = Os efeitos que a salinidade do solo e da água provocam nas culturas podem ser superados utilizandose biofertilizantes. Assim, objetivou-se com o presente estudo avaliar o efeito da salinidade e do biofertilizante bovino no crescimento, na produção de óleos essenciais e nos teores de carboidratos e cloreto de plantas de malvariço (Plectranthus amboinicus. O experimento foi conduzido em casa de vegetação no período de março a maio de 2013, em vasos plásticos com capacidade de 7,5 L. O delineamento experimental utilizado foi inteiramente casualizado, em um arranjo fatorial 2 x 4, sendo dois níveis de salinidade da água de irrigação (S1=0,7 e S2=3,1 dS m-1 e quatro níveis de

  3. Sobrevivência de alevinos de Jundiá (Rhamdia quelen Quoy & Gaimard, 1824) à variação de salinidade da água Survival of fingerlings of the Jundiá (Rhamdia quelen Quoy & Gaimard, 1824) to changes on water salinity

    OpenAIRE

    Maria Ignez Marchioro; Bernardo Baldisserotto

    1999-01-01

    O objetivo deste trabalho foi testar a sobrevivência de alevinos de jundiá a diferentes concentrações de salinidade (sal marinho comum e água do mar), pois o sal é indicado no tratamento de algumas doenças e também para reduzir o estresse durante o manuseio e transporte de peixes. Os alevinos (1,68 ± 0,87g) permaneceram de 3 a 7 dias em tanques de 1400l, com água corrente e temperatura entre 23 e 25°C, sendo alimentados diariamente. Após esse período, foram colocados 50 alevinos em...

  4. Variación estacional e influencia de la turbidez y la salinidad sobre el zooplancton de un lago salino de la región central de Argentina Seasonal variation and influence of turbidity and salinity on the zooplankton of a saline lake in central Argentina

    Directory of Open Access Journals (Sweden)

    Santiago Andrés Echaniz

    2011-07-01

    Full Text Available The limnology of saline water bodies at other latitudes is fairly well known, but in Argentina such studies have only recently begun. The applicability of many conclusions regarding the functioning of these environments around the world is limited due to the scant ecological knowledge of some endemic species recorded in the assemblages of Argentine lakes. The aims of this work were to determine the effects of salinity and inorganic turbidity on the taxonomic composition, abundance, and zooplankton biomass in a shallow, hypereutrophic, mesosaline lake in the north of La Pampa province characterized by seasonality, variations in level and salinity, and the lack of macrophytes and fishes, and to compare it with other shallow lakes of the province. We found important differences with other saline lakes: the species richness was lower; the mean abundance of zooplankton was between four and six times higher; and rotifers, which were not affected by salinity or the concentration of inorganic suspended solids, were numerically predominant. Crustaceans, on the other hand, were negatively affected by these environmental factors. Biomass was twofold higher than that recorded in the same period in two shallow lakes of Pampa, with similar nutrient concentrations but lower salinities.La limnología de los cuerpos de agua salinos de otras latitudes es bastante conocida, pero en Argentina se ha comenzado a estudiar recientemente. Muchas conclusiones sobre el funcionamiento de estos ambientes a nivel mundial son de aplicación restringida debido a que las asociaciones registradas en los lagos argentinos tienen algunas especies endémicas, cuyo conocimiento ecológico es escaso. Los objetivos de este trabajo fueron determinar los efectos de la salinidad y la turbidez inorgánica sobre la composición taxonómica, abundancia y biomasa zooplanctónica en un lago somero mesosalino hipereutrófico del norte de La Pampa, caracterizado por su temporalidad, variaciones

  5. Interaction in PhD supervision

    DEFF Research Database (Denmark)

    Kobayashi, Sofie; Grout, Brian William Wilson; Rump, Camilla Østerberg

    This paper contains an analysis of a single supervision session, undertaken with the aim of identifying how learning opportunities might be created for a PhD student. The supervision session concerned methodologies to be employed in a PhD study related to storm water management and included the P...

  6. Ph og børnenes rum

    DEFF Research Database (Denmark)

    de Coninck-Smith, Ning

    2008-01-01

    Arkiteten og kulturkritikeren PH tegnede to bygninger til børn, nemlig fabriksbørnehaven ved Dehns Vaskeri fra 1948 og det ombyggede børnehjem Mindet fra 1954. Bidraget diskuterer PH's særlige greb om arkitektur til børn og placerer det ind i samtidens diskussion om børn, deres udvikling og behov....

  7. Urbanism PhD Research 2008 - 2010

    NARCIS (Netherlands)

    Smit, M.; Van der Hoeven, F.D.; Brand, N.; Van der Burg, L.; Çal??kan, O.; Tan, E.R.; Wang, C.Y.; Zhou, J.

    2009-01-01

    To ensure the quality of the Ph.D. research the Department introduced a special procedure for periodic evaluation: after a period of nine months the potential Ph.D. candidates are asked to present their research design, theoretical framework and methodological approach to the members of the

  8. On Calibration of pH Meters

    Directory of Open Access Journals (Sweden)

    Da-Ming Zhu

    2005-04-01

    Full Text Available The calibration of pH meters including the pH glass electrode, ISE electrodes,buffers, and the general background for calibration are reviewed. Understanding of basicconcepts of pH, pOH, and electrode mechanism is emphasized. New concepts of pH, pOH,as well as critical examination of activity, and activity coefficients are given. Theemergence of new solid state pH electrodes and replacement of the salt bridge with aconducting wire have opened up a new horizon for pH measurements. A pH buffer solutionwith a conducting wire may be used as a stable reference electrode. The misleadingunlimited linear Nernstian slope should be discarded. Calibration curves with 3 nonlinearportions for the entire 0—14 pH range due to the isoelectric point change effect areexplained. The potential measurement with stirring or unstirring and effects by double layer(DL and triple layer (TL will be discussed.

  9. Coaching af ph.d.-studerende

    DEFF Research Database (Denmark)

    Godskesen, Mirjam Irene

    Rapporten danner grundlag for at etablere et koncept for ph.d.-coaching. Erfaringerne fra et 2-årigt projekt om ph.d.-coaching i SCKK regi beskrives. De centrale temaer er tilrettelæggelse af den individuelle coaching, typiske temaer i coachingen og arbejdsdeling mellem coach og vejleder. Der er...

  10. (ajst) the influence of ph and adsorbent

    African Journals Online (AJOL)

    goethite sorbed a little more metal ion than the natural goethite. This was attributed to the higher proportion of goethite in synthetic than .... The dependence of metal ion adsorption on pH as observed by some researchers over a wider range of pH ..... “Uranium Uptake from. Aqueous Solution by Interaction with Goethite,.

  11. Determination Of Ph Including Hemoglobin Correction

    Science.gov (United States)

    Maynard, John D.; Hendee, Shonn P.; Rohrscheib, Mark R.; Nunez, David; Alam, M. Kathleen; Franke, James E.; Kemeny, Gabor J.

    2005-09-13

    Methods and apparatuses of determining the pH of a sample. A method can comprise determining an infrared spectrum of the sample, and determining the hemoglobin concentration of the sample. The hemoglobin concentration and the infrared spectrum can then be used to determine the pH of the sample. In some embodiments, the hemoglobin concentration can be used to select an model relating infrared spectra to pH that is applicable at the determined hemoglobin concentration. In other embodiments, a model relating hemoglobin concentration and infrared spectra to pH can be used. An apparatus according to the present invention can comprise an illumination system, adapted to supply radiation to a sample; a collection system, adapted to collect radiation expressed from the sample responsive to the incident radiation; and an analysis system, adapted to relate information about the incident radiation, the expressed radiation, and the hemoglobin concentration of the sample to pH.

  12. The influence of pH on the corrosion of medium strength aerospace alloy 8090, 2091 and 2014

    DEFF Research Database (Denmark)

    Ambat, Rajan; Dwarakadasa, E.S.

    1992-01-01

    The influence of pH on the corrosion behaviour of two aluminium-lithium-copper-magnesium-zirconium (8090 and 2091) alloys was studied and compared with a standard aircraft alloy, 2014 (Al-4.4% Cu) and 99.9% pure Al. In constant exposure and potentiodynamic polarization studies conducted in 3.5% Na......Cl solution having different pH values, all the alloys exhibited high corrosion rates in acidic and alkaline environments, with a minimum in less hostile environments close to neutral pH. The pitting potentials for aluminium-lithium alloys were slightly lower than those for 2014 and pure Al. The effect of p......H on the passive current density was also less for aluminium-lithium alloys....

  13. The Influence of Backwater Al3+ on Diaspore Bauxite Flotation

    Directory of Open Access Journals (Sweden)

    Chaojun Fang

    2017-10-01

    Full Text Available The effect of Al3+ in backwater on the flotation of diaspore bauxite was investigated by micro-flotation tests and the underlying mechanisms were investigated by inductively coupled plasma (ICP measurement, zeta potential measurements, solution chemistry analyses, and synchrotron near edge X-ray absorption fine structure (NEXAFS analyses. The ICP measurement results show the concentration of Al3+ in backwater was up to 1 × 10−4 mol/L. The micro-flotation results indicated that backwater Al3+ reduced the flotation recovery of diaspore and improved the flotation recovery of kaolinite at pH 9, which was the pH value used in the industrial flotation. The adsorption of Al3+ species changed the zeta potential, the Al atomic abundance, and the number of active sites on the mineral surface. In particular, the result of solution chemistry analyses and synchrotron NEXAFS analyses show that the Al3+ in backwater was adsorbed on the mineral surface in the form of Al(OH3 (s, and the bond of –Al–O–Al–(OH2 or –Al/Si–O–Al–(OH2 was formed at pH 9. It changed the intensity of hydrogen bond force between minerals and collectors, and resulted in the depression of diaspore flotation and the activation of kaolinite flotation. This study can be used to guide the application of backwater in the flotation of diaspore bauxite in industry.

  14. Battala et al pdf

    African Journals Online (AJOL)

    david

    Several hundreds of pesticides of diverse chemical nature are widely ... little research in the identification of a comprehensive list of OP degradation .... the Malathion is more stable at acidic pH. At pH 8.5 the degradation rate of malathion is more. The results show that alkaline hydrolysis was the most competitive pathway for.

  15. Comparison of two pH meters used for skin surface pH measurement: the pH meter 'pH900' from Courage & Khazaka versus the pH meter '1140' from Mettler Toledo.

    Science.gov (United States)

    Ehlers, C; Ivens, U I; Møller, M L; Senderovitz, T; Serup, J

    2001-05-01

    Measurement of skin surface pH is used in clinical research to evaluate hazardous shifts in pH following external exposures and to evaluate the state of diseased skin with acute or chronic changes. It is therefore important to measure skin surface pH as precisely as possible. The aim of this study was to compare two commercially available pH meters used for skin surface pH measurement, to reveal differences between them in measured skin pH on the forearm. The first pH meter (pH900) had a pointed electrode and a stabilisation period of 3 s. The second pH meter (pH meter 1140) had a circular electrode and no fixed stabilisation period. Twelve healthy subjects (6 male and 6 female Caucasians) entered the study. The pH measurements were performed once an hour from 8 a.m. to 3 p.m. on both forearms in five areas from the elbow to the "wristwatch" zone. In each area, three measurements were performed next to each other with both pH meters (15 measurements per arm per hour per pH meter). The pH900 has a higher measuring level and a higher variation than the pH meter 1140. A skin surface pH meter with a circular electrode and with no fixed stabilisation period is preferable. It is recommended that the pH meter be allowed to stabilise for at least 7 s before the result is read.

  16. Avaliação da tolerância de larvas do pacamã Lophiosilurus alexandri Steindachner, 1877 (Pisces:Siluriformes a diferentes salinidades - DOI: 10.4025/actascibiolsci.v30i4.791 Evaluation of the tolerance of “pacamã” Lophiosilurus alexandri Steindachner, 1877 (Pisces:Siluriformes larvae to different salinities - DOI: 10.4025/actascibiolsci.v30i4.791

    Directory of Open Access Journals (Sweden)

    Ronald Kennedy Luz

    2008-11-01

    Full Text Available O objetivo deste trabalho foi avaliar a tolerância de larvas de pacamã Lophiosilurus alexandri ao teste agudo de salinidade da água em diferentes idades. Os testes foram realizados em larvas recém-eclodidas, com oito e 12 dias pós-eclosão. As larvas foram aclimatadas às condições experimentais por 24h, sendo estocadas em 18 tanques plásticos de 1 L na densidade de 15 larvas L-1. Após esse período, as larvas foram transferidas para as salinidades: água doce, 2, 4, 6, 8 e 10 g de sal L-1 e observadas durante 96h. Larvas recém- eclodidas apresentaram mortalidade total em 6, 8 e 10 g de sal L-1 e 100% de sobrevivência para água doce, 2 e 4 g de sal L-1; porém, com redução dos valores de peso e comprimento mediante as duas salinidades. Larvas com oito dias pós-eclosão apresentaram CL(I50-96hde 8,9 g de sal L-1. Para o peso, verificou-se redução gradativa a partir da salinidade de 2 g de sal L-1, mas sem diferenças para o comprimento das larvas entre os tratamentos. Para as larvas com 12 dias pós-eclosão, não se registraram diferenças no comprimento e peso e a sobrevivência foi menor a 8 e 10 g de sal L-1. Larvas com oito e 12 dias pós-eclosão tiveram alterações no comportamento natatório em salinidades superiores a 6 g de sal L-1. Larvas de pacamã apresentaram maior tolerância às diferentes salinidades da água com o desenvolvimento ontogenético.The aim of this study was to analyze the salinity tolerance of “pacamã” Lophiosilurus alexandri larvae at different ages. The test was conducted in post-hatching-larvae and larvae with 8 and 12 days old post-hatching. Larvae were acclimatized to experimental conditions for 24h, kept in 18 plastic tanks with 1 L at a density of 15 larvae L-1. After this period, larvae were subjected to the salinities: freshwater, 2, 4, 6, 8 and 10 g salt L-1, and observed over a period of 96h. Post-hatching larvae exhibited complete mortality in 6, 8 and 10 g salt L-1. Survival was

  17. Evaluation of boron isotope ratio as a pH proxy in the deep sea coral Desmophyllum dianthus: Evidence of physiological pH adjustment

    Science.gov (United States)

    Anagnostou, E.; Huang, K.-F.; You, C.-F.; Sikes, E. L.; Sherrell, R. M.

    2012-10-01

    The boron isotope ratio (δ11B) of foraminifers and tropical corals has been proposed to record seawater pH. To test the veracity and practicality of this potential paleo-pH proxy in deep sea corals, samples of skeletal material from twelve archived modern Desmophyllum dianthus (D. dianthus) corals from a depth range of 274-1470 m in the Atlantic, Pacific, and Southern Oceans, ambient pH range 7.57-8.05, were analyzed for δ11B. The δ11B values for these corals, spanning a range from 23.56 to 27.88, are found to be related to seawater borate δ11B by the linear regression: δ11Bcoral=(0.76±0.28) δ11Bborate+(14.67±4.19) (1 standard error (SE)). The D. dianthus δ11B values are greater than those measured in tropical corals, and suggest substantial physiological modification of pH in the calcifying space by a value that is an inverse function of seawater pH. This mechanism partially compensates for the range of ocean pH and aragonite saturation at which this species grows, enhancing aragonite precipitation and suggesting an adaptation mechanism to low pH environments in intermediate and deep waters. Consistent with the findings of Trotter et al. (2011) for tropical surface corals, the data suggest an inverse correlation between the magnitude of a biologically driven pH offset recorded in the coral skeleton, and the seawater pH, described by the equation: ΔpH=pH recorded by coral-seawater pH=-(0.75±0.12) pHw+(6.88±0.93) (1 SE). Error analysis based on 95% confidence interval(CI) and the standard deviation of the regression residuals suggests that the uncertainty of seawater pH reconstructed from δ11Bcoral is ±0.07 to 0.12 pH units. This study demonstrates the applicability of δ11B in D. dianthus to record ambient seawater pH and holds promise for reconstructing oceanic pH distribution and history using fossil corals.

  18. Effect of pH decline on foraminiferal stable isotopes during the Paleocene-Eocene Thermal Maximum?

    Science.gov (United States)

    Uchikawa, J.; Zeebe, R. E.

    2009-12-01

    Pioneering culture experiments by Spero et al. (1997) demonstrated that seawater pH (or carbonate chemistry) has a marked effect on planktonic foraminiferal stable oxygen and carbon isotopes (δ18O and δ13C). Both δ18O and δ13C become isotopically heavier as seawater pH decreases (the “pH effect”). Several studies now argue that δ18O and δ13C of benthic foraminifera are similarly influenced by the pH effect. As a result, paleooceanographic information based on foraminiferal δ18O and δ13C can be significantly biased for the time-window during which seawater pH was notably different from the modern condition or varied rapidly. A prime example of such is the Paleocene-Eocene Thermal Maximum (PETM). Widespread dissolution of sedimentary CaCO3 in the PETM strata (e.g., Zachos et al., 2005) suggests significant ocean acidification during this time interval. In this study, we examine the magnitude of the pH effect on foraminiferal δ18O and δ13C during the PETM. First we will estimate the relative pH decline from the pre-PETM steady state in the surface and deep ocean reservoirs in response to 2,000 ~ 5,000 Pg of carbon input using a carbon cycle model (Zeebe et al., 2009). We will then apply the empirical relationships obtained from the culture experiments by Spero et al. (1997) to calculate the ranges of errors in the foraminiferal δ18O and δ13C that could arise due to the pH effect during the PETM. {REFERENCES} Spero et al. (1997) Nature, v390, p497-500: Zachos et al. (2005) Science, v308, p1611-1615: Zeebe et al. (2009) Nature Geoscience, v2, p576-580.

  19. PH Regulation by Breast Cancer Cells In Vitro and In Vivo

    National Research Council Canada - National Science Library

    Gillies, Robert

    1999-01-01

    ...) and inorganic phosphate (Pi) (Gillies et al., 1994, Am J Physiol 267, C195-C203). However, this method is limited to measuring average tumor pHe, and was not capable of reporting the pH range or localized values...

  20. pH relationship and nutrient availability for cacao in an Entisol from the Colombian Amazon

    Directory of Open Access Journals (Sweden)

    Gelber Rosas-Patiño

    2017-09-01

    Full Text Available Liming is a common practice in acid soil manage-ment; however, the information on liming in cacao soils of the Colombian Amazon region is precarious. Incubation curves were built in a highly acid Typic Udorthents cultivated with cacao (Theobroma cacao L. - Malvaceae, for which increasing doses (0 - 1 - 3 - 5 - 7 - 9 -11 Mg/ha of dolomite lime (Ca M g (CO32 and calcium carbonate (CaCO3 were used, in order to establish the type and amount of liming material (ME with better reactivity, and the one that is better favored with the acidity changes: pH, Al3+, H+, total acidity. Models to estimate the ME dose needed to manage the soil in order to obtain the desired pH (≥5.5 were generated. Sub-sequently, the soil was then limed under field conditions and pH, Al3+, Al in solution (Alsol, aluminum saturation (SAI, cation exchange capacity (CEC and N, P, K, Ca, Mg, Zn, Cu, B, Fe and Mn availability were evaluated. The results show that the greatest reaction of liming materials in these soils occurs after 60 days; applications of 7 Mg/ha allowed to raise the pH from 5.5 to 6.0 and decreases Al and Fe levels. These changes improved the CECand nutrient availability (Ca, Mg, P, Zn for cacao without affecting other nutrients such as N and K.

  1. /Cu-Al System

    Science.gov (United States)

    Kish, Orel; Froumin, Natalya; Aizenshtein, Michael; Frage, Nachum

    2014-05-01

    Wettability and interfacial interaction of the Ta2O5/Cu-Al system were studied. Pure Cu does not wet the Ta2O5 substrate, and improved spreading is achieved when relatively a high fraction of the active element (~40 at.% Al) was added. The Al2O3 and AlTaO4 phases were observed at the Ta2O5/Cu-Al interface. A thermodynamic evaluation allowed us to suggest that the lack of wetting bellow 40 at.% Al is due to the presence of a native oxide, which covers the drop. The conditions of the native oxide decomposition and the formation of the volatile Al2O suboxide strongly depend on the vacuum level during sessile drop experiments and the composition of the Cu-Al alloy. In our case, Al contents greater than 40% provides thermodynamic conditions for the formation of Al2O (as a result of Al reaction with Al2O3) and the drop spreading. It was suggested that the final contact angle in the Ta2O5/Cu-Al system (50°) is determined by Ta adsorption on the newly formed alumina interlayer.

  2. Synthesis of core-shell AlOOH hollow nanospheres by reacting Al nanoparticles with water

    Science.gov (United States)

    Lozhkomoev, A. S.; Glazkova, E. A.; Bakina, O. V.; Lerner, M. I.; Gotman, I.; Gutmanas, E. Y.; Kazantsev, S. O.; Psakhie, S. G.

    2016-05-01

    A novel route for the synthesis of boehmite nanospheres with a hollow core and the shell composed of highly crumpled AlOOH nanosheets by oxidizing Al nanopowder in pure water under mild processing conditions is described. The stepwise events of Al transformation into boehmite are followed by monitoring the pH in the reaction medium. A mechanism of formation of hollow AlOOH nanospheres with a well-defined shape and crystallinity is proposed which includes the hydration of the Al oxide passivation layer, local corrosion of metallic Al accompanied by hydrogen evolution, the rupture of the protective layer, the dissolution of Al from the particle interior and the deposition of AlOOH nanosheets on the outer surface. In contrast to previously reported methods of boehmite nanoparticle synthesis, the proposed method is simple, and environmentally friendly and allows the generation of hydrogen gas as a by-product. Due to their high surface area and high, slit-shaped nanoporosity, the synthesized AlOOH nanostructures hold promise for the development of more effective catalysts, adsorbents, vaccines and drug carriers.

  3. Objective determination of pH thresholds in the analysis of 24 h ambulatory oesophageal pH monitoring

    NARCIS (Netherlands)

    Weusten, B. L.; Roelofs, J. M.; Akkermans, L. M.; vanBerge-Henegouwen, G. P.; Smout, A. J.

    1996-01-01

    In 24 h oesophageal pH monitoring, pH 4 is widely but arbitrarily used as the threshold between reflux and non-reflux pH values. The aim of the study was to define pH thresholds objectively, based on Gaussian curve fitting of pH frequency distributions. Single-channel 24 h oesophageal pH monitoring

  4. Aussprache als motorische Fertigkeit

    DEFF Research Database (Denmark)

    Bonner, Maria

    2013-01-01

    Authentische Aussprache gilt im Fremdsprachenunterricht als schwer erreichbares Ziel, fremdsprachlicher Akzent wird als nahezu unvermeidbar gesehen. Weder die Hypothese einer kritischen Periode für den Erwerb einer authentischen Aussprache noch das Konzept der Fossilierung im Sprachlernprozess...

  5. Genetic Testing for ALS

    Science.gov (United States)

    ... In Your Community Advocate Get Involved Donate Familial Amyotrophic Lateral Sclerosis (FALS) and Genetic Testing By Deborah Hartzfeld, MS, CGC, Certified Genetic Counselor Familial ALS Most of the time ALS is not inherited. ...

  6. Initial Symptoms of ALS

    Science.gov (United States)

    ... Chapters Certified Centers and Clinics Support Groups About ALS About Us Our Research In Your Community Advocate ... Diagnosis En español Symptoms The initial symptoms of ALS can be quite varied in different people. One ...

  7. Amyotrophic Lateral Sclerosis (ALS)

    Science.gov (United States)

    ... cognitive problems involving word fluency, decision-making, and memory. Most cases of ALS happen ... and edaravone have approved by the Food and Drug Administration (FDA) to treat ALS. Riluzole ...

  8. Hybrid density functional study on the photocatalytic properties of AlN/MoSe2, AlN/WS2, and AlN/WSe2 heterostructures

    Science.gov (United States)

    Wang, Guangzhao; Dang, Suihu; Zhang, Peng; Xiao, Shuyuan; Wang, Cuihong; Zhong, Mingmin

    2018-01-01

    Hybrid density functional has been adopted to theoretically investigate the structural, electronic, and optical properties of AlN/MoSe2, AlN/WS2, and AlN/WSe2 heterostructures with the consideration of effects of strains and pH so as to explore their potential visible light photocatalytic activities for water splitting. AlN/MoSe2, AlN/WS2, and AlN/WSe2 heterostructures with proper strains are energetically favorable due to the good lattice mismatch and the interface adhesion energies between the constituent monolayers. The charge accumulation/depletion around the interfaces of these heterostructures are beneficial for the generation and separation of photogenerated carriers, which is also favorable for improving the photocatalytic activities. Through adjusting the strains and the pH of the electrolyte, the AlN/MoSe2, AlN/WS2, and AlN/WSe2 heterostructures could own suitable bandgaps for absorbing visible light and appropriate band edge positions with respect to water redox levels for the spontaneous generation of hydrogen and oxygen. The band edge positions of AlN/MoSe2, AlN/WS2, and AlN/WSe2 heterostructures are thermodynamically feasible for over water splitting when the pHs of the electrolyte are respectively around 13, in the range of 4.5–8.1, and greater than 10.7. These findings pave a way to design the efficient AlN-based heterostructures for visible light photocatalytic water splitting.

  9. El injerto en tomate (Solanum licopersicum Mill. alternativa al cambio climático

    Directory of Open Access Journals (Sweden)

    Santiago Maradiaga

    2017-03-01

    Full Text Available En la actualidad la producción de hortalizas a campo abierto en Honduras se ha vuelto difícil para poder concluir el ciclo vegetativo por las inclemencias del cambio climático que en la mayoría de las áreas con potencial para establecer esto cultivos sobre todo las solanáceas y cucurbitáceas son afectados por enfermedades de origen telúrico. Estos organismos causan considerables pérdidas en los rendimientos. El injerto herbáceo es una práctica cultural que confiere a las plantas una mayor tolerancia frente a los factores abióticos (temperatura, salinidad, estrés hídrico, etc.. En la Universidad Nacional de Agricultura se ha venido investigando con esta técnica a cieloabierto con resultados aceptables sin desmejorar los rendimientos y calidad. Se evaluó el comportamiento de dos portainjertos criollos en tomate con dos variedades de uso común en los productores Pony y Belfas donde los tratamientos fueron T1 (Cherry/Pony, T2 (Cherry/Belfast, T3 (Belfast/Pony, T4 (Pony y T5 (Belfast. Se utilizó un diseño en bloques completos al azar con tres repeticiones, las variables evaluadas fueron: Porcentaje de pegue,compatibilidad, altura de planta, días a floración, diámetro de tallo, calibres de fruto, grados brix en el fruto, biomasafresca de la raíz, numero de frutos por planta y rendimiento. Los resultados obtenidos para todas las variables muestra que las plantas injertadas mostraron mayores valores que las no injertadas, resaltando rendimiento donde el T1 reporto 60 ton/ha en relación al testigo 40 ton/ha.

  10. Amyotrophic lateral sclerosis (ALS)

    Science.gov (United States)

    Lou Gehrig disease; ALS; Upper and lower motor neuron disease; Motor neuron disease ... One out of 10 cases of ALS is due to a genetic defect. The cause is unknown in most other cases. In ALS, motor nerve cells (neurons) waste away ...

  11. Abiodun et al (19)

    African Journals Online (AJOL)

    DELL

    2018-03-01

    Mar 1, 2018 ... carboxymethylation) and enzymatic technique. (Abbas et al., 2010; Jyothi et al., 2013). Modification of other starches from corn, cassava, potato and some yam ..... release of water from the polymeric network. (syneresis). The water thus released leaves the starch gel with a sponge-like texture. Abiodun et al.

  12. Esophageal pH monitoring (image)

    Science.gov (United States)

    Esophageal pH monitoring is a test that measures how often and how long stomach acid is entering the esophagus. ... to a monitor which records the level of acidity in the esophagus. The patient records symptoms and ...

  13. Fetal scalp pH testing

    Science.gov (United States)

    Sometimes fetal heart monitoring doesn't provide enough information about the well-being of a baby. In these cases, testing the scalp pH can help the doctor decide whether the fetus is getting enough oxygen ...

  14. pH regulation in anoxic plants.

    Science.gov (United States)

    Felle, Hubert H

    2005-09-01

    pH regulation is the result of a complex interaction of ion transport, H+ buffering, H+-consuming and H+-producing reactions. Cells under anoxia experience an energy crisis; an early response thereof (in most tissues) is a rapid cytoplasmic acidification of roughly half a pH unit. Depending on the degree of anoxia tolerance, this pH remains relatively stable for some time, but then drops further due to an energy shortage, which, in concert with a general breakdown of transmembrane gradients, finally leads to cell death unless the plant finds access to an energy source. In this review the much-debated origin of the initial pH change and its regulation under anoxia is discussed, as well as the problem of how tissues deal with the energy crisis and to what extent pH regulation and membrane transport from and into the vacuole and the apoplast is a part thereof. It is postulated that, because a foremost goal of cells under anoxia must be energy production (having an anaerobic machinery that produces insufficient amounts of ATP), a new pH is set to ensure a proper functioning of the involved enzymes. Thus, the anoxic pH is not experienced as an error signal and is therefore not reversed to the aerobic level. Although acclimated and anoxia-tolerant tissues may display higher cytoplasmic pH than non-acclimated or anoxia-intolerant tissues, evidence for an impeded pH-regulation is missing even in the anoxia-intolerant tissues. For sufficient energy production, residual H+ pumping is vital to cope with anoxia by importing energy-rich compounds; however it is not vital for pH-regulation. Whereas the initial acidification is not due to energy shortage, subsequent uncontrolled acidosis occurring in concert with a general gradient breakdown damages the cell but may not be the primary event.

  15. Effect of two mouthwashes on salivary ph.

    Science.gov (United States)

    Belardinelli, Paola A; Morelatto, Rosana A; Benavidez, Tomás E; Baruzzi, Ana M; López de Blanc, Silvia A

    2014-01-01

    To analyze the effect of two mouthwashes on salivary pH and correlate it with age, buffer capacity and saliva flow rate in healthy volunteers, a crossover phase IV clinical study involving three age-based groups was designed. Two commercial mouthwashes (MW), Cool Mint ListerineR (MWa) and Periobacter R (MWb) were used. The unstimulated saliva of each individual was first characterized by measuring flow rate, pH, and buffer capacity. Salivary pH was evaluated before rinsing with a given MW, immediately after rinsing, 5 minutes later, and then every 10 min (at 15, 25, 35 min) until the baseline pH was recovered. Paired t-test, ANOVA with a randomized block design, and Pearson correlation tests were used. Averages were 0.63 mL/min, 7.06, and 0.87 for flow rate, pH, and buffer capacity, respectively. An immediate significant increase in salivary pH was observed after rinsing, reaching average values of 7.24 (MWb) and 7.30 (MWa), which declined to an almost stable value 15 minutes. The great increase in salivary pH, after MW use shows that saliva is a dynamic system, and that the organism is capable of responding to a stimulus with changes in its composition. It is thus evident that pH of the external agent alone is not a good indicator for its erosive potential because biological systems tend to neutralize it. The results of this study enhance the importance of in vivo measurements and reinforce the concept of the protective action of saliva.

  16. Enhanced fluoride adsorption using Al (III) modified calcium hydroxyapatite

    International Nuclear Information System (INIS)

    Nie, Yulun; Hu, Chun; Kong, Chuipeng

    2012-01-01

    Highlights: ► Al modified hydroxyapatite possessed a higher defluoridation capacity of 32.57 mg/g. ► Hydroxyl groups on the surface of Al-HAP was the adsorption sites for F − removal. ► Enhanced F − removal over Al-HAP was attributed to the modification with aluminum. - Abstract: Aluminum-modified hydroxyapatite (Al-HAP) was prepared and characterized using XRD and BET analyses. Al-HAP possessed higher defluoridation capacity (DC) of 32.57 mgF − /g than unmodified hydroxyapatite (HAP) which showed a DC of 16.38 mgF − /g. The effect of Al/Ca atomic ratio in Al-HAP, solution pH and co-existing anions was further studied. The results indicated that the adsorption data could be well described by the Langmuir isotherm model and the adsorption kinetic followed the pseudo-second-order model. The pH changes during the adsorption process suggested that the -OH on the surface of Al-HAP was the adsorption sites. The more adsorption sites were formed on Al modified HAP, which possessed abundant surface hydroxyl groups, resulting in higher efficiency of F − removal. Thermodynamic parameters such as ΔG°, ΔH° and ΔS° were calculated in order to understand the nature of adsorption process. The results revealed that the adsorption reaction was a spontaneous and endothermic process.

