WorldWideScience

Sample records for al ph salinidad

  1. 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

    Directory of Open Access Journals (Sweden)

    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

  2. Evolução da salinidade e pH de solo sob cultivo de melão irrigado com água salina Evolution of salinity and pH of soil cultivated with melon irrigated with brackish water

    Directory of Open Access Journals (Sweden)

    Francisco de Q. Porto Filho

    2011-11-01

    Full Text Available Com o presente trabalho objetivou-se estudar os efeitos da irrigação com águas salinas em um solo cultivado com melão a evolução da salinidade e reação do solo. O experimento foi conduzido na Fazenda Santa Júlia, município de Mossoró, RN, em dois plantios consecutivos, no período de 2001 a 2002. As plantas de melão (Cucumis melo L. cv. AF646 foram irrigadas com água de salinidade 0,6 (testemunha; 1,9; 3,2 e 4,5 dS m-1 durante todo o ciclo (70 dias e de forma incremental, em três fases de desenvolvimento do meloeiro (1-30, 31-50, 51-70 dias após a semeadura - DAS. O delineamento experimental adotado foi em blocos ao acaso, com 15 tratamentos e quatro repetições. A salinidade e o pH do solo foram medidos no início e aos 30, 50 e 70 DAS, em amostras de solo coletadas nas camadas de 0-15, 15-30 e 30-45 cm. Observou-se maior acúmulo de sais no solo na camada superficial (até 15 cm em todos os níveis de salinidade e que a utilização de águas de maior salinidade aumentou a salinidade média no perfil do solo. Os valores médios de pH estiveram dentro da faixa ótima de absorção de nutrientes requerida para a cultura do melão, com pequena variação entre os tratamentos estudados.This work aimed to study the effects of irrigation with saline waters in an area cultivated with melon on soil salinity and pH. The experiment was conducted in the Santa Julia Farm, Mossoró city, Rio Grande do Norte State, Brazil, during the years 2001 to 2002. Water with different salinity levels (0.6; 1.9; 3.2 and 4.5 dS m-1 was used throughout the cycle and in incremental way in three periods of melon development, forming 15 treatments, arranged in randomized blocks with four replications. The salinity was measured at 0, 30, 50 and 70 days after sowing in soil samples collected in layers of 0-15, 15-30 and 30-45 cm. There was greater accumulation of salts in the surface layer (up to 15 cm in all salinity levels and the use of more saline water

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  6. High Sensitive pH Sensor Based on AlInN/GaN Heterostructure Transistor.

    Science.gov (United States)

    Dong, Yan; Son, Dong-Hyeok; Dai, Quan; Lee, Jun-Hyeok; Won, Chul-Ho; Kim, Jeong-Gil; Chen, Dunjun; Lee, Jung-Hee; Lu, Hai; Zhang, Rong; Zheng, Youdou

    2018-04-24

    The AlInN/GaN high-electron-mobility-transistor (HEMT) indicates better performances compared with the traditional AlGaN/GaN HEMTs. The present work investigated the pH sensor functionality of an analogous HEMT AlInN/GaN device with an open gate. It was shown that the Al 0.83 In 0.17 N/GaN device demonstrates excellent pH sense functionality in aqueous solutions, exhibiting higher sensitivity (−30.83 μA/pH for AlInN/GaN and −4.6 μA/pH for AlGaN/GaN) and a faster response time, lower degradation and good stability with respect to the AlGaN/GaN device, which is attributed to higher two-dimensional electron gas (2DEG) density and a thinner barrier layer in Al 0.83 In 0.17 N/GaN owning to lattice matching. On the other hand, the open gate geometry was found to affect the pH sensitivity obviously. Properly increasing the width and shortening the length of the open gate area could enhance the sensitivity. However, when the open gate width is too larger or too small, the pH sensitivity would be suppressed conversely. Designing an optimal ratio of the width to the length is important for achieving high sensitivity. This work suggests that the AlInN/GaN-based 2DEG carrier modulated devices would be good candidates for high-performance pH sensors and other related applications.

  7. High Sensitive pH Sensor Based on AlInN/GaN Heterostructure Transistor

    Directory of Open Access Journals (Sweden)

    Yan Dong

    2018-04-01

    Full Text Available The AlInN/GaN high-electron-mobility-transistor (HEMT indicates better performances compared with the traditional AlGaN/GaN HEMTs. The present work investigated the pH sensor functionality of an analogous HEMT AlInN/GaN device with an open gate. It was shown that the Al0.83In0.17N/GaN device demonstrates excellent pH sense functionality in aqueous solutions, exhibiting higher sensitivity (−30.83 μA/pH for AlInN/GaN and −4.6 μA/pH for AlGaN/GaN and a faster response time, lower degradation and good stability with respect to the AlGaN/GaN device, which is attributed to higher two-dimensional electron gas (2DEG density and a thinner barrier layer in Al0.83In0.17N/GaN owning to lattice matching. On the other hand, the open gate geometry was found to affect the pH sensitivity obviously. Properly increasing the width and shortening the length of the open gate area could enhance the sensitivity. However, when the open gate width is too larger or too small, the pH sensitivity would be suppressed conversely. Designing an optimal ratio of the width to the length is important for achieving high sensitivity. This work suggests that the AlInN/GaN-based 2DEG carrier modulated devices would be good candidates for high-performance pH sensors and other related applications.

  8. 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)

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  11. La agricultura, la salinidad y los hongos micorrízicos arbusculares꞉ una necesidad, un problema y una alternativa

    OpenAIRE

    Medina-García, Laura R.

    2016-01-01

    Entre las condiciones adversas de los sistemas agrícolas, la salinidad es el factor que más ha influido sobre el establecimiento de las poblaciones humanas. La misma inhibe el crecimiento de las plantas y su productividad, induce desequilibrios en las relaciones osmóticas entre el suelo y las plantas y en el metabolismo de estas. La tolerancia al estrés en la plantas es un fenómeno complejo que involucra numerosos cambios a nivel bioquímico y fisiológico. Los mecanismos detrás de la toleranci...

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

    Directory of Open Access Journals (Sweden)

    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

  13. 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.

  14. Molecular gated-AlGaN/GaN high electron mobility transistor for pH detection.

    Science.gov (United States)

    Ding, Xiangzhen; Yang, Shuai; Miao, Bin; Gu, Le; Gu, Zhiqi; Zhang, Jian; Wu, Baojun; Wang, Hong; Wu, Dongmin; Li, Jiadong

    2018-04-18

    A molecular gated-AlGaN/GaN high electron mobility transistor has been developed for pH detection. The sensing surface of the sensor was modified with 3-aminopropyltriethoxysilane to provide amphoteric amine groups, which would play the role of receptors for pH detection. On modification with 3-aminopropyltriethoxysilane, the transistor exhibits good chemical stability in hydrochloric acid solution and is sensitive for pH detection. Thus, our molecular gated-AlGaN/GaN high electron mobility transistor acheived good electrical performances such as chemical stability (remained stable in hydrochloric acid solution), good sensitivity (37.17 μA/pH) and low hysteresis. The results indicate a promising future for high-quality sensors for pH detection.

  15. Hydroxy-Al and cell-surface negativity are responsible for the enhanced sensitivity of Rhodotorula taiwanensis to aluminum by increased medium pH.

    Science.gov (United States)

    Zhao, Xue Qiang; Bao, Xue Min; Wang, Chao; Xiao, Zuo Yi; Hu, Zhen Min; Zheng, Chun Li; Shen, Ren Fang

    2017-10-01

    Aluminum (Al) is ubiquitous and toxic to microbes. High Al 3+ concentration and low pH are two key factors responsible for Al toxicity, but our present results contradict this idea. Here, an Al-tolerant yeast strain Rhodotorula taiwanensis RS1 was incubated in glucose media containing Al with a continuous pH gradient from pH 3.1-4.2. The cells became more sensitive to Al and accumulated more Al when pH increased. Calculations using an electrostatic model Speciation Gouy Chapman Stern indicated that, the increased Al sensitivity of cells was associated with AlOH 2+ and Al(OH) 2 + rather than Al 3+ . The alcian blue (a positively charged dye) adsorption and zeta potential determination of cell surface indicated that, higher pH than 3.1 increased the negative charge and Al adsorption at the cell surface. Taken together, the enhanced sensitivity of R. taiwanensis RS1 to Al from pH 3.1-4.2 was associated with increased hydroxy-Al and cell-surface negativity.

  16. Gate less-FET pH Sensor Fabricated on Undoped AlGaN/ GaN HEMT Structure

    International Nuclear Information System (INIS)

    Maneea Eizadi Sharifabad; Mastura Shafinaz Zainal Abidin; Shaharin Fadzli Abd Rahman; Abdul Manaf Hashim; Abdul Rahim Abdul Rahman

    2011-01-01

    Gallium nitride with wurtzite crystal structure is a chemically stable semiconductor with high internal spontaneous and piezoelectric polarization, which make it highly suitable materials to create very sensitive and robust sensors for the detection of ions, gases and liquids. Sensing characteristics of an open-gate liquid-phase sensor fabricated on undoped-AlGaN/ GaN high-electron-mobility-transistor (HEMT) structure in aqueous solution was investigated. In ambient atmosphere, the open-gate undoped AlGaN/ GaN HEMT clearly showed only the presence of linear region of currents while Si-doped AlGaN/ GaN showed the linear and saturation regions of currents, very similar to those of gated devices. This seems to show that very low Fermi level pinning by surface states exists in undoped AlGaN/ GaN sample. In aqueous solution, the typical current-voltage (I-V) characteristics of HEMTs with good gate controllability were observed. The potential of the AlGaN surface at the open-gate area is effectively controlled via aqueous solution by Ag/ AgCl reference gate electrode. The open-gate undoped AlGaN/ GaN HEMT structure is capable of stable operation in aqueous electrolytes and exhibit linear sensitivity, and high sensitivity of 1.9 mA/ pH or 3.88 mA/ mm/ pH at drain-source voltage, VDS = 5 V was obtained. Due to large leakage current where it increases with the negative reference gate voltage, the Nernstians like sensitivity cannot be determined. Suppression of current leakage is likely to improve the device performance. The open-gate undoped-AlGaN/ GaN structure is expected to be suitable for pH sensing application. (author)

  17. Open-Gated pH Sensor Fabricated on an Undoped-AlGaN/GaN HEMT Structure

    Directory of Open Access Journals (Sweden)

    Taizoh Sadoh

    2011-03-01

    Full Text Available The sensing responses in aqueous solution of an open-gated pH sensor fabricated on an AlGaN/GaN high-electron-mobility-transistor (HEMT structure are investigated. Under air-exposed ambient conditions, the open-gated undoped AlGaN/GaN HEMT only shows the presence of a linear current region. This seems to show that very low Fermi level pinning by surface states exists in the undoped AlGaN/GaN sample. In aqueous solution, typical current-voltage (I-V characteristics with reasonably good gate controllability are observed, showing that the potential of the AlGaN surface at the open-gated area is effectively controlled via aqueous solution by the Ag/AgCl gate electrode. The open-gated undoped AlGaN/GaN HEMT structure is capable of distinguishing pH level in aqueous electrolytes and exhibits linear sensitivity, where high sensitivity of 1.9 mA/pH or 3.88 mA/mm/pH at drain-source voltage, VDS = 5 V is obtained. Due to the large leakage current where it increases with the negative gate voltage, Nernstian like sensitivity cannot be determined as commonly reported in the literature. This large leakage current may be caused by the technical factors rather than any characteristics of the devices. Surprisingly, although there are some imperfections in the device preparation and measurement, the fabricated devices work very well in distinguishing the pH levels. Suppression of current leakage by improving the device preparation is likely needed to improve the device performance. The fabricated device is expected to be suitable for pH sensing applications.

  18. Open-gated pH sensor fabricated on an undoped-AlGaN/GaN HEMT structure.

    Science.gov (United States)

    Abidin, Mastura Shafinaz Zainal; Hashim, Abdul Manaf; Sharifabad, Maneea Eizadi; Rahman, Shaharin Fadzli Abd; Sadoh, Taizoh

    2011-01-01

    The sensing responses in aqueous solution of an open-gated pH sensor fabricated on an AlGaN/GaN high-electron-mobility-transistor (HEMT) structure are investigated. Under air-exposed ambient conditions, the open-gated undoped AlGaN/GaN HEMT only shows the presence of a linear current region. This seems to show that very low Fermi level pinning by surface states exists in the undoped AlGaN/GaN sample. In aqueous solution, typical current-voltage (I-V) characteristics with reasonably good gate controllability are observed, showing that the potential of the AlGaN surface at the open-gated area is effectively controlled via aqueous solution by the Ag/AgCl gate electrode. The open-gated undoped AlGaN/GaN HEMT structure is capable of distinguishing pH level in aqueous electrolytes and exhibits linear sensitivity, where high sensitivity of 1.9 mA/pH or 3.88 mA/mm/pH at drain-source voltage, V(DS) = 5 V is obtained. Due to the large leakage current where it increases with the negative gate voltage, Nernstian like sensitivity cannot be determined as commonly reported in the literature. This large leakage current may be caused by the technical factors rather than any characteristics of the devices. Surprisingly, although there are some imperfections in the device preparation and measurement, the fabricated devices work very well in distinguishing the pH levels. Suppression of current leakage by improving the device preparation is likely needed to improve the device performance. The fabricated device is expected to be suitable for pH sensing applications.

  19. Monitoring the corrosion process of Al alloys through pH induced fluorescence

    International Nuclear Information System (INIS)

    Pidaparti, R M; Neblett, E B; Miller, S A; Alvarez, J C

    2008-01-01

    A sensing and monitoring set-up based on electrochemical pH induced fluorescence to systematically control the electrochemical corrosion process has been developed for possible applications in the field of localized corrosion. The sensing and monitoring concept is based on exposing the corroding metal surface to solutions that contain selected redox chemicals which will react in local regions where anodic or cathodic polarizations occur. Redox couples that produce or consume protons in their electrochemical reactions were used so that local pH gradients can indicate electrochemical activity by inducing fluorescence in dyes. This approach has been applied to study the corrosion initiation in aircraft aluminum metal 2024-T3 in a controlled electrochemical cell. Preliminary results obtained suggest that monitoring of localized corrosion based on pH can be achieved for field applications

  20. 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; La Bella, Vincenzo; 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; Brunetti, Maura; Barberis, Marco; Restagno, Gabriella

    2015-10-01

    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. Copyright © 2015 Elsevier Inc. All rights reserved.

  1. 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.

  2. Effect of Fe, Ni, and Cr on the corrosion behaviour of hyper-eutectic Al-Si automotive alloy under different pH conditions

    Directory of Open Access Journals (Sweden)

    Mohammad Salim Kaiser

    2018-05-01

    Full Text Available Effect of Fe, Ni and Cr on the corrosion behaviour of hyper-eutectic Al-Si automotive alloy was studied. The test of corrosion behaviour at different environmental pH 1, 3, 5, 7, 9, 11 and 13 was performed using conventional gravimetric measurements and complemented by resistivity, optical micrograph, scanning electron microscopy (SEM and X-ray analyser (EDX investigations. The highest corrosion rate was observed at pH 13 followed by pH 1, while in the pH range of 3.0 to 11, there is a high protection of surface due to formation of stable surface oxide film. The highest corrosion rate at pH 13 is due to presence of sodium hydroxide in the solution in which the surface oxide film is soluble. At pH 1, however, high corrosion rate can be attributed to dissolution of Al due to the surface attack by aggressive chloride ions. Presence of Fe, Ni and Cr in hyper-eutectic Al-Si automotive alloy has significant effect on the corrosion rate at both environmental pH values. Resistivity of alloy surfaces initially decreases at pH 1 and pH 13 due to formation of thin films. The SEM images of corroded samples immersed in pH 1 solution clearly show pores due to uniform degradation of the alloy. In pH 13 solution, however, the corrosion layer looks more packed and impermeable.

  3. 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

  4. Comparative study on sorption of radiocobalt to montmorillonite and its Al-pillared and cross-linked samples. Effect of pH, ionic strength and fulvic acid

    International Nuclear Information System (INIS)

    Yu, S.; Cheng, J.; Chen, C.; Wang, X.

    2007-01-01

    Effects of pH, ionic strength and fulvic acid on sorption of radiocobalt on montmorillonite and its Al-pillared and cross-linked samples were studied using batch technique. The results indicate that the sorption of cobalt is strongly dependent on pH values and independent of ionic strength. Fulvic acid enhances the sorption of cobalt slightly at low pH, but has no influence at high pH values. Surface complexation is considered the main mechanism of cobalt sorption to montmorillonite. The sequences of FA/Co 2+ additions to the system did not affect cobalt sorption. (author)

  5. 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.

  6. Enhanced Al and Zn removal from coal-mine drainage during rapid oxidation and precipitation of Fe oxides at near-neutral pH

    Science.gov (United States)

    Burrows, Jill E.; Cravotta, Charles A.; Peters, Stephen C.

    2017-01-01

    Net-alkaline, anoxic coal-mine drainage containing ∼20 mg/L FeII and ∼0.05 mg/L Al and Zn was subjected to parallel batch experiments: control, aeration (Aer 1 12.6 mL/s; Aer 2 16.8 mL/s; Aer 3 25.0 mL/s), and hydrogen peroxide (H2O2) to test the hypothesis that aeration increases pH, FeII oxidation, hydrous FeIII oxide (HFO) formation, and trace-metal removal through adsorption and coprecipitation with HFO. During 5.5-hr field experiments, pH increased from 6.4 to 6.7, 7.1, 7.6, and 8.1 for the control, Aer 1, Aer 2, and Aer 3, respectively, but decreased to 6.3 for the H2O2 treatment. Aeration accelerated removal of dissolved CO2, Fe, Al, and Zn. In Aer 3, dissolved Al was completely removed within 1 h, but increased to ∼20% of the initial concentration after 2.5 h when pH exceeded 7.5. H2O2 promoted rapid removal of all dissolved Fe and Al, and 13% of dissolved Zn.Kinetic modeling with PHREEQC simulated effects of aeration on pH, CO2, Fe, Zn, and Al. Aeration enhanced Zn adsorption by increasing pH and HFO formation while decreasing aqueous CO2 available to form ZnCO30 and Zn(CO3)22− at high pH. Al concentrations were inconsistent with solubility control by Al minerals or Al-containing HFO, but could be simulated by adsorption on HFO at pH oxidation with pH adjustment to ∼7.5 could be effective for treating high-Fe and moderate-Zn concentrations, whereas chemical oxidation without pH adjustment may be effective for treating high-Fe and moderate-Al concentrations.

  7. Aluminium Uptake and Translocation in Al Hyperaccumulator Rumex obtusifolius Is Affected by Low-Molecular-Weight Organic Acids Content and Soil pH

    Science.gov (United States)

    Vondráčková, Stanislava; Száková, Jiřina; Drábek, Ondřej; Tejnecký, Václav; Hejcman, Michal; Müllerová, Vladimíra; Tlustoš, Pavel

    2015-01-01

    Background and Aims 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. Methods 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. Results Al availability correlated positively to the extraction of organic acids (citric acid 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. Conclusions 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. PMID:25880431

  8. 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.

  9. 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.

  10. A naphthalene exciplex based Al3+ selective on-type fluorescent probe for living cells at the physiological pH range: experimental and computational studies.

    Science.gov (United States)

    Banerjee, Arnab; Sahana, Animesh; Das, Sudipta; Lohar, Sisir; Guha, Subarna; Sarkar, Bidisha; Mukhopadhyay, Subhra Kanti; Mukherjee, Asok K; Das, Debasis

    2012-05-07

    2-((Naphthalen-6-yl)methylthio)ethanol (HL) was prepared by one pot synthesis using 2-mercaptoethanol and 2-bromomethylnaphthalene. It was found to be a highly selective fluorescent sensor for Al(3+) in the physiological pH (pH 7.0-8.0). It could sense Al(3+) bound to cells through fluorescence microscopy. Metal ions like Mn(2+), Fe(3+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Ag(+), Cd(2+), Hg(2+), Cr(3+) and Pb(2+) did not interfere. No interference was also observed with anions like Cl(-), Br(-), F(-), SO(4)(2-), NO(3)(-), CO(3)(2-), HPO(4)(2-) and SCN(-). Experimentally observed structural and spectroscopic features of HL and its Al(3+) complex have been substantiated by computational calculations using density functional theory (DFT) and time dependent density functional theory (TDDFT).

  11. The Effect of Saccharomyces Strains and Fermentation Condition on the pH, Foam Property and CO2 Concentration of Non-alcoholic Beer (Ma-al-shaeer

    Directory of Open Access Journals (Sweden)

    S. Sohrabvandi

    2014-12-01

    Full Text Available This study aims to determine the effect of fermentation condition and Saccharomyces strains on the pH, foam property and CO2 concentration of non-alcoholic beer (Ma-al-shaeer. For this, the beer samples were inoculated with four different species of Saccharomyces (Saccharomyces rouxii 70531, S. rouxii 70535, S. ludwigii 3447 and S. cerevisiae 70424 and fermented for 48h in both aerobic and periodic aeration at three different temperatures. Then their pH, CO2 concentration and foam property were analyzed in 12h intervals during 48h fermentation. The results shows that the treatments with 4×107 CFU.ml-1 and periodic aeration at 24˚C showed the greatest decrease in pH, and the treatments with 107 CFU.ml-1 and aerobic-periodic aeration at 4˚C showed the lowest decrease in pH. The highest and lowest amounts of CO2 and foam property were obtained in the treatments with 4×107 CFU.ml-1 inoculation, aerobic condition, and the treatments with 107 CFU.ml-1, periodic aeration, respectively. These results further demonstrated that the highest drop in pH, and the highest ability of producing CO2 and foam were for S. cerevisiae 70424, and the lowest belonged to S. rouxii 70531. The overall outcome of the study points to the fact that physico-chemical properties of Ma-al-shaeer is important from the consumers' point of view. Therefore, S. cerevisiae with 4×107 CFU.ml-1 inoculation and aerobic condition at 4˚C has promising potential for producing Ma-al-shaeer with good physicochemical properties.

  12. RESPUESTA DE 12 VARIEDADES DE TRIGO A LA SALINIDAD EN LAS ETAPAS INICIALES DEL CRECIMIENTO

    OpenAIRE

    L. Argentel; L. M. González; R. Plana

    2006-01-01

    Con el objetivo de analizar la respuesta varietal del cultivo de trigo a la salinidad en las etapas iniciales del crecimiento de las plántulas, se montó un experimento con 12 variedades, aplicando dos niveles de NaCl en la solución. Las variables evaluadas fueron la absorción de agua por las semillas, altura de las plantas y longitud de la raíz, y la acumulación de biomasas fresca y seca. Mediante un análisis de componentes principales, se establecieron los indicadores de mayor contribución a...

  13. Influência do tempo de aclimatação na resposta do cajueiro à salinidade

    OpenAIRE

    Brilhante, Jean C. A.; Silveira, Joaquim A. G.; Rocha, Iza M. A.; Morais, Déborah L. de; Viégas, Ricardo A.

    2007-01-01

    A resposta das plantas à salinidade depende de fatores fisiológicos, bioquímicos e genéticos. Com este trabalho, objetivou-se estudar o impacto do tempo de aclimatação à solução nutritiva sobre a resposta do cajueiro à salinidade. Plantas de Anarcadium occidentale L., CCP06, cultivadas em vermiculita durante 28 dias, foram transferidas para solução nutritiva de Hoagland com 1/10 de sua força iônica, onde permaneceram por 1 e 7 dias. Ao final dos dois tempos, a solução nutritiva foi suplementa...

  14. Evaluación de tecnologías para la recuperación de suelos degradados por salinidad.

    OpenAIRE

    Zúñiga Escobar, Orlando; Osorio Saravia, Juan Carlos; Cuero Guependo, Ramiro; Peña Ospina, Julián Andrés

    2012-01-01

    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) Electromagneti...

  15. 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 ...

  16. pH sensor using AlGaN/GaN high electron mobility transistors with Sc2O3 in the gate region

    International Nuclear Information System (INIS)

    Kang, B. S.; Wang, H. T.; Ren, F.; Gila, B. P.; Abernathy, C. R.; Pearton, S. J.; Johnson, J. W.; Rajagopal, P.; Roberts, J. C.; Piner, E. L.; Linthicum, K. J.

    2007-01-01

    Ungated AlGaN/GaN high electron mobility transistors (HEMTs) exhibit large changes in current upon exposing the gate region to polar liquids. The polar nature of the electrolyte introduced leds to a change of surface charges, producing a change in surface potential at the semiconductor/liquid interface. The use of Sc 2 O 3 gate dielectric produced superior results to either a native oxide or UV ozone-induced oxide in the gate region. The ungated HEMTs with Sc 2 O 3 in the gate region exhibited a linear change in current between pH 3 and 10 of 37 μA/pH. The HEMT pH sensors show stable operation with a resolution of <0.1 pH over the entire pH range. The results indicate that the HEMTs may have application in monitoring pH solution changes between 7 and 8, the range of interest for testing human blood

  17. 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.

  18. 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.

  19. 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.

  20. Study of the effect of PH, surface finish and thermal treatment on the corrosion of AlFeNi aluminum alloy

    International Nuclear Information System (INIS)

    Nabhan, Diana

    2013-01-01

    The Jules Horowitz Reactor (JHR) is a research reactor under construction at the CEA Cadarache research center, France. It is scheduled to start operating by 2020. The fuel elements of this reactor core consist of eight concentric rows of cylindrical plates, each row being composed of three thin aluminum coated plates. Cooling water circulates between these plates through very thin gaps smaller than 2 mm. The aluminum alloy used to coat the fuel plates is an alloy called AlFeNi, which contains 1% wt. Fe, 1% wt. Ni and 1% wt. Mg. In the reactor environment, this alloy may undergo corrosion. The oxide layer formed on the AlFeNi alloy is composed of two different types of oxides: an inner oxide layer formed by a diffusion mechanism and an outer oxide layer formed by re-precipitation. As a consequence, formation of an oxide scale on the aluminum coating could reduce the gap between the cladding plates, thus allowing less water to circulate. This could in turn lead to local heating of the fuel cladding. In addition, the metal consumption and the softening of the metal at high temperatures can lead to a decrease of the mechanical strength of the cladding. In order to qualify the fuel elements of the JHR, several specimens of AlFeNi, representative of the future cladding, were corroded at 250 .deg. C for different durations (9 to 34 days) in distilled water of different pH: 4.9; 5.2 and 5.6. These pH values have been chosen to simulate the ones currently predicted for the JHR. The effect of surface finish (polished and not polished) and thermal treatment (annealed and not annealed) on the oxide growth rate was also investigated. For long tests over 30 days, the pH 5,6 appears to be more favorable than the pH 5,2 and 4,9 to limit the oxide thickness, but this pH effect is reduced on unpolished samples. In one hand, the effect of surface finish on the corrosion behavior as measured by optical microscopy appears to be strong. On the other hand, the effect of thermal

  1. Study of the effect of PH, surface finish and thermal treatment on the corrosion of AlFeNi aluminum alloy

    Energy Technology Data Exchange (ETDEWEB)

    Nabhan, Diana [Comissariat a l' Energie Atomique, Paris (France)

    2013-07-01

    The Jules Horowitz Reactor (JHR) is a research reactor under construction at the CEA Cadarache research center, France. It is scheduled to start operating by 2020. The fuel elements of this reactor core consist of eight concentric rows of cylindrical plates, each row being composed of three thin aluminum coated plates. Cooling water circulates between these plates through very thin gaps smaller than 2 mm. The aluminum alloy used to coat the fuel plates is an alloy called AlFeNi, which contains 1% wt. Fe, 1% wt. Ni and 1% wt. Mg. In the reactor environment, this alloy may undergo corrosion. The oxide layer formed on the AlFeNi alloy is composed of two different types of oxides: an inner oxide layer formed by a diffusion mechanism and an outer oxide layer formed by re-precipitation. As a consequence, formation of an oxide scale on the aluminum coating could reduce the gap between the cladding plates, thus allowing less water to circulate. This could in turn lead to local heating of the fuel cladding. In addition, the metal consumption and the softening of the metal at high temperatures can lead to a decrease of the mechanical strength of the cladding. In order to qualify the fuel elements of the JHR, several specimens of AlFeNi, representative of the future cladding, were corroded at 250 .deg. C for different durations (9 to 34 days) in distilled water of different pH: 4.9; 5.2 and 5.6. These pH values have been chosen to simulate the ones currently predicted for the JHR. The effect of surface finish (polished and not polished) and thermal treatment (annealed and not annealed) on the oxide growth rate was also investigated. For long tests over 30 days, the pH 5,6 appears to be more favorable than the pH 5,2 and 4,9 to limit the oxide thickness, but this pH effect is reduced on unpolished samples. In one hand, the effect of surface finish on the corrosion behavior as measured by optical microscopy appears to be strong. On the other hand, the effect of thermal

  2. 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

  3. Avaliação da influência da salinidade na germinação, no desenvolvimento e diversidade de microrganismos endofíticos da leguminosa Mucuna aterrima

    Directory of Open Access Journals (Sweden)

    Alan Passos Cruz

    2018-02-01

    Full Text Available A utilização de leguminosas é um método visado para a recuperação de fertilidade dos solos, visto que além de fornecerem matéria orgânica também fixam nitrogênio ao solo. Por isso, mostram-se relevantes pesquisas acerca da capacidade das leguminosas para utilização em solos salinos com o intuito de se auxiliar a recuperação destes. Dessa forma, este trabalho teve como objetivo avaliar a influência da salinidade na germinação, no desenvolvimento e no isolamento de microrganismos endofíticos da leguminosa mucuna preta (Mucuna aterrima. O experimento foi realizado com tratamentos de NaCl, em delineamento inteiramente casualizado (5x3 com cinco tratamentos (0,0; 0,025; 0,05; 0,1; 0,2 mol NaCl/L e três repetições. Foram analisados a porcentagem de germinação, a massa seca da raiz, caule e folhas e efetuada a contagem de bactérias e fungos endofíticos. Como resultado, verificou-se uma redução da porcentagem da taxa de germinação com o aumento da salinidade. Apesar de não ser observada interferência na riqueza de microrganismos, verificou-se maior resistência das bactérias à salinidade. Dessa forma, este estudo indica que a mucuna preta não é indicada para plantio em solos com concentrações salinas maiores que 0,1 mol NaCL/L, pois essa concentração apresenta toxicidade para a planta e não favorece sua germinação.

  4. Efecto de la calidad de agua del acuífero Valle de Guadalupe en la salinidad de suelos agrícolas Water quality effect on the Valle de Guadalupe aquifer in the agricultural soils salinity

    OpenAIRE

    Jorge Arturo Salgado Tránsito; Oscar Palacios Vélez; Arturo Galvis Spínola; Francisco Gavi Reyes; Enrique Mejía Sáenz

    2012-01-01

    Para determinar el efecto de la calidad del agua en el Acuífero del Valle de Guadalupe, Baja California, México, en la salinidad de los suelos agrícolas se midió el pH, conductividad eléctrica, sólidos disueltos totales y la concentración de los principales iones en las aguas de 66 pozos, de un total de 754 que se encontraban en operación en el acuífero durante 2009 .Y se analizó en el extracto de pasta de saturación de muestras de suelo el pH, conductividad eléctrica, carbonato, bicarbonato,...

  5. Surface plasmon resonance based fiber optic pH sensor utilizing Ag/ITO/Al/hydrogel layers.

    Science.gov (United States)

    Mishra, Satyendra K; Gupta, Banshi D

    2013-05-07

    The fabrication and characterization of a surface plasmon resonance based pH sensor using coatings of silver, ITO (In2O3:SnO2), aluminium and smart hydrogel layers over an unclad core of an optical fiber have been reported. The silver, aluminium and ITO layers were coated using a thermal evaporation technique, while the hydrogel layer was prepared using a dip-coating method. The sensor works on the principle of detecting changes in the refractive index of the hydrogel layer due to its swelling and shrinkage caused by changes in the pH of the fluid surrounding the hydrogel layer. The sensor utilizes a wavelength interrogation technique and operates in a particular window of low and high pH values. Increasing the pH value of the fluid causes swelling of the hydrogel layer, which decreases its refractive index and results in a shift of the resonance wavelength towards blue in the transmitted spectra. The thicknesses of the ITO and aluminium layers have been optimized to achieve the best performance of the sensor. The ITO layer increases the sensitivity while the aluminium layer increases the detection accuracy of the sensor. The proposed sensor possesses maximum sensitivity in comparison to the sensors reported in the literature. A negligible effect of ambient temperature in the range 25 °C to 45 °C on the performance of the sensor has been observed. The additional advantages of the sensor are short response time, low cost, probe miniaturization, probe re-usability and the capability of remote sensing.