  17. Efeitos da salinidade da água de irrigação na brotação e desenvolvimento inicial da cana-de-açúcar (Saccharum spp e em solos com diferentes níveis texturais Effects of irrigation water salinity upon the sprouting and initial development of sugar cane (Saccharum spp and on soils with different textural levels

    Directory of Open Access Journals (Sweden)

    Márcio José de Santana

    2007-10-01

    Full Text Available Foram avaliados os efeitos de diferentes concentrações de sal na água de irrigação, no desenvolvimento inicial da cana-de-açúcar, cultivar SP80-1842, cultivada em solos com diferentes níveis texturais. O experimento foi conduzido em casa-de-vegetação do Departamento de Engenharia da Universidade Federal de Lavras, em Lavras, MG. A finalidade do cultivo em ambiente protegido foi de possibilitar os tratamentos de níveis de sal na água de irrigação, sem a interferência das precipitações pluviométricas. Os tratamentos consistiram em quatro níveis de salinidade da água de irrigação (condutividade elétrica de 0,10; 2,0; 5,0 e 8,0 dS m-1, e três classes texturais de solo (texturas arenosa, média e argilosa, totalizando doze tratamentos e caracterizando um delineamento inteiramente casualizado (DIC, em esquema fatorial de 4 X 3, com oito repetições. No início e após experimentação, foram coletadas amostras dos solos para obtenção da condutividade elétrica do extrato saturado, retratando o efeito da salinidade da água de irrigação sobre os tipos de solo. Aos 38 dias após plantio das gemas, obteve-se a massa seca da raiz e da parte aérea, sendo que, durante a experimentação foram contados, diariamente, o número de gemas que brotavam em cada vaso. Os resultados mostraram que a cana-de-açúcar, cultivar SP80-1842, é sensível a salinidade da água de irrigação, durante sua fase inicial de cultivo. Todos os parâmetros vegetativos foram reduzidos com aumento da salinidade da água de irrigação. Houve um aumento da salinidade do solo em virtude do aumento da condutividade elétrica da água de irrigação. As maiores médias dessas variáveis foram obtidas no solo de textura média.The different concentrations of salt in the irrigation water on the initial development of sugar cane, cultivar SP80-1842, grown in soils with different textural levels were evaluated. The experiment was conducted in a greenhouse of

  18. Sol-gel synthesis of ZnO transparent conductive films: The role of pH

    Science.gov (United States)

    Addonizio, Maria Luisa; Aronne, Antonio; Daliento, Santolo; Tari, Orlando; Fanelli, Esther; Pernice, Pasquale

    2014-06-01

    The sol-gel synthesis of undoped and B- or Al-doped ZnO thin films were critically examined with particular reference to the influence of the pH of the reaction medium on some of their specific characteristics, such as thickness, morphology, doping level and optical properties, in view of their application in the photovoltaic field. Using triethanolamine (TEA) as chelating agent, a range of basic pH from 7.66 to 8.76 was explored starting from a very concentrated zinc acetate dehydrate (ZAD) solution in ethanol, [Zn2+] = 1.0 M, and keeping the ZAD/TEA = 1. A more basic environment gives more porous films whose thickness and crystallinity are higher than those achieved at lower pH. It was found that the morphology, as well as the sheet resistance (Rs) of films, depends on both pH and doping. Increasing the pH the Rs decreases for both undoped and doped films. At a certain pH undoped films exhibit a granular microstructure and lower Rs than B- or Al-doped films which exhibit a finer texture, characterized by a lower porosity. Optical properties strongly depend on the pH as well. Increasing the pH, a noticeable blue shift effect was observed, that was attributed mainly to structural changes and to a lesser extent to the Burnstein-Moss effect.

  19. PhD Education Outcomes: Results of a National Survey of Nursing PhD Alumni.

    Science.gov (United States)

    Ellenbecker, Carol Hall; Nwosu, Chizoba; Zhang, Yuqing; Leveille, Suzanne

    A national survey was conducted to examine the relationship between individual students' experiences and nursing PhD program characteristics and program outcomes. In light of the shortage of doctorally prepared nurse scientists and a growth in nursing PhD programs, an examination of the PhD nursing education experience in relation to educational outcomes is timely. Data were collected from graduates of a 50 percent random sample of nursing PhD programs in the United States. Graduates who had worked as research assistants, attended classroom-based programs, and worked as a nurse no more than 12 hours per week during their PhD education were more likely to have successful publication records and receive external research grant funding than graduates who did not have these experiences. On the basis of traditionally accepted measures of research productivity, our results indicate that nursing PhD programs have limited success in producing nurse researchers.

  20. pH. Training Module 5.305.2.77.

    Science.gov (United States)

    Kirkwood Community Coll., Cedar Rapids, IA.

    This document is an instructional module package prepared in objective form for use by an instructor familiar with pH, measurement of pH with a pH meter and maintenance of pH meter electrodes. Included are objectives, instructor guides, student handouts and transparency masters. This module considers the definition of pH, types of electrodes and…

  1. 143 - 148_Makeri et al.

    African Journals Online (AJOL)

    USER

    2015-06-01

    Jun 1, 2015 ... Yuan et al., 2003), antimicrobial activity (Sundarrao et al., 1993; Betancur-Galvis et al., 1999; Takashi et al., 2006), anti-parasitic, anti-malarial activities (Alali et al., 1998; Jaramillo et al., 2000; Luna et al.,. 2005). This study evaluates the antibacterial activity of extract of stem –bark and leaf extracts of Annona.

  2. Pornographie als Metapher

    Directory of Open Access Journals (Sweden)

    Caroline Schubarth

    2010-02-01

    Full Text Available In diesem Artikel werden unterschiedliche metaphorische Verwendungen des Pornografiebegriffs und deren Implikationen untersucht. Während die Existenz von Pornografie der feministischen Anti-Porno-Bewegung als Erklärung für die anhaltende Diskriminierung von Frauen in westlichen Gesellschaften dient, nutzen rechtskonservative Kräfte den Pornografievorwurf als Rechtfertigung für die Zensur von als deviant empfundenen Identitäten und sexuellen Praktiken.

  3. Exchangeable hydrogen explains the pH of spodosol Oa horizons

    Science.gov (United States)

    Ross, D.S.; David, M.B.; Lawrence, G.B.; Bartlett, R.J.

    1996-01-01

    The chemistry of extremely acid Oa horizons does not conform to traditional pH, Al, and base saturation relationships. Results from two separate studies of northeastern U.S. forested soils were used to investigate relationships between pH in water or dilute salt solutions and other soil characteristics. In Oa horizons with pH below 4, soil pH in dilute CaCl2 solution was correlated with exchangeable H+ measured either by titration (r = -0.88, P = 0.0001, n = 142) or by electrode (r = -0.89, P = 0.0001, n = 45). Exchangeable H+ expressed as a percentage of the cation-exchange capacity (CEC) was linear with pH and showed similar slopes for data from both studies. For all samples, pHw = 4.21 - 1.80 x H+/CEC (R2 = 0.69, n = 194). The reciprocal of the H+/CEC ratio is base saturation with Al added to the bases. Because of the low pH, exchangeable Al does not appear to behave as an acid. Exchangeable H+ remains an operationally defined quantity because of the difficulty in separating exchange and hydrolysis reactions. In a variety of neutral-salt extractants, concentration of H+ were correlated with 0.1 M BaCl2-exchangeable H+ (r > 0.91, P = 0.0001, n = 26) regardless of the strength of the extract. Nine successive extractions with 0.33 mM CaCl2 removed more H+ than was removed by single batch extractions with either 1 M KCl or 0.1 M BaCl2 (average H+ of 70, 43, and 49 mmol kg-1, respectively for 26 samples). The data showed little difference in the chemical behavior of Oa horizons from a variety of geographical sites and vegetation types.

  4. The final frontier of pH and the undiscovered country beyond.

    Directory of Open Access Journals (Sweden)

    Wojciech Bal

    Full Text Available The comparison of volumes of cells and subcellular structures with the pH values reported for them leads to a conflict with the definition of the pH scale. The pH scale is based on the ionic product of water, K(w = [H(+]×[OH(-].We used K(w [in a reversed way] to calculate the number of undissociated H(2O molecules required by this equilibrium constant to yield at least one of its daughter ions, H(+ or OH(- at a given pH. In this way we obtained a formula that relates pH to the minimal volume V(pH required to provide a physical meaning to K(w, V(pH=10(pH-pK(w/2 x 10(pK(w/2/N(A (where N(A is Avogadro's number. For example, at pH 7 (neutral at 25°C V(pH =16.6 aL. Any deviation from neutral pH results in a larger V(pH value. Our results indicate that many subcellular structures, including coated vesicles and lysosomes, are too small to contain free H(+ ions at equilibrium, thus the definition of pH based on K(w is no longer valid. Larger subcellular structures, such as mitochondria, apparently contain only a few free H(+ ions. These results indicate that pH fails to describe intracellular conditions, and that water appears to be dissociated too weakly to provide free H(+ ions as a general source for biochemical reactions. Consequences of this finding are discussed.

  5. The Final Frontier of pH and the Undiscovered Country Beyond

    Science.gov (United States)

    Bal, Wojciech; Kurowska, Ewa; Maret, Wolfgang

    2012-01-01

    The comparison of volumes of cells and subcellular structures with the pH values reported for them leads to a conflict with the definition of the pH scale. The pH scale is based on the ionic product of water, K w = [H+]×[OH−].We used K w [in a reversed way] to calculate the number of undissociated H2O molecules required by this equilibrium constant to yield at least one of its daughter ions, H+ or OH− at a given pH. In this way we obtained a formula that relates pH to the minimal volume VpH required to provide a physical meaning to K w, (where N A is Avogadro’s number). For example, at pH 7 (neutral at 25°C) VpH = 16.6 aL. Any deviation from neutral pH results in a larger VpH value. Our results indicate that many subcellular structures, including coated vesicles and lysosomes, are too small to contain free H+ ions at equilibrium, thus the definition of pH based on K w is no longer valid. Larger subcellular structures, such as mitochondria, apparently contain only a few free H+ ions. These results indicate that pH fails to describe intracellular conditions, and that water appears to be dissociated too weakly to provide free H+ ions as a general source for biochemical reactions. Consequences of this finding are discussed. PMID:23049874

  6. Contribuição de solutos orgânicos e inorgânicos no ajustamento osmótico de pinhão-manso submetido à salinidade Contribution of organic and inorganic solutes to osmotic adjustment of physic nut under salinity

    Directory of Open Access Journals (Sweden)

    Evandro Nascimento da Silva

    2009-05-01

    Full Text Available O objetivo deste trabalho foi avaliar a acumulação de solutos orgânicos e inorgânicos e suas contribuições para o ajustamento osmótico de folhas de pinhão-manso (Jatropha curcas L. submetido à salinidade. O experimento foi conduzido em delineamento experimental inteiramente casualizado, com cinco tratamentos (0, 25, 50, 75 e 100 mmol L-1 de NaCl e quatro repetições. As plantas foram cultivadas hidroponicamente em casa de vegetação, em condições controladas de fotoperíodo (12 horas, temperatura (média de 28ºC e umidade relativa do ar (média de 65%, com radiação fotossinteticamente ativa máxima média de 700 µmol m-1 s-1. O potencial osmótico das folhas decresceu progressivamente e variou de -0,84 a -2,05 MPa, enquanto o conteúdo relativo de água aumentou nos tratamentos com 75 e 100 mmol L-1. Os íons Na+ e Cl- foram os mais importantes, em termos quantitativos, e contribuíram com cerca de 52 e 20%, respectivamente, para o ajustamento osmótico das folhas de plantas tratadas com NaCl. A contribuição do K+ decresceu de modo acentuado e foi de 17 e 5% nos tratamentos com 25 e 100 mmol L-1 de NaCl. A contribuição média dos solutos orgânicos, açúcares, aminoácidos, glicina betaína e prolina, foi de 5,5, 6, 4 e 0,03%, respectivamente. As folhas de pinhão-manso ajustam-se osmoticamente em presença de salinidade, e mantêm bom nível de hidratação, principalmente por meio da acumulação de Na+ e Cl-. A glicina betaína tem papel quantitativo mais importante do que a prolina no ajustamento osmótico, tanto em presença quanto em ausência de salinidade.The objectives of this work were to evaluate the organic and inorganic solutes accumulation and measure their contribution to the osmotic adjustment of physic nut (Jatropha curcas L. leaves under salinity. The experiment was carried out using a completely randomized design with five treatments (0, 25, 50, 75, and 100 mmol L-1 of NaCl and four replications. Plants

  7. Electron irradiation effect on short-range ordering in Cu-Al and Ag-Al alloys

    International Nuclear Information System (INIS)

    Kulish, N.P.; Mel'nikova, N.A.; Petrenko, P.V.; Ryabishchuk, A.L.; Tatarov, A.A.

    1990-01-01

    Method of X-ray diffuse scattering is used to study short-range order variation in Cu-Al and Ag-Al alloys under radiation effect and the following heat treatment. Irradiation was carried out at -40 deg C by 1.6 MeV electrons, fluence of 5x10 7 cm -2 and 0.5 MeV gamma-rays, the dose being 10 7 pH

  8. PhD supervisor-student relationship

    Directory of Open Access Journals (Sweden)

    FILIPE PRAZERES

    2017-10-01

    Full Text Available The relationship between the PhD supervisor and the PhD student is a complex one. When this relationship is neither effective nor efficient, it may yield negative consequences, such as academic failure (1. The intricacy of the supervisor-student relationship may be in part comparable to the one between the physician and his/her patient [see, for example (2]. Both interactions develop over several years and the players involved in each relationship – PhD supervisor-student on the one side and physician-patient on the other side – may at some point of the journey develop different expectations of one another [see, for example (3, 4] and experience emotional distress (5. In both relationships, the perceived satisfaction with the interaction will contribute to the success or failure of the treatment in one case, and in the other, the writing of a thesis. To improve the mentioned satisfaction, not only there is a need to invest time (6, as does the physician to his/ her patients, but also both the supervisor and the PhD student must be willing to negotiate a research path to follow that would be practical and achievable. The communication between the physician and patient is of paramount importance for the provision of health care (7, and so is the communication between the supervisor and PhD student which encourages the progression of both the research and the doctoral study (8. As to a smooth transition to the postgraduate life, supervisors should start thinking about providing the same kind of positive reinforcement that every student is used to experience in the undergraduate course. The recognition for a job well done will mean a lot for a PhD student, as it does for a patient. One good example is the increase in medication compliance by patients with high blood pressure who receive positive reinforcement from their physicians (9. Supervisors can organize regular meetings for (and with PhD students in order to not only discuss their projects

  9. Das sogenannte "Kinderdefizit" als Phänomen der Archäologie des Mittelalters

    DEFF Research Database (Denmark)

    Atzbach, Rainer

    2009-01-01

    In German archaeology the problem of statistical lack of children in medieval graveyards have been discussed intensively. Although it seems to be a consequence of misinterpretation of archaeological data there is an unexplained increasing share of children between the 10th and the 16th century ac...... according to shoes....

  10. Sprachliche Entfremdung als Phänomen des Umbruchs in der früheren DDR

    Directory of Open Access Journals (Sweden)

    H. Ester

    1997-04-01

    The Federal Republic of Germany and the German Democratic Republic have not yet grown into a coherent unity since the political unification of the two 'Germanies' in 1990. The reason for the lack of sympathy and the irritations on both sides possibly lies in the fact that the actual developments did not meet the general expectations during the first years after 1990. The thesis of my article is that the more profound reasons for the alienation between the western and the eastern part of Germany can be found in the little interest on the western side for the developments in the GDR from 1949 until the fall of the Wall in 1989. The lack of interest in the forty years of the GDR’s existence finds its expression in the alienation of language. In order to improve communication between the Germans of both spheres, the reading of literary texts from the former GDR by members of the entire new Federal Republic of Germany can be a reconcilliatory device. In this way the reader can obtain insight into forty years of history.

  11. Improving Aspergillus niger as a production host through manipulation of pH responding transcription factors

    DEFF Research Database (Denmark)

    Poulsen, Lars; Bruno, K.S.; Thykær, Jette

    ). In the present study the effect of modulation of transcription factors in Aspergillus niger, which is an industrially important micro-organism used in various processes including organic acid and enzyme production, was investigated. The strategy described in this work focuses on regulation connected to pH....... It was chosen as an important process parameter, due to its significant influences on both organic acid and enzyme production. A previous transcription analysis identified several putative transcription factors with pH responding behavior (Andersen et al., 2009). A number of these genes were selected as targets...

  12. CONTINUOUS MEASUREMENT OF THE CYTOPLASMIC PH IN LACTOCOCCUS-LACTIS WITH A FLUORESCENT PH INDICATOR

    NARCIS (Netherlands)

    MOLENAAR, D; ABEE, T; KONINGS, WN

    1991-01-01

    The cytoplasmic pH of Lactococcus lactis was studied with the fluorescent pH indicator 2',7'-bis-(2-carboxyethyl)-5 (and-6)-carboxyfluorescein (BCECF). A novel method was applied for loading bacterial cells with BCECF, which consists of briefly treating a dense cell suspension with acid in the

  13. Differential genotoxicity of diphenyl diselenide (PhSe2 and diphenyl ditelluride (PhTe2

    Directory of Open Access Journals (Sweden)

    Daiane Francine Meinerz

    2014-03-01

    Full Text Available Organoselenium compounds have been pointed out as therapeutic agents. In contrast, the potential therapeutic aspects of tellurides have not yet been demonstrated. The present study evaluated the comparative toxicological effects of diphenyl diselenide (PhSe2 and diphenyl ditelluride (PhTe2 in mice after in vivo administration. Genotoxicity (as determined by comet assay and mutagenicicity were used as end-points of toxicity. Subcutaneous administration of high doses of (PhSe2 or (PhTe2 (500 µmol/kg caused distinct genotoxicity in mice. (PhSe2 significantly decreased the DNA damage index after 48 and 96 h of its injection (p < 0.05. In contrast, (PhTe caused a significant increase in DNA damage (p < 0.05 after 48 and 96 h of intoxication. (PhSe2 did not cause mutagenicity but (PhTe2 increased the micronuclei frequency, indicating its mutagenic potential. The present study demonstrated that acute in vivo exposure to ditelluride caused genotoxicity in mice, which may be associated with pro-oxidant effects of diphenyl ditelluride. In addition, the use of this compound and possibly other related tellurides must be carefully controlled.

  14. PhD Dissertations Tesi di dottorato

    Directory of Open Access Journals (Sweden)

    Redazione Reti Medievali (a cura di

    2004-06-01

    Full Text Available

    Report of PhD Dissertations.

    Francesco Barone

    Istituzioni, società ed economia a Catania nel tardo medioevo (XIV-XV secolo, Tesi di dottorato in Storia medievale (XVI ciclo, Università degli Studi di Firenze, 2004

     

    Laura Berti Ceroni

    Il territorio e le strutture di Cesarea e Classe tra tarda antichità e alto medioevo in rapporto con Ravenna, Tesi di dottorato di ricerca in Storia e Informatica, Università degli studi di Bologna, 2002-2003.

     

    Marco Bicchierai

    Poppi dalla signoria dei conti Guidi al vicariato del Casentino (1360-1480, Tesi di dottorato in Storia medievale (XIV ciclo, Università degli Studi di Firenze, 2004

     

    Emanuela Garimberti

    Spatiosa ad habitandum loca. Luoghi e identità nella Historia Langobardorum di Paolo Diacono, Tesi di dottorato in Storia medievale (XV ciclo, Università degli Studi di Bologna, 2004

     

    Lorenzo Tanzini

    Sistemi normativi e pratiche istituzionali a Firenze dalla fine del XIII all’inizio del XV secolo, Tesi di dottorato di ricerca in Storia medievale (XVI ciclo, Università degli Studi di Firenze, 2004

     

    Stefania Tarquini

    Pellegrinaggio e asseto urbano di Roma, Tesi di dottorato di ricerca in Storia dei centri, delle vie e della cultura dei pellegrinaggi nel Medioevo euro mediterraneo (XV ciclo, Università degli studi di Lecce, 2003

    Segnalazione di tesi di dottorato.

    Francesco Barone

    Istituzioni, società ed economia a Catania nel tardo medioevo (XIV-XV secolo, Tesi di dottorato in Storia medievale (XVI ciclo, Università degli Studi di Firenze, 2004

     

    Laura Berti Ceroni

  15. Alles is al uitgevonden

    NARCIS (Netherlands)

    J.G.M. van Marrewijk (Charles)

    1996-01-01

    textabstractDe voordelen van vrijhandel zijn zeer beperkt, al-thans als we de empirische schattingen van vooraanstaande economen en internationale organisaties mogen geloven. Zo worden de voordelen van liberalisatie voor de Europese Unie geraamd op ongeveer 0,5% van het bnp 1. De door het IMF

  16. ALS (Amyotrophic Lateral Sclerosis)

    Science.gov (United States)

    ... here Home » Disorders » Patient & Caregiver Education » Fact Sheets Amyotrophic Lateral Sclerosis (ALS) Fact Sheet What is amyotrophic lateral sclerosis? Who ... Where can I get more information? What is amyotrophic lateral sclerosis? Amyotrophic lateral sclerosis (ALS) is a group of ...

  17. Lukman et al. (5)

    African Journals Online (AJOL)

    DELL

    1 Civil Engineering Department, Obafemi Awolowo University, Ile-Ife- Nigeria and Corresponding author. 2Department of Water Resources and Environmental Engineering, Ahmadu Bello University, Samaru, Zaria- Nigeria s Department of Civil Engineering, University of Hafr Al-Batin, Hafr Al-Batin, Saudi Arabia.

  18. Taiwo et al (8)

    African Journals Online (AJOL)

    DELL

    gender equity (Waddington et al., 2009). These benefits act as barriers to transmission of diseases from the environment to the human body (Kosek et al., 2003). The disease burden that results from poor access to improved source of drinking water is significant; the WHO estimated that more than. 9% of the disease burden ...

  19. Adekola et al (7)

    African Journals Online (AJOL)

    Timothy Ademakinwa

    Orange Basin as part of oil exploration protocols. (van Der Spuy, 2003; Hirsch et al., 2009; Hirsch et al., 2010). ... in the determination of both oil and gas reservoirs and potential source rocks (Franca and Potter,. 1988). ...... opening. Geophysical Journal International. 168, 353-361. Franca, A.B., and Potter, P.E. 1988.

  20. Lukman et al. (5)

    African Journals Online (AJOL)

    DELL

    Keywords: Access to Safe Water Supply Technologies, Piped Water, Borehole, Millennium Development. Goals ... treated water to consumers (Ishaku et al., 2011). .... visited to ascertain access to safe water supply technologies. Lukman et al.: Effect of Selected Factors on Water Supply and Access to Safe Water in Nigeria ...

  1. Oloyede et al (19)

    African Journals Online (AJOL)

    Timade VENTURE

    field grasshopper) and Lirnicolaria oleira (small snails) feed on the leaflets of N. furcans.Herbivores feeding on some species of pteridophytes have been reported (Babayemi et al., 2006; Biplap and. Subir, 2007; Oloyede et al., 2008, 2010, 2012) as further evidence of nutritious value of some pteridophytes. The lethal dose ...

  2. Alimba et al (5)

    African Journals Online (AJOL)

    USER

    other countries. Numerous genotoxic and. c a r c i n o g e n i c c o m p o u n d s ; alkenylbenzenesestragole, methyleugenol, safrole, β-asarone, unsaturated pyrrolizidine, aromatic steroids, cytochalasin, concentricolide, are increasingly being reported in many of these medicinal botanicals(Qin et al., 2006; Rietjens et al.,.

  3. Adsorptie van Al-ionen aan het kleimineraal montmorilloniet

    NARCIS (Netherlands)

    Bruggenwert, M.G.M.

    1972-01-01

    The adsorption of aluminium ions onto sodium and calcium montmorillonite was studied. Under the experimental conditions (pH 3.5 and 5 and different total salt concentrations) the adsorbed aluminium ions were found to be in the form Al 3+, except when adsorbed onto calcium

  4. Chemical equilibrium modeling of organic acids, pH, aluminum, and iron in Swedish surface waters.

    Science.gov (United States)

    Sjöstedt, Carin S; Gustafsson, Jon Petter; Köhler, Stephan J

    2010-11-15

    A consistent chemical equilibrium model that calculates pH from charge balance constraints and aluminum and iron speciation in the presence of natural organic matter is presented. The model requires input data for total aluminum, iron, organic carbon, fluoride, sulfate, and charge balance ANC. The model is calibrated to pH measurements (n = 322) by adjusting the fraction of active organic matter only, which results in an error of pH prediction on average below 0.2 pH units. The small systematic discrepancy between the analytical results for the monomeric aluminum fractionation and the model results is corrected for separately for two different fractionation techniques (n = 499) and validated on a large number (n = 3419) of geographically widely spread samples all over Sweden. The resulting average error for inorganic monomeric aluminum is around 1 µM. In its present form the model is the first internally consistent modeling approach for Sweden and may now be used as a tool for environmental quality management. Soil gibbsite with a log *Ks of 8.29 at 25°C together with a pH dependent loading function that uses molar Al/C ratios describes the amount of aluminum in solution in the presence of organic matter if the pH is roughly above 6.0.

  5. Optoelectronic pH Meter: Further Details

    Science.gov (United States)

    Jeevarajan, Antony S.; Anderson, Mejody M.; Macatangay, Ariel V.

    2009-01-01

    A collection of documents provides further detailed information about an optoelectronic instrument that measures the pH of an aqueous cell-culture medium to within 0.1 unit in the range from 6.5 to 7.5. The instrument at an earlier stage of development was reported in Optoelectronic Instrument Monitors pH in a Culture Medium (MSC-23107), NASA Tech Briefs, Vol. 28, No. 9 (September 2004), page 4a. To recapitulate: The instrument includes a quartz cuvette through which the medium flows as it is circulated through a bioreactor. The medium contains some phenol red, which is an organic pH-indicator dye. The cuvette sits between a light source and a photodetector. [The light source in the earlier version comprised red (625 nm) and green (558 nm) light-emitting diodes (LEDs); the light source in the present version comprises a single green- (560 nm)-or-red (623 nm) LED.] The red and green are repeatedly flashed in alternation. The responses of the photodiode to the green and red are processed electronically to obtain the ratio between the amounts of green and red light transmitted through the medium. The optical absorbance of the phenol red in the green light varies as a known function of pH. Hence, the pH of the medium can be calculated from the aforesaid ratio.

  6. The Ph.D. Value Proposition

    Science.gov (United States)

    Cooper, Kenneth J.

    2012-01-01

    Atlanta University launched its doctor of arts in humanities (DAH) programs almost 40 years ago, and, since the 1988 merger with Clark College, Clark Atlanta University has continued to award the degrees. This fall, for the first time, its students will be able to earn Ph.D.s in humanities instead. In DAH programs around the country, there's been…

  7. Electrical Impedance Myography (EIM) in the Evaluation of the Tongue Musculature in Amyotrophic Lateral Sclerosis (ALS)

    Science.gov (United States)

    Shellikeri, Sanjana; Yunusova, Yana; Green, Jordan R.; Pattee, Gary L.; Berry, James D.; Rutkove, Seward B.; Zinman, Lorne

    2015-01-01

    Introduction Electrical impedance myography (EIM) quantifies muscle health and is used as a biomarker of muscle abnormalities in neurogenic and myopathic diseases. EIM has yet to be evaluated in the tongue musculature in people with amyotrophic lateral sclerosis (ALS), who often show clinical bulbar signs. Methods The lingual musculature of 19 subjects with motor neuron disease and 21 of normal participants were assessed using EIM, strength and endurance testing, and clinical observation. Results Tongue musculature in the ALS group was characterized by significantly smaller phase (Ph) and larger resistance (R) when compared to the healthy cohort. Ph and tongue endurance were correlated in the ALS group. Discussion EIM of tongue musculature could distinguish people with ALS from healthy controls. The demonstrated relationship between tongue function and Ph supports further testing of EIM of the tongue as a potential biomarker in ALS. PMID:25580728

  8. Influence of the pH on the accumulation of phosphate by red mud (a bauxite ore processing waste).

    Science.gov (United States)

    Castaldi, Paola; Silvetti, Margherita; Garau, Giovanni; Deiana, Salvatore

    2010-10-15

    In the present work we investigated the interactions established between red mud (RM) and phosphate anions (P) at pH 4.0, 7.0 and 10.0. The amount of P sorbed by RM (P-RM) increased as the pH decreased being equal to 4.871 mmol g(-1) at pH 4.0, 0.924 mmol g(-1) at pH 7.0, and 0.266 mmol g(-1) at pH 10.0. Sequential extractions' data of P-RM equilibrated at pH 4.0 and 7.0, suggested that the phosphate sorption at these pH values was mainly regulated by two different mechanisms that gave rise to a chemical adsorption on RM phases, and to the formation of metal phosphate precipitates. By contrast, at pH 10.0 the P-sorption was regulated by a chemisorption mechanism on Fe-Al phases of RM. These findings were supported by FT-IR analysis, which showed a broad band at 1114 and 1105 cm(-1) in P-RM spectra at pH 4.0 and 7.0 respectively, attributable to P-O(H) stretching nu(3)-modes associated to inner-sphere complexes of phosphate on Fe-Al phases, or alternatively to stretching vibrations of PO(4)(3-) tetrahedra, arising from a precipitate of aluminium phosphate. Importantly, the FT-IR spectroscopy showed a phosphate-promoted dissolution of tectosilicates, notably cancrinite and sodalite, in RM exchanged with phosphate at pH 4.0 and 7.0. 2010 Elsevier B.V. All rights reserved.

  9. Komolafe et al (8)

    African Journals Online (AJOL)

    USER

    fishing gears employed was gill net and fish traps. The gill net which measured 50 m in length and 3.4 m deep with ... net and the traps were removed, transferred into an ice chest and brought into the laboratory for processing. ..... Ecological Aspects of Fishes in Two. Reservoirs in Osun State, Nigeria. Ph.D. Thesis, Zoology ...

  10. August Reichensperger als Rechtspolitiker

    OpenAIRE

    Strauch, Dieter Prof. Dr.

    2006-01-01

    August Reichensperger, dessen Tätigkeit als Kölner Appellationsgerichtsrat, als Förderer der Fertigstellung des Kölner Domes und als Parlamentarier des Zentrums heute durch die Namensgebung für den Platz vor dem Kölner Oberlandesgericht geehrt wird, wurde 1808 in Koblenz geboren und wuchs bei seiner juristischen Ausbildung in das französisch/rheinische Recht hinein, das er zeitlebens gegen preußische Versuche, es durch altpreußisches Recht zu ersetzen, verteidigte. Er wurde Mitglied der ...

  11. Universitat popular al Cabanyal

    OpenAIRE

    Ribés Granell, Juan Miguel

    2012-01-01

    La intención es dotar al barrio de un gran espacio verde y de un edificio de interés para los vecinos que enriquezca al Cabanyal, ya que actualmente se encuentra en proceso de degradación. Se pretende desarrollar un proyecto que signifique una mejora en la predisposición del visitante, cubriendo sus necesidades. Al mismo tiempo, se busca crear un espacio arquitectónico que mejore la relación entre las actividades que incluye y su entorno. El proyecto está condicionado por cuatro aspectos fund...