  6. Increasing Al-Tolerance of Sugarcane Using Ethyl Methane Sulphonate and In Vitro Selection in the Low pH Media

    Directory of Open Access Journals (Sweden)

    Ragapadmi Purnamaningsih

    2016-01-01

    Full Text Available Increased production of sugarcane in Indonesia can be done with extensification sugarcane plantations which largely dominated by acidic upland red-yellow podzolic soil. High aluminium (Al content and low pH of the soil can inhibit plant growth and development. Tolerant sugarcane in acid soil is the most efficient way, but the adaptive variety is still limited. In vitro culture technique can increase genetic variability to assemble new varieties through somaclonal variation combined with mutation using ethyl methane sulphonate (EMS. The new characters was directed by in vitro selection using AlCl3.6H2O with pH = 4 as a component of selection for resistance to high aluminium. VMC 7616 and PS 862 varieties were used as materials. Mutation induced using EMS at concentrations of 0.1%, 0.3%, and 0.5% for 30, 60 and 120 minutes. Plantlets mutant obtained through callus formation, immersion callus in EMS, in vitro selection, and regeneration of callus. Result of study showed that the long immersion in the EMS solution caused greater damage to the cells, as indicated by the change in callus colour. Callus immersion time in EMS gave greater influence to regeneration compared to concentration of EMS. PS 862 had higher Al tolerance than VMC 7616. Rooting of shoot induced using indole-3-butyric acid (IBA 3 mg/L.

  7. 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

  8. 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

  9. 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.

  10. Influence of sulfate ion concentration and pH on the corrosion of Mg-Al-Zn-Mn (GA9 magnesium alloy

    Directory of Open Access Journals (Sweden)

    Sudarshana Shetty

    2015-09-01

    Full Text Available The corrosion behavior of Mg-Al-Zn-Mn (GA9 alloy in sodium sulfate solutions was studied over a range of concentrations and solution temperatures at different pH conditions by electrochemical techniques like Tafel extrapolation and electrochemical impedance spectroscopy (EIS. The studies were carried out in solutions with sodium sulfate concentrations 0.1M, 0.5M, 1M, 1.5M and 2M; and at five different temperatures of 30, 35, 40, 45 and 50 °C in a pH range of 3–12. As per the experimental data, the corrosion rate of the alloy increased with the increase in temperature, and also with the increase in concentration of sodium sulfate in the medium. It was observed that the rate of corrosion decreased with the increase in pH. The activation parameters like activation energy, enthalpy of activation and entropy of activation for the corrosion process were calculated. The surface morphology of the alloy was examined before and after corrosion using scanning electron microscopy (SEM.

  11. Analysis of the biocompatibility of Ti6Al4V and stainless steel 316 LVM based on effects of pH, applying criteria of ASTM F2129 standard

    International Nuclear Information System (INIS)

    Caballero Sarmiento, Jeniffer; Correa Munoz, Estefania; Estupinan Duran, Hugo

    2017-01-01

    The effect of pH on corrosion behaviour in stainless steel 316 LVM and alloy Ti6Al4V was studied by various electrochemical techniques such as cyclic potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The corrosion rate was calculated with Tafel extrapolations and the pitting corrosion was also analysed for each material in different conditions of concentration 3% of NaCl and range pH (4.5-6-7.5-10-12). The results exhibited that the conditions of pH 4,5 has negative effect in the corrosion rate for both materials compared with other pH

  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. 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

  14. Caracterización de los flujos de agua subterránea a partir de su salinidad

    OpenAIRE

    Fagundo-Castillo, Juan R.; Alconada-Magliano, Margarita M.; Carrillo-Rivera, J. Joel; González-Hernández, Patricia

    2014-01-01

    La vinculación entre elementos del paisaje puede ser explicada mediante la teoría de los sistemas de flujo de agua subterránea, que reconoce los diferentes flujos y sus zonas de descarga y recarga, que manifiestan en forma complementaria su funcionamiento hidrológico. Es esencial la caracterización de los diferentes flujos para conocer su potencialidad, salinidad y su posibilidad de uso en diferentes prácticas de manejo agropecuario y forestal; en esta definición quedan implícitas sus caracte...

  15. Influência de diferentes níveis de salinidade nas características sensoriais do tomate

    OpenAIRE

    Eloi,Waleska M.; Duarte,Sergio N.; Soares,Tales M.; Silva,Ênio F. de F. e

    2011-01-01

    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...

  16. 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...

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

    Directory of Open Access Journals (Sweden)

    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. Influência do tempo de aclimatação na resposta do cajueiro à salinidade Influence of acclimatization time on response of cashew plant to salinity

    OpenAIRE

    Jean C. A. Brilhante; Joaquim A. G. Silveira; Iza M. A. Rocha; Déborah L. de Morais; Ricardo A. Viégas

    2007-01-01

    A resposta das plantas à salinidade depende de fatores fisiológicos, bioquímicos e genéticos. Com este trabalho, objetivou-se estudar o impacto do tempo de aclimatação à solução nutritiva sobre a resposta do cajueiro à salinidade. Plantas de Anarcadium occidentale L., CCP06, cultivadas em vermiculita durante 28 dias, foram transferidas para solução nutritiva de Hoagland com 1/10 de sua força iônica, onde permaneceram por 1 e 7 dias. Ao final dos dois tempos, a solução nutritiva foi suplementa...

  19. 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.

  20. 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

  1. Crecimiento y composición bioquímica de limnothrix sp. a diferentes salinidades y concentraciones de nitrato

    OpenAIRE

    Lemus, Nathalie; Guevara Acosta, Miguel Angel; Lodeiros, César; Vásquez, Aleikar; Freites, Luis; Licet, Berenice

    2013-01-01

    Título en ingles: Growth and biochemical composition of Limnothrix sp. at different salinities and concentrations of nitrateTítulo corto: Crecimiento y composición bioquímica de Limnothrix sp.ResumenSe evalúo el efecto de la salinidad  (15, 25 y 35 UPS) y concentración de nitrato (4, 8 y 16 mmoles L-1) sobre el crecimiento y composición bioquímica de la  cianobacteria Limnothrix sp. (LAEP- 52) con miras a su explotación para fines biotecnológicos. La cianobacteria se cultivó durante 20 días...

  2. Influência da salinidade da água no crescimento de seis genótipos de helicônias

    Directory of Open Access Journals (Sweden)

    Helder M. M. Barros

    2010-12-01

    Full Text Available No Nordeste brasileiro a qualidade das águas utilizadas em irrigação é muito variável tanto em termos geográficos como ao longo do ano, principalmente em pequenos açudes. Com a utilização de águas com altos níveis de salinidade aliada às condições climáticas, comumente encontradas no final do período de estiagem, há riscos de salinização dos solos irrigados com prejuízos, também, para as culturas. Para helicônias, não existem quaisquer indicativos relacionados ao efeito da salinidade da água no desenvolvimento. Propôs-se, neste trabalho, avaliar o crescimento na altura de planta mediante altura, número de folhas, teor de água na planta e fitomassa seca de seis genótipos de helicônias irrigados com águas salinas. O experimento foi conduzido em casa de vegetação pertencente à UFCG/Campina Grande, PB, compondo um esquema fatorial 6 x 6 em delineamento experimental de blocos ao acaso, com três repetições, cada um com dois vasos. O crescimento das helicônias foi afetado significativamente pelos níveis de salinidade. A H. latispatha cv. Red-Yellow Gyro e a H. psittacorum cv. Red Opal foram as helicônias menos afetadas pela salinidade. O teor de água na planta diminuiu com o aumento da CE da água de irrigação. Com o aumento da salinidade, ocorreu decréscimo na fitomassa seca. A H. x nickeriensis apresentou os menores índices em comparação com as demais helicônias, sendo mais sensível à salinidade.

  3. Monitoramento da salinidade de águas subterrâneas em várzea cultivada com cana-de-açúcar fertirrigada com vinhaça

    Directory of Open Access Journals (Sweden)

    Wellington P. da Silva

    2014-04-01

    Full Text Available Propôs-se, neste trabalho, avaliar o risco potencial da vinhaça em proporcionar a salinidade e sodicidade das águas subterrâneas em área de várzea cultivada com cana-de-açúcar. O experimento foi conduzido em uma Usina da Mata Sul de Pernambuco durante o período de dezembro de 2010 a setembro de 2011. O dispositivo experimental adotado foi composto de uma malha georreferenciada de 81 poços de monitoramento distribuídos ao longo de uma área de 7,5 ha constituindo três subáreas com 2,5 ha, todas cultivadas com cana-de-açúcar. Na área foram aplicadas doses equivalentes a 50, 60 e 65 m³ ha-1 de vinhaça de mosto de melaço. Para a avaliação da qualidade da água subterrânea foram realizadas seis amostragens e analisados os parâmetros CE, pH, Na+, Ca2+, Mg2+ e RAS. A aplicação de doses de vinhaça até 65 m³ ha-1, em áreas de várzea, para os parâmetros analisados, não proporcionou riscos de salinização das águas subterrâneas nem, tampouco, a CE e a RAS para a salinidade e sodicidade no período avaliado. O monitoramento dos parâmetros químicos do lençol freático mostrou, ao longo do tempo, redução de suas concentrações em função da precipitação pluviométrica ocorrida no período estudado.

  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. PH sensor

    OpenAIRE

    Artero, C.; Nogueras Cervera, Marc; Manuel Lázaro, Antonio

    2012-01-01

    This paper presents a design of a marine instrument for the measurement of pH in seawater. The measurement system consists of a pH electrode connected to the underwater observatory OBSEA. The extracted data are useful for scientists researching ocean acidification. Peer Reviewed

  6. Manejo da fertirrigação e controle da salinidade do solo sob ambiente protegido, utilizando-se extratores de solução do solo

    OpenAIRE

    Dias,Nildo da S.; Duarte,Sergio N.; Gheyi,Hans R.; Medeiros,José F. de; Soares,Tales M.

    2005-01-01

    Com o objetivo de avaliar o uso de extratores de soluções do solo no auxílio ao manejo da fertirrigação e no controle da salinidade em solo cultivado com melão rendilhado, conduziu-se um estudo em ambiente protegido na área experimental do Departamento de Engenharia Rural da ESALQ/USP, localizada no município de Piracicaba, SP. Os tratamentos se compunham da combinação de dois fatores: 6 níveis de salinidade inicial do solo (S1 = 1,0; S2 = 2,0; S3 = 3,0; S4 = 4,0; S5 = 5,0 e S6 = 6,0 dS m-1) ...

  7. Dissociation kinetics of Fe(III)- and Al(III)-natural organic matter complexes at pH 6.0 and 8.0 and 25 °C

    Science.gov (United States)

    Jones, Adele M.; Pham, A. Ninh; Collins, Richard N.; Waite, T. David

    2009-05-01

    The rate at which iron- and aluminium-natural organic matter (NOM) complexes dissociate plays a critical role in the transport of these elements given the readiness with which they hydrolyse and precipitate. Despite this, there have only been a few reliable studies on the dissociation kinetics of these complexes suggesting half-times of some hours for the dissociation of Fe(III) and Al(III) from a strongly binding component of NOM. First-order dissociation rate constants are re-evaluated here at pH 6.0 and 8.0 and 25 °C using both cation exchange resin and competing ligand methods for Fe(III) and a cation exchange resin method only for Al(III) complexes. Both methods provide similar results at a particular pH with a two-ligand model accounting satisfactorily for the dissociation kinetics results obtained. For Fe(III), half-times on the order of 6-7 h were obtained for dissociation of the strong component and 4-5 min for dissociation of the weak component. For aluminium, the half-times were on the order of 1.5 h and 1-2 min for the strong and weak components, respectively. Overall, Fe(III) complexes with NOM are more stable than analogous complexes with Al(III), implying Fe(III) may be transported further from its source upon dilution and dispersion.

  8. 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

  9. 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

  10. 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

  11. 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.

  12. O efeito da salinidade no desenvolvimento larval do caranguejo - uçá, Ucides cordatus (Linnaeus, 1763) (Decapoda: Ocypodidae) no Norte do Brasil The effect of salinity on the larval development of the uçá-crab, Ucides cordatus (Linnaeus, 1763) (Decapoda: Ocypodidae) in Northern Brazil

    OpenAIRE

    Darlan de Jesus de Brito Simith; Karen Diele

    2008-01-01

    O presente trabalho estudou o efeito da salinidade na sobrevivência e na duração do desenvolvimento larval do caranguejo-uçá, Ucides cordatus (do estuário do Rio Caeté, Norte do Brasil), até a fase de megalopa em sete tratamentos de salinidade (0, 5, 10, 15, 20, 25 e 30). A salinidade afetou significativamente a sobrevivência das larvas zoea, no entanto não afetou a duração do desenvolvimento larval (20,77 ± 1,56 dias). Nas salinidades 0, 5 e 10 houve total mortalidade das larvas zoea. Soment...

  13. 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.

  14. 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

  15. An active structure preservation method for developing functional graphitic carbon dots as an effective antibacterial agent and a sensitive pH and Al(iii) nanosensor.

    Science.gov (United States)

    Hou, Peng; Yang, Tong; Liu, Hui; Li, Yuan Fang; Huang, Cheng Zhi

    2017-11-16

    Functional engineering is a crucial prerequisite for specific and wide applications of optical probes. In this study, we proposed a facile active structure preservation (ASP) method to directly develop new self-functional graphitic carbon dots (g-CDs) through a hydrothermal synthesis route by taking ciprofloxacin hydrochloride, an antibiotic belonging to a group of fluoroquinolone drugs, as an example. To retain the functional structures of the starting materials, the reaction temperature is intentionally controlled below the decomposition temperature of the reactants that hold the functional groups. As a proof of concept, we successfully prepared g-CDs with ciprofloxacin-like structures on its surface, as identified by mass spectrometric (MS) analysis. The as-prepared g-CDs not only exhibit effective antibacterial activity towards the bacteria Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative), but can also optically sense pH in the range from 5.02 to 9.91. Furthermore, the g-CDs can coordinate with aluminum ions to show a chelation-enhanced photoluminescence (CHEP) effect. These results indicate that the ASP method can be promising for engineering CDs with various properties.

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

    Directory of Open Access Journals (Sweden)

    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.

  17. 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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

  19. Relações hídricas em cultivares de beterraba em diferentes níveis de salinidade do solo

    Directory of Open Access Journals (Sweden)

    Alexsandro O. da Silva

    2013-11-01

    Full Text Available O excesso de sais no solo pode afetar diretamente o desenvolvimento e a produtividade das plantas, motivo pelo qual investigações sob as relações hídricas das culturas em tais condições se fazem necessárias para prevenir ou remediar tal problema. O estudo foi conduzido em casa de vegetação, na Universidade Estadual Paulista no Departamento de Engenharia Rural. O delineamento estatístico adotado foi o de blocos casualizados com 4 repetições, 5 níveis de salinidade no solo (1,0; 3,0; 6,0; 9,0; 12,0 dS m-1, duas cultivares de beterraba (Early Wonder e Itapuã e dois manejos de fertirrigação totalizando, assim, 80 parcelas experimentais. Foram realizados medidas do teor relativo de água nas folhas, resistência difusa ao vapor de água, transpiração, área foliar e o consumo hídrico da cultura. Houve um decréscimo de acordo com o incremento da salinidade para os parâmetros fisiológicos analisados na cultivar Early Wonder enquanto para a cultivar Itapuã um aumento crescente foi observado até a salinidade de 6 dS m-1. O consumo de água pelas plantas apresentou uma redução para as duas cultivares estudadas.

  20. Evapotranspiração e produção da abóbora cultivar bárbaba sob diferentes níveis de salinidade e de adubação nitrogenada

    OpenAIRE

    Lima, Rozana Maria de Sousa

    2013-01-01

    A maior demanda por água para irrigação tem levado os agricultores a utilizarem águas com salinidade mais elevada, sendo que sua utilização fica condicionada à tolerância das culturas à salinidade e ao manejo da irrigação. A adubação nitrogenada tem proporcionado um aumento significativo na produção e em ambiente salino reduz o efeito dos sais. Este trabalho teve como objetivo estudar os efeitos de diferentes níveis de salinidade da água de irrigação e de doses de nitrogênio aplicado via fert...

  1. Variaciones en el pH de la rizosfera y en el porcentaje de materia seca de Vicia sativa al aplicar dos fuentes fosfatadas de baja solubilidad en un andisol del departamento de Nariño, Colombia

    Directory of Open Access Journals (Sweden)

    Menjivar F. Juan Carlos

    2006-06-01

    Full Text Available

    En el estudio se utilizaron seis tratamientos: el testigo (T0, sin fuentes fosfatadas (T1 y con adiciones de 25 y 50 kg/ha de P como fosforita Huila (T2 y T3 y calfós (T4 y T5. Los cambios generados por la raíz se evaluaron utilizando la solución nutritiva de Marschner Römheld y Ossenberg-Neuhaus, acondicionada con agar. El porcentaje de materia seca parcial de Vicia sativa se incrementó significativamente al aplicar 25 y 50 kg/ha de P como fosforita Huila (T2 y T3 y calfos (T5 y T6 en la localidad de Genoy. El pH de la solución agarizada sufrió disminuciones significativas a través del tiempo especialmente en los tratamientos T3 y T2.

    Palabras claves: pH rizosférico, Vicia sativa, Papilionoidea, fuentes fosfatadas, solubilidad

  2. Efecto de la salinidad por cloruro de sodio sobre el balance de nutrientes en plantas de lulo (Solanum quitoense L.

    Directory of Open Access Journals (Sweden)

    Casierra Posada Fanor

    2000-12-01

    -height: 115%; font-family: ";Times New Roman";,";serif";;" lang="EN-US">experiment site was the Horticulture Institute of the Humboldt University in Berlin (Germany. The influence ofNaCI salinity on the uptake of analyzed ions, salinity accumulation and distribution into the plant tissues and ratio ions were al so researched throughout this experiment. Plants were supplied with a nutrient solution of Wuxal (1 ppm (Schering, Germany. AII plants were transferred to bigger pots with quartz sand, six weeks after germination. After a one-week adaptation period, the salt treatments were initiated with 30 and 60 of mM NaCI in Wuxal solution. Controls were supplied only with Wuxal solution 1ppm. K+,Ca2+, Mg2 + and Na+ concentrations were determinated through atomic absorption spectrophotometer. Cl was conclusive through the use of chloride meter. Cl and Na+accumulation in tissues presented a trend similar to the NaCI concentration in the nutrient solution. The salt lessened K+ concentration in leaves and shoots. Na/Ca, Na/Mg, Na/K and Na/Ca+Mg+K ratios were increased in leaves and shoots throughout the NaCI concentration in the nutrient solution. Na+ accumulation was greater in roots that in shoots and leaves. These results suggest that Lulo might be a moderately salt-tolerant plant comparable to other Solanaceae species.

    Se analizaron las concentraciones de K+, Ca2+,Mg2+,Na+ y Cl en hojas, tallos y raíces de plantas de Lulo (Solanum quitoense L. que crecieron bajo invernadero en condiciones salinas. El ensayo se realizó en la Sección de Fruticultura del Instituto de Horticultura de la Universidad Humboldt de Berlín. Mediante este estudio, se evaluó la influencia de la salinidad por NaCl sobre la toma de los elementos estudiados, sobre la acumulación de Cl y Na+ en los tejidos de las plantas, así como la relación del Sodio con los demás cationes acumulados en los tejidos vegetales. Después de la germinación de las semillas, se regaron las plántulas con una soluci

  3. Rendimento quântico e trocas gasosas em maracujazeiro amarelo sob salinidade hídrica, biofertilização e cobertura morta

    Directory of Open Access Journals (Sweden)

    José Lucínio de Oliveira Freire

    Full Text Available Um experimento foi conduzido a céu aberto no município de Remígio, PB, para se avaliar as respostas do maracujazeiro amarelo relacionadas à eficiência fotossintética e trocas gasosas. O delineamento experimental utilizado foi em blocos casualizados, no esquema fatorial 2 x 2 x 2, referente à irrigação com água não salina (0,5 dS m-1 e salina (4,5 dS m-1, sem e com biofertilizante bovino, sem e com cobertura morta, com três repetições e três plantas por parcela, em recipientes plásticos circulares utilizados como lisímetros de pressão, com 130 dm³ de volume e drenos na parte inferior para a lixiviação do excesso de sais. A irrigação com água de baixa salinidade e aplicação de biofertilizante bovino comum estimularam a eficiência fotossintética das plantas. O uso simultâneo de água de alta salinidade, biofertilizante e cobertura morta reduziram a condutância estomática do maracujazeiro amarelo. As plantas sob estresse salino apresentaram atividade fotoquímica do fotossistema II e fotossíntese líquida inibida.

  4. Estabelecimento do arroz irrigado e absorção de cátions em função do manejo da adubação potássica e do nível de salinidade no solo Initial growth of flooded rice and cation absorption according to potassium fertilizer management and soil salinity

    Directory of Open Access Journals (Sweden)

    Felipe de Campos Carmona

    2009-04-01

    Full Text Available O uso da água para a irrigação do arroz no Rio Grande do Sul, cujos mananciais hídricos têm ligação com o mar, pode ocasionar acúmulo de sais no solo em concentrações prejudiciais ao estabelecimento da cultura nos anos subsequentes, especialmente quando são aplicadas altas doses de fertilizante potássico na linha de semeadura. Este trabalho foi realizado com o objetivo de avaliar o efeito do manejo da adubação potássica sobre o estabelecimento e a absorção de cátions pelo arroz (cultivar IRGA 417 em um solo com diferentes níveis de saturação por Na. Foram utilizados um Planossolo Háplico com saturações por Na na troca de 5, 10 e 20 %; três manejos da adubação com cloreto de K equivalentes a 120 kg ha-1 de K2O a lanço; 120 kg ha-1 de K2O na linha de semeadura e 60 kg ha-1 de K2O na linha de semeadura, além de uma testemunha, sem adição de sal e de fertilizante, fatorial (3 x 3 + 1. O estande de plântulas não foi afetado pelos níveis de salinidade do solo e manejo da adubação potássica. A ontogenia da planta foi afetada pela salinidade, com atraso na emergência das plântulas. A salinidade do solo, a partir de 10 % de saturação por Na no complexo de troca, inibiu a absorção de K e reduziu o crescimento das plântulas de arroz, assim como diminuiu as relações K/Na, Ca/Na e Mg/Na no tecido. A interação entre manejo da adubação x salinidade reduziu o teor de Ca trocável no solo, aumentou o teor de Na na parte aérea e reduziu a relação Ca/Na na parte aérea do arroz.The use of water for rice irrigation in Rio Grande do Sul, Brazil, where the water courses are connected with the sea, may cause salt accumulation in the soil at harmful levels for the establishment of rice plants in the following years, especially when high rates of potassium fertilizer are applied in the plant rows. The study was carried out with the purpose of evaluating the effect of potassium chloride management on the establishment

  5. Interação entre salinidade e fósforo na cultura do rabanete Phosphorus-salinity interaction in radish

    Directory of Open Access Journals (Sweden)

    Francisco Ronaldo Alves de Oliveira

    2010-12-01

    Full Text Available O uso de água salina, na irrigação, tem sido um desafio para os pesquisadores e produtores rurais, sendo constantemente desenvolvidos estudos que possibilitem o uso de água, de qualidade inferior, sem afetar o rendimento e qualidade dos produtos agrícolas. Este trabalho foi realizado com o objetivo de avaliar o efeito de diferentes níveis de salinidade da água de irrigação e doses de fósforo na cultura do rabanete. O delineamento experimental adotado foi inteiramente ao acaso, arranjados em esquema fatorial 4 x 4 com três repetições. Os tratamentos resultaram da combinação de quatro níveis de salinidade da água de irrigação (S1-0,5; S2-2,0; S3-3,5 e S4-5,0 dS m-1 com quatro doses de fósforo (0; 100; 200 e 300 mg dm-3. As variáveis avaliadas foram: número de folhas, área foliar, massa fresca e seca das raízes. A cultura do rabanete respondeu significativamente a interação entre salinidade e fósforo para área foliar, massa fresca e seca das raízes; e de forma isolada para número de folhas. Doses crescentes de fósforo reduziram à sensibilidade da cultura do rabanete à salinidade de até 3,5 dS m-1. O manejo da adubação fosfatada é uma alternativa para amenizar o efeito da salinidade no desenvolvimento da cultura do rabanete.The use of saline water for irrigation has been a challenge for the researchers and farmers, studies continually being developed to enable the use of lower quality water without interfering with the yield and quality of products. This work was conducted to evaluate the effect of different salinity levels water irrigation and phosphorus doses in radish. It was used an entirely statistical randomized design, in factorial scheme 4 x 4, with three replications. The treatments resulted from the combination of four salinity levels of irrigation water (S1-0.5; S2-2.0; S3-3.5 and S4-5.0 dS m-1 with four phosphorus levels (0; 100; 200 and 300 mg dm-3. The variables evaluated were: number of leaves

  6. Farklı pH Değerlerinin Lemna gibba L. ve Lemna minor L.’de Nikel Alınımı ve Klorofi lMiktarına Etkisi

    OpenAIRE

    URUÇ, Kadriye; YILMAZ, Dilek DEMİREZEN; AKBULUT, Hatice

    2008-01-01

    In this study, the effect of different pH on the nickel absorbtion capacity and amount of chlorophyll of Lemna minor and Lemna gibba was investigated under laboratory conditions.At high pH value (pH = 7), we observed increasing amount of kla and klb with increasing pH. Additionally, nickel accumulation capacity was signifi cantly reduced at pH 4. It means, nickel absorbtion capacity was stimulated by an decrease in pH value. Furthermore, considerably higher accumulation of nickel were found i...

  7. 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

    Directory of Open Access Journals (Sweden)

    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

  8. Effect of trace elements (ZnSO/sub 4/, MnSO/sub 4//sub /and Al/sub 2/(SO/sub 4/)/sub 3/) on soil Ph, Zinc and manganese concentrations in case of mature teat bushes

    International Nuclear Information System (INIS)

    Nosheen, M.; Riaz, A.K.

    2005-01-01

    A field experiment was conducted to study the effect of trace elements on growth and yield of mature tea bushes, at National Tea Research Inst., Shinkiari, Mansehra, Pakistan, during 2003. The treatments included control (no fertilizer), recommended dose of NPK (432:111:74 kg ha/sup -1/ alone and NPK in combination with either two doses of (5.5 and 11 kg ha/sup -1/) ZnSO/sub 4/ or (2.0 and 4.0 kg ha/sup -1/)MnSO/sub 4/ or (0.225 and 0.45 kg ha/sup -1/) Al/sub 2/(SO/sub 4/)/sub 3/ to soil and one dose of each (11 kg ha/sup -1/) ZnSO/sub 4/, (4.0 kg ha/sup -1) MnSO/sub 4/ and (0.45 kg ha/sup -1/) Al/sub 2/(SO/sub 4/)/sub 3/ applied as spray solution. Treatments including soil application of NPK alone and NPK + either ZnSO/sub 4/, MnSO/sub 4/ or Al/sub 2/(SO/sub 4/)/sub 3/ significantly (P < 0.001) increased tea yield (fresh weight of three leaves + bud), shoot height and tissue Zn and Mn concentrations with significant interactions (T x t) on tissue Zn and Mn levels. As compared to control the yield increased by 7.0,30,.37,42,37 and 34% with NPK alone, NPK + 5.5, + 11.0 ZnSO/sub 4/, + 2.0, + 4.0 MnSO/sub 4/, + 0.225, + 0.45 kg ha/sup -1/ Al/sub 2/(SO/sub 4/)/sub 3/, respectively during fist three months while the yield of six months plucking showed similar response to treatments but was significantly lower than the first three months. Soil pH, Zn and Mn concentrations were significantly affected by treatments, time of sampling, and depth of sampling. Except ZnSO/sub 4/, lower doses of MnSO/sub 4/ (2.0 kg ha-l) and Al/sub 2/(SO/sub 4/)/sub 3/ (0.225 kg ha/sup -1/), were more effective as compared to their higher doses when applied to soil, regarding tea yield and shoot height. Foliar application of 11 kg ha-l ZnSO/sub 4/ significantly increased yield as compared to its both levels when applied to soil. It is concluded that MnSO/sub 4/ and Al/sub 2/(SO/sub 4/)/sub 3/ should be applied at the rate of 2.0 and 0.225 kg ha/sup -l/. (author)

  9. 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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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

  15. Acúmulo e exportação de macronutrientes em beterraba sob diferentes manejos de fertirrigação e salinidade

    Directory of Open Access Journals (Sweden)

    Alexsandro Oliveira da Silva

    Full Text Available RESUMO A fertirrigação é uma das principais formas de adubação parcelada; entretanto, se aplicados em excesso, os fertilizantes podem prejudicar o desenvolvimento da cultura. O objetivo deste trabalho foi avaliar o acúmulo e exportação de macronutrientes em um cultivo de beterraba sob 2 manejos de fertirrigação em diferentes níveis de salinidade do solo. O experimento foi realizado em casa de vegetação no município de Botucatu (SP. Os tratamentos constituíram-se da combinação dos fatores salinidade do solo (1,0; 3,0; 6,0; 9,0; 12,0 dS∙m−1, manejo da fertirrigação (M1= tradicional e M2= com controle da concentração iônica e cultivares de beterraba (C1 = Early Wonder e C2 = Itapuã, em um esquema fatorial 5 × 2 × 2, com 4 repetições em blocos casualizados. Após a colheita, foram determinados os acúmulos dos macronutrientes (N, P, K, Ca, Mg, P e S mg∙planta−1. Houve um aumento do acúmulo dos nutrientes estudados para ambas as cultivares e manejos de fertirrigação até níveis de condutividade elétrica entre 3 (M1 e 6 (M2 dS∙m−1. A ordem de exportação dos macronutrientes foi diferenciada para as cultivares estudadas. Para a cultivar Early Wonder, seguiu-se a seguinte ordem: K > N > Ca > Mg > P > S, enquanto que, para a cultivar Itapuã, a ordem foi K > N > Mg > Ca > S > P.

  16. 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.Batimetry, salinity, temperature, and dissolved oxigen water of the Marino Ballena National Park, Pacific, Costa Rica. Between September 2003 and April

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

    Directory of Open Access Journals (Sweden)

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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

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

    Directory of Open Access Journals (Sweden)

    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

  2. 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.

  3. 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.

  4. 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

  5. Índice spad em feijão caupi inoculado com rizóbio e submetidos a diferentes níveis de salinidade

    Directory of Open Access Journals (Sweden)

    Jailma Ribeiro de Andrade

    2012-10-01

    Full Text Available O feijão-caupi (Vigna unguiculata também conhecido como feijão macassar ou feijão-de corda representa alimento básico para as populações de baixa renda do Nordeste brasileiro. Apresenta ciclo curto, baixa exigência hídrica e capacidade para fixar nitrogênio do ar, através de bactérias fixadoras, na forma de simbiose, que pode permitir o aumento do rendimento da cultura. Objetivou-se com esse trabalho comparar os níveis de clorofila nas folhas da cultivar BRS-JURUÁ através do uso do SPAD-512 (Soil Plant Analysis Development, inoculados com o rizóbio Br 3267. O experimento foi conduzido em casa de vegetação. Utilizou-se o delineamento inteiramente ao acaso, num fatorial 5x4(cinco genótipos de feijão caupi e quatro níveis de salinidade com 4 repetições. O melhor resultado encontrado em porcentagem de clorofila total (SPAD foi aos 7 dias após o desbaste no nível de 6,0 dSm-1.

  6. 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.

  7. PhD Dissertations

    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

  8. O efeito da salinidade no desenvolvimento larval do caranguejo - uçá, Ucides cordatus (Linnaeus, 1763 (Decapoda: Ocypodidae no Norte do Brasil The effect of salinity on the larval development of the uçá-crab, Ucides cordatus (Linnaeus, 1763 (Decapoda: Ocypodidae in Northern Brazil

    Directory of Open Access Journals (Sweden)

    Darlan de Jesus de Brito Simith

    2008-01-01

    Full Text Available O presente trabalho estudou o efeito da salinidade na sobrevivência e na duração do desenvolvimento larval do caranguejo-uçá, Ucides cordatus (do estuário do Rio Caeté, Norte do Brasil, até a fase de megalopa em sete tratamentos de salinidade (0, 5, 10, 15, 20, 25 e 30. A salinidade afetou significativamente a sobrevivência das larvas zoea, no entanto não afetou a duração do desenvolvimento larval (20,77 ± 1,56 dias. Nas salinidades 0, 5 e 10 houve total mortalidade das larvas zoea. Somente a partir da salinidade 15 observou-se um desenvolvimento completo até a fase de megalopa. A taxa de sobrevivência foi maior em salinidade 30 (72% e menor em 15 (16%. A reduzida taxa de sobrevivência das larvas zoea de U. cordatus, em salinidades baixas, indica a necessidade de dispersão larval do estuário para as águas costeiras onde as condições de salinidade para o desenvolvimento larval são mais favoráveis. Caso contrário se não houvesse a dispersão, a reduzida salinidade das águas estuarinas no período chuvoso, causaria uma elevada mortalidade, afetando desta forma o recrutamento, a manutenção e o crescimento da população de U. cordatus nos manguezais.The present work studied the effect of salinity on the survival and duration of larval development of the mangrove crab, Ucides cordatus (from the Caeté River estuary, North of Brazil until the megalopal phase in seven salinity treatments (0, 5, 10, 15, 20, 25 e 30. Salinity significantly affected the survival of the zoea larvae, however it did not affect the duration of the larval development (20.77 ± 1.56 days. In salinity 0, 5 and 10 all zoea larvae died. Only from off salinity 15, complete development until the megalopal phase occurred. The survival rate was highest in salinity 30 (72% and lowest in 15 (16%. The reduced survival rate of the U. cordatus zoea larvae, in low salinities, indicates the necessity of larval dispersion from the estuary to coastal waters, where

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Influência do tempo de aclimatação na resposta do cajueiro à salinidade Influence of acclimatization time on response of cashew plant to salinity

    Directory of Open Access Journals (Sweden)

    Jean C. A. Brilhante

    2007-04-01

    Full Text Available A resposta das plantas à salinidade depende de fatores fisiológicos, bioquímicos e genéticos. Com este trabalho, objetivou-se estudar o impacto do tempo de aclimatação à solução nutritiva sobre a resposta do cajueiro à salinidade. Plantas de Anarcadium occidentale L., CCP06, cultivadas em vermiculita durante 28 dias, foram transferidas para solução nutritiva de Hoagland com 1/10 de sua força iônica, onde permaneceram por 1 e 7 dias. Ao final dos dois tempos, a solução nutritiva foi suplementada com 200 mM de NaCl, condições em que as plantas foram cultivadas por 0, 12, 24, 48 e 72 h. As plantas aclimatadas por 7 dias á solução de Hoagland apresentaram sinais fisiológicos mais compatíveis com a tolerância ao NaCl, como menor acumulação de Na+ e, também, menores danos nas membranas, peroxidação dos lipídeos, degradação de proteínas, acumulação de aminoácidos livres e acumulação de prolina. A amônia livre foi o melhor indicador da intensidade do estresse salino. Os danos de membranas aumentaram com a acumulação de Na+ nas folhas. Os resultados evidenciam que o tempo de aclimatação das raízes à solução nutritiva influencia a expressão de fatores capazes de atenuar os efeitos do estresse salino.The plant response to salinity depends on physiological, biochemical and genetic factors and on their interaction with external environment. This work aimed to study the impact of adaptation time in nutrient solution on the cashew response to salinity. Seedlings of Anacardium occidentale L (CCP06 grown in vermiculite, for 28 days, were placed to grow in 1/10 ionic strength Hoagland solution for 1 and 7 days. At the end of each time the solution was supplemented with 200 mM NaCl, and under this condition the plants were monitored for 0, 12, 24, 48 and 72 h. The 7 days Hoagland solution acclimated plants had physiological index more compatible to tolerance to NaCl such as low Na+ accumulation and also low membrane

  11. Crescimento do meloeiro cultivado sob diferentes níveis de salinidade, com e sem cobertura do solo Growth of muskmelon under different levels of salinity, with and without soil covering

    Directory of Open Access Journals (Sweden)

    José F. de Medeiros

    2007-06-01

    Full Text Available Objetivou-se, neste trabalho, avaliar o crescimento de híbridos de meloeiro submetidos a três níveis de salinidade da água de irrigação, com presença e ausência de cobertura do solo. O experimento foi conduzido na Fazenda São João, em Mossoró, RN. Utilizou-se um esquema fatorial 3 x 2 x 2 em blocos completos casualizados, com quatro repetições. Os fatores foram três níveis de salinidade da água de irrigação, com condutividade elétrica de 1,2, 2,5 e 4,5 dS m-1, dois híbridos, Gold Mine e Trusty, com e sem cobertura de solo, por filme de polietileno dupla face preto-prateado. A área foliar, fitomassa e taxa de crescimento absoluto foram afetadas pela salinidade da água e cobertura do solo, variando com a idade da planta. A cobertura do solo proporcionou maior área foliar e fitomassa das plantas. O híbrido Trusty reduziu a fitomassa apenas quando se utilizou água de maior salinidade. A taxa de crescimento absoluto (TCA foi máxima entre 35 e 45 dias após o plantio e neste período foi reduzida com o aumento da salinidade. As taxas de crescimento relativo (TCR e de assimilação líquida (TAL não foram afetadas pela salinidade da água, cobertura do solo e híbridos.The objective of this work was to evaluate the growth of melon hybrids submitted to three irrigation water salinity levels with and without soil covering. The experiment was conducted at the São João Farm, Mossoró in the State of Rio Grande do Norte, Brazil. The factorial (3 x 2 x 2 scheme was adapted in completely randomized blocks, with four repetitions. The factors were three salinity levels of irrigation water, with electrical conductivity of 1.2, 2.5 and 4.5 dS m-1, two hybrids (Gold Mine and Trusty, with and without soil covering by a film of double face black-silvery polyethylene. The leaf area, dry weight and rate of absolute growth were affected by water salinity and soil covering, varying with plant age. The soil covering provided a larger leaf

  12. 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

  13. 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

  14. 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

  15. 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

  16. 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.

  17. 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.

  18. Acúmulo de matéria seca e nutrientes no meloeiro irrigado sob estratégias de manejo da salinidade Accumulation of dry matter and nutrients in irrigated melon under strategies of salimity management

    Directory of Open Access Journals (Sweden)

    Cícero P. C. Terceiro Neto

    2012-10-01

    Full Text Available O presente estudo foi realizado com o objetivo de investigar estratégias de uso de água salobra sobre o acúmulo de matéria seca e nutrientes, duas cultivares de melão (Sancho- C1 e Medellín- C2 irrigadas com água de baixa (S1 = 0,61 dS m-1 e alta (S2 = 4,78 dS m-1 salinidade por fase da cultura: S1S1S2S2- T1, S2S1S2S2- T2, S2S2S1S2- T3 (os 1, 2, 3 e 4º termos correspondem, respectivamente, às fases de crescimento, floração, crescimento dos frutos e maturação e colheita e, ainda a irrigação alternada, durante todo o ciclo, com água S1 por 2 dias consecutivos seguido com água S2 por um dia (S12dias + S21dia- T4 e a irrigação com água S2 durante todo o ciclo- T5. Além disto foi utilizada, como testemunha, a irrigação com a mistura de 37% da água S1 e 63% da água S2- T0 (manejo adotado atualmente na fazenda em que o experimento foi conduzido. O delineamento experimental utilizado foi o de blocos inteiramente casualizados em um esquema de parcelas subdivididas 6 x 2 (manejo da água salina x cultivar com quatro repetições. O acúmulo de fitomassa seca total na parte aérea da cultivar Sancho foi superior ao de Medellín, em todas as estratégias de manejo utilizado; os nutrientes mais absorvidos pelas plantas das duas cultivares foram o cálcio, o potássio e o nitrogênio.A study was carried out aiming to investigate management strategies for use of brackish water in the accumulation of dry matter and nutrients in two cultivars of melon (C1 - Sancho and C2 - MedeLλi n irrigated with low (S1 = 0.61 dS m-1 and high (S2 = 4.78 dS m-1 salinity water in different phases of crop: S1S1S2S2 - T1, S2S1S2S2 - T2, S2S2S1S2 - T3. The 1st, 2nd, 3rd and 4th term correspond, respectively, to different phases - initial growth, flowering, fruit maturation and harvest. Alternate irrigation during the crop cycle, two days of consecutive application with S1 water followed by one day with S2 water (S1 2 days + S2 1day - T4 and irrigation with

  19. 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.

  20. 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.

  1. 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

  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. Influência da matéria orgânica e do ambiente no crescimento e acúmulo de solutos em Morinda citrifolia submetida à salinidade

    Directory of Open Access Journals (Sweden)

    Maria Cristina Martins Ribeiro de Souza

    2014-09-01

    Full Text Available O Noni (Morinda citrifolia L. é uma planta tolerante aos efeitos salinos e alcalinos dos solos e desenvolve-se em regiões de clima seco ou úmido. Apesar da adaptabilidade intercontinental, ainda são poucas as informações sobre sua tolerância aos sais no solo brasileiro. Baseado no exposto, objetivou-se com o presente trabalho avaliar os efeitos da água salina no crescimento inicial do Noni. Para isso, foi conduzido um experimento em vasos de polietileno com capacidade para 20 L, em Sobral, Ceará. O delineamento estatístico adotado foi em blocos ao acaso, disposto no esquema de parcelas subsubdivididas, com 5 repetições. As parcelas foram constituídas pelos ambientes de cultivo (céu aberto e telado, as subparcelas pelos níveis de salinidade da água de irrigação (CEa: 0,3;1,5; 3,0; 4,5 e 6,0 dS m-1 e as subsubparcelas foram representadas pela ausência e presença de matéria orgânica. Aos 110 dias após a aplicação dos tratamentos (DAT, avaliaram-se: altura, massa seca da parte aérea (MSPA, da raiz (MSR, total (MST e área foliar (AF, e aos 90 (DAT os teores foliares de solutos orgânicos. Todas as variáveis de crescimento estudadas foram afetadas negativamente pela salinidade, sendo que o efeito observado a céu aberto foi mais expressivo do que no ambiente telado. A matéria orgânica não teve efeito atenuante sobre os efeitos deletérios da salinidade em plantas de noni. O acúmulo de prolina mostrou-se um sinalizador de dano causado pelo estresse, visto que os maiores acúmulos ocorreram nas plantas que sofreram maiores reduções no crescimento.

  6. 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.

  7. 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 ...

  8. Flooded rice yield as affected by levels of water salinity in different stages of its cycle Produção de grãos de arroz em função de níveis de salinidade da água de irrigação em distintos períodos do seu ciclo

    Directory of Open Access Journals (Sweden)

    Thiago Isquierdo Fraga

    2010-02-01

    ógico da cultura em diferentes níveis de salinidade da lâmina de água em distintos períodos do seu ciclo. O experimento foi realizado em casa de vegetação, em vasos preenchidos com 11 L de um Planossolo Háplico. Os níveis de salinidade utilizados foram 0,3 (controle, 0,75, 1,5, 3,0 e 4,5 dS m-1, que foram mantidos na lâmina d'água pela adição de solução salina de cloreto de sódio, com exceção do controle, em diferentes períodos de desenvolvimento do arroz: V4 (perfilhamento à diferenciação do primórdio floral; V4 ao florescimento pleno; V4 à maturação fisiológica; diferenciação do primórdio floral ao florescimento pleno; diferenciação do primórdio floral à maturação fisiológica e florescimento pleno à maturação fisiológica. Foram determinados o número de panículas por vaso, o número de grãos por panícula, o peso de mil grãos, a esterilidade de espiguetas e a produção de grãos, além do ciclo da cultura. Todos os atributos foram alterados negativamente, de forma quadrática, com o aumento da salinidade, em todos os períodos do desenvolvimento do arroz. Dos componentes de rendimento avaliados, o que mais se relacionou com o rendimento de grãos de arroz foi a esterilidade de espiguetas.

  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. 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

  12. 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

  13. 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

  14. 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

  15. PhD Dissertations

    OpenAIRE

    Redazione Reti Medievali (a cura di)

    2010-01-01

    Report of PhD Dissertations.Anna Airò La scrittura delle regole. Politica e istituzioni a Taranto nel Quattrocento, Tesi di dottorato di ricerca in Storia medievale, Università degli studi di Firenze, 2005 Pasquale Arfé La Clavis Physicae II (316-529) di Honorius Augustodunensis. Studio ed edizione critica, Tesi di dottorato in Storia della filosofia medievale, Università degli Studi di Napoli "L'Orientale", 2005 Alessandro Azzimonti Scrittura agiografica e strutture di potere nell'Italia c...

  16. 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

  17. 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.

  18. Esophageal pH monitoring

    Science.gov (United States)

    pH monitoring - esophageal; Esophageal acidity test ... Esophageal pH monitoring is used to check how much stomach acid is entering the esophagus. It also checks how well the acid is cleared downward into the ...

  19. 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 dissolved...

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

    Directory of Open Access Journals (Sweden)

    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

  1. 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

  2. CRESCIMENTO E SOBREVIVÊNCIA DO CAMARÃO BRANCO DO PACIFÍCO Litopenaeus vannamei (BOONE, 1931 EM DIFERENTES SALINIDADES GROWTH AND SURVIVAL OF PACIFIC WHITE SHRIMP Litopenaeus vannamei (BOONE, 1931 IN DIFFERENT SALINITIES

    Directory of Open Access Journals (Sweden)

    Carlos Henrique dos Anjos dos Santos

    2009-09-01

    Full Text Available O presente estudo teve como objetivo avaliar o desenvolvimento de pós-larvas de Litopenaeus vannamei cultivadas em diferentes salinidades. Realizou-se o experimento no Centro de Tecnologia em Aquicultura da Universidade Federal do Ceará, durante o período de 1.o de setembro de 2006 a 31 de outubro de 2006. Em vinte aquários com volume útil de 30L foram distribuídos, em um delineamento inteiramente casualizado, cinco tratamentos (controle – 35%, 30‰, 20‰, 10‰ e 0‰ com quatro repetições cada. Foi utilizada a densidade de trinta indivíduos/aquário. As pós-larvas, em fase de PL 10, apresentavam peso e comprimento médio total inicial de 0,008 ± 0,001g e 11,00 ± 0,05mm, respectivamente. Os animais foram, gradativamente, aclimatados nas salinidades experimentais. Para as análises estatísticas, aplicou-se a análise de variância (ANOVA e, posteriormente, caso se verificassem diferenças significativas entre os tratamentos, o teste Tukey de separação de médias (? = 0,001. Os parâmetros de qualidade de água analisados mantiveram-se dentro dos padrões aceitáveis para o cultivo da espécie. As pós-larvas cultivadas em 0‰ apresentaram os melhores valores de peso final, incremento em peso, incremento relativo diário de biomassa e taxa de sobrevivência (P<0,001. Todavia, os animais cultivados em 10% mostraram os melhores valores de comprimento total e incremento em comprimento (P<0,001. Os resultados do presente estudo sugerem que pós-larvas de L. vannamei apresentam taxas similares de crescimento e sobrevivência quando cultivadas em diferentes salinidades.

    PALAVRAS-CHAVES: Gradiente salino, laboratório Litopenaeus vannamei, osmorregulação.
    The aim of this work was to evaluate the development of Litopenaeus vannameiat post-larvae (PL at different salinities. This experiment was carried out at the “Centro de Tecnologia em Aqüicultura/UFC” at the period from 01/09/2006 to 31/10/2006. Twenty

  3. 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

  4. Limnología e ictiofauna de la laguna José María (Córdoba, Argentina, con especial referencia al pejerrey (Odontesthes bonariensis -Valenciennes, 1835-

    Directory of Open Access Journals (Sweden)

    M. Mancini

    2016-09-01

    Full Text Available La región sur de la provincia de Córdoba presenta numerosas lagunas cuyo origen y salinidad varían ampliamente. Muchos de estos ambientes son utilizados para la pesca recreativa del pejerrey (Odontesthes bonariensis. El objetivo del presente trabajo fue caracterizar la calidad del agua y determinar la diversidad del zooplancton y de la ictiofauna con especial referencia a O. bonariensis, de la laguna José María (34º50’17’’S, 63º37’23’’O. Este ambiente se ubica en la cuenca del río Quinto (Córdoba y está comunicado con numerosas lagunas. Se analizaron in situ (n=8, el pH, el oxígeno, la temperatura y transparencia del agua y se tomaron muestras de agua y zooplancton para su análisis en laboratorio. Para la captura de peces se utilizaron redes de enmalle, arrastre, trampa y espineles. La profundidad promedio fue de 1,99 m, con un máximo de 2,20 m. Los registros medios del pH, oxígeno disuelto, temperatura y transparencia fueron 8,51, 9,03 mg/L, 24,3 ºC y 44 cm respectivamente. Por su transparencia, la laguna fue caracterizada como “turbia”. El agua se clasificó como oligohalina (4,09 g/L, sulfatada-sódica y muy dura (484 ppm de CO3Ca. El zooplancton estuvo representado por 3 especies de crustáceos y 7 de rotíferos. Entre los primeros, Metacyclops mendocinus fue el que registró la mayor densidad (162,2 ind/L, mientras que entre los rotíferos fue Brachionus plicatilis con 482,7 ind/L. Se capturaron 12 especies de peces, pertenecientes a 5 órdenes y 9 familias (Shannon = 2,23 bits. El pejerrey fue la especie de mayor abundancia (50,8% y junto al sabalito Cyphocharax voga y la carpa Cyprinus carpio representaron el 85 % del total de biomasa de los peces capturados. Los parámetros poblacionales de O. bonariensis fueron: Peso= 0,0000047081*LEst3,178 (R2=0,99, n=116; longitud total= 5,854+LEst*1,168 (R2= 0,99, n= 117; LEst(t= 489,02 (1-e-0,225(t-0,46 y W(t= 1647,5 (1- e-0,225(t-0,463,177.

  5. Colonização micorrízica e nodulação radicular em mudas de sabiá (Mimosa caesalpiniaefolia Benth. sob diferentes níveis de salinidade Mycorrhizal colonization and root nodulation in sabiá seedlings (Mimosa caesalpiniaefolia Benth. at different salinity levels

    Directory of Open Access Journals (Sweden)

    Rodrigo Castro Tavares

    2012-09-01

    Full Text Available O sabiá (Mimosa caesalpiniaefolia Benth. é uma espécie vegetal nativa do nordeste brasileiro e reúne algumas características fundamentais para compor programas de reabilitação de áreas salinizadas, principalmente quanto associado aos fungos micorrízicos arbusculares (FMAs e a bactérias fixadoras de nitrogênio (BFN. O objetivo do presente estudo foi avaliar a colonização micorrízica e a nodulação radicular de mudas de sabiá adubadas com composto orgânico e irrigadas com águas de diferentes condutividades elétricas. O experimento foi conduzido em casa de vegetação, com delineamento experimental inteiramente casualizado, em esquema fatorial com 2 (presença e ausência de fungos micorrízicos arbusculares x 2 (presença e ausência de composto orgânico x 5 níveis de condutividade elétrica da água de irrigação (0,7; 1,2; 2,2; 3,2 e 4,2 dS m-1, com 3 repetições. Os resultados obtidos indicam que: a salinidade reduziu a colonização micorrízica e a nodulação radicular das mudas de sabiá; a intensificação das condições de estresse salino aumentaram a dependência micorrízica das mudas de sabiá; a colonização das mudas de sabiá com os FMAs proporcionou aumentos na matéria seca dos nódulos radiculares da ordem de 1900%; as micorrizas arbusculares reduziram o pH após o cultivo do solo; e a adição de vermicomposto não promoveu efeito sobre a colonização micorrízica das mudas de sabiá, entretanto, aumentou a produção de matéria seca dos nódulos radiculares.The sabiá (Mimosa caesalpiniaefolia Benth. is a plant species native to the Brazilian northeast and brings together some fundamental features for use in rehabilitation programs of salinized areas, especially if associated with arbuscular mycorrhizal fungi (AMF and nitrogen-fixing bacteria (BFN. The aim of this study was to evaluate the mycorrhizal colonization and root nodulation of sabiá seedlings fertilized with organic compost and irrigated

  6. PhD Dissertations

    Directory of Open Access Journals (Sweden)

    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

  7. PhD Dissertations

    Directory of Open Access Journals (Sweden)

    Redazione Reti Medievali (a cura di

    2003-06-01

    Full Text Available Reporto of PhD Dissertations.   Mario Dalle Carbonare Società, potere e clientele nell’Irlanda altomedievale (secoli V-IX, Tesi di dottorato di ricerca in Storia sociale europea, Università "Ca' Foscari" di Venezia, 2003 Vieri Mazzoni La legislazione antighibellina e la politica oligarchica della Parte Guelfa di Firenze nel secondo Trecento (1347-1378, Tesi di dottorato di ricerca in Storia Medievale (ciclo XII, Università degli Studi di Firenze   Alma Poloni Pisa dalle origini del movimento popolare alla discesa di Ludovico il Bavaro. I gruppi dirigenti cittadini tra continuità e trasformazione, Tesi di dottorato di ricerca in Storia dell'Europa nel medioevo, Università degli studi di Pisa, 2003   Andrea Puglia Potere marchionale, amministrazione del territorio, società locali dalla morte di Ugo di Tuscia a Guelfo VI di Baviera (1001-1160, Tesi di dottorato di ricerca in Storia medievale, Università degli studi di Milano, 2003

  8. 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

  9. 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 ...

  10. Corrosion analysis of AlMg2 and AlMgSi using electrochemical method

    International Nuclear Information System (INIS)

    Dian A; Maman Kartaman; Rosika K; Yanlinastuti

    2014-01-01

    Corrosion test of cladding materials and structures of research reactor fuel, AlMgSi and AlMg2 have been performed in demineralized water of pH 2 and 6.7 using an electrochemical method. Corrosion phenomenon is affected by several factor such as composition and condition of solution. The purpose of this activity is to investigate the corrosion phenomena through the determination of the parameters of corrosion and polarization curve. The materials used are AlMg2 and AlMgSi alloy in circular dish shape with an area of 1 Cm"2. Preparation of the test sample is performed through several stages polishing, cleaning and drying procedures followed ASTM G3. The electrochemical method is done by measuring the open circuit potential (OCP), polarization resistance and potentiodynamic in demineralized water of pH 2 and pH 6.7 at temperature of 25°C. The results of the OCP is the corrosion potential (Ecorr) of AlMg2 and AlMgSi each of -906.1 mV and -619.8 mV at pH 2 and -868.6 and -756.7 mV at pH 6.7 mV. The results of measurements by polarization resistance technique showed that the corrosion rate of AlMg2 and AlMgSi in safe category (<2 mpy) at pH 6.7 and at pH 2 corrosion rate increased significantly, but still in the lightweight category (<20 mpy). Potentiodynamic curves showed that the passivation at pH 6.7 is very low while the passivation at pH 2 occurs within a relatively short range potential and followed events corroded. (author)

  11. 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

  12. 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...

  13. 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...

  14. The pH Game.

    Science.gov (United States)

    Chemecology, 1996

    1996-01-01

    Describes a game that can be used to teach students about the acidity of liquids and substances around their school and enable them to understand what pH levels tell us about the environment. Students collect samples and measure the pH of water, soil, plants, and other natural material. (DDR)

  15. Sensitivity of early-life-stage golden trout to low pH and elevated aluminum

    International Nuclear Information System (INIS)

    DeLonay, A.J.; Little, E.E.; Woodward, F.; Brumbaugh, W.G.; Farag, A.M.; Rabeni, C.F.

    1993-01-01

    Early-life-stage golden trout (Oncorhynchus aguabonita) were exposed to acid and Al to examine the response and determine the sensitivity of a western, alpine salmonid to conditions simulating an episodic pH depression. Freshly fertilized eggs, alevins, and swim-up larvae were exposed for 7 d to one of 12 combinations of pH and Al, and surviving fish were held to 40 d post-hatch to determine the effect of exposure on subsequent survival and recovery. Golden trout are sensitive to conditions simulating episodic acidification events typically observed in the field. Significant mortality occurred when the pH of test waters was below 5.0 in the absence of Al or when pH was 5.5 in the presence of 100 μg/L total Al. Behavioral impairments were sensitive indicators of low pH and Al stress. Impaired locomotory and feeding behavior occurred at pH 5.5 without Al and at Al concentrations ≥ μg/L. In contrast, growth, RNA-to-DNA ratio, and whole-body ion concentration were relatively less sensitive indicators of sublethal acid and Al stress

  16. 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

  17. 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

  18. 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

  19. 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

  20. 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.

  1. 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 ...

  2. Exercise and Pulmonary Hypertension (PH)

    Science.gov (United States)

    ... Situations Find a Doctor PH Care Centers PHA Classroom PHA Registry Insurance Guide Specialty Pharmacy Other Resources ... no published data in the medical literature regarding routine exercise in patients with PAH. However, there are ...

  3. 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.

  4. 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.

  5. Salt accumulation and distribution in a greenhouse soil as affected by salinity of irrigation water and leaching management Acúmulo e distribuição de sais no solo em um ambiente protegido em função da salinidade da água de irrigação e manejo da lixiviação

    Directory of Open Access Journals (Sweden)

    Flávio F. Blanco

    2002-12-01

    Full Text Available The effects of irrigation water salinity, leaching fraction and its frequency of application on soil salinization were studied. Three water salinities (S1=1.54, S2=3.10 and S3=5.20 dS m-1 and two irrigation water depths associated with their application frequencies (W1=1.00 ETc; W2F1=1.25 ETc in all irrigations and W2F2=1.25 ETc when the irrigation water depth of W1 reached 100 mm where ETc is the crop evapotranspiration, were applied during the growing period of a grafted-cucumber crop in a greenhouse. The experimental design consisted of randomized blocks of 3 x 3 factorial scheme with 3 replications. Soil salinity at 0.1, 0.3 and 0.5 m depths increased linearly with salinity levels of water and the leaching fraction did not have any effect regardless of its management. Salt concentration was higher near the soil surface and between the adjacent drippers.Estudaram-se os efeitos da salinidade da água de irrigação, fração de lixiviação e sua freqüência de aplicação na salinização de um solo. Durante um ciclo de pepino enxertado em ambiente protegido, foram aplicadas águas de diferentes salinidades (S1=1,54, S2=3,10 e S3=5,20 dS m-1 e duas lâminas de irrigação associadas às suas freqüências de aplicação (W1=1,00 ETc; W2F1=1,25 ETc em todas as irrigações e W2F2=1,25 ETc quando a lâmina de irrigação acumulada em W1 alcançou 100 mm em que ETc é a evapotranspiração da cultura. O delineamento experimental foi o de blocos casualizados em esquema fatorial 3x3 com 3 repetições. A salinidade do solo nas profundidades de 0,1, 0,3 e 0,5 m aumentou linearmente com a salinidade e a fração de lixiviação não teve efeito independente do seu manejo. A concentração de sais foi maior próximo à superfície do solo e na região compreendida entre dois gotejadores.

  6. 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

  7. The pH sensor for flavivirus membrane fusion

    OpenAIRE

    Harrison, Stephen C.

    2008-01-01

    Viruses that infect cells by uptake through endosomes have generally evolved to ?sense? the local pH as part of the mechanism by which they penetrate into the cytosol. Even for the very well studied fusion proteins of enveloped viruses, identification of the specific pH sensor has been a challenge, one that has now been met successfully, for flaviviruses, by Fritz et al. (Fritz, R., K. Stiasny, and F.X. Heinz. 2008. J. Cell Biol. 183:353?361) in this issue. Thorough mutational analysis of con...

  8. 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

  9. 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.

  10. Variabilidade espacial de classes de textura, salinidade e condutividade hidráulica de solos em planície aluvial Spatial variability of textural classes, salinity and hydraulic conductivity of soil in an alluvial plain

    Directory of Open Access Journals (Sweden)

    Abelardo A. A. Montenegro

    2006-03-01

    Full Text Available Visando-se avaliar a distribuição de classes texturais e sua correlação espacial com a infiltrabilidade e salinidade de uma área aluvial, no Agreste de Pernambuco, utilizou-se a geoestatística indicadora segundo uma distribuição binária baseada na presença/ausência de solos francos. Considerando-se pontos de amostragem e de testes de infiltração dispostos ao longo do eixo principal do aluvião, e aleatoriamente distribuídos, analisou-se a variabilidade espacial das classes de solo predominantes, da velocidade de infiltração básica (condutividade hidráulica saturada e da condutividade elétrica do extrato de saturação da camada subsuperficial, cujos alcances dos semi-variogramas ajustados foram de 333, 320 e 520 m, respectivamente. Verificou-se que a geoestatística indicadora preservou a correlação espacial entre a textura e a condutividade hidráulica, e entre a textura e a condutividade elétrica. Deste modo, as classes de solo predominantes podem ser usadas para representar distintos padrões no tocante ao potencial de lixiviação e à susceptibilidade de salinização. A metodologia indicadora mostra-se promissora para estudo da variabilidade espacial de propriedades físicas de solos aluviais onde predominam classes contrastantes.Aiming to evaluate the soil textural classes distribution and the spatial correlation between the soil textural classes and both infiltration rate and salinity in an alluvial area, in Pernambuco State "agreste" region, indicator geostatistics has been applied, adopting a binary distribution based on the presence/absence of loam soils. Considering sampling points and test locations along the main longitudinal transect in the valley, as well as randomly distributed locations, the spatial variability of the main soil classes, the infiltration rate, and the electrical conductivity of the saturated extract have been analyzed, for the subsurface soil layer. The fitted semivariogram ranges were 333

  11. 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

  12. Paulette Gray, Ph.D.

    Science.gov (United States)

    Paulette S. Gray, Ph.D. is the Director for the Division of Extramural Activities (DEA). As the director of the division, she is responsible for the overall scientific, fiscal, and administrative management of the division, including broad strategic planning, development, implementation, and evaluation.

  13. 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,

  14. 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...

  15. 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....

  16. 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...

  17. 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.

  18. In Vivo determination of intracellular pH using pHLuorin proteins in Fusarium Oxysporum

    OpenAIRE

    Serrano Salces, Antonio

    2016-01-01

    Premio extraordinario de Trabajo Fin de Máster curso 2013-2014. Molecular and Cellular, Biotechnology and Genetics. El pH extracelular juega un papel clave en los niveles de fosforilación de las MAP quinasas de Fusarium oxysporum. Además, existen evidencias significativas de que la virulencia de distintos patógenos fúngicos se ve alterada directamente por el pH extracelular. Actualmente se desconoce como el pH extracelular afecta al pH intracelular. En este trabajo, hemos hecho uso de una ...

  19. 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.

  20. Alkaline pH sensor molecules.

    Science.gov (United States)

    Murayama, Takashi; Maruyama, Ichiro N

    2015-11-01

    Animals can survive only within a narrow pH range. This requires continual monitoring of environmental and body-fluid pH. Although a variety of acidic pH sensor molecules have been reported, alkaline pH sensor function is not well understood. This Review describes neuronal alkaline pH sensors, grouped according to whether they monitor extracellular or intracellular alkaline pH. Extracellular sensors include the receptor-type guanylyl cyclase, the insulin receptor-related receptor, ligand-gated Cl- channels, connexin hemichannels, two-pore-domain K+ channels, and transient receptor potential (TRP) channels. Intracellular sensors include TRP channels and gap junction channels. Identification of molecular mechanisms underlying alkaline pH sensing is crucial for understanding how animals respond to environmental alkaline pH and how body-fluid pH is maintained within a narrow range. © 2015 Wiley Periodicals, Inc.

  1. An efficient and sensitive fluorescent pH sensor based on amino functional metal-organic frameworks in aqueous environment.

    Science.gov (United States)

    Xu, Xiao-Yu; Yan, Bing

    2016-04-28

    A pH sensor is fabricated via a reaction between an Al(III) salt and 2-aminoterephthalic acid in DMF which leads to a MOF (Al-MIL-101-NH2) with free amino groups. The Al-MIL-101-NH2 samples show good luminescence and an intact structure in aqueous solutions with pH ranging from 4.0 to 7.7. Given its exceptional stability and pH-dependent fluorescence intensity, Al-MIL-101-NH2 has been applied to fluorescent pH sensing. Significantly, in the whole experimental pH range (4.0-7.7), the fluorescence intensity almost increases with increasing pH (R(2) = 0.99688) which can be rationalized using a linear equation: I = 2.33 pH + 26.04. In addition, error analysis and cycling experiments have demonstrated the accuracy and utilizability of the sensor. In practical applications (PBS and lake water), Al-MIL-101-NH2 also manifests its analytical efficiency in pH sensing. And the samples can be easily isolated from an aqueous solution by incorporating Fe3O4 nanoparticles. Moreover, the possible sensing mechanism based on amino protonation is discussed in detail. This work is on of the few cases for integrated pH sensing systems in aqueous solution based on luminescent MOFs.