  12. PhD on Track – designing learning for PhD students

    Directory of Open Access Journals (Sweden)

    Gunhild Austrheim

    2013-12-01

    Full Text Available Three years ago we started the project "Information Management for Knowledge Creation". The project was initiated to create online information literacy modules for PhD students. The result of our endeavours, PhD on Track, will be launched in May 2013. The initial stage of the project was mapping out the information behaviour of PhD students, as well as what services they require from the library through a literature review and a focus group study. The findings of these inquiries formed the knowledge base from which we developed our information literacy modules. Our paper will focus on the interaction between content production and user testing when creating PhD on Track. Methods: User testing has been employed throughout the production stage. We have tested navigation and organisation of the web site, content and usability. The project team have conducted expert testing. Analysis: The results from our user testing have played an important part in decisions concerning content production. Our working hypothesis was that the PhD students would want an encyclopaedic website, a place to quickly find answers. However, the user tests revealed that PhD students understood and expected the website to be learning modules. Conclusions: The PhD students in the tests agreed that a site such as this would be useful, especially to new PhD students. They also liked the design, but had some qualms with the level of information. They preferred shorter text, but with more depth. The students would likewise have preferred more practical examples, more illustrations and more discipline specific information. The current content of PhD on Track reflects the feedback from the user testing. We have retained initial ideas such as one section for reviewing and discovering research literature and one section for publishing PhD research work. In addition, we have included more practical examples to indicate efficient workflows or relevant actions in context. Illustrations

  13. Relation between pH in the Trunk and Face: Truncal pH Can Be Easily Predicted from Facial pH.

    Science.gov (United States)

    Kim, Sung Ae; Kim, Bo Ri; Chun, Mi Young; Youn, Sang Woong

    2016-04-01

    The clinical symptoms of facial and truncal acne differ. Skin surface acidity (pH), which is affected by sebum secretions, reflects the different clinical characteristics of the face and trunk. However, no studies have been conducted on truncal sebum production and skin pH. We evaluated the differences and relationship between pH values of the face and trunk. We also evaluated the relationship between pH and the quantity of sebum produced in the trunk. A total of 35 female patients clinically diagnosed with truncal acne were included. We measured pH on the face and truncal area using the Skin-pH-Meter PH 905®. We measured truncal sebum secretions using the Sebumeter SM 815®. Statistical analysis was performed to evaluate the correlations and differences between pH and sebum. Facial pH was significantly higher than chest and back pH values. The correlation between pH on the trunk and the face was significant. We used linear regression equations to estimate truncal pH using only measured pH from the chin. There was no significant relationship between truncal sebum secretion and pH. This was the first study that evaluated the differences and correlations between facial and truncal pH. We found that facial pH can predict truncal pH. In addition, we conclude that differences in pH and sebum secretion between the face and trunk are one of the reasons for differences in acne symptom at those sites.

  14. The pH of Enceladus' ocean

    Science.gov (United States)

    Glein, Christopher R.; Baross, John A.; Waite, J. Hunter

    2015-08-01

    Saturn's moon, Enceladus, is a geologically active waterworld. The prevailing paradigm is that there is a subsurface ocean that erupts to the surface, which leads to the formation of a plume of vapor and ice above the south polar region. The chemistry of the ocean is just beginning to be understood, but is of profound geochemical and astrobiological interest. Here, we determine the pH of the ocean using a thermodynamic model of carbonate speciation. Observational data from the Cassini spacecraft are used to make a chemical model of ocean water on Enceladus. The model suggests that Enceladus' ocean is a Na-Cl-CO3 solution with an alkaline pH of ∼11-12. The dominance of aqueous NaCl is a feature that Enceladus' ocean shares with terrestrial seawater, but the ubiquity of dissolved Na2CO3 suggests that soda lakes are more analogous to the Enceladus ocean. The high pH implies that the hydroxide ion should be relatively abundant, while divalent metals should be present at low concentrations owing to buffering by carbonates and phyllosilicates on the ocean floor. Carboxyl groups in dissolved organic species would be negatively charged, while amino groups would exist predominately in the neutral form. Knowledge of the pH improves our understanding of geochemical processes in Enceladus' ocean. The high pH is interpreted to be a key consequence of serpentinization of chondritic rock, as predicted by prior geochemical reaction path models; although degassing of CO2 from the ocean may also play a role depending on the efficiency of mixing processes in the ocean. Serpentinization leads to the generation of H2, a geochemical fuel that can support both abiotic and biological synthesis of organic molecules such as those that have been detected in Enceladus' plume. Serpentinization and H2 generation should have occurred on Enceladus, like on the parent bodies of aqueously altered meteorites; but it is unknown whether these critical processes are still taking place, or if

  15. Living organisms influence on environmental conditions: pH modulation by amphibian embryos versus aluminum toxicity.

    Science.gov (United States)

    Herkovits, Jorge; Castañaga, Luis Alberto; D'Eramo, José Luis; Jourani, Victoria Platonova

    2015-11-01

    The LC10, 50 and 90/24h of aluminum for Rhinella arenarum embryos at complete operculum stage were 0.55, 0.75 and 1mgAl(3+)/L respectively. Those values did not change significantly by expanding the exposure period till 168h. The aluminum toxicity was evaluated in different pH conditions by means of a citrate buffer resulting for instance, 1mgAl(3+)/L at pH 4, 4.1, 5 and 6 in 100%, 70%, 35% and 0% of lethality respectively. As an outstanding feature, the embryos changed the pH of the maintaining media both in the case of Al(3+) or citrate buffer treatments toward neutral. 10 embryos in 40mL of AMPHITOX solution were able to increase the pH from 4.2 to 7.05, a fact related with a metabolic shift resulting in an increase in nitrogen loss as ammonia. Our study point out the natural selection of the most resistant amphibian embryos both for pH or aluminum as well as the capacity of living organisms (as a population) to alter their chemical environment toward optimal conditions for their survival. As these facts occur at early life stages, it expand the concept that living organisms at ontogenic stages are biomarker of environmental signatures of the evolutionary process (Herkovits, 2006) to a global Onto-Evo concept which imply also the feedback mechanisms from living organisms to shape environmental conditions in a way that benefits them. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. De pH van waschvloeistoffen bij verschillende temperaturen

    NARCIS (Netherlands)

    Smit, R.; Hannewijk, J.

    1943-01-01

    De pH is een begrip, dat de laatste jaren in wasscherijkringen veel opgang heeft gemaakt; men spreekt van de pH van soda, metasilicaat enz. en in de literatuur wordt dikwijls aangegeven, dat men het beste kan wasschen bij pH 10,7, terwijl anderen alleen verklaren, dat de pH boven of beneden een

  17. EVALUATION OF A NEW CATHETER FOR ESOPHAGEAL PH MONITORING

    NARCIS (Netherlands)

    KUIT, JA; SCHEPEL, SJ; BIJLEVELD, CMA; KLEIBEUKER, JH

    A new catheter, provided with an Ion Sensitive Field Effect Transistor as a pH sensor and incorporating a reference electrode, was evaluated for esophageal pH recording. The pH-sensitivity was 54 mV/pH in vitro, with a linear response between pH 2 and pH 9. Clinical semi-ambulatory 24-hour

  18. Cartas al editor

    Directory of Open Access Journals (Sweden)

    Facultad de Medicina Revista

    1995-10-01

    Full Text Available Con respecto al ensayo "Evaluación del aprendizaje en la educación superior" de la Dra. Análida Pinilla / Ciencia y conciencia en la medicina colombiana / Farmacovigilancia: Una necesidad urgente

  19. Platt et al. 1988

    African Journals Online (AJOL)

    denise

    dependent values of chlorophyll concentration (Sathyendranath et al. 1995). This sub- surface chlorophyll structure needs to be extrapolated spatially and temporally for the estimation of integrated pigment content and primary production (Sathyen-.

  20. Advanced Light Source (ALS)

    Data.gov (United States)

    Federal Laboratory Consortium — The Advanced Light Source (ALS), a world leader in soft x-ray science, generates light in the wavelengths needed for examining the atomic and electronic structure of...

  1. Kulturmorphologie als Zivilisationskritik

    DEFF Research Database (Denmark)

    Peters, Rikke Alberg

    2010-01-01

    Der Untergang des Abendlandes wird oft als dasjenige Werk betrachtet, das am tiefsten die national gefärbte Gegenüberstellung von Kultur und Zivilisation in der Zwischenkriegszeit geprägt und propagiert hat. Wie auch bei anderen Autoren der Konservativen Revolution, vor allem bei Thomas Mann und...... Arthur Moeller van den Bruck, tritt der Begriff ‚Kultur’ bei Spengler als normativer Wertbegriff auf, der im Kontrast zu einer degenerierten und seelenlosen Zivilisation steht....

  2. Falaiye et al (19)

    African Journals Online (AJOL)

    (5.8%), goethite [Fe O .H O] (4.6%), halloysite [Al Si O (OH) ·8H O] (3.9%) and kaolinite [Al Si O (OH) ]. 2. 3. 2. 4. 4. 10. 8. 2. 4. 4. 10. 8 ..... Journ of Theor and App. Clim.,40(3), 161-169. Balogun, E.E. 1974. The Phenomenology of the. Atmosphere over West African. Proceedings of Ghana Scope's. Conference on Environment ...

  3. Two growth mechanisms in one-step fabrication of the oxide matrix for FeSiAl soft magnetic composites

    Science.gov (United States)

    Wu, Chen; Gao, Xinwei; Zhao, Guoliang; Jiang, Yinzhu; Yan, Mi

    2018-04-01

    Hydrolysis precipitation as a new method was used in the preparation of oxide insulation matrix for FeSiAl soft magnetic composites (SMCs). The growth and composition of the matrix can be tuned by the concentration of the Al(NO3)3 solution, reaction temperature and pH value during the hydrolysis. With optimized Al(NO3)3 concentration of 0.6 mol/L and hydrolysis temperature of 75 °C, two mechanisms have been revealed in the formation of the insulation coating depending on the pH of the Al(NO3)3 solution. When pH = 3, the coating layer contains a mixture of Al2O3 and Fe2O3, while Al2O3 and SiO2 form as the coating for pH = 8. Despite that the Al2O3 dominates for both conditions, it grows via different routes. The Al(OH)3 as the precursor forms through Al3+ hydrolysis and heterogeneous nucleation for pH = 3. With increased pH to 8, the Al3+ directly reacts with OH- to form Al(OH)3 colloidal particles which adsorb onto the surface of FeSiAl powders via electrostatic attraction. Both mechanisms give rise to satisfactory magnetic performance with high effective permeability (μe = 103.5 and 113.4) and low core loss (Pcv = 278.4 mW·cm-3 and 237.8 mW·cm-3) for pH = 3 and 8 measured at 100 mT, 50 kHz.

  4. Field and laboratory measurement of pH in low-conductivity natural waters

    Science.gov (United States)

    Neal, C.; Thomas, A. G.

    1985-07-01

    The accurate measurement of pH is fundamental to most environmental and hydrogeological studies. Many mineral and ion exchange equilibria are controlled by acidity levels and establishment of saturation indices requires accuracies to within 0.1 pH units. Correspondingly, in studies of the impact of acidic deposition, accurate pH measurement of rainfall, surface runoff and unsaturated zone/groundwater it is essential to establish the proton sources and sinks in the various hydrological pathways. Measurement of pH both in the field and laboratory almost universally involves electrode systems based on silver-silver chloride and calomel cells; these devices, although convenient, inexpensive and portable, are in many instances not sufficiently accurate for low-conductivity waters such as rainfall and many upland streams. Numerous studies for biological and inorganic systems as well as inter-laboratory comparisons have demonstrated this problem (Illingworth, 1981; Tyree, 1981; Mason, 1984; Covington et al., 1985a); hydrogen ion activity/concentration discrepancies of up to an order of magnitude are observed even under laboratory conditions (pH = -log H + activity and for very low ionic strengths H + activity ⋍ H+ concentration). Such inaccuracies will be exacerbated in the more testing environment of field measurement. Improved electrodes based on a free-diffusion liquid junction and flowing sample are being designed (Covington et al., 1983, 1985b), however, these are not readily available and may not be suitable for field use. A description of the sources of these errors is given and suggestions are made for pragmatic solutions to the problems encountered. It is concluded that a fresh approach to field and laboratory measurement of the pH of low-conductivity waters is urgently needed.

  5. PhD competences of food studies

    Directory of Open Access Journals (Sweden)

    Chelo Gonzalez-Martinez

    2014-10-01

    Full Text Available In European Higher Education, learning outcomes and competences have been used sometimes with different meanings and sometimes with the same meaning. But both terms have been more commonly used to refer to knowledge, understanding and abilities a student must demonstrate at the end of a learning experience.  Their use is a consequence of the paradigm shift of the Bologna Process to a learner centered education environment. The definition of standards of competences (or learning outcomes for the PhD degree is thus a need for the quality assurance of this degree. In this work, subject-specific and generic competences for the PhD in Food Science and Technology and their alignment with the European Qualifications Framework (EQF level descriptors for quality assurance purposes have been identified.

  6. ATLAS PhD Grant Scholarship Programme

    CERN Multimedia

    Abha Eli Phoboo

    2014-01-01

    On 11 February, the first recipients of the ATLAS PhD Grant were presented with a certificate by the programme’s selection committee. The three scholars - Lailin Xu of China, Josefina Alconada of Argentina and Gagik Vardanyan of Armenia - were delighted at being able to continue their PhD programmes at CERN.   With certificates, from left: Lailin Xu, Josefina Alconada, and Gagik Vardanyan. The selection committee members, from left: IFAE Barcelona’s Martine Bosman, Fabiola Gianotti, Peter Jenni and from CERN HR James Purvis. (Image: ATLAS/Claudia Marcelloni). Former ATLAS spokespersons Peter Jenni and Fabiola Gianotti started the fund with the Fundamental Physics Prize award money they received last year. Both have used the entirety of their prizes for educational and humanitarian programmes. "We wanted to do something for students who are working on ATLAS, in particular those who otherwise could not come here and actually see the detector they are working on,&am...

  7. Effects of pH and concentration on ability of Cl and NO to intercalate ...

    Indian Academy of Sciences (India)

    Wintec

    3 (Cl. –. –HT and NO. –. 3–HT, respectively). We examined the effects of pH after the reaction, the concen- trations of Cl. – and NO. –. 3 in the solutions, and the Mg: Al molar ratio of the HTs in relation to anion intercalation into the interlayer during synthesis. *Author for correspondence (kameda@env.che.tohoku.ac.jp) ...

  8. Fiber-optic pH detection in small volumes of biosamples

    Czech Academy of Sciences Publication Activity Database

    Kašík, Ivan; Mrázek, Jan; Martan, Tomáš; Pospíšilová, Marie; Podrazký, Ondřej; Matějec, Vlastimil; Hoyerová, Klára; Kamínek, Miroslav

    2010-01-01

    Roč. 398, č. 5 (2010), s. 1883-1889 ISSN 1618-2642 R&D Projects: GA MŠk(CZ) LC06034; GA ČR(CZ) GP102/08/P639; GA AV ČR IAA600380805 Institutional research plan: CEZ:AV0Z20670512; CEZ:AV0Z50380511 Keywords : optic al fiber sensor * plants * pH Subject RIV: JB - Sensors, Measurment, Regulation Impact factor: 3.841, year: 2010

  9. Der Preis als Kaufbarriere?

    DEFF Research Database (Denmark)

    Mueller Loose, Simone

    2012-01-01

    Die Preispolitik hat eine herausragende Stellung im Marketing. Der Preis eines Produktes ist für Verbraucher ein direkter Kostenfaktor und für Unternehmen die Stellgröße im Mar-ketingmix, die den Umsatz am stärksten beeinflusst (vgl. Nieschlag et al. 2002). Wenn die Akzeptanz und der regelmäßige...... Verzehr gesunder Lebensmittel erhöht werden soll, ist es sowohl für die Verbraucherpolitik als auch für Lebensmittelproduzenten wichtig, den Ein-fluss des Preises auf die Kaufentscheidung zu verstehen. Aus Verbrauchersicht ist der Preis neben dem Geschmack die wichtigste Produkteigen-schaft beim Kauf von...... Lebensmitteln (vgl. Brunsø/Grunert 1998) und stellt eine Kaufbarrie-re für Lebensmittel mit gesundheitsfördernden Eigenschaften dar. Studien in den USA (vgl. Cassady et al. 2007), Frankreich (vgl. Drewnowski et al. 2004; Andrieu et al. 2005) und Deutschland (vgl. Karg et al. 2008) kommen übereinstimmend zu dem...

  10. pH dependence of the aqueous dissolution rates of perovskite and zirconolite at 90 C

    International Nuclear Information System (INIS)

    McGlinn, P.J.; Hart, K.P.; Loi, E.H.; Vance, E.R.

    1995-01-01

    Perovskite and zirconolite are two of the major phases of the Synroc titanate mineral assemblage. Their aqueous durability under a range of pH conditions at 90 C has been examined. Solution analysis, electron microscopy and X-ray diffraction have been used to investigate the dissolution behavior of these phases, and a perovskite phase doped with Nd, Sr and Al, using buffered solutions at pH levels of 2.1, 3.7, 6.1, 7.9 and 12.9. After 43 days of leaching, Ca and Ti extractions from perovskite and zirconolite show only a weak pH-dependence. SEM investigation of the samples leached at pH 2.1, 6.1 and 12.9 showed that a titanaceous surface layer formed on the perovskite specimens. XRD analysis of the perovskite samples showed that anatase formed on the leached surface at acidic and neutral pHs, but not under alkaline conditions, and that minor amounts of rutile also formed. In the leached perovskite specimens doped with Nd, Sr and Al, no rule was found by XRD and anatase was only detected in the sample leached at pH 2.1. There were no detectable changes in the leached zirconolite samples examined by SEM and XRD

  11. Iodine evolution and pH control

    International Nuclear Information System (INIS)

    Beahm, E.C.; Lorenz, R.A.; Weber, C.F.

    1993-01-01

    The pH is the major factor in determining the extent of I 2 in solution. In containment where no pH-control chemicals are present, the acidity or basicity of the water pool will be determined by materials that are introduced into containment as a result of the accident itself. These materials may be fission products (i.e., cesium compounds), thermally produced products (i.e., core-concrete aerosols), or compounds produced by radiation (i.e., nitric acid). In situations where pH levels fall below ∼7, the formation of I 2 will occur in irradiated iodide solutions. A correlation between pH and iodine formation is needed so that the amounts I 2 in water pools can be assessed. This, in turn, determines the amount of I 2 in the atmosphere available for escape by containment leakage. A number of calculational routines based on more than 100 differential equations representing individual reactions can be found in the literature. In this work, it is shown that a simpler approach based on the steady-state decomposition of hydrogen peroxide should correctly describe iodine formation in severe accidents. Comparisons with test data show this approach to be valid. The most important acids in containment will be nitric acid (HNO 3 ), produced by irradiation of water and air, and hydrochloric acid (HCl), produced by irradiation or heating of electrical cable insulation. The most important bases in containment will be cesium hydroxide, cesium borate (or cesium carbonate), and in some plants pH additives, such as sodium hydroxide or sodium phosphate

  12. DİŞ PLAĞINDA pH ÖLÇÜM YÖNTEMLERİ-DENTAL PLAQUE pH MEASUREMENTS

    OpenAIRE

    Koparal, Ece; Eronat, Cemal

    2013-01-01

    ÖzetBir substraün yenmesinden sonra diş üzerindeki plakta meydana gelen pH değişikliklerinin saptanmasına dayanan plak pH'ı ölçüm çalışmaları üç yöntemle yapılabilmektedir. İn vitro plak pH ölçümünde, diş üzerinden plak örnekleri alınarak ağız boşluğunun dışında ölçüm gerçekleştirilmektedir. İn vivo plak pH'ı ölçümünde ise telemetri ve yüzey duyarlı elektrot ile plağa dokundurularak ağız içinde ölçümler yapılmaktadır.Anahtar sözcükler: Dental plak, pH, plak örnekleme yöntemi, yüzey ...

  13. Anion exchange removal of Al3+ from Li+-Al3+ aqueous solution (originating from lithium recovery from brine

    Directory of Open Access Journals (Sweden)

    Anissa Somrani

    2014-06-01

    Full Text Available The purpose of this study is to separate aluminum(III ion from an aqueous solution containing Li+ at 25°C. Al3+ was transferred into [Al(C2O43]3- by means of complexation and removed by an anion exchange resin. This resin was anionic type Amberlite IRA 402 regenerated by sodium chloride. Hence, a theoretical study based on speciation diagrams was carried out to determine the best pH domain for separation. The complexation of aluminum ions by ammonium oxalate was studied. The motar ratio of Ox/Al and pH was investigated. Optimum values of these factors were found to be 3 and 4 respectively. In this case, the remaining lithium is 98.5%.

  14. Condensation of rye chromatin in somatic interphase nuclei of Ph1 and ph1b wheat

    Czech Academy of Sciences Publication Activity Database

    Kopecký, David; Allen, D.C.; Duchoslav, M.; Doležel, Jaroslav; Lukaszewski, A.J.

    2007-01-01

    Roč. 119, 3-4 (2007), s. 263-267 ISSN 1424-8581 R&D Projects: GA MŠk(CZ) LC06004 Institutional research plan: CEZ:AV0Z50380511 Source of funding: V - iné verejné zdroje Keywords : hexaploid wheat * Ph1 and ph1b * rye chromatin Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.402, year: 2007

  15. Optimum pH and pH Stability of Crude Polyphenol Oxidase (PPO ...

    African Journals Online (AJOL)

    The effect of pH on the activity and stability of crude polyphenol oxidase (PPO) extracted from garden egg (Solanum aethiopicum), pawpaw (Carica papaya), pumpkin ... Optimum pH values were found to be 6.0,6.5,6.0, 4.5 and 4.0/or 8.0 for the enzyme extracted from Solanum aethiopicum, Carica papaya, Cucurbita pepo, ...

  16. Effects of pH and calcination temperature on structural and optical properties of alumina nanoparticles

    Science.gov (United States)

    Amirsalari, A.; Farjami Shayesteh, S.

    2015-06-01

    In this study, we describe the synthesis of alumina nanoparticles using a chemical wet method in at varying pH. The optimized prepared particles with pH equals to 9 were calcined at various temperatures. For characterization of structural and optical properties of nanoparticles had been used X-ray diffraction, Infrared Fourier transform spectroscopy, field effect-scanning electron microscopy, photoluminescence and ultraviolet-visible spectroscopy. The results revealed that the nanoparticles calcined at 500 °C consist of an Al2O3 tetragonal structure and tetragonal distortion decreases with increasing calcination temperature up to 750 °C then increased with increasing temperature. Another phase similar to γ-Al2O3 was formed instead of δ-Al2O3 in the transition sequence from the γ to θ phase. FT-IR analysis; suggests that there are a few different types of functional groups on the surface of the alumina nanoparticles such as hydroxy groups and oxy groups. The transmittance spectra showed that the absorption bands in the UV region strongly depend on the calcination temperature. Moreover, the results showed that alumina has an optical direct band gap and that the energy gap decreases with increasing the calcination temperature and pH of the reaction. Luminescence spectra showed that some luminescent centers such as OH-related radiative centers and oxygen vacancies (F, F22+ and F2 centers) centers exist in the nanoparticles.

  17. Proteorhodopsin Photocycle Kinetics Between pH 5 and pH 9.

    Science.gov (United States)

    Köhler, Thomas; Weber, Ingrid; Glaubitz, Clemens; Wachtveitl, Josef

    2017-05-01

    The retinal protein proteorhodopsin is a homolog of the well-characterized light-driven proton pump bacteriorhodopsin. Basic mechanisms of proton transport seem to be conserved, but there are noticeable differences in the pH ranges of proton transport. Proton transport and protonation state of a carboxylic acid side chain, the primary proton acceptor, are correlated. In case of proteorhodopsin, the pK a of the primary proton acceptor Asp-97 (pK a  ≈ 7.5) is unexpectedly close to environmental pH (pH ≈ 8). A significant fraction of proteorhodopsin is possibly inactive at natural pH, in contrast to bacteriorhodopsin. We investigated photoinduced kinetics of proteorhodopsin between pH 5 and pH 9 by time resolved UV/vis absorption spectroscopy. Kinetics is inhomogeneous within that pH region and can be considered as a superposition of two fractions. These fractions are correlated with the Asp-97 titration curve. Beside Asp-97, protonation equilibria of other groups influence kinetics, but the observations do not point toward major differences of primary proton acceptor function in proteorhodopsin and bacteriorhodopsin. The pK a of proteorhodopsin and some of its variants is suspected to be an example of molecular adaptation to the physiology of the original organisms. © 2017 The American Society of Photobiology.

  18. Pyrite oxidation at circumneutral pH

    Science.gov (United States)

    Moses, Carl O.; Herman, Janet S.

    1991-02-01

    Previous studies of pyrite oxidation kinetics have concentrated primarily on the reaction at low pH, where Fe(III) has been assumed to be the dominant oxidant. Studies at circumneutral pH, necessitated by effective pH buffering in some pyrite oxidation systems, have often implicitly assumed that the dominant oxidant must be dissolved oxygen (DO), owing to the diminished solubility of Fe(III). In fact, Fe(III)(aq) is an effective pyrite oxidant at circumneutral pH, but the reaction cannot be sustained in the absence of DO. The purpose of this experimental study was to ascertain the relative roles of Fe(III) and DO in pyrite oxidation at circumneutral pH. The rate of pyrite oxidation was first-order with respect to the ratio of surface area to solution volume. Direct determinations of both Fe(II) (aq)> and Fe(III) (aq) demonstrated a dramatic loss of Fe(II) from the solution phase in excess of the loss for which oxidation alone could account. Based on rate data, we have concluded that Fe(II) is adsorbed onto the pyrite surface. Furthermore, Fe(II) is preferred as an adsorbate to Fe(III), which we attribute to both electrostatic and acid-base selectivity. We also found that the rate of pyrite oxidation by either Fe(III) (aq) or DO is reduced in the presence of aqueous Fe(II), which leads us to conclude that, under most natural conditions, neither Fe(III) (aq) nor DO directly attacks the pyrite surface. The present evidence suggests a mechanism for pyrite oxidation that involves adsorbed Fe( II ) giving up electrons to DO and the resulting Fe(III) rapidly accepting electrons from the pyrite. The adsorbed Fe is, thus, cyclically oxidized and reduced, while it acts as a conduit for electrons traveling from pyrite to DO. Oxygen is transferred from the hydration sphere of the adsorbed Fe to pyrite S. The cycle of adsorbed Fe oxidation and reduction and the successive addition of oxygen to pyrite S continues until a stable sulfoxy species dissociates from the surface. Prior

  19. Reaction mechanisms of phosphate with Al(OH)3 and a sandy soil

    NARCIS (Netherlands)

    Riemsdijk, van W.H.

    1979-01-01

    Al(OH) 3 is a very effective sorbent for orthophosphate especially at low pH. At low phosphate concentration c p , phosphate is adsorbed by an exchange mechanism with singly coordinated OH(H) groups residing on the surface of the Al(OH)

  20. Anonymität und Geschlecht in der Phänomenologie Merleau-Pontys

    Directory of Open Access Journals (Sweden)

    Kerstin Andermann

    2014-04-01

    Full Text Available In diesem Beitrag wird die Bedeutung von Anonymität für die allgemeine Wahrnehmung und die Wahrnehmung von Geschlechtlichkeit untersucht. Im Ausgang der Phänomenologie Merleau-Pontys und mit Blick auf den Begriff der Singularität bei Deleuze wird Anonymität als latenter Untergrund der Existenz ausgemacht. Erst durch die Sinnesorgane wird die anonyme Existenz des Körpers überschritten, und so erscheint Anonymität jenseits der Organisation des Körpers als eines Funktionszusammenhangs strukturierter, signifizierter und unterschiedlich privilegierter Schichten. Ausgehend von Anonymität wird das personale Leben als eine Übernahme von Situationen und als Wechsel zwischen anonym-singulärem und personal-individuellem Leben des Menschen sichtbar. Auch Geschlechtlichkeit wird so als Eintritt in geschlechtlich geprägte Situationen und als eine vieldeutige Spannung zwischen anonymer Existenz und Sein in Situationen deutlich. In diesem Sinne erweist sie sich als eine Übernahme von Situationen aus der Anonymität heraus und ihrer Ausgestaltung sind entsprechende Freiheitsgrade zuzuschreiben.

  1. Fabrication and Characterization of a Ruthenium Nitride Membrane for Electrochemical pH Sensors

    Science.gov (United States)

    Liao, Yi-Hung; Chou, Jung-Chuan

    2009-01-01

    The pH sensing and nonideal characteristics of a ruthenium nitride (RuN) sensing membrane pH sensor were investigated. RuN thin films were deposited from a 99.9% ruthenium target on p-type silicon substrates using radio frequency (r.f.) sputtering with N2 gas. Subsequently, the nanometric structure and surface morphology of RuN thin films were determined. The sensitivity of the RuN sensing membrane pH sensor was 58.03 mV/pH, obtained from ID-VG curves with a current-voltage (I–V) measurement system in standard buffer solutions from pH 1 to pH 13 at room temperature (25 °C). Moreover, the nonideal characteristics of the RuN sensing membrane, such as temperature coefficient, drift with light influence, drift rate and hysteresis width, etc. were also investigated. Finally, the sensing characteristics of the RuN membrane were compared with titanium nitride (TiN), aluminum nitride (AlN) and silicon nitride (Si3N4) membranes. PMID:22574026

  2. EFFECT OF ANION, PH, AND TEMPERATURE ON THE DISSOLUTION BEHAVIOR OF ALUMINUM OXIDE FILMS.

    Energy Technology Data Exchange (ETDEWEB)

    LEE,H.; ISAACS,H.S.

    2001-09-02

    The growth and dissolution behavior of oxide film on abraded pure Al has been investigated using cyclic polarization and has been found to be highly dependent on solution chemistry and temperature. The nature of the anions, borate, chromate, phosphate, and sulfate, at pH 3 to 11, and temperatures 0 to 60 C were examined. In near neutral solutions the dissolution behavior was greatly affected by each anion. In borate and chromate solutions at near neutral pH and room temperature, the currents continued to decrease with each subsequent cycle due to oxide thickening. In contrast, a significant rate of oxide dissolution occurred to produce reproducible repetitive curves during subsequent cycles in a phosphate and sulfate. Sulfate also produced a distinctly different mode during high field oxide growth. In increasing acidic (pH < 4) or basic (pH >9) solutions the oxide dissolution rate increased rapidly. The oxide dissolution rate was always enhanced with increasing temperature. At high pH (>9) or elevated temperature (60 C), a current maximum was observed in chromate, due to a diffusion controlled monochromate ion enhanced dissolution reaction at the oxide/solution interface.

  3. Comparison of Rumen Fluid pH by Continuous Telemetry System and Bench pH Meter in Sheep with Different Ranges of Ruminal pH

    OpenAIRE

    Reis, Leonardo F.; Minervino, Antonio H. H.; Araújo, Carolina A. S. C.; Sousa, Rejane S.; Oliveira, Francisco L. C.; Rodrigues, Frederico A. M. L.; Meira-Júnior, Enoch B. S.; Barrêto-Júnior, Raimundo A.; Mori, Clara S.; Ortolani, Enrico L.

    2014-01-01

    We aimed to compare the measurements of sheep ruminal pH using a continuous telemetry system or a bench pH meter using sheep with different degrees of ruminal pH. Ruminal lactic acidosis was induced in nine adult crossbred Santa Ines sheep by the administration of 15 g of sucrose per kg/BW. Samples of rumen fluid were collected at the baseline, before the induction of acidosis (T 0) and at six, 12, 18, 24, 48, and 72 hours after the induction for pH measurement using a bench pH meter. During ...

  4. A new approach to measuring pH in brines and other concentrated electrolytes

    Science.gov (United States)

    Knauss, Kevin G.; Wolery, Thomas J.; Jackson, Kenneth J.

    1990-05-01

    We propose an operational and theoretical approach to dealing with pH in brines and other concentrated aqueous solutions. The operational method is analogous to the standard procedure for measuring pH in dilute solutions, but uses a liquid-junction-free cell consisting of an ion specific electrode (ISE) for H + and another for a different ion, such as Cl -. The latter ISE replaces the standard reference electrode used in the usual procedure. The potential measured is proportional to pHCl = pH + pCl, or any corresponding quantity, such as pH/Na = pH - pNa, depending on the type of second ISE. The procedure also requires the separate measurement of the total concentration of the ion to which the second ISE responds, and input of these and other solution data to a geochemical modeling code (EQ3NR), which uses the Pitzer equations (Pitzer, 1973) to compute a thermodynamic model of the solution. High ionic strength standard solutions, whose compositions are calculated using the same code, are used to calibrate the liquid-junction-free cell. A pH scale convention is then used to decouple pH from pCl, pNa, pBr, etc. We investigated ISE couples pairing cations (K + and Na +) as well as anions (Br -) against H + to demonstrate the general applicability of this approach to measuring pH. The effects of these and other potentially interfering ions (Ca 2+, Mg 2+, BO 3-3, SO 2-4, and HCO -3) on the various ISE couples were studied. By making a HCl measurements in sample solutions equilibrated with calcite we have used the solubility of calcite in high ionic strength solutions (determined using the HARVIE et al., 1984, derived thermodynamic data consistent with the Pitzer formulation) as an independent verification of the method.