  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. 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

  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. Manejo da fertirrigação e controle da salinidade do solo sob ambiente protegido, utilizando-se extratores de solução do solo Fertigation management and soil salinity control in a protected ambient using soil solution extractors

    Directory of Open Access Journals (Sweden)

    Nildo da S. Dias

    2005-12-01

    Full Text Available Com o objetivo de avaliar o uso de extratores de soluções do solo no auxílio ao manejo da fertirrigação e no controle da salinidade em solo cultivado com melão rendilhado, conduziu-se um estudo em ambiente protegido na área experimental do Departamento de Engenharia Rural da ESALQ/USP, localizada no município de Piracicaba, SP. Os tratamentos se compunham da combinação de dois fatores: 6 níveis de salinidade inicial do solo (S1 = 1,0; S2 = 2,0; S3 = 3,0; S4 = 4,0; S5 = 5,0 e S6 = 6,0 dS m-1 e dois manejos de fertirrigação: tradicional e com controle da condutividade elétrica da solução do solo. Procedeu-se à salinização inicial do solo por meio da aplicação de soluções salinas preparadas a partir de fertilizantes, em que a quantidade de sais a ser adicionada foi determinada tomando-se por base uma curva de salinização artificial, obtida previamente em laboratório. Os resultados mostraram que, com o uso de extratores de solução do solo, pode-se monitorar a concentração iônica da solução do solo, com precisão satisfatória. A salinidade do solo evoluiu com o tempo, estando os maiores níveis próximos à superfície do solo e do gotejador. A diferença no consumo de água entre os níveis de salinidade foi mais evidenciada no manejo controlado da fertirrigação, ajustando-se a um modelo quadrático.A study was carried out under greenhouse conditions at the experimental area of the Department of Rural Engineering of "Escola Superior de Agricultura Luiz de Queiroz-USP", Piracicaba, São Paulo state, Brazil, aiming to evaluate the performance of ceramic cup samplers in fertigation management and soil salinity control in a plot cultivated with netmelon. The treatments consisted of combination of two factors: six levels of initial soil salinity (S1 = 1.0, S2 = 2.0, S3 = 3.0, S4 = 4.0, S5 = 5.0 and S6 = 6.0 dS m-1 and two fertigation management control: the traditional and the control of electrical conductivity of soil

  6. Fetal scalp pH testing

    Science.gov (United States)

    Fetal scalp blood; Scalp pH testing; Fetal blood testing - scalp; Fetal distress - fetal scalp testing; Labor - fetal scalp testing ... a baby. In these cases, testing the scalp pH can help the doctor decide whether the fetus ...

  7. 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 ...

  8. 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)

  9. 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...

  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. 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

  12. Sorptive stabilization of organic matter by amorphous Al hydroxide

    NARCIS (Netherlands)

    Schneider, M.P.W.; Scheel, T.; Mikutta, R.; van Hees, P.; Kaiser, K.; Kalbitz, K.

    2010-01-01

    Amorphous Al hydroxides (am-Al(OH)(3)) strongly sorb and by this means likely protect dissolved organic matter (OM) against microbial decay in soils. We carried out batch sorption experiments (pH 4.5; 40 mg organic C L-1) with OM extracted from organic horizons under a Norway spruce and a European

  13. Effects of Al(III and Nano-Al13 Species on Malate Dehydrogenase Activity

    Directory of Open Access Journals (Sweden)

    Rong Fu Chen

    2011-05-01

    Full Text Available 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 Al13 can activate the enzymatic activity of MDH, and the activation reaches maximum levels as the Al(III and Al13 concentration increase. Our study also found that the effects of Al(III and Al13 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 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.

  15. Dynamic regulation of gastric surface pH by luminal pH

    OpenAIRE

    Chu, Shaoyou; Tanaka, Shin; Kaunitz, Jonathan D.; Montrose, Marshall H.

    1999-01-01

    In vivo confocal imaging of the mucosal surface of rat stomach was used to measure pH noninvasively under the mucus gel layer while simultaneously imaging mucus gel thickness and tissue architecture. When tissue was superfused at pH 3, the 25 μm adjacent to the epithelial surface was relatively alkaline (pH 4.1 ± 0.1), and surface alkalinity was enhanced by topical dimethyl prostaglandin E2 (pH 4.8 ± 0.2). Luminal pH was changed from pH 3 to pH 5 to mimic the fasted-to-fed transition in intra...

  16. 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 ...

  17. Phänomenologie und qualitative Datenanalyse-Software (QDAS): Versuch einer Aussöhnung

    OpenAIRE

    Sohn, Brian Kelleher

    2017-01-01

    Ein häufig zitierter Phänomenologe, Max VAN MANEN (2014), erachtet qualitative Datenanalyse-Software (QDAS) als ungeeignet für phänomenologische Forschung, und Phänomenolog/innen diskutieren nur selten, wie geforscht werden sollte: mit Stift, Papier, Computer? DAVIDSON und DI GREGORIO (2011) laden QDAS-Kritiker/innen wie VAN MANEN ein, ihre methodologische Loyalität zu überdenken und an der digitalen Welt teilzuhaben, zumal alle qualitativen Forscher/innen unabhängig von ihrer methodologische...

  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. 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)

  20. 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

  1. Classification of some Linseed (Linum usitatissimum L. Genotypes for Salinity Tolerance using Germination, Seedling Growth, and Ion Content Clasificación de algunos Genotipos de Linaza (Linum usitatissimum L. para Tolerancia a Salinidad usando Germinación, Crecimiento de Plántulas y Contenido de Iones

    Directory of Open Access Journals (Sweden)

    Mehmet Demir Kaya

    2012-03-01

    Full Text Available Salinity reduces germination, delays emergence, and inhibits seedling growth of linseed (Linum usitatissimum L. while some varieties are less affected by salinity than others. In this study, we aimed to determine the effects of NaCl levels (0, 5, 10, 20 and 30 dS m-1 on germination and seedling growth of 10 linseed genotypes (lines 87, 89, 104, 114, 193, 194, 209, 215, C-90 and cv. San-85 and to classify the genotypes for salinity tolerance using germination and seedling characteristics. Germination percentage, mean germination time, root and shoot length, seedling fresh and dry weight, Na+ content and Na:K ratio of seedlings were investigated. Classification of linseed genotypes for salinity tolerance was done according to (i combination of Principal Component and Cluster Analysis, (ii Na+ content, and (iii Na:K ratio of seedling. The results showed that the highest values were obtained from lines 193, 194 and 215 except for mean germination time, while germination percentage was not adversely influenced by NaCl up to 20 dS m-1. Seedling growth was inhibited at 20 dS m-1 although genotypes exhibited varying responses. Na+ content was enhanced by NaCl, but seedling from lines 194, 193 and 215 had the lowest Na+ content at all NaCl levels. Cluster analysis performed by multiple parameters revealed three groups for salinity tolerance. It was concluded that lines 193, 194, and 215 were tolerant, lines 87, 209, C-90, and cv. Sari-85 were moderately tolerant and lines 89, 104, and 114 were salt-sensitive genotypes. Classification of genotypes for Na+ content and Na:K ratio showed similar result for tolerant genotypes while different genotypes for sensitive group were detected.La salinidad reduce germinación, retrasa emergencia, e inhibe el crecimiento de plántulas de lino (Linum usitatissimum L. mientras algunas variedades son menos afectadas por la salinidad que otras. El objetivo de este estudio fue determinar los efectos de niveles de NaCl (0, 5

  2. 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....

  3. Electroless Cu Plating on Anodized Al Substrate for High Power LED.

    Science.gov (United States)

    Rha, Sa-Kyun; Lee, Youn-Seoung

    2015-03-01

    Area-selective copper deposition on screen printed Ag pattern/anodized Al/Al substrate was attempted using a neutral electroless plating processes for printed circuit boards (PCBs), according to a range of variation of pH 6.5-pH 8 at 70 °C. The utilized basic electroless solution consisted of copper(II) sulfate pentahydrate, sodium phosphinate monohydrate, sodium citrate tribasic dihydrate, ammonium chloride, and nickel(II) sulfate hexahydrate. The pH of the copper plating solutions was adjusted from pH 6.5 to pH 8 using NH4OH. Using electroless plating in pH 6.5 and pH 7 baths, surface damage to the anodized Al layer hardly occurred; the structure of the plated Cu-rich films was a typical fcc-Cu, but a small Ni component was co-deposited. In electroless plating at pH 8, the surface of the anodized Al layer was damaged and the Cu film was composed of a lot of Ni and P which were co-deposited with Cu. Finally, in a pH 7 bath, we can make a selectively electroless plated Cu film on a PCB without any lithography and without surface damage to the anodized Al layer.

  4. 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.

  5. 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

  6. 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...

  7. Salivary pH: A diagnostic biomarker

    Directory of Open Access Journals (Sweden)

    Sharmila Baliga

    2013-01-01

    Full Text Available Objectives: Saliva contains a variety of host defense factors. It influences calculus formation and periodontal disease. Different studies have been done to find exact correlation of salivary biomarkers with periodontal disease. With a multitude of biomarkers and complexities in their determination, the salivary pH may be tried to be used as a quick chairside test. The aim of this study was to analyze the pH of saliva and determine its relevance to the severity of periodontal disease. Study Design: The study population consisted of 300 patients. They were divided into three groups of 100 patients each: Group A had clinically healthy gingiva, Group B who had generalized chronic gingivitis and Group C who had generalized chronic periodontitis. The randomized unstimulated saliva from each patient was collected and pH was tested. Data was analyzed statistically using analysis of variance technique. Results: The salivary pH was more alkaline for patients with generalized chronic gingivitis as compared with the control group (P = 0.001 whereas patients with generalized chronic periodontitis had more acidic pH as compared with the control group (P = 0.001. Conclusion: These results indicate a significant change in the pH depending on the severity of the periodontal condition. The salivary pH shows significant changes and thus relevance to the severity of periodontal disease. Salivary pH may thus be used as a quick chairside diagnostic biomarker.

  8. Salivary pH: A diagnostic biomarker.

    Science.gov (United States)

    Baliga, Sharmila; Muglikar, Sangeeta; Kale, Rahul

    2013-07-01

    Saliva contains a variety of host defense factors. It influences calculus formation and periodontal disease. Different studies have been done to find exact correlation of salivary biomarkers with periodontal disease. With a multitude of biomarkers and complexities in their determination, the salivary pH may be tried to be used as a quick chairside test. The aim of this study was to analyze the pH of saliva and determine its relevance to the severity of periodontal disease. The study population consisted of 300 patients. They were divided into three groups of 100 patients each: Group A had clinically healthy gingiva, Group B who had generalized chronic gingivitis and Group C who had generalized chronic periodontitis. The randomized unstimulated saliva from each patient was collected and pH was tested. Data was analyzed statistically using analysis of variance technique. The salivary pH was more alkaline for patients with generalized chronic gingivitis as compared with the control group (P = 0.001) whereas patients with generalized chronic periodontitis had more acidic pH as compared with the control group (P = 0.001). These results indicate a significant change in the pH depending on the severity of the periodontal condition. The salivary pH shows significant changes and thus relevance to the severity of periodontal disease. Salivary pH may thus be used as a quick chairside diagnostic biomarker.

  9. 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....

  10. PER PhDs & Bachelor's Degrees

    Science.gov (United States)

    White, Susan C.

    2017-01-01

    Recently, the editor remarked to me that physics departments that offered a PhD with a specialization in Physics Education Research (PER) seemed to graduate more bachelor's degree recipients than those physics PhD departments that did not have the specialization. I was not convinced. That led to quite a bit of discussion between us. He compiled a…

  11. 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

  12. (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 ... was greatly governed by pH with nearly 100% adsorption of Pb occurring at initial pH of 5. Generally, Pb was ... extensively study and applied for the removal of heavy .... Goethite has variable surface charge characteristics, which gave it a ...

  13. 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.

  14. Relationship among Phosphorus Circulation Activity, Bacterial Biomass, pH, and Mineral Concentration in Agricultural Soil

    Directory of Open Access Journals (Sweden)

    Dinesh Adhikari

    2017-12-01

    Full Text Available Improvement of phosphorus circulation in the soil is necessary to enhance phosphorus availability to plants. Phosphorus circulation activity is an index of soil’s ability to supply soluble phosphorus from organic phosphorus in the soil solution. To understand the relationship among phosphorus circulation activity; bacterial biomass; pH; and Fe, Al, and Ca concentrations (described as mineral concentration in this paper in agricultural soil, 232 soil samples from various agricultural fields were collected and analyzed. A weak relationship between phosphorus circulation activity and bacterial biomass was observed in all soil samples (R2 = 0.25, and this relationship became significantly stronger at near-neutral pH (6.0–7.3; R2 = 0.67. No relationship between phosphorus circulation activity and bacterial biomass was observed at acidic (pH < 6.0 or alkaline (pH > 7.3 pH. A negative correlation between Fe and Al concentrations and phosphorus circulation activity was observed at acidic pH (R2 = 0.72 and 0.73, respectively, as well as for Ca at alkaline pH (R2 = 0.64. Therefore, bacterial biomass, pH, and mineral concentration should be considered together for activation of phosphorus circulation activity in the soil. A relationship model was proposed based on the effects of bacterial biomass and mineral concentration on phosphorus circulation activity. The suitable conditions of bacterial biomass, pH, and mineral concentration for phosphorus circulation activity could be estimated from the relationship model.

  15. Spectroscopic determination of pH

    International Nuclear Information System (INIS)

    Faanu, A.; Glover, E.T.; Bailey, E.; Rochelle, C.

    2009-01-01

    A technique of measuring pH at temperature range of 20 - 70 0 C and high pressure conditions of 1 - 200 atmospheres 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 measured at 20 0 C and 70 0 C indicated slight temperature dependence, while the pressure had no effect. The pH of the buffer solutions increased with temperature with relative standard deviations in the range 0.4 - 0.5 % at 95 % confidence interval. The possible causes of the temperature dependence were attributed to changes in pH values as the temperature changed. (au)

  16. 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.

  17. Endoscopic sensing of alveolar pH.

    Science.gov (United States)

    Choudhury, D; Tanner, M G; McAughtrie, S; Yu, F; Mills, B; Choudhary, T R; Seth, S; Craven, T H; Stone, J M; Mati, I K; Campbell, C J; Bradley, M; Williams, C K I; Dhaliwal, K; Birks, T A; Thomson, R R

    2017-01-01

    Previously unobtainable measurements of alveolar pH were obtained using an endoscope-deployable optrode. The pH sensing was achieved using functionalized gold nanoshell sensors and surface enhanced Raman spectroscopy (SERS). The optrode consisted of an asymmetric dual-core optical fiber designed for spatially separating the optical pump delivery and signal collection, in order to circumvent the unwanted Raman signal generated within the fiber. Using this approach, we demonstrate a ~100-fold increase in SERS signal-to-fiber background ratio, and demonstrate multiple site pH sensing with a measurement accuracy of ± 0.07 pH units in the respiratory acini of an ex vivo ovine lung model. We also demonstrate that alveolar pH changes in response to ventilation.

  18. 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.

  19. 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.

  20. Adebayo et al (6)

    African Journals Online (AJOL)

    Timade VENTURE

    The least nitrogen solubility of defatted kariya flour occurred at pH 4, hence the iso-electric pH ... Until recently, soy protein has been the main .... digestion, and F = protein content of DKKF after digestion. .... macro and micro mineral elements.

  1. 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.

  2. 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.

  3. Thermal and pH stabilities of partially purified polyphenol oxidase ...

    African Journals Online (AJOL)

    Dr. Paul Chidoka Chikezie

    2012-07-30

    Jul 30, 2012 ... indices of the two PPO extracts is summarized in Table. 1. At the end of the .... activity near neutral pH values (Jime´nez-Atie´nzar et al.,. 2004; Dogan and Dogan, 2004). ..... oxidase from white cherry fruit (Starks gold). GIDA.

  4. Biochar contribution to soil pH buffer capacity

    Science.gov (United States)

    Tonutare, Tonu; Krebstein, Kadri; Utso, Maarius; Rodima, Ako; Kolli, Raimo; Shanskiy, Merrit

    2014-05-01

    Biochar as ecologically clean and stable form of carbon has complex of physical and chemical properties which make it a potentially powerful soil amendment (Mutezo, 2013). Therefore during the last decade the biochar application as soil amendment has been a matter for a great number of investigations. For the ecological viewpoint the trend of decreasing of soil organic matter in European agricultural land is a major problem. Society is faced with the task to find possibilities to stabilize or increase soil organic matter content in soil and quality. The availability of different functional groups (e.g. carboxylic, phenolic, acidic, alcoholic, amine, amide) allows soil organic matter to buffer over a wide range of soil pH values (Krull et al. 2004). Therefore the loss of soil organic matter also reduces cation exchange capacity resulting in lower nutrient retention (Kimetu et al. 2008). Biochar can retain elements in soil directly through the negative charge that develops on its surfaces, and this negative charge can buffer acidity in the soil. There are lack of investigations about the effect of biochar to soil pH buffering properties, The aim of our investigation was to investigate the changes in soil pH buffer capacity in a result of addition of carbonizated material to temperate region soils. In the experiment different kind of softwood biochars, activated carbon and different soil types with various organic matter and pH were used. The study soils were Albeluvisols, Leptosols, Cambisols, Regosols and Histosols . In the experiment the series of the soil: biochar mixtures with the biochar content 0 to 100% were used. The times of equiliberation between solid and liquid phase were from 1 to 168 hours. The suspension of soil: biochar mixtures was titrated with HCl solution. The titration curves were established and pH buffer capacities were calculated for the pH interval from 3.0 to 10.0. The results demonstrate the dependence of pH buffer capacity from soil type

  5. Al cation induces aggregation of serum proteins.

    Science.gov (United States)

    Chanphai, P; Kreplak, L; Tajmir-Riahi, H A

    2017-07-15

    Al cation is known to induce protein fibrillation and causes several neurodegenerative disorders. We report the spectroscopic, thermodynamic analysis and AFM imaging for the Al cation binding process with human serum albumin (HSA), bovine serum albumin (BSA) and milk beta-lactoglobulin (b-LG) in aqueous solution at physiological pH. Hydrophobicity played a major role in Al-protein interactions with more hydrophobic b-LG forming stronger Al-protein complexes. Thermodynamic parameters ΔS, ΔH and ΔG showed Al-protein bindings occur via hydrophobic and H-bonding contacts for b-LG, while van der Waals and H-bonding interactions prevail in HSA and BSA adducts. AFM clearly indicated that aluminum cations are able to force BSA and b-LG into larger or more robust aggregates than HSA, with HSA 4±0.2 (SE, n=801) proteins per aggregate, for BSA 17±2 (SE, n=148), and for b-LG 12±3 (SE, n=151). Thioflavin T test showed no major protein fibrillation in the presence of Al cation. Al complexation induced major alterations of protein conformations with the order of perturbations b-LG>BSA>HSA. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. 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

  7. /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.

  8. Functional photoacoustic microscopy of pH.

    Science.gov (United States)

    Chatni, Muhammad Rameez; Yao, Junjie; Danielli, Amos; Favazza, Christopher P; Maslov, Konstantin I; Wang, Lihong V

    2011-10-01

    pH is a tightly regulated indicator of metabolic activity. In mammalian systems, an imbalance of pH regulation may result from or result in serious illness. In this paper, we report photoacoustic microscopy (PAM) of a commercially available pH-sensitive fluorescent dye (SNARF-5F carboxylic acid) in tissue phantoms. We demonstrated that PAM is capable of pH imaging in absolute values at tissue depths of up to 2.0 mm, greater than possible with other forms of optical microscopy.

  9. Bankole et al (2)

    African Journals Online (AJOL)

    DELL

    Relationships of Clay-filled Channels on the Delta Flanks (Modified after Doust and Omatsola, 1990 and Lawrence et al., 2002). ... and in the Indo-Malaysian area (Germeraad et al.,. 1968). The genus ..... Upper Cretaceous of British Guiana.

  10. Lou Gehrig's Disease (ALS)

    Science.gov (United States)

    ... disease. Who Gets ALS? Although this disease can strike anyone, ALS is extremely rare in kids. According ... home to provide care that the family cannot handle alone. Living With Lou Gehrig's Disease Living with ...

  11. 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...

  12. The PhD by Publication

    Directory of Open Access Journals (Sweden)

    Susi Peacock

    2017-07-01

    Full Text Available Aim/Purpose: The purpose of this work is to develop more nuanced understandings of the PhD by publication, particularly raising awareness of the retrospective PhD by publication. The article aims to contribute to contemporary debates about the differing pathways to the attainment of doctoral study completion and the artifacts submitted for that purpose. It also seeks to support prospective graduate students and supervisors who are embarking upon alternative routes to doctoral accreditation. Background: The PhD is considered the pinnacle of academic study – highly cherished, and replete with deeply held beliefs. In response to changes in job markets, developments in the disciplines, and more varied student cohorts, diverse pathways to completion of this award have emerged, such as the PhD by publication (PhDP. A PhDP may either be prospective or retrospective. For the former, publications are planned and created with their contributions to the PhDP in mind. The retrospective PhD is assembled after some, or most, of the publications have been completed. The artifact submitted for examination in this case consists of a series of peer-reviewed academic papers, books, chapters, or equivalents that have been published or accepted for publication, accompanied by an over-arching narrative. The retrospective route is particularly attractive for professionals who are research-active but lack formal academic accreditation at the highest level. Methodology: This article calls upon a literature review pertaining to the award of PhDP combined with the work of authors who offer their personal experiences of the award. The author also refers to her candidature as a Scottish doctoral student whilst studying for the award of PhD by publication. Contribution: This work raises awareness of the PhDP as a credible and comparable pathway for graduate students. The article focuses upon the retrospective PhDP which, as with all routes to doctoral accreditation, has

  13. Al 3+ - Ca2+ INTERACTION IN PLANTS GROWING IN ACID SOILS: AL-PHYTOTOXICITY RESPONSE TO CALCAREOUS AMENDMENTS

    OpenAIRE

    Meriño-Gergichevich, C; Alberdi, M; Ivanov, A.G; Reyes-Diaz, M

    2010-01-01

    High aluminum (Al) concentrations as Al3+ represent an important growth and yield limiting factor for crops in acid soils (pH ≤5.5). The most recognized effect of Al-toxicity in plants is observed in roots. However, damages in the upper parts (including stem, leaves and fruits) may also be present. In addition, Al-toxicity triggers an increase in reactive oxygen species (ROS), causing oxidative stress that can damage the roots and chloroplasts, decreasing normal functioning of photo synthetic...

  14. 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 ...

  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. Salivary pH: A diagnostic biomarker

    OpenAIRE

    Baliga, Sharmila; Muglikar, Sangeeta; Kale, Rahul

    2013-01-01

    Objectives: Saliva contains a variety of host defense factors. It influences calculus formation and periodontal disease. Different studies have been done to find exact correlation of salivary biomarkers with periodontal disease. With a multitude of biomarkers and complexities in their determination, the salivary pH may be tried to be used as a quick chairside test. The aim of this study was to analyze the pH of saliva and determine its relevance to the severity of periodontal disease. Study D...

  17. 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.

  18. Reduction of mercury (II) by humic substances-influence of pH, salinity of aquatic system

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, P.; Vudamala, K.; Coulibaly, M.; Ramteke, D.; Chennuri, K.; Lean, D.

    60 80 pH 4.0 pH 7.0 pH 8.0 pH 9.0 Time (h-1) 0 20 40 60 80 100 120 140 160 0 10 20 30 40 pH 4.0 pH 5.0 pH 6.0 pH 7.0 pH 8.0 pH 9.0 Figure 5 a b c Pe rc en ta ge o f t he to ta l d is so lv ed H g re du ce d b y H S an d tr ap ed in o xi di... humic substances (wt %) 0.42 0.44 0.46 0.48 0.50 0.52 0.54 0.56 Fr ac tio n (p er ce nt ag e) o f t ot al H g re du ce d by H S 20 30 40 50 60 70 Salinity = 5 PSU Salinity = 10 PSU Salinity = 15 PSU Salinity = 20PSU Salinity = 30 PSU 0.42 0...

  19. 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.

  20. Utilización de azufre micronizado en la corrección del pH de compost de residuos de poda Correction of the pH of pruning waste compost with micronized sulphur

    Directory of Open Access Journals (Sweden)

    L.A. Barbaro

    2010-12-01

    Full Text Available Los compost actualmente son muy utilizados como componentes de sustratos, aunque en algunos casos presentan pH alcalinos y causan problemas nutricionales. Por ello se recomienda hacer una corrección previa a su utilización o luego de elaborar el sustrato. Algunas alternativas para bajar el pH es mezclando el compost con materiales ácidos o mediante la adición de azufre, sulfato ferroso u otros compuestos azufrados. El objetivo de este trabajo fue corregir el pH de un compost de residuos de poda con azufre micronizado y hallar la dosis adecuada para el pH deseado. Se conformaron siete tratamientos, incorporando al compost de poda diferentes dosis de azufre micronizado: 0, 1, 2, 3, 4, 6 y 8 g/litro. Al compost de cada tratamiento se le midió el pH semanalmente y una vez estabilizados se analizó la conductividad eléctrica, concentración de nitrato, calcio, magnesio, potasio y sodio. Para un pH entre 5,3 y 6,2 se necesitaron 2 a 3 g de azufre/litro. El pH del compost disminuyó con el incremento de la dosis de azufre, y la CE aumentó. El azufre micronizado es una alternativa viable para corregir el pH del compost de restos de poda a los valores deseados.Nowadays, composts are widely used for incorporation into substrates and in some cases they present alkaline pH, causing nutritional problems. Therefore, it is suggested that a correction should be made prior to its use or after its preparation. Some alternatives to decrease pH values are mixing compost with acid materials or adding sulphur, ferrous sulphate or other sulphur compounds. The aim of this work was to correct the pH of pruning waste compost with micronized sulphur and find the appropriate dose for the desired pH. Seven treatments were performed incorporating different doses of micronized sulphur: 0, 1, 2, 3, 4, 6 and 8 g per liter of compost. Compost pH was measured weekly in each treatment. Once stabilized, electrical conductivity and concentration of nitrate, calcium, magnesium

  1. Abu al-Layth al-Libi

    Science.gov (United States)

    2015-02-01

    success. As an Arab participant acknowledged very early on, “the situation was really harsh. All the brothers were tired,” as they lacked food and... glorious battles that occurred during the early Islamic period.133 He stressed the importance of the battlefield as the path to achieve honor and dignity...diaspora in Waziristan. In the words of Walid Othmani, a French jihadi trained by al-Qa`ida in Waziristan in 2008, “[Al-Libi] was someone well-known and

  2. 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.

  3. 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

  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. 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

  6. Mechanisms of intragastric pH sensing.

    Science.gov (United States)

    Goo, Tyralee; Akiba, Yasutada; Kaunitz, Jonathan D

    2010-12-01

    Luminal amino acids and lack of luminal acidity as a result of acid neutralization by intragastric foodstuffs are powerful signals for acid secretion. Although the hormonal and neural pathways underlying this regulatory mechanism are well understood, the nature of the gastric luminal pH sensor has been enigmatic. In clinical studies, high pH, tryptic peptides, and luminal divalent metals (Ca(2+) and Mg(2+)) increase gastrin release and acid production. The calcium-sensing receptor (CaSR), first described in the parathyroid gland but expressed on gastric G cells, is a logical candidate for the gastric acid sensor. Because CaSR ligands include amino acids and divalent metals, and because extracellular pH affects ligand binding in the pH range of the gastric content, its pH, metal, and nutrient-sensing functions are consistent with physiologic observations. The CaSR is thus an attractive candidate for the gastric luminal sensor that is part of the neuroendocrine negative regulatory loop for acid secretion.

  7. Regulation of pH During Amelogenesis.

    Science.gov (United States)

    Lacruz, Rodrigo S; Nanci, Antonio; Kurtz, Ira; Wright, J Timothy; Paine, Michael L

    2010-02-01

    During amelogenesis, extracellular matrix proteins interact with growing hydroxyapatite crystals to create one of the most architecturally complex biological tissues. The process of enamel formation is a unique biomineralizing system characterized first by an increase in crystallite length during the secretory phase of amelogenesis, followed by a vast increase in crystallite width and thickness in the later maturation phase when organic complexes are enzymatically removed. Crystal growth is modulated by changes in the pH of the enamel microenvironment that is critical for proper enamel biomineralization. Whereas the genetic bases for most abnormal enamel phenotypes (amelogenesis imperfecta) are generally associated with mutations to enamel matrix specific genes, mutations to genes involved in pH regulation may result in severely affected enamel structure, highlighting the importance of pH regulation for normal enamel development. This review summarizes the intra- and extracellular mechanisms employed by the enamel-forming cells, ameloblasts, to maintain pH homeostasis and, also, discusses the enamel phenotypes associated with disruptions to genes involved in pH regulation.

  8. Temperature and pH conditions for mycelial growth of Agaricus brasiliensis on axenic cultivation

    OpenAIRE

    Colauto, Nelson Barros; Universidade Paranaense; Aizono, Patrícia Midori; Universidade Paranaense; Carvalho, Lis Ribeiro Magalhães de; Universidade Paranaense; Paccola-Meirelles, Luzia Doretto; Universidade Estadual de Londrina; Linde, Giani Andrea; Universidade Paranaense

    2008-01-01

    Few studies have been done to determine Agaricus brasiliensis Wasser et al. (A. blazei; A. subrufescens) basic mycelial growth characteristics on axenic cultivation. This study aimed to determine the optimal temperature and initial pH for mycelial growth of A. brasiliensis on malt extract agar medium to develop axenic cultivation techniques. Studied initial pH values for mycelial growth were adjusted to 3.0, 4.0, 5.0, 5.5, with HCl, 6.0, 7.0, 8.0, with NaOH, and again 7.0 and 8.0, with CaCO3....

  9. 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.

  10. Frequently Asked Questions for Parents of Children with PH

    Science.gov (United States)

    ... Frequently Asked Questions for Parents of Children with PH What causes pulmonary hypertension in children? I’ve ... of what I read is about adults with PH. What are the primary differences between PH in ...

  11. Microscopic monitoring of extracellular pH in dental biofilms

    DEFF Research Database (Denmark)

    Schlafer, Sebastian; Garcia, Javier; Greve, Matilde

    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...... been limited to monitoring bulk pH with electrodes. Although pH microelectrodes with a better spatial resolution have been developed, they do not permit to monitor horizontal pH gradients in real-time. Quantitative fluorescent microscopic techniques, such as fluorescence lifetime imaging or pH...... 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...

  12. 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

  13. pH dependent polymeric micelle adsorption

    Energy Technology Data Exchange (ETDEWEB)

    McLean, S C; Gee, M L [The University of Melbourne, VIC (Australia). School of Chemistry

    2003-07-01

    Full text: Poly(2-vinylpyridine)-poly(ethylene oxide) (P2VP-PEO) shows potential as a possible drug delivery system for anti-tumour drugs since it forms pH dependent polymeric micelles. Hence to better understand the adsorption behaviour of this polymer we have studied the interaction forces between layers of P2VP-PEO adsorbed onto silica as a function of solution pH using an Atomic Force Microscope (AFM). When P2VP-PEO is initially adsorbed above the pKa of the P2VP block, P2VP-PEO adsorbs from solution as micelles that exist as either partially collapsed- or a hemi-micelles at the silica surface. Below the pKa of P2VP, the P2VP-PEO adsorbs as unimers, forming a compact layer with little looping and tailing into solution. When initial adsorption of P2VP-PEO is in the form of unimers, any driving force to self-assembly of the now charge neutral polymer is kinetically hindered. Hence, after initial adsorption at pH 3.6, a subsequent increase in pH to 6.6 results in a slow surface restructuring towards self-assembly and equilibrium. When the pH is increased from pH 6.6 to 9.7 there is a continuation of the evolution of the system to its equilibrium position during which the adsorbed P2VP-PEO unimers continue to 'unravel' from the surface, extending away from it, towards eventual complete surface self-assembly.

  14. 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.

  15. 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

  16. A Busy period analysis of the level dependent PH/PH/1/K queue

    NARCIS (Netherlands)

    Al Hanbali, Ahmad

    2011-01-01

    In this paper, we study the transient behavior of a level dependent single server queuing system with a waiting room of finite size during the busy period. The focus is on the level dependent PH/PH/1/K queue. We derive in closed form the joint transform of the length of the busy period, the number

  17. Complexometric determination of aluminium and scandium using fluorides as masking agent at low pH value

    International Nuclear Information System (INIS)

    Tikhonov, V.N.

    1978-01-01

    A complexometric method is suggested to determine Al and Sc by back titration of Bi(NO 3 ) 3 solution with xylenol orange indicator at low pH values. To increase selectivity fluoride additions were used which were masked by boron acid at the end titration point. EDTA was used as a complexing agent. Metals which create at low pH values stable complexes with EDTA undestroyed by fluoride, do not interfere with Al and Sc determination. Scandium is shown to be determined more selectively than aluminium

  18. 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

  19. 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

  20. 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.