  5. Gastric emptying of two radiolabelled antacids with simutaneous montoring of gastric pH

    International Nuclear Information System (INIS)

    Mones, J.; Carrio, I.; Sainz, S.; Berna, L.; Clave, P.; Liszkay, M.; Roca, M.; Vilardell, F.

    1995-01-01

    The aim of this study was to assess the gastric emptying rate of two antacids using an scintigraphic technique and simultaneous monitoring of gastric pH in 16 healthy male volunteers. Ten ml of Talcid (hydrotalcite 1 g) and Maalox (Mg-Al-hydroxide), with a similar neutralization capacity, were labelled with technetium-99m using a pyrophosphate bridge. Labelled antacids were given on separate days (within 2 weeks), 1 h after a standard meal. Intragastric pH was measured for at least 4 h, using ambulatory pH-metry with a dual-crystant antimony catheter. Continuous monitoring was started 1 h prior to the meal (baseline) and lasted 3 h (post-prandial, post-antacid and final periods). The antacid capacity of labelled and unlabelled antacids was similar. The mean percentages of antacids retained in the stomach fitted a linear model. The mean half-emptying time of Talcid was 63.9±27.9 min, while that of Maalox was 57.3±23.9 min (P = NS). The recordings of gastric pH (mean values of pH for each period) showed a similar profile for both antacids. The mean pH (Maalox vs Talcid) was 1.69 vs 2.07 in the baseline period, 1.95 vs 1.93 in the post-prandial period, 1.79 vs 1.15 in the post-antacid period (P = NS) and 0.4 vs 0.52 in the final period (P < 0.05 vs prior periods). In conclusion, the gastric emptying of Talcid and Maalox was similar and pH profiles were parallel and remained unchanged for the two antacids within the first hour of intake. A significant decrease in pH was observed 1 h after intake of the antacids, suggesting a possible rebound effect. (orig.)

  6. Gastric emptying of two radiolabelled antacids with simutaneous montoring of gastric pH

    Energy Technology Data Exchange (ETDEWEB)

    Mones, J. [Servicio de Patologia Digestiva, Hospital de la Santa Creu i Sant Pau, Univ. Autonoma Barcelona (Spain); Carrio, I. [Servicio de Medicina Nuclear, Hospital de La Santa Creu i Pau, Univ. Autonoma Barcelona (Spain); Sainz, S. [Servicio de Patologia Digestiva, Hospital de la Santa Creu i Sant Pau, Univ. Autonoma Barcelona (Spain); Berna, L. [Servicio de Medicina Nuclear, Hospital de La Santa Creu i Pau, Univ. Autonoma Barcelona (Spain); Clave, P. [Servicio de Patologia Digestiva, Hospital de la Santa Creu i Sant Pau, Univ. Autonoma Barcelona (Spain); Liszkay, M. [Bayer AG, Leverkusen (Germany); Roca, M. [Servicio de Medicina Nuclear, Hospital de La Santa Creu i Pau, Univ. Autonoma Barcelona (Spain); Vilardell, F. [Servicio de Patologia Digestiva, Hospital de la Santa Creu i Sant Pau, Univ. Autonoma Barcelona (Spain)

    1995-10-01

    The aim of this study was to assess the gastric emptying rate of two antacids using an scintigraphic technique and simultaneous monitoring of gastric pH in 16 healthy male volunteers. Ten ml of Talcid (hydrotalcite 1 g) and Maalox (Mg-Al-hydroxide), with a similar neutralization capacity, were labelled with technetium-99m using a pyrophosphate bridge. Labelled antacids were given on separate days (within 2 weeks), 1 h after a standard meal. Intragastric pH was measured for at least 4 h, using ambulatory pH-metry with a dual-crystant antimony catheter. Continuous monitoring was started 1 h prior to the meal (baseline) and lasted 3 h (post-prandial, post-antacid and final periods). The antacid capacity of labelled and unlabelled antacids was similar. The mean percentages of antacids retained in the stomach fitted a linear model. The mean half-emptying time of Talcid was 63.9{+-}27.9 min, while that of Maalox was 57.3{+-}23.9 min (P = NS). The recordings of gastric pH (mean values of pH for each period) showed a similar profile for both antacids. The mean pH (Maalox vs Talcid) was 1.69 vs 2.07 in the baseline period, 1.95 vs 1.93 in the post-prandial period, 1.79 vs 1.15 in the post-antacid period (P = NS) and 0.4 vs 0.52 in the final period (P < 0.05 vs prior periods). In conclusion, the gastric emptying of Talcid and Maalox was similar and pH profiles were parallel and remained unchanged for the two antacids within the first hour of intake. A significant decrease in pH was observed 1 h after intake of the antacids, suggesting a possible rebound effect. (orig.)

  7. Microscopic monitoring of extracellular pH in dental biofilms

    DEFF Research Database (Denmark)

    Schlafer, Sebastian; Garcia, Javier; Greve, Matilde

    extracellular pH irrespective of the dye concentration. We showed that at pH stained 15 bacterial species frequently isolated from dental biofilm and visualized the entire bacterial biomass in dental biofilms grown intraorally on glass slabs mounted on individually designed lower jaw splints. We......pH in dental biofilm is a key virulence factor for the development of caries lesions. The complex three-dimensional architecture of dental biofilms leads to steep gradients of nutrients and metabolites, including organic acids, across the biofilm. For decades, measuring pH in dental biofilm has......H ratiometry, can be employed to map the pH landscape in dental biofilm with more detail. However, when pH sensitive fluorescent probes are used to visualize pH in biofilms, it is crucial to differentiate between extracellular and intracellular pH. Intracellular microbial pH and pH in the extracellular matrix...

  8. Influence of pH and temperature on alunite dissolution rates and products

    Science.gov (United States)

    Acero, Patricia; Hudson-Edwards, Karen

    2015-04-01

    Aluminium is one of the main elements in most mining-affected environments, where it may influence the mobility of other elements and play a key role on pH buffering. Moreover, high concentrations of Al can have severe effects on ecosystems and humans; Al intake, for example, has been implicated in neurological pathologies (e.g., Alzheimer's disease; Flaten, 2001). The behaviour of Al in mining-affected environments is commonly determined, at least partially, by the dissolution of Al sulphate minerals and particularly by the dissolution of alunite (KAl3(SO4)2(OH)6), which is one of the most important and ubiquitous Al sulphates in mining-affected environments (Nordstrom, 2011). The presence of alunite has been described in other acid sulphate environments, including some soils (Prietzel & Hirsch, 1998) and on the surface of Mars (Swayze et al., 2008). Despite the important role of alunite, its dissolution rates and products, and their controlling factors under conditions similar to those found in these environments, remain largely unknown. In this work, batch dissolution experiments have been carried out in order to shed light on the rates, products and controlling factors of alunite dissolution under different pH conditions (between 3 and 8) and temperatures (between 279 and 313K) similar to those encountered in natural systems. The obtained initial dissolution rates using synthetic alunite, based on the evolution of K concentrations, are between 10-9.7 and 10-10.9 mol-m-2-s-1, with the lowest rates obtained at around pH 4.8, and increases in the rates recorded with both increases and decreases in pH. Increases of temperature in the studied range also cause increases in the dissolution rates. The dissolution of alunite dissolution is incongruent, as has been reported for jarosite (isostructural with alunite) by Welch et al. (2008). Compared with the stoichiometric ratio in the bulk alunite (Al/K=3), K tends to be released to the solution preferentially over Al

  9. The leaching of major and trace elements from MSWI bottom ash as a function of pH and time

    NARCIS (Netherlands)

    Dijkstra, J.J.; Sloot, van der H.A.; Comans, R.N.J.

    2006-01-01

    In this paper, the leaching behaviour of major components (Al, Ca, SO4, Mg, Si, Fe, Na and DOC) and trace elements (Ni, Zn, Cd, Cu, Pb, Mo and Sb) from MSWI bottom ash is studied as a function of time over a wide range of pH, under pH-controlled conditions. Equilibrium geochemical modelling using

  10. The simultaneous influence of pH and Acid Volatile Sulphide on the speciation of heavy metals in calcareous sediments

    NARCIS (Netherlands)

    Buykx SEJ; Hoop MAGT van den; LAC

    1996-01-01

    In een aantal kalkrijke zoetwater sedimenten is de invloed van de pH en het zuur extraheerbaar sulfidegehalte (AVS) op de speciatie van zware metalen experimen-teel bestudeerd. Zowel de som van de simultaan ge-extraheerde metalen (SEM: Cd, Cu, Ni, Pb en Zn), als het zuur extraheerbare

  11. Pornographie als Metapher

    Directory of Open Access Journals (Sweden)

    Caroline Schubarth

    2010-03-01

    Full Text Available In diesem Artikel werden unterschiedliche metaphorische Verwendungen des Pornografiebegriffs und deren Implikationen untersucht. Während die Existenz von Pornografie der feministischen Anti-Porno-Bewegung als Erklärung für die anhaltende Diskriminierung von Frauen in westlichen Gesellschaften dient, nutzen rechtskonservative Kräfte den Pornografievorwurf als Rechtfertigung für die Zensur von als deviant empfundenen Identitäten und sexuellen Praktiken.This article examines different metaphorical uses of the term pornography and the resulting implications. While the existence of pornography for the feminist anti-porno movement serves as factor in the continuing discrimination of women in western societies, conservative powers on the right use the allegation of pornography as a justification for censorship of those identities and sexual practices deemed deviant.

  12. Al-doped SnO2 nanocrystals from hydrothermal systems

    International Nuclear Information System (INIS)

    Jin Haiying; Xu Yaohua; Pang Guangsheng; Dong Wenjun; Wan Qiang; Sun Yan; Feng Shouhua

    2004-01-01

    Nanoparticles of Al-doped SnO 2 have been hydrothermally synthesized. The influences of the hydrothermal reaction time, the molar ratio of Sn/Al as well as the pH value of the solution have been studied. During the hydrothermal synthesis, the particle's core is rich in Sn and the surface is rich in Al. The Al-rich surface prevents the particles from further growing up either in the hydrothermal condition or during the calcination at 600 deg. C for a short period of time. The optimal hydrothermal synthesis condition of the nanoparticles is pH 5, Sn/Al=4:1 and 12 h at 160 deg. C. The products have been studied by XRD, TEM and 27 Al solid-state NMR

  13. Photoelectron spectroscopy of the aluminum hydride anions: AlH2(-), AlH3(-), Al2H6(-), Al3H9(-), and Al4H12(-).

    Science.gov (United States)

    Zhang, Xinxing; Wang, Haopeng; Collins, Evan; Lim, Alane; Ganteför, Gerd; Kiran, Boggavarapu; Schnöckel, Hansgeorg; Eichhorn, Bryan; Bowen, Kit

    2013-03-28

    We report measurements of the negative ion photoelectron spectra of the simple aluminum hydride anions: AlH2(-), AlH3(-), Al2H6(-), Al3H9(-), and Al4H12(-). From these spectra, we measured the vertical detachment energies of the anions, and we estimated the electron affinities of their neutral counterparts. Our results for AlH2(-), AlH3(-), and Al2H6(-) were also compared with previous predictions by theory.

  14. Coupled growth of Al-Al2Cu eutectics in Al-Cu-Ag alloys

    International Nuclear Information System (INIS)

    Hecht, U; Witusiewicz, V; Drevermann, A

    2012-01-01

    Coupled eutectic growth of Al and Al 2 Cu was investigated in univariant Al-Cu-Ag alloys during solidification with planar and cellular morphology. Experiments reveal the dynamic selection of small spacings, below the minimum undercooling spacing and show that distinct morphological features pertain to nearly isotropic or anisotropic Al-Al 2 Cu interfaces.

  15. Selbstkritik als wissenschaftliches Projekt?

    Directory of Open Access Journals (Sweden)

    Barbara Scholand

    2007-11-01

    Full Text Available Wallner kritisiert die aktuelle feministische Darstellung der rund 30jährigen Geschichte der Mädchenarbeit als „Legendenbildung“ (S. 9: Sie verkürze und verschweige im Interesse einer Selbst-Heroisierung und sei daher ideologisch. Als eine derjenigen, die seit zwanzig Jahren feministische Mädchenarbeit und -politik betreibt, arbeitet die Autorin damit auch ihre eigenen (Nicht-Bezugnahmen kritisch auf. Ihr grundlegendes Interesse ist es, eine aus ihrer Sicht erforderliche Neupositionierung der Mädchenarbeit in der Jugendhilfe im Zeitalter von Gender Mainstreaming zu befördern.

  16. ALS superbend magnet system

    International Nuclear Information System (INIS)

    Zbasnik, J.; Wang, S.T.; Chen, J.Y.; DeVries, G.J.; DeMarco, R.; Fahmie, M.; Geyer, A.; Green, M.A.; Harkins, J.; Henderson, T.; Hinkson, J.; Hoyer, E.H.; Krupnick, J.; Marks, S.; Ottens, F.; Paterson, J.A.; Pipersky, P.; Portmann, G.; Robin, D.A.; Schlueter, R.D.; Steier, C.; Taylor, C.E.; Wahrer, R.

    2000-01-01

    The Lawrence Berkeley National Laboratory is preparing to upgrade the Advanced Light Source (ALS) with three superconducting dipoles (Superbends). In this paper we present the final magnet system design which incorporates R and D test results and addresses the ALS operational concerns of alignment, availability, and economy. The design incorporates conduction-cooled Nb-Ti windings and HTS current leads, epoxy-glass suspension straps, and a Gifford-McMahon cryocooler to supply steady state refrigeration. We also present the current status of fabrication and testing

  17. ATLAS PhD Grants 2015

    CERN Multimedia

    Marcelloni De Oliveira, Claudia

    2015-01-01

    ATLAS PHd Grants - We are excited to announce the creation of a dedicated grant scheme (thanks to a donation from Fabiola Gianotti and Peter Jenni following their award from the Fundamental Physics Prize foundation) to encourage young and high-caliber doctoral students in particle physics research (including computing for physics) and permit them to obtain world class exposure, supervision and training within the ATLAS collaboration. This special PhD Grant is aimed at graduate students preparing a doctoral thesis in particle physics (incl. computing for physics) to spend one year at CERN followed by one year support also at the home Institute.

  18. Forum for Almen Medicinske ph.d.-studerende

    DEFF Research Database (Denmark)

    Vedsted, Peter; Waldorff, Frans Boch; Eriksson, Tina

    Rapport fra første fællesmøde mellem nuværende og kommende almenmedicinske ph.d.-studerende. Rapporten anbefaler dannelse af et egentligt almenmedicinsk ph.d.-forum, der søges optaget i DSAM som en interessegruppe. Ph.d.-forum betragter sig som en ressource ved forskellige initiativer og ønsker...... blandt andet at arbejde for en værdig ansættelse af yngre forskere. Blandt de konkrete forslag, Ph.d.-forum har stillet, er almenmedicinske ph.d.-kurser og ph.d.-stipendium med henblik på udarbejdelse af protokol....

  19. An assessment of the human nail plate pH.

    OpenAIRE

    Murdan, S.; Milcovich, G.; Goriparthi, G. S.

    2011-01-01

    Purpose of Study: To measure the pH of the surface of healthy nail plates. Procedures: The surface pH of human fingernails and big toenails was measured in vivo using a skin pH meter. The influence of washing, anatomical site (fingers/toes), side (left/right), digit (digits 1–5) and gender was determined. The pH of the nail interior was also measured. Results: The pH of the nail plate surface was around 5, with toenails having a significantly higher pH than fingernails. Immediately after hand...

  20. Dichtung als Erfahrungsmetaphysik

    DEFF Research Database (Denmark)

    Magnusson, Gisli

    Rilkeforskning. Fordi Rilke ikke – uden at gøre vold mod hans værk – kan fortolkes ud fra et traditionelt religiøst verdensbillede, har man fortolket ham som en antimetafysisk mo­dernist. Afhandlingen Dichtung als Erfahrungsmetaphysik. Esoterische und okkultistische Modernität bei R. M. Rilke argumenterer for...

  1. Okusanya et al (5)

    African Journals Online (AJOL)

    DELL

    subcontinent and it is distributed in various tropical and sub-tropical regions including Asia,. Central and South America, Australia, West. Indies, Africa, (Orwa et al., 2009) and in Florida and Texas in the United States of America. (Brown, 2001). It has recently been spotted in. Brick Township, New Jersey, U. S. A. and in Israel.

  2. Adjei et al.

    African Journals Online (AJOL)

    PUBLICATIONS1

    Glass products appear in varied types based on the material composition. It is an amorphous. (non-crystalline) solid material which is often transparent with widespread practical, techno- logical, and decorative applications. Examples are windowpanes, beverage containers, table wares, and optoelectronics (Babcock et al,.

  3. Adeleye et al (20)

    African Journals Online (AJOL)

    DELL

    2018-03-03

    Mar 3, 2018 ... terrestrial and aquatic settings and the proxies are mostly drawn from sedimentary deposits such as lakes, marine deposits, peatlands and other wetlands such as marshes and swamps (Jeglum and Rydin, 2006; Smol et al., 2001). It is commonly stated that the present condition of the biosphere is the result ...

  4. Onojeghuo et al (16)

    African Journals Online (AJOL)

    USER

    one under community-based forest management and the other a protected area were compared to evaluate the efficiency of community forest management. The results showed ... Onojeghuo et al.: Community Participation in Forest Management Across Protected Areas .... using the unsupervised Iterative Self Organising.

  5. Oke et al. (12)

    African Journals Online (AJOL)

    the enforcement of good quality control measures. Keywords: Hand Sanitizer, Hand Hygiene, Bactericidal, Bacteriostatic, MIC, MBC. ABSTRACT. INTRODUCTION. Hospital and community-acquired infections constitute a serious public health problem all over the world (Hassan et al., 2012). Hospital acquired. (nosocomial) ...

  6. BERKELEY: ALS ring

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    Everybody at Lawrence Berkeley Laboratory's Center for Beam Physics is pleased with the rapid progress in commissioning LBL's Advanced Light Source (ALS) electron storage ring, the foundation for this third-generation synchrotron radiation facility. Designed for a maximum current of 400 mA, the ALS storage ring reached 407 mA just 24 days after storing the first beam on 16 March. ALS construction as a US Department of Energy (DOE) national user facility to provide high-brightness vacuum ultra-violet and soft x-ray radiation began in October 1987. One technical requirement marking project completion was to accumulate a 50-mA current in the storage ring. The ALS passed this milestone on 24 March, a week ahead of the official deadline. Once injected, the electron beam decays quasi-exponentially primarily because of interactions with residual gas molecules in the storage-ring vacuum chamber. Eventually, when the pressure in the vacuum chamber with beam decreases toward the expected operating level of 1 nano Torr, it will only be necessary to refill the storage ring at intervals of four to eight hours. At present the vacuum is improving rapidly as surfaces are irradiated (scrubbed) by the synchrotron radiation itself. At 100 mA, beam lifetime was about one hour (9 April)

  7. Ojo et al. (15)

    African Journals Online (AJOL)

    DELL

    This work presents analyses of data on cancers diagnosed and recorded at the Ife-Ijesa Cancer Registry located ... physical inactivity, as well as changing dietary and lifestyle patterns. [Sylla and Wild, 2011, Jedy-Agba et al., 2012]. It is generally accepted that a large number of cancers .... for Appendix, Bowel and Duodenal.

  8. Akpen et al.2

    African Journals Online (AJOL)

    PUBLICATIONS1

    reduction of pollution in the stream. Sharma et al. (2003) monitored the water quality of Hathli. Akpen et ... dium roughness and the degree of sinusoidality is low to moderate with some few sharp bends. The temperature ... U, is the velocity in m/sec and H, is the depth in meters. The dispersion coefficient (Ex) was calculated ...

  9. Ipeaiyeda et al (15)

    African Journals Online (AJOL)

    DELL

    arousing public interest. Previous studies published so far on air pollution in Nigeria are on heavy metals in atmosphere using tree bark as indicator and airborne cement dust (Odukoya et al., 2000; Onianwa, 2001; Gbadebo and Bankole,. 2007). Estimation of air pollution arising from vehicular exhaust emission on Nigeria ...

  10. Adjaotor et al

    African Journals Online (AJOL)

    PUBLICATIONS1

    A mathematical model was developed using multiple regression analysis to predict MRR during hard turning of AISI 304L ... regression line fits well for both results data at 95% confidence interval. INTRODUCTION. In order to respond ... replacement and regrinding times, ordering time etc. Tonshoff et al. (1995) stated that ...

  11. Joda et al (16)

    African Journals Online (AJOL)

    DELL

    treating gonorrhea, gonococcal urethritis and the vaginal/urethral discharge syndrome in developing countries like Nigeria (Abebe et al.,. 2001; WHO, 2007). In addition to being effective against Neiseria gonorrhoea, ciprofloxacin is indicated for bacterial infections like urinary tract infections (UTIs), acute uncomplicated ...

  12. Nucleosynthesis of 26Al

    International Nuclear Information System (INIS)

    Casse, M.

    1986-07-01

    A burst of interest has followed the discovery in the galactic plane of the 1.8 MeV gamma line attached to the decay of 26 Al. We discuss the relative merits of supernovae, novae, massive and supermassive mass-losing stars as potential sources of this expressive isotope

  13. Adeyemi et al (10)

    African Journals Online (AJOL)

    Acevedo-Rodríguez et al.(2011). The vegetative and reproductive morphology of. Sapindaceae shows similarities and differences among the various genera constituting the family. Pair-wise analysis of qualitative data generated a dendogram. A common feature in the dendogram is the clear separation of the family into two ...

  14. Ekun et al (6)

    African Journals Online (AJOL)

    DELL

    It must be noted that a significantly low total testosterone value as was observed among the hypertensive group may be an indicator to suggesting a subclinical hypogonadism. Furthermore, it was observed that the mean LH value in test group though marginally higher than. Ekun et al.: Levels of Reproductive Hormones ...

  15. Odukoya et al (25)

    African Journals Online (AJOL)

    USER

    Human exposure to toxic metals has increased dramatically in the last 50 years as a result of an exponential increase in the use of heavy metals in industrial processes and products (Sekabira et al.,. 2010). Solid and liquid wastes from these industries eventually get discharged into dumps or rivers from where they enter the ...

  16. Taiwo et al (15)

    African Journals Online (AJOL)

    Timothy Ademakinwa

    Extracted lipids were then analyzed by gas chromatography to determine the composition and relative abundance of the fatty acids present. .... allow for phase separation. The bottom chloroform layer was then collected after ..... in membranes than DHA (Subhadra et al., 2006). This could be the reason for the lower levels of.

  17. aboagye et al.2

    African Journals Online (AJOL)

    PUBLICATIONS1

    14 Aboagye et al. wide variety of birds, including chickens, by piercing the quills of feathers and gnawing the epidermis. In doing so, they can spread disease and lower .... evolution. Oikos, 97: 223-228. Nordenfors, H. and Chirico, J. (2001). Evalua- tion of a sampling trap for Dermanyssus gal- linae (Acari: Dermanyssidae).

  18. Iraq and Al Qaeda

    National Research Council Canada - National Science Library

    Katzman, Kenneth

    2008-01-01

    .... The Administration assertions were derived from U.S. intelligence showing a pattern of contacts with Al Qaeda when its key founder, Osama bin Laden, was based in Sudan in the early to mid-1990s and continuing after he relocated to Afghanistan in 1996...

  19. Iraq and Al Qaeda

    National Research Council Canada - National Science Library

    Katzman, Kenneth

    2007-01-01

    .... The Administration's assertions were derived from U.S. intelligence showing a pattern of contacts with Al Qaeda when its founder, Osama bin Laden, was based in Sudan in the early to mid-1990s and continuing after he relocated to Afghanistan in 1996...

  20. Ismail et al (6)

    African Journals Online (AJOL)

    USER

    Analysis and design of pipes in water distribution networks generally create a relatively complex problem, particularly when the network consists of large number of pipes as frequently occurs in water distribution systems of large metropolitan areas and cities. (Saminu et al., 2013). There are various types of loops in pipeline ...

  1. Adeoti et al

    African Journals Online (AJOL)

    PUBLICATIONS1

    Hence, for groundwater exploration, integration of techniques is most essential for success to be achieved economically (Rosli et al., 2012). The application of geophysics for the successful exploration of groundwater in sedimentary ter- rain requires a proper understanding of its hy- dro-geological characteristics. Evidence ...

  2. Ajibola et al (7)

    African Journals Online (AJOL)

    USER

    ponds and streams (Mohneke et al., 2010). The larval stage of the African tiger frog. (Hoplobatrachus occipitalis) is carnivorous and feeds on small aquatic animals like tadpoles and mosquito larvae, making them an important part of the food chain. A drop in population of H. occipitalis as a predator, due to overexploitation of.

  3. Comentarios al Salto Social

    Directory of Open Access Journals (Sweden)

    Facultad de Ciencias Económicas

    1995-06-01

    Full Text Available 1. El Plan considera que la política social es un componente central de la estrategia macroeconómica. A diferencia de la administración Gaviria, lo social ha dejado de ser un asunto marginal, es consustancial al desarrollo y, por tanto, se le confiere una dimensión cualitativamente diferente.

  4. Taiwo et al (10)

    African Journals Online (AJOL)

    DELL

    duration of marriage, birth interval, birth order and breast feeding practice. Uddin et al. (2009) in their study, investigated child mortality in. Bangladesh also using the logistic regression. Results of analysis showed that father's education, occupation of father, occupation of mother, standard of living index, breastfeeding status ...

  5. Olonisakin et al (15)

    African Journals Online (AJOL)

    DELL

    of a small probe were considered death (Su, 1976). Filter paper test. Bioassay on the toxicity of T. orientalis and E. camaldulensis essential oils against adult C. maculates was similar to the method described in Ukeh et al.,. 2012) in Pyrex glass Petri dishes (10 cm diameter). Different doses of each essential oil (0.01, 0.02,.

  6. Agwu et al (6)

    African Journals Online (AJOL)

    DELL

    Enterobacteriaceae, the bacteria Escherichia coli is regarded as non-halophilic, and cannot tolerate high salt concentrations (Abdulkarim et al., 2009). Nevertheless, some strains of E. coli are halo- tolerant and survive in high salt concentrations. The ability to demonstrate such high osmotic pressure is possibly due to the ...

  7. Alabi et al (19)

    African Journals Online (AJOL)

    is attractive as a selective solar absorber since it has high solar absorbency and a low thermal emittance. (Johan et al.,2011). The p-type semiconductor of copper oxide (CuO) is an important functional material used for gas sensors, magnetic storage media, solar energy transformation, electronics, semiconductors, varistors ...

  8. Samuel et al (13)

    African Journals Online (AJOL)

    DELL

    detrimental to the health of the users especially those with wounds on their skin. Keywords: Microbial contaminant, shea butter, local ... natural plant extract is almost magical in its healing effects on burns, skin rashes, ulcerated skin, ... aging and troubled skin to rejuvenate (Esiegbuya et al.,2014). Recently, there have been ...

  9. Quagraine et al.2

    African Journals Online (AJOL)

    PUBLICATIONS1

    ties, as discussed by Moore et al (2003) include education, retail, employment and other social services. These opportunities serve as both ru- ral or suburban push and urban pull factors for migration into major cities in Ghana (Ghana. Statistical Service, (GSS) 2005). Thus, about. 75% of migrants into the major cities in ...

  10. Hamid et al (24)

    African Journals Online (AJOL)

    USER

    acne, and eye problems (Diaz-Bolio, 1975). Cnidoscolus aconitifolius roots and leaves have been taken as a laxative, diuretic, circulation stimulant, to increase digestion, stimulant for lactation, and to harden the fingernails (Rowe, 1994; Kuti, and. Torres, 1996). Oyagbemi et al., (2011) reported the proximate analysis and ...

  11. Nanomechanical DNA Origami pH Sensors

    Directory of Open Access Journals (Sweden)

    Akinori Kuzuya

    2014-10-01

    Full Text Available Single-molecule pH sensors have been developed by utilizing molecular imaging of pH-responsive shape transition of nanomechanical DNA origami devices with atomic force microscopy (AFM. Short DNA fragments that can form i-motifs were introduced to nanomechanical DNA origami devices with pliers-like shape (DNA Origami Pliers, which consist of two levers of 170-nm long and 20-nm wide connected at a Holliday-junction fulcrum. DNA Origami Pliers can be observed as in three distinct forms; cross, antiparallel and parallel forms, and cross form is the dominant species when no additional interaction is introduced to DNA Origami Pliers. Introduction of nine pairs of 12-mer sequence (5'-AACCCCAACCCC-3', which dimerize into i-motif quadruplexes upon protonation of cytosine, drives transition of DNA Origami Pliers from open cross form into closed parallel form under acidic conditions. Such pH-dependent transition was clearly imaged on mica in molecular resolution by AFM, showing potential application of the system to single-molecular pH sensors.

  12. Nanomechanical DNA origami pH sensors.

    Science.gov (United States)

    Kuzuya, Akinori; Watanabe, Ryosuke; Yamanaka, Yusei; Tamaki, Takuya; Kaino, Masafumi; Ohya, Yuichi

    2014-10-16

    Single-molecule pH sensors have been developed by utilizing molecular imaging of pH-responsive shape transition of nanomechanical DNA origami devices with atomic force microscopy (AFM). Short DNA fragments that can form i-motifs were introduced to nanomechanical DNA origami devices with pliers-like shape (DNA Origami Pliers), which consist of two levers of 170-nm long and 20-nm wide connected at a Holliday-junction fulcrum. DNA Origami Pliers can be observed as in three distinct forms; cross, antiparallel and parallel forms, and cross form is the dominant species when no additional interaction is introduced to DNA Origami Pliers. Introduction of nine pairs of 12-mer sequence (5'-AACCCCAACCCC-3'), which dimerize into i-motif quadruplexes upon protonation of cytosine, drives transition of DNA Origami Pliers from open cross form into closed parallel form under acidic conditions. Such pH-dependent transition was clearly imaged on mica in molecular resolution by AFM, showing potential application of the system to single-molecular pH sensors.

  13. Discordance between urine pH measured by dipstick and pH meter: implications for methotrexate administration protocols.

    Science.gov (United States)

    Wockenfus, Amy M; Koch, Christopher D; Conlon, Patricia M; Sorensen, Linda D; Cambern, Kari L; Chihak, Amy J; Zmolek, Julie A; Petersen, Amy E; Burns, Bradley E; Lieske, John C; Karon, Brad S

    2013-01-01

    To minimize toxicity of high-dose methotrexate (MTX) therapy, urinary alkalinization with frequent monitoring of urine pH is required. Urine pH is usually assessed by fast and convenient dipstick methods. When urine color interferes with dipstick measurement, as occurs in patients receiving MTX, alternative methods such as pH meters are used. Nursing staff caring for patients on high-dose MTX reported that urine pH results from dipstick and pH analyzers were often clinically discordant. As a result urine pH by dipstick and pH meter were compared in patients on high-dose MTX therapy and patients with normal-colored urine samples. We measured urine pH by dipstick and pH meter in 116 urine samples from 4 patients receiving high-dose MTX therapy, and in 50 normal-colored urine samples from 50 patients not on MTX therapy. In patients on MTX therapy the mean (±standard deviation) bias between dipstick and pH meter urine pH was 0.7±0.4, compared to 0.4±0.3 in patients not on MTX. For patients on MTX clinical concordance between dipstick and pH meter urine results was poor around a clinical cut-off of pH 8.0. Of the 92 samples with a meter urine pH≤8.0, 72 had a discordant value by dipstick (pH>8). Urine pH readings by dipstick and pH meter are not equivalent, and the bias between them is exacerbated in patients on MTX. Institutions with high-dose MTX therapy protocols should not alternate between dipstick and pH meter urine pH monitoring. Copyright © 2012 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  14. Metal extraction from Cetraria islandica (L. Ach. lichen using low pH solutions

    Directory of Open Access Journals (Sweden)

    ANA A. CUCULOVIC

    2008-04-01

    Full Text Available Extraction of metals (K, Al, Ca, Mg, Fe, Cu, Ba, Zn, Mn and Sr from dry Cetraria islandica (L. Ach. lichen was performed using solutions similar to acid rain (solution A – H2SO4–HNO3–(NH42SO4 and solution B – H2SO4–HNO3–(NH42SO4–NH4NO3. The pH values of these solutions were 2.00, 2.58, 2.87, 3.28, and 3.75. Five consecutive extractions were performed with each solution. In all solutions, the extracted metal content, except Cu and Ca, was the highest in the first extract. The highest percentage of the metals desorbed in the first extraction was obtained using solutions with low pH values, 2.00, 2.58, and 2.87. The lowest percentage in the first extraction was obtained using solutions with pH 3.28 and 3.75, indicating influence of the H+ ion on the extraction. According to the results obtained, the investigated metals form two groups. The first group includes K, Al, Ca, Mg, and Fe. They were extracted in each of the five extractions at each of the pH values. The second group includes Ba, Zn, Mn, Cu, and Sr, which were not all extracted at each pH value. The first group yielded three types of extraction curves when the logarithms of extracted metal amounts were plotted as a function of the number of successive extractions. These effects indicate that three different positions (centres of metal ion accumulation exist in the lichen (due to sorption, complex formation, or other processes present in the tissues.

  15. Sobrevivência de alevinos de Jundiá (Rhamdia quelen Quoy & Gaimard, 1824 à variação de salinidade da água Survival of fingerlings of the Jundiá (Rhamdia quelen Quoy & Gaimard, 1824 to changes on water salinity

    Directory of Open Access Journals (Sweden)

    Maria Ignez Marchioro

    1999-06-01

    Full Text Available O objetivo deste trabalho foi testar a sobrevivência de alevinos de jundiá a diferentes concentrações de salinidade (sal marinho comum e água do mar, pois o sal é indicado no tratamento de algumas doenças e também para reduzir o estresse durante o manuseio e transporte de peixes. Os alevinos (1,68 ± 0,87g permaneceram de 3 a 7 dias em tanques de 1400l, com água corrente e temperatura entre 23 e 25°C, sendo alimentados diariamente. Após esse período, foram colocados 50 alevinos em tanques de 250l, com circulação fechada, biofiltro e aeração constante. A concentração da água nos tanques foi de 8,0; 9,0; 9,25; 9,50 e 10,0g/l de sal marinho comum ou 10,0; 12,0 e 14,0‰ de água do mar artificial. A sobrevivência dos alevinos foi observada ao longo de 96h. Para cada grupo de testes houve um grupo controle nas mesmas condições, mas com salinidade de 0‰. Não houve mortalidade e alteração do comportamento nos grupos expostos a 8g/l sal marinho comum e a 10‰ água do mar. O grupo exposto a 9g/l sal marinho comum também não apresentou mortalidade, mas houve alteração do comportamento alimentar. O aumento da concentração de sal marinho comum ou da água do mar causou uma elevação da porcentagem de mortalidade e alteração do comportamento alimentar. Como R. quelen suportou sal marinho comum até 9g/l pelo período de 96h, o mesmo pode ser testado na prevenção ou tratamento de doenças e na redução do estresse durante o transporte.The aim of this study was to analyze the survival of fingerlings of Rhamdia quelen to different concentrations of salinity (common marine salt and seawater. Salt is used in the treatment of some fish diseases and to reduce the stress of handling and transport. Fingerlings (1.68 ± 0.87g were kept in a 1400l tank with running freshwater at 23-25°C, for 3 to 7 days, being fed daily. Later groups of 50 specimens were transferred to 250l tanks with a water re-use system. The water

  16. Crescimento e nutrição mineral de mudas de umbuzeiro (Spondias tuberosa Arr. Cam. submetidas a níveis de salinidade em solução nutritiva Growth and mineral nutrition of umbuzeiro seedlings (Spondias tuberosa Arr. Cam. under salt stress in nutrient solution

    Directory of Open Access Journals (Sweden)

    Orlando Sílvio Caires Neves

    2004-10-01

    Full Text Available Para avaliar o crescimento e a nutrição mineral de mudas de umbuzeiro em solução nutritiva com diferentes níveis de NaCl, conduziu-se este experimento em casa-de-vegetação do Departamento de Ciência do Solo da Universidade Federal de Lavras. Adotou-se o delineamento em blocos casualizados com quatro repetições e seis doses de NaCl (0, 20, 40, 60, 80 e 100 mmol L-1. As mudas foram adaptadas na solução de Hoagland a 25%, 33% e 50% da sua força iônica, permanecendo durante 15 dias em cada concentração. Após esse período, conduziram-se as plantas por 60 dias em solução com 100% da força iônica e os tratamentos com NaCl. A troca das soluções foi feita quinzenalmente. O NaCl na solução nutritiva afetou negativamente o crescimento das mudas de umbuzeiro. O umbuzeiro foi classificado como moderadamente tolerante à salinidade quando cultivado em até 31 mmol L-1 de NaCl na solução nutritiva, sendo a compartimentalização nas raízes o possível mecanismo de tolerância à salinidade. A ordem de acumulação dos macronutrientes foi: N > K > Ca > P > S > Mg e N > Ca > K > P > S > Mg, na ausência e com 100 mmol L-1, respectivamente, e a dos micronutrientes, exceto o Cl, foi: Fe > B > Mn > Zn > Cu, independente da concentração de NaCl no meio.To evaluate the growth and the mineral nutrition of umbuzeiro seedlings, under salt stress, an experiment in nutrient solution was conducted, under greenhouse conditions in the Soil Science Department of the Federal University of Lavras, Brazil. The experimental design was randomized blocs, with four replications and six doses of NaCl (0, 20, 40, 60, 80, and 100 mmol L-1. The seedlings were adapted in the Hoagland solution to 25, 33 and 50% of ionic forces, staying for fifteen days in each concentration. After this period the seedlings were conduced for 60 days in nutrient solution with 100% of the ionic force and the treatments with NaCl. The change of the solutions was made biweekly

  17. Vaginal pH: Home-Use Tests

    Science.gov (United States)

    ... a combination of: pH, microscopic examination of the vaginal discharge, amine odor, culture, wet preparation, and Gram stain. Does a positive test mean you have a vaginal infection? No, a positive test (elevated pH) could ...

  18. Biomedical PhD education - an international perspective

    DEFF Research Database (Denmark)

    Mulvany, Michael J.

    2013-01-01

    The PhD, otherwise known as the doctor of philosophy or Dr. Phil., is an internationally recognized degree, indicating that the PhD graduate has received training in research under supervision. Traditionally, the PhD was the route to an academic career, with most successful PhD graduates receiving...... tenured university positions. However, over the past 20–30 years, and particularly the past 10 years, the situation has changed dramatically. Governments in many countries have invested massively in PhD education, believing that trained researchers will contribute to the ‘knowledge society’, and thus...... increase the competitiveness of their countries in the future economies of the world. Thus, only a small fraction of PhD graduates now end up in academic research. Yet, the PhD remains a research degree, and indeed, institutions have become heavily dependent on PhD students for their research output...

  19. (PCP) degradation subjected to pH shock

    African Journals Online (AJOL)

    enoh

    2012-02-08

    Feb 8, 2012 ... Compared with pH = 6.0,. PCP and CODCr removal rate decreased distinctly when. pH was 9.0. Most of the bacteria except methanogenic bacteria could maintain their regular behavior when pH was 6.0, while hardly any bacteria could keep activity when pH was 9.0. During the recovery experiments, the.

  20. Polymeric gel nanoparticle pH sensors for intracellular measurements

    DEFF Research Database (Denmark)

    Almdal, Kristoffer; Andresen, Thomas Lars; Benjaminsen, Rikke Vicki

    pH range is approximately 4 pH units and thus a nanoparticle sensor with two pH sensitive fluorophores is appropriate. With one pH sensitive fluorophore the output from the sensor follows R=R0+R1/10(pKa-pH), where R is the ratio of fluorescence for the two fluorophores, R0 is the minimum value of R...

  1. Decrease in Daphnia egg viability at elevated pH

    NARCIS (Netherlands)

    Vijverberg, J.; Kalf, D.F.; Boersma, M.

    1996-01-01

    The effect of high pH on the reproduction of two Daphnia galeata clones was experimentally investigated in the laboratory. We observed that the mortality of juveniles and adults did not increase with increasing pH in the range pH 9.0- 10.5, which agrees with what is generally reported in the

  2. Indigenous development and airworthiness certification of 15–5 PH ...

    Indian Academy of Sciences (India)

    and good resistance to stress-corrosion cracking in marine atmosphere (Armco 15–5 PH VAC. CE). Because of its ease of fabrication, the 15–5 PH stainless steel has been found economical and appropriate to replace low alloy carbon steels. The PH stainless steel retains useful strengths at temperatures up to 315.

  3. Factores asociados al bajo peso al nacer

    Directory of Open Access Journals (Sweden)

    Georgina J Peraza Roque

    2001-10-01

    Full Text Available El bajo peso al nacer (BPN ha constituido un enigma en la ciencia a través de los tiempos. Múltiples son las investigaciones realizadas acerca de las causas que lo producen y las consecuencias que provoca. Su importancia no solo radica en lo que significa en la morbilidad y la mortalidad infantil, sino que estos niños tienen habitualmente múltiples problemas posteriores. El Programa para la Reducción del BPN señala que los niños nacidos con un peso inferior a los 2 500 g presentan riesgo de mortalidad 14 veces mayor durante el primer año de vida, en comparación con los niños que nacen con un peso normal a término. Dentro de los factores de riesgo del BPN se han encontrado con mayor frecuencia en estudios realizados por diferentes autores, los siguientes: el embarazo en la adolescencia, la desnutrición en la madre, el hábito de fumar, la hipertensión arterial durante el embarazo, la sepsis cervicovaginal, la anemia y los embarazos gemelares, entre otros. Es innegable la influencia que el BPN tiene sobre las futuras generaciones, por lo que debe constituir la diana de los esfuerzos que el médico y la enfermera deben desarrollar en su prevención, sobre todo en la comunidadLow birth weight has been an enigma for Science through times. A lot of research works have been carried out about its causes and consequences. The importance of LBW not only lies in its meaning for infant mortality and morbidity but also in the many problems that low birth weight children regularly face in the future. The program for the reduction of LBW points out that newborns weighing under 2500g have during his/her first year of life a mortality risk 14 times higher than newborns with a normal weight at term. Among the low birth weight risk factors, a number of studies by various authors have frequently found the following; pregnancy at adolescence; undernourishment in mothers, smoking, blood hypertension during pregnancy, cervix-vaginal sepsis; anemia, twin

  4. Intracellular pH in sperm physiology.

    Science.gov (United States)

    Nishigaki, Takuya; José, Omar; González-Cota, Ana Laura; Romero, Francisco; Treviño, Claudia L; Darszon, Alberto

    2014-08-01

    Intracellular pH (pHi) regulation is essential for cell function. Notably, several unique sperm ion transporters and enzymes whose elimination causes infertility are either pHi dependent or somehow related to pHi regulation. Amongst them are: CatSper, a Ca(2+) channel; Slo3, a K(+) channel; the sperm-specific Na(+)/H(+) exchanger and the soluble adenylyl cyclase. It is thus clear that pHi regulation is of the utmost importance for sperm physiology. This review briefly summarizes the key components involved in pHi regulation, their characteristics and participation in fundamental sperm functions such as motility, maturation and the acrosome reaction. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. PH Department: at the heart of CERN

    CERN Document Server

    Antonella Del Rosso

    2014-01-01

    The Physics Department is where the Laboratory’s scientific activity takes place. Some 1000 members of the personnel and 11,000 users work together on CERN’s highly diversified experimental programme. The challenges for the coming years are twofold: maintain the level of excellence that led the Laboratory to the discovery of the Higgs boson, and preserve the diversity of the scientific programme. The new Department Head discusses his vision with us.   Livio Mapelli. “On paper, our plan for the next two years shows no surprises,” says Livio Mapelli, former Deputy Department Head and now, since January, Head of the Physics Department (PH). “We have to finish the completion, consolidation and initial upgrades of the experiments planned for LS1. In 2015, our core activity will be supporting the experiments during the restart of the accelerator complex. However, as physicists, the best reward for us would be to obtain new breakthroughs and importa...

  6. ALS Project Management Manual

    Energy Technology Data Exchange (ETDEWEB)

    Krupnick, Jim; Harkins, Joe

    2000-05-01

    This manual has been prepared to help establish a consistent baseline of management practices across all ALS projects. It describes the initial process of planning a project, with a specific focus on the production of a formal project plan. We feel that the primary weakness in ALS project management efforts to date stems from a failure to appreciate the importance of ''up-front'' project planning. In this document, we present a guide (with examples) to preparing the documents necessary to properly plan, monitor, and control a project's activities. While following the manual will certainly not guarantee good project management, failure to address the issues we raise will dramatically reduce the chance of success. Here we define success as meeting the technical goals on schedule and within the prescribed budget.

  7. Relation between pH in the Trunk and Face: Truncal pH Can Be Easily Predicted from Facial pH

    OpenAIRE

    Kim, Sung Ae; Kim, Bo Ri; Chun, Mi Young; Youn, Sang Woong

    2016-01-01

    Background The clinical symptoms of facial and truncal acne differ. Skin surface acidity (pH), which is affected by sebum secretions, reflects the different clinical characteristics of the face and trunk. However, no studies have been conducted on truncal sebum production and skin pH. Objective We evaluated the differences and relationship between pH values of the face and trunk. We also evaluated the relationship between pH and the quantity of sebum produced in the trunk. Methods A total of ...

  8. Comparison of Rumen Fluid pH by Continuous Telemetry System and Bench pH Meter in Sheep with Different Ranges of Ruminal pH

    Directory of Open Access Journals (Sweden)

    Leonardo F. Reis

    2014-01-01

    Full Text Available We aimed to compare the measurements of sheep ruminal pH using a continuous telemetry system or a bench pH meter using sheep with different degrees of ruminal pH. Ruminal lactic acidosis was induced in nine adult crossbred Santa Ines sheep by the administration of 15 g of sucrose per kg/BW. Samples of rumen fluid were collected at the baseline, before the induction of acidosis (T0 and at six, 12, 18, 24, 48, and 72 hours after the induction for pH measurement using a bench pH meter. During this 72-hour period, all animals had electrodes for the continuous measurement of pH. The results were compared using the Bland-Altman analysis of agreement, Pearson coefficients of correlation and determination, and paired analysis of variance with Student’s t-test. The measurement methods presented a strong correlation (r=0.94, P<0.05 but the rumen pH that was measured continuously using a telemetry system resulted in lower values than the bench pH meter (overall mean of 5.38 and 5.48, resp., P=0.0001. The telemetry system was able to detect smaller changes in rumen fluid pH and was more accurate in diagnosing both subacute ruminal lactic acidosis and acute ruminal lactic acidosis in sheep.

  9. Comparison of rumen fluid pH by continuous telemetry system and bench pH meter in sheep with different ranges of ruminal pH.

    Science.gov (United States)

    Reis, Leonardo F; Minervino, Antonio H H; Araújo, Carolina A S C; Sousa, Rejane S; Oliveira, Francisco L C; Rodrigues, Frederico A M L; Meira-Júnior, Enoch B S; Barrêto-Júnior, Raimundo A; Mori, Clara S; Ortolani, Enrico L

    2014-01-01

    We aimed to compare the measurements of sheep ruminal pH using a continuous telemetry system or a bench pH meter using sheep with different degrees of ruminal pH. Ruminal lactic acidosis was induced in nine adult crossbred Santa Ines sheep by the administration of 15 g of sucrose per kg/BW. Samples of rumen fluid were collected at the baseline, before the induction of acidosis (T 0) and at six, 12, 18, 24, 48, and 72 hours after the induction for pH measurement using a bench pH meter. During this 72-hour period, all animals had electrodes for the continuous measurement of pH. The results were compared using the Bland-Altman analysis of agreement, Pearson coefficients of correlation and determination, and paired analysis of variance with Student's t-test. The measurement methods presented a strong correlation (r = 0.94, P pH that was measured continuously using a telemetry system resulted in lower values than the bench pH meter (overall mean of 5.38 and 5.48, resp., P = 0.0001). The telemetry system was able to detect smaller changes in rumen fluid pH and was more accurate in diagnosing both subacute ruminal lactic acidosis and acute ruminal lactic acidosis in sheep.

  10. Pemikiran Filsafat Al-kindi

    OpenAIRE

    Madani, Abu Bakar

    2015-01-01

    Al-Kindi is the first Muslim philosopher to construct Islamic philosophical thoughts in a systematic and clear way. Philosophical thoughts of Al-Kindi are reflection of doctrines that he received from classic Greece sources and the legacy of Neo-Platonic thoughts combined with Islamic faith. Al-Kindi opens the room of dialogue to combine philosophical doctrines and religion. Knowledge about God, according to Al-Kindi, is early philosophy or the first philosophy; philosophy that states al-Haqq...

  11. Derecho al desarrollo y globalidad

    OpenAIRE

    Álvarez Vita, Juan

    2014-01-01

    La presente disertación, que he intitulado Derecho al Desarrollo y Globalidad, consta de cuatropuntos principales:I. El derecho al desarrollo en el contexto de los derechos humanosII. La noción del derecho al desarrolloIII. El derecho al desarrollo en el marco de las llamadas generaciones de derechos humanosIV. El derecho al desarrollo y la aldea globalPalabras clave: derechos humanos, Derecho Natural, Derecho Positivo, sociedad global.

  12. Religion als soziale Deutungspraxis

    Directory of Open Access Journals (Sweden)

    Ulrike Lingen-Ali

    2016-12-01

    Full Text Available ENGLISH: During the last decades, the topos religion transformed into a powerful category of difference, which is also relevant for educationsystems and settings. Religion as a tool to differentiate between subjects is linked with power and dominance and, thus,with ideas about the constructed identities of “the other”. With this respects, religion functions as a code to define in- andexclusions and mark “the other”, e.g. “the Muslim” in predominantly Christian societies in Europe. Critical theories on racismenable to recognize, describe and define these practices and their effects. They can provide a useful tool to question and challengeintercultural and interreligious educational approaches which potentially reproduce and, thus, strengthen cultural/religiousdifferentiations. DEUTSCH: Die Differenz- und Heterogenitätskategorie Religion hat sich in den letzten Jahren im europäischen und auch deutschsprachigenDiskursraum zu einer medial, wissenschaftlich und politisch wirkmächtigen Kategorie entwickelt. Dabei zeigt sich Religion sowohlals soziale Unterscheidungspraxis (auch in pädagogischen Arrangements, als auch als Mittel zur Identifikation und Charakterisierungbestimmter Gruppen und Individuen als religiöse Subjekte. Religion stellt in diesem Zusammenhang einen Zugehörigkeitscodedar, mit dem Personen als natio-ethno-kulturell Andere markiert werden, wie die Markierung von MuslimInnen durchAngehörige der mehrheitlich christlichen Dominanzgesellschaft zeigt. Rassismuskritische Ansätze ermöglichen es zumeist eherimplizit an Rassekonstruktionen anschließende Unterscheidungen zu erkennen und zu beschreiben, den Bedingungen ihres Wirksamwerdensnachzugehen sowie ihre Konsequenzen zu bestimmen. Eine rassismuskritische und migrationspädagogisch informierteReligionspädagogik ermöglicht AkteurInnen, weniger auf gewaltvolle Unterscheidungspraxen angewiesen zu sein undalternative Veränderungs- und Handlungsmöglichkeiten zu

  13. DEUTSCHLAND ALS EINWANDERUNGSLAND

    OpenAIRE

    IVANDA, Katica

    2010-01-01

    Die vorliegende Arbeit versucht einen kurzen sozialhistorischen Überblick über das Migrationsgeschehen in Deutschland zu geben. Aus dem Auswanderungsland des 19. Jahrhunderts wurde ein Einwanderungsland neuen Typs. Die Anwerbephase der 60er-Jahre erweist sich retrospektiv als zeitliches Bindeglied zum „Einwanderungsland wider Willen“. Obgleich alle Beteiligten auf deutscher wie ausländischer Seite noch lange am Gastarbeitermythos der baldigen Rückkehr in die jeweiligen...

  14. Ausbildung als zentrale Aufgabe

    Science.gov (United States)

    Krämer, Walter; Schmerbach, Sibylle

    Anders als Lesen und Schreiben zählen Grundkenntnisse in Statistik heute noch nicht zu den Voraussetzungen einer sinnvollen Teilhabe am Sozialgeschehen. Und auch in der akademischen Statistik-Ausbildung gibt es noch einiges zu tun. Das vorliegende Kapitel zeichnet die Geschichte dieser akademischen Ausbildung an deutschen Universitäten nach dem zweiten Weltkrieg nach, stellt aktuelle Defizite vor und weist auf mögliche Verbesserungen hin.

  15. Disentangling the effects of low pH and metal mixture toxicity on macroinvertebrate diversity

    Science.gov (United States)

    Fornaroli, Riccardo; Ippolito, Alessio; Tolkkinen, Mari J.; Mykrä, Heikki; Muotka, Timo; Balistrieri, Laurie S.; Schmidt, Travis S.

    2018-01-01

    One of the primary goals of biological assessment of streams is to identify which of a suite of chemical stressors is limiting their ecological potential. Elevated metal concentrations in streams are often associated with low pH, yet the effects of these two potentially limiting factors of freshwater biodiversity are rarely considered to interact beyond the effects of pH on metal speciation. Using a dataset from two continents, a biogeochemical model of the toxicity of metal mixtures (Al, Cd, Cu, Pb, Zn) and quantile regression, we addressed the relative importance of both pH and metals as limiting factors for macroinvertebrate communities. Current environmental quality standards for metals proved to be protective of stream macroinvertebrate communities and were used as a starting point to assess metal mixture toxicity. A model of metal mixture toxicity accounting for metal interactions was a better predictor of macroinvertebrate responses than a model considering individual metal toxicity. We showed that the direct limiting effect of pH on richness was of the same magnitude as that of chronic metal toxicity, independent of its influence on the availability and toxicity of metals. By accounting for the direct effect of pH on macroinvertebrate communities, we were able to determine that acidic streams supported less diverse communities than neutral streams even when metals were below no-effect thresholds. Through a multivariate quantile model, we untangled the limiting effect of both pH and metals and predicted the maximum diversity that could be expected at other sites as a function of these variables. This model can be used to identify which of the two stressors is more limiting to the ecological potential of running waters.

  16. Proximity effect Nb/Al,AlOxide, Al/Nb Josephson tunnel junctions

    NARCIS (Netherlands)

    Houwman, Evert Pieter; Gijsbertsen, J.G.; Gijsbertsen, Hans; Flokstra, Jakob; Rogalla, Horst; Le grand, J.B.; de Korte, P.A.J.; Golubov, Alexandre Avraamovitch

    1993-01-01

    Regions with reduced energy gap induced by the proximity effect give rise to quasi-particle loss in Josephson-junction X-ray detectors, but may also be used advantageously for quasi-particle collection. The influence of the thickness of the Al proximity layers in Nb/Al1 , AlOx, Al2/Nb Josephson

  17. pH in atomic scale simulations of electrochemical interfaces

    DEFF Research Database (Denmark)

    Rossmeisl, Jan; Chan, Karen; Ahmed, Rizwan

    2013-01-01

    Electrochemical reaction rates can strongly depend on pH, and there is increasing interest in electrocatalysis in alkaline solution. To date, no method has been devised to address pH in atomic scale simulations. We present a simple method to determine the atomic structure of the metal......|solution interface at a given pH and electrode potential. Using Pt(111)|water as an example, we show the effect of pH on the interfacial structure, and discuss its impact on reaction energies and barriers. This method paves the way for ab initio studies of pH effects on the structure and electrocatalytic activity...

  18. Evaluating high pH for control of dreissenid mussels

    Directory of Open Access Journals (Sweden)

    Dave Evans

    2013-04-01

    Full Text Available Two field experiments were carried out using a custom built flow-through laboratory to test the effect of elevated pH on dreissenid musselsas a potential control method. Both experiments tested the ability of dreissenid pediveligers to settle under conditions of elevated pH and thelong-term survival of adult dreissenids under the same conditions. The two experimental sites had different water quality and differentspecies of dreissenids present. The settlement of quagga mussel pediveligers at the lower Colorado River was inhibited with increasing pH.At the maximum achieved pH of 9.1, there was approximately 90% reduction compared to the maximum settlement observed in the controls.Since the settlement was almost as low in pH 8.9 as at pH 9.1, the inhibition in settlement may have been due to the presence of a precipitateformed under high pH conditions rather than the increase in background pH. No mortality of quagga mussel adults was observed in theexperimental pH levels at the lower Colorado River. At San Justo Reservoir, zebra mussel settlement decreased with increasing pH. Newsettlement was almost entirely absent at the highest pH tested (pH 9.6. The observed mortality of adult zebra mussels was low, but did tendto increase with increasing pH. We also tested the response of adult zebra mussels to short-term exposure to very high pH levels (i.e. pH 10,11, and 12. Adult mussels in poor physical condition experienced 90% mortality after 12 hours at pH 12. For unstressed adult zebra mussels,90% mortality was reached after 120 hours at pH 12. Significant mortalities were also observed both at pH 10 and pH 11. From this study,we conclude that pH elevation could be used both as a preventative treatment to eliminate settlement by dreissenid mussels and as an end ofseason treatment to eliminate adults. The high pH treatment would have to be tailored to the site water quality to prevent formation ofprecipitate during treatment and to minimize corrosive

  19. ph Sensitive hydrogel as colon specific drug delivery

    International Nuclear Information System (INIS)

    Alarifi, A.S.

    2011-01-01

    γ-radiation induced graft copolymerization and crosslinking was for the synthesis of ph-sensitive hydrogels composed of poly (vinyl pyrrolidone) acrylic acid. The prepared hydrogels were subjected to swelling test to evaluate the effects of ph and ionic strength of the surrounding solution. Drastic changes in the swelling parameters where observed by changing the surrounding solution ph values. The release of ibuprofen from hydrogels was monitored as a function of time at ph 1 and ph 7 in order to evaluate the prepared copolymer ability for colon- specific drug carrier uses.

  20. The effects of low pH and elevated aluminum on yellowstone cutthroat trout (Oncorhynchus clarki bouvieri)

    International Nuclear Information System (INIS)

    Farag, A.M.; Woodward, D.F.; Little, E.E.; Steadman, B.; Vertucci, F.A.

    1993-01-01

    Although acid deposition is not considered a problem in the western US, surface waters in high elevations and fish inhabiting these waters may be vulnerable to acidification. This study examined the sensitivity of a wester salmonid to acid and aluminum stress. Yellowstone cutthroat trout (Oncorhynchus clarki bouvieri; YSC) were exposed for 7 d during each of four early life stages, or continuously from fertilization to 40 d post-hatch, to decreased pH and elevated Al. The authors monitored survival, growth, whole-body ion content, and behavior of the exposed fish. Sensitivity of early life stages of YSC may be expressed by survival or by survival and sublethal effects. In their study, eggs were the most sensitive life stage of YSC to low pH if survival alone was considered. However, the sublethal effects on growth, tissue ion content, and behavior revealed the alevins and swim-up larvae were more sensitive to reduced pH and increased Al than eggs or eyed embryos. They also observed that survival was significantly decreased if YSC were exposed to pH 6.0 and 50 μg Al per liter continuously from fertilization to 40 d post-hatch

  1. Random coil chemical shift for intrinsically disordered proteins: effects of temperature and pH

    International Nuclear Information System (INIS)

    Kjaergaard, Magnus; Brander, Søren; Poulsen, Flemming M.

    2011-01-01

    Secondary chemical shift analysis is the main NMR method for detection of transiently formed secondary structure in intrinsically disordered proteins. The quality of the secondary chemical shifts is dependent on an appropriate choice of random coil chemical shifts. We report random coil chemical shifts and sequence correction factors determined for a GGXGG peptide series following the approach of Schwarzinger et al. (J Am Chem Soc 123(13):2970–2978, 2001). The chemical shifts are determined at neutral pH in order to match the conditions of most studies of intrinsically disordered proteins. Temperature has a non-negligible effect on the 13 C random coil chemical shifts, so temperature coefficients are reported for the random coil chemical shifts to allow extrapolation to other temperatures. The pH dependence of the histidine random coil chemical shifts is investigated in a titration series, which allows the accurate random coil chemical shifts to be obtained at any pH. By correcting the random coil chemical shifts for the effects of temperature and pH, systematic biases of the secondary chemical shifts are minimized, which will improve the reliability of detection of transient secondary structure in disordered proteins.

  2. [Vulvovaginitis: vaginal pH changes and associated microflora].

    Science.gov (United States)

    Saturnino, Ana Conceiçáo Ribeiro Dantas; Sisenando, Herbert Ary Arzabe Anteza Costa Nóbrega; Pereira, Alessandra Ramalho; Vale, Ana Patrícia Medeiros; Pires, Leila Monte; de Araújo, Jarine Torres; Ramos, Eleni Souto Nóbrega

    2005-01-01

    To establish a correlation between pH vaginal and the microflora associated in carriers of vulvovaginites. In the present study, the cytopathological examination and the vaginal flow in a group of 65 sexually active women had been carried through, 20 and 72 years, taken care of in the Laboratório de Citologia Clínica do Departamento de Análises Clínicas e Toxicológicas da Universidade Federal do Rio Grande do Norte, for determination of microorganisms in cervicovaginal sample and of pH in the vaginal flow. Associating pH vaginal with the presence of vulvovaginitis, it was evidenced that the Candida sp. occurred more frequently in pH 4.0, Trichomonas vaginalis in pH 6.0, Gardnerella vaginalis in pH 5.0, coconuts in pH 5.0, bacilli in pH 4.0 and cocos/bacilos in pH 6.0. It was observed that all the patients had presented at least one type of ethiological agent of vulvovaginiti and an associated microflora. The joint accomplishment of the cytological examinations and the determination of pH revealed important for directing the microflora associated with the vulvovaginiti, suggesting, of this form, that pH vaginal plays preponderant role how much to the presence of the infectious agents in the vaginal ecosystem.