  1. Low pH, Aluminum, and Phosphorus Coordinately Regulate Malate Exudation through GmALMT1 to Improve Soybean Adaptation to Acid Soils1[W][OA

    Science.gov (United States)

    Liang, Cuiyue; Piñeros, Miguel A.; Tian, Jiang; Yao, Zhufang; Sun, Lili; Liu, Jiping; Shaff, Jon; Coluccio, Alison; Kochian, Leon V.; Liao, Hong

    2013-01-01

    Low pH, aluminum (Al) toxicity, and low phosphorus (P) often coexist and are heterogeneously distributed in acid soils. To date, the underlying mechanisms of crop adaptation to these multiple factors on acid soils remain poorly understood. In this study, we found that P addition to acid soils could stimulate Al tolerance, especially for the P-efficient genotype HN89. Subsequent hydroponic studies demonstrated that solution pH, Al, and P levels coordinately altered soybean (Glycine max) root growth and malate exudation. Interestingly, HN89 released more malate under conditions mimicking acid soils (low pH, +P, and +Al), suggesting that root malate exudation might be critical for soybean adaptation to both Al toxicity and P deficiency on acid soils. GmALMT1, a soybean malate transporter gene, was cloned from the Al-treated root tips of HN89. Like root malate exudation, GmALMT1 expression was also pH dependent, being suppressed by low pH but enhanced by Al plus P addition in roots of HN89. Quantitative real-time PCR, transient expression of a GmALMT1-yellow fluorescent protein chimera in Arabidopsis protoplasts, and electrophysiological analysis of Xenopus laevis oocytes expressing GmALMT1 demonstrated that GmALMT1 encodes a root cell plasma membrane transporter that mediates malate efflux in an extracellular pH-dependent and Al-independent manner. Overexpression of GmALMT1 in transgenic Arabidopsis, as well as overexpression and knockdown of GmALMT1 in transgenic soybean hairy roots, indicated that GmALMT1-mediated root malate efflux does underlie soybean Al tolerance. Taken together, our results suggest that malate exudation is an important component of soybean adaptation to acid soils and is coordinately regulated by three factors, pH, Al, and P, through the regulation of GmALMT1 expression and GmALMT1 function. PMID:23341359

  2. Low pH, aluminum, and phosphorus coordinately regulate malate exudation through GmALMT1 to improve soybean adaptation to acid soils.

    Science.gov (United States)

    Liang, Cuiyue; Piñeros, Miguel A; Tian, Jiang; Yao, Zhufang; Sun, Lili; Liu, Jiping; Shaff, Jon; Coluccio, Alison; Kochian, Leon V; Liao, Hong

    2013-03-01

    Low pH, aluminum (Al) toxicity, and low phosphorus (P) often coexist and are heterogeneously distributed in acid soils. To date, the underlying mechanisms of crop adaptation to these multiple factors on acid soils remain poorly understood. In this study, we found that P addition to acid soils could stimulate Al tolerance, especially for the P-efficient genotype HN89. Subsequent hydroponic studies demonstrated that solution pH, Al, and P levels coordinately altered soybean (Glycine max) root growth and malate exudation. Interestingly, HN89 released more malate under conditions mimicking acid soils (low pH, +P, and +Al), suggesting that root malate exudation might be critical for soybean adaptation to both Al toxicity and P deficiency on acid soils. GmALMT1, a soybean malate transporter gene, was cloned from the Al-treated root tips of HN89. Like root malate exudation, GmALMT1 expression was also pH dependent, being suppressed by low pH but enhanced by Al plus P addition in roots of HN89. Quantitative real-time PCR, transient expression of a GmALMT1-yellow fluorescent protein chimera in Arabidopsis protoplasts, and electrophysiological analysis of Xenopus laevis oocytes expressing GmALMT1 demonstrated that GmALMT1 encodes a root cell plasma membrane transporter that mediates malate efflux in an extracellular pH-dependent and Al-independent manner. Overexpression of GmALMT1 in transgenic Arabidopsis, as well as overexpression and knockdown of GmALMT1 in transgenic soybean hairy roots, indicated that GmALMT1-mediated root malate efflux does underlie soybean Al tolerance. Taken together, our results suggest that malate exudation is an important component of soybean adaptation to acid soils and is coordinately regulated by three factors, pH, Al, and P, through the regulation of GmALMT1 expression and GmALMT1 function.

  3. 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.

  4. PhAST: pharmacophore alignment search tool.

    Science.gov (United States)

    Hähnke, Volker; Hofmann, Bettina; Grgat, Tomislav; Proschak, Ewgenij; Steinhilber, Dieter; Schneider, Gisbert

    2009-04-15

    We present a ligand-based virtual screening technique (PhAST) for rapid hit and lead structure searching in large compound databases. Molecules are represented as strings encoding the distribution of pharmacophoric features on the molecular graph. In contrast to other text-based methods using SMILES strings, we introduce a new form of text representation that describes the pharmacophore of molecules. This string representation opens the opportunity for revealing functional similarity between molecules by sequence alignment techniques in analogy to homology searching in protein or nucleic acid sequence databases. We favorably compared PhAST with other current ligand-based virtual screening methods in a retrospective analysis using the BEDROC metric. In a prospective application, PhAST identified two novel inhibitors of 5-lipoxygenase product formation with minimal experimental effort. This outcome demonstrates the applicability of PhAST to drug discovery projects and provides an innovative concept of sequence-based compound screening with substantial scaffold hopping potential. 2008 Wiley Periodicals, Inc.

  5. PH of Hawaiian precipitation: A preliminary report

    International Nuclear Information System (INIS)

    Miller, J.M.; Yoshinaga, A.M.

    1981-01-01

    Daily or biweekly precipitation samples have been collected at various sites on the island of Hawaii since 1974. The elevations of the sites ranged from sea level to 3400 m. Samples were analyzed on the day of collection for pH and conductivity. Detection of major anions, such as sulfate and nitrate, were made on selected samples during the period

  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. Optimization of urinary dipstick pH: Are multiple dipstick pH readings reliably comparable to commercial 24-hour urinary pH?

    Science.gov (United States)

    Abbott, Joel E; Miller, Daniel L; Shi, William; Wenzler, David; Elkhoury, Fuad F; Patel, Nishant D; Sur, Roger L

    2017-09-01

    Accurate measurement of pH is necessary to guide medical management of nephrolithiasis. Urinary dipsticks offer a convenient method to measure pH, but prior studies have only assessed the accuracy of a single, spot dipstick. Given the known diurnal variation in pH, a single dipstick pH is unlikely to reflect the average daily urinary pH. Our goal was to determine whether multiple dipstick pH readings would be reliably comparable to pH from a 24-hour urine analysis. Kidney stone patients undergoing a 24-hour urine collection were enrolled and took images of dipsticks from their first 3 voids concurrently with the 24-hour collection. Images were sent to and read by a study investigator. The individual and mean pH from the dipsticks were compared to the 24-hour urine pH and considered to be accurate if the dipstick readings were within 0.5 of the 24-hour urine pH. The Bland-Altman test of agreement was used to further compare dipstick pH relative to 24-hour urine pH. Fifty-nine percent of patients had mean urinary pH values within 0.5 pH units of their 24-hour urine pH. Bland-Altman analysis showed a mean difference between dipstick pH and 24-hour urine pH of -0.22, with an upper limit of agreement of 1.02 (95% confidence interval [CI], 0.45-1.59) and a lower limit of agreement of -1.47 (95% CI, -2.04 to -0.90). We concluded that urinary dipstick based pH measurement lacks the precision required to guide medical management of nephrolithiasis and physicians should use 24-hour urine analysis to base their metabolic therapy.

  8. Effect of pH on the adsorption of carbendazim in Polish mineral soils

    International Nuclear Information System (INIS)

    Paszko, Tadeusz

    2012-01-01

    The study aimed to determine the influence of pH on the adsorption of carbendazim in soil profiles of three mineral agricultural soils: Hyperdystric Arenosol, Haplic Luvisol and Hypereutric Cambisol. In the examined pH range between 3 and 7 the adsorption of carbendazim was inversely correlated to the pH of the soil. The adsorption coefficients were in the range between 0.3 and 151.8 mL g −1 . Decreasing the pH in the soil suspensions from 7 to 3 increased the value of this coefficient by 3 to 70 times. A decrease in the amounts of organic matter down the soil profiles was not associated with weaker carbendazim adsorption. In the samples from all soil horizons, at pH values between 3 and 6, the predominant sorption process was carbendazim adsorption on clay minerals. The adsorption of carbendazim on organic matter prevailed over that on clays only at pH > 6 and only in the Ap horizon of the examined soils. The developed mathematical models yielded very good results when the adsorption of the protonated form of carbendazim was assumed to be the predominant adsorption process on clays together with the adsorption of neutral molecules on organic matter and clays. The results from both the model fitting and the experiments revealed the negative effect of Al oxides and hydroxides and Al cations on the adsorption of the protonated form of carbendazim on clay minerals. The developed models successfully described the pH-dependent adsorption processes of carbendazim for both data from particular soil horizons and those from all three examined soil profiles. -- Highlights: ► Adsorption of carbendazim in soils was inversely correlated to soil pH. ► At low pH carbendazim was adsorbed predominantly by clay minerals. ► Al 3+ influenced adsorption of the protonated form of carbendazim on clays. ► Created models predict pH-dependent sorption processes in the whole soil profiles.

  9. Ogunwande et al (1)

    African Journals Online (AJOL)

    (p £ 0.05) effect on the substrate temperature, pH and biogas production. The mean substrate ... wastes, plant residues, industrial wastes, etc). Swine and poultry manures, ... studies, information on the co-digestion of swine manure with high ...

  10. Oladele et al (16)

    African Journals Online (AJOL)

    USER

    lead and zinc, in polluted soils was investigated in a pot experiment. The soils were polluted with 100, ... Bambara nut (Accession TVSU 102) can stabilize Pb and Zn within its roots by .... 28.58%, clay 30.93% and sand 49.81%). Soil pH. 6.42.

  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. Die FPÖ - ein Phänomen im internationalen Vergleich : Erfolg und Misserfolg des identitären Rechtspopulismus

    OpenAIRE

    Heinisch, Reinhard

    2004-01-01

    'Der Aufsatz versteht sich als Bestandsaufnahme der verzweigten Rechtspopulismusforschung. Konkret soll hier versucht werden, die Entwicklung der Haider-FPÖ als integraler Teil des neuen europäischen Rechtspopulismus zu beschreiben, dessen politische Stärken und Schwächen sich weitgehend aus den spezifischen strukturellen Eigenschaften dieses Phänomens ergeben. Nach einer eingehenden Analyse der Konvergenz rechtspopulistischer Strömungen in Richtung identitärer Programmatik wird besonders das...

  13. 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

  14. GRP1 PH Domain, Like AKT1 PH Domain, Possesses a Sentry Glutamate Residue Essential for Specific Targeting to Plasma Membrane PI(3,4,5)P3

    Science.gov (United States)

    Pilling, Carissa; Landgraf, Kyle E.; Falke, Joseph J.

    2011-01-01

    During the appearance of the signaling lipid PI(3,4,5)P3, an important subset of pleckstrin homology (PH) domains target signaling proteins to the plasma membrane. To ensure proper pathway regulation, such PI(3,4,5)P3-specific PH domains must exclude the more prevalant, constitutive plasma membrane lipid PI(4,5)P2 and bind the rare PI(3,4,5)P3 target lipid with sufficiently high affinity. Our previous study of the E17K mutant of protein kinase B (AKT1) PH domain, together with evidence from Carpten et al (1), revealed that the native AKT1 E17 residue serves as a sentry glutamate that excludes PI(4,5)P2, thereby playing an essential role in specific PI(3,4,5)P3 targeting (2). The sentry glutamate hypothesis proposes that an analogous sentry glutamate residue is a widespread feature of PI(3,4,5)P3-specific PH domains, and that charge reversal mutation at the sentry glutamate position will yield both increased PI(4,5)P2 affinity and constitutive plasma membrane targeting. To test this hypothesis the present study investigates the E345 residue, a putative sentry glutamate, of General Receptor for Phosphoinositides 1 (GRP1) PH domain. The results show that incorporation of the E345K charge reversal mutation into GRP1 PH domain enhances PI(4,5)P2 affinity 8-fold and yields constitutive plasma membrane targeting in cells, reminiscent of the effects of the E17K mutation in AKT1 PH domain. Hydrolysis of plasma membrane PI(4,5)P2 releases E345K GRP1 PH domain into the cytoplasm and the efficiency of this release increases when target Arf6 binding is disrupted. Overall, the findings provide strong support for the sentry glutamate hypothesis and suggest that the GRP1 E345K mutation will be linked to changes in cell physiology and human pathologies, as demonstrated for AKT1 E17K (1, 3). Analysis of available PH domain structures suggests that a lone glutamate residue (or, in some cases an aspartate) is a common, perhaps ubiquitous, feature of PI(3,4,5)P3-specific binding

  15. 21 CFR 876.1400 - Stomach pH electrode.

    Science.gov (United States)

    2010-04-01

    ... 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) Identification. A stomach pH electrode is a device used to measure intragastric and intraesophageal pH (hydrogen...

  16. 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

  17. 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

  18. 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

  19. 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%.

  20. Role of Metal Cations on the corrosion behaviour of 8090-T851 in a pH 2.0 solution

    DEFF Research Database (Denmark)

    Murthy, K.S.N.; Ambat, Rajan; Dwarakadasa, E.S.

    1994-01-01

    The influence of cations such as Cu2+, Al3+ and Li+ on the corrosion behaviour of 8090-T851(Al-Li) alloy in a pH 2.0 HCl solution was investigated by weight loss and polarisation techniques. Weight loss experiments showed that the effect of cation is a strong function of its nature...

  1. 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 ...

  2. 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...

  3. Taiwo et al (15)

    African Journals Online (AJOL)

    Timothy Ademakinwa

    geometric rise in preference for commercial aquaculture .... content, malondialdehyde level and lipid content of the muscle of the .... other researchers on the gilthead sea bream (Mnari et al., 2007), the .... 23, Orlando, Florida, USA, pp. 18–28.

  4. Okusanya et al (5)

    African Journals Online (AJOL)

    DELL

    rainfall and number of days with rain per month were obtained from Meteorological Institute, Oshodi, Lagos- ... Central and South America, Australia, West. Indies, Africa, (Orwa et al., 2009) and in Florida .... dominant forest tree species. In this ...

  5. Initial Symptoms of ALS

    Science.gov (United States)

    ... have trouble grasping a pen or lifting a coffee cup, while another person may experience a change ... Start your own fundraising event & help create a world without ALS Start an Event Site Map | Press ...

  6. ALS (Amyotrophic Lateral Sclerosis)

    Science.gov (United States)

    ... FDA) has approved the drugs riluzole (Rilutek) and edaravone (Radicava) to treat ALS. Riluzole is believed to ... reverse the damage already done to motor neurons. Edaravone has been shown to slow the decline in ...

  7. Amyotrophic Lateral Sclerosis (ALS)

    Science.gov (United States)

    ... found for ALS. However, the drugs riluzole and edaravone have approved by the Food and Drug Administration ( ... 2-3 months but does not relieve symptoms. Edaravone can slow the clinical decline in daily functioning ...

  8. Obuotor et al (16)

    African Journals Online (AJOL)

    DELL

    fractions and essential oils from the leaves of Eugenia uniflora were investigated on some multidrug resistant pathogens. ... et al., 1987), a reduction in blood pressure measured ..... from E. uniflora suggests high efficacy against this bacterium.

  9. Fakinle et al (11)

    African Journals Online (AJOL)

    DELL

    management issues; there is however a concern about air emissions from the ... poses risks to humans and animals through ... Nigeria have focused on cement industries. (Adejumo et al. ... based MCA which controls the sample holder and.

  10. Ogunyemi et al (17)

    African Journals Online (AJOL)

    DELL

    The results of physicochemical analysis revealed that the concentrations of ... scientific basis for regulating the discharge of potentially ... method for genotocity evaluation using Allium cepaand it ..... al., 2013). National agency for food and drug.

  11. Omotayo et al (4)

    African Journals Online (AJOL)

    DELL

    using biochemical technique and API 20E identification system. The isolates were .... sulphate, phosphate, ammonia and appearance. Heavy metals ... technique as described by Collee et al. (1989) was ..... enzymatic methods. Water Res. 36,.

  12. David et al (12)

    African Journals Online (AJOL)

    DELL

    larger mesophyll cells, xylem tissues, vascular bundles and bundle sheaths than other cultivars. Thus, larger ... mechanism to cope with drought stress. There was an ... where solar radiation is intense (Løe et al., 2007). Most ecological studies ...

  13. 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

  14. 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)

  15. 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....

  16. 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.

  17. 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...

  18. PhD students share their work

    CERN Multimedia

    Joannah Caborn Wengler

    2012-01-01

    Last week, the second Doctoral Student Assembly gave students in the final stages of their PhD at CERN the chance to meet and present their work.   On 9 May, 24 students who are completing their PhD under the CERN Doctoral Student Programme were joined by their CERN supervisors and some of their university supervisors at an event organised by HR and the Technical Students Committee (TSC). After an address by the Director-General Rolf Heuer and short presentations by Ingrid Haug from HR and TSC Chair Stephan Russenschuck, the students presented their work in a poster session. Held in a packed Council Chamber, the event was a great opportunity for the doctoral students to get to know each other and to share their work in fields as diverse as radiation protection, computing, physics and engineering.

  19. Complexation Key to a pH Locked Redox Reaction

    Science.gov (United States)

    Rizvi, Masood Ahmad; Dangat, Yuvraj; Shams, Tahir; Khan, Khaliquz Zaman

    2016-01-01

    An unfavorable pH can block a feasible electron transfer for a pH dependent redox reaction. In this experiment, a series of potentiometric titrations demonstrate the sequential loss in feasibility of iron(II) dichromate redox reaction over a pH range of 0-4. The pH at which this reaction failed to occur was termed as a pH locked reaction. The…

  20. The PhD Conundrum in South African Academia

    Science.gov (United States)

    Breier, Mignonne; Herman, Chaya

    2017-01-01

    South African universities need more academics with PhDs, from historically disadvantaged population groups in particular, but they face a conundrum. In order to have more staff with PhDs, they need to produce more PhD graduates. But in order to produce more PhD graduates, they need more staff with PhDs to supervise. This article explores this…

  1. 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

  2. The GRP1 PH domain, like the AKT1 PH domain, possesses a sentry glutamate residue essential for specific targeting to plasma membrane PI(3,4,5)P(3).

    Science.gov (United States)

    Pilling, Carissa; Landgraf, Kyle E; Falke, Joseph J

    2011-11-15

    During the appearance of the signaling lipid PI(3,4,5)P(3), an important subset of pleckstrin homology (PH) domains target signaling proteins to the plasma membrane. To ensure proper pathway regulation, such PI(3,4,5)P(3)-specific PH domains must exclude the more prevalant, constitutive plasma membrane lipid PI(4,5)P(2) and bind the rare PI(3,4,5)P(3) target lipid with sufficiently high affinity. Our previous study of the E17K mutant of the protein kinase B (AKT1) PH domain, together with evidence from Carpten et al. [Carpten, J. D., et al. (2007) Nature 448, 439-444], revealed that the native AKT1 E17 residue serves as a sentry glutamate that excludes PI(4,5)P(2), thereby playing an essential role in specific PI(3,4,5)P(3) targeting [Landgraf, K. E., et al. (2008) Biochemistry 47, 12260-12269]. The sentry glutamate hypothesis proposes that an analogous sentry glutamate residue is a widespread feature of PI(3,4,5)P(3)-specific PH domains, and that charge reversal mutation at the sentry glutamate position will yield both increased PI(4,5)P(2) affinity and constitutive plasma membrane targeting. To test this hypothesis, we investigated the E345 residue, a putative sentry glutamate, of the general receptor for phosphoinositides 1 (GRP1) PH domain. The results show that incorporation of the E345K charge reversal mutation into the GRP1 PH domain enhances PI(4,5)P(2) affinity 8-fold and yields constitutive plasma membrane targeting in cells, reminiscent of the effects of the E17K mutation in the AKT1 PH domain. Hydrolysis of plasma membrane PI(4,5)P(2) releases the E345K GRP1 PH domain into the cytoplasm, and the efficiency of this release increases when Arf6 binding is disrupted. Overall, the findings provide strong support for the sentry glutamate hypothesis and suggest that the GRP1 E345K mutation will be linked to changes in cell physiology and human pathologies, as demonstrated for AKT1 E17K [Carpten, J. D., et al. (2007) Nature 448, 439-444; Lindhurst, M. J., et al

  3. 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

  4. 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, ...

  5. pH and Protein Sensing with Functionalized Semiconducting Oxide Nanobelt FETs

    Science.gov (United States)

    Cheng, Yi; Yun, C. S.; Strouse, G. F.; Xiong, P.; Yang, R. S.; Wang, Z. L.

    2008-03-01

    We report solution pH sensing and selective protein detection with high-performance channel-limited field-effect transistors (FETs) based on single semiconducting oxide (ZnO and SnO2) nanobelts^1. The devices were integrated with PDMS microfluidic channels for analyte delivery and the source/drain contacts were passivated for in-solution sensing. pH sensing experiments were performed on FETs with functionalized and unmodified nanobelts. Functionalization of the nanobelts by APTES was found to greatly improve the pH sensitivity. The change in nanobelt conductance as functions of pH values at different gate voltages and ionic strengths showed high sensitivity and consistency. For the protein detection, we achieved highly selective biotinylation of the nanobelt channel with through APTES linkage. The specific binding of fluorescently-tagged streptavidin to the biotinylated nanobelt was verified by fluorescence microscopy; non-specific binding to the substrate was largely eliminated using PEG-silane passivation. The electrical responses of the biotinylated FETs to the streptavidin binding in PBS buffers of different pH values were systematically measured. The results will be presented and discussed. ^1Y. Cheng et al., Appl. Phys. Lett. 89, 093114 (2006). *Supported by NSF NIRT Grant ECS-0210332.

  6. 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

  7. 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

  8. 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.)

  9. 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.)

  10. 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

  11. The panacea toolbox of a PhD biomedical student.

    Science.gov (United States)

    Skaik, Younis

    2014-01-01

    Doing a PhD (doctor of philosophy) for the sake of contribution to knowledge should give the student an immense enthusiasm through the PhD period. It is the time in one's life that one spends to "hit the nail on the head" in a specific area and topic of interest. A PhD consists mostly of hard work and tenacity; however, luck and genius might also play a little role. You can pass all PhD phases without having both luck and genius. The PhD student should have pre-PhD and PhD toolboxes, which are "sine quibus non" for getting successfully a PhD degree. In this manuscript, the toolboxes of the PhD student are discussed.

  12. Amperometric micro pH measurements in oxygenated saliva.

    Science.gov (United States)

    Chaisiwamongkhol, Korbua; Batchelor-McAuley, Christopher; Compton, Richard G

    2017-07-24

    An amperometric micro pH sensor has been developed based on the chemical oxidation of carbon fibre surfaces (diameter of 9 μm and length of ca. 1 mm) to enhance the population of surface quinone groups for the measurement of salivary pH. The pH analysis utilises the electrochemically reversible two-electron, two-proton behaviour of surface quinone groups on the micro-wire electrodes. A Nernstian response is observed across the pH range 2-8 which is the pH range of many biological fluids. We highlight the measurement of pH in small volumes of biological fluids without the need for oxygen removal and specifically the micro pH electrode is examined by measuring the pH of commercial synthetic saliva and authentic human saliva samples. The results correspond well with those obtained by using commercial glass pH electrodes on large volume samples.

  13. Sequestration of uranium on fabricated aluminum co-precipitated with goethite (Al-FeOOH)

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Yubing; Yang, Shubin; Wang, Qi; Wang, Xiangke [Chinese Academy of Science, Hefei (China). Key Laboratory of Novel Thin Film Solar Cells; Alsaedi, Ahmad [King Abdulaziz Univ., Jeddah (Saudi Arabia). Nonlinear Analysis and Applied Mathematics (NAAM) Research Group

    2014-11-01

    Aluminum co-precipitated with goethites (Al-FeOOHs) are ubiquitous within (sub)-surface environments, which are considered one of the most important sinks for radionuclide pollution management. Accordingly, various mole ratios Al-FeOOH were synthesized and characterized by XRD, FT-IR, TEM, specific surface area and potentiometric acid-base titration. According to XRD and TEM images, the morphology of Al-FeOOH was transformed from acicular-like goethite to cotton-like gibbsite with increasing Al content. The adsorption and sequential desorption of U(VI) on Al-FeOOHs were conducted by batch techniques under N{sub 2} conditions. The batch adsorption results showed that the adsorption of U(VI) on Al-FeOOHs slightly increased at pH < 4.0, then the significant increase of U(VI) adsorption was observed at pH from 4.0 to 7.0, whereas the suppressed adsorption at pH > 8.0 was due to the electrostatic repulsion between negative charge surface and negative carbonato-complexes. The adsorption of U(VI) on Al-FeOOHs was independent of ionic strength at pH > 5.0, indicating that the inner-sphere surface complexation predominated their adsorption behaviors, whereas U(VI) adsorption on Al-FeOOH could be the outer-sphere surface/cation exchange reaction. The sequential extraction texts showed that the desorption of U(VI) from Al-FeOOHs decreased with increasing Al content. These findings highlighted the effect of Al content on the sequestration and immobilization of U(VI) onto Al-FeOOHs from (sub)-surface environments in pollution management.

  14. Laser-induced breakdown spectroscopy: Extending its application to soil pH measurements

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Edilene Cristina, E-mail: edilene@iq.unesp.br [São Paulo State University – UNESP, Analytical Chemistry Department, Rua Prof. Francisco Degni 55, CEP 14800-060, Araraquara, SP (Brazil); Gomes Neto, José A. [São Paulo State University – UNESP, Analytical Chemistry Department, Rua Prof. Francisco Degni 55, CEP 14800-060, Araraquara, SP (Brazil); Milori, Débora M.B.P.; Ferreira, Ednaldo José [Embrapa Agricultural Instrumentation, Rua XV de Novembro 1452, CEP 13560-970, São Carlos, SP (Brazil); Anzano, Jesús Manuel [Laser Laboratory & Environment, Faculty of Sciences, University of Zaragoza, C/. Pedro Cerbuna 12, 50009, Zaragoza (Spain)

    2015-08-01

    Acid–base equilibria are involved in almost all the processes that occur in soil. The bioavailability of nutrients for plants, for instance, depends on the solubilization of mineral nutrients in the soil solution, which is a pH-dependent process. The determination of pH in soil solutions is usually carried out by potentiometry using a glass membrane electrode, after extracting some of the soil components with water or CaCl{sub 2} solution. The present work describes a simple method for determining the pH of soil, using laser-induced breakdown spectroscopy (LIBS). Sixty samples presenting different textural composition and pH (previously determined by potentiometry) were employed. The samples were divided into a calibration set with fifty samples and a validation set with ten samples. LIBS spectra were recorded for each pelleted sample using laser pulse energy of 115 mJ. The intensities of thirty-two emission lines for Al, Ca, H, and O were used to fit a partial least squares (PLS) model. The model was validated by prediction of the pH of the validation set samples, which showed good agreement with the reference values. The prediction mean absolute error was 0.3 pH units and the root mean square error of the prediction was 0.4. These results highlight the potential of LIBS for use in other applications beyond elemental composition determinations. For soil analysis, the proposed method offers the possibility of determining pH, in addition to nutrients and contaminants, using a single LIBS measurement. - Highlights: • Physical, chemical, and biological properties of soil are influenced by pH. • The pH of mineral soils is normally determined in slurries of water and soil sample by potentiometric measurements. • The association of LIBS elemental emissions with multivariate strategies of analysis has become LIBS a powerful technique. • LIBS was unprecedentedly applied for direct pH determination in different kinds of soil sample. • The clean and fast proposed

  15. 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.

  16. Electrochemical Corrosion Behaviour of Alumina-Al 6061 and Silicon Carbide-Al 6061 Metal-Matrix Composites

    International Nuclear Information System (INIS)

    Mohamed, K.E.; Gad, M.M.A.; El-Sayed, A.A.; Moustafa, O.H.

    2001-01-01

    The electrochemical corrosion behaviour of powder metallurgy-processed metal-matrix composites (MMCs)based on Al alloy 6061 reinforced with particulate Al 2 O 3 or Sic has been studied in chloride-containing environment. Also, the corrosion behaviour of the unrein forced Al 6061 produced by the same route investigated. Electrochemical tests were conducted on composites containing 10 and 20 vo l% of both reinforced particulates. Potentiodynamic polarization tests have been carried out in neutral as well as acidic and alkaline de-aerated 10 -3 M Na CI solution. In the neutral environment, the addition of Al 2 O 3 particulates was found to shift both the corrosion potential (E corr ) and the break down potential (E b ) slightly into the positive direction irrespective of the volume fraction added (10 and 20 vo l%). On the other hand , Sic caused a shift of E corr into the active site while the E b value was slightly ennobled. For both composites, the corrosion current values at the break down potentials were almost the same as the unrein forced alloy. In an attempt to further clarify the role of both particulate addition, cathodic polarization runs were conducted in both acidic (ph 3) and alkaline (ph 9)solutions for 20 vo l% of Al 2 O 3 and 20 vo l% Sic composite specimens. This indicated that cathodic current values for Sic composites were higher than those corresponding to the unrein forced alloy 6061, and those for the Al 2 O 3 composites were lower

  17. Interaction between Al3+ and acrylic acid and polyacrylic acid in acidic aqueous solution: a model experiment for the behavior of Al3+ in acidified soil solution.

    Science.gov (United States)

    Etou, Mayumi; Masaki, Yuka; Tsuji, Yutaka; Saito, Tomoyuki; Bai, Shuqin; Nishida, Ikuko; Okaue, Yoshihiro; Yokoyama, Takushi

    2011-01-01

    From the viewpoint of the phytotoxicity and mobility of Al(3+) released from soil minerals due to soil acidification, the interaction between Al(3+) and acrylic acid (AA) and polyacrylic acid (PAA) as a model compound of fulvic acid was investigated. The interaction was examined at pH 3 so as to avoid the hydrolysis of Al(3+). The interaction between Al(3+) and AA was weak. However, the interaction between Al(3+) and PAA was strong and depended on the initial (COOH in PAA)/Al molar ratio (R(P)) of the solution. For the range of 1/R(P), the interaction between Al(3+) and PAA can be divided into three categories: (1) 1:1 Al-PAA-complex (an Al(3+) combines to a carboxyl group), (2) intermolecular Al-PAA-complex (an Al(3+) combines to more than 2 carboxyl groups of other Al-PAA-complexes) in addition to the 1:1 Al-PAA-complex and (3) precipitation of intermolecular complexes. In conclusion, R(P) is an important factor affecting the behavior of Al(3+) in acidic soil solution.

  18. 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.

  19. 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....

  20. Adsorption of Cs(I), Sr(II), Eu(III), Co(II) and Cd(II) by Al2O3

    International Nuclear Information System (INIS)

    Shiao, S.Y.; Egozy, Y.; Meyer, R.E.

    1981-01-01

    Adsorption of Cs(I), Sr(II), Eu(III), Co(II) and Cd(II) by Al 2 O 3 was carried out over a wide range of NaCl concentration and solution pH. In the medium pH region (pH 5 to 9), adsorption depends strongly on pH and less on salt concentration. However, in the high pH region (pH above 9), the salt dependence of the distribution coefficient becomes important. (author)

  1. 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.

  2. 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.

  3. 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

  4. Sorption of Cs onto γ-Al2O3 using batch technique

    International Nuclear Information System (INIS)

    Wang Xiangke

    2004-01-01

    The sorption of Cs onto γ-Al 2 O 3 is studied by using batch technique, ultra-filtration method and UV vis spectrophotometer at room temperature, pH 4.0, 6.0 and 8.0, the ionic strength of NaClO 4 is from 0.001 mol/L to 0.1 mol/L. The concentration of humic acid in the solution is determined at wavelength of 254 nm. The sorption of humic acid on the γ-Al 2 O 3 is strong (≅98% HA is sorbed on the surface of alumina at pH zpc =9.2)) and strongly dependent on pH values. At pH>9.2, the sorption of HA is decreased markedly with the increasing of pH. Humic acid has a little negative effect on the sorption of Cs onto alumina, this may be attributed to the formation of HA-Cs complexation in the solution. The sorption of Cs onto γ-Al 2 O 3 is weakly dependent on the pH and independent on the ionic strength. Freundlich isotherm can fit the sorption isotherms very well. The sorption of Cs onto γ-Al 2 O 3 may be contributed to cation exchange and surface complexation mechanisms. (authors)

  5. BERKELEY: ALS ring

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1993-06-15

    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)

  6. Alimba et al (5)

    African Journals Online (AJOL)

    USER

    There was significant (p<0.05) increase in erythrocytes, haemoglobin ... for its anti-hemorrhoid and anti-inflammatory properties (Afolabi et al., 2008), ... genome instability which may lead to genetic related diseases ... membrane, behavioral pattern, morbidity and mortality. ..... extracts of Phyllanthus amarus in mice and rats.