  3. Aluminum coprecipitates with Fe (hydr)oxides: Does isomorphous substitution of Al 3+ for Fe 3+ in goethite occur?

    Science.gov (United States)

    Bazilevskaya, Ekaterina; Archibald, Douglas D.; Aryanpour, Masoud; Kubicki, James D.; Martínez, Carmen Enid

    2011-08-01

    Iron (hydr)oxides are common in natural environments and typically contain large amounts of impurities, presumably the result of coprecipitation processes. Coprecipitation of Al with Fe (hydr)oxides occurs, for example, during alternating reduction-oxidation cycles that promote dissolution of Fe from Fe-containing phases and its re-precipitation as Fe-Al (hydr)oxides. We used chemical and spectroscopic analyses to study the formation and transformation of Al coprecipitates with Fe (hydr)oxides. In addition, periodic density functional theory (DFT) computations were performed to assess the structural and energetic effects of isolated or clustered Al atoms at 8 and 25 mol% Al substitution in the goethite structure. Coprecipitates were synthesized by raising the pH of dilute homogeneous solutions containing a range of Fe and Al concentrations (100% Fe to 100% Al) to 5. The formation of ferrihydrite in initial suspensions with ⩽20 mol% Al, and of ferrihydrite and gibbsite in initial suspensions with ⩾25 mol% Al was confirmed by infrared spectroscopic and synchrotron-based X-ray diffraction analyses. While base titrations showed a buffer region that corresponded to the hydrolysis of Fe in initial solutions with ⩽25 mol% Al, all of the Al present in these solutions was retained by the solid phases at pH 5, thus indicating Al coprecipitation with the primary Fe hydroxide precipitate. In contrast, two buffer regions were observed in solutions with ⩾30 mol% Al (at pH ˜2.25 for Fe 3+ and at pH ˜4 for Al 3+), suggesting the formation of Fe and Al (hydr)oxides as two separate phases. The Al content of initial coprecipitates influenced the extent of ferrihydrite transformation and of its transformation products as indicated by the presence of goethite, hematite and/or ferrihydrite in aged suspensions. DFT experiments showed that: (i) optimized unit cell parameters for Al-substituted goethites (8 and 25 mol% Al) in clustered arrangement (i.e., the formation of diaspore

  4. Electrochemical oxidation of 4-chloro phenol over a carbon paste electrode modified with Zn Al layered double hydroxides

    Energy Technology Data Exchange (ETDEWEB)

    Hernandez F, D.; Palomar P, M.; Licona S, T. de J.; Romero R, M. [Universidad Autonoma Metropolitana, Unidad Azcapotzalco, Departamento de Materiales, Av. San Pablo 180, Col. Reynosa-Tamaulipas, 02200 Mexico D. F. (Mexico); Valente, Jaime S., E-mail: mepp@correo.azc.uam.mx [Instituto Mexicano del Petroleo, Eje Central No. 152, 07730 Mexico D. F. (Mexico)

    2014-07-01

    A study is presented on the electrochemical oxidation of 4-chloro phenol (4cp) in aqueous solution using a bare carbon paste electrode, Cpe, and another one that was modified with Zn Al layered double hydroxides (Cpe/Zn Al-LDH). The electro-oxidation was effected at ph values ranging from 3 up to 11. It was found through cyclic voltammetry that this process was irreversible, namely, there were no reduction peaks, and that depending on the nature of the electrode, the anodic current was limited either by adsorption (Cpe) or diffusion (Cpe/Zn Al-LDH). The energy required and the oxidation reaction rate depended on the ph and on the nature of the electrode, such that the greater rates were obtained when the Cpe/Zn Al-LDH electrode and acid ph were used. The Zn Al-LDH was characterized by means of X-ray diffraction. (Author)

  5. Skin pH, Atopic Dermatitis, and Filaggrin Mutations

    DEFF Research Database (Denmark)

    Bandier, Josefine; Johansen, Jeanne Duus; Petersen, Lars Jelstrup

    2014-01-01

    mutations may influence skin pH. OBJECTIVE: We aimed to determine the epidermal pH in different groups stratified by filaggrin mutations and atopic dermatitis. Further, we investigated the changes in pH according to severity of mutational status among patients with dermatitis, irrespective of skin condition....... METHODS: pH was measured with a multiprobe system pH probe (PH 905), and the study population was composed of 67 individuals, who had all been genotyped for 3 filaggrin mutations (R501X, 2282del4, R2447X). RESULTS: We found no clear pattern in relation to filaggrin mutation carrier status. Individuals...... with wild-type filaggrin displayed both the most acidic and most alkaline values independent of concomitant skin disease; however, no statistical differences between the groups were found. CONCLUSIONS: The lack of significant diversity in skin pH in relation to filaggrin mutation carrier status suggests...

  6. SALIVARY PH CHANGES AFTER GIC RESTORATION ON DECIDUOUS TEETH

    Directory of Open Access Journals (Sweden)

    Chandra Nila Sukma

    2015-06-01

    Full Text Available Glass Ionomer Cement (GIC is the most widely used material in pediatric dentistry. The purpose of this study was to analyze pH changes of saliva after GIC restoration on primary teeth. For this purpose, 20 primary canines which were restored with GIC 24 hours previously were plunged into 20 tubes containing each 1,5 ml pH 6,8 Fusayama artificial saliva and then stored in incubator at the temperature of 37°C. The pH changes were measured at 30, 60, and 90 minutes later with digital pH meter PH-201. It was revealed that the highest pH acceleration was at 30 minutes exposure an decrease thereafter and the lowest pH acceleration was at 90 minutes exposure. Statistical analysis was performed by Anova and Tukey HSD.

  7. Net acidity indicates the whole effluent toxicity of pH and dissolved metals in metalliferous saline waters.

    Science.gov (United States)

    Degens, Bradley P; Krassoi, Rick; Galvin, Lynette; Reynolds, Brad; Micevska, Tina

    2018-05-01

    Measurements of potential acidity in water are used to manage aquatic toxicity risks of discharge from acid sulfate soils or acid mine drainage. Net acidity calculated from pH, dissolved metals and alkalinity is a common measurement of potential acidity but the relevance of current risk thresholds to aquatic organisms are unclear. Aquatic toxicity testing was carried out using four halophytic organisms with water from four saline sources in southern Western Australia (3 acidic drains and one alkaline river; 39-40 g TDS/L) where acidity was varied by adjusting pH to 4.5-6.5. The test species were brine shrimps (Artemia salina), locally sourced ostracods (Platycypris baueri), microalgae (Dunaliella salina) and amphipods (Allorchestes compressa). Testing found the EC 10 and IC 10 of net acidity ranged from -7.8 to 10.5 mg CaCO 3 /L with no survival or growth of any species at >47 mg CaCO 3 /L. Reduced net acidity indicated reduced whole effluent toxicity more reliably than increased pH alone with organisms tolerating pH up to 1.1 units lower in the absence of dissolved metals. Variation in toxicity indicated by net acidity was mostly attributed to reduced concentrations of dissolved Al and Fe combined with higher pH and alkalinity and some changes in speciation of Al and Fe with pH. These results indicate that rapid in-field assessments of net acidity in acidic, Al dominated waters may be an indicator of potential acute and sub-chronic impacts on aquatic organisms. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

  8. Englisch als Weltsprache

    OpenAIRE

    Locher, Miriam A.

    2011-01-01

    In den Medien wird Englisch oft als die Weltsprache schlechthin dargestellt. So titelte zum Beispiel Newsweek am 7. März 2005: «Who owns English? Non-native speakers are transforming the Global Language», und im Internet gibt es eine beachtliche Anzahl kommerzieller Unternehmen, die «Global English» anbieten. Was aber ist «Global English» und wie kam es überhaupt zu einer derart weiten Verbreitung und der überaus großen Bedeutung des Englischen in der heutigen Zeit? Der vorliegende Aufsatz wi...

  9. Del Pasadismo al Futurismo

    OpenAIRE

    Agudo-Martínez, M. J.

    2003-01-01

    Uno de los habituales prejuicios a la hora de abordar el análisis del movimiento futurista, al igual que sucede con el constructivismo, es la consideración del contexto político en el que se desarrollaron ambas vanguardias. Sin embargo, y dejando a un lado un enfoque del arte con finalidad política de signo diverso, habría que insistir en el hecho de que posiblemente sean tanto el futurismo italiano como el constructivismo ruso, los movimientos que con mayor entusiasmo se manifestaron, en un ...

  10. Programa Padres al Colegio

    OpenAIRE

    Viñeglas Fernández, Sandra

    2014-01-01

    El presente trabajo, es un proyecto orientado a la promoción de la salud, en referencia al virus del papiloma humano (VPH), ya que este virus es el causante de una de las infecciones de transmisión sexual más frecuentes en el mundo, el objetivo de este trabajo, es diseñar una serie de intervenciones que contribuyan a sensibilizar e informar a la ciudadanía, para lograr mejorar la prevención del virus del papiloma humano y el cáncer de cérvix. Como ya es sabido, cualquier intervención sobre...

  11. Efecto de las cargas articulares sobre el flujo y pH salival Effect of TMJ loading on salivary flow and pH

    Directory of Open Access Journals (Sweden)

    RJ Castro

    2011-04-01

    Full Text Available Una alteración del flujo salival es clave en el desarrollo de caries, enfermedad periodontal e infecciones oportunistas. El flujo salival está determinado por diversos estímulos que actúan sobre receptores de distinta naturaleza, entre ellos mecanoreceptores articulares. Algunos estudios demuestran que las cargas articulares actúan sobre estos receptores, modificando cualitativa y cuantitativamente la secreción salival. El objetivo de este estudio fue determinar si existe una relación entre la aplicación controlada de cargas articulares y cambios en el flujo y pH salival. 30 voluntarios fueron seleccionados según criterios de inclusión establecidos. Se elaboró un dispositivo interoclusal que en relación a piezas 1.5 y 2.5, tenía botones acrílicos de 1 mm de espesor, los que al ejercer fuerzas sobre ellos provocan cargas reversibles sobre la ATM. Antes de usar el dispositivo, en cada individuo se midió flujo salival no estimulado (FSNE el flujo salival estimulado (FSE y el pH de ambos. Tras un periodo de adaptación diaria por una semana, cada participante usó el dispositivo durante 1 hora, ejerciendo fuerza masticatoria sostenida. Luego se midieron ambos flujos y el pH correspondiente. El procedimiento fue repetido por 7 días, bajo supervisión. No se observó una relación aparente entre la aplicación controlada de cargas articulares y cambios volumétricos de flujo salival. Las mujeres tuvieron un FSE y FSNE menor al de los hombres. La aplicación de sobrecargas articulares por un breve período de tiempo provoca una caída del pH del FSE luego de 3 días de aplicación.Altered salivary flow is key for the onset of dental caries, periodontal disease and opportunistic infections. Salivary flow is determined by various stimuli on several receptors, including joint mechanoreceptors. Some studies show that loads on the TMJ affect these receptors causing changes on the quality and quantity of saliva secretion. The aim of this

  12. Coral calcifying fluid pH is modulated by seawater carbonate chemistry not solely seawater pH.

    Science.gov (United States)

    Comeau, S; Tambutté, E; Carpenter, R C; Edmunds, P J; Evensen, N R; Allemand, D; Ferrier-Pagès, C; Tambutté, S; Venn, A A

    2017-01-25

    Reef coral calcification depends on regulation of pH in the internal calcifying fluid (CF) in which the coral skeleton forms. However, little is known about calcifying fluid pH (pH CF ) regulation, despite its importance in determining the response of corals to ocean acidification. Here, we investigate pH CF in the coral Stylophora pistillata in seawater maintained at constant pH with manipulated carbonate chemistry to alter dissolved inorganic carbon (DIC) concentration, and therefore total alkalinity (A T ). We also investigate the intracellular pH of calcifying cells, photosynthesis, respiration and calcification rates under the same conditions. Our results show that despite constant pH in the surrounding seawater, pH CF is sensitive to shifts in carbonate chemistry associated with changes in [DIC] and [A T ], revealing that seawater pH is not the sole driver of pH CF Notably, when we synthesize our results with published data, we identify linear relationships of pH CF with the seawater [DIC]/[H + ] ratio, [A T ]/ [H + ] ratio and [[Formula: see text

  13. Virtual PhD courses – A new mode of PhD education?

    OpenAIRE

    Munkvold, Bjørn E.; Zigurs, Ilze; Khazanchi, Deepak

    2012-01-01

    Published version of an article from the proceedings of the NOKOBIT conference. Also available from Tapir:http://www.tapironline.no/fil/vis/1029 This paper presents experiences from a joint virtual PhD course for doctoral students at a Norwegian and a US university. Based on an experiential learning approach, the course focused on practices for virtual research collaboration. Through six synchronous online sessions, interspersed with interaction in sub-teams, the participants worked on dev...

  14. Aluminium (Al) fractionation and speciation; getting closer to describing the factors influencing Al(3+) in water impacted by acid mine drainage.

    Science.gov (United States)

    Chamier, Jessica; Wicht, Merrill; Cyster, Lilburne; Ndindi, Nosintu P

    2015-07-01

    Acid mine drainage (AMD) severely impacts the water chemistry of a receiving resource, changing the occurrence, speciation and toxicity of metals such as Aluminium (Al). The toxicity of Al is determined by its speciation represented by the labile monomer Al fraction or Al(3+). The purpose of the study was to combine fractionation and Visual MINTEQ speciation to calculate the effect of AMD altered water chemistry on Al speciation and Al(3+) concentration. Water in rivers impacted by AMD presented with monomeric Al (Almon) concentrations between 0.35 and 15.37mgL(-)(1) which existed almost exclusively in the toxic labile form (98%). For the reference site, Almon was less than 2% (10μgL(-1)), suggesting significantly lower Al toxicity. Principal component analysis plots illustrated that labile Al was directly related to the total Al and iron concentrations and strongly influenced by parameters such as pH, electrical conductivity, sulphate and dissolved organic carbon. Visual MINTEQ modelling was used to determine the primary Al species distribution. The dominant form of Al in AMD impacted water was AlSO4(+), which increased proportionally with the sulphate and Al(3+) concentration. Heavily impacted areas, presented with an average of 1mgmL(-)(1) Al(3+), which poses a potential human health risk. A novel centrifugal ultrafiltration method was investigated as an alternative to determining Almon to simplify the speciation of Al. Monomeric and centrifugal ultrafiltrated (<10kD) Al fractions were significantly similar (p=0.74), suggesting that ultrafiltration may present a time, energy and cost saving alternative to organic extraction of Almon. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Gliricidia sepium al establecimiento

    Directory of Open Access Journals (Sweden)

    J. L. Valle

    2004-01-01

    Full Text Available Se asoció Cenchrus ciliaris (Cc y Gliricidia sepium (Gs para evaluar la producción de biomasa y la composición química de los forrajes en la fase de establecimiento, en el estado de Morelos, México, en condiciones de trópico seco. Se empleó un análisis de varianza con diseño en bloques al azar, en donde T1 fue pasto solo, T2 Cc más Gs con 5,000 plantas ha-1 y el T3 Cs más Gs con 14,285 plantas ha-1. Se midió la producción de forraje individual y asociado con materia seca (t MS/Ha, la altura (A en cm, la proteína cruda (PC%, las fracciones de fibra (FDN% y FDA% y la digestibilidad in vitro de la materia seca (DIVMS%. El T3 tuvo una mejor producción de biomasa (P0.05. La asociación de 14,285 plantas ha-1 de G. sepium con pasto Cenchrus ciliaris mejoró la producción de biomasa y la disponibilidad total de nutrientes por superficie cultivada al establecimiento

  16. Derivados vinculados al seguro.

    Directory of Open Access Journals (Sweden)

    De Paz Cobo, Sonia

    2003-01-01

    Full Text Available El presente trabajo tiene como objetivo la presentación de los derivados financieros como instrumentos de cobertura de los riesgos del seguro, así como de los principales proyectos que se desarrollan a través de los mismos, como por ejemplo los derivados sobre el clima. Hay que tener presente las pérdidas multimillonarias ocasionadas en casos como el de la banca Baring’s, o el de Orange County, por citar algunas, que si bien ciertos autores afirman que están en relación directa con el uso de estos productos, no podemos olvidar que los instrumentos derivados se desarrollaron con el objetivo principal de proteger al usuario de la posible volatilidad del activo subyacente. Ya en la industria aseguradora los derivados vinculados a tal actividad son instrumentos donde el pago se condiciona a la ocurrencia de su suceso de siniestro, o serie de sucesos múltiples que disparen las pérdidas. Tras el repaso efectuado y la descripción que este tipo de instrumentos puede tener en la gestión del riesgo por parte de la industria aseguradora, concluiremos con la exposición de las relaciones con el reaseguro tradicional así como una breve referencia al futuro de este tipo de instrumentos

  17. AL-USRCRN Station Information

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Documentation of United States Alabama Regional Climate Reference Network (AL-USRCRN) installations in 2006. Installations documented are for AL-USRCRN pilot project...

  18. Chemical genetic screening identifies sulfonamides that raise organellar pH and interfere with membrane traffic.

    Science.gov (United States)

    Nieland, Thomas J F; Feng, Yan; Brown, Jing Xu; Chuang, Tuan Daniel; Buckett, Peter D; Wang, Jin; Xie, Xiao-Song; McGraw, Timothy E; Kirchhausen, Tomas; Wessling-Resnick, Marianne

    2004-07-01

    Chemical genetics seeks to identify small molecules that afford functional dissection of cell biological pathways. Previous screens for small molecule inhibitors of exocytic membrane traffic yielded the identification and characterization of several compounds that block traffic from the Golgi to the cell surface as well as transport from the endoplasmic reticulum to the Golgi network [Feng et al. Proc Natl Acad Sci USA 2003;100:6469-6474; Yarrow et al. Comb Chem High Throughput Screen 2003;6:279-286; Feng et al. EMBO Reports 2004: in press]. Here, we screened these inhibitors for potential effects on endocytic membrane traffic. Two structurally related sulfonamides were found to be potent and reversible inhibitors of transferrin-mediated iron uptake. These inhibitors do not block endoplasmic reticulum-to-Golgi transport, but do disrupt Golgi-to-cell surface traffic. The compounds are members of a novel class of sulfonamides that elevate endosomal and lysosomal pH, down-regulate cell surface receptors, and impair recycling of internalized transferrin receptors to the plasma membrane. In vitro experiments revealed that the sulfonamides directly inhibit adenosine triphosphate (ATP) hydrolysis by the V-ATPase and that they also possess a potent proton ionophore activity. While maintenance of organellar pH is known to be a critical factor in both endocytosis and exocytosis, the precise role of acidification, beyond the uncoupling of ligands from their receptors, remains largely unknown. Identification of this novel class of sulfonamide inhibitors provides new chemical tools to better understand the function of organelle pH in membrane traffic and the activity of V-ATPases in particular.

  19. Dinámica de nutrientes en la fase vegetativa del cultivo del lulo (Solanum quitoense Lam., en respuesta a salinidad con NaCl

    Directory of Open Access Journals (Sweden)

    Flórez Sandra

    2008-08-01

    Full Text Available

    Se evaluó el efecto de tres concentraciones de NaCl (0, 30 y 60 mM sobre el comportamiento de iones presentes en tejido foliar de la planta de lulo, en lixiviados y sustratos utilizados para el cultivo. El experimento se estableció en un invernadero ubicado en Bogotá a 2.556 msnm, con temperatura promedio de 15,6 °C y humedad relativa promedio de 61%. Plántulas de lulo (Solanum quitoense var. quitoense de dos meses de edad se transplantaron en materas con los sustratos: turba rubia (Klassman®, arena cuarcítica y mezcla de suelo, turba y arena en proporción 3:1:1 en peso; además se hizo un tratamiento adicional en suelo, con sistema de fertirriego. Se observó una relación inversa entre las concentraciones de NaCl y la magnitud de los cambios producidos en las plantas. La altura se redujo entre 4% y 16% para plantas en turba y mezcla y 65% para plantas en arena; para las plantas en turba, el área foliar se redujo entre 14% y 17% y para plantas en arena, 65%. La masa seca decreció entre 38% y 50% para plantas en turba. El contenido foliar de nutrientes se afectó por las concentraciones de NaCl. En lixiviados, los iones Ca2+, K+ y Mg2+ incrementaron sus concentraciones en los sustratos orgánicos (turba y mezcla. En los sustratos los contenidos de N se incrementaron, con respecto a las muestras iniciales; lo mismo ocurrió con el Na+, mientras que las concentraciones de K+, Ca2+ y Mg2+ disminuyeron, al compararlas con las obtenidas en las muestras iniciales.

  20. Niveles de carbono orgánico y ph en suelos agrícolas de las regiones pampeana y extrapampeana argentina Organic carbon and ph levels in agricultural soils of the pampa and extra-pampean regions of argentina

    Directory of Open Access Journals (Sweden)

    Hernán René Sainz Rozas

    2011-07-01

    Full Text Available El carbono orgánico (CO y el pH de los suelos son indicadores clave de la salud del suelo. El objetivo de este trabajo fue relevar el contenido de CO y pH actual (0-20 cm de los suelos agrícolas de las regiones pampeana y extrapampeana de la Argentina y realizar mapas con ambas variables, utilizando la mediana de cada partido. Otro objetivo fue comparar la eficiencia de predicción (EP de dos métodos de interpolación: 1 el método inversa de la distancia ponderada (IDP y 2 el método Kriging ordinario (KO. El número de muestras utilizados para CO y pH fue de 31.619 y 31.398, respectivamente, las que fueron tomadas en lotes de producción en 2005 y 2006. Ambos métodos produjeron mapas similares de CO y pH, pero la EP fue ligeramente mayor para el KO (65 a 80% comparado al IDP (63 a 79%. Los valores de CO variaron de 5,5 a 38,0 g kg-1, determinándose los contenidos más bajos al oeste y norte, y los más elevados al sudeste (SE de la región. Los suelos de la mayor parte del área relevada presentaron valores de pH de 6 a 7,5, salvo algunos del norte de Buenos Aires, centro-sur de Santa Fe y este de Córdoba que mostraron valores de pH de 5,5-6. El contenido de CO manifiesta una tendencia declinante e indica la necesidad de aplicar prácticas de manejo de suelo tendientes a revertir este proceso degradativo. El pH de los suelos no sería limitante para la producción de cultivos en la mayor parte del área, pero se pueden presentar potenciales problemas de acidez en determinadas zonas.Soil organic carbon (SOC and pH are considered key indicators of soil health. The objective of this study was to determine SOC and soil pH of agricultural soils (0-20 cm in the pampeana and extrapampeana regions of Argentina and to elaborate maps with both variables, using the median of each county. Soil samples were taken from fields that were sampled in 2005 and 2006 at a 20 cm-soil depth and totalled 31,619 and 31,398 for SOM and pH, respectively. The

  1. Temperature and pH Effects on Alunite Dissolution and Implications for Mars

    Science.gov (United States)

    Miller, J.; Elwood Madden, M.; Madden, A. S.; Pritchett, B. N.

    2013-12-01

    Water is necessary for all known life; therefore, determining the duration of liquid water on Mars is crucial to understanding its habitability. Alunite (KAl3(SO4)2(OH)6) is a hydrated sulfate occurring in wet, acidic environments rich in S and Al. Sulfates have been observed on Mars in areas such as Meridiani Planum and Iani Chaos, providing evidence of liquid water in the past. pH and temperature affect the degree to which minerals dissolve in water, controlling their lifetimes. The purpose of this study is to determine the rate of alunite dissolution in water at varied pH (1-8) and temperature (20-50 °C). Results for alunite are compared to previous works investigating jarosite ((K, H, Na)Fe3(SO4)2(OH)6), the ferric sulfate end-member of the solid solution series. Dissolved K concentrations were used to determine surface area normalized dissolution rates, and compared to A-cation site concentrations in previous jarosite studies. First, pH was set at 1, 2, 4, 5, or 8 at 20 °C. The initial K rate steadily increases with increasing pH; however, the long-term K rate increases at pH 6 (minimum at 6). Initial dissolution rates for alunite (expressed as log rate in units of mol m-2 s-2) range from -9.8 to -11.5 over pH 1-8. Comparable dissolution rates from previous studies range from -7.5 to -9.1 for K-jarosite, and from -6.6 to -7.4 for Na-jarosite. A comparison of all three sulfates shows that Na-jarosite is the fastest, followed by K-jarosite, and finally, alunite is the slowest to dissolve. Dissolution rates of the three sulfates reach minimums at different pHs: alunite at pH 6, K-jarosite at pH 3.8, and Na-jarosite at 3.5. Alunite dissolution rates were further studied at 20, 40, or 50 °C, in unbuffered ultra-pure water. Initial dissolution rates range from -9.84 to -10.8 over 20 to 50 °C. Comparable dissolution rates from previous studies range from -9.2 to -8.59 for K-jarosite, and from -8.80 to -9.50 for Na-jarosite. K-jarosite rates are the fastest

  2. Njan et al (9).cdr

    African Journals Online (AJOL)

    Timothy Ademakinwa

    induced pain through analgesiometer, tail immersion test, hot-plate, and acetic acid-induced analgesic test methods. HME, significantly and dose-dependently produced analgesic effects ... intensive work has been done in this area of ethnopharmacology (Iwalewa et al., 2003,. Omisore et al., 2004, Fadeyi et al., 2004, ...

  3. Carbide precipitates in solution-quenched PH13-8 Mo stainless steel

    Indian Academy of Sciences (India)

    Small-angle neutron scattering (SANS) is an important non- destructive technique to investigate the morphology and size distribution of such precipitates in mesoscopic length scale. PH 13-8 Mo stainless steel (nominal composition in wt%: Cr 12.25–13.25, Ni. 7.5–8.5, Mo 2–2.5, Al 0.9–1.35, C 0.5max, P 0.01max, Si 0.1max ...

  4. Critical review of pH sensing with optical fibers

    Science.gov (United States)

    Baldini, Francesco

    1999-02-01

    The chemical parameter most investigated with optical fibers is doubtless pH. The first pH optical fiber sensor was described in 1980. Since then, more than one hundred and twenty original papers describing different pH sensors have been published, based on absorption-based indicators on fluorophores. Such interest is perfectly justified, since pH detection is essential in many fields of application, ranging from the environment and medicine to industry and process control. Moreover, pH transduction can be used for measuring different chemical species, such as carbon dioxide, ammonia and pesticides. Notwithstanding the great number of prototypes realized in different laboratories all over the world, only a few products are available on the market. A critical analysis of the state of art in pH sensing using optical fibers is described, outlining the advantages and disadvantages of an optical approach.

  5. Relations among pH, sulfate, and metals concentrations in anthracite and bituminous coal-mine discharges, Pennsylvania

    Science.gov (United States)

    Cravotta, III, Charles A.

    2006-01-01

    Water-quality data for discharges from 140 abandoned mines in the Bituminous and Anthracite Coalfields of Pennsylvania illustrate relations among pH, sulfate, and dissolved metal concentrations. The pH for the 140 samples ranged from 2.7 to 7.3, with two modes at pH 2.5 to 4 (acidic) and 6 to 7 (near neutral). Generally, flow rates were smaller and solute concentrations were greater for low-pH samples; flow rates increased with pH. Although the pH distribution was similar for the bituminous and anthracite subsets, the bituminous discharges had smaller median flow rates, greater concentrations of sulfate, iron, and aluminum, and smaller concentrations of barium and lead than anthracite discharges with the same pH values. The observed relations between the pH and constituent concentrations can be attributed to (1) dilution of acidic water by alkaline ground water; (2) solubility control of aluminum, iron, manganese, barium, and lead by hydroxide, sulfate, and/or carbonate minerals; and (3) aqueous sulfate-complex formation. The formation of AlSO4+ and AlHSO4+2 complexes adds to the total dissolved aluminum concentration at pH of equilibrium with aluminum hydroxide or hydroxysulfate minerals and can account for 10 to 20 times greater concentrations of dissolved aluminum in bituminous discharges compared to anthracite discharges at similar pH. Sulfate complexation also can account for 10 to 30 times greater concentrations of dissolved ferric iron concentrations at equilibrium with ferrihydrite (Fe(OH)3) and/or schwertmannite (Fe8O8(OH)4.5(SO4)1.75) at pH of 3 to 5. In contrast, lower barium and lead concentrations in bituminous than anthracite discharges indicates elevated sulfate concentration could decrease mobility of these metals by the formation of insoluble minerals such as barite (BaSO4) or anglesite (PbSO4). Most samples were saturated with barite, but none were saturated with anglesite. Hence, lead concentrations could be controlled by coprecipitation with

  6. Lowering of cytoplasmic pH is essential for growth of Streptococcus faecalis at high pH.

    Science.gov (United States)

    Kakinuma, Y

    1987-09-01

    The growth of Streptococcus faecalis at high pH was significantly stimulated by carbonate. In the absence of added carbonate the cells were unable to grow at a pH above 9.5, but in media containing 50 mM HCO3- they grew even at pH 10.5. Both rate and yield of growth at pH 9.5 were significantly stimulated by as little as 5 mM carbonate. The cytoplasmic pH in growing cells was maintained at about 7.8 to 8.2, whereas the medium pH ranged from 8.4 to 9.5. Nigericin and gramicidin D, ionophores which conduct protons, blocked growth at pH 9.5 but not at pH 7.5. These results indicate that lowering of the cytoplasmic pH is essential for the growth of this organism at high pH.

  7. Salvar al planeta

    Directory of Open Access Journals (Sweden)

    Thomas Sancton

    2015-01-01

    Full Text Available El desastre de Exxon Valdez en Canadá (1989en que derramaron 262 mil barriles de petróleo en las aguas de Alaska cambió la conciencia de los norteamericanos para bien. Comienzan a preocuparse, les gusta ser ecologistas. Se espera que no sea moda o novelería y que asuman el liderazgo para salvar al planeta, pues la deforestación, el incremento de la población, la quema de combustibles fósiles, el calentamiento global, el agujero de ozono sobre la Antártida dejan intuir que la Tierra está en grave peligro. Se recomienda entonces optar por un desarrollo sustentable.

  8. COMENTARIO AL CASO PINOCHET

    Directory of Open Access Journals (Sweden)

    Alberto Contreras Clunes

    2002-01-01

    Full Text Available El fallo en el caso Pinochet tiene distintas formas de ser analizado. De partida, desde un punto de vista político, también constitucional, del derecho penal. Sin embargo, nos abocaremos al estudio desde el punto de vista procesal, en especial a lo referido al Debido Proceso. Para ello se analizará los presupuestos, la solución dada por la Excma. Corte Suprema y las consecuencias del mismo. Además, se criticará la solución dada, desde la óptica de las garantías procesales del imputado, contenidas en el nuevo proceso penal y lo dispuesto en la Constitución y la Convención Americana de Derechos Humanos. Finalmente, se argumentará en favor de una interpretación finalista y armónica de la Constitución y los tratados internacionales de derechos humanos.The verdict of the Pinochet Case has different ways of being analyzed: from the political, the constitutional, and the penal law points of view. However, we will approach this study from the legal point of view, especially to that referred to as the Proper Process. To do this, the budgets, the solution given by the Most Excellent Supreme Court, and its consequences will be analyzed. Furthermore, the given solution will be criticized from the point of view of the legal guarantees of the accused contained in the new penal process and what is contained in the Constitution and in the American Convention of Human Rights. In conclusion, we will argue in favor of a final and harmonious interpretation of the Constitution and the international agreement of human rights.

  9. Spectroscopic determination of pH | Faanu | Journal of Applied ...

    African Journals Online (AJOL)

    A technique of measuring pH at temperature range of 20 - 70 ºC and high pressure conditions of 1 - 200 atmosp-heres has been developed by relating the ratio of absorbance peaks of indicator solutions (basic and acidic) as a function of pH, using ultraviolet-visible spectrophotometer. The pH values of the buffer solutions ...

  10. Measurement of brain pH with positron emission tomography

    International Nuclear Information System (INIS)

    Buxton, R.B.; Alpert, N.M.; Ackerman, R.H.; Wechsler, L.R.; Elmaleh, D.R.; Correia, J.A.

    1985-01-01

    With positron emission tomography (PET) it is now possible to measure local brain pH noninvasively in humans. The application of PET to the determination of pH is relatively new, so only a handful of papers on the subject have appeared in print. This chapter reviews the current strategies for measuring brain pH with PET, discuss methodological problems, and present initial results

  11. Update to Millstone 3 elevated pH tests

    Energy Technology Data Exchange (ETDEWEB)

    Bergmann, C.A.; Perock, J.D. [Westinghouse Electric Corp., Pittsburgh, PA (United States); Hudson, M.J.B.; King, R.W.; Macklin, S. [Northeast Utilities, Hartford, CT (United States)

    1995-03-01

    In view of the potential radiological benefits of elevated coolant pH operation, Northwest Utilities (NU), in support of an EPRI-Westinghouse program, agreed to operate the Millstone 3 plant at the start of its second fuel cycle as a demonstration of the effect of elevated coolant pH on out-of-core radiation fields. Operating with an elevated pH is defined as operating with an average lithium concentration of 3.35 ppm, until reaching an end of cycle pH of 7.2 or 7.4. The plant operated during its second and third cycles with an elevated coolant pH. The end of cycle pH during the second cycle was 7.4, and 7.2 during the third cycle. (During the first cycle, operation was with a coordinated pH of 7.0). Evaluation of the dose rate trends in Millstone 3 after two cycles of elevated coolant pH operation concluded that an elevated coolant pH resulted in a 15 percent lower component dose rate compared to other plants that operated with coordinated pH 6.9. However, due to a possible increase in fuel clad corrosion, operation during cycle 4 was restricted to pH 6.9 coordinated chemistry, with the exception of the last two months during which the pH increased to 7.35. At the end of cycle 4 (EOC4), there was a greater increase in component and crud trap dose rates than expected. This paper reviews the radiological trends in the plant and discusses the potential causes for the increase in the dose rates at EOC4.

  12. Ratiometric Imaging of Extracellular pH in Dental Biofilms.

    Science.gov (United States)

    Schlafer, Sebastian; Dige, Irene

    2016-03-09

    The pH in bacterial biofilms on teeth is of central importance for dental caries, a disease with a high worldwide prevalence. Nutrients and metabolites are not distributed evenly in dental biofilms. A complex interplay of sorption to and reaction with organic matter in the biofilm reduces the diffusion paths of solutes and creates steep gradients of reactive molecules, including organic acids, across the biofilm. Quantitative fluorescent microscopic methods, such as fluorescence life time imaging or pH ratiometry, can be employed to visualize pH in different microenvironments of dental biofilms. pH ratiometry exploits a pH-dependent shift in the fluorescent emission of pH-sensitive dyes. Calculation of the emission ratio at two different wavelengths allows determining local pH in microscopic images, irrespective of the concentration of the dye. Contrary to microelectrodes the technique allows monitoring both vertical and horizontal pH gradients in real-time without mechanically disturbing the biofilm. However, care must be taken to differentiate accurately between extra- and intracellular compartments of the biofilm. Here, the ratiometric dye, seminaphthorhodafluor-4F 5-(and-6) carboxylic acid (C-SNARF-4) is employed to monitor extracellular pH in in vivo grown dental biofilms of unknown species composition. Upon exposure to glucose the dye is up-concentrated inside all bacterial cells in the biofilms; it is thus used both as a universal bacterial stain and as a marker of extracellular pH. After confocal microscopic image acquisition, the bacterial biomass is removed from all pictures using digital image analysis software, which permits to exclusively calculate extracellular pH. pH ratiometry with the ratiometric dye is well-suited to study extracellular pH in thin biofilms of up to 75 µm thickness, but is limited to the pH range between 4.5 and 7.0.

  13. 21 CFR 876.1400 - Stomach pH electrode.

    Science.gov (United States)

    2010-04-01

    ... ion concentration). The pH electrode is at the end of a flexible lead which may be inserted into the... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Stomach pH electrode. 876.1400 Section 876.1400...) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Diagnostic Devices § 876.1400 Stomach pH electrode. (a...

  14. Design of PH sensor signal acquisition and display system

    Science.gov (United States)

    Qian, Huifa; Zhang, Quanzhu; Deng, Yonghong

    2017-06-01

    With the continuous development of sensor manufacturing technology, how to better deal with the signal is particularly important. PH value of the sensor voltage generated by the signal as a signal, through the MCU acquisition A / D conversion, and ultimately through the digital display of its PH value. The system uses hardware and software to achieve the results obtained with the high-precision PH meter to strive to improve the accuracy and reduce error.

  15. Differential Sensor for PH Monitoring of Environmental Objects

    Directory of Open Access Journals (Sweden)

    Romanenko Sergey

    2016-01-01

    Full Text Available Differential pH sensor is proposed. Reference electrode and measuring electrode are the same type. Reference electrode is immersed in standard buffer solution with known pH value. The differential pH sensor has longer service life as compared with the traditionally used sensors with silver chloride reference electrode. Ultrasonic cleaning system is proposed to clean the primary measuring transducer from pollution that form as result of silting during long-term operation with the sensor.

  16. Evaluating Nanoparticle Sensor Design for Intracellular pH Measurements

    DEFF Research Database (Denmark)

    Benjaminsen, Rikke Vicki; Sun, Honghao; Henriksen, Jonas Rosager

    2011-01-01

    quantification of pH is an unfortunate result when measuring pH too close to the limit of the sensitive range of the sensors. Triple-labeled nanosensors with a pH measurement range of 3.2-7.0, which was synthesized by adding two pH-sensitive fluorophores with different pKa to each sensor, seem to be a solution...

  17. Spectral pH dependence of erythrosin B in sol-gel silica coatings and buffered solutions

    Directory of Open Access Journals (Sweden)

    Montero, E.

    2008-02-01

    Full Text Available Thin coatings optically sensitive against pH are obtained by entrapping erythrosin B molecules in a sol-gel silica matrix. Comparisons between optical spectra of erythrosin B in solutions and those once entrapped in silica coatings are performed for pH ranging from 0.5 to 12.0. Significant differences between both kinds of spectra (solutions and coatings of erythrosin B are observed. Main changes are displayed in the absorption spectra for neutral to basic pH. Furthermore, the erythrosin B doped coatings show memory effect or hysteresis in their spectral response against pH. This means that absorption spectra depend on the direction of the pH change. Likewise, the photoluminescent spectra of erythrosin B in buffered solutions exhibit pH dependence and a maximized response in the basic pH range. On contrast, no significant photoluminescence from the erythrosin B entrapped in the silica coatings is observed. Results are mainly discussed on the basis of different optical response of polyprotic forms of erythrosin B and possible interactions between the molecule and oxygen as well as the porous walls of the sol-gel silica matrix. In addition, the presence of diffusional barriers, which hamper the flowing of protons and other associated ions, is taken into account. Good agreement with previous observations about low absorption of polyprotic cationic and neutral forms of erythrosin B is found.

    Se han obtenido recubrimientos delgados ópticamente sensibles al pH mediante atrapamiento de moléculas de eritrosina B en matrices de sílice obtenidas por sol-gel. Se compara la respuesta espectral de la eritrosina B en solución y atrapada en los recubrimientos de sílice para un intervalo de pH comprendido entre 0,5 y 12. Se observan apreciables diferencias entre ambos tipos de espectros (en solución y en recubrimiento de la eritrosina B. Los principales cambios aparecen en los espectros de absorción para el intervalo neutro y básico de pH. Adem

  18. Carta al Editor

    Directory of Open Access Journals (Sweden)

    Darío Maldonado Romero

    1991-03-01

    Full Text Available

    Bogotá, 01 de Agosto de 1990
    Señores
    Miembros del Consejo Editorial
    Academia Nacional de Medicina
    E.S.D.

    Señores doctores:

    Con toda consideración y respeto me permito agregar algunas anotaciones al escrito del Académico Alberto Cárdenas Escobar, aparecido en el No. 22 de Medicina, para destacar algunos aspectos de la personalidad del doctor Alberto Schweitzer galardonado con el Premio Nobel de la Paz.

    A los 30 años de edad tomó una decisión dramática: Estudiar Medicina para trabajaren el África Ecuatorial. Cuando terminó sus investigaciones sobre enfermedades tropicales y sus prácticas hospitaLarias, partió para el Gabon al pequeño pueblo de Lambarené. La tarea era desconsoladora; La atención médica había que prestarla al aire libre; iba con su esposa, como enfermera y amanuense, y no se encontraba ni un intérprete, ni un ayudante. Cuando le llegaron la medicina y el equipaje hubo que acomodarlos en un viejo gallinero abandonado; el calor era insoportable y le venían enfermos de varias millas a la redonda, a pie o en Canoas.

    Las enfermedades más difundidas eran Malaria, Disentería, estreptococias y la más mortífera, la Tripanosomiasis Gambiense, para la que empezaban a llegar medicinas nuevas eficaces y las medidas preventivas como el suministro de agua potable y enmallado de ventanas impedían muchas contaminaciones.

    Pero la que causaba mayores dificultades y trabajo era la Mycobacteriasis Anestesiante, incurable, de difícil diagnóstico, afectando a varios miembros de la misma familia, de aspecto horripilante, con complicaciones neuríticas muy dolorosas, frecuente ceguera, e invalideces y procesos erisepelatososacrotéricos, que exigían acompañante para el cambio y lavado de vendas y suministro de alimentos.

    A menos de un año de

  19. Long term salinity stress in relation to lipid peroxidation, super oxide dismutase activity and proline content of salt-sensitive and salt-tolerant wheat cultivars Estrés salino a largo plazo en relación con peroxidación lipídica, actividad superóxido dismutasa y contenido de prolina de cultivares de trigo sensibles y tolerantes a la salinidad

    Directory of Open Access Journals (Sweden)

    Azam Borzouei

    2012-12-01

    Full Text Available Salinity is a widespread root medium problem limiting productivity of cereal crops worldwide. The ability of plants to tolerate salt is determined by multiple biochemical pathways that facilitate retention and/or acquisition of water, protect chloroplast functions, and maintain ion homeostasis. Therefore, the ability of salt-sensitive ('Tajan' and salt-tolerant cultivar ('Bam' of Triticum aestivum L. to adapt to a saline environment were evaluated in a set of greenhouse experiments under salt stress during three growth stages (tillering, 50% anthesis, and 10 d after anthesis. Plants were irrigated by different saline waters with electrical conductivities of 1.3, 6, 8, 10, and 12 dS m-1, which were obtained by adding NaCl:CaCl2 in 10:1 molar ratio to fresh water. Differences in growth parameters, lipid peroxidation, superoxide dismutase (SOD activity, and proline accumulation were tested in order to put forward the relative tolerance or sensitivity of cultivars. Results indicated that both parameters differ according to the cultivar's ability in coping oxidative stress caused by salinity. We observed a greater decline in the growth parameters and grain yield under salt stress in 'Tajan' than in 'Bam'. Malondialdehyde content was also higher in 'Tajan'. The improved performance of the 'Bam' under high salinity was accompanied by an increase in SOD (EC 1.15.1.1 activity and proline content at all growth stages. Growth parameters, lipid peroxidation and proline accumulation results are also in good correlation with supporting this cultivar is being relatively tolerant.La salinidad es un problema del medio radical ampliamente distribuido que limita la productividad de los cultivos de cereal en todo el mundo. La capacidad de las plantas para tolerar la sal está determinada por multiples vías bioquímicas que facilitan la retención y/o adquisición de agua, protegen las funciones del cloroplasto, y mantienen la homeostasis iónica. Por lo tanto, se

  20. UNESCO-L'ORÉAL-legat til argentinsk DMU-gæsteforsker

    DEFF Research Database (Denmark)

    Voigt, Steen

    2008-01-01

    Carolina Trochine, biolog, ph.d. og i fjor gæsteforsker ved Danmarks Miljøundersøgelser (DMU) ved Aarhus Universitet har modtaget UNESCO-L'ORÉAL's to-årige naturvidenskabelige forskerlegat "Young Women in Life Sciences" for 2008. Udgivelsesdato: 6. marts......Carolina Trochine, biolog, ph.d. og i fjor gæsteforsker ved Danmarks Miljøundersøgelser (DMU) ved Aarhus Universitet har modtaget UNESCO-L'ORÉAL's to-årige naturvidenskabelige forskerlegat "Young Women in Life Sciences" for 2008. Udgivelsesdato: 6. marts...

  1. Cd-Sb-Al system

    International Nuclear Information System (INIS)

    Belotskij, D.P.; Dundich, M.S.; Kotsyumakha, M.P.; Makhova, M.K.; Lesina, N.V.; Noval'kovskij, N.P.

    1985-01-01

    The methods of differential-thermal, microstructural analyses and measuring microhardness are used to investigate the phase diagrams of polythermal sections CdSb-AlSb, CdSb-Al, Cd-AlSb, Cdsub(0.5)Alsub(0.5)-Sb, CdSb-Alsub(0.2)Cdsub(0.8) of the ternary system Cd-Sb-Al. The liquidus projection of the Cd-Sb-Al system is plotted; it has been found that the surface of aluminium antimonide formation occupies a large part of the phase diagram in the field of which the lamination region is located

  2. Fiber Bragg Grating Based pH Sensor

    Science.gov (United States)

    Yulianti, Ian; Sahmah, Abu; Supa'at, M.; Idrus, M.; Kassim, Norazan M.; Al-hetar, Abdulaziz M.

    2011-05-01

    This paper demonstrates the modeling of pH sensor based on pH sensitive hydrogel coated FBG. The modeling was done by simulating the hydrogel swelling behavior, then calculating the strain induced by hydrogel expansion. Meshless numerical method was adopted to solve the Poison Nernst Planck equation coupled to mechanical equation to simulate the hydrogel swelling. The strain induced in the FBG due to mechanical expansion of hydrogel was calculated analytically. Strain of more than 10 μɛ was obtained at pH> 5. At pH of 5, λB shift of more than 10 pm was achieved.

  3. Marine teleost locates live prey through pH sensing.

    Science.gov (United States)

    Caprio, John; Shimohara, Mami; Marui, Takayuki; Harada, Shuitsu; Kiyohara, Sadao

    2014-06-06

    We report that the Japanese sea catfish Plotosus japonicus senses local pH-associated increases in H(+)/CO2 equating to a decrease of ≤0.1 pH unit in ambient seawater. We demonstrated that these sensors, located on the external body of the fish, detect undamaged cryptic respiring prey, such as polychaete worms. Sensitivity is maximal at the natural pH of seawater (pH 8.1 to 8.2) and decreases dramatically in seawater with a pH <8.0. Copyright © 2014, American Association for the Advancement of Science.

  4. Estimativa da acidez potencial pelo pH SMP em solos do semi-árido do Nordeste brasileiro

    OpenAIRE

    C. A. Silva; M. L. Avellar; A. C. C. Bernardi

    2000-01-01

    Neste estudo avaliou-se a relação entre o teor de H + Al e o pH SMP, visando estabelecer uma equação para estimar a acidez potencial de solos do Semi-Árido do Nordeste Brasileiro. As análises dos teores de H + Al e dos valores de pH SMP foram realizadas em 81 amostras de solo, variando os teores de carbono de 1,8 a 35,6 g kg-1 e os de argila de 60 a 590 g kg-1. Os resultados demonstraram que a acidez potencial dessas amostras de solo, expressa em mmol c dm-3, pode ser estimada pelo valor do p...

  5. Extracellular pH modulates GABAergic neurotransmission in rat hypothalamus.

    Science.gov (United States)

    Chen, Z L; Huang, R Q

    2014-06-20

    Changes in extracellular pH have a modulatory effect on GABAA receptor function. It has been reported that pH sensitivity of the GABA receptor is dependent on subunit composition and GABA concentration. Most of previous investigations focused on GABA-evoked currents, which only reflect the postsynaptic receptors. The physiological relevance of pH modulation of GABAergic neurotransmission is not fully elucidated. In the present studies, we examined the influence of extracellular pH on the GABAA receptor-mediated inhibitory neurotransmission in rat hypothalamic neurons. The inhibitory postsynaptic currents (IPSCs), tonic currents, and the GABA-evoked currents were recorded with whole-cell patch techniques on the hypothalamic slices from Sprague-Dawley rats at 15-26 postnatal days. The amplitude and frequency of spontaneous GABA IPSCs were significantly increased while the external pH was changed from 7.3 to 8.4. In the acidic pH (6.4), the spontaneous GABA IPSCs were reduced in amplitude and frequency. The pH induced changes in miniature GABA IPSCs (mIPSCs) similar to that in spontaneous IPSCs. The pH effect on the postsynaptic GABA receptors was assessed with exogenously applied varying concentrations of GABA. The tonic currents and the currents evoked by sub-saturating concentration of GABA ([GABA]) (10 μM) were inhibited by acidic pH and potentiated by alkaline pH. In contrast, the currents evoked by saturating [GABA] (1mM) were not affected by pH changes. We also investigated the influence of pH buffers and buffering capacity on pH sensitivity of GABAA receptors on human recombinant α1β2γ2 GABAA receptors stably expressed in HEK 293 cells. The pH influence on GABAA receptors was similar in HEPES- and MES-buffered media, and not dependent on protonated buffers, suggesting that the observed pH effect on GABA response is a specific consequence of changes in extracellular protons. Our data suggest that the hydrogen ions suppress the GABAergic neurotransmission

  6. The Semen pH Affects Sperm Motility and Capacitation.

    Science.gov (United States)

    Zhou, Ji; Chen, Li; Li, Jie; Li, Hongjun; Hong, Zhiwei; Xie, Min; Chen, Shengrong; Yao, Bing

    2015-01-01

    As the chemical environment of semen can have a profound effect on sperm quality, we examined the effect of pH on the motility, viability and capacitation of human sperm. The sperm in this study was collected from healthy males to avoid interference from other factors. The spermatozoa cultured in sperm nutrition solution at pH 5.2, 6.2, 7.2 and 8.2 were analyzed for sperm total motility, progressive motility (PR), hypo-osmotic swelling (HOS) rate, and sperm penetration. Our results showed that these parameters were similar in pH 7.2 and 8.2 sperm nutrition solutions, but decreased in pH 5.2 and 6.2 solutions. The HOS rate exhibited positive correlation with the sperm total motility and PR. In addition, the sperm Na(+)/K(+)-ATPase activity at different pHs was measured, and the enzyme activity was significantly lower in pH 5.2 and 6.2 media, comparing with that in pH 8.2 and pH 7.2 solutions. Using flow cytometry (FCM) and laser confocal scanning microscopy (LCSM) analysis, the intracellular Ca2(+ )concentrations of sperm cultured in sperm capacitation solution at pH 5.2, 6.2, 7.2 and 8.2 were determined. Compared with that at pH 7.2, the mean fluorescence intensity of sperm in pH 5.2 and 6.2 media decreased significantly, while that of pH 8.2 group showed no difference. Our results suggested that the declined Na(+)/K(+)-ATPase activity at acidic pHs result in decreased sperm movement and capacitation, which could be one of the mechanisms of male infertility.

  7. Mapping Soil pH Buffering Capacity of Selected Fields

    Science.gov (United States)

    Weaver, A. R.; Kissel, D. E.; Chen, F.; West, L. T.; Adkins, W.; Rickman, D.; Luvall, J. C.

    2003-01-01

    Soil pH buffering capacity, since it varies spatially within crop production fields, may be used to define sampling zones to assess lime requirement, or for modeling changes in soil pH when acid forming fertilizers or manures are added to a field. Our objective was to develop a procedure to map this soil property. One hundred thirty six soil samples (0 to 15 cm depth) from three Georgia Coastal Plain fields were titrated with calcium hydroxide to characterize differences in pH buffering capacity of the soils. Since the relationship between soil pH and added calcium hydroxide was approximately linear for all samples up to pH 6.5, the slope values of these linear relationships for all soils were regressed on the organic C and clay contents of the 136 soil samples using multiple linear regression. The equation that fit the data best was b (slope of pH vs. lime added) = 0.00029 - 0.00003 * % clay + 0.00135 * % O/C, r(exp 2) = 0.68. This equation was applied within geographic information system (GIS) software to create maps of soil pH buffering capacity for the three fields. When the mapped values of the pH buffering capacity were compared with measured values for a total of 18 locations in the three fields, there was good general agreement. A regression of directly measured pH buffering capacities on mapped pH buffering capacities at the field locations for these samples gave an r(exp 2) of 0.88 with a slope of 1.04 for a group of soils that varied approximately tenfold in their pH buffering capacities.

  8. Idaaratu al Wahdah al Namthiyah li at Tathwiri al Tarbiyah al Islamiyah

    Directory of Open Access Journals (Sweden)

    Ahmad Danusiri

    2016-04-01

    Full Text Available Islam, through the Quran, proclaims that its mission includes the teachings to the whole universe, Everything in the universe is maintained by Islam, and none of the symptoms are ignored. The revelations also include the traditions of the Prophet that are authentic (shahih and good (hasan in quality. Both the Quran and maqbulah hadiths are accepted by Muslims on the basis of faith. When some experts of UIN Walisongo from various disciplines try to understand the sacred words of these two resources, their understanding continues, reaching the paradigm of the unity of science which essentially unites the normative, social, and natural sciences. The effect of this paradigm has brought up an issue for the author. Is there any hadiths or Prophetic traditions that can be used as a grand theory in the management disciplines of Islamic education.To address this issue, the authors conducted a literature research with the title Development of Islamic Education Management Module. Sources of data were focused on nine books of Hadiths : Sahih al-Bukhari, Sahih al-Muslim, Sunan Abu Dawud, Sunan at-Turmudzi, Sunan an-Nasai, Sunan Ibn Majah, Sunan ad-Darimi, Muwatta Malik, and Musnad Imam Ahmad bin Hanbal in the form of digital data Lidwa Reader Software Book 9 Imam Hadith. The findings of the study stated that the meaning of the word Rabb includes: creating, nurturing, maintaining, teaching, educating, and organizing. Thus, in an academic term, the word Rabb implies a manager or leader. Meanwhile, in the concept of comprehensive manager it contains at least 14 nomenclature denotations: planning, responsibility, organization, coordination, system of employee payroll, learning, resources, humanity, principle of making it easier for the manager to the employee, motivated to achieve optimal performance, preventing unproductivity, education participation, institutional costs, monitoring, and evaluation system. Each nomenclature has numerous hadiths that could serve

  9. Preparing MD-PhD Students for Clinical Rotations: Navigating the Interface Between PhD and MD Training

    OpenAIRE

    Goldberg, Charles; Insel, Paul A.

    2013-01-01

    Many aspects of MD-PhD training are not optimally designed to prepare students for their future roles as translational clinician-scientists. The transition between PhD research efforts and clinical rotations is one hurdle that must be overcome. MD-PhD students have deficits in clinical skills compared with those of their MD-only colleagues at the time of this transition. Reimmersion programs (RPs) targeted to MD-PhD students have the potential to help them navigate this transition. The author...

  10. SHC1, a high pH inducible gene required for growth at alkaline pH in Saccharomyces cerevisiae.

    Science.gov (United States)

    Hong, S K; Han, S B; Snyder, M; Choi, E Y

    1999-02-05

    In this study, we carried out a large-scale transposon tagging screening to identify genes whose expression is regulated by ambient pH. Of 35,000 transformants, two strains carrying the genes whose expression is strictly dependent on pH of growth medium were identified. One of the genes with 20-fold induction by alkali pH was identified as SHC1 gene in the Yeast Genome Directory and its expression was the highest at alkaline pH and moderately induced by osmotic stress. However, the gene was expressed neither at acidic pH nor by other stress conditions. The haploid mutant with truncated shc1 gene showed growth retardation and an abnormal morphology at alkaline pH. On the other hand, the mutant strain carrying the wild-type SHC1 gene reverted to the mutant phenotype. To confirm that Shc1p is an alkali-inducible protein, a monoclonal antibody to Shc1p was produced. While a 55-kDa protein band appeared on the Western blot of cells grown at alkaline pH, Shc1p was barely detectable on the blots of cells grown in YPD. Our results indicate that yeast cells have an efficient system adapting to large variations in ambient pH and SHC1 is one of the genes required for the growth at alkaline pH. Copyright 1999 Academic Press.

  11. Preparation of Al-based metal matrix composites reinforced by Cu coated SiC particles

    Energy Technology Data Exchange (ETDEWEB)

    Wang Hailong; Zhang Rui; Xu Hongliang; Lu Hongxia; Guan Shaokang [Coll. of Materials Engineering, Zhengzhou Univ., HEN (China)

    2005-07-01

    In order to improve the interfacial behavior between SiC and Al, a surface layer of Cu was coated on SiC particles. The influence of pH value on the coating process was analyzed. A powder metallurgy method was used to prepare the Al-based metal matrix composites (MMCs). SEM, XRD techniques were used to characterize the sintered compacts. It was found that the optimized pH value during the coating process was 1{proportional_to}2. The specimen showed the maximum density when sintered at 750 C. Inter-metallic compound of Al{sub 3.21}Si{sub 0.47} was detected which contributed to the enhancement at the interface between SiC and Al. The hardness of the composites is improved to 90 MPa. (orig.)

  12. Alternativen als Programm

    Directory of Open Access Journals (Sweden)

    Paulina Dobroć

    2018-03-01

    Full Text Available Der vorliegende Artikel soll einen Beitrag zu theoretischen Überlegungen einer Technikfolgenabschätzung (TA der Alternativen leisten. Ausgehend von der Annahme, dass TA seit ihrer Entstehung den Anspruch auf die Entwicklung von (technischen Alternativen erhoben hat, wird hier der Versuch unternommen, die Rolle der TA im Rahmen aktueller Innovationsprozesse zu reflektieren und (neu zu definieren. Dies scheint vor allem im Hinblick auf aktuelle gesellschaftliche Herausforderungen notwendig. Zu diesem Zweck wird eine Grundannahme Lothar Hacks über das Verhältnis von Gesellschaft und Technik herangezogen. Seine Annahme besagt, dass die kontinuierliche Überführung von sozialen Problemen und Leitbildern in enge technische Lösungsansätze in hochindustrialisierten Ländern dominant und Teil der aktuellen gesellschaftlichen Probleme ist. Diese These wird im vorliegenden Artikel im Hinblick auf einen Perspektivenwechsel als Ausgangspunkt eines zukünftigen Forschungsprogramms der TA fruchtbar gemacht. Hierbei bildet das Denken in Alternativen von gesellschaftlichen Zukünften den zentralen Fokus.

  13. Hydrolysis and speciation of Al bound to pectin and plant cell wall material and its reaction with the dye chrome azurol S.

    Science.gov (United States)

    Wehr, J Bernhard; Blamey, F P C; Hanna, J V; Kopittke, P M; Kerven, G L; Menzies, N W

    2010-05-12

    Hydrolysis of aluminum (Al) in solution increases at pH >or= 4 and with an Al concentration. Pectin, an important anionic polysaccharide of plant cell walls, adsorbs Al, but this phenomenon is poorly understood. This study showed that Al(3+) hydrolysis results in binding of Al to pectin in excess of the stoichiometric equivalent, leading to oversaturation of the pectin with Al. However, the degree of pectin methyl-esterification did not affect the extent of Al hydrolysis. Binding of Al to purified cell wall material also resulted in Al hydrolysis in a pH- and soluble Al concentration-dependent manner, but the source of cell wall material had no effect at fixed pH. Staining of Al-treated pectin and cell wall material from wheat ( Triticum aestivum L.) and sunflower ( Helianthus annuus L.) with the Al-specific dye, chrome azurol S (CAS), resulted in the formation of a purple color, with the intensity related to the extent of Al hydrolysis.

  14. Malamih al-Ashwat al-'Arabiyyah wa Makharijaha

    Directory of Open Access Journals (Sweden)

    Amrah Muhammad Kasim

    2015-12-01

    Full Text Available This writing discusses on al-ashwat al-‘arabiyyah that is known with “phonetic” term. It talks and interprets makharij al-huruf or place for producing sounds and also processing production of sounds by parts of mouth in Arabic language. The problems of sounds and its systems in Arabic language have been conducted by the scholars of al-ashwat al-‘arabiyyah attractively, neatly, and detail and gotten ahead the phonetic western scholars. Part of their analysis results formulate the study about al-ashwat al-sakinah (al-Shamit is known with vocal and consonant sounds in research questions shawait – shawamit. Ibnu Jinni has formulated “harakat”(wowel in Arabic language and dimension of letter  mad and liyn on alif  letter - waw - ya’ (ا و ي, from these letters create  harakat fathah, dammah, and kasrah. Moreover, in this writing also exist the description of hija’i letters and its makhraj that are correct from parts of mouth and the unity of coordinative sounds that produce sounds in morphemes arrangement, in one word that produces meaning. The result of phonological study has divided al-ashwat to be kinds of sound like the pronounced sounds, produced sounds from mouth, and heard sound.

  15. [Stop the compulsive PhD trajectory for junior doctors].

    Science.gov (United States)

    Clevers, J C Hans

    2014-01-01

    It has become the rule rather than the exception that junior doctors in training spend 3-4 years on a research project, culminating in a thesis. Without a PhD, clinical career prospects within and outside academia look rather bleak. Here I argue that PhD degrees should be pursued only by the most talented and motivated young clinicians.

  16. Proteolytische activiteit bij neutrale pH in rundermilt

    NARCIS (Netherlands)

    Marrink, Jan

    1969-01-01

    Intracellular enzymes, hydrolysing proteins optimally at acid pH values (acid proteases), have been studied in detail by several investigators. The existence of proteolytic activity at neutral pH in animal tissue extracts, on the other hand, has often been mentioned, but with few reports on the

  17. Critical assessment of the pH of children's soap

    Directory of Open Access Journals (Sweden)

    Bruna Rafaela Mendes

    2016-05-01

    Conclusions: Knowledge of the pH of children's soap by doctors and users is important, considering the great pH variability found in this study. Moreover, liquid soaps, and especially syndets, are the most recommended for the sensitive skin of neonates and infants, in order to guarantee skin barrier efficacy.

  18. The PhD Viva: A Space for Academic Development

    Science.gov (United States)

    Share, Michelle

    2016-01-01

    This study examined the viva experiences of 87 social science PhD graduates from three Irish higher education institutions through a questionnaire that assessed outcome, preparation, conduct and post-viva. The majority were awarded their PhD with minor corrections, considered their viva as a summative assessment, and emphasised its purpose as…

  19. A quinoline based pH sensitive ratiometric fluorescent sensor ...

    Indian Academy of Sciences (India)

    Fluorescence measurements were performed on a Hitachi F7000 spectrofluorimeter. Mass spectra measurement was carried out by Waters Xevo G2-. S QTof Mass Spectrometer. pH measurements were carried out using Orion 3-Star Plus pH Benchtop Meter. 2.2 Synthesis. The compound 1 was synthesized by stirring an.

  20. The effect of biogeochemical processes on pH

    NARCIS (Netherlands)

    Soetaert, K.E.R.; Hofmann, A.F.; Middelburg, J.J.; Meysman, F.J.R.; Greenwood, J.E.

    2007-01-01

    The impact of biogeochemical and physical processes on aquatic chemistry is usually expressed in terms of alkalinity. Here we show how to directly calculate the effect of single processes on pH. Under the assumptions of equilibrium and electroneutrality, the rate of change of pH can be calculated as

  1. Indigenous development and airworthiness certification of 15–5 PH ...

    Indian Academy of Sciences (India)

    Indigenous development and airworthiness certification of 15–5 PH precipitation hardenable stainless steel for aircraft applications. Ashok Kumar Y ... Keywords. Martensitic stainless steel 15–5 PH; processing; heat treatment; macro and micro structure; tensile properties; fatigue properties; development and certification.

  2. Intracellular pH in rat pancreatic ducts

    DEFF Research Database (Denmark)

    Novak, I; Hug, M; Greger, R

    1997-01-01

    In order to study the mechanism of H+ and HCO3- transport in a HCO3- secreting epithelium, pancreatic ducts, we have measured the intracellular pH (pHi) in this tissue using the pH sensitive probe BCECF. We found that exposures of ducts to solutions containing acetate/acetic acid or NH4+/NH3 buff...

  3. The Early Development of Electronic pH Meters

    Science.gov (United States)

    Hines, Wallis G.; de Levie, Robert

    2010-01-01

    A 19-year-old undergraduate at the University of Chicago, Kenneth Goode, in 1921 came up with the idea of an electronic pH meter, worked out some of its initial problems, and set in motion an international scientific effort that culminated in the current, wide availability of electronic pH meters. Except for the replacement of vacuum tubes by…

  4. Rethinking PhD Learning Incorporating Communities of Practice

    Science.gov (United States)

    Shacham, Miri; Od-Cohen, Yehudit

    2009-01-01

    This paper grows from research which focuses on the learning characteristics of PhD students, incorporating communities of practice both during their studies and beyond completion of their PhD, and drawing on theories of adult learning and lifelong learning. It shows how professional discourse enhances academic discourse through student engagement…

  5. Critical assessment of the pH of children's soap.

    Science.gov (United States)

    Mendes, Bruna Rafaela; Shimabukuro, Danielle Midori; Uber, Marjorie; Abagge, Kerstin Taniguchi

    2016-01-01

    To evaluate the pH value of children's antibacterial soaps and syndets used in children's baths and verify whether there is information regarding pH on the product label. Quantitative, cross-sectional, analytical observational study that included ninety soap samples, both in bar and liquid presentations, as follows: 67 children's soap (group 1), 17 antibacterial soaps (group 2), and 6 syndets (group 3). Each sample had its pH measured after 1% dilution. In addition to descriptive statistics, the Pearson-Yates chi-squared test and Student's t-tests were applied, considering the minimal significance level of 5%. The Wilcoxon-Mann-Whitney test, Fisher's exact test, and the Kruskal-Wallis test were used for inferential statistics. The pH levels varied considerably between liquid and bar presentations, with lower levels (4.4-7.9) found for the liquids (psoaps showed the highest pH levels (up to 11.34) (psoaps included in the study had information about their pH levels on the product packaging. Knowledge of the pH of children's soap by doctors and users is important, considering the great pH variability found in this study. Moreover, liquid soaps, and especially syndets, are the most recommended for the sensitive skin of neonates and infants, in order to guarantee skin barrier efficacy. Copyright © 2016 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.