  7. Taiwo et al (8)

    African Journals Online (AJOL)

    DELL

    Ife Journal of Science. (2016) vol. 18, no. 4. SPATIAL ... Ogun State. On the contrary, published work in some parts of Nigeria had ..... Prevalence among. Age Group (%). Cause of Infection. (%). Adeoye et al.,. 2007. Lagos. Kato-Katz. A. lumbricoides =29.7. Hookworm = 0.7. T. Trichiura = 18.4. S. stercoralis =0.3. Total =49.1.

  8. Rossie et al

    African Journals Online (AJOL)

    PUBLICATIONS1

    ing onto the torso for bike riders (Blocken et al., 2013) or it might ... designing new vehicles as well as for drawing up specific training ... These models were chosen because they repre- ..... muscles is relevant since the bio-mechanical workload ...

  9. 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).

  10. Fadimu et al

    African Journals Online (AJOL)

    coconut water has the potential to increase growth and nutritional value of S. mombin(Linn.) so that S. mombin ... of plant growth and development, including seed maturation and ... et al., 2000). Auxins are primary regulators of plant form while ...

  11. Bello et al (9)

    African Journals Online (AJOL)

    Timade VENTURE

    family Solanaceae and it is one of the largest and ... al.,2004). The taxonomy of this important genus is of ... importance of numerical taxonomic method in ..... SME. SAE. SAM. SNI. SER. SWR. SMA. SGI. -6.4. -4.8. -3.2. -1.6. 0. 1.6. 3.2. 4.8.

  12. 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...

  13. 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...

  14. Ojo et al (2)

    African Journals Online (AJOL)

    DELL

    network geometry hence control how the samples' ... generate different permeability curves from wire- ... occupy in the reservoir pore system (McPhee et. ..... Fig.3. Poroperm cross-plot for a homogenous reservoir. Ojo et al.: Rock Type Based ...

  15. 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 ...

  16. 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...

  17. 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

  18. Njukeng et al. + DOI

    African Journals Online (AJOL)

    confo

    3 Institute of Agricultural Research and Development (IRAD), Bambui, North West Province, Cameroon. ... Potato (Solanum tuberosum L.) is an important cash-food crop, which is widely ... production in Africa nearly tripled over the past 35 years ... Njukeng et al, Prevalence of Viruses in Potato Seed Tubers in the North West ...

  19. 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.

  20. 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 ...

  1. 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)

  2. 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.

  3. 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.

  4. Proton irradiation studies on Al and Al5083 alloy

    Science.gov (United States)

    Bhattacharyya, P.; Gayathri, N.; Bhattacharya, M.; Gupta, A. Dutta; Sarkar, Apu; Dhar, S.; Mitra, M. K.; Mukherjee, P.

    2017-10-01

    The change in the microstructural parameters and microhardness values in 6.5 MeV proton irradiated pure Al and Al5083 alloy samples have been evaluated using different model based techniques of X-ray diffraction Line Profile Analysis (XRD) and microindendation techniques. The detailed line profile analysis of the XRD data showed that the domain size increases and saturates with irradiation dose both in the case of Al and Al5083 alloy. The corresponding microstrain values did not show any change with irradiation dose in the case of the pure Al but showed an increase at higher irradiation doses in the case of Al5083 alloy. The microindendation results showed that unirradiated Al5083 alloy has higher hardness value compared to that of unirradiated pure Al. The hardness increased marginally with irradiation dose in the case of Al5083, whereas for pure Al, there was no significant change with dose.

  5. 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...

  6. The removal of bisphenol A from aqueous solutions by MIL-53(Al) and mesostructured MIL-53(Al).

    Science.gov (United States)

    Zhou, Meimei; Wu, Yi-Nan; Qiao, Junlian; Zhang, Jing; McDonald, Amanda; Li, Guangtao; Li, Fengting

    2013-09-01

    In this work, metal-organic framework MIL-53(Al){Al(OH)[O2C-C6H4-CO2]} and MIL-53(Al)-F127{Al(OH)[O2C-C6H4-CO2]} were synthesized and used as sorbents to remove bisphenol A (BPA) from aqueous system. The sorption kinetics data of BPA were found to be in agreement with the pseudo-second-order model. The equilibrium sorption amounts of BPA on MIL-53(Al) and MIL-53(Al)-F127 reached 329.2±16.5 and 472.7±23.6 mg g(-1), respectively, far more than that of commercial activated carbons (ranging from 129.6 to 263.1 mg g(-1)). Both MIL-53(Al) and MIL-53(Al)-F127 could remove BPA fast from aqueous solutions, and the required contact time to reach equilibrium was approximately 90 min for MIL-53(Al) and 30 min for MIL-53(Al)-F127, respectively. The optimum pH levels for the removal of BPA using MIL-53 (Al) and MIL-53(Al)-F127 were 4 and 6 separately. The optimum temperature for the sorption behavior of BPA on the two sorbents was 20 °C. The results performed show that the resulting products, as one kind of MOFs, can be regarded as a new class of sorbents for water treatment and could find great applications in the fields of environmental water pollution control and resources reuse. Copyright © 2013 Elsevier Inc. All rights reserved.

  7. 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...

  8. Electron-phonon interaction on an Al(001) surface

    International Nuclear Information System (INIS)

    Sklyadneva, I Yu; Chulkov, E V; Echenique, P M

    2008-01-01

    We report an ab initio study of the electron-phonon (e-ph) interaction and its contribution to the lifetime broadening of excited hole (electron) surface states on Al(001). The calculations based on density-functional theory were carried out using a linear response approach in the plane-wave pseudopotential representation. The obtained results show that both the electron-phonon coupling and the linewidth experience a weak variation with the energy and momentum position of a hole (electron) surface state in the energy band. An analysis of different contributions to the e-ph coupling reveals that bulk phonon modes turn out to be more involved in the scattering processes of excited electrons and holes than surface phonon modes. It is also shown that the role of the e-ph coupling in the broadening of the Rayleigh surface phonon mode is insignificant compared to anharmonic effects

  9. 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

  10. Acid Rain, pH & Acidity: A Common Misinterpretation.

    Science.gov (United States)

    Clark, David B.; Thompson, Ronald E.

    1989-01-01

    Illustrates the basis for misleading statements about the relationship between pH and acid content in acid rain. Explains why pH cannot be used as a measure of acidity for rain or any other solution. Suggests that teachers present acidity and pH as two separate and distinct concepts. (RT)

  11. 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.

  12. 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

    2018-04-01

    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. Copyright © 2018 Elsevier Ltd. All rights reserved.

  13. Sorption of selenium on Mg-Al and Mg-Al-Eu layered double hydroxides

    International Nuclear Information System (INIS)

    Curtius, H.; Paparigas, Z.; Kaiser, G.

    2008-01-01

    Salt domes represent deep geological formations which are under consideration as final repositories for irradiated research reactor fuel elements. For long-term safety aspects the mobilisation of the radionuclides due to a water ingress is intensively investigated. At the Institute of Energy Research (IEF-6), leaching experiments were performed in a hot cell facility with UAl x -Al and U 3 Si 2 -Al dispersed research reactor fuel elements in repository-relevant MgCl 2 -rich salt brines under anaerobic conditions. The fuel plates corroded completely within one year and a Mg-Al-layered double hydroxide (LDH) with chloride as interlayer anion was identified as one crystalline phase component of the corrosion products (secondary phases). This Mg-Al-LDH was synthesized, characterized, and the ability to retard europium by an incorporation process was investigated. Europium, as a representative for lanthanides, was identified to be one of the radionuclides which were found in the corrosion products. We could show that europium was incorporated in the lattice structure. LDHs have high anion exchange capacities that enhance their potential to remove anionic contaminants from aqueous systems. In this work the sorption behaviour of selenium in the chemical form as selenite (SeO 3 2- ) on Mg-Al-LDH and on Mg-Al-Eu-LDH was investigated. Especially the influence of the larger europium-III ion was of interest. It represents in the Mg-Al-Eu-LDH about 10% of the molar aluminium amount. The sorption has been experimentally studied in a wide range of pH, ionic strength, radionuclide and sorbent concentration. Both LDHs with chloride as interlayer anion were synthesized by a coprecipitation method under controlled conditions, and their main physico-chemical properties were analyzed prior to the sorption experiments. The sorption kinetics of selenite on the LDHs in water and in MgCl 2 -rich brine were rapid using a LDH concentration of 10 g/L. Equilibrium, indicated by stable pH

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

    International Nuclear Information System (INIS)

    Hernandez F, D.; Palomar P, M.; Licona S, T. de J.; Romero R, M.; Valente, Jaime S.

    2014-01-01

    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)

  15. 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)

  16. 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

  17. 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.

  18. Thermodynamic properties of pressurized PH3 superconductor

    Science.gov (United States)

    Koka, S.; Rao, G. Venugopal

    2018-05-01

    The paper presents the superconducting thermodynamic functions determined for pressurized phosphorus trihydride (PH3). In particular, free energy difference ΔF, thermodynamic critical field Hc, specific heat etc. have been calculated using analytical expressions. The calculations were performed in the frame work of the strong-coupling formalism. The obtained dimensionless parameters: RΔ ≡ 2Δ(0)/kBTc, RC ≡ ΔC(Tc)/CN(Tc) and RH≡TcCN(Tc)/Hc2(0) are 4.05, 1.96 and 0.156 respectively, which significantly differ from the values arising from the BCS theory of superconductivity. The thermodynamic properties strongly depend on the depairing electron correlations and retardation effects.

  19. PH Department: at the heart of CERN

    CERN Multimedia

    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...

  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. De GPS al mapa

    Directory of Open Access Journals (Sweden)

    Esteban Dörries

    2016-03-01

    Full Text Available Las coordenadas Lambert obtenidas a partir de mediciones con equipos GPS de mano, llamados a veces navegadores, en ciertos casos confunden al usuario, por diferir claramente de su posición real al ser graficadas en un mapa del Instituto Geográfico Nacional (IGN: Esto puede resolverse con suficiente exactitud mediante una transformación de Molodensky, seguida de la correspondiente proyección cartográfica. Sin embargo, los tres parámetros necesarios para la transformación, supuestamente válidos para Costa Rica, se encuentran en muchas variantes y producen obviamente resultados diferentes. En este trabajo se analizan los fundamentos del problema y sus posibles soluciones, culminando con un estudio comparativo de ocho casos, que permite seleccionar los valores más adecuados para los parámetros.

  2. ALS insertion devices

    International Nuclear Information System (INIS)

    Hoyer, E.; Chin, J.; Halbach, K.; Hassenzahl, W.V.; Humphries, D.; Kincaid, B.; Lancaster, H.; Plate, D.

    1990-11-01

    The Advanced Light Source (ALS), the first US third generation synchrotron radiation source, is currently under construction at the Lawrence Berkeley Laboratory. The low-emittance, 1.5 GeV electron storage ring and the insertion devices are specifically designed to produce high brightness beams in the UV to soft X-Ray range. The planned initial complement of insertion devices includes four 4.6 m long undulators, with period lengths of 3.9 cm, 5.0 cm (2) and 8.0 cm, and a 2.9 m long wiggler of 16 cm period length. Undulator design is well advanced and fabrication has begun on the 5.0 cm and 8.0 cm period length undulators. This paper discusses ALS insertion device requirements; general design philosophy; and design of the magnetic structure, support structure/drive systems, control system and vacuum system. 18 refs., 9 figs., 5 tabs

  3. Adekola et al (7)

    African Journals Online (AJOL)

    Timothy Ademakinwa

    the South Atlantic between Latitudes 31° and 33.5 ... South Atlantic Ocean in the Early Cretaceous, around 136 Ma (Brown et al., 1996; Reeves and de. Wit, 2000 ..... 3244. 3246.70. L o w e r C re ta c e o u s. P e rio d. /E p o c h. 3244. 3246.70. B a ..... moderate counts of forest species such as ... The other, near shore is rich.

  4. New fluorescent pH sensors based on covalently linkable PET rhodamines

    Science.gov (United States)

    Aigner, Daniel; Borisov, Sergey M.; Orriach Fernández, Francisco J.; Fernández Sánchez, Jorge F.; Saf, Robert; Klimant, Ingo

    2012-01-01

    A new class of rhodamines for the application as indicator dyes in fluorescent pH sensors is presented. Their pH-sensitivity derives from photoinduced electron transfer between non-protonated amino groups and the excited chromophore which results in effective fluorescence quenching at increasing pH. The new indicator class carries a pentafluorophenyl group at the 9-position of the xanthene core where other rhodamines bear 2-carboxyphenyl substituents instead. The pentafluorophenyl group is used for covalent coupling to sensor matrices by “click” reaction with mercapto groups. Photophysical properties are similar to “classical” rhodamines carrying 2′-carboxy groups. pH sensors have been prepared with two different matrix materials, silica gel and poly(2-hydroxyethylmethacrylate). Both sensors show high luminescence brightness (absolute fluorescence quantum yield ΦF≈0.6) and high pH-sensitivity at pH 5–7 which makes them suitable for monitoring biotechnological samples. To underline practical applicability, a dually lifetime referenced sensor containing Cr(III)-doped Al2O3 as reference material is presented. PMID:22967541

  5. 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...

  6. Polymeric gel nanoparticle pH sensors for intracellular measurements

    OpenAIRE

    Almdal, Kristoffer; Andresen, Thomas Lars; Benjaminsen, Rikke Vicki; Christensen, Nynne Meyn; Henriksen, Jonas Rosager; Sun, Honghao

    2011-01-01

    Precise measurements of pH in cells and intracellular compartments are of importance to both the fundamental understanding of metabolism and to the development of drugs that are released from the endosomes-lysome pathway. We have developed polymer gel nanoparticles as carriers of covalently bound fluorophores for ratiometric measurements of pH. One pH insensitive fluorophore serves as a reference while one or more pH sensitive fluorophores serve to give the desired pH dependence of the output...

  7. 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

  8. 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.

  9. 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.

  10. 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...

  11. Corrosion of zirconium alloys in alternating pH environment

    International Nuclear Information System (INIS)

    Mayer, P.; Manolescu, A.V.

    1985-01-01

    Behaviour of two commercial alloys, Zircaloy-2 and zirconium-2.5 wt% niobium were investigated in an environment of alternating pH. Corrosion advancement and scale morphology of coupons exposed to aqueous solution of LiOH (pH 10.2 and 14) were followed as a function of temperature (300-360 degreesC) and time (up to 165 days). The test sequence consisted of short term exposure to high pH and re-exposure to low pH solutions for extended period of time followed by a short term test in high pH. The results of these tests and detailed post-corrosion analysis indicate a fundamental difference between the corrosion behaviour of these two materials. Both alloys corrode fast in high pH environments, but only zirconium-2.5 wt% niobium continues to form detectable new oxide in low pH solution

  12. Efecto del pH de los sitemas adhesivos autoacondicionantes sobre las características adhesivas de resinas compuestas.

    OpenAIRE

    Azócar Cabello, Teresa

    2015-01-01

    Objetivo: El presente estudio tiene como propósito analizar la ultraestructura microscópica de la dentina tratada con sistemas adhesivos autoacondicionantes de distinto pH. Métodos: 8 terceros molares humanos sanos fueron cortados horizontalmente para exponer dentina superficial y fueron distribuidos al azar en 4 grupos (n=2): Adper Single Bond 2 (SB), 3M ESPE, Go!, SDI (Go), pH leve, Adper Prompt L Pop, 3M ESPE (PLP), moderado, Xeno III, Dentsply (XE), fuerte. Se talló una cavidad clase I co...

  13. Characterization of Anodic Aluminum Oxide Membrane with Variation of Crystallizing Temperature for pH Sensor.

    Science.gov (United States)

    Yeo, Jin-Ho; Lee, Sung-Gap; Jo, Ye-Won; Jung, Hye-Rin

    2015-11-01

    We fabricated electrolyte-dielectric-metal (EDM) device incorporating a high-k Al2O3 sensing membrane from a porous anodic aluminum oxide (AAO) using a two step anodizing process for pH sensors. In order to change the properties of the AAO template, the crystallizing temperature was varied from 400 degrees C to 700 degrees C over 2 hours. The structural properties were observed by field emission scanning electron microscopy (FE-SEM). The pH sensitivity increased with an increase in the crystallizing temperature from 400 degrees C to 600 degrees C. However at 700 degrees C, deformation occurred. The porous AAO sensor with a crystallizing temperature of 600 degrees C displayed the good sensitivity and long-term stability and the values were 55.7 mV/pH and 0.16 mV/h, respectively.

  14. 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

  15. Flipped Classroom al laboratori

    OpenAIRE

    Molés Bort, Jaume

    2014-01-01

    L'article presenta una experiència d'aprenentatge de la geologia mitjançant el treball en grups d'experts. Els alumnes han d'indagar i promoure el seu propi aprenentatge per a assolir un repte que se'ls proposa, i consensuar els criteris per els que avaluaran els seus propis resultats mitjançant rúbriques. L'activitat inclou aspectes artístics, TIC i matemàtics, i segueix un esquema similar al de les WebQuest. Els resultats de l'activitat es presenten juntament amb una enquesta realitzada ent...

  16. Teatro al aire libre

    Directory of Open Access Journals (Sweden)

    Philippe Canac

    2016-11-01

    Full Text Available Siendo cada vez más frecuentes y numerosas las peregrinaciones a la basílica de Notre Dame, de Laus (Altos Alpes, su capacidad resultaba hace tiempo insuficiente para acoger a sus peregrinos. Este fue el motivo de crear, en un terreno situado ante el atrio de la basílica, un conjunto, que permitiese celebrar misas al aire libre, ceremonias litúrgicas o representaciones de teatro religioso y que dispusiese de todas las posibilidades para conseguir la libertad del juego escénico.

  17. Architektur als Vermittlung

    OpenAIRE

    Ott, Konrad

    2016-01-01

    Mit Anbruch der Moderne hat sich die Architektur bewußt von den Stilen vorangegangener Epochen losgesagt und sich fortan als Ausdruck einer neuen Kultur, eines neuen Zeitgeistes legitimiert. Der Philosoph Konrad Ott setzt sich mit dem Spannungsfeld zwischen den humanistischen und ästhetischen Ansprüchen der modernen Architektur, wie sie etwa von LeCorbusier formuliert worden sind, und der Realität, die sich etwa in der "Behältnis-Architektur" der Großstädte zeigt, auseinander. Die kritische T...

  18. Salvar al planeta

    OpenAIRE

    Thomas Sancton

    2015-01-01

    El desastre de Exxon Valdez en Canadá (1989)en 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 g...

  19. 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...

  20. 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 ...

  1. Manufacture and application of RuO2 solid-state metal-oxide pH sensor to common beverages.

    Science.gov (United States)

    Lonsdale, W; Wajrak, M; Alameh, K

    2018-04-01

    A new reproducible solid-state metal-oxide pH sensor for beverage quality monitoring is developed and characterised. The working electrode of the developed pH sensor is based on the use of laser-etched sputter-deposited RuO 2 on Al 2 O 3 substrate, modified with thin layers of sputter-deposited Ta 2 O 5 and drop-cast Nafion for minimisation of redox interference. The reference electrode is manufactured by further modifying a working electrode with a porous polyvinyl butyral layer loaded with fumed SiO 2 . The developed pH sensor shows excellent performance when applied to a selection of beverage samples, with a measured accuracy within 0.08 pH of a commercial glass pH sensor. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Synthesizing (ZrAl3 + AlN)/Mg-Al composites by a 'matrix exchange' method

    Science.gov (United States)

    Gao, Tong; Li, Zengqiang; Hu, Kaiqi; Han, Mengxia; Liu, Xiangfa

    2018-06-01

    A method named 'matrix exchange' to synthesize ZrAl3 and AlN reinforced Mg-Al composite was developed in this paper. By inserting Al-10ZrN master alloy into Mg matrix and reheating the cooled ingot to 550 °C, Al and Mg atoms diffuse to the opposite side. As a result, liquid melt occurs once the interface areas reach to proper compositions. Then dissolved Al atoms react with ZrN, leading to the in-situ formation of ZrAl3 and AlN particles, while the Al matrix is finally replaced by Mg. This study provides a new insight for preparing Mg composites.

  3. In vitro synthesis and purification of PhIP-deoxyguanosine and PhIP-DNA oligomer covalent complexes

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, J.

    1994-12-01

    2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a heterocyclic amine compound formed when meats are cooked at high temperatures. PhIP damages DNA by forming covalent complexes with DNA carcinogen. In an effort to understand how the binding of PhIP to DNA may cause cancer, it is important to characterize the structures of PhIP-damaged DNA molecules. Our HPLC data support fluorescence and {sup 32}P Post-labeling studies which indicate the formation of several species of 2{prime}deoxyguanosine-(dG) or oligodeoxynucleotide-PhIP adducts. The reaction of PhIP with dG resulted in a reddish precipitate that was likely the major adduct, N-(deoxyguanosin-8-yl)-PhIP (dG-C8-PhIP) adduct, with a more polar adduct fraction remaining in the supernatant. Reversed-phase HPLC analysis of the adducts in the supernatant revealed the existence of species of much shorter retention times than the dG-C8-PhIP adduct, confirming that these species are more polar than dG-C8-PhIP. At least four adducts were formed in the reaction of PhIP with DNA oligomer. HPLC analysis of the PhIP-DNA oligomer supernatant after butanol extractions revealed four unresolved peaks which spectra had maximum wavelengths between 340 and 360 nm. Though adduct peaks were not completely resolved, there was {approximately}3 minutes interval between the DNA oligomer peak and the adduct peaks. Furthermore, fluorescence emission data of the DNA oligomer-PhIP adduct solution show heterogeneous binding. The more polar PhIP adducts were fraction-collected and their structures will be solved by nuclear magnetic resonance or x-ray crystallography.

  4. Appiah-Adjei et al

    African Journals Online (AJOL)

    PUBLICATIONS1

    ing, sale of automobile spare parts, and metal fabrication. Some of these activities generate huge ... Keywords: Groundwater quality, pollution, waste disposal, Suame, Ghana ... of fertilizers (Chen et al., 2007; Parris, 2011;. Shen et al., 2011), ...

  5. 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...

  6. 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

  7. 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

  8. Sample size and saturation in PhD studies using qualitative interviews

    OpenAIRE

    Mason, Mark

    2010-01-01

    Sample-Größen sind in qualitativen Forschungsarbeiten von verschiedenen Einflüssen abhängig. Das Leitprinzip sollte jedoch immer die Sättigung, bezogen auf das jeweilige Forschungsthema sein. Diese Frage, mit der sich viele Autor/innen beschäftigt haben, wird weiter heiß diskutiert und – so einige – kaum hinreichend verstanden. Für eine eigene Untersuchung habe ich ein Sample von PhD-Studien, in denen qualitative Interviews als Erhebungsmethode genutzt wurde, aus theses.com gezogen und ...

  9. Bukti Kebenaran Al-quran

    OpenAIRE

    Aliyah, Sri

    2015-01-01

    Al Quran is the greatest miracles of Muhammad SAW as the direction of humankind in order to reach eternal happiness. Scientific evidences show that Al Quran has the truth massages, although it was released far before the finding of modern sciences. The researches continue to study the truth of Al Quran an it revealed the historical fact.

  10. 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.

  11. A graphene oxide pH sensor for wound monitoring.

    Science.gov (United States)

    Melai, B; Salvo, P; Calisi, N; Moni, L; Bonini, A; Paoletti, C; Lomonaco, T; Mollica, V; Fuoco, R; Di Francesco, F

    2016-08-01

    This article describes the fabrication and characterization of a pH sensor for monitoring the wound status. The pH sensitive layer consists of a graphene oxide (GO) layer obtained by drop-casting 5 μΐ of GO dispersion onto the working electrode of a screen-printed substrate. Sensitivity was 31.8 mV/pH with an accuracy of 0.3 unit of pH. Open-circuit potentiometry was carried out to measure pH in an exudate sample. The GO pH sensor proved to be reliable as the comparison with results obtained from a standard glass electrode pH-meter showed negligible differences (pH units in the worst case) for measurements performed over a period of 4 days.

  12. A quantum dot-spore nanocomposite pH sensor.

    Science.gov (United States)

    Zhang, Xingya; Li, Zheng; Zhou, Tao; Zhou, Qian; Zeng, Zhiming; Xu, Xiangdong; Hu, Yonggang

    2016-04-01

    A new quantum dot (QD)-based pH sensor design is investigated. The sensor is synthesized based on the self-assembly of green QDs onto treated spores to form QD@spore nanocomposites. The nanocomposites are characterized using laser scanning confocal microscopy, transmission electron microscope, and fluorescence spectroscopy, among others. Fluorescence measurements showed that these nanocomposites are sensitive to pH in a broad pH range of 5.0-10.0. The developed pH sensors have been satisfactorily applied for pH estimation of real samples and are comparable with those of the commercial assay method, indicating the potential practical application of the pH sensors. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Evaluating Nanoparticle Sensor Design for Intracellular pH Measurements

    DEFF Research Database (Denmark)

    Benjaminsen, Rikke Vicki; Sun, Honghao; Henriksen, Jonas Rosager

    2011-01-01

    Particle-based nanosensors have over the last decade been designed for optical fluorescent-based ratiometric measurements of pH in living cells. However, quantitative and time-resolved intracellular measurements of pH in endosomes and lysosomes using particle nanosensors is challenging...... and there is a need to improve measurement methodology. In the present paper, we have successfully carried out time resolved pH measurements in endosomes and lyosomes in living cells using nanoparticle sensors and show the importance of sensor choice for successful quantification. We have studied two nanoparticle...... 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...

  14. Cell wall pH and auxin transport velocity

    Science.gov (United States)

    Hasenstein, K. H.; Rayle, D.

    1984-01-01

    According to the chemiosmotic polar diffusion hypothesis, auxin pulse velocity and basal secretion should increase with decreasing cell wall pH. Experiments were designed to test this prediction. Avena coleoptile sections were preincubated in either fusicoccin (FC), cycloheximide, pH 4.0, or pH 8.0 buffer and subsequently their polar transport capacities were determined. Relative to controls, FC enhanced auxin (IAA) uptake while CHI and pH 8.0 buffer reduced IAA uptake. Nevertheless, FC reduced IAA pulse velocity while cycloheximide increased velocity. Additional experiments showed that delivery of auxin to receivers is enhanced by increased receiver pH. This phenomenon was overcome by a pretreatment of the tissue with IAA. Our data suggest that while acidic wall pH values facilitate cellular IAA uptake, they do not enhance pulse velocity or basal secretion. These findings are inconsistent with the chemiosmotic hypothesis for auxin transport.

  15. The potential of selected macroalgal species for treatment of AMD at different pH ranges in temperate regions.

    Science.gov (United States)

    Oberholster, Paul J; Cheng, Po-Hsun; Botha, Anna-Maria; Genthe, Bettina

    2014-09-01

    The metal bioaccumulation potential of selected macroalgae species at different pH ranges was study for usage as part of a possible secondary passive acid mine drainage (AMD) treatment technology in algae ponds. Two separate studies were conducted to determine the suitability of macroalgae for passive treatment when metabolic processes in macrophytes and microorganisms in constructed wetlands decrease during winter months. In the field study, the bioconcentration of metals (mg/kg dry weight) measured in the benthic macroalgae mats was in the following order: site 1. Oedogonium crassum Al > Fe > Mn > Zn; site 2. Klebsormidium klebsii, Al > Fe > Mn > Zn; site 3. Microspora tumidula, Fe > Al > Mn > Zn and site 4. M. tumidula, Fe > Mn > Al > Zn. In the laboratory study, cultured macroalgae K. klebsii, O. crassum and M. tumidula isolated from the field sampling sites were exposed to three different pH values (3, 5 and 7), while bioaccumulation of the metals, Al, Fe, Mn and Zn and glutathione S-transferase (GST) activity were measured in the different selected algae species at a constant water temperature of 14 °C. Bioaccumulation of Al was the highest for O. crassum followed by K. klebsii and M. tumidula (p macroalgae O. crassum at all three tested pH values under constant low water temperature. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Determining pH of strip-mine spoils

    Science.gov (United States)

    W. A. Berg

    1969-01-01

    Results with the LaMotte-Morgan method for determining soil pH-or the solution modification of this method-usually agreed fairly well with the results from using a pH meter, the recognized standard. Results obtained with the Soiltex and Hellige-Truog methods often deviated somewhat from the pH meter readings; and the Hydrion papers and the Kelway pH tester often gave...

  17. 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.

  18. Time dependence of the pH of rain

    Science.gov (United States)

    John A. Kadlecek; Volkar A. Mohnen

    1976-01-01

    Standard procedures for determining the pH of rain samples usually involve substantial delays from the time of rainfall to the time of analysis. This assumes that no change in pH occurs during the storage period. We have found that this is not always true. We have determined that individual rain water samples possess a time dependent pH which can be correlated with the...

  19. 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

  20. Chapter A6. Section 6.4. pH

    Science.gov (United States)

    Wilde, Franceska D.; Busenberg, Eurybiades; Radtke, Dean B.

    2006-01-01

    Measurement of pH is critical to the understanding of the viability and vulnerability of environmental waters and is considered a master variable in determining the aqueous geochemistry of an aqueous system. pH is a measure that represents the hydrogen-ion concentration (activity) of a solution. This section of the National Field Manual (NFM) describes U.S. Geological Survey (USGS) guidance and protocols for measurement of pH in ground and surface waters.

  1. 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.

  2. 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.

  3. 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.

  4. pH Sensing and Regulation in Cancer

    OpenAIRE

    Mehdi eDamaghi; Jonathan W. Wojtkowiak; Robert J. Gillies

    2013-01-01

    Cells maintain intracellular pH (pHi) within a narrow range (7.1-7.2) by controlling membrane proton pumps and transporters whose activity is set by intra-cytoplasmic pH sensors. These sensors have the ability to recognize and induce cellular responses to maintain the intracellular pH, often at the expense of acidifying the extracellular pH. In turn, extracellular acidification impacts cells via specific acid-sensing ion channels (ASICs) and proton-sensing G-protein coupled receptors (GPCRs...

  5. Molecular aspects of bacterial pH sensing and homeostasis

    Science.gov (United States)

    Krulwich, Terry A.; Sachs, George; Padan, Etana

    2011-01-01

    Diverse mechanisms for pH-sensing and cytoplasmic pH homeostasis enable most bacteria to tolerate or grow at external pH values that are outside the cytoplasmic pH range they must maintain for growth. The most extreme cases are exemplified by the extremophiles that inhabit environments whose pH is below 3 or above 11. Here we describe how recent insights into the structure and function of key molecules and their regulators reveal novel strategies of bacterial pH-homeostasis. These insights may help us better target certain pathogens and better harness the capacities of environmental bacteria. PMID:21464825

  6. Temporal and spatial variability of rainfall pH

    Science.gov (United States)

    Richard G. Semonin

    1977-01-01

    The distribution of average rainwater pH over an area of 1,800 km² containing 81 collectors was determined from 25 storm events. The areal average of the data was pH 4.9, with a range of values from 4.3 to 6.8. A single storm event was studied to determine the change of pH as a function of time. The initial rain was pH 7.1, decreasing to 4.1. An excellent...

  7. Understanding thermostability and pH dependent properties of proteins

    DEFF Research Database (Denmark)

    Galberg, Pernille

    The work performed in this thesis is part of a larger project (“Computational design of stable enzymes”) involving several research teams, which aimed to improve PROPKA (http://propka.ki.ku.dk) and to provide the scientific community with a computational protocol and associated PROPKA program......, which could be used for predicting mutations with expectation of increased thermostability at a certain pH value or a shifted pH activity optimum. The ability of a Bacillus circulans xylanase (BCX) mutant (N35D/A115E) to induce a decrease in pH activity optimum was evaluated by a pH dependent xylanase...

  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. Role of Acidophilic Methanotrophs in Long Term Natural Attenuation of cVOCs in Low pH Aquifers

    Science.gov (United States)

    2017-06-15

    grow well only in dilute , oligtrophic media (Kip et al., 2011; Dedysh et al., 2002). It is likely that these organisms or similar ones may exist in...Carbon tetrachloride Cu – Copper cVOCs – Chlorinated volatile organic compounds 1,1-DCA – 1,2-Dichloroethane 1,2-DCA – 1,2-Dichloroethane DCM...the biodegradation of chlorinated volatile organic compounds (cVOCs) in low pH groundwater aquifers. Our objectives included (1) determining whether

  10. 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

  11. Study on synthesizing Mg/Al layered double hydroxides at different pHs

    Directory of Open Access Journals (Sweden)

    E Otgonjargal

    2014-12-01

    Full Text Available Mg/Al layered double hydroxide (LDH was successfully synthesized at different pHs values. The Mg/AL LDH was well characterized by X-Ray diffraction and Fourier transform infrared analysis. The morphology of the LDH was observed using Scanning electron microscopy with energy dispersive X-ray spectroscopy. The influence of pH values on the morphology of the Mg/Al LDHs were studied. The result showed that the well-synthesized Mg/Al LDHs could be obtained when the pH value was about 10.0 at room temperature.DOI: http://doi.dx.org/10.5564/mjc.v15i0.319 Mongolian Journal of Chemistry 15 (41, 2014, p36-39

  12. Effects of Iodide and Hydrogen Peroxide on Measuring High Temperature pH in Various Lithium Borate Buffer Solutions

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Jae Sik; Yun, Myung Hee; Yeon, Jei Won; Song, Kyu Seok [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2008-10-15

    In a reactor coolant system of nuclear power plants, the need for reliable high temperature pH electrodes has resulted from interests in the corrosion and corrosion product behaviors of the structural materials in a high temperature coolant system. In developing the electrodes for measuring the high temperature pH of aqueous solutions, it is necessary to note two major problems: the chemical stability of an electrode against other chemical impurities, and an electrode's integrity as the temperature and pressure are varied between operational extremes. Over the past decade Macdonald et al. and Danielson et al. have developed many ceramic membrane pH electrodes based on a yttrium stabilized zirconium oxide. However, there are still many experimental difficulties associated with the problems in obtaining electrochemical information across different pressure boundaries and against many kinds of chemical impurities caused by the radiolysis of water and the leakage of a fuel clad. In the present work, we investigated the effects of the environmental factors on a high temperature pH. The selected environmental factors are as follows: system pressure, and chemical species such as iodide and hydrogen peroxide ions.

  13. 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

  14. 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.

  15. Proceedings of the First PhD Symposium on Sustainable Ultrascale Computing Systems (NESUS PhD 2016)

    OpenAIRE

    Carretero Pérez, Jesús; García Blas, Javier; Petcu, Dana

    2016-01-01

    Proceedings of the First PhD Symposium on Sustainable Ultrascale Computing Systems (NESUS PhD 2016) Timisoara, Romania. February 8-11, 2016. The PhD Symposium was a very good opportunity for the young researchers to share information and knowledge, to present their current research, and to discuss topics with other students in order to look for synergies and common research topics. The idea was very successful and the assessment made by the PhD Student was very good. It also helped t...

  16. Functional characterization of PhGR and PhGRL1 during flower senescence in the petunia.

    Science.gov (United States)

    Yang, Weiyuan; Liu, Juanxu; Tan, Yinyan; Zhong, Shan; Tang, Na; Chen, Guoju; Yu, Yixun

    2015-09-01

    Petunia PhGRL1 suppression accelerated flower senescence and increased the expression of the genes downstream of ethylene signaling, whereas PhGR suppression did not. Ethylene plays an important role in flowers senescence. Homologous proteins Green-Ripe and Reversion to Ethylene sensitivity1 are positive regulators of ethylene responses in tomato and Arabidopsis, respectively. The petunia flower has served as a model for the study of ethylene response during senescence. In this study, petunia PhGR and PhGRL1 expression was analyzed in different organs, throughout floral senescence, and after exogenous ethylene treatment; and the roles of PhGR and PhGRL1 during petunia flower senescence were investigated. PhGRL1 suppression mediated by virus-induced gene silencing accelerated flower senescence and increased ethylene production; however, the suppression of PhGR did not. Taken together, these data suggest that PhGRL1 is involved in negative regulation of flower senescence, possibly via ethylene production inhibition and consequently reduced ethylene signaling activation.

  17. Integrating chemical imaging of cationic trace metal solutes and pH into a single hydrogel layer

    International Nuclear Information System (INIS)

    Hoefer, Christoph; Santner, Jakob; Borisov, Sergey M.; Wenzel, Walter W.; Puschenreiter, Markus

    2017-01-01

    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"-"1, cation binding capacity ∼24 μg cm"−"2). The dynamic range for PO-based pH mapping was between pH 5.5 and 7.5 with t_9_0 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"3"+, Co"2"+, Cu"2"+, Fe, Mn"2"+, Ni"2"+ and Pb"2"+, indicating pH-induced metal solubilisation. - Highlights: • Diffusive gradients in thin films (DGT) and planar optode (PO) imaging is combined. • A

  18. 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

  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. 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

  1. Structural reversibility of a ternary CuO–ZnO–Al2O3 ex hydrotalcite-containing material during wet Pd impregnation

    NARCIS (Netherlands)

    López Granados, M.; Melián-Cabrera, I.; Fierro, J.L.G.

    2002-01-01

    A Cu–Zn–Al precursor was synthesized by coprecipitation of the corresponding cations with sodium carbonate at constant pH and temperature. CuO–ZnO–Al2O3 composite oxide support was obtained by calcination (673 K) of the Cu–Zn–Al precursor. Two palladium-modified CuO–ZnO–Al2O3 samples were prepared

  2. 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.

  3. 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.

  4. 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

  5. Electrical conductivity and pH of groundwater: important exploratory ...

    African Journals Online (AJOL)

    Electrical conductivity and pH of groundwater: important exploratory tools in groundwater surveys. ... Journal of Technology and Education in Nigeria ... An analysis of the spatial variation of these parameters indicates that the EC and pH values of groundwater allow us to make deductions not only on the changes in the ...

  6. Diet, faecal pH and colorectal cancer

    NARCIS (Netherlands)

    Dokkum, W. van; Boer, B.C.J. de; Faassen, A. van; Pikaar, N.A.; Hermus, R.J.J.

    1983-01-01

    We suggest that a lower faecal pH may be correlated with a lower mortality of large-bowel cancer and that faecal pH should always be considered in epidemiological studies on the role of diet in colon carcinogenesis.

  7. EVALUATION OF pH OF COMMON CARBOHYDRATE FOOD ...

    African Journals Online (AJOL)

    DJFLEX

    This work evaluates and provides data on the seasonal pH of common ... keep an optimal body pH balance is recommended so as to discourage the growth of ... can be reduced during the manufacturing process by manufacturing companies.

  8. [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.

  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. 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.

  11. PH- Mapping Of Prepubertal Skin Of Indian Subjects

    Directory of Open Access Journals (Sweden)

    Gupta A B

    1995-01-01

    Full Text Available PH- mapping of skin was made by measuring the skin surface pH in 61 normal Indian subjects (35M, 26F in the prepubertal age group at 21 different sites from scalp to sole at an ambient temperature 25-32C and a relative humidity 60-65%. The pH values at axilla, umbilicus, palm, fingerfolds, foot, sole, and cheek were found to be consistently higher than those at scalp, forehead, retroauricular folds, antecubital and popliteal fossae, anterior arm, anterior the mean pH of male skin appeared to be lower than that of female. The highest pH recorded was in axilla (5.98 for male, 6.00 for female, irrespective of sex. The lowest value however was in anterior neck (4.59 for male and in antecubital fossa (4.83 for female. While the origin of the skin pH is yet to be definitely known, it was observed that a high density of both sweat gland and bacteria flora leads to a high pH, and high concentration of sebaceous gland and of bacterial flora to a lower pH.

  12. Vaginal pH: Home-Use Tests

    Science.gov (United States)

    ... doesn't always mean that you have a vaginal infection. pH changes also do not help or differentiate ... of infection from another. Your doctor diagnoses a vaginal infection by using a combination of: pH, microscopic examination ...

  13. 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.

  14. A microbent fiber optic pH sensor

    NARCIS (Netherlands)

    Thomas Lee, S.; Aneeshkumar, B.N.; Radhakrishnan, P.; Vallabhan, C.P.G.; Nampoori, V.P.N.

    2002-01-01

    Optical fiber sensors developed for measuring pH values usually employ an unclad and unstrained section of the fiber. In this paper, we describe the design and fabrication of a microbent fiber optic sensor that can be used for pH sensing. In order to obtain the desired performance, a permanently

  15. 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

  16. Morton et al. Reply

    Science.gov (United States)

    Morton, Douglas C.; Nagol, Jyoteshwar; Carabajal, Claudia C.; Rosette, Jacqueline; Palace, Michael; Cook, Bruce D.; Vermote, Eric F.; Harding, David J.; North, Peter R. J.

    2016-01-01

    Multiple mechanisms could lead to up-regulation of dry-season photosynthesis in Amazon forests, including canopy phenology and illumination geometry. We specifically tested two mechanisms for phenology-driven changes in Amazon forests during dry-season months, and the combined evidence from passive optical and lidar satellite data was incompatible with large net changes in canopy leaf area or leaf reflectance suggested by previous studies. We therefore hypothesized that seasonal changes in the fraction of sunlit and shaded canopies, one aspect of bidirectional reflectance effects in Moderate Resolution Imaging Spectroradiometer (MODIS) data, could alter light availability for dry-season photosynthesis and the photosynthetic capacity of Amazon forests without large net changes in canopy composition. Subsequent work supports the hypothesis that seasonal changes in illumination geometry and diffuse light regulate light saturation in Amazon forests. These studies clarify the physical mechanisms that govern light availability in Amazon forests from seasonal variability in direct and diffuse illumination. Previously, in the debate over light limitation of Amazon forest productivity, seasonal changes in the distribution of light within complex Amazon forest canopies were confounded with dry-season increases in total incoming photosynthetically active radiation. In the accompanying Comment, Saleska et al. do not fully account for this confounding effect of forest structure on photosynthetic capacity.

  17. 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.

  18. Efeito da salinidade e do esgoto orgânico sobre a comunidade zooplanctônica, com ênfase nos copépodes, do estuário do rio Itanhaém, Estado de São Paulo - DOI: 10.4025/actascibiolsci.v26i1.1652 Effects of salinity and organic wastes on zooplancton community, with emphasis on copepodes, in the Itanhaém river estuary, São Paulo state - DOI: 10.4025/actascibiolsci.v26i1.1652

    Directory of Open Access Journals (Sweden)

    Antonio Fernando Monteiro Camargo

    2004-04-01

    Full Text Available A partir da hipótese de que a comunidade zooplanctônica é influenciada pela salinidade e pelo lançamento de esgotos orgânicos, o objetivo deste trabalho é analisar a influência desses fatores sobre essa comunidade no estuário do rio Itanhaém, Estado de São Paulo. Foram realizadas amostragens do zooplâncton e de variáveis físicas e químicas da água em quatro estações de coleta, localizadas entre a linha de costa e a parte superior do estuário, incluindo um canal secundário que recebe esgotos domésticos sem tratamento prévio. As amostragens foram realizadas em baixa-mar e preamar no inverno e verão. Os resultados mostraram que este estuário possui uma variação temporal de características físicas e químicas, especialmente salinidade, devido à variação de marés e à variação sazonal de pluviosidade. Os maiores valores de salinidade foram observados no inverno e preamar. A comunidade zooplanctônica respondeu às variações de salinidade, com espécies adaptadas aos maiores valores de salinidade na parte baixa do estuário, no inverno. Embora o estuário do rio Itanhaém possua a mesma dinâmica temporal e espacial de outros estuários, os valores de salinidade são bastante reduzidos em comparação com outros estuários da costa sul paulista. Em conseqüência, a comunidade zooplanctônica foi constituída principalmente por organismos oligoalinos e de água doce. Essas características se devem à maior área de drenagem da bacia do rio Itanhaém quando comparada com a área dos outros rios costeiros do Estado de São Paulo. O esgoto orgânico modificou as características físicas e químicas da água, que possuiu maior concentração de nutrientes, maior quantidade de material em suspensão e menor concentração de oxigênio. Foi observada uma relação positiva entre densidade de náuplios de copépodes e poluição orgânica no estuário do rio ItanhaémThe objective of this work is to analyze the effects of

  19. Efeito do pH e da hidrólise tríptica sobre as propriedades emulsionantes da globina bovina The effect of the pH and the tryptic hydrolysis on the emulsifying properties of bovine globin

    Directory of Open Access Journals (Sweden)

    Cleia Batista Dias ORNELLAS

    2001-01-01

    Full Text Available No intuito de estudar o efeito do pH e da ação da tripsina sobre as propriedades emulsionantes da globina bovina, extraída pelo método da acetona acidificada, foram determinados neste trabalho, a capacidade emulsionante (EC, o índice de atividade emulsionante (EAI e a estabilidade da emulsão (ES. Testaram-se os valores de pH de 3,0 a 8,0 e os tempos de hidrólise de 5,0 a 60 min. Os dados obtidos indicam que os maiores valores de EC e ES foram obtidos no pH 5,0 e 6,0, respectivamente, correspondente à faixa de alta solubilidade da proteína. Por outro lado, o EAI, além de apresentar um máximo no pH 3,0, foi igualmente elevado nos valores de pH 7,0 e 8,0, situados na zona onde a globina é praticamente insolúvel. A hidrólise tríptica, nas condições empregadas, contribuiu para melhorar a EC, em toda a faixa de pH estudada, enquanto que para o EAI somente foi benéfico em pH 4,0 e 5,0. No caso da ES, este tratamento enzimático não foi vantajoso, promovendo melhoras apenas no pH 7,0, onde a proteína é insolúvel, e somente após 60 min de hidrólise.The effect of the pH and of the trypsin on the emulsifying properties of bovine globin, extracted by the acidified acetone method, was studied. The emulsifying capacity (EC, the emulsifying activity index (EAI and the emulsion stability (ES were determined at pH varying from 3.0 to 8.0 and employing hydrolysis times from 5 to 60 min. The highest vaules for EC and ES were obtained at pH 5.0 and 6.0, respectively, corresponding to the range of large protein solubility. On the other hand, the EAI was higher at pH 3.0 and also at pH 7.0 and 8.0, where the protein is insoluble. The tryptic hydrolysis produced an increase in EC, in all pH ranges studied, while for the EAI the same effect was observed only in pH 4.0 and 5.0, and for ES at pH 7.0 after 60 min of hydrolysis.

  20. Nanosensors for pH measurements in plants

    DEFF Research Database (Denmark)

    Ytting, Cecilie Karkov; Fuglsang, Anja Thoe

    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...... 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...

  1. 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 ...

  2. 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

  3. Geoquímica de las aguas subterráneas en rocas metamórficas al SE de Salamanca

    Directory of Open Access Journals (Sweden)

    García, A.

    1991-08-01

    Full Text Available This paper describes the results of 77 chemical analyses of groundwater from springs and wells in the «Complejo Esquisto Grauváquico» and other paleozoic materials from the south of Salamanca province. The types of groundwater are very diverse, usually bicarbonate dominant, with TDS (Total Dissolved Solids between 0.6 and 16 milimoles/l. Salinity is shown to be greater in the drilled wells than in the dug wells and springs, which confirms the existence of deep flow. Principal Component Analysis indicates that the chemical composition of groundwater must be the result of multiple reactions between the water and the minerals that occur in parallel, with none of the reactions being specially predominant. The organization and geographic distribution of sorne of the elements suggest the existence of regional flow systems.Se presentan los resultados de 77 análisis químicos de aguas subterráneas procedentes de manantiales, pozos excavados y sondeos en el Complejo Esquisto Grauváquico y otros materiales paleozoicos al Sur de la provincia de Salamanca. Se trata de aguas muy dispares, en general bicarbonatadas mixtas, con TSD (total de sólidos disueltos entre 0,6 y 16 milimoles/l. Se pone de manifiesto una mayor salinidad de las aguas de sondeos en relación con las de pozos y manantiales, lo que demuestra la existencia de una circulación a cierta profundidad. El análisis de componentes principales muestra que la composición química de las aguas debe ser el resultado de múltiples reacciones entre el agua y los minerales que se producen en paralelo, sin que destaque ninguna en especial. La distribución geográfica ordenada de algunos elementos obliga a plantear como posible la hipótesis de la existencia de un flujo regional.

  4. 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.

  5. [Composition diversity of lactic acid bacteria (LAB) community Al2 used for alfalfa silage].

    Science.gov (United States)

    Wang, Xiao-Fen; Gao, Li-Juan; Yang, Hong-Yan; Wang, Wei-Dong; Cui, Zong-Jun

    2006-10-01

    Alfalfa is the most important forage grass that is difficult to ensile for good quality. Using silage inoculants are the important way for preservation of alfalfa silage. Through continuous restricted subcultivation, a lactic acid bacteria (LAB) community Al2 was selected from well-fermented alfalfa silage. Plate isolation and Denaturing Gradient Gel Electrophoresis (DGGE), construction of 16S rDNA clone library were used to identify the composition diversity of Al2 community, with 7 strains detected, and they were all belonged to Lactobacillus. The composition ratios of the 7 strains were 55.21%, 19.79%, 14.58%, 3.13%, 3.13%, 3.13%, 1.03% according to 16S rDNA clone library. Al2-1i, Al2-2i, Al2-3i, corresponding to L. plantarum (99.9%), L. kimchii (99.4%), L. farciminis (100%) were detected by plate isolation. Among 3 isolates, Al2-1i had the highest ability of dropping pH and producing lactic acid, and the amount of lactic acid was reach to 18g/L at 24h cultivated in MRS media. The ability of dropping pH and producing lactic acid of Al2-3i was the lowest. From DGGE profiles, the dominant strains in Al2 community were L. plantarum and L. kimchii. L. plantarum was detected during the whole process, and L. kimchii was detected in the later phase.

  6. 31P NMR studies of pH homeostasis in intact adult Fasciola hepatica

    NARCIS (Netherlands)

    Tielens, A.G.M.; Nicolaij, K.; Bergh, van S.G.

    1982-01-01

    31P NMR was used to measure the intracellular pH in live adult Fasciola hepatica. The results demonstrate that at external pH values above 7.0, pH homeostasis keeps the intracellular pH at 7.0. At external pH values below 7.0 the intracellular pH is less strictly regulated.

  7. 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.

  8. 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

  9. 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.

  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. Temperature and pH conditions for mycelial growth of Agaricus brasiliensis on axenic cultivation/ Condições de temperatura e pH para o crescimento micelial de Agaricus brasiliensis em cultivo axênico

    Directory of Open Access Journals (Sweden)

    Luzia Doretto Paccola-Meirelles

    2008-08-01

    Full Text Available Few studies have been done to determine Agaricus brasiliensis Wasser et al. (A. blazei; A. subrufescens basic mycelial growth characteristics on axenic cultivation. This study aimed to determine the optimal temperature and initial pH for mycelial growth of A. brasiliensis on malt extract agar medium to develop axenic cultivation techniques. Studied initial pH values for mycelial growth were adjusted to 3.0, 4.0, 5.0, 5.5, with HCl, 6.0, 7.0, 8.0, with NaOH, and again 7.0 and 8.0, with CaCO3. Studied temperatures for mycelial growth were 22 ºC, 25 ºC, 28 ºC, 31 ºC and 34 ºC. It was concluded that A. brasiliensis can grow in axenic cultivation at temperature range from 22 oC to 34 ºC, with optimal temperature range from 28 oC to 31 ºC and optimal temperature value of 30.5 ºC ± 0.3 ºC. It also grows in initial pH range from 4.0 to 7.0, adjusted with HCl or NaOH but not CaCO3, with optimal initial pH range from 5.5 to 6.0 and optimal initial pH value of 5.56 ± 0.05. Mycelial growth is inhibited with pH of 3.0 or lower, 8.0 or higher, or when CaCO3 is used to adjust pH in the substratum to 7.0 or higher.Poucos estudos foram desenvolvidos para determinar as condições básicas de crescimento micelial do fungo Agaricus brasiliensis Wasser et al. (A. blazei, A. subrufescens. O objetivo deste trabalho foi determinar a faixa ótima de temperatura e pH para o crescimento micelial, em agar-extrato-de-malte, de A. brasiliensis, visando o desenvolvimento de técnicas de cultivo axênica. Os valores de pH estudados foram 3,0, 4,0, 5,0 e 5,5, ajustados com HCl, 6,0, 7,0 e 8,0, ajustados com NaOH, e 7,0 e 8,0, ajustados com CaCO3. As temperaturas de crescimento estudadas foram 22 ºC; 25 ºC; 28 ºC; 31 ºC e 34 oC. Concluiu-se que A. brasiliensis cresce em uma faixa de temperatura ótima de 28 oC a 31 ºC, com valor ótimo de temperatura de 30,5 ºC ± 0,3 ºC. A faixa de pH inicial ótimo no substrato é de 5,5 a 6,0 e o valor de pH inicial

  12. Constant pH Accelerated Molecular Dynamics Investigation of the pH Regulation Mechanism of Dinoflagellate Luciferase.

    Science.gov (United States)

    Donnan, Patrick H; Ngo, Phong D; Mansoorabadi, Steven O

    2018-01-23

    The bioluminescence reaction in dinoflagellates involves the oxidation of an open-chain tetrapyrrole by the enzyme dinoflagellate luciferase (LCF). The activity of LCF is tightly regulated by pH, where the enzyme is essentially inactive at pH ∼8 and optimally active at pH ∼6. Little is known about the mechanism of LCF or the structure of the active form of the enzyme, although it has been proposed that several intramolecularly conserved histidine residues in the N-terminal region are important for the pH regulation mechanism. Here, constant pH accelerated molecular dynamics was employed to gain insight into the conformational activation of LCF induced by acidification.

  13. Groundwater chemistry of Al under Dutch sandy soils: Effects of land use and depth

    NARCIS (Netherlands)

    Fest, E.P.M.J.; Temminghoff, E.J.M.; Griffioen, J.; Grift, B. van der; Riemsdijk, W.H. van

    2007-01-01

    Aluminium has received great attention in the second half of the 20th century, mainly in the context of the acid rain problem mostly in forest soils. In this research the effect of land use and depth of the groundwater on Al, pH and DOC concentration in groundwater under Dutch sandy soils has been

  14. Al-induced root cell wall chemical components differences of wheat ...

    African Journals Online (AJOL)

    Jane

    2011-07-13

    Jul 13, 2011 ... 2Wuhan Military Economic Academy, No. 122 Luojiadun, Qiaokou ... The analysis indicated that under Al stress, differences in cell wall .... with a pestle in a mortar in 2 ml of 50 mM acetate buffer (pH 5.5) that contained 6% ...

  15. Perrhenate sorption kinetics in zerovalent iron in high pH and nitrate media

    International Nuclear Information System (INIS)

    Lenell, Brian A.; Arai, Yuji

    2017-01-01

    Graphical abstract: Ammonium adsorption enhanced ReO 4 − adsorption in ZVI under alkaline conditions (modified from Cho et al., 2015) [39]. - Highlights: • ZVI effectively sorbs Re(VII) at near neutral pH. • Sorption of Re(VII) in ZVI is attributed to the reductive precipitation of Re(IV)O 2 . • The extent of Re(VII) sorption in ZVI decreases with increasing pH from 8 to 10. • The rate of Re(VII) sorption in ZVI increases with increasing nitrate concentration. - Abstract: Technetium(Tc)-99 is one of major risk drivers in low level radioactive liquid waste at the U.S. Department of Energy sites. Cementitious waste technology (CWT) has been considered immobilizing pertechnetate, Tc(VII)O 4 − , in brine and alkaline waste solutions, as Tc(IV) oxides and/or sulfides with the use of reducing agents like slag. In this study, zero valent iron (ZVI) was evaluated as a potential reducing agent in CWT as a function of pH and [nitrate] (0–0.1 M) using perrhenate, Re(VII)O 4 − , as an analogue for Tc(VII)O 4 − . Batch Re(VII)O 4 − sorption experiments in conjunction with X-ray absorption spectroscopic analysis showed that the Re(VII) sorption occurred via the reductive precipitation of Re(IV)O 2 (s) and the extent of sorption decreased with increasing pH from 8 to 10. Interestingly, pseudo 2nd order kinetic rates increased with increasing [nitrate] which was attributed to co-adsorption of NH 4 + (i.e., a reaction product of reduced nitrate by ZVI), facilitating electrostatic attraction towards ReO 4 − under alkaline conditions. Considering the thermodynamically favorable reduction of Tc(VII) over Re(VII), ZVI might have potential for improving the reduction capacity of the current CWT.

  16. Adsorption of cadmium onto Al{sub 13}-pillared acid-activated montmorillonite

    Energy Technology Data Exchange (ETDEWEB)

    Yan Liangguo [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Shan Xiaoquan [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China)], E-mail: xiaoquan@rcees.ac.cn; Wen Bei [State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, P.O. Box 2871, Beijing 100085 (China); Owens, Gary [Centre for Environmental Risk Assessment and Remediation, University of South Australia, Mawson Lakes Campus, Mawson Lakes, Boulevard, South Australia 5095 (Australia)

    2008-08-15

    The optimal preparation conditions for Al{sub 13}-pillared acid-activated Na{sup +}-montmorillonite (Al{sub 13}-PAAMt) were (1) an acid-activated Na{sup +}-montmorillonite (Na{sup +}-Mt) solution of pH 3.0, (2) a OH{sup -}/Al{sup 3+} molar ratio of 2.4 and (3) Al{sup 3+}/Na{sup +}-Mt ratio of 1.0 mmol g{sup -1}. The effects of OH{sup -}/Al{sup 3+} and Al{sup 3+}/Na{sup +}-Mt ratios on the adsorption of Cd{sup 2+} onto Al{sub 13}-PAAMt were studied. A comparison of the adsorption of Cd{sup 2+} onto Al{sub 13}-PAAMt, Al{sub 13}-pillared Na{sup +}-montmorillonite (Al{sub 13}-PMt) and Na{sup +}-Mt suggested that Al{sub 13}-PAAMt had higher adsorption affinity for Cd{sup 2+} than the other two adsorbents. A pseudo-second-order model described the adsorption kinetics well. Cadmium adsorption followed the Langmuir two-site equation, while desorption was hysteretic.

  17. Diffusion-induced quadrupole relaxation of 27Al nuclei in dilute Al-Ti, Al-Cr, Al-Mn, and Al-Cu alloys at high temperatures

    International Nuclear Information System (INIS)

    Bottyan, L.; Beke, D.L.; Tompa, K.

    1983-01-01

    The temperature dependence of the laboratory frame spin-lattice relaxation time of 27 Al nuclei is measured in 5N Al and in dilute Al-Ti, Al-Cr, Al-Mn, and Al-Cu alloys at 5.7 and 9.7 MHz resonance frequencies. The relaxation in pure aluminium is found to be purely due to the conduction electrons. An excess T 1 -relaxation contribution is detected in all Al-3d alloys investigated above 670 K. The excess relaxation rate is proportional to the impurity content and the temperature dependence of the excess contribution is of Arrhenius-type with an activation energy of (1.3 +- 0.3) eV for all of the investigated alloys. The relaxation contribution is found to be quadrupolar in origin and is caused by the relative diffusional jumps of solute atoms and Al atoms relatively far from the impurity. (author)

  18. Development of an accurate pH measurement methodology for the pore fluids of low pH cementitious materials

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, M. C.; Garcia Calvo, J. L. [The Spanish National Research Council (CSIC), Madrid (Spain); Walker, C. [Japan Atomic Energy Agency (JAEA), Ibaraki (Japan)] [and others

    2012-08-15

    The main objective of this project has been the development of an agreed set of protocols for the pH measurement of the pore fluid of a low pH cementitious material. Three protocols have been developed (Chapter 2), a reference method, based on pore fluid expression (PFE), and two routine methods with and without filtering, based on Ex Situ Leaching (ESL) procedures. Templates have been designed on which to record details of the pH measurement for the reference (PFE) method (Appendix C) and the routine (ESL) methods without and with filtering (Appendix D). Preliminary protocols were based on a broad review of the literature (Appendix A) and refined through a series of test experiments of the more critical parameters (Appendix B). After definition of the preliminary protocols, two phases of interlaboratory tests were performed. The first phase (Chapter 3) used the same low pH cement paste and enabled the nine participating laboratories to use, become familiar with and to identify any problems/uncertainties in the preliminary protocols. The reported pH values were subjected to a statistical analysis of the (within laboratory) repeatability and (between-laboratory) reproducibility and so provided a reliability test of the preliminary protocols. The second phase (Chapter 4) of interlaboratory tests used four different candidate low pH cementitious materials in the same nine laboratories, which allowed testing, validation and comparison of the reported pH values, which were obtained using the final protocols for the reference (PFE) and routine (ESL) methods by statistical analysis. The proposed final protocols (Chapter 2) have resulted in the reported pH values having low deviation and high reproducibility and repeatability. This will allow confidence in the pH value when selecting a candidate low pH cementitious material to be used in the engineered component of a high-level nuclear waste repository.

  19. Development of an accurate pH measurement methodology for the pore fluids of low pH cementitious materials

    International Nuclear Information System (INIS)

    Alonso, M. C.; Garcia Calvo, J. L.; Walker, C.

    2012-08-01

    The main objective of this project has been the development of an agreed set of protocols for the pH measurement of the pore fluid of a low pH cementitious material. Three protocols have been developed (Chapter 2), a reference method, based on pore fluid expression (PFE), and two routine methods with and without filtering, based on Ex Situ Leaching (ESL) procedures. Templates have been designed on which to record details of the pH measurement for the reference (PFE) method (Appendix C) and the routine (ESL) methods without and with filtering (Appendix D). Preliminary protocols were based on a broad review of the literature (Appendix A) and refined through a series of test experiments of the more critical parameters (Appendix B). After definition of the preliminary protocols, two phases of interlaboratory tests were performed. The first phase (Chapter 3) used the same low pH cement paste and enabled the nine participating laboratories to use, become familiar with and to identify any problems/uncertainties in the preliminary protocols. The reported pH values were subjected to a statistical analysis of the (within laboratory) repeatability and (between-laboratory) reproducibility and so provided a reliability test of the preliminary protocols. The second phase (Chapter 4) of interlaboratory tests used four different candidate low pH cementitious materials in the same nine laboratories, which allowed testing, validation and comparison of the reported pH values, which were obtained using the final protocols for the reference (PFE) and routine (ESL) methods by statistical analysis. The proposed final protocols (Chapter 2) have resulted in the reported pH values having low deviation and high reproducibility and repeatability. This will allow confidence in the pH value when selecting a candidate low pH cementitious material to be used in the engineered component of a high-level nuclear waste repository

  20. Removal of arsenic from drinking water by the electrocoagulation using Fe and Al electrodes

    International Nuclear Information System (INIS)

    Kobya, M.; Gebologlu, U.; Ulu, F.; Oncel, S.; Demirbas, E.

    2011-01-01

    Highlights: → Removal percentages of arsenic from drinking water at optimum operating conditions in electrocoagulation process were 93.5% for Fe electrode and 95.7% for Al electrode. → Operating costs at the optimum conditions were 0.020 Euro m -3 for Fe and 0.017 Euro m -3 for Al electrodes. → Surface topography of the solid particles at Fe/Al electrodes was analyzed with scanning electron microscope. → The adsorption of arsenic followed pseudo second-order adsorption model. - Abstract: A novel technique of electrocoagulation (EC) was attempted in the present investigation to remove arsenic from drinking waters. Experiments were carried out in a batch electrochemical reactor using Al and Fe electrodes with monopolar parallel electrode connection mode to assess their efficiency. The effects of several operating parameters on arsenic removal such as pH (4-9), current density (2.5-7.5 A m -2 ), initial concentration (75-500 μg L -1 ) and operating time (0-15 min) were examined. Optimum operating conditions were determined as an operating time of 12.5 min and pH 6.5 for Fe electrode (93.5%) and 15 min and pH 7 for Al electrode (95.7%) at 2.5 A m -2 , respectively. Arsenic removal obtained was highest with Al electrodes. Operating costs at the optimum conditions were calculated as 0.020 Euro m -3 for Fe and 0.017 Euro m -3 for Al electrodes. EC was able to bring down aqueous phase arsenic concentration to less than 10 μg L -1 with Fe and Al electrodes. The adsorption of arsenic over electrochemically produced hydroxides and metal oxide complexes was found to follow pseudo second-order adsorption model. Scanning electron microscopy was also used to analyze surface topography of the solid particles at Fe/Al electrodes during the EC process.