  6. Titratable acidity of beverages influences salivary pH recovery.

    Science.gov (United States)

    Tenuta, Livia Maria Andaló; Fernández, Constanza Estefany; Brandão, Ana Carolina Siqueira; Cury, Jaime Aparecido

    2015-01-01

    A low pH and a high titratable acidity of juices and cola-based beverages are relevant factors that contribute to dental erosion, but the relative importance of these properties to maintain salivary pH at demineralizing levels for long periods of time after drinking is unknown. In this crossover study conducted in vivo, orange juice, a cola-based soft drink, and a 10% sucrose solution (negative control) were tested. These drinks differ in terms of their pH (3.5 ± 0.04, 2.5 ± 0.05, and 5.9 ± 0.1, respectively) and titratable acidity (3.17 ± 0.06, 0.57 ± 0.04 and buffering capacity kept 15 mL of each beverage in their mouth for 10 s, expectorated it, and their saliva was collected after 15, 30, 45, 60, 90, and 120 s. The salivary pH, determined using a mini pH electrode, returned to the baseline value at 30 s after expectoration of the cola-based soft drink, but only at 90 s after expectoration of the orange juice. The salivary pH increased to greater than 5.5 at 15 s after expectoration of the cola drink and at 30 s after expectoration of the orange juice. These findings suggest that the titratable acidity of a beverage influences salivary pH values after drinking acidic beverages more than the beverage pH.

  7. Consideration of Factors Affecting Strip Effluent PH and Sodium Content

    Energy Technology Data Exchange (ETDEWEB)

    Peters, T. [Savannah River Site (SRS), Aiken, SC (United States)

    2015-07-29

    A number of factors were investigated to determine possible reasons for why the Strip Effluent (SE) can sometimes have higher than expected pH values and/or sodium content, both of which have prescribed limits. All of the factors likely have some impact on the pH values and Na content.

  8. A quinoline based pH sensitive ratiometric fluorescent sensor ...

    Indian Academy of Sciences (India)

    Abstract. A new quinoline based hydrazone was synthesized via a condensation reaction and characterized by NMR, mass and single crystal X-ray diffraction studies. It was investigated for suitability as a reversible ratiometric fluorescent pH sensor in acidic pH region. The sensor exhibits intramolecular charge transfer (ICT).

  9. Tracking the PhD Students' Daily Computer Use

    Science.gov (United States)

    Sim, Kwong Nui; van der Meer, Jacques

    2015-01-01

    This study investigated PhD students' computer activities in their daily research practice. Software that tracks computer usage (Manic Time) was installed on the computers of nine PhD students, who were at their early, mid and final stage in doing their doctoral research in four different discipline areas (Commerce, Humanities, Health Sciences and…

  10. The optimum pH for the derivative spectrophotometric determination ...

    African Journals Online (AJOL)

    Absorbance fluctuations were also observed at the same drug concentrations in the pH range 2 to 3.5 and 5 to 7 when the solutions were scanned, even at the wavelength where the spectra seem to converge. However there were no absorbance differences between pH 4 and 5. Conclusion: The UV spectrophotometric ...

  11. Can Community Colleges Survive the PhD Glut?

    Science.gov (United States)

    Taylor, Anita

    The impact of the current employment situation on hiring faculty for community college teaching is examined. It is concluded that prospects for improving the quality of learning in community colleges are not particularly enhanced by the apparently growing surplus of new PhDs in our field. On the contrary, it is suggested that hiring PhDs for…

  12. Sulfate reduction at low pH in organic wastewaters

    NARCIS (Netherlands)

    Lopes, S.I.C.

    2007-01-01

    The objective of the research described in this thesis was to investigate the operational window of dissimilatory sulfate reduction at low pH (6, 5 and 4) during the acidification of organic wastewaters. High sulfate reduction efficiencies at low pH are desirable for a more sustainable operation of

  13. A quinoline based pH sensitive ratiometric fluorescent sensor ...

    Indian Academy of Sciences (India)

    A new quinoline based hydrazone was synthesized via a condensation reaction and characterized by NMR, mass and single crystal X-ray diffraction studies. It was investigated for suitability as a reversible ratiometric fluorescent pH sensor in acidic pH region. The sensor exhibits intramolecular charge transfer (ICT) type ...

  14. Indigenous development and airworthiness certification of 15–5 PH ...

    Indian Academy of Sciences (India)

    Heat treatment. Type testing/evaluation. Finished product for dispatch. Figure 2. Process flow chart for manufacturing of 15–5 PH martensitic stainless steel. machining ... Data Sheet of 15–5 PH Stainless Steel 2007). Hence, for ..... obtained (see data in table 3) show that the composition is within the specified limit and in.

  15. Mapping bark pH to better understand the cortisphere

    Science.gov (United States)

    Levia, D. F., Jr.; Köhler, S.; Jungkunst, H. F.; Gerold, G.

    2016-12-01

    The biogeochemistry of the cortisphere is poorly understood, despite the fact that a large variety of microbes, epiphytes, and insects live on, within, and just beneath corticular surfaces. Bark pH is a critical parameter that partially controls the chemodynamics of the cortisphere and its habitability by bark dwelling organisms as well as the chemistry of throughfall and stemflow. This presentation articulates, tests, and validates a method to accurately determine bark pH in situ. We employed agar-agar panels, embedded with a pH marker, to determine the spatiality of bark pH on cacao trees in Indonesia. In contrast to existing ex situ methods, we were able to record spatial differences in bark pH. In particular, bark pH was observed to fluctuate in relation to both morphological features on the bark, possibly corresponding to preferential flowpaths of stemflow, and epiphytic coverage. Due to its simplicity and economical nature, our method may be attractive to a variety of researchers interested in bark pH, its spatial variability, influence on stemflow chemistry, and its effect on organisms dwelling in the cortipshere. Publication note: This presentation is based on the following article: Köhler, S., Levia, D.F., Jungkunst, H.F. and Gerold, G. 2015. An in situ method to measure and map bark pH. Journal of Wood Chemistry and Technology 35(6): 438-449. [DOI: 10.1080/02773813.2015.1025285

  16. (PCP) degradation subjected to pH shock

    African Journals Online (AJOL)

    enoh

    2012-02-08

    Feb 8, 2012 ... few were coccus. ECPs were obviously packed within the outer layer. When the pH was 6.0, a part of bacteria decayed in morphology with irregular shape formed for a long time pH shock, though the most microbes were still bacillus. There were no obvious polymers observed, but the bacteria flocked tightly ...

  17. The Undergraduate Origins of PhD Economists Revisited

    Science.gov (United States)

    Stock, Wendy A.; Siegfried, John J.

    2015-01-01

    The authors update prior analyses of the undergraduate origins of individuals who earn a PhD in economics in the United States. They include the list of the top institutions worldwide graduating the largest number of undergraduates who subsequently earn an economics PhD from a U.S. university and lists of American institutions with the largest…

  18. Effect Of Ph On The Growth Performance Of Heterobranchus ...

    African Journals Online (AJOL)

    Twelve plastic basins each filled with 6 litres of dechlorinated tap water at pH 6 7 (control), 75 and 8 such that each pH treatment was replicated three timesin a Latin square design were used for the study. The tanks were randomly stocked with 10 four-week-old Clarias gariepinus (♀) x Heterobranchus bidorsalis (♂) hybrid ...

  19. Retention of chromium by modified Al-Bentonite Retenção de cromo por Al-bentonita modificada

    Directory of Open Access Journals (Sweden)

    C. Volzone

    2002-09-01

    Full Text Available Retention of chromium (III from a tanning wastewater by modified Al-bentonites was studied. One bentonite from San Juan province, Argentina, was used. Al-bentonite was prepared by contact of bentonite with hydrolyzed OH-Al solutions (0.10 M in Al for 24 hours. The modified Al-bentonites were obtained by: a treatment with 0.5 M sodium chloride; b with 0.5 M sodium chloride adjusted at pH 8; and c treatment with an hexametaphosphate solution after sodium addition. Then, the samples were dried at 100 °C and heated at 500 °C. The chromium (III retention by samples was carried out in batch system putting in contact the material with a 2000 ppm Cr tannery waste at different times. The retained chromium was characterized by analyzing the supernatant using UV-visible spectroscopy. The different chromium retention was correlated with structural characteristics of the solids.Foi estudada a retenção de cromo (III de águas residuais por meio de Al-bentonitas modificadas. Foi usada uma bentonita da província de San Juan, Argentina. As bentonitas-Al forma preparadas colocando-as em contato com soluções (0,10 M Al hydrolizadas de OH-Al durante 24 horas. As bentonitas-Al modidicadas foram obtidas por meio de: a tratamento com cloreto de sódio 0,5 M; b com cloreto de sódio 0,5 M sodium com pH ajustado para 8; e c tratamento com uma solução de hexametafosfato após a adição de sódio. As amostras foram então secas a 100 °C e aquecidas a 500 °C. A retenção do cromo (III pelas amostras foi feita em lotes colocando o material em contato em diferentes tempos com um resíduo contendo 2000 ppm de cromo. O cromo retido foi caracterizado por meio de análise do sobrenadante usando espectroscopia UV-visível. As diferentes retenções de cromo foram correlacionadas com características estruturais dos sólidos.

  20. PhD Dissertations Tesi di dottorato

    Directory of Open Access Journals (Sweden)

    Redazione Reti Medievali (a cura di

    2003-12-01

    Full Text Available Report of PhD Dissertations.Guido Antonioli Conservator pacis et iustitie. La signoria di Taddeo Pepoli a Bologna (1337-1347, Tesi di dottorato di ricerca in Filologia romanza e cultura medievale (XIII ciclo, Università degli Studi di Bologna, 2001   Elisabetta Filippini «In vassallatico episcopi permanere debent». Rapporti vassallatici e concessioni beneficiali dei vescovi di Cremona fra X e XIII secolo, Tesi di dottorato di Ricerca in Storia Medievale (XV ciclo, Università Cattolica del Sacro Cuore di Milano, 2003   Marco Meschini, Innocenzo III e il "negotium pacis et fidei" in Linguadoca tra il 1198 e il 1215, Tesi di dottorato di ricerca in Storia medievale, Università Cattolica del Sacro Cuore, 2003   Fabrizio Ricciardelli The Politics of Exclusion in Florence (1215-1434, thesis submitted in partial fulfilment of the requirements for the degree of Doctor of Philosophy in History, University of Warwick, Department of History, April 2003 Renata Salvarani Baptizare pueros et decimas dare. Cura delle anime, strutturazione ecclesiastica e organizzazione delle campagne in area gardesana fra VIII e XIII secolo (diocesi di Brescia, Verona, Mantova e Trento, Tesi di dottorato in Storia medievale (XV ciclo, Università Cattolica del Sacro Cuore di Milano, 2002-2003   Vito Sibilio Le parole della prima crociata, Tesi di dottorato di ricerca in Storia dei centri delle vie e della cultura dei pellegrinaggi nel medioevo euromediterraneo, Università degli studi di Lecce, 2003Segnalazione di tesi di dottorato. Guido Antonioli Conservator pacis et iustitie. La signoria di Taddeo Pepoli a Bologna (1337-1347, Tesi di dottorato di ricerca in Filologia romanza e cultura medievale (XIII ciclo, Università degli Studi di Bologna, 2001   Elisabetta Filippini «In vassallatico episcopi permanere debent». Rapporti vassallatici e concessioni beneficiali dei vescovi di Cremona fra X e XIII secolo, Tesi di dottorato di Ricerca in Storia Medievale (XV

  1. Integrating chemical imaging of cationic trace metal solutes and pH into a single hydrogel layer

    Energy Technology Data Exchange (ETDEWEB)

    Hoefer, Christoph [Department of Forest and Soil Sciences, Institute of Soil Research, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz-Strasse 24, A-3430 Tulln (Austria); Santner, Jakob, E-mail: jakob.santner@boku.ac.at [Department of Forest and Soil Sciences, Institute of Soil Research, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz-Strasse 24, A-3430 Tulln (Austria); Department of Crop Sciences, Division of Agronomy, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz-Strasse 24, 3430 Tulln (Austria); Borisov, Sergey M. [Institute of Analytical Chemistry and Food Chemistry, Graz University of Technology, Stremayrgasse 9, A-8010, Graz (Austria); Wenzel, Walter W.; Puschenreiter, Markus [Department of Forest and Soil Sciences, Institute of Soil Research, University of Natural Resources and Life Sciences, Vienna, Konrad-Lorenz-Strasse 24, A-3430 Tulln (Austria)

    2017-01-15

    Gel-based, two-dimensional (2D) chemical imaging techniques are versatile methods for investigating biogeochemically active environments at high spatial resolution (sub-mm). State-of-the-art solute imaging techniques, such as diffusive gradients in thin films (DGT) and planar optodes (PO), employ passive solute sampling or sensing. Combining these methods will provide powerful tools for studying the biogeochemistry of biological niches in soils and sediments. In this study we aimed at developing a combined single-layer gel for direct pH imaging using PO and sampling of anionic and cationic solutes by DGT, with subsequent analysis of the bound solutes by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). We tested three ultra-thin (<100 μm) polyurethane-based gels, incorporating anion and cation binding materials and the fluorescent pH indicator DCIFODA (2′,7′-dichloro-5(6)-N-octadecyl-carboxamidofluorescein). Results showed that PO-based pH sensing using DCIFODA was impossible in the presence of the anion binding materials due to interferences with DCIFODA protonation. One gel, containing only a cation binding material and DCIFODA, was fully characterized and showed similar performance characteristics as comparable DGT-only gels (applicable pH range: pH 5–8, applicable ionic strength range: 1–20 mmol L{sup -1}, cation binding capacity ∼24 μg cm{sup −2}). The dynamic range for PO-based pH mapping was between pH 5.5 and 7.5 with t{sub 90} response time of ∼60 min. In a case study we demonstrated the gel's suitability for multi-analyte solute imaging and mapped pH gradients and concurrent metal solubility patterns in the rhizosphere of Salix smithiana. pH decreases in the rooted soil were co-localized with elevated solute fluxes of Al{sup 3+}, Co{sup 2+}, Cu{sup 2+}, Fe, Mn{sup 2+}, Ni{sup 2+} and Pb{sup 2+}, indicating pH-induced metal solubilisation. - Highlights: • Diffusive gradients in thin films (DGT) and planar

  2. Enhancement of MgAl2 O4 spinel formation from coprecipitated ...

    Indian Academy of Sciences (India)

    Administrator

    by suitable design of process flow chart is the primary objective for any ... process manipulation such as control of precipitation rate, adjustment of pH .... Table 1. Chemical analysis of the precursor powders dried at. 110°C. Wt%. Powder. Wt% L.O.I. Molar ratio. (Batch). Al2O3. MgO (1200°C, 2 h) (Al2O3 : MgO). A. 21⋅93.

  3. Biolixiviação de metais do lodo de curtume em duas etapas: influência do pH = Bioleaching of metals from tannery sludge in two stages: effect of pH

    Directory of Open Access Journals (Sweden)

    Fábio Moreira da Silva

    2009-04-01

    Full Text Available O presente trabalho avaliou a influência do pH final sobre a biolixiviação de Cr e outros metais do lodo de curtume, utilizando um sistema com a separação das etapas de oxidação biológica do enxofre elementar e de lixiviação do resíduo. A concentração de enxofre elementar foi de 5 g L-1. O pH final de biolixiviação variou de 3,0 a 1,0. A concentração de sólidos do lodo de curtume lixiviado foi de 100 g L-1 e as temperaturas foram de 298,15 e 308,15 K. As porcentagens de extração de Al, Cr e Zn tiveram acréscimos para menores valores de pH final, enquanto as de Ca decresceram nessas condições. A extração máxima de Cr foi de 70,11% em concentração de sólidos do lodo de 100 g L-1, pH final de 1,0 e temperatura de 298,15 K. A fração de Cr ligada aos óxidos de Fe e Mn teve maior variação no teor do metal do que as outras frações, pelas mudanças de pH final. Arazão em massa dos metais e do Cr decresceu para menores valores de pH final. A concentração de Cr lixiviado do lodo de curtume, após a biolixiviação em pH final 1,0, foi reduzida a valores satisfatórios.The present work assessed the effect of the pH in the bioleaching of Cr and other metals from tannery sludge with stage separation of biologic oxidation of elemental sulfur and leaching of solid waste. The concentration of elemental sulfur was 5 g L-1. The finalbioleaching pH ranged from 3.0 to 1.0. The concentration of sludge solids was 100 g L-1 and the temperatures were 298.15 and 308.15 K. The leaching extractions of Al, Cr and Zn increased at lower final pH and the leaching extraction of Ca decreased in this condition.The maximum extraction of Cr was 70.11% at sludge solids concentration of 100 g L-1, final pH 1.0 and temperature of 298.15 K. The fraction of Cr bound to Fe and Mn oxides was more affected by changes at final pH than others fractions. The mass ratio of metals and Cr decreased at lower final pH. The concentration of Cr leached from

  4. Growth and production of castor bean under different levels of irrigation water salinity and nitrogen dosesCrescimento e produção da mamoneira cultivada sob diferentes níveis de salinidade da água de irrigação e doses de nitrogênio

    Directory of Open Access Journals (Sweden)

    Reginaldo Gomes Nobre

    2013-06-01

    mamoneira cv. BRS Energia. O experimento foi conduzido em lisímetros sob condições de campo, no Centro de Ciências e Tecnologia Agroalimentar da Universidade Federal de Campina Grande. Adotou-se o delineamento em blocos inteiramente casualizados em esquema fatorial 5 x 5, com três repetições. Os tratamentos consistiram da combinação de cinco níveis de condutividade elétrica da água de irrigação (0,4; 1,4; 2,4; 3,4 e 4,4 dS m-1 e cinco doses de nitrogênio (50; 75; 100; 125 e 150% da dose recomendada. O número de folhas, o diâmetro caulinar, a altura de planta, a fitomassa seca do caule e de folhas, e o número de frutos no racemo primário da mamoneira cv. BRS Energia foram afetados linear e negativamente pela salinidade da água a partir de 0,4 dS m-1; a fitomassa seca de folhas e a produção do racemo primário são as variáveis mais sensíveis ao estresse salino; doses crescentes de adubação nitrogenada promoveram, na colheita, aumento na fitomassa seca de caule e de folhas e no número de frutos no racemo primário; a aplicação de doses crescentes de nitrogênio reduziu o efeito da salinidade sobre o diâmetro de caule da mamoneira cv. BRS Energia.

  5. Nanosensors for pH measurements in plants

    DEFF Research Database (Denmark)

    Ytting, Cecilie Karkov; Fuglsang, Anja Thoe

    of the green fluorescent protein, GFP, have become available, some of which are pH sensitive. This offers the opportunity to simply express the pH sensitive protein in different plant tissues, making it possible to conduct in vivo pH measurements in a non-invasive manner. One sensor being characterized......Traditionally in vivo pH measurements in plants are carried out using different fluorescent probes such as BCECF and SNARFs by injecting plant cells or incubating tissues with the probes. This approach, however, carries several problems, the most important one being the handling of the plant cells...... or tissues. Stress and wounding of the plant can possibly influence the outcome of the pH measurements. Other problems are the difficulties of getting the probes more than a few cell layers into the plant tissue and to get an even distribution of the probe. Increasing numbers of different variants...

  6. pH control in RCW loops at ORGDP

    International Nuclear Information System (INIS)

    Spann, B.M.

    1982-01-01

    The pH of RCW is a vital parameter in limiting corrosion and scaling in cooling water systems. At ORGDP, pH has in the past been adjusted by the addition of sulfuric acid to makeup water from the softeners. Since each of the RCW loops is independent and operates at varying flow rates, temperatures, and cycles of concentration that require different quantities of sulfuric acid for pH adjustment, acid addition only to the makeup water header has resulted in unsatisfactory pH control. This has resulted in increased blowdown requirements to maintain acceptable sulfate levels in the RCW. To minimize blowdown, system improvements are to be provided by an FY 1981 GPP project which will permit independent pH adjustment in each of the six RCW and blowdown resoftening loops

  7. Analysis list: ph-d [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available ph-d Cell line,Embryo + dm3 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/p...h-d.1.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/ph-d.5.tsv http://dbarchive.biosciencedbc.jp.../kyushu-u/dm3/target/ph-d.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/ph-d.Cell_line.tsv,http://dbarchive.bioscience...dbc.jp/kyushu-u/dm3/colo/ph-d.Embryo.tsv http://dbarchive.bioscience...dbc.jp/kyushu-u/dm3/colo/Cell_line.gml,http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/Embryo.gml ...

  8. Influence of pH on Δ17O using the conventional equilibration device and a comparision to the CoF3 method

    Science.gov (United States)

    Ranjan, S.; Leuenberger, M.; Winkler, R.; Landais, A.

    2012-04-01

    We have analysed precipitaion samples taken from Jungfraujoch for pH variations, using a pH sonde (WTW company) with a repeatibility of ±.01 pH unit. The values range between 3.78 and 6.95 pH units; average of four measurements of each sample. Previously samples have been analysed for stable isotopes (d18O, dD) and from d45, d46, Δ17O has been calculated. Elsig and Leuenberger (2008) observed that the pH has a strong influence on the Δ17O during the isotope equilibration between water and CO2 (13C effect) if pH values are above 4 pH units. We rerun all samples, now buffered to pH 4. Those 13C independent values were compared to those obtained by a CoF3 method (Barkan et.al, 2007). The precision of the CoF3 method is superior over the equilibration method even under buffered condition.

  9. Plant based dietary supplement increases urinary pH

    Directory of Open Access Journals (Sweden)

    Rao A Venket

    2008-11-01

    Full Text Available Abstract Background Research has demonstrated that the net acid load of the typical Western diet has the potential to influence many aspects of human health, including osteoporosis risk/progression; obesity; cardiovascular disease risk/progression; and overall well-being. As urinary pH provides a reliable surrogate measure for dietary acid load, this study examined whether a plant-based dietary supplement, one marketed to increase alkalinity, impacts urinary pH as advertised. Methods Using pH test strips, the urinary pH of 34 healthy men and women (33.9 +/- 1.57 y, 79.3 +/- 3.1 kg was measured for seven days to establish a baseline urinary pH without supplementation. After this initial baseline period, urinary pH was measured for an additional 14 days while participants ingested the plant-based nutritional supplement. At the end of the investigation, pH values at baseline and during the treatment period were compared to determine the efficacy of the supplement. Results Mean urinary pH statistically increased (p = 0.03 with the plant-based dietary supplement. Mean urinary pH was 6.07 +/- 0.04 during the baseline period and increased to 6.21 +/- 0.03 during the first week of treatment and to 6.27 +/- 0.06 during the second week of treatment. Conclusion Supplementation with a plant-based dietary product for at least seven days increases urinary pH, potentially increasing the alkalinity of the body.

  10. Undulators at the ALS

    International Nuclear Information System (INIS)

    Hoyer, E.; Akre, J.; Chin, J.

    1994-07-01

    At Lawrence Berkeley Laboratory's (LBL) Advanced Light Source (ALS), three 4.6 m long undulators have been completed, tested and installed. A fourth is under construction. The completed undulators include two 5.0 cm period length, 89 period devices (U5.0s) which achieve a 0.85 T effective field at a 14 mm minimum gap and a 8.0 cm period length, 55 period device (U8.0) that reaches a 1.2 T effective field at a 14 mm minimum gap. The undulator under construction is a 10.0 cm period length, 43 period device (U10.0) that is designed to achieve 0.98 T at a 23 mm gap. Undulator magnetic gap variation (rms) is within 25 microns over the periodic structure length. Reproducibility of the adjustable magnetic gap has been measured to be within +/- 5 microns. Gap adjusting range is from 14 mm to 210 mm, which can be scanned in one minute. The 5.1 m long vacuum chambers are flat in the vertical direction to within 0.74 mm and straight in the horizontal direction to within 0.08 mm over the 4.6 m magnetic structure sections. Vacuum chamber base pressures after UHV beam conditioning are. in the mid 10 -11 Torr range and storage ring operating pressures with full current are in the low 10 -10 Torr range. Measurements show that the uncorrelated magnetic field errors are 0.23%, and 0.20% for the two U5.Os and the U8.0 respectively and that the field integrals are small over the 1 cm by 6 cm beam aperture. Device description, fabrication, and measurements are presented

  11. Bilder machen - Fotografie als Praxis

    OpenAIRE

    Bove, Jens; Kaschek, Bertram

    2010-01-01

    In der Ausstellung „Bilder machen – Fotografie als Praxis“ stellt die Deutsche Fotothek der SLUB Dresden in Kooperation mit der Universitätssammlung Kunst+Technik die Fotografie als vielgestaltige kulturelle Praxis vor. Fast alle Exponate stammen von der Deutschen Fotothek, deren Bestand mehr als drei Mio. Aufnahmen umfasst. Die Ausstellung wird von einer öffentlichen Ringvorlesung begleitet, in der weitere Gebrauchsweisen der Fotografie in den Blick genommen werden. Außerdem ist ein Katalog ...

  12. O pH das soluções nutritivas no comportamento de cultivares de trigo à toxicidade de alumínio Effect of pH in nutrient solution on tolerance to aluminum toxicity in wheat cultivars

    Directory of Open Access Journals (Sweden)

    Carlos Eduardo de Oliveira Camargo

    1984-01-01

    Full Text Available Foram estudados nove cultivares de trigo em soluções nutritivas contendo quatro níveis de alumínio (0, 5, 10 e 20mg/litro combinados com três níveis de pH (4,0, 5,0 e 6,0. A tolerância foi medida pela capacidade de as raízes primárias continuarem a crescer em solução sem alumínio, após um período de permanência de 48 horas em solução contendo determinados níveis de pH e de alumínio. Os cultivares BH-1146, IAC-18, IAC-13 e C-3 foram tolerantes; IAC-17 e Alondra-4546 foram moderadamente tolerantes, e Síete Cerros, Super-x e CNT-8 foram sensíveis à presença de quantidades crescentes de Al3+ nas soluções de tratamentos quando foi mantido o pH 4,0. Todos os cultivares foram tolerantes às dosagens de alumínio estudadas quando foram mantidos os níveis de pH 5,0 ou 6,0. Ficou confirmado que um controle rigoroso do pH da solução tratamento é um fator de grande importância no estudo da toxicidade do alumínio a diferentes cultivares de trigo.The aluminum tolerance of nine wheat cultivars was studied in nutrient solutions using three different levels of pH combined with four different concentrations of this element. The tolerance was evaluated by measuring the root growth in an aluminum-free complete nutrient solution after a previous treatment in aluminum added solutions (0, 5, 10 and 20mg/l under a particular pH (4.0, 5.0 and 6.0. The wheat cultivars BH-1146, IAC-18, IAC-13 and C-3 presented tolerance, IAC-17 and Alondra-4546 showed moderate tolerance and Siete Cerros, Super-x and CNT-8 were sensitive to the presence of increasing concentrations of Al3+ in the treatment solution under pH 4.0. All cultivars were tolerant to the different concentrations of aluminum under pH 5.0 and 6.0. The aluminum toxicity symptom (inhibition of root growth was dependent on the pH and the amount of aluminum in the treatment solution. For the same level of aluminum, toxicity symptoms increased, when the pH decreased in the solution from 6

  13. Half life of 26Al

    International Nuclear Information System (INIS)

    Norris, T.L.; Gancarz, A.J.; Rokop, D.J.; Thomas, K.W.

    1983-01-01

    The half-life of 26 Al has been redetermined because of suggestions of an error in the accepted value based on its use in calculating 21 Ne production rates from cosmic rays in meteorites. Two solutions of 26 Al were analyzed for the specific radioactivity and mass spectrometric determination of the 26 Al concentration. The half-life obtained for 26 Al was 7.05 x 10 5 years +- 3.7% at the two sigma level. This is identical to the accepted value of 7.16 x 10 5 years and indicates that problems with the 21 Ne production rate is not due to an erroneous half-life

  14. Onderzoek naar optimale pH bij komkommer : Lage pH positief, verhoging van NH4 kan beperkt helpen

    NARCIS (Netherlands)

    Voogt, W.

    2009-01-01

    Het gewas komkommer reageert positief op een lage pH waarde in het substraat. De productie is hoger en er treedt minder chlorose op. Dit komt door een betere opname van spoorelementen. Bij een hoge pH geeft een extra NH4-dosering compensatie voor het hoge niveau, maar te veel NH4 werkt negatief.

  15. Ambulatory oesophageal pH monitoring: a comparison between antimony, ISFET, and glass pH electrodes

    NARCIS (Netherlands)

    Hemmink, Gerrit J. M.; Weusten, Bas L. A. M.; Oors, Jac; Bredenoord, Albert J.; Timmer, Robin; Smout, André J. P. M.

    2010-01-01

    BACKGROUND AND AIM: Ambulatory oesophageal pH-impedance monitoring is a widely used test to evaluate patients with reflux symptoms. Several types of pH electrodes are available: antimony, ion sensitive field effect transistor (ISFET), and glass electrodes. These pH electrodes have not been compared

  16. Bifunctional Probes of Cathepsin Protease Activity and pH Reveal Alterations in Endolysosomal pH during Bacterial Infection

    NARCIS (Netherlands)

    Sanman, L.E.; Linden, W.A. van der; Verdoes, M.; Bogyo, M.

    2016-01-01

    Cysteine cathepsins are lysosomal proteases involved in regulation of both normal cellular processes and disease. Biochemical studies with peptide substrates indicate that cathepsins have optimal activity at acidic pH and highly attenuated activity at neutral pH. In contrast, there is mounting

  17. Continuous pH monitoring in a perfused bioreactor system using an optical pH sensor

    Science.gov (United States)

    Jeevarajan, Antony S.; Vani, Sundeep; Taylor, Thomas D.; Anderson, Melody M.

    2002-01-01

    Monitoring and regulating the pH of the solution in a bioprocess is one of the key steps in the success of bioreactor operation. An in-line optical pH sensor, based on the optical absorption properties of phenol red present in the medium, was developed and tested in this work for use in NASA space bioreactors based on a rotating wall-perfused vessel system supporting a baby hamster kidney (BHK-21) cell culture. The sensor was tested over three 30-day and one 124-day cell runs. The pH sensor initially was calibrated and then used during the entire cell culture interval. The pH reported by the sensor was compared to that measured by a fiber optically coupled Shimadzu spectrophotometer and a blood gas analyzer. The maximum standard error of prediction for all the four cell runs for development pH sensor against BGA was +/-0.06 pH unit and for the fiber optically coupled Shimadzu spectrophotometer against the blood gas analyzer was +/-0.05 pH unit. The pH sensor system performed well without need of recalibration for 124 days. Copyright 2002 Wiley Periodicals, Inc.

  18. Nuclear magnetic resonance studies of intracellular pH and pH homeostasis in the hog carotid artery

    International Nuclear Information System (INIS)

    Grieder, T.A.

    1989-01-01

    Intracellular pH (pH i ) is an important determinant of vascular smooth muscle (VSM) contractility and relaxation. Most NMR measurement of pH have been calculated from the chemical shift of inorganic phosphate (P i ) in 31 P spectra. An alternative approach is to calculate pH from the difference in chemical shifts of signals in the 19 F spectrum of cells loaded with difluoromethylalanine. This technique has higher sensitivity to pH changes and provides better time resolution than other NMR methods. In this study we report simultaneous measurements of pH i and the contractile state of single, intact hog carotid arterial segments, closed at both ends and superfused with HCO 3 - -buffered Krebs solution at physiological pressures. At 28 degree C, resting arteries maintained a pH i of 7.15 ± 0.03 units (n = 16). In a parallel study, helically cut strips studied with 31 P NMR maintained a similar resting pH (7.18 ± 0.09)

  19. eLectures – Lehrkräftefortbildung der Zukunft - Erfahrungsbericht über mehr als 1 Jahr synchrones e-Learning

    Directory of Open Access Journals (Sweden)

    Alfred Peherstorfer

    2011-09-01

    Full Text Available Seit mehr als einem Jahr wird seitens der Virtuellen PH auf der Live Online Plattform Adobe Connect Weiterbildung für Lehrkräfte angeboten: eLectures. Hier ein Erfahrungsbericht.

  20. Effect of soy and bovine milks on the dental plaque pH

    Directory of Open Access Journals (Sweden)

    Peyvand Moeiny

    2016-11-01

    (P<0.05. Conclusion: Bovine milk in none of frequent timing dropped its pH below basic pH but also significantly increased the plaque pH above the critical pH. The maximum pH drop for soy milk was in 2minutes after consumption but it never reached below the critical pH.