  1. Human vaginal pH and microbiota: an update.

    Science.gov (United States)

    Godha, Keshav; Tucker, Kelly M; Biehl, Colton; Archer, David F; Mirkin, Sebastian

    2018-06-01

    A woman's vaginal pH has many implications on her health and it can be a useful tool in disease diagnosis and prevention. For that reason, the further examination of the relationship between the human vaginal pH and microbiota is imperative. In the past several decades, much has been learned about the physiological mechanisms modulating the vaginal pH, and exogenous/genetic factors that may influence it. A unified, coherent understanding of these concepts is presented to comprehend their interrelationships and their cumulative effect on a woman's health. In this review, we explore research on vaginal pH and microbiota throughout a woman's life, vaginal intermediate cell anaerobic metabolism and net proton secretion by the vaginal epithelial, and the way these factors interact to acidify the vaginal pH. This review provides foundational information about what a microbiota is and its relationship with human physiology and vaginal pH. We then evaluate the influence of physiological mechanisms, demographic factors, and propose ideas for the mechanisms behind their action on the vaginal pH.

  2. A ph sensor based on a flexible substrate

    Science.gov (United States)

    Huang, Wen-Ding

    pH sensor is an essential component used in many chemical, food, and bio-material industries. Conventional glass electrodes have been used to construct pH sensors, however, have some disadvantages. Glass electrodes are easily affected by alkaline or HF solution, they require a high input impedance pH meter, they often exhibit a sluggish response. In some specific applications, it is also difficult to use glass electrodes for in vivo biomedical or food monitoring applications due to the difficulty of size miniaturization, planarization and polymerization based on current manufacturing technologies. In this work, we have demonstrated a novel flexible pH sensor based on low-cost sol-gel fabrication process of iridium oxide (IrOx) sensing film (IROF). A pair of flexible miniature IrOx/AgCl electrode generated the action potential from the solution by electrochemical mechanism to obtain the pH level of the reagent. The fabrication process including sol-gel, thermal oxidation, and the electro-plating process of the silver chloride (AgCl) reference electrode were reported in the work. The IrOx film was verified and characterized using electron dispersive analysis (EDAX), scanning electron microscope (SEM), and x-ray diffraction (XRD). The flexible pH sensor's performance and characterization have been investigated with different testing parameters such as sensitivity, response time, stability, reversibility, repeatability, selectivity and temperature dependence. The flexible IrOx pH sensors exhibited promising sensing performance with a near-Nernstian response of sensitivity which is between --51.1mV/pH and --51.7mV/pH in different pH levels ranging from 1.5 to 12 at 25°C. Two applications including gastroesophageal reflux disease (GERD) diagnosis and food freshness wireless monitoring using our micro-flexible IrOx pH sensors were demonstrated. For the GERD diagnosing system, we embedded the micro flexible pH sensor on a 1.2cmx3.8cm of the capsule size of wireless sensor

  3. Evaluating nanoparticle sensor design for intracellular pH measurements.

    Science.gov (United States)

    Benjaminsen, Rikke V; Sun, Honghao; Henriksen, Jonas R; Christensen, Nynne M; Almdal, Kristoffer; Andresen, Thomas L

    2011-07-26

    Particle-based nanosensors have over the past decade been designed for optical fluorescent-based ratiometric measurements of pH in living cells. However, quantitative and time-resolved intracellular measurements of pH in endosomes and lysosomes using particle nanosensors are challenging, and there is a need to improve measurement methodology. In the present paper, we have successfully carried out time-resolved pH measurements in endosomes and lyosomes in living cells using nanoparticle sensors and show the importance of sensor choice for successful quantification. We have studied two nanoparticle-based sensor systems that are internalized by endocytosis and elucidated important factors in nanosensor design that should be considered in future development of new sensors. From our experiments it is clear that it is highly important to use sensors that have a broad measurement range, as erroneous 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 pK(a) to each sensor, seem to be a solution to some of the earlier problems found when measuring pH in the endosome-lysosome pathway.

  4. Titratable acidity of beverages influences salivary pH recovery

    Directory of Open Access Journals (Sweden)

    Livia Maria Andaló TENUTA

    2015-01-01

    Full Text Available 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 < 0.005 mmols OH- to reach pH 5.5, respectively. Eight volunteers with a normal salivary flow rate 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.

  5. 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 pH 5.5, respectively). Eight volunteers with a normal salivary flow rate 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.

  6. Diurnal variation of intraoral pH and temperature.

    Science.gov (United States)

    Choi, Jung Eun; Lyons, Karl M; Kieser, Jules A; Waddell, Neil J

    2017-01-01

    The aim of this study was to measure continuously the intraoral pH and temperature of healthy individuals to investigate their diurnal variations. Seventeen participants (mean age, 31±9 years) wore a custom-made intraoral appliance fitted with a pH probe and thermocouple for two sets of 24 h, while carrying out normal daily activities including sleep. The continuous changes in intraoral pH and temperature were captured using a sensor placed on the palatal aspect of the upper central incisors. The collected data were categorised into different status (awake and sleep) and periods (morning, afternoon, evening and night). Both quantitative and qualitative analyses were conducted. The intraoral pH change was found to show a distinctive daily rhythm, showing a 12-h interval between maximum (7.73) and minimum (6.6) pH values. The maximum and minimum values were found to repeat after 24 h. The mean pH over 48 h (two sets of 24 h) was found to be 7.27 (±0.74). There was significant difference found in pH when subjects were awake and asleep and different periods during the day ( P pH. There was a significant difference found in temperature depending on the time of the day, except between morning and afternoon ( P =0.78). Our results showed that there is a distinctive daily, circadian-like pattern in intraoral pH variation over a 24-h period, which has been considered as one of the risk factors in sleep-related dental diseases.

  7. Critical assessment of the pH of children's soap

    Directory of Open Access Journals (Sweden)

    Bruna Rafaela Mendes

    2016-06-01

    Full Text Available Abstract Objective: 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. Methods: 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. Results: The pH levels varied considerably between liquid and bar presentations, with lower levels (4.4-7.9 found for the liquids (p < 0.05. Syndets showed pH levels close to the ideal (slightly acid and the antibacterial soaps showed the highest pH levels (up to 11.34 (p < 0.05. Only two of the soaps included in the study had information about their pH levels on the product packaging. 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.

  8. 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 (p<0.05). Syndets showed pH levels close to the ideal (slightly acid) and the antibacterial soaps showed the highest pH levels (up to 11.34) (p<0.05). Only two of the soaps 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.

  9. Aluminum Coprecipitates with Fe (hydr)oxides: Does Isomorphous Substitution of Al3plus for Fe3plus in Goethite Occur

    Energy Technology Data Exchange (ETDEWEB)

    E Bazilevskaya; D Archibald; M Aryanpour; J Kubicki; C Martinez

    2011-12-31

    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 {approx}2.25 for Fe{sup 3+} and at pH {approx}4 for Al{sup 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

  10. Method for producing rapid pH changes

    Science.gov (United States)

    Clark, J.H.; Campillo, A.J.; Shapiro, S.L.; Winn, K.R.

    A method of initiating a rapid pH change in a solution comprises irradiating the solution with an intense flux of electromagnetic radiation of a frequency which produces a substantial pK change to a compound in solution. To optimize the resulting pH change, the compound being irradiated in solution should have an excited state lifetime substantially longer than the time required to establish an excited state acid-base equilibrium in the solution. Desired pH changes can be accomplished in nanoseconds or less by means of picosecond pulses of laser radiation.

  11. Optic nerve pH and PO2

    DEFF Research Database (Denmark)

    Pedersen, Daniella B; Stefánsson, Einar; Kiilgaard, Jens Folke

    2006-01-01

    Earlier studies have demonstrated that carbonic anhydrase inhibitors (CAIs) increase optic nerve oxygen tension (ONPO(2)) in pigs. We hypothesized that the mechanism of this effect was either a CO(2) increase or a pH decrease in tissue and blood. To test this hypothesis we investigated and compared...... how optic nerve pH (ONpH) and ONPO(2) are affected by: (1) carbonic anhydrase inhibition; (2) respiratory acidosis, and (3) metabolic acidosis. We measured ONpH with a glass pH electrode and ONPO(2) with a polarographic oxygen electrode. One of the electrodes was placed in the vitreous cavity 0.5 mm...

  12. Some observations of the pH of precipitation elements

    Energy Technology Data Exchange (ETDEWEB)

    Landsberg, H

    1954-01-01

    A year of observations of pH values of individual rain drops and snowflakes near Boston, Mass., showed acidic values ranging from 3 to 5.5 with a mean value of 4. There was no systematic relation between pH and the duration of rainfall. Drizzle and light rain had the lowest values, heavy rain and solid precipitation had the highest. There is a tendency for smaller drops to have lower values of pH than the larger ones. Measurements of dew and frost showed also a range from 3 to 5.5 with a mean value of 4.3.

  13. pH sensor based on boron nitride nanotubes.

    Science.gov (United States)

    Huang, Q; Bando, Y; Zhao, L; Zhi, C Y; Golberg, D

    2009-10-14

    A submicrometer-sized pH sensor based on biotin-fluorescein-functionalized multiwalled BN nanotubes with anchored Ag nanoparticles is designed. Intrinsic pH-dependent photoluminescence and Raman signals in attached fluorescein molecules enhanced by Ag nanoparticles allow this novel nanohybrid to perform as a practical pH sensor. It is able to work in a submicrometer-sized space. For example, the sensor may determine the environmental pH of sub-units in living cells where a traditional optical fiber sensor fails because of spatial limitations.

  14. pH sensor based on boron nitride nanotubes

    International Nuclear Information System (INIS)

    Huang, Q; Bando, Y; Zhao, L; Zhi, C Y; Golberg, D

    2009-01-01

    A submicrometer-sized pH sensor based on biotin-fluorescein-functionalized multiwalled BN nanotubes with anchored Ag nanoparticles is designed. Intrinsic pH-dependent photoluminescence and Raman signals in attached fluorescein molecules enhanced by Ag nanoparticles allow this novel nanohybrid to perform as a practical pH sensor. It is able to work in a submicrometer-sized space. For example, the sensor may determine the environmental pH of sub-units in living cells where a traditional optical fiber sensor fails because of spatial limitations.

  15. [Intraesophageal pH in children with suspected reflux].

    Science.gov (United States)

    Calva-Rodríguez, R; García-Aranda, J A; Bendimez-Cano, A; Estrada-Saavedra, R

    1989-05-01

    We study 22 children with clinical symptoms of gastroesophageal reflux. The main manifestations were: frequent vomiting, failure to thrive and repetitive pneumonia. In all of them we perform barium esophagogram (SEGD) with fluoroscopy, esophageal manometry (EM) and a four hours intraesophageal pH measurement. Thirteen of the twenty two children present a pathologic reflux (ERGE); in 16 we found SEGD that show reflux; three of them had an abnormal EM, the other 13 were normal. Seven patients showed alteration of the intraesophageal pH measurement. In conclusion the intraesophageal pH measurement in short period of time (4 hours) is a good method in the diagnosis of patients with ERGE.

  16. Seven steps towards a PhD in psychiatry.

    Science.gov (United States)

    Molina-Ruiz, Rosa María

    2016-12-01

    The present review aims to describe the main steps for completing a psychiatric PhD thesis with success. A selective review of the literature and the author's experience as a psychiatrist completing a PhD. Deciding upon a topic, choosing a mentor, organising your time, persevering and remaining motivated are the key elements. Preparedness and diligence lead the way towards a PhD. This advice is also relevant for those undertaking research at any stage of their career. © The Royal Australian and New Zealand College of Psychiatrists 2016.

  17. FLEXIBLE PH SENSOR WITH POLYANILINE LAYER BASED ON IMPEDANCE MEASUREMENT

    OpenAIRE

    Chuang, Cheng-Hsin; Wu, Hsun-Pei; Chen, Cheng-Ho; Wu, Peng-Rong

    2012-01-01

    A flexible sensor with conducting polyaniline layer for detecting pH value based on the impedance measurement is fabricated and demonstrated in this study. The pH sensor consists of an interdigital electrode array on a flexible printed circuit and a thin-film polyaniline as the sensing layer. As the conductivity of polyaniline depends on the redox state, the impedance change of the polyaniline after it has reacted with different pH value solutions works as the sensing mechanism. In order to o...

  18. Control de ph para planta de tratamiento de aguas residuales

    Directory of Open Access Journals (Sweden)

    Wilson Fabián Amaya

    2004-01-01

    Full Text Available En este trabajo se presenta el problema de controlar el pH en una planta de tratamiento de aguas residuales (PTAR, la cual recibe soluciones ácidas provenientes de la producción de jugos (pH 2-5 que se dosifica con la sustancia usada para aseo (soda cáustica 0.04% con valores oscilatorios de pH 9-11. Se desarrolló e implementó un controlador clásico PI en un PLC comercial y se automatiza la PTAR mostrando el resultado obtenido en simulación en MatLAB.

  19. Control de ph para planta de tratamiento de aguas residuales

    OpenAIRE

    Wilson Fabián Amaya; Óscar Alberto Cañón; Óscar F. Avilés

    2004-01-01

    En este trabajo se presenta el problema de controlar el pH en una planta de tratamiento de aguas residuales (PTAR), la cual recibe soluciones ácidas provenientes de la producción de jugos (pH 2-5) que se dosifica con la sustancia usada para aseo (soda cáustica 0.04%) con valores oscilatorios de pH 9-11. Se desarrolló e implementó un controlador clásico PI en un PLC comercial y se automatiza la PTAR mostrando el resultado obtenido en simulación en MatLAB.

  20. B cell markers in Ph1-positive acute lymphoblastic leukemia.

    Science.gov (United States)

    Alimena, G; De Rossi, G; Gastaldi, R; Guglielmi, C; Mandelli, F

    1980-01-01

    A case of acute lymphoblastic leukemia (ALL) where the blast cells had B cell markers and displayed the presence of a typical Ph1 chromosome, originated by a standard t (9;22) translocation, is reported. Cytological and clinical aspects during the entire course of the disease were consistent with the diagnosis of ALL. Evidence of differentiation along a well-defined lymphoid cell line in a Ph1-positive cell confirms the presence of the Ph1 chromosome in conditions other than chronic granulocytic leukemia and shows that it possibly does not occur in an exclusively undifferentiated totipotent stem cell.

  1. PhD Dissertations Tesi di dottorato

    Directory of Open Access Journals (Sweden)

    Redazione Reti Medievali (a cura di

    2005-12-01

    Full Text Available Report of PhD Dissertations.Anna Airò La scrittura delle regole. Politica e istituzioni a Taranto nel Quattrocento, Tesi di dottorato di ricerca in Storia medievale, Università degli studi di Firenze, 2005 Pasquale Arfé La Clavis Physicae II (316-529 di Honorius Augustodunensis. Studio ed edizione critica, Tesi di dottorato in Storia della filosofia medievale, Università degli Studi di Napoli "L'Orientale", 2005 Alessandro Azzimonti Scrittura agiografica e strutture di potere nell'Italia centro-settentrionale (X-XII secolo, Tesi di dottorato di ricerca in Forme del sapere storico dal medioevo alla contemporaneità, Università degli Studi di Trieste, 2004 Domenico Cerami Il "Confine conteso". Uomini, istituzioni, culture a Monteveglio tra VIII-XII secolo, Tesi di dottorato di ricerca in Storia Medievale, Università degli studi di Bologna, 2005 Federica Chilà Ostaggi. Uno strumento di pacificazione e governo tra i secoli VIII e XII, Tesi di dottorato di ricerca in Istituzioni, società, religioni dal Tardo Antico alla fine del Medioevo, Università degli Studi di Torino, 2004 Enrico Faini Firenze nei secoli X-XIII: economia e società, Tesi di dottorato di ricerca in Storia medievale, Università degli studi di Firenze, 2005Alessio FioreStrutture e pratiche del potere signorile in area umbro-marchigiana (secoli XI-XIII, Tesi di dottorato ricerca in Storia, Università degli studi di Pisa, 2004Giampaolo FrancesconiTra Riforma, vescovo e clientes. Camaldoli e le società locali (secoli XI-XIII, Tesi di dottorato di ricerca in Storia medievale, Università degli studi di Firenze, 2005 [09/05] Giuseppe Gardoni "Episcopus et potestas". Vescovi e società a Mantova nella prima metà del Duecento, Tesi di dottorato di ricerca in Storia del Cristianesimo e delle Chiese (antichità, medioevo, età moderna, Università degli Studi di Padova, 2005 Nicola Mancassola La gestione delle campagne tra Langobardia e Romània in età carolingia e post

  2. Deformation mechanisms of nanotwinned Al

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Xinghang [Texas A & M Univ., College Station, TX (United States)

    2016-11-10

    The objective of this project is to investigate the role of different types of layer interfaces on the formation of high density stacking fault (SF) in Al in Al/fcc multilayers, and understand the corresponding deformation mechanisms of the films. Stacking faults or twins can be intentionally introduced (via growth) into certain fcc metals with low stacking fault energy (such as Cu, Ag and 330 stainless steels) to achieve high strength, high ductility, superior thermal stability and good electrical conductivity. However it is still a major challenge to synthesize these types of defects into metals with high stacking fault energy, such as Al. Although deformation twins have been observed in some nanocrystalline Al powders by low temperature, high strain rate cryomilling or in Al at the edge of crack tip or indentation (with the assistance of high stress intensity factor), these deformation techniques typically introduce twins sporadically and the control of deformation twin density in Al is still not feasible. This project is designed to test the following hypotheses: (1) Certain type of layer interfaces may assist the formation of SF in Al, (2) Al with high density SF may have deformation mechanisms drastically different from those of coarse-grained Al and nanotwinned Cu. To test these hypotheses, we have performed the following tasks: (i) Investigate the influence of layer interfaces, stresses and deposition parameters on the formation and density of SF in Al. (ii) Understand the role of SF on the deformation behavior of Al. In situ nanoindentation experiments will be performed to probe deformation mechanisms in Al. The major findings related to the formation mechanism of twins and mechanical behavior of nanotwinned metals include the followings: 1) Our studies show that nanotwins can be introduced into metals with high stacking fault energy, in drastic contrast to the general anticipation. 2) We show two strategies that can effectively introduce growth twins in

  3. Deformation mechanisms of nanotwinned Al

    International Nuclear Information System (INIS)

    Zhang, Xinghang

    2016-01-01

    The objective of this project is to investigate the role of different types of layer interfaces on the formation of high density stacking fault (SF) in Al in Al/fcc multilayers, and understand the corresponding deformation mechanisms of the films. Stacking faults or twins can be intentionally introduced (via growth) into certain fcc metals with low stacking fault energy (such as Cu, Ag and 330 stainless steels) to achieve high strength, high ductility, superior thermal stability and good electrical conductivity. However it is still a major challenge to synthesize these types of defects into metals with high stacking fault energy, such as Al. Although deformation twins have been observed in some nanocrystalline Al powders by low temperature, high strain rate cryomilling or in Al at the edge of crack tip or indentation (with the assistance of high stress intensity factor), these deformation techniques typically introduce twins sporadically and the control of deformation twin density in Al is still not feasible. This project is designed to test the following hypotheses: (1) Certain type of layer interfaces may assist the formation of SF in Al, (2) Al with high density SF may have deformation mechanisms drastically different from those of coarse-grained Al and nanotwinned Cu. To test these hypotheses, we have performed the following tasks: (i) Investigate the influence of layer interfaces, stresses and deposition parameters on the formation and density of SF in Al. (ii) Understand the role of SF on the deformation behavior of Al. In situ nanoindentation experiments will be performed to probe deformation mechanisms in Al. The major findings related to the formation mechanism of twins and mechanical behavior of nanotwinned metals include the followings: 1) Our studies show that nanotwins can be introduced into metals with high stacking fault energy, in drastic contrast to the general anticipation. 2) We show two strategies that can effectively introduce growth twins in

  4. 1990, Aide et al., 1995, Alves et al., 1997), 117

    African Journals Online (AJOL)

    Dr Osondu

    Effective cation exchange capacity in the topsoil and the subsoil increased linearly with increasing age of secondary forest, while soil pH decreased with increasing age of secondary forest. These results demonstrate that fallowing exerts beneficial effects on soil fertility (i.e. soil fertility improved as fallow age increased).

  5. Zn–Al layered double hydroxides intercalated with carbonate, nitrate, chloride and sulphate ions: Synthesis, characterisation and dye removal properties

    Directory of Open Access Journals (Sweden)

    Fatima Zahra Mahjoubi

    2017-01-01

    Full Text Available In this work, Zn–Al layered double hydroxides intercalated with carbonate, nitrate, chloride and sulphate ions were synthesised via a co-precipitation method at a constant solution pH. The as-synthesised samples were characterised by X-ray diffraction (XRD, Fourier transform infrared spectroscopy (FTIR, transmission electron microscopy (TEM and simultaneous thermogravimetric/differential thermal analysis (TGA-DTA. The XRD patterns showed that Zn-Al-SO4 had the greatest interlayer spacing, followed by Zn-Al-Cl, Zn-Al-NO3 and Zn-Al-CO3. The FTIR spectra clearly confirmed the presence of intercalated anions in the structure of the LDHs. Batch experiments for methyl orange (MO adsorption onto synthesised samples were investigated under various conditions such as contact time, initial dye concentration and solution pH. The experimental results show that pH is the most influencing factor. The effective pH range for the MO removal was found to be 3.5–4.5. The kinetics data can be described accurately by a pseudo-second-order kinetic model instead of a pseudo-first-order model. The equilibrium data were analysed using the Langmuir, Freundlich and Dubinin–Radushkevich models. The results showed that the Langmuir and Dubinin–Radushkevich isotherm models fit well to the experimental data. The Zn-Al-LDH samples exhibited exceptional Langmuir maximum adsorption capacities of 2758, 2455, 2270 and 1684 mg/g for Zn-Al-SO4, Zn-Al-Cl, Zn-Al-NO3 and Zn-Al-CO3, respectively.

  6. Label-Free Carbon-Dots-Based Ratiometric Fluorescence pH Nanoprobes for Intracellular pH Sensing.

    Science.gov (United States)

    Shangguan, Jingfang; He, Dinggeng; He, Xiaoxiao; Wang, Kemin; Xu, Fengzhou; Liu, Jinquan; Tang, Jinlu; Yang, Xue; Huang, Jin

    2016-08-02

    Measuring pH in living cells is of great importance for better understanding cellular functions as well as providing pivotal assistance for early diagnosis of diseases. In this work, we report the first use of a novel kind of label-free carbon dots for intracellular ratiometric fluorescence pH sensing. By simple one-pot hydrothermal treatment of citric acid and basic fuchsin, the carbon dots showing dual emission bands at 475 and 545 nm under single-wavelength excitation were synthesized. It is demonstrated that the fluorescence intensities of the as-synthesized carbon dots at the two emissions are pH-sensitive simultaneously. The intensity ratio (I475 nm/I545 nm) is linear against pH values from 5.2 to 8.8 in buffer solution, affording the capability as ratiometric probes for intracellular pH sensing. It also displays that the carbon dots show excellent reversibility and photostability in pH measurements. With this nanoprobe, quantitative fluorescence imaging using the ratio of two emissions (I475 nm/I545 nm) for the detection of intracellular pH were successfully applied in HeLa cells. In contrast to most of the reported nanomaterials-based ratiometric pH sensors which rely on the attachment of additional dyes, these carbon-dots-based ratiometric probes are low in toxicity, easy to synthesize, and free from labels.

  7. Preparing MD-PhD students for clinical rotations: navigating the interface between PhD and MD training.

    Science.gov (United States)

    Goldberg, Charles; Insel, Paul A

    2013-06-01

    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 authors draw on their experience creating and implementing an RP that incorporates multiple types of activities (clinical exam review, objective structured clinical examination, and supervised practice in patient care settings) designed to enhance the participants' skills and readiness for clinical efforts. On the basis of this experience, they note that MD-PhD students' time away from the clinical environment negatively affects their clinical skills, causing them to feel underprepared for clinical rotations. The authors argue that participation in an RP can help students feel more comfortable speaking with and examining patients and decrease their anxiety regarding clinical encounters. The authors propose that RPs can have positive outcomes for improving the transition from PhD to clinical MD training in dual-degree programs. Identifying and addressing this and other transitions need to be considered to improve the educational experience of MD-PhD students.

  8. Iridium Oxide pH Sensor Based on Stainless Steel Wire for pH Mapping on Metal Surface

    Science.gov (United States)

    Shahrestani, S.; Ismail, M. C.; Kakooei, S.; Beheshti, M.; Zabihiazadboni, M.; Zavareh, M. A.

    2018-03-01

    A simple technique to fabricate the iridium oxide pH sensor is useful in several applications such as medical, food processing and engineering material where it is able to detect the changes of pH. Generally, the fabrication technique can be classified into three types: electro-deposition iridium oxide film (EIrOF), activated iridium oxide film (AIROF) and sputtering iridium oxide film (SIROF). This study focuses on fabricating electrode, calibration and test. Electro-deposition iridium oxide film is a simple and effective method of fabricating this kind of sensor via cyclic voltammetry process. The iridium oxide thick film was successfully electrodeposited on the surface of stainless steel wire with 500 cycles of sweep potential. A further analysis under FESEM shows detailed image of iridium oxide film which has cauliflower-liked microstructure. EDX analysis shows the highest element present are iridium and oxygen which concluded that the process is successful. The iridium oxide based pH sensor has shown a good performance in comparison to conventional glass pH sensor when it is being calibrated in buffer solutions with 2, 4, 7 and 9 pH values. The iridium oxide pH sensor is specifically designed to measure the pH on the surface of metal plate.

  9. SANANDO AL SANADOR

    Directory of Open Access Journals (Sweden)

    Juan Pablo Acuña, Dr.

    2017-09-01

    Full Text Available RESUMEN: La dependencia o adicción a sustancias de uso profesional es un problema que puede afectar gravemente a médicos de diferentes especialidades. En la anestesiología hay mayor riesgo de dependencia a opioides e hipnóticos que en otras especialidades y puede llegar a afectar al 1% de los médicos anestesiólogos.La fisiopatología del trastorno por uso de sustancias tiene hechos comunes para diferentes drogas. Interactúan la vulnerabilidad genética y factores psicosociales como predisponentes y los efectos psicobiológicos de la sustancia como factor gatillante. En el caso de los anestesiólogos, la sustancia se encuentra en el lugar de trabajo y por lo tanto, el individuo está constantemente expuesto.Una disfunción previa del sistema de recompensa en el circuito mesocorticolímbico o causada por la exposición a la sustancia adictiva es la piedra central de la neurobiología de las adicciones. Los opioides, anfetaminas, canabinoides, alcohol y nicotina, son algunas de las sustancias exógenas que activan el circuito y causan inicialmente un efecto hedónico que reforzará la conducta por repetir la experiencia. Con el tiempo la interacción con la droga será para evitar los síntomas de abstinencia.Dada la exposición laboral de los anestesiólogos, es necesario prevenir, detectar y tratar precozmente a quienes están abusando de sustancias durante su ejercicio profesional.Por las características de estos fármacos, aspectos psicológicos especiales de los médicos y el contexto laboral se hace necesario un tratamiento especializado y en anestesiólogos la reinserción laboral debe ser un proceso controlado, gradual y con un seguimiento prolongado. SUMMARY: Prescription drugs dependence seriously impairs doctors from differents fields of medicine. Anesthesiology has greater risk than other specialties to opioids and hypnotics dependence, with prevalence up to 1%.Substances use disorder has common mechanisms of disease regardless

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

    Science.gov (United States)

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

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

  11. Growth and Tissue Elemental Composition Response of Butterhead Lettuce (Lactuca sativa, cv. Flandria to Hydroponic Conditions at Different pH and Alkalinity

    Directory of Open Access Journals (Sweden)

    Tyler S. Anderson

    2017-07-01

    Full Text Available Biomass and tissue elemental differences were quantified for lettuce grown in deep-water conventional hydroponic conditions at two pH and alkalinity conditions. Nutrient solutions were created using inorganic salts and either reverse osmosis (RO water or municipal water with high alkalinity. Three treatments were evaluated: (a nutrient solution created with reverse osmosis (RO water and maintained at pH 5.8 (H5; (b same as H5 but maintained at pH 7.0 (H7; and (c nutrient solution created using municipal water and maintained at pH 7.0, referred to as HA7. Averaged across three trials, the HA7 and H7 treatments produced 26% less shoot fresh weight (FW than the H5 treatment with an 18% reduction in dry weight (DW. The H5 treatment had the least biomass in root FW and DW. In tissue elemental analyses, both the pH 7.0 treatments showed lower concentrations than H5 in Cu, N, Mo, and Sr, and increased concentrations in Ba, Mg, Na, and Zn. There were no differences in Al, C, Ca, Fe, K, Mn, Ni, P, S, and Si concentrations among treatments (p = 0.05. The results from this experiment can be used to isolate the effects of pH and alkalinity in aquaponic conditions where pH and alkalinity will mimic HA7 conditions.

  12. Meet EPA Natural Resource Economist Marisa Mazzotta, Ph.D.

    Science.gov (United States)

    Marisa Mazzotta, Ph.D. currently works as an Economist at EPA's Atlantic Ecology Division. Her research focuses on the public's valuation and prioritization of natural resources, and the relationship between ecological changes and economic benefits.

  13. The Training and Work of Ph.D. Physical Scientists

    Science.gov (United States)

    Smith, S. J.; Schweitzer, A. E.

    2003-05-01

    Doctoral education has often been viewed as the pinnacle of the formal education system. How useful is doctoral training in one's later career? In an NSF-funded project, we set out to perform a study of the training, careers, and work activities of Ph.D. physical scientists. The study included both in-depth interviews and a survey sent out to a sample of Ph.D. holders 4-8 years after graduation. Come and find out the results of this study: What skills are most Ph.D. physical scientists using? What should graduate programs be teaching? Are Ph.D.'s who are working in their specific field of training happier than their counterparts working different jobs? What skills and preparation lead to future job satisfaction, perhaps the most important indicator of the "success" of graduate education? A preprint and further details can be found at the project web site at: spot.colorado.edu/ phdcarer.

  14. Meet EPA Scientist Jordan West, Ph.D.

    Science.gov (United States)

    Jordan West, Ph.D. is an aquatic ecologist at EPA. Her areas of expertise include freshwater & marine ecology, climate change impacts and adaptation, resilience and threshold theory, environmental risk assessment, expert elicitation & stakeholder processes

  15. THE EFFECTS OF TEMPERATURE AND pH ON BACTERIAL ...

    African Journals Online (AJOL)

    PROF EKWUEME

    The effect of temperature and pH on bacterial degradation of latex paint under humid condition by .... blade and plastic bags as described by Okpokwasili and. Ituen(1996) and .... provided different ecological niche for bacteria at favourable ...

  16. 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...... buffers (20 mmol/l) led to pHi changes in accordance with entry of lipid-soluble forms of the buffers, followed by back-regulation of pHi by duct cells. In another type of experiment, changes in extracellular pH of solutions containing HEPES or HCO3-/CO2 buffers led to significant changes in pHi that did....... Under some conditions, these exchangers can be invoked to regulate cell pH....

  17. Meet EPA Scientist Susan Yee, Ph.D.

    Science.gov (United States)

    Susan Yee, Ph.D., is an ecologist at EPA's Gulf Ecology Division. She is working on the Puerto Rico Sustainable Communities program, developing decision support tools to evaluate how alternative decisions impact coastal ecosystem goods and services

  18. Meet EPA Engineer Shawn Ryan, Ph.D.

    Science.gov (United States)

    Shawn Ryan, Ph.D. is a chemical engineer at EPA's National Homeland Security Research Center. He has worked at EPA for 12 years, nine of which have been devoted to leading research to support decontamination and consequence management.

  19. Meet EPA Chemist Quincy Teng, Ph.D.

    Science.gov (United States)

    EPA research chemist Quincy Teng, Ph.D., focuses on the application of metabolomics—a relatively new, specialized field of biochemistry focused on studying small molecules known as metabolites—on environmental and life sciences.

  20. pH Regulatory Transporters in Pancreatic Ductal Adenocarcinoma

    DEFF Research Database (Denmark)

    Kong, Su Chii

    The abnormal features of hypoxia and altered metabolisms in solid tumours lead to an increased glycolysis that is uncoupled from oxidative phosphorylation in the TCA cycle. Tumoural cells often exhibit dysregulated expressions and activities of various membrane pH regulatory transporters to cope...... with the elevated acid production from this glycolysis, as well as from cellular ATP hydrolysis, sequentially creating a favourable intracellular pH and hostile acidic tumour microenvironment, fortify the tumour cells with highly invasive, metastatic and drug resistant phenotype. In current work, we study...... proliferation was found to be decreased while apoptosis was increased with concanamycin A treatment, indicative of V-ATPases being involved in PDAC cell survival mechanisms as well. Comprehending pH regulation in tumour cells might provide insights in preventing tumourigenesis by pH disruptions. Data presented